Lubricating oil composition for automotive transmissions

Abstract

The present invention provides a lubricating oil composition comprising: at least one base oil; and at least one additive having formula (I), wherein R and R 1 are selected independently from one another from: a hydrogen atom; or a saturated or unsaturated linear hydrocarbon group containing 8 to 20 carbon atoms; two radicals R or R 1 and at least one of the groups is a saturated or unsaturated linear hydrocarbon group containing 8 to 20 carbon atoms. JPEG2025539225000010.jpg2439

Description

[Technical Field]

[0001] The present invention relates to the field of lubricating oil compositions, particularly for use in motor vehicles, especially for lubricating motor vehicle transmission components, especially gears in the transmissions of internal combustion engines or electric motors. [Background technology]

[0002] Automotive transmission components operate under high loads and high speeds, so oils (also called "lubricating oil compositions" or "lubricants") for these transmissions must be particularly effective in protecting the components from wear, particularly the phenomenon of gear seizure (or scoring / scuffing) of gear teeth.

[0003] Seizure occurs under high load conditions and can be assessed by monitoring visual degradation.

[0004] Prevention of this phenomenon involves reducing contact stresses by ensuring proper geometry of the parts and reducing friction by avoiding adhesion. The lubricating oil composition plays a key role in this prevention process, mainly through the physicochemical reactivity of its additives.

[0005] Sulfur, phosphorus, or boron containing anti-wear, extreme pressure additives are commonly added to transmission oils to impart anti-seize properties. Other additives present in the lubricating oil composition may also have a positive or negative effect on this phenomenon.

[0006] Another advantage offered by the subject matter of the present invention is the avoidance of the need to introduce any additives, in particular sulfur-containing extreme pressure anti-wear additives. In transmission oils, and in particular in transmission oils for electric vehicles, it is desirable to limit, or indeed completely eliminate, sulfur in order to limit the occurrence of corrosion phenomena and to limit the conductivity values ​​to the required level.

[0007] Advantageously, the object of the present invention also relates to compositions that do not contain zinc-based antiwear additives.

[0008] Document EP 3546550 discloses a composition comprising a reaction product from the reaction of an acidic phosphoric acid ester with a nitrogen compound.

[0009] Document EP 3812445 discloses a composition comprising an acidic phosphoric acid ester containing a hydrocarbon group having 1 to 6 carbon atoms.

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

[0011] It is therefore an object of the present invention to provide a composition that functions to lubricate manual or automatic transmission components, particularly transmission gears in internal combustion engine vehicles or, preferably, electric vehicles, which composition exhibits good durability and is free of any sulfur-based additives. Summary of the Invention

[0012] More specifically, the present invention relates to a lubricating oil composition comprising: with at least one base oil; Formula (I): [ka] and at least one additive having In the formula, R and R 1 are selected independently from one another from: a hydrogen atom; or a saturated or unsaturated linear hydrocarbon group containing 8 to 20 carbon atoms; two radicals R or R 1 At least one of the groups is a saturated or unsaturated linear hydrocarbon group containing 8 to 20 carbon atoms.

[0013] According to one embodiment, the hydrocarbon group is chosen from alkyl and alkenyl groups.

[0014] Preferably, R and R 1are each independently selected from linear alkyl groups containing 8 to 18 carbon atoms.

[0015] Preferably, the lubricating oil composition comprises: - 250 to 1300 ppm by weight of phosphorus, preferably 400 to 1400 ppm by weight of phosphorus provided by one or more additives having formula (I); and / or Contains less than 10 ppm by weight of sulfur, preferably less than 5 ppm by weight of sulfur, more preferably less than 1 ppm by weight of sulfur.

[0016] According to one preferred embodiment, the lubricating oil composition according to the invention further comprises 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.

[0017] Preferably, the lubricating oil composition comprises 0.01 to 10 wt. %, preferably 0.05 to 5 wt. %, more preferably 0.1 to 3 wt. % of one or more additives having formula (I) relative to the total weight of the lubricating oil composition.

[0018] According to one preferred embodiment, the lubricating oil composition according to the present invention comprises: - 0.01 to 5% by weight, preferably 0.02 to 2% by weight, of one or more additives having formula (I); 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.

[0019] According to one embodiment of the present invention, the lubricating oil composition further comprises at least one dispersant, preferably a borated dispersant, even more preferably a borated dispersant selected from borated succinimides, even more preferably a borated polyisobutene succinimide.

[0020] According to one embodiment of the present invention, the lubricating oil composition according to the present invention comprises: based on the total weight of the lubricating oil composition: at least 70% by weight, preferably 75 to 99.5% by weight, of one or more non-aqueous base oils; - 0.01 to 5% by weight, in particular 0.02 to 2% by weight, of one or more additives having formula (I); 0.05 to 5% by weight, preferably 0.1 to 2% by weight, of one or more additives chosen from phosphites containing 1 to 24 carbon atoms; Optionally, 0.1 to 15 wt %, preferably 1 to 10 wt %, of one or more functional additives preferably selected from dispersants, antioxidants, pour point depressants, antifoaming or defoaming agents, and mixtures thereof.

[0021] Preferably, the kinematic viscosity at 100°C of the one or more base oils is 1.5 to 35 cSt.

[0022] The present invention also relates to the use of a lubricating oil composition according to the invention for lubricating at least one mechanical part of a motor vehicle which is preferably present in a transmission part of the motor vehicle, preferably in a gear of the motor vehicle.

[0023] The present invention also relates to the use of an additive in a lubricating oil composition comprising at least one base oil to improve the load-carrying capacity of the lubricating oil composition, said additive being represented by formula (I): [ka] and In the formula, R and R 1 are selected independently from one another from: a hydrogen atom; or a saturated or unsaturated linear hydrocarbon group containing 8 to 20 carbon atoms; and two radicals R and R 1 At least one of the groups is a saturated or unsaturated linear hydrocarbon group containing 8 to 20 carbon atoms.

[0024] Preferably, the additive having formula (I) is present in the lubricating oil composition in combination with an additive selected from phosphites containing 1 to 24 carbon atoms, preferably in an amount of: 0.01 to 5% by weight, preferably 0.02 to 2% by weight, of one or more additives having formula (I): One or more additives selected from phosphites containing 1 to 24 carbon atoms are used in a proportion of 0.05 to 5% by weight, preferably 0.1 to 2% by weight.

[0025] Preferably, the lubricating oil composition implemented in the use of the additive according to the invention is as defined in the present invention. In particular, the lubricating oil composition implemented in the use of the additive according to the invention has one or more of the following characteristics: the hydrocarbon groups are selected from alkyl and alkenyl groups, and / or -R and R 1 are independently selected from linear alkyl groups containing 8 to 18 carbon atoms, and / or the lubricating oil composition comprising: 250 to 1300 ppm by weight of phosphorus, preferably 400 to 1400 ppm by weight of phosphorus provided by one or more additives having formula (I); and / or less than 10 ppm by weight of sulfur, preferably less than 5 ppm by weight of sulfur, more preferably less than 1 ppm by weight of sulfur; and / or the lubricating oil composition further comprises 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, and / or the lubricating oil composition comprises from 0.01 to 10% by weight, preferably from 0.05 to 5% by weight, more preferably from 0.1 to 3% by weight, of one or more additives having formula (I), relative to the total weight of the lubricating oil composition; and / or the lubricating oil composition comprising, based on the total weight of the lubricating oil composition: 0.01 to 5% by weight, preferably 0.02 to 2% by weight, of one or more additives having formula (I); 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; and / or the lubricating oil composition further comprises at least one dispersant, preferably a borated dispersant, even more preferably a borated dispersant selected from borated succinimides, even more preferably from borated polyisobutene succinimides; and / or the lubricating oil composition comprising, based on the total weight of the lubricating oil composition: at least 70% by weight, preferably 75 to 99.5% by weight, of one or more non-aqueous base oils; 0.01 to 5% by weight, in particular 0.02 to 2% by weight, of one or more additives having formula (I); 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; optionally 0.1 to 15 wt. %, preferably 1 to 10 wt. %, of one or more functional additives, preferably selected from dispersants, antioxidants, pour point depressants, antifoaming or defoaming agents, and mixtures thereof; The kinematic viscosity at 100°C of one or more base oils is 1.5 to 35 cSt.

[0026] The lubricating oil composition according to the invention offers the advantage of having very good properties in reducing the phenomenon of gear seizure (scoring / scuffing).

[0027] The lubricating oil compositions according to the present invention also exhibit good durability.

[0028] The lubricating oil compositions exhibit particularly satisfactory performance levels with respect to wear reduction even under high loads, even in the absence of sulfur-based and / or zinc-based additives.

[0029] In the remainder of this document, the terms "between and," "from to," and "through" are used interchangeably and are intended to indicate inclusion of both endpoints unless otherwise specified. Unless otherwise specified, amounts in products are expressed by weight relative to the total weight of the product. DETAILED DESCRIPTION OF THE INVENTION

[0030] The present invention provides with at least one base oil; - at least one anti-wear additive having the formula (I):

[0031] (Acidic phosphate ester-type anti-wear additive having formula (I)) The lubricating oil composition according to the present invention comprises at least one acidic phosphate ester type additive having formula (I): [ka] where: wherein R and R 1 are selected independently from one another from: a hydrogen atom; or a saturated or unsaturated linear hydrocarbon group containing 8 to 20 carbon atoms; two radicals R or R 1 At least one of the groups is a saturated or unsaturated linear hydrocarbon group containing 8 to 20 carbon atoms.

[0032] For the purposes of the present invention, the term "linear hydrocarbon group" is understood to refer to a linear hydrocarbon chain (comprising carbon and hydrogen atoms), optionally containing one or more heteroatoms, such as oxygen or nitrogen atoms.

[0033] Preferably, the hydrocarbon group is selected from alkyl and alkenyl groups.

[0034] According to one embodiment, R and R 1are independently selected from a hydrogen atom or a linear alkyl group containing 8 to 20 carbon atoms, preferably R and R 1 are independently selected from linear alkyl groups containing 8 to 18 carbon atoms, and R or R 1 It is understood that at least one of the groups is a straight chain alkyl group.

[0035] The lubricating oil composition may optionally contain a mixture of compounds having formula (I).

[0036] Preferably, the anti-wear product having formula (I) provides 250 to 1300 ppm by weight of phosphorus.

[0037] Preferably, the anti-wear additive having formula (I) represents 0.01 to 10% by weight, preferably 0.05 to 5% by weight, more preferably 0.1 to 3% by weight of the total weight of the lubricating oil composition according to the invention.

[0038] (Phosphite-type anti-wear additive) According to one advantageous embodiment of the invention, the lubricating oil composition according to the invention comprises at least one anti-wear additive selected from phosphites containing from 1 to 24 carbon atoms, preferably from phosphites containing from 4 to 12 carbon atoms.

[0039] Advantageously, the phosphite-type anti-wear additive is chosen from phosphites containing two alkyl groups each having from 2 to 6 carbon atoms.

[0040] In a particularly advantageous manner, the phosphite-type anti-wear additive is dibutyl hydrogen phosphite.

[0041] According to one embodiment, the phosphite-type anti-wear additive represents 0.05 to 5% by weight, preferably 0.1 to 2% by weight, of the total weight of the lubricating oil composition according to the invention.

[0042] According to one embodiment of the present invention, the lubricating oil composition comprises, based on the total weight of the lubricating oil composition: having formula (I), in which R and R 1 are selected independently from one another from: a hydrogen atom; or a saturated or unsaturated linear hydrocarbon group containing 8 to 20 carbon atoms; two radicals R or R 1 0.01 to 5 wt %, preferably 0.02 to 2 wt %, of one or more antiwear additives, at least one of which is a saturated or unsaturated linear hydrocarbon group containing 8 to 20 carbon atoms; 0.05 to 5% by weight, preferably 0.1 to 2% by weight, of one or more anti-wear additives selected from phosphites containing 1 to 24 carbon atoms.

[0043] According to one embodiment of the present invention, the lubricating oil composition comprises, based on the total weight of the lubricating oil composition: having formula (I), in which R and R 1 0.01 to 5 wt. %, preferably 0.02 to 2 wt. %, of one or more antiwear additives selected independently from saturated or unsaturated alkyl or alkenyl linear groups containing 8 to 20 carbon atoms; 0.05 to 5% by weight, preferably 0.1 to 2% by weight, of one or more anti-wear additives selected from phosphites containing 1 to 24 carbon atoms.

[0044] According to one embodiment of the present invention, the lubricating oil composition comprises, based on the total weight of the lubricating oil composition: having formula (I), in which R and R 1 0.01 to 5 wt. %, preferably 0.02 to 2 wt. %, of one or more antiwear additives selected independently from linear alkyl groups containing 8 to 18 carbon atoms; 0.05 to 5% by weight, preferably 0.1 to 2% by weight, of one or more anti-wear additives selected from phosphites containing two alkyl groups each having 2 to 6 carbon atoms.

[0045] (base oil) The lubricating oil composition according to the invention comprises one or more base oils, preferably in a content of at least 70% by weight, preferably between 75 and 99.5% by weight, preferably between 80 and 99% by weight, preferentially between 85 and 98% by weight, relative to the total weight of the lubricating oil composition.

[0046] Preferably, the lubricating oil composition according to the invention comprises at least one base oil having a kinematic viscosity at 100°C of 1.5 to 35 cSt according to the ASTM D445 standard. Advantageously, the base oil of the lubricating oil composition according to the invention has a kinematic viscosity at 100°C of 1.5 to 35 cSt.

[0047] These base oils are selected from those conventionally used in the lubricating oil field, such as mineral oils, synthetic or natural oils, animal or vegetable oils, or mixtures thereof. Typically, the base oils are non-aqueous base oils.

[0048] It may also be a mixture of multiple base oils, such as a mixture of two, three or four base oils.

[0049] The base oil of the lubricating oil composition according to the invention may in particular be a mineral or synthetic oil, or a mixture thereof, belonging to groups I to V of the categories defined by the classification of the American Petroleum Institute (API) (or equivalent according to the classification of the ATIEL - European Technical Association of the Lubricating Oil Industry), as set out in Table 1 below.

[0050] [Table 1]

[0051] Mineral oil base oils include all types of base oils obtained by atmospheric and vacuum distillation of crude oil and subsequently subjected to refining operations such as solvent extraction, deasphalting, solvent dewaxing, hydrotreating, hydrocracking, hydroisomerization and hydrofinishing.

[0052] Blends of synthetic and mineral oils (which may be bio-based) may also be used.

[0053] There are generally no limitations as to the use of different base oils to prepare compositions operatively implemented in accordance with the present invention, provided that the properties, particularly viscosity, viscosity index or antioxidant properties, are suitable for use in electric or hybrid vehicle propulsion systems.

[0054] The base oil of the compositions operatively practiced in accordance with the present invention may be selected from synthetic oils such as certain esters of carboxylic acids and alcohols; polyalphaolefins (PAOs); and polyalkylene glycols (PAGs) obtained by polymerization or copolymerization of alkylene oxides containing from 2 to 8 carbon atoms, particularly from 2 to 4 carbon atoms.

[0055] The PAOs used as base oils are derived, for example, from monomers containing 4 to 32 carbon atoms, such as octene or decene. The weight average molecular weight of the PAOs is available over a wide range. Preferably, the weight average molecular weight of the PAO is less than 600 Da. The weight average molecular weight of the PAO may be 100 to 600 Da, 150 to 600 Da, or even 200 to 600 Da.

[0056] Advantageously, the base oil or oils of the lubricating oil composition according to the present invention may be selected from Group II or III base oils.

[0057] According to another embodiment, the one or more base oils of the composition operatively practiced in accordance with the present invention are selected from polyalphaolefins (PAOs), polyalkylene glycols (PAGs), and esters of carboxylic acids and alcohols.

[0058] (Other auxiliary additives) The lubricating oil composition according to the present invention may further comprise any type of functional additive suitable for use in motor vehicles, in particular in lubricating oils for manual or automatic transmissions of motor vehicles, other than the anti-wear additive having formula (I) and the phosphite-type anti-wear additive defined in the present invention.

[0059] Such additives are known to those skilled in the art of automotive lubrication and may be selected from detergents, dispersants, antioxidants, pour point depressants, antifoam or defoaming agents, viscosity index improvers (or viscosity modifiers), and mixtures thereof.

[0060] Advantageously, the composition according to the invention comprises at least one functional additive selected from detergents, dispersants, antioxidants, pour point depressants, antifoams or defoamers, viscosity index improvers (or viscosity modifiers), and mixtures thereof.

[0061] Typically, when present, these additional functional additives comprise from 1 to 30 wt. %, preferably from 1.5 to 25 wt. %, preferentially from 2 to 20 wt. % (in total) of the total weight of the lubricating oil composition.

[0062] These additives may be introduced individually or in the form of mixtures similar to those already available in commercial automotive engine lubricant formulations having performance levels defined by ACEA (European Automobile Manufacturers Association) and / or API (American Petroleum Institute), as is well known to those skilled in the art.

[0063] The lubricating oil composition according to the present invention may contain at least one antioxidant additive.

[0064] Antioxidant additives generally serve to retard degradation of the composition during on-line use, which may result in deposit formation or an increase in viscosity of the composition, especially in the presence of sludge.

[0065] The antioxidant additive acts in particular as a radical inhibitor or hydroperoxide decomposer (scavenger). Commonly used antioxidant additives that can be mentioned include 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 additive may be selected in particular from sterically hindered phenols; sterically hindered phenol esters; sterically hindered phenols with thioether bridges; diphenylamines; diphenylamines substituted with at least one C1-C12 alkyl group; N,N'-dialkyl-aryl-diamines; and mixtures thereof.

[0066] Preferably, according to the present invention, the sterically hindered phenol has at least one vicinal carbon adjacent to the carbon bearing the alcohol functional group, and at least one C1-C 10 The alkyl group is selected from compounds containing a phenol group substituted with an alkyl group, preferably a C1 to C6 alkyl group, more preferably a C4 alkyl group, in particular a tert-butyl group.

[0067] Amino compounds are another class of antioxidant additives that may optionally be used in combination with phenolic antioxidant additives. Examples of amino compounds include aromatic amines, such as those of the formula NR 10 R 11 R 12 Aromatic amines having the formula 10 represents an optionally substituted aliphatic or aromatic group; R 11 represents an optionally substituted aromatic group; R 12 is a hydrogen atom, an alkyl group, an aryl group, or a group of the formula R 13 S(O)zR 14 (In the formula, R 13 represents an alkylene group or an alkenylene group, R 14 represents an alkyl group, an alkenyl group, or an aryl group, and z represents 0, 1, or 2).

[0068] Sulfurized alkylphenols or their alkali metal and alkaline earth metal salts can also be used as antioxidant additives.

[0069] Copper compounds constitute another class of antioxidant additives, such as salts of copper with carboxylic acids, copper phenates, copper acetylacetonates, etc. Copper I and II salts, salts of succinic acid or succinic anhydride may also be used.

[0070] The lubricating oil composition according to the present invention may contain all types of antioxidant additives known to those skilled in the art.

[0071] Advantageously, the lubricating oil composition according to the invention comprises at least one ashless antioxidant additive.

[0072] The lubricating oil composition according to the present invention may comprise from 0.5 to 2% by weight, relative to the total weight of the composition, of at least one antioxidant additive.

[0073] The lubricating oil composition according to the present invention may also contain at least one detergent additive.

[0074] Detergent additives generally provide a means of reducing deposit formation on metal component surfaces by dissolving oxidation and combustion by-products.

[0075] Detergent additives that can be used in the lubricating oil compositions according to the present invention are generally known to those skilled in the art. The detergent additives may be anionic compounds containing a long, lipophilic hydrocarbon chain and a hydrophilic head. The associated cation may be a metal cation of an alkali metal or alkaline earth metal.

[0076] The detergent additives are preferably selected from alkali metal or alkaline earth metal salts of carboxylic acids, salicylates, naphthenates, and phenates. The alkali and alkaline earth metals are preferably calcium, magnesium, sodium, or barium.

[0077] These metal salts generally contain the metal in a stoichiometric amount or actually in an excess amount, i.e., greater than the stoichiometric amount. They are therefore overbased detergent additives; the excess metal that imparts the overbasing character to the detergent additive is generally in the form of an oil-insoluble metal salt, such as carbonate, hydroxide, oxalate, acetate, glutamate, preferentially carbonate.

[0078] Lubricating oil compositions suitable for the present invention may, for example, contain from 0.5 to 4% by weight of detergent additive, based on the total weight of the composition.

[0079] The lubricating oil composition according to the present invention may also contain at least one dispersant, which typically serves to ensure the maintenance in suspension and removal of insoluble solid contaminants consisting of oxidation by-products formed when the lubricating oil composition is used in service.

[0080] The dispersant may be selected from Mannich bases; succinimide type compounds, such as optionally boronated polyisobutene succinimides (PIBSI); or boronated dispersants other than succinimides; preferably boronated dispersants; even more preferably boronated succinimide dispersants, especially boronated PIBSI.

[0081] Lubricating oil compositions according to the invention may, for example, contain from 0.2 to 10% by weight of one or more dispersants relative to the total weight of the composition.

[0082] The lubricating oil composition according to the present invention may further comprise at least one antifoam agent.

[0083] The antifoaming agent may be selected from silicones.

[0084] The lubricating oil composition according to the invention may comprise from 0.01 to 2% or from 0.01 to 5% by weight, and preferentially from 0.1 to 1.5% or from 0.1 to 2% by weight, of an antifoaming agent relative to the total weight of the composition.

[0085] Lubricating oil compositions according to the present invention may also contain at least one pour point depressant (PPD) additive.

[0086] Pour point depressant additives generally improve the low temperature behavior of a composition by retarding the formation of paraffin crystals. Examples that may be mentioned of pour point depressant additives include alkyl polymethacrylates, polyacrylates, polyarylamides, polyalkylphenols, polyalkylnaphthalenes, and alkylated polystyrenes.

[0087] The lubricating oil composition according to the present invention may also contain at least one viscosity index improver (or VI modifier). Examples that may be mentioned of VI improvers include polymethacrylates, polyisobutenes or fatty acid esters. When present, these additives may represent 1 to 25 wt. % of the total weight of the lubricating oil composition.

[0088] Preferably, the lubricating oil composition according to the present invention does not contain any zinc-containing anti-wear additives.

[0089] For formulating such lubricating oil compositions, one or more anti-wear additives according to the present invention may be added to a base oil or mixture of base oils, followed by the addition of other supplemental additives.

[0090] Alternatively, one or more anti-wear additives according to the present invention may be added to existing conventional lubricating oil formulations, particularly those containing one or more base oils and, optionally, other auxiliary additives.

[0091] Alternatively, one or more anti-wear additives according to the present invention may be combined with one or more additional additives, if present, and the "additive package" thus formed may be added to a base oil or blend of base oils.

[0092] Advantageously, the lubricating oil composition according to the invention has a kinematic viscosity of 5 to 300 mm, measured at 40°C according to the ASTM D445 standard. 2 / s, especially 10-25mm 2 / s.

[0093] Advantageously, the lubricating oil composition according to the invention has a kinematic viscosity measured at 100°C according to the ASTM D445 standard of between 1 and 20 mm 2 / s, especially 2-15mm 2 / s.

[0094] Preferably, the lubricating oil composition according to the invention comprises 400 to 1400 ppm by weight of phosphorus, of which advantageously 250 to 1300 ppm by weight of phosphorus is provided by one or more antiwear agents having formula (I).

[0095] Preferably, lubricating oil compositions according to the present invention are substantially sulfur-free, preferably completely sulfur-free.

[0096] In particular, the lubricating oil composition according to the present invention is preferably free of sulfur-containing additives.

[0097] Thus, lubricating oil compositions according to the present invention generally contain less than 10 ppm by weight of sulfur, or indeed less than 5 ppm by weight of sulfur, or even less than 1 ppm by weight of sulfur.

[0098] According to one particular embodiment, the lubricating oil composition according to the invention comprises or actually consists of: - base oil or mixture of base oils; antiwear additives having formula (I); optionally an antiwear additive selected from phosphites containing 1 to 24 carbon atoms; optionally one or more additional additives selected from dispersants, antioxidants, pour point depressants, antifoaming or defoaming agents, and mixtures thereof.

[0099] According to one particular embodiment, the lubricating oil composition according to the invention comprises or actually consists of: based on the total weight of the lubricating oil composition, at least 70% by weight, preferably 75 to 99.5% by weight, of one or more base oils; 0.01 to 10% by weight, in particular 0.05 to 5% by weight, of one or more antiwear additives of formula (I); optionally 0.05 to 5% by weight, in particular 0.1 to 2% by weight, of one or more antiwear additives chosen from phosphites containing 1 to 24 carbon atoms; - optionally 0.1 to 15 wt. %, preferably 1 to 10 wt. %, of one or more functional additives, preferably chosen from dispersants, antioxidants, pour point depressants, antifoaming or defoaming agents, and mixtures thereof.

[0100] According to one particular embodiment of the lubricating oil composition, the lubricating oil composition according to the invention comprises or actually consists of: based on the total weight of the lubricating oil 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, in particular 0.02 to 2% by weight, of one or more antiwear additives of formula (I); 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; - optionally 0.1 to 15 wt. %, preferably 1 to 10 wt. %, of one or more functional additives, preferably chosen from dispersants, antioxidants, pour point depressants, antifoaming or defoaming agents, and mixtures thereof.

[0101] According to one particular embodiment, the lubricating oil composition according to the invention comprises: based on the total weight of the lubricating oil 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, in particular 0.02 to 2% by weight, of one or more additives having formula (I); - 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, preferably 4 to 12, carbon atoms, preferably from phosphites containing two alkyl groups each having 2 to 6 carbon atoms; - optionally 0.1 to 15 wt. %, preferably 1 to 10 wt. %, of one or more functional additives, preferably chosen from dispersants, antioxidants, pour point depressants, antifoaming or defoaming agents, and mixtures thereof.

[0102] According to one particular embodiment, the lubricating oil composition according to the present invention comprises: based on the total weight of the lubricating oil 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, in particular 0.02 to 2% by weight, of one or more antiwear additives of formula (I); 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; optionally comprising or essentially consisting of 0.1 to 15% by weight, preferably 1 to 10% by weight, of one or more functional additives, preferably chosen from dispersants, antioxidants, pour point depressants, antifoaming or defoaming agents, and mixtures thereof, The composition contains less than 10 ppm by weight of sulfur.

[0103] According to one particular embodiment, the lubricating oil composition according to the invention comprises or actually consists of: based on the total weight of the lubricating oil composition, at least 70% by weight, preferably 75 to 99.5% by weight, of one or more base oils; having formula (I), in which R and R 1 0.01 to 5 wt. %, preferably 0.02 to 2 wt. %, of one or more antiwear additives, each of which is independently selected from linear alkyl groups containing 8 to 18 carbon atoms; - 0.05 to 5% by weight, preferably 0.1 to 2% by weight, of one or more antiwear additives chosen from phosphites containing two alkyl groups each having 2 to 6 carbon atoms; - optionally 0.1 to 15 wt. %, preferably 1 to 10 wt. %, of one or more functional additives, preferably chosen from dispersants, antioxidants, pour point depressants, antifoaming or defoaming agents, and mixtures thereof.

[0104] According to one particular embodiment, the lubricating oil composition according to the invention comprises or actually consists of: based on the total weight of the lubricating oil 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, in particular 0.02 to 2% by weight, of one or more antiwear additives of formula (I); 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; 0.5 to 5% by weight, preferably 0.1 to 2% by weight, of one or more dispersants, preferably chosen from boronated dispersants; Optionally, 0.1 to 10% by weight, preferably 0.5 to 5% by weight, of one or more functional additives, preferably chosen from antioxidants, pour point depressants, antifoaming or defoaming agents, and mixtures thereof.

[0105] The object of the present invention also relates to the use of the lubricating oil composition according to the invention for lubricating the gears of a motor vehicle transmission, in particular the transmission, which may be a manual or automatic transmission.

[0106] Preferably, the lubricating oil composition according to the present invention is used to reduce wear of mechanical parts of an automobile transmission, in particular automobile gears. Thus, according to this embodiment, the lubricating oil composition according to the present invention provides a means for reducing wear of transmission gears.

[0107] Preferably, the lubricating oil compositions according to the present invention are used to reduce spalling or scoring in mechanical parts of an automobile transmission, particularly automobile gears.

[0108] According to one advantageous embodiment, the lubricating oil composition according to the invention is used both to reduce wear and to reduce spalling or scoring in mechanical parts of motor vehicle transmissions, in particular in motor vehicle gears.

[0109] According to another aspect of the present invention, the present invention also relates to a method of lubricating at least a portion of a motor vehicle transmission, particularly a motor vehicle gear, which method comprises at least one step of contacting at least the portion with the lubricating oil composition described above.

[0110] According to another aspect of the present invention, the present invention also relates to a process for increasing the durability of a lubricating oil composition, which process comprises the step of mixing at least one anti-wear additive having formula (I) as defined in the present invention with at least one base oil, preferably mixing said anti-wear additive having formula (I) with an anti-wear additive selected from phosphites containing 1 to 24 carbon atoms.

[0111] All features and preferences described with respect to the lubricating oil compositions and their uses according to the invention are also applicable to said methods and processes.

[0112] According to the invention, the particular, advantageous or preferred characteristics of the compositions according to the invention make it possible to define likewise particular, advantageous or preferred uses according to the invention.

[0113] The present invention will now be described by the following examples, which obviously are not intended to limit the invention but are provided for illustrative purposes. [Example]

[0114] Example 1: Preparation of lubricating oil compositions The lubricating oil compositions were prepared according to methods well known to those skilled in the art by mixing the ingredients at a temperature of about 40° C. Details of the lubricating oil compositions prepared and tested are set out in Tables 2 and 3 below.

[0115] The content of elemental phosphorus and sulfur was calculated based on the elemental content in the components and is also shown in Table 2 in ppm by weight.

[0116] The lubricating oil composition tested has a viscosity of about 4.5 cSt measured at 100° C. according to ASTM D445 standard.

[0117] [Table 2]

[0118] In the compositions of Table 2: the base oil is a Group III base oil; the antiwear agent I1 has the formula (I), in which R and R 1 are two linear C8 alkyl chains; - the antiwear agent P1 is dibutyl hydrogen phosphite; - the antiwear agent C1 is an acidic phosphate ester with a branched chain containing 8 carbon atoms and therefore does not have formula (I); - the antiwear agent C2 is an acidic phosphate ester with a chain containing 5 carbon atoms and therefore does not have formula (I); the dispersant is a boronated PIBSI dispersant capable of delivering about 85 ppm boron; the antioxidant comprises a phenolic antioxidant and / or an aminic antioxidant; - the rust inhibitor is a triazole derivative; -The additive package includes a pour point improver and an antifoam / defoamer.

[0119] Example 2: Test study on the performance of lubricating oil compositions The scuffing load carrying capacity of the lubricating oil compositions listed in Table 2 was tested using the FZG A10 / 16.6R / 90 method (in accordance with the revised CEC-L-84-02 standard), and the results are shown in Table 4 below.

[0120] The average coefficient of friction was measured by a mini-traction machine (MTM) under the following conditions: - Load = 5N, -Rolling speed / driving speed = 3mm / s, -Temperature=90℃, -Time = 10 minutes, -SSR (Slide-Roll Ratio) = 330%.

[0121] [Table 3]

[0122] The compositions CI1 to CI4 according to the invention exhibit very good load-carrying capacity. These load-carrying capacity values ​​(FZG) indicate a very high durability of the lubricating oil compositions, especially in transmission use.

[0123] Compositions CI1 to CI4 according to the invention also have low average coefficients of friction and therefore exhibit excellent lubricating properties.

[0124] The antiwear agents having formula (I) as defined in the present invention provide a means for enhancing the performance level of lubricating oil compositions, and in particular, the antiwear agents having formula (I) as defined in the present invention provide superior properties compared to prior art antiwear agents C1 and C2.

Claims

1. at least one base oil; Formula (I): 【Chemistry 1】 and at least one additive having wherein R and R １ are selected independently from one another from: a hydrogen atom; or a saturated or unsaturated linear hydrocarbon group containing 8 to 20 carbon atoms and optionally containing one or more heteroatoms; and two radicals R or R １ wherein at least one of is a saturated or unsaturated linear hydrocarbon group containing from 8 to 20 carbon atoms.

2. 2. The lubricating oil composition of claim 1, wherein the hydrocarbon group is selected from alkyl and alkenyl groups.

3. R and R １ 3. The lubricating oil composition of claim 1, wherein are independently selected from linear alkyl groups containing from 8 to 18 carbon atoms.

4. - 250 to 1300 ppm by weight of phosphorus, preferably 400 to 1400 ppm by weight, provided by one or more of said additives having formula (I) as defined above; and / or A lubricating oil composition according to any one of claims 1 to 3, containing less than -10 ppm by weight of sulphur, preferably less than 5 ppm by weight of sulphur, more preferably less than 1 ppm by weight of sulphur.

5. 5. The lubricating oil composition of any one of claims 1 to 4, 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. 6. A lubricating oil composition according to any one of claims 1 to 5, comprising 0.01 to 10 wt %, preferably 0.05 to 5 wt %, more preferably 0.1 to 3 wt %, of one or more additives having formula (I), based on the total weight of the lubricating oil composition.

7. based on the total weight of the lubricating oil composition - 0.01 to 5% by weight, preferably 0.02 to 2% by weight, of one or more additives having formula (I) as defined above; - 0.05 to 5 wt. %, preferably 0.1 to 2 wt. %, of one or more additives selected from phosphites containing two alkyl groups each having from 2 to 6 carbon atoms.

8. 8. The lubricating oil composition of any one of claims 1 to 7, further comprising at least one dispersant, preferably a borated dispersant, even more preferably a borated dispersant selected from borated succinimides, even more preferably a borated polyisobutene succinimide.

9. based on the total weight of the lubricating oil 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, in particular 0.02 to 2% by weight, of one or more additives having formula (I) as defined above; 9. A lubricating oil composition according to any one of claims 1 to 8, comprising 0.05 to 5 wt. %, preferably 0.1 to 2 wt. %, of one or more additives selected from phosphites containing 1 to 24, preferably 4 to 12, carbon atoms, preferably phosphites containing two alkyl groups each having 2 to 6 carbon atoms.

10. based on the total weight of the lubricating oil composition - at least 70% by weight, preferably 75 to 99.5% by weight, of one or more non-aqueous base oils; - 0.01 to 5% by weight, in particular 0.02 to 2% by weight, of one or more additives having formula (I) as defined above; - 0.05 to 5% by weight, preferably 0.1 to 2% by weight, of one or more additives chosen from phosphites containing from 1 to 24 carbon atoms; 10. A lubricating oil composition according to any one of claims 1 to 9, optionally comprising 0.1 to 15 wt. %, preferably 1 to 10 wt. %, of one or more functional additives, preferably selected from dispersants, antioxidants, pour point depressants, antifoam or defoaming agents, and mixtures thereof.

11. 11. The lubricating oil composition according to any one of claims 1 to 10, wherein the one or more base oils have a kinematic viscosity at 100°C of 1.5 to 35 cSt.

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

13. 1. Use of an additive in a lubricating oil composition comprising at least one base oil to improve the load-carrying capacity of the lubricating oil composition, the additive comprising a compound represented by formula (I): 【Chemistry 2】 and wherein R and R １ are selected independently from one another from: a hydrogen atom; or a saturated or unsaturated linear hydrocarbon group containing 8 to 20 carbon atoms and optionally containing one or more heteroatoms; and two radicals R or R １ at least one of which is a saturated or unsaturated linear hydrocarbon group containing 8 to 20 carbon atoms.

14. The additive having formula (I) is preferably present in the lubricating oil composition in combination with an additive selected from phosphites containing 1 to 24 carbon atoms in an amount of: 0.01 to 5% by weight, preferably 0.02 to 2% by weight, of one or more additives having formula (I) as defined above: Use according to claim 13, characterized in that one or more additives selected from phosphites containing from 1 to 24 carbon atoms are used in a proportion of from 0.05 to 5% by weight, preferably from 0.1 to 2% by weight.

15. Use according to claim 13 or 14, wherein the lubricating oil composition is as defined in any one of claims 2 to 11.

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