FR2986801A1 - LUBRICATING COMPOSITIONS FOR TRANSMISSIONS - Google Patents

Abstract

The present invention relates to a lubricating composition comprising at least one base oil, at least one compound comprising a dithiocarbamate group, at least one compound comprising a phosphite group and at least one compound comprising a dithiophosphate group. The lubricant composition simultaneously has good antiwear, extreme pressure and a low coefficient of friction. The lubricant composition is useful for lubricating transmissions such as gearboxes, bridges, preferably manual gearboxes of motor vehicles.

Description

TECHNICAL FIELD The present invention relates to lubricating compositions for transmissions, in particular for manual gearboxes, bridges or double clutches. BACKGROUND OF THE INVENTION The lubricant compositions according to the invention simultaneously have good extreme-pressure properties, anti-wear properties and a low coefficient of friction. TECHNOLOGICAL BACKGROUND It is very difficult to formulate lubricating compositions having simultaneously good extreme-pressure properties, good anti-wear properties and good friction properties. Thus, most lubricating compositions exhibit only two of these properties without the third of the properties. Moreover, despite the existence of many anti-wear additives, extreme pressure additives or friction modifying additives, all do not have the same effectiveness, some may improve a property and at the same time damage a second property. Similarly, the chemistry of these additives is complex and the additives can react with each other to form new chemical species whose influence on extreme-pressure, wear and friction properties is not known at the end. It is known that additives such as diphosphites, which may be friction modifiers as well as anti-wear components, react with the sulfur used as an extreme-pressure agent to form thiophosphonic derivatives, for example, whose properties are significantly different from those initial molecules. Thus, many extreme-pressure components react with anti-wear additives or friction modifiers to give new chemical entities. These reactions are not controlled and the exact properties of the final product are also not mastered over time. Interactions can occur between the various extreme-pressure / anti-wear / friction modifier additives and lead to antagonistic effects on the final properties of the additive compositions. Brief description of the invention The Applicant Company has developed a novel lubricating composition comprising three essential additives to simultaneously obtain good extreme-pressure properties, anti-corrosion properties and the like. wear and friction.

This combination of additives is based on the presence of at least one compound comprising a dithiocarbamate group, at least one compound comprising a phosphite group and at least one compound comprising a dithiophosphate group. The lubricating composition according to the invention, comprising at least one compound comprising a dithiocarbamate group, at least one compound comprising a phosphite group and at least one compound comprising a dithiophosphate group, simultaneously has good properties in terms of wear, extreme pressure and friction. Moreover, this lubricant composition also has good properties in terms of oxidation and corrosion. The invention relates to a lubricating composition comprising at least one base oil, at least one compound comprising a dithiocarbamate group, at least one compound comprising a phosphite group and at least one compound comprising a dithiophosphate group.

Preferably, the compound comprising a dithiocarbamate group is selected from the group consisting of bisdithiocarbamates, ammonium dithiocarbamates, amine dithiocarbamates, ester dithiocarbamates and metal dithiocarbamates, alone or in admixture. Preferably, the bisdithiocarbamate has the formula (Ia), in which R1, R2, R3 and R4 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms, R5 represents a group hydrocarbon of 1 to 8 carbon atoms: SS Ri ... N .... ....., -... sR5-S Il Il, ... C ......., C R3 NN Preferably, the ammonium dithiocarbamate has the formula (Ib), wherein R 6 and R 7 independently represent one of the following groups: ## STR1 ## ## STR2 ## on the other, optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms: ## STR1 ## Preferably, the amine dithiocarbamate has the formula (Ic), in which R3 and R9 are, independently of each other, optionally substituted hydrocarbon groups having from 1 to 30 carbon atoms, R10, R11 and R12 independently of one another; a hydrogen atom or a hydrocarbon group of 1 to 30 carbon atoms, it being understood that at least one of the groups R10, R11 and R12 is not a hydrogen atom: ## STR2 ## Preferably, the ester dithiocarbamate has the formula (Id), in which R13 and R14 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms. carbon atoms, R15 and R16 represent, independently of one another, a hydrocarbon group of 1 to 18 carbon atoms: R 1, R 3,. 77C ......... s. Preferably, the metal dithiocarbamate has the formula (Ie) in which R17 and R18 are of the formula ## STR1 ## wherein R17 and R18 are as follows: ## STR2 ## independently of one another represent optionally substituted hydrocarbon groups having from 1 to 30 carbon atoms, M represents a metal cation and n is the valency of said metal cation: S 1 1 R 17, .. '.. Preferably, the lubricating composition comprises from 0.1 to 5% by weight of compound comprising a compound of the present invention. dithiocarbamate group, relative to the total weight of lubricating composition, preferably from 0.2 to 4%, more preferably from 0.3 to 2%, even more preferably from 0.5 to 1%.

Preferably, the compound comprising a phosphite group is chosen from phosphite monoesters, phosphite diesters or phosphite triesters, taken alone or as a mixture. Preferably, the phosphite monoester has the general formula (II-a) in its alcohol and / or ketone form, in which R19 represents an optionally substituted hydrocarbon group of 1 to 30 carbon atoms: H 0 0 0 ^ 0 Preferably, the phosphite diester has the general formula (II-b) in its alcohol and / or ketone form, in which R 20 and R 21 represent independently of each other hydrocarbon groups, optionally substituted, of 1 to 30 carbon atoms: R: \ 33600 \ 33698 TFE \ 33698--120215-deposit-text.doc 30 -111 ...._ (II-b) R21 HO / 0 Wherein the phosphite triester has the general formula (II-c) in which R22, R23 and R24 are, independently of one another, hydrocarbon-based groups optionally substituted, comprising from 1 to 30 carbon atoms: R22 P R23 1 (11-c) 0 R24 Preferably, the composition rifying agent comprises from 0.1 to 5% by weight of compound comprising a phosphite group, relative to the total mass of lubricating composition, preferably from 0.2 to 4%, more preferably from 0.3 to 2%, and even more preferably from 0.5 to 1%. Preferably, the compound comprising a dithiophosphate group is selected from the group consisting of ammonium dithiophosphates, amine dithiophosphates, ester dithiophosphates and metal dithiophosphates, alone or in admixture. Preferably, the ammonium dithiophosphate has the general formula (III-a), in which R 25 and R 26 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms: S R 25 Preferably, the amine dithiophosphate has the following formula: ## STR2 ## Preferably, the amine dithiophosphate has the following formula: ## STR1 ## wherein R27 and R28 independently of one another are optionally substituted hydrocarbon groups having from 1 to 30 carbon atoms, R29, R30 and R31 independently represent one of the other a hydrogen atom or a hydrocarbon group of 1 to 30 carbon atoms, it being understood that at least one of R29, R30 and R31 is not a hydrogen atom: S R29 R30 (III-b) Preferably, the ester dithiophosphate has the general formula (III-c), wherein R33 and R34 represent depending on each other, optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms, R 35 and R 36 represent, independently of one another, hydrocarbon groups comprising from 1 to 18 carbon atoms: R 33 Preferably, the metal dithiophosphate has the general formula (111-d), in which R37 and R38 are independently of one another of the following formulas: ## STR5 ## hydrocarbon groups, optionally substituted, comprising from 1 to 30 carbon atoms, M represents a metal cation and n is the valency of this metal cation: S R37 -011 0 / PS / R38-0 (III-d) R: \ 33600 Preferably, the lubricating composition comprises from 0.1 to 5% by weight of the compound comprising a dithiophosphate group, relative to the total weight of the lubricating composition, preferably from 0.1 to 5% by weight. 0.2 to 4%, more preferably 0.3 to 2%, even more preferable only 0.5 to 1%.

Preferably, the lubricating composition further comprises an antioxidant selected from the group consisting of aromatic amines or phenol derivatives. Preferably, the lubricating composition further comprising a dispersant derived from polyisobutene.

Preferably, the lubricating composition further comprises a polymer of polymethacrylate type. Preferably, the lubricating composition has a kinematic viscosity at 100 ° C according to ASTM D445 of between 4 and 40 cSt, preferably between 4.1 and 32.5 cSt, preferably between 6 and 18.5 cSt.

The invention also relates to the use of a lubricant composition as defined above for the lubrication of transmissions such as gearboxes, bridges, preferably manual gearboxes of motor vehicles. Preferably, the lubricant composition is used to reduce the fuel consumption of vehicles, particularly motor vehicles. The invention also relates to the use of at least one compound comprising a dithiocarbamate group, at least one compound comprising a phosphite group and at least one compound comprising a dithiophosphate group in a base oil to improve the wear properties. , extreme pressure and friction of a lubricating composition. The lubricating composition according to the invention comprises at least one compound comprising a dithiocarbamate group. For the sake of simplification of the description, the compound comprising a dithiocarbamate group is called "dithiocarbamate" in the following description. A usable dithiocarbamate is a dithiocarbamate selected from the group consisting of bisdithiocarbamates, ammonium dithiocarbamates, amine dithiocarbamates, ester dithiocarbamates, and dithiocarbamates. and metal dithiocarbamates, alone or in admixture.

In a first embodiment, the dithiocarbamate is a bisdithiocarbamate of general formula (Ia), in which R 1, R 2, R 3 and R 4 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 1 to 30 atoms R 5 represents a hydrocarbon group of 1 to 8 carbon atoms: ## STR1 ## Preferably, R 1, R 2, R 3 and R 4 represent independently of one another hydrocarbon groups, optionally substituted, comprising from 2 to 24 carbon atoms, more preferably from 3 to 18 carbon atoms, even more preferably from 5 to 12 carbon atoms. Preferably, R 1, R 2, R 3 and R 4 represent, independently of each other, unsubstituted hydrocarbon groups, said hydrocarbon groups possibly being alkyl, alkenyl, alkynyl, phenyl or benzyl groups. Preferably, R 1, R 2, R 3 and R 4 represent, independently of one another, linear or branched alkyl hydrocarbon groups, more preferably linear alkyl hydrocarbon groups.

Preferably, R 1, R 2, R 3 and R 4 represent, independently of one another, hydrocarbon groups optionally substituted with oxygen, nitrogen, sulfur and / or phosphorus atoms, preferably oxygen atoms. . Preferably, R5 represents a hydrocarbon group of 2 to 6 carbon atoms.

Commercial compounds are, for example, Vanlube® 7723 or Additin® RC 6340. In a second embodiment, dithiocarbamate is a dithiocarbamate. ammonium of general formula (Ib), wherein R6 and R7 represent, independently of each other, optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms: S II R6 CO Preferably, R 6 and R 7 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 2 to 24 carbon atoms, more preferably from 3 to 18 carbon atoms, and even more preferably from 5 to 12 carbon atoms. Preferably, R6 and R7 represent, independently of each other, unsubstituted hydrocarbon groups, said hydrocarbon groups possibly being alkyl, alkenyl, alkynyl, phenyl or benzyl groups. Preferably, R6 and R7 represent independently of each other linear or branched alkyl hydrocarbon groups, more preferably linear alkyl hydrocarbon groups.

Preferably, R 6 and R 7 represent, independently of one another, hydrocarbon groups optionally substituted with oxygen, nitrogen, sulfur and / or phosphorus atoms, preferably with oxygen atoms. In a third embodiment, the dithiocarbamate is an amine dithiocarbamate of the general formula (Ic), in which Rg and R9 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms. carbon, R10, R11 and R12 represent, independently of one another, a hydrogen atom or a hydrocarbon group of 1 to 30 carbon atoms, it being understood that at least one of the groups R10, R11 and R12 is not not hydrogen: R: \ 33600 \ 33698 TFE \ 33698--120215-text-deposit.doc S Rio R8 NCS ^ C) HN i -R11 (Ic) 1 IR R12 9 Preferably, R3 and R9 represent independently of each other optionally substituted hydrocarbon groups comprising from 2 to 24 carbon atoms, more preferably from 3 to 18 carbon atoms, even more preferably from 5 to 12 carbon atoms.

Preferably, R 3 and R 9 represent, independently of each other, unsubstituted hydrocarbon groups, said hydrocarbon groups possibly being alkyl, alkenyl, alkynyl, phenyl or benzyl groups. Preferably, R3 and R9 represent independently of each other linear or branched alkyl hydrocarbon groups, more preferably linear alkyl hydrocarbon groups. Preferably, R 3 and R 9 represent, independently of one another, hydrocarbon groups optionally substituted with oxygen, nitrogen, sulfur and / or phosphorus atoms, preferably with oxygen atoms. Preferably, R10, R11 and R12 represent, independently of one another, a hydrocarbon group 2 to 24 carbon atoms, more preferably 3 to 18 carbon atoms, even more preferably 5 to 12 carbon atoms. Particularly preferred compounds are diamyl amine diamyldithiocarbamate and diamyl amine dibutyldithiocarbamate.

Commercial compounds are for example Vanlube® EZ. In a fourth embodiment, the dithiocarbamate is an ester dithiocarbamate of the general formula (Id), in which R13 and R14 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms. carbon, R15 and R16 represent independently of each other hydrocarbon groups comprising from 1 to 18 carbon atoms: R: \ 33600 \ 33698 TFE \ 33698--120215-text-deposit.doc o R13 ,,,, ........ 7C. ,, .... ss Preferably, R13 and R14 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 2 to 24 carbon atoms, more preferably from 3 to 18 carbon atoms. carbon atoms, more preferably from 5 to 12 carbon atoms. Preferably, R13 and R14 represent, independently of each other, unsubstituted hydrocarbon groups, said hydrocarbon groups possibly being alkyl, alkenyl, alkynyl, phenyl or benzyl groups. Preferably, R13 and R14 represent, independently of one another, linear or branched alkyl hydrocarbon groups, more preferably linear alkyl hydrocarbon groups.

Preferably, R13 and R14 represent, independently of one another, hydrocarbon groups optionally substituted with oxygen, nitrogen, sulfur and / or phosphorus atoms, preferably with oxygen atoms. Preferably, R 15 and R 16 represent independently of each other hydrocarbon groups of 2 to 6 carbon atoms.

In a fifth embodiment, the dithiocarbamate is a metal dithiocarbamate of general formula (Ie), in which R 17 and R 13 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms, M represents a metal cation and n is the valency of this metal cation: ## STR1 ## Preferably, the metal is selected 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 and antimony, preferably zinc and molybdenum, preferably zinc. Mixtures of metals can be used. The metal dithiocarbamates are neutral as exemplified in formula (I-d) or basic when a stoichiometric excess of metal is present. Preferably, R 17 and R 18 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 2 to 24 carbon atoms, more preferably from 3 to 18 carbon atoms, even more preferably from 5 to 12 carbon atoms. carbon. Preferably, R 17 and R 18 represent, independently of each other, unsubstituted hydrocarbon groups, said hydrocarbon groups possibly being alkyl, alkenyl, alkynyl, phenyl or benzyl groups. Preferably, R 17 and R 18 represent independently of each other linear or branched alkyl hydrocarbon groups, more preferably linear alkyl hydrocarbon groups. Preferably, R 17 and R 18 represent, independently of each other, hydrocarbon groups optionally substituted with oxygen, nitrogen, sulfur and / or phosphorus atoms, preferably with oxygen atoms. Useful metal dithiocarbamates are compounds well known to those skilled in the art. One of the processes for preparing these compounds is described in US Patent 2492314. Suppliers of such additives are, for example, Vanderbilt, Rhein Chemie, Adeka, King Industries. Commercial compounds are, for example, Vanlube® AZ, Vanlube® EZ, Vanlube® 73, Vanlube® 73 Super Plus, Molyvan® A, Molyvan® 807, Molyvan® 822, Additin® RC 6301, Additin® RC 6320, Sakura-Lube® 200, Sakura-Lube® 165, Sakura-Lube® 525, Sakura-Lube® 600, Na-Lube® ADTC. Preferably, the metal dithiocarbamate is a molybdenum dithiocarbamate of the formula (Ie-1), in which R 17 and R 18 have the same meaning as in the formula (II). (Ie): ## STR1 ## Preferably, the metal dithiocarbamate is a zinc dithiocarbamate of formula (Ie-2) in which R 17 and R 18 have the same meaning as in formula (Ie): R 17 / R 17 (Ie-2) Zn C / N-7 R 18 SS R 18 Particularly preferred compounds having the formula (Ie-2) ) are such that R17 and R18 independently of one another are linear alkyl hydrocarbon groups and are, for example, zinc diamyldithiocarbamate and zinc dibutyldithiocarbamate, Preferably the dithiocarbamate may be a mixture of two or more of dithiocarbamates of formula (Ia), (Ib), (Ic), (Id), (Ie) described above. In fact, the dithiocarbamate may be a mixture of the dithiocarbamates of formula (I-c) and (I-e) described above. Preferably, the dithiocarbamate may be a mixture of the dithiocarbamates of formula (I-c) and (I-e-2) described above. The lubricating composition according to the invention comprises from 0.1 to 5% by weight of dithiocarbamate, relative to the total weight of the lubricating composition, preferably from 0.2 to 4%, more preferably from 0.3 to 2%. more preferably from 0.5 to 1%.

Phosphite The lubricating composition according to the invention comprises at least one compound comprising a phosphite group. For the sake of simplification of the description, the compound comprising a phosphite group is called "phosphite" in the following description. By phosphite is meant a phosphite ester, whether it is a phosphite monoester, a phosphite diester or a phosphite triester, taken alone or in mixture. Phosphite monoesters are found in two equilibrium forms, a "ketone" form and an "alcohol" form. It is the same for phosphite diesters. A phosphite which may be used may be a phosphite monoester of general formula (II-a) in its alcohol and / or ketone form, in which R19 represents an optionally substituted hydrocarbon group of 1 to 30 carbon atoms: H 0 0 0 Preferably, R 19 represents an optionally substituted hydrocarbon-based group comprising from 2 to 24 carbon atoms, more preferably from 3 to 20 carbon atoms, even more preferably from 4 to 18 carbon atoms. carbon atoms, more preferably 6 to 16 carbon atoms, more preferably 8 to 12 carbon atoms.

Preferably, R 19 represents an unsubstituted hydrocarbon group, said hydrocarbon group possibly being alkyl, lenyl, alkynyl, phenyl or benzyl. Preferably, R19 represents a linear or branched alkyl hydrocarbon group, more preferably a linear alkyl hydrocarbon group. Preferably, R.sub.19 represents a hydrocarbon group substituted with oxygen, nitrogen, sulfur and / or phosphorus atoms, preferably atoms. oxygen. As examples of phosphite monoesters, mention may be made of the alkyl (C10) bisphenol A phosphite, the alkyl (C12-C15) bisphenol A phosphite. A phosphite which may be used may also be a phosphite diester of general formula (II-b) in its alcohol and / or ketone form, in which R 20 and R 21 represent, independently of each other, optionally substituted hydrocarbon groups of 1 to 30 carbon atoms: -111 .... (II-b) R21 HO / o R20 c) R21 0 0 \ PH R20 o- 'form alcohol ketone form R20 and R21 preferably represent hydrocarbon groups, optionally substituted comprising from 2 to 24 carbon atoms, more preferably from 3 to 20 carbon atoms, even more preferably from 4 to 18 carbon atoms, even more preferably from 6 to 16 carbon atoms, even more preferably from 8 to 12 atoms. of carbon. Preferably, R 20 and R 21 represent, independently of each other, unsubstituted hydrocarbon groups, said hydrocarbon groups possibly being alkyl, alkenyl, alkynyl, phenyl or benzyl groups. Preferably, R 20 and R 21 represent independently of each other linear or branched alkyl hydrocarbon groups, more preferably linear alkyl hydrocarbon groups. Preferably, R 20 and R 21 represent hydrocarbon groups substituted with oxygen, nitrogen, sulfur and / or phosphorus atoms, preferably oxygen atoms.

As examples of phosphite diesters, mention may be made of dimethyl phosphite, diethyl phosphite, diisopropyl phosphite, dibutyl phosphite, dihexyl phosphite, dicylohexyl and diethyl phosphite. phosphite, diisodecyl phosphite, di-n-octyl phosphite, dibenzyl phosphite, diphenyl phosphite, dioleyl phosphite. A phosphite that may be used may also be a phosphite triester of general formula (II-c) in which R22, R23 and R24 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms: Preferably R22, R23 and R24 represent hydrocarbon groups, optionally substituted, comprising from 2 to 24 carbon atoms, more preferably from 3 to 20 carbon atoms, even more preferably from 4 to 20 carbon atoms. 18 carbon atoms, more preferably 6 to 16 carbon atoms, even more preferably 8 to 12 carbon atoms. Preferably, R22, R23 and R24 represent, independently of each other, unsubstituted hydrocarbon groups, said hydrocarbon groups possibly being alkyl, alkenyl, alkynyl, phenyl or benzyl groups. Preferably, R22, R23 and R24 represent independently of each other linear or branched alkyl hydrocarbon groups, more preferably linear alkyl hydrocarbon groups. Preferably, R22, R23 and R24 represent hydrocarbon groups substituted with oxygen, nitrogen, sulfur and / or phosphorus atoms, preferably oxygen atoms.

As examples of phosphite triesters, mention may be made of diphenyl isodecyl phosphite, diphenyl isooctyl phosphite, tridimethylphenyl phosphite, diphenyl ethylhexyl phosphite, phenyl diisodecyl phosphite, triisodecyl phosphite, trilauryl phosphite, triphenyl phosphite, tris (dipropylene glycol). ) phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, tris (5-norbornene-2-methyl) phosphite, tris (tridecyl) phosphite, trimethyl phosphite, triethyl phosphite, triisopropyl phosphite, tributyl phosphite, triisoctyl phosphite, tribenzylphosphite, triphenyl phosphite, poly (dipropylene glycol) phenyl phosphite, tris (dipropylene glycol) phosphite. Commercial compounds are, for example, Duraphos® AP230, Duraphos® AP240L, Duraphos® DBHP, Doverphos® 4, Doverphos® 10, Doverphos® 213, Doverphos® 6, Doverphos® 7, Doverphos® 8 , Doverphos® 9, Doverphos® 11, Doverphos® 12, Doverphos® 613, Doverphos® 675, Doverphos® 49, Doverphos® 53, Doverphos® 72, Doverphos® 253, Doverphos® 271 , Irgaphos® OPH, or products in the Rhodaphos® range marketed by Rhodia.

The lubricant composition according to the invention comprises from 0.1 to 5% by weight of phosphite, relative to the total weight of the lubricating composition, preferably from 0.2 to 4%, more preferably from 0.3 to 2%. more preferably from 0.5 to 1%. Dithiophosphate The lubricating 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 following description. A suitable dithiophosphate is a dithiophosphate selected from the group consisting of ammonium dithiophosphates, amine dithiophosphates, ester dithiophosphates and metal dithiophosphates, alone or in admixture. Ammonium dithiophosphates, amine dithiophosphates and ester dithiophosphates have the advantage of being dithiophosphate without ash and in particular without zinc.

In a first embodiment, the dithiophosphate is an ammonium dithiophosphate of general formula (III-a), in which R 25 and R 26 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms: S R25 -0 11 e C) NH4 / PS (III-a) / R26 - (-) R: \ 33600 \ 33698 TFE \ 33698--120215-text-deposit.doc Preferably, R25 and R26 represent, independently of each other, optionally substituted hydrocarbon groups comprising from 2 to 24 carbon atoms, more preferably from 3 to 18 carbon atoms, even more preferably from 5 to 12 carbon atoms. Preferably, R 25 and R 26 represent, independently of each other, unsubstituted hydrocarbon groups, said hydrocarbon groups possibly being alkenyl, alkynyl, phenyl or benzyl groups. Preferably, R 25 and R 26 represent independently of each other linear or branched alkyl hydrocarbon groups, more preferably linear alkyl hydrocarbon groups. Preferably, R 25 and R 26 represent, independently of one another, hydrocarbon groups optionally substituted with oxygen, nitrogen, sulfur and / or phosphorus atoms, preferably oxygen atoms.

Examples of commercial products are ammonium dimethyl dithiophosphates, ammonium diethyl dithiophosphates, ammonium dibutyl dithiophosphates. In a second embodiment, the dithiophosphate is an amine dithiophosphate of the general formula (III-b), in which R27 and R28 represent, independently of each other, optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms, R29, R30 and R31 represent, independently of one another, a hydrogen atom or a hydrocarbon group of 1 to 30 carbon atoms, it being understood that at least one of the groups R29, R30 and R31 n is not a hydrogen atom: ## STR2 ## R 27 and R 28 are preferably independently substituted hydrocarbon groups of one or more of the following groups: R 29 R 30 (III-b) , comprising from 2 to 24 carbon atoms, more preferably from 3 to 18 carbon atoms, more preferably from 5 to 12 carbon atoms. Preferably, R 27 and R 28 represent, independently of each other, unsubstituted hydrocarbon groups, said hydrocarbon groups possibly being alkyl, alkenyl, alkynyl, phenyl or benzyl groups. Preferably, R 27 and R 28 represent independently of each other linear or branched alkyl hydrocarbon groups, more preferably linear alkyl hydrocarbon groups. Preferably, R 27 and R 28 represent, independently of one another, hydrocarbon groups optionally substituted with oxygen, nitrogen, sulfur and / or phosphorus atoms, preferably with oxygen atoms. Preferably, R 29, R 30 and R 31 represent independently of one another a hydrocarbon group 2 to 24 carbon atoms, more preferably 3 to 18 carbon atoms, even more preferably 5 to 12 carbon atoms. Commercial compounds are, for example, Additin® RC 3880. In a third embodiment, dithiophosphate is an ester dithiophosphate of general formula (III-c), in which R33 and R34 independently of one another represent hydrocarbon groups, optionally substituted, comprising from 1 to 30 carbon atoms, R35 and R36 represent, independently of one another, hydrocarbon groups comprising from 1 to 18 carbon atoms: R33-0 MS 0 IL / PS-R35 - C OR36 (III-c) R34-0 Preferably, R33 and R34 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 2 to 24 carbon atoms, more preferably from 3 to 18 carbon atoms more preferably 5 to 12 carbon atoms. Preferably, R33 and R34 represent, independently of one another, unsubstituted hydrocarbon groups, said hydrocarbon groups possibly being alkyl or alkenyl groups. , alkynyls, phenyls or benzyls. Preferably, R33 and R34 represent independently of each other linear or branched alkyl hydrocarbon groups, more preferably linear alkyl hydrocarbon groups. Preferably, R33 and R34 represent, independently of one another, hydrocarbon groups optionally substituted with oxygen, nitrogen, sulfur and / or phosphorus atoms, preferably oxygen atoms.

Preferably, R33 and R34 represent, independently of one another, a hydrocarbon group of 2 to 6 carbon atoms. Preferably, R 35 and R 36 represent independently of each other hydrocarbon groups of 2 to 6 carbon atoms. Commercial compounds are, for example Irgalube® 63.

In a fourth embodiment, the dithiophosphate is a metal dithiophosphate of general formula (III-d), in which R37 and R38 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms. carbon, M represents a metal cation and n is the valence of this metal cation: ## STR2 ## Preferably, the metal is selected from the group consisting of zinc, aluminum and , 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, preferably zinc. Mixtures of metals can be used. Metal dithiophosphates are neutral as exemplified in formula (III-d) or basic when a stoichiometric excess of metal is present. Preferably, R 37 and R 38 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 2 to 24 carbon atoms, more preferably from 3 to 18 carbon atoms, even more preferably from 5 to 12 carbon atoms. carbon. Preferably, R37 and R38 represent, independently of each other, unsubstituted hydrocarbon groups, said hydrocarbon groups possibly being alkyl, alkenyl, alkynyl, phenyl or benzyl groups.

Preferably, R37 and R38 represent independently of each other linear or branched alkyl hydrocarbon groups, more preferably linear alkyl hydrocarbon groups. Preferably, R37 and R38 represent, independently of one another, hydrocarbon groups optionally substituted with oxygen, nitrogen, sulfur and / or phosphorus atoms, preferably with oxygen atoms. Useful metal dithiophosphates are compounds well known to those skilled in the art. Commercial compounds are, for example, Additin® RC 3038, Additin® RC 3045, Additin® RC 3048, Additin® RC 3058, Additin® RC 3080, Additin® RC 3180, Additin® RC 3212, Additin® RC 3580, Kikulube® Z112, Lubrizol® 1371, Lubrizol® 1375, Lubrizol® 1395, Lubrizol® 5179, Oloa® 260, Oloa® 267. preferably, the metal dithiophosphate is a molybdenum dithiophosphate of formula (III-d-1), wherein R37 and R38 have the same meaning as in formula (III-d): 0 0 (III-d-1) R370 Preferably, the metal dithiophosphate is a zinc dithiophosphate of the formula (III-d-2), wherein R37 and R38 are of the formula (III-d-2). same meaning as in formula (III-d): R: \ 33600 \ 33698 TFE \ 33698--120215-text-deposit.doc (III-d-2) SS OR-R370 / / - / a 'P * The lubricating composition according to the invention comprises from 0.1 to 5% by weight of dithio. phosphate, with respect to the total mass of the lubricating composition, preferably from 0.2 to 4%, more preferably from 0.3 to 2%, even more preferably from 0.5 to 1%. Base oil The lubricant compositions according to the invention may contain any type of mineral lubricating base, synthetic or natural, animal or vegetable adapted (s) to their use. The base oil (s) used in the lubricant compositions according to the present invention may be oils of mineral or synthetic origin of 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 mixed. Saturated content Viscosity index (VI) content sulfur Group I Mineral oils <90%> 0.03% 80 VI <120 Group II Oils> 90% 0.03% 80 VI <120 hydrocracked Group III> 90% <_0.03%> _120 Hydrocracked or hydro-isomerized oils Group IV Polyalphaolefines (PAO) Group V Esters and other bases not included in bases I to IV The mineral base oils according to the invention include all types of bases obtained by atmospheric distillation and under vacuum of petroleum crude, followed by refining operations such as solvent extraction, desalphating, solvent dewaxing, hydrotreating, hydrocracking and hydroisomerization, hydrofinishing. The base oils of the compositions according to the present invention may 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 containing 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 ASTM D5296. Mixtures of synthetic and mineral oils can also be used. There is no limitation on the use of a particular lubricating base for producing the lubricating compositions according to the invention, except that they must have properties, in particular viscosity, viscosity index, sulfur, oxidation resistance, adapted for use in a gearbox, in particular in a gearbox of motor vehicles, particularly in a manual gearbox. Preferably, the lubricating bases represent at least 50% by weight, relative to the total mass of the lubricating composition, preferably at least 60%, or at least 70%. Typically, they represent between 75 and 90% by weight, relative to the total mass of the lubricating compositions according to the invention. Preferably, the lubricant compositions according to the invention comprise Group I and / or III mineral bases, or Group IV synthetic bases according to the API classification.

Preferably, the lubricant compositions according to the invention have a kinematic viscosity at 100 ° C., measured according to the ASTM D445 standard of between 4 and 41 cSt, according to classification SAE J 306, preferably between 4.1 and 32.5 cSt. Preferred grades are all grades from 75W to 140, including 75W, 75W80 and 75W90.

Preferably, the lubricant compositions according to the invention have a viscosity index (VI) greater than 120 (ASTM 2270 standard). Other additives The lubricating compositions according to the invention may also contain any type of additive suitable for use in transmission oil formulations, for example one or more additives selected from polymers, antioxidants, corrosion inhibitors, dispersants, present at the usual contents required for the application. The polymers are selected from the group of shear-stable polymers, preferably from the group consisting of copolymers of ethylene and alpha-olefin, polyacrylates such as polymethacrylates, copolymer olefins (OCP), ethylene propylene diene Monomers (EPDM), polybutenes, copolymers of styrene and olefin, hydrogenated or not, copolymers of styrene and acrylate. The preferred polymers are polymethacrylates (PMA). The preferred dispersants are polyisobutylenes (PIB), polyisobutylene succinic anhydride, amino derivatives of polyisobutylene succinic anhydride (PIB succinimides). Preferred antioxidants are, for example, amino antioxidants, preferably diphenylamines, in particular dialkylphenylamines, such as octadiphenylamines, phenyl-alpha-naphthyl amines, or phenolic antioxidants (dibutylhydroxytoluene BHT and derivatives) or sulfur antioxidants (sulfurized phenates). ). The preferred anti-corrosion additives are phenolic derivatives, in particular ethoxylated phenol derivatives substituted with ortho-position alkyl groups. The corrosion inhibitors may be derivatives of dimercaptothiadiazole. The invention also relates to a method of lubricating transmissions such as gearboxes, bridges, preferably manual gearboxes of motor vehicles, said method comprising a step of contacting the lubricating composition as defined above with transmissions such as gearboxes. Preferably, this method simultaneously makes it possible to reduce wear, improve the extreme-pressure properties and reduce the friction of the lubricant composition. Advantageously, this method makes it possible to reduce the fuel consumption of vehicles, in particular of motor vehicles.

The use of these three additives in a lubricant composition simultaneously makes it possible to reduce wear, improve the extreme-pressure properties and reduce the coefficient of friction of the lubricant composition. In a preferred embodiment, the lubricating composition comprises at least one base oil, at least one compound comprising a dithiocarbamate group, at least one compound comprising a phosphite group, at least one compound comprising a dithiophosphate group, at least one antioxidant and at least one less a dispersant. The presence of these two additional additives, and in particular the presence of the dispersant, does not impair the extreme-pressure, wear and friction properties, which are always very good and at the same time ensures excellent resistance to oxidation. It is surprising to note that the use of the dispersant makes it possible to significantly improve the resistance to oxidation. EXAMPLES Example 1 Lubricant compositions 1-7 were prepared from: - PAO Group IV base oil having a viscosity at 100 ° C. of 6 cSt according to ASTDM D445, and viscosity equal to 125 according to ASTM 2270; - a dithiocarbamate which is a mixture of zinc diamyldithiocarbamate and diamylamino diamyldithiocarbamate, - a phosphite P1 which is di-n-octyl phosphite, - a dithiophosphate, 3 - [(bis-isopropyloxyphosphinothioyl) thio] propionic acid ethyl ester. Table I - Mass Composition (%) of Lubricating Compositions 1-7 Lubricating Composition 1 2 3 4 5 6 7 Base Oil PAO6 99 99 99 98 98 98 97 Dithiocarbamate 1 1 1 1 Phosphite P, 1 1 1 1 Dithiophosphate 1 1 1 1 The wear, extreme-pressure and friction properties of these lubricant compositions 1 to 7 are then measured. Table II - Properties of the lubricating compositions 1 to 7 Composition lubricant 1 2 3 4 5 6 7 Wear (mm) I- 0.63 0.54 0.65 0.43 0.56 0.51 0.42 Extreme pressure, weld load (daN) 2 80 90 100 90 120 110 110 Coefficient of friction 3 0.346 0.125 0.052 0.084 0.113 0.080 0.067 I- Test 4B (4 balls) wear D55 1078 2 Test 4B (4 balls) EP (Extreme Pressure) D55 1136 3 The friction properties of the formulas were evaluated using a Cameron-Plint TE-77 alternative tribometer. The operating principle is for example described in the publication "Friction Force Measurement in Reciprocating Tribometers" AG Plint, published by STLE (Society of Tribologists and Lubrication Engineers) in 2011. The procedure used measures the coefficient of friction of a roller on a plane, all immersed in the test lubricant, under conditions of temperatures (60 ° C, 100 ° C and 140 ° C), load (50, 100, 150 and 200N) and frequency (5, 10). , 20 and 40 Hz) variables in order to reproduce the friction conditions encountered in the control mechanisms of the gearboxes in use. The roller stroke on the plane, that is to say the reciprocating back and forth movement, is set at 7 mm. The duration of the test is 10 R: \ 33600 \ 33698 TFE \ 33698--120215-text-deposit.doc min. The reduction of the friction under these test conditions makes it possible to indicate a reduction in shifting forces and friction losses in the gears of the gearbox operating with the type of lubricant studied. The value of the coefficient of friction measured p.min, taken at different temperatures, corresponds to the minimum value of the coefficient of friction taken on the average of the 4 charges for the last minute of the test. Lubricating compositions 1 to 6 are control lubricating compositions comprising only one or two of the three essential additives to the invention. Lubricating compositions 1 to 6 do not simultaneously have good properties in anti-wear, extreme pressure and friction. Only the lubricant composition 7, which is a lubricant composition according to the invention, simultaneously has good properties in anti-wear, extreme pressure and friction.

EXAMPLE 2 Lubricating compositions 8 to 9 according to the invention are then prepared from: a PAO group IV base oil having a viscosity at 100 ° C. of 6 cSt according to ASTDM D445, and viscosity number equal to 125 according to ASTM 2270, - a dithiocarbamate (Vanlube® E2) which is a mixture of zinc diamyldithiocarbamate and diamylamino diamithyldithiocarbamate, - a phosphite P1 which is di-n -octyl phosphite, - a dithiophosphate, 3 - [(bis-isopropyloxyphosphinothioyl) thio] propionic acid ethyl ester. an aminated antioxidant, a diphenylamine dialkylated with C 4 and C 6 groups, a dispersant derived from polyisobutylene, in particular derived from polyisobutylene succinimide. Table III - Mass Composition (%) of Lubricating Compositions 7 to 9 Lubricating Composition 7 8 9 PAO6 Base Oil 97 96.5 96 Dithiocarbamate 1 1 1 Phosphite 1 1 1 Dithiophosphate 1 1 1 Antioxidant 0.5 0.5 Dispersant 0.5 The extreme pressure properties (via the FZG test), oxidation and corrosion of these lubricant compositions 7 to 9 are then measured.

Table IV - Properties of lubricating compositions 7 to 9 Lubricating composition 7 8 9 FZG test (deterioration bearing) 4 12 12 10 Oxidation Increasing viscosity at 100 ° C (%) 5 + 1.1 - 0.7 + 1.1 Content in insolubles (% by mass) 0.045 0.175 0.055 Deposit (% by mass) 6 0.11 Corrosion steel grade 10 10 10 Corrosion copper quotation 4h 8 lb lb lb Copper corrosion quotation 24h 8 lb lb 4 CEC L84 (A / 16.6R / 120) GFC T-021-A-90 R: \ 33600 \ 33698 TFE \ 33698--120215-text-filing.doc 6 GFC T-022-A-90 ASTM D665 8 ASTM D130 at 150 ° C * deposit content too high to be measured It is found that the compositions 7 to 9 have a very satisfactory extreme-pressure level. The compositions 7 and 8 give a deterioration stage of 12, the composition 9 gives a deterioration stage of 10. These results are comparable (and better for the compositions 7 and 8) to the results obtained with a reference oil H which has a deterioration stage of 9. This reference oil H comprises 72% by weight of Group I base oil, relative to the weight of oil, 11% by weight of polymer of polymethacrylate type, 8% by weight of PAO , 8% by weight of a package comprising a zinc dialkyldithiophosphate, a dibutyl phosphite, an aryl phosphite and a diphenylamine as an antioxidant. Lubricating compositions 7 to 9 therefore have a better extreme-pressure behavior than this reference oil H since their failure occurs at higher loads. Similarly, the lubricant compositions 7 to 9 and especially the composition 9 are insensitive to corrosion (copper or steel) and oxidation.

EXAMPLE 3 Control lubricant compositions 10 to 15 are then prepared from: - PAO Group IV base oil having a viscosity at 100 ° C. of 6 cSt according to ASTDM D445, and viscosity equal to 125 according to ASTM 2270; - a dithiocarbamate which is a mixture of zinc diamyldithiocarbamate and diamyl dithiocarbamate diamyl amine. This mixture is identical to that used in Example 1, - a phosphite P2 which is triphenyl phosphite, - a sulfur olefin known for its extreme pressure properties Additin® RC 2545. R: \ 33600 \ Table V - Mass Composition (%) of Lubricating Compositions 1-7 Lubricating Composition 1 10 11 12 13 14 15 Base Oil PAO6 99 99 99 98 98 98 97 Dithiocarbamate 1 1 1 1 Phosphite P2 1 1 1 1 Olefin sulfur 1 1 1 1 The wear and extreme-pressure properties of these lubricant compositions 10 to 15 are then measured.

Table VI - Properties of Lubricating Compositions 10 to 15 Lubricating Composition 1 10 11 12 13 14 15 Wear (mm) 1 0.63 0.46 0.63 0.50 0.59 0.75 0.71 Extreme pressure, load 80 70 100 70 120 80 100 weld (daN) 2 1 Test 4B (4 balls) wear D55 1078 2 Test 4B (4 balls) EP (Extreme Pressure) D55 1136 Additin® RC 2545 is an extreme pressure additive it has the same function as the compound comprising a dithiophosphate group used in the compositions according to the invention. However, it is found that the combination of a dithiocarbamate, a phosphite with a sulfur olefin rather than a dithiophosphate does not simultaneously achieve good anti-wear and extreme-pressure properties. Thus, when at least one compound of different chemical structure is selected from one of the compounds constituting the lubricating composition according to the invention but having the same function (therefore a compound belonging to another R: \ 33600 \ 33698 TFE \ 33698- -120215-text-filing.doc family of additives), no simultaneous improvement of the three anti-wear, extreme pressure and friction properties is observed. R: \ 33600 \ 33698 TFE \ 33698--120215-deposit-text.doc

Claims (4)

REVENDICATIONS1. A lubricating composition comprising at least one base oil, at least one compound comprising a dithiocarbamate group, at least one compound comprising a phosphite group and at least one compound comprising a dithiophosphate group. The lubricating composition of claim 1 wherein the compound comprising a dithiocarbamate group is selected from the group consisting of bisdithiocarbamates, ammonium dithiocarbamates, amine dithiocarbamates, ester dithiocarbamates and metal dithiocarbamates, taken alone. or in mixture. 3. Lubricating composition according to claim 2 wherein the bisdithiocarbamate has the formula (Ia), wherein R1, R2, R3 and R4 represent, independently of each other, optionally substituted hydrocarbon groups comprising from 1 to 30 atoms of carbon, R5 represents a hydrocarbon group of 1 to 8 carbon atoms: II R3 R5 N R2 R4 The lubricating composition according to claim 2, wherein the ammonium dithiocarbamate has the formula (Ib), wherein R6 and R7 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms. carbon: R6 0NR4 R7. A lubricating composition according to claim 2 wherein the amine dithiocarbamate has the formula (Ic), wherein R8 and R9 independently of one another are optionally substituted hydrocarbon groups having 1 to 30 carbon atoms, R10, R11 and R12 represent, independently of one another, a hydrogen atom or a hydrocarbon group of 1 to 30 carbon atoms, it being understood that at least one of the groups R10, R11 and R12 is not a hydrogen atom: R8 R9 6. Lubricating composition according to claim 2 wherein the ester dithiocarbamate has the formula (Id), in which R13 and R14 represent, independently of each other, optionally substituted hydrocarbon groups , comprising from 1 to 30 carbon atoms, R15 and R16 represent independently of one another a hydrocarbon group of 1 to 18 carbon atoms: R13 S -R15 -C -0 R16 (Id) R14 7. Composition lubricant according to the claimed cation 2 in which the metal dithiocarbamate has the formula (Ie) in which R 17 and R 18 represent, independently of one another, optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms, M represents a metal cation and is the valence of this metal cation: Rio c'ElNiI -R11 (Ic) R12 mn + (Ie). Lubricating composition according to any one of claims 1 to 7 comprising from 0.1 to 5% by weight of compound comprising a dithiocarbamate group, relative to the total weight of lubricating composition, preferably from 0.2 to 4%, more preferably from 0.3 to 2%, even more preferably from 0.5 to 1%. 9. Lubricating composition according to any one of claims 1 to 8 wherein the compound comprising a phosphite group is selected from phosphite monoesters, phosphite diesters or phosphite triesters, alone or in mixture. The lubricating composition of claim 9 wherein the phosphite monoester has the general formula (II-a) in its alcohol and / or ketone form, wherein R19 represents an optionally substituted hydrocarbon group of 1 to 30 carbon atoms. HO .... '0 0 0', - .., .. ..... z .... '. ',, P R19,. Wherein the phosphite diester has the general formula (II-b) in its alcohol and / or ketone form, wherein R 20 and R 21 independently represent from each other optionally substituted hydrocarbon groups of 1 to 30 carbon atoms: HO 0 0 ,,, .. .., ..,, .. P R20PH R20 III 0 0 R21 R21 form alcohol form ketone 12. The lubricating composition according to claim 9, wherein the phosphite triester has the general formula (II-c) in which R22, R23 and R24 represent, independently of each other, optionally substituted hydrocarbon groups comprising from 1 to at 30 carbon atoms: R23. The lubricating composition according to any one of claims 1 to 12 comprising from 0.1 to 5% by weight of compound comprising a phosphite group, relative to the total mass of lubricating composition, preferably 0.2 to 4%, more s preferably from 0.3 to 2%, more preferably from 0.5 to 1%. The lubricating composition according to any one of claims 1 to 13 wherein the compound comprising a dithiophosphate moiety is selected from the group consisting of ammonium dithiophosphates, amine dithiophosphates, ester dithiophosphates and metal dithiophosphates. , taken alone or mixed. The lubricating composition of claim 14 wherein the ammonium dithiophosphate has the general formula (III-a), wherein R25 and R25 independently of one another are optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms: S (31) 11-14 (I11-a) R25- ## STR2 ## 16. Lubricating composition according to claim 14, wherein the amine dithiophosphate has the general formula (III-b), in which R 27 and R 28 independently of one another represent optionally substituted hydrocarbon groups comprising from 1 to 30 carbon atoms, R 29, R 30 and R 31 represent, independently of one another, a hydrogen atom or a hydrocarbon group of 1 to 30 carbon atoms, it being understood that at least one of the groups R29, R30 and R31 is not a hydrogen atom: ## STR2 ## b) R31 17. Lubricating composition according to claim 14 wherein the dith Ester iophosphate has the general formula (III-c), wherein R33 and R34 independently of one another are optionally substituted hydrocarbon groups having from 1 to 30 carbon atoms, R35 and R36 independently represent from one another hydrocarbon groups comprising from 1 to 18 carbon atoms: ## STR5 ## claim 14 wherein the metal dithiophosphate has the general formula (III-d), wherein R37 and R38 are, independently of each other, optionally substituted hydrocarbon groups having from 1 to 30 carbon atoms, M represents a metal cation and n is the valency of this metal cation: -s (III-d) 19. A lubricating composition according to any one of claims 1 to 18 comprising from 0.1 to 5% by weight of compound comprising a dithiophosphate group, compared to the total mass of compo lubricating composition, preferably from 0.2 to 4%, more preferably from 0.3 to 2%, even more preferably from 0.5 to 1%. Lubricating composition according to any one of claims 1 to 19, further comprising an antioxidant selected from the group consisting of aromatic amines or phenol derivatives. 21. Lubricating composition according to any one of claims 1 to 20 further comprising a dispersant derived from polyisobutene. 22. Lubricating composition according to any one of claims 1 to 21 further comprising a polymer polymethacrylate type. 23. Lubricating composition according to any one of claims 1 to 22 having a kinematic viscosity at 100 ° C according to ASTM D445 of between 4 and 40 cSt, preferably between 4.1 and 32.5 cSt, preferably between 6 and 18.5 cSt. 24. Use of a lubricant composition according to any one of claims 1 to 23 for the lubrication of transmissions such as gearboxes, bridges, preferably the manual gearboxes of motor vehicles. 25. Use of a lubricant composition according to any one of claims 1 to 23 for reducing the fuel consumption of vehicles, particularly motor vehicles. 26. Use of at least one compound comprising a dithiocarbamate group, at least one compound comprising a phosphite group and at least one compound comprising a dithiophosphate group in a base oil to improve the properties of wear, extreme pressure and friction of a lubricating composition.