F O R M 2
THE PATENTS ACT, 1970
(39 of 1970)
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION
THICKENING AGENT FOR AQUEOUS SYSTEMS, FORMULATIONS CONTAINING SAME
AND USE THEREOF
2. APPLICANT(S)
(a) NAME
(b) NATIONALITY
(c) ADDRESS
COATEX
FRENCH Company
35, RUE AMPÈRE,,
F-69730 GENAY,
FRANCE
3. PREAMBLE TO THE DESCRIPTION
PROVISIONAL
The following specification describes invention
COMPLETE (√)
The following specification particularly describes the invention
and the manner in which it is to be performed
4. DESCRIPTION (Description shall start from next page)
5. CLAIMS (not applicable for provisional specification. Claims should start with the preamble – “I/We claim”
on separate page)
6. DATE AND SIGNATURE ( to be given on the last page of specification)
7. ABSTRACT OF THE INVENTION (to be given along with complete specification on the separate page)
Note:
*Repeat boxes in case of more than one entry
*To be signed by the applicant(s)or the authorized registered patent agent
*Name of the applicant should be given in full, family name in the beginning
*Complete address of the applicant should be given stating with postal index no. / code, state and country
*Strike out the column which is/are not applicable
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The present invention relates to novel associative thickeners belonging to the category of the
HEURs (Hydrophobically modified Ethoxylated URethanes). These products comprise an
associative compound of bicycloheptene type. The present invention also relates to
intermediate formulations comprising such thickeners and to the final compositions, for
example paint compositions.
Paints consist of fillers, pigments and at least one organic polymer known as binder. In
addition to the fillers, the pigments and the binder, a paint composition also comprises a
solvent (which is water in the case of aqueous-phase paints), additives for the rheology,
additives for the stability (storage, formation of the film, UV) and other additives for
obtaining special properties. The behaviour and the properties of the paints depend on the
nature of the constituents, in particular of the binder, fillers, pigments and also rheological
additives. They generally comprise one or more thickeners, the role of which is to control the
rheology of the compositions, both at the stage of their manufacture and during their
transportation, their storage or during their implementation. Given the diversity of the
constraints practised at each of these stages, it is advantageous for the formulator to have
available a range of thickeners exhibiting different rheological behaviours in composition.
The following are distinguished among all the thickeners for paints:
- natural cellulose-based thickeners, also known as cellulose ethers, of HEC type or of
HMHEC (Hydrophobically Modified HEC) type,
- acrylic thickeners of non-associative type, known as ASE (Alkali Swellable
Emulsions) and those of associative type, known as HASEs (Hydrophobically
modified Alkali Swellable Emulsions), and
- associative thickening polyurethanes of HEUR (Hydrophobically modified
Ethoxylated URethane) type.
The HASE thickeners can, for example, be obtained by polymerization in the presence of an
anionic surface-active agent, of a (meth)acrylic acid monomer, of an alkyl (meth)acrylate
monomer and of a hydrophobe monomer consisting of a long aliphatic chain.
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The thickening polyurethanes or HEURs, for their part, result from the condensation between
a compound of poly(alkylene glycol) type, a polyisocyanate and a reactant which confers the
associativity of alkyl, aryl or arylalkyl type consisting of a hydrophobic end group.
Although the HASE and HEUR thickeners belong to the category of associative thickeners,
the thickening mechanism cannot be regarded as completely identical. This is because the
mechanism of thickening of the aqueous formulation in the presence of an HASE is due to
the presence of the hydrophobic groups, which are liable to assemble together in the form of
micellar aggregates, but also to the formation of a gel which results from ionic interactions
between the carboxyl function groups carried by the backbone of the polymer and the water
molecules of the aqueous solvent (JCT Research, Vol. 2, N°. 6, April 2005 – W. Wu and
G.D. Shay – Tailoring HASE Rheology Through Polymer Design: Effects of Hydrophobe
Size, Acid Content, and Molecular Weight). In contrast to the HASE thickeners, the HEUR
thickeners are non-ionic compounds and their thickening mechanism is not dependent on
ionic interactions in the medium (Polymers as Rheology Modifiers – Chap. 12 : Systems
Approach to Rheology Control – pp. 207-221 – ACS Symposium Series 462, 1991).
Thus, the rheological behaviours of the HEUR and HASE thickeners can vary considerably,
whereas the functional hydrophobic groups are identical.
The behaviours of the different thickeners on the market can be summarized in the following
way:
Thickener Associative
thickening Non-associative thickening Typical molecular
weight
HEUR Yes Negligible < 50 000 g/mol
ASE No Yes 100 000 -
HASE Yes Yes 1 000 000 g/mol
HEC No Yes 3000 -
HMHEC Yes Yes 100 000 g/mol
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Coatex is the source of numerous research studies on paint thickeners. Furthermore, Coatex
markets the products of the Coapur® range, for example the Coapur® XS products, which
are non-ionic polyurethane thickeners providing rheological profiles which vary between the
newtonian type (low viscosity at low shear gradient) and/or the pseudoplastic type (high
viscosity at low shear gradient). Such non-ionic products exhibit the advantage of developing
a thickening power which is less dependent on the pH of the formulation than the thickeners
of HASE type.
The document WO 02/102868 (Coatex), for example, relates to thickening polyurethanes of
polymer comprising ethylene oxide chains type which comprise, at the chain ends,
hydrophobic groups comprising several aromatic rings, in particular distyrylphenyl and
tristyrylphenyl. Such thickeners make it possible to obtain a high viscosity at low shear
gradient and a good pigmentary compatibility, whatever the type of paint (matt or satin).
The document WO 2006/048539 (Coatex) describes thickeners of HASE type exhibiting a
hydrophobic group of alkyl type which can comprise up to 32 carbon atoms or of aromatic
type which can comprise more than 50 carbon atoms which make it possible to obtain a good
dynamic behaviour (high viscosity at a high shear gradient) and a good static behaviour (high
viscosity at a low shear gradient).
The inventors have developed a novel thickening polyurethane which makes it possible to
very notably increase the viscosity at a high shear gradient and to thus confer, on the aqueous
composition which contains it, a good dynamic behaviour, that is to say a high viscosity at a
high shear gradient, while maintaining a very good pigmentary compatibility. This thickener
can be classified in the category of the thickeners of newtonian or ICI builder type.
This novel thickener can, for example, be used alone in an aqueous paint composition where
it is necessary to have a high viscosity at a high shear gradient (for example a satin or gloss
paint comprising a high latex content).
It can also be used in combination with a thickener of pseudoplastic type. Such a combination
thus makes it possible to obtain an aqueous composition exhibiting a good dynamic
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behaviour related to the presence of the newtonian thickener and a good static behaviour
related to the presence of the thickener of pseudoplastic type.
Such a thickener can be formulated in the aqueous phase and, as a result of its specific
structure, it makes possible thickening of the final aqueous composition without requiring
specific equipment or high shear energy.
This novel thickener exhibits, at the chain ends, hydrophobic groups of bicycloheptenyl type
which are optionally polyalkoxylated.
The document WO 2011/100071 describes rheology-modifying polymers for aqueous
systems, in particular shampoo or shower gel formulations. The thickeners described, of
acrylic thickener type, can comprise in particular ethyl acrylate (EA), methacrylic acid
(MAA) and monomer units comprising a bicycloheptyl-polyether or bicycloheptenylpolyether
group. Such acrylic polymers exhibit a different rheological profile to that of the
thickeners of the present invention: namely, they come within the category of acrylic
thickeners of pseudoplastic type (high viscosity at low shear gradient).
DEFINITIONS
In the description of the present invention, the term “HEUR” is an acronym for
“Hydrophobically modified Ethoxylated URethane”.
In the description of the present invention, unless otherwise indicated, the percentages
expressed represent percentages by weight and are expressed with respect to the total weight
of the reference element. For example, when it is indicated that a polymer comprises 10% of
a monomer or of a reactant, it is understood that the polymer comprises 10% by weight of
this monomer or reactant, with respect to the total weight of this polymer.
In the description of the present invention, the expression “at least one” denotes one or more
compounds (for example one or more bicycloheptenyl compounds, one or more polyols, one
or more polyisocyanates), such as a mixture of 2 to 5 compounds.
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“Alkyl” is understood to mean a linear or branched CxH2x+1 group, where x varies from 1 to
30, preferably from 10 to 30, indeed even from 12 to 28.
“Formulation” is understood to mean the intermediate thickening entity comprising the
polyurethane agent according to the invention, formulated in order to be easier to use in the
final composition to be thickened. For example, the thickening agent according to the
invention can be formulated in the presence of water and of surfactants, in order to be more
easily flowable/pourable and easier to incorporate in the composition to be thickened at
ambient temperature. The viscosity of the formulation, before its incorporation in the final
aqueous composition, is, for example, less than 10 000 mPa.s at 25°C and at 100 revolutions
per minute.
“Composition” is understood to mean the final entity, thickened or to be thickened,
comprising the polyurethane agent according to the invention, optionally formulated in the
presence, for example, of water and of surface-active agents, and also all of its constituents,
the list of which depends on the final application. For example, the final composition
comprises mineral pigments and binders, if a paint composition is involved.
DETAILED DESCRIPTION OF THE INVENTION
The polyurethanes of the present invention are thickeners for aqueous compositions, for
example aqueous paint compositions. They make it possible to obtain high viscosities at a
high shear gradient and to thus confer, on the compositions, a good dynamic behaviour.
These thickening polyurethanes can be categorized in the category of thickeners of newtonian
or ICI builder type.
Some paint compositions, for example satin or gloss paints, which comprise little in the way
of pigments (in comparison with a matt paint, for example) and a great deal of latex, have to
exhibit the highest possible viscosity at a high shear gradient. It is called Cone Plan viscosity
or ICI viscosity, denoted µI (mPa.s). The thickening polyurethane of the present invention is
entirely suited to aqueous compositions of this type.
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The thickening polyurethane of the present invention can also be used in combination with a
thickener of pseudoplastic type. Such a combination thus makes it possible to obtain a
composition exhibiting a good dynamic behaviour related to the presence of the newtonian
thickener and a good static behaviour related to the presence of the thickener of pseudoplastic
type.
This novel thickener exhibits, at the chain ends, hydrophobic groups of bicycloheptenyl type
which are optionally polyalkoxylated.
HEUR thickener
A subject-matter of the present invention is a thickening belonging to the category of the
HEURs (Hydrophobically modified Ethoxylated URethanes). It concerns a non-ionic
associative thickening polymer of aqueous compositions.
The thickening polyurethanes or HEURs of the present invention result from the reaction
between a reactant which confers the associativity and which consists of an end hydrophobic
group, a compound of polyol (for example poly(alkylene glycol)) type and a polyisocyanate.
In the context of the present invention, the terms “reaction”, “condensation” and
“polycondensation” are used equivalently.
More specifically, it concerns a polyurethane resulting from the condensation:
a) of at least one bicycloheptenyl compound, which is optionally polyalkoxylated, of
formula (I):
R – (CH2)a – [ (OE)m – (OP)n – (OB)p ] – OH (I)
in which :
- R represents a bicycloheptenyl radical, optionally substituted by one or more
identical or different alkyl groups, comprising between 1 and 20 carbon atoms,
- a is equal to 0, 1 or 2,
- [ (OE)m – (OP)n – (OB)p ] represents a polyalkoxyl chain consisting of alkoxyl units,
distributed in blocks, alternating or random, chosen from ethoxyl OE units, propoxyl
OP units and butoxyl OB units, and
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- m, n and p represent, independently of one another, 0 or a number varying between 1
and 250 (limits included), the sum of m, n and p being between 0 and 250,
b) of at least one polyol, for example of at least one poly(alkylene glycol), and
c) of at least one polyisocyanate.
It is these novel polyurethanes which make it possible, for example, to thicken a paint
composition at a high shear gradient (measurement of the ICI viscosity, for example).
The polyurethane according to the present invention comprises, as constituent a), a compound
of formula (I). Such a compound is known, in the context of the present invention,
as “bicycloheptenyl compound”. The compounds of formula (I) can comprise a
polyalkoxyl chain, itself consisting of at least two alkoxyl units. Alternatively, the
compounds of formula (I) do not comprise a polyalkoxyl chain.
Furthermore, the polyurethane comprises, as constituent b), a polyol which can be a
poly(alkylene glycol).
“Poly(alkylene glycol)” is understood to mean a polymer of an alkylene glycol derived from
an olefin oxide. The poly(alkylene glycol)s chains of the constituent b) according to the
present invention include a proportion of ethyleneoxy groups, a proportion of propyleneoxy
groups and/or of a portion of butyleneoxy groups. The poly(alkylene glycol)s chains
according to the present invention can, for example, comprise a dominant proportion of
ethyleneoxy groups in combination with a secondary proportion of propyleneoxy groups.
Specific examples of alkylene glycol polymers comprise: poly(alkylene glycol)s having an
average molecular weight of 1000, 4000, 6000 and 10 000 g/mol, and polyethylenepolypropylene
glycols having a percentage of ethylene oxides of between 20 and 80% by
weight and a percentage of propylene oxides of between 20 and 80% by weight.
According to one aspect of the present invention, the polyurethanes result from the
condensation in particular of a poly(alkylene glycol) which is poly(ethylene glycol). It can,
for example, be a poly(ethylene glycol), the molecular weight of which varies
between 2000 g/mol and 20 000 g/mol, for example between 8000 g/mol and 15 000 g/mol
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(limits included). Mention may be made, by way of example, of poly(ethylene glycol)
(or PEG) with a molecular weight of 10 000 g/mol and 12 000 g/mol (limits included).
According to another aspect of the present invention, the polyurethanes result from the
condensation of several poly(alkylene glycol)s, for example of several poly(ethylene glycol)s.
Furthermore, the polyurethane comprises, as constituent c), at least one polyisocyanate.
“Polyisocyanate” is understood to mean a compound which comprises at least two isocyanate
–N=C=O functional groups.
According to one aspect of the present invention, the polyurethanes result from the
condensation in particular of a polyisocyanate which is chosen from the group consisting of
toluene diisocyanate, toluene diisocyanate dimers, toluene diisocyanate trimers,
1,4-butane diisocyanate, 1,6-hexane diisocyanate, isophorone diisocyanate,
1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate,
4,4’-diisocyanatodicyclohexylmethane, 1-methyl-2,4-diisocyanatocyclohexane,
diphenylmethylene diisocyanate (MDI), for example 2,2’-MDI, 2,4’-MDI, 4,4’-MDI,
polymeric MDI or their mixtures, dibenzyl diisocyanate, a mixture of 1-methyl-2,4-
diisocyanatocyclohexane and 1-methyl-2,6-diisocyanatocyclohexane, hexamethylene
diisocyanate biuret, hexamethylene diisocyanate biuret dimers, hexamethylene diisocyanate
biuret trimers, 2,2,4-trimethylhexamethylene diisocyanate and a mixture of at least two of
these compounds.
According to one embodiment of the present invention, the bicycloheptenyl compound of
formula (I) does not comprise a polyalkoxyl chain. Thus, in this case, the values m, n and p
are equal to 0.
According to another embodiment of the present invention, the bicycloheptenyl compound of
formula (I) comprises a polyalkoxyl chain.
According to one example of this embodiment, in the formula (I) below:
R – (CH2)a – [ (OE)m – (OP)n – (OB)p ] – OH (I)
- m represents a number being between 1 and 250 (other than 0) and
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- n and p represent, independently of one another, 0 or a number being between 1 and
250 (limits included),
the sum of m, n and p being between 2 and 250, for example between 2 and 150 or for
example between 3 and 100.
According to another example of this embodiment of the present invention, in the formula (I)
above:
- m and n represent a number being between 1 and 250 (other than 0) and
- p is equal to 0,
the sum of m and n being between 2 and 250, for example between 2 and 150 for example
between 3 and 100.
According to yet another example of this embodiment, in the formula (I) above:
- m represents a number varying between 2 and 250, for example between 2 and 150, or
for example between 3 and 100, and
- n and p are equal to 0.
According to this example of embodiment, said polyalkoxyl chain of the compound of
formula (I) consists exclusively of ethoxyl units OE.
The polyurethane of the present invention thus comprises a compound of formula (I), also
known as bicycloheptenyl compound, which is optionally substituted.
According to one embodiment of the present invention, the bicycloheptenyl compound,
which is optionally polyalkoxylated, of formula (I) is such that R represents a
bicyclo[d.e.f]heptenyl radical in which d is 2, 3 or 4, e is 1 or 2 and f is 0 or 1 and the sum d
+ e + f = 5, optionally substituted by one or more identical or different alkyl groups,
comprising between 1 and 20 carbon atoms.
According to another embodiment of the present invention, the said bicycloheptenyl
compound of formula (I) is such that R represents a bicyclo[3.1.1]heptenyl radical substituted
by two CH3 groups.
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According to yet another embodiment, the said bicycloheptenyl compound of formula (I):
R – (CH2)a – [ (OE)m – (OP)n – (OB)p ] – OH (I)
is such that:
- a is equal to 2,
- m, n and p are equal to 0 and
- R represents:
According to this embodiment, the said bicycloheptenyl compound of formula (I) is such
that:
This compound is also known under the name of Nopol or
2-(6,6-dimethylbicyclo[3.1.1]hept-2-en-2-yl)ethanol.
According to one aspect of the invention, the said polyurethane results from the condensation
of:
a) from 1% to 29% by weight of at least one compound of formula (I),
b) from 70% to 98% by weight of at least one poly(alkylene glycol) and
c) from 1% to 29% by weight of at least one polyisocyanate,
the sum of these percentages by weight being equal to 100%.
According to another aspect of the invention, the said polyurethane results from the
condensation of:
a) from 3% to 10% by weight of at least one compound of formula (I),
b) from 80% to 94% by weight of at least one poly(alkylene glycol) and
c) from 3% to 10% by weight of at least one polyisocyanate,
the sum of these percentages by weight being equal to 100%.
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According to one embodiment of the present invention, the polyurethane exhibits a
rheological profile of newtonian type, that is to say that it makes it possible to obtain a low
viscosity at a low shear gradient (for example, Brookfield viscosity). According to this
embodiment, the polyurethane makes it possible to additionally obtain a high viscosity at a
high shear gradient (for example, ICI viscosity).
The manufacture of the polyurethanes, which belong to the family of the thickeners of HEUR
type, is known to a person skilled in the art, who may refer to the teaching of the documents
cited above in the technological background of the present invention.
A subject-matter of the present invention is also a process for the preparation of a
polyurethane as described above, the said process consisting of a condensation of its different
constituents.
Formulation of the HEUR thickener
The polyurethane according to the invention can be formulated or coformulated with other
constituents or components.
Thus, the present invention also relates to an aqueous formulation comprising a polyurethane
according to the invention, as described above.
This aqueous thickening formulation is intended to be incorporated in a final composition, for
example a paint, a paper coating colour or a detergent composition.
The polyurethane according to the invention can be coformulated in the presence of water.
According to one embodiment, the said aqueous formulation according to the invention
consists of:
1) from 5% to 50% by weight of at least one polyurethane according to the invention, as
described above, and
2) from 50% to 95% by weight of water,
the sum of these percentages by weight being equal to 100%.
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According to another embodiment, the said aqueous formulation according to the invention
consists of:
1) from 5% to 25% by weight of at least one polyurethane according to the invention, as
described above, and
2) from 75% to 95% by weight of water,
the sum of these percentages by weight being equal to 100%.
The polyurethane according to the invention can be coformulated in water, in the presence of
at least one surface-active agent. This surface-active agent makes it possible to formulate the
thickener in the form of a less viscous aqueous liquid solution which can thus be more easily
employed by the formulator.
Thus, according to one embodiment of the present invention, the said aqueous formulation
comprises a polyurethane, as described above, and also water and at least one surface-active
agent.
“Surfactant” or “surface-active agent” is understood to mean a molecule or a polymer
consisting of at least a hydrophilic part and of at least a hydrophobic part.
The surface-active agent used in the context of the invention can be different in nature; for
example, it can be anionic or non-ionic.
This surfactant can be selected from the categories of ionic surfactants (in this case,
preferably an ionic surfactant) and/or non-ionic surfactants and/or mixed surfactants
(comprising, in the same molecule, a non-ionic and anionic structure). The preferred
surfactant is composed of at least one surfactant selected from the category of non-ionic
surfactants, optionally in the presence of an anionic surfactant.
Mention may be made, among the suitable anionic surfactants, of sodium, lithium, potassium,
ammonium or magnesium salts derived from alkyl ether sulphates with alkyl(s) varying from
C6 to C12, in linear, iso, oxo, geminal, cyclic or aromatic configuration, or from C12 alkyl
sulphates, from alkyl phosphate esters or from dialkyl sulfosuccinates. The anionic
surfactants are preferably used with at least one non-ionic surfactant.
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Mention may be made, as examples of mixed surfactants, of alkoxylated alkylphenol
sulfonates. The non-ionic surfactants can be used alone or in combination with an anionic
surfactant. Mention may be made, as preferred examples of suitable non-ionic surfactants, of:
ethoxylated (2 to 15 OE) C4-C18 alcohols, ethoxylated (2 to 40 OE) C4-C18 Guerbet alcohols,
ethoxylated (2 to 40 OE) single-branched C10-C18 alcohols, C18 sorbitol esters, ethoxylated
(2 to 20 OE units) sorbitol esters, ethoxylated (less than 15 OE) C4-C18 acids, ethoxylated
(30 to 40 OE) castor oil, ethoxylated (7 to 60 OE) hydrogenated castor oil, esters, such as
glycerol palmitate, glycerol stearate, ethylene glycol stearate, diethylene glycol stearate,
propylene glycol stearate, polyethylene glycol 200 stearate and ethoxylated (2 to 15 OE) C18
esters. The hydrophobic chains can correspond to linear, iso, oxo, cyclic or aromatic
structures.
According to one embodiment, the formulation comprises at least one non-ionic surfactant
optionally combined with at least one anionic surfactant, at a total content by weight ranging
from 0.1 to 40% by weight, for example from 5% to 20% by weight or from 10% to 17% by
weight. In this case, the ratio by weight between the two surface active agents can, for
example, vary between 25/75 and 75/25.
According to one embodiment of the present invention, the polyurethane of the present
invention is formulated in the presence of more than two surface-active agents, for example
three or four surface-active agents.
According to one embodiment, the said aqueous formulation according to the invention
consists of:
1) from 2% to 50% by weight of at least one polyurethane according to the invention, as
described above, preferably from 5% to 30% by weight,
2) from 0.1% to 40% by weight of at least one surface-active agent, preferably from 5%
to 30% by weight, and
3) from 10% to 93% by weight of water, preferably from 40% to 85% by weight,
the sum of these percentages by weight being equal to 100%.
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The polyurethane according to the invention can be formulated in a water-miscible solvent.
The main reason for the addition of an organic cosolvent is to lower the viscosity of this
polyurethane in the water, in order to facilitate the handling. The polyurethane is, for
example, formulated with one or more polar solvents belonging in particular to the group
consisting of water, methanol, ethanol, propanol, isopropanol, butanols, acetone,
tetrahydrofuran or their mixtures.
Two specific examples of water-miscible organic solvent are:
- diethylene glycol monobutyl ether (also known under the name of Butyl CarbitolTM)
or ethylene or propylene glycol ether, and
- butylene glycol ether.
The viscosity of the polyurethane as it is, before it is incorporated in a paint composition, for
example, is preferably less than 10 000 mPa.s at 25°C and at 100 revolutions per minute, so
that it is easier to pour from the storage container and more rapidly incorporated in the
composition to be thickened at room temperature. The water-miscible solvent chosen from
such commercial compositions has, to date, exclusively been an organic solvent.
The polyurethane according to the invention can be coformulated in water, in the presence of
a coalescence agent. Equivalently to a solvent, the coalescence agent makes it possible to
formulate the thickener in the form of a less viscous aqueous liquid solution which can thus
be more easily employed by the formulator.
According to one embodiment, the said aqueous formulation according to the invention
consists of:
1) from 5% to 50% by weight of at least one polyurethane according to the invention, as
described above,
2) from 5% to 30% by weight of at least one solvent and/or coalescence agent and
3) from 20% to 75% by weight of water,
the sum of these percentages by weight being equal to 100%.
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According to one aspect of the invention, the aqueous formulation additionally comprises at
least one additive selected from the group consisting of a biocide, a solvent, an antifoaming
agent, a pH regulator, a coalescence agent, an encapsulating agent and their mixtures.
“Biocide” is understood to mean a chemical substance intended to destroy, repel or render
inoffensive harmful organisms, to prevent the action thereof or to combat them in any other
way, by chemical or biological action.
“Antifoaming agent” is understood to mean a substance or a formulation intended to destroy
air bubbles within a homogeneous or heterogeneous liquid medium (or at its surface) or to
prevent their formation.
“pH regulator” or “pH-regulating agent” is understood to mean a chemical compound which
makes it possible to adjust the pH to the expected value. For example, the pH-regulating
agent can increase the pH; this is the case with bases, such as NaOH. Alternatively, the pHregulating
agent can decrease the pH; this is the case with acids.
“Coalescence agent” is understood to mean an agent used in paints which makes it possible to
lower the paint minimum film formation temperature (MFFT) to a temperature suited to the
application conditions desired (for example an MFFT of 5°C for an external application).
Mention may be made, as examples of coalescence agents according to the invention, of
propylene glycol, butyl glycol, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate or 2,2,4-
trimethyl-1,3-pentanediol diisobutyrate, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate,
glycol or ether derivatives of Dowanol® type.
“Encapsulating agent” is understood to mean an agent which creates a hydrophobic
environment, for example a solvation cage. Mention may in particular be made, as
encapsulating agent, of cyclodextrin.
According to one embodiment, the said aqueous formulation according to the invention
consists of:
1) from 2% to 50% by weight of at least one polyurethane according to the invention, as
described above, preferably from 2% to 30% by weight,
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2) from 0.1% to 40% by weight of at least one surface-active agent, preferably from 5%
to 30% by weight,
3) from 10% to 93% by weight of water, preferably from 40% to 85% by weight, and
4) from 0% to 5% by weight of at least one other additive chosen from the group
consisting of a biocide, a solvent, an antifoaming agent, a pH regulator, a coalescence
agent, an encapsulating agent and their mixtures, preferably from 0.5% to 4% by weight,
the sum of these percentages by weight being equal to 100%.
Final aqueous composition
A subject-matter of the present invention is an aqueous composition comprising a
polyurethane according to the invention or an aqueous thickening formulation according to
the invention, the said final aqueous composition being selected from the group consisting of
a paint, a putty, a render coating, a thick covering, a waterproof covering, a lacquer, a
varnish, an ink, a mineral suspension (slurry), a paper coating colour, a cosmetic formulation
and a detergent formulation.
The said composition is thickened using a polyurethane or an aqueous thickening formulation
according to the invention.
Furthermore, the present invention also relates to the use of a polyurethane according to the
invention or of an aqueous thickening composition according to the invention for thickening
an aqueous composition, the said aqueous composition being selected from the group
consisting of a lacquer, a varnish, a paint, a putty, a render coating, a thick covering, a
waterproof covering, an ink, a mineral suspension (slurry), a paper coating colour, a cosmetic
formulation and a detergent formulation.
According to one embodiment, the aqueous composition to be thickened is of the following
types: gloss paint, semi-gloss paint, satin paint, or all other paints having a low pigment
volume concentration (PVC).
18
The “pigment volume concentration” is defined by the following formula:
PVC (%) = 100 x Vf / (Vf+Vb)
with Vf which represents the volume of the mineral fillers and
Vb which represents the volume of binders in the paint formulation.
According to another embodiment, the aqueous composition to be thickened is of the
following type: paint comprising a medium or high pigment volume concentration (PVC),
varying between eggshell paint and matt paint. In this case, the polyurethane thickener of the
present invention can be combined with another thickener exhibiting a pseudoplastic profile.
According to one aspect of the present invention, the aqueous composition comprises from
0.02% to 5% by weight of active material of the said thickener.
According to another aspect of the present invention, the aqueous formulation comprises
from 0.05% to 2% by weight of active material of the said thickener.
“Weight of active material” is understood to mean the dry weight of polyurethane according
to the invention, independently of the coformulation ingredients.
According to yet another aspect of the present invention, the aqueous formulation comprises
at least one mineral filler selected from the group consisting of calcium carbonate, kaolin, talc
and silicate and/or at least one pigment selected from the group consisting of titanium
dioxide, iron oxide and zinc.
According to one aspect of the invention, the aqueous formulation is a paint and comprises at
least one dispersing agent, at least one mineral pigment or filler, at least one binder, at least
one biocide, at least one antifoaming agent and optionally one surface-active agent, a surface
agent and/or a coalescence agent, a solvent.
The examples which follow make possible a better understanding of the present invention,
without limiting the scope thereof.
19
EXAMPLE
The viscosity of the test formulations or of the paint formulations is determined at different
rate gradients:
- at a low rate gradient, the Brookfield viscosity, which is measured using a RVT-type
Brookfield viscometer, in the unstirred flask, at a temperature of 25°C and at two rotational
speeds of 10 and 100 revolutions per minute with the appropriate spindle. Reading is carried
out after rotating for one minute. Two Brookfield viscosity measurements, respectively
denoted µBk10 and µBk100 (mPa.s), are thus obtained,
- at a moderate rate gradient, the Stormer viscosity, denoted µS (Krebs units), and
- at a high rate gradient: the Cone Plan viscosity or ICI viscosity, denoted µI (mPa.s).
Example 1
This example illustrates the use of a thickener according to the invention in a solvent-free
aqueous satin paint formulation, the composition of which is given in Table 1 below.
It illustrates the thickening power of a polyurethane according to the invention (test 1-4),
employing a compound of formula (I). At the same time, this example also illustrates
polyurethanes outside the invention (Tests 1-1 to 1-3).
Text 1-1 (outside the invention)
The said polyurethane results from the condensation of, expressed as % by weight with
respect to the total weight of the polyurethane:
- 2.7% by weight of a linear C8 alcohol,
- 92.8% by weight of PEG 10 000 and
- 4.5% by weight of isophorone diisocyanate (IPDI).
Test 1-2 (outside the invention)
The said polyurethane results from the condensation of, expressed as % by weight with
respect to the total weight of the polyurethane:
20
- 4.6% by weight of a linear C11 alcohol,
- 89.4% by weight of PEG 10 000 and
- 6.0% by weight of isophorone diisocyanate (IPDI).
Test 1-3 (outside the invention)
The said polyurethane results from the condensation of, expressed as % by weight with
respect to the total weight of the polyurethane:
- 4.2% by weight of an isoborneol compound (a cyclic compound without unsaturation and
without a spacer arm),
- 89.8% by weight of PEG 10 000 and
- 6.0% by weight of isophorone diisocyanate (IPDI).
Test 1-4 (according to the invention)
The said polyurethane results from the condensation of, expressed as % by weight with
respect to the total weight of the polyurethane:
- 4.5% by weight of a bicycloheptene compound of formula:
(Nopol or 2-(6,6-dimethylbicyclo[3.1.1]hept-2-en-2-yl)ethanol),
- 89.5% by weight of PEG 10 000 and
- 6.0% by weight of isophorone diisocyanate (IPDI).
The four polyurethanes are formulated in water in the presence of a surfactant which is a
C8-C10 fraction of an alkoxylated fatty alcohol (Simulsol® OX1008). The
PU/surfactant/water ratios are 20/5/75. As the paint composition comprises 44 g of
polyurethane for a total weight of 1000 g of paint (see Table 1), the dose of thickener in the
final composition is 0.88% of active agent (or of active ingredient) by weight, taking into
account the formulation of the thickeners tested (surfactants and water).
All the results have been combined in Table 2 below.
21
For each of the tests, the µBk10, µBk100, µI (in mPa.s) and µS (in Krebs units, KU, measured
with the standard module) viscosities were determined according to the methods described
above at T = 0 and at T = 24 h at room temperature.
Constituent of the paint Weight (g)
Water 191
Dispersant (Coadis® BR3) 6
Biocide (Acticide® MBS) 2
Antifoaming agent (Airex® 901W) 2
TiO2 (RHD2) 188
CaCO3 (Omyacoat® 850OG) 130
Binder (Acronal 290D) 416
Monopropylene glycol 10
Texanol 10
Antifoaming agent (Tego® 825) 1
PU thickener (according to the tests) 44
Table 1
Results
Test 1-1 Test 1-2 Test 1-3 Test 1-4
OInv OInv OInv Inv
T = 0
µBk10 2 040 13 500 1 000 2 600
µBk100 1 108 7 390 514 1 428
µS 83 141 66 89
µI 2.3 3.5 1.5 3.0
T = 24 h
µBk10 2 320 18 000 1 040 3 080
µBk100 1 324 11 080 589 1 816
µS 88 142 70 97
µI 2.4 3.5 1.5 3.1
Table 2
OInv: Outside the Invention
Inv: According to the Invention
A significantly improved thickening at a high rate gradient (µI) is observed in the paint
formulation according to Test 1-4 (according to the invention), in comparison with that of
Test 1-1 and of Test 1-3 (outside the invention).
The polyurethane of Test 1-2 generates a high ICI viscosity but it is coupled to excessively
high viscosities at low and at medium rate gradients. The profile of this polyurethane is not
sufficiently newtonian.
22
The polyurethane according to the present invention exhibits a rheological profile of
newtonian type: high viscosity at a high shear gradient and low viscosity at a low shear
gradient.
Example 2
This example illustrates the use of a thickener outside the invention, of HASE type, in a
solvent-free aqueous satin paint formulation, the composition of which is the same as that of
Example 1 above.
Test 2-1 (outside the invention)
This test employs a HASE acrylic thickener consisting of, expressed as % by weight with
respect to the total weight of the compound:
- 37.9% by weight of methacrylic acid;
- 54.8% by weight of ethyl acrylate; and
- 7.3% by weight of a monomer which is an ethoxylated methacrylate which comprises,
at the chain end, a bicycloheptene compound of Nopol or
2-(6,6-dimethylbicyclo[3.1.1]hept-2-en-2-yl)ethanol type, it being possible for the
formula of this monomer to be represented in the following way:
Results
Test 2-1
Dose: 0.17% of
active agent
OInv
T = 0
µBk10 13 800
µBk100 3 250
µS 104
µI 0.4
T = 24 h
µBk10 33 400
µBk100 5 740
µS 119
µI 0.4
Table 3
23
The HASE thickener according to this test exhibits a rheological profile of pseudoplastic
type: high viscosity at a low shear gradient. It does not correspond to the subject-matter of the
present invention, that is to say to thus confer, on the aqueous composition which contains it,
a good dynamic behaviour, that is to say a high viscosity at a high shear gradient.