CN108699474B

CN108699474B - Lubricant composition based on neutralized amine and molybdenum

Info

Publication number: CN108699474B
Application number: CN201780012826.1A
Authority: CN
Inventors: 拉斐尔·约维内; 凯瑟琳·沙兰
Original assignee: Total Marketing Services SA
Current assignee: TotalEnergies Marketing Services SA
Priority date: 2016-03-03
Filing date: 2017-03-03
Publication date: 2021-05-11
Anticipated expiration: 2037-03-03
Also published as: CN108699474A; JP2019507230A; KR20180122337A; KR102329180B1; FR3048433A1; BR112018016701A2; FR3048433B1; WO2017149119A1; EP3423551A1; JP6889175B2

Abstract

The present invention relates to the use of a lubricant composition to reduce friction between two surfaces, at least one of which is coated with carbon, said composition comprising: -at least one base oil; -at least one molybdenum compound; -at least one fully or partially neutralized amine salt, the amine corresponding to the following formula (I): R-N (X) -Y (I).

Description

Lubricant composition based on neutralized amine and molybdenum

[ technical field ] A method for producing a semiconductor device

The present invention relates to the field of lubricant compositions, in particular for transmissions or engines and in particular motor vehicle engines.

[ background of the invention ]

One of the purposes of the lubricant composition is to reduce the friction phenomena and wear of the mechanical parts moving in contact with each other. One particular purpose of the lubricant composition is to limit these friction phenomena in vehicle engines, in particular motor vehicle engines. In addition, the use of carbon coatings in engines, particularly in motor vehicle engines, is expanding. It would therefore be advantageous to be able to propose lubricant compositions that allow to reduce the friction phenomena for whatever steel/steel, carbon/carbon coating or steel/carbon coating contact.

In general, to limit the friction phenomenon, a friction modifier may be incorporated into the lubricant composition. In particular, the addition of fatty amines as friction modifiers is known. However, these amines can have a detrimental effect on seals, particularly seals for mechanical parts, and notably fluorinated polymer seals. These amines can effectively lead to an accelerated degradation of the mechanical properties of the seal.

It is also known to use organomolybdenum compounds to reduce friction phenomena, more particularly friction phenomena directed at contact between two steel surfaces. However, it is known to those skilled in the art that the use of organomolybdenum compounds, particularly those containing dithiocarbamates, can lead to increased wear of mechanical components. It has also been observed that organo-molybdenum compounds contained in lubricants can degrade the carbon coating and even detach it from the surface, and that this degradation can be exacerbated as the content of organo-molybdenum compounds in the lubricant increases.

It would therefore be advantageous to provide a lubricant composition that has a moderate impact on other engine components and in particular on seals while reducing the friction phenomena, in particular in the presence of carbon-coated surfaces.

Additionally, one of the goals of the lubricant composition is to improve engine productivity and thus permit fuel savings.

[ summary of the invention ]

It is therefore an object of the present invention to provide a lubricant composition which allows reducing the tribological phenomena, in particular in the presence of surfaces with a carbon coating, which has a limited impact on the degradation of seals, in particular engine seals, in particular seals for vehicle engines, for example seals for motor vehicle engines.

It is a further object of the present invention to provide said composition which allows to reduce the friction phenomena for whatever steel/steel, carbon coating/carbon coating or steel/carbon coating contact.

It is a further object of the present invention to provide said composition which also allows to reduce fuel consumption.

Other objects will become apparent upon reading the following description of the invention.

To address these objects and the disadvantages of known lubricant compositions, the present invention proposes a lubricant composition comprising:

-at least one base oil;

-at least one organomolybdenum compound;

-at least one fully or partially neutralized amine salt, the amine corresponding to the following formula (I):

R-N(X)-Y (I)

wherein:

r is a linear or branched, fully or partially saturated hydrocarbon group having from 2 to 24 carbon atoms, preferably from 4 to 24 carbon atoms, and more preferably from 14 to 24 carbon atoms, in particular from 16 to 24 carbon atoms, for example from 18 to 24 carbon atoms;

x is a hydrogen atom; straight-chain or branched, fully or partially saturated hydrocarbon radicals having from 1 to 24 carbon atoms, preferably from 1 to 10 carbon atoms, in particular from 1 to 8 carbon atoms; a benzyl group; or the formula-R¹-[NH-R²]_n-NH₂A group of (a);

y is a hydrogen atom; straight-chain or branched, fully or partially saturated hydrocarbon radicals having from 1 to 24 carbon atoms, preferably from 1 to 10 carbon atoms, in particular from 1 to 8 carbon atoms; a benzyl group; or the formula-R¹-[NH-R²]_n-NH₂A group of (a);

n is an integer from 0 to 3, preferably from 0 to 2, preferably 0 or 1;

R¹and R²Identical or different, are linear or branched alkyl radicals having from 2 to 4 carbon atoms, preferably from 2 to 3 carbon atoms, preferably CH₂CH₂Or CH₂CH₂CH₂；

At least one of X or Y is a hydrogen atom or-R¹-[NH-R²]_n-NH₂；

X, Y or at least one of R is a straight or branched, fully or partially saturated hydrocarbon radical having from 4 to 24 carbon atoms, preferably from 14 to 24 carbon atoms, in particular from 16 to 24 carbon atoms, for example from 18 to 24 carbon atoms;

the acid that neutralizes the amine is selected from monoacids of formula (II):

R’COOH (II)

wherein R' is a linear or branched, fully or partially saturated hydrocarbon radical having from 2 to 24 carbon atoms.

The inventors have unexpectedly demonstrated that the combination of the fully or partially neutralized amine salts of the present invention with organomolybdenum compounds allows for the limiting of the tribological phenomena against contact of either steel/steel, carbon coating/carbon coating or steel/carbon coating with minimal or limited impact on seal degradation. In addition, the inventors have also demonstrated that the partially or fully neutralized amine salts of the present invention have better seal compatibility, particularly with engine seals and particularly motor vehicle engine seals, than the corresponding non-neutralized amines. In the present application, the seal is a seal used in the design of an engine, which is generally a polymer seal, in particular an elastomeric seal, preferably a fluorinated elastomeric seal. In particular, the lubricant composition of the present invention comprising at least one partially or fully neutralized amine salt allows to limit the wear of engine seals, in particular motor vehicle engine seals, as opposed to non-neutralized amines.

The amine intended to be neutralized and used in the composition of the invention is preferably an amine corresponding to the following formula (Ia):

R-N(X)-R¹-[NHR²]_n-NH₂ (Ia)

r, X, R therein¹、R²And n has the definition given above, and

at least one of X or R is a linear or branched, fully or partially saturated hydrocarbon radical having from 4 to 24 carbon atoms, preferably from 14 to 24 carbon atoms, in particular from 16 to 24 carbon atoms, for example from 18 to 24 carbon atoms.

Preferably, in the compounds of formula (I) or (Ia) of the present invention:

r is a linear or branched, fully or partially saturated hydrocarbon radical having from 14 to 24 carbon atoms, in particular from 16 to 24 carbon atoms, for example from 18 to 24 carbon atoms; and is

X is a hydrogen atom; a linear or branched alkyl group having 2 to 8 carbon atoms; a benzyl group; or the formula-R¹-[NH-R²]_n-NH₂A group of (1).

Preferably, in the compounds of formula (I) or (Ia) of the present invention:

X is hydrogenAtom or formula-R¹-[NH-R²]_n-NH₂A group of (1).

Preferably, in the compounds of formula (I) of the present invention:

r is a linear or branched, fully or partially saturated hydrocarbon radical having from 14 to 24 carbon atoms, in particular from 16 to 24 carbon atoms, for example from 18 to 24 carbon atoms;

y is-R¹-[NH-R²]_n-NH₂；

n＝0；

R¹Is CH₂CH₂CH₂(ii) a And is

X is CH₂CH₂CH₂NH₂Or H.

Preferably, in the compounds of formula (Ia) of the present invention:

n＝0；

R¹is CH₂CH₂CH₂(ii) a And is

X is CH₂CH₂CH₂NH₂Or H.

In a particularly preferred manner, the amine is selected from the following amines:

RNHCH₂CH₂CH₂NH₂wherein R represents a linear or branched, fully or partially saturated hydrocarbon group having 16 to 18 carbon atoms; or

N(R)(CH₂CH₂CH₂NH₂)(CH₂CH₂CH₂NH₂) Wherein R represents a linear or branched, fully or partially saturated hydrocarbon group having 16 to 18 carbon atoms.

In the present invention, the acid used for neutralizing the amine of formula (I) or (Ia) defined above in the form of a salt is preferably selected from acids of formula (II) wherein R' is a linear or branched, fully or partially saturated hydrocarbon radical having from 7 to 24 carbon atoms, preferably from 10 to 24 carbon atoms, for example from 14 to 20 carbon atoms, in particular from 16 to 20 carbon atoms.

In a particularly preferred manner, the acid which allows neutralization of the amine of formula (I) or (Ia) is oleic acid.

The amines used in the compositions of the present invention are fully or partially neutralized. Preferably, the molar ratio between the number of moles of nitrogen atoms in the amine and the number of moles of acid functions of formula (II) is between 9:1 and 1:1, preferably between 5:1 and 1: 1.

By organomolybdenum compound according to the present invention, it is intended to mean any organomolybdenum compound that is soluble in oil, in particular in base oils.

The organo-molybdenum compound of the present invention may be selected from organo-molybdenum complexes such as carboxylates, esters, molybdenum amides obtainable via the reaction of molybdenum oxide or ammonium molybdate with fats, glycerides, fatty acids or derivatives of fatty acids (esters, amines, amides …).

Preferably, the organomolybdenum compound is selected from sulfur-and phosphorus-free molybdenum complexes, with amide-type ligands, prepared mainly by reaction of a molybdenum source (e.g., molybdenum trioxide) and an amine derivative with a fatty acid having, for example, 4 to 28 carbon atoms, preferably 8 to 18 carbon atoms, such as a fatty acid contained in a vegetable oil or an animal oil.

The synthesis of such compounds is described, for example, in patents US4889647, EP0546357, US5412130, EP 1770153.

In a preferred embodiment of the invention, the organo-molybdenum compound is selected from organo-molybdenum complexes obtained by reaction of:

(i) a monoglyceride, diglyceride, or triglyceride type fat, or a fatty acid;

(ii) an amine source of formula (A):

wherein:

-X¹is an oxygen atom or a nitrogen atom;

-X²is an oxygen atom or a nitrogen atom;

when X is¹Or X²When is an oxygen atom, n and m are 1;

when X is¹Or X²When it is a nitrogen atom, n and m are 2;

and (iii) a source of molybdenum selected from molybdenum trioxide or molybdate, preferably ammonium molybdate, in an amount sufficient to provide 0.1% to 30% molybdenum, relative to the total weight of the complex.

In one embodiment of the present invention, the organo-molybdenum complex may comprise from 2% to 8.5% by weight of molybdenum, relative to the total weight of the complex.

In a preferred embodiment of the invention, the organomolybdenum complex is composed of at least one compound of formula (III) or (IV), alone or in a mixture:

wherein:

X¹is an oxygen atom or a nitrogen atom;

X²is an oxygen atom or a nitrogen atom;

when X is present¹N is 1 when it is an oxygen atom, and when X is²M is 1 when it is an oxygen atom;

when X is present¹N is 2 when it is a nitrogen atom, and when X is²M is 2 when it is a nitrogen atom;

R₁is a linear or branched, saturated or unsaturated alkyl group having from 3 to 30 carbon atoms, preferably from 3 to 20 carbon atoms, advantageously from 7 to 17 carbon atoms;

wherein:

X¹is an oxygen atom or a nitrogen atom;

X²is an oxygen atom or a nitrogen atom;

R₂is a linear or branched, saturated or unsaturated alkyl radical having from 3 to 30 carbon atoms, preferably from 3 to 20 carbon atoms, advantageously from 7 to 17 carbon atoms.

In one embodiment of the present invention, the organomolybdenum complex is prepared by the reaction:

(i) a monoglyceride, diglyceride, or triglyceride type fat, or a fatty acid;

(ii) diethanolamine or 2- (2-aminoethyl) aminoethanol; and

(iii) a molybdenum source selected from molybdenum trioxide or a molybdate salt, preferably ammonium molybdate, in an amount sufficient to provide 0.1% to 20.0% molybdenum, relative to the total weight of the complex.

In a preferred embodiment of the invention, the organomolybdenum complex is composed of at least one compound of formula (III-a) or (III-b), alone or in a mixture:

wherein:

R₁is a linear or branched, saturated or unsaturated alkyl radical having from 3 to 30 carbon atoms, preferably from 3 to 20 carbon atoms, advantageously from 7 to 17 carbon atoms,

wherein R is₁Is a linear or branched, saturated or unsaturated alkyl radical having from 3 to 30 carbon atoms, preferably from 3 to 20 carbon atoms, advantageously from 7 to 17 carbon atoms.

Molybdenum complexation as a sulfur-free according to the inventionAs an example of substances, mention may be made of Molyvan sold by Vanderbilt

In another embodiment, the organo-molybdenum compound may be selected from molybdenum dithiophosphates or molybdenum dithiocarbamates.

In a preferred embodiment of the invention, the organo-molybdenum compound is selected from molybdenum dithiocarbamates.

Molybdenum dithiocarbamate compounds (Mo-DTC compounds) are complexes of a metal core bound to one or more ligands, which are alkyldithiocarbamates. These compounds are well known to those skilled in the art.

In one embodiment of the invention, the Mo-DTC compound may comprise from 1 to 40% by weight, preferably from 2 to 30% by weight, more preferably from 3 to 28% by weight, advantageously from 4 to 15% by weight, of molybdenum, relative to the total weight of the Mo-DTC compound.

In another embodiment of the invention, the Mo-DTC compounds may comprise from 1 to 40% by weight, preferably from 2 to 30% by weight, more preferably from 3 to 28% by weight, advantageously from 4 to 15% by weight of sulfur, relative to the total weight of the Mo-DTC compounds.

In another embodiment of the invention, the Mo-DTC compound may be selected from Mo-DTC compounds having a core containing 2 molybdenum atoms (also known as dimeric Mo-DTC) and Mo-DTC compounds having a core containing 3 molybdenum atoms (also known as trimeric Mo-DTC).

In another embodiment of the invention, the trimeric Mo-DTC compound corresponds to the formula Mo₃S_kL_nWherein:

k is an integer of at least 4, preferably from 4 to 10, advantageously from 4 to 7;

n is an integer from 1 to 4; and is

L is an alkyldithiocarbamate, the alkyl group having from 1 to 100 carbon atoms, preferably from 1 to 40 carbon atoms, advantageously from 3 to 20 carbon atoms.

As examples of trimeric Mo-DTC compounds according to the invention, mention may be made, for example, of the compounds described in documents WO 98/26030 and US 2003/022954, and of the processes for their preparation.

In a preferred embodiment of the invention, the Mo-DTC compound is a dimeric Mo-DTC compound.

As examples of dimeric Mo-DTC compounds, mention may be made, for example, of the compounds described in documents EP 0757093, EP150719851, EP 0743354 or EP 1013749 and the processes for their preparation.

Dimeric Mo-DTC compounds generally correspond to compounds of the formula (V):

wherein:

R₃、R₄、R₅、R₆the same or different, each independently a hydrocarbyl group selected from: alkyl, alkenyl, aryl, cycloalkyl or cycloalkenyl;

X₃、X₄、X₅and X₆The same or different, each independently an oxygen atom or a sulfur atom.

With alkyl in the meaning of the present invention it is meant a straight or branched, saturated or unsaturated hydrocarbon radical having from 1 to 24 carbon atoms.

In one embodiment of the present invention, the alkyl group is selected from the group consisting of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, hexadecyl, stearyl, eicosyl, docosyl, tetracosyl, triacontyl, 2-ethylhexyl, 2-butyloctyl, 2-butyldecyl, 2-hexyloctyl, 2-hexyldecyl, 2-octyldecyl, 2-hexyldodecyl, 2-octyldodecyl, 2-decyltetradecyl, 2-dodecylhexadecyl, 2-hexadecyloctadecyl, 2-tetradecyloctadecyl, myristyl, palmityl and stearyl groups.

With alkenyl in the meaning of the present invention it is meant a straight or branched chain hydrocarbon radical comprising at least one double bond and having 2 to 24 carbon atoms. The alkenyl group may be selected from the group consisting of vinyl, allyl, propenyl, butenyl, isobutenyl, pentenyl, isopentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tetradecenyl, and oleyl.

With aryl in the meaning of the present invention it is meant a polycyclic aromatic hydrocarbon or aromatic group, which is substituted or unsubstituted by alkyl. The aryl group may have 6 to 24 carbon atoms.

In one embodiment, the aryl group can be selected from the group consisting of phenyl, toluyl, xylyl, cumyl, mesityl, benzyl, phenethyl, styryl, cinnamyl, benzhydryl, trityl, ethylphenyl, propylphenyl, butylphenyl, pentylphenyl, hexylphenyl, heptylphenyl, octylphenyl, nonylphenyl, decylphenyl, undecylphenyl, dodecylphenyl, phenylphenyl, benzylphenyl, phenyl-styrene, p-cumylphenyl, and naphthyl.

Cycloalkyl and cycloalkenyl groups within the meaning of the present invention can be selected from, but are not limited to, cyclopentyl, cyclohexyl, cycloheptyl, methylcyclopentyl, methylcyclohexyl, methylcycloheptyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, methylcyclopentenyl, methylcyclohexenyl. Cycloalkyl and cycloalkenyl groups can have 3 to 24 carbon atoms.

In a preferred embodiment of the invention, R₃、R₄、R₅And R₆The same or different, each independently an alkyl group having 4 to 18 carbon atoms or an alkenyl group having 2 to 24 carbon atoms.

In an embodiment of the present invention, X₃、X₄、X₅And X₆May be the same and may represent a sulfur atom.

In another embodiment of the present invention, X₃、X₄、X₅And X₆May be the same and may represent an oxygen atom.

In another embodiment of the present invention, X₃And X₄May represent a sulfur atom, and X₅And X₆May represent an oxygen atom.

In another embodiment of the present invention, X₃And X₄May represent an oxygen atom, and X₅And X₆May represent a sulfur atom.

In another embodiment of the present invention, the ratio of the number of sulfur atoms to the number of oxygen atoms (S/O) of the Mo-DTC compound can be varied from (1:3) to (3: 1).

In another embodiment of the present invention, the Mo-DTC compound of formula (V) can be selected from the group consisting of symmetric Mo-DTC compounds, asymmetric Mo-DTC compounds, and combinations thereof.

With regard to the symmetrical Mo-DTC compounds according to the invention, they represent Mo-DTC compounds of the formula (V), wherein R₃、R₄、R₅And R₆The groups are the same.

With regard to the asymmetric Mo-DTC compounds according to the invention, they represent Mo-DTC compounds of the formula (V) in which the radical R₃And R₄Same, radical R₅And R₆Are identical, and the radicals R₃And R₄Is different from the group R₅And R₆。

In a preferred embodiment of the invention, the Mo-DTC compound is a mixture of at least one symmetrical Mo-DTC compound and at least one asymmetrical Mo-DTC compound.

In one embodiment of the present invention, R₃And R₄Same and represents an alkyl group having 5 to 15 carbon atoms, and R₅And R₆Identical, but different from R₃And R₄And represents an alkyl group having 5 to 15 carbon atoms.

In a preferred embodiment of the invention, R₃And R₄Identical and represents an alkyl radical having from 6 to 10 carbon atoms, R₅And R₆Represents an alkyl group having 10 to 15 carbon atoms.

In another preferred embodiment of the present invention, R₃And R₄Same, represents an alkyl group having 10 to 15 carbon atoms, and R₅And R₆Is an alkyl group having 6 to 10 carbon atoms.

In another preferred embodiment of the present invention, R₃、R₄、R₅And R₆Identical, and represents an alkyl group having from 5 to 15 carbon atoms, preferably from 8 to 13 carbon atoms.

Advantageously, the Mo-DTC compound is selected from compounds of the formula (V),

wherein:

-X₃and X₄Is an oxygen atom;

-X₅and X₆Is a sulfur atom;

-R₃is an alkyl group having 8 carbon atoms or an alkyl group having 13 carbon atoms;

-R₄is an alkyl group having 8 carbon atoms or an alkyl group having 13 carbon atoms;

-R₅is an alkyl group having 8 carbon atoms or an alkyl group having 13 carbon atoms;

-R₆is an alkyl group having 8 carbon atoms or an alkyl group having 13 carbon atoms.

Advantageously, therefore, the Mo-DTC compound is selected from compounds of formula (V-a):

wherein the radical R₃、R₄、R₅And R₆For example as defined for formula (V).

More advantageously, the Mo-DTC compound is a mixture of:

Mo-DTC compounds of the formula (V-a), in which R₃、R₄、R₅And R₆Represents an alkyl group having 8 carbon atoms;

Mo-DTC compounds of the formula (V-a), in which R₃、R₄、R₅And R₆Represents an alkyl group having 13 carbon atoms; and

Mo-DTC compounds of the formula (V-a), in which R₃、R₄Represents an alkyl group having 13 carbon atoms, and R₅And R₆Represents an alkyl group having 8 carbon atoms; and/or

Mo-DTC compounds of the formula (V-a), in which R₃、R₄Is represented byAlkyl of 8 carbon atoms, and R₅And R₆Represents an alkyl group having 13 carbon atoms.

As an example of Mo-DTC compounds, mention may be made of R.T Vanderbilt

Product sold Molyvan

Molyvan

Or Molyvan

Or the product Sakura-lube sold by Adeka

Sakura-lube

Sakura-lube

Or Sakura-lube

Preferably, the lubricant composition of the present invention comprises from 0.05% to 5% by weight, preferably from 0.1% to 2% by weight of the partially or fully neutralized amine salt, relative to the total weight of the composition.

Preferably, the lubricant composition of the invention comprises from 0.01% to 3% by weight, preferably from 0.05% to 3% by weight, for example from 0.1% to 2% by weight, of the organomolybdenum compound, relative to the total weight of the composition.

In general, the lubricant compositions of the present invention may comprise any type of mineral, synthetic or natural, animal or vegetable lubricant base oil known to the skilled artisan.

The base oil used in the lubricant composition of the present invention may be an oil of mineral or synthetic origin (or its equivalent in the ATIEL classification) belonging to classes I to V in the classification defined in the API classification (table a) or a mixture thereof.

TABLE A

The mineral base oils of the present invention include all types of base oils obtained by: the crude oil is distilled under vacuum and atmospheric pressure and then subjected to refining operations such as solvent extraction, deasphalting, solvent dewaxing, hydrotreating, hydrocracking, hydroisomerization, and hydrofinishing.

Mixtures of synthetic and mineral oils may also be employed.

In general, there is no limitation as to the use of the different lubricating base oils used to prepare the lubricating compositions of the present invention, except that they must have properties suitable for use in an engine or vehicle transmission, in particular viscosity, viscosity index, sulphur content, oxidation resistance.

The base oil of the lubricant composition of the present invention may also be selected from synthetic oils such as certain esters of carboxylic acids and alcohols; and is selected from polyalphaolefins. The polyalphaolefins used as base oils are obtained, for example, from monomers having from 4 to 32 carbon atoms, for example from octene or decene, and have a thickness of from 1.5 to 15mm at 100 ℃ according to the standard ASTM D445².s^-1Viscosity of (2). They generally have an average molecular weight of between 250 and 3000 according to the standard ASTM D5296.

Preferably, the base oil of the present invention is selected from the above base oils having an aromatics content of between 0% and 45%, preferably between 0% and 30%. The aromatic content of the oil was measured according to the UV burdet method. Without wishing to be bound by any theory, the aromaticity of the base oil is a characteristic that allows the working of the polymer to be optimized as a function of temperature. The choice of an oil with a low aromaticity content allows optimization at higher temperatures.

Advantageously, the lubricant composition of the invention comprises at least 50% by weight of base oil, relative to the total weight of the composition.

More advantageously, the lubricant composition of the invention comprises at least 60% by weight, even at least 70% by weight, of base oil, relative to the total weight of the composition.

More particularly advantageously, the lubricant composition of the invention comprises from 60% to 99.5% by weight of base oil, preferably from 70% to 99.5% by weight of base oil, relative to the total weight of the composition.

A wide variety of additives may be employed in the lubricant compositions of the present invention.

Preferred additives for use in the lubricant composition used in the present invention are selected from the group consisting of detergents, anti-wear additives, friction modifiers other than organo-molybdenum compounds, extreme pressure additives, dispersants, pour point depressants, anti-foaming agents, thickeners, and mixtures thereof.

Preferably, the lubricant composition of the present invention comprises at least one anti-wear additive, at least one extreme pressure additive, or mixtures thereof.

Antiwear and extreme pressure additives protect the friction surface by forming a protective film that adsorbs on the surface.

A wide variety of anti-wear additives exist. Preferably, for the lubricating composition of the present invention, the anti-wear additive is selected from phosphorus-vulcanizing additives such as metal alkyl thiophosphates, in particular zinc alkyl thiophosphates, and more particularly zinc dialkyl dithiophosphate or ZnDTP. Preferred compounds have the formula Zn ((SP (S)) (OR)¹)(OR²))₂Wherein R is²And R³The same or different, are each independently an alkyl group, preferably an alkyl group having 1 to 18 carbon atoms.

Amine phosphates are also anti-wear additives that may be used in the lubricant compositions of the present invention. However, the phosphorus contributed by these additives can have a deleterious effect on the catalytic system of the motor vehicle as these additives generate ash. These effects can be minimized by partial replacement of the amine phosphate by additives that do not contain phosphorus, such as, for example, polysulfides, in particular sulfurized olefins.

Advantageously, the lubricating composition of the present invention may comprise from 0.01% to 6% by weight, preferably from 0.05% to 4% by weight, more preferably from 0.1% to 2% by weight of antiwear and extreme pressure additives, relative to the total weight of the lubricant composition.

Advantageously, the lubricant composition of the present invention may comprise at least one additional friction modifying additive different from the organomolybdenum compound. The additional friction modifying additive may be selected from the group consisting of metal element providing compounds and ashless compounds. Among the compounds providing the metal element, transition metal complexes such as Mo, Sb, Sn, Fe, Cu, Zn, whose ligands may be hydrocarbon compounds containing an oxygen atom, a nitrogen atom, a sulfur atom, or a phosphorus atom, may be mentioned. The ash-free friction modifying additive is typically organic derived and may be selected from monoesters of fatty acids and polyols, fatty epoxides, boric acid fatty epoxides; or fatty acid glycerides. According to the invention, the fatty compound comprises at least one hydrocarbon group having from 10 to 24 carbon atoms.

Advantageously, the lubricant composition of the present invention may comprise from 0.01% to 2% by weight or from 0.01% to 5% by weight, preferably from 0.1% to 1.5% by weight or from 0.1% to 2% by weight of friction modifying additives, relative to the total weight of the lubricant composition.

Advantageously, the lubricant composition of the present invention may comprise at least one antioxidant additive.

Antioxidant additives generally allow for delayed degradation of the lubricant composition in use. This degradation may be explained, inter alia, by the formation of deposits, by the presence of sludge or by an increase in the viscosity of the lubricant composition.

The antioxidant additive acts in particular as a radical inhibitor or hydroperoxide decomposer. Among the antioxidant additives frequently used, mention may be made of antioxidant additives of the phenol type, antioxidant additives of the amino type, antioxidant additives of the phosphorus-sulfide type. Some of these antioxidant additives, such as phosphorus-vulcanizing antioxidant additives, can generate ash. The phenolic antioxidant additives may be ashless or may be in the form of neutral or basic metal salts. The antioxidant additive may be chosen in particular from sterically hindered phenols, esters of sterically hindered phenols andsterically hindered phenols containing thioether bridges, diphenylamines, by at least one C₁-C₁₂Alkyl-substituted diphenylamines, N' -dialkyl-aryl-diamines, and mixtures thereof.

Preferably, according to the invention, the sterically hindered phenol is chosen from compounds comprising a phenol group in which at least one adjacent carbon of the carbon carrying the alcohol function is substituted by at least one C₁-C₁₀Alkyl, preferably C₁-C₆Alkyl, preferably C₄Alkyl is preferably substituted by tert-butyl.

Amino compounds are another class of antioxidant additives that can be used, optionally in combination with phenolic antioxidant additives. Examples of amino compounds are aromatic amines, e.g. of the formula NR³R⁴R⁵Wherein R is³Is an optionally substituted aliphatic or aromatic radical, R⁴Is an optionally substituted aromatic radical, R⁵Is a hydrogen atom, an alkyl group, an aryl group or a compound of the formula R⁶S(O)_zR⁷Wherein R is⁶Is alkylene or alkenylene, R⁷Is alkyl, alkenyl or aryl, and z is 0, 1 or 2.

Sulfurized alkylphenols or their alkali or alkaline earth metal salts can also be used as antioxidant additives.

Another class of antioxidant additives are copper compound antioxidant additives, such as copper thiophosphates or dithiophosphates, salts of copper with carboxylic acids; copper dithiocarbamates, sulfonates, phenates, and acetylacetonates. Salts of copper salts I and II, succinic acid or anhydrides may also be used.

The lubricant compositions of the present invention may contain any type of antioxidant additive known to those skilled in the art.

Advantageously, the lubricant composition comprises at least one ashless antioxidant additive.

Also advantageously, the lubricant composition according to the invention comprises from 0.5% to 2% by weight of at least one antioxidant additive, relative to the total weight of the composition.

The lubricant compositions of the present invention may also comprise at least one detergent additive.

Detergent additives generally allow for the reduction of the formation of deposits on the surfaces of metal parts by dissolving secondary oxidation and combustion products.

Detergent additives which may be used in the lubricant compositions of the present invention are generally known to those skilled in the art. The detergent additive may be an anionic compound comprising a long chain of a lipophilic hydrocarbon and a hydrophilic head. The associated cation may be an alkali metal or alkaline earth metal cation.

The detergent additive is preferably selected from alkali or alkaline earth metal carboxylates, sulphonates, salicylates, naphthenates and phenates. The alkali and alkaline earth metals are preferably calcium, magnesium, sodium or barium.

These metal salts generally contain a stoichiometric amount of the metal or an excess (i.e., an amount greater than the stoichiometric amount) of the metal. They are overbased detergent additives; the excess metal which imparts the overbased nature to the detergent additive is then typically in the form of an oil-insoluble metal salt, for example a carbonate, hydroxide, oxalate, acetate, glutamate, preferably a carbonate.

Advantageously, the lubricant composition of the present invention may comprise from 2% to 4% by weight of detergent additive, relative to the total weight of the lubricant composition.

Also advantageously, the lubricating composition of the present invention may further comprise at least one pour point depressant additive.

Pour point depressants generally improve the performance of the lubricant compositions of the present invention at low temperatures by slowing the formation of paraffin crystals.

Mention may be made, as examples of pour point depressant additives, of alkyl polymethacrylates, polyacrylates, polyarylamides, polyalkylphenols, polyalkylnaphthalenes, alkylated polystyrenes.

Advantageously, the lubricating composition of the present invention may further comprise at least one dispersant.

The dispersant may be selected from mannich bases, succinimides and derivatives thereof.

Also advantageously, the lubricant composition of the present invention may comprise from 0.2 to 10% by weight of dispersant, relative to the total weight of the lubricant composition.

The lubricant compositions of the present invention may also comprise at least one additional polymer that improves viscosity index. As examples of additional polymers which improve the viscosity index, mention may be made of polymeric esters; hydrogenated or unhydrogenated homopolymers or copolymers of styrene, butadiene and isoprene; polymethacrylate (PMA).

The invention also relates to the use of the lubricant composition according to the invention for lubricating mechanical parts, in particular in transmissions and/or vehicle engines, preferably motor vehicle engines.

The composition of the invention is particularly useful for reducing friction between two surfaces (in particular between two steel surfaces, between two carbon-coated surfaces or between a steel surface and a carbon-coated surface), in particular in vehicle engines and preferably in motor vehicle engines.

In a particularly advantageous manner, the present invention relates to the use of the lubricant composition according to the invention for lubricating mechanical parts, in particular in transmissions and/or vehicle engines, preferably motor vehicle engines, wherein at least one of the parts is carbon-coated. Preferably, one of the components is carbon coated and the other component(s) is steel or carbon.

In a particularly advantageous manner, the composition according to the invention is used to reduce friction between two surfaces, at least one of which is carbon-coated, preferably one of which is carbon-coated and the other of which is a steel surface or both of which are carbon-coated, in particular in vehicle engines, preferably motor vehicle engines.

In the present invention, by "carbon coating" or "carbon coated" it is meant any coating comprising carbon. By carbon coating it is meant in particular a diamond coating and more particularly a nanodiamond coating. These coatings may in particular be in the form of at least one layer of nanocrystalline diamond having a purity of 70% to 99%. Preferably, the carbon coating is selected from the group of nanodiamond coatings in the form of: at least one layer of nanocrystalline diamond, having a purity of 70% to 99%, preferably 70% to 97%, advantageously 75%, and a thickness of 0.1 μm to 3 μm, preferably 0.5 μm to 2 μm, advantageously 1.5 μm.

These carbon coatings may also be chosen from coatings of the DLC type (diamond-like carbon). Any type of DLC coating may be used. In general, DLC groups a family of amorphous materials that contain carbon in nature. Among these families, hydrogenated DLC, especially a-C: H; and unhydrogenated DLC, particularly a-C or ta-C.

DLC has properties that vary with its sp 3-hybridized carbon content and hydrogen content. Some DLC variants may be doped with a metal element, such as iron, chromium, or tungsten.

DLC coatings generally have lower mechanical and thermal resistance than diamond coatings, as they are amorphous materials. On the other hand, they are generally less rough and more particularly they can be deposited on most substrates at low temperatures. Preferably, the DLC is a hydrogenated DLC, especially a-C: H containing 10% to 40% hydrogen.

Advantageously, the use of the lubricant composition of the invention prevents exacerbation and even reduces wear between two surfaces, in particular between two steel surfaces, between two carbon-coated surfaces or between a steel surface and a carbon-coated surface, in particular in vehicle engines, preferably motor vehicles.

The invention also relates to the use of the lubricant composition according to the invention for reducing the fuel consumption of a vehicle, in particular a motor vehicle.

Advantageously, the inventors have also demonstrated that the partially or fully neutralized amine salts of the present invention have better compatibility with seals (in particular engine seals and in particular seals of motor vehicle engines) than the corresponding non-neutralized amines. In the present invention, the seal is a seal employed in engine design, and is typically a polymeric seal, particularly an elastomeric seal, preferably a fluorinated elastomeric seal. The compositions of the invention allow in particular to limit the wear of engine seals, in particular in motor vehicle engines, compared with unneutralized amines.

The invention therefore also relates to the use of the composition according to the invention for additionally reducing the deterioration of seals housed in the engine of a vehicle, preferably a motor vehicle.

The invention also relates to a method for lubricating a mechanical component, in particular in a transmission and/or a vehicle engine, in particular a motor vehicle engine, comprising at least one step for placing at least one component in contact with a lubricant composition according to the invention. Preferably, at least one of the components is carbon coated and the other component(s) is a steel component or a carbon coated component.

The invention also relates to a method for reducing friction between two surfaces of a vehicle engine, in particular a motor vehicle, comprising at least one step to place at least one of the surfaces in contact with a lubricant composition according to the invention. The surfaces are for example as defined above. In particular, the method relates to reducing friction between two steel surfaces, between two carbon coated surfaces, or between a steel surface and a carbon coated surface. Preferably, the present invention relates to a method for reducing friction between two surfaces of a vehicle engine, in particular a motor vehicle engine, at least one of the surfaces being carbon-coated, the method comprising at least one step of placing at least one of the surfaces in contact with a lubricant composition according to the invention. Preferably one of the surfaces is carbon coated and the other is steel, or both surfaces are carbon coated.

Advantageously, the wear between two surfaces, in particular between two steel surfaces, between two carbon-coated surfaces or between a steel surface and a carbon-coated surface, in particular in a vehicle engine and preferably a motor vehicle engine, can be unabated and even reduced using the method of the invention.

Advantageously, the wear between two surfaces, at least one of which is carbon-coated, can be not exacerbated and even reduced using the method of the present invention.

The invention also relates to a method for reducing the fuel consumption of a vehicle, preferably a motor vehicle, comprising at least one step to place a mechanical component of the vehicle engine in contact with a lubricant composition such as defined above.

The engine of the invention may be a two-stroke internal combustion engine or a four-stroke internal combustion engine. The engine may be a gasoline engine or a diesel engine intended to be driven by conventional gasoline or diesel. In the present invention, with respect to conventional gasoline or with respect to conventional diesel oil, it means an engine driven by a fuel obtained after refining an oil of mineral origin (e.g., crude oil). The engine may also be a gasoline engine or a diesel engine modified to be driven by an oil-containing fuel derived from renewable materials, such as an alcohol-based fuel or biodiesel.

The vehicle of the present invention may be a light vehicle such as a car and a motorcycle. The vehicle may also be a heavy vehicle, a construction machine, a ship.

The transmission of the present invention may be a transmission, in particular a gearbox, for use in a light vehicle such as a motor vehicle.

The transmission of the invention may also be a transmission, in particular a gearbox or a shaft, used in heavy vehicles, construction machinery.

The transmission of the invention may also be a transmission used in industrial machines, in particular a gear or gearbox for a wind turbine.

A further subject of the present invention is the use of a combination of a fully or partially neutralized amine salt (such as defined above) and at least one organomolybdenum compound in a lubricant composition comprising at least one base oil, to reduce friction between two surfaces, in particular between two steel surfaces, between a steel surface and a carbon-coated surface, or between two carbon-coated surfaces in an engine, in particular a vehicle engine and in particular a motor vehicle engine.

A further subject of the present invention is the use of a combination of a fully or partially neutralized amine salt (such as defined above) and at least one organomolybdenum compound in a lubricant composition comprising at least one base oil, for reducing friction between two surfaces in an engine (in particular a vehicle engine and in particular a motor vehicle), at least one of said surfaces being carbon-coated. Preferably, one of the surfaces is a carbon surface and the other is a steel surface, or both surfaces are carbon surfaces.

With the above use it is also possible to not aggravate and even reduce wear, in particular between two steel surfaces, between a steel surface and a carbon-coated surface or between two carbon-coated surfaces in a vehicle engine, and preferably in a motor vehicle engine.

With the above use, it is also possible to not aggravate and even reduce the wear between two surfaces (in particular in vehicle engines, preferably in motor vehicle engines), at least one of which is carbon-coated. Preferably, one of the surfaces is carbon coated and the other surface is a steel surface, or both surfaces are carbon coated.

The different uses mentioned before also allow to reduce the deterioration of the seals housed in the vehicle engine, preferably a motor vehicle.

[ detailed description ] embodiments

The invention is described below by means of non-limiting examples.

Example 1: lubricant compositions of the invention, preparation of comparative lubricant compositions, and use of these compositions and automotive applications Compatibility evaluation of seals used in vehicle engines.

Lubricant compositions (reference 1) were prepared according to table 1 below (composition given in weight (g)).

-base oil 1: group III basestocks (kinematic viscosity at 40 ℃ ═ 20mm, measured according to standard ASTM D445)²/s)；

-base oil 2: group III basestocks (kinematic viscosity at 40 ℃ ═ 25mm, measured according to standard ASTM D445)²/s)；

-a viscosity index improver: hydrogenated styrene/isoprene polymers;

-an additive package: zinc dithiophosphate type antiwear agents, diphenylamine type antioxidants, calcium salicylate type detergents (sold by infinium)

)；

-pour point depressants: polymethacrylate (Lubrizol sold by Lubrizol

)；

-amine 1: neutralized aliphatic diamine (Duomeen sold by Akzo Nobel

)；

-amine 2: unneutralized aliphatic diamine (Duomeen sold by Akzo Nobel

)；

-a friction modifier: molybdenum dithiocarbamate (Sakuralube sold by Adeka)

)。

TABLE 1

Lubricant compositions of the present invention and comparative compositions were prepared according to table 2 below (compositions given in weight (g)).

TABLE 2

The compatibility of the prepared lubricant compositions with elastomeric seals of RE1 type was evaluated according to the standard CEC-L-39-T96, and the results obtained are given in Table 3.

TABLE 3

The results show that the lubricant composition of the present invention comprising a combination of a neutralized amine and an organomolybdenum compound (composition 1) has better compatibility with seals used in engines, particularly fluorinated elastomeric seals, than the lubricant composition comprising a combination of an unneutralized amine and an organomolybdenum compound (comparative composition 1).

Example 2: lubricant compositions of the invention, preparation of comparative lubricant compositions and their reduction in DLC- Evaluation of the Friction Properties of Steel contacts

Lubricant compositions (reference 2) were prepared according to table 4 below (composition given in weight (g)).

-a base oil: group III basestocks (kinematic viscosity at 40 ℃ ═ 19mm, measured according to standard ASTM D445)²/s)；

-a viscosity index improver: hydrogenated styrene/isoprene polymers;

-an additive package: a dispersant, a calcium phenate detergent, a calcium carboxylate detergent, and a calcium sulfonate detergent;

-pour point depressants: polymethacrylates (sold by Evonik

)；

-amine 1: neutralized aliphatic diamine (Duomeen sold by Akzo Nobel

)；

-amine 2: unneutralized aliphatic diamine (Duomeen sold by Akzo Nobel

)；

-amine 3: neutralized fatty triamines (Armolube sold by Akzo Nobel

)；

-amine 4: unneutralized fatty triamines (Triameen sold by Akzo Nobel

)；

-a friction modifier: molybdenum dithiocarbamate (Sakuralube sold by Adeka)

)。

TABLE 4

Lubricant compositions of the present invention and comparative compositions were prepared according to table 5 below (compositions given in weight (g)).

TABLE 5

The first test was used to evaluate the friction performance of the lubricant composition.

The coefficient of friction was evaluated using a linear tribometer, DLC bead/steel plane, under the following conditions:

type of steel: 100c 6;

type of DLC coating on beads: a CH hydrogenated DLC containing between 31 and 33% hydrogen and having a molar ratio (sp) of 55:45²Carbon/sp³Carbon);

thickness of DLC layer: 1.5 mu;

-temperature: 110 ℃;

-a normal load of 5N;

-10mm stroke distance.

A second test was also performed to evaluate the friction performance of the lubricant composition, which allowed the engine friction to be characterized on operating points representative of the points scanned during the NEDC cycle (new european driving cycle).

The test engine was a RENAULT H4BT engine, which corresponds to a 3-cylinder multipoint indirect injection gasoline engine, and meets EURO 5 standards.

The non-spark-ignited heat engine is driven by the generator at the desired speed. The fluids (coolant and lubricant) were temperature controlled because no combustion occurred using this type of test. The torque provided by the generator to drive the heat engine is measured at each operating point. A comparison between the drive torques of engines using different lubricants allows identification of those lubricants that exhibit the best frictional properties.

The test operating points are as follows:

-engine speed (rpm): 4000-3500-3000-2500-2000-1500-1000-750

-regulated lubricant temperature at manifold: 40-60-90-110 DEG C

-water temperature regulated at the engine outlet: 40-60-90-100 DEG C

At the completion of the test, the lower the value obtained, the better the friction reducing properties of the tested lubricant.

The properties of the prepared lubricant compositions were evaluated, and the results are given in table 6.

TABLE 6

The results show that the inventive lubricant compositions comprising a combination of a neutralized amine and an organomolybdenum compound (compositions 2 and 3) exhibit friction reducing properties, particularly on DLC/steel contacts, which are at least comparable to and even better than the lubricant compositions comprising a combination of an unneutralized amine and an organomolybdenum compound (comparative compositions 3 and 4).

Claims

1. Use of a lubricant composition to reduce friction between two surfaces, at least one of which is carbon coated, said composition comprising:

-at least one base oil;

-at least one organomolybdenum compound;

R-N(X)-Y (I)

wherein:

r is a linear or branched, fully or partially saturated hydrocarbon group having from 2 to 24 carbon atoms;

x is a hydrogen atom; a linear or branched, fully or partially saturated hydrocarbon group having 1 to 24 carbon atoms; benzyl or of the formula-R¹-[NH-R²]_n-NH₂A group of (a);

y is a hydrogen atom; a linear or branched, fully or partially saturated hydrocarbon group having 1 to 24 carbon atoms; a benzyl group; or the formula-R¹-[NH-R²]_n-NH₂A group of (a);

n is an integer of 0 to 3;

R¹and R²Identical or different, are linear or branched alkyl groups having from 2 to 4 carbon atoms;

at least one of X or Y is a hydrogen atom or-R¹-[NH-R²]_n-NH₂；

X, Y or at least one of R is a straight or branched chain, fully or partially saturated hydrocarbon group having from 4 to 24 carbon atoms;

the acid that neutralizes the amine is selected from monoacids of formula (II):

R’COOH (II)

2. Use according to claim 1, wherein the amine corresponds to the following formula (Ia):

R-N(X)-R¹-[NHR²]_n-NH₂ (Ia)

r, X, R therein¹、R²And n has the definitions given in claim 1,

at least one of X or R is a straight or branched, fully or partially saturated hydrocarbon group having from 4 to 24 carbon atoms.

3. Use according to claim 1 or 2, wherein:

r is a linear or branched, fully or partially saturated hydrocarbon radical having from 14 to 24 carbon atoms;

x is a hydrogen atom; a linear or branched alkyl group having 2 to 8 carbon atoms; benzyl or of the formula-R¹-[NH-R²]_n-NH₂A group of (1).

4. The use as claimed in claim 1 or 2, wherein:

x is a hydrogen atom or a group of the formula-R¹-[NH-R²]_n-NH₂A group of (1).

5. The use as claimed in claim 1 or 2, wherein:

y is-R¹-[NH-R²]_n-NH₂；

n＝0；

R¹Is CH₂CH₂CH₂(ii) a And is

X is CH₂CH₂CH₂NH₂Or H.

6. Use according to claim 1 or 2, wherein the composition has a molar ratio between the number of moles of nitrogen atoms in the amine and the number of moles of acid of formula (II) comprised between 9:1 and 1: 1.

7. Use according to claim 1 or 2, wherein R' is a linear or branched, fully or partially saturated hydrocarbon radical having from 7 to 24 carbon atoms.

8. The use as claimed in claim 1 or 2, wherein the organomolybdenum compound is a molybdenum dithiocarbamate compound.

9. Use according to claim 1 or 2, wherein the amine is selected from the following amines:

RNHCH₂CH₂CH₂NH₂wherein R is a linear or branched, fully or partially saturated hydrocarbon radical having from 16 to 18 carbon atoms; or

N(R)(CH₂CH₂CH₂NH₂)(CH₂CH₂CH₂NH₂) Wherein R is a linear or branched, fully or partially saturated hydrocarbon radical having from 16 to 18 carbon atoms.

10. Use according to claim 1 or 2, wherein the composition comprises from 0.05% to 5% by weight of neutralized amine, relative to the total weight of the composition.

11. Use according to claim 1 or 2, wherein the composition comprises from 0.01% to 3% by weight of the organomolybdenum compound relative to the total weight of the composition.

12. Use according to claim 1 or 2, wherein the composition further comprises at least one anti-wear additive.

13. Use according to claim 1 or 2 to reduce friction in a vehicle engine.

14. Use according to claim 1 or 2 to reduce friction between steel surfaces and carbon coated surfaces in vehicle engines.

15. Use according to claim 1 or 2 to reduce friction between two carbon coated surfaces in a vehicle engine.

16. Use according to claim 1 or 2, additionally to reduce the deterioration of seals housed in a vehicle engine.