EP3083907B1 - Lubricant composition made from fatty triamines - Google Patents

Description

Technical area

The present invention is applicable to the field of lubricants, in particular lubricants for engine, and more particularly for engine of motor vehicles. More particularly, the present invention relates to a lubricating composition comprising at least one base oil, at least one organomolybdenum compound, at least one compound comprising a dithiophosphate group and at least one fatty triamine. The lubricant composition according to the invention has both good friction properties for steel / steel contacts, for steel / carbon coating contacts as well as for carbon coating / carbon coating contacts, while retaining good anti-wear properties. .

The present invention also relates to a lubrication process using this composition.

The present invention also relates to a method for reducing friction between two steel surfaces, in particular in an engine, and more particularly in a motor vehicle engine.

The present invention also relates to a method for reducing friction between a steel surface and a surface covered with carbon, in particular in an engine, and more particularly in a motor vehicle engine.

The present invention also relates to a method for reducing friction between two carbon-coated surfaces, and more particularly in a motor vehicle engine.

The present invention also relates to a method for reducing the fuel consumption of a vehicle, and more particularly of a motor vehicle.

The present invention also relates to the use of a fatty triamine in a lubricating composition to reduce friction between two steel surfaces, in particular in an engine, and more particularly in a motor vehicle engine.

The present invention also relates to the use of a fatty triamine in a lubricating composition to reduce friction between a steel surface and a surface covered with carbon, in particular in an engine, and more particularly in a motor vehicle engine.

The present invention also relates to the use of an oily triamine in a lubricating composition to reduce friction between two surfaces covered with carbon, in particular in an engine, and more particularly in an engine of motor vehicles.

The present invention also relates to the use of a fatty triamine in a lubricating composition for reducing the fuel consumption of a vehicle, and more particularly of a motor vehicle.

The present invention also relates to a concentrated composition type of additives comprising at least one organomolybdenum compound, at least one compound comprising a dithiophosphate group and at least one fatty triamine.

Technological background

The purpose of lubricants is to reduce the friction and wear phenomena of mechanical parts, in particular in vehicle engines, and more particularly in motor vehicles.

To reduce these friction phenomena, it is known to incorporate friction modifiers in lubricants.

Among the friction modifiers, organomolybdenum compounds represent a family of compounds whose properties for reducing friction phenomena have been widely described, and more particularly in the contacts between two steel surfaces.

However, it is known to those skilled in the art that the use of organomolybdenum compounds, in particular organomolybdenum compounds comprising a dithiocarbamate group, can cause aggravation of the phenomena of wear of mechanical parts.

Thus, to solve this problem, the combination of an organomolybdenum compound and an antiwear product such as a compound comprising a dithiophosphate group in a lubricating composition has been widely described.

The document US 5,650,381 describes in particular a lubricating composition comprising an organomolybdenum compound and a zinc dithiophosphate.

Furthermore, it is known to apply a coating to parts, in particular metal parts, making it possible to increase their resistance to wear under conditions of intensive and repeated friction. Among the existing technologies, it is known carbon coatings, and in particular DLC coatings (Diamond Like Carbon) based on an amorphous carbon material with properties close to those of diamond.

Thus, DLC coatings are used as coatings on the surfaces of parts in vehicle engines, and in particular in motor vehicle engines.

However, it is also known that the properties of reduction of the friction phenomena of a carbon coating, and in particular of a DLC coating, can be altered, even degraded in the presence of a lubricant.

More particularly, it has been observed that the organomolybdenum compounds present in a lubricant can degrade or even peel off a carbon coating present on a surface and that this degradation can be accentuated with the increase in the content of organomolybdenum compounds in the lubricant. Thus, lubricants compatible with surfaces covered with a carbon material, and in particular a DLC coating or a nanodiamond coating, have been sought, these lubricants not comprising organolmolybdenum compounds. For example, the document EP 2479247 describes a lubricant comprising a compound based on a zinc phosphate compound and a sulfur compound.

Furthermore, the document EP 1338641 describes a lubricant comprising an amine as a friction modifier compatible with a surface having a DLC coating.

However, this document gives no teaching as to the properties of reduction of the phenomena of friction of these lubricants for steel / steel contacts.

In addition, this document gives no teaching as to the anti-wear properties of these lubricants, whether for steel / steel or steel / carbon coating contacts. US 5,650,381 describes an engine oil comprising an organomolybdenum compound and a zinc dithiophosphate to reduce friction.

The use of carbon coating in engines, in particular of motor vehicles being growing, there is therefore always a need to look for lubricants having at the same time good friction properties for steel / steel contacts, for steel / carbon coating contacts and for carbon coating / carbon coating contacts, while retaining good anti-wear properties.

An objective of the present invention is to provide a lubricating composition which overcomes all or part of the aforementioned drawbacks.

Another objective of the invention is to provide a lubricating composition the formulation of which is easy to use.

Another object of the present invention is to provide a lubrication method for reducing friction between two steel surfaces, between a steel surface and a carbon coated surface as well as between two carbon coated surfaces.

Summary of the invention

The invention is defined in subsequent claims 1 to 14.

• au moins une huile de base,
• de 0.05 à 3 % en poids d'au moins un composé organomolybdène,
• de 0,1 à 5 % en poids d'au moins un composé comprenant un groupement dithiophosphate, et
• de 0.1 à 5 % en poids d'au moins une triamine grasse.

The invention thus relates to a lubricating composition comprising:

• at least one base oil,
• from 0.05 to 3% by weight of at least one organomolybdenum compound,
• from 0.1 to 5% by weight of at least one compound comprising a dithiophosphate group, and
• from 0.1 to 5% by weight of at least one fatty triamine.

Surprisingly, the Applicant has found that the presence of at least one organomolybdenum compound, at least one compound comprising a dithiophosphate group and at least one fatty triamine in a lubricating composition makes it possible to confer on the lubricating composition simultaneously good friction properties for steel / steel contacts, for steel / carbon coating contacts and for carbon coating / carbon coating contacts.

Thus, the present invention makes it possible to formulate lubricant compositions comprising an optimized content of organomolybdenum compounds and having good friction properties for steel / steel contacts, for steel / carbon coating contacts as well as for carbon coating / carbon coating contacts.

Advantageously, the lubricant compositions according to the invention have good friction properties for steel / steel contacts, for steel / carbon coating contacts and for carbon coating / carbon coating contacts, while retaining good anti-wear properties.

Advantageously, the lubricant compositions according to the invention allow fuel savings in all the operating phases of an engine. vehicle, preferably motor vehicles, and more particularly at start-up.

Advantageously, the lubricant compositions according to the invention exhibit good storage stability as well as a viscosity which does not vary or varies very little.

• au moins une huile de base,
• au moins un composé organomolybdène,
• au moins un composé comprenant un groupement dithiophosphate, et
• au moins une triamine grasse.

In one embodiment of the invention, the lubricating composition essentially consists of:

• at least one base oil,
• at least one organomolybdenum compound,
• at least one compound comprising a dithiophosphate group, and
• at least one fatty triamine.

The invention also relates to a motor oil comprising a lubricating composition as defined above.

The invention also relates to the use of a lubricating composition as defined above for the lubrication of mechanical parts, in particular in transmissions and / or vehicle engines, preferably motor vehicles.

The invention also relates to the use of a lubricating composition as defined above for reducing friction between two steel surfaces, in particular in a vehicle engine, preferably a motor vehicle.

The invention also relates to the use of a lubricant composition above to reduce friction between a steel surface and a surface covered with carbon, in particular in a vehicle engine, preferably a motor vehicle.

The invention also relates to the use of a lubricating composition as defined above for reducing friction between two surfaces covered with carbon, in particular in a vehicle engine, preferably a motor vehicle.

The invention also relates to the use of a lubricating composition as defined above for reducing the fuel consumption of vehicles, preferably motor vehicles.

The invention also relates to a method of lubricating mechanical parts, in particular in transmissions and / or engines of vehicles, preferably motor vehicles, comprising at least one step of bringing at least one part into contact with a lubricating composition such as defined above.

The invention also relates to a method for reducing friction between two steel surfaces, in particular in a vehicle engine, preferably of a motor vehicle, comprising at least one step of bringing at least one of the steel surfaces into contact with a composition. lubricant as defined above.

The invention also relates to a method for reducing friction between a steel surface and a surface covered with carbon, in particular in a vehicle engine, preferably a motor vehicle, comprising at least one step of bringing at least one of the surfaces with a lubricating composition as defined above.

The invention also relates to a method for reducing the friction between two surfaces covered with carbon, in particular in a vehicle engine, preferably a motor vehicle, comprising at least one step of bringing at least one of the surfaces covered with carbon into contact with a lubricating composition as defined above.

The invention also relates to a method for reducing the fuel consumption of a vehicle, preferably a motor vehicle, comprising at least one step of bringing a mechanical part of the engine of the vehicle into contact with a lubricating composition as defined above.

The invention also relates to the use of a fatty triamine in a lubricating composition comprising at least one base oil, at least one organomolybdenum compound and at least one compound comprising a dithiophosphate group for reducing friction between two steel surfaces, in particular in a vehicle engine, preferably a motor vehicle. The invention also relates to the use of a fatty triamine in a lubricating composition comprising at least one base oil, at least one organomolybdenum compound and at least one compound comprising a dithiophosphate group for reducing friction between a steel surface and a surface covered with carbon, in particular in a vehicle engine, preferably a motor vehicle.

The invention also relates to the use of a fatty triamine in a lubricating composition comprising at least one base oil, at least one organomolybdenum compound and at least one compound comprising a dithiophosphate group for reducing friction between two carbon-coated surfaces, in particular in a vehicle engine, preferably a motor vehicle.

The invention also relates to the use of a fatty triamine in a lubricating composition comprising at least one base oil, at least one organomolybdenum compound and at least one compound comprising a dithiophosphate group for reducing the fuel consumption of a vehicle, preferably a motor vehicle.

• au moins un composé organomolybdène,
• au moins un composé comprenant un groupement dithiophosphate, et
• au moins une triamine grasse.

There is also described a composition of concentrated additive type comprising:

• at least one organomolybdenum compound,
• at least one compound comprising a dithiophosphate group, and
• at least one fatty triamine.

Detailed description of the invention

The percentages given below correspond to percentages by mass of active material.

Organomolybdenum compound

The lubricant composition according to the invention comprises at least one organomolybdenum compound.

By organomolybdenum compound according to the invention is meant any organomolybdenum compound soluble in an oil.

In one embodiment of the invention, the organomolybdenum compound can be chosen from organic molybdenum complexes such as carboxylates, esters, molybdenum amides, which can be obtained by reaction of molybdenum oxide or molybdates of ammonium with fatty substances, glycerides, fatty acids or derivatives of fatty acids (esters, amines, amides ...).

In a preferred embodiment of the invention, the organomolybdenum compound is chosen from molybdenum complexes free from sulfur and phosphorus, with ligands of amide type, mainly prepared by reaction of a source of molybdenum, which can be by example molybdenum trioxide, and an amine derivative, and fatty acids comprising for example from 4 to 28 carbon atoms, preferably from 8 to 18 carbon atoms, such as for example the fatty acids contained in vegetable or animal oils.

The synthesis of such compounds is for example described in the patents US 4,889,647 , EP 0546357 , US 5,412,130 , EP 1770153 .

1. (i) d'un corps gras de type mono, di ou tri glycéride, ou acide gras,
2. (ii) d'une source aminée de formule (A) :
   

In a preferred embodiment of the invention, the organomolybdenum compound is chosen from the organic complexes of molybdenum obtained by reaction:

1. (i) a fatty substance of the mono, di or tri glyceride or fatty acid type,
2. (ii) from an amino source of formula (A):
   

• X¹ représente un atome d'oxygène ou un atome d'azote,
• X² représente un atome d'oxygène ou un atome d'azote,
• n et m représentent 1 lorsque X¹ ou X² représentent un atome d'oxygène,
• n et m représentent 2 lorsque X¹ ou X² représentent un atome d'azote, (iii) et d'une source de molybdène choisie parmi le trioxyde de molybdène ou les molybdates, préférentiellement le molybdate d'ammonium, en quantité suffisante pour fournir 0,1 à 30% de molybdène par rapport au poids total de complexe.

In which :

• X ¹ represents an oxygen atom or a nitrogen atom,
• X ² represents an oxygen atom or a nitrogen atom,
• n and m represent 1 when X ¹ or X ² represent an oxygen atom,
• n and m represent 2 when X ¹ or X ² represent a nitrogen atom, (iii) and a source of molybdenum chosen from molybdenum trioxide or molybdates, preferably ammonium molybdate, in sufficient quantity to provide 0.1 to 30% molybdenum relative to the total weight of complex.

In one embodiment of the invention, the organic molybdenum complex can comprise from 2 to 8.5% by weight of molybdenum relative to the weight of complex.

dans laquelle :

• X¹ représente un atome d'oxygène ou un atome d'azote ;
• X² représente un atome d'oxygène ou un atome d'azote ;
• n représente 1 lorsque X¹ représente un atome d'oxygène et m représente 1 lorsque X² représente un atome d'oxygène ;
• n représente 2 lorsque X¹ représente un atome d'azote et m représente 2 lorsque X² représente un atome d'azote ;
• R₁ représente un groupement alkyle linéaire ou ramifiée, saturé ou insaturé, comprenant de 3 à 30 atomes de carbone, préférentiellement de 3 à 20 atomes de carbone, avantageusement de 7 à 17 atomes de carbone ;

dans laquelle :

• X¹ représente un atome d'oxygène ou un atome d'azote ;
• X² représente un atome d'oxygène ou un atome d'azote ;
• n représente 1 lorsque X¹ représente un atome d'oxygène et m représente 1 lorsque X² représente un atome d'oxygène ;
• n représente 2 lorsque X¹ représente un atome d'azote et m représente 2 lorsque X² représente un atome d'azote ;
• R₁ représente un groupement alkyle linéaire ou ramifiée, saturé ou insaturé, comprenant de 3 à 30 atomes de carbone, préférentiellement de 3 à 20 atomes de carbone, avantageusement de 7 à 17 atomes de carbone ;
• R₂ représente un groupement alkyle linéaire ou ramifiée, saturé ou insaturé, comprenant de 3 à 30 atomes de carbone, préférentiellement de 3 à 20 atomes de carbone, avantageusement de 7 à 17 atomes de carbone.

In a preferred embodiment of the invention, the organic molybdenum complex consists of at least one of the compounds of formula (I) or (II), alone or as a mixture:

in which :

• X ¹ represents an oxygen atom or a nitrogen atom;
• X ² represents an oxygen atom or a nitrogen atom;
• n represents 1 when X ¹ represents an oxygen atom and m represents 1 when X ² represents an oxygen atom;
• n represents 2 when X ¹ represents a nitrogen atom and m represents 2 when X ² represents a nitrogen atom;
• R ₁ represents a linear or branched, saturated or unsaturated alkyl group comprising from 3 to 30 carbon atoms, preferably from 3 to 20 carbon atoms, advantageously from 7 to 17 carbon atoms;

in which :

• X ¹ represents an oxygen atom or a nitrogen atom;
• X ² represents an oxygen atom or a nitrogen atom;
• n represents 1 when X ¹ represents an oxygen atom and m represents 1 when X ² represents an oxygen atom;
• n represents 2 when X ¹ represents a nitrogen atom and m represents 2 when X ² represents a nitrogen atom;
• R ₁ represents a linear or branched, saturated or unsaturated alkyl group comprising from 3 to 30 carbon atoms, preferably from 3 to 20 carbon atoms, advantageously from 7 to 17 carbon atoms;
• R ₂ represents a linear or branched, saturated or unsaturated alkyl group, comprising from 3 to 30 carbon atoms, preferably from 3 to 20 carbon atoms, advantageously from 7 to 17 carbon atoms.

1. (i) d'un corps gras de type mono, di ou tri glycéride, ou acide gras,
2. (ii) de diéthanolamine ou de 2-(2-aminoethyl) aminoethanol,
3. (iii) et d'une source de molybdène choisie parmi le trioxyde de molybdène ou les molybdates, préférentiellement le molybdate d'ammonium, en quantité suffisante pour fournir 0,1 à 20,0% de molybdène par rapport au poids de complexe.

In one embodiment of the invention, the organic complex of molybdenum is prepared by reaction:

1. (i) a fatty substance of the mono, di or tri glyceride or fatty acid type,
2. (ii) diethanolamine or 2- (2-aminoethyl) aminoethanol,
3. (iii) and from a source of molybdenum chosen from molybdenum trioxide or molybdates, preferably ammonium molybdate, in an amount sufficient to provide 0.1 to 20.0% of molybdenum relative to the weight of complex.

dans laquelle R₁ représente un groupement alkyle linéaire ou ramifiée, saturé ou insaturé, comprenant de 3 à 30 atomes de carbone, préférentiellement de 3 à 20 atomes de carbone, avantageusement de 7 à 17 atomes de carbone,

dans laquelle R₁ représente un groupement alkyle linéaire ou ramifiée, saturé ou insaturé, comprenant de 3 à 30 atomes de carbone, préférentiellement de 3 à 20 atomes de carbone, avantageusement de 7 à 17 atomes de carbone.In a preferred embodiment of the invention, the organic molybdenum complex consists of at least one compound of formula (Ia) or (II-a), alone or as a mixture:

in which R ₁ represents a linear or branched, saturated or unsaturated alkyl group, comprising from 3 to 30 carbon atoms, preferably from 3 to 20 carbon atoms, advantageously from 7 to 17 carbon atoms,

in which R ₁ represents a linear or branched, saturated or unsaturated alkyl group, comprising from 3 to 30 carbon atoms, preferably from 3 to 20 carbon atoms, advantageously from 7 to 17 carbon atoms.

In another embodiment, the organomolybdenum compound can be chosen from molybdenum dithiophosphates or molybdenum dithiocarbamates.

In a preferred embodiment of the invention, the organomolybdenum compound is chosen from molybdenum dithiocarbamates.

Molybdenum dithiocarbamate compounds (Mo-DTC compounds) are complexes formed from a metal nucleus linked to one or more ligands, the ligand being an alkyl dithiocarbamate group. These compounds are well known to those skilled in the art.

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

In another embodiment of the invention, the Mo-DTC compound can comprise from 1 to 40%, preferably from 2 to 30%, more preferably from 3 to 28%, advantageously from 4 to 15% by mass of sulfur , based on the total mass of the Mo-DTC compound.

In another embodiment of the invention, the compound Mo-DTC can be chosen from those whose nucleus has two molybdenum atoms (also called dimeric Mo-DTC) and those whose nucleus has three molybdenum atoms (also called Mo-DTC trimer).

• k représente un nombre entier au moins égal à 4, de préférence allant de 4 à 10, avantageusement de 4 à 7,
• n est un entier allant de 1 à 4, et
• L étant un groupement dithiocarbamate d'alkyles comprenant de 1 à 100 atomes de carbone, de préférence de 1 à 40 atomes de carbone, avantageusement de 3 à 20 atomes de carbone.

In another embodiment of the invention, the trimeric Mo-DTC compounds correspond to the formula Mo ₃ S _k L _n in which:

• k represents an integer at least equal to 4, preferably ranging from 4 to 10, advantageously from 4 to 7,
• n is an integer ranging from 1 to 4, and
• L being an alkyl dithiocarbamate group comprising 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 of the compounds and their methods of preparation as described in the documents WO 98/26030 and US 2003/022954 .

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 of the compounds and their methods of preparation as described in the documents EP 0757093 , EP 0719851 , EP 0743354 or EP 1013749 .

dans laquelle :

• R₃, R₄, R₅, R₆, identiques ou différents, représentent indépendamment un groupement hydrocarboné choisi parmi les groupements alkyle, alcényle, aryle, cycloalkyle ou cycloalcényle,
• X₃, X₄, X₅ et X₆, identiques ou différents, représentent indépendamment un atome d'oxygène ou un atome de soufre.

The dimeric Mo-DTC compounds generally correspond to the compounds of formula (III):

in which :

• R ₃ , R ₄ , R ₅ , R ₆ , identical or different, independently represent a hydrocarbon group chosen from alkyl, alkenyl, aryl, cycloalkyl or cycloalkenyl groups,
• X ₃ , X ₄ , X ₅ and X ₆ , identical or different, independently represent an oxygen atom or a sulfur atom.

By alkyl group within the meaning of the invention means a hydrocarbon group, linear or branched, saturated or unsaturated, comprising from 1 to 24 carbon atoms.

In one embodiment of the invention, the alkyl group is chosen from the group formed by methyl, ethyl, propyl, isopropyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, l hexadecyl, stearyl, icosyl, 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, myristyle, palmityl and stearyl.

By alkenyl group within the meaning of the present invention means a linear or branched hydrocarbon group comprising at least one double bond and comprising from 2 to 24 carbon atoms. The alkenyl group can be chosen from vinyl, allyl, propenyl, butenyl, isobutenyl, pentenyl, isopentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, l 'undecenyl, dodecenyl, tetradecenyl and oleic.

By aryl group within the meaning of the present invention, is meant a polycyclic aromatic hydrocarbon or an aromatic group, substituted or not by an alkyl group. The aryl group can comprise from 6 to 24 carbon atoms. In one embodiment, the aryl group can be chosen from the group formed by phenyl, toluyl, xylyl, cumenyl, mesityl, benzyl, phenethyl, styryl, cinnamyl, benzhydryl, trityl, ethylphenyl, propylphenyl, butylphenyl, pentylphenyl, hexylphenyl, heptylphenyl, octylphenyl, nonylphenyl, decylphenyl, undecylphenyl, dodecylphenyl, phenylphenyl, benzylphenyl, phenylphenyl, phenylphenyl and phenylphenyl naphthyle.

Within the meaning of the present invention, the cycloalkyl groups and the cycloalkenyl groups can be chosen, without limitation, from the group consisting of cyclopentyl, cyclohexyl, cycloheptyl, methylcyclopentyl, methylcyclohexyl, methylcycloheptyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, methylcyclopentenyl, methylcyclohexenyl. Cycloalkyl groups and cycloalkenyl groups can have from 3 to 24 carbon atoms.

In a preferred embodiment of the invention, R ₃ , R ₄ , R ₅ and R ₆ , identical or different, independently represent an alkyl group comprising from 4 to 18 carbon atoms or an alkenyl group comprising from 2 to 24 carbon atoms.

In one embodiment of the invention, X ₃ , X ₄ , X ₅ and X ₆ may be identical and may represent a sulfur atom.

In another embodiment of the invention, X ₃ , X ₄ , X ₅ and X ₆ can be identical and can be an oxygen atom.

In another embodiment of the invention, X ₃ and X ₄ may represent a sulfur atom and X ₅ and X ₆ may represent an oxygen atom.

In another embodiment of the invention, X ₃ and X ₄ can represent an oxygen atom and X ₅ and X ₆ can represent a sulfur atom.

In another embodiment of the invention; the ratio in number of sulfur atoms relative to the number of oxygen atoms (S / O) of the Mo-DTC compound can vary from (1/3) to (3/1).

In another embodiment of the invention, the Mo-DTC compound of formula (A) can be chosen from a symmetrical Mo-DTC compound, an asymmetric Mo-DTC compound and their combination.

By symmetrical Mo-DTC compound according to the invention is meant a Mo-DTC compound of formula (III) in which the groups R ₃ , R ₄ , R ₅ and R ₆ are identical.

The expression asymmetric Mo-DTC compound according to the invention means a Mo-DTC compound of formula (III) in which the groups R ₃ and R ₄ are identical, the groups R ₅ and R ₆ are identical and the groups R ₃ and R ₄ are different from the groups R ₅ and R ₆ .

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 asymmetric Mo-DTC compound.

In one embodiment of the invention, R ₃ and R ₄ , identical, represent an alkyl group comprising from 5 to 15 carbon atoms and R ₅ and R ₆ , identical and different from R ₃ and R ₄ , represent a group alkyl comprising from 5 to 15 carbon atoms.

In a preferred embodiment of the invention, R ₃ and R ₄ , which are identical, represent an alkyl group comprising from 6 to 10 carbon atoms and R ₅ and R ₆ represent an alkyl group comprising from 10 to 15 carbon atoms.

In another preferred embodiment of the invention, R ₃ and R ₄ , which are identical, represent an alkyl group comprising from 10 to 15 carbon atoms and R ₅ and R ₆ represent an alkyl group comprising from 6 to 10 carbon atoms . In another preferred embodiment of the invention, R ₃ , R ₄ , R ₅ and R ₆ , which are identical, represent an alkyl group comprising from 5 to 15 carbon atoms, preferably from 8 to 13 carbon atoms.

• X₃ et X₄ représentent un atome d'oxygène,
• X₅ et X₆ représentent un atome de soufre,
• R₃ représente un groupement alkyle comprenant 8 atomes de carbone ou un groupement alkyle comprenant 13 atomes de carbone,
• R₄ représente un groupement alkyle comprenant 8 atomes de carbone ou un groupement alkyle comprenant 13 atomes de carbone,
• R₅ représente un groupement alkyle comprenant 8 atomes de carbone ou un groupement alkyle comprenant 13 atomes de carbone,
• R₆ représente un groupement alkyle comprenant 8 atomes de carbone ou un groupement alkyle comprenant 13 atomes de carbone.

Advantageously, the compound Mo-DTC is chosen from the compounds of formula (III) in which:

• X ₃ and X ₄ represent an oxygen atom,
• X ₅ and X ₆ represent a sulfur atom,
• R ₃ represents an alkyl group comprising 8 carbon atoms or an alkyl group comprising 13 carbon atoms,
• R ₄ represents an alkyl group comprising 8 carbon atoms or an alkyl group comprising 13 carbon atoms,
• R ₅ represents an alkyl group comprising 8 carbon atoms or an alkyl group comprising 13 carbon atoms,
• R ₆ represents an alkyl group comprising 8 carbon atoms or an alkyl group comprising 13 carbon atoms.

dans laquelle les groupements R₃, R₄, R₅ et R₆ sont tels que définis pour la formule (III).Thus, advantageously, the compound Mo-DTC is chosen from the compounds of formula (III-a)

in which the groups R ₃ , R ₄ , R ₅ and R ₆ are as defined for formula (III).

• d'un composé Mo-DTC de formule (III-a) dans laquelle R₃, R₄, R₅ et R₆ représentent un groupement alkyle comprenant 8 atomes de carbone,
• d'un composé Mo-DTC de formule (III-a) dans laquelle R₃, R₄, R₅ et R₆ représentent un groupement alkyle comprenant 13 atomes de carbone, et
• d'un composé Mo-DTC de formule (III-a) dans laquelle R₃, R₄ représentent un groupement alkyle comprenant 13 atomes de carbone et R₅ et R₆ représentent un groupement alkyle comprenant 8 atomes de carbone, et/ou
• d'un composé Mo-DTC de formule (A1) dans laquelle R₃, R₄ représentent un groupement alkyle comprenant 8 atomes de carbone et R₅ et R₆ représentent un groupement alkyle comprenant 13 atomes de carbone.

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

• of a Mo-DTC compound of formula (III-a) in which R ₃ , R ₄ , R ₅ and R ₆ represent an alkyl group comprising 8 carbon atoms,
• of a Mo-DTC compound of formula (III-a) in which R ₃ , R ₄ , R ₅ and R ₆ represent an alkyl group comprising 13 carbon atoms, and
• of a Mo-DTC compound of formula (III-a) in which R ₃ , R ₄ represent an alkyl group comprising 13 carbon atoms and R ₅ and R ₆ represent an alkyl group comprising 8 carbon atoms, and / or
• of a Mo-DTC compound of formula (A1) in which R ₃ , R ₄ represent an alkyl group comprising 8 carbon atoms and R ₅ and R ₆ represent an alkyl group comprising 13 carbon atoms.

As examples of Mo-DTC compounds, mention may be made of the products Molyvan L, Molyvan 807 or Molyvan 822 sold by the company RT Vanderbilt Compagny or the products Sakura-lube 200, Sakura-lube 165, Sakura-lube 525 or Sakura-lube 600 marketed by the company Adeka.

The content by weight of organomolybdenum compound ranges from 0.05 to 3%, preferably from 0.1 to 2%, advantageously from 0.1 to 1% relative to the total weight of the lubricating composition.

Compound comprising a dithiophosphate group

The lubricant composition according to the invention comprises at least one compound comprising a dithiophosphate group.

For the sake of simplification of the description, the compound comprising a dithiophosphate group is called “dithiophosphate” in the remainder of the present description.

The dithiophosphate, without being limiting, can be chosen from ammonium dithiophosphates, amine dithiophosphates, ester dithiophosphates and metallic dithiophosphates, taken alone or as a mixture.

dans laquelle R₇ et R₈ représentent indépendamment l'un de l'autre un groupe hydrocarboné, éventuellement substitué, comprenant de 1 à 30 atomes de carbone. Dans un mode de réalisation préféré de l'invention, R₇ et R₈ représentent indépendamment l'un de l'autre un groupe hydrocarboné, éventuellement substitué, comprenant de 2 à 24 atomes de carbone, plus préférentiellement de 3 à 18 atomes de carbone, avantageusement de 5 à 12 atomes de carbone.In one embodiment of the invention, the dithiophosphate is chosen from ammonium dithiophosphates of formula (IV):

in which R ₇ and R ₈ represent, independently of one another, an optionally substituted hydrocarbon group comprising from 1 to 30 carbon atoms. In a preferred embodiment of the invention, R ₇ and R ₈ represent, independently of one another, an optionally substituted hydrocarbon group, comprising from 2 to 24 carbon atoms, more preferably from 3 to 18 carbon atoms, advantageously from 5 to 12 carbon atoms.

In another preferred embodiment of the invention, R ₇ and R ₈ represent, independently of one another, an unsubstituted hydrocarbon group, said hydrocarbon group possibly being an alkyl, alkenyl, alkynyl, phenyl or benzyl group.

In another preferred embodiment of the invention, R ₇ and R ₈ represent, independently of one another, a linear or branched alkyl hydrocarbon group, more preferably a linear alkyl hydrocarbon group.

In another preferred embodiment of the invention, R ₇ and R ₈ independently of one another represent a hydrocarbon group optionally substituted by at least one oxygen, nitrogen, sulfur and / or phosphorus, preferably by at least one oxygen atom.

As examples of ammonium dithiophosphate, mention may be made of ammonium dimethyl dithiophosphates, ammonium diethyl dithiophosphates and ammonium dibutyl dithiophosphates.

dans laquelle :

• R₉ et R₁₀ représentent indépendamment l'un de l'autre un groupe hydrocarboné, éventuellement substitué, comprenant de 1 à 30 atomes de carbone,
• R₁₁, R₁₂ et R₁₃ représentent indépendamment l'un de l'autre un atome d'hydrogène ou un groupement hydrocarboné de 1 à 30 atomes de carbone, étant entendu qu'au moins un des groupes R₁₁, R₁₂ et R₁₃ ne représente pas un atome d'hydrogène.

In another embodiment of the invention, the dithiophosphate is chosen from the amine dithiophosphates of general formula (V):

in which :

• R ₉ and R ₁₀ independently of one another represent a hydrocarbon group, optionally substituted, comprising from 1 to 30 carbon atoms,
• R ₁₁ , R ₁₂ and R ₁₃ independently of one another represent a hydrogen atom or a hydrocarbon group of 1 to 30 carbon atoms, it being understood that at least one of the groups R ₁₁ , R ₁₂ and R ₁₃ does not represent a hydrogen atom.

In a preferred embodiment of the invention, R ₉ and R ₁₀ independently of one another represent an optionally substituted hydrocarbon group comprising from 2 to 24 carbon atoms, more preferably from 3 to 18 carbon atoms , advantageously from 5 to 12 carbon atoms.

In another preferred embodiment of the invention, R ₉ and R ₁₀ represent, independently of one another, an unsubstituted hydrocarbon group, said hydrocarbon group possibly being an alkyl, alkenyl, alkynyl, phenyl or benzyl group.

In another preferred embodiment of the invention, R ₉ and R ₁₀ represent, independently of one another, a linear or branched alkyl hydrocarbon group, more preferably a linear alkyl hydrocarbon group.

In another preferred embodiment of the invention, R ₉ and R ₁₀ independently of one another represent a hydrocarbon group optionally substituted by at least one oxygen, nitrogen, sulfur and / or phosphorus, preferably by at least one oxygen atom.

In another preferred embodiment of the invention, R ₁₁ , R ₁₂ and R ₁₃ independently of one another represent a hydrocarbon group comprising from 2 to 24 carbon atoms, more preferably from 3 to 18 carbon atoms , advantageously from 5 to 12 carbon atoms.

dans laquelle :

• R₁₄ et R₁₅ représentent indépendamment l'un de l'autre un groupe hydrocarboné, éventuellement substitué, comprenant de 1 à 30 atomes de carbone,
• R₁₆ et R₁₇ représentent indépendamment l'un de l'autre un groupe hydrocarboné comprenant de 1 à 18 atomes de carbone.

In another embodiment of the invention, the dithiophosphate is chosen from the ester dithiophosphates of general formula (VI):

in which :

• R ₁₄ and R ₁₅ represent, independently of each other, an optionally substituted hydrocarbon group comprising from 1 to 30 carbon atoms,
• R ₁₆ and R ₁₇ independently of one another represent a hydrocarbon group comprising from 1 to 18 carbon atoms.

In a preferred embodiment of the invention, R ₁₄ and R ₁₅ independently of one another represent an optionally substituted hydrocarbon group comprising from 2 to 24 carbon atoms, more preferably from 3 to 18 carbon atoms , advantageously from 5 to 12 carbon atoms.

In another preferred embodiment of the invention, R ₁₄ and R ₁₅ independently of one another represent an unsubstituted hydrocarbon group, said hydrocarbon group possibly being an alkyl, alkenyl, alkynyl, phenyl or benzyl group.

In another preferred embodiment of the invention, R ₁₄ and R ₁₅ represent, independently of one another, a linear or branched alkyl hydrocarbon group, more preferably a linear alkyl hydrocarbon group.

In another preferred embodiment of the invention, R ₁₄ and R ₁₅ represent, independently of one another, a hydrocarbon group optionally substituted by at least one oxygen, nitrogen, sulfur and / or phosphorus, preferably by at least one oxygen atom.

In another preferred embodiment of the invention, R ₁₄ and R ₁₅ represent, independently of one another, a hydrocarbon group comprising from 2 to 6 carbon atoms.

In another preferred embodiment of the invention, R ₁₆ and R ₁₇ represent, independently of one another, a hydrocarbon group comprising from 2 to 6 carbon atoms.

dans laquelle :

• R₁₈ et R₁₉ représentent indépendamment l'un de l'autre un groupe hydrocarboné, éventuellement substitué, comprenant de 1 à 30 atomes de carbone,
• M représente un cation métallique, et
• n est la valence de ce cation métallique.

In another embodiment, the dithiophosphate is chosen from the metallic dithiophosphates of general formula (VII):

in which :

• R ₁₈ and R ₁₉ represent, independently of one another, an optionally substituted hydrocarbon group comprising from 1 to 30 carbon atoms,
• M represents a metal cation, and
• n is the valence of this metallic cation.

In a preferred embodiment of the invention, the metal is chosen from the group consisting of zinc, aluminum, copper, iron, mercury, silver, cadmium, tin, lead, antimony, bismuth, thallium, chromium, molybdenum, cobalt, nickel, tungsten, sodium, calcium, magnesium, manganese and arsenic. The preferred metals are zinc, molybdenum, antimony, preferably zinc and molybdenum. *

In a preferred embodiment of the invention, the metal is zinc.

Mixtures of metals can be used. The metallic dithiophosphates are neutral as exemplified in formula (VII) or basic when a stoichiometric excess of metal is present.

In a preferred embodiment of the invention, R ₁₈ and R ₁₉ independently of one another represent a hydrocarbon group, optionally substituted, comprising from 2 to 24 carbon atoms, more preferably from 3 to 18 carbon atoms , advantageously from 5 to 12 carbon atoms.

In another preferred embodiment of the invention, R ₁₈ and R ₁₉ represent, independently of one another, an unsubstituted hydrocarbon group, said hydrocarbon group possibly being an alkyl, alkenyl, alkynyl, phenyl or benzyl group.

In another preferred embodiment of the invention, R ₁₈ and R ₁₉ represent, independently of one another, a linear or branched alkyl hydrocarbon group, more preferably a linear alkyl hydrocarbon group.

In another preferred embodiment of the invention, R ₁₈ and R ₁₉ independently of one another represent a hydrocarbon group optionally substituted by at least one oxygen, nitrogen, sulfur and / or phosphorus, preferably by at least one oxygen atom.

dans lesquelles R₁₈ et R₁₉ sont tels que définis ci-dessus.Advantageously, the dithiophosphate according to the invention is a zinc dithiophosphate of formula (VII-a) or of formula (VII-b):

in which R ₁₈ and R ₁₉ are as defined above.

As metallic dithiophosphate according to the invention, there may be mentioned for example the Additin® RC 3038, the Addin® RC 3045, the Addin® RC 3048, the Addin® RC 3058, the Addin® RC 3080, Addin® RC 3180, Addin® RC 3212, Addin® RC 3580, Kikulube® Z112, Lubrizol® 1371, Lubrizol® 1375, Lubrizol® 1395, Lubrizol® 5179, Oloa® 260, Olaa® 267.

The content by weight of dithiophosphate ranges from 0.1 to 5%, preferably from 0.1 to 3%, advantageously from 0.5 to 2% relative to the total weight of the lubricating composition.

Oily triamine

The lubricant composition according to the invention comprises at least one fatty triamine.

The fatty triamines are mainly obtained from carboxylic acids. The starting fatty acids for obtaining fatty triamines according to the invention can be chosen from myristic, pentadecylic, palmitic, margaric, stearic, nonadecylic, arachidic, heneicosanoic, behenic, tricosanoic, lignoceric, pentacosanoic, cerotic, heptacosanoic, montanic acids. nonacosanoic, melissic, hentriacontanoic, laceroic or unsaturated fatty acids such as palmitoleic, oleic, erucic, nervonic, linoleic, a-linolenic, gamma-linolenic, di-homo-gamma-linolenic, arachidonic, eicosapentaenoic, docosahexaenoic.

The preferred fatty acids can be derived from the hydrolysis of the triglycerides present in vegetable and animal oils, such as coconut oil, palm oil, olive oil, peanut oil, rapeseed oil, sunflower oil, soybean oil, cotton, linen, beef tallow, ....

Natural oils may have been genetically modified to enrich their content of certain fatty acids. By way of example, mention may be made of rapeseed oil or oleic sunflower oil.

In one embodiment of the invention, the fatty triamines can be obtained from natural, plant or animal resources.

In another embodiment of the invention, the fatty triamine is chosen from the compounds of formula (VIII):

R ₂₀ -N - [(CH ₂ ) ₃ -NH ₂ ] ₂ (VIII)

in which R ₂₀ represents a linear or branched, saturated or unsaturated alkyl group comprising at least 10 carbon atoms, preferably from 10 to 22 carbon atoms, more preferably from 14 to 22 carbon atoms, advantageously from 16 to 20 carbon atoms .

In a preferred embodiment of the invention, R ₂₀ represents a mixture of at least one saturated alkyl group comprising from 16 to 18 carbon atoms and a mono-unsaturated alkyl group comprising from 16 to 18 carbon atoms. In another embodiment of the invention, the fatty triamine is chosen from the compounds of formula (IX):

R ₂₁ -NH- (CH ₂ -CH ₂ -CH ₂ -NH) ₂ -H (IX)

in which R ₂₁ represents a linear or branched, saturated or unsaturated alkyl group comprising at least 10 carbon atoms, preferably from 10 to 22 carbon atoms, more preferably from 14 to 22 carbon atoms, advantageously from 16 to 20 carbon atoms .

The content by weight of fatty triamine ranges from 0.1 to 5%, preferably from 0.1 to 3%, advantageously from 0.5 to 2% relative to the total weight of the composition.

In another embodiment of the invention, the lubricating composition comprises a mass ratio (organomolybdenum / fatty triamine compound) ranging from 1/10 to 1, preferably from 1/5 to 4/5.

In another embodiment of the invention, the lubricating composition comprises a mass ratio (organomolybdenum compound / compound comprising a dithiophosphate / fatty triamine group) ranging from 1/10/10 to 1/1/1, preferably ranging from 1 / 5/5 to 4/5/5.

Base oil

The lubricating compositions according to the invention may contain any type of mineral, synthetic or natural, animal or vegetable lubricating base oil suitable for their use.

The base oil or oils used in the lubricating compositions according to the present invention may be oils of mineral or synthetic origin from groups I to V according to the classes defined in the API classification (or their equivalents according to the ATIEL classification) as summarized below, alone or in mixture. Table I Saturated content Sulfur content Viscosity index (VI) Group I Mineral oils <90% > 0.03% 80 ≤ VI <120 Group II Hydrocracked oils ≥ 90% ≤ 0.03% 80 ≤ VI <120 Group III Hydrocracked or hydro-isomerized oils ≥ 90% ≤ 0.03% ≥ 120 Group IV Polyalphaolefins (PAO) Group V Esters and other bases not included in groups I to IV bases

The mineral base oils according to the invention include all types of bases obtained by atmospheric distillation and under vacuum of crude petroleum, followed by refining operations such as solvent extraction, dealphating, solvent dewaxing, hydrotreatment, hydrocracking and hydroisomerization, hydrofinishing.

The base oils of the lubricating compositions according to the invention can also be synthetic oils, such as certain esters of carboxylic acids and alcohols, or polyalphaolefins. The polyalphaolefins used as base oils, are for example obtained from monomers having from 4 to 32 carbon atoms (for example octene, decene), and a viscosity at 100 ° C of between 1.5 and 15 cSt according to the standard ASTM D445. Their weight average molecular weight is typically between 250 and 3000 according to standard ASTM D5296. Mixtures of synthetic and mineral oils can also be used. There is no limitation as to the use of such or such a lubricating base for producing the lubricating compositions according to the invention, except that they must have properties, in particular of viscosity, viscosity index, content of sulfur, oxidation resistance, suitable for use in a vehicle engine, preferably motor vehicles.

In one embodiment of the invention, the lubricating bases represent at least 50% by mass, relative to the total mass of the lubricating composition, preferably at least 60%, or even at least 70%. Typically, they represent between 75 and 99.9% by mass, relative to the total mass of the lubricant compositions according to the invention.

In a preferred embodiment of the invention, the lubricating compositions comprise group I and / or III mineral bases, or group IV synthetic bases according to the API classification.

In another preferred embodiment of the invention, the lubricant compositions have a kinematic viscosity at 100 ° C. measured according to standard ASTM D445 ranging from 4 to 25 cSt, preferably from 5 to 22 cSt, advantageously from 5 to 13 cSt .

In another preferred embodiment of the invention, the lubricant compositions have a viscosity index (VI) greater than or equal to 140, preferably greater than or equal to 150, measured according to standard ASTM 2270.

Other additives

The lubricant compositions according to the invention may also contain at least one additive chosen from detergents, anti-wear additives other than a dithiophosphate, extreme pressure additives, dispersants, pour point improvers, anti - foam, thickeners and their mixtures.

In one embodiment, the lubricant composition can further comprise at least one antioxidant additive. The antioxidant additives delay the degradation of the lubricating compositions in service, in particular of engine oils in service, degradation which can in particular result in the formation of deposits, the presence of sludge, or an increase in the viscosity of the lubricating composition, in particular of the engine oil. The antioxidant additives act in particular as radical inhibitors or destroyers of hydroperoxides. Among the antioxidants commonly used, there may be mentioned antioxidants of phenolic type or of amino type, phosphosulfur antioxidants. Some of these antioxidants, for example phosphosulfurics, can generate ash. The phenolic antioxidants can be ashless, or they can be in the form of neutral or basic metal salts.

The antioxidant agents can be chosen in particular from sterically hindered phenols, sterically hindered phenol esters and sterically hindered phenols comprising a thioether bridge, diphenylamines, diphenylamines substituted by at least one C1-C12 alkyl group, N, N 'dialkyl aryl diamines and combinations thereof. By sterically hindered phenol is meant within the meaning of the present invention a compound comprising a phenol group in which at least one vicinal carbon of the carbon carrying the alcohol function is substituted by at least one C1-C10 alkyl group, preferably a C1-C6 alkyl group, preferably a C4 alkyl group, preferably by the ter-butyl group. Amino compounds are another class of antioxidants that can be used, possibly in combination with phenolic antioxidants. Typical examples are the aromatic amines, of formula R ₂₂ R ₂₃ R ₂₄ N, in which R ₂₂ represents an aliphatic group or an optionally substituted aromatic group, R ₂₃ represents an optionally substituted aromatic group, R ₂₄ represents a hydrogen atom , an alkyl group, an aryl group or a group of formula R ₂₅ S (O) _z R ₂₆ , where R ₂₅ represents an alkylene group or an alkenylene group, R ₂₆ represents an alkyl group, an alkenyl group or an aryl group and z represents an integer of 0, 1 or 2. Sulfurized alkyl phenols or their alkali and alkaline earth metal salts can also be used as antioxidants. Another class of antioxidants is that of copper-containing compounds, for example copper thio- or dithiophosphates, copper and carboxylic acid salts, dithiocarbamates, sulphonates, phenates, copper acetylacetonates. The copper I and II salts, succinic acid or anhydride can also be used.

The lubricant composition according to the invention can contain any type of antioxidant additive known to those skilled in the art. Advantageously, ashless antioxidants are used.

In one embodiment, the lubricant composition according to the invention can comprise from 0.5 to 2% of at least one antioxidant additive by weight relative to the total mass of the lubricant composition.

In one embodiment, the lubricant composition according to the invention can also comprise a detergent additive. Detergent additives in particular reduce the formation of deposits on the surface of metal parts by dissolving secondary oxidation and combustion products. The detergents which can be used in the lubricant composition according to the invention are well known to those skilled in the art. The detergents commonly used in the formulation of lubricating compositions can be anionic compounds comprising a long lipophilic hydrocarbon chain and a hydrophilic head. The associated cation is typically a metal cation of an alkali or alkaline earth metal. The detergents are preferably chosen from the alkali or alkaline earth metal salts of carboxylic acids, sulfonates, salicylates, naphthenates, as well as the phenate salts. The alkali and alkaline earth metals are preferably calcium, magnesium, sodium or barium. These metal salts may contain the metal in an approximately stoichiometric amount or in excess (in an amount greater than the stoichiometric amount). In the latter case, these detergents are said to be overbased detergents. The excess metal, bringing the overbased character to the detergent, is in the form of metal salts insoluble in oil, for example carbonate, hydroxide, oxalate, acetate, glutamate, preferably carbonate. In one embodiment, the lubricant composition according to the invention can comprise from 2 to 4% by weight of detergent, relative to the total mass of the lubricant composition.

In one embodiment, the lubricant composition according to the invention can also comprise at least one pour point lowering additive. Pour point lowering additives notably improve the cold behavior of lubricating compositions, by slowing down the formation of paraffin crystals. As an example of pour point lowering additives, mention may be made of alkyl polymethacrylates, polyacrylates, polyarylamides, polyalkylphenols, polyalkylnaphthalenes, alkylated polystyrenes.

In one embodiment, the lubricant composition according to the invention can also comprise at least one dispersant. The dispersants can be chosen from the groups formed by or Mannich bases.

In one embodiment, the lubricant composition according to the invention may comprise from 0.2 to 10% by mass of dispersants relative to the total mass of the lubricant composition.

In one embodiment, the lubricating composition can also comprise at least one polymer improving the viscosity index. Among these polymers, mention may be made of polymeric esters, copolymers of ethylene and propylene, homopolymers or copolymers of styrene, butadiene or isoprene, hydrogenated or not, polymethacrylates (PMA).

In one embodiment, the lubricant composition according to the invention can comprise from 1 to 15% by mass of polymers improving the viscosity index, relative to the total mass of the lubricant composition.

• de 75 à 99,75 % d'au moins une huile de base,
• de 0,05 à 3% d'au moins un composé organomolybdène,
• de 0,1 à 5% d'au moins un composé comprenant un groupement dithiophosphate,
• de 0,1 à 5% d'au moins une triamine grasse.

In one embodiment of the invention, the lubricating composition comprises:

• from 75 to 99.75% of at least one base oil,
• from 0.05 to 3% of at least one organomolybdenum compound,
• from 0.1 to 5% of at least one compound comprising a dithiophosphate group,
• 0.1 to 5% of at least one fatty triamine.

• de 75 à 99,25 % d'au moins une huile de base,
• de 0,05 à 3% d'au moins un composé organomolybdène,
• de 0,1 à 5% d'au moins un composé comprenant un groupement dithiophosphate,
• de 0,1 à 5% d'au moins une triamine grasse,
• de 0,5 à 5 % d'au moins un autre additif.

In another embodiment of the invention, the lubricating composition comprises:

• from 75 to 99.25% of at least one base oil,
• from 0.05 to 3% of at least one organomolybdenum compound,
• from 0.1 to 5% of at least one compound comprising a dithiophosphate group,
• from 0.1 to 5% of at least one fatty triamine,
• from 0.5 to 5% of at least one other additive.

• 75 à 99,75 % d'au moins une huile de base,
• 0,05 à 3% d'au moins un composé organomolybdène,
• 0,1 à 5% d'au moins un composé comprenant un groupement dithiophosphate,
  • 0,1 à 5% d'au moins une triamine grasse.

In another embodiment of the invention, the lubricating composition essentially consists of:

• 75 to 99.75% of at least one base oil,
• 0.05 to 3% of at least one organomolybdenum compound,
• 0.1 to 5% of at least one compound comprising a dithiophosphate group,
  • 0.1 to 5% of at least one fatty triamine.

• 75 à 99,25 % d'au moins une huile de base,
• 0,05 à 3% d'au moins un composé organomolybdène,
• 0,1 à 5% d'au moins un composé comprenant un groupement dithiophosphate,
• 0,1 à 5% d'au moins une triamine grasse,
• 0,5 à 5 % d'au moins un autre additif.

In another embodiment of the invention, the lubricating composition essentially consists of:

• 75 to 99.25% of at least one base oil,
• 0.05 to 3% of at least one organomolybdenum compound,
• 0.1 to 5% of at least one compound comprising a dithiophosphate group,
• 0.1 to 5% of at least one fatty triamine,
• 0.5 to 5% of at least one other additive.

All the characteristics and preferences presented for the base oil, the organomolybdenum compound, the compound comprising a group dithiophosphate, fatty triamine and the additional additive also applies to the above lubricating compositions.

In one embodiment of the invention, the lubricating composition is not an emulsion.

In another embodiment of the invention, the lubricating composition is anhydrous.

The invention also relates to a motor oil comprising a lubricating composition according to the invention.

All the characteristics and preferences presented for the lubricating composition also apply to the engine oil according to the invention.

In one embodiment of the invention, the engine oil can be of grade 0W-20 and 5W-30 according to the classification SAEJ300, characterized by a kinematic viscosity at 100 ° C (KV100) ranging from 5.6 to 12, 5 cSt measured according to international standard ASTM D445.

In another embodiment of the invention, the engine oil can be characterized by a viscosity index, calculated according to international standard ASTM D2230, greater than or equal to 130, preferably greater than or equal to 150.

To formulate an engine oil, it is advantageously possible to use base oils having a sulfur content of less than 0.3%, for example group III mineral oils, and sulfur-free synthetic bases, preferably group IV, or mixtures thereof. .

The invention also relates to the use of a lubricating composition as defined above for the lubrication of mechanical parts, in particular in transmissions and / or engines of vehicles, preferably motor vehicles.

The invention also relates to the use of a lubricating composition as defined above to reduce friction between two steel surfaces, in particular in a vehicle engine, preferably a motor vehicle. The invention also relates to the use of a lubricant composition above to reduce friction between a steel surface and a surface covered with carbon, in particular in a vehicle engine, preferably a motor vehicle.

The invention also relates to the use of a lubricating composition as defined above to reduce friction between two surfaces covered with carbon, in particular in a vehicle engine, preferably a motor vehicle.

By carbon coating according to the invention is meant any coating comprising carbon.

These carbon coatings can be chosen from diamond coatings, and more particularly nanodiamond coatings.

Such coatings can in particular be in the form of at least one layer of nanocrystalline diamond, having a purity ranging from 70 to 99%.

In one embodiment of the invention, the carbon coatings are chosen from nanodiamond coatings in the form of at least one layer of nanocrystalline diamond having a purity ranging from 70 to 99%, preferably ranging from 70 to 97%, advantageously of 75% and a thickness ranging from 0.1 to 3 μ, preferably ranging from 0.5 to 2 μ, advantageously 1.5 μ.

These carbon coatings can also be chosen from DLC (Diamond Like Carbon) type coatings.

Any type of DLC coating can be used as a carbon coating according to the invention.

The DLC bring together a set of families of amorphous materials containing mainly carbon.

Among these families, two families are mainly known and used: hydrogenated DLCs, in particular hydrogenated DLCs called a-C: H and non-hydrogenated DLCs, in particular non-hydrogenated DLCs called a-C or non-hydrogenated DLCs called ta-C.

The DLCs have properties which vary according to their content of sp3 hybridized carbons and their hydrogen content. Certain variants of DLC can be doped with metallic elements, such as iron, chromium or tungsten.

Compared to diamond coatings, DLC coatings are generally less mechanically and thermally resistant because they are amorphous materials. On the other hand, they are generally less rough and above all can be deposited at low temperature on the majority of substrates.

In one embodiment of the invention, the DLCs are chosen from hydrogenated DLCs, in particular hydrogenated DLCs called a-C: H.

In a preferred embodiment of the invention, the DLCs are chosen from hydrogenated DLCs, in particular hydrogenated DLCs called a-C: H containing from 10 to 40% of hydrogen.

The above use also makes it possible not to aggravate or even reduce the wear between two steel surfaces, in particular in a vehicle engine, preferably a motor vehicle.

The above use also makes it possible not to aggravate or even reduce the wear between a steel surface and a surface covered with carbon, in particular in a vehicle engine, preferably a motor vehicle.

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

The invention also relates to the use of a lubricating composition as defined above for reducing the fuel consumption of vehicles, preferably motor vehicles.

All the characteristics and preferences presented for the lubricant composition also apply to the above uses.

The invention also relates to a method of lubricating mechanical parts, in particular in transmissions and / or engines of vehicles, preferably motor vehicles, comprising at least one step of bringing at least one part into contact with a lubricating composition such as defined above.

The invention also relates to a method for reducing friction between two steel surfaces, in particular in a vehicle engine, preferably of a motor vehicle, comprising at least one step of bringing at least one of the steel surfaces into contact with a lubricating composition as defined above.

A subject of the invention is also a method for reducing friction between a steel surface and a surface covered with carbon, in particular in a vehicle engine, preferably a motor vehicle, comprising at least one step of bringing into contact at least one of the surfaces with a lubricating composition as defined above.

The invention also relates to a method for reducing friction between two surfaces covered with carbon, in particular in a vehicle engine, preferably a motor vehicle, comprising at least one step of bringing at least one of the surfaces covered with carbon with a lubricating composition as defined above.

The above method also makes it possible not to aggravate, or even reduce the wear between two steel surfaces, in particular in a vehicle engine, preferably a motor vehicle.

The above method also makes it possible not to aggravate, or even reduce the wear between a steel surface and a surface covered with carbon, in particular in a vehicle engine, preferably a motor vehicle.

The above method also makes it possible not to aggravate, or even reduce the wear between two surfaces covered with carbon, in particular in a vehicle engine, preferably a motor vehicle.

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

All the characteristics and preferences presented for the lubricant composition also apply to the above processes.

Vehicles may include a two- or four-stroke internal combustion engine.

The engines can be petrol or diesel engines intended to be powered by conventional petrol or diesel. By "conventional gasoline" or by "conventional diesel" is meant in the sense of the present invention engines which are powered by a fuel obtained after refining an oil of mineral origin (such as petroleum for example). The engines can also be petrol engines or diesel engines modified to be powered by a fuel based on oils derived from renewable materials such as alcohol-based fuels or biodiesel fuel.

The vehicles can be light vehicles such as automobiles and motorcycles. Vehicles can also be heavy goods vehicles, construction equipment, ships.

The subject of the invention is also the use of a fatty triamine in a lubricating composition comprising at least one base oil, at least one organomolybdenum compound and at least one compound comprising a dithiophosphate group for reducing friction between two steel surfaces , especially in a vehicle engine, preferably a motor vehicle.

Another subject of the invention is the use of a fatty triamine in a lubricating composition comprising at least one base oil, at least one organomolybdenum compound and at least one compound comprising a dithiophosphate group for reducing friction between a steel surface and a surface covered with carbon, in particular in a vehicle engine, preferably a motor vehicle.

The subject of the invention is also the use of a fatty triamine in a lubricating composition comprising at least one base oil, at least one organomolybdenum compound and at least one compound comprising a dithiophosphate group for reducing friction between two surfaces covered with carbon, in particular in a vehicle engine, preferably a motor vehicle.

The above use also makes it possible not to aggravate or even reduce the wear between two steel surfaces, in particular in a vehicle engine, preferably a motor vehicle.

The above use also makes it possible not to aggravate or even reduce the wear between a steel surface and a surface covered with carbon, in particular in a vehicle engine, preferably a motor vehicle.

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

The invention also relates to the use of a fatty triamine in a lubricating composition comprising at least one base oil, at least one organomolybdenum compound and at least one compound comprising a dithiophosphate group for reducing the fuel consumption of a vehicle, preferably a motor vehicle.

All the characteristics and preferences presented for the base oil, the fatty triamine, the organomolybdenum compound and the compound comprising a dithiophosphate group also apply to the uses above.

• au moins un composé organomolybdène,
• au moins un composé comprenant un groupement dithiophosphate, et
• au moins une triamine grasse.

There is also described a composition of concentrated additive type comprising:

• at least one organomolybdenum compound,
• at least one compound comprising a dithiophosphate group, and
• at least one fatty triamine.

All of the characteristics and preferences presented for fatty triamine, the organomolybdenum compound and the compound comprising a dithiophosphate group also apply to the composition of the concentrated additive type above.

In one embodiment, the composition of concentrated additive type further comprises at least one additional additive.

The additional additive can be chosen from the additives mentioned above.

In one embodiment, at least one base oil can be added to the composition of concentrated additive type according to the invention to obtain a lubricant composition according to the invention.

The various objects of the present invention and their implementations will be better understood on reading the examples which follow. These examples are given as an indication, without limitation.

Examples: Example 1

• d'une huile de base de groupe III ayant une viscosité à 100°C de 4,3 cSt mesurée selon la norme ASTM D445,
• d'un composé comprenant un groupement dithiophosphate : dithiophosphate de zinc (Lz 1371 commercialisé par la société Lubrizol),
• d'un composé organomolybdène 1 : complexe organomolybdène de formule (I-a) dans laquelle R₁ représente un groupement hydrocarboné comprenant 11 atomes de carbone (Molyvan 855 commercialisé par la société Vanderbilt),
• d'un composé organomolybdène 2 : dithiocarbamate de molybdène (Sakura-lube 525 commercialisé par la société Adeka),
• d'une triamine grasse de formule (VIII) dans laquelle R₂₀ représente un groupement hydrocarboné comprenant de 16 à 18 atomes de carbone (Triameen YT commercialisé par la société AKZO).

Lubricant compositions No. 1 to No. 6 were prepared from the following compounds:

• a group III base oil having a viscosity at 100 ° C. of 4.3 cSt measured according to standard ASTM D445,
• of a compound comprising a dithiophosphate group: zinc dithiophosphate (Lz 1371 sold by the company Lubrizol),
• an organomolybdenum compound 1: organomolybdenum complex of formula (Ia) in which R ₁ represents a hydrocarbon group comprising 11 carbon atoms (Molyvan 855 sold by the company Vanderbilt),
• an organomolybdenum 2 compound: molybdenum dithiocarbamate (Sakura-lube 525 sold by the company Adeka),
• of a fatty triamine of formula (VIII) in which R ₂₀ represents a hydrocarbon group comprising from 16 to 18 carbon atoms (Triameen YT sold by the company AKZO).

Lubricant compositions No. 1 to No. 6 are described in Table II; the percentages given are mass percentages. Table II Lubricating composition # 1 # 2 # 3 # 4 N ° 5 N ° 6 Base oil 100 98.5 98.6 97.5 97.6 99 Compound comprising a dithiophosphate group 1 1 1 1 Organomolybdenum compound 1 0.5 0.5 Organomolybdenum compound 2 0.4 0.4 Oily triamine 1 1 1

Test 1 : evaluation of the friction properties of lubricating compositions on a steel / steel contact

This involves evaluating the friction properties of lubricant compositions No. 1, No. 2 and No. 4 on the steel / steel contacts by measuring the coefficient of friction.

• nature de l'acier : 100c6
• température : 80°C,
• charge normale de 5N,
• course de 5mm.

The coefficient of friction is evaluated using a linear ball / plane tribometer under the following conditions:

• type of steel: 100c6
• temperature: 80 ° C,
• normal charge of 5N,
• 5mm stroke.

A difference of at least 0.01 between two values of coefficient of friction is considered significant to show the influence on said coefficient of friction.

Table III presents the coefficient of friction of lubricant compositions N ° 1, N ° 2 and N ° 4. Table III Composition # 1 # 2 # 4 Coefficient of steel / steel friction 0.150 0.035 0.025

These results show that the lubricant composition according to the invention No. 4 has improved friction properties for steel / steel contacts, compared to a lubricant composition comprising an organomolybdenum compound according to the invention and a compound comprising a dithiophosphate group according to l invention but not comprising fatty triamine according to the invention (composition N ° 2).

In addition to these results relating to the coefficient of friction, it has been observed that, by the use of the lubricating composition according to invention No. 4, the wear on the surface of the balls has not worsened, compared with lubricant composition No. 2.

Test 2 : evaluation of the friction properties of lubricating compositions on a DLC / steel contact

It is a question of evaluating the friction properties of the lubricating compositions N ° 1, N ° 2, N ° 4 and N ° 6 on the contacts DLC / steel, by the measurement of the coefficient of friction.

• nature de l'acier : 100c6,
• nature du revêtement DLC des billes : DLC hydrogéné a:CH contenant entre 31 et 33% d'hydrogène et ayant un ratio molaire (carbone sp²/carbone sp³) égal à 55/45,
• épaisseur de la couche DLC : 1,5µ,
• température : 110°C,
• charge normale de 5N,
• course de 10mm.

The friction coefficient is evaluated using a linear DLC ball / steel plane tribometer under the following conditions:

• type of steel: 100c6,
• nature of the DLC coating of the beads: hydrogenated DLC a: CH containing between 31 and 33% of hydrogen and having a molar ratio (carbon sp ² / carbon sp ³ ) equal to 55/45,
• thickness of the DLC layer: 1.5 μ,
• temperature: 110 ° C,
• normal charge of 5N,
• 10mm stroke.

A difference of at least 0.01 between two values of coefficient of friction is considered significant to show the influence on said coefficient of friction.

Table IV presents the coefficient of friction of lubricant compositions N ° 1, N ° 2, N ° 4 and N ° 6. Table IV Composition # 1 # 2 # 4 N ° 6 DLC / steel coefficient of friction 0.070 0.070 0.053 0.080

These results show that the lubricant composition according to the invention No. 4 has improved friction properties on DLC / steel contacts, compared to a lubricant composition comprising an organomolybdenum compound according to the invention and a compound comprising a dithiophosphate group according to the invention but not comprising a fatty triamine according to the invention (composition No. 2), as well as compared to a lubricating composition comprising a fatty triamine according to the invention but not comprising an organomolybdenum compound according to the invention nor of a compound comprising a dithiophosphate group according to the invention (composition No. 6).

It is interesting to note that the coefficients of friction of the lubricant compositions No. 2 and No. 6 are higher than the coefficient of friction of the lubricant composition according to the invention No. 4, thus demonstrating a synergistic effect of the combination of an organomolybdenum compound according to the invention, a compound comprising a dithiophosphate group according to the invention and a fatty triamine according to the invention to reduce friction on DLC / steel contacts.

In addition to these results relating to the coefficient of friction, it has been observed that, by the use of the lubricating composition according to the invention No. 4, the wear of the DLC coating of the balls has not worsened, compared to the lubricant compositions No. 2 and No. 6.

Test 3 : evaluation of the friction properties of lubricating compositions on a DLC / steel contact

This involves evaluating the friction properties of lubricant compositions No. 1, No. 2 and No. 4 on the DLC / steel contacts, by measuring the coefficient of friction.

• nature de l'acier : 100c6
• nature du revêtement DLC : DLC hydrogéné a:CH contenant entre 31 et 33% d'hydrogène et ayant un ratio molaire (carbone sp²/carbone sp³) égal à 55/45,
• épaisseur de la couche DLC : 1,5µ,
• température : 110°C,
• fréquence : 20Hz.

The friction coefficient is evaluated using a HFFR ball DLC / steel plane tribometer under the following conditions:

• type of steel: 100c6
• nature of the DLC coating: hydrogenated DLC a: CH containing between 31 and 33% of hydrogen and having a molar ratio (carbon sp ² / carbon sp ³ ) equal to 55/45,
• thickness of the DLC layer: 1.5 μ,
• temperature: 110 ° C,
• frequency: 20Hz.

A difference of at least 0.01 between two values of coefficient of friction is considered significant to show the influence on said coefficient of friction.

Table V presents the coefficient of friction of lubricant compositions N ° 1, N ° 2 and N ° 4. Table V Composition # 1 # 2 # 4 DLC / steel coefficient of friction 0.070 0.090 0.060

These results confirm the results of test 2; in fact, they demonstrate that the lubricant composition according to the invention No. 4 has improved friction properties for DLC / steel contacts, compared to a lubricant composition comprising an organomolybdenum compound according to the invention and a compound comprising a dithiophosphate group according to the invention but not comprising fatty triamine according to the invention (composition No. 2).

Test 4 : evaluation of the friction properties of lubricating compositions on a DLC / steel contact

It is a question of evaluating the friction properties of the lubricating compositions N ° 1, N ° 3 and N ° 5 on the contacts DLC / steel, by the measurement of the coefficient of friction.

The coefficient of friction is evaluated according to the method described in test 3.

A difference of at least 0.01 between two values of coefficient of friction is considered significant to show the influence on said coefficient of friction.

Table VI presents the friction coefficient of the lubricant compositions N ° 1, N ° 3 and N ° 5. Table VI Composition # 1 # 3 N ° 5 DLC / steel coefficient of friction 0.070 0.090 0.060

These results confirm the results of test 2 and test 3; indeed, they demonstrate that the lubricant composition according to the invention No. 5 has improved friction properties for DLC / steel contacts, compared to a lubricant composition comprising an organomolybdenum compound according to the invention and a compound comprising a dithiophosphate group according to the invention but not comprising fatty triamine according to the invention (composition No. 3), this in the presence of an organomolybdenum compound 2 different from the organomolybdenum compound 1.

Example 2

• d'une huile de type polyalphaoléfine ayant une viscosité à 100°C de 4 cSt mesurée selon la norme ASTM D445,
• d'un composé comprenant un groupement dithiophosphate : dithiophosphate de zinc (Lz 1371 commercialisé par la société Lubrizol),
• d'un composé organomolybdène 1 : complexe organomolybdène de formule (I-a) dans laquelle R₁ représente un groupement hydrocarbone comprenant 11 atomes de carbone (Molyvan 855 commercialisé par la société Vanderbilt),
• d'une triamine grasse de formule (VIII) dans laquelle R₂₀ représente un groupement hydrocarbone comprenant de 16 à 18 atomes de carbone (Triameen YT commercialisé par la société AKZO).

Lubricant compositions No. 7 to No. 10 were prepared from the following compounds:

• a polyalphaolefin type oil having a viscosity at 100 ° C. of 4 cSt measured according to standard ASTM D445,
• of a compound comprising a dithiophosphate group: zinc dithiophosphate (Lz 1371 sold by the company Lubrizol),
• an organomolybdenum compound 1: organomolybdenum complex of formula (Ia) in which R ₁ represents a hydrocarbon group comprising 11 carbon atoms (Molyvan 855 sold by the company Vanderbilt),
• of a fatty triamine of formula (VIII) in which R ₂₀ represents a hydrocarbon group comprising from 16 to 18 carbon atoms (Triameen YT sold by the company AKZO).

Lubricant compositions No. 7 to No. 10 are described in Table VII; the percentages given are mass percentages. Table VII Lubricating composition # 7 # 8 N ° 9 # 10 Base oil 100 98.5 97.5 99 Compound comprising a dithiophosphate group 1 1 Organomolybdenum compound 1 0.5 0.5 Oily triamine 1 1

Test 5 : evaluation of the friction properties of lubricating compositions on a steel / steel contact

This involves evaluating the friction properties of lubricant compositions N ° 7, N ° 8, N ° 9 and N ° 10 on the steel / steel contacts by measuring the coefficient of friction. The coefficient of friction is evaluated according to the method described in test 1.

A difference of at least 0.01 between two values of coefficient of friction is considered significant to show the influence on said coefficient of friction.

Table VIII presents the coefficient of friction of the lubricant compositions N ° 7, N ° 8, N ° 9 and N ° 10. Table VIII Composition # 7 # 8 N ° 9 # 10 Coefficient of steel / steel friction 0.140 0.050 0.035 0.120

These results show that the lubricating composition according to the invention No. 9 has improved friction properties on steel / steel contacts, compared to a lubricating composition comprising an organomolybdenum compound according to the invention and a compound comprising a dithiophosphate group according to the invention but not comprising a fatty triamine according to the invention (composition No. 8), as well as compared to a lubricating composition comprising a fatty triamine according to the invention but not comprising an organomolybdenum compound according to the invention nor of a compound comprising a dithiophosphate group according to the invention (composition No. 10).

It is interesting to note that the coefficients of friction of the lubricant compositions No. 8 and No. 10 are higher than the coefficient of friction of the lubricant composition according to the invention No. 9, thus demonstrating a synergistic effect of the combination of an organomolybdenum compound according to the invention, a compound comprising a dithiophosphate group according to the invention and a fatty triamine according to the invention to reduce friction on steel / steel contacts. In addition to these results relating to the coefficient of friction, it has been observed that, by the use of the lubricating composition according to the invention No. 9, the wear on the surface of the balls has not worsened, compared to the lubricant compositions N ° 8 and 10.

Test 6 : evaluation of the friction properties of lubricating compositions on a steel / diamond contact

This involves evaluating the friction properties of lubricant compositions No. 7, No. 8 and No. 9 on the steel / diamond contacts, by measuring the coefficient of friction.

• nature de l'acier : 100c6,
• nature du revêtement nanodiamant : couche de diamant nanocristallin comprenant environ 75% d'atomes de carbone hybridés sp³ (pureté d'environ 75%), d'épaisseur égale à 1,5µ, de rugosité de surface égale à 14nm, de dureté aux environs de 74GPa et ayant un module d'Young égal à 620GPa,
• température : 80°C,
• charge normale de 10N,
• course de 5mm.

The coefficient of friction is evaluated using a linear nanodiamond ball / steel plane tribometer under the following conditions:

• type of steel: 100c6,
• nature of the nanodiamond coating: nanocrystalline diamond layer comprising approximately 75% of sp ³ hybridized carbon atoms (purity of approximately 75%), thickness equal to 1.5 μ, surface roughness equal to 14 nm, hardness to around 74GPa and having a Young's modulus equal to 620GPa,
• temperature: 80 ° C,
• normal load of 10N,
• 5mm stroke.

A difference of at least 0.01 between two values of coefficient of friction is considered significant to show the influence on said coefficient of friction.

Table IX presents the coefficient of friction of lubricant compositions N ° 7, N ° 8 and N ° 9. Table IX Composition # 7 # 8 N ° 9 Coefficient of steel / diamond friction 0.110 0.070 0.060

These results show that the lubricant composition according to the invention No. 9 has improved friction properties for steel / diamond contacts, compared to a lubricant composition comprising an organomolybdenum compound according to the invention and a compound comprising a dithiophosphate group according to l invention but not comprising fatty triamine according to the invention (composition N ° 8).

In addition to these results relating to the coefficient of friction, it has been observed that, by the use of the lubricating composition according to the invention No. 9, the wear of the nanodiamond coating of the beads has not worsened, compared with lubricant composition No. 8.

Test 7 : evaluation of the friction properties of lubricating compositions on a DLC / steel contact

This involves evaluating the friction properties of lubricant compositions No. 7, No. 8 and No. 9 on the DLC / steel contacts, by measuring the coefficient of friction.

The coefficient of friction is evaluated according to the method described in test 2.

A difference of at least 0.01 between two values of coefficient of friction is considered significant to show the influence on said coefficient of friction.

Table X presents the friction coefficient of lubricant compositions N ° 7, N ° 8 and N ° 9. Paintings Composition # 7 # 8 N ° 9 Coefficient of steel / diamond friction 0.070 0.080 0.070

These results show that the lubricant composition according to the invention No. 9 has improved friction properties for DLC / steel contacts, compared to a lubricant composition comprising an organomolybdenum compound according to the invention and a compound comprising a dithiophosphate group according to l invention but not comprising fatty triamine according to the invention (composition N ° 8).

Thus, all of the examples and tests above demonstrate that the presence of a combination of an organomolybdenum compound according to the invention, of a compound comprising a dithiophosphate group according to the invention and of a fatty triamine according to l invention in a lubricating composition makes it possible to confer on this composition equivalent or even improved friction properties both on steel / steel contacts and on steel / carbon coating contacts, and in particular on steel / nanodiamond contacts but also on contacts steel / DLC. The presence of such a combination in a lubricating composition also allows the lubricating composition to retain good anti-wear properties, both on steel / steel contacts and on steel / carbon coating contacts, and in particular on steel contacts. / nanodiamond but also steel / DLC contacts.

Claims (14)

1. A lubricant composition comprising, with respect to the total weight of the lubricating composition:

   - at least one base oil,

   - from 0.05 to 3% by weight of at least one organomolybdenum compound,

   - from 0.1 to 5% by weight of at least one compound comprising a dithiophosphate group, and

   - from 0.1 to 5% by weight of at least one fatty triamine.
2. Lubricant composition according to claim 1 in which the organomolybdenum compound is a molybdenum dithiocarbamate compound.
3. Lubricant composition according to claim 1 in which the organomolybdenum compound is a molybdenum complex comprising at least one compound selected from:

   - the compounds of formula (I)

   

   in which:

   • X¹ represents an oxygen atom or a nitrogen atom;

   • X² represents an oxygen atom or a nitrogen atom;

   • n represents 1 when X¹ represents an oxygen atom and m represents 1 when X² represents an oxygen atom;

   • n represents 2 when X¹ represents a nitrogen atom and m represents 2 when X² represents a nitrogen atom;

   • R₁ represents a linear or branched, saturated or unsaturated alkyl group, comprising from 3 to 30 carbon atoms, preferentially from 3 to 20 carbon atoms, advantageously from 7 to 17 carbon atoms;

   - the compounds of formula (II)

   

   in which:

   • X¹ represents an oxygen atom or a nitrogen atom;

   • X² represents an oxygen atom or a nitrogen atom;

   • n represents 1 when X¹ represents an oxygen atom and m represents 1 when X² represents an oxygen atom;

   • n represents 2 when X¹ represents a nitrogen atom and m represents 2 when X² represents a nitrogen atom;

   • R₁ represents a linear or branched, saturated or unsaturated alkyl group, comprising from 3 to 30 carbon atoms, preferentially from 3 to 20 carbon atoms, advantageously from 7 to 17 carbon atoms;

   • R₂ represents a linear or branched, saturated or unsaturated alkyl group, comprising from 3 to 30 carbon atoms, preferentially from 3 to 20 carbon atoms, advantageously from 7 to 17 carbon atoms.

   - a mixture of at least one compound of formula (I) and at least one compound of formula (II).
4. Lubricant composition according to claim 3 in which the molybdenum complex comprises at least one compound of formula (I-a)

   

   in which R₁ represents a linear or branched, saturated or unsaturated alkyl group, comprising from 3 to 30 carbon atoms, preferentially from 3 to 20 carbon atoms, advantageously from 7 to 17 carbon atoms.
5. Lubricant composition according to claim 3 in which the molybdenum complex comprises at least one compound of formula (II-a)

   

   in which R₁ represents a linear or branched, saturated or unsaturated alkyl group, comprising from 3 to 30 carbon atoms, preferentially from 3 to 20 carbon atoms, advantageously from 7 to 17 carbon atoms.
6. Lubricant composition according to any one of the previous claims in which:

   - the content by weight of organomolybdenum compound ranges from 0.1 to 2%, advantageously from 0.1 to 1% with respect to the total weight of the lubricant composition, and/or

   - the content by weight of compound comprising a dithiophosphate group ranges from 0.1 to 3%, advantageously from 0.5 to 2% with respect to the total weight of the lubricant composition, and/or

   - the content by weight of fatty triamine ranges from 0.1 to 3%, advantageously from 0.5 to 2% with respect to the total weight of the lubricant composition.
7. Lubricant composition according to any one of the previous claims in which the compound comprising a dithiophosphate group is selected from the group constituted by the ammonium dithiophosphates, amine dithiophosphates, ester dithiophosphates and metal dithiophosphates, alone or in a mixture.
8. Lubricant composition according to any one of the previous claims in which the compound comprising a dithiophosphate group is a compound of formula (VII)

   

   in which:

   • R₁₈ represents a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group, comprising from 1 to 30 carbon atoms;

   • R₁₉ represents a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group, comprising from 1 to 30 carbon atoms;

   • M represents a metal cation, preferably a Zn²⁺ cation;

   • n represents the valency of the metal cation.
9. Lubricant composition according to any one of the previous claims in which the compound comprising a dithiophosphate group is a compound of formula (VII-a) or formula (VII-b):

   

   

   in which:

   • R₁₈ represents a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group, comprising from 1 to 30 carbon atoms;

   • R₁₉ represents a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group, comprising from 1 to 30 carbon atoms.
10. Lubricant composition according to any one of the previous claims in which the fatty triamine is selected from:

    - the compounds of formula (VIII)
    
            R₂₀-N-[(CH₂)₃-NH₂]₂     (VIII)
    
    in which R₂₀ represents a linear or branched, saturated or unsaturated alkyl group, comprising at least 10 carbon atoms;

    - the compounds of formula (IX)
    
            R₂₁-NH-(CH₂-CH₂-CH₂-NH)₂-H     (IX)
    
    in which R₂₁ represents a linear or branched, saturated or unsaturated alkyl group, comprising at least 10 carbon atoms.
11. Lubricant composition according to any one of the previous claims in which the mass ratio (organomolybdenum compound/fatty triamine) ranges from 1/10 to 1, preferably from 1/5 to 4/5 and/or the mass ratio (organomolybdenum compound/compound comprising a dithiophosphate group/fatty triamine) ranges from 1/10/10 to 1/1/1, preferably from 1/5/5 to 4/5/5.
12. Lubricant composition according to any one of the previous claims further comprising at least one additive selected from the detergents, anti-wear additives different from ammonium dithiophosphates, amine dithiophosphates, ester dithiophosphates and metal dithiophosphates, extreme-pressure additives, dispersants, pour-point improvers, anti-foaming agents, thickeners and mixtures thereof.
13. Use of a lubricant composition according to any one of claims 1 to 12 for reducing friction between two steel surfaces, between a steel surface and a carbon covered surface or between two carbon covered surfaces, in a vehicle engine, preferentially a motor vehicle engine.
14. Use of a lubricant composition according to any one of claims 1 to 12 for reducing the fuel consumption of vehicles, preferentially of motor vehicles.