LUBRICATING COMPOSITIONS COMPRISING THERMOASSOCIATIVE AND
EXCHANGEABLE COPOLYMERS
FIELD OF THE INVENTION
5 The present invention relates to a composition resulting from the mixture of at least one
lubricating oil, at least one statistical copolymer Al, and at least one compound A2 comprisim2,
at least two boronic ester functions: the statistical copolymer Al results from the
copolymerization of at least one first monomer MI bearing diol functions and at least one
second monomer M2 of different chemical structure to that of the monomer Ml.
10 The invention also relates to the use of this composition for lubricating a mechanical
part.
The field of the present invention is that of lubricants.
TECHNICAL BACKGROUND
15 Lubricating compositions are compositions applied between the surfaces, in particular
metallic surfaces, of moving parts. They make it possible to reduce the friction and wear
between two parts that are in contact and moving with respect to each other. They also serve to
dissipate part of the heat energy generated by this friction. The lubricating compositions form a
protective film between the surfaces of the parts on which they are applied.
20 The compositions used for the lubrication of mechanical parts are generally constituted
by a base oil and additives. The viscosity of the base oil, in particular of petroleum or synthetic
origin, varies when the temperature is changed.
Indeed, when the temperature of a base oil increases, its viscosity reduces, and when the
temperature of the base oil reduces, its viscosity increases. Now, the thickness of the protective
25 film is proportional to the viscosity and therefore also depends on the temperature. A
composition has good lubricating properties if the thickness of the protective film remains
substantially constant whatever the conditions and duration of use of the lubricant.
In an internal combustion engine, a lubricating composition can be subjected to changes
in external or internal temperature. The changes in external temperature are due to the variations
30 in temperature of the ambient air, such as the variations in temperature between summer and
winter for example. The internal changes in temperature result from the running of the engine.
The temperature of an engine is lower during its start-up phase, in particular in cold weather,
than during prolonged use. As a result, the thickness of the protective film can vary in these
different situations.
35 A need therefore exists to have available a lubricating composition having good
lubrication properties and the viscosity of which is not significantly affected by variations in
temperature.
It is known to add additives that improve the viscosity of a lubricating composition.
2
These additives have the function of modifying the rheological behaviour of the lubricating
composition. They make it possible to promote a substantially constant viscosity over a
temperature range at which the lubricating composition is used. For example, these additives
limit the reduction in the viscosity of the lubricating composition when the temperature increases
5 or limit the increase in the viscosity of the lubricating composition when the temperature
reduces.
The additives improving the viscosity (or additives improving the viscosity index)
currently used are polymers such as the polyalpha-olefins, methyl polymethacrylates,
copolymers resulting from the polymerization of an ethylene monomer and an alpha-olefin.
10 These are high molecular weight polymers. In general, the contribution of these polymers to
controlling the viscosity is greater, the higher their molecular weight.
I lowever, the high molecular weight polymers have the drawback of having a low
permanent shear strength compared with polymers of the same nature but a smaller size.
Now, a lubricating composition is subjected to significant shear stresses in particular in
15 internal combustion engines, where the surfaces subject to friction have a very small clearance
and the pressures exerted on the parts are high. These shearing constraints on the high molecular
weight polymers lead to macromolecular chain cleavages. The polymer thus degraded no longer
has thickening properties, and the viscosity drops irreversibly. This loss of permanent shear
strength therefore leads to a degradation of the lubrication properties of the lubricating
20 composition.
The polymers of the prior art, in particular PMMA (methyl polymethacrylates) have a
shear thickening behaviour. At a high shear rate, the PMMA chain breaks. This results in the
formation of two molecules having approximately half of the molar weight of the initial PMMA.
The total hydrodynamic volume of these two small molecules is less than that of the initial
25 PPMA, which leads to a smaller contribution to the viscosity and this results in a reduction in the
viscosity.
The ethylene-alphaolefin copolymers having a high ethylene content are additives
improving the viscosity and are stable under shear. However, these polymers have the drawback
of aggregating in the compositions containing them and lead to lubricating compositions that are
30 extremely viscous, such as gels. This aggregation generally takes place under ambient conditions
or during cooling.
Therefore the Applicant has set himself the objective of the formulation of novel
lubricating compositions the viscosity of which is better controlled compared with respect to the
lubricating compositions of the prior art. In particular, his objective is to provide novel
35 rheological additives, the behaviour of which when they are introduced into a base oil, is
opposite as regards temperature change compared with the behaviour of the base oil and the
rheological additives of polymer type of the prior art.
This objective is achieved thanks to novel rheological additives capable of associating,
3
in order to optionally form a gel_ and exchanging in thermoreversible manner. Unlike the base
oil which liquefies when the temperature increases, the additives of the present invention have
the advantage of thickening the medium in which they are dispersed when the temperature
increases.
5 This characteristic results from the associated use of two particular compounds, a
copolymer bearing diol functions and a compound comprising boronic ester functions.
Polymers, of which at least one monomer comprises boronic ester functions are known
from document W02013147795. These polymers are used for the production of electronic
devices, in particular for devices in which it is desired to obtain a flexible user interface. These
10 polymers are also used as synthesis intermediates. They allow the functionalization of the
polymers by coupling with luminescent groups, electron-transporter groups, etc. The coupling of
these groups is carried out by standard organic chemistry reactions, involving the boron atom,
such as for example Suzuki coupling. However, no other use of these polymers in the field of
lubricating compositions, nor an association with other compounds is envisaged.
15 A copolymer resulting from the copolymerization of a methyl methacrylate (MMA)
monomer and a glyceryl methacrylate monomer optionally protected by a boronic ester (namely
butyl boronic acid adduct of glyceryl methacrylate (BBA-GMA)) is known from document US
4.401,797. This copolymer forms a hydrogel in the presence of water and is used for the
production of contact lenses. However, no other use of this copolymer in the field of lubricating
20 compositions. nor a association via exchangeable chemical bonds with other compounds is
envisaged.
Document EP0570073 discloses an additive which improves the viscosity index of a
lubricating composition in which it is added. This additive is a copolymer resulting from the
polymerization of 1-(methacryloylethoxy)-4,4.6-trimethyl-dioxaborinane and a methacrylate of a
25 linear (C12-C1 8) alkyl. This additive belongs to the family of the borate compounds which can be
represented by the general formula B(OR)3 with R an alkyl or aryl group. This additive does not
belong to the family of the boronate compounds which can be represented by the general
formula R-B(OR)2 with R an alkyl or aryl group. This additive cannot be associated with other
compounds via exchangeable chemical bonds.
30 Unexpectedly, the Applicant observed that at low temperature, the polydiol copolymer
of the invention is not or only slightly cross-linked by the compounds comprising boronic ester
functions. When the temperature increases, the diol functions of the copolymer react with the
boronic ester functions of the compound containing them by a transesterification reaction. The
polydiol statistical copolymers and the compounds comprising boronic ester functions then link
35 together and can exchange. Depending on the functionality of the polydiols and of the
compounds comprising boronic ester functions, as well as depending on the composition of the
mixtures. a gel may form in the base oil. When the temperature reduces again, the boronic ester
bonds between the polydiol statistical copolymers and the compounds containing them break;
4
the composition loses its gelled character, if applicable.
The Applicant has set himself the objective of the formulation of novel rheology
additives which are more stable under shearing compared to the compounds of the prior art.
This objective is achieved thanks to novel rheological additives which can associate and
5 cross-link in a thermoreversible manner. Unlike the• polymers of the prior art, it was noted that
the molar weight of the copolymers of the invention is not or only slightly modified when a high
shear rate is applied. The copolymers of the invention therefore have the advantage of being
more stable under shearing stresses.
10 SUMMARY OF TIlE INVENTION
Thus, a subject of the invention is a composition resulting from mixing:
• at least one lubricating oil,
• at least one statistical copolymer Al and at least one compound A2 comprising at
least two boronic ester functions;
15 o the statistical copolymer Al resulting from the copolymerization:
• of at least one first monomer MI of general formula (I)
20
H2C
X10
0
25
OX2
(I)
in which:
RI is selected from the group formed by and —C142-CI-I5.
x is an integer ranging from 2 to 18;
30
y is an integer equal to 0 or 1:
Xi and X2, identical or different, are selected from the group formed by
hydrogen. tetrahydropyranyl. rnethyloxymethyl, ter-butyl, benzyl.
trimethylsilyl and t-butyl dimethylsilyl;
Or
35 — X i and X, form with the oxygen atoms a bridge of following formula
R" 2
5
5 or
10
15
in which:
- the stars (*) symbolize the bonds to the oxygen atoms.
- R'2 and R"2, identical or different, are selected from the group
formed by hydrogen and a CI-Cii alkyl, preferably methyl;
-- X i and X2 form with the oxygen atoms a boronic ester of following
formula
in which:
the stars (*) symbolize the bonds to the oxygen atoms,
R"'2 is selected from the group formed by a C6-C18 aryl, a
C7-C1s aralkyl and CT-Cis alkyl, preferably a C6-C18 aryl;
• with at least one second monomer M2 of general formula (II-A):
R2
H2C
(
R31
(II-A)
20 in which:
R, is selected from the group formed by —I-I, —C1-13 and —CI-12—CH
K3 is selected from the group formed by a C6-C18 aryl, a C6-C18 aryl
substituted by an Rl3, —C(0)—O—R'3 —0—R'3, --S—R'3 and —C(0)--
N(1-1)—R'3 group with R'3 a C1 -C30 alkyl group; and
25 In a variant, the statistical copolymer Al results from the copolymerization of at least
one monomer Ml with at least two monomers M2 having different 1231 groups.
Preferably, one of the monomers M2 of the statistical copolymer Al has the general
formula (II-Al):
30 H2C
O
O
R' 31
(II-AI)
35 in which:
— R, is selected from the group formed by —H, --CI- I3 and —C11,--C1-13,
K"31 is a C1-C11 alkyl group,
and the other monomer M2 of the statistical copolymer Al has the general formula (II-A2):
6
H2C
0
O
5
(II-A2)
in which:
R2 is selected from the group formed by —H, CH3 and
R""3, is a C15-C:0 alkyl group.
10 In a variant of the composition, compound A2 is a compound of formula (III):
R6
15
0
O B—O
\ /
B—L
O
R7
in which:
wi and w2, identical or different are integers selected between 0 and 1;
20 Ks, R6 and K7, identical or different are selected from the group formed by
hydrogen and a hydrocarbon-containing group having from 1 to 24 carbon
atoms, preferably between 4 and 18 carbon atoms, preferably between 6 and 14
carbon atoms;
L is a divalent bond group and is selected from the group formed by a C6-C1 8
25 aryl, a C6-C18 aralkyl and a C2-C24 hydrocarbon-containing chain.
In another variant of the composition, compound A2 is a statistical copolymer resulting
from the copolymerization:
• of at least one monomer M3 of formula (IV):
R10
30
O
B—M
/
\ X—f 28)
R-11
R9
H2C
35 (IV)
in which:
- t is an integer equal to 0 or 1;
- u is an integer equal to 0 or 1;
7
M and R8 are divalent bond groups, identical or different, selected from the
group formed by a C6-C18 aryl, a C7-C24 aralkyl and a C2-C24 alkyl, preferably
a (26-C18 aryl,
X is a function selected from the group formed by -0-C(0)-, -C(0)-0-.
5 -C(0)-N(I -N(H)-C(0)-, -S- , -N(1)- , -N(R'4)- and -0- with R'4 a
hydrocarbon-containing chain comprising from I to 15 carbon atoms;
R9 is selected from the group formed by -H. -CH3and CI-I2 CI I3
R I, and R1 1 identical or different are selected from the group formed by
hydrogen and a hydrocarbon-containing group having from 1 to 24 carbon
10 atoms, preferably between 4 and 18 carbon atoms, preferably between 6 and
14 carbon atoms;
n with at least one second monomer M4 of general formula (V):
R12
H2C
15 R13
(V)
in which:
R is selected from the group formed by II,-CI-I3 and -C112- CH3 ,
R,3 is selected from the group formed by a C6-C18 aryl, a C6-C.18 aryl
20 substituted by an R' -C(0) O--R' 13: 0-R' 13 .
-S-R' 13 and C(0)-N(H)-R' ,3 group, with R'r; a C1-C25 alkyl group.
Preferably, the compositions described above comprise one or more of the
characteristics below, taken separately or in combination:
• the chain formed by the sequence of the R10, M, X and (R8)u groups with u an
25 integer equal to 0 or I of the monomer of general formula (IV) has a total
number of carbon atoms comprised between 8 and 38, preferably between 10
and 26 carbon atoms;
• the side chains of the copolymer A2 have an average length greater than or equal
to 8 carbon atoms, preferably ranging from I I to 16 carbon atoms;
30 • the statistical copolymer A2 has a molar percentage of monomer of formula (IV)
in said copolymer ranging from 0.25 to 20%, preferably from 1 to 10%;
• the statistical copolymer A2 has a number-average degree of polymerization
ranging from 50 to 1500, preferably from 80 to 800;
• the side chains of the statistical copolymer Al have a average length ranging
35 from 8 to 20 carbon atoms, preferably from 9 to 15 carbon atoms;
• the statistical copolymer Al has a molar percentage of monomer Ml of formula
(I) in said copolymer ranging from I to 30%, preferably ranging from 5 to 25,
more preferably ranging from 9 to 21°/0;
8
• the statistical copolymer A 1 has an average degree of polymerization ranging
from 100 to 2,000. preferably from 150 to 1,000;
• the lubricating oil is selected from the oils of Group 1, Group II, Group III,
Group IV, Group V of the API classification and one mixture thereof;
5 • the composition further comprises a functional additive selected from the group
formed by the detergents, anti-wear additives, extreme-pressure additives.
additional antioxidants, polymers improving the viscosity index, pour point
improvers. anti-foaming agents. corrosion inhibitors, thickeners, dispersants.
friction modifiers and mixtures thereof;
10 • the mass ratio in the composition between the statistical copolymer A 1 and the
compound A2 (ratio Al/A2) ranges from 0.001 to 100, preferably from 0.05 to
20. yet more preferably from 0.1 to 10, yet more preferably from 0.2 to 5;
• the sum of the masses of the statistical copolymer Al and of the compound A2
in the composition ranges from 0.5 to 20% with respect to the total mass of the
15 lubricating composition and the mass of lubricating oil ranges from 80% to
99.5% with respect to the total mass of the lubricating composition.
A subject of the invention is also the use of a composition such as described above for
lubricating a mechanical part.
20
A subject of the invention is also a stock composition resulting from the mixture of :
• at least one statistical copolymer Al;
• at least one compound A2 comprising at least two boronic ester functions; and
• at least one functional additive selected from the group formed by the detergents,
25 anti-wear additives, extreme-pressure additives, antioxidants, polymers improving
the viscosity index, pour point improvers, anti-foaming agents, corrosion inhibitors.
thickeners, dispersants, friction modifiers and mixtures thereof;
o the statistical copolymer A I resulting from the copolymerization
n of at least one first monomer MI of general formula (I)
30
9
5
H2C
0
Xi0
(I)
in which:
Ri is selected from the group formed by -1-1, -C1-13 and 012-C1-13,
x is an integer ranging from 2 to 18;
15
y is an integer equal to 0 or I;
X1 and X. identical or different, are selected from the group formed by
hydrogen. tetrahydropyranyl, methyloxyrnethyl, ter-butyl. benzyl.
trimethylsilyl and t-butyl dimethylsilyl;
or
20 - Xi and X, form with the oxygen atoms a bridge of following formula
in which:
25
- the stars (*) symbolize the bonds to the oxygen atoms,
- R', and 12"2, identical or different, are selected from the group
formed by hydrogen and a CI-CI' alkyl, preferably methyl;
or
- XI and X, form with the oxygen atoms a boronic ester of the following
30 formula
R'" 2
in which:
the stars (*) symbolize the bonds to the oxygen atoms,
35 is selected from the group formed by a C6-C1 8 aryl, a
C-7-C18 aralkyl and C2-C18 alkyl, preferably a C6-C1 8 aryl;
• with at least one second monomer M2 of general formula (II-A):
10
5 in which:
H2C
R2
R31
(II-A)
R2 is selected from the group formed by —1-1, C113 and ---C1-12--CI-13 •
R31 is selected from the group formed by a Co-CIS aryl, a C6-C18 aryl
substituted by an R'3, —C(0)-0—R) , and —C(0)
N(1-1)--V group with R.3 a C1-C30 alkyl group.
10
BRIEF DESCRIPTION OF THE FIGURES
Figure 1 shows diagrammatically a statistical copolymer (13 1). a gradient copolymer (P2)
and a block copolymer (P3): each circle shows a monomer unit. The difference in chemical
structure between the monomers is symbolized by a different colour (light grey/black).
15 Figure 2 shows diagrammatically a comb copolymer.
Figure 3 illustrates and shows diagrammatically a solubility test of the composition
according to the invention in tetrahydrofuran (111F).
Figure 4 shows diagrammatically the behaviour of the composition of the invention as a
function of temperature. A statistical copolymer (2) having diol functions (function A) can
20 associate in a thermoreversible manner with a statistical copolymer (1) having boronic ester
functions (function 13) via a transesterification reaction. The organic group of the boronic ester
functions (function B) which are exchanged during the transesterification reaction is a diol
symbolized by a black crescent. A chemical bond (3) of boronic ester type forms with the release
of a diol compound.
25 Figure 5 shows the variation, for different temperatures comprised between 10°C and
110"C, of the viscosity (Pa.s, y-axis) as a function of the shear rate (s-I, x-axis) of a solution at
10% by weight of a polydiol statistical copolymer A1-1 and 0.77% by weight of a diboronic
ester compound A2-1 in the group III base oil.
Figure 6A shows the change in the relative viscosity (without units, y-axis) as a function
30 of the temperature (c)C, x-axis) of the compositions A, 13-1, C-1 and D-1.
Figure 613 shows the change in the relative viscosity (without units. y-axis) as a function
of the temperature (CC, x-axis) of the compositions A, B-2, C-2 and D-2.
Figure 6C shows the change in the relative viscosity (without units, y-axis) as a function
of the temperature (°C, x-axis) of the compositions A, 13-3 and C-3.
35 Figure 6D shows the change in the relative viscosity (without units, y-axis) as a function
of the temperature (CC, x-axis) of the compositions A, 13-4, C-4 and D-4.
11
Figure 7 shows the variation, for different temperatures comprised between 10°C and
110°C. in the viscosity (Pa.s. y-axis) as a function of the shear rate (s- ', x-axis) of the
composition E.
Figure 8 shows the change in the relative viscosity (without units, y-axis) as a function
5 of the temperature (°C, x-axis) of the compositions A, B, C, D and E.
Figure 9 shows diagrammatically the exchange reactions of boronic ester bonds between
two polydiol statistical polymers (A1-1 and Al-2) and two boronic ester statistical polymers
(A2-1 and A2-2) in the presence of diols.
10 DESCRIPTION OF EMBODIMENTS OF THE INVENTION
A first subject of the invention is a composition resulting from the mixing of :
• at least one lubricating oil,
• at least one statistical copolymer Al, and
15 • at least one compound A2 comprising at least two boronic ester functions;
the statistical copolymer Al resulting from the copolymerization of at least one first monomer
M I hearing diol functions and at least one second monomer M2 of different chemical structure
to that of the monomer MI.
20 o Luhricatink base oil
By "oil" is meant a fatty substance which is liquid at ambient temperature (25°C) and
atmospheric pressure (760 mm of Fig, i.e. 105 Pa).
By "lubricating oil" is meant a oil which attenuates the friction between two moving
parts with a view facilitating the operation of these parts. Lubricating oils can be of natural.
25 mineral or synthetic origin.
The lubricating oils of natural origin can be oils of vegetable or animal origin, preferably
oils of vegetable origin such as rapeseed oil, sunflower oil, palm oil, coconut oil etc.
The lubricating oils of mineral origin are of petroleum origin and are extracted from
petroleum cuts originating from the atmospheric and vacuum distillation of crude oil. The
30 distillation can be followed by refining operations such as solvent extraction, deasphalting,
solvent dewaxing, hydrotreatment, hydrocracking, hydroisomerization, hydrofinishing etc. By
way of illustration, the following can be mentioned: the paraffinic mineral base oils such as
Bright Stock Solvent (13SS oil, napthenic mineral base oils, aromatic mineral oils. hydrorefined
mineral bases the viscosity index of which is approximately 100, hydrocracked mineral bases the
35 viscosity index of which is comprised between 120 and 130, hydroisomerized mineral bases the
viscosity index of which is comprised between 140 and 150.
The lubricating oils of synthetic origin (or synthetic base) originate as their name
indicates from chemical synthesis such as addition of a product with itself or polymerization, or
12
the addition of a product to another such as esterification, alkylation, fluorination. etc., of
compounds originating from petrochemistry. carbochemistry, and mineral chemistry such as:
olefins, aromatics. alcohols, acids, halogenated, phosphorus-containing, silicon-containing
compounds, etc. 13y way of illustration, the following can be mentioned:
5 the synthetic oils based on synthesis hydrocarbons such as polyalphaolefins
(PAO). internal polyolefins (PIO), polybutenes and polyisobutenes (PI13),
dialkylbenenes, alkylated polyphenyls;
the synthetic oils based on esters such as diacid esters, neopolyol esters:
the synthetic oils based on polyglycols such as monoalkyleneglycols,
10 polyalkyleneglycols and polyalkyleneglycol monoethers;
the synthetic oils based on ester-phosphates;
the synthetic oils based on silicon-containing derivatives such as the silicone oils
or polysiloxanes.
The lubricating oils which can be used in the composition of the invention can be
15 selected from any of the oils of Groups I to V specified in the Base Oil Interchangeability
Guidelines of the American Petroleum Institute (API) (or their equivalents according to the
ATIEL classification (Association Technique de l'Industrie Europeenne des Lubrifiants) such as
summarized below:
13
Saturates content * Sulphur
content **
Viscosity
index (VI)**
Group I Mineral oils < 90% > 0.03% 80 ... VI < 120
Group II flydrocracked
oils
>_ 90% < 0.03% 80 VI < 120
I Group III
Flydrocracked or hydroisomcrized
oils
Group IV
> 90% 0.03% > 120
(PA()) Polyalphaolefins
Group V Esters and other bases not included in bases of Groups I
to IV
* measured according to the standard ASTM D2007
** measured according to the standards ASTM D2622, ASTM D4294, ASTM D4927 and
ASTM D3120
5 ** measured according to the standard ASTM D2270
The compositions of the invention can comprise one or more lubricating oils. The
lubricating oil or the mixture of lubricating oils represents at least 50% by weight with respect to
the total weight of the composition.
10 Preferably, the lubricating oil or the mixture of lubricating oils represents at least 70%
by weight with respect to the total weight of the composition.
In an embodiment of the invention, the lubricating oil is selected from the group formed
by the oils of Group I, Group 11, Group III, Group IV, Group V of the API classification and one
of the mixtures thereof. Preferably, the lubricating oil is selected from the group formed by the
15 oils of Group III, Group IV. Group V of the API classification and mixtures thereof. Preferably,
the lubricating oil is an oil of group Ill of the API classification.
The lubricating oil has a kinematic viscosity at 100°C measured according to the
standard ASTM D445 ranging from 2 to 150 cSt, preferably ranging from 5 to 15 cSt.
The lubricating oils can range from grade SAE 15 to grade SAE 250, and preferably
20 from grade SAL 20W to grade SAL 50 (SAE means Society of Automotive Engineers).
o Polydiol statistical copolymers (statistical copolymer Al)
The composition of the invention comprises at least one polydiol statistical copolymer
resulting from the copolymerization of at least one first monomer MI hearing diol functions and
25 at least one second monomer M2, of different chemical structure to that of the monomer MI.
By "copolymer", is meant an oligomer or a linear or branched macromolecule having a
sequence constituted by several repetitive units (or monomer unit) at least two units of which
14
have a different chemical structure.
By "monomer unit" or "monomer", is meant a molecule capable of being converted to
an oligomer or a macromolecule by association with itself or with of other molecules of the same
type. A monomer denotes the smallest constitutive unit the repetition of which leads to an
5 oligomer or to a macromolecule.
By "statistical copolymer", is meant an oligomer or a macromolecule in which the
sequential distribution of the monomer units obeys known statistical laws. For example, a
copolymer is said to be statistical when it is constituted by monomer units the distribution of
which is a Markovian distribution. A diagrammatic statistical polymer (P1) is shown in Figure 1.
10 The distribution in the polymer chain of the monomer units depends on the reactivity of the
polymerizable functions of the monomers and on the relative concentration of the monomers.
The polydiol statistical copolymers of the invention are distinguished from the block copolymers
and from the gradient copolymers. By "block" is meant a part of a copolymer comprising several
identical or different monomer units which has at least one feature of its constitution or
15 configuration making it possible to distinguish it from its adjacent parts. A diagrammatic block
copolymer (P3) is shown in Figure 1. A gradient copolymer denotes a copolymer of at least two
monomer units of different structures the monomer composition of which changes in a gradual
fashion along the polymer chain, thus passing progressively from one end of the polymer chain
rich in one monomer unit, to the other end rich in the other comonomer. A diagrammatic
20 gradient polymer (P2) is shown in Figure 1.
By "copolymerization", is meant a process which allows a mixture of at least two
monomer units of different chemical structures to be converted to an oligomer or to a copolymer.
In the remainder of the present application, "B" represents a boron atom.
By "C;-C, alkyl" is meant a saturated, linear or branched hydrocarbon-containing chain
25 comprising from i to j carbon atoms. For example, by "C i -C1 () alkyl", is meant a saturated, linear
or branched. hydrocarbon-containing chain comprising from 1 to 10 carbon atoms.
By "C-6-Cis aryl". is meant a functional group which derives from an aromatic
hydrocarbon-containing compound comprising from 6 to 18 carbon atoms. This functional group
can be monocyclic or polycyclic. By way of illustration, a C0-C18 aryl can be phenyl,
30 naphthalene. anthracene, phenanthrene and tetracene.
By "C3-C10" alkenyl, is meant a linear or branched hydrocarbon-containing chain
comprising at least one unsaturation. preferably a double bond, and comprising from 2 to 10
carbon atoms.
By "C7-Cis aralkyr is meant an aromatic hydrocarbon-containing compound, preferably
35 monocyclic. substituted by at least one linear or branched alkyl chain and of which the total
number of carbon atoms of the aromatic ring and of its substituents ranges from 7 to 18 carbon
atoms. By way of illustration a C7-Cis aralkyl can be selected from the group formed by benzyl,
tolyl and xylyl.
15
By "Cc-Cis aryl group substituted by an R'3 group", is meant an aromatic hydrocarboncontaining
compound, preferably monocyclic, comprising from 6 to 18 carbon atoms of which at
least one carbon atom of the aromatic ring is substituted by an R'3 group.
By "Hal" or "halogen" is meant a halogen atom selected from the group formed by
5 chlorine, bromine. fluorine and iodine.
• Monomer MI
The first monomer MI of the polydiol statistical copolymer (Al) of the invention has the
general formula (I):
10
15
H2C
X10
0
OX2
(I)
in which:
20 RI is selected from the group formed by 11, —CH3 and —C1-1,-CH3 preferably -11 and
1-13:
x is an integer ranging from 2 to 18; preferably of 3 to 8; more preferably x is equal to
4;
y is an integer equal to 0 or 1; preferably y is equal to 0;
25 X i and X2, identical or different, are selected from the group formed by hydrogen,
tetrahydropyranyl, methyloxymethyl, ter-butyl, benzyl, trimethylsilyl and t-butyl
dimethylsilyl,
X1 and X,, identical or different, are selected from the group formed by hydrogen, the
tetrahydropyranyl. methyloxymethyl, the ter-butyl, the benzyl, the trimethylsilyl and
30 the t-butyl dimethylsilyl:
or
X1 and X, form with the oxygen atoms a bridge of the following formula
35
in which:
- the stars (*) symbolize the bonds to the oxygen atoms,
- and R"2, identical or different, are selected from the group
16
formed by hydrogen and a C1-C11 alkyl group;
or
— X1 and X, form with the oxygen atoms a boronic ester of the following formula:
R"'2
5
B'
in which:
the stars (*) symbolize the bonds to the oxygen atoms,
12'"_ is selected from the group formed by a C6-Cis aryl, a C,-C ts
aralkyl and a C2-Cis alkyl, preferably a C6-C18 aryl, more preferably
10 phenyl.
Preferably, when R:2 and R",. is a CJ-C11 alkyl group, the hydrocarbon-containing chain
is a linear chain. Preferably, the Ci-C1 , alkyl group is selected from the group formed by methyl,
ethyl. n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decycl and n-undecyl.
More preferably. the C1-C11 alkyl group is methyl.
15 Preferably. when R is a C2-C18 alkyl group; the hydrocarbon-containing chain is a
linear chain.
Among the monomers of formula (I), the monomers corresponding to formula (I-A)
form part of those preferred:
20
25
H2C
HO
0
OH
(I-A)
in which:
R1 is selected from the group formed by —H, —CI-13 and —CH2-013, preferably --11 and
30 —C1-13;
x is an integer ranging from 2 to 18; preferably from 3 to 8; more preferably x is equal
to 4;
y is an integer equal to 0 or 1; preferably y is equal to 0.
Among the monomers of formula (1), the monomers corresponding to formula (I-B)
35 form part of those preferred:
aralkyl and a C2-C18 alkyl, preferably a C6-Cis aryl, more preferably
phenyl.
25
35 atoms,
in which:
R'"2
- the stars (*) symbolize the bonds to the oxygen
is selected from the group formed by a C6-C18 aryl, a C7-C18
17
5
H2C
Yi 0
0
0Y2
10
(1-13)
in which:
- R ] is selected from the group formed by CI I3 and C112-CI-13, preferably I I and
-CH::
15
- x is an integer ranging from 2 to 18; preferably from 3 to 8; more preferably x is equal
to 4:
- y is an integer equal to 0 or 1; preferably y is equal to 0;
- Y1 and Y2, identical or different, are selected from the group formed by
tetrahydropyranyl, methyloxymethyl, ter-butyl, benzyl, trimethylsilyl and t-butyl
20 dimethylsilyl;
or
Yi and Y2 form with the oxygen atoms a bridge of the following formula:
in which:
- the stars (*) symbolize the bonds to the oxygen atoms,
- R',2 and R"2, identical or different, are selected from the group
formed by hydrogen and a CI-C11 alkyl group;
30 or
Y, and Y, form with the oxygen atoms a boronic ester of the following formula:
30
0
H2C
0
35
HO
Yi 0
0Y2
(I-b)
H2C
Y10
(I-B) 0Y2
18
Preferably. when R'7 and IC? is a CH-C11 alkyl group the hydrocarbon-containing chain
is a linear chain. Preferably, the CI-CI, alkyl group is selected from the group formed by methyl,
ethyl, n-propyl, n-butyl, n-pcntyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decycl and n-undecyl.
More preferably. the C 1-C II alkyl group is methyl.
5 Preferably, when R"'2 is a C2-C18 alkyl group; the hydrocarbon-containing chain is a
linear chain.
• Obtaining the monomer MI
The monomer M l of general formula (I-A) is obtained by deprotection of the alcohol
10 functions of the monomer of general formula (I-13) according to the reaction diagram 1 below:
H2C
0
H2C
0
15
YiO
HO
OH
(I-A)
20
0Y2
Diagram 1
with R1, Y1, Y2, x and y as defined in the general formula (I13) described above.
The deprotection reaction of diol functions of the monomer of general formula (I-13) is
well known to a person skilled in the art. Ile knows how to adapt the deprotection reaction
25 conditions as a function of the nature of the protective groups Y1 and Y? .
The monomer M 1 of general formula (1-13) can be obtained by a reaction of a compound
of general formula (I-c) with an alcohol compound of general formula (I-b) according to the
reaction diagram 2 below:
Diagram 2
HO
HO
OH
(I-a)
15
HO
Y-10
0Y2
19
in which
Y3 is selected from the group formed by a halogen atom. preferably
chlorine. —OH and 0-C(0)-W with WI selected from the group formed
by CI-I3 and CI l2-CI-13, preferably Il and CI
5 R I , Y1 , Y3, x and y have the same meaning as that given in general
formula (1-13).
These coupline, reactions are well known to a person skilled in the art.
The compound of general formula (I-c) is commercially available from the suppliers:
Sigma-Aldrich® and Alfa Aesar®.
10 The alcohol compound of general formula (I-b) is obtained from the corresponding polyol
of formula (I-a) by protection of the diol functions according to the following reaction diagram
3:
protection
(I-b)
20 Diagram 3
with x. y. Y i and Y2 as defined in the general formula (I-B).
The protection reaction of the diol functions of the compound of general formula (I-a) is
well known to a person skilled in the art. Ile knows how to adapt the deprotection reaction
conditions as a function of the nature of the protective groups Yi and Y2 used.
25 The polyol of general formula (I-a) is commercially available from the suppliers: Sigma-
Aldrich® and Alfa Aesar®.
• Monomer M2
"the second monomer of the statistical copolymer of the invention has the general formula
30 (II):
R2
H2C
R3
(II)
35 in which:
R, is selected from the group formed by II, —CD3 and CI I, CI Is , preferably I1 or
R3 is selected from the group formed by a hydrogen atom, a C1 -C10 alkyl group. a C2-
20
alkenyl group, a C6-C18 aryl group, a Co-C1 8 aryl substituted by an R '3, -C(0)
0- R',. -S R'3 and --C(0)---N(1-1)- R'3 group with R'3 a C1-C3o alkyl group.
Preferably. is a C1-C3o alkyl group of which the hydrocarbon-containing chain is
5 Among the monomers of formula (11), the monomers corresponding to formula (11-A)
form part of those preferred
R2
H2C
10
in which:
(
R31
(11-A)
R2 is selected from the group formed by ----C1-13 and --C1-12.---C1 13 , preferably --
H or ---CEL
R31 is selected from the group formed by a C6-C1 8 aryl group. a C6-C[8 aryl
15 substituted by an R'3, —C(0) 0 R•3: -0 , —S --R'3 and
-C(0)----N(1--1)—R'.; group with R'3 a C,-C30 alkyl group.
Preferably. R'3 is a CI-Cm alkyl group of which the hydrocarbon-containing chain is
linear.
20 Among the monomers of formula (11-A), the monomers corresponding to formula (11-
A 1 ) ) form part of those preferred:
25
H2C
O
O
R" 31
(II-A1)
in which:
R2 is selected from the group formed by --H, and--C1 13 preferably —11 and
30 -C1
R"3 , is a CI-C11 alkyl group.
By "Ci-Cir alkyl group", is meant a saturated, linear or branched hydrocarbon-containing
chain comprising from 1 to 14 carbon atoms. Preferably, the hydrocarbon-containing chain is
linear. Preferably, the hydrocarbon-containing chain comprises from 4 to 12 carbon atoms.
35
Among the monomers of formula (11-A), the monomers corresponding to formula (11-
A2)also form part of those preferred:
21
H2C
O
5
R°' 31
(II-A2)
in which:
R2 is selected from the group formed by II. and —C1-12—C1-13 preferably 11 and
10 R '31 is a (215-C30 alkyl group.
By "C1 3-C30 alkyl group", is meant a saturated, linear or branched hydrocarbon-containing
chain comprising from 15 to 30 carbon atoms. Preferably, the hydrocarbon-containing chain is
linear. Preferably, the hydrocarbon-containing chain comprises from 16 to 24 carbon atoms.
15 Among the monomers of formula (II); the monomers corresponding to formula (11-13)
form part of those preferred:
R22
H2C
R32
20 (II-B)
in which:
R22 is selected from the group formed by 1-1 and CI-I3;
R33 is selected from the group formed by a hydrogen atom, a C1 -C1 0 alkyl group and a
C2-C10 alkenyl group.
25
• monomer Al2
The monomers of formula (II). (II-A), in particular (II-A1) and (II-A2), (II-13) are well
known to a person skilled in the art. They are marketed by Sigma-Aldrich® and TCI®.
30 • Preferred polydiol copolymers
In an embodiment, a preferred statistical copolymer results from the copolymerization of
at least:
a first monomer M l of general formula (I) as described previously;
a second monomer M2 of formula (II) as described previously, in which R2 is -II
35 and R3 is a Co-Cis aryl group: preferably R3 is phenyl.
In another embodiment, a preferred statistical copolymer results from the
copolymerization of at least:
a first monomer MI of general formula (I) as described previously;
22
a second monomer M2 of formula (II-A ) as described previously; and
— a third monomer M2 of formula (II-A2) as described previously.
According to this other embodiment, a preferred statistical copolymer results from the
copolymerization of at least:
5 a first monomer MI of general formula (I) as described previously:
a second monomer M2 of formula (II-Al) in which R2 is CI-13 and R"u is a C.1-
C1 2 alkyl group, preferably a linear C1-C p alkyl;
a third monomer M2 of formula (II-A2) in which R2 is CI-13 and R.— is a C 16-
C21 alkyl group, preferably a linear in Cu,-C21 alkyl.
10 According to this embodiment, a preferred statistical copolymer results from the
copolymerization of at least:
a first monomer MI of general formula (I) as described previously;
a second monomer M2 selected from the group formed by n-octyl methacrylate.
n-dccyl methacrylate and n-dodecyl methacrylate;
15 a third monomer M2 selected from the group formed by palmityl methacrylate,
stearyl methacrylate, arachidyl methacrylate and behenyl methacrylate.
In another embodiment. a preferred statistical copolymer results from the
copolymerization of at least:
a first monomer MI of general formula (I) as defined previously;
20 a second monomer M2 of formula (II-B) as defined previously, in which R22 and
R.:, are a hydrogen atom;
a third monomer M2 of formula (II-B) as defined previously in which R22 is a
hydrogen atom. fZ3 is a C1 -C t o alkyl group, preferably R;:) a linear C I -C lo alkyl
group, preferably R;7 is selected from the group constituted by CI13.
25 CI 12-C1-12-C1-13, C112-(C112 )2-CH3 and CI-12-(CI-12)3-C1-13
According to this embodiment, a preferred statistical copolymer results from the
copolymerization of at least:
a first monomer MI of general formula (I) as defined previously;
a second monomer M2 of formula (II-B) which is ethylene;
30 a third monomer M2 of formula (1143) which is propylene.
In another embodiment, a preferred statistical copolymer results from a
copolymerization step of at least:
a first monomer MI of general formula (I) as defined previously;
35 a second monomer M2 of general formula (II-B) as defined previously, in which
R» is a hydrogen atom and R3-) is selected from the group formed by a hydrogen
and a C1 -C 10 alkyl group,
a third monomer M2 of general formula (II-A 1 ) as defined previously.
23
In another embodiment, a preferred statistical copolymer results from a
copolymerization step of at least:
a first monomer Ml of general formula (I) as described previously;
5 a second monomer M2 of formula (II) as described previously, in which R3, is II
and R3 is a C6-C18 aryl group, preferably R3 is phenyl; and
a third monomer M2 of formula (II-B) as described previously, in which R?., is
selected from the group formed by H or CH3, R32 is a C2-C10 alkenyl group,
preferably R32 is —C(11)--CI12;
10 and a hydrogenation step.
Hydrogenation can he accomplished by any technique well known to a person skilled in the art.
• Process _for po_lycliol copolymers
A person skilled in the art is in a position to synthesize the polydiol statistical
15 copolymers A 1 of the invention by calling on his general knowledge.
The copolymerization can be initiated in by bulk polymerization or in solution in an
organic solvent by compounds that generate free radicals. For example. the copolymers of the
invention, in particular those resulting from the copolymerization of at least one monomer of
formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula
20 (I) with at least one monomer of formula (II-Al) and at least one monomer of formula (II-A2),
are obtained by the processes known as radical copolymerization, in particular controlled radical
copolymerization. such as the method called radical copolymerization controlled by Reversible
Addition-Fragmentation Chain Transfer (RAFT) and the method called radical copolymerization
controlled by Atom Transfer Radical Polymerization (ARTP). Conventional radical
25 polymerization and telomerization can also be used for the preparation of the copolymers of the
invention (Moad. a; Solomon. D. I I., The Chemistry of Radical Polymerization. 2nd ed.;
Elsevier Ltd: 2006; p 639; Matyaszewski, K.; Davis. T. P. Handbook of Radical Polymerization;
Wiley-Interscience: Hoboken. 2002; p 936).
30 A process for the preparation of a statistical copolymer comprises at least one
polymerization step (a) in which at least the following are brought into contact:
i) a first monomer MI of general formula (I):
35
24
H2C
O
5 X10
OX2
(I)
10 in which:
R1 is selected from the group formed by —H, —CH3 and —CF12-C1-13:
x is an integer ranging from 2 to 18:
y is an integer equal to 0 or 1;
X1 and X2, identical or different, are selected from the group formed by
15 hydrogen, tetrahydropyranyl, methyloxymethyl, ter-butyl, benzyl,
trimethylsilyl and t-butyl dimethylsilyl;
or
20
25
or
30
— X1 and X2 form with the oxygen atoms a bridge of following formula
R" 2
in which:
- the stars (*) symbolize the bonds to the oxygen atoms;
- W and R-2. identical or different, are selected from the group
formed by hydrogen and a C1 -C11 alkyl, preferably methyl;
— X1 and X2 form with the oxygen atoms a boronic ester of the following
formula
zR2"'
in which:
- the stars (*) symbolize the bonds to the oxygen atoms;
- R-7 is selected from the group formed by a C6-C13 aryl, a
35
C,-C18 aralkyl and C2-C18 alkyl, preferably a C 6-C 18 aryl
ii) at least one second monomer M2 of general formula (II-A):
25
H2C
(
R2
R3
5 in which:
R2 is selected from the group formed by —CI-13 and —C1-12—C1-13
R3 is selected from the group formed by a C6-C1 5 aryl, a C,-C18 aryl
substituted by an R'3, —C(0)—O-0 —S —R'3 and --C(0)--
I\1(11)--R'3group with R'3 a CI-C30 alkyl;
10 iii) at least one source of free radicals.
In an embodiment, the process can comprise moreover iv) at least one chain-transfer
agent.
By "a source of free radicals" is meant a chemical compound or making it possible to
generate a chemical species having one or more electrons which are not paired in its outer shell.
15 A person skilled in the art can use any source of free radicals known per .s.e such as suitable for
the polymerization processes, in particular controlled radical polymerization. Among the sources
of free radicals, the following are preferred, by way of illustration: benzoyl peroxide, tert-butyl
peroxide. the diazo compounds such as azo-his-iso-butyronitrile, the peroxygenated compounds
such as persulphates or hydrogen peroxide, the redox systems such as the oxidation of Fe'', the
20 persulphates/sodium-metabisulphite mixtures, or ascorbic acid/hydrogen peroxide mixtures or
also the compounds which can be cleaved photochemically or by ionizing radiation, for example
ultra-violet rays or by beta or gamma radiation.
By "chain-transfer agent", is meant a compound the goal of which is to ensure
homogeneous growth of the macromolecular chains by transfer reactions which are reversible
25 between species during growth, i.e. polymer chains terminated by a carbon radical, and dormant
species. i.e. polymer chains terminated by a transfer agent. This reversible transfer process
makes it possible to control the molecular masses of copolymers thus prepared. Preferably in the
process of the invention, the chain-transfer agent comprises a thiocarbonylthio group --S—C(--S)--
. By way of illustration of a chain-transfer agent. the dithioesters. trithiocarbonates, xanthates
30 and dithiocarbamates can be mentioned. A preferred transfer agent is cumyl dithiobenzoate or 2-
cyano-2-propyl benzodithioate.
By "chain-transfer agent", is also meant a compound the goal of which is to limit the
growth of the macromolecular chains during formation by the addition of monomer molecules
and to initiate of new chains. which makes it possible to limit the final molecular masses. or
35 even to control them. Such a type of transfer agent is used in telomerization. A preferred transfer
agent is cysteamine.
The process for the preparation of a polydiol statistical copolymer can comprise:
at least one step of polymerization (a) as defined above, in which the
26
monomers MI and M2 are selected with X1 and X2 different from hydrogen,
and moreover
at least one step of deprotection (b) of the diol functions of the copolymer
obtained at the end of step (a), so as to obtain a copolymer in which XI and
5 X, are identical and are a hydrogen atom.
In an embodiment, the polymerization step (a) comprises the bringing into contact of at
least one monomer MI with at least two monomers M2 having different R31 groups.
In this embodiment, one of the monomers M2 has the general formula (II-A1):
10
H2C
0
R"31
15 (II-A1)
in which:
R2 is selected from the group formed by -H, --CH3 and -CE13-C1-13 , preferably -H and
R"si is a CI-C.14 alkyl group,
20 and the other monomer M2 has the general formula (II-A2)
H2C
O
O
25
R"' 31
(II-A2)
in which:
R2 is selected from the group formed by II, -C113 and -CH2-CH3. preferably -F1 and
30 -C113:
R-'31 is a C 15-C30 alkyl group.
The preferences and definitions described for the general formulae (I), (I-A), (1-13), (11-
A), (I-B), (II-A), (II-A 1 ) and (II-A2) apply also to the processes described above.
35 • Properties of the polydiol copolymers Al
The polydiol statistical copolymers Al of the invention are comb copolymers.
By "comb copolymers", is meant a copolymer having a main chain (also called backbone)
and side chains. The side chains are pendant on both sides of the main chain. The length of each
27
side chain is less than the length of the main chain. Figure 2 diagrammatically shows a comb
polymer.
The copolymers of the invention in particular those resulting from the copolymerization of
at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least
5 one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one
monomer of formula (II-A2), have a backbone of polymerizable functions, in particular a
backbone of methacrylate functions, and a mixture of hydrocarbon-containing side chains
substituted or not by diol functions.
As the monomers of formula (I) and (II-A) have polymerizable functions of identical or
10 substantially identical reactivity, a copolymer is obtained the monomers of which, having diol
functions, are distributed statistically along the backbone of the copolymer with respect to the
monomers the alkyl chains of which are non-substituted by diol functions.
The polydiol statistical copolymers of the invention, in particular those resulting from the
copolymerization of at least one monomer of formula (I) with at least one monomer of formula
15 (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (H-Al)
and at least one monomer of formula (II-A2), have the advantage of being sensitive to external
stimuli, such as the temperature, pressure, shear rate; this sensitivity being demonstrated by a
change in properties. In response to a stimulus, the spatial conformation of the copolymer chains
is modified and the diol functions are rendered more accessible or less accessible to the
20 association reactions capable of generating cross-linking, as well as to the exchange reactions.
These association and exchange processes are reversible. The copolymer of the invention Al is a
thermosensitive copolymer, i.e. it is sensitive to changes in temperature.
Advantageously, the side chains of the polydiol statistical copolymer, in particular that
resulting from the copolymerization of at least one monomer of formula (I) with at least one
25 monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer
of formula (II-A1) and at least one monomer of formula (II-A2), have an average length ranging
from 8 to 20 carbon atoms, preferably from 9 to 15 carbon atoms. By "average length of side
chain- is meant the average length of the side chains of each monomer constituting the
copolymer. A person skilled in the art knows how to obtain this average length by appropriately
30 selecting the types and the ratio of monomers constituting the polydiol statistical copolymer. The
choice of this average chain length makes it possible to obtain a polymer which is soluble in a
hydrophobic medium, whatever the temperature at which the copolymer is dissolved. The
copolymer Al is therefore miscible in a hydrophobic medium. By "hydrophobic medium" is
meant a medium which has no or very little affinity for water, i.e. it is not miscible in water or in
35 an aqueous medium.
Advantageously, the polydiol statistical copolymer of the invention, in particular that
resulting from the copolymerization of at least one monomer of formula (I) with -at least one
monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer
28
of formula (1I-A1) and at least one monomer of formula (II-A2), has a molar percentage of
monomer M1 of formula (I) in said copolymer ranging from I to 30%, preferably ranging from 5
to 25%, more preferably ranging from 9 to 21%.
In a preferred embodiment of the invention, the copolymer of the invention has a molar
5 percentage of monomer Ml of formula (1) in said copolymer ranging from 1 to 30%, preferably
5 to 25%, more preferably ranging from 9 to 21%, a molar percentage of monomer M2 of
formula (1I-Al) in said copolymer ranging from 8 to 92% and a molar percentage of monomer
M2 of formula (11-A2) in said copolymer ranging from 0.1 to 62%. The molar percentage of
monomers in the copolymer results directly from adjustment of the quantities of monomers
10 utilized for the synthesis of the copolymer.
In a preferred embodiment, the copolymer Al has a molar percentage of monomer MI of
formula (I) in said copolymer ranging from 1 to 30%, a molar percentage of monomer M2 of
formula (II-A) in said copolymer ranging from 8 to 62% and a molar percentage of monomer
M2 of formula (II-B) in said copolymer ranging from 8 to 91%. The molar percentage of
15 monomers in the copolymer results directly from adjustment of the quantities of monomers
utilized for the synthesis of the copolymer.
Advantageously, the polydiol statistical copolymer of the invention, in particular that
resulting from the copolymerization of at least one monomer of formula (I) with at least one
monomer of formula (11-A) or of at least one monomer of formula (I) with at least one monomer
20 of formula (II-Al ) and at least one monomer of formula (11-A2), has a number-average degree of
polymerization ranging from 100 to 2000. preferably from 150 to 1000. The degree of
polymerization is controlled in a known way by using a controlled radical polymerization
technique, a telomerization technique, or by adjusting the source quantity of free radicals when
the copolymers of the invention are prepared by conventional radical polymerization.
25 Advantageously, the polydiol statistical copolymer of the invention, in particular that
resulting from the copolymerization of at least one monomer of formula (I) with at least one
monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer
of formula (11-A1) and at least one monomer of formula (II-A2), has a polydispersity index
(PD1) ranging from 1.05 to 3.75; preferably ranging from 1.10 to 3.45. The polydispersity index
30 is obtained by steric exclusion chromatography measurement using a polystyrene calibration.
Advantageously, the polydiol statistical copolymer of the invention, in particular that
resulting from the copolymerization of at least one monomer of formula (I) with at least one
monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer
of formula (11-A1) and at least one monomer of. formula (II-A2). has a number-average molar
35 mass ranging from 10,000 to 400,000 gimol, preferably from 25,000 to 150,000 gimol, the
number-average molar mass being obtained by steric exclusion chromatography measurement
using a polystyrene calibration.
The method of steric exclusion chromatography measurement using a polystyrene
29
calibration is described in the work (Fontanille, M.; Gnanou, Y., Chimie et physico-chimie des
polymeres. 2nd ed.; Dunod: 2010; p 546).
o Compound A2 dihoronic ester
5
In an embodiment of the composition of the invention, the compound A2 comprising two
boronic ester functions has the general formula (III):
R6
0
0 B—O
\ /
B—L
R7
15 (III)
in which:
w, and w2, identical or different, are integers selected between 0 and 1,
R4, R5, R6 and R7, identical or different, are selected from the group formed by
hydrogen and a hydrocarbon-containing group having from 1 to 24 carbon
20
atoms, preferably from 4 to 18 carbon atoms, preferably from 6 to 14 carbon
atoms:
L is a divalent bond group and selected from the group formed by a C6-C 1 8 aryl,
a C7-C2.1 aralkyl and a C?-C24 hydrocarbon-containing chain, preferably a C6-Cis
aryl.
25
By "hydrocarbon-containing group having from I to 24 carbon atoms" is meant a linear
or branched alkyl or alkenyl group, having from 1 to 24 carbon atoms. Preferably, the
hydrocarbon-containing group comprises from 4 to 18 carbon atoms, preferably from 6 to 14
carbon atoms. Preferably, the hydrocarbon-containing group is a linear alkyl.
By "C2-C24 hydrocarbon-containing chain" is meant a linear or branched alkyl or alkenyl
30
group, comprising from 2 to 24 carbon atoms. Preferably, the hydrocarbon-containing chain is a
linear alkyl group. Preferably the hydrocarbon-containing chain comprises from 6 to 16 carbon
atoms.
In an embodiment of the invention, the compound A2 is a compound of general formula
(III) above in which:
35 w, and W. identical or different, are integers selected between 0 and 1;
R. and R6 are identical and are hydrogen atoms;
RS and R7 are identical and are a hydrocarbon-containing group, preferably a
linear alkyl, having from 1 to 24 carbon atoms, preferably from 4 to 18 carbon
10
30
atoms, preferably from 6 to 16 carbon atoms:
- L is a divalent bond group and is a C6-C Ix aryl, preferably phenyl.
The boronic diester compound A2 of formula (III) as described above is obtained by a
condensation reaction between a boronic acid of general formula (III-a) and diol functions of the
5 compounds of general formula (III-b) and (11I-c) according to the reaction diagram 4 below:
Acetone, H2O
R6
O
0
\ B -0
B—L
R7
10
OH OH
MgS0,
OH OH (111-b)
(III)
Diagram 4
15 with wl, w?, L, R.i, R5, R, and R7, as defined above.
Indeed, by condensation of the boronic acid functions of the compound (III-a) with diol
functions of the compounds of formula (Ill-b) and of formula (III-c), compounds having two
boronic ester functions are obtained (compound of formula (III)). This step is carried out
according to means well known to a person skilled in the art.
20 Within the context of the present invention, the compound of general formula (III-a) is
dissolved, in the presence of water, in a polar solvent such as acetone. The presence of water
allows the chemical equilibria between the molecules of boronic acid of formula (III-a) and the
boroxine molecules obtained from the boronic acids of formula (III-a) to be shifted. In fact, it is
well known that the boronic acids can spontaneously form boroxine molecules at ambient
25 temperature. Now, the presence of boroxine molecules is undesirable within the context of the
present invention.
The condensation reaction is carried out in the presence of a dehydration agent such as
magnesium sulphate. This agent makes it possible to trap the water molecules initially
introduced as well as those that are released by the condensation between the compound of
30 formula (III-a) and the compound of formula (III-b) and between the compound of formula (IIIa)
and the compound of formula (III-c).
In an embodiment. the compound (III-b) and the compound (III-c) are identical.
A person skilled in the art knows how to adapt the quantities of reagents of formula (III-b)
and/or (Ill-c) and of formula (III-a) in order to obtain the product of formula (III).
35
• Compound A2 boronic ester copolymer
In another embodiment of the composition of the invention, the compound A2 comprising
31
at least two boronic ester functions is a boronic ester statistical copolymer resulting from the
copolymerization of at least one monomer M3 of formula (IV) as described below with at least
one monomer M4 of formula (V) as described below.
5
V Monomer M3 of formula (IV)
The monomer M3 of the boronic ester statistical copolymer compound A2 has the general
formula (IV) in which:
Rlo
10
0
B—M
/
0 \ X-0=28)
H2C
R1-1 R9
(IV)
15 in which:
t is an integer equal to 0 or 1;
u is an integer equal to 0 or 1;
M and R8 are divalent bond groups, identical or different, and are selected
from the group formed by a Co-Cis aryl, a C7-C21 aralkyl and C2-C21 alkyl,
20 preferably a Co-C i s aryl,
X is a function selected from the group formed by 0--C(0) , C(0) 0
, N(11) C(0)- • S-, -N(II) NI(R'.1)--- and -0- with It' t a
hydrocarbon-containing chain comprising from 1 to 15 carbon atoms;
R9 is selected from the group formed by ClIs and CH7 CI-13; preferably
25 -H and--CH,;
R10 and R1 1, identical or different, are selected from the group formed by
hydrogen and a hydrocarbon-containing chain having from 1 to 24 carbon
atoms, preferably between 4 and 18 carbon atoms. preferably between 6 and
12 carbon atoms;
30
By "C,.-C2.1 alkyl" is meant a saturated, linear or branched hydrocarbon-containing chain
comprising from 2 to 24 carbon atoms. Preferably, the hydrocarbon-containing chain is linear.
Preferably the hydrocarbon-containing chain comprises from 6 to 16 carbon atoms.
By "hydrocarbon-containing chain comprising from 1 to 15 carbon atoms" is meant a
linear or branched alkyl or alkenyl group, comprising from 1 to 15 carbon atoms. Preferably, the
35
hydrocarbon-containing chain is a linear alkyl group. Preferably, it comprises from 1 to 8 carbon
atoms.
By "hydrocarbon-containing chain comprising from 1 to 24 carbon atoms" is meant a
linear or branched alkyl or alkenyl group, comprising from 1 to 24 carbon atoms. Preferably. the
32
hydrocarbon-containing chain is a linear alkyl group. Preferably, it comprises from 4 to 18
carbon atoms, preferably between 6 and 12 carbon atoms.
In an embodiment of the invention, the monomer M3 has the general formula (IV) in
which:
5 - t is an integer equal to 0 or 1;
- u is an integer equal to 0 or 1;
M and Rs are divalent bond groups and are different, M is a C6-C i0 aryl.
preferably phenyl, R8 is a C7-C24 aralkyl, preferably benzyl;
X is a function selected from the group formed by -0-C(0)-, -C(0)-0-,
10 -C(0)-N(H)-and 0-, preferably -C(0)-0-or -0C(0)-;
R, is selected from the group formed by -H, -0-13, preferably -I-I:
R io and Rilare different, one of the Rio or RI, groups is H and the other Rio
or R I' group is a hydrocarbon-containing chain, preferably a linear alkyl
group, having from 1 to 24 carbon atoms, preferably between 4 and 18
15
carbon atoms, preferably between 6 and 12 carbon atoms.
V Synthesis of the monomer M3 of formula (IV)
In all the diagrams shown below, unless stated otherwise, the variables Rio, R i i , M, u, t,
20 X, R8. R', and R, have the same definition as in formula (IV) above.
The monomers M3 of formula (IV) are in particular obtained from a preparation process
comprising at least one step of condensation of a boronic acid of general formula (IV-1) with a
diol compound of general formula (IV-g) according to the reaction diagram 5 below:
25
Rio
(R8
M
30 /B—OH
HO
B—M
/ 0 X R8
H2C
1) Acetone, H2O
O
OH OH 2) MgSO4
R11
R9
(IV-f) (IV-g) (IV)
35 Diagram 5
Indeed, by condensation of the boronic acid functions of the compound of formula (1V-1)
with diol functions of the compounds of formula (IV-g), a boronic ester compound of formula
(IV) is obtained. This step is carried out according to methods well known to a person skilled in
10
R12
H2O
15
R9
CH2
Rau
X
M
/
B—OH
HO
(IV-f)
0
B—M
/
0 \ X--(R8
R9
H2C
(IV-e)
R12
R12
30
R9
(IV-e) H2C
0
B—M
0
/ Y4
(IV-c)
Y5-(R9),
R9
H2C
(IV-d)
0
B—M
O
/ X—tF28 )u
33
the art.
Within the context of the present invention, the compound of general formula (1V-1) is
dissolved, in the presence of water, in a polar solvent such as acetone. The condensation reaction
is carried out in the presence of a dehydration agent, such as magnesium sulphate.
5
The compounds of formula (IV-g) are commercially available from the following
suppliers: Sigma-Aldrich®, Alfa Aesar® and TCI®.
The compound of formula (IV-f) is obtained directly from the compound of formula (IVe)
by hydrolysis according to the following reaction diagram 6:
Diagram 6
20 with
z an integer equal to 0 or 1;
Rp is selected from the group formed by 11, CII3and
u, X, M, R8 and Rq as defined above.
The compound of formula (IV-e) is obtained by a condensation reaction of a compound of
25 formula (IV-c) with at least one compound of formula (IV-d) according to the following reaction
diagram 7:
Diagram 7
with
35 z, R12. M. R'.1 , R, and R8 as defined above;
and in this diagram when:
and in this diagram when:
• X represents —0—C(0)—. then Y4 represents an alcohol function —OH or a halogen
34
atom, preferably chlorine or bromine and Y5 is a carboxylic acid function -C(0)--
01-1;
• X represents --C(0) 0 , then Y. represents a carboxylic acid function -C(0)-01-1
and Y5 is an alcohol function -011 or a halogen atom, and preferably chlorine or
5 bromine;
• X represents --C(0)--N(11)--, then Y4 represents a carboxylic acid function-C(0)--
01-1 or a-C(0) Hal function, and Y5 is an amine function NI-I2;
• X represents -N(I-1)--C(0)--, then Y4 represents an amine function NH2 and Y5 is a
carboxylic acid function ---C(0)-OH or a-C(0)--Hal function;
10 • X represents -S--, then Y4 is a halogen atom and Y5 is a thiol function SI-1 or Y4 is
a thiol function -SH and Y5 is a halogen atom;
• X represents --N(1-1)-, then Y. is a halogen atom and Y5 is an amine function
or Y,, is an amine function -NI-12 and Y5 is a halogen atom;
• X represents --N(R'4)---, then Y4 is a halogen atom and Y5 is an amine
15 function -N(H)(R'4) or Y4 is an amine function -N(11)(R•4) and Y5 is a halogen
atom:
• X represents -0-, then Y. is a halogen atom and Y5 is an alcohol function
--OH or Y. is an alcohol function -OH and Y5 is a halogen atom.
These esterification, etherification, thioetherification, alkylation or condensation reactions
20 between an amine function and a carboxylic acid function are well known to a person skilled in
the art. A person skilled in the art therefore knows how to select the reaction conditions
depending on the chemical nature of the Y1 and Y, groups in order to obtain the compound of
formula (IV-e).
The compounds of formula (IV-d) are commercially available from the suppliers: Sigma-
25 Aldrich® and TCI®.
The compound of formula (IV-c) is obtained by a condensation reaction between a
boronic acid of formula (IV-a) with at least one diol compound of formula (IV-b) according to
the following reaction diagram 8
R12
30 HO
~B~M ~Y4
OH
(IV-a)
Acetone, H 2O 0
B—M
/ 0 Y4
(IV-c)
OH OH MgS0,
(IV-b)
35 Diagram 8
with M, Y4, z and R12 as defined above,
Among the compounds of formula (IV-b), the one in which R12 is methyl and z=0 is
preferred.
35
The compounds of formula (IV-a) and (IV-b) are commercially available from the
following suppliers Sigma-Aldrich®, Alfa Aesar® and TCI®.
V Monomer M4 of general formula (V):
5
The monomer M4 of the boronic ester statistical copolymer compound A2 has the
general formula (V
R12
H2C
R13 (V)
10 in which:
Rig is selected from the group formed by —I-1, —CI-12 and -C112—C112
preferably —1-1 and --CI-13;
R H is selected from the group formed by a Cs-Co aryl, a Cs-Co aryl
substituted by an R' ,3 group, —C(0)—O—R'13; R' [3, S R' [3
15 and -C(0)—N(11)—R'13 with R'13 a C1-C25 alkyl group.
By "C1 -C2 5 alkyl group", is meant a saturated, linear or branched hydrocarboncontaining
chain comprising from 1 to 25 carbon atoms. Preferably, the hydrocarbon-containing
chain is linear.
By "C6-C15 aryl substituted by an R13 group" group, is meant an aromatic hydrocarbon-
20
containing compound comprising from 6 to 18 carbon atoms of which at least one carbon atom
of the aromatic ring is substituted by a C1-C'25 alkyl group as defined above.
Among the monomers of formula (V), the monomers corresponding to formula (V-A) are
preferred:
25 H2C
(V-A)
30 in which:
R2 is selected from the group formed by —H, —CTI3 and —CI-b.—CI-12.
preferably and —CI-12 ,
R'13 a C1-C75 alkyl group, preferably a linear C1-C25 alkyl, yet more
preferably a linear C5-C15 alkyl.
35
V Obtaining the monomer M4:
The monomers of formulae (V) and (V-A) are well known to a person skilled in the art.
They are marketed by Sigma-Aldrich® and TCI®.
36
,z Synthesis of boronic ester statistical copolymer compound A2
A person skilled in the art is in a position to synthesize the boronic ester statistical
copolymers by calling on his general knowledge. The copolymerization can he initiated by bulk
5 polymerization or in solution in an organic solvent by compounds generating free radicals. For
example, the boronic ester statistical copolymers are obtained by the processes known as radical
copolymerization, in particular controlled radical polymerization, such as the method called
controlled radical copolymerization by Reversible Addition-Fragmentation Chain Transfer
(RAFT) and the method called controlled radical polymerization by Atom Transfer Radical
10 Polymerization (ARTP). Conventional radical polymerization and telomerization can also be
used for the preparation of the copolymers of the invention (Moad, G.; Solomon, D. H., The
Chemistry of Radical Polymerization. 2nd ed.; Elsevier Ltd: 2006; p 639; Matyaszewski, K.;
Davis, T. P. I landbook of Radical Polymerization; Wiley-Interscience: Hoboken, 2002; p 936).
Thus another subject of the present invention is a process for the preparation of a boronic
15 ester statistical copolymer comprises at least one polymerization step (a) in which at least the
following are brought into contact:
i) a first monomer M3 of. general formula (IV):
R1 0
20
0
B—M
O
/
\X—R8)
u
H2C
R11 R9
25 (IV)
in which:
t is an integer equal to 0 or 1;
u is an integer equal to 0 or 1;
M and Rs are divalent bond groups, identical or different, and are selected
30
from the group formed by a C6-C i s aryl, a C7-C21 aralkyl and a C2-C24 alkyl,
preferably a C6-C1 aryl;
X is a function selected from the group formed by 0 C(0) , C(0) O-.
C(0) N(1-1) --N(H) C(0) , S N(l I) , N(R•:0 and -0- with ft' t a
hydrocarbon-containing chain comprising from I to 15 carbon atoms;
35
R, is selected from the group formed by -I-1, -CI-13 and -C1-12-C1-13; preferably
-11 and --C113:
Rio and R11 , identical or different, are selected from the group formed by
hydrogen and a hydrocarbon-containing chain having from 1 to 24 carbon
37
atoms, preferably between 4 and 18 carbon atoms, preferably between 6 and
12 carbon atoms;
ii) at least one second monomer M4 of general formula (V):
5 R12
H2C
R13
(V)
in which:
R12 is selected from the group formed by 11, —013 and CAT, -C113 ,
10 preferably: -1-I 013;
R 1 3 is selected from the group formed by a C6-05 aryl. a CL-C1 8 aryl
substituted by an R' 13. --C(0)—O--R' 13; -0--R' 13. --S-R' 13 and --C(0)-
N(11)—R' 13 group with R'1 3 a Ci-C25 alkyl group.
iii) at least one source of free radicals.
15 In an embodiment, the process can comprise moreover iv) at least one chain-transfer
agent.
The preferences and definitions described for the general formulae (IV) and (V) also
apply to the process.
The sources of radicals and the transfer agents are those that have been described for the
20 synthesis of polydiol statistical copolymers. The preferences described for the sources of radicals
and of the transfer agents also apply to this process.
V Properties of the boronic ester statistical copolymers compounds A2
Advantageously, the chain formed by the sequence of the R io, M. (R8)„ groups with u. an
25 integer equal to () or 1, and X of the monomer M3 of general formula (IV) has a total number of
carbon atoms ranging from 8 to 38. preferably ranging from 10 to 26.
Advantageously, the side chains of the boronic ester statistical copolymer have an
average length greater than 8 carbon atoms, preferably ranging from I I to 16. This chain length
makes it possible to solubilize the boronic ester statistical copolymer in a hydrophobic medium.
30 By "average length of side chain" is meant the average length of the side chains of each
monomer constituting the copolymer. A person skilled in the art knows how to obtain this
average length by appropriately selecting the types and the ratio of monomers constituting the
boronic ester statistical copolymer.
Advantageously, the boronic ester statistical copolymer has a molar percentage of
35 monomer of formula (IV) in said copolymer ranging from 0.25 to 200/0. preferably from I to
I 0%.
Advantageously. the boronic ester statistical copolymer has a molar percentage of
monomer of formula (IV) in said copolymer ranging from 0.25 to 20%, preferably from 1 to
38
10% and a molar percentage of monomer of formula (V) in said copolymer ranging. from 80 to
99.75%, preferably from 90 to 99%.
Advantageously, the boronic ester statistical copolymer has a number-average degree of
polymerization ranging from 50 to 1500, preferably from 80 to 800.
5 Advantageously, the boronic ester statistical copolymer has a polydispersity index (PDI)
ranging from 1.04 to 3.54; preferably ranging from 1.10 to 3.10. These values are obtained by
steric exclusion chromatography using tetrahydrofuran as eluent and a polystyrene calibration.
Advantageously, the boronic ester statistical copolymer has a number-average molar
mass ranging from 10,000 to 200,000 g/mol preferably from 25,000 to 100,000 g/mol. These
10 values are obtained by steric exclusion chromatography using tetrahydrofuran as eluent and a
polystyrene calibration.
V Characteristics of the novel compositions of the invention
"Fhe novel compositions of the invention have the advantage of being cross-linkable in a
15 thermoreversible manner.
hhe polydiol statistical copolymers Al, in particular those resulting from the
copolymerization of at least one monomer of formula (I) with at least one monomer of formula
(11-A) or of at least one monomer of formula (I) with at least one monomer of formula (1I-A1)
and at least one monomer of formula (II-A2), and the compounds A2 as defined above have the
20 advantage of being associative and of exchanging chemical bonds in a thermoreversible manner,
in particular in a hydrophobic medium, in particular an apolar hydrophobic medium.
Under certain conditions, the polydiol statistical copolymers Al, in particular those
resulting from the copolymerization of at least one monomer of formula (I) with at least one
monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer
25 of formula (II-A1) and at least one monomer of formula (II-A2), and the compounds A2 as
defined above can be cross-linked.
The polydiol statistical copolymers Al, in particular those resulting from the
copolymerization of at least one monomer of formula (I) with at least one monomer of formula
(11-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A 1 )
30 and at least one monomer of formula (II-A2), and the compounds A2 also have the advantage of
being exchangeable.
By "associative'', is meant that covalent chemical bonds of boronic ester type are
established between the polydiol statistical copolymers Al, in particular those resulting from the
copolymerization of at least one monomer of formula (I) with at least one monomer of formula
35 (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1)
and at least one monomer of formula (II-A2), and the compounds A2 comprising at least two
boronic ester functions. Figure 4 shows associative polymers. Depending on the functionality of
the polydiols Al, in particular those resulting from the copolymerization of at least one
R
25
20
+ 2
OAR
B-0
R
OH
R
OH
OH
39
monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer
of formula (I) with at least one monomer of formula (11-A1) and at least one monomer of
formula (11-A2), and the compounds A2 and depending on the composition of the mixtures, the
formation of the covalent bonds between the polydiols Al and the compounds A2 may or may
5 not lead to the formation of a three-dimensional polymeric network.
By "chemical bond", is meant a covalent chemical bond of boronic ester type.
By "exchangeable-, is meant that the compounds are capable of exchanging chemical
bonds between each other without the total number of chemical functions being modified. The
boronic ester bonds of the compounds A2 as well as the boronic ester bonds formed by
10 association of the polydiol statistical copolymers A 1, in particular those resulting from the
copolymerization of at least one monomer of formula (1) with at least one monomer of formula
(11-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A l )
and at least one monomer of formula (11-A2), and the compounds A2 can be exchanged with diol
functions present in the composition in order to form new boronic esters and new diol functions
15 without the total number of boronic ester functions and diol functions being affected. The
chemical exchange reaction (transesterification) is shown in the following reaction 9:
Diagram 9
with:
30
R a chemical group of compound A2,
the hatched circle symbolizes the remainder of the chemical structure of the
compound A2,
the cross-hatched rectangle symbolizes the remainder of the chemical structure
of the polydiol statistical copolymer A1, in particular that resulting from the
35
copolymerization of at least one monomer of formula (I) with at least one
monomer of formula (II-A) or of at least one monomer of formula (I) with at
least one monomer of formula (II-A1) and at least one monomer of formula (IIA2).
40
"[he boronic ester bonds of the compounds A2 as well as the boronic ester bonds formed
by association of the polydiol statistical copolymers Al, in particular those resulting from the
copolymerization of at least one monomer of formula (I) with at least one monomer of formula
5 (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1)
and at least one monomer of formula (II-A2), and the compounds A2 can also be exchanged in
order to form new boronic esters without the total number of boronic ester functions being
affected. This other process of exchange of chemical bonds is carried out by metathesis reaction,
via successive exchanges of boronic ester functions in the presence of diols; this process is
10 shown in Figure 9. The polydiol statistical copolymer A1-1, which was associated with the
polymer A2-1, has exchanged a boronic ester bond with the boronic ester statistical copolymer
A2-2. The polydiol statistical copolymer Al-2, which was associated with the polymer A2-2, has
exchanged a boronic ester bond with the boronic ester statistical copolymer A2-1; the total
number of boronic ester bonds in the composition being unchanged and equal to 4. The
15 copolymer Al-I is then associated both with the polymer A2-1 and with the copolymer A2-2.
The copolymer A1-2 is then associated both with the copolymer A2-1 and with the copolymer
A")-1'
Another process of exchange of chemical bonds is shown in Figure 9, in which it can be
observed that the polydiol statistical copolymer Al-I, which was associated with the polymer
20 A2-l. has exchanged two boronic ester bonds with the boronic ester statistical copolymer A2-2.
The polydiol statistical copolymer Al-2, which was in association with the polymer A2-2. has
exchanged two boronic ester bonds with the boronic ester statistical copolymer A2-1; the total
number of boronic ester bonds in the composition being unchanged and equal to 4. The
copolymer A1-1 is then associated with the polymer A2-2. The copolymer A1-2 is then
25 associated with the polymer A2-1. The copolymer A2-1 has been exchanged with the polymer
A2-2.
By "cross-linked". is meant a copolymer in the form of a network obtained by the
establishment of bridges between the macromolecular chains of the copolymer. These chains,
linked together. are mainly distributed in the three spatial dimensions. A cross-linked copolymer
30 forms a three-dimensional network. In practice, the formation of a copolymer network is ensured
by a solubility test. It is possible to verify that a network of copolymers has been formed by
placing the copolymer network in a known solvent in order to dissolve the non-crosslinked
copolymers of the same chemical composition. If the copolymer swells instead of dissolving, a
person skilled in the art knows that a network has been formed. Figure 3 illustrates this solubility
35 test.
By "cross-linkable" is meant a copolymer capable of being cross-linked.
By "cross-linked in a reversible manner" is meant a cross-linked copolymer the bridges
of which are formed by a reversible chemical reaction. The reversible chemical reaction can be
41
shifted in one direction or another, leading to a change in structure of the polymer network. The
copolymer can pass from an initial non cross-linked state to a cross-linked state (threedimensional
network of copolymers) and from a cross-linked state to an initial non cross-linked
state. Within the context of the present invention, the bridges which form between the copolymer
5 chains are labile. These bridges can form or be exchanged thanks to a chemical reaction which is
reversible. Within the context of the present invention, the reversible chemical reaction is a
transesterification reaction between diol functions of a statistical copolymer (copolymer Al) in
particular that resulting from the copolymerization of at least one monomer of formula (I) with
at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least
10 one monomer of formula (II-Al) and at least one monomer of formula (II-A2)) and the boronic
ester functions of compound A2. The bridges formed are bonds of the boronic ester type. These
boronic ester bonds are covalent and labile due to the reversibility of the transesterification
reaction.
By "cross-linked in a thermoreversible manner", is meant a copolymer which is cross-
15 linked due to a reversible reaction the shift of which in one direction or in the other direction is
controlled by the temperature. The thermoreversible cross-linking mechanism of the
composition of the invention is shown diagrammatically in Figure 4. Unexpectedly, the
Applicant observed that at low temperature, the polydiol copolymer Al, in particular that
resulting from the copolymerization of at least one monomer of formula (I) with at least one
20 monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer
of formula (II-A ) and at least one monomer of formula (II-A2) (symbolized by the copolymer
bearine, the functions A in Figure 4) is not, or only slightly, cross-linked by the boronic ester
compounds A2 (symbolized by the compound bearing the functions B in Figure 4). When the
temperature increases, the diol functions of the copolymer react with the boronic ester functions
25 of the compound A2 by a transesterification reaction. The polydiol statistical copolymers A 1. in
particular those resulting from the copolymerization of at least one monomer of formula (I) with
at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least
one monomer of formula (II-Al) and at least one monomer of formula (II-A2), and the
compounds A2 comprising at least two boronic ester functions then link together and can
30 exchange. Depending on the functionality of the polydiols A 1, in particular those resulting from
the copolymerization of at least one monomer of formula (I) with at least one monomer of
formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula
(II-Al) and at least one monomer of formula (II-A2), and of the compounds A2 and depending
on the composition of the mixtures, a gel may form in the medium, in particular when the
35 medium is apolar. When the temperature reduces again, the boronic ester bonds between the
polydiol statistical copolymers Al, in particular those resulting from the copolymerization of at
least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one
monomer of formula (I) with at least one monomer of formula (II-A I) and at least one monomer
42
of formula (II-A2), and the compounds A2 break, and if applicable, the composition loses its gel
character.
The quantity of boronic ester bonds (or boronic ester links) that can be established
between the polydiol statistical copolymers Al and the compounds A2 is adjusted by a person
5 skilled in the art by means of an appropriate selection of the polydiol statistical copolymer Al, in
particular that resulting from the copolymerization of at least one monomer of formula (I) with
at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least
one monomer of formula (11-A1) and at least one monomer of formula (II-A2), and of compound
A2 and of the composition of the mixture.
10 Moreover, a person skilled in the art knows how to select the structure of the compound
A2 as a function of the structure of the statistical copolymer Al, in particular that resulting from
the copolymerization of at least one monomer of formula (I) with at least one monomer of
formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula
(II-A1) and at least one monomer of formula (II-A2). Preferably, when in the statistical
15 copolymer Al, in particular that resulting from the copolymerization of at least one monomer of
formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula
(I) with at least one monomer of formula (II-A 1 ) and at least one monomer of formula (II-A2).
comprising at least one monomer MI in which y-1. then compound A2 of general formula (III)
or the copolymer A2 comprising at least one monomer M3 of formula (IV) is preferably selected
20 with wl -- 1, vo-1 and t—I, respectively.
Advantageously, the content of statistical copolymer Al , in particular that resulting from
the copolymerization of at least one monomer of formula (I) with at least one monomer of
formula (11-A) or of at least one monomer of formula (I) with at least one monomer of formula
(II-A1) and at least one monomer of formula (II-A2) in the composition ranges from 0.25% to
25 20% by weight with respect to the total weight of the final composition. preferably from I to
1 0% by weight with respect to the total weight of the final composition.
Advantageously, the content of compound A2 in the composition ranges from 0.25% to
20% by weight with respect to the total weight of the final composition, preferably from 0.5 to
10% by weight with respect to the total weight of the final composition.
30 Preferentially, the mass ratio between the polydiol statistical compound Al. in particular
that resulting from the copolymerization of at least one monomer of formula (I) with at least one
monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer
of formula (II-A1) and at least one monomer of formula (II-A2), and the compound A2 (ratio
A 1/A2) in the composition ranges from 0.001 to 100, preferably from 0.05 to 20, yet more
35 preferably from 0.1 to 10. most preferably from 0.2 to 5.
In an embodiment of the invention, the sum of the masses of the statistical copolymer
Al.in particular that resulting from the copolymerization of at least one monomer of formula (I)
with at least one monomer of formula (11-A) or of at least one monomer of formula (I) with at
43
least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and of the
compound A2 ranges from 0.5 to 20% with respect to the total mass of the lubricating
composition and the mass of lubricating oil ranges from 80% to 99.5% with respect to the total
mass of the lubricating composition.
5 In an embodiment, the composition of the invention can comprise moreover a functional
additive selected from the group formed by the detergents, anti-wear additives. extreme-pressure
additives, antioxidants. polymers improving the viscosity index, pour point improvers, antifoaming
agents. thickeners. corrosion inhibitors, dispersants, friction modifiers and mixtures
thereof.
10
Functional additives
The functional additive(s) which are added to the composition of the invention are
selected depending on the final use of the lubricating composition. These additives can be
introduced in two different ways:
15 either each additive is added separately and sequentially into the composition,
or the mixture of additives is added simultaneously into the composition, the
additives are in this case generally available in the form of a package, called
package of additives.
The functional additive or the mixtures of functional additives, when they are present,
20 represent from 0.1 to 10% by weight with respect to the total weight of the composition,
3 The detergents:
These detergent additives reduce the formation of deposits on the surface of the metal
parts by dissolving the by-products of oxidation and combustion. The detergents that can be used
25 in the lubricant composition according to the invention are well known to a person skilled in the
art. The detergents commonly used in the formulation of lubricant compositions are typically
anionic compounds comprising a long lipophilic hydrocarbon-containing chain and a hydrophilic
head. The associated cation is typically a metal cation of an alkali or alkaline-earth metal. The
detergents are preferentially chosen from the alkali or alkaline-earth metal salts of carboxylic
30 acids, sulphonates, salicylates, naphthcnates, as well as the salts of phenates. The alkali or
alkaline-earth metals are preferentially calcium, magnesium. sodium or barium. These metal
salts can contain the metal in an approximately stoichiometric quantity or in excess (in a quantity
greater than the stoichiometric quantity). In the latter case, these detergents are referred to as
overbased detergents. The excess metal providing the detergent with its overbased character is
35 present in the form of metal salts which are insoluble in oil, for example carbonate, hydroxide,
oxalate, acetate, glutamate, preferentially carbonate,
3 The anti-wear additives and extreme-pressure additives:
44
These additives protect the friction surfaces by the formation of a protective film
adsorbed on these surfaces. A great variety of anti-wear and extreme-pressure additives exists.
By way of examples. the following can be mentioned: phosphorus- and sulphur-containing
additives such as the metallic alkylthiophosphates. in particular zinc alkylthiophosphates. and
5 more specifically zinc dialkyldithiophosphates or ZnDTP, amine phosphates, polysulphides, in
particular sulphur-containing olefins and metallic dithiocarbamates.
3 The antioxidants:
These additives slow down the degradation of the composition. The degradation of the
10 composition may become apparent through the formation of deposits, the presence of sludges. or
an increase in the viscosity of the composition. The antioxidant additives act as radical inhibitors
or hydroperoxide destroyers. Phenolic or amine type antioxidants are among those is current use.
3 The corrosion inhibitors:
15 These additives cover the surface with a film which prevents oxygen access to the
surface of the metal. They can sometimes neutralize acids or certain chemical products in order
to avoid corrosion of the metal. By way of illustration, the following can be mentioned for
example: dimercaptothiadiazole (DMTD), benzotriazoles, phosphites (capture of the free
sulphur).
20
3 The polymers improving the viscosity index:
These additives make it possible to guarantee good resistance to cold and a minimum
viscosity at high temperature of the composition. By way of illustration, the following can be
mentioned for example: polymeric esters, olefin copolymers (0CP), homopolymers or
25 copolymers of styrene, butadiene or isoprene and polymethacrylates (PMA).
3 The pour point improvers:
These additives improve the low-temperature behaviour of the compositions. by slowing
down the formation of paraffin crystals. They are for example alkyl polymethacrylates,
30 polyacrylates, polyarylamides, polyalkylphenols, polyalkylnaphthalenes and alkylated
polystyrenes.
3 '[he anti-foaming agents:
These additives have the effect of countering the effect of the detergents. By way of
illustration, the following can be mentioned: polymethylsiloxanes and polyacrylates.
35
3 The thickeners:
The thickeners are additives used above all for industrial lubrication and make it
45
possible to formulate lubricants with a higher viscosity than engine lubricating compositions. By
way of illustration, the following can be mentioned: polysiobutenes having a molar mass by
weight from 10,000 to 100,000 g/mol.
5 3 The dispersants:
These additives ensure the maintenance in suspension and the removal of the insoluble
solid contaminants constituted by the by-products of oxidation which form during use of the
composition. By way of illustration, the following can be mentioned: succinimides, P113
(polyisobutene) succinimides and Mannich bases.
10
3 The friction modifiers;
These additives improve the coefficient of friction of the composition. By way of
illustration, the following can be mentioned: molybdenum dithiocarbamate, the amines having at
least one hydrocarbon-containing chain of at least 16 carbon atoms, the esters of fatty acids and
15 polyols such as the esters of fatty acids and glycerol, in particular glycerol monooleate.
3 Process for the preparation of the novel compositions of the invention
The novel compositions of the invention are prepared by means well known to a person
skilled in the art. For example, it is sufficient for a person skilled in the art in particular to:
20 sample a desired quantity of a solution comprising the polydiol statistical
copolymer A 1 as defined above, in particular that resulting from the
copolymerization of at least one monomer of formula (I) with at least one
monomer of formula (II-A) or of at least one monomer of formula (I) with at
least one monomer of formula (II-A1) and at least one monomer of formula
25 (11-A2);
sample a desired quantity of a solution comprising compound A2 as defined
above;
mix the two solutions sampled in a lubricating base oil in order to obtain the
composition of the invention.
30 A person skilled in the art also knows how to adjust the different parameters of the
composition of the invention in order to obtain a cross-linkable composition. For example, a
person skilled in the art knows how to adjust in particular:
the molar percentage of the monomer MI bearing diol functions in the
polydiol statistical copolymer Al, in particular that resulting from the
35 copolymerization of at least one monomer of formula (I) with at least one
monomer of formula (II-A) or of at least one monomer of formula (I) with at
least one monomer of formula (II-A1) and at least one monomer of formula
(II-A2);
46
the molar percentage of monomer M3 bearing the boronic ester functions in
the boronic ester statistical copolymer A2,
- the average length of the side chains of the polydiol statistical copolymer Al ,
in particular that resulting from the copolymerization of at least one
5
monomer of formula (I) with at least one monomer of formula (II-A) or of at
least one monomer of formula (I) with at least one monomer of formula (IIA
l ) and at least one monomer of formula (II-A2);
the average length of the side chains of the boronic ester statistical copolymer
A2,
10 - the length of the monomer M3 of the boronic ester statistical copolymer A2.
- the length of boronic diester compound A2,
- the average degree of polymerization of the polydiol statistical copolymers
Al, in particular that resulting from the copolymerization of at least one
monomer of formula (I) with at least one monomer of formula (II-A) or of at
15
least one monomer of formula (I) with at least one monomer of formula (IIA
I ) and at least one monomer of formula (II-A2). and the boronic ester
statistical copolymers A2.
- the percentage by weight of the polydiol statistical copolymers AI, in
particular that resulting from the copolymerization of at least one monomer
20
of formula (I) with at least one monomer of formula (II-A) or of at least one
monomer of formula (I) with at least one monomer of formula (II-A ) and at
least one monomer of formula (II-A2),
the percentage by weight of the diboronic ester compound A2,
the percentage by weight of the boronic ester statistical copolymer A2,
25
etc.
3 Use of the novel compositions of the invention
Another subject of the present invention is the use of the composition as defined above
for lubricating a mechanical part.
30 The compositions of the invention can be used to lubricate the surfaces of the parts that
can conventionally he found in an engine, such as the pistons, rings, liners system.
Thus another subject of the present invention is a composition for lubricating at least one
engine comprising a composition resulting from the mixing of:
97% to 99.9% by weight of a lubricating oil, and
35 0.1% to 3% by weight of at least one statistical copolymer A 1 , in particular that resulting
from the copolymerization of at least one monomer of formula (I) with at least one
monomer of formula (II-A) or of at least one monomer of formula (I) with at least one
monomer of formula (II-A ) and at least one monomer of formula (II-A2), and at least
47
one compound A2 comprising at least two boronic ester functions such as defined
previously;
the composition having a kinematic viscosity at 100°C measured according to the standard
ASTM D445 ranging from 3.8 to 26.1 cSt; the percentages being expressed with respect to the
5 total weight of the lubricating composition.
In a composition for lubricating at least one engine, at least one statistical copolymer Al.
in particular that resulting from the copolymerization of at least one monomer of formula (I)
with at least one monomer of formula (11-A) or of at least one monomer of formula (I) with at
least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and at least
10 one compound A2 comprising at least two boronic ester functions such as defined previously can
associate and exchange in a thermoreversible manner; but they do not form three-dimensional
networks. They are not cross-linked.
In an embodiment, the composition for lubricating at least one engine moreover
comprises at least one functional additive selected from the group formed by the detergents, anti-
15 wear additives, extreme-pressure additives, additional antioxidants, corrosion inhibitors,
polymers improving the viscosity index, pour point improvers, anti-foaming agents, thickeners,
dispersants, friction modifiers and mixtures thereof.
In an embodiment of the invention, the composition for lubricating at least one engine
essentially consists ()la composition resulting from the mixing of:
20 970/0 to 99.9% by weight of a lubricating oil, and
0.1% to 3% by weight of at least one statistical copolymer Al. in particular that resulting
from the copolymerization of at least one monomer of formula (I) with at least one
monomer of formula (II-A) or of at least one monomer of formula (I) with at least one
monomer of formula (II-Al) and at least one monomer of formula (II-A2), and at least
25 one compound A2 comprising at least two boronic ester functions as defined previously;
the composition having a kinematic viscosity at 100°C measured according to the standard
ASTM D445 ranging from 3.8 to 26.1 cSt; the percentages being expressed with respect to the
total weight of the lubricating composition.
In an embodiment of the invention, the composition for lubricating at least one engine
30 essentially consists of a composition resulting from the mixing of:
82% to 99.8% by weight of a lubricating oil, and
-
0. I % to 3% by weight of at least one statistical copolymer Al, in particular that resulting
from the copolymerization of at least one monomer of formula (I) with at least one
monomer of formula (II-A) or of at least one monomer of formula (I) with at least one
35 monomer of formula (II-A1) and at least one monomer of formula (II-A2). and at least
one compound A2 comprising at least two boronic ester functions such as defined
previously;
0.1% to 15% by weight of at least one functional additive selected from the group
48
formed by the detergents, anti-wear additives, extreme-pressure additives. additional
antioxidants, corrosion inhibitors, polymers improving the viscosity index, pour point
improvers, anti-foaming agents, thickeners, dispersants, friction modifiers and mixtures
thereof;
5 the composition having a kinematic viscosity at 100°C measured according to the standard
ASTM 1)445 ranging from 3.8 to 26.1 cSt; the percentages being expressed with respect to the
total weight of the lubricating composition.
The definitions and preferences relating to the lubricating oils, statistical copolymers Al,
in particular that resulting from the copolymerization of at least one monomer of formula (I)
10 with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at
least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and
compounds A2 also apply to the compositions for lubricating at least one engine.
Another subject of the present invention is a composition for lubricating at least one
transmission, such as the manual or automatic gearboxes.
15 In a composition for lubricating at least one transmission, at least one statistical
copolymer A 1 , in particular that resulting from the copolymerization of at least one monomer of
formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula
(I) with at least one monomer of formula (II-AI) and at least one monomer of formula (II-A2),
and at least one compound A2 comprising at least two boronic ester functions such as defined
20 previously can associate and exchange in a thermoreversible manner; but they do not form threedimensional
networks. They are not cross-linked.
Thus another subject of the present invention is a composition for lubricating at least one
transmission comprising a composition resulting from the mixing of:
85% to 99.5% by weight of a lubricating oil, and
25 0.5% to 15% by weight of at least one statistical copolymer Al. in particular that
resulting from the copolymerization of at least one monomer of formula (I) with at least
one monomer of formula (II-A) or of at least one monomer of formula (I) with at least
one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and at
least one compound A2 comprising at least two boronic ester functions as defined
30 previously:
the composition having a kinematic viscosity at 100°C measured according to the standard
ASTM 1)445 ranging from 4.1 to 41 cSt; the percentages being expressed with respect to the
total weight of the lubricating composition.
In an embodiment, the composition for lubricating at least one transmission comprises
35 moreover at least one functional additive selected from the group formed by the detergents, antiwear
additives, extreme-pressure additives, additional antioxidants, corrosion inhibitors,
polymers improving the viscosity index, pour point improvers, anti-foaming agents, thickeners,
dispersants, friction modifiers and mixtures thereof.
49
In an embodiment of the invention, the composition for lubricating at least one
transmission essentially consists of a composition resulting from the mixing of:
95% to 99.5% by weight of a lubricating oil, and
0.5% to 15% by weight of at least one statistical copolymer A1, in particular that
5 resulting from the copolymerization of at least one monomer of formula (I) with at least
one monomer of formula (II-A) or of at least one monomer of formula (I) with at least
one monomer of formula (11-A 1 ) and at least one monomer of formula (1I-A2), and at
least one compound A2 comprising at least two boronic ester functions as defined
previously:
10 the composition having a kinematic viscosity at 100°C measured according to the standard
ASTM D445 ranging From 4.1 to 41 cSt.
In an embodiment of the invention, the composition for lubricating at least one
transmission essentially consists of a composition resulting from the mixing of:
70% to 99.4% by weight of a lubricating oil, and
15 0.5% to 15% by weight of at least one statistical copolymer A 1 , in particular that
resulting from the copolymerization of at least one monomer of formula (I) with at least
one monomer of formula (II-A) or of at least one monomer of formula (I) with at least
one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and at
least one compound A2 comprising at least two boronic ester functions such as defined
20 previously:
0.1% to 15% by weight of at least one functional additive selected from the group
formed by the detergents. anti-wear additives, extreme-pressure additives, additional
antioxidants, corrosion inhibitors, polymers improving the viscosity index, pour point
improvers. anti-foaming agents. thickeners, dispersants, friction modifiers and mixtures
25 thereof:
the composition having a kinematic viscosity at 100°C measured according to the standard
ASTM D445 ranging from 4.1 to 41 cSt; the percentages being expressed with respect to the
total weight of the lubricating composition.
The definitions and preferences relating to the lubricating oils, statistical copolymers Al,
30 in particular that resulting from the copolymerization of at least one monomer of formula (I)
with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at
least one monomer of formula (11-A1) and at least one monomer of formula (II-A2), and
compounds A2 also apply to the compositions for lubricating at least one transmission.
The compositions of the invention can be used for the engines or transmissions of light
35 vehicles. lorries but also ships.
Another subject of the present invention is a process for lubricating at least one
mechanical part, in particular at least one engine or at least one transmission, said process
SO
comprising a step in which said mechanical part is brought into contact with at least one
composition as defined above.
The definitions and preferences relating to the lubricating oils, statistical copolymers Al,
in particular that resulting from the copolymerization of at least one monomer of formula (1)
5 with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at
least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and
compounds A2 also apply to the process for lubricating at least one mechanical part.
Another subject of the present invention relates to a stock composition resulting from the
mixing of at least at least one statistical copolymer Al as defined-above, in particular that
10 resulting from the copolymerization of at least one monomer of formula (I) with at least one
monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer
of formula (II-A ) and at least one monomer of formula (II-A2), at least one compound A2
comprising at least two boronic ester functions, at least one functional additive selected from the
group formed by the detergents, anti-wear additives, extreme-pressure additives. additional
15 antioxidants, polymers improving the viscosity index, pour point improvers, anti-foaming
agents. corrosion inhibitors, thickeners, dispersants, friction modifiers and mixtures thereof.
By "stock composition'. is meant, a composition from which a person skilled in the art
can make working solutions by sampling a certain quantity of stock solution completed by
making up with a necessary quantity of diluent (solvent or other) in order to obtain a desired
20 concentration. A working composition is therefore obtained by dilution of a stock composition.
In an embodiment the lubricating compositions of the invention can be obtained by diluting in a
lubricating oil, in particular a base oil of Group I, Group II, Group III, Group IV, Group V of the
API classification or a mixture thereof, the stock composition as defined above.
25 EXAMPLES
The following examples illustrate the invention without limiting it.
1 Synthesis of polymethacrylate statistical copolymers Al of the invention bearing a
diol function
30
a 1. I: Startingfrom a monomer bearing a diol function protected in ketal _form
In an embodiment, the statistical copolymer Al of the invention is obtained according to
the following reaction diagram 10:
35
51
CH
HO
OH
L Protection of the diol function
0
OH
2_ Reaction with MAC 1
r C1 0
0
0 0
.1. Polymerization
Protected copolyrners
4. Deprotection
Poly(alkyl methacrylate-co-alkyldiol methacrylate) copolymers
Diagram 10
1.1.1 Synthesis of the monomer M1 bearing a diol function protected in ketal form
5
The synthesis of a methacrylate monomer bearing a diol function protected in ketal form
is carried out in two steps (steps 1 and 2 of reaction diagram 10) according to the protocol
below:
step:
10 42.1 g (314 mmol) of 1,2.6-hexane triol (1,2,6-11exTri) is introduced into a I-I, flask. 5.88
g of molecular sieve (4°A) is added followed by 570 m1_, of acetone. 5.01 g (26.3 mmol) of paratoluene-
sulphonic acid (pTSA) is then slowly added. The reaction medium is left under stirring
for 24 hours at ambient temperature. 4.48 g (53.3 mmol) of NaI IC03 is then added. The reaction
medium is left under stirring for 3 hours at ambient temperature before being filtered. The
15 filtrate is then concentrated under vacuum by means of a rotary evaporator until a suspension of
white crystals is obtained. 500 m1., of water is then added to this suspension. "Fhe solution thus
obtained is extracted with 4 X 300 mI. of dichloromethane. The organic phases are combined
and dried over MgS0.1 . The solvent is then completely evaporated off under vacuum at 25°C by
means of a rotary evaporator.
20 god step:
The product thus obtained is then introduced into a 11. flask surmounted by a dropping
funnel. "[he glassware used having been previously dried overnight in an oven thermostatically
controlled at 100°C. 500 mL of anhydrous dichloromethane is then introduced into the flask
followed by 36.8 g (364 mmol) of triethylamine. A solution of 39.0 g (373 mmol) of
52
methacryloyl chloride (MAC) in 50 ml, of anhydrous dichloromethane is introduced into the
dropping funnel. The flask is then placed in an ice bath in order to lower the temperature of the
reaction medium to around 0°C. The methacryloyl chloride solution is then added dropwise
under vigorous stirring. Once the addition of the methacryloyl chloride is completed, the
5 reaction medium is left under stirring at 0°C for 1 hour, then at ambient temperature for 23
hours. The reaction medium is then transferred into a 3-L Erlenmeyer flask and I L. of
dichloromethane is added. The organic phase is then successively washed with 4 x 300 mL of
water. 6 x 300 ml, of a 0.5M aqueous solution of hydrochloric acid, 6 x 300 mL of a saturated
aqueous solution of Nal IC03 and again 4 x 300 mL of water. The organic phase is dried over
10 Mg,S0.1, filtered then concentrated under vacuum using a rotary evaporator in order to produce
64.9 g (yield of 85.3%) of protected diol monomer in the form of a light yellow liquid the
characteristics of which are as follows:
NMR (400 MHz, CDCI3) 6: 6.02 (singlet, 11-1), 5.47 (singlet. 1F1), 4.08 (triplet, J 6.8
I-1z, 2F1), 4.05-3.98 (multiplet. 11-1). 3.96 (doublet of doublets, J = 6 liz and J = 7.6 1-1z, IF1), 3.43
15 (doublet of doublets, J 7.2 Hz and J 7.2 Hz, 11-1), 1.86 (doublet of doublets. J 1.2 Hz and J
- 1.6 I-Iz, 311). 1.69-1.33 (multiplet, 611), 1.32 (singlet, 31-1), 1.27 (singlet, 3H).
1.1.2 Synthesis of methacrylate copolymers according to the invention hearingdioljimctions
The synthesis of the methacrylate copolymers bearing diol functions according, to the
20 invention is carried out in two steps (steps 3 and 4 of reaction diagram 10):
Copolymerization of two alkyl methacrylate monomers with a methacrylate
monomer hearing a diol function protected in ketal form ;
Deprotection of the copolymer.
25 More precisely, the synthesis of the copolymer is carried out according to the following
protocol:
10.5 g (31.0 mmol) of stearyl methacrylate (StMA). 4.76 g (18.7 mmol) of lauryl
methacrylate (1_MA), 3.07 g (12.7 mmol) of methacrylate bearing a diol function protected in
ketal form obtained according to the protocol described in paragraph 1.1.1, 68.9 mg (0.253
30 mmol) of cumyl dithiobenzoate and 19.5 ml, of anisole are introduced into a 100-mL Schlenk
tube. The reaction medium is placed under stirring and 8.31 mg (0.0506 mmol) of
azobisisobutyronitrile (AII3N) in solution in 85 gL of anisole is introduced into the Schlenk tube.
The reaction medium is then degassed for 30 minutes by bubbling argon through it before being
brought to 65°C for a period of 16 hours. The Schlenk tube is placed in an ice bath in order to
35 stop the polymerization, then the polymer is isolated by precipitation from methanol, followed
by filtration and drying under vacuum at 30°C overnight.
A copolymer is thus obtained, having a number-average molar weight (A) of 41,000
gimol, a polydispersity index (13D1) of 1.22 and a number-average degree of polymerization
53
(DP„) of 167. These values are obtained respectively by steric exclusion chromatography using
tetrahydrofuran as eluent and a polystyrene calibration and by monitoring the conversion to
monomers during the copolymerization.
Deprotection of the copolymer is carried out according to the following protocol:
5
7.02 g of copolymer containing approximately 20% protected diol function obtained
previously is introduced into a 500-ml, Erlenmeyer flask. 180 m1_, of dioxane is added and the
reaction medium is placed under stirring at 30°C. 3 mi. of a 1M aqueous solution of
hydrochloric acid, then 2.5 ml. of an aqueous solution of hydrochloric acid, 35% by weight. are
added dropwise. The reaction medium then becomes slightly opaque and 20 ml, of 11-11: is
10
introduced in order to make the medium completely homogeneous and transparent. The reaction
medium is then left under stirring at 40"C for 48 hours. The copolymer is recovered by
precipitation from methanol, filtration and drying under vacuum at 30°C overnight.
A poly(alkyl methacrylate-co-alkyldiol methacrylate) copolymer is obtained, containing
approximately 20 mol.% diol monomer units M1 and having an average pendant alkyl chain
15 length of 13.8 carbon atoms.
o 1.2: Startingfrom a monomer hearing a diol function protected in boronic ester form
In another embodiment, the statistical copolymer Al of the invention is obtained
according to the following reaction diagram 11:
20
OH
HO
OH
1. Protection of the dial function
B 0
0
OH
2. Reaction with roAc
CI
B 0
0
0 0
1. Polymerization
Protected copolymers
4. Deprotection
V
Poly(alkyl methacrylate-co-alkyldiol methacrylatej copolymers
Diagram 11
54
1.2.1 Synthesis ()Idle monomer MI bearinga diol function protected in boronic esterjOrm
The synthesis of a methacrylate monomer bearing a diol function protected in ester form
is carried out in two steps (steps I and 2 of Diagram 11) according to the following protocol:
5 I' step:
6.01 g (49.3 mmol) of phenylboronic acid (1313A) and 300 mI. of acetone are introduced
into a 500-mL beaker, followed by 1.5 ml. of water. The reaction medium is placed under
stirring and 6.07 g (45.2 mmol) of 1,2,6-hexanetriol is added slowly. An excess of magnesium
sulphate is added to the reaction medium in order to trap the water initially introduced as well as
10 the water released by the condensation between the phenylboronic acid and the 1,2,6-
hexanetriol. The reaction medium is left under stirring at ambient temperature for 30 minutes
before being filtered then concentrated under vacuum by means of a rotary evaporator.
2" step:
The light yellow liquid thus obtained in the preceding step is then introduced into a I-1.
15 flask surmounted by a dropping funnel. The glassware used having been pre-dried beforehand
overnight in an oven thermostatically controlled at 100°C. 90 mL of anhydrous dichloromethane
is then introduced into the flask followed by 6.92 g (68.4 mmol) of triethylamine. A solution of
5.82 g (55.7 mmol) of methacryloyl chloride (MAC) in 10 mL of anhydrous dichloromethane is
introduced into the dropping funnel. The flask is then placed in an ice bath in order to lower the
20 temperature of the reaction medium to around 0°C, The methacryloyl chloride solution is then
added dropwise under vigorous stirring. Once the addition of the methacryloyl chloride is
completed. the reaction medium is left under stirring at 0°C for 1 hour. then at ambient
temperature for 17 hours. The reaction medium is then transferred into a 500-mL Erlenmeyer
flask and 300 ml. of dichloromethane is added. The organic phase is then successively washed
25 with 4 x 100 mL of water, 4 x 100 mL of a 0.1M aqueous solution of hydrochloric acid, 4 x 100
mL of a saturated aqueous solution of NaFIC03 and again 4 x 100 mL of water. The organic
phase is dried over Mg.SO4, filtered then concentrated under vacuum using a rotary evaporator in
order to produce 11.6 g (yield of 89%) of protected diol monomer in the form of a light yellowcoloured
liquid the characteristics of which are as follows:
30 NMR (400 MHz, CDCI3) (5: 7.81 (doublet of doublets, J = 4 Hz and J = 8 Hz. 21-1),
7.48 (triplet of triplets. .1 1.2 I Iz and .1 --- 7.2 Hz, 11-1), 7.38 (triplet of triplets, J 1.2 Hz and J
6.8 I Is. 1 II). 6.10 (singlet. 11 5.55(singlet, 1 H), 4.63-4.53 (multiplet, 1 II), 4.44 (doublet of
doublets. J 7.6 Hz and J = 8.8 Hz, II-I), 4.18 (triplet, .1- 6.8 Hz, 211), 3.95 (doublet of doublets.
6.8 Hz and J 8.8 Hz, I II), 1.94 (doublet of doublets, J = 1.2 Hz and J = 1.6 Hz. 3H), 1.81-
35 1.47 (multiplet, 6H)
1.2.2 _ Synthesis of methacrylate copolymers according to the invention bearing dioljtincti(ms
55
The synthesis of the methacrylate copolymers bearing dial functions according to the
invention is carried out in two steps (steps 3 and 4 of Diagram 11):
Copolymerization of two alkyl methacrylate monomers with a methacrylate
monomer bearing a diol function protected in boronic ester form;
5 Deprotection of the copolymer.
The following procedures describe the synthesis of a poly(alkyl methacrylate-co-alkyldiol
methacrylate) copolymer containing approximately 10 mol.% of dial monomer units, and having
an average pendant alkyl chain length of 13.8 carbon atoms.
10 The synthesis of the polymer is carried out according to the following protocol:
13.5 g (40 mmol) of stearyl methacrylate (StMA), 12 g (47.2 mmol) of lauryl
methacrylate (1,MA), 3.12 g (10.8 mmol) of methacrylate hearing a dial function protected in
boronic ester form, 92.1 mg (0.416 mmol) of cumyl dithiobenzoate and 34 ml. of anisole arc
15 introduced into a 100-mI. Schlenk tube. The reaction medium is placed under stirring and 13.7
mg (0.0833 mmol) of azobisisobutyronitrile (AII3N) in solution in 135 gi of anisole is
introduced into the Schlenk tube. The reaction medium is then degassed for 30 minutes by
bubbling argon through it before being brought to 65°C for a period of 24 hours. The Schlenk
tube is placed in an ice bath in order to stop the polymerization and 30 ml. of tetrahydrofuran
20 (T111) is then added to the reaction medium. The polymer is isolated by precipitation from cold
methanol, followed by filtration and drying under vacuum at 30°C overnight.
A copolymer is thus obtained, having a number-average molar weight (M„) of 70.400
g/mol. a polydispersity index (PD1) of 3.11 and a number-average degree of polymerization
(DP„) of 228. These values arc obtained respectively by steric exclusion chromatography using
25 tetrahydrofuran as eluent and a polystyrene calibration and by monitoring the conversion to
monomers during the copolymerization.
Deprotection of the copolymer is carried out according to the following protocol:
19 g of copolymer obtained in the preceding step and containing approximately 10%
30 protected dial function is introduced into a I -L Erlenmeyer flask. 250 ml. of dichloromethane
and 30 mr, of an aqueous solution of hydrochloric acid are added. The reaction medium is stirred
at ambient temperature for 24 hours before being poured dropwise into 1 L of aqueous solution
of sodium hydroxide (p11 10) then stirred at ambient temperature for another 24 hours.
Throughout this period of stirring. the reaction medium is composed of two phases. The organic
35 phase is recovered using a separating funnel and the polymer is precipitated from cold methanol.
The polymer thus obtained is re-dissolved in 100 ml of dichloromethane in order to be
precipitated from cold methanol again. The polymer is recovered and dried under vacuum at
30°C overnight.
56
A poly(alkyl methacrylate-co-alkyldiol methacrylate) copolymer is obtained containing
approximately 10 mol.% diol monomer units. and having an average pendant alkyl chain length
of 13.8 carbon atoms.
5 2. Synthesis of the compounds A2 of the invention
c 2.1: Synthesis of horonic diester as cross-linkinQ agent
The synthesis of a compound A2 according to the invention is carried out according to the
10 following, protocol and according to reaction diagram 12:
HO " OH
1.
ft
HO- 'OH
1.Acetone, FLO
2 NI g5.0.
0-
13
0,B.
,
HO OH
15 Diagram 12
1.4 Benzenecliboronic acid (1,4-13DBA) (1.5 g; 9.05 mmol) is introduced into a 500-rri1.
beaker. followed by 300 mL of acetone. The reaction medium is placed under stirring and 0.300
g (16.7 mmol) of water is introduced dropwise. The reaction medium then becomes transparent
and homogeneous and 1,2-dodecanediol (4.02 g; 19.9 mmol) is slowly added. After the latter is
20 completely dissolved. an excess of magnesium sulphate is added in order to trap the water
introduced initially as well as the water released by the condensation between the 1,4-13DBA and
the 1.2-clodecanediol. After 15 minutes under stirring, the reaction medium is filtered. The
solvent is then removed from the filtrate by means of a rotary evaporator, in order to produce
4.41 g of boronic diester and 1,2-dodecanediol (yield of 989/o) in the form of a white solid.
25 The characteristics arc as follows:
[ II NMR (400 MHz. CDC13) Boronic diester: 6: 7.82 (singlet. 21-1), 4.63-4.51 (multiplet,
211), 4.42 (doublet of doublets, J = 8 Hz and J = 8.8 Hz, 211), 3.95 (doublet of doublets, J = 7.2
I lz and J 8.8 Hz, 21-1), 1.81-1.31 (multiplet, 361-1), 0.88 (triplet, J = 7.2 Hz, 611): 1,2-
dodecancdiol: 6: 3.85-3.25 (multiplet, approximately 2.17H). 1.81-1.31 (multiplet,
30 approximately 13.021-1). 0.88 (triplet, J = 7.2 Hz. approximately 2.171-1)
o 2.2: Synthesis of the poly(alkyl methacylute-co-boronic ester monomer) copolymer
57
2.2.1 Synthesis of the boronic ester monomer
The boronic ester monomer of the invention is synthesized according to the following
reaction diagram 13:
OH
HO CH3
9
8-OH
OH
OJ 9CH3
Diagram 13
5
COOH
1. HO OH
CH3
HO' OH 2.
10 CI
The monomer is obtained according to the two-step protocol:
The first step consists of synthesizing a boronic acid and the second step consists of
obtaining a boronic ester monomer.
15 1 -" step:
4-Carboxyphenylboronic acid (CPBA) (5.01 g; 30.2 mmol) is introduced into a 1-L
beaker followed by 350 ml. of acetone and the reaction medium is placed under stirring. 7.90
m1_, (439 mmol) of water is added dropwise until the 4-carboxyphenylboronic acid is completely
dissolved. The reaction medium is then transparent and homogeneous. 1,2-Propanediol (2.78 g;
20
36.6 mmol) is then slowly added, followed by an excess of magnesium sulphate in order to trap
the water initially introduced as well as the water released by the condensation between the
CPBA and the 1,2-propanectiol. The reaction medium is left under stirring for 1 hour at 25°C
before beinf2. filtered. The solvent is then removed from the filtrate by means of a rotary
evaporator. The product thus obtained and 85 mL of DMS0 are introduced into a 250-mL flask.
25
The reaction medium is placed under stirring then after complete homogenization of the reaction
medium, 8.33 g (60.3 mmol) of K2CO3 is added. 4-(Chloromethyl)styrene (3.34 g; 21.9 mmol) is
then slowly introduced into the flask. The reaction medium is then left under stirring at 50°C for
16 hours. The reaction medium is transferred into a 2-L Erlenmeyer flask, then 900 ml, of water
is added. The aqueous phase is extracted with 8 x 150 mL of ethyl acetate. The organic phases
30
are combined, then extracted with 3 x 250 ml, of water. The organic phase is dried over MgSai
and filtered. "[he solvent is removed from the filtrate by means of a rotary evaporator in order to
produce the boronic acid monomer (5.70 g; yield of 92.2%) in the form of a white powder, the
characteristics of which are as follows:
'11 NMR (400 Ml Iz, CDC13) 6: 7.98 (doublet, J = 5.6 Hz, 41-1), 7.49 (doublet, J = 4 Hz,
35 411). 6.77 (doublet of doublets, J = 10.8 Hz and J = 17.6 Hz, 1H), 5.83 (doublet of doublets.
-- 1.2 liz and J -- 17.6 Hz, I 1 1), 5.36 (singlet. 2H), 5.24 (doublet of doublets, J 1.2 Hz and J =-
11.2 Hz, 11-1).
58
2, step:
The boronic acid monomer (5.7 g; 20.2 mmol) obtained during the first step and 500 ml.
of acetone are introduced into a 1-L Erlenmeyer flask. The reaction medium is placed under
stirring and 2.6 mE, (144 mmol) of water is added dropwise until the boronic acid monomer is
5 completely dissolved. The reaction medium is then transparent and homogeneous. A solution of
1.2-dodecanediol (5.32 g; 26.3 mmol) in 50 ml, of acetone is slowly added to the reaction
medium, followed by an excess of magnesium sulphate in order to trap the water initially
introduced as well as the water released by the condensation between the boronic acid monomer
and the 1.2-dodecanediol. After 3 hours under stirring at ambient temperature. the reaction
10 medium is filtered. The solvent is then removed from the filtrate by means of a rotary evaporator
in order to produce 10.2 g of a mixture of boronic ester monomer and 1,2-dodecanediol in the
form of a light yellow solid, the characteristics of which are as follows:
A EI NMR (400 MHz, CDC1.3): I3oronic ester monomer: 6: 8.06 (doublet, J 8 Hz, 211),
7.89 (doublet. J 8 I lz. 211). 7.51 (doublet, J = 4 I lz, 41-1), 6.78 (doublet of doublets, J 8 Hz
15 and ,1 16 1-lz, 11-1). 5.84 (doublet of doublets. J = 1.2 liz and J = 17.6 Hz, 141), 5.38 (singlet,
21-1), 5.26 (doublet of doublets, J - 1.2 Ilz and J = 11.2 I lz, 11-1), 4.69-4.60 (multiplet, 111), 4.49
(doublet of doublets. J 8 liz and J 9.2 Hz, 11-1), 3.99 (doublet of doublets, J - 7.2 Hz and J =
9.2 lIz. 11-1), 1.78-1.34 (multiplet, 1811), 0.87 (triplet, J 6.4 Hz, 31-I); 1,2-dodecanectiol: 6: 3.61-
3.30 (multiplet, approximately 1.62H), 1.78-1.34 (multiplet, approximately 9.72H), 0.87 (triplet,
20 J = 6.4 Hz, approximately 1.62H)
2.2.2 Synthesis of compound A2_poly(alkyl methacrylate-co-boronic ester monomers
statistical copolymer
The statistical copolymer A2 of the invention is obtained according to the following
25 protocol:
2.09 g of a previously prepared mixture of boronic ester monomer and 1.2-dodecanediol
(containing 3.78 mmol of boronic ester monomer), 98.3 mg (0.361 mmol) of cumyl
dithiobenzoate, 22.1 g (86.9 mmol) of lauryl methacrylate (LMA) and 26.5 ml, of anisole are
introduced into a 100-m1., Schlenk tube. The reaction medium is placed under stirring and 11.9
30 mg (0.0722 mmol) of azobisisobutyronitrile (AIBN) in solution in 120 tit of anisole is
introduced into the Schlenk tube. The reaction medium is then degassed for 30 minutes by
bubbling argon through it before being brought to 65°C for a period of 16 hours. The Schlenk
tube is placed in an ice bath in order to stop the polymerization, then the polymer is isolated by
precipitation from anhydrous acetone. followed by filtration and drying under vacuum at 30°C
35 overnight.
A copolymer is thus obtained, having the following structure:
59
5
n
with m =0.96 and n-0.04.
The boronic ester copolymer obtained has a number-average molar weight (MO equal to 37.200
10 gimol, a polydispersity index (PIN) equal to 1.24 and a number-average degree of
polymerization (DP„) equal to 166. These values are obtained respectively by steric exclusion
chromatography using tetrahydrofuran as eluent and a polystyrene calibration and by monitoring
the conversion to monomers during the copolymerization. NMR analysis of the proton of the
final copolymer gives a composition of 4 mol.% boronic ester monomer and 96% lauryl
15 methacryl ate.
3. }theological studies
20 a 3.1 Eginpment and protocols for measurinQ- viscosity
The rheological studies were carried out using a stress-controlled Couette MCR 501
rheometer from the company Anton Paar. The measurements were carried out on formulations of
polymers in solution in a Group Ill base oil using a cylindrical geometry of reference DG 26.7.
The viscosity was measured as a function of the shear rate for a temperature range varying from
25 l0°C to 110°C. For each temperature, the viscosity of the system was measured as a function of
a shear rate of 0.01 to 1000 The measurements of viscosity as a function of the shear rate at T
- 10°C, 20°C, 30°C, 50°C, 70°C, 90°C and 110°C were carried out (ranging from 10°C to
110°C) followed by new measurements at 10°C and/or 20°C in order to assess the reversibility
of the systems. An average viscosity was then calculated for each temperature using the
30 measurement points situated on the same plate.
The relative viscosity
( nrePotIve
ribose
was also selected in order to represent the change in the viscosity of the system as a function of
35
temperature, as this variable directly reflects the compensation for the loss of natural viscosity of
the base oil of Group Ill of the polymer systems studied.
60
o 3.2: Compositions hosed on polydiol statistical copolymers Al and boronic diester
compounds A2.
5 • Compositions tested
Copolymers Al:
Four poly(alkyl methacrylate-co-alkyldiol methacrylate) statistical copolymers of the
invention are tested. The copolymers are as follows:
3 Copolymer A1-1: This copolymer comprises 20 mol.% monomers having diol
10 functions. The average side chain length is 13.8 carbon atoms. Its number-average
molar weight is 49,600 g/mol. Its polydispersity index is 1.51, Its number-average
degree of polymerization (DP„) is 167. The number-average molar weight and the
polydispersity index are measured by steric exclusion chromatography measurement
using a polystyrene calibration.
15 3 Copolymer A1-2: This copolymer comprises 20 mol.% monomers having diol
functions. The average side chain length is 10.8 carbon atoms. Its number-average
molar weight is 59.700 g/mol. Its polydispersity index is 1.6. Its number-average
degree of polymerization (DP„) is 196. The number-average molar weight and the
polydispersity index are measured by steric exclusion chromatography measurement
20 using a polystyrene calibration.
3 Copolymer A1-3: This copolymer comprises 10 mol.% monomers having diol
functions. The average side chain length is 13.8 carbon atoms. Its number-average
molar weight is 47,800 g/mol. Its polydispersity index is 1.3. Its number-average
degree of polymerization (DP„) is 198. The number-average molar weight and the
25 polydispersity index are measured by steric exclusion chromatography measurement
using a polystyrene calibration.
3 Copolymer A1-4: This copolymer comprises 10 mol.% monomers having diol
functions. The average side chain length is 13.8 carbon atoms. Its number-average
molar weight is 97,100 gimol. Its polydispersity index is 3.11. Its number-average
30 degree of polymerization (DP„) is 228. The number-average molar weight and the
polydispersity index are measured by steric exclusion chromatography measurement
using a polystyrene calibration.
The copolymers A1-1, A 1-2, A 1-3 and A1-4 are obtained according to one of the
protocols described in paragraph 1.
35
Compound A2:
Compound A2-1 is the boronic diester obtained according to the protocol described in
paragraph 2.1.
61
Lubricating base oil
The lubricating base oil used in the compositions to be tested is an oil of Group III of the
API classification. marketed by SK under the name Yubase 4. It has the following
5 characteristics:
its kinematic viscosity at 40°C measured according to the standard ASTM D445 is 19.57
cSt:
its kinematic viscosity measured at 100°C according to the standard ASTM D445 is 4.23
cSt;
10 its viscosity index measured according to the standard ASTM D2270 is 122;
its Noack volatility in percentage by weight, measured according to the standard DIN
51581 is 14.5;
Its flash point in degrees Celsius measured according to the standard ASTM D92 is
230°C:
15 Its pour point in degrees Celsius measured according to the standard ASTM D97 is -15°C.
Composition A (not according to the invention) is used as reference.
It contains a solution with 4.2% by weight of a polymethacrylate polymer in a
lubricating base oil of Group III of the API classification. The polymer has a number-average
20 molar weight (Me ) equal to 106.000 gimol, a polydispersity index (PDI ) equal to 3.06, a numberaverage
degree of polymerization of 466 and the average pendant chain length is 14 carbon
atoms.
Ihis polymethacrylate is used as viscosity index improver additive.
4.95 g of a fbrmulation having a concentration by weight of 42% of this
25 polymethacrylate in a Group III base oil and 44.6 g of Group III base oil arc introduced into a
flask. The solution thus obtained is maintained under stirring at 90°C until the polymethacrylate
is completely dissolved.
A solution with 4.2% by weight of this polymethacrylate is obtained.
30
Composition B-1 (not according to the invention) is obtained as follows:
4.14 g of polydiol copolymer A1-1 and 37.2 g of Group III base oil are introduced into a
flask. The solution thus obtained is maintained under stirring at 90°C until the polydiol is
completely dissolved.
35 A solution with 10% by weight polydiol copolymer A1-1 is obtained.
Composition C-1 (according to the invention) is obtained as follows:
62
8 g of the solution with 10% by weight polydiol copolymer A1-1 in the Group Ill base
oil prepared previously is introduced into a flask. 55.8 mg of boronic diester A2-1 is added to
this solution. The solution thus obtained is maintained under stirring at 90°C until the boronic
diester is completely dissolved.
5 A solution with 10% by weight polydiol copolymer A1-1 and 20 mol.% boronic diester
A2-1 with respect to the diol functions of the polydiol copolymer Al-1 is obtained.
Composition 1)-1 (according to the invention) is obtained as follows:
8 a of the solution with 10% by weight polydiol copolymer A 1 -1 in the Group III base
10 oil prepared previously is introduced into a flask. 223 mg of boronic diester A2-1 is added to this
solution. The solution thus obtained is maintained under stirring at 90°C until the boronic diester
is completely dissolved.
A solution with 10% by weight polydiol copolymer A1-1 and 80 mol.% boronic diester
A2-1 with respect to the diol functions of the polydiol copolymer A1-1 is obtained.
15
Composition B-2 (not according to the invention) is obtained as follows:
6.52 g of polydiol copolymer A1-2 and 58.7 g of Group III base oil are introduced into a
flask. The solution thus obtained is maintained under stirring at 90°C until the polydiol is
completely dissolved.
20 A solution with 10% by weight polydiol copolymer A1-2 is obtained.
Composition C-2 (according to the invention) is obtained as follows:
8 g of the solution with 10% by weight polydiol copolymer A1-2 in the Group III base
oil prepared previously is introduced into a flask. 65.4 mg of boronic diester A2-1 is added to
25 this solution. The solution thus obtained is maintained under stirring at 90°C until the boronic
diester is completely dissolved.
A solution with 10% by weight polydiol copolymer A1-2 and 20 mol.% boronic diester
A2-1 with respect to the diol functions of the polydiol copolymer A 1-2 is obtained.
30 Composition D-2 (according to the invention) is obtained as follows:
8 g of the solution with 10% by weight polydiol copolymer Al-2 in the Group Ill base
oil prepared previously is introduced into a flask. 262 mg of boronic diester A2-1 is added to this
solution. The solution thus obtained is maintained under stirring at 90°C until the boronic diester
is completely dissolved.
35 A solution with 10% by weight polydiol copolymer A1-2 and 80 mol.% boronic diester
A2-1 with respect to the diol functions of the polydiol copolymer A 1-2 is obtained.
Composition B-3 (not according to the invention) is obtained as follows:
63
7.24 g of polydiol copolymer Al-3 and 65.2 g of Group III base oil are introduced into a
flask. The solution thus obtained is maintained under stirring at 90°C until the polydiol is
completely dissolved.
A solution with 10% by weight polydiol copolymer A1-3 is obtained.
5
Composition C-3 (according to the invention) is obtained as follows:
8 g of the solution with 10% by weight polydiol copolymer A1-3 in the Group Ill base
oil prepared previously is introduced into a flask. 28.2 mg of boronic diester A2-1 is added to
this solution. The solution thus obtained is maintained under stirring at 90°C until the boronic
10 diester is completely dissolved.
A solution with 10% by weight polydiol copolymer A1-3 and 20 mol.% boronic diester
A2-1 with respect to the diol functions of the polydiol copolymer A1-3 is obtained.
Composition B-4 (not according to the invention) is obtained as follows:
15 4.99 g of polydiol copolymer A1-4 and 44.4 g of Group III base oil are introduced into a
flask. The solution thus obtained is maintained under stirring at 90°C until the polydiol is
completely dissolved.
A solution with 10% by weight polydiol copolymer A1-4 is obtained.
20 Composition C-4 (according to the invention) is obtained as follows:
6.01 g of the solution with 10% by weight polydiol copolymer A1-4 in the Group III
base oil prepared previously is introduced into a flask. 18.6 mg of boronic diester A2-1 is added
to this solution. The solution thus obtained is maintained under stirring at 90°C until the boronic
diester is completely dissolved.
25 A solution with 10% by weight polydiol copolymer A1-4 and 20 mol.% boronic diester
A2-1 with respect to the diol functions of the polydiol copolymer A1-4 is obtained.
Composition D-4 (according to the invention) is obtained as follows:
6.03 g of the solution with 10% by weight polydiol copolymer A1-4 in the Group III
30 base oil prepared previously is introduced into a flask. 74.7 mg of boronic diester A2-1 is added
to this solution. The solution thus obtained is maintained under stirring at 90°C until the boronic
diester is completely dissolved.
A solution with 10% by weight polydiol copolymer A1-4 and 80 mol.% boronic diester
A2-I with respect to the diol functions of the polydiol copolymer A1-4 is obtained.
35
Rheology results obtained
The rheological behaviour of composition CI-1 was studied in the case of a temperature
64
range from 10°C to 110°C, The results are presented in Figure 5. The dynamic viscosity of
composition C1-1 varies at low shear rates and for temperatures below 50°C. Composition C1-1
deforms under shear stress at temperatures below 50°C.
For temperatures above 50°C, the dynamic viscosity of composition C1-1 varies very
5 slightly or does not vary at low shear rates. Composition C1-1 no longer deforms under shear
stress at these temperatures.
The relative viscosity of compositions A, B-1, C-1, D-1, 13-2, C-2, D-2, 13-3. C-3. D-3,
13-4, C-4, D-4 was studied. The change in the relative viscosity of these compositions is
10 illustrated in Figures 6A-6D. By comparing the results obtained, it is observed that certain
parameters influence the relative viscosity of the compositions.
The influence of 14 (average pendant side chain length)
polydiol copolymers A1-1 and A1-2 have the same percentage of diol monomer
15 (M I ) per chain. comparable molar weights, but a different average alkyl chain length of the
monomers (Lc - 13.8 and 10.8 respectively).
"Fhe change in the relative viscosity as a function of the temperature for the solutions
formulated from these polymers (Figure 6A and 613) indicate that the average alkyl chain length
of the monomers constituting the polydiol copolymer plays a role in the rheological properties of
20 the formulations.
The influence of the molar percentage of diol monomer (% diol)
The polydiol copolymers A I -1 and A1-3 have the same average alkyl chain length (Le),
comparable molar weights but a different percentage of diol monomer (M1) per backbone chain
25 (2 0% and 10% respectively).
The change in the relative viscosity as a function of the temperature for the solutions
formulated from these polymers (Figure 6A and 6C) indicates that the percentage of diol
monomer per skeletal chain plays a role in the rheological properties of the formulations.
30 The influence of the molar weights (DP„)
The polydiols A 1-3 and A 1-4 have the same percentage of diol monomer (M1) per
chain, the same average alkyl chain length (1.c) but substantially different molar weights (47,800
glmol and 97.100 g/mol respectively) and substantially different number-average degrees of
polymerization (DP„ of 198 and 228 respectively).
35 The change in the relative viscosity as a function of the temperature for the solutions
formulated from these polymers (Figure 6.0 and 6.D) indicates that the molar weight of the
polydiol copolymers (Mn) plays a role in the rheological properties of the formulations.
65
a 3.2: Compositions based on polydiol statistical copolymers AI and boronic ester polymer
compounds A2
• Compositions tested
5 Copolymers Al:
A poly(alkyl methacrylate-co-alkyldiol methacrylate) statistical copolymer of the
invention is tested. The copolymer is as follows:
3 Copolymer A l -I : "[his copolymer comprises 20 mol.% monomers having diol
functions. "[he average side chain length is 13.8 carbon atoms. Its number-average
10 molar weight is 49.600 gimol. Its polydispersity index is 1.51. Its number-average
degree of polymerization (DP,,) is 167. 'I'he number-average molar weight and the
polydispersity index are measured by steric exclusion chromatography measurement
using a polystyrene calibration.
Copolymer A1-1 is obtained according to one of the protocols described in paragraph 1.
15
Compound A2:
Compound A2-2 is the boronic ester polymer obtained according to the protocol
described in paragraph 2.2. "[his copolymer comprises 4 mol.% monomers having boronic ester
functions. The average side chain length is greater than 12 carbon atoms. Its number-average
20 molar weight is 37.200 g/mol. Its polydispersity index is 1.24. Its number-average degree of
polymerization (DP,,) is 166. The number-average molar weight and the polydispersity index are
measured by steric exclusion chromatography measurement using a polystyrene calibration.
Lubricating base oil
25 '[he lubricating base oil used in the compositions to be tested is the Group III oil
described previously in paragraph 3.1.
The composition A (not according to the invention) used as reference is the same as the
composition A used in paragraph 3.1.
30
Composition B (not according to the invention) is obtained as follows:
Composition B is the same composition B-I used in paragraph 3.1.
Composition C (according to the invention) is obtained as follows:
35
4 g of the solution with 10% by weight polydiol copolymer A1-1 in the Group III base
oil prepared previously is introduced into a flask. 76.8 mg of boronic ester polymer A2-2 and 4 g
of the Group III base oil are added to this solution. The solution thus obtained is maintained
under stirring at 90°C until the boronic ester polymer is completely dissolved.
66
A solution with 5% by weight polydiol copolymer A1-1 and 1% by weight boronic ester
polymer A2-2 with respect to the total weight of the composition is obtained.
Composition I) (according to the invention) is obtained as follows:
5 6 g of the preceding composition C (i.e. a composition at 5% by weight polydiol
copolymer A1-1 and 1% by weight boronic ester polymer A2-2 with respect to the total weight
of the composition) is introduced into a flask. 61.9 mg of boronic ester polymer A2-2 is added to
this solution. The solution thus obtained is maintained under stirring at 90°C until the boronic
ester polymer is completely dissolved.
10 A solution with 5% by weight polydiol copolymer A1-1 and 2% by weight boronic ester
polymer A2-2 with respect to the total weight of the composition is obtained.
Composition E (according to the invention) is obtained as follows:
3 g of the solution with 10°/0 by weight polydiol copolymer A1-1 in the Group III base
15 oil prepared previously is introduced into a flask. 176 mg of boronic ester polymer A2-2 and 3 g
of the Group III base oil are added to this solution. The solution thus obtained is maintained
under stirring at 90°C until the boronic ester polymer is completely dissolved.
A solution with 5% by weight polydiol copolymer Al-I and 3% by weight boronic ester
polymer A2-2 with respect to the total weight of the composition is obtained.
20
n Rheology results obtained
The rheological behaviour of composition F was studied for a temperature range from
10°C to 110°C. The results are presented in Figure 7. The dynamic viscosity of composition 12,
varies at low shear rates and for temperatures below 50°C. Composition E deforms under shear
25 stress at temperatures below 50°C.
In the case of temperatures above 50°C, the dynamic viscosity of composition E varies
very slightly or does not vary at low shear rates. Composition E no longer deforms under shear
stress at these temperatures.
30 The relative viscosity of compositions A, B. C, D and E was studied. The change in the
relative viscosity of these compositions is illustrated in Figure 8. This figure indicates that the
polydiol/poly(boronic ester) systems make it possible to very significantly compensate for the
drop in natural viscosity of the base oil as a function of the temperature. Furthermore, the effect
obtained can be regulated by adjusting the concentrations by weight of the different polymers in
35 solution in the base oil III.
Composition F (not according to the invention) is obtained as follows:
A VI booster polymer (Viscoplex V6.850 marketed by the company Rohmax) is added
67
to the lubricating base oil described above.
Viscoplex 6.850 comprises 41.8% linear polymethacrylate active material.
The composition thus obtained has the following characteristics; the percentages shown
correspond to percentages by weight with respect to the total weight of composition F:
Lubricating base oil
Viscoplex V6.850
80.86
19.14 (corresponding to 8% polymethacrylate
active material)
5
The kinematic viscosities at 40°C and at 100°C are measured for compositions F and F
according to the standard ASTM D445 and the VI (Viscosity Index) is calculated for these two
compositions; the results are shown in 'Fable I below.
Table I
Composition E
Composition 1:
KV 40 (mm2/s)
48.16
98.17
KV 100 (mm2/s)
21.417
23.82
VI 450
274
10
These results shown that the lubricating compositions according to the invention exhibit a very
clear increase in VI with respect to a lubricating composition comprising a conventional VI
booster polymer.
It is to be noted that this increase in VI is demonstrated without increasim2, the polymer content
15 of the lubricating composition.
- X, and X, form with the oxygen atoms a boronic ester of the following
formula
0
10
15
H2C
X10
35
in which:
- the stars (*) symbolize the bonds to the oxygen atoms,
- R'2 and R-2, identical or different, are selected from the group
formed by hydrogen and a C I -Cn alkyl, preferably methyl;
68
CLAIMS
Composition resulting from the mixture:
• at least one lubricating oil,
5 • at least one statistical copolymer Al and at least one compound A2 comprising at
least two boronic ester functions;
a the statistical copolymer A l resulting from the copolymerization:
n of at least one first monomer MI of general formula (1)
OX2
(I)
20 in which:
R I is selected from the group formed by -H, -CH3 and --CH3-Cl13:
x is an integer ranging from 2 to 18;
y is an integer equal to 0 or 1;
X! and X2, identical or different, are selected from the group formed by
25 hydrogen, tetrahydropyranyl, methyloxymethyl, ter-butyl. benzyl,
trimethylsily1 and t-butyl dimethylsilyl;
or
- X1 and Xz form with the oxygen atoms a bridge of the following formula
or
30
69
5
in which:
the stars (*) symbolize the bonds to the oxygen atoms.
is selected from the group formed by a C6-Ci s aryl. a
C7-C is aralkyl and C2-C 18 alkyl, preferably a C6-C is aryl;
10 • with at least one second monomer M2 of general formula (II-A):
R2
H2C
(
R31
(II-A)
15 in which:
12, is selected from the group formed by —I-I, —CI i3 and —C1-12—C113,
R31 is selected from the group formed by a C6-Cis aryl. a Co-C i s aryl
substituted by an R'3, —C(0) 0 R',; R'3 , S R.'3 and —C(0)—
N(I-I)—R'3 group with R'3 a C1 -C30 alkyl group.
20
2. Composition according to claim I, in which statistical copolymer Al results from the
copolymerization of at least one monomer M l with at least two monomers M2 having different
R31 groups.
25 3. Composition according to claim 2. in which one of the monomers M2 of the statistical
copolymer A l has the general formula (II-Al):
H2C
0
0
30
(II-Al)
in which:
- R, is selected from the group formed by —CI-13 and —CI-12—C1-13,
R-31 is a C I -C.1 alkyl group,
35 and the other monomer M2 of the statistical copolymer A I has the general formula (II-A2):
25
wi and w3. identical or different are integers selected between 0 and 1,
R5. R6 and R7, identical or different are selected from the group formed by
hydrogen and a hydrocarbon-containing group having from 1 to 24 carbon
atoms, preferably between 4 and 18 carbon atoms, preferably between 6 and 14
carbon atoms
I. is a divalent bond group and is selected from the group formed by a Cb-Cis
aryl. a C(,-Cu aralkyl and a C3-C2.1 hydrocarbon-containing chain.
70
5 0
R' 31
(II-A2)
in which:
is selected from the group formed by -H, —CH3and CH2 CI I3.
10 R"'3, is a C15-C30 alkyl group.
4. Composition according to any one of claims 1 to 3, in which the compound A2 is a
compound of formula (III):
R6
0 R7
0 B-0
\ /
B—L
0
15
in which:
30 5 Composition according to any one of claims 1 to 3, in which the compound A2 is a
statistical copolymer resulting from the copolymerization
• of at least one monomer M3 of formula (IV):
R1 0
0
B—M
/ 0 X (R8),
H2C
H2C
O
35
R11 R9
(IV)
71
in which:
t is an integer equal to 0 or I;
u is an integer equal to 0 or 1;
M and Rs arc divalent bond groups. identical or different, are selected from
5 the group formed by a Co-C18 aryl, a C7-C,4 aralkyl and alkyl.
preferably a C0-CI8 aryl.
-- X is a function selected from the group formed by - -C(01 0- .
-S- -N(R'4)-- and 0- with
hydrocarbon-containing chain comprising from 1 to 15 carbon atoms;
10 R, is selected from the group formed by -11, -C113 and-C112-CI-1;
R10 and RI, identical or different selected from the group formed by hydrogen
and a hydrocarbon-containing group having from 1 to 24 carbon atoms.
preferably between 4 and 18 carbon atoms, preferably between 6 and 14
carbon atoms.
15 • with at least one second monomer M4 of general formula (V):
R12
H2C
R13
(V)
20 in which:
R12 is selected from the group formed by El, -Cl I3 and --C1-12-013,
R13 is selected from the group formed by a C6-C18 aryl, a C0-C,8 aryl
substituted by an R '13, --C(0) R.13; , S -R' 13 and C(0) -
N(11)--R' 13 group with R' 13 a C1 -C25 alkyl group.
25
6. Composition according to claim 5, in which the chain formed by the sequence of K1 0. M.
X and (R8)0 groups with u equal to 0 or 1 of the monomer of general formula (IV) has a total
number of carbon atoms comprised between 8 and 38, preferably between 10 and 26.
30 7. Composition according to one of claims 5 to 6, in which the side chains of the
copolymer A2 have an average length greater than 8 carbon atoms, preferably ranging from 11
to 16 carbon atoms.
8. Composition according to one of claims 5 to 7, in which the statistical copolymer A2 has
35 a molar percentage of monomer of formula (IV) in said copolymer ranging from 0.25 to 20%,
preferably from 1 to 10%.
9. Composition according to one of claims 5 to 8. in which the statistical copolymer A2 has
72
a number-average degree of polymerization ranging from 50 to 1500, preferably from 80 to 800.
10. Composition according to one of claims 1 to 9, in which in which the side chains of the
statistical copolymer A I have a average length ranging from 8 to 20 carbon atoms, preferably
5 from 9 to 15 carbon atoms.
1 I . Composition according to one of claims 1 to 10, in which the statistical copolymer A 1
has a molar percentage of monomer MI of formula (I) ranging in said copolymer from 1 to 30%,
preferably ranging from 5 to 25%, more preferably ranging from 9 to 21%.
10
12. Composition according to one of claims 1 to 11, in which the statistical copolymer A 1
has an average degree of polymerization rangim?, from 100 to 2000, preferably from 150 to 1000.
13. Composition according to any one of claims 1 to 12, in which the lubricating oil is
15 selected from the oils of Group 1. Group II, Group III, Group IV, Group V of the API
classification and a mixture thereof.
14. Composition according to one of claims 1 to 13. further comprising a functional additive
selected from the group formed by the detergents, anti-wear additives, extreme-pressure
20 additives, additional antioxidants. polymers improving the viscosity index, pour point improvers.
anti-foaming agents. corrosion inhibitors, thickeners, dispersants, friction modifiers and mixtures
thereof.
15. Composition according to one of claims 1 to 14, in which the mass ratio between the
25 statistical copolymer Al and the compound A2 (ratio Al /A2) ranges from 0.001 to 100.
preferably from 0.05 to 20, even more preferably from 0.01 to 10, even more preferably from 0.2
to 5.
16. Composition according to one of claims 1 to 14, in which the sum of the masses of the
30 statistical copolymer Al and of the compound A2 ranges from 0.5 to 20% with respect to the
total mass of the lubricating composition and the mass of lubricating oil ranges from 80% to
99.5% with respect to the total mass of the lubricating composition.
17. Use of a composition according to one of claims 1 to 16 for lubricating a mechanical
35
18. Stock composition resulting from mixing:
• at least one statistical copolymer Al;
73
• at least one compound A2 comprising at least two boronic ester functions; and
• at least one functional additive selected from the group formed by the detergents,
anti-wear additives, extreme-pressure additives, antioxidants, polymers improving
the viscosity index, pour point improvers, anti-foaming agents, thickeners,
5
dispersants, friction modifiers and mixtures thereof;
o the statistical copolymer Al resulting from the copolymerization
• of at least one first monomer MI of general formula (1)
10
15
H2C
Xi0
0
OX2
(I)
in which:
RI is selected from the group formed by —1-1, CH3 and is;
20
x is an integer ranging from 2 to 18;
y is an integer equal to 0 or 1;
X1 and X7. identical or different, are selected from the group formed by
hydrogen, tetrahydropyranyl, methyloxymethyl, ter-butyl, benzyl,
trimethylsilyl and t-butyl dimethylsilyl;
25 or
X1 and X2 form with the oxygen atoms a bridge of following formula
R° 2
30
in which:
- the stars (*) symbolize the bonds to the oxygen atoms,
- R*2 and R'°?. identical or different, are selected from the group
fbrmed by hydrogen and a CI-C11 alkyl, preferably methyl;
or
35 X1 and Xz form with the oxygen atoms a boronic ester of the following
formula
74
in which:
- the stars (*) symbolize the bonds to the oxygen atoms,
- R"'2 is selected from the group formed by a C6-C18 aryl, a
C7-C18 aralkyl and C2-C18 alkyl, preferably a C6-C18 aryl;
5
• with at least one second monomer M2 of general formula (II-A):
R2
H2C
R31
(II-A)
10 in which:
— R2 is selected from the group formed by H, —CH: and —CI-2—C1-13,
R31 is selected from the group formed by a C6-C18 aryl, a C6-C18 aryl
substituted by an R'3, —C(0)0R1 3;
—0—R1 3, —S—R' and —C(0)—N(H)—R'3 group with R:3 a C i -C3o alkyl
15
group,