Use of molybdenum compounds in driveline lubricants for reducing friction and copper corrosion

Abstract

A driveline lubricating composition for an electric or hybrid electric motor system includes a phosphorus antiwear additive and a multifunctional oil-soluble organic molybdenum friction modifier to provide friction improvement and low copper leaching.

Description

Technical Field

[0001] This disclosure relates to a lubricating fluid for a transmission system in an electric motor system and a method for lubricating the transmission system. In particular, the disclosed method and lubricating fluid relate to a lubricating fluid comprising an oil having a lubricating viscosity and a multifunctional organic molybdenum complex of an organic ester and / or an amide. Background Technology

[0002] A major challenge in developing lubricants for electric and hybrid electric vehicle drivetrains and powertrains is achieving acceptable frictional performance while maintaining material compatibility with components in the electric motor system. Therefore, lubricants for electric and hybrid electric vehicles face problems not found in lubricants for non-electric vehicles. For example, to achieve good frictional performance, lubricants typically contain friction modifiers to reduce metal-to-metal friction. However, many friction modifiers tend to negatively impact copper corrosion (e.g., through copper leaching and / or copper rusting), which can be detrimental to the electrical components of various electric and / or hybrid electric vehicle drivetrains or powertrains. Since lubricants for electric motor systems also come into contact with electrical components in the motor and / or drivetrain, formulating lubricants with acceptable frictional performance and low copper corrosion resistance is often challenging, given the predicament that conventional friction modifiers, while providing low friction, unfortunately tend to provide undesirable poor copper corrosion in electric motor systems. Summary of the Invention

[0003] In one embodiment, a transmission system lubrication composition for electric or hybrid electric vehicles is disclosed herein. In this embodiment, the transmission system lubrication composition comprises one or more base oils having a lubricating viscosity; a multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor having one or more ester and / or amide portions and having about 1% to about 15% molybdenum by weight; a phosphorus anti-wear additive providing about 100 ppm or less of phosphorus to the transmission system lubrication composition; and wherein the transmission system lubrication composition has less than about 300 ppm of total sulfur.

[0004] In other methods or embodiments, the transmission system lubrication composition of the preceding paragraph includes other features or embodiments in any combination. These other features or embodiments include one or more of the following: wherein the phosphorus anti-wear additive comprises an ashless dialkyl dithiophosphate ester, which provides the transmission system lubrication composition with about 100 ppm or less phosphorus and about 150 ppm or less sulfur; and / or wherein the ashless dialkyl dithiophosphate ester is prepared by a method comprising the steps of: reacting an organic hydroxyl compound with phosphorus pentasulfide to form a reaction product, and further reacting the reaction product with an unsaturated carboxylic acid to form an oil-soluble phosphorus anti-wear additive comprising the ashless dialkyl dithiophosphate ester; and / or wherein the ashless dialkyl dithiophosphate ester comprises a compound of formula V or a salt thereof.

[0005]

[0006] R3 and R4 are independently C3 to C8 straight-chain or branched alkyl groups, and R6 is -H or -CH3; and / or wherein the multifunctional oil-soluble organomolybdenum friction modifier and corrosion inhibitor provides 20 ppm to 500 ppm molybdenum; and / or wherein the multifunctional oil-soluble organomolybdenum friction modifier and corrosion inhibitor having ester and / or amide ligands is substantially free of sulfur and / or phosphorus; and / or wherein the multifunctional oil-soluble organomolybdenum friction modifier and corrosion inhibitor having ester and / or amide ligands is derived from aliphatic derivatives of dialkylolamines and a molybdenum source; and / or wherein the aliphatic derivative of the dialkylolamine is an aliphatic derivative of diethanolamine, and the molybdenum source is an oxygen-containing molybdenum compound; and / or wherein the oxygen-containing molybdenum compound is selected from ammonium molybdate, molybdenum oxide, or mixtures thereof; and / or wherein the multifunctional oil-soluble organomolybdenum friction modifier and corrosion inhibitor having one or more ester and / or amide moieties... The formulation comprises about 1 mol of a fatty oil or fatty acid having 12 or more carbon atoms, about 1 mol to about 2.5 mol of diethanolamine, and a reaction product of an oxygen-containing molybdenum compound, the amount of which is sufficient to produce a reaction product having about 1% to about 15% molybdenum based on the weight of the reaction product; and / or wherein the weight ratio of total sulfur and total phosphorus to total molybdenum (S+P) / Mo is about 0.7 to about 10.0; and / or wherein the transmission system lubrication composition is substantially free of individual corrosion inhibitors and / or substantially free of individual friction modifiers; and / or wherein individual corrosion inhibitors include monocarboxylic acid and / or polycarboxylic acid corrosion inhibitors, alkenyl succinic acid, acid / ester or acid anhydride corrosion inhibitors, ether amine corrosion inhibitors, imidazoline corrosion inhibitors, benzotriazole corrosion inhibitors, or combinations thereof; and / or wherein the transmission system lubrication composition, when conforming to ASTM... When D130 is evaluated at approximately 150°C for approximately 168 hours, it has a copper leaching of less than 120 ppm; and / or the transmission system lubricating composition has a coefficient of friction of less than 0.160 when measured using a high-frequency reciprocating tester (HFRR) and evaluated using a 400 g load, a 20 Hz frequency, and a composition temperature of 130°C for 3 minutes.

[0007] In other methods or embodiments, this document provides a method for lubricating a drivetrain of an electric or hybrid electric vehicle. In one aspect of this method or embodiment, the method includes lubricating the drivetrain of the electric or hybrid electric vehicle with a lubricating composition; and wherein the lubricating composition comprises (i) one or more base oils having a lubricating viscosity; (ii) a phosphorus anti-wear additive that provides about 100 ppm or less of phosphorus to the drivetrain lubricating composition; (iii) a multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor having one or more ester and / or amide portions and having about 1% to about 15% molybdenum by weight; and wherein the drivetrain lubricating composition has less than about 300 ppm of total sulfur.

[0008] In other methods or embodiments, the methods described in the preceding paragraph may include other features, embodiments, or method steps in any combination. These other features, embodiments, or method steps include one or more of the following: wherein the phosphorus anti-wear additive comprises an ashless dialkyl dithiophosphate anti-wear additive that provides about 100 ppm or less of phosphorus and 150 ppm or less of sulfur to the transmission system lubrication composition; and / or wherein the ashless dialkyl dithiophosphate is prepared by a method comprising the steps of: reacting an organic hydroxyl compound with phosphorus pentasulfide to form a reaction product, and further reacting the reaction product with an unsaturated carboxylic acid to form an oil-soluble phosphorus anti-wear additive comprising an ashless dialkyl dithiophosphate; and / or wherein the ashless dialkyl dithiophosphate comprises a compound of formula V or a salt thereof.

[0009]

[0010] R3 and R4 are independently C3 to C8 straight-chain or branched alkyl groups, and R6 is -H or -CH3; and / or wherein the multifunctional oil-soluble organomolybdenum friction modifier and corrosion inhibitor provides 20 ppm to 500 ppm molybdenum; and / or wherein the multifunctional oil-soluble organomolybdenum friction modifier and corrosion inhibitor having ester and / or amide ligands is substantially free of sulfur and / or phosphorus; and / or wherein the multifunctional oil-soluble organomolybdenum friction modifier and corrosion inhibitor having ester and / or amide ligands is substantially free of sulfur and / or phosphorus; and / or wherein the multifunctional oil-soluble organomolybdenum friction modifier and corrosion inhibitor having ester and / or amide ligands is derived from an aliphatic derivative of a dialkylolamine and a molybdenum source; and / or wherein the aliphatic derivative of the dialkylolamine is an aliphatic derivative of diethanolamine, and the molybdenum source is an oxymolybdenum compound; and / or wherein the oxymolybdenum compound is selected from ammonium molybdate, molybdenum oxide, or mixtures thereof; and / or The multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor having one or more ester and / or amide moieties is a reaction product consisting of about 1 mol of a fatty oil or fatty acid having 12 or more carbon atoms, about 1 mol to 2.5 mol of diethanolamine, and a molybdenum source sufficient to produce about 1% to about 15% by weight of molybdenum based on the additive; and / or wherein the weight ratio of total sulfur and total phosphorus to total molybdenum (S+P) / Mo is about 0.7 to about 10.0; and / or wherein the transmission system lubrication composition is substantially free of separate corrosion inhibitors and / or substantially free of separate friction modifiers; and / or wherein separate corrosion inhibitors include monocarboxylic acid and / or polycarboxylic acid corrosion inhibitors, alkenyl succinic acid, acid / ester or acid anhydride corrosion inhibitors, ether amine corrosion inhibitors, imidazoline corrosion inhibitors, benzotriazole corrosion inhibitors, or combinations thereof; and / or wherein the transmission system lubrication composition, when conforming to ASTM... When D130 is evaluated after 168 hours at 150°C, it has a copper leaching of less than 120 ppm; and / or the transmission system lubrication composition has a coefficient of friction of less than 0.160 when measured using a high-frequency reciprocating tester (HFRR) and evaluated using a 400 g load, a 20 Hz frequency, and at the composition temperature of 130°C for 3 minutes.

[0011] In other methods or embodiments, the use of any embodiment of the multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor described in this invention and / or the use of a lubricating composition comprising (i) one or more base oils having a lubricating viscosity; (ii) a phosphorus anti-wear additive that provides about 100 ppm or less of phosphorus to the transmission system lubricating composition; (iii) a multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor having one or more ester and / or amide portions and having about 1% to about 15% molybdenum; and wherein the transmission system lubricating composition has less than about 300 ppm of total sulfur to achieve one or both of the following: (i) when according to ASTM When D130 is evaluated after 168 hours at 150°C, copper leaching is less than 120 ppm and / or (ii) the transmission system lubricating composition has a coefficient of friction of less than 0.160 when measured using a high-frequency reciprocating tester (HFRR) and evaluated using a 400 g load, a 20 Hz frequency, and at the composition temperature of 130°C for 3 minutes. Any embodiment of the method or composition as described in the invention summary may also be provided for the described use.

[0012] Other embodiments of this disclosure will be apparent to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. Detailed Implementation

[0013] According to an exemplary embodiment, this document describes a lubrication composition for a powertrain of electric and / or hybrid electric vehicles that achieves good frictional performance and low copper corrosion through the use of a multifunctional organic molybdenum friction modifier. In one aspect, the organic molybdenum friction modifier is an oil-soluble organic molybdenum compound or complex having one or more ester and / or amide moieties, configured to achieve good frictional performance and low copper corrosion in a single additive. While some organic molybdenum compounds have been used as friction modifiers, it is not expected that certain oil-soluble organic molybdenum compounds and / or their complexes having one or more ester and / or amide moieties will act as good friction modifiers providing an acceptable HFRR coefficient of friction while simultaneously providing low copper leaching.

[0014] In one method or embodiment, the transmission system lubrication composition herein suitable for lubricating a transmission, drivetrain, and / or powertrain of an electric or hybrid electric vehicle comprises at least one or more base oils having a lubricating viscosity; a multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor having one or more ester and / or amide portions; a phosphorus anti-wear additive providing about 100 ppm or less of phosphorus; and wherein the transmission system lubrication composition has less than about 300 ppm of total sulfur. In another method or embodiment, the transmission system lubrication composition herein suitable for lubricating a transmission, drivetrain, and / or powertrain of an electric or hybrid electric vehicle comprises one or more base oils having a lubricating viscosity; a multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor having one or more ester and / or amide portions; a phosphorus and sulfur anti-wear additive in the form of an ashless dialkyl dithiophosphate anti-wear additive, in some embodiments providing about 100 ppm or less of phosphorus and about 150 ppm or less of sulfur to the transmission system lubrication composition; and wherein the transmission system lubrication composition has less than about 300 ppm of total sulfur. Each component additive is further described below.

[0015] Oil-soluble organic molybdenum additives

[0016] The transmission system lubrication composition described herein comprises a multifunctional, oil-soluble organic molybdenum friction modifier and corrosion inhibitor additive having one or more ester and / or amide moieties. This additive is typically a mixture of one or more compounds and / or a complex of an oil-soluble molybdenum component, and in one embodiment, is a reaction product of a fatty acid or fatty oil, a dialkylamine, and a molybdenum source to produce a mixture of reaction products comprising a complex of one or more molybdenum compounds or compounds having ester and / or amide moieties. The main components of the reaction product include one or more compounds of formula I, formula II, and / or formula III:

[0017]

[0018] In formulas I, II, and / or III, R1 is a C10 to C30 hydrocarbon chain (or a C12 to C26 hydrocarbon chain), each R2 is independently an oxygen atom or a nitrogen atom, wherein at least one R2 is an oxygen atom, and preferably, each R2 is oxygen; and each n is independently 1 to 4, preferably 1 to 3, and most preferably an integer of 1 or 2. In one embodiment, R1 is a C12 to C26 hydrocarbon chain, each R2 is oxygen, and n is 1 or 2. As used herein, the oil-soluble organomolybdenum reaction product is a mixture of one or more compounds or a complex of compounds, wherein a complex is generally understood to be a loose arrangement of two or more components or compounds associated with compounds that are generally weaker than covalent bonds.

[0019] In one embodiment, the oil-soluble organomolybdenum compound or complex is prepared by reacting a fatty acid or fatty oil, a dialkylamine (preferably diethanolamine), and a molybdenum source. In one method, the organomolybdenum compound or complex is prepared by sequentially reacting a fatty acid or fatty oil with diethanolamine to form a reaction intermediate, followed by reacting it with a molybdenum source. The reaction temperature can be from about 70°C to about 160°C. Suitable fatty acids can be C12 to C30 fatty acids, and / or suitable fatty oils can be vegetable or animal oils, including glycerides of higher fatty acids having at least 12 carbon atoms, and may contain up to 22 carbon atoms, or in some embodiments, up to 30 carbon atoms in a higher carbon chain. Suitable examples of vegetable oils include coconut oil, corn oil, cottonseed oil, linseed oil, peanut oil, soybean oil, and / or sunflower oil. Suitable examples of animal fats include tallow and other oils. In other embodiments, the molybdenum source can be any suitable molybdenum compound, such as, but not limited to, oxygen-containing molybdenum compounds capable of reacting with an intermediate reaction product of a fatty acid / fatty oil and a dialkylolamine to form a molybdenum compound or complex comprising an ester and / or an amide in the resulting reaction product. In one method, the molybdenum source includes, but is not limited to, ammonium molybdate, molybdenum oxide, and / or mixtures thereof. In one method, an oil-soluble organic molybdenum compound or complex is prepared by reacting about 1 mole of a fatty acid or fatty oil, about 1.0 mole to about 2.5 moles of a dialkylolamine (preferably diethanolamine), and a sufficient amount of a molybdenum source to form a reaction product or mixture containing up to about 15% molybdenum, or in other methods, up to about 12% by weight of molybdenum or up to about 10% by weight of molybdenum.

[0020] In the methods or embodiments described herein, the multifunctional oil-soluble compounds or complexes comprise about 1% to about 15% molybdenum (or about 1% to about 12% by weight, or about 6% to about 12% by weight molybdenum), and in other embodiments, are substantially free of sulfur and / or substantially free of phosphorus. In this document, substantially free of sulfur and / or phosphorus means that the reaction products described herein have sulfur and / or phosphorus levels of less than 10 ppm, less than 5 ppm, less than 2 ppm, less than 1 ppm, or undetectable levels.

[0021] In the method, a multifunctional oil-soluble organic molybdenum compound or complex is added to the lubricating oil composition herein in an amount providing about 20 ppm to about 500 ppm of molybdenum (in other methods, about 30 ppm to about 400 ppm of molybdenum, or about 30 ppm to about 200 ppm of molybdenum, or about 100 ppm of molybdenum to about 400 ppm of molybdenum, or about 150 ppm to about 400 ppm of molybdenum, or about 200 ppm to about 400 ppm of molybdenum).

[0022] As illustrated in the following examples, when the lubricating oil composition contains such amounts of oil-soluble organic molybdenum compounds or complexes, the composition achieves the desired HFRR boundary friction coefficient while simultaneously achieving low copper leaching, and surprisingly (in some embodiments) no additional corrosion inhibitors and / or additional friction modifiers are required. In one embodiment, for example, the transmission system lubricating composition of this article, when evaluated according to ASTM D130 at 150°C for 168 hours, exhibits a copper leaching of less than 120 ppm (in other methods, less than 100 ppm, less than 80 ppm, or less than 65 ppm), and / or the transmission system lubricating composition of this article, when measured using a high-frequency reciprocating tester (HFRR) and evaluated using a 400 g load, a 20 Hz frequency, and at the composition temperature of 130°C for 3 minutes, also exhibits a friction coefficient of less than 0.160 (in other methods, less than 0.150, less than 0.120, less than 0.100, or less than 0.080).

[0023] This frictional performance and corrosion resistance are achieved using the transmission system lubrication composition described herein, which is substantially free of other conventional corrosion inhibitors and, in some embodiments, also substantially free of other friction modifiers. Herein, "substantially free of other conventional corrosion inhibitors and / or other friction modifiers" means less than 0.5% by weight, less than 0.1% by weight, less than 0.05% by weight, or no functional amount of a single corrosion inhibitor additive and / or a single friction modifier additive. As used herein, a single corrosion inhibitor additive includes, but is not limited to, monocarboxylic acid and / or polycarboxylic acid corrosion inhibitors, alkenyl succinic acid, acid / ester or acid anhydride corrosion inhibitors, ether amine corrosion inhibitors, imidazoline corrosion inhibitors, toluenetriazole corrosion inhibitors, benzotriazole corrosion inhibitors, and / or combinations thereof. As used herein, other individual friction modifiers include, but are not limited to, imidazolines, succinimides, alkoxylated amines, alkoxylated ether amines, amine oxides, nitriles, betaine, quaternary amines, imines, amine salts, aminoguanidines, alkanolamides, phosphonates, glycerides, sulfurized fatty compounds and olefins, sunflower oil, other naturally occurring plant or animal oils, dicarboxylic acid esters, esters or metaesters of polyols, and one or more aliphatic or aromatic carboxylic acids.

[0024] Phosphorus anti-wear additives

[0025] In one embodiment, the transmission system lubrication composition of this document comprises a phosphorus anti-wear additive that provides about 100 ppm or less of phosphorus (in other methods, about 40 ppm to 100 ppm of phosphorus or about 50 ppm to about 80 ppm of phosphorus is provided to the lubricating oil composition). Examples of suitable phosphorus anti-wear additives include, but are not limited to, metal thiophosphates; metal dialkyl dithiophosphates; phosphate esters or salts thereof; phosphate esters; phosphites; phosphorus-containing carboxylic esters, ethers or amides; and / or mixtures thereof. The metal in any dialkyl dithiophosphate of this document may be an alkali metal, an alkaline earth metal, aluminum, lead, tin, molybdenum, manganese, nickel, copper, titanium and / or zinc. Suitable phosphoric acid-containing compounds include phosphoric acid, phosphonic acid, hypophosphonic acid and / or thiophosphoric acid, including dithiophosphoric acid as well as monothiophosphoric acid, thiohynthophosphonic acid and thiophosphonic acid.

[0026] In one embodiment, the phosphorus anti-wear additive is a phosphate ester prepared by reacting one or more phosphoric acid or anhydride-containing compounds with an alcohol containing one or at most about three carbon atoms. The alcohol typically contains at most about 30 carbon atoms, preferably at most about 24, and more preferably at most about 12. The phosphoric acid or anhydride-containing compound is typically an inorganic phosphorus reagent, such as phosphorus pentoxide, phosphorus trioxide, phosphorus tetroxide, phosphoric acid, phosphorus halides, lower phosphate esters, or phosphorus sulfides. The phosphate ester can be a dialkyl phosphate ester or a trialkyl phosphate ester. Typically, the phosphate ester is a dialkyl phosphate ester, a trialkyl phosphate ester, or an aryl phosphate ester. The hydrocarbon group typically contains about 6 to about 24 carbon atoms, preferably about 6 to about 18. When the hydrocarbon group is an aryl group, the group contains at least about six carbon atoms. In one embodiment, the phosphate ester is a diaryl phosphate ester or a triaryl phosphate ester having about six to about eight carbon atoms in each aryl group. Examples of phosphate esters include tricresyl phosphate (TCP), triphenyl phosphate, trioctyl phosphate, trilauryl phosphate, tristearyl phosphate, trioleyl phosphate, etc.

[0027] Suitable phosphites can be dialkyl phosphites or trialkyl phosphites, preferably dialkyl phosphites. Alkyl phosphonates can be alkyl phosphonate diesters, preferably dialkyl esters. The alkyl groups of the phosphites and phosphonates independently contain one, or about three to about 24, or about 18, or about eight carbon atoms. In one embodiment, the phosphites and phosphonates have alkyl groups independently containing about three to about six, or about five carbon atoms. Exemplary dialkyl phosphites include dimethyl phosphite, diethyl phosphite, dipropyl phosphite, dibutyl phosphite, dipentyl phosphite, and dihexyl phosphite. Mixed alkyl phosphites made from mixtures of alcohols can also be used as phosphorus anti-wear additives. Examples of mixtures of alcohols include ethanol and butanol, propanol and pentanol, and methanol and pentanol.

[0028] Alkyl phosphonates can also be used as phosphorus anti-wear additives. Suitable alkyl phosphonates can be prepared by reacting an alkyl halide with a trialkyl phosphite. Examples of alkyl phosphonates include diethyl butyl phosphonate; dibutyl butyl phosphonate; 2-ethylhexyl phosphonate, etc.

[0029] Phosphorus anti-wear additives can also be thiophosphates or their salts. Thiophosphates can be prepared by reacting phosphorus sulfide with an alcohol. Thiophosphates can be monothiophosphates or dithiophosphates. Thiophosphates are also commonly referred to as thiophosphoric acid.

[0030] The phosphate ester can be a monothiophosphate or a monothiophosphate. In one embodiment, the monothiophosphate is prepared by reacting a sulfur source with a dialkyl phosphite. The sulfur source can be, for example, elemental sulfur. The sulfur source can also be a monosulfide, such as a sulfur-coupled olefin or a sulfur-coupled dithiophosphate. Elemental sulfur is a preferred sulfur source.

[0031] Phosphorus anti-wear additives can also be dithiophosphoric acid or phosphorodithioic acid. Dithiophosphoric acid can be represented by the formula (RO)2PSSH, where each R is independently a hydrocarbon group containing 3 to about 30 carbon atoms. R typically contains up to about 18, or up to about 12, or up to about 8 carbon atoms. Exemplary R groups include, but are not limited to, isopropyl, isobutyl, n-butyl, sec-butyl, various pentyl, n-hexyl, methylisobutylcarbinyl, heptyl, 2-ethylhexyl, isooctyl, nonyl, dodecyl, decyl, dodecyl, and tridecyl. Exemplary alkylphenyl R groups include butylphenyl, pentylphenyl, heptylphenyl, and other groups. Examples of mixtures of R groups include, but are not limited to, 1-butanol and 1-octanol; 1-pentanol and 2-ethyl-1-hexanol; isobutanol and 1-hexanol; isobutanol and isoamyl alcohol; 2-propanol and 2-methyl-4-pentanol; isopropanol and sec-butanol; and isopropanol and isooctanol.

[0032] Phosphorus anti-wear additives can also be metal thiophosphates, preferably metal dithiophosphates. Examples of metal dithiophosphates include zinc isopropyl dithiophosphate, zinc methylpentyl dithiophosphate, zinc isopropyl isooctyl dithiophosphate, barium di(nonyl)dithiophosphate, zinc di(cyclohexyl)dithiophosphate, zinc di(isobutyl)dithiophosphate, calcium di(hexyl)dithiophosphate, zinc isobutyl isopentyl dithiophosphate, and zinc isopropyl sec-butyl dithiophosphate.

[0033] The phosphorus anti-wear additive may also be (a) at least one dithiophosphoric acid and (b) at least one aliphatic or alicyclic carboxylic acid metal salt. Dithiophosphoric acid is as described above. The carboxylic acid may be a monocarboxylic acid or a polycarboxylic acid, typically containing 1 to about 3 or only one carboxylic acid group. Preferred carboxylic acids are those having the formula R'COOH, wherein R' is preferably an aliphatic or alicyclic hydrocarbon group that does not contain an alkynyl unsaturated group. R' typically contains about 2 or about 4 carbon atoms. R' typically contains up to about 40, or up to about 24, or up to about 12 carbon atoms. In one embodiment, R' contains 4, or about 6 to about 12, or up to about 8 carbon atoms. In one embodiment, R' is an alkyl group. Suitable acids include butyric acid, valeric acid, hexanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, octadecanoic acid, and eicosanoic acid, as well as olefinic acids, such as oleic acid, linoleic acid, and linolenic acid and linoleic acid dimers.

[0034] Phosphorus-based anti-wear additives can also be phosphoramide-containing. Phosphoramides are prepared by reacting one of the aforementioned phosphoric acids (preferably dithiophosphoric acid) with an unsaturated amide. Examples of unsaturated amides include acrylamide, N,N'-methylenebisacrylamide, methacrylamide, crotonamide, etc. The reaction product of the phosphoric acid and the unsaturated amide can be further reacted with a linking or coupling compound (such as formaldehyde or paraformaldehyde).

[0035] Phosphorus-containing anti-wear additives can also be phosphorus-containing carboxylic acid esters. Phosphorus-containing carboxylic acid esters are prepared by reacting one of the aforementioned phosphoric acids (preferably dithiophosphoric acid) with an unsaturated carboxylic acid or ester. If a carboxylic acid is used, the ester can then be formed by a subsequent reaction of the phosphoric acid-unsaturated carboxylic acid adduct with an alcohol (such as those described herein). In one embodiment, the alcohol has 1 to about 12 carbon atoms. In one embodiment, the unsaturated carboxylic acid ester is a vinyl ester. A vinyl ester can be represented by the formula R"CH=CH-O(O)CR"', where R" is a hydrocarbon group having 1 to about 30, or about 12 carbon atoms, preferably hydrogen, and R"' is a hydrocarbon group having 1 to about 30, or about 12, or about 8 carbon atoms. Examples of vinyl esters include vinyl acetate, vinyl 2-ethylhexanoate, vinyl butyrate, etc. Examples of unsaturated carboxylic acid esters include methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, ethyl maleate, butyl maleate, and 2-ethylhexyl maleate.

[0036] Ash-free dialkyl dithiophosphate :

[0037] In other methods or embodiments, the phosphorus anti-wear additive comprises an anti-wear additive providing phosphorus and sulfur in the form of an acid thiophosphate or a thiophosphate. In this form, the additive providing phosphorus and sulfur can be an ashless, amine-free dialkyl dithiophosphate or a sulfur-containing phosphate. In this method, the ashless, amine-free dialkyl dithiophosphate provides about 100 ppm or less of phosphorus and about 150 ppm or less of sulfur to the transmission system lubrication composition herein.

[0038] The acid thiophosphate, thiophosphate, or sulfur-containing phosphate that provides sulfur and phosphorus to the lubricant herein may have one or more sulfur-phosphorus bonds. In one embodiment, the sulfur-containing phosphate may be an acid thiophosphate, thiophosphate, thiophosphate, or a salt thereof. The thiophosphate may be a dithiophosphate. In some more specific methods, the acid thiophosphate or thiophosphate may have the structure of formula IV or a salt thereof.

[0039]

[0040] In formula IV, R3 and R4 are each independently a straight chain or a branched chain C1 to C2. 10 Hydrocarbon group, and R5 of formula IV is C1 to C5. 10 Straight-chain or branched carboxyl groups or C1 to C1 groups 10 A straight-chain or branched alkyl ester group of alkyl alkanoates. Preferably, R3 and R4 of formula IV are each C3 to C8 straight-chain or branched alkyl groups and R5 of formula IV is derived from 2-methylpropionic acid, such that the phosphorus product (or its salt) has the structure of formula V:

[0041]

[0042] In formula V above, R3 and R4 are independently C3 to C8 straight-chain or branched alkyl groups (preferably branched C4 groups), and R6 of formula V above is -H or -CH3. In some methods or embodiments, the phosphorus additive is preferably 3-[[bis(2-methylpropoxy)thiophosphono]thio]-2-methylpropionic acid.

[0043] In some methods, phosphorus anti-wear additives comprising ashless dialkyl dithiophosphates are prepared by a method comprising the following steps: (a) reacting an organic hydroxyl compound with phosphorus pentasulfide (in some forms, its monomer or dimer) to form a reaction product, and further reacting the reaction product with an unsaturated carboxylic acid to form an oil-soluble phosphorus anti-wear additive comprising ashless dialkyl dithiophosphates.

[0044] Suitable organic hydroxyl compounds may include straight-chain alcohols, branched alcohols, hydroxyaryl compounds (such as phenol and naphthol), substituted aryl hydroxyl compounds (such as dipentylphenol), or any other hydroxyl organic material wherein the hydroxyl group will react with phosphorus pentasulfide. In one method, the starting alcohol is a saturated alcohol or a substituted aryl hydroxyl compound, such as an aryl hydroxyl compound substituted with a saturated alkyl radical. In some methods, the organic hydroxyl compound may be C1 to C2. 10 (In other methods, C1 to C6) straight-chain or branched alcohols, hydroxyaryl compounds, or mixtures thereof, such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, tert-butanol, sec-butanol, phenol, naphthol, pentanol, hexanol, isohexanol, octanol, decanol, dodecyl alcohol, octadecyl alcohol, 2-ethylhexanol, 4-methyl-2-pentanol, phenyl alcohol, butylphenyl alcohol, cyclohexanol, methylcyclopentanol, propenyl alcohol, butenyl alcohol, or combinations thereof. Preferred organic hydroxyl compounds herein include C1 to C4 alcohols, such as ethanol, propanol, or isopropanol, and most preferably, isobutanol.

[0045] Suitable unsaturated carboxylic acids that form the oil-soluble phosphorus anti-wear additives of this disclosure may include a wide variety of unsaturated carboxylic acids or fatty acids. Preferred unsaturated carboxylic acids may include C1 to C2. 20 Unsaturated fatty acids, such as acrylic acid, methacrylic acid, 2-ethylacrylic acid, or combinations thereof, with methacrylic acid being the most preferred. (As used herein, (meth)acrylic acid refers to acrylic acid or methacrylic acid.)

[0046] In some embodiments, the anti-wear additive providing phosphorus and sulfur is an acid thiophosphate or thiophosphate ester, which is present in the composition herein in an amount not exceeding about 100 ppm of phosphorus and not exceeding about 150 ppm of sulfur to the transmission system lubricating oil composition herein. In another embodiment, the anti-wear additive providing phosphorus and sulfur is an acid thiophosphate or thiophosphate ester, which is present in an amount of 40 ppm to 100 ppm of phosphorus and about 80 ppm to about 150 ppm of sulfur to the lubricating oil composition. In one method, the additive providing phosphorus and sulfur is an acid thiophosphate or thiophosphate ester, which is present in an amount of 50 ppm to 80 ppm of phosphorus and about 100 ppm to about 150 ppm of sulfur to the lubricating oil composition.

[0047] Transmission system lubrication composition

[0048] In other methods, the transmission system lubricant composition of this invention balances the amount of total sulfur and total phosphorus provided by other additives (e.g., phosphorus anti-wear additives, ashless dialkyl dithiophosphate anti-wear additives, or other additives as discussed above and / or other sulfur and phosphorus additives) relative to the amount of molybdenum from oil-soluble organic molybdenum compounds or complexes (as discussed above, which are substantially free of sulfur and / or phosphorus). In one method, the lubricant composition of this invention includes an additive providing up to about 300 ppm of total sulfur (in other methods, up to about 200 ppm of total sulfur, or up to about 150 ppm of total sulfur) and an additive providing up to about 200 ppm of total phosphorus (in other methods, up to about 175 ppm of total phosphorus, or up to about 150 ppm of total phosphorus). In some embodiments, as shown in the following examples, the transmission system lubricant composition herein also balances total sulfur and total phosphorus relative to total molybdenum (e.g., (S+P) / Mo) at a weight ratio of about 0.7 to about 10.0 (in other methods, about 0.7 to about 9.9, or about 1.0 to about 9.8, or about 1.9 to about 9.8 or any other range thereof).

[0049] base oil :

[0050] The transmission system lubrication compositions described herein comprise one or more base oils having a lubricating viscosity. Base oils suitable for formulating transmission system lubrication compositions for electric and / or hybrid electric motor vehicles according to this disclosure may be selected from any suitable synthetic or natural oils or mixtures thereof having a suitable lubricating viscosity. Natural oils may include animal and vegetable oils (e.g., castor oil, lard) and mineral oils, such as liquid petroleum and solvent-treated or acid-treated alkanes, naphthenes, or mixed alkanes-naphthenes. Oils derived from coal or shale may also be suitable. Furthermore, oils derived from gas-to-liquid processes are also suitable. As measured by ASTM D2270-10, the base oil may have a kinematic viscosity of about 2 cSt to about 15 cSt at 100°C.

[0051] The base oil used in the transmission system lubrication compositions described herein may be a single base oil or a mixture of two or more base oils selected from API Groups I-V. In one embodiment, one or more base oils may be selected from any Group III and / or Group IV base oils as specified in the American Petroleum Institute (API) Base Oil Interchangeability Guide. These base oil classes are shown in Table 1 below:

[0052] Table 1

[0053]

[0054] API Group III base oils may include oils derived from Fischer-Tropsch synthesis hydrocarbons. Fischer-Tropsch synthesis hydrocarbons are prepared from syngas containing H2 and CO using a Fischer-Tropsch catalyst. These hydrocarbons typically require further processing before use as base oils. These types of oils are commonly referred to as gas-to-liquid (GTL) oils. For example, the hydrocarbons can be hydroisomerized using the methods disclosed in U.S. Patent Nos. 6,103,099 or 6,180,575; hydrocracking and hydroisomerization using the methods disclosed in U.S. Patent Nos. 4,943,672 or 6,096,940; dewaxing using the methods disclosed in U.S. Patent No. 5,882,505; or hydroisomerization and dewaxing using the methods disclosed in U.S. Patent Nos. 6,013,171, 6,080,301; or 6,165,949.

[0055] API Group IV base oils, PAOs, are typically derived from monomers having 4 to 30, 4 to 20, or 6 to 16 carbon atoms. Examples of PAOs that can be used in this invention include those derived from octene, decene, mixtures thereof, etc. As measured by ASTM D2270-10, PAOs can have a kinematic viscosity of 2 to 15, 3 to 12, or 4 to 8 cSt at 100°C. Examples of PAOs include PAOs with a viscosity of 4 cSt at 100°C, PAOs with a viscosity of 6 cSt at 100°C, and mixtures thereof.

[0056] The base oil is combined with the additive compositions disclosed in the embodiments herein to provide a transmission system lubrication composition for use in an electric motor system having an electric motor, gears, and a clutch. Therefore, the base oil may be present in the transmission system lubrication composition in an amount greater than about 80% by weight, based on the total weight of the lubrication composition. In some embodiments, the base oil may be present in the transmission system lubrication composition in an amount greater than about 85% by weight, based on the total weight of the transmission system lubrication composition.

[0057] Other additives

[0058] In addition to the components described above, the transmission system lubrication compositions described herein may also contain other types of additives for transmission fluid compositions. Depending on the specific application, such additives include, but are not limited to, antioxidants, viscosity modifiers, phosphorus-containing components, detergents, rust inhibitors, defoamers, demulsifiers, pour point depressants, sealing and swelling agents, dispersants, and / or sulfur-containing components.

[0059] Antioxidants: In some embodiments, the transmission system lubrication composition contains one or more antioxidants. Suitable antioxidants include phenolic antioxidants, aromatic amine antioxidants, sulfur-containing antioxidants, and organophosphites, etc.

[0060] Examples of phenolic antioxidants include 2,6-di-tert-butylphenol, liquid mixtures of tert-butylphenol, 2,6-di-tert-butyl-4-cresol, 4,4'-methylenebis(2,6-di-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), and mixtures of methylene-bridged polyalkylphenols and 4,4'-thiobis(2-methyl-6-tert-butylphenol), N,N'-di-sec-butylphenylenediamine, 4-isopropylaminodiphenylamine, benzene-α-naphthylamine, benzene-α-naphthylamine, and cycloalkylated diphenylamines. Examples include sterically hindered tert-butylated phenols, bisphenols, and cinnamic acid derivatives, and combinations thereof.

[0061] Aromatic amine antioxidants include, but are not limited to, diarylamines having the following formula:

[0062]

[0063] R' and R” each independently represent a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. Examples of substituents for aryl groups include aliphatic hydrocarbon groups such as alkyl, hydroxyl, halogen, carboxylic, ester, or nitro groups having 1 to 30 carbon atoms.

[0064] The aryl group is preferably a substituted or unsubstituted phenyl or naphthyl group, particularly wherein one or both of these aryl groups are substituted with at least one alkyl group having 4 to 30 carbon atoms, preferably 4 to 18 carbon atoms, and most preferably 4 to 9 carbon atoms. It is preferred that one or both aryl groups are substituted, for example, monoalkylated diphenylamine, dialkylated diphenylamine, or a mixture of monoalkylated diphenylamine and dialkylated diphenylamine.

[0065] Examples of diarylamines that may be used include, but are not limited to: diphenylamine; various alkylated diphenylamines, 3-hydroxydiphenylamine, N-phenyl-1,2-phenylenediamine, N-phenyl-1,4-phenylenediamine, monobutyldiphenylamine, dibutyldiphenylamine, monooctyldiphenylamine, dioctyldiphenylamine, monononyldiphenylamine, dinonyldiphenylamine, monotetradecyldiphenylamine, tetradecyldiphenylamine, benzene-α-naphthylamine, monooctylphenyl-α-naphthylamine, benzene-β-naphthylamine, monoheptyldiphenylamine, diheptyldiphenylamine, p-oriented styrylated diphenylamine, mixed butyloctyldiphenylamine and mixed octylstyryldiphenylamine.

[0066] Sulfur-containing antioxidants include, but are not limited to, sulfurized olefins, characterized by the type of olefin used in their production and the final sulfur content of the antioxidant. High molecular weight olefins (i.e., those with an average molecular weight of 168 g / mol to 351 g / mol) are preferred. Examples of olefins that can be used include α-olefins, isomerized α-olefins, branched olefins, cycloolefins, and combinations thereof.

[0067] α-olefins include, but are not limited to, any C4 to C5 olefins.25 α-Alkenes. α-Alkenes can be isomerized before or during sulfidation. Structural and / or conformational isomers of α-alkenes containing internal double bonds and / or branches can also be used. For example, isobutene is a branched alkene counterpart of the α-alkene 1-butene.

[0068] Sulfur sources that can be used in olefin sulfidation reactions include elemental sulfur, sulfur monochloride, sulfur dichloride, sodium sulfide, sodium polysulfide, and mixtures thereof, either together or added at different stages of the sulfidation process.

[0069] Unsaturated oils, due to their unsaturation, can also be sulfurized and used as antioxidants. Examples of oils or fats that can be used include corn oil, canola oil, cottonseed oil, grapeseed oil, olive oil, palm oil, peanut oil, coconut oil, rapeseed oil, safflower oil, sesame oil, soybean oil, sunflower oil, tallow, and combinations thereof.

[0070] The total amount of antioxidant in the lubricating composition described herein may be present in an amount delivering up to about 200 ppm of nitrogen or up to about 150 ppm of nitrogen or about 100 ppm to about 150 ppm of nitrogen.

[0071] Cleaning Agents: Metal cleaners that may be included in the transmission system lubrication compositions described herein typically comprise a polar head with a long, hydrophobic tail, wherein the polar head contains a metal salt of an acidic organic compound. The salt may contain substantially stoichiometric amounts of metal, in which case they are typically described as normal or neutral salts and generally have a total base number (TBN) of 0 to less than 150 (as measured by ASTM D2896). A significant amount of metal base may be included by reacting an excess of a metal compound (such as an oxide or hydroxide) with an acidic gas (such as carbon dioxide). The resulting highly alkaline cleaner comprises micelles of neutralizing cleaner surrounding an inorganic metal base (e.g., hydrated carbonate) core. Such highly alkaline cleaners may have a TBN of 150 or higher, such as 150 to 450 or higher.

[0072] Cleaning agents suitable for embodiments of the present invention include oil-soluble highly alkaline, low alkaline, and neutral sulfonates, phenolates, sulfurized phenolates, and salicylates of metals, particularly alkali metals or alkaline earth metals (e.g., sodium, potassium, lithium, calcium, and magnesium). More than one metal may be present, such as calcium and magnesium. Mixtures of calcium and / or magnesium with sodium are also suitable. Suitable metal cleaning agents may be highly alkaline calcium or magnesium sulfonates with a TBN of 150 to 450 TBN, highly alkaline calcium or magnesium phenolates or sulfurized phenolates with a TBN of 150 to 300 TBN, and highly alkaline calcium or magnesium salicylate with a TBN of 130 to 350 TBN. Mixtures of these salts may also be used.

[0073] Based on the total weight of the lubricating composition, the metal-containing detergent may be sufficient to provide up to 500 ppm of alkali metals and / or alkaline earth metals present in the fluid. In one example, the metal-containing detergent may be sufficient to provide about 50 ppm to about 500 ppm of alkali metals and / or alkaline earth metals present. In another embodiment, the metal-containing detergent may be sufficient to provide about 100 ppm to about 400 ppm of alkali metals and / or alkaline earth metals present. In one method, the preferred detergent may be a neutral, low-alkaline, or high-alkaline sulfonate, and in some methods it is a high-alkaline calcium sulfonate. A suitable detergent may be calcium sulfonate having a TBN of 250 or higher (such as about 250 to about 450 or 280 to 400) and providing the lubricant with more than about 50 ppm of calcium. In other methods, the cleaning agent may provide the lubricating composition herein with about 50 ppm to about 500 ppm of calcium, about 100 ppm to about 400 ppm of calcium, or about 100 ppm to about 300 ppm of calcium, or about 100 ppm to 200 ppm of calcium.

[0074] Dispersants: Lubricating compositions may contain one or more selected dispersants or mixtures thereof. Dispersants are often referred to as ashless dispersants because they do not contain ash-forming metals before being incorporated into the lubricating composition and typically do not provide any ash when added to the lubricant. Ashless dispersants are characterized by polar groups attached to a relatively high molecular weight or weight hydrocarbon chain. Typical ashless dispersants include N-substituted long-chain alkenyl succinimides. N-substituted long-chain alkenyl succinimides include polyisobutylene (PIB) substituents, wherein the number average molecular weight of the polyisobutylene substituent is in the range of about 800 to about 2500, as determined by gel permeation chromatography (GPC) using polystyrene (number average molecular weight from 180 to about 18,000) as a calibration benchmark. PIB substituents used as dispersants typically have a viscosity of about 2100 cSt to about 2700 cSt at 100°C, as determined using ASTM D445-18. Succinimidide dispersants and their preparation are disclosed, for example, in U.S. Patent Nos. 7,897,696 and 4,234,435, which are incorporated herein by reference. Succinimidide dispersants are typically composed of polyamines, typically poly(ethylenediamine) imides. The dispersant may comprise two succinimidide moieties linked by a polyamine. The polyamine may be tetraethylenepentamine (TEPA), triethylenetetramine (TETA), pentaethylenehexamine (PEHA), other higher ethylenediamine species, and / or mixtures thereof. The polyamine may be a mixture of linear, branched, and cyclic amines. PIB substituents may be linked to each succinimidide moieties.

[0075] In some embodiments, the lubricant composition comprises at least one polyisobutylene succinimide dispersant derived from polyisobutylene with a number average molecular weight in the range of about 350 to about 5000, or about 500 to about 3000, as measured by the GPC method described herein. Polyisobutylene succinimide may be used alone or in combination with other dispersants.

[0076] In some embodiments, when polyisobutylene (PIB) is included, it may have terminal double bonds in amounts greater than 50 mol%, greater than 60 mol%, greater than 70 mol%, greater than 80 mol%, or greater than 90 mol%. Such PIBs are also referred to as highly reactive PIBs (“HR-PIB”). HR-PIBs with a number average molecular weight in the range of about 800 to about 5000 are suitable for embodiments of this disclosure. Conventional non-highly reactive PIBs typically have terminal double bonds in amounts less than 50 mol%, less than 40 mol%, less than 30 mol%, less than 20 mol%, or less than 10 mol%.

[0077] HR-PIB with a number average molecular weight in the range of about 900 to about 3000 is suitable, as measured by the GPC method described herein. This HR-PIB is commercially available or can be synthesized by polymerizing isobutylene in the presence of a non-chlorinated catalyst (e.g., boron trifluoride), as described in U.S. Patent Nos. 4,152,499 and 5,739,355. When used in the aforementioned thermo-olefin reaction, HR-PIB can increase the conversion rate and reduce the amount of sediment formed due to enhanced reactivity.

[0078] In some embodiments, the lubricant composition comprises at least one dispersant derived from polyisobutylene succinic anhydride. In one embodiment, the dispersant may be derived from polyalphaolefin (PAO) succinic anhydride. In one embodiment, the dispersant may be derived from an olefin maleic anhydride copolymer. For example, the dispersant may be described as polyPIBSA. In one embodiment, the dispersant may be derived from an anhydride grafted onto an ethylene-propylene copolymer.

[0079] One suitable class of dispersants is the Mannich base. Mannich bases are substances formed by the condensation of alkyl-substituted phenols, polyalkylene polyamines, and aldehydes (such as formaldehyde) with higher molecular weight alkyl groups. Mannich bases are described in more detail in U.S. Patent No. 3,634,515.

[0080] Suitable dispersants can be high molecular weight esters or hemiesteramides.

[0081] Dispersants can also be post-treated by conventional methods through reaction with any of a variety of reagents. These reagents include boron, urea, thiourea, dimercaptothiadiazole, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleic anhydrides, nitriles, epoxides, carbonates, cyclic carbonates, hindered phenolic esters, and phosphorus compounds. Suitable post-treatment methods and post-treatment products are described in U.S. Patent Nos. 7,645,726, 7,214,649, and 8,048,831.

[0082] Suitable boron compounds that can be used to form the dispersants of the present invention include any boron compound or mixture of boron compounds capable of introducing boron-containing substances into ashless dispersants. Any organic or inorganic boron compound capable of carrying out this reaction can be used. Thus, boron oxide, boron oxide hydrate, boron trifluoride, boron tribromide, boron trichloride, HBF4, boric acids such as borous acid (e.g., alkyl-B(OH)2 or aryl-B(OH)2), boric acid (i.e., H3BO3), tetraboric acid (i.e., H2B5O7), metaboric acid (i.e., HBO2), ammonium salts of such boric acids, and esters of these boric acids can be used. Using a complex of boron trihalide with an ether, organic acid, inorganic acid, or hydrocarbon is a convenient method for introducing boron reactants into the reaction mixture. Such complexes are known, for example, boron trifluoride-diethyl ether, boron trifluoride-phenol, boron trifluoride-phosphoric acid, boron trichloride-chloroacetic acid, boron tribromide-dioxane, and boron trifluoride-methyl ethyl ether.

[0083] Suitable phosphorus compounds for forming the dispersants of the present invention include phosphorus compounds or mixtures of phosphorus compounds capable of introducing phosphorus-containing substances into ashless dispersants. Therefore, any organic or inorganic phosphorus compound capable of carrying out such a reaction can be used. Thus, inorganic phosphorus compounds such as inorganic phosphoric acid and inorganic phosphorus oxides, including their hydrates, can be used. Typical organic phosphorus compounds include phosphoric acid-containing esters and metaesters, such as monophosphates, diesters, triphosphates, thiophosphoric acid, dithiophosphoric acid, trithiophosphoric acid, and tetrathiophosphoric acid; monophosphite, diester, triphosphite, thiophosphite, dithiophosphite, and trithiophosphite; trialkylphosphine oxides: trialkylphosphine sulfides; monoalkylphosphinates and dialkylphosphinates (RPO(OR')(OR"), where R and R' are hydrocarbon groups and R" is hydrogen or a hydrocarbon group), and their mono, di, and trithio analogs; monoalkylphosphinates and dialkylphosphinates (RP(OR')(O)). R), where R and R' are hydrocarbon groups, and R" is a hydrogen or hydrocarbon group) and their monothiolated and dithiolated analogs; etc. Therefore, compounds such as phosphorous acid (H3PO3, sometimes described as H2(HPO3), sometimes called orthophosphorous acid or phosphonic acid), phosphoric acid (H3PO4, sometimes called orthophosphoric acid), hypophosphorous acid (H4P2O6), metaphosphoric acid (HPO3), pyrophosphoric acid (H4P2O7), hypophosphorous acid (H3PO2, sometimes called hypophosphonic acid), pyrophosphorous acid (H4P2O5, sometimes called pyrophosphonic acid), hypophosphonic acid (H3PO), tripolyphosphoric acid (H5P3O) 10 ), tetrapolyphosphoric acid (H5P4O) 13 Phosphoric acid includes trimethomorphic acid (H3P3O9), phosphorus trioxide, phosphorus tetroxide, and phosphorus pentoxide. Some or all of these are sulfur analogues, such as tetrathioacetic acid (H3PS4), thiophosphoric acid (H3PO3S), dithiophosphoric acid (H3PO2S2), trithiophosphoric acid (H3POS3), sesquisulfide, phosphorus heptasulfide, and phosphorus pentasulfide (P2S5, sometimes called P4S). 10 It can also be used to form the dispersant disclosed herein. Inorganic phosphorus halide compounds, such as PCl3, PBr3, POCl3, PSCl3, etc., can also be used.

[0084] Such organophosphorus compounds can also be used, such as mono, di, and triesters of phosphoric acid (e.g., trialkyl phosphate, dialkyl monoacid phosphate, monoalkyl diacid phosphate, and mixtures thereof), mono, di, and triesters of phosphorous acid (e.g., trialkyl phosphite, dialkyl hydrogen phosphite, alkyl diacid phosphite, and mixtures thereof), esters of phosphonic acids (“primary” RP(O)(OR)2 and “secondary” R2P(O)(OR)), esters of hypophosphonic acids, and phosphonyl halides (e.g., RP(O)Cl2 and R2...). P(O)Cl), halophosphites (e.g., (RO)PCl2 and (RO)2PCl), halophosphates (e.g., ROP(O)Cl2 and (RO)2P(O)Cl), pyrophosphate triesters (e.g., (RO)2P(O)-OP(O)(OR)2), and partial sulfur analogs of any of the aforementioned organophosphorus compounds, wherein each hydrocarbon group contains up to about 100 carbon atoms, or up to about 50 carbon atoms, or up to about 24 carbon atoms, or up to about 12 carbon atoms. Halogenated phosphine halides (e.g., alkyl tetrahalides, dialkyl trihalides, and trialkyl dihalides) and phosphine halides (monohalides and dihalides) may also be used.

[0085] The lubricant described herein may include a mixture of one or more of the above-described boronized and phosphoricated dispersants with non-boronized and non-phosphoricated dispersants.

[0086] In one embodiment, the lubricating oil composition may comprise at least one borate dispersant, wherein the dispersant is a reaction product of an olefin copolymer or an olefin copolymer with succinic anhydride, and at least one polyamine. The PIBSA:polyamine ratio may be from 1:1 to 10:1, or from 1:1 to 5:1, or from 4:3 to 3:1, or from 4:3 to 2:1. Particularly suitable dispersants contain polyisobutylene groups of PIBSA with a number average molecular weight (Mn) in the range of about 500 to 5000, as determined by the GPC method described herein, and (B) a polyamine having the general formula H2N(CH2). m -[NH(CH2) m ] n —NH2, where m is in the range of 2 to 4 and n is in the range of 1 to 2.

[0087] In addition to the above, the dispersant can be post-treated with aromatic carboxylic acids, aromatic polycarboxylic acids, or aromatic anhydrides, wherein all carboxylic acid or anhydride groups are directly attached to the aromatic ring. The carboxyl-containing aromatic compounds may be selected from 1,8-naphthalenedicarboxylic acid or anhydride and 1,2-naphthalenedicarboxylic acid or anhydride, 2,3-naphthalenedicarboxylic acid or anhydride, naphthalene-1,4-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, phthalic anhydride, phenylmethyltetracarboxylic anhydride, 1,2,4-phenyltricarboxylic acid anhydride, biphenyl acid or anhydride, 2,3-pyridinedicarboxylic acid or anhydride, 3,4-pyridinedicarboxylic acid or anhydride, 1,4,5,8-naphthalenetetracarboxylic acid or anhydride, perylene-3,4,9,10-tetracarboxylic acid anhydride, pyrene dicarboxylic acid or anhydride, etc. The molar ratio of this post-treatment component per mole of polyamine reaction can range from about 0.1:1 to about 2:1. In the reaction mixture, the typical molar ratio of this post-treatment component to the polyamine can range from about 0.2:1 to about 2:1. Another usable molar ratio of this post-treatment component to the polyamine can range from about 0.25:1 to about 1.5:1. This post-treatment component can react with other components at temperatures ranging from about 140°C to about 180°C.

[0088] Alternatively, or in addition to the post-treatments described above, the dispersant may be post-treated with a non-aromatic dicarboxylic acid or anhydride. The number-average molecular weight of the non-aromatic dicarboxylic acid or anhydride may be less than 500, as measured by the GPC method described herein. Suitable carboxylic acids or their anhydrides may include (but are not limited to) acetic acid or anhydride, oxalic acid and anhydride, malonic acid and anhydride, succinic acid and anhydride, alkenyl succinic acid and anhydride, glutaric acid and anhydride, adipic acid and anhydride, pimelic acid and anhydride, octanoic acid and anhydride, azelaic acid and anhydride, sebacic acid and anhydride, maleic acid and anhydride, fumaric acid and anhydride, tartaric acid and anhydride, glycolic acid and anhydride, 1,2,3,6-tetrahydronaphthalenedicarboxylic acid and anhydride, etc.

[0089] Non-aromatic carboxylic acids or anhydrides react with polyamines in a molar ratio ranging from about 0.1 mol to about 2.5 mol per mole of polyamine. Typically, the amount of non-aromatic carboxylic acid or anhydride used will be relative to the number of secondary amino groups in the polyamine. Thus, about 0.2 to about 2.0 mol of non-aromatic carboxylic acid or anhydride per secondary amino group in component B can react with other components to provide a dispersant according to embodiments of this disclosure. Another molar ratio of non-aromatic carboxylic acids or anhydrides to polyamines that can be used can be from about 0.25:1 to about 1.5:1 per mole of polyamine. The non-aromatic carboxylic acids or anhydrides can react with other components at a temperature of about 140°C to about 180°C.

[0090] The percentage by weight of active ingredient (%) of alkenyl or alkyl succinic anhydride can be determined using chromatographic techniques. This method is described in columns 5 and 6 of U.S. Patent No. 5,334,321. The conversion percentage of the polyolefin is calculated from the percentage of active ingredient (%) using the equations in columns 5 and 6 of U.S. Patent No. 5,334,321.

[0091] The TBN of a suitable borate dispersant can be from about 10 mg to about 65 mg KOH per gram of composition on an oil-free basis, or, if measured based on a dispersant sample containing about 50% diluent oil, it is equivalent to about 5 mg to about 30 mg KOH per gram of composition.

[0092] Typically, the above-mentioned dispersant is provided in the lubricant in an amount of about 1% to about 15% by weight, and in other methods in an amount of about 1.5% to about 8% by weight, and in other methods in an amount of about 2% to about 6% by weight.

[0093] Viscosity modifier: The transmission system lubrication composition may optionally contain one or more viscosity modifiers. Suitable viscosity modifiers may include polyolefins, olefin copolymers, ethylene / propylene copolymers, polyisobutylene, hydrogenated styrene-isoprene polymers, styrene / maleate copolymers, hydrogenated styrene / butadiene copolymers, hydrogenated isoprene polymers, α-olefin maleic anhydride copolymers, polymethyl methacrylates, polyacrylates, polyalkylstyrene, hydrogenated alkenylaryl conjugated diene copolymers, or mixtures thereof. Viscosity modifiers may include star polymers, and suitable examples are described in U.S. Publication 2012 / 0101017A1.

[0094] In addition to or in place of viscosity modifiers, the transmission system lubrication compositions described herein may optionally contain one or more dispersant viscosity modifiers. Suitable dispersant viscosity modifiers may include functionalized polyolefins, such as ethylene-propylene copolymers functionalized with the reaction product of an acylation agent (such as maleic anhydride) and an amine; amine-functionalized polymethyl methacrylates; or esterified maleic anhydride-styrene copolymers reacted with an amine.

[0095] When present, the total amount of viscosity modifier and / or dispersant may be up to about 2.0% by weight, or up to about 1.0% by weight, or up to about 0.5% by weight, or up to about 0.3% by weight, based on the total weight of the lubricating composition.

[0096] Demulsifiers: Demulsifiers include trialkyl phosphates, and various polymers and copolymers of ethylene glycol, ethylene oxide, propylene oxide, or mixtures thereof, including polyethylene oxide, polypropylene oxide, and (ethylene oxide-propylene oxide) polymers. When present, the amount of demulsifier in the lubricating composition may be up to about 0.05% by weight, up to about 0.02% by weight, or less than about 0.015% by weight, based on the total weight of the lubricating composition.

[0097] Defoamer: Defoamers used to reduce or prevent the formation of stable foam include siloxanes, polyacrylates, or organic polymers. Foam inhibitors that can be used in the compositions of the disclosed invention include polysiloxanes, copolymers of ethyl acrylate and 2-ethylhexyl acrylate, and optionally vinyl acetate. When present, the amount of defoamer in the lubricating composition may be at most about 0.1% by weight, at most about 0.05% by weight, or less than about 0.04% by weight, based on the total weight of the lubricating composition.

[0098] Generally, the transmission system lubrication compositions described herein may include additive components within the range listed in Table 2.

[0099] Table 2

[0100]

[0101] The percentages for each component above represent the weight percentage of each component based on the total weight of the transmission system lubrication composition containing said component. Additives used to formulate the compositions described herein can be blended into the base oil individually or in various sub-combinations. However, it may be suitable to simultaneously blend all components using an additive concentrate (i.e., an additive plus a diluent, such as a hydrocarbon solvent). The use of an additive concentrate utilizes the compatibility offered by the combination of components in additive concentrate form. Furthermore, the use of the concentrate reduces blending time and the possibility of blending errors.

[0102] The following terminology definitions are provided to clarify the meaning of certain terms as used herein.

[0103] The terms “lubricating oil,” “lubricant composition,” “lubricating composition,” “lubricant,” and “transmission lubricating composition” refer to finished lubricating products that contain a major amount of base oil plus a minor amount of additives.

[0104] As used herein, the terms “additive package,” “additive concentrate,” and “additive composition” refer to a portion of a lubricating oil composition that does not include a major amount of base oil.

[0105] As used herein, the term "hydrocarbon substituent" or "hydrocarbon group" is used in its common sense, as is well known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly connected to the rest of the molecule and having predominantly hydrocarbon characteristics. Each hydrocarbon group is independently selected from hydrocarbon substituents and hydrocarbon substituents containing one or more of a halogen group, hydroxyl group, alkoxy group, mercapto group, nitro group, nitroso group, amino group, pyridyl group, furanyl group, imidazolyl group, oxygen, and nitrogen, and wherein there are no more than two non-hydrocarbon substituents present for every ten carbon atoms in the hydrocarbon group.

[0106] As used herein, unless otherwise expressly stated, the terms “weight percentage” or “weight %” mean the percentage of the said component by weight of the whole composition.

[0107] As used herein, the terms “soluble,” “oil-soluble,” or “dispersible” may, but do not necessarily, mean that a compound or additive is soluble, miscible, or capable of being suspended in oil in all proportions. However, the foregoing terms do mean that they are, for example, soluble, suspended, dispersible, or stably dispersed in oil to a degree sufficient to exert their intended effect in an environment where oil is used. Furthermore, if desired, additional admixtures may be permitted at higher levels of specific additives.

[0108] As used herein, the term "alkyl" refers to a straight-chain, branched, cyclic, and / or substituted saturated chain moiety of about 1 to about 200 carbon atoms.

[0109] As used herein, the term "alkenyl" refers to a straight-chain, branched, cyclic, and / or substituted unsaturated chain portion of about 3 to about 30 carbon atoms.

[0110] As used herein, the term "aryl" refers to monocyclic and polycyclic aromatic compounds, which may include alkyl, alkenyl, alkylaryl, amino, hydroxyl, alkoxy, halogen substituents and / or heteroatoms including but not limited to nitrogen and oxygen.

[0111] As used herein, “number-average molecular weight” or “Mn” was determined by gel permeation chromatography (GPC) using commercially available polystyrene standards (where Mn was approximately 180 to approximately 18,000 as a calibration reference).

[0112] It should be understood that throughout this disclosure, the terms “comprising,” “including,” “containing,” etc., are considered open-ended and include any element, step, or ingredient not expressly listed. The phrase “consisting substantially of…” means including any expressly listed element, step, or ingredient, as well as any additional element, step, or ingredient that does not substantially affect the basic and novel aspects of the invention. This disclosure also considers that any composition described using the terms “comprising,” “including,” or “containing” is also to be interpreted as including the disclosure of the same composition “consisting substantially of its specifically listed components” or “consisting of its specifically listed components.”

[0113] Example

[0114] The present disclosure and its many advantages can be better understood through the following examples. These examples are illustrative and do not limit its scope or spirit. Those skilled in the art will readily understand that variations of the components, methods, steps, and apparatus described in these examples can be used. Unless otherwise stated or apparent from the context discussed in the following examples and throughout the disclosure, claims, and examples, all percentages, ratios, and parts mentioned in this disclosure are by weight. Any standardized test methods pointed to in the examples, disclosure, or claims, unless obvious from the context of their use, refer to a version of the test method publicly available at the time of filing this disclosure.

[0115] As used herein, frictional properties were assessed using a high-frequency reciprocating test chamber (HFRR) obtained from PCS Instruments, etc., under test conditions generally described in the SAE paper “Critical Oil Physical Properties that control the Fuel Economy Performance of General Motors Vehicles,” SAE Technical Paper 982503, 1998, and further described herein. As used herein, this friction coefficient test determined the friction coefficient of the lubricating composition between an SAE 52100 metal ball and an SAE 52100 metal disc. For this test, the test sample was measured by immersing the contact between the SAE 52100 metal ball and the SAE 52100 metal disc in a temperature-controlled lubricant bath, which was evaluated forward and backward under a fixed load at a set stroke frequency. The friction coefficient of the transmission lubricating composition described herein was evaluated at a temperature of approximately 130°C, and the friction coefficient and temperature were monitored throughout the test. The ability of the lubricant to reduce boundary layer friction is reflected by the determined boundary lubrication state friction coefficient. Lower values ​​indicate lower friction. For evaluation, a ball oscillates across a disk at a frequency of 20 Hz along a 1 mm path while a load of 400 g is applied. Each sample is tested in an HFRR for 3 minutes, and the data from the last 2 minutes are averaged to produce the coefficient of friction.

[0116] Copper corrosion was assessed using ASTM D130 at 150°C for 168 hours. Results are provided in ppm of copper leaching and visually assessed copper corrosion grade.

[0117] The formulations of this invention in this embodiment contain varying amounts of the discovered organic molybdenum friction modifier, while the comparative formulations of this embodiment contain other molybdenum friction modifiers, amine friction modifiers, and / or conventional toluenetriazole corrosion inhibitors. Each evaluated transmission system lubricant also contains the same base additive package (except for the friction modifier and corrosion inhibitor components shown in Table 3) and the same dispersants, anti-wear agents, antioxidants, defoamers, and viscosity modifiers. All evaluated lubricants contain less than about 0.01% by weight of methyl-1H-benzotriazole (some comparative lubricants added additional amounts of this compound as shown in the table below). The formulations of this invention and the comparative formulations were tested at their respective processing rates in the same base oil blends of API Group III base oils to obtain a finished fluid (ASTM D445) with a kV of about 3.7 cSt at 100°C. The varying components in the fluids in Table 3 below include the following:

[0118] · Phosphorus anti-wear additive (P1) Ash-free dialkyl dithiophosphates, which contain at least 3-

[0119] [[bis(2-methylpropoxy)thiophosphono]thio]-2-methylpropionic acid, having about 9.5% phosphorus and about 19.5% sulfur.

[0120] · Organic molybdenum friction modifier 1 (FM 1) Commercially available oil-soluble organic molybdenum complexes having ester and amide moieties and being derived from fatty derivatives of diethanolamine and oxygen-containing molybdenum compounds having about 8% to about 12% molybdenum.

[0121] · Organic molybdenum friction modifier 2 (FM 2) Molybdenum dithiocarbamate contains approximately 10% molybdenum and approximately 10% sulfur.

[0122] · Amine-based friction modifier 3 (FM 3) Fatty polyamines.

[0123] · Corrosion inhibitor (CI1) : Another methyl-1H-benzotriazole

[0124] As shown in the table below, all embodiments of the present invention exhibit improved coefficients of friction and improved copper leaching protection compared to the baseline composition (BL). The baseline composition does not contain friction modifiers or additional corrosion inhibitors. Comparative lubricants include alternative friction modifiers or additional corrosion inhibitors and exhibit poorer friction performance and / or copper leaching compared to the baseline composition (BL).

[0125] Table 3: Lubricating Compositions for Transmission Systems

[0126]

[0127] Table 4: Elemental Analysis of Fluids

[0128]

[0129] Table 5: Fluid Properties

[0130]

[0131] While comparative samples 1 through 4 exhibited good tribological properties, their copper corrosion performance was worse than and / or significantly worse than the baseline fluid compared to the samples of this invention. Comparative sample 5, with the addition of a corrosion inhibitor, showed good copper corrosion performance, but its coefficient of friction was worse than the baseline. Only the samples of this invention demonstrated improved tribological properties and low copper corrosion without the need for additional tribological modifiers and / or corrosion inhibitors.

[0132] It should be understood that although the lubricating compositions and formulations of this disclosure have been described in conjunction with their detailed description and summary herein, the foregoing description is intended to be illustrative and not limiting of the scope of this disclosure, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are also within the scope of the claims. This specification and the examples are intended to be illustrative only, wherein the true scope of this disclosure is indicated by the appended claims.

[0133] Other embodiments of this disclosure will be apparent to those skilled in the art upon consideration of this specification and the practices of the embodiments disclosed herein. As used throughout the specification and claims, “a / an (a)” and / or “an / an (a)” may refer to one or more. Unless otherwise indicated, all figures expressing quantities of components and properties, such as molecular weight, percentage, ratio, reaction conditions, etc., used in this specification should be understood to be modified in all cases by the term “about,” regardless of whether the term “about” is present. Therefore, unless indicated to the contrary, the numerical parameters set forth in this specification are approximations that may vary depending on the desired properties sought to be obtained through this disclosure. To a minimum, and without attempting to limit the application of the equivalence principle to the scope of the claims, each numerical parameter should be interpreted at least according to the number of significant figures reported and by applying general rounding techniques. Although the numerical ranges and parameters set forth in the broad scope of this disclosure are approximations, the values ​​set forth in particular embodiments are reported as precisely as possible. However, any numerical value inherently contains some error necessarily caused by the standard deviation found in its corresponding test measurement.

[0134] It should be understood that each component, compound, substituent or parameter disclosed herein should be interpreted as disclosed for use alone or in combination with one or more of each other component, compound, substituent or parameter disclosed herein.

[0135] It should also be understood that each range disclosed herein should be interpreted as a disclosure of each specific value within the disclosed range having the same significant digits. Thus, the range 1-4 will be interpreted as an explicit disclosure of the values ​​1, 2, 3, and 4, as well as any range of these values, such as 1-4, 1-3, 1-2, 2-4, 2-3, etc.

[0136] It should also be understood that each lower limit of each range disclosed herein should be interpreted as a combination of each upper limit of each range and each specific value within each range disclosed herein for the same component, compound, substituent, or parameter. Therefore, this disclosure should be interpreted as a disclosure of all ranges derived by combining each lower limit of each range with each upper limit of each range or with each specific value within each range, or by combining each upper limit of each range with each specific value within each range.

[0137] Furthermore, the specific amounts / values ​​of components, compounds, substituents, or parameters disclosed in this specification or examples should be interpreted as disclosures of a lower or upper limit of a range, and therefore can be combined with any other lower or upper limit or specific amount / value of the range of the same components, compounds, substituents, or parameters disclosed elsewhere in this disclosure to form such a range of components, compounds, substituents, or parameters.

Claims

1. A transmission system lubrication composition for electric or hybrid electric vehicles, the transmission system lubrication composition comprising... One or more base oils with lubricating viscosity; A multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor, wherein the multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor has one or more ester and / or amide moieties and has about 1% to about 15% molybdenum by weight; A phosphorus anti-wear additive, wherein the phosphorus anti-wear additive provides about 100 ppm or less of phosphorus to the transmission system lubrication composition; and The transmission system lubricating composition has a total sulfur content of less than about 300 ppm.

2. The transmission system lubrication composition according to claim 1, wherein the phosphorus anti-wear additive comprises an ashless dialkyl dithiophosphate ester, which provides the transmission system lubrication composition with about 100 ppm or less phosphorus and about 150 ppm or less sulfur; and / or wherein the ashless dialkyl dithiophosphate ester is prepared by a method comprising the steps of: reacting an organic hydroxyl compound with phosphorus pentasulfide to form a reaction product, and further reacting the reaction product with an unsaturated carboxylic acid to form an oil-soluble phosphorus anti-wear additive comprising the ashless dialkyl dithiophosphate ester; and / or wherein the ashless dialkyl dithiophosphate ester comprises a compound of formula V or a salt thereof: R3 and R4 are independently C3 to C8 straight-chain or branched alkyl groups, and R6 is -H or -CH3.

3. The transmission system lubrication composition according to claim 1, wherein the multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor provides about 20 ppm to 500 ppm of molybdenum; and / or wherein the multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor having ester and / or amide ligands is substantially free of sulfur and / or phosphorus; and / or wherein the multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor having ester and / or amide ligands is derived from aliphatic derivatives of dialkylolamines and molybdenum sources; and / or wherein the multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor having ester and / or amide ligands is derived from aliphatic derivatives of dialkylolamines and molybdenum sources.

4. The transmission system lubrication composition according to claim 3, wherein the fatty derivative of the dialkylolamine is a fatty derivative of diethanolamine, and the molybdenum source is an oxygen-containing molybdenum compound; and / or wherein the oxygen-containing molybdenum compound is selected from ammonium molybdate, molybdenum oxide, or mixtures thereof.

5. The transmission system lubrication composition according to claim 4, wherein the multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor having one or more ester and / or amide moieties is a reaction product of about 1 mol of a fatty oil or fatty acid having 12 or more carbon atoms, about 1 mol to about 2.5 mol of diethanolamine and an oxygen-containing molybdenum compound, the amount of said oxygen-containing molybdenum compound being sufficient to produce a reaction product having about 1% to about 15% molybdenum based on the weight of the reaction product.

6. The transmission system lubrication composition according to claim 1, wherein the weight ratio of total sulfur and total phosphorus to total molybdenum (S+P) / Mo is from about 0.7 to about 10.

0.

7. The transmission system lubrication composition of claim 1, wherein the transmission system lubrication composition is substantially free of individual corrosion inhibitors and / or substantially free of individual friction modifiers; and / or wherein the individual corrosion inhibitors comprise monocarboxylic acid and / or polycarboxylic acid corrosion inhibitors, alkenyl succinic acid, acid / ester or acid anhydride corrosion inhibitors, ether amine corrosion inhibitors, imidazoline corrosion inhibitors, benzotriazole corrosion inhibitors, or combinations thereof.

8. The transmission system lubricating composition of claim 1, wherein the transmission system lubricating composition has less than 120 ppm of copper leaching when evaluated according to ASTM D130 at about 150°C for about 168 hours; and / or wherein the transmission system lubricating composition has a coefficient of friction of less than 0.160 when measured using a high-frequency reciprocating tester (HFRR) and evaluated using a 400 g load, a 20 Hz frequency, and a composition temperature of 130°C for 3 minutes.

9. A method for lubricating a transmission system of an electric or hybrid electric vehicle, the method comprising: The drivetrain of the electric or hybrid electric vehicle is lubricated with a lubricating composition; and The lubricating composition comprises: (i) one or more base oils having a lubricating viscosity; (ii) a phosphorus anti-wear additive that provides about 100 ppm or less of phosphorus to the transmission system lubricating composition; (iii) a multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor having one or more ester and / or amide portions and having about 1% to about 15% molybdenum; and the transmission system lubricating composition having less than about 300 ppm of total sulfur.

10. The method of claim 9, wherein the phosphorus anti-wear additive comprises an ashless dialkyl dithiophosphate anti-wear additive that provides about 100 ppm or less of phosphorus and about 150 ppm or less of sulfur to the transmission system lubrication composition; and / or wherein the ashless dialkyl dithiophosphate is prepared by a method comprising the steps of: reacting an organic hydroxyl compound with phosphorus pentasulfide to form a reaction product, and further reacting the reaction product with an unsaturated carboxylic acid to form an oil-soluble phosphorus anti-wear additive comprising the ashless dialkyl dithiophosphate; and / or wherein the ashless dialkyl dithiophosphate comprises a compound of formula V or a salt thereof: R3 and R4 are independently C3 to C8 straight-chain or branched alkyl groups, and R6 is -H or -CH3.

11. The method of claim 9, wherein the multifunctional oil-soluble organomolybdenum friction modifier and corrosion inhibitor provides 20 ppm to 500 ppm of molybdenum; and / or wherein the multifunctional oil-soluble organomolybdenum friction modifier and corrosion inhibitor having ester and / or amide ligands is substantially free of sulfur and / or phosphorus; and / or wherein the multifunctional oil-soluble organomolybdenum friction modifier and corrosion inhibitor having ester and / or amide ligands is substantially free of sulfur and / or phosphorus; and / or wherein the multifunctional oil-soluble organomolybdenum friction modifier and corrosion inhibitor having ester and / or amide ligands is derived from an aliphatic derivative of a dialkylolamine and a molybdenum source; and / or wherein the aliphatic derivative of the dialkylolamine is an aliphatic derivative of diethanolamine, and the molybdenum source is an oxygen-containing molybdenum compound; and / or wherein the oxygen-containing molybdenum compound is selected from ammonium molybdate, molybdenum oxide, or mixtures thereof.

12. The method of claim 9, wherein the multifunctional oil-soluble organic molybdenum friction modifier and corrosion inhibitor having one or more ester and / or amide moieties is a reaction product consisting of about 1 mol of a fatty oil or fatty acid having 12 or more carbon atoms, about 1 mol to 2.5 mol of diethanolamine, and a molybdenum source sufficient to produce about 1% to about 15% by weight of molybdenum based on the additives.

13. The method of claim 9, wherein the weight ratio of total sulfur and total phosphorus to total molybdenum (S+P) / Mo is from about 0.7 to about 10.

0.

14. The method of claim 9, wherein the transmission system lubrication composition is substantially free of individual corrosion inhibitors and / or substantially free of individual friction modifiers; and / or preferably wherein the individual corrosion inhibitors comprise monocarboxylic acid and / or polycarboxylic acid corrosion inhibitors, alkenyl succinic acid, acid / ester or acid anhydride corrosion inhibitors, ether amine corrosion inhibitors, imidazoline corrosion inhibitors, benzotriazole corrosion inhibitors, or combinations thereof.

15. The method of claim 9, wherein the transmission system lubricating composition has a copper leaching of less than 120 ppm when evaluated according to ASTM D130 at 150°C for 168 hours; and / or wherein the transmission system lubricating composition has a coefficient of friction of less than 0.160 when measured using a high-frequency reciprocating tester (HFRR) and evaluated using a 400 g load, a 20 Hz frequency, and at a composition temperature of 130°C for 3 minutes.

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