EP4689028A1

EP4689028A1 - Lubricant additive composition for electric vehicle

Info

Publication number: EP4689028A1
Application number: EP24720682.4A
Authority: EP
Inventors: Michael P. Gahagan; Stephen JEFFREYS
Original assignee: Lubrizol Corp
Current assignee: Lubrizol Corp
Priority date: 2023-03-29
Filing date: 2024-03-28
Publication date: 2026-02-11
Also published as: JP2026511699A; KR20250168247A; WO2024206581A1; CN120936697A

Abstract

The disclosed technology relates to a lubricant additive containing a dispersant, corrosion inhibitor, phosphorous antiwear agent, an antioxidant, and a sulfur-free detergent. The disclosed technology also relates to a lubricating composition containing the lubricant additive, where the lubricating composition is used to lubricant a transmission, and in particular for use in a gearbox, of electric vehicles.

Description

TITLE

LUBRICANT ADDITIVE COMPOSITION FOR ELECTRIC VEHICLE

BACKGROUND OF THE INVENTION

[0001] The disclosed technology relates to a lubricating composition for a driveline, and in particular for use in a gearbox, of electric vehicles, the lubricant additive composition containing an oil of lubricating viscosity, a dispersant, corrosion inhibitor, phosphorus antiwear, antioxidant and a sulfur-free detergent.

[0002] Electric and hybrid-electric vehicles may contain a power source (a traditional combustion engine such as a gasoline or diesel engine and/or a battery source coupled to an electric motor) combined with a transmission for transferring power to the wheels of the vehicle. The transmission may include an electric motor and/or a gear reduction unit coupled to the wheels. In some applications, a lubricant reservoir is provided containing a lubricant composition for lubricating both the electric motor and the power gear reduction unit.

[0003] In electric and hybrid-electric vehicle applications, the lubricating fluid may be in contact with parts of the electric motor as well as parts of a traditional combustion engine gear reduction unit. As such, suitable fluids must have applicability over very different types of vehicle componentry. For example, the lubricating fluid may be in contact with electrical windings in the motor stator as well as the gears in the mechanical portions of the transmission. Suitable fluids for these applications, therefore, not only must have traditional lubricating properties, but also need to be compatible with electronic componentry.

[0004] To be suitable for electric components, the fluids must simultaneously provide good lubricating, electrical conductivity, and cooling performance. Often, one or more of the desired properties needed for electric and hybrid-electric applications is compromised due to the collection of additives commonly used in such traditional fluids and, thus these traditional fluids may be unsuitable for electric or hybrid electric vehicles.

[0005] However, the lubricant must still provide proper lubrication, including, for example, dispersancy, cleanliness, anti-wear and anti-corrosion. Likewise, it is desirable to maintain a low viscosity fluid for such vehicles to improve the vehicle efficiency. Accordingly, new lubricating compositions are needed to achieve these often competing results. SUMMARY OF THE INVENTION

[0006] The disclosed technology provides a lubricant additive composition containing a dispersant, corrosion inhibitor, phosphorus antiwear, antioxidant, and a sulfur-free detergent. The lubricant containing the lubricant additive composition can have a viscosity of 1 to 32 cSt at 100°C as measured by ASTM D445.

[0007] The lubricant additive composition may be mixed with a base oil, such as an API Group III base oil, Group IV base oil, or mixtures thereof to prepare a lubricating composition.

[0008] The lubricating composition containing the lubricant additive composition can be employed in a method of lubricating an electric vehicle by supplying it to a driveline of the electric vehicle. In some instances, the method may be employed where the driveline does not include a shifting clutch. In some instance, the lubricant additive provides improvements in dispersancy, cleanliness, anti-wear, oxidation performance (control) and anti-corrosion.

DETAILED DESCRIPTION OF THE INVENTION

[0009] Various preferred features and embodiments will be described below by way of non-limiting illustration.

[0010] One aspect of the present technology is a lubricant additive composition. The lubricant additive composition can be employed in a lubricating composition with a base oil to provide lubrication in the driveline of an electric vehicle. The lubricant additive composition can include, among other things, a sufficient amount of at least dispersant, corrosion inhibitor, antiwear additive, antioxidant and a sulfur-free detergent.

Dispersant

[0011] Dispersants can include, for example, “succinimide dispersants,” a species of carboxylic dispersants prepared by the reaction of a hydrocarbyl- substituted succinic anhydride or reactive equivalent thereof with an amine such as a poly(ethyleneamine); “amine dispersants,” which are reaction products of relatively high molecular weight aliphatic or alicyclic halides and amines, such as polyalkylene polyamines; “Mannich dispersants,” i.e., the reaction products of alkyl phenols in which the alkyl group contains at least 30 carbon atoms with aldehydes (especially formaldehyde) and amines (especially polyalkylene polyamines); and “ester dispersants,” similar to the above-described succinimide dispersants except that they may be seen as having been prepared by reaction of a hydrocarbyl acylating agent and a polyhydric aliphatic alcohol such as glycerol, pentaerythritol, or sorbitol, as described in US Patent 3,381,022.

[0012] Another class of ashless dispersant is high molecular weight esters. These materials are similar to the above described succinimides except that they may be seen as having been prepared by reaction of a hydrocarbyl acylating agent and a polyhydric aliphatic alcohol such as glycerol, pentaerythritol, or sorbitol. Such materials are described in more detail in U.S. Pat. No. 3,381,022. Aromatic succinate esters may also be prepared as described in United States Patent Publication 2010/0286414. In some instances, these ester type dispersants can be post-treated with an amine such as a poly(ethyleneamine).

[0013] Post-treated dispersants may also be used. Post-treated dispersants are generally obtained by reacting a carboxylic (e.g., succinimide), amine or Mannich dispersant with reagents such as urea, thiourea, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, nitriles, epoxides, boron compounds such as boric acid (to give “borated dispersants” as noted above), phosphorus compounds such as phosphorus acids or anhydrides, 2,5-dimercapto- thiadiazole (DMTD), or an aromatic diacid having acid groups in 1,3 or 1,4 positions on a benzene ring (such as terepthahlic acid).

[0014] Borated dispersants are generally obtained by reacting a carboxylic (e.g., succinimide), amine or Mannich dispersant with a boron compound reagent, such as boric acid (to give “borated dispersants”). Dispersants and their method of production are well-known in the art. The borated dispersant may be further functionalized with a sulfur or phosphorus moiety. The dispersant component in the borated dispersant may be a mixture of multiple dispersants which may be of different types; optionally at least one may be a succinimide dispersant. In one embodiment the borated dispersant may be a borated polyisobutylene succinimide dispersant, in which the polyisobutylene portion thereof may have a number average molecular weight of 750 to 2200, or 750 to 1600, or 950 to 1550. The borated dispersant(s) may be prepared in such a way to have a N:CO ratio of 0.9: 1 to 1.6: 1, or 0.95: 1 to 1.5: 1, or 1 : 1 to 1.4: 1. The amount of borated dispersant in the compositions, may be, for instance, 0.05 to 2.0 percent by weight. In other embodiments, the amount is 0.1 to 1.0 percent or 0.15 to 0.75 percent of the final blended fluid formulation. In a concentrate, the amounts will be proportionately higher.

[0015] Mixtures of dispersants can also be used. The dispersant can have a nitrogen content of greater than or equal to about 11,000 ppm by weight of the dispersant, or greater than or equal to about l l,500ppm or greater than or equal to about 12,000 ppm.

[0016] The total amount of dispersant or dispersants, whether post-treated or not (e.g., borated or non-borated) or combinations thereof, in the compositions, may be, for instance, 0.01 to 3 percent by weight, or, for example, 0.025 to 2.75 weight percent or 0.05 to 2.5 weight percent, or 1 to 2.5 weight percent of the final blended fluid formulation, although in a concentrate, the amounts will be proportionately higher. To the extent the dispersant is borated, the dispersant may provide less then 250 ppm boron, or less than 200 ppm boron, or even less than 150 ppm boron, or less than 100 ppm boron, or less then 90 ppm boron, or even less than 80 ppm boron to the composition, and in some instances less than 70 ppm boron to the composition.

[0017] In certain embodiments, the dispersant can be prepared by a process that involves the presence of small amounts of chlorine or other halogen, as described in U.S. Pat. No. 7,615, 521 (see, e.g., col. 4, lines 18-60 and preparative example A). Such dispersants typically have some carbocyclic structures in the attachment of the hydrocarbyl substituent to the acidic or amidic "head" group. In other embodiments, the dispersant can be prepared by a thermal process involving an "ene" reaction, without the use of any chlorine or other halogen, as described in U.S. Pat. No. 7,615,521; dispersants made in this manner are often derived from high vinylidene (i.e., greater than 50% terminal vinylidene) polyisobutylene (See col. 4, line 61 to col. 5, line 30 and preparative example B). Such dispersants typically do not contain the above-described carbocyclic structures at the point of attachment. In certain embodiments, the dispersant can be prepared by free radical catalyzed polymerization of high-vinylidene polyisobutylene with an ethylenically unsaturated acylating agent, as described in U.S. Pat. No. 8,067,347.

[0018] The dispersant can also be a grafted copolymer that is a condensation reaction product of an olefin polymer having carboxylic acid (or equivalent) functionality grafted thereon, the grafted olefin reacted with a monoamine or a polyamine which may have a single primary amino group. If the olefin polymer is an ethyl ene/propyl ene copolymer, then said polyamine is not a poly(ethylene amine).

[0019] The polymer substrate will be an olefin polymer such as that described above. The olefin polymer substrate employed in the derivatized graft copolymer will contain grafted carboxylic acid functionality or a reactive equivalent of carboxylic acid functionality (e.g., anhydride or ester). The reactive carboxylic acid functionality will typically be present as a pendant group attached by, for instance, a grafting process.

[0020] An ethylenically unsaturated carboxylic acid material is typically radically grafted onto the polymer backbone. These materials which are attached to the polymer typically contain at least one ethylenic bond (prior to reaction) and at least one, such as two, carboxylic acid (or its anhydride) groups or a polar group which is convertible into said carboxyl groups by oxidation or hydrolysis. Maleic anhydride or a derivative thereof is suitable. It grafts onto the olefin polymer, (e.g., ethylene copolymer or terpolymer) to give two carboxylic acid functionalities. Examples of additional unsaturated carboxylic materials include maleic anhydride, itaconic anhydride, or the corresponding dicarboxylic acids, such as maleic acid, fumaric acid and their esters, as well as cinnamic acid and esters thereof.

[0021] The ethylenically unsaturated carboxylic acid material may be radically grafted onto the polymer (such as the ethyl ene/propylene copolymer). The free-radical induced grafting of ethylenically unsaturated carboxylic acid materials may also be conducted in solvents, such as hexane or mineral oil. It may be carried out at an elevated temperature in the range of 100°C to 250°C, e.g., 120°C to 190°C, or 150°C to 180°C, e.g., above 160°C.

[0022] The free-radical initiators which may be used include peroxides, hydroperoxides, and azo compounds, typically those which have a boiling point greater than about 100°C and which decompose thermally within the grafting temperature range to provide free radicals. Representative of these free-radical initiators include azobisisobutyronitrile and 2,5-dimethyl-hex-3-yne-2,5-bis-tertiary-butyl peroxide. The initiator may be used in an amount of 0.005% to 1% by weight based on the weight of the reaction mixture solution. The grafting may be carried out in an inert atmosphere, such as under nitrogen blanketing. The resulting polymer intermediate is characterized by having carboxylic acid acylating functions within its structure.

[0023] In an alternative embodiment, the unsaturated carboxylic acid material, such as maleic anhydride, can be first condensed with a monoamine or polyamine, typically having a single primary amino group (described below) and the condensation product itself then grafted onto the polymer backbone in analogous fashion to that described above.

[0024] The amount of the reactive carboxylic acid on the polymer chain, and in particular the amount of grafted carboxylic acid on the chain is typically 0.5 to 8 weight percent, or 1 to 7 weight percent, or 1.5 to 6 weight percent, based on the weight of the polymer backbone, or in some embodiments 2 to 5 weight percent. In some embodiments the amount of the reactive carboxylic acid on the polymer chain, and in particular the amount of grafted carboxylic acid on the chain can be from about 1 to about 2, or in other embodiments from about 2 to 3, or from about 3 to 4 weight percent or 4 to 5 weight percent. These numbers represent the amount of carboxyl-containing species with particular reference to maleic anhydride as the graft material. The amounts may be adjusted to account for carboxyl-containing species having higher or lower molecular weights or greater or lesser amounts of acid functionality per molecule, as will be apparent to the person skilled in the art. The grafting may be of an extent to provide an acid functionalized polymer having a total acid number (TAN per ASTM D664) of 5 to 100, 10 to 80, or 15 to 75, or 20 to 70, or about 20 to about 60 or 65 mgKOH/g.

[0025] The acid-containing polymer is reacted with a monoamine or a polyamine typically having a single primary amino group. If the olefin polymer is an ethyl ene/propylene copolymer, then said polyamine is not a poly(ethyleneamine). The reaction may consist of condensation to form an imide, amide, or half-amide or amideester (assuming a portion of alcohol is also reacted) or an amine salt. A primary amino group will typically condense to form an amide or, in the case of maleic anhydride, an imide. It is noted that in certain embodiments the amine will have a single primary amino group, that is, it will not have two or more primary amino groups (except perhaps a very small an inconsequential amount of additional primary amino groups within the entire amine component, e.g., less than 5% or 2% or 1% or 0.5%, or 0.01 to 0.1%, especially 1% or less, such as 0.01 to 1%, of amine groups being primary). This feature will minimize the amount of crosslinking that might otherwise occur. Poly(ethyleneamine)s may generally, and in an oversimplified manner, be depicted as H2N-(C₂H4-NH-)n-C2H₄-NH2, where n may be, for instance, 2 through 6. These typically have on average about 2 primary amino groups, so their use is typically undesirable for functionalization of ethylene/propylene copolymers, so that any undesirable crosslinking may be minimized or avoided. In those embodiments in which the polyamine is not a poly(ethyleneamine), the amine component employed to make the condensation product will be free of or substantially free of poly(ethyleneamine), such as less than 5 percent by weight of the amine component is poly(ethyleneamine), or less than 1 percent, or 0.01 to 0.1 percent by weight.

[0026] Suitable primary amines may include aromatic amines, such as amines wherein a carbon atom of the aromatic ring structure is attached directly to the amino nitrogen. The amines may be monoamines or polyamines. The aromatic ring will typically be a mononuclear aromatic ring (i.e., one derived from benzene) but can include fused aromatic rings, such as those derived from naphthalene. Examples of aromatic amines include aniline, N-alkylanilines such as N-methylaniline, and N- butylaniline, di-(para-methylphenyl)amine, naphthylamine, 4-aminodiphenylamine, N,N-dimethylphenylenediamine, 4-(4-nitrophenylazo)aniline (disperse orange 3), sulfamethazine, 4-phenoxyaniline, 3 -nitroaniline, 4-aminoacetanilide, 4-amino-2- hydroxy-benzoic acid phenyl ester (phenyl amino salicylate), N-(4-amino-5-methoxy- 2-methyl-phenyl)-benzamide (fast violet B), N-(4-amino-2,5-dimethoxy-phenyl)- benzamide (fast blue RR), N-(4-amino-2,5-diethoxy-phenyl)-benzamide (fast blue BB), N-(4-amino-phenyl)-benzamide and 4-phenylazoaniline. Other examples include para-ethoxyaniline, para-dodecylaniline, cyclohexyl-substituted naphthylamine, and thienyl-substituted aniline. Examples of other suitable aromatic amines include amino-substituted aromatic compounds and amines in which an amine nitrogen is a part of an aromatic ring, such as 3 -aminoquinoline, 5-aminoquinoline, and 8-aminoquinoline. Also included are aromatic amines such as 2-aminobenzimidazole, which contains one secondary amino group attached directly to the aromatic ring and a primary amino group attached to the imidazole ring. Other amines include N-(4- anilinophenyl)-3-aminobutanamide (i.e., <|)-NH-<|)-NH-COCH2CH(CH3)NH2 .

Additional aromatic amines include aminocarbazoles, aminoindoles, aminopyrroles, aminoindazolinones, aminoperimidines, mercaptotriazoles, aminophenothiazines, aminopyridines, aminopyrazines, aminopyrimidines, pyridines, pyrazines, pyrimidines, aminothiadiazoles, aminothiothiadiazoles, and aminobenzotriaozles. Other suitable amines include 3-amino-N-(4-anilinophenyl)-N-isopropyl butanamide, and N-(4-anilinophenyl)-3-{(3-aminopropyl)-(cocoalkyl)amino} butanamide. Other aromatic amines which can be used include various aromatic amine dye intermediates containing multiple aromatic rings linked by, for example, amide structures. Examples include materials of the general structure (|)-CONH-(|)-NH2 where the phenyl groups may be substituted. Suitable aromatic amines include those in which the amine nitrogen is a substituent on an aromatic carboxylic compound, that is, the nitrogen is not sp² hybridized within an aromatic ring.

[0027] The amine may also be non-aromatic, or in other words, an amine in which an amino nitrogen is not attached directly to a carbon atom of an aromatic ring, or in which an amine nitrogen is not a part of an aromatic ring, or in which an amine nitrogen is not a substituent on an aromatic carboxylic compound. In some instances, such non- aromatic amines may be considered to be aliphatic, or cycloaliphatic. Such amines may be straight or branched or functionalized with some functional group. The non- aromatic amines can include monoamines having, e.g., 1 to 8 carbon atoms, such as methylamine, ethylamine, and propylamine, as well as various higher amines. Diamines or polyamines can also be used, and typically will have only a single primary amino group. Examples include dimethylaminopropylamine, di ethylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, di ethylaminoethylamine, dibutylaminoethylamine, l-(2-aminoethyl)piperidine, l-(2- aminoethyl)pyrrolidone, N,N-dimethylethylamine; 3 -(dimethylamino)- 1 - propylamine; O-(2-aminopropyl)-O'-(2-methoxyethyl)polypropylene glycol; N,N- dimethyldipropylenetriamine, aminoethylmorpholine, 3 -morpholinopropyl amine; aminoethylethyleneurea and aminopropylmorpholine.

[0028] In certain embodiments non-aromatic amines can be used alone or in combination with each other or in combination with aromatic amines. The amount of aromatic amine may, in some embodiments, be a minor amount compared with the amount of the non-aromatic amines, or in some instance, the composition may be substantially free or free of aromatic amine. [0029] In certain embodiments the grafted olefin polymer may have a nitrogen content, calculated using ASTM D5291, of 0.05 to 3 percent by weight, or 0.1 to 2.5, or 0.15 to 2, or 0.2 to 1.75, or 0.25 to 1.6 percent by weight.

Corrosion Inhibitor

[0030] The corrosion inhibitor may also be described as a metal deactivator or a yellow-metal passivator.

[0031] Examples of a corrosion inhibitor include triazoles, such as benzotriazoles and 1,2,4-triazoles, benzimidazoles, or mixtures thereof. In one embodiment the corrosion inhibitor includes a benzotri azole. In another embodiment, the corrosion inhibitor includes bis(2-ethylhexyl)-[l,2,4-triazole-l-yl)methyl]amine. [0032] Triazoles include those containing hydrocarbyl substitutions on at least one of the following ring positions 1- or 2- or 4- or 5- or 6- or 7-. The hydrocarbyl groups in different embodiments contain 1 to about 30, or 1 to about 15, or 1 to about 16 carbon atoms. In one embodiment the corrosion inhibitor includes tolyltriazole. In one embodiment hydrocarbyl triazoles substituted at positions 4- or 5- or 6- or 7- are further reacted with an aldehyde and an amine.

[0033] Examples of suitable hydrocarbyl benzotri azoles further reacted with an aldehyde and an amine include N,N-bis(2-ethylhexyl)-ar-methyl-lH- benzotriazole-l-methanamine, N,N-bis(2-ethylhexyl)-4-m ethyl -IH-benzotri azole- 1- m ethanamine, N,N-bis(2-ethylhexyl)-4-m ethyl- IH-benzotri azole- 1-methanamine, 2H-benzotriazole-2-methanamine, N-(4-m ethoxyphenyl)- IH-benzotri azole- 1- m ethanamine, N,N-didodecyl- IH-benzotri azole- 1-methanamine, N-(1H- benzotriazol- 1 -ylmethyl)-N-(2-ethylhexyl)- IH-benzotriazole- 1 -methanamine, N- m ethyl -N-phenyl- IH-benzotri azole- 1-methanamine, 4,5,6,7-tetrahydro-N,N- ditridecyl-lH-benzotriazole- 1-methanamine, N,N-dioctadecyl-lH-benzotriazole-l- m ethanamine, 5-methyl-N,N-dioctyl-lH-benzotriazole- 1-methanamine, N,N- dibutyl- IH-benzotri azole- 1-methanamine, N-(4-methylphenyl)- IH-benzotri azole- 1- m ethanamine, N,N-bis(2-ethylhexyl)-lH-benzotriazole- 1-methanamine, N,N- dioctyl-2H-benzotriazole-2-methanamine, N-dodecyl-lH-benzotriazole-1- m ethanamine, N-phenyl- IH-benzotri azole- 1-methanamine, N,N-didodecyl-4,5,6,7- tetrahydro-lH-benzotriazole- 1-methanamine, N, N-bis(2-ethylhexyl)-5-m ethyl- 1H- benzotriazole- 1-methanamine, N-octadecyl-lH-benzotriazole- 1-methanamine, N,N- didodecyl-2H-benzotriazole-2-methanamine, N,N-dioctyl-lH-benzotriazole-l- m ethanamine, N-(2-ethylhexyl)- IH-benzotri azole- 1-methanamine, 4, 5,6,7- tetrahydro-N,N-ditetradecyl-lH-benzotriazole-l-methanamine, or mixtures thereof. In one embodiment the corrosion inhibitor includes N,N-bis(2-ethylhexyl)-4-methyl- IH-benzotriazole-l-methanamine or N,N-bis(2-ethylhexyl)-ar-methyl-lH- benzotri azole- 1 -methanamine.

[0034] Examples of suitable hydrocarbyl 1,2,4-riazoles further reacted with an amine include A,A-Bis(l-methylethyl)-lZ/-l,2,4-triazole-l-methanamine, N,N- diisobutyl- 1H- 1 ,2,4-triazole- 1 -methanamine, TV, 7V-di cyclohexyl- 1H- 1 ,2,4-triazole- 1 - methanamine, N, 7V-bis(2-ethylhexyl)- 1/7-1, 2, 4-Tri azole- 1 -methanamine, 1-((1H- l,2,4-triazol-l-yl)methyl)piperidine, N, A-bis(tridecyl)- 1H- 1,2, 4-Tri azole- 1- m ethanamine, N,N-dimethyl-l-(lH-l,2,4-triazol-l-yl)methanamine, N,N-dibutyl- 1H- 1, 2, 4-tri azole- 1 -methanamine, N,N-dicoco-l-(lH-l,2,4-triazol-l- yl)m ethanamine, N-((lH-l,2,4-triazol-l-yl)methyl)octan-3-amine.

[0035] In different embodiments, the corrosion inhibitor is a triazole. Triazole corrosion inhibitors may be present, alone, or as mixtures with other triazoles or other azole corrosion inhibitors, in ranges including about 0.005 or 0.01 wt % to about 0.1 wt %, or about 0.03 wt % to about 0.08 wt %, or about 0.04 wt % to about 0.068 wt %, or about 0.045 wt % to about 0.057 wt % of the lubricant additive composition. Phosphorus Antiwear Compound

[0036] The lubricant additive composition contains at least one phosphorus antiwear compound. The phosphorus antiwear compound may be an acid, salt or ester. In one embodiment the phosphorus antiwear compounds are in the form of a mixture of two or three, or two to four (typically two or three) phosphorus antiwear compounds. In some embodiments the phosphorus antiwear compounds are in the form of a mixture of phosphites and phosphate amines compounds.

[0037] In some embodiments, the phosphorus antiwear compound is a phosphite. Suitable phosphites include those having at least one hydrocarbyl group with 3 or 4 or more, or 8 or more, or 12 or more, carbon atoms. The phosphite may be a mono-hydrocarbyl substituted phosphite, a di -hydrocarbyl substituted phosphite, or a tri-hydrocarbyl substituted phosphite.

[0038] In one embodiment, the phosphite is sulphur-free i.e., the phosphite is not a thiophosphite. [0039] The phosphite may be represented by the formulae: wherein at least one R may be a hydrocarbyl group containing at least 3 carbon atoms and the other R groups may be hydrogen. In one embodiment, two of the R groups are hydrocarbyl groups, and the third is hydrogen. In one embodiment every R group is a hydrocarbyl group, i.e., the phosphite is a tri -hydrocarbyl substituted phosphite. The hydrocarbyl groups may be alkyl, cycloalkyl, aryl, acyclic or mixtures thereof.

[0040] The R hydrocarbyl groups may be linear or branched, typically linear, and saturated or unsaturated, typically saturated.

[0041] In one embodiment, the phosphorus antiwear compound can be a C3-8 hydrocarbyl phosphite, or mixtures thereof, i.e., wherein each R may independently be hydrogen or a hydrocarbyl group having 3 to 8, or 4 to 6 carbon atoms, typically 4 carbon atoms. Typically, the C3-8 hydrocarbyl phosphite comprises a dialkyl phosphite where each R is 1 to 14 carbon atoms, or 2 to 12 carbon atoms, or 3 to 8 or 4 to 6 carbon atoms. The dialkyl phosphite can be, for example, dibutyl phosphite or dioleyl phosphite. The C3-8 hydrocarbyl phosphite, or C3-8 dialkyl phosphite, may deliver at least 175 ppm, or at least 200 ppm of the total amount of phosphorus delivered by the phosphorus antiwear compounds. The C3-8 hydrocarbyl phosphite, or dialkyl phosphite, may deliver at least 45 wt %, or 50 wt % to 100 wt %, or 50 wt % to 90 wt % or 60 wt % to 80 wt % of the total amount of phosphorus from the phosphorus antiwear compound.

[0042] In one embodiment, the phosphorus anti wear compound can be a C 12- 24 hydrocarbyl phosphite, or mixtures thereof, i.e., wherein each R may independently be hydrogen or a hydrocarbyl group having 12 to 24, or 14 to 20 carbon atoms, typically 16 to 18 carbon atoms. Typically, the Cl 2-24 hydrocarbyl phosphite comprises a C 16-18 dialkyl phosphite. Examples of alkyl groups for R3, R4 and R5 include octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, octadecenyl, nonadecyl, eicosyl or mixtures thereof. The C 12-24 hydrocarbyl phosphite, or Cl 2-24 dialkly phosphite, may be present in the lubricant additive composition at about 0.05 wt.% to about 1.0 wt.% of the lubricant additive composition, or from about 0.1 wt.% to about 0.5 wt.% of the lubricant additive composition.

[0043] In some embodiments, the phosphorous containing compound can include both a C3-8 and a C12-14 hydrocarbyl phosphite.

[0044] The phosphorus anti wear compound can include a phosphite at 0.1 to 2 wt.% of the additive composition, or even from 0.1 to 1.8 wt.%, or 0.1 to 1.4 or 1.6 wt.% of the lubricant additive composition, or even from 0.1 to 1 or 1.2 wt.% of the lubricant additive composition. The phosphorus antiwear compound can include a phosphite at 0.1 to 0.5 wt.% of the additive composition, or even from 0.1 to 0.4 wt.%, or 0.1 to 0.2 wt.% of the lubricant additive composition.

[0045] The phosphorus antiwear compound can be a phosphite ester composition that is the reaction product, e.g., condensation product, of a monomeric phosphorous acid or an ester thereof with at least two alkylene diols. In an embodiment, the foregoing phosphite ester does not contain zinc.

[0046] By “monomeric” phosphorous acid or ester is meant a phosphorous acid or ester, typically containing one phosphorus atom, which may be reacted with a diol in order to form an oligomeric, polymeric, or other condensed species. The monomeric phosphorous acid or ester thereof may be phosphorous acid itself (H3PO3), although a monomeric partial ester such as a dialkylphosphite may be used for ease of handling or other reasons. The alkyl group or groups may be relatively low molecular weight groups of 1 to 6 or 1 to 4 carbon atoms, such as methyl, ethyl, propyl, or butyl, such that the alcohol generated upon reaction with the alkylene diols may be easily removed. An exemplary phosphorous acid ester is dimethyl phosphite; others include diethyl phosphite, dipropyl phosphite, dioleyl phosphite and dibutyl phosphite. Sulfur-containing analogues may also be employed (e.g., thiophosphites). Other esters include trialkyl phosphites. Mixtures of di-and trialkyl phosphites may also be useful. In these materials, the alkyl groups may be the same or different each independently typically having 1 to 6 or 1 to 4 carbon atoms as described above.

[0047] The monomeric phosphorus acid or ester will be reacted or condensed with at least two alkylene diols to form a phosphorus antiwear compound, which may include a polymeric (or oligomeric) phosphorus ester and optionally monomeric species. The first alkylene diol (i) will be a 1,4- or 1,5- or 1,6- alkylene diol. That is to say, there will be two hydroxy groups in a 1,4 or 1,5 or 1,6 relationship to each other, separated by a chain of 4, 5, or 6 carbon atoms, respectively. The first hydroxy group may be literally on the 1 carbon atom, that is, on the a carbon of the diol, or it may be on a higher numbered carbon atom. For example, the diol may also be a 2,5- or 2,6-, or 2,7-diol or a 3,6- or 3,7- or 3 , 8 -diol, as will be evident to the skilled person. The alkylene diol may be branched (e.g., alkyl -substituted) or unbranched and in one embodiment is unbranched. Unbranched, that is, linear diols (a, o -diols) include 1,4- butanediol, 1,5-pentane diol, and 1,6-hexanediol. Branched or substituted diols include 1,4-pentanediol, 2-methyl-l,5-pentanediol, 3-methyl-l,5-pentanediol, 3,3- dimethyl- 1,5 -pentanediol, 1,5-hexanediol, 2,5-hexanediol, and 2,5-dimethyl-2,5- hexanediol. A diol having one or more secondary hydroxy groups (such as 2,5- hexanediol) may be referred to as a branched or substituted diol, even though the carbon chain itself may be linear. The location of the hydroxy groups in the 1,4-, 1,5-, or 1,6- positions (that is, either positions relative to each other or literal positions) may be helpful to promote oligomerization with the phosphorous species rather than formation of cyclic structures (which would be sterically disfavored). In certain embodiments the first alkylene diol may be 1,6-hexanediol.

[0048] The first alkylene dihydroxy compound (diol) may, if desired, have additional hydroxy groups, that is, more than two per molecule, or there may be exactly two. In one embodiment, there are exactly two hydroxy groups per molecule. If there are more than two hydroxy groups, care should be taken to assure that there is no excessive cyclization such as might interfere with the polymerization reaction, if there are fewer than 4 atoms separating any of the hydroxy groups. Also, care should be taken to avoid excessive branching or crosslinking in the product, which could lead to undesirable gel formation. Such problems may be avoided by careful control of reaction conditions such as control of the ratio of reagents and the order of their addition, performing the reaction under suitably dilute conditions, and reacting under low acid conditions. These conditions can be determined by the person skilled in the art with only routine experimentation.

[0049] The phosphorous acid or ester is also reacted with a second alkylene diol (ii). The second alkylene diol is an alkyl-substituted 1,3 -propylene diol with one or more of the alkyl substituents thereof being on one or more of the carbon atoms of the propylene unit, the total number of carbon atoms in the alkyl-substituted 1,3- propylene diol being 5 to 12 or 6 to 12 or 7 to 11 or 8 to 18 or, in certain embodiments, 9. That is, the alkyl -substituted 1,3 -propylene diol may be represented by the general formula: where the various R groups may be the same or different and may be hydrogen or an alkyl group, provided that at least 1 R is an alkyl group and that the total number of carbon atoms in the R groups is 2 to 9 or 3 to 9, so that the total carbon atoms in the diol will be 5 to 12 or 6 to 12, respectively, and likewise for the other ranges of total carbons. By analogy with the above-described, 1,4-, 1,5-, or 1 ,6-diols, reference here to 1,3 -diols means that the two hydroxy groups are in a 1,3 relationship to each other, that is, separated by a chain of 3 carbon atoms. A 1 ,3-diol may thus also be named as a 2,4- or 3,5-diol. If the 1 ,3 -diol has one or more secondary hydroxy groups, such a molecule will be considered to be a substituted diol. In one embodiment the number of alkyl substituents is 2 and the total number of carbon atoms in the molecule is 9. Suitable substituents may include, for instance, methyl, ethyl, propyl, and butyl (in their various possible isomers).

[0050] Examples of the second alkylene diol may include 2,2-dimethyl-l,3- propanediol, 2-ethyl-2-butylpropane-l,3-diol, 2-ethylhexane-l,3-diol, 2,2- dibutylpropane- 1,3 -diol, 2,2-diisobutylpropane-l,3-diol, 2-methyl-2-propylpropane- 1,3-diol, 2-propyl-propane-l,3-diol, 2-butylpropane-l,3-diol, 2-pentylpropane-l,3- diol, 2-methyl-2-propylpropane- 1,3 -diol, 2,2-diethylpropane-l,3-diol, 2,2,4- trimethylpentane- 1,3 -diol, 2-methylpentane-2,4-diol, 2,4,-dimethyl-2,4-pentanediol, and 2,4-hexanediol. It should be noted that some of the foregoing nomenclature emphasizes the propane- 1,3 -diol structure of the molecules, for clarity. For instance, 2-pentylpropane- 1,3 -diol might also be named 2-hydroxymethylheptan-l-ol, but the latter nomenclature does not so clearly illustrate the 1,3 -nature of the diol.

[0051] The relative molar amounts of the first alkylene diol (i) and the second alkylene diol (ii) may be in a ratio of 30:70 to 65:35, or alternatively 35:65 to 60:40 or 40:60 to 50:50 or 40:60 to 45:55. If the ratio is less than about 30:70, the resulting product may not fully exhibit the benefits of the disclosed technology, and if it is greater than about 65:35, its compatibility with other components in a lubricant formulation may be reduced.

[0052] The relative molar amounts of the monomeric phosphorous acid or ester thereof (a) and the total molar amounts of the alkylene diols (b) may be in a ratio of 0.9: 1.1 to 1.1 :0.9, or 0.95: 1.05 to 1.05:0.95, or 0.98: 1.02 to 1.02:0.98, or about 1 : 1. Reaction in approximately equimolar ratios will tend to encourage formation of oligomers or polymer formation. An exact 1 : 1 ratio could theoretically lead to extremely long chain formation and consequently very high molecular weight. In practice, however, this is not typically attained since competing reactions and incompleteness of reaction will provide materials of a lesser degree of polymerization, and a certain fraction of the material will be in the form of cyclic monomer.

[0053] The reaction product will typically comprise a mixture of individual species, including some oligomeric or polymeric species as well as cyclic monomeric species. The cyclic monomeric species may comprise 1 phosphorus atom and one alkylene group, derived principally from the 1,3-diol (ii), as the 1,3-diol is capable of either participation in oligomerization or cyclic ester formation. The oligomeric or polymeric species may typically comprise 2 or 3 to 20 phosphorus atoms, or alternatively 5 to 10 phosphorus atoms, linked together by alkylene groups derived from the diols (i) and (ii), and may exhibit a relative preference for incorporation of the 1,4-, 1,5-, or 1 ,6-diols, which are less readily able to cyclize with the phosphorus to form a cyclic monomeric species.

[0054] The product may be a mixture of species that may be represented by the structures shown:

(oligomeric species) (cyclic monomer species) where x and y represent the relative amounts of the two diols incorporated into the oligomer. The structure shown is not intended to indicate that the polymer is necessarily a block polymer, since the structures represented by the x and y brackets may be more or less randomly distributed, as influenced by or depending on the availability of the various diol reactants. Each X is independently a terminating group, which may be, for instance, an alkyl group (such as methyl), or hydrogen or a diol-derived moiety which might terminate in an OH group. In the above scheme, for illustrative purposes only, the diene (i) is selected to be 1,6-hexanediol and diene (ii) is selected to be 2-butyl-2-ethyl-l,3- propanediol. Corresponding structures and mixtures would be formed using different diols (i) and (ii).

[0055] The relative amounts of oligomeric species and cyclic monomer species in the reaction mixture will depend, to some extent, on the specific diols selected and the reaction conditions. For reaction products prepared from 1,6-hexane diol and 2-butyl-2-ethyl-l,3-propanediol, as in the structures above, the amount of oligomeric product may be approximately as shown in the table below: and the amount of the cyclic monomer may be 100% minus the percentage of the oligomer. It is also possible that, regardless of the specific diols employed, mixtures having the above weight percentages of oligomer and cyclic monomer may be usefully prepared. In certain embodiments, 55 to 60 weight percent of the product is in oligomeric form and 45 to 40 percent is in cyclic monomer form. In some embodiments the relative amount of the cyclic monomeric species to the amount of the oligomeric species is 1 :3 to 1 : 1 or alternatively 1 :3 to 1 :0.8 by weight.

[0056] The condensation reaction between the phosphorus acid or ester and the diol may be accomplished by mixing the reagents and heating until the reaction is substantially complete. Typically, the first and second alkylene diols may be mixed with the phosphorous compound at the same time or nearly the same time, that is, typically before the reaction with one of the alkylene diols is complete. A small amount of a basic material such as sodium methoxide may also be present. If a methyl ester of the phosphorous acid is used as a reagent, substantial completion of the reaction may correspond with the cessation of evolution and distillation of methanol from the reaction mixture. Suitable temperatures include those in the range of 100 to 140°C, such as 110 to 130°C or 115 to 120°C. If reaction temperatures in excess of about 140°C are employed, there is a risk that the desired product may not be formed in useful yields or with useful purity, since competing reactions may occur. Reaction times may typically be up to 12 hours, depending on temperature, applied pressure (if any), agitation, and other variables. In some instances, reaction times of 2 to 8 hours or 4 to 6 hours may be appropriate.

[0057] Other monomers may be included within the reaction mixture if desired. In particular, the inclusion of a polycarboxylic acid, such as a dicarboxylic acid, is sometimes seen as beneficial. For example, inclusion of a relatively minor amount of tartaric acid or citric acid may provide products with useful properties. The amount of polyacid or diacid may an amount suitable to incorporate at least 1, or approximately 1, monomeric unit of poly- or dicarboxylic acid per product oligomer molecule. The amount of polyacid or diacid actually charged to the reaction mixture may be higher than this amount. Without intending to be bound by any theory, it is believed that when a minor amount of tartaric acid is present, it may be incorporated as an end unit of the polymer, possibly being condensed through an ester linkage with an OH group of an alkylene diol. Such materials may exhibit good performance in terms of antiwear protection and corrosion inhibition, as well as seals performance. Suitable polyacids (or their esters or anhydrides) include maleic acid, fumaric acid, tartaric acid, citric acid, phthalic acid, terephthalic acid, malonic acid (e.g., ester), succinic acid, malic acid, adipic acid, oxalic acid, sebacic acid, dodecanedioic acid, glutaric acid, and glutamic acid. Another type of monomer which may be included is a monocarboxylic acid which contains a reactive hydroxy group, or a reactive equivalent of such a material, such as an anhydride, ester, or lactone. Examples include glyoxylic acid, caprolactone, valerolactone, and hydroxystearic acid.

[0058] The amount of the phosphorous ester product described above used in lubricants may be an amount sufficient to provide 0.01 to 0.3 or to 0.1 weight percent phosphorus to the composition or, in other embodiments, 0.02 to 0.07 weight percent or 0.025 to 0.05 weight percent. The actual amount of the product which corresponds to these amounts of phosphorus will, of course, depend upon its phosphorus content. Suitable amounts of the ester product in the lubricant additive composition may be 0.01 to 1.0 weight percent, or 0.02 to 0.5 weight percent, or 0.03 to 0.30 weight percent, or even 0.05 to 0.25 weight percent.

[0059] While each of the phosphorus antiwear compounds described above may be present in the lubricant additive composition on its own, the lubricant additive composition may also include a mixture of two or more. In some embodiments, the phosphorous containing compound can include a C3-8 hydrocarbyl phosphite and a phosphite ester product. In some embodiments, the phosphorous containing compound can include each of a C3-8 hydrocarbyl phosphite, a C12 to C24 hydrocarbyl phosphite, and a phosphite ester product. In either event, the phosphorus antiwear compound should be present in an amount to deliver 100 to 4000 ppm of phosphorus to the lubricant additive composition. In some embodiments, the at least one phosphorus antiwear compound can be present in an amount to deliver 125 to 1000 ppm of phosphorus, or from 150 to 800 ppm phosphorus to the lubricant additive composition.

[0060] The lubricant additive composition can include a substantially sulfur-free alkyl phosphate salt, as further described. In this salt composition, at least 30 mole percent of the phosphorus atoms are in an alkyl pyrophosphate structure, as opposed to an orthophosphate (or monomeric phosphate) structure. The percentage of phosphorus atoms in the pyrophosphate structure may be 30 to 100 mole %, or 40 to 90 % or 50 to 80% or 55 to 70 % or 55 to 65%. The remaining amount of the phosphorus atoms may be in an orthophosphate structure or may consist, in part, in unreacted phosphorus acid or other phosphorus species. In one embodiment, up to 60 or up to 50 mole percent of the phosphorus atoms are in mono- or di-alkyl-orthophosphate salt structure.

[0061] The substantially sulfur-free alkyl phosphate salt, as present in the pyrophosphate form (sometimes referred to as the POP structure). In certain embodiments, at least 80 mole percent, or at least 85, 90, 95, or 99 percent, of the alkyl groups of the alkyl phosphate salt will be primary alkyl groups. In some embodiments, the alkyl groups will have 4 to 22, or 4 to 20, or 4 to 18, or even 4 to 12 carbon atoms, or 5 to 10, or 6 to 8 carbon atoms. Such groups include 2-butyl, 2-pentyl, 3-pentyl, 3- methyl-2-butyl, 2-hexyl, 3-hexyl, cyclohexyl, 4-methyl-2-pentyl, and other such primary groups and isomers thereof having 6, 7, 8, 9, 10, 11, or 12 carbon atoms. In some embodiments, the alkyl group will have a methyl branch at the a-position of the group, an example being the 4-methyl-2-pentyl (also referred to as 4-methylpent-2-yl) group.

[0062] Such alkyl (including cycloalkyl) groups will typically be provided by the reaction of the corresponding alcohol or alcohols with phosphorus pentoxide (taken herein to be P2O5 although it is recognized the more probable structure may be represented by P4O10). Thus, the alkyl phosphate salt may be prepared by the reaction of phosphorus pentoxide with a primary alcohol having 4 to 12 carbon atoms, and reacting the product thereof with the salting material, as described in further detail below.

[0063] While the pyrophosphate ester may be isolated, if desired, from the orthoesters, it is also possible, and may be commercially preferable, to use the reaction mixture without separation of the components.

[0064] In one embodiment the phosphorus antiwear compound can include a phosphorus-containing acid, salt or ester, or mixtures thereof. In one embodiment the phosphorus antiwear compoundcan be in the form of a mixture.

[0065] The phosphorus antiwear compound can include those derived from phosphoric acid, phosphorous acid, thiophosphoric acid, thiophosphorous acid, or mixtures thereof.

[0066] In one embodiment, the phosphorus antiwear compound can include (i) a non-ionic phosphorus compound; (ii) an amine salt of a phosphorus compound; or (hi) an ammonium salt of a phosphorus compound.

[0067] In one embodiment, the phosphorus antiwear compound can include an ammonium or amine salt of a phosphorus-containing acid or ester.

[0068] The amine salt of a phosphorus acid or ester includes phosphoric acid esters and amine salts thereof; dialkyldithiophosphoric acid esters and amine salts thereof; amine salts of phosphites; and amine salts of phosphorus containing carboxylic esters, ethers, and amides; and mixtures thereof. [0069] The alkyl groups of the phosphorus antiwear compound can be from 2 to 12 carbons, or from 3 to 10 or 4 to 8 carbon atoms in length.

[0070] The amine salt of a phosphorus acid or ester may be used alone or in combination.

[0071] In one embodiment the amine salt of a phosphorus acid or ester includes a partial amine salt, or a partial amine-metal salt compound or mixtures thereof.

[0072] The pyrophosphate, phosphate ester or mixture of phosphate esters will be reacted with a salting material. The salting material can be a metal to form a metal salt, or an amine to form an amine salt.

[0073] The metal of the metal salt includes aluminium, calcium, magnesium, strontium, chromium, iron, cobalt, nickel, zinc, tin, lead, manganese, silver, or mixtures thereof. In one embodiment the metal is zinc.

[0074] The amine of the amine salt may be represented by R²sN, where each R² is independently hydrogen or a hydrocarbyl group or an ester-containing group, or an ether-containing group, provided that at least one R² group is a hydrocarbyl group or an ester-containing group or an ether-containing group (that is, not NH3). Suitable hydrocarbyl amines include primary amines having 1 to 18 carbon atoms, or 3 to 12, or 4 to 10 carbon atoms, such as methylamine, ethylamine, propylamine, isopropylamine, butylamine and isomers thereof, pentylamine and isomers thereof, hexylamine and isomers thereof, heptylamine and isomers thereof, octylamine and isomers thereof such as isooctylamine and 2-ethylhexylamine, as well as higher amines. Other primary amines include dodecylamine, fatty amines as n-octylamine, n- decylamine, n-dodecylamine, n-tetradecylamine, n-hexadecylamine, n-octadecylamine and oleyamine. Other useful fatty amines include commercially available fatty amines such as “Armeen®” amines (products available from Akzo Chemicals, Chicago, Ill.), such as Armeen® C, Armeen® O, Armeen® OL, Armeen® T, Armeen® HT, Armeen® S and Armeen® SD, wherein the letter designation relates to the fatty group, such as coco, oleyl, tallow, or stearyl groups.

[0075] Secondary amines that may be used include dimethylamine, diethylamine, dipropylamine, dibutylamine, diamylamine, dihexylamine, diheptylamine, methylethylamine, ethylbutylamine, bis-2-ethylhexylamine, N-methyl-l-amino- cyclohexane, Armeen® 2C, and ethylamylamine. The secondary amines may be cyclic amines such as piperidine, piperazine and morpholine.

[0076] Suitable tertiary amines include tri-n-butylamine, tri-n-octylamine, tridecylamine, tri-laurylamine, tri-hexadecylamine, and dimethyloleylamine (Armeen® DMOD). Triisodecylamine or tridecylamine and isomers thereof may be used.

[0077] Examples of mixtures of amines include (i) an amine with 11 to 14 carbon atoms on tertiary alkyl primary groups, (ii) an amine with 14 to 18 carbon atoms on tertiary alkyl primary groups, or (iii) an amine with 18 to 22 carbon atoms on tertiary alkyl primary groups. Other examples of tertiary alkyl primary amines include tertbutylamine, tert-hexylamine, tert-octylamine (such as 1,1 -dimethylhexylamine), tertdecylamine (such as 1,1 -dimethyloctylamine), tertdodecylamine, tert-tetradecylamine, tert-hexadecylamine, tert-octadecylamine, tert-tetracosanylamine, and tert- octacosanylamine. In one embodiment a useful mixture of amines includes “Primene® 81R” or “Primene® JMT.” Primene® 81R and Primene® JMT (both produced and sold by Rohm & Haas) may be mixtures of Cl l to C14 tertiary alkyl primary amines and C18 to C22 tertiary alkyl primary amines, respectively.

[0078] In one embodiment, the amine salt of a phosphorus acid or ester as described above can include an amine with about C_n to about Ci4 tertiary alkyl primary groups or mixtures thereof. In one embodiment the amine salt of a phosphorus compound includes an amine with about C M to about Cis tertiary alkyl primary amines or mixtures thereof. In one embodiment, the amine salt of a phosphorus compound includes an amine with about Cis to about C22 tertiary alkyl primary amines or mixtures thereof.

[0079] In one embodiment, the amine salt of a phosphorus acid or ester as described above can be the reaction product of a C14 to Cis alkylated phosphoric acid with Primene® 81R (produced and sold by Rohm & Haas) which is a mixture of Cn to C14 tertiary alkyl primary amines. In other embodiments, the amine may be an ester-containing amine such as an N-hydrocarbyl-substituted y- or 6-amino(thio)ester, which is therefore a secondary amine. One or both of the O atoms of the ester group may be replaced by sulfur, although typically there may be no sulfur atoms. [0080] There may also be one or more additional substituents or groups at the a, 0, y, or 6 positions of the aminoester. In one embodiment, there are no such substituents. In another embodiment there is a substituent at the 0 position. That is, a substituent at the 0 position of the chain may comprise an ester, thioester, carbonyl, or hydrocarbyl group. The analogous structures for a 6-amino ester will be understood to be encompassed.

[0081] In one embodiment, the material may be a methyl succinic acid diester, with amine substitution on the methyl group. In certain embodiments, the material will be or will comprise a 2-((hydrocarbyl)-aminomethyl succinic acid dihydrocarbyl ester (which may also be referred to as a dihydrocarbyl 2-((hydrocarbyl)aminomethyl succinate).

[0082] The N-hydrocarbyl-substituted y-aminoester or y-aminothioester materials disclosed herein may be prepared by a Michael addition of a primary amine, typically having a branched hydrocarbyl group as described above, with an ethylenically unsaturated ester or thio ester of the type described above. The ethylenic unsaturation, in this instance, would be between the 0 and y carbon atoms of the ester.

[0083] The N-hydrocarbyl-substituted 5-aminoester or 6-aminothioester materials disclosed herein may be prepared by reductive amination of the esters of 5-oxy substituted carboxylic acids or 5-oxy substituted thiocarboxylic acids. They may also be prepared by amination of the esters of 5-halogen substituted carboxylic acids or 5- halogen substituted thiocarboxylic acids, or by reductive amination of the esters of 2- amino substituted hexanedioc acids, or by alkylation of the esters of 2-aminohexane- dioic acids.

[0084] Further detailed description of the N-substituted y-amino ester and details of its synthesis may be found in WO2014/074335, Lubrizol, May 15, 2014. Further detailed description of the N-substituted 6-amino ester and details of its synthesis may be found in PCT application PCT/US2015/027958, Lubrizol, filed April 28, 2015, and US 61/989306, filed May 6, 2015. [0085] The amine, of whatever type, will be reacted to neutralize the acidic group(s) on the phosphorus ester component, which will comprise the pyrophosphate ester as described above as well as any orthophosphate esters that may be present.

[0086] When the amine salt is an amine salt of the phosphate ester described above, the amount of the amine salts used in lubricants may be 0.05 to 2.0 weight percent or 0.75 to 1.5 weight percent or 0.1 to 1.2 weight percent.

[0087] The amount of phosphorous antiwear agent may be suitable to provide phosphorus to the lubricant formulation in an amount of 200 to 3000 parts per million by weight (ppm).

[0088] When the lubricant composition is substantially free of sulfur (less than 250 part per million, or less than 100 part per million, or less than 50 part per million, or less than 25 parts per million, or even completely free) the phosphorous antiwear agent may be a phosphate salt suitable to provide phosphorous to the lubricant formulation in an amount of 100 to 5000 parts per million, or 125 to 3000 parts per million, or 125 to 2000 parts per million, or 125 to 2000 parts per million, or 100 to 200 parts per million.

Antioxidant

[0089] The lubricant additive composition may also include antioxidants, e.g., aromatic amine antioxidants, hindered phenolic antioxidants including ester- containing hindered phenolic antioxidants, and sulfurized olefin antioxidants. These antioxidants may be present in amounts of 0.01 to 5, or 0.15 to 3or 0.2 to 1.5, 0.2 to 1 or 0.25 to 0.7 percent by weight.

[0090] In one embodiment, the lubricant additive composition of the invention includes an aryl amine antioxidant. The aryl amine antioxidant may be a phenyl-a- naphthylamine (PANA) or a hydrocarbyl substituted diphenylamine, or mixtures thereof. The hydrocarbyl substituted diphenylamine may include mono- or di- C4 to C16-, or C6 to C12-, or C9- alkyl diphenylamine. For example, the hydrocarbyl substituted diphenylamine may be octyl diphenylamine, or di-octyl diphenylamine, dinonyl diphenylamine, typically dinonyl diphenylamine.

[0091] When present the aryl amine antioxidant may be present at 0. 1 wt % to 1.2 wt %, or 0.15 wt % to 0.8 wt %, or 0.2 wt % to 0.6 wt % or 0.3 wt % to 0.5 wt %, of the lubricant additive composition. [0092] The hindered phenol antioxidant often contains a secondary butyl and/or a tertiary butyl group as a sterically hindering group. The phenol group is often further substituted with a hydrocarbyl group and/or a bridging group linking to a second aromatic group. Examples of suitable hindered phenol antioxidants include 2, 6-di -tert -butylphenol, 4-methyl-2,6-di-tert-butylphenol, 4-ethyl-2,6-di-tert- butylphenol, 4-propyl-2,6-di-tert-butylphenol or 4-butyl-2,6-di-tert-butylphenol, or 4-dodecyl-2,6-di-tert-butylphenol. In one embodiment, the hindered phenol antioxidant may be an ester and may include, e.g., Irganox™ L-135 from Ciba, or butyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate.

[0093] If present, the hindered phenol antioxidant may be present at 0.1 wt % to 1 wt %, or 0.2 wt % to 0.9 wt % or 0.1 wt % to 0.4 wt %, or 0.4 wt % to 1.0 wt %, of the lubricant additive composition.

[0094] Antioxidants also include sulfurized olefins such as mono-, or disulfides or mixtures thereof. These materials generally have sulfide linkages having 1 to 10 sulfur atoms, for instance, 1 to 4, or 1 or 2. Materials which can be sulfurized to employ as sulfurized antioxidants in the lubricant additive composition can include oils, fatty acids and esters, olefins and polyolefins made thereof, terpenes, or Diels- Alder adducts. Details of methods of preparing some such sulfurized materials can be found in U.S. Pat. Nos. 3,471,404 and 4,191,659.

Sulfur-Free Detergent

[0095] The lubricant additive composition also includes a sulfur-free detergent composition. Sulfur -free detergents may be selected from salicylates, phenates, or salixarate detergents. Typically, such detergents are metal-containing detergents, where the metal may be sodium, potassium, calcium, magnesium or mixtures thereof.

[0096] Sulfur-free metal-containing detergents used in the present invention may be an overbased detergent, a non-overbased detergent, or mixtures thereof. Typically, the detergent is overbased.

[0097] The preparation of metal-containing detergent is known in the art. Patents describing the preparation of overbased metal-containing detergents include U.S. patents 2,501,731; 2,616,905; 2,616,911; 2,616,925; 2,777,874; 3,256,186; 3,384,585; 3,365,396; 3,320,162; 3,318,809; 3,488,284; and 3,629,109. [0098] The metal-containing detergent may be a non-overbased detergent (may also be referred to as a neutral detergent). The TBN of a non-overbased may be 20 to less than 200, or 30 to 100, or 35 to 50 mg KOH/g. The TBN of a non- overbased metal-containing detergent may also be 20 to 175, or 30 to 100 mg KOH/g. [0099] As used herein, the TBN values quoted and associated range of TBN is on “an as is basis,” i.e., containing conventional amounts of diluent oil. Conventional amounts of diluent oil typically range from 30 wt % to 60 wt % (often 40 wt % to 55 wt %) of the detergent component.

[0100] The metal-containing detergent may be an overbased detergent, having, for example, a TBN of greater than 200 mg KOH/g (typically 250 to 600, or 300 to 500 mg KOH/g).

[0101] The overbased metal-containing detergent may be formed by the reaction of a basic metal compound, for example, containing sodium, potassium, calcium or magnesium, and an acidic detergent substrate. The acidic detergent substrate may include an alkyl salicylic acid.

[0102] The basic metal compound is used to supply basicity to the detergent. The basic metal compound is a compound of a hydroxide or oxide of the metal.

[0103] The oxides and/or hydroxides may be used alone or in combination. The oxides or hydroxides may be hydrated or dehydrated, although hydrated is typical. In one embodiment the basic metal compound may be calcium hydroxide, which may be used alone or mixtures thereof with other metal basic compounds. Calcium hydroxide is often referred to as lime. In one embodiment the calcium basic compound may be calcium oxide which may be used alone or mixtures thereof with other metal basic compounds.

[0104] Salicylate detergents are typically derived from p-hydrocarbyl phenols or, generally, alkylpheols. Alkylphenols of this type are carboxylated to form salicylate detergents. Suitable alkylsalicylates include those alkylated with oligomers of propylene, oligomers of butene, especially tetramers and pentamers of n-butenes, as well as those alkylated with alpha-olefins, isomerized alpha-olefins, and polyolefins like polyisobutylene.

[0105] The detergent may be borated or non-borated.

[0106] Chemical structures for salicylate detergents are known to a person skilled in the art. The standard textbook entitled “Chemistry and Technology of Lubricants”, Third Edition, Edited by R. M. Mortier and S. T. Orszulik, Copyright 2010, pages 220 to 223 under the sub-heading 7.2.6 provide general disclosures of said detergents and their structures.

[0107] In one embodiment, the sulfur-free metal-containing detergent may be a sodium, potassium, calcium, or magnesium containing detergent, or mixtures thereof. Such detergents and the preparation thereof are well known in the art but may also include those hereafter developed. The TBN and metal ratios may however, differ slightly. A more detailed description of the expressions “metal ratio”, TBN and “soap content” are known to a person skilled in the art and explained in standard textbooks, such as, for example, “Chemistry and Technology of Lubricants”, Third Edition, Edited by R. M. Mortier and S. T. Orszulik, Copyright 2010, pages 219 to 220 under the sub-heading 7.2.5. Detergent Classification.

[0108] In one embodiment of the present invention, the detergent is a calcium- containing detergent. In one embodiment, the detergent comprises or consists of calcium salicylate. The calcium-containing detergent is included in an amount to deliver up to 2000 ppm of calcium to the composition, or from 100 ppm to 1000 ppm, or 100 ppm to 600 ppm of calcium, or from 100 ppm to 250 ppm, or even from 400 ppm to 750 ppm of calcium.

Other Additives

[0109] The lubricant additive composition can contain additives in addition to those listed above.

[0110] The lubricant additive composition can also contain a poly(meth)acrylate polymer viscosity modifier. As used herein ranges below for the viscosity modifier are measured by GPC using polystyrene standards with a weight average molecular weight ranging from 350 to 100,000.

[OHl] The lubricant additive composition in one embodiment includes a linear poly(meth)acrylate polymer with a weight average molecular weight of 5,000 to 25,000, or 8000 to 20,000.

[0112] The linear poly(meth)acrylate polymer may be present in the lubricant additive composition at about 0.1 wt % to about 5 wt %, or 0.1 wt % to 4 wt %, or 0.2 wt % to 3 wt %, or 0.5 wt % to 3 wt %, or 1.0 wt % to 4 wt %, 0.6 wt% to 4 wt%, or 0.75 wt% to 3 wt%, or 0.2 wt% to 0.75 wt%of the lubricant additive composition. [0113] The poly(meth)acrylate polymer may be derived from a monomer composition comprising:(a) 50 wt % to 95 wt %, or 60 wt % to 80 wt % of an alkyl (meth)acrylate, wherein the alkyl group of the (meth)acrylate has 10 to 15 carbon atoms; (b) 1 wt % to 40 wt %, or 4 wt % to 35 wt % of an alkyl (meth)acrylate, wherein the alkyl group of the (meth)acrylate has 1 to 9 carbon atoms; (c) 1 wt % to 10 wt %, or 1 wt % to 8 wt % of a monomer having dispersant functionality, (d) 0 wt % to 4 wt %, or 0 wt % to 2 wt %, or 0 wt % of a vinyl aromatic monomer (typically styrene); and (e) 0 wt % to 9 wt %, or 0 wt % to 6 wt % of an alkyl (meth)acrylate, wherein the alkyl group of the (meth)acrylate has 16 to 18 carbon atoms. In one embodiment the linear polymer may contain 0 wt % to 20 wt % of 16 to 18 alkyl (meth)acrylate.

[0114] In one embodiment, the linear polymer includes a poly(meth)acrylate (typically a polymethacrylate) with units derived from a mixture of alkyl (meth)acrylate ester monomers containing, (a) 8 to 24, or 10 to 18, or 12 to 15 carbon atoms in the alcohol-derived portion of the ester group and (b) 6 to 11, or 8 to 11, or 8 carbon atoms in the alcohol-derived portion of the ester group, and which have 2- (Cl-4 alkyl)-substituents, and optionally, at least one monomer selected from the group consisting of (meth)acrylic acid esters containing 1 to 7 carbon atoms in the alcohol-derived portion of the ester group and which are different from (meth)acrylic acid esters (a) and (b), vinyl aromatic compounds (or vinyl aromatic monomers); and nitrogen-containing vinyl monomer; provided that no more than 60% by weight, or no more than 50% by weight, or no more than 35% by weight of the esters contain not more than 10 carbon atoms in the alcohol-derived portion of the ester group. The linear polymer of this type is described in more detail in US 6,124,249, or EP 0 937 769 Al paragraphs [0019] and [0031] to [0067], (The “alcohol-derived portion” refers to the “-OR” portion of an ester, when written as R'C(=O)-OR, whether or not it is actually prepared by reaction with an alcohol.) Optionally, the linear polymer may further contain a third monomer. The third monomer may be styrene, or mixtures thereof. The third monomer may be present in an amount 0% to 25% of the polymer composition, or from 1% to 15% of the composition, 2% to 10% of the composition, or even from 1% to 3% of the composition.

[0115] Typically, the mole ratio of esters (a) to esters (b) in the copolymer ranges from 95:5 to 35:65, or 90: 10 to 60:40, or 80:20 to 50:50.

[0116] The esters are usually aliphatic esters, typically alkyl esters. In one embodiment the ester of (a) may be a C12-15 alkyl (meth)acrylate and the ester of (b) may be 2-ethylhexyl (meth)acrylate.

[0117] In one embodiment, the ester groups in ester (a) contain branched alkyl groups. The ester groups may contain 2 to 65%, or 5 to 60% of the ester groups having branched alkyl groups. The branched alkyl groups may be B-branched and may contain 8 to 60, or 8 to 30, or 8 to 16 carbon atoms. For examples branched alkyl groups may be derived from 2-ethylhexanol, 2-butyloctanol, 2-hexyldecanol, 2- octyldodecanol, 2-decyltetradecanol, or mixtures thereof, or commercially available alcohols such as Isofol® branched Guerbet alcohols available from Sasol.

[0118] The Cl-4 alkyl substituents may be methyl, ethyl, and any isomers of propyl and butyl.

[0119] The weight average molecular weight of the linear poly(meth)acrylate may be 45,000 or less, or 35,000 or less, or 25,000 or less, or 8000 to 25,000, or, 10,000 to 35,000, or 12,000 to 20,000.

[0120] The linear polymer may be called a viscosity modifier, or a dispersant viscosity modifier as it may exhibit dispersant functionality. Reference to a “dispersant viscosity modifier” herein is exclusive of dispersants, which are a separate class of compounds. The linear polymer may be used as a sole viscosity modifier (or dispersant viscosity modifier) present at 0.5 wt % to 4 wt % of a linear (meth)acrylic polymer viscosity modifier having dispersant functionality, wherein the linear polymer has a weight average molecular weight of 5,000 to 25,000, or 10,000 to 20,000, and wherein oil the of lubricating viscosity has a kinematic viscosity at 100°C of 4 to 6 cSt (mm2/s) and a viscosity index of 120 to 150.

[0121] The lubricant additive composition in one embodiment may contain only two linear polymer viscosity modifiers having dispersant functionality, wherein the linear polymer has a weight average molecular weight of 5,000 to 25,000, or 10,000 to 20,000.

[0122] In one embodiment, the lubricant additive composition may comprise 0.1 wt% to 4 wt % (or 0.2 wt % to 3 wt %) of a linear (meth)acrylic polymer viscosity modifier having dispersant functionality, wherein the linear polymer has a weight average molecular weight of greater than 25,000 to 400,000 (or to 350,000) or 30,000 to 150,000. The linear (meth)acrylic polymer a weight average molecular weight of greater than 25,000 to 400,000 (or to 350,000) may be considered chemically similar to the linear (meth)acrylic polymer a weight average molecular weight of 5,000 to 25,000 except the weight average molecular weight is different.

[0123] The lubricant additive composition may comprise a linear polymer viscosity modifier having dispersant functionality comprises: 0.1 wt % to 5 wt % (or 1 wt % to 4 wt %) of a linear (meth)acrylic polymer viscosity modifier having dispersant functionality, wherein the linear polymer has a weight average molecular weight of 10,000 to 20,000; and 0.1 wt % to 4 wt % (or 1 wt % to 3 wt %) of a linear (meth)acrylic polymer viscosity modifier having dispersant functionality, wherein the linear polymer has a weight average molecular weight of greater than 20,000 to 250,000 (or 30,000 to 150,000).

[0124] As described hereinafter, the molecular weight of the viscosity modifier has been determined using known methods, such as GPC analysis using polystyrene standards. Methods for determining molecular weights of polymers are well known. The methods are described for instance: (i) P.J. Flory, “Principles of star polymer Chemistry”, Cornell University Press 91953), Chapter VII, pp 266-315; or (ii) “Macromolecules, an Introduction to star polymer Science”, F. A. Bovey and F. H. Winslow, Editors, Academic Press (1979), pp 296-312.

[0125] In one embodiment, the lubricant additive can also include a boron containing compound.

[0126] The lubricant additive composition can contain a boron-containing compound in an amount sufficient to provide from about 75ppm to about 500 ppm of boron to the lubricant additive composition, or from about 85 to about 450 ppm or about 95 to about 350 ppm boron, or from about 100 to about 400ppm boron to the lubricant additive composition.

[0127] The boron can be delivered by many types of boron-containing compounds.

[0128] The boron-containing compound can be a dispersant post-treated with a source of boron, as described above.

[0129] The boron-containing compound can include boron containing friction modifiers, such as, for example, borated fatty epoxides, borated glycerol esters, and borated alkoxylated fatty amines.

[0130] The boron containing compound can also include borated detergents. The borated detergents can include, for example, overbased borated materials, which are described in U.S. Patents 5,403,501 and 4,792,410.

[0131] The boron containing compound can also include a borate ester. The borate ester may be a compound represented by one or more of the formulae: wherein each R can be, independently a hydrocarbyl group, as that term is defined herein, and any two adjacent R groups may together form a cyclic group. Mixtures of two or more of the foregoing may be used. The total number of carbon atoms in the R groups in each formula should be sufficient to render the compound soluble in the base oil. Generally, the total number of carbon atoms in the R groups is at least about 3, and in one embodiment at least about 5, and in one embodiment at least about 8. There is no limit to the total number of carbon atoms in the R groups that is required, but a practical upper limit is about 400 or about 500 carbon atoms.

[0132] In embodiments, each R can independently be a hydrocarbyl group containing 1 to 14, or from 2 to 13 or even 3 to 10 or 12 carbon atoms, provided the sum total number of carbon atoms in all R is 3 or more, preferably 4 or more and even more preferably 6 or more. In some embodiments, each R, independently, can be a C3 to C22, or C3 to Cl 8, or C3 to C12 alkyl. Examples of useful R groups include isopropyl, n-butyl, isobutyl, amyl, 4-methyl-2-pentyl, 2-ethyl-l -hexyl, isooctyl, decyl, dodecyl, 2-propylheptyl, tetradecyl, 2-pentenyl, dodecenyl, phenyl, naphthyl, alkylphenyl, and the like.

[0133] Suitable examples of the borate ester include, for example, tripropyl borate, tributyl borate, tripentyl borate, trihexyl borate, triheptyl borate, trioctyl borate, trinonyl borate and tridecyl borate. Other borate ester examples can include, for example, the compound of formula I, wherein each R is, independently, a C3 to C22, or C3 to C18, or C3 to C12 alkyl, such as, for example, tri-2-ethylhexyl borate, tris(2 -propylheptyl) borate and mixtures thereof. In an embodiment the borate ester can be a C8 borate ester, or a CIO borate ester. In one embodiment the borate ester can be tris(2-propylheptyl) borate. In some embodiments, the borate ester can be tri - 2-ethylhexyl borate.

[0134] In one embodiment, the borated ester can be represented by the formula B(OC5H11)3 or B(OC4H9)3. In one embodiment, the borated ester can be tri-n-butyl borate.

[0135] In one embodiment, the borated ester can be a phenolic compound represented by the formula:

VII wherein in formula VII: Ri, R2, R3 and R4 are independently hydrocarbyl groups of 1 to about 12 carbon atoms; and R5 and Re are independently alkylene groups of 1 to about 6 carbon atoms, and in one embodiment about 2 to about 4 carbon atoms, and in one embodiment about 2 or about 3 carbon atoms. In one embodiment, Ri and R2 independently contain 1 to about 6 carbon atoms, and in one embodiment each is a t- butyl group. In one embodiment, R3 and R4 are independently hydrocarbyl groups of about 2 to about 12 carbon atoms, and in one embodiment about 8 to about 10 carbon atoms. In one embodiment, R5 and R6 are independently — CH2CH2 — or — CH2CH2CH2 -.

[0136] In one embodiment, the borated ester can be a compound represented by the formula: wherein in formula IX, each R is independently hydrogen or a hydrocarbyl group. Each of the hydrocarbyl groups may contain from 1 to about 12 carbon atoms, and in one embodiment 1 to about 4 carbon atoms. An example is 2,2'-oxy-bis-(4,4,6- timethyl-l,3,2-dioxaborinane).

[0137] The borate ester may be employed in the lubricant additive composition at about 0.2 or 0.3 to about 2.0 wt.% based on the weight of the lubricant additive composition, or in some cases about 0.35 to 2.0 wt.%, and in one embodiment from about 0.25 to about 1.0 wt.%, and in one embodiment about 0.25 to about 0.75 wt.%.

[0138] In one embodiment, the lubricant additive composition can include an ester of a polyol and an aliphatic carboxylic acid containing 12 to 24 carbon atoms. [0139] Polyols include diols, triols, and alcohols with higher numbers of alcoholic OH groups. Polyhydric alcohols include ethylene glycols, including di-, tri - and tetraethylene glycols; propylene glycols, including di-, tri- and tetrapropylene glycols; glycerol; butane diol; hexane diol; sorbitol; arabitol; mannitol; sucrose; fructose; glucose; cyclohexane diol; erythritol; and pentaerythritols, including di- and tripentaerythritol; preferably, diethylene glycol, triethylene glycol, glycerol, sorbitol, pentaerythritol and dipentaerythritol.

[0140] The aliphatic carboxylic acids which form the esters are those acids containing 12 to 24 carbon atoms. Such acid can be characterized by the following general formula R1 — (CO)OH, wherein R1 is a hydrocarbyl group, which can be a straight chain hydrocarbyl group, a branched chain or cyclic-containing hydrocarbyl group, or mixtures thereof. Straight chain hydrocarbyl group containing 12 to 24 carbon atoms are preferred, for instance, 14 to 20 or 16 to 18 carbon atoms. Such acids can be used in combination with acids with more or fewer carbon atoms as well. [0141] Generally, the acid R1 — (CO)OH is a monocarboxylic acid since polycarboxylic acids tend to form polymeric products if the reaction conditions and amounts of reactants are not carefully regulated. Mixtures of monocarboxylic acids and minor amounts of dicarboxylic acids or anhydrides, however, can be used in preparing the esters. Examples of carboxylic acids include dodecanoic acid, stearic acid, lauric acid, behenic acid, and oleic acid.

[0142] The foregoing esters are in particular the monoesters of such polyols and such carboxylic acids. A preferred ester is glycerol monooleate. It is to be understood that glycerol monooleate, as is the case with other such materials, in its commercially available grade, is a mixture which includes such materials as glycerol, oleic acid, other long chain acids, glycerol dioleate, and glycerol trioleate. The commercial material is believed to include about 60 ± 5 percent by weight of the chemical species "glycerol monooleate," along with 35 ± 5 percent glycerol di oleate, and less than about 5 percent trioleate and oleic acid. The amounts of the monoesters, described below, are calculated based on the actual, corrected, amount of polyol monoester present in any such mixture.

[0143] The amount of the foregoing ester in the lubricant additive composition is typically on the order of from about 0.01 to about 1.0 wt.% but can also be from about 0.05 to about 0.5 or 0.8 or about 0.1 to about 0.6 wt.% of the lubricant additive composition.

[0144] In addition to the foregoing ester, the lubricant additive composition can also contain an ester of an alcohol, and an aliphatic carboxylic acid containing about 4 to about 8 carbon atoms.

[0145] The alcohol includes both monohydric alcohol and polyhydric alcohol (i.e., polyol). The carbon atoms of the alcohol may be linear, branched, or mixtures thereof.

[0146] Suitable polyols are the same as mentioned above.

[0147] When branched, the alcohol may be a Guerbet alcohol, or mixtures thereof. The Guerbet alcohols may have alkyl groups including the following: 1) alkyl groups containing C15-16 polymethylene groups, such as 2-C1-15 alkylhexadecyl groups (e.g., 2-octylhexadecyl) and 2-alkyl-octadecyl groups (e.g., 2- ethyloctadecyl, 2-tetradecyl-octadecyl and 2-hexadecyloctadecyl); 2) alkyl groups containing C13-14 polymethylene groups, such as 1-C1-15 alkyl -tetradecyl groups (e.g., 2-hexyltetradecyl, 2-decyltetradecyl and 2-undecyltridecyl) and 2-C1-15 alkylhexadecyl groups (e.g., 2-ethyl-hexadecyl and 2-dodecylhexadecyl); 3) alkyl groups containing CIO-12 polymethylene groups, such as 2-C1-15 alkyl-dodecyl groups (e.g., 2-octyldodecyl) and 2-C1-15 alkyl-dodecyl groups (2-hexyldodecyl and 2- octyldodecyl), 2-C1-15 alkyl-tetradecyl groups (e.g., 2-hexyltetradecyl and 2- decyltetradecyl); 4) alkyl groups containing C6-9 polymethylene groups, such as 2- Cl-15 alkyl-decyl groups (e.g., 2-octyldecyl) and 2,4-di-Cl-15 alkyl-decyl groups (e.g., 2-ethyl-4-butyl-decyl group); 5) alkyl groups containing Cl -5 polymethylene groups, such as 2-(3-methylhexyl)-7-methyl-decyl and 2-(l,4,4-trimethylbutyl)- 5,7,7-trimethyl-octyl groups; and 6) and mixtures of two or more branched alkyl groups, such as alkyl residues of oxoalcohols corresponding to propylene oligomers (from hexamer to undecamer), ethylene/propylene (molar ratio 16: 1-1 : 11) oligomers, iso-butene oligomers (from pentamer to octamer), C5-17 a-olefin oligomers (from dimer to hexamer).

[0148] Examples of a suitable branched monohydric alcohol include 2- ethylhexanol, 2-butyloctanol, 2-hexyldecanol, 2-octyldodecanol, 2-decyltetra- decanol, iso-tridecanol, iso-octanol, oleyl alcohol, Guerbet alcohols, or mixtures thereof. Examples of a monohydric linear alcohol include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, or mixtures thereof. In one embodiment, the monohydric alcohol contains 6 to 30, or 8 to 20, or 8 to 15 carbon atoms (typically 8 to 15 carbon atoms).

[0149] The aliphatic carboxylic acids which form the esters are those acids containing 4 to 8 carbon atoms. While aliphatic, the aliphatic carboxylic acids can contain ethylenic unsaturation along the C4 to C8 alkyl group backbone. In addition, such acids can be mono-carboxylic or di-carboxylic acids or anhydrides, or mixtures thereof. Examples of carboxylic acids include, for example, succinic acid, maleic acid, fumaric acid, glutaconic acid, glutaric acid, adipic acid, citraconic acid, mesaconic acid, pimelic acid, suberic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid and the like.

[0150] A particularly preferred ester can be an adipate ester, such as, for example, a C8-13 or C8-12 adipate ester, such as diisoctyl adipate or di-tridecyl adipate. Other esters can include, for example, pentaerythritol esters, neo-pentyl esters and tri-methylol esters.

[0151] The amount of the foregoing ester in the lubricant additive composition is typically on the order of from about 0.1 to about 3.0 wt.% but can also be from about 0.2 to about 2.5 or about 0.3 to about 2.0 wt.% of the lubricant additive composition.

[0152] The carboxylic esters are prepared by the very well-known reaction of at least one carboxylic acid (or reactive equivalent thereof, such as ester, halide, or anhydride) with at least one of the above-described hydroxy compounds.

[0153] Another component of the lubricant additive composition can be a metal deactivator. Examples of such materials include 2,5-dimercapto-l,3,4- thiadiazole and/or derivatives thereof. Such materials are described in European Patent Publication 0761805, incorporated herein by reference. [0154] The metal deactivators that are useful herein reduce the corrosion of metals, such as copper. Metal deactivators are also referred to as metal passivators. These metal deactivators are typically nitrogen and/or sulfur containing heterocyclic compounds, such as dimercaptothiadi azoles, triazoles, aminomercaptothiadiazoles, imidazoles, thiazoles, tetrazoles, hydroxyquinolines, oxazolines, imidazolines, thiophenes, indoles, indazoles, quinolines, benzoxazines, dithiols, oxazoles, oxatriazoles, pyridines, piperazines, triazines, and derivatives of any one or more thereof. The metal deactivator preferably comprises at least one triazole, which may be substituted or unsubstituted. Examples of suitable compounds are benzotri azole, alkyl-substituted benzotriazole (e.g., tolyltriazole, ethylbenzotriazole, hexylbenzotriazole, octylbenzotriazole, etc.), aryl -substituted benzotriazole (e.g., phenol benzotriazoles, etc.), and alkylaryl- or arylalkyl-substituted benzotriazole and substituted benzotriazoles where the substituent may be hydroxy, alkoxy, halo (especially chloro), nitro, carboxy and carb oxy alkoxy. Preferably, the triazole is a benzotriazole or an alkylbenzotri azole in which the alkyl group contains 1 to about 20 carbon atoms, preferably 1 to about 8 carbon atoms. Benzotriazole and tolyltriazole are useful.

[0155] In one embodiment, the metal deactivator is the reaction product of a dispersant with a dimercaptothiadiazole. The dispersants may be generally characterized as the reaction products of carboxylic acids with amines and/or alcohols. These reaction products are commonly used in the lubricant arts as dispersants and are sometimes referred to generically as dispersants despite the fact that they may have other uses in addition to or instead of that as dispersants. The carboxylic dispersants include succinimide dispersants, ester type dispersants and the like. Succinimide dispersants are generally the reaction of a polyamine with an alkenyl succinic anhydride or acid. Ester type dispersants are the reaction product of an alkenyl succinic anhydride or acid with a polyol compound. The reaction product may then be further treated with an amine such as a polyamine. Examples of useful dispersants are disclosed in U.S. Pat. Nos. 3,219,666 and 4,234,435, incorporated herein by reference. Useful dispersants also include the ashless dispersants discussed below. Generally, the reaction occurs between the dispersant and the dimercaptothiadiazole by mixing the two and heating to a temperature above about 100°C. U.S. Pat. Nos. 4,140,643 and 4,136,043 describe compounds made by the reaction of such dispersants with a dimercaptothiadiazole. These patents are incorporated herein by reference for their disclosure of dispersants, dimercaptothiadiazole, the method for reacting the two and the products obtained from such reaction.

[0156] In one embodiment, the metal deactivator is the reaction product of a phenol with an aldehyde and a dimercaptothiadiazole. The phenol is preferably an alkyl phenol wherein the alkyl group contains at least about 6, preferably from 6 to about 24, more preferably about 6, or about 7, to about 12 carbon atoms. The aldehyde is preferably an aldehyde containing from 1 to about 7 carbon atoms or an aldehyde synthon, such as formaldehyde. Preferably, the aldehyde is formaldehyde or paraformaldehyde. The aldehyde, phenol and dimercaptothiadiazole are typically reacted by mixing them at a temperature up to about 150°C, preferably about 50°C to about 130°C, in molar ratios of about 0.5 to about 2 moles of phenol and about 0.5 to about 2 moles of aldehyde per mole of dimercaptothiadiazole. Preferably, the three reagents are reacted in equal molar amounts.

[0157] In one embodiment, the metal deactivator is a bis(hydrocarbyldithio)thiadiazole. Preferably each hydrocarbyl group is independently an alkyl, aryl or aralkyl group, having from 6 to about 24 carbon atoms. Each hydrocarbyl can be independently t-octyl, nonyl, decyl, dodecyl or ethylhexyl. The metal deactivator can be bis-2,5-tert-octyl-dithio-l,3,4-thiadiazole or a mixture thereof with 2-tert-octylthio-5-mercapto-l,3,4-thiadiazole. These materials are available commercially under the trade name of Amoco 150, which is available from Amoco Chemical Company. These dithiothiadi azole compounds are disclosed as Component (d) in PCT Publication WO 88/03551, incorporated by reference for its disclosure of dithiothiadi azole compounds. In the preferred embodiments the metal deactivator is a dimercaptothiadiazole derivative. The following D-l and D-2 are specific examples.

Example D-l

[0158] 2,5-dimercapto-l,3,4-thiadiazole oxidatively coupled with t-nonyl mercaptan; 100% chemical, 36% S, 64% N.

Example D-2

[0159] Heptylphenol coupled with 2,5-dimercapto-l,3,4-thiadiazole using formaldehyde (the thiadiazole is generated in situ); 20% oil, 17.75% S, 5.5% N.

[0160] When used, the amount of metal deactivator in the lubricant additive composition can be generally in the range of about 0.01 to about 0.5 wt.% by weight of the lubricant additive composition. In some embodiments, the amount of the metal deactivator can be in the range of about 0.02 to about 0.42 wt.% or about 0.03 to about 0.33 wt.% or about 0.04 to about 0.24 wt.% by weight of the lubricant additive composition.

[0161] Another component of the present invention can be a borated epoxide containing 12-24 carbon atoms. This material can alternatively be described as a borate ester of a vicinal diol containing 12 to 24 carbon atoms. Such a material may be represented by the structures: wherein each of R¹, R², R³, and R⁴ are independently hydrogen or an aliphatic radical, or any two thereof together with the carbon atom or atoms to which they are attached form a cyclic radical. Preferably at least one of the R groups can be an alkyl group containing at least 8 or at least 10 carbon atoms. In one embodiment one of the R groups can be such an alkyl group and the remaining R groups are hydrogen. Borated epoxides are described in detail in U.S. Pat. No. 4,584,115. Borated epoxides are generally prepared by reacting an epoxide with a boron source such as boric acid or boron tri oxide. Borated epoxides are not themselves epoxides but are the ring-opened boron-containing reaction products of epoxides. Suitable epoxides include commercial mixtures of C14-16 or C14-18 or C16-18 epoxides, which can be purchased from Elf-Atochem or Union Carbide and which can be prepared from the corresponding olefins by known methods. Purified epoxy compounds such as 1,2- epoxyhexadecane can be purchased from Aldrich Chemicals. The borated compounds are prepared by blending the boron compound and the epoxide and heating them at a suitable temperature, typically 80° to 250°C, until the desired reaction has occurred. An inert liquid, such as toluene, xylene, or dimethylformamide can be used as a reaction medium. Water is formed and is typically distilled off during the reaction. Alkaline reagents can be used to catalyze the reaction. A preferred borated epoxide can be the borated epoxide of a predominantly 16 carbon olefin. The amount of the borate epoxide can be 0.01 or 0.05 to 0.5 or 1.0 parts by weight of the composition, or alternatively 0.1 to 0.9 percent.

[0162] The lubricant additive composition preferably exhibits an electrical conductivity of up to 1x10-9 S/cm as measured by ASTM D2624, or from 9.5x10-10 S/cm, or from 9x10-10 S/cm, or from 8.5x10-10 S/cm, or from 8x10-10 S/cm, or from 7.0x10-10 S/cm as measured by ASTM D2624, or from 6.5x10-10 S/cm, or 6.0x10- 10 S/cm or 5.5x10-10 S/cm or 5.0x10-10 S/cm conductivity at 100°C and 500 V. It is highly preferably that the lubricant additive composition has no conductivity, but practically speaking conductivities on the order of 4.0x10-10 or 4.5x10-10 at 100°C may be achievable.

[0163] In an embodiment, the lubricant additive composition is substantially free of friction modifiers. In some embodiments, the lubricant additive composition is completely free of friction modifiers.

[0164] The lubricant additive composition may be in the form of a concentrate and/or a fully formulated lubricant when added to a base oil. That is, the lubricant additive composition can be added to a base oil to prepare a lubricating composition. Base Oil

[0165] The base oil may be defined as specified in the American Petroleum Institute (API) Base Oil Interchangeability Guidelines. The five base oil groups are as follows: Group I (sulphur content >0.03 wt %, and/or <90 wt % saturates, viscosity index 80-120); Group II (sulphur content <0.03 wt %, and >90 wt % saturates, viscosity index 80-120); Group III (sulphur content <0.03 wt %, and >90 wt % saturates, viscosity index >120); Group IV (all polyalphaolefins (PAOs)); and Group V (all others not included in Groups I, II, III, or IV). The base oil can include, for example, an API Group I, Group II, Group III, Group IV, Group V oil or mixtures thereof.

[0166] Often the base oil is an API Group I, Group II, Group III, Group IV oil or mixtures thereof. Alternatively, the base oil can be an API Group II, Group III or Group IV oil or mixtures thereof.

[0167] In one embodiment, the base oil may be prepared by a Fischer-Tropsch gas-to-liquid synthetic procedure as well as other gas-to-liquid oils.

[0168] In one embodiment, the base oil may be an API Group IV oil. The amount of Group IV oil may be 0 wt % to 20 wt %, or 0.1 wt % to 20 wt %, or 1 wt % to 15 wt %, or 5 to 10 wt % of the lubricant additive composition. [0169] The amount of the base oil present is typically the balance remaining after subtracting from 100 wt % the sum of the amount of lubricant additive composition of the present invention. If the lubricant additive composition is in the form of a concentrate (which may be combined with base oil to form, in whole or in part, a finished lubricant), the ratio of the lubricant additive composition to the base oil and/or to diluent oil include the ranges of 1 :99 to 99: 1 by weight, or 2:98 to 98:2, or 5:95 to 95:5, or 10:90 to 90: 10, or 15:85 to 85: 15, or 20:80 to 80:20 by weight.

[0170] A lubricating composition containing the lubricant additive composition may have a kinematic viscosity at 40°C by ASTM D445 of from 10 cSt to 30 cSt, or for example, from 14 cSt to 25 cSt, or even 15 cSt to 22 cSt, or from 9 cSt to 25 or 22 cSt, or, for example, from 10 cSt to 25 or 22 cSt, or even from 14 cSt to 25 or 22 cSt, or from 18 cSt to 22 cSt.

[0171] A lubricating composition containing the lubricant additive composition may have a kinematic viscosity at 100 °C by ASTM D445 of between 2 and 25 cSt A lubricating composition containing the lubricant additive composition may have a kinematic viscosity at 100 °C by ASTM D445 of between 2 and 15 cSt. A lubricating composition containing the lubricant additive composition may have a kinematic viscosity at 100 °C by ASTM D445 of between 2 and 12 cSt. A lubricating composition containing the lubricant additive composition may have a kinematic viscosity at 100 °C by ASTM D445 of between 2 and 9 cSt. A lubricating composition containing the lubricant additive composition may have a kinematic viscosity at 100 °C by ASTM D445 of between 2 and 7 cSt. A lubricating composition containing the lubricant additive composition may have a kinematic viscosity at 100 °C by ASTM D445 of between 2 and 6 cSt. A lubricating composition containing the lubricant additive composition may have a kinematic viscosity at 100 °C by ASTM D445 of between 2 and 4 cSt.

[0172] The lubricant additive composition will be suitable for lubricating a driveline of an electric vehicle, and in particular, a gearbox of an electric motor in the electric vehicle when in the form of a lubricating composition. In particular, the lubricant additive composition will be suitable for lubricating a transmission in a vehicle with an electric motor, which may be a full electric vehicle or a hybridelectric vehicle having both an electric motor and an engine powered by hydrocarbon or other fuels.

[0173] In particular, the disclosed technology provides a method of lubricating a driveline power transmitting device, comprising supplying thereto a lubricating composition as described herein, that is, containing base oil, succinimide dispersant, azole corrosion inhibitor, phosphorus antiwear compound, and antioxidant, and operating the driveline power transmitting device for a sufficient period to allow the lubricating composition to achieve the improved results as described herein.

[0174] In particular, the disclosed technology provides a method of lubricating a driveline power transmitting device, comprising supplying thereto a lubricating composition as described herein, that is, containing base oil, succinimide dispersant, azole corrosion inhibitor, phosphorus antiwear compound, an antioxidant, and viscosity modifier, and operating the driveline power transmitting device for a sufficient period to allow the lubricating composition to achieve the improved results as described herein.

[0175] The driveline power transmitting device may comprise at least two gears as in a gearbox of a vehicle (e.g., a manual transmission) or in an axle or differential, or in other driveline power transmitting devices. The driveline power transmitting device may also include bearings. The rolling elements of the bearings may be cylindrical or ball in design. Lubricated gears may include amboid, or spiral bevel, or more commonly hypoid gears, such as those for example in a drive axle. The axles may have a gear ratio of 2: 1 to 8: 1, and the ring gear maybe be approximately 13 to 64 cm in diameter. The axle may incorporate an open differential or some type of traction enabling device. The axle may be part of a drivetrain with one or more drive axles, such as a tandem or tridem design, in which the axles may be coupled together with a power divider. Application of these axles includes light, medium and heavy duty vehicles (e.g., vocational or line haul service), and could be used on or off highway. The axle may be from a traditional petroleum powered vehicle, may be from an electrically driven vehicle, or a hybrid thereof. The electrically driven axle can combine an electric motor, power electronics and transmission in a unit directly powering the vehicle's axle.

[0176] One aspect is therefore a method of lubricating an electric vehicle comprising supplying to a driveline of the electric vehicle a lubricating composition containing the lubricant additive composition as described herein and operating the driveline.

[0177] Another aspect is a method of lubricating a transmission, and particularly a transmission in a vehicle with an electric motor, comprising supplying to the transmission a lubricating composition containing the lubricant additive composition as described herein, and operating the transmission. [0178] The lubricant should be able to meet the aspects expected of it in normal operation of the driveline power transmitting device.

[0179] The transmissions in which the lubricant additive composition may be suitable include automatic transmissions and dual clutch transmissions. The transmission may or may not include a shifting clutch, and, where the transmission includes a shifting clutch, the clutch may be a dry clutch or a wet clutch. In one embodiment, the lubricant may be used on a transmission that does not contain a shifting clutch. In another embodiment, the lubricant additive composition may be employed in a transmission having a wet clutch. In a further embodiment, the lubricant additive composition may be employed on a transmission having a dry clutch.

[0180] The driveline device may be a manual transmission that may or may not contain a synchronizer system, or an axle. In one embodiment the driveline device contains a synchronizer, or axle.

[0181] In one embodiment, the driveline device contains a synchronizer. The synchronizer system may have an operating surface comprising brass, carbon, molybdenum, phenolic resin, or a sintered metal (typically bronze), or mixtures thereof.

[0182] As used herein, the term “condensation product” is intended to encompass esters, amides, imides and other such materials that may be prepared by a condensation reaction of an acid or a reactive equivalent of an acid (e.g., an acid halide, anhydride, or ester) with an alcohol or amine, irrespective of whether a condensation reaction is actually performed to lead directly to the product. Thus, for example, a particular ester may be prepared by a transesterification reaction rather than directly by a condensation reaction. The resulting product is still considered a condensation product.

[0183] The amount of each chemical component described is presented exclusive of any solvent or diluent oil, which may be customarily present in the commercial material, that is, on an active chemical basis, unless otherwise indicated. However, unless otherwise indicated, each chemical or composition referred to herein should be interpreted as being a commercial grade material which may contain the isomers, by-products, derivatives, and other such materials which are normally understood to be present in the commercial grade.

[0184] As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl group" is used in its ordinary sense, which is well-known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character. Examples of hydrocarbyl groups include:

[0185] hydrocarbon substituents, that is, aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic-, aliphatic-, and alicyclic- substituted aromatic substituents, as well as cyclic substituents wherein the ring is completed through another portion of the molecule (e.g., two substituents together form a ring);

[0186] substituted hydrocarbon substituents, that is, substituents containing non-hydrocarb on groups which, in the context of this invention, do not alter the predominantly hydrocarbon nature of the substituent (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulfoxy); [0187] hetero substituents, that is, substituents which, while having a predominantly hydrocarbon character, in the context of this invention, contain other than carbon in a ring or chain otherwise composed of carbon atoms and encompass substituents as pyridyl, furyl, thienyl and imidazolyl. Heteroatoms include sulfur, oxygen, and nitrogen. In general, no more than two, or no more than one, nonhydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl group; alternatively, there may be no non-hydrocarbon substituents in the hydrocarbyl group.

[0188] It is known that some of the materials described above may interact in the final formulation, so that the components of the final formulation may be different from those that are initially added. For instance, metal ions (of, e.g., a detergent) can migrate to other acidic or anionic sites of other molecules. The products formed thereby, including the products formed upon employing the composition of the present invention in its intended use, may not be susceptible of easy description. Nevertheless, all such modifications and reaction products are included within the scope of the present invention; the present invention encompasses the composition prepared by admixing the components described above.

[0189] As used herein, the term "about" means that a value of a given quantity is within ±20% of the stated value. In other embodiments, the value is within ±15% of the stated value. In other embodiments, the value is within ±10% of the stated value. In other embodiments, the value is within ±5% of the stated value. In other embodiments, the value is within ±2.5% of the stated value. In other embodiments, the value is within ±1% of the stated value. [0190] Additionally, as used herein, the term "substantially" means that a value of a given quantity is within ±10% of the stated value. In other embodiments, the value is within ±5% of the stated value. In other embodiments, the value is within ±2.5% of the stated value. In other embodiments, the value is within ±1% of the stated value.

[0191] In different embodiments, the lubricating composition may have a composition as described in the following table:

[0192] The invention herein is useful for lubricating an automatic transmission for a hybrid electric vehicle, which may be better understood with reference to the following clauses:

[0193] CLAUSE 1 : A lubricant composition comprising (a) an oil of lubricating viscosity; (b) a dispersant; (c) a triazole corrosion inhibitor; (d) a phosphorous containing antiwear compound; (e) an antioxidant; and (f) a sulfur-free detergent; wherein the lubricant composition contains no more than 40 ppm sulfur, or no more than 30 ppm sulfur, or no more than 20 ppm sulfur.

[0194] CLAUSE 2: The lubricant composition of clause 1, wherein the sulfur- free detergent comprises or consists of a salicylate detergent.

[0195] CLAUSE 3 : The lubricant composition of any preceding clause, wherein the sulfur-free detergent comprises or consists of calcium salicylate and the calcium salicylate detergent is present in an amount sufficient to deliver up to 2000 ppm, or 100 ppm to 1000 ppm, or 100 ppm to 600 ppm, or 100 ppm to 250 ppm, or 400 ppm to 750 ppm of calcium to the lubricant composition.

[0196] CLAUSE 4: The lubricant composition of any preceding clause, wherein the phosphorous antiwear compound comprises a dialkylphosphite having the formula: wherein R3 and R4 are independently alkyl groups with 1 to 24 carbon atoms.

[0197] CLAUSE 5: The lubricant composition of clause 4, wherein the dialkyl phosphite comprises or consists of dibutyl hydrogen phosphite.

[0198] CLAUSE 6: The lubricant composition of any preceding clause, wherein the phosphorous containing anti wear compound comprises or consists of a phosphonate ester.

[0199] CLAUSE 7: The lubricant composition of the preceding clause, wherein the phosphonate ester comprises the reaction product of (a) a monomeric phosphorous acid or an ester thereof with (b) at least two alkylene diols: a first alkylene diol (i) having two hydroxy groups in a 1, 4 or 1, 5 or 1, 6 relationship and a second alkylene diol (ii) being an alkyl -substituted 1, 3 -propylene diol with one or more of the alkyl substituents thereof being on one or more of the carbon atoms of the propylene unit, the total number of carbon atoms in the alkyl-substituted 1, 3-propylene diol being about 5 to about 12; wherein the relative molar amounts of monomeric phosphorous acid or ester thereof (a) and the total of the alkylene diols (b) are in a ratio of about 0.9: 1.1 to about 1.1 :0.9; and wherein the relative molar amounts of the first alkylene diol (i) and the alkyl-substituted 1, 3-propylene diol (ii) are in a ratio of about 30:70 to about 65:35.

[0200] CLAUSE 8: The lubricant composition of any preceding clause, wherein the dispersant comprises or consists of a succinimide dispersant having a number average molecular weight of 750 to 2200 or 750 to 1600 or 950 to 1550.

[0201] CLAUSE 9: The lubricant composition of any of clauses 1 to 7, wherein the dispersant comprises or consist of an olefin polymer dispersant.

[0202] CLAUSE 10: The lubricant composition of clause 9, wherein the dispersant comprises or consists of an ethylene/propylene copolymer dispersant.

[0203] CLAUSE 11 : The lubricant composition of any of clauses 1 to 8, wherein the dispersant comprises a borated PIB Succinimide dispersant having a number average molecular weight of 1000. [0204] CLAUSE 12: The lubricant composition of clause 11, wherein the dispersant comprises a non-borated PIB Succinimide dispersant having a number average molecular weight of 1550.

[0205] CLAUSE 13: The lubricant composition of any preceding clause, wherein the dispersant comprises a polyisobutylene succinic anhydride (PIBSA) prepared by a thermal process.

[0206] CLAUSE 14: The lubricant composition of any preceding clause, wherein the triazole corrosion inhibitor comprises or consist of 1,2,4-triazole.

[0207] CLAUSE 15: The lubricant composition of any preceding clause, wherein the triazole corrosion inhibitor comprises or consist of N,N-Bis(2-ethylhexyl)- [(l,2,4-triazol-l-yl)methyl]amine.

[0208] CLAUSE 16: The lubricant composition of any of clauses 1 to 13, wherein the triazole corrosion inhibitor comprises or consists of a tolutriazole derivative.

[0209] CLAUSE 17: The lubricant composition of any of claims 1 to 13, wherein the triazole corrosion inhibitor comprises or consists of bis(2-ethylhexyl)- [(l,2,4-triazol-l-yl)methyl]amine.

[0210] CLAUSE 18: The lubricant composition of any preceding clause, wherein the antioxi-dant comprises or consists of an aryl amine antioxidant.

[0211] CLAUSE 19: The lubricant composition of any preceding clause, wherein the antioxidant comprises or consists of a phenyl-a-naphthylamine (PANA).

[0212] CLAUSE 20: The lubricant composition of any preceding clause, wherein the antioxidant comprises or consists of a hydrocarbyl substituted diphenylamine.

[0213] CLAUSE 21: The lubricant composition of any preceding clause, wherein the antioxi-dant is selected from the group consisting of octyl diphenylamine, or di-octyl diphenylamine, dinonyl diphenylamine or mixtures thereof.

[0214] CLAUSE 22: The lubricant composition of any preceding clause, wherein the lubricant composition comprises: 0.5 wt% to 5 wt% of the dispersant; 0.01 wt% to 0.11 wt% of the triazole corrosion inhibitor; 0.05 wt% to 2 wt% of the phosphorous antiwear compound; 0.2 wt% to 1.2 wt% of the antioxidant; and 0.1 wt% to 1.0 wt% of the sulfur-free detergent.

[0215] CLAUSE 23: The lubricant composition of any preceding clause, wherein the lubricant composition comprises: 1.0 wt% to 3 wt% of the dispersant; 0.01 wt% to 0.11 wt% of the triazole corrosion inhibitor; 0.05 to 1 wt% of the phosphorous antiwear compound; or 0.2 wt % to 1.0 wt %, of the antioxidant; and 0.2 wt% to 0.8wt% of the sulfur-free detergent.

[0216] CLAUSE 24: The lubricant composition of any preceding clause, wherein the lubricant composition comprises: 0.2. wt% to 3 wt% of the dispersant; 0.01 wt% to 0.11 wt% of the triazole corrosion inhibitor; 0.1 wt % to 0.5 wt% of the phosphorous antiwear compound; or 0.2 wt % to 0.7 wt % of the antioxidant; and or 0.2 wt % to 0.5 wt % of the sulfur-free detergent.

[0217] CLAUSE 25: The lubricant composition of any preceding clause, wherein the lubricant composition comprises: 1 to 2 wt% of the dispersant; 0.01 wt% to 0.11 wt% of the triazole corrosion inhibitor; 1 to 2 wt% of the phosphorous antiwear compound; 0.2 wt % to 0.4 wt % of the antioxidant; and 0.2 wt % to 0.5 wt % of the sulfur-free detergent.

[0218] CLAUSE 26: The lubricant composition of any preceding clause, wherein the lubricant composition is substantially free of borate esters.

[0219] CLAUSE 27: The lubricant composition of any preceding clause wherein the oil of lubricating viscosity is selected from the group consisting of API Group III base oil, Group IV base oil, or mixtures thereof.

[0220] CLAUSE 28: The lubricant composition of any preceding clause, wherein the viscosity of the lubricant composition is from 1 cSt to 32 cSt at 100°C as measured by ASTM D445.

[0221] CLAUSE 29: The lubricant composition of any preceding clause, wherein the viscosity of the lubricant composition is from 1.5 cStto 15 cSt as measured by ASTM D445.

[0222] CLAUSE 30: The lubricant composition of any preceding clause, wherein the viscosity of the lubricant composition is from 2 to 12 cSt at 100°C as measured by ASTM D445.

[0223] CLAUSE 31 : The lubricant composition of any preceding clause, wherein the oil of lubricating viscosity comprises or consists of an API Group III base oil.

[0224] CLAUSE 32: The lubricant composition of any preceding clause, wherein the oil of lubricating viscosity comprises or consists of an API Group IV base oil.

[0225] CLAUSE 33: The lubricating composition of any preceding clause, wherein the phos-phorous antiwear agent is present in an amount sufficient to deliver to the composition 100 to 5000 parts per million phosphorus to the composition. [0226] CLAUSE 34: A method of lubricating an electric vehicle comprising supplying to a driveline of the electric vehicle the lubricant composition of any of any preceding clauses and operating the driveline.

[0227] CLAUSE 35: A method of reducing wear in an electric vehicle driveline by supplying to the driveline the lubricant composition of any of clauses 1 to 33.

[0228] CLAUSE 36: The use of a lubricating composition as recited in any of clauses 1 to 33 to reduce wear in an electric vehicle driveline.

[0229] CLAUSE 37: The use of a lubricating composition as received in any of clauses 1 to 33 to reduce corrosion.

EXAMPLES

[0230] Lubricating compositions were prepared according to Table 1 below.

Table 1 (weights are oil free - Base Oil is added to 100%)

¹ Aminic C9-diphenylamine

² C14 dialkyl amide of an a-hydroxy acid

³ 1000 Mn Borated PIB Succinimide (3.8%N, 0.81%B)

⁴ 1550 Mn Non-borated PIB Succinimide (1.41%N)

⁵ Polyalkylsiloxane

⁶ Dibutyl hydrogen phosphite

⁷ Condensation product of a monomeric phosphorous acid or an ester thereof with at least two alkylene diols.

⁸ Amine salt of a C14-C18 dialkyl hydrogen phosphate and a C12-C14 tertiary alkyl amine

⁹ Bis(2-ethylhexyl)-[ 1 ,2,4-triazol- 1 -yl)methyl] amine

[0231] The FE8 Roller Bearing Testis a wear test used to assess a lubricant’s effect under service conditions on the frictional behavior and wear of a variety of bearings, including cylindrical roller thrust bearings. To conduct the test, two test cylindrical roller thrust bearings, 81212, are mounted in the FE8 test rig, subjected to an axial bearing load, operated at a particular speed and held at a test temperature.

[0232] Lubricating compositions from Table 1 were evaluated under the FE8 Roller Bearing Test using a rig and testing protocol pursuant to DIN 51819 T1-T3. The test is conducted in duplicate to confirm the results. The test conditions are listed below and the results are summarized in Table 2.

Conditions

• Test parameters

• Axial load 800kN

• Speed 7.5 rpm

• Fluid volume 4 liters

• Temperature 80°C (at the housing washers)

• Cage material brass

• Oil flow rate 0.1 1/min (each bearing

• Test duration 2 runs x 80 h

Table 2

[0233] In the wear test, the loss of weight of the bearing components reflects the ability of the lubricant to protect bearings. The formulation comprising the salicylate detergent performed better than the formulation comprising the sulfonate detergent.

[0234] The copper corrosion tests are conducted by the “ZF copper corrosion test” procedure, in which a weighed copper coupon is placed in the test oil, heated to 150° C. for 168 hours with 83 mL/min air purge. At the end of the test, copper weight loss from the coupon, % copper in the test drain, and visual rating (ASTM D-130) are measured. The results are summarized in Table 3. Table 3

[0235] Example 2, which contains the non-borated dispersant, exhibited higher weight loss of copper at the end of the test than Examples 4 and 5 which contain the non-borated dispersant and calcium salicylate detergent, as shown by the amount of copper measured in the test fluid at end of test.

[0236] Each of the documents referred to above is incorporated herein by reference, including any prior applications, whether or not specifically listed above, from which priority is claimed. The mention of any document is not an admission that such document qualifies as prior art or constitutes the general knowledge of the skilled person in any jurisdiction. Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reaction conditions, molecular weights, number of carbon atoms, and the like, are to be understood as modified by the word "about." It is to be understood that the upper and lower amount, range, and ratio limits set forth herein may be independently combined. Similarly, the ranges and amounts for each element of the invention can be used together with ranges or amounts for any of the other elements. [0237] As used herein, the transitional term “comprising,” which is synonymous with “including,” “containing,” or “characterized by,” is inclusive or open-ended and does not exclude additional, un-recited elements or method steps. However, in each recitation of “comprising” herein, it is intended that the term also encompass, as alternative embodiments, the phrases “consisting essentially of’ and “consisting of,” where “consisting of’ excludes any element or step not specified and “consisting essentially of’ permits the inclusion of additional un-recited elements or steps that do not materially affect the essential or basic and novel characteristics of the composition or method under consideration. [0238] As used herein, “substantially free” means that the amount of the material in question is less than an amount that will affect the relevant performance of the fluid in a measurable way. “Substantially free” may also mean that the material in question is not intentionally added to the composition but does not exclude the presence of such material as contaminants. “Substantially free” may also mean that the material in question may be present in amounts lower than the detection limit of standard test methods now known to those skilled in the art or hereafter developed. In some embodiments, “substantially free” may mean less than 10 ppm by weight or even less than 5 ppm by weight.

[0239] While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. In this regard, the scope of the invention is to be limited only by the following claims.

Claims

What is claimed is:

1. A lubricant composition comprising:

(a) an oil of lubricating viscosity;

(b) a dispersant;

(c) a triazole corrosion inhibitor;

(d) a phosphorous containing antiwear compound;

(e) an antioxidant; and

(f) a sulfur-free detergent; wherein the lubricant composition contains no more than 40 ppm sulfur, or no more than 30 ppm sulfur, or no more than 20 ppm sulfur.

2. The lubricant composition of claim 1, wherein the sulfur-free detergent comprises or consists of a salicylate detergent.

3. The lubricant composition of any preceding claim, wherein the sulfur-free detergent comprises or consists of calcium salicylate.

4. The lubricant composition of claim 3, wherein the calcium salicylate detergent is present in an amount sufficient to deliver up to 2000 ppm, or 100 ppm to 1000 ppm, or 100 ppm to 600 ppm, or 100 ppm to 250 ppm, or 400 ppm to 750 ppm of calcium to the lubricant composition.

5. The lubricant composition of any preceding claim, wherein the phosphorous antiwear compound comprises a dialkylphosphite.

6. The lubricant additive composition of claim 5, wherein the di-alkylphosphite has the formula: wherein R3 and R4 are independently alkyl groups with 1 to 24 carbon atoms.

7. The lubricant composition of claims 5, wherein the dialkyl phosphite comprises or consists of dibutyl hydrogen phosphite.

8. The lubricant composition of any of claims 1 to 4, wherein the phosphorous containing antiwear compound comprises or consists of a phosphonate ester.

9. The lubricant composition of claim 8, wherein the phosphonate ester comprises the reaction product of

(a) a monomeric phosphorous acid or an ester thereof with

(b) at least two alkylene diols: a first alkylene diol (i) having two hydroxy groups in a 1, 4 or 1, 5 or 1, 6 relationship; a second alkylene diol (ii) being an alkyl-substituted 1, 3-propylene diol with one or more of the alkyl substituents thereof being on one or more of the carbon atoms of the propylene unit, the total number of carbon atoms in the alkyl-substituted 1, 3-propylene diol being about 5 to about 12; wherein the relative molar amounts of monomeric phosphorous acid or ester thereof (a) and the total of the alkylene diols (b) are in a ratio of about 0.9: 1.1 to about 1.1 :0.9; and wherein the relative molar amounts of the first alkylene diol (i) and the alkyl-substituted 1, 3-propylene diol (ii) are in a ratio of about 30:70 to about 65:35.

10. The lubricant composition of any preceding claim, wherein the dispersant comprises or consists of a succinimide dispersant.

11. The lubricant composition of claim 10, wherein the dispersant comprises or consist of succinimide dispersant having a number average molecular weight of 750 to 2200 or 750 to 1600 or 950 to 1550.

12. The lubricant composition of any of claims 1 to 9, wherein the dispersant comprises or consist of an olefin polymer dispersant.

13. The lubricant composition of claim 12, wherein the dispersant comprises or consists of an ethylene/propylene copolymer dispersant.

14. The lubricant composition of any preceding claim, wherein the dispersant comprises a borated dispersant.

15. The lubricant composition of any preceding claim, wherein the dispersant comprises a non-borated dispersant.

16. The lubricant composition of any preceding claim, wherein the triazole corrosion inhibitor comprises or consist of 1,2,4-triazole.

17. The lubricant composition of any preceding claim, wherein the triazole corrosion inhibitor comprises or consist of N,N-Bis(2-ethylhexyl)-[(l,2,4- triazol-l-yl)methyl]amine.

18. The lubricant composition of any of claims 1 to 15, wherein the triazole corrosion inhibitor comprises or consists of a tolutriazole derivative.

19. The lubricant composition of any of claims 1 to 15, wherein the triazole corrosion inhibitor comprises or consists of bis(2-ethylhexyl)-[(l,2,4-triazol- 1 -yl)methyl]amine.

20. The lubricant composition of any preceding claim, wherein the antioxidant comprises or consists of an aryl amine antioxidant.

21. The lubricant composition of any preceding claim, wherein the antioxidant comprises or consists of a phenyl-a-naphthylamine (PANA).

22. The lubricant composition of any preceding claim, wherein the antioxidant comprises or consists of a hydrocarbyl substituted diphenylamine.

23. The lubricant composition of any preceding claim, wherein the antioxidant is selected from the group consisting of octyl diphenylamine, or di-octyl diphenylamine, dinonyl diphenylamine or mixtures thereof.

24. The lubricant composition of any preceding claim, wherein the lubricant composition comprises,

0.5 wt% to 5 wt% or 1.0 wt% to 3 wt% or 0.2. wt% to 3 wt% or 1 to 2 wt% of the dispersant;

0.01 wt% to 0.11 wt% of the triazole corrosion inhibitor;

0.05 wt% to 2 wt% or 0.05 to 1 wt% or 0.1 wt % to 0.5 wt% or 1.0 to 2 wt% of the phosphorous antiwear compound;

0.2 wt% to 1.2 wt% or 0.2 wt % to 1.0 wt %, or 0.2 wt % to 0.7 wt % or 0.2 wt % to 0.4 wt % of the antioxidant; and

0.1 wt% to 1.0 wt% or 0.2 wt% to 0.8wt% or 0.2 wt % to 0.5 wt % of the sulfur-free detergent.

25. The lubricant composition of any preceding claim, wherein the lubricant composition is substantially free of borate esters.

26. The lubricant composition of any preceding claim wherein the oil of lubricating viscosity is selected from the group consisting of API Group III base oil, Group IV base oil, or mixtures thereof.

27. The lubricant composition of any preceding claim, wherein the viscosity of the lubricant composition is from 1 cSt to 32 cSt, or 1.5 cSt to 15 cSt, or 2 to 12 cSt at 100°C as measured by ASTM D445.

28. The lubricant composition of any preceding claim, wherein the oil of lubricating viscosity comprises or consists of an API Group III base oil.

29. The lubricant composition of any preceding claim, wherein the oil of lubricating viscosity comprises or consists of an API Group IV base oil.

30. The lubricating composition of any preceding claim, wherein the phosphorous antiwear agent is present in an amount sufficient to deliver to the composition 100 to 5000 parts per million phosphorus to the composition.

31. A method of lubricating an electric vehicle comprising supplying to a driveline of the electric vehicle the lubricant composition of any of any preceding claim and operating the driveline.

32. A method of reducing wear in an electric vehicle driveline by supplying to the driveline the lubricant composition of any of claims 1 to 30.

33. The use of a lubricating composition as recited in any of claims 1 to 30 to reduce wear in an electric vehicle driveline.