Lubricating composition for and method of lubricating a driveline device

Abstract

The present invention provides, among other things, a lubricant formulation containing a sulfur-free poly(meth)acrylate P(M)A polymer, as well as a method for lubricating a driveline device of an automotive vehicle.

Description

TITLELubricating Composition for and Method of Lubricating a Driveline Device BACKGROUND OF THE INVENTION

[0001] The present invention provides, among other things, a lubricant formulation containing a sulfur-free poly(meth)acrylate P(M)A polymer, as well as a method for lubricating a driveline device of an automotive vehicle.

[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] For example, much of the conductive componentry in electric and hybrid electric vehicles is copper. Sulfur species present in lubricating formulations can cause copper corrosion. Thus, sulfur-free formulations would be advantageous from the perspective of copper corrosion. However, the lubricant must still provide properlubrication, including, for example, dispersancy, cleanliness, and anti-wear. Accordingly, new lubricating compositions are needed to achieve these often competing results.SUMMARY OF THE INVENTION

[0006] The disclosed technology, therefore, solves the problem of poly(meth)acrylate (“P(M)A”) polymers contributing to sulfur load in driveline formulations by preparing a lubricant formulation containing a sulfur-free P(M)A.

[0007] One aspect of the technology is therefore directed to a lubricant formulation having a) an oil of lubricating viscosity, and a sulfur-free poly(meth)acrylate (“P(M)A”) polymer.

[0008] In an embodiment, the P(M)A can have a number-average molecular weight of about 1000 to about 25,000 g / mol. The P(M)A can also optionally include nitrogen-containing groups.

[0009] The formulation may also include, for example, a phosphorous antiwear agent sufficient to provide 100 to 5000 parts per million phosphorus to the composition as well as a triazole corrosion inhibitor, such as, for example, a 1,2,4-triazole.

[0010] Another aspect of the technology includes a method of lubricating a driveline of a vehicle by applying to the driveline the lubricant formulation as described here, and then operating the vehicle. The vehicle can be a hybrid electric or full electric vehicle.DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention provides, among other things, a lubricant formulation having a) an oil of lubricating viscosity, and a sulfur-free poly (meth) aery late (“P(M)A”) polymer, as well as a method for lubricating a driveline device.Oil of Lubricating Viscosity

[0012] One component of the disclosed technology is an oil of lubricating viscosity, also referred to as a base oil. The base oil may be selected from any of the base oils in Groups I-V of the American Petroleum Institute (API) Base Oil Interchangeability Guidelines (2011), namelyBase Oil Category Sulfur (%) Saturates (%) Viscosity IndexGroup I >0.03 and / or <90 80 to less than 120Group IT <0.03 and >90 80 to less than 120Group III <0.03 and >90 >120Group IV All polyalphaolefins (PAOs)Group V All others not included in Groups I, II, III or IV

[0013] Groups I, II and III are mineral oil base stocks. Other generally recognized categories of base oils may be used, even if not officially identified by the API: Group 11+ , referring to materials of Group II having a viscosity index of 110-119 and lower volatility than other Group II oils; and Group III+, referring to materials of Group III having a viscosity index greater than or equal to 130. The oil of lubricating viscosity can include natural or synthetic oils and mixtures thereof. Mixtures of mineral oil and synthetic oils, e.g., polyalphaolefin oils and / or polyester oils, may be used.

[0014] In one embodiment the oil of lubricating viscosity has a kinematic viscosity at 100 °C by ASTM D445 of 1.5 to 7.5, or 2 to 7, or 2.5 to 6.5, or 3 to 6 mm2 / s. In one embodiment the oil of lubricating viscosity comprises a poly alpha olefin having a kinematic viscosity at 100 °C by ASTM D445 of 1.5 to 7.5 or any of the other aforementioned ranges.Polyfmethjacrylate “P(M)A ’’Polymers

[0015] The use of parentheses indicates the chemistry enclosed in the parentheses may or may not be present. For example, the use of (meth) indicates (throughout this specification) that the referenced methyl chemistry in parentheses is optionally present.

[0016] The P(M)A polymers useful in the current technology are those prepared without the presence of sulfur. Such P(M)A polymers can be made, for example, by free radical polymerization with sulfur-free addition fragmentation chain transfer agents.

[0017] Alpha-methylstyrene dimers (AMSDs) may be used as sulfur-free addition fragmentation chain transfer agents to prepare P(M)A polymers. The methods used to prepare P(M)A polymers are those well known in the art such as radical polymerization or group transfer polymerization, for example. The polymers formed comprise at least one polymerized dimer of an alpha-methylstyrene derivative as shown in Formula I belowwherein Rl, R2, R3, R4, R5 and R6 are each independently selected from group consisting of hydrogen, — CH(O), — CN, isocyanato, and salts and esters thereof, NR7R8, a silane, a halogen, — C(O)OR9, — C(O)NR10Rl 1, — CR12(O), — C(O)OC(O)R13, — C(O)NR14COR15, — OC(O)R16, — OR17, substituted and unsubstituted alkyl, substituted and unsubstituted alkenyl, substituted and unsubstituted alkynyl, and substituted and unsubstituted aryl; R7, R8, R9, R10, Rl 1, R12, R13, R14, R15, and R16 are each independently selected from the group consisting of H, alkyl, aryl, substituted alkyl or substituted aryl; R17 is selected from the group consisting of alkyl, aryl, substituted alkyl or substituted aryl; Rl, R2, R3, R4, R5 and R6 cannot all simultaneously be hydrogen; and the alkyl and substituted alkyls have a chain consisting of 1 to 12 carbons.

[0018] In an embodiment, each of Rl, R2, R3, R4, R5 and R6 are H.

[0019] In one embodiment, the P(M)A can be synthesized by catalytic chain transfer polymerization (“CCTP”), in which the desired (meth)acrylate monomers are reacted with a catalytic amount of a chain transfer agent. Examples of catalytic chain transfer agents can include, but are not limited to, low-spin Co(II) complexes such as Cobaloxime [J. Am. Chem. Soc., 1984, 106, 5197-5202] and derivatives thereof.

[0020] Desired monomers for preparation of the poly (meth)acryl ate polymers can include, for example, a (meth)acrylate monomer mixture comprising (meth)acrylate monomers having alkyl groups of varying length. The (meth)acrylate monomers may contain alkyl groups that are straight chain or branched chain groups or aromatic groups. The alkyl groups may contain 1 to 24 carbon atoms, for example 1 to 20 carbon atoms.

[0021] The poly(meth)acrylate polymer described herein can be formed from monomers derived from saturated alcohols, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-methylpentyl (meth)acrylate, 2-propylheptyl (meth)acrylate, 2-butyloctyl (meth)acrylate, 2- ethylhexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, 2-tert-butylheptyl (meth)acrylate, 3 -isopropylheptyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, 5 -methylundecyl (meth)acrylate, dodecyl (meth) aery late, 2-methyldodecyl (meth)acrylate, tridecyl (meth)acrylate, 5-methyltridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, 2 -methylhexadecyl (meth)acrylate, heptadecyl (meth)acrylate, 5 -isopropylheptadecyl (meth)acrylate, 4-tert-butyloctadecyl (meth)acrylate, 5 -ethyloctadecyl(meth)acrylate, 3-isopropyloctadecyl-(meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, (meth)acrylates derived from unsaturated alcohols, such as oleyl (meth)acrylate; and cycloalkyl (meth)acrylates, such as 3-vinyl-2-butylcyclohexyl (meth)acrylate or bornyl (meth)acrylate.

[0022] Other examples of monomers for preparing the poly(meth)acrylate polymer can include alkyl (meth)acrylates with long-chain alcohol-derived groups which may be obtained, for example, by reaction of a methacrylic acid (by direct esterification) or methyl (meth)acrylate (by transesterification) with long-chain fatty alcohols. These fatty alcohols include Nafol® 1620, Alfol® 10, Alfol® 810, Alfol® 12, Alfol® 1012EE, Alfol® 1014CDC, Alfol® 1214, Alfol® 1214GC, Alfol® 1214HA, Alfol® 1216, and Lial® 125 of Sasol; Neodol® 91, Neodol® 23, Neodol® 25, Neodol® 45 and Neodol® 135 of Shell AG; C13-C15 Alcohol, Isotridecanol, Hydrenol® and Lorol® of BASF; Kalcol® 2465, Kalcol® 2470, Kalcol® 8655 of Kao Corporation, as well as Ecorol® 80, Ecorol® 24, Ecorol® 26, Ecorol® 28, and Ecorol® 68 of Ecogreen Oleochemicals. Further examples of monomers include alkyl (meth)acrylates with branched chain alcohol-derived groups which may be obtained, for example, by reaction of a methacrylic acid (by direct esterification) or methyl (meth)acrylate (by transesterification) with Guerbet alcohols. Examples of Guerbet alcohols include 2-butyloctanol, 2-butyldecanol, 2-hexyloctanol, 2-hexyldecanol, 2- octyldecanol, 2-hexyldodecanol, 2-octyldodecanol, 2-decyltetradecanol, 2- dodecylhexadecanol, and 2-tetradecyl octadecanol.

[0023] Aromatic monomers may also be employed to prepare the poly(meth)acrylatepolymer and can include, for example, benzyl (meth)acrylate. In another embodiment, the aromatic monomers may be selected from phenyl (meth)acrylate, phenylpropyl (meth)acrylate or styrene. It is contemplated that other oil insoluble (meth)acrylate monomers that are polymerizable in oil may also be used. Mixtures of these and other oil insoluble monomers may also be used in the present invention.

[0024] The P(M)A can optionally include a nitrogen-containing group. The nitrogencontaining compound 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-methyl aniline, and N-butylaniline, di- (para-methylphenyl)amine, naphthylamine, 4-aminodiphenylamine, N,N- dimethylphenylenediamine, 4-(4-nitrophenylazo)aniline (disperse orange 3), 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 paraethoxyaniline, para-dodecylaniline, and cyclohexyl-substituted naphthylamine. 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., <j)-NH-(|)-NH-COCH2CH(CH3)NH2). Additional aromatic amines include aminocarbazoles, aminoindoles, aminopyrroles, amino-indazolinones, aminoper- imidines, aminopyridiens, aminopyrazines, aminopyrimidines, pyridines, pyrazines, pyrimidines, 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 thegeneral structure (j)-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.

[0025] The nitrogen-containing compound may also include non-aromatic amines, 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, diethylaminopropylamine, dibutyl aminopropylamine, dimethylaminoethylamine, di ethyl aminoethylamine, dibutyl aminoethylamine, l-(2-aminoethyl)piperidine, l-(2-aminoethyl)pyrrolidone, N,N-dimethylethylamine; 3 -(dimethyl amino)- 1 -propylamine; O-(2-aminopropyl)-O'- (2-m ethoxy ethyl)polypropylene glycol; N,N-dimethyldipropylenetriamine, aminoethylmorpholine, 3 -morpholinopropylamine; aminoethylethyleneurea and aminopropylmorpholine.

[0026] 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.

[0027] In certain embodiments aromatic amines can be used alone or in combination with each other or in combination with non-aromatic amines. The amount of non- aromatic amine may, in some embodiments, be a minor amount compared with the amount of the aromatic amines, or in some instance, the composition may be substantially free or free of non-aromatic amine.

[0028] The P(M)A can have a number average molecular weight (“Mn”) of from about 1000 to about 25,000, or from about 1500 to about 22,500, or even from about 2000to about 20,000, or 2500 to 17,500, or 3000 to 15,000, as measured by gel permeation chromatography (“GPC”). All chromatography measurements were conducted using an Agilent 390-LC MDS instrument equipped with a differential refractive index and dual wavelength UV detectors. Poly(methyl methacrylate) and polystyrene standards were used for calibration.

[0029] The lubricating compositions of the present invention comprise 1 wt. % to 35 wt. %, or 5 wt. % to 30 wt. %, or 10 to 25 wt. % of the P(M)A as described herein.Phosphorus Antiwear Compound

[0030] The lubricant additive composition contains at least one phosphorus antiwear compound, such as a phosphate salt, alkyl phosphate salt or alkyl phosphite. 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 (thio)phosphate amines compounds.

[0031] 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.

[0032] In one embodiment the phosphite is sulfur-free i.e., the phosphite is not a thiophosphite.

[0033] 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.

[0034] The R hydrocarbyl groups may be linear or branched, typically linear, and saturated or unsaturated, typically saturated.

[0035] 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.

[0036] In one embodiment, the phosphorus antiwear compound can be a C12-24 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 Cl 2-24 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.

[0037] In some embodiments, the phosphorous containing compound can include both a C3-8 and a C12-14 hydrocarbyl phosphite.

[0038] The phosphorus antiwear compound can include a phosphite at 0. 1 to 2 wt.%of the additive composition, or even from 0.2 to 1.8 wt.%, or 0.2 to 1.4 or 1.6 wt.% of the lubricant additive composition, or even from 0.2 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 0.2 to 0.4 wt.%, or 0.2 to 0.3 wt.% of the lubricant additive composition.

[0039] 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.

[0040] 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.

[0041] 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,® -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.

[0042] 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.

[0043] 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 formulawhere 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).

[0044] 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- 1,3- diol, 2-methyl-2-propylpropane-l,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.

[0045] 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.

[0046] 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 ofoligomers 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.

[0047] 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.

[0048] The product may be a mixture of species that may be represented by the structures shown:(oligomeric species) plus(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).

[0049] 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.

[0050] 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 methylester 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.

[0051] 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 hydroxy stearic acid.

[0052] 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 percentphosphorus 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.

[0053] 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 3500 ppm of phosphorus, or from 150 to 3000 ppm phosphorus to the lubricant additive composition.

[0054] 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.

[0055] The substantially sulfur-free alkyl phosphate salt, as present in the pyrophosphate form (sometimes referred to as the POP structure). In certainembodiments 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.

[0056] 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.

[0057] 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.

[0058] The phosphorus antiwear compound may also be an amine alkylthiophosphate, wherein the alkylthiophosphate is represented by the formula (R’O)2PSSH, wherein each R’ is independently a hydrocarbyl group containing from about 3 to about 30, preferably from about 3 up to about 18, or from about 3 up to about 12, or from up to about 8 carbon atoms. Example R’ groups can include isopropyl, isobutyl, n-butyl, sec-butyl, the various amyl, n-hexyl, methylisobutyl carbinyl, heptyl, 2-ethylhexyl, isooctyl, nonyl, behenyl, decyl, dodecyl, and tridecyl groups. Illustrative lower alkylphenyl R’ groups include butylphenyl, amylphenyl, heptylphenyl, etc. Examples of mixtures of R’ groups include: 1-butyl and 1-octyl; 1-pentyl and 2-ethyl-l -hexyl; isobutyl and n-hexyl; isobutyl and isoamyl; 2-propyl and 2-methyl-4-pentyl; isopropyl and sec-butyl; and isopropyl and isooctyl.

[0059] In one embodiment, the alkylthiophosphate of the amine alkylthiophosphate may be reacted with an epoxide or a polyhydric alcohol, such as glycerol. This reaction product may be used alone, or further reacted with a phosphorus acid, anhydride, or lower ester. The epoxide is generally an aliphatic epoxide or a styrene oxide. Examples of useful epoxides include ethylene oxide, propylene oxide, butene oxide, octene oxide, dodecene oxide, styrene oxide, etc. Ethylene oxide and propylene oxide are preferred. The polyhydric alcohols are described above. The glycols may be aliphatic glycols having from 2 to about 12, or from about 2 to about 6, or from 2 or 3 carbon atoms. Glycols include ethylene glycol, propylene glycol, and the like. The alkylthiophosphate, glycols, epoxides, inorganic phosphorus reagents and methods of reacting the same are described in U.S. Pat. Nos. 3, 197,405 and 3,544,465 which are incorporated herein by reference for their disclosure to these.

[0060] 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 compound can be in the form of a mixture.

[0061] The phosphorus antiwear compound can include those derived from phosphoric acid, phosphorous acid, thiophosphoric acid, thiophosphorous acid, or mixtures thereof.

[0062] 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.

[0063] In one embodiment the phosphorus antiwear compound can include an ammonium or amine salt of a phosphorus-containing acid or ester.

[0064] 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.

[0065] 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.

[0066] The amine salt of a phosphorus acid or ester may be used alone or in combination.

[0067] 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. In one embodiment the amine salt of a phosphorus acid or ester further contains a sulfur atom in the molecule.

[0068] The pyrophosphate, thiophosphate ester, 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.

[0069] The metal of the metal salt includes aluminum, calcium, magnesium, strontium, chromium, iron, cobalt, nickel, zinc, tin, lead, manganese, silver, or mixtures thereof. In one embodiment the metal is zinc.

[0070] The amine of the amine salt may be represented by R23N, 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.

[0071] Secondary amines that may be used include dimethylamine, diethylamine, dipropylamine, dibutylamine, diamylamine, dihexylamine, diheptylamine,methyl ethyl amine, ethylbutyl amine, bis-2-ethylhexylamine, N-methyl-1 -aminocyclohexane, Armeen® 2C, and ethylamylamine. The secondary amines may be cyclic amines such as piperidine, piperazine and morpholine.

[0072] 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.

[0073] 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, terttetradecyl amine, 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.

[0074] In one embodiment the amine salt of a phosphorus acid or ester as described above can include an amine with about Cn to about C14 tertiary alkyl primary groups or mixtures thereof. In one embodiment the amine salt of a phosphorus compound includes an amine with about C14 to about C18 tertiary alkyl primary amines or mixtures thereof. In one embodiment the amine salt of a phosphorus compound includes an amine with about C18 to about C22 tertiary alkyl primary amines or mixtures thereof.

[0075] In one embodiment the amine salt of a phosphorus acid or ester as described above can be the reaction product of a C14 to Cl 8 alkylated phosphoric acid with Primene® 81R (produced and sold by Rohm & Haas) which is a mixture of Cl l 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 5-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.

[0076] There may also be one or more additional substituents or groups at the a, P, y, or 5 positions of the aminoester. In one embodiment there are no such substituents. In another embodiment there is a substituent at the 3 position. That is, a substituent at the P position of the chain may comprise an ester, thioester, carbonyl, or hydrocarbyl group. The analogous structures for a 5-amino ester will be understood to be encompassed.

[0077] 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).

[0078] 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 P and y carbon atoms of the ester.

[0079] The N-hydrocarbyl-substituted 6-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.

[0080] 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 5-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.

[0081] 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.

[0082] 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 0.1 to 2.0 weight percent or 0.15 to 1.5 weight percent or 0.15 to 2.5 weight percent.

[0083] When the amine salt is an amine salt of a thiophosphate ester described above, the amount of the amine salts used in the lubricant may be 0.05 to 0.5 weight percent, or 0.1 to 0.3 weight percent, or 0.15 to 2 weight percent.

[0084] The amount of phosphorous antiwear agent may be suitable to provide phosphorus to the lubricant formulation in an amount of 100 to 5000 parts per million by weight (ppm).

[0085] The phosphorous antiwear agent may be a phosphate salt, alkyl phosphate salt or alkyl phosphite suitable to provide phosphorous to the lubricant formulation in an amount of 100 to 5000 parts per million, or 150 to 4000 parts per million, or 200 to 3000 parts per million, or 250 to 2000 parts per million, or 100 to 1000 parts per million, or 1000 to 5000 parts per million, 1250 to 4000 parts per million, 1500 to 3000 parts per million or 1600 to 2700 parts per million.Other Performance Additives

[0086] A lubricating composition may be prepared by adding the P(M)A to an oil of lubricating viscosity, optionally in the presence of other performance additives (as described herein below).

[0087] The lubricating composition of the invention optionally comprises other performance additives such as, for example, dispersants, antioxidants, corrosion inhibitors, such as triazoles, polyethers, detergents, and antiwear agents, to name a few.

[0088] 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 apoly(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.

[0089] 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).

[0090] 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).

[0091] 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 dispersantmay 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 1350, or 750 to 1150. 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.

[0092] 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.

[0093] The total amount of dispersant or dispersants, whether post-treated or not (e.g., borated or non-borated, but preferably 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 percent or 0.05 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 than 250 ppm boron, or less than 200 ppm boron, or even less than 150 ppm boron, or less than 100 ppm boron, or less than 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.

[0094] 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.

[0095] The lubricant formulation may also include a corrosion inhibitor, which may also be described as a metal deactivator or a yellow-metal passivator.

[0096] Examples of a corrosion inhibitors include triazoles, such as benzotriazoles and 1,2,4-triazoles, benzimidazoles, 2-alkyldithiobenzimidazoles, 2-alkyldithiobenzothiazoles, 2-(N,N-dialkyldithiocarbamoyl)benzothiazoles, 2,5- bis(alkyl-dithio)- 1, 3, 4-thiadi azoles, 2,5-bis(N,N-dialkyldithiocarbamoyl)-l,3,4- thiadiazoles, 2-alkyldithio-5-mercapto thiadiazoles or mixtures thereof. In one embodiment the corrosion inhibitor includes a benzotriazole. In one embodiment the corrosion inhibitor includes a 2,5-bis(alkyl-dithio)-l,3,4-thiadiazole.

[0097] 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.

[0098] Examples of suitable hydrocarbyl benzotriazoles further reacted with an aldehyde and an amine include N,N-bis(2-ethylhexyl)-ar-methyl-lH-benzotriazole-l- m ethanamine, N,N-bis(2-ethylhexyl)-4-m ethyl- IH-benzotri azole- 1-methanamine, N,N-bis(2-ethylhexyl)-4-methyl-lH-benzotriazole-l-methanamine, 2H- benzotriazole-2-methanamine, N-(4-m ethoxyphenyl)- IH-benzotriazole- 1- m ethanamine, N,N-didodecyl-lH-benzotriazole- 1-methanamine, N-(1H- benzotriazol- 1 -ylmethyl)-N-(2-ethylhexyl)- IH-benzotriazole- 1 -methanamine, N- methyl-N-phenyl-lH-benzotri azole- 1-methanamine, 4,5,6,7-tetrahydro-N,N-ditridecyl-lH-benzotriazole-l-methanamine, N,N-dioctadecyl-lH-benzotriazole-l - m ethanamine, 5-methyl-N,N-dioctyl-lH-benzotri azole- 1-methanamine, N,N-dibutyl- IH-benzotriazole-l-m ethanamine, N-(4-methylphenyl)-lH-benzotriazole-l- m ethanamine, N,N-bis(2-ethylhexyl)-lH-benzotri azole- 1-methanamine, N,N- dioctyl-2H-benzotriazole-2-methanamine, N-dodecyl-lH-benzotriazole-1- m ethanamine, N-phenyl-lH-benzotri azole- 1-methanamine, N,N-didodecyl-4,5,6,7- tetrahydro-lH-benzotriazole- 1-methanamine, N,N-bi s(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)-lH-benzotri azole- 1-methanamine, 4,5,6,7- tetrahydro-N,N-ditetradecyl-lH-benzotriazole- 1-methanamine, or mixtures thereof. In one embodiment the corrosion inhibitor includes N,N-bis(2-ethylhexyl)-4-methyl- IH-benzotri azole- 1-methanamine or N,N-bis(2-ethylhexyl)-ar-methyl-lH- benzotri azole- 1 -methanamine.

[0099] Examples of suitable hydrocarbyl 1,2,4-riazoles further reacted with an amine include N,N-Bis(l-methylethyl)-lH-l,2,4-triazole-l-methanamine, N,N- diisobutyl- 1H- 1 ,2,4-triazole- 1 -methanamine, N,N-di cyclohexyl- 1 H- 1 ,2,4-triazole- 1 - methanamine, N,N-bis(2-ethylhexyl)-lH-l, 2, 4-Tri azole- 1-methanamine, 1-((1H-1.2.4-triazol-l-yl)methyl)piperidine, N, N-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.

[0100] 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.

[0101] In an embodiment the corrosion inhibitor can be a thiadiazole, such as a1.3.4-thiadiazole. In embodiments, the 1,3,4-thiadiazole can include substituents atthe 2 and 5 positions of the thiadiazole ring, such as, for example, alkyl di sul fan eyl moieties. Such corrosion inhibitors can include those of formulawherein R1 and R2 are independently alkyl groups with 1 to 12 carbons.

[0102] In one embodiment, the corrosion inhibitor includes (i) a 2,5-bis(alkyl- dithio)-l,3,4-thiadiazole, (ii) a benzotriazole containing a hydrocarbyl substitution on at least one of the following ring positions 4- or 5- or 6- or 7-, or (iii) a benzotriazole containing a hydrocarbyl substitution (typically a benzotriazole further reacted with an aldehyde and an amine) at least one of the following ring positions 1- or 2-.

[0103] In one embodiment, the corrosion inhibitor includes 2,5 -bis(alkyl-dithio)-1.3.4-thiadiazoles. In different embodiments the alkyl groups of 2,5-bis(alkyl- dithio)-l,3,4-thiadiazoles contain 1 to about 30, or about 2 to about 25, or 4 to about 20, or about 6 to about 16 carbon atoms. Examples of suitable 2,5-bis(alkyl-dithio)-1.3.4-thiadiazoles include 2,5-bis(tert-octyldithio)-l,3,4-thiadiazole, 2,5-bis(tert- nonyldithio)-l,3,4-thiadiazole, 2,5-bis(tert-decyldithio)-l,3,4-thiadiazole, 2,5- bis(tert-undecyldithio)-l,3,4-thiadiazole, 2,5-bis(tert-dodecyldithio)-l,3,4- thiadi azole, or mixtures thereof.

[0104] The corrosion inhibitor may be used alone or in combination with two, three or more corrosion inhibitors. In one embodiment the corrosion inhibitor includes a mixture of (i) a 2,5-bis(alkyl-dithio)-l,3,4-thiadiazole, (ii) a benzotriazole containing a hydrocarbyl substitution on at least one of the following ring positions 4- or 5- or 6- or 7-, and (iii) a benzotriazole containing a hydrocarbyl substitution (typically a benzotriazole further reacted with an aldehyde and an amine) on at least one of the following ring positions, 1- or 2-.

[0105] In different embodiments the corrosion inhibitor is a thiadiazole. Thiadiazole corrosion inhibitors may be present alone or in mixtures with otherthiadiazole corrosion inhibitors or other azole corrosion inhibitors in ranges including about 0.01 wt % to about 1 wt %, or about 0.05 wt % to about 0.9 wt %, or about 0.1 wt % to about 0.8 wt %, or about 0.2 wt % to about 0.7 wt % of the lubricant additive composition or 0.2 wt % to about 0.5 wt % or 0.25 wt % to about 0.35 wt % of the lubricant additive composition.

[0106] 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.

[0107] 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.

[0108] When present the aryl amine antioxidant may be present at 0.2 wt % to 1.2 wt %, or 0.3 wt % to 1.0 wt %, or 0.4 wt % to 0.9 wt % or 0.5 wt % to 0.8 wt %, of the lubricant additive composition.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] In one embodiment, the lubricant additive can also include a boron containing compound.

[0113] 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.

[0114] The boron can be delivered by many types of boron-containing compounds.

[0115] The boron-containing compound can be a dispersant post-treated with a source of boron, as described above.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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 C18, or C3 to C12 alkyl. Examples of useful R groups includeisopropyl, 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.

[0120] 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 Cl 8, 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 C IO 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.

[0121] 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.

[0122] In one embodiment, the borated ester can be a phenolic compound represented by the formulaVIIwherein in formula VII: Rl, R2, R3 and R4 are independently hydrocarbyl groups of 1 to about 12 carbon atoms; and R5 and R6 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, Rl and R2 independently contain 1 to about 6 carbon atoms, and in one embodiment each is a t-butylgroup. 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 — .

[0123] 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).

[0124] 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.%.

[0125] 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.

[0126] 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, di ethylene glycol, tri ethylene glycol, glycerol, sorbitol, pentaerythritol and dipentaerythritol.

[0127] The aliphatic carboxylic acids which form the esters are those acids containing 12 to 24 carbon atoms. Such acid can be characterized by the followinggeneral 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.

[0128] 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.

[0129] 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 dioleate, 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] Suitable polyols are the same as mentioned above.

[0134] 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 alkyl-hexadecyl 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 alkyl- hexadecyl 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).

[0135] 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).

[0136] 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.

[0137] 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 trimethylol esters.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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 dimercaptothiadiazoles, 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 maybe 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 alkylbenzotriazole in which the alkyl group contains 1 to about 20 carbon atoms, preferably 1 to about 8 carbon atoms. Benzotriazole and tolyltriazole are useful.

[0142] 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.

[0143] 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.

[0144] 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 dithiothiadiazole compounds are disclosed as Component (d) in PCT Publication WO 88 / 03551, incorporated by reference for its disclosure of dithiothiadiazole compounds. In the preferred embodiments the metal deactivator is a dimercaptothiadiazole derivative. The following D-l and D-2 are specific examples.

[0145] Example D-l

[0146] 2,5-dimercapto-l,3,4-thiadiazole oxidatively coupled with t-nonyl mercaptan; 100% chemical, 36% S, 64% N.

[0147] Example D-2

[0148] 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.

[0149] 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.

[0150] 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 structureswherein each of Rl, 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 trioxide. Borated epoxides are not themselves epoxides, but are the ring-opened boron-containing reaction products of epoxides. Suitable epoxides include commercial mixtures of Cl 4- 16 or Cl 4- 18 or Cl 6- 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 heatingthem 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.

[0151] The lubricant additive composition may also include a calcium-containing detergent. While the calcium-containing detergent is preferably not present, it can be included in an amount to deliver up to 300 ppm of calcium to the composition, or from 30 ppm to 300 ppm, or 30 ppm to 275 ppm of calcium, or from 60 ppm to 250 ppm, or even from 60 ppm to 225 ppm of calcium.

[0152] In some embodiments, the calcium-containing detergent may be present at 900 ppm or less, or from 1 to 900 ppm, or even from 5 to 800 ppm or 10 to 700 ppm, or even from 15 to 600 or 500 ppm.

[0153] The calcium-containing detergent may be an overbased detergent, a nonoverbased detergent, or mixtures thereof. Typically the detergent is overbased.

[0154] The preparation of the calcium-containing detergent is known in the art. Patents describing the preparation of overbased calcium-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.

[0155] The calcium-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 calcium-containing detergent may also be 20 to 175, or 30 to 100 mg KOH / g. When a non-overbased calcium-containing detergent is prepared from a strong acid such as a hydrocarbyl -substituted sulphonic acid, the TBN may be lower (for example 0 to 50 mg KOH / g, or 10 to 20 mg KOH / g).

[0156] 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. Conventionalamounts of diluent oil typically range from 30 wt % to 60 wt % (often 40 wt % to 55 wt %) of the detergent component.

[0157] The calcium-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).

[0158] The overbased calcium-containing detergent may be formed by the reaction of a basic calcium compound and an acidic detergent substrate. The acidic detergent substrate may include an alkyl aromatic sulphonic acid (such as, alkyl naphthalene sulphonic acid, alkyl toluene sulphonic acid or alkyl benzene sulphonic acid), an alkyl salicylic acid, or mixtures thereof.

[0159] The basic calcium compound is used to supply basicity to the detergent. The basic calcium compound is a compound of a hydroxide or oxide of the calcium.

[0160] 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 calcium 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.

[0161] In one embodiment the calcium-containing detergent may be a sulphonate, or mixtures thereof. The sulphonate may be prepared from a mono- or di- hydrocarbyl-substituted benzene (or naphthalene, indenyl, indanyl, or bicyclopentadienyl) sulphonic acid, wherein the hydrocarbyl group may contain 6 to 40, or 8 to 35 or 9 to 30 carbon atoms.

[0162] The hydrocarbyl group may be derived from polypropylene or a linear or branched alkyl group containing at least 10 carbon atoms. Examples of a suitable alkyl group include branched and / or linear decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, octadecenyl, nonodecyl, eicosyl, un-eicosyl, do-eicosyl, tri-eicosyl, tetra-eicosyl, penta-eicosyl, hexa-eicosyl or mixtures thereof.

[0163] In one embodiment the hydrocarbyl-substituted sulphonic acid may include polypropene benzenesulphonic acid and / or C16-C24 alkyl benzenesulphonic acid, or mixtures thereof.

[0164] In one embodiment a calcium sulphonate detergent may be a predominantly linear alkylbenzene sulphonate detergent having a metal ratio of at least 8 as is described in paragraphs

[0026] to

[0037] of US Patent Application 2005065045 (and granted as US 7,407,919). In some embodiments the linear alkyl group may be attached to the benzene ring anywhere along the linear chain of the alkyl group, but often in the 2, 3 or 4 position of the linear chain, and in some instances predominantly in the 2 position.

[0165] When neutral or slightly basic, a calcium sulphonate detergent may have TBN of less than 100, or less than 75, typically 20 to 50 mg KOH / g, or 0 to 20 mg KOH / g.

[0166] When overbased, a calcium sulphonate detergent may have a TBN greater than 200, or 300 to 550, or 350 to 450 mg KOH / g.

[0167] Phenate detergents are typically derived from p-hydrocarbyl phenols or, generally, alkylphenols. Alkylphenols of this type may be coupled with sulfur and overbased, coupled with aldehyde and overbased, or carboxylated to form salicylate detergents. Suitable alkyl salicylates 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. In one embodiment, the lubricant additive composition comprises less than 0.2 wt %, or less than 0.1 wt %, or even less than 0.05 wt % of a salicylate detergent derived from PDDP. In one embodiment, the lubricant additive composition comprises a salicylate detergent that is not derived from PDDP. In one embodiment, the lubricant additive composition comprises a salicylate detergent prepared from PDDP, such detergent contains less than 1.0 weight percent unreacted PDDP, or less than 0.5 weight percent unreacted PDDP, or is substantially free of PDDP.

[0168] The detergent may be borated or non-borated.

[0169] Chemical structures for sulphonates, and 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.

[0170] In one embodiment the calcium-containing detergent may be an overbased calcium sulphonate, an overbased calcium salicylate, or mixtures thereof. Typically the detergent may be an overbased calcium sulphonate.

[0171] In one embodiment the calcium-containing detergent may be in a mixture with a zinc-, barium-, sodium-, or magnesium- containing detergent. The zinc-, barium-, sodium-, or magnesium- containing detergent is also well known in the art and described in the same references describing a calcium-containing detergent. The TBN and metal ratios may however, differ slightly. The zinc-, barium-, sodium-, or magnesium- containing detergent may be a phenate, a sulfur-containing phenate, sulphonate, salixarate or salicylate. Typically a zinc-, barium-, sodium-, or magnesium- containing detergent may be a magnesium phenate, a magnesium sulfur- containing phenate, or a magnesium sulphonate.

[0172] 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.

[0173] 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.

[0174] 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.

[0175] 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.

[0176] The sulfur content of the lubricating composition may be 100 ppm or less, or 80 ppm or less, or 60 ppm or less, or 40 ppm or less. In one embodiment the sulfur content may be in the range of 1 ppm to 100 ppm. In an embodiment, the lubricating composition is sulfur free.

[0177] In one embodiment the phosphorus content may be 100 ppm to 5000 ppm. In one embodiment the phosphorus content may be 100 ppm to 4000 ppm, or 200 ppm to 3000 ppm, or even from 100 ppm to 2000 ppm or 100 ppm to 1000 ppm, or 200 ppm to 600 ppm. The total sulfated ash content may be 0.3 wt % to 1.2 wt %, or 0.5 wt % to 1.1 wt % of the lubricating composition. In one embodiment the sulfated ash content may be 0.5 wt % to 1.1 wt % of the lubricating composition.Industrial Application

[0178] The P(M)A may be employed in a method of lubricating a driveline of a vehicle. The method includes applying the lubricant formulation as disclosed to the driveline and operating the vehicle.

[0179] The driveline device can be, for example, a gear, an axle, a drive shaft, an automatic or manual transmission, or a driveline of an off-highway vehicle (such as a farm tractor). Such driveline devices are lubricated by gear oils, axle oils, drive shaft oils, traction oils, manual transmission oils, automatic transmission oils, or off highway oils (such as a farm tractor oil).

[0180] In one embodiment a method of lubricating a manual transmission that may or may not contain a synchronizer system is provided. In one embodiment there is provided a method of lubricating an automatic transmission. In one embodiment the invention provides a method of lubricating an axle.

[0181] Automatic transmissions that may be encompassed by the disclosed method include, for example, continuously variable transmissions (CVT), infinitely variable transmissions (IVT), toroidal transmissions, continuously slipping torque converter clutches (CSTCC), stepped automatic transmissions or dual clutch transmissions (DCT).

[0182] The automatic transmissions can contain continuously slipping torque converter clutches (CSTCC), wet start and shifting clutches and in some cases may also include metal or composite synchronizers. Dual clutch transmissions or automatic transmissions may also incorporate electric motor units.

[0183] With respect to axles and gears, the method can include employing a gear oil or axle oil in a planetary hub reduction axle, a mechanical steering and transfer gear box in utility vehicles, a synchromesh gear box, a power take-off gear, a limited slip axle, and a planetary hub reduction gear box. Axles may also incorporate electric motors units. Motors may be placed, for example, “in-wheel” or on the front or rear axle. The electric motor may also be incorporated into the driveshaft.

[0184] The following examples provide illustrations of the invention. These examples are non-exhaustive and are not intended to limit the scope of the invention.

[0185] EXAMPLES

[0186] P(M)A 1 - Sulfur-containing poly(methacrylate) copolymer with amine functionality prepared by free radical polymerization with 1 -dodecanethiol as the chain transfer agent.

[0187] P(M)A 2 -Sulfur-free poly(methacrylate) copolymer with amine functionality prepared by free radical polymerization with AMSD as the chain transfer agent. The composition of P(M)A 2 is equivalent to P(M)A 1 with the exception of the chain transfer agent.

[0188] P(M)A 3 -Sulfur-free poly(methacrylate) copolymer without amine functionality prepared by free radical polymerization with AMSD as the chain transfer agent. The composition of P(M)A 3 is equivalent to P(M)A 2 with the exception of the amine-containing monomer.

[0189] The P(M)A samples were tested as concentrates with just oil, as shown in Table 1 below. Components are listed on an oil-free basis.Table 1

[0190] Test results

[0191] Comparing the sulfur content of the fluids, it can be seen that the Sulfur- free P(M)A formulations 2 and 3 do not have measurable sulfur by method D4951.

[0192] Comparing the viscosity of the conventional P(M)A in formulation 1, to the Sulfur-free P(M)A formulations 2 and 3 it can be seen that they are all equal, showing equivalency in the polymers.

[0193] An industry standard Cu corrosion test is D130. There was significantly less copper corrosion from formulations with the Sulfur-free P(M)A formulations 2 and 3.

[0194] Comparing ZF copper corrosion test data, it showed lower copper in solution, and lower mass loss from the test piece for the formulations containing Sulfur-free P(M)A.

[0195] The P(M)A samples were tested in fully formulated fluids, as shown in Table 2 below. Components are listed on an oil-free basis.Table 21 - Additive package includes at least one of an antioxidant, dispersant, antiwear agent, and corrosion inhibitor and combination thereof.

[0196] Testing description

[0197] Comparing the sulfur content of the fluids and it can be seen that the Sulfur- free P(M)A formulations 5 and 6 do not increase sulfur content above the baseline 47. This confirms Sulfur-free P(M)A.

[0198] Comparing the viscosity of the conventional P(M)Ain formulation 4, to the Sulfur-free P(M)A formulations 5 and 6 it can be seen that they are all equal, showing equivalency in the polymers.

[0199] An industry standard copper corrosion test is D130. There was significantly less copper corrosion from formulations with Sulfur-free PMA, formulations 5 and 6. In fact the Sulfur-free P(M)A without amine functionality has no more copper corrosion than the baseline with no polymer, formulation 7.

[0200] Comparing ZF copper corrosion test data, tests showed lower copper in solution, and lower mass loss from the test piece for the formulations containing the Sulfur-free P(M)As. 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. The products formed thereby, including the products formed upon employing lubricant 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 lubricant composition prepared by admixing the components described above.

[0201] Each of the documents referred to above is incorporated herein by reference. 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." 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. However, the amount of each chemical component is presented exclusive of any solvent or diluent oil, which may be customarily present in the commercial material, unless otherwise indicated. It is to be understood that the upper and lower amount, range, and ratio limits set forth herein may be independentlycombined. Similarly, the ranges and amounts for each element of the invention may be used together with ranges or amounts for any of the other elements.

[0202] 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: hydrocarbon substituents, including aliphatic, alicyclic, and aromatic substituents; substituted hydrocarbon substituents, that is, substituents containing non-hydrocarbon groups which, in the context of this invention, do not alter the predominantly hydrocarbon nature of the substituent; and hetero substituents, that is, substituents which similarly have a predominantly hydrocarbon character but contain other than carbon in a ring or chain. A more detailed definition of the term "hydrocarbyl substituent" or "hydrocarbyl group" is described in paragraphs

[0118] to

[0119] of International Publication W02008147704, or a similar definition in paragraphs

[0137] to

[0141] of published application US 2010-0197536.

[0203] 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.

[0204] While the invention has been explained in relation to its preferred embodiments, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. Therefore, it is to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims.

Claims

What is claimed is:1 . A lubricant formulation comprising a. an oil of lubricating viscosity, and b. a sulfur-free poly(meth)acrylate polymer (“PMA”) having a numberaverage molecular weight of about 1000 to about 25,000 g / mol and optionally nitrogen -containing groups c. less than 100 ppm sulfur and from 100 to 5000 ppm phosphorus.

2. The lubricant formulation of claim 1, further comprising a phosphorous antiwear agent sufficient to provide 100 to 5000 parts per million phosphorus to the composition.

3. The lubricant formulation of any previous claim, further comprising a triazole corrosion inhibitor.

4. The lubricant formulation of claim 3, wherein the triazole comprises a 1,2,4-triazole.

5. The lubricant formulation of any previous claim, wherein the low molecular weight, sulfur-free poly(meth)acrylate polymer is prepared by reversible addition-fragmentation chain transfer polymerization of (meth) acrylate monomers, optionally where one or more (meth) crylate monomers has a nitrogen-containing group.

6. The lubricant formulation of any previous claim, wherein the low molecular weight, sulfur-free dispersant poly (meth) acrylate polymer comprises, a. a (meth)aciylate backbone, b. a copolymerized amine-functional monomer(s) c. a chain transfer agent having the structure,wherein R1, R2, R3, R4, R5and R6are each independently selected from group consisting of hydrogen, — CH(O), — CN, isocyanato, and salts and esters thereof, NR7R8, a silane, a halogen, — C(O)OR9, — C(O)NRi°Rii, — CR12(O), — C(O)OC(O)R13, — C(O)NRi4COR15, — OC(O)R16, — OR17, substituted and unsubstituted alkyl, substituted and unsubstituted alkenyl, substituted and unsubstituted alkynyl, and substituted and unsubstituted aryl; R7, R8, R9, R10, R11, R12, R13, R14, R15, and R16are each independently selected from the group consisting of H, alkyl, aryl, substituted alkyl or substituted aryl; R17is selected from the group consisting of alkyl, aryl, substituted alkyl or substituted aryl; and the alkyl and the substituted alkyls have a chain consisting of 1 to 12 carbons, wherein the poly(meth)aciylate polymer contains no more than 40 ppm sulfur, or no more than 30 ppm sulfur, or no more than 20 ppm sulfur.

7. The lubricant of claim 6, wherein at least one of Rl, R2, R3, R4, R5, R6 is hydrogen.

8. The lubricant of claim 6, wherein the chain transfer agent is alphamethylstyrene dimer (“AMSD”).

9. A method of lubricating a driveline of a vehicle comprising, a. applying to the driveline a lubricant formulation as set forth in any of claims 1 to 8, b. operating the vehicle.

10. The method of claim 9, wherein the vehicle is a hybrid electric vehicle.

11. The method of claim 9, wherein the vehicle is an electric vehicle.

Images