Process for preparinq a complex calcium sulphonate clrease
Technical field
The present invention relates to the field of greases, and more particularly to the field of
5 greases thickened with a calcium sulphonate complex soap. The invention relates to a
single-phase process for the preparation of a calcium sulphonate complex grease. More
particularly, the invention relates to a single-phase process for the preparation of a
calcium sulphonate complex grease in the absence of boric acid and comprising the
implementation of at least one step under pressure. The process according to the
lo invention makes it possible to reduce the manufacturing time of a calcium sulphonate
complex grease, while maintaining or even improving the manufacturing yield.
The present invention also relates to a production unit for the implementation of such a
process.
The present invention also relates to a calcium sulphonate complex grease capable of
15 being obtained by a single-phase process in the absence of boric acid and comprising the
implementation of at least one step under pressure. The grease according to the invention
has in particular good mechanical properties as well as improved thermal resistance and
extreme pressure properties.
20 Prior art
Numerous applications exist where the liquid lubricants are not suitable because they
"drift" with respect to the lubrication point. These are in particular rolling-contact bearings
and slider bearings, open gear sets, metal cables and chain drives, and more generally for
applications not comprising a sealing system.
25 For these applications, lubricating greases are used, which are solid or semi-fluid
substances resulting from the dispersion of a thickener in a liquid lubricant, optionally
incorporating additives which give them specific properties.
The thickeners can be organic or inorganic compounds.
Among the organic thickeners used in the manufacturing of greases, the fatty acid metal
30 salts and polycarbamides (polyureas) can in particular be mentioned.
The vast majority of the lubricating greases are prepared with thickeners of the fatty acid
metal salt type. The fatty acid is dissolved in the base oil at a relatively high temperature,
and then an appropriate metal hydroxide is added. After evaporating the water which
forms during the reaction by boiling, cooling is carried out for a precise amount of time, in
35 order to form the soap lattice.
Lithium, sodium, calcium, barium, titanium or aluminium hydroxides, or certain aluminium
trimers, are suitable for example as metal compounds for manufacturing grease. Longchain
fatty acids, of the order of C14 to C28, mainly C18, generally originate from
vegetable (castor oil for example), or animal (for example tallow) oils. They can be
5 hydrogenated or hydroxylated. The best-known derivative is 12-hydroxystearic acid
originating from ricinoleic acid.
In combination with the long-chain fatty acids, it is also possible to use short-chain acids,
typically comprising between 6 and 12 carbon atoms, such as for example azelaic acid,
benzoic acid.
lo Other, in particular inorganic, thickeners such as, for example, bentonite and silica gel can
be used.
For applications where the grease is located in an unconfined enclosure (for example
open gear sets in cement works etc.), the greases thickened with metal soaps, and in
particular with simple or complex metal soaps of aluminium are greatly superior to the
15 other greases.
The greases thickened with polyureas do not have sufficient mechanical stability, in
particular due to their thixotropic nature, which leads to their becoming destructured under
mechanical stresses.
The inorganic thickeners also present problems of mechanical strength and water
20 resistance.
The greases thickened with a calcium sulphonate complex soap (or calcium sulphonate
complex greases) have been known and used for many years, as they have numerous
properties such as extreme-pressure and anti-wear properties, mechanical resistance,
25 corrosion resistance, water resistance and thermal stability, in particular at high
temperatures. This type of grease is obtained from the conversion of an overbased
calcium sulphonate in the presence in particular of at least one base oil, at least two
different acids, one of which is a fatty acid and at least one base (cf. Gareth Fish et al,
"Calcium Sulphonate Grease Formulation", 2012).
30 They find their application in numerous industrial fields, in particular automobiles, the steel
industry, mining operations or also paper manufacturing.
Several processes for the preparation of calcium sulphonate complex greases have
already been described or implemented.
Single-phase processes for the preparation of calcium sulphonate complex greases have
in particular been described; the objective being to reduce the preparation time while
maintaining or even improving the yield.
5 By single-phase preparation process, is meant more particularly a process for the
preparation of a calcium sulphonate complex grease comprising a single continuous rise
in temperature and a single fall in temperature.
Document US 5338467 describes a process for the preparation of a calcium sulphonate
10 complex grease, the particles of calcium carbonate being in the form of calcite, said
process being able to be implemented in a single phase and being able to include
pressurizing the mixture constituting the grease. However, the examples of the process
cited in this document all describe the presence of boric acid. The same is true for
document US 201 31220704.
15
Document US 4560489 describes a process for the preparation of a calcium sulphonate
complex grease being able to be implemented in one phase and can include pressurizing
the mixture constituting the grease. Moreover, this document describes that this process
can be implemented in the absence of boric acid. However, this pressurization is carried
20 out by the introduction of C02 into the reactor comprising the mixture.
Moreover, the examples described in this document show the importance of the presence
of boric acid on the thermal stability properties of the grease obtained at the end of the
process. In fact, in the absence of boric acid, the thermal stability of the grease obtained
at the end of the process is very low, whereas this stability improves with the increase in
25 the boric acid content.
Document CN 102703185 describes a single-phase process for the preparation of a
calcium sulphonate complex grease and the mixing of different components in a reactor
under pressure.
30 However, the process described in this document includes the presence of boric acid.
Moreover, the pressurization of the mixture in the reactor is obtained by the addition of
CO*.
Moreover, the process described in this document requires the presence of a co-solvent
of the methanol or ethanol type, these co-solvents being able to give off volatile organic
35 compounds (VOCs). Now, it is known that these compounds can represent a potential
danger to human health.
It would therefore be desirable to have a process available for the preparation of a calcium
sulphonate complex grease, which can be implemented both in a single phase and in the
absence of boric acid. In fact, boric acid is a product classed as CMR (carcinogenic,
mutagenic or toxic to reproduction) and therefore represents a potential danger to human
5 health.
It would also be desirable to have available a single-phase process for the preparation of
a calcium sulphonate complex grease making it possible to significantly reduce the
preparation time and maintain or even increase the yield, while retaining or even
10 improving the properties of the grease.
It would also be desirable to have available a single-phase process for the preparation of
a calcium sulphonate complex grease, comprising at least one step of pressurizing the
mixture constituting the grease, this pressurization not requiring the addition of gas, and in
15 particular of carbon dioxide.
It would also be desirable to have available a single-phase process for the preparation of
a calcium sulphonate complex grease, not requiring the addition of solvents or co-solvents
which give off VOCs.
20
An objective of the present invention is to provide a process overcoming all or some of the
aforementioned drawbacks.
Another objective of the invention is to provide a simple process which can be easily
25 implemented.
Another objective of the invention is to provide a calcium sulphonate complex grease the
thermal stability of which is improved.
30 Summary of the invention
Therefore an object of the invention is a process for the preparation of a calcium
sulphonate complex grease comprising at least the following steps:
a) preparing, in a reactor, a calcium sulphonate complex soap comprising calcium
carbonate, the calcium carbonate being presented in the form of calcite,
b) closing the reactor,
c) raising the temperature in the reactor to a temperature of at least 130°C under a
pressure of at least 400 kPa,
d) depressurizing and removing the water contained in the reactor,
e) cooling the reactor,
said process not comprising the addition of boric acid.
Surprisingly, the applicant has found that it is possible to prepare a calcium sulphonate
complex grease by a single-phase process including a step of pressurizing the mixture
10 constituting the grease, without the addition of boric acid or co-solvent.
Thus, the present invention allows implementation of a process for the preparation of a
calcium sulphonate complex grease making it possible to maintain or even improve the
yield, while reducing the preparation time.
15
Advantageously, the process according to the invention makes it possible to reduce or
even eliminate the risks to human health.
Advantageously, the process according to the invention makes it possible to reduce or
20 even eliminate the risks of foaming phenomena.
Advantageously, the calcium sulphonate complex grease obtained at the end of the
process according to the invention has equivalent properties, in particular mechanicalstability
and anti-wear properties, compared with the existing calcium sulphonate complex
25 greases.
Advantageously, the calcium sulphonate complex grease obtained at the end of the
process according to the invention has improved properties, in particular therrnalresistance
and extreme-pressure properties, compared with the existing calcium
30 sulphonate complex greases.
Thus, the invention also relates to a calcium sulphonate complex grease capable of being
obtained by a process comprising at least the following steps:
a) preparing, in a reactor, a calcium sulphonate complex soap comprising calcium
carbonate, the calcium carbonate being presented in the form of calcite,
b) closing the reactor,
c) raising the temperature in the reactor to a temperature of at least 130°C under a
pressure of at least 400 kPa,
d) depressurizing and removing the water contained in the reactor,
e) cooling the reactor,
5 said process not comprising the addition of boric acid.
The invention also relates to a production unit for the implementation of a process
described above comprising:
- a reactor (I)pr ovided with at least one stirring device (2) and at least one
pressurizing (3) and heating (4) means,
- a tank (5) for receiving said calcium sulphonate complex grease,
- at least one means (6) for transferring said calcium sulphonate complex grease
from the reactor ( I ) to the receiving tank (5).
15 Detailed description
The percentages indicated below correspond to the percentages by mass of active
material with respect to the mass of the starting reagents.
20 The process for the preparation of a calcium sulphonate complex grease according to the
invention comprises at least the following steps:
a) preparing, in a reactor, a calcium sulphonate complex soap comprising calcium
carbonate, the calcium carbonate being presented in the form of calcite,
b) closing the reactor,
25 c) raising the temperature in the reactor to a temperature of at least 130°C and
under a pressure of at least 400 kPa,
d) depressurizing and removing the water contained in the reactor,
e) cooling the reactor,
said process not comprising the addition of boric acid.
30
In an embodiment of the invention, step a) comprises the steps of:
a.i) mixing, in the reactor, at least one base oil and at least one overbased calcium
sulphonate,
a.ii) adding at least one first carboxylic acid comprising at least 12 carbon atoms,
and optionally at least one -OH group, at a temperature of at least 20°C
a.iii) adding at least one sulphonic acid comprising at least 12 carbon atoms at a
temperature of at least 50°C,
a.iv) adding water at a temperature of at least 50°C
a.v) adding at least one second carboxylic acid comprising at least 2 carbon atoms
at a temperature of at least 50°C,
a.vi) closing the reactor,
a.vii) raising the temperature to a temperature of at least 80°C,
a.viii) opening the reactor,
a.ix) adding lime at a temperature of at least 90°C.
10 In another embodiment of the invention, steps a.i) to a.iii) can be implemented in a
different order.
Thus, the sulphonic acid comprising at least 12 carbon atoms can first be added to the
mixture of step a.i) at a temperature of at least 50°C, then carboxylic acid comprising at
least 12 carbon atoms, and optionally at least one -OH group can be added to the mixture
15 thus obtained.
In a preferred embodiment of the invention, the order of implementation of steps a.iv) to
a.ix) is fixed and therefore cannot be modified.
Surprisingly, the applicant has found that it is possible to reduce or even eliminate the
20 risks of foaming in the reactor when the order of implementation of steps a.iv) to a.ix) is
strictly adhered to.
Thus, by this limitation or even this elimination of the risks of foaming, the process
according to the invention makes it possible to limit the risks of product loss during its
implementation and therefore to optimize its yield.
2 5
Step a.i)
The base oil of step a.i) according to the present invention can be selected from oils of
mineral, synthetic or natural origin as well as mixtures thereof.
30 The mineral or synthetic oils generally used for the preparation of grease belong to one of
Groups I to V according to the classes defined in the API classification (or their
equivalents according to the ATlEL classification) as summarized in Table I below. The
API classification is defined in American Petroleum Institute 1509 "Engine oil Licensing
and Certification System" 17th edition, September 2012.
35 The ATlEL classification is defined in "The ATIEL Code of Practice", number 18,
November 2012.
Table I
The mineral base oils include any type of bases obtained by atmospheric and vacuum
5 distillation of crude oil, followed by refining operations such as solvent extraction,
deasphalting, solvent dewaxing, hydrotreatment, hydrocracking and hydroisomerization,
hydrofinishing.
The synthetic base oils can be selected from the esters, silicones, glycols, polybutene,
polyalphaolefines (PAOs), alkylbenzene or alkylnaphthalene.
10 The base oils can also be oils of natural origin, for example the esters of alcohols and
carboxylic acids, which can be obtained from natural resources such as sunflower,
rapeseed, palm, soya oil etc.
Viscosity index
8O_ 0.03%
< 0.03%
10.03%
Group I Mineral oils
Group II Hydrocracked oils
Group Ill Hydrocracked or
hydro-isomerized oils
In step a.i) of the process according to the invention, at least one overbased calcium
sulphonate is mixed with the base oil present in the reactor.
Saturates
content
< 90%
2 90%
Group IV
Group V
PA0 (Poly Alpha Olefins)
Esters and other bases not included in bases of
Groups I to IV
This compound is known to a person skilled in the art as a detergent and is constituted by
a calcium salt of a sulphonate.
When the metal, i.e. calcium, is in excess (in a quantity greater than the stoichiometric
quantity with respect to the anionic group (s) of the detergent), we are dealing with so-
5 called overbased detergents.
The excess metal providing the detergent with its overbased character is presented in the
form of metal salts which are insoluble in oil, for example carbonate, hydroxide, oxalate,
acetate, glutamate, preferentially carbonate.
In the same overbased detergent, the metals of these insoluble salts can be the same as
10 those of the soluble detergents in the base oil or they can be different. They are
preferentially selected from calcium, magnesium, sodium or barium.
The overbased detergents are thus presented in the form of micelles composed of
insoluble metal salts maintained in suspension in the base oil by the detergents in the
form of oil-soluble metal salts.
15 Preferably, the overbased calcium sulphonate is an overbased calcium sulphonate with
calcium carbonate.
It is known that the BN (Base Number) of the overbased calcium sulphonates is high,
preferably greater than 150 mg KOHIg of detergent.
20 The BN is measured according to the standard ASTM D-2896.
In an embodiment of the invention, the overbased calcium sulphonate of step a.i) has a
BN of at least 300 mg KOHIg of detergent, preferably ranging from 300 to 500 mg KOHIg
of detergent, advantageously from 350 to 450 mg KOHIg of detergent.
25
In a preferred embodiment of the invention, the content by weight of calcium sulphonate
ranges from 35 to 55%, preferably from 40 to 50% with respect to the total weight of the
starting reagents.
In another preferred embodiment of the invention, the content by weight of base oil ranges
30 from 45 to 65%, preferably from 50 to 60% with respect to the total weight of the starting
reagents.
In an embodiment of the invention, the mixture of step a.i) can be heated to a temperature
of at least 60°C, preferably at least 7WC, advantageously from 70 to 80°C.
3 5
Step a.ii)
In step a.ii) of the process according to the invention at least one carboxylic acid
comprising at least 12 carbon atoms, and optionally at least one -OH group, is added at a
temperature of at least 20°C.
5
In an embodiment of the invention, the carboxylic acid of step a.ii) is selected from the
carboxylic acids or the hydroxycarboxylic acids comprising from 12 to 24 carbon atoms,
preferably from 16 to 20 carbon atoms.
10 In a preferred embodiment of the invention, the carboxylic acid of step a.ii) is selected
from the hydroxycarboxylic acids comprising from 12 to 24 carbon atoms, preferably from
16 to 20 carbon atoms.
Advantageously, the carboxylic acid of step a.ii) is 12-hydroxystearic acid.
15
In a preferred embodiment of the invention, the content by weight of carboxylic acid
ranges from 1 to 4%, preferably from 1.5 to 3% with respect to the total weight of the
starting reagents.
20 In another embodiment, step a.ii) also comprises the addition of an anti-foaming additive.
The anti-foaming additives used in greases are well known to a person skilled in the art
and can be in particular selected from the silicon-containing compounds.
25 In a preferred embodiment of the invention, the content by weight of anti-foaming additive
ranges from 0.01 to 1% with respect to the total weight of the starting reagents.
In an embodiment of the invention, step a.ii) is implemented at a temperature ranging from
20 to 60°C, preferably from 40 to 60°C.
30 Step a.iii)
In step a.iii) of the process according to the invention at least one sulphonic acid
comprising at least 12 carbon atoms is added at a temperature of at least 50°C.
The liposoluble sulphonic acids which can be used in the process according to the
invention are well known for preparing thick thixotropic compositions using a calcium
sulphonate complex and in which the calcium carbonate is in the form of calcite crystals.
5 In an embodiment of the invention, the sulphonic acid of step a.iii) can be selected from
the sulphonic acids of formula (I):
[(RI-A)~-SO~M~I
(1)
in which:
R1 represents a saturated or unsaturated, linear or branched alkyl group,
comprising at least 10 carbon atoms, preferably from 10 to 30 carbon
atoms, advantageously from 10 to 15 carbon atoms;
A represents an aromatic hydrocarbon-containing group, preferably a
group selected from benzene, naphthalene or phenanthrene;
M represents a hydrogen atom or a calcium atom;
x represents 1 or 2;
y represents 1 or 2;
when M represents a calcium atom, y represents 2,
when M represents a hydrogen atom, y represents 1.
20
In an embodiment of the invention, R1 represents a saturated, linear or branched alkyl
group comprising at least 10 carbon atoms, preferably from 10 to 30 carbon atoms, more
preferentially from 10 to 15 carbon atoms, advantageously 12 carbon atoms.
In another embodiment of the invention, A represents a benzene group.
25 In another embodiment of the invention, x is equal to 1.
In another embodiment of the invention, M represents a hydrogen atom and y is equal to
1.
In a preferred embodiment of the invention, the sulphonic acid of step a.iii) is
30 dodecylbenzene sulphonic acid.
In another preferred embodiment of the invention, the content by weight of sulphonic acid
ranges from 0.5 to 4%, preferably from 1 to 3% with respect to the total weight of the
starting reagents.
3 5
In an embodiment of the invention, step a.iii) is implemented at a temperature ranging
from 50 to 60°C preferably from 50 to 55°C.
Step a.iv)
5
In step a.iv) of the process according to the invention water is added.
In an embodiment of the invention, the content by weight of water ranges from 1 to lo%,
preferably from 3 to 8% with respect to the total weight of the starting reagents.
10
In another embodiment of the invention, step a.iv) is implemented at a temperature
ranging from 50 to 60°C.
Step a.v)
15
In step a.v) of the process according to the invention at least one carboxylic acid
comprising at least 2 carbon atoms is added at a temperature of at least 50°C.
In an embodiment of the invention, the carboxylic acid of step a.v) can be selected from
20 the carboxylic acids comprising from 2 to 6 carbon atoms, preferably from 2 to 4 carbon
atoms.
In a preferred embodiment of the invention, the carboxylic acid of step a.v) is acetic acid.
25 In another preferred embodiment of the invention, the content by weight of carboxylic acid
ranges from 0.1 to I%, preferably from 0.4 to 0.8% with respect to the total weight of the
starting reagents.
In an embodiment of the invention, step a.v) is implemented at a temperature of at least
30 60°C, preferably ranging from 60 to 65°C.
In a preferred embodiment of the invention, the carboxylic acid comprising from 2 to 6
carbon atoms, preferably from 2 to 4 carbon atoms is slowly added to the mixture present
in the reactor.
By slowly addition according to the invention, is meant the fact that not all the quantity of
carboxylic acid is added to the mixture present in the reactor in a single go andlor over a
very short period of time.
In fact, the applicant has found that the fact of slowly adding the carboxylic acid
5 comprising at least 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, to the mixture
present in the reactor makes it possible to reduce or even eliminate the phenomena of
foaming of the mixture present in the reactor.
Step a.vii)
10
In step a.vii) of the process according to the invention the temperature is raised to a
temperature of at least 80°C.
In an embodiment of the invention, step a.vii) is implemented at a temperature of at least
15 85"C, preferably from 85 to 95°C.
In a preferred embodiment of the invention, the temperature is maintained at 90°C for a
duration of at least 15 min, preferably ranging from 15 min to 1 h.
20 Step a.ix)
In step a.ix) of the process according to the invention lime is added at a temperature of at
least 90°C.
By lime according to the invention, is meant more particularly calcium hydroxide.
25
The lime can be presented in solid form such as a powder, or in liquid form such as an
aqueous solution of lime.
In a preferred embodiment of the invention, the lime is presented in the form of a powder.
30
In another preferred embodiment of the invention, the content by weight of added lime
ranges from 0.1 to 4%, preferably from 0.5 to 2.5% with respect to the total weight of the
starting reagents.
35 In an embodiment of the invention, step a.ix) is implemented at a temperature ranging
from 90 to 95°C.
In another embodiment of the invention, step a.ix) can also comprise moreover the
addition of at least one base oil.
5 In a preferred embodiment of the invention, the base oil added in step a.ix) is identical to
the base oil of step a.i)
In a preferred embodiment of the invention, the content by weight of base oil added
ranges from 1 to 20%, preferably from 5 to 15Oh with respect to the total weight of the
lo starting reagents.
Step C)
In step c) of the process according to the invention the temperature in the reactor is raised
15 to a temperature of at least 130°C under a pressure of at least 400 kPa.
In an embodiment of the invention, the temperature of step c) ranges from 130 to 160°C,
preferably from 130 to 150°C, advantageously 140°C.
In a preferred embodiment of the invention, raising the temperature of step c) is carried
20 out according to a temperature gradient ranging from 1 to 3"CImin.
In another preferred embodiment of the invention, the pressure of step c) ranges from 400
to 700 kPa, preferably from 500 to 650 kPa.
25 In a more preferred embodiment of the invention, the pressure in the reactor in step c) is
maintained at a pressure ranging from 500 to 650 kPa, preferably close to 600 kPa, at a
temperature ranging from 130 to 150°C, preferably close to 140°C, for a duration of at
least 15 min, preferably ranging from 15 to 80 min, advantageously from 15 to 60 min.
30 Surprisingly, the applicant has discovered that the implementation of step c) of the
process according to the invention under such conditions allows an optimal conversion to
calcite.
By optimal conversion, is meant that all of the amorphous calcium carbonate has been
converted to calcite and that therefore no more calcium carbonate remains in the
35 amorphous form at the end of the process.
The conversion of the amorphous calcium carbonate to calcite can be monitored by an
infra-red spectrometry measurement method.
Without being bound by a particular theory, this complete conversion of the amorphous
calcium carbonate to calcium carbonate in the form of calcite could be explained by the
5 combination of a first reaction carried out in the absence of pressure, in particular in step
a.vi) and of a second reaction carried out at a pressure of at least 400 kPa (after step
a.ix)).
In addition, the implementation of step c) of the process according to the invention in the
lo absence of co-solvents which give off VOCs makes it possible to obtain a process for the
preparation of a calcium sulphonate complex grease which poses very little or no danger
to human health, and more particularly to the health of the people involved in its
implementation.
15 Step d)
In step d) of the process according to the invention depressurizing and removing the water
contained in the reactor is carried out.
Depressurizing can be implemented by different means well known to a person skilled in
20 the art.
In an embodiment of the invention, depressurizing is implemented by opening the reactor.
In a preferred embodiment of the invention, the duration of depressurizing is at least 1 h,
preferably ranging from 1 h to 3 h.
25 In another preferred embodiment of the invention, depressurizing is implemented at a
temperature of at least 13OoC, preferably ranging from 130 to 150°C, advantageously
close to 140°C.
In a more preferred embodiment of the invention, depressurizing is implemented for a
30 duration of at least 1 h and at a temperature of at least 13OoC, preferably ranging from
130 to 1 50°C, advantageously close to 140°C.
Implementation of depressurizing under such temperature and time conditions allows in
particular better control of the final consistency of the grease with the objective of
35 obtaining a Grade 2 grease.
During the depressurizing, all or part of the water contained in the mixture present in the
reactor is removed.
In order to remove all of the water contained in the mixture present in the reactor, a
5 drawing off under vacuum can be applied to the mixture present in the reactor afler
depressurizing.
Thus, in a preferred embodiment of the invention, during the implementation of step d),
depressurizing is followed by the application of a drawing off under vacuum of the mixture
10 present in the reactor.
The drawing off under vacuum can be implemented by different means, for example using
a vacuum pump or a deaerator.
15 In an embodiment of the invention, the drawing off under vacuum is implemented using at
least one deaerator.
The process according to the invention can also comprise a step d.i) implemented afler
step d) and before step e) and comprising the supplementary addition of at least one base
oil.
20 In a preferred embodiment of the invention, the base oil added in step d.i) is identical to
the base oil of step a.i).
In a preferred embodiment of the invention, the content by weight of base oil ranges from
1 to 20%, preferably from 5 to 15% with respect to the total weight of the starting
25 reagents.
Step e)
In step e) of the process according to the invention the reactor is cooled.
30
Cooling the reactor can be implemented by different means, for example by maintaining
the reactor at ambient temperature, by placing a water circulation cooling device around
the reactor, by placing a refrigerant device around the reactor etc.
35 In an embodiment of the invention, the cooling is implemented by maintaining the mixture
present in the reactor at ambient temperature.
In an embodiment of the invention, the cooling of step e) is implemented by lowering the
temperature to a temperature of less than or equal to 90"C, preferably from 70 to 90°C.
5 In a preferred embodiment of the invention, the cooling of step e) is implemented
according to a drop ranging from 1 to J0Clmin, preferably close to 2"Clmin.
Other steps
10 The process according to the invention can also comprise a step f) implemented afler step
e) and comprising the addition of at least one supplementary additive, optionally followed
by a step of grinding the product obtained.
The additive can be selected from the additives well known to a person skilled in the art.
15 such as antioxidant additives, for example antioxidants of the phenolic or amine type, antirust
additives, such as for example dodecylsuccinic acid, calcium phenates, calcium
salicylates, oxidized waxes or amine phosphates, corrosion-inhibiting additives such as
tolyltriazoles or dimercaptothiadiazole derivatives, anti-foaming additives or mixtures
thereof.
20
In an embodiment of the invention, the additive is selected from the antioxidants, the anticorrosion
agents or mixtures thereof.
In another embodiment of the invention, the content by weight of additive ranges from 0.1
25 to lo%, preferably from 0.1 to 5% with respect to the total weight of the starting reagents.
In an embodiment of the invention, the additive of step f) is added at a temperature of at
most 90°C, preferably ranging from 60 to 90°C, advantageously from 70 to 90°C.
30 The invention also relates to a process for the preparation of a calcium sulphonate
complex grease comprising at least the following steps:
a) preparing, in a reactor, a calcium sulphonate complex soap comprising calcium
carbonate, the calcium carbonate being presented in the form of calcite, said
preparation comprising the steps of:
3 5 a.i) mixing, in the reactor, at least one base oil and at least one overbased
calcium sulphonate,
a.ii) adding at least one carboxylic acid comprising at least 12 carbon
atoms, and optionally at least one -OH group, at a temperature of at least
2O0C,
a.iii) adding at least one sulphonic acid comprising at least 12 carbon
atoms at a temperature of at least 50°C,
a.iv) adding water at a temperature of at least 50°C,
a.v) adding at least one carboxylic acid comprising at least 2 carbon atoms
at a temperature of at least 50°C,
a.vi) closing the reactor,
a.vii) raising the temperature to a temperature of at least 80°C,
a.viii) opening the reactor,
a.ix) adding lime at a temperature of at least 90°C,
b) closing the reactor,
c) raising the temperature in the reactor to a temperature of at least 130°C under a
pressure of at least 400 kPa,
d) depressurizing and removing the water contained in the reactor,
e) cooling the reactor,
said process not comprising the addition of boric acid.
20 The invention also relates to a process for the preparation of a calcium sulphonate
complex grease comprising at least the following steps:
a) preparing, in a reactor, a calcium sulphonate complex soap comprising calcium
carbonate, the calcium carbonate being presented in the form of calcite, said
preparation comprising the steps of:
a.i) mixing, in the reactor, at least one base oil and at least one overbased
calcium sulphonate,
a.ii) adding at least one carboxylic acid comprising at least 12 carbon
atoms, and optionally at least one -OH group, at a temperature of at least
2O0C,
a.iii) adding at least one sulphonic acid comprising at least 12 carbon
atoms at a temperature of at least 50°C,
a.iv) adding water at a temperature of at least 50°C,
a.v) adding at least one carboxylic acid comprising at least 2 carbon atoms
at a temperature of at least 50°C,
a.vi) closing the reactor,
a.vii) raising the temperature to a temperature of at least 80°C,
a.viii) opening the reactor,
a.ix) adding lime at a temperature of at least 90°C,
b) closing the reactor,
c) raising the temperature in the reactor to a temperature of at least 130°C under a
pressure of at least 400 kPa,
d) depressurizing and removing the water contained in the reactor,
e) cooling the reactor,
f) adding at least one supplementary additive to the reactor,
said process not comprising the addition of boric acid.
10
All the characteristics and preferences presented for steps a), a.i), a.ii), a.iii), ah), a.v),
a.vii), a.ix), b), c), d), e) and f) also apply to the processes above.
The invention also relates to a process for the preparation of a calcium sulphonate
15 complex grease comprising at least the following steps:
a) preparing, in a reactor, a calcium sulphonate complex soap comprising calcium
carbonate, the calcium carbonate being presented in the form of calcite, said
preparation comprising the steps of:
a.i) mixing, in the reactor, from 45 to 65% by weight of at least one base oil
and from 35 to 55% by weight of at least one overbased calcium
sulphonate, with respect to the total weight of the starting reagents,
a.ii) adding from1 to 4% by weight, with respect to the total weight of the
starting reagents, of at least one carboxylic acid comprising at least 12
carbon atoms, and optionally at least one -OH group, at a temperature of
at least 2OoC,
a.iii) adding from 0.5 to 4% by weight, with respect to the total weight of the
starting reagents, of at least one sulphonic acid comprising at least 12
carbon atoms at a temperature of at least 5OoC,
ah) adding from 1 to 10% by weight, with respect to the total weight of the
starting reagents, of water at a temperature of at least 50°C,
a.v) adding from 0.1 to 1% by weight, with respect to the total weight of the
starting reagents, of at least one carboxylic acid comprising at least 2
carbon atoms at a temperature of at least 50°C,
a.vi) closing the reactor,
a.vii) raising the temperature to a temperature of at least 80°C,
a.viii) opening the reactor,
a.ix) adding from 0.1 to 4% by weight, with respect to the total weight of the
starting reagents, of lime at a temperature of at least 90°C,
b) closing the reactor,
c) raising the temperature in the reactor to a temperature of at least 130°C and
under a pressure of at least 400 kPa,
d) depressurizing and removing the water contained in the reactor,
e) cooling the reactor,
said process not comprising the addition of boric acid.
10 The invention also relates to a process for the preparation of a calcium sulphonate
complex grease comprising at least the following steps:
a) preparing, in a reactor, a calcium sulphonate complex soap comprising calcium
carbonate, the calcium carbonate being presented in the form of calcite, said
preparation comprising the steps of:
a.i) mixing, in the reactor, from 45 to 65% by weight of at least one base oil
and from 35 to 55% by weight of at least one overbased calcium
sulphonate, with respect to the total weight of the starting reagents,
a.ii) adding from 1 to 4% by weight, with respect to the total weight of the
starting reagents, of at least one carboxylic acid comprising at least 12
carbon atoms, and optionally at least one -OH group, at a temperature of
at least 20°C,
a.iii) adding from 0.5 to 4% by weight, with respect to the total weight of the
starting reagents, of at least one sulphonic acid comprising at least 12
carbon atoms at a temperature of at least 50°C,
a.iv) adding from 1 to 10% by weight, with respect to the total weight of the
starting reagents, of water at a temperature of at least 50°C,
a.v) adding from 0.1 to 1% by weight, with respect to the total weight of the
starting reagents, of at least one carboxylic acid comprising at least 2
carbon atoms at a temperature of at least 50°C,
a.vi) closing the reactor,
a.vii) raising the temperature to a temperature of at least 80°C,
a.viii) opening the reactor,
a.ix) adding from 0.1 to 4% by weight, with respect to the total weight of the
starting reagents, of lime at a temperature of at least 90°C,
b) closing the reactor,
c) raising the temperature in the reactor to a temperature of at least 130°C under a
pressure of at least 400 kPa,
d) depressurizing and removing the water contained in the reactor,
e) cooling the reactor,
f) adding from 0.1 to 10% by weight, with respect to the total weight of the starting
reagents, of at least one supplementary additive to the reactor,
said process not comprising the addition of boric acid.
All the characteristics and preferences presented for steps a), a.i), a.ii), a.iii), ah), a.v),
10 a.vii), a.ix), b), c), d), e) and f) also apply to the processes above.
The invention also relates to a calcium sulphonate grease capable of being obtained by a
process described above.
15 Depending on their consistency, the greases are divided into 9 NLGl (National Lubricating
Grease Institute) classes or grades commonly used in the field of greases. These grades
are indicated in the table below.
Table II: Grade
20 In an embodiment, the greases according to the invention have a consistency comprised
between 220 and 430 tenths of a millimetre according to the standard ASTM D217, in
NLGl grade
000
00
0
1
2
3
4
5
6
order to cover the grades 00, 0, 1, 2 and 3
Consistency according to ASTM D217 (tenths of a millimetre)
445 - 475
400 - 430
355 - 385
31 0 - 340
265 - 295
220 - 250
175 - 205
130 - 160
85- 115
In a preferred embodiment, the greases according to the invention have a consistency
comprised between 265 and 295 tenths of a millimetre according to the standard ASTM
25 D217, in order to cover grade 2.
Technical performances of the areases
The greases according to the invention have a very good thermal resistance. In particular,
5 the greases according to the invention exhibit bleeding of less than 0.8% (percentage by
mass of loss of oil) measured according to the standard ASTM D6184 (50 h, 100°C) and
bleeding of less than 0.5% (percentage by mass of loss of oil) measured according to the
standard NF T60-191 (168 h, 40°C). Moreover, the greases according to the invention are
more stable when hot, and more particularly above 140°C.
10
The greases according to the invention have good extreme-pressure performances. In
particular, the greases according to the invention have a welding load measured
according to the standard ASTM D2596 greater than 350 kg, preferably greater than or
equal to 400 kg. In particular, the grease compositions according to the invention have a
15 welding load measured according to the standard DIN 5135014 greater than 350 daN,
preferably greater than or equal to 360 daN, more preferentially greater than or equal to
370 daN, yet more preferentially greater than or equal to 380 daN (daN: decanewton).
Moreover, the greases according to the invention have a rolling bearing wear, obtained by
the FAG FE 8 test according to the standard DIN 51819, of less than 2.
20
The greases according to the invention are also not very corrosive, in particular vis-a-vis
metals and metal alloys, and more particularly vis-a-vis copper.
The invention also relates to a process for the lubrication of a mechanical part, comprising
25 at least contacting the mechanical part with a grease such as defined above.
All the characteristics and preferences presented for the grease also apply to the process
for the lubrication of a mechanical part according to the invention.
The invention also relates to a production unit for a calcium sulphonate complex grease
30 for the implementation of a process described above comprising:
- a reactor (I) provided with at least one stirring device (2) and at least one
pressurizing (3) and heating (4) means,
- a receiving tank (5) for said calcium sulphonate complex grease,
- at least one means for transferring (6) said calcium sulphonate complex grease
3 5 from the reactor (I) to the receiving tank (5).
In an embodiment of the invention, the reactor (1) has a capacity ranging from 2 to 10
tonnes, preferably from 3 to 6 tonnes.
The stirring device (2) present in the reactor (1) can be selected from any type of stirring
5 device known to a person skilled in the art and used in the preparation of a grease.
By pressurizing means according to the invention, is meant any means making it possible
to introduce and maintain a particular pressure inside the reactor.
10 In an embodiment of the invention, the pressurizing means (3) can be an autoclave.
By heating means according to the invention, is meant any means making it possible to
introduce a rise in temperature and to maintain a particular temperature inside the reactor.
In an embodiment of the invention, the heating means (4) can be a boiler heating a heattransfer
fluid.
15
In an embodiment of the invention, the receiving tank (5) has a capacity ranging from 2 to
10 tonnes, preferably from 3 to 6 tonnes.
In an embodiment of the invention, the receiving tank (5) can also comprise at least one
20 cooling means (7).
The cooling means can be selected from the cooling means used in step e) and described
above.
The transfer means (6) make it possible to convey the calcium sulphonate complex
25 grease from the reactor (I) to the receiving tank (5).
The transfer means (6) can be in particular selected from circulation pumps or pipes.
In an embodiment of the invention, the transfer means comprise a circulation pump (8)
30 capable of pumping the calcium sulphonate complex grease to the outside of the reactor
(1) in order for it to be transferred into the receiving tank (5).
In another embodiment of the invention, the production unit also comprises an additives
tank (9)
35 By additives tank according to the invention, is meant any tank containing at least one
additive intended to be added to the mixture present in the reactor (1).
The different objects of the present invention and their implementations will be better
understood on reading the examples which follow. These examples are given by way of
indication, without being limitative.
5
Examples:
Example 1 (according to the invention): process A for the preparation of a grease
10 A grease composition was prepared according to a process A according to the invention
comprising the following steps:
- In a reactor, a mixture comprising 18.9% by weight of a Group I base oil of SN 330 type
(density at 15°C ranging from 880 to 900 kglm3, kinematic viscosity at 100°C of approximately
12 mm2/s measured according to the standard ASTM D-445), 22.5% by weight of a Group I
15 base oil of BSS type (kinematic viscosity at 100°C of approximately 30 mm2/s measured
according to the standard ASTM D-445 and density at 15°C ranging from 895 to 915 kglm3),
13.5% by weight of a naphthenic Group I base oil (viscosity of 100 cSt at 40°C measured
according to the standard ASTM D-445) and 45.1% by weight of an overbased calcium
sulphonate with a BN measured according to the standard ASTM D-2896 equal to 400 mg
20 KOH/g of detergent was prepared, the percentages corresponding to percentages with
respect to the total weight of the starting reagents,
- The mixture in the reactor was heated to a temperature of 75°C according to a temperature
gradient of 1.5"C/min,
-At a temperature of 50°C 2.2% by weight of 12-hydroxystearic acid, with respect to the total
25 weight of the starting reagents, and 0.01% by weight of an anti-foaming agent of silicone
type, with respect to the total weight of the starting reagents, were added into the reactor,
-At a temperature of 55"C, 2.4% by weight, with respect to the total weight of the starting
reagents, of dodecylbenzene sulphonic acid was added into the reactor,
-At a temperature of 57"C, 6% by weight, with respect to the total weight of the starting
30 reagents, of water was added into the reactor,
-At a temperature comprised between 60 and 65"C, 0.7% by weight, with respect to the total
weight of the starting reagents, of acetic acid was slowly added into the reactor,
- The reactor was closed then the temperature was raised to 90°C and this temperature was
maintained for a duration of 30 min,
35 - The reactor was opened and 0.9% by weight, with respect to the total weight of the starting
reagents, of lime as well as 10.5% by weight, with respect to the total weight of the starting
reagents, of a Group I base oil of BSS type (kinematic viscosity at 100°C of approximately
30 mm2/s measured according to the standard ASTM D-445 and density at 15°C ranging from
895 to 915 kg/m3) were added into the reactor at a temperature of 90"C,
- The reactor was closed again,
5 -A pressure of 600 kPa was applied inside the reactor while heating in order to raise the
temperature to 140°C,
- This temperature was maintained for a duration of 1 h,
- Depressurizing was then applied to the reactor, this being carried out for at least 1 h at a
temperature of 140°C by opening the reactor (opening the bypass),
lo -At a temperature of 140°C, 9.5% by weight, with respect to the total weight of the starting
reagents, of a Group I base oil of BSS type (kinematic viscosity at 100°C of approximately
30 rnrn2/s measured according to the standard ASTM D-445 and density at 15°C ranging from
895 to 91 5 kg/m3) was slowly added
- The temperature was brought back to 80°C according to a gradient of 2"C/min,
15 -At a temperature of 80°C, 0.5% by weight, with respect to the total weight of the starting
reagents, of a package of additives comprising an amine antioxidant (Irganox L57 from the
BASF company) was added,
-The mixture present in the reactor is then subjected to grinding using a Fryma corundum
grinding mill from the frymaKoruma company.
20
Example 2 (comparative): process B for the preparation of a grease
A grease was prepared according to process A in which a derivative of boric acid (calcium
metaborate) was added to the mixture present in the reactor: the calcium metaborate was
25 added in a quantity of 2.9% by weight with respect to the total weight of the starting reagents,
with the package of additives comprising an amine antioxidant and at a temperature of
approximately 80°C.
The calcium metaborate behaves in the same way as boric acid, the only difference is that
calcium metaborate is not a product that is classed as CMR.
30
Example 3 (comparative): process C for the preparation of a grease
A grease was prepared according to a comparative process C, in two phases in the presence
of boric acid comprising the following steps:
35 First phase
- In a reactor, a mixture comprising 17.5% by weight of a Group I base oil of SN 330 type
(density at 15°C ranging from 880 to 900 kg/m3, kinematic viscosity at 100°C of approximately
12 mm2/s measured according to the standard ASTM D-445), 28.5% by weight of a Group I
base oil of BSS type (kinematic viscosity at 100°C of approximately 30 mm2/s measured
5 according to the standard ASTM D-445 and density at 15°C ranging from 895 to 915 kg/m3),
12.2% by weight of a naphthenic Group I base oil (viscosity of 100 cSt at 40°C measured
according to the standard ASTM D-445) and 41.6% of an overbased calcium sulphonate with
a BN measured according to the standard ASTM D-2896 equal to 400 mg KOHIg of detergent
was prepared, the percentages corresponding to percentages with respect to the total weight
10 of the starting reagents,
- The mixture in the reactor was heated to a temperature of 75°C according to a temperature
gradient of 1.5"C/min,
-At a temperature of 50°C, 1.2% by weight, with respect to the total weight of the starting
reagents, of 12-hydroxystearic acid was added into the reactor,
15 -At a temperature of 55"C, 2.2% by weight, with respect to the total weight of the starting
reagents, of dodecylbenzene sulphonic acid was added into the reactor,
-At a temperature of 57"C, 5.6% by weight, with respect to the total weight of the starting
reagents, of water was added into the reactor,
-At a temperature comprised between 60 and 65"C, 0.7% by weight, with respect to the total
20 weight of the starting reagents, of acetic acid was slowly added into the reactor,
- The reactor was closed,
- A rise under pressure to 120°C during I h (according to a rate of 2"CImin) was carried out,
-After this step, while maintaining the pressure inside the reactor between 200 and 250
kPa, the temperature was lowered to 90°C,
25 - Depressurizing was then applied to the reactor, by opening the latter,
Second phase
-At a temperature of 90°C 1.4% of 12-hydroxystearic acid, 2.5% of lime and 2.1% of boric
acid were added to the mixture present in the reactor, the percentages corresponding to
30 percentages with respect to the total weight of the starting reagents,
- The reactor was heated to a temperature of 140°C,
- The reactor was closed, the pressure ranging from 500 to 700 kPa and the temperature
was maintained for a duration of 1 h,
-The reactor was opened then the residual water was removed by drawing off under
35 vacuum;
- 9.4% by weight, with respect to the total weight of the starting reagents, of a Group I base
oil of BSS type (kinematic viscosity at 100°C of approximately 30 mm2/s measured according
to the standard ASTM D-445 and density at 15°C ranging from 895 to 91 5 kg/rn3) was added
into the mixture, thus making it possible to reduce the temperature to 70°C
5 -At this temperature 0.4% by weight, with respect to the total weight of the starting reagents,
of a package of additives was added comprising an amine antioxidant (Irganox L57 from the
BASF com pany),
- The mixture present in the reactor was then subjected to grinding using a Fryrna corundum
grinding mill from the frymaKoruma company.
10
Example 4: process D for the preparation of a grease
A grease was prepared according to the process A, with the exception that the step of the
addition of water at 57°C and the step of the addition of acetic acid between 60 and 65°C
15 were reversed.
Example 5 (according to the invention): process E for the preparation of a grease
A grease composition was prepared according to a process E according to the invention
20 comprising the following steps:
- In a reactor, a mixture comprising 29.3% by weight of a Group I base oil of BSS type
(kinematic viscosity at 100°C of approximately 30 mm2/s measured according to the standard
ASTM D-445 and density at 15°C ranging from 895 to 915 kg/m3), 37.6% by weight of a
naphthenic Group I base oil (viscosity of 100 cSt at 40°C measured according to the
25 standard ASTM D-445) and 33.0% by weight of an overbased calcium sulphonate with a BN
measured according to the standard ASTM D-2896 equal to 400 mg KOHIg of detergent was
prepared, the percentages corresponding to percentages with respect to the total weight of
the starting reagents,
- The mixture in the reactor was heated to a temperature of 75°C according to a temperature
30 gradient of 1 .S"Clmin,
-At a temperature of 50"C, 2.4% by weight of 12-hydroxystearic acid, with respect to the total
weight of the starting reagents, and 0.01% by weight of an anti-foaming agent of silicone
type, with respect to the total weight of the starting reagents, were added into the reactor,
-At a temperature of 55"C, 2.0% by weight, with respect to the total weight of the starting
35 reagents, of dodecylbenzene sulphonic acid was added into the reactor,
-At a temperature of 57"C, 3.5% by weight, with respect to the total weight of the starting
reagents, of water was added into the reactor,
-At a temperature of approximately 65"C, 0.6% by weight, with respect to the total weight of
the starting reagents, of acetic acid was slowly added into the reactor,
5 - The reactor was closed then the temperature was raised to 90°C and this temperature was
maintained for a duration of 30 min,
- The reactor was opened and 1.2% by weight, with respect to the total weight of the starting
reagents, of lime was added into the reactor at a temperature of 90°C,
- The reactor was closed again,
lo -A pressure of 600 kPa was applied inside the reactor while heating in order to raise the
temperature to 140°C,
- This temperature was maintained for a duration of 1 h,
- Depressurizing was then applied to the reactor, the latter being carried out for at least 1 h at
a temperature of 140°C by opening the reactor (opening the bypass),
15 -At a temperature of 140°C 8.4% by weight, with respect to the total weight of the starting
reagents, of a Group I base oil of BSS type (kinematic viscosity at 100°C of approximately
30 mm2/s measured according to the standard ASTM D445 and density at 15°C ranging from
895 to 915 kg/m3) and 5.8% by weight of a naphthenic Group I base oil (viscosity of 100 cSt
at 40°C measured according to the standard ASTM D445) were slowly added,
20 - The temperature was reduced to 80°C according to a gradient of TCImin,
-At a temperature of 80°C 0.5% by weight, with respect to the total weight of the starting
reagents, of a package of additives comprising an amine antioxidant (Irganox L57 from the
BASF company) and 1.5% by weight, with respect to the total weight of the starting reagents,
of a package of additives comprising a detergent of salicylate type (M7121 from the lnfineum
25 company) were added,
- The mixture present in the reactor was then subjected to grinding using a Fryma corundum
grinding mill from the frymaKoruma company.
The product obtained by the process E according to the invention is in the form of a smooth
30 and shiny grease.
Example 6 (comparative): process F for the preparation of a grease
A grease composition was prepared according to a comparative process F comprising the
35 following steps:
- In a reactor, a mixture comprising 29.3% by weight of a Group I base oil of BSS type
(kinematic viscosity at 100°C of approximately 30 mmYs measured according to the standard
ASTM D-445 and density at 15°C ranging from 895 to 915 kglm3), 37.6% by weight of a
naphthenic Group I base oil (viscosity of 100 cSt at 40°C measured according to the
5 standard ASTM D-445) and 33.0% by weight of an overbased calcium sulphonate with a BN
measured according to the standard ASTM D-2896 equal to 400 mg KOHlg of detergent was
prepared, the percentages corresponding to percentages with respect to the total weight of
the starting reagents,
- The mixture in the reactor was heated to a temperature of 75°C according to a temperature
10 gradient of 1.5"C/min,
-At a temperature of 50°C, 2.4% by weight of 12-hydroxystearic acid, with respect to the total
weight of the starting reagents, and 0.01% by weight of an anti-foaming agent of silicone
type, with respect to the total weight of the starting reagents, were added into the reactor,
-At a temperature of 55"C, 2.0% by weight, with respect to the total weight of the starting
15 reagents, of dodecylbenzene sulphonic acid was added into the reactor,
-At a temperature of 57"C, 3.5% by weight, with respect to the total weight of the starting
reagents, of water was added into the reactor,
-At a temperature of approximately 65"C, 0.6% by weight, with respect to the total weight of
the starting reagents, of acetic acid was slowly added into the reactor,
20 -The temperature was raised to 90°C and this temperature was maintained for a duration of
30 min,
- 1.2% by weight, with respect to the total weight of the starting reagents, of lime was added
into the reactor at a temperature of 90°C,
- The temperature was raised to 140°C and maintained for a duration of 1 h,
25 -At this temperature of 140°C 8.4% by weight, with respect to the total weight of the starting
reagents, of a Group I base oil of BSS type (kinematic viscosity at 100°C of approximately
30 mm2/s measured according to the standard ASTM D-5 and density at 15°C ranging from
895 to 915 kglm3) and 5.8% by weight of a naphthenic Group I base oil (viscosity of 100 cSt
at 40°C measured according to the standard ASTM D-5) were slowly added,
30 - The temperature was brought back to 80°C according to a gradient of 2"Clmin,
-At a temperature of 80°C 0.5% by weight, with respect to the total weight of the starting
reagents, of a package of additives comprising an amine antioxidant (Irganox L57 from the
BASF company) and 1.5% by weight, with respect to the total weight of the starting reagents,
of a package of additives comprising a detergent of salicylate type (M7121 from the lnfineum
35 company) were added,
-The mixture present in the reactor was then subjected to grinding using a Fryma corundum
grinding mill from the frymaKoruma company.
Thus, the process F does not comprises a pressurization step corresponding to step C)
5 according to the invention.
The product obtained by the process F is in the form of a liquid grease.
Test 1: evaluation of the preparation time associated with the processes A, B and C.
10 In this case it is a question of evaluating the implementation time of the processes.
The preparation time of each grease obtained by the processes A, B and C respectively is
described in Table Ill.
Table Ill
- -
Grease obtained by Grease obtained by Grease obtained by
the implementation of the implementation of the implementation of
process A process B process C
(process according to (comparative (comparative
the invention) process) process)
Preparation time (h) 8 8 14-1 6
15 The results of Table Ill show that the preparation time associated with the implementation of a
process according to the invention (process A) is significantly shorter than that associated with
the implementation of a two-phase process (process C).
Test 2: evaluation of the phvsico-chemical characteristics of the clreases obtained by
20 the r~rocessesA . B and C.
In this case it is a question of evaluating the physico-chemical characteristics of the greases
obtained by the processes A, B and C, and more particularly their grade.
The NLGl grade of the greases A, B and C is described in Table IV.
25
Table IV
Grease obtained by I the implementation of I process A 1 (process according to
The results show that the implementation of the process according to the invention
Grease obtained by
the implementation of
process B
(comparative
process)
5 (process A) makes it possible to obtain the same grade of grease as that obtained by a
two-phase process (process C) or by a single-phase process but comprising a derivative
of boric acid (process B).
Thus, these results show that the physico-chemical characteristics of the greases
obtained by a process according to the invention are maintained, compared with the
Grease obtained by
the implementation of
process C
(comparative
process)
10 greases obtained by a two-phase process or by a single-phase process but comprising a
derivative of boric acid.
Test 3: evaluation of the properties of mechanical stabilitv of the qreases obtained by
the processes A, B and C.
15
In this case it is a question of evaluating the mechanical stability of the greases obtained by
the processes A, B and C, by measuring the penetrability and by the "Shell Roller" test.
The penetrability is measured according to the standard IS0 2137 afler 100,000 strokes
and is expressed in 1/10 mm.
20 The "Shell Roller" test is carried out according to the standard ASTM Dl831 afler 100 h at
80°C and the results are expressed in 1/10 mm; this test principally consists of rolling the
grease using rollers and makes it possible to evaluate the stability of a grease when the
latter is rolled.
The results are described in Table V.
Table V
The results of Table V show that the mechanical stability of the greases obtained by the
5 process according to the invention (process A) is maintained or even improved compared
with a grease obtained by a two-phase process (process C) or by a single-phase process
but comprising a derivative of boric acid (process B).
Test 4: evaluation of the properties of thermal resistance of the qreases obtained by
10 the processes A, B and C.
Grease obtained by
the implementation of
process C
(com parative
process)
292
279
In this case it is a question of evaluating the thermal resistance of greases obtained by the
processes A, B and C by measurement of the dropping point and by evaluation of the
bleeding.
15
The dropping point is measured according to the standard NF T60-627 and is expressed
in degrees Celsius.
The bleeding after 50 h at 100°C is evaluated according to the standard ASTM D6184 and
is expressed in percentage corresponding to a percentage by mass of loss of oil.
20 The bleeding after 168 h at 40°C is evaluated according to the standard NF T60-191 and
is expressed as a percentage corresponding to a percentage by mass of loss of oil.
More particularly, the bleeding allows evaluation of the thermal stability of a grease; the
lower the percentage obtained, the better the thermal resistance; evaluation of the
bleeding is a good indication of the capacity of a thickener to retain the oil present in a
25 grease.
Grease obtained by
the implementation of
process B
(comparative
process)
300
283
Penetrability
"Shell Roller" Test
The results are described in Table VI.
Grease obtained by
the implementation of
process A
(process according to
the invention)
292
295
Table VI
Dropping point ("C)
Bleeding 50h1100aC
Bleeding 168h/40aC
Grease obtained by
the implementation of
process A
(process according to
the invention)
>300
0.70
0.47
The results of the table show that the implementation of a process according to the
Grease obtained by
the implementation of
process B
(comparative
process)
>300
0.85
0.77
invention (process A) makes it possible to obtain calcium sulphonate complex greases the
5 thermal resistance of which is not only maintained but is improved compared with a
grease obtained by a two-phase process (process C) or by a single-phase process but
comprising a derivative of boric acid (process B).
Grease obtained by
the implementation of
process C
(comparative
process)
>300
2.70
0.74
Test 5: evaluation of the shear resistance properties of the qreases obtained by the
10 processes A and C
In this case it is a question of evaluating the shear resistance, and more particularly the
shear resistance when hot of the greases obtained by the processes A and C, by
measurement of the viscosity as a function of the temperature.
The viscosity is measured according to the standard DIN 51810-2 and is expressed in
15 Pas.
The results are described in Table VII.
Table VII
(process according to the (com parative process)
The results of Table VII show a significant difference in the behaviour when hot between a
grease obtained by a process according to the invention (process A) and a grease
5 obtained by a two-phase process (process C). In fact, the greases obtained by a process
according to the invention show a small reduction in viscosity when the temperature
increases, whereas the greases obtained by a two-phase process show a significant drop
in viscosity, more particularly from 99°C.
Thus, the greases obtained by a process according to the invention have a better thermal
resistance when hot, and more particularly above 140°C.
5
Test 6: evaluation of the extreme-~ressurep roperties of the qreases obtained by the
processes A, B and C.
In this case it is a question of evaluating the extreme-pressure performances of the greases
10 obtained by the processes A, B and C by the EP 4-ball test and by the FAG FE8 test.
The EP 4-ball test is carried out according to the standard DIN 5135014 and is expressed
in daN.
The FAG FE8 test is evaluated according to the standard DIN 51 819 under the following
15 conditions:
- speed of rotation: 7.5 rpm,
- load: 80 kN,
- temperature: 160°C,
- duration of the test: 500h,
20 - ball bearings greased with each of the greases obtained by the processes A, B and C.
The results of the FAG FE8 test correspond to wear of the balls and are expressed in mg;
the lower the values, the better the extreme-pressure performances.
The results are described in Table Vlll
25
Table Vlll
The results of Table Vlll show that the implementation of a process according to the
invention (process A) makes it possible to obtain calcium sulphonate complex greases the
5 extreme-pressure performances of which are not only maintained but are improved
compared with a grease obtained by a two-phase process (process C) or by a singlephase
process but comprising a derivative of boric acid (process B).
Test 7: evaluation of the anticorrosion properties of the clreases obtained by
10 processes A. B and C.
Grease obtained by
the implementation of
process C
(corn parative
process)
420-440
3911 6
In this case it is a question of evaluating, by the Emcor test, the anti-corrosion properties of
the greases obtained by the processes A, B and C.
Grease obtained by
the implementation of
process B
(comparative
process)
420-440
214
EP 4-ball test
FAG FE8 test
15 The Emcor test is evaluated according to the standard IS0 11007
Grease obtained by
the implementation of
process A
(process according to
the invention)
380-400
<2/<2
The results are described in Table IX.
Table IX
20 The results show that the anti-corrosion performances of the greases obtained by the
process according to the invention (process A) are maintained compared with a grease
Emcor test
Grease obtained by
the implementation of
process C
(comparative
process)
0-0
Grease obtained by
the implementation of
process A
(process according to
the invention)
@O
Grease obtained by
the implementation of
process B
(comparative
process)
0-0
obtained by a two-phase process (process C) or by a single-phase process but
comprising a derivative of boric acid (process B).
Test 8: evaluation of the anti-wear ropert ties of the qreases obtained by the
5 processes A, B and C
In this case it is a question of evaluating the anti-wear properties of the greases obtained by
the processes A, B and C, by implementation of the 4-ball test according to the standard
ASTM D2266.
10 The 4-ball test is implemented under the following conditions:
- duration: I h,
- load: 40 kgs,
- temperature: 75°C.
15 The results are described in Table X.
Table X
4 B wear test
The results show that the anti-wear performances of the greases obtained by the process
according to the invention (process A) are maintained compared with a grease obtained
20 by a two-phase process (process C) or by a single-phase process but comprising a
derivative of boric acid (process B).
Grease obtained by
the implementation of
process A
(process according to
the invention)
0.38
Grease obtained by
the implementation of
process B
(comparative
process)
0.39
Test 9: evaluation of the foaminq associated with the Drocess accordinq to the
invention
2 5
In this case it is a question of evaluating the existence of the foaming phenomenon during
the implementation of the process according to the invention.
Foaming can have harmful consequences for the process, it may in particular become
apparent by a risk of the mixture present in the reactor overflowing and therefore a loss of
30 product at the end of the process but also by a longer preparation time.
Grease obtained by
the implementation of
process C
(comparative
process)
0.40
Foaming can also have harmful consequences on the grease obtained at the end of the
process, it could in particular become apparent by a deterioration in the physico-chemical
properties of the grease.
A grease according to process A and a grease according to process D were prepared.
5
The phenomenon of foaming during the manufacture of the greases obtained by the
process A and process D respectively was evaluated by visual observation.
During the manufacture of the grease by process A according to the invention, no foaming
10 phenomenon was observed, while process D for the manufacture of a grease caused
significant foaming to appear.
The results show that the implementation of the process according to the invention (process
E) makes it possible to obtain a grease with the required grade, while the implementation of
the comparative process (process F) not comprising a pressurization step according to the
25 invention leads to a liquid grease that does not in any way correspond to the grade sought.
Test 10: evaluation of the physicochemical characteristics of the areases obtained by
the processes E and F
15
In this case it is a question of evaluating the physico-chemical characteristics of the greases
obtained by the processes E and F, and more particularly their grade.
The NLGl grade of greases E and F is described in Table XI.
Table XI
NLGl graden)
20 ("cf Table II above .
Grease obtained by
the implementation of
process E
(process according to
the invention)
1.5-2
Grease obtained by
the implementation of
process F
(comparative
process)
Not measurable
Test 11 : evaluation of the thermal resistance properties of the qreases obtained bv the
processes E and F.
In this case it is a question of evaluating the thermal resistance of greases obtained by the
5 processes E and F by measuring the dropping point.
The dropping point is measured according to the standard NF T60-627 and is expressed
in degrees Celsius.
I ( the implementation of ( the implementation of I
The results are described in Table XII.
Table XI1
1 process E I process F I
Grease obtained by
I I (process according to ( (comparative I
Grease obtained by
I 1 ( (liquid product) I
Dropping point ("C)
The results show that the implementation of a process according to the invention (process E)
makes it possible to obtain a grease having a good thermal resistance, whereas the
implementation of a comparative process (process F) not comprising a pressurization step
15 according to the invention leads to a liquid grease the thermal resistance of which cannot be
evaluated.
Thus, the examples above demonstrate the benefit of the implementation of the process
according to the invention for the preparation of a calcium sulphonate complex grease
compared with a two-phase process, making it possible to have a significantly reduced
20 preparation time. In addition, the calcium sulphonate complex greases obtained by the
the invention)
>300
process according to the invention retain a good mechanical stability, good anti-corrosion
and anti-wear performances while having improved thermal resistance and extremepressure
performances despite the absence of boric acid.
The examples also show the importance of step c) according to the invention with the
25 objective of obtaining of calcium sulphonate complex greases having a satisfactory
structure as well as physico-chemical, mechanical and thermal resistance properties.
process)
Not measurable

CLAIMS
1. Process for the preparation of a calcium sulphonate complex grease comprising at
least the following steps:
a) preparing, in a reactor, a calcium sulphonate complex soap comprising calcium
carbonate, the calcium carbonate being presented in the form of calcite,
b) closing the reactor,
c) raising the temperature in the reactor to a temperature of at least 130°C under a
pressure of at least 400 kPa,
d) depressurizing and removing the water contained in the reactor,
e) cooling the reactor,
said process not comprising the addition of boric acid.
2. Process according to claim 1 in which step a) comprises the steps of:
a.i) mixing, in the reactor, at least one base oil and at least one overbased calcium
sulphonate,
a.ii) adding at least one carboxylic acid comprising at least 12 carbon atoms, and
optionally at least one -OH group, at a temperature of at least 20°C,
a.iii) adding at least one sulphonic acid comprising at least 12 carbon atoms at a
temperature of at least 50°C,
a.iv) adding water at a temperature of at least 50"C,
a.v) adding at least one carboxylic acid comprising at least 2 carbon atoms at a
temperature of at least 50"C,
a.vi) closing the reactor,
a.vii) raising the temperature to a temperature of at least 8OoC,
a.viii) opening the reactor,
a.ix) adding lime at a temperature of at least 90°C.
3. Process according to claim 2 in which steps a.i) to a.iii) are implemented in a
different order.
4. Process according to claim 2 or 3 in which the content by weight of calcium
sulphonate ranges from 35 to 55%, preferably from 40 to 50% with respect to the
total weight of the starting reagents and the content by weight of base oil ranges
from 45 to 65%, preferably from 50 to 60% with respect to the total weight of the
starting reagents.
5. Process according to any one of claims 2 to 4 in which the carboxylic acid of step
a.ii) is selected from the carboxylic acids or the hydroxycarboxylic acids
comprising from 12 to 24 carbon atoms, preferably from 16 to 20 carbon atoms.
6. Process according to any one of claims 2 to 5 in which the content by weight of
carboxylic acid added in step a.ii) ranges from 1 to 4%, preferably from 1.5 to 3%
with respect to the total weight of the starting reagents.
7. Process according to any one of claims 2 to 6 in which the sulphonic acid of step
a.iii) is selected from the sulphonic acids of formula (I):
[(Rq-A)x-S03Myl
(1)
in which:
R, represents a saturated or unsaturated, linear or branched alkyl group,
comprising at least 10 carbon atoms, preferably from 10 to 30 carbon
atoms, advantageously from 10 to 15 carbon atoms;
A represents an aromatic hydrocarbon-containing group, preferably a
group selected from benzene, naphthalene or phenanthrene;
M represents a hydrogen atom or a calcium atom;
x represents 1 or 2;
y represents 1 or 2;
when M represents a calcium atom, y represents 2,
when M represents a hydrogen atom, y represents 1.
8. Process according to any one of claims 2 to 7 in which the content by weight of
sulphonic acid added in step a.iii) ranges from 0.5 to 4%, preferably from 1 to 3%
with respect to the total weight of the starting reagents.
9. Process according to any one of claims 2 to 8 in which the content by weight of
water added in step a.iv) ranges from 1 to lo%, preferably from 3 to 8% with
respect to the total weight of the starting reagents.
10. Process according to any one of claims 2 to 9 in which step a.iv) is implemented at
a temperature ranging from 50 to 60°C.
11. Process according to any one of claims 2 to 10 in which the carboxylic acid of step
a.v) is selected from the carboxylic acids comprising from 2 to 6 carbon atoms,
preferably from 2 to 4 carbon atoms.
12. Process according to any one of claims 2 to 11 in which the content by weight of
carboxylic acid added in step a.v) ranges from 0.1 to I%, preferably from 0.4 to
0.8% with respect to the total weight of the starting reagents.
13. Process according to any one of claims 2 to 12 in which step a.vii) is implemented
at a temperature of at least 85"C, preferably from 85 to 95°C.
14. Process according to any one of claims 2 to 13 in which the content by weight of
lime added in step a.ix) ranges from 0.1 to 4%, preferably from 0.5 to 2.5% with
respect to the total weight of the starting reagents.
15. Process according to any one of the preceding claims in which the temperature of
step c) ranges from 130 to 160°C, preferably from 130 to 150°C.
16. Process according to any one of the preceding claims in which the pressure of
step c) ranges from 400 to 700 kPa, preferably from 500 to 650 kPa.
17. Process according to any one of the preceding claims in which the pressure in the
reactor in step c) is maintained at a pressure ranging from 500 to 650 kPa,
preferably close to 600 kPa, at a temperature ranging from 130 to 150°C,
preferably close to 14O0C, for a duration of at least 15 min, preferably ranging from
15 to 80 min, advantageously from 15 to 60 min.
18. Process according to any one of the preceding claims in which the cooling of step
e) is implemented by lowering the temperature to a temperature of less than or
equal to 9O0C, preferably from 70 to 90°C.
19. Process according to any one of the preceding claims comprising a step d.i)
implemented after step d) and before step e) and comprising the supplementary
addition of at least one base oil.
20. Process according to any one of the preceding claims comprising a step f)
implemented after step e) and comprising the addition of at least one
supplementary additive, optionally followed by a step of grinding the product
obtained.