Lubricant composition for motor vehicle transmission

Abstract

The invention relates to a lubricant composition comprising:-at least one base oil; -at least one additive of formula (I): [Chemical Formula 1] # imgabs0 # wherein R and R1 are each independently selected from the group consisting of: a hydrogen atom; or a linear or branched saturated or unsaturated hydrocarbyl group containing from 8 to 40 carbon atoms; wherein at least one of R and R1 is a hydrocarbyl group containing at least two ethoxylated and / or propoxylated units.

Description

Field of the Invention

[0001] The present invention relates to the field of lubricant compositions, particularly for motor vehicles, and more particularly to lubricant compositions for lubricating components of a motor vehicle transmission, especially gears of an internal combustion engine or an electric motor transmission. Background Art

[0002] Components of motor vehicle transmissions operate under heavy loads and high speeds. Therefore, the oils used for these transmissions (also referred to as "lubricant compositions" or "lubricants") must particularly effectively protect the components against wear, especially the teeth of the gears against the phenomenon of gear seizure (or scuffing / scratching).

[0003] The seizure phenomenon occurs under high load conditions and can be evaluated by monitoring visible deterioration.

[0004] Measures to prevent this phenomenon involve reducing the contact stress by ensuring the proper geometry of the components and reducing friction by avoiding adhesion. Lubricant compositions play a key role in this prevention process, mainly through the physico-chemical reactivity of their additives.

[0005] Anti-wear and extreme pressure additives containing sulfur, phosphorus, or borates are usually added, thereby imparting protective anti-seizure properties to the transmission oil. Other additives present in the lubricant composition may also have a positive or negative impact on this phenomenon.

[0006] Another advantage provided by the subject matter covered by the present invention is to avoid using any additives, and more particularly any extreme pressure anti-wear additives containing sulfur. It is desired to limit or even completely eliminate sulfur in the transmission oil (especially for electric vehicle transmissions), thereby limiting the occurrence of corrosion phenomena and limiting the conductivity value within the required range.

[0007] Advantageously, the object of the present invention relates to a composition that is also free of zinc-based anti-wear additives.

[0008] Document EP3546550A1 discloses a composition comprising a reaction product of an acidic phosphate ester and a nitrogen compound.

[0009] Document EP3812445A1 discloses a composition comprising an acidic phosphate ester having a hydrocarbon group containing 1 to 6 carbon atoms.

[0010] The compounds described in these documents do not always provide satisfactory lubricating properties, especially in terms of durability and load-carrying capacity.

[0011] Accordingly, an object of the present invention is to provide a composition for lubricating components of a manual or automatic transmission, in particular the transmission gears of an internal combustion engine vehicle or preferably an electric vehicle, said composition exhibiting good durability and being free of any sulfur-based additives. Summary of the Invention

[0012] More precisely, the present invention relates to a lubricant composition comprising:

[0013] - at least one base oil;

[0014] - at least one additive having the formula (I):

[0015] [Chemical Formula 1]

[0016]

[0017] wherein,

[0018] R and R 1 each independently selected from: a hydrogen atom; or a straight-chain or branched-chain saturated or unsaturated hydrocarbon group containing 8 to 40 carbon atoms; wherein at least one of the groups R and R 1 is a hydrocarbon group containing at least two ethoxylated and / or propoxylated units.

[0019] Preferably, R and R 1 each independently selected from: a hydrogen atom; a straight-chain or branched-chain alkyl or alkenyl group; at least one of the groups R and R 1 is also an alkyl or alkenyl group containing at least two ethoxylated units; preferably a straight-chain or branched-chain alkyl or alkenyl group; wherein at least one of the groups R and R 1 is an alkyl or alkenyl group additionally containing at least two ethoxylated units.

[0020] Preferably, R and / or R 1 each independently selected from a hydrogen atom or a hydrocarbon group consisting of:

[0021] - an alkyl chain containing 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, preferably straight-chain; and

[0022] - 2 to 15 ethoxylated units, preferably 3 to 10 ethoxylated units,

[0023] It should be understood that at least one of the groups R or R 1 is a hydrocarbon group consisting of:

[0024] - an alkyl chain containing 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, preferably straight-chain; and

[0025] - 2 to 15 ethoxylated units, preferably 3 to 10 ethoxylated units;

[0026] Preferably, the two groups R and R 1 are each independently selected from hydrocarbon groups consisting of:

[0027] - an alkyl chain having 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, preferably a straight chain; and

[0028] - 2 to 15 ethoxylation units, preferably 3 to 10 ethoxylation units.

[0029] According to one embodiment, the lubricant composition comprises:

[0030] - phosphorus in an amount of 250 ppm to 1300 ppm by weight, preferably 400 ppm to 1400 ppm by weight, provided by one or more additives having the formula (I); and / or

[0031] - sulfur in an amount of less than 10 ppm by weight, preferably less than 5 ppm by weight, more preferably less than 1 ppm by weight.

[0032] According to a preferred embodiment, the lubricant composition further additionally comprises at least one additive selected from: phosphites having 1 to 24 carbon atoms; preferably phosphites having 4 to 12 carbon atoms; preferably phosphites having two alkyl groups each having 2 to 6 carbon atoms.

[0033] According to one embodiment, relative to the total weight of the lubricant composition, the lubricant composition comprises 0.01 wt% to 10 wt%, preferably 0.05 wt% to 5 wt%, more preferably 0.1 wt% to 3 wt% of one or more additives having the formula (I).

[0034] According to one embodiment, relative to the total weight of the lubricant composition, the lubricant composition comprises:

[0035] - 0.01 wt% to 5 wt%, preferably 0.02 wt% to 2 wt% of one or more additives having the formula (I); and

[0036] - 0.05 wt% to 5 wt%, preferably 0.1 wt% to 2 wt% of one or more additives selected from phosphites having two alkyl groups each having 2 to 6 carbon atoms.

[0037] According to a preferred embodiment of the present invention, the lubricant composition further additionally comprises at least one dispersant, preferably a borated dispersant, more preferably a borated dispersant selected from borated succinimides, even more preferably borated polyisobutylene succinimides.

[0038] According to a preferred embodiment, the lubricant composition of the present invention comprises:

[0039] relative to the total weight of the lubricant composition,

[0040] - at least 70% by weight, preferably 75% to 99.5% by weight of one or more non-aqueous base oils;

[0041] - 0.01% to 5% by weight, in particular 0.02% to 2% by weight of one or more additives having the formula (I);

[0042] - 0.05% to 5% by weight, preferably 0.1% to 2% by weight of one or more additives selected from phosphites containing 1 to 24 carbon atoms;

[0043] - optionally 0.1% to 15% by weight, preferably 1% to 10% by weight of one or more functional additives, said one or more functional additives preferably selected from dispersants, antioxidants, pour point depressants, defoamers or antifoaming agents and mixtures thereof.

[0044] Preferably, the kinematic viscosity of one or more base oils at 100 °C ranges from 1.5 cSt to 35 cSt.

[0045] The present invention also equally relates to the use of the composition of the present invention for lubricating at least one mechanical component of a motor vehicle, said component preferably being present in the transmission assembly of a motor vehicle, preferably a gear of a motor vehicle.

[0046] The present invention also relates to the use of an additive in a lubricant composition containing at least one base oil for improving the load-carrying capacity of the lubricant composition, said additive having the formula (I):

[0047] [Chemical formula 1]

[0048]

[0049] wherein,

[0050] - R and R 1 each independently selected from: a hydrogen atom; or a straight-chain or branched-chain saturated or unsaturated hydrocarbon group containing 8 to 40 carbon atoms; wherein at least one of the groups R and R 1 is a hydrocarbon group containing at least two ethoxylated and / or propoxylated units.

[0051] According to one embodiment, the additive having the formula (I) is used in combination with an additive selected from phosphites containing 1 to 24 carbon atoms in the lubricant composition, preferably in the following proportions:

[0052] relative to the total weight of the lubricant composition,

[0053] - from 0.01% to 5% by weight, preferably from 0.02% to 2% by weight, of one or more additives having the formula (I);

[0054] - from 0.05% to 5% by weight, preferably from 0.1% to 2% by weight, of one or more additives selected from phosphites containing from 1 to 24 carbon atoms.

[0055] According to one embodiment, the lubricant composition to which the additive is applied is as defined in the present invention.

[0056] In particular, the lubricant composition to which the additive of the present invention is applied advantageously exhibits one or more of the following characteristics:

[0057] - R and R 1 each independently selected from: a hydrogen atom; a linear or branched alkyl or alkenyl group, and at least one of the groups R and R 1 is an alkyl or alkenyl group further containing at least two ethoxylation units, preferably a linear or branched alkyl or alkenyl group, and at least one of the groups R and R 1 is an alkyl or alkenyl group containing at least two ethoxylation units, and / or -R and / or R 1 each independently selected from a hydrogen atom or a hydrocarbon group consisting of:

[0058] o - an alkyl chain containing 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, preferably linear; and

[0059] o 2 to 15 ethoxylation units, preferably 3 to 10 ethoxylation units;

[0060] It should be understood that at least one of the groups R or R 1 is a hydrocarbon group consisting of:

[0061] o - an alkyl chain containing 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, preferably linear; and

[0062] o 2 to 15 ethoxylation units, preferably 3 to 10 ethoxylation units;

[0063] Preferably, the two groups R and R 1 are each independently selected from the hydrocarbon groups consisting of:

[0064] - an alkyl chain containing 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, preferably linear; and

[0065] - 2 to 15 ethoxylation units, preferably 3 to 10 ethoxylation units; and / or

[0066] - The lubricant composition, which comprises:

[0067] o Phosphorus in an amount of 250 ppm to 1300 ppm by weight, preferably 400 ppm to 1400 ppm by weight, provided by one or more additives having formula (I); and / or

[0068] o Sulfur in an amount of less than 10 ppm by weight, preferably less than 5 ppm by weight, more preferably less than 1 ppm by weight; and / or

[0069] - The lubricant composition further additionally comprises at least one additive selected from: phosphites having 1 to 24 carbon atoms; preferably phosphites having 4 to 12 carbon atoms; preferably phosphites having two alkyl groups each having 2 to 6 carbon atoms; and / or

[0070] - Relative to the total weight of the lubricant composition, the lubricant composition comprises 0.01 wt% to 10 wt%, preferably 0.05 wt% to 5 wt%, more preferably 0.1 wt% to 3 wt% of one or more additives having formula (I); and / or

[0071] - Relative to the total weight of the lubricant composition, the lubricant composition comprises:

[0072] o 0.01 wt% to 5 wt%, preferably 0.02 wt% to 2 wt% of one or more additives having formula (I); and

[0073] o 0.05 wt% to 5 wt%, preferably 0.1 wt% to 2 wt% of one or more additives selected from phosphites having two alkyl groups each having 2 to 6 carbon atoms; and / or

[0074] - The lubricant composition further additionally comprises at least one dispersant, preferably a borated dispersant, more preferably a borated dispersant selected from borated succinimides, even more preferably borated polyisobutylene succinimides; and / or

[0075] - Relative to the total weight of the lubricant composition, the lubricant composition comprises:

[0076] o At least 70 wt%, preferably 75 wt% to 99.5 wt% of one or more non-aqueous base oils;

[0077] o 0.01 wt% to 5 wt%, especially 0.02 wt% to 2 wt% of one or more additives having formula (I);

[0078] o 0.05 wt% to 5 wt%, preferably 0.1 wt% to 2 wt% of one or more additives selected from phosphites having 1 to 24 carbon atoms;

[0079] - Optionally, one or more functional additives in an amount of 0.1% to 15% by weight, preferably 1% to 10% by weight, and the one or more functional additives are preferably selected from dispersants, antioxidants, pour point depressants, defoamers or antifoaming agents and mixtures thereof; and / or

[0080] - The kinematic viscosity of one or more base oils ranges from 1.5 cSt to 35 cSt at 100 °C.

[0081] An advantage of the lubricant composition of the present invention is that it has very good performance in reducing gear jamming (scuffing / scratching).

[0082] The lubricant composition of the present invention also exhibits good durability.

[0083] The lubricant composition of the present invention exhibits particularly satisfactory anti-wear performance even under heavy load conditions, even in the absence of sulfur-based additives and / or zinc-based additives.

[0084] In the remainder of this document, unless otherwise specified, the terms "between...", "in the range from... to...", and "ranging from... to..." can be used interchangeably and are intended to indicate inclusion of the limits.

[0085] Unless otherwise specified, the amounts of products are expressed by weight relative to the total weight of the product. Detailed Description

[0086] The present invention relates to a lubricant composition comprising:

[0087] - At least one base oil;

[0088] - At least one anti-wear additive having the formula (I):

[0089] Acidic phosphate type anti-wear additive having formula (I)

[0090] The lubricant composition of the present invention comprises at least one acidic phosphate ester type additive having the formula (I):

[0091] [Chemical Formula 1]

[0092]

[0093] Wherein:

[0094] - R and R 1 Each independently selected from: a hydrogen atom; or a straight-chain or branched-chain saturated or unsaturated hydrocarbon group containing 8 to 40 carbon atoms; wherein R and R 1At least one of the groups is a hydrocarbyl group containing at least two ethoxylated and / or propoxylated units.

[0095] For the purposes of the present invention, the term "hydrocarbyl group" is to be understood to mean a hydrocarbon chain (comprising carbon and hydrogen atoms) which optionally contains one or more heteroatoms, such as oxygen or nitrogen atoms.

[0096] For the purposes of the present invention, the term "ethoxylated unit" is to be understood to mean the divalent group -OCH2CH2-.

[0097] For the purposes of the present invention, the term "propoxylated unit" is to be understood to mean the divalent group -OCH2CH(CH3)- or -OCH2CH2CH2.

[0098] Preferably, R and R 1 are each independently selected from straight-chain or branched-chain alkyl or alkenyl groups containing at least two ethoxylated and / or propoxylated units.

[0099] More preferably, R and R 1 are each independently selected from straight-chain or branched-chain alkyl or alkenyl groups; at least one of R and R 1 is an alkyl or alkenyl group containing at least two ethoxylated units;

[0100] Advantageously, R and / or R 1 comprises 2 to 20 ethoxylated and / or propoxylated units, preferably ethoxylated units. According to one embodiment, R and / or R 1 comprises 2 to 15 ethoxylated and / or propoxylated units, preferably ethoxylated units, or even 3 to 10 ethoxylated and / or propoxylated units, preferably ethoxylated units.

[0101] Preferably, in addition to the ethoxylated and / or propoxylated units, the R and R 1 groups each independently further contain an alkyl chain having 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, preferably straight-chain.

[0102] Thus, according to one embodiment, the composition of the present invention comprises at least one antiwear additive having the formula (I), wherein R and / or R 1 are each independently selected from a hydrogen atom or a hydrocarbyl group consisting of:

[0103] - an alkyl chain having 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, preferably straight-chain, and

[0104] - 2 to 15 ethoxylated units, preferably 3 to 10 ethoxylated units,

[0105] It should be understood that R or R 1at least one of the groups is a hydrocarbon group consisting of:

[0106] - an alkyl chain containing 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, preferably straight-chain; and

[0107] - 2 to 15 ethoxylation units, preferably 3 to 10 ethoxylation units;

[0108] Preferably, the two groups R and R 1 each independently selected from hydrocarbon groups consisting of:

[0109] - an alkyl chain containing 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, preferably straight-chain; and

[0110] - 2 to 15 ethoxylation units, preferably 3 to 10 ethoxylation units.

[0111] The lubricant composition may optionally contain a mixture of compounds of formula (I). These compounds may differ, for example, in the number of ethoxylation and / or propoxylation units and / or the number of carbon atoms.

[0112] Preferably, the antiwear product of formula (I) provides 250 ppm to 1300 ppm of phosphorus by weight.

[0113] Preferably, the antiwear additive of formula (I) accounts for 0.01% to 10% by weight, more preferably 0.05% to 5% by weight, and even more preferably 0.1% to 3% by weight of the total weight of the lubricant composition of the present invention.

[0114] Phosphite type anti-wear additive

[0115] According to an advantageous embodiment of the present invention, the additive of formula (I) is combined with a phosphite additive.

[0116] Thus, according to an advantageous embodiment of the present invention, the lubricant composition of the present invention further additionally contains at least one antiwear additive selected from phosphites containing 1 to 24 carbon atoms, preferably phosphites containing 4 to 12 carbon atoms.

[0117] Advantageously, the phosphite antiwear additive is selected from phosphites containing two alkyl groups each having 2 to 6 carbon atoms.

[0118] Particularly advantageously, the phosphite antiwear additive is dibutyl hydrogen phosphite.

[0119] According to one embodiment, the phosphite antiwear additive accounts for 0.05% to 5% by weight, preferably 0.1% to 2% by weight of the total weight of the lubricant composition of the present invention.

[0120] According to one embodiment of the present invention, the lubricant composition comprises:

[0121] - 0.01% to 5% by weight, preferably 0.02% to 2% by weight, of one or more antiwear additives having the formula (I) relative to the total weight of the lubricant composition, wherein R and R 1 are each independently selected from: a hydrogen atom; or a straight-chain or branched-chain saturated or unsaturated hydrocarbon group containing 8 to 40 carbon atoms; wherein at least one of the groups R and R 1 is a hydrocarbon group containing at least two ethoxylated and / or propoxylated units; and

[0122] - 0.05% to 5% by weight, preferably 0.1% to 2% by weight, of one or more antiwear additives selected from phosphites containing 1 to 24 carbon atoms.

[0123] According to one embodiment of the present invention, the lubricant composition comprises:

[0124] Relative to the total weight of the lubricant composition,

[0125] - 0.01% to 5% by weight, preferably 0.02% to 2% by weight, of one or more antiwear additives having the formula (I) wherein R and R 1 are each independently selected from: a hydrogen atom; a straight-chain or branched-chain alkyl or alkenyl group, and at least one of the groups R and R 1 is an alkyl or alkenyl group further containing at least two ethoxylated units; and

[0126] - 0.05% to 5% by weight, preferably 0.1% to 2% by weight, of one or more antiwear additives selected from phosphites containing two alkyl groups each having 2 to 6 carbon atoms.

[0127] According to one embodiment of the present invention, the lubricant composition comprises:

[0128] Relative to the total weight of the lubricant composition,

[0129] - 0.01% to 5% by weight, preferably 0.02% to 2% by weight, of one or more antiwear additives having the formula (I) wherein R and R 1 are each independently selected from straight-chain or branched-chain alkyl or alkenyl groups, wherein at least one of the groups R and R 1 is an alkyl or alkenyl group further additionally containing at least two ethoxylated units; and

[0130] -0.05% to 5% by weight, preferably 0.1% to 2% by weight of one or more antiwear additives selected from phosphites containing two alkyl groups each having 2 to 6 carbon atoms.

[0131] Base oil

[0132] The lubricant composition of the present invention comprises one or more base oils, the content of which is preferably at least 70% by weight, preferably 75% to 99.5% by weight, more preferably 80% to 99% by weight, and particularly preferably 85% to 98% by weight, based on the total weight of the lubricant composition.

[0133] Preferably, the lubricant composition of the present invention comprises at least one base oil having a kinematic viscosity of 1.5 cSt to 35 cSt as measured at 100 °C according to standard ASTM D445. Advantageously, the base oil of the lubricant composition of the present invention has a kinematic viscosity of 1.5 cSt to 35 cSt at 100 °C.

[0134] These base oils may be selected from base oils commonly used in the lubricant field, such as mineral oils, synthetic oils or natural oils, animal oils or vegetable oils, or mixtures thereof. Generally, the base oil is a non-aqueous base oil.

[0135] It may be a mixture of multiple base oils, such as a mixture of two, three or four base oils.

[0136] The base oils of the lubricant composition contemplated by the present invention may in particular be mineral oils or synthetic oils belonging to Groups I to V according to the classification of the American Petroleum Institute (API) (or equivalent classification according to the classification of the Association Technique de l'Industrie Européenne des Lubrifiants (ATIEL)), as shown in Table 1 below, or mixtures thereof.

[0137] [Table 1]

[0138]

[0139] Mineral base oils include various base oils obtained by atmospheric and vacuum distillation of crude oil and refined by refining processes such as solvent extraction, deasphalting, solvent dewaxing, hydrotreating, hydrocracking, hydroisomerization and hydrorefining.

[0140] Mixtures of synthetic oils and mineral oils, which may be of biological origin, may also be used.

[0141] For the production of the compositions according to the operation of the present invention, there are generally no restrictions on the use of different base oils, provided that they must have properties suitable for use in the propulsion systems of electric vehicles or hybrid vehicles - particularly in terms of viscosity, viscosity index or antioxidant properties.

[0142] The base oil of the composition operated according to the present invention may also be selected from synthetic oils, such as esters of certain carboxylic acids and alcohols; polyalphaolefins (PAO); and polyalkylene glycols (PAG) obtained by polymerization or copolymerization of alkylene oxides containing 2 to 8 carbon atoms, especially 2 to 4 carbon atoms.

[0143] PAO used as a base oil is, for example, made from monomers containing 4 to 32 carbon atoms, such as octene or decene. The weight average molecular weight of PAO can vary widely. Preferably, the weight average molecular weight of PAO is less than 600 Da. The weight average molecular weight of PAO can also be 100 Da to 600 Da, 150 Da to 600 Dda, or even 200 Da to 600 Da.

[0144] Advantageously, one or more base oils of the lubricant composition of the present invention may be selected from Group II or Group III base oils.

[0145] According to another embodiment, one or more base oils of the lubricant composition operated according to the present invention are selected from polyalpha-olefins (PAO), polyalkylene glycols (PAG), and esters of carboxylic acids and alcohols.

[0146] Other supplementary additives

[0147] The lubricant composition of the present invention may also contain various functional additives, which are different from the antiwear additives having formula (I) and the phosphite-type antiwear additives defined in the present invention, but are suitable for lubricants for motor vehicles, especially for lubricants for manual or automatic transmissions of motor vehicles.

[0148] Such additives are known to those skilled in the art of motor vehicle lubrication and may be selected from detergents, dispersants, antioxidants, pour point depressants, defoamers or antifoaming agents, viscosity index improvers (or viscosity regulators), and mixtures thereof.

[0149] Advantageously, the composition of the present invention contains at least one functional additive selected from detergents, dispersants, antioxidants, pour point depressants, defoamers or antifoaming agents, viscosity index improvers (or viscosity regulators), and mixtures thereof.

[0150] Generally, when these additional functional additives are present, these additional functional additives (in total) account for 0.1% to 15% by weight, preferably 1% to 10% by weight, of the total weight of the lubricant composition.

[0151] These additives can be introduced individually and / or in the form of a mixture, similar to those already available on the market for formulating lubricants for commercial vehicle engines, the performance levels of which are defined by ACEA (Association des Constructeurs Européens d'Automobiles / European Automobile Manufacturers Association) and / or API (American Petroleum Institute), which are well known to those skilled in the art.

[0152] The lubricant composition of the present invention may comprise at least one antioxidant additive.

[0153] Antioxidant additives are generally used to retard the deterioration that occurs during the use of the composition. Such deterioration can in particular lead to the formation of deposits, the presence of sludge or an increase in the viscosity of the composition.

[0154] Antioxidant additives are particularly used as free radical inhibitors or peroxide destroyers (or scavengers). Among the commonly used antioxidant additives, mention may be made of phenolic antioxidant additives and amine antioxidant additives. The phenolic antioxidant additives may be ashless or may be in the form of neutral or basic metal salts. The antioxidant additives may be particularly selected from sterically hindered phenols; sterically hindered phenol esters; sterically hindered phenols containing a thioether bridge; diphenylamines, diphenylamines substituted by at least one C1-C12 alkyl group, N,N'-dialkyl-aryldiamines; and mixtures thereof.

[0155] Preferably, according to the present invention, the sterically hindered phenol is selected from compounds containing a phenol group, wherein at least one ortho-carbon adjacent to the carbon bearing the alcohol functional group is substituted by at least one C1-C 10 alkyl group, preferably a C1-C6 alkyl group, preferably a C4 alkyl group, preferably a tert-butyl group.

[0156] Amine compounds are another class of antioxidant additives that can be used and can be used in combination with phenolic antioxidant additives. Examples of amine compounds include aromatic amines, such as aromatic amines having the formula NR 10 R 11 R 12 where: R 10 represents an optionally substituted aliphatic group or aromatic group; R 11 represents an optionally substituted aromatic group; R 12 represents a hydrogen atom, an alkyl group, an aryl group or a group having the formula R 13 S(O) z R 14 where: R 13 represents an alkylene or alkenylene group, R 14 represents an alkyl group, an alkenyl group or an aryl group, and z represents 0, 1 or 2.

[0157] Alkylphenol sulfides or their alkali and alkaline earth metal salts can also be used as antioxidant additives.

[0158] Copper compounds constitute another class of antioxidant additives, such as salts of copper with carboxylic acids, copper phenolates, and copper acetylacetonate. Copper I and II salts, succinate salts, or succinic anhydride salts can also be used.

[0159] The lubricant composition of the present invention can contain all types of antioxidant additives known to those skilled in the art.

[0160] Advantageously, the lubricant composition of the present invention contains at least one ashless antioxidant additive.

[0161] The lubricant composition of the present invention can contain at least one antioxidant additive in an amount of 0.5% to 2% by weight relative to the total weight of the composition.

[0162] The lubricant composition of the present invention can further contain at least one detergent additive.

[0163] Detergent additives generally reduce the formation of deposits on the surface of metal parts by dissolving the by-products of oxidation and combustion.

[0164] Detergent additives that can be used in the lubricant composition of the present invention are generally known to those skilled in the art. Detergent additives can be anionic compounds containing a lipophilic long hydrocarbon chain and a hydrophilic tip. The associated cation can be a metal cation of an alkali metal or an alkaline earth metal.

[0165] Detergent additives are preferably selected from alkali metal or alkaline earth metal salts of carboxylic acids; salicylates; naphthenates; and phenolates. The alkali metals and alkaline earth metals are preferably calcium, magnesium, sodium, or barium.

[0166] These metal salts usually contain stoichiometric amounts of metal or even an excess of metal, i.e., the amount of metal is greater than stoichiometric. Therefore, they are overbased detergent additives; the excess metal that imparts the overbased characteristic to the detergent additive is usually in the form of a metal salt insoluble in oil, such as carbonate, hydroxide, oxalate, acetate, glutamate, preferably carbonate.

[0167] The lubricant composition according to the present invention can contain, for example, 0.5% to 4% by weight of the detergent additive relative to the total weight of the composition.

[0168] In addition, the lubricant composition of the present invention can contain at least one dispersant. Generally, dispersants are used to ensure that insoluble solid contaminants composed of oxidation by-products formed during the use of the lubricant composition remain in suspension and are discharged.

[0169] The dispersant can be selected from: Mannich bases; succinimide-type compounds, such as optionally borated polyisobutylene succinimide (PIBSI); or borated dispersants other than succinimides; preferably borated dispersants; more preferably borated succinimide dispersants, especially borated PIBSI.

[0170] The lubricant composition of the present invention can contain, for example, 0.2% to 10% by weight of one or more dispersants relative to the total weight of the composition.

[0171] The lubricant composition of the present invention can also additionally contain at least one defoaming agent.

[0172] The defoaming agent can be selected from silicones.

[0173] The lubricant composition of the present invention can contain 0.01% to 2% by weight or 0.01% to 5% by weight, preferably 0.1% to 1.5% by weight or 0.1% to 2% by weight of the defoaming agent relative to the total weight of the composition.

[0174] The lubricant composition of the present invention can also contain at least one pour point depressant (PPD) additive.

[0175] By slowing the formation of paraffin crystals, the pour point depressant additive generally improves the cold behavior of the composition. Examples of pour point depressant additives that can be used include polymethacrylic acid alkyl esters, polyacrylates, polyaryl amides, polyalkyl phenols, polyalkyl naphthalenes, and alkylated polystyrenes.

[0176] The lubricant composition of the present invention can also contain at least one viscosity index improver (VI modifier). Examples of VI improvers that can be cited include polymethacrylates, polyisobutylene, or fatty acid esters. If present, these additives can account for 1% to 25% by weight of the total weight of the lubricant composition.

[0177] Preferably, the lubricant composition of the present invention does not contain zinc-containing antiwear additives.

[0178] For the formulation of such lubricant compositions, one or more antiwear additives of the present invention can be added to a base oil or a base oil mixture, and then any other supplementary additives can be added.

[0179] Alternatively, one or more antiwear additives of the present invention can be added to an existing conventional lubricant formulation, which particularly contains one or more base oils and optionally other supplementary additives.

[0180] Alternatively, one or more antiwear additives of the present invention can be combined with one or more additional additives (if present), and the resulting "additive package" can be added to a base oil or a base oil mixture.

[0181] Advantageously, the lubricant composition of the present invention has a kinematic viscosity measured at 40 °C according to standard ASTM D445 of 5 mm 2 / s to 300 mm 2 / s, particularly 10 mm 2 / s to 25 mm 2 / s.

[0182] Advantageously, the lubricant composition of the present invention has a kinematic viscosity measured at 100 °C according to standard ASTM D445 of 1 mm 2 / s to 20 mm 2 / s, particularly 2 mm 2 / s to 15 mm 2 / s.

[0183] Preferably, the lubricant composition comprises from 400 ppm to 1400 ppm of phosphorus by weight, of which advantageously from 250 ppm to 1300 ppm of phosphorus is provided by an antiwear agent having the formula (I).

[0184] Preferably, the lubricant composition is substantially free of sulfur, preferably completely free of sulfur.

[0185] In particular, the lubricant composition of the present invention preferably does not contain any sulfur-containing additives.

[0186] Thus, the lubricant composition of the present invention generally contains less than 10 ppm of sulfur by weight, even less than 5 ppm of sulfur by weight, or even less than 1 ppm of sulfur by weight.

[0187] According to a specific embodiment, the lubricant composition of the present invention comprises or consists essentially of:

[0188] - a base oil or a mixture of base oils;

[0189] - an antiwear additive having the formula (I):

[0190] -- an optional antiwear additive selected from phosphites containing 1 to 24 carbon atoms;

[0191] - an optional one or more additional additives selected from dispersants, antioxidants, pour point depressants, defoamers or antifoaming agents and mixtures thereof.

[0192] According to a specific embodiment, the lubricant composition of the present invention comprises or consists essentially of:

[0193] Relative to the total weight of the lubricant composition,

[0194] - At least 70% by weight, preferably 75% to 99.5% by weight, of one or more base oils;

[0195] - 0.01% to 10% by weight, especially 0.05% to 5% by weight, of one or more antiwear additives having the formula (I);

[0196] - Optionally 0.05% to 5% by weight, especially 0.1% to 2% by weight, of one or more antiwear additives selected from phosphites containing 1 to 24 carbon atoms;

[0197] - Optionally 0.1% to 15% by weight, preferably 1% to 10% by weight, of one or more functional additives, preferably selected from dispersants, antioxidants, pour point depressants, defoamers or antifoaming agents and mixtures thereof.

[0198] According to a specific embodiment, the lubricant composition of the present invention comprises:

[0199] Relative to the total weight of the lubricant composition,

[0200] - At least 70% by weight, preferably 75% to 99.5% by weight, of one or more base oils;

[0201] - 0.01% to 5% by weight, especially 0.02% to 2% by weight, of one or more additives having the formula (I);

[0202] - 0.05% to 5% by weight, preferably 0.1% to 2% by weight, of one or more additives selected from phosphites containing 1 to 24 carbon atoms, preferably 4 to 12 carbon atoms, preferably selected from phosphites containing two alkyl groups each having 2 to 6 carbon atoms.

[0203] - Optionally 0.1% to 15% by weight, preferably 1% to 10% by weight, of one or more functional additives, preferably selected from dispersants, antioxidants, pour point depressants, defoamers or antifoaming agents and mixtures thereof.

[0204] According to a specific embodiment, the lubricant composition of the present invention consists of or essentially consists of the following:

[0205] Relative to the total weight of the lubricant composition,

[0206] - At least 70% by weight, preferably 75% to 99.5% by weight, of one or more base oils;

[0207] - 0.01% to 10% by weight, in particular 0.05% to 5% by weight, of one or more antiwear additives of formula (I);

[0208] - Optionally 0.05% to 5% by weight, in particular 0.1% to 2% by weight, of one or more antiwear additives selected from phosphites containing 1 to 24 carbon atoms;

[0209] - Optionally 0.1% to 15% by weight, preferably 1% to 10% by weight, of one or more functional additives, which are preferably selected from dispersants, antioxidants, pour point depressants, defoamers or antifoaming agents and mixtures thereof;

[0210] The composition contains less than 10 ppm of sulfur by weight.

[0211] According to a specific embodiment, the lubricant composition of the present invention comprises or consists essentially of:

[0212] Relative to the total weight of the lubricant composition,

[0213] - At least 70% by weight, preferably 75% to 99.5% by weight, of one or more base oils;

[0214] - 0.01% to 5% by weight, in particular 0.02% to 2% by weight, of one or more antiwear additives of formula (I);

[0215] - 0.05% to 5% by weight, preferably 0.1% to 2% by weight, of one or more antiwear additives selected from phosphites containing 1 to 24 carbon atoms;

[0216] - Optionally 0.1% to 15% by weight, preferably 1% to 10% by weight, of one or more functional additives, which are preferably selected from dispersants, antioxidants, pour point depressants, defoamers or antifoaming agents and mixtures thereof.

[0217] According to a specific embodiment, the lubricant composition of the present invention comprises or consists essentially of:

[0218] Relative to the total weight of the lubricant composition,

[0219] - At least 70% by weight, preferably 75% to 99.5% by weight, of one or more base oils;

[0220] - 0.01% to 5% by weight, preferably 0.02% to 2% by weight, of one or more antiwear additives of formula (I), wherein R and / or R1 Each independently selected from hydrocarbon groups consisting of the following:

[0221] - an alkyl chain containing 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms; and

[0222] - 2 to 15 ethoxylation units, preferably 3 to 10 ethoxylation units;

[0223] - 0.05% to 5% by weight, preferably 0.1% to 2% by weight of one or more antiwear additives selected from phosphites containing two alkyl groups each having 2 to 6 carbon atoms;

[0224] - Optionally 0.1% to 15% by weight, preferably 1% to 10% by weight of one or more functional additives, said one or more functional additives preferably selected from dispersants, antioxidants, pour point depressants, defoamers or antifoaming agents and mixtures thereof.

[0225] According to a specific embodiment, the lubricant composition of the present invention comprises or consists essentially of the following:

[0226] Relative to the total weight of the lubricant composition,

[0227] - at least 70% by weight, preferably 75% to 99.5% by weight of one or more base oils;

[0228] - 0.01% to 5% by weight, especially 0.02% to 2% by weight of one or more antiwear additives having the formula (I);

[0229] - 0.05% to 5% by weight, preferably 0.1% to 2% by weight of one or more antiwear additives selected from phosphites containing 1 to 24 carbon atoms;

[0230] - 0.5% to 5% by weight, preferably 0.1% to 2% by weight of one or more dispersants, preferably selected from borated dispersants;

[0231] - Optionally 0.1% to 10% by weight, preferably 0.5% to 5% by weight of one or more functional additives, said one or more functional additives preferably selected from antioxidants, pour point depressants, defoamers or antifoaming agents and mixtures thereof.

[0232] According to a specific embodiment, the lubricant composition of the present invention comprises or consists essentially of the following:

[0233] Relative to the total weight of the lubricant composition,

[0234] - At least 70% by weight, preferably 75% to 99.5% by weight of one or more base oils;

[0235] - 0.01% to 5% by weight, especially 0.02% to 2% by weight of one or more antiwear additives of formula (I), where R and / or R 1 are each independently selected from hydrocarbon groups consisting of:

[0236] - An alkyl chain containing 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms; and

[0237] - 2 to 15 ethoxylation units, preferably 3 to 10 ethoxylation units;

[0238] - 0.05% to 5% by weight, preferably 0.1% to 2% by weight of one or more antiwear additives selected from phosphites containing 1 to 24 carbon atoms;

[0239] - 0.5% to 5% by weight, preferably 0.1% to 2% by weight of one or more dispersants, preferably selected from borated dispersants;

[0240] - Optionally 0.1% to 10% by weight, preferably 0.5% to 5% by weight of one or more functional additives, preferably selected from antioxidants, pour point depressants, defoamers or antifoaming agents and mixtures thereof.

[0241] The object of the present invention also relates to the use of the lubricant composition of the present invention for lubricating a motor vehicle transmission, especially the gears of the transmission. These transmissions can be manual transmissions or automatic transmissions.

[0242] Preferably, the lubricant composition of the present invention is used to reduce the wear of mechanical components of a motor vehicle transmission, especially the wear of motor vehicle gears. Thus, according to this embodiment, the lubricant composition of the present invention provides a method for reducing the wear of transmission gears.

[0243] Preferably, the lubricant composition of the present invention is used to reduce spalling or scratching of mechanical components of a motor vehicle transmission (especially motor vehicle gears).

[0244] According to an advantageous embodiment, the lubricant composition of the present invention is used to simultaneously reduce wear and reduce spalling or scratching of mechanical components of a motor vehicle transmission (especially motor vehicle gears).

[0245] According to another aspect thereof, the present invention also relates to a lubrication method for at least one component of a motor vehicle transmission, in particular a motor vehicle gear, the method comprising at least one step of bringing at least said component into contact with the above lubricant composition.

[0246] According to another aspect thereof, the present invention also relates to a process for enhancing the durability of a lubricant composition, the process comprising the step of mixing at least one antiwear additive having formula (I) as defined in the present invention with at least one base oil, and preferably further mixing the antiwear additive having formula (I) with an antiwear additive selected from phosphites containing 1 to 24 carbon atoms.

[0247] All the features and preferences described for the lubricant composition of the present invention and its uses are equally applicable to the said method and process.

[0248] According to the present invention, the particularly advantageous or preferred features of the composition of the present invention may define the particularly advantageous or preferred uses of the present invention.

[0249] The present invention will now be illustrated by the following examples, which are provided for illustrative purposes only and are not intended to limit the present invention.

[0250] Examples

[0251] Example 1: Preparation of the lubricant composition

[0252] The lubricant composition was prepared by mixing the components at a temperature of about 40 °C according to a method known to those skilled in the art. The prepared and tested lubricant compositions are shown in detail in Tables 2 and 3 below.

[0253] The contents of elemental phosphorus and sulfur were calculated based on the elemental contents in the components and are listed in Tables 2 and 3 in ppm by weight.

[0254] The viscosity of the tested lubricant composition measured at 100 °C according to standard ASTM D445 was approximately 4.5 cSt.

[0255] [Table 2]

[0256] CC1 CC2 Base oil 94.65％ 94.65％ Anti-wear agent P1 0.1％ 0.1％ Anti-wear agent C1 1％ Anti-wear agent C2 1％ Antioxidant 1.4％ 1.4％ Anti-corrosion agent 0.05％ 0.05％ Dispersant 2.25％ 2.25％ Additive package 0.55％ 0.55％ Total (wt%) 100％ 100％ Total P content (ppm) 1120 1460 P content from C1 or C2 (ppm) 970 1310 S content (ppm) 0 0

[0257] [Table 3]

[0258] CI5 CI6 CI7 CI8 CI9 Base oil 94.65％ 95.15％ 94.75％ 94.65％ 94.65％ Anti-wear agent I2 1％ 0.5％ 1％ Anti-wear agent I3 1％ Anti-wear agent I4 1％ Anti-wear agent P1 0.1％ 0.1％ 0.1％ 0.1％ Antioxidant 1.4％ 1.4％ 1.4％ 1.4％ 1.4％ Anti-corrosion agent 0.05％ 0.05％ 0.05％ 0.05％ 0.05％ Dispersant 2.25％ 2.25％ 2.25％ 2.25％ 2.25％ Additive package 0.55％ 0.55％ 0.55％ 0.55％ 0.55％ Total (wt%) 100％ 100％ 100％ 100％ 100％ Total P content (ppm) 720 440 560 660 590 P content from (I) (ppm) 570 290 410 510 440 S content (ppm) 0 0 0 0 0

[0259] In the compositions of Tables 2 and 3:

[0260] - The base oil is a Group III base oil;

[0261] - The antiwear agent I2 has formula (I), wherein R and R 1are two straight-chain C18 alkyl chains, and at least one of the groups R or R 1 further contains five ethoxylation units;

[0262] - Antiwear agent I3 has the formula (I), where R and R 1 are straight-chain C18 alkyl chains, and at least one of the groups R or R 1 further contains five ethoxylation units;

[0263] - Antiwear agent I4 contains a mixture having the formula (I), where R and R 1 are straight-chain C10-C16 alkyl chains, and at least one of the groups R or R 1 further contains five ethoxylation units;

[0264] - Antiwear agent P1 is dibutyl hydrogen phosphite;

[0265] - Antiwear agent C1 does not have the formula (I) because it is an acidic phosphate ester with a branched C8 alkyl chain;

[0266] - Antiwear agent C2 does not have the formula (I) because it is an acidic phosphate ester with a C5 chain;

[0267] - The dispersant is a boric acid-modified PIBSI dispersant that can provide approximately 85 ppm of boron;

[0268] - The antioxidant contains a phenolic antioxidant and / or an amine antioxidant;

[0269] - The anti-corrosion agent is a triazole derivative;

[0270] - The additive component contains a pour point depressant and an antifoaming / defoaming agent.

[0271] Example 2: Test study on the performance of the lubricant composition

[0272] The anti-seizure load-carrying capacity of the lubricant compositions described in Tables 2 and 3 was tested using the FZG A10 / 16.6R / 90 method (according to the revised standard CEC-L-84-02). The results are shown in Table 4 and Table 5 below.

[0273] The average coefficient of friction was measured on a Mini Traction Machine (MTM) under the following conditions:

[0274] - Load = 5 N;

[0275] - Rolling speed / driving speed = 3 mm / s;

[0276] - Temperature = 90 °C;

[0277] Duration = 10 minutes;

[0278] SSR (Sliding Scroll Ratio) = 330%.

[0279] [Table 4]

[0280] CC1 CC2 FZG 4 5 Friction coefficient 0.130 0.122

[0281] [Table 5]

[0282] CI5 CI6 CI7 CI8 CI9 FZG 8 7 6 7 7 Friction coefficient 0.066 0.069 0.065 0.065 0.089

[0283] The compositions CI5 to CI9 of the present invention exhibit very good load-carrying capacity. These load-carrying capacity values (FZG) prove that the lubricant composition has very high durability and is particularly suitable for use in transmission devices.

[0284] The compositions CI5 to CI9 of the present invention also exhibit a lower average coefficient of friction, thus proving their excellent lubricating performance.

[0285] The antiwear agent having the formula (I) defined in the present invention provides a way to improve the performance level of the lubricant composition. More specifically, the antiwear agent having the formula (I) defined in the present invention provides more excellent performance compared with the prior art antiwear agents C1 and C2.

Claims

1. A lubricant composition comprising: - at least one base oil; - at least one additive having the formula (I): [Chemical formula 1] Wherein, R and R 1 each independently selected from: a hydrogen atom; or a straight-chain or branched-chain saturated or unsaturated hydrocarbon group having 8 to 40 carbon atoms and optionally containing one or more heteroatoms; at least one of R and R 1 is a hydrocarbon group containing at least two ethoxylation and / or propoxylation units.

2. The lubricant composition according to claim 1, wherein, R and R 1 are each independently selected from: a hydrogen atom; or a linear or branched alkyl or alkenyl group; wherein at least one of R and R 1 is a linear or branched alkyl or alkenyl group further comprising at least two ethoxylation units; preferably, R and R 1 are each independently selected from linear or branched alkyl or alkenyl groups, wherein at least one of R and R 1 is an alkyl or alkenyl group further containing at least two ethoxylation units.

3. The lubricant composition according to any one of the preceding claims, wherein, R and / or R 1 each independently selected from a hydrogen atom or a hydrocarbon group consisting of: - an alkyl chain containing 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, preferably a straight chain; and - 2 to 15 ethoxylation units, preferably 3 to 10 ethoxylation units; It should be understood that at least one of the groups R or R 1 is a hydrocarbon group consisting of the following: - an alkyl chain containing 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, preferably a straight chain; and - 2 to 15 ethoxylation units, preferably 3 to 10 ethoxylation units; Preferably, the two groups R and R 1 are each independently selected from hydrocarbon groups consisting of the following: - an alkyl chain containing 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, preferably a straight chain; and - 2 to 15 ethoxylation units, preferably 3 to 10 ethoxylation units.

4. The lubricant composition according to any one of the preceding claims, comprising: - phosphorus in an amount of 250 ppm to 1300 ppm by weight, preferably 400 ppm to 1400 ppm by weight, provided by one or more additives having the formula (I); and / or - sulfur in an amount of less than 10 ppm by weight, preferably less than 5 ppm by weight, more preferably less than 1 ppm by weight.

5. The lubricant composition according to any one of the preceding claims, further comprising at least one additive selected from: phosphites containing 1 to 24 carbon atoms; preferably phosphites containing 4 to 12 carbon atoms; preferably phosphites containing two alkyl groups each having 2 to 6 carbon atoms.

6. The lubricant composition according to the preceding claim, comprising 0.01% to 10% by weight, preferably 0.05% to 5% by weight, more preferably 0.1% to 3% by weight of one or more additives having the formula (I) relative to the total weight of the lubricant composition.

7. The lubricant composition according to any one of the preceding claims, comprising: - 0.01% to 5% by weight, preferably 0.02% to 2% by weight of one or more additives having the formula (I); and - 0.05% to 5% by weight, preferably 0.1% to 2% by weight of one or more additives selected from phosphites containing two alkyl groups each having 2 to 6 carbon atoms relative to the total weight of the lubricant composition.

8. The lubricant composition according to any one of the preceding claims, further comprising at least one dispersant, preferably a borated dispersant, more preferably a borated dispersant selected from borated succinimides, even more preferably borated polyisobutylene succinimides.

9. The lubricant composition according to any one of the preceding claims, comprising: Relative to the total weight of the lubricant composition, - at least 70% by weight, preferably 75% to 99.5% by weight of one or more base oils; - 0.01% to 5% by weight, especially 0.02% to 2% by weight of one or more additives having the formula (I); - 0.05 wt% to 5 wt%, preferably 0.1 wt% to 2 wt% of one or more additives selected from phosphites having 1 to 24 carbon atoms, preferably 4 to 12 carbon atoms, preferably phosphites having two alkyl groups each having 2 to 6 carbon atoms.

10. The lubricant composition according to any one of the preceding claims, comprising: Relative to the total weight of the lubricant composition, - at least 70 wt%, preferably 75 wt% to 99.5 wt% of one or more non-aqueous base oils; - 0.01 wt% to 5 wt%, in particular 0.02 wt% to 2 wt% of one or more additives of formula (I); - 0.05 wt% to 5 wt%, preferably 0.1 wt% to 2 wt% of one or more additives selected from phosphites having 1 to 24 carbon atoms; - Optionally 0.1 wt% to 15 wt%, preferably 1 wt% to 10 wt% of one or more functional additives, preferably selected from dispersants, antioxidants, pour point depressants, defoamers or antifoaming agents and mixtures thereof.

11. The lubricant composition according to any one of the preceding claims, wherein, The one or more base oils have a kinematic viscosity at 100 °C of 1.5 cSt to 35 cSt.

12. Use of the composition according to any one of claims 1 to 11 for lubricating at least one mechanical component of a motor vehicle, preferably present in the transmission assembly of a motor vehicle, preferably a gear of a motor vehicle.

13. Use of an additive in a lubricant composition containing at least one base oil for improving the load-carrying capacity of the lubricant composition, the additive having formula (I): [Chemical formula 1] wherein, -R and R 1 each independently selected from: a hydrogen atom; or a straight-chain or branched-chain saturated or unsaturated hydrocarbon group having 8 to 40 carbon atoms and optionally containing one or more heteroatoms; at least one of R and R 1 is a hydrocarbon group containing at least two ethoxylated and / or propoxylated units.

14. The use according to claim 13, wherein, The additive of formula (I) is combined with an additive selected from phosphites having 1 to 24 carbon atoms for the lubricant composition, preferably in the following proportions: Relative to the total weight of the lubricant composition, - 0.01 wt% to 5 wt%, preferably 0.02 wt% to 2 wt% of one or more additives of formula (I); - 0.05 wt% to 5 wt%, preferably 0.1 wt% to 2 wt% of one or more additives selected from phosphites having 1 to 24 carbon atoms.

15. The use according to claim 13 or 14, wherein The lubricant composition is as defined in any one of claims 2 to 11.

Images