DRIVE TRAIL LUBRICANT CONTAINING POLYETHER

Description

BACKGROUND OF THE INVENTION

[0001] The present technology is directed to a lubricant formulation containing a polyether, and where the lubricant contains a thiadiazole, as well as a method of minimizing conductive deposits therewith.

[0002] Powertrains and other devices in electric vehicles are often lubricated with an oil-based lubricant composition which serves to lubricate moving parts and remove heat. Such compositions may include a lubricating base oil as a major component, and one or more lubricant oil additives, as a minor component, such as antioxidants, detergents, dispersants, antiwear additives, corrosion inhibitors, viscosity modifiers, metal passivators, pour point depressants, seal compatibility agents, antifoam agents, extreme pressure agents, friction modifiers, and the like. Electrical wiring and other current-carrying components of the lubricated device are generally sheathed or coated to minimize contact with the lubricant composition. However, over time, the electrical components may become exposed to the lubricant composition due to wear or heat damage. For example, copper conductors can become overheated, putting stress on the coating, causing it to fail. When this occurs, the lubricant composition can come into contact with the exposed electrical wiring and deposits may form on the wiring. Depending on the chemical nature of the deposits, they may be electrically conducting or non-conducting. Conductive deposits are particularly problematic as they can lead to current flow between closely spaced wires and eventual failure of the electrical device. Additionally, in some components, such as circuit boards, the wiring may be uncoated. These can be exposed to the vapor phase of the lubricant composition and may also suffer deposit formation.

[0003] It is to be expected that certain lubricant additives, singly or in combination, may be more prone to cause such deposits in electromechanical devices, such as drivetrains. Further, such devices may be exposed to a vapor phase of the lubricant, which could cause a different type or rate of deposition formation to the liquid phase. However, to date, there has been no method to evaluate lubricant compositions under the conditions commonly experienced in devices which may operate at relatively high temperatures and employing high voltages.

[0004] Lubricating fluids for conventional internal combustion engines commonly employ additives to provide sufficient amounts of sulfur and phosphorus to deliver wear and extreme-pressure protection to mechanical components. However, such additives in lubricating fluids for electric motor or hybrid-electric motors may pose problems because active sulfur and phosphorus compounds are often chemically aggressive to copper wire and copper-based alloys used in electric and or hybrid-electric motors. In addition, sulfur and phosphorus compounds are often conductive, and the inclusion of active sulfur and phosphorus compounds in a lubricant can lead to undesirable increase in the lubricant's electrical conductivity. Thus, lubricating fluids for electric and hybrid-electric motors have the added challenge of maintaining a relatively low electrical conductivity while still protecting copper components and delivering sufficient protection for mechanical components

[0005] In general, it is necessary to implement, in electric or hybrid vehicles, lubricating compositions, also called "lubricants", for the main purposes of reducing the frictional forces between the various parts of the propulsion system. of the vehicle, especially between moving metal parts in the engines. These lubricating compositions are also effective in preventing premature wear or even damage to these parts, and in particular to their surface.

[0006] To do this, a lubricating composition is conventionally composed of one or more base oil(s) and "anti-wear" additives to reduce the wear of the mechanical parts of the engine, and thus prevent a deterioration in the durability of the engine. There is a wide variety of anti-wear additives, among which mention may be made, for example, of dimercaptothiadiazoles, polysulfides, in particular sulfur olefins, amine phosphates, or even phospho-sulfur additives, such as amine salts of alkylthiophosphates.

[0007] Unfortunately, these amine and / or sulfur anti-wear additives, such as dimercaptothiadiazoles and amine (thio)phosphate salt have the when used in lubricants have the disadvantage of deposits forming on the wiring, especially copper, when the lubricant comes in contact with the electrical componentry in the transmission of an electric or hybrid vehicle. Conductive deposits are particularly problematic as they can lead to current flow between closely spaced wires and eventual failure of the electrical device. The deposit formation is particularly critical in electric propulsion systems. In particular, this deposit formation can lead to a risk of damage to the winding of the stator and rotor, to the sensors in the propulsion system, to the solenoid valves in the hydraulic system, but also to the bearings located between the rotor and the stator of a motor. electrical, generally copper-based, and therefore particularly sensitive to corrosion, or seals or varnishes present in the propulsion system.

[0008] WO PCT Patent applications WO2020260458A1, WO2020260457A1, WO2020260462A1, and WO2020260460A1 disclose the use of benzotriazole, succinimides, hindered aromatic amines or phenols, and sulfur and amine free phosphorous compounds for use with amine salts and / or sulfur anti-wear additives to minimize copper corrosion. These approaches are concerned with the loss in the diameter of a copper wire as measured by the variation in the value of the electrical resistance of the copper wire while immersed in the lubricating fluid. These approaches do not address the problem of deposit formation, especially conductive deposits on the copper components in a propulsion system of a hybrid or electric vehicle when amines salts and / or sulfur anti-wear agents a present in the lubricant.

[0009] US Patent US11,326,123 discloses a durable lubricating fluid for an electric motor or hybrid-electric motor. The disclosed technology relates to a durable, as measured ty the electrical conductivity durability, said lubricating fluid comprising an oil of lubricating viscosity, a thiadiazole or derivative thereof, an amine salt of a phosphoric acid ester, and having a sulfur plus phosphorus to nitrogen ((S+P) / N)) weight ratio of at least 2.3 and at least 2000ppm of sulfur delivered by the thiadiazole compound. The focus of this patent is on the durability of the conductivity of the lubricating fluid and is silent on the issue of copper corrosion caused by the thiadiazole and amine salt of the phosphoric acid ester.

[0010] BEYER MONICA ET AL: "Lubricant Concepts for Electrified Vehicle Transmissions and Axles", TRIBOLOGY ONLINE, vol. 14, no. 5, 15 December 2019 (2019-12-15), pages 428-437, ISSN: 1881-218X, DOI: 10.2474 / trol.14.428, CN 115 161 097 A, WO 2021 / 247428 A1 disclose that conductive deposits / vapour phase corrosion are an issue when lubricating electrified vehicle powertrains.

[0011] Thus, there is a need for a lubricant formulation, particularly in lubricant's containing sulfur, to prevent conductive deposits.SUMMARY OF THE INVENTION

[0012] In one embodiment, the disclosed technology, solves the problem of conductive deposits by preparing a formulation containing a polyether.

[0013] Thus, one aspect of the technology includes a lubricant composition including an oil of lubricating viscosity, an amine (thio)phosphate salt, and 0.5 to 10.0 % weight of a polyether comprising formula I, II, or III.

[0014] The polyether can include, for example, those of formula I: wherein R1 can be a hydrocarbyl group having 6 to 30 carbon atoms, R2 can be hydrogen or an alkyl group having 1 to 5 carbon atoms, and R3 can be hydrogen, an C1-C4 alkyl group, or -C(O)R4, and wherein R4 can be a C1-C4 alkyl group and x can be an integer from 10-40 (15-35 or 20-30 or 22-26).

[0015] The polyether can also include those of formula II: wherein R5 can be a linear or branched aliphatic group having from 1 to 30 carbon atoms, in another embodiment 10 to 20 carbon atoms, R2 can be hydrogen or an alkyl group having 1 to 5 carbon atoms, and R3 can be hydrogen, an C1-C4 alkyl group, -C(O)R4 wherein R4 can be a C1-C4 alkyl group and n can be an integer from 10-40 (15-35 or 20-30 or 22-26) m can be an integer from 1 to 3.

[0016] The polyether also includes those of formula III: wherein the hydrocarbyl group R1 can be a linear or branched aliphatic group having from 7 to 23 carbon atoms, R2 can be hydrogen or an alkyl group having 1 to 5 carbon atoms, and R3 can be hydrogen, an C1-C4 alkyl group, or - C(O)R4 and wherein R4 can be a C1-C4 alkyl group and n can be an integer from 10-40 (15-35 or 20-30 or 22-26), and m can be an integer from 1 to 3.

[0017] The lubricant also includes a thiadiazole, such as a 1,3,4-thiadiazole or a 2,5-thiadiazole.

[0018] The lubricant can also include other common additives known in the art, such as, dispersant, antioxidant, dispersant viscosity modifier, detergent, anti-wear additive, etc.

[0019] Also included in the technology is a method of minimizing electrically conductive deposits in the propulsion system of an electric or hybrid vehicle. The method includes applying to said propulsion system a lubricant as discussed herein, and operating the propulsion system.DETAILED DESCRIPTION OF THE INVENTION

[0020] Various preferred features and embodiments will be described below by way of non-limiting illustration.

[0021] The technology provides a method of minimizing electrically conductive deposits in the propulsion system of an electric or hybrid vehicle by applying to the propulsion system a lubricant containing an oil of lubricating viscosity, a polyether, and an amine (thio)phosphate salt.

[0022] The lubricating composition includes an oil of lubricating viscosity. Such oils include natural and synthetic oils, oil derived from hydrocracking, hydrogenation, and hydrofinishing, unrefined, refined, re-refined oils or mixtures thereof. A more detailed description of unrefined, refined and rerefined oils is provided in International Publication WO2008 / 147704, paragraphs

[0054] to

[0056] (a similar disclosure is provided in US Patent Publication 2010 / 0197536, see

[0072] to

[0073] ). Amore detailed description of natural and synthetic lubricating oils is described in paragraphs

[0058] to

[0059] respectively of WO2008 / 147704 (a similar disclosure is provided in US Patent Publication 2010 / 0197536, see

[0075] to

[0076] ). Synthetic oils may also be produced by Fischer-Tropsch reactions and typically may be hydroisomerized Fischer-Tropsch hydrocarbons or waxes. In one embodiment, oils may be prepared by a Fischer-Tropsch gas-to-liquid synthetic procedure as well as other gas-to-liquid oils.

[0023] Oils of lubricating viscosity may also be defined as specified in the April 2008 version of "Appendix E-API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils", section 1.3 Subheading 1.3. "Base Stock Categories". The API Guidelines are also summarized in U.S. Pat. No. 7,285,516 (see column 11, line 64 to column 12, line 10). In one embodiment, the oil of lubricating viscosity may be an API Group II, Group III, or Group IV oil, or mixtures thereof. The five base oil groups are as follows: Base Oil CategorySulfur (%)Saturates (%)Viscosity IndexGroup I>0.03 and / or<9080 to 120Group II≤0.03 and≥9080 to 120Group III≤0.03 and≥90≥120Group IVAll polyalphaolefins (PAO)Group VAll others not included in Groups I, II, III, or IV

[0024] The amount of the oil of lubricating viscosity present is typically the balance remaining after subtracting from 100 weight % (wt %) the sum of the amount of the compound of the invention and the other performance additives.

[0025] The lubricating composition may be in the form of a concentrate and / or a fully formulated lubricant. If the lubricating composition of the invention (comprising the additives disclosed herein) is in the form of a concentrate which may be combined with additional oil to form, in whole or in part, a finished lubricant, the ratio of the of these additives to the oil of lubricating viscosity and / or to diluent oil include the ranges of 1:99 to 99:1 by weight, or 80:20 to 10:90 by weight.

[0026] In one embodiment, the base oil has a kinematic viscosity at 100° C. from 2 mm2 / s (centi Stokes-cSt) to 16 mm2 / s, from 3 mm2 / s to 10 mm2 / s, or even from 4 mm2 / s to 8 mm2 / s.

[0027] The ability of a base oil to act as a solvent (i.e. solvency) may be a contributing factor in increasing the frequency of LSPI events during operation of a direct fuel-injected engine. Base oil solvency may be measured as the ability of unadditized base oil to act as a solvent for polar constituents. In general, base oil solvency decreases as the base oil group moves from Group I to Group IV (PAO). That is, solvency of base oil may be ranked as follows for oil of a given kinematic viscosity: Group I>Group II>Group II>Group IV. Base oil solvency also decreases as the viscosity increases within a base oil group; base oil of low viscosity tends to have better solvency than similar base oil of higher viscosity. Base oil solvency may be measured by aniline point (ASTM D611).

[0028] In one embodiment, the base oil contains at least 30 wt % of Group II or Group III base oil. In another embodiment, the base oil contains at least 60 weight % of Group II or Group III base oil, or at least 80 wt % of Group II or Group III base oil. In one embodiment, the lubricant composition contains less than 20 wt % of Group IV (i.e. polyalphaolefin) base oil. In another embodiment, the base oil contains less than 10 wt % of Group IV base oil. In one embodiment, the lubricating composition is substantially free of (i.e. contains less than 0.5 wt %) of Group IV base oil.

[0029] Ester base fluids, which are characterized as Group V oils, have high levels of solvency as a result of their polar nature. Addition of low levels (typically less than 10 wt %) of ester to a lubricating composition may significantly increase the resulting solvency of the base oil mixture. Esters may be broadly grouped into two categories: synthetic and natural. An ester base fluid would have a kinematic viscosity at 100° C. suitable for use in an engine oil lubricant, such as between 2 cSt and 30 cSt, or from 3 cSt to 20 cSt, or even from 4 cSt to 12 cSt.

[0030] Synthetic esters may comprise esters of dicarboxylic acids (e.g., phthalic acid, succinic acid, alkyl succinic acids and alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acids, and alkenyl malonic acids) with any of variety of monohydric alcohols (e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, and propylene glycol). Specific examples of these esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl diester of linoleic acid dimer, and the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two moles of 2-ethylhexanoic acid. Other synthetic esters include those made from C5 to C12 monocarboxylic acids and polyols and polyol ethers such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, and tripentaerythritol. Esters can also be monoesters of monocarboxylic acids and monohydric alcohols.

[0031] Natural (or bio-derived) esters refer to materials derived from a renewable biological resource, organism, or entity, distinct from materials derived from petroleum or equivalent raw materials. Natural esters include fatty acid triglycerides, hydrolyzed or partially hydrolyzed triglycerides, or transesterified triglyceride esters, such as fatty acid methyl ester (or FAME). Suitable triglycerides include, but are not limited to, palm oil, soybean oil, sunflower oil, rapeseed oil, olive oil, linseed oil, and related materials. Other sources of triglycerides include, but are not limited to, algae, animal tallow, and zooplankton. Methods for producing bio-lubricants from natural triglycerides are described in, e.g., United States Patent Publication 2011 / 0009300A1.

[0032] In one embodiment, the lubricating composition can include at least 2 wt % of an ester base fluid. In one embodiment the lubricating composition of the invention comprises at least 4 wt % of an ester base fluid, or at least 7 wt % of an ester base fluid, or even at least 10 wt % of an ester base fluid

[0033] Polyethers can be prepared by condensing an alcohol, a hydrocarbyl carboxylic acid, or alkylphenol with an alkylene oxide, mixture of alkylene oxides or with several alkylene oxides in sequential fashion in a 1:2-50 mole ratio of hydric compound to alkylene oxide to form a polyether. U.S. Pat. No. 5,094,667 provides reaction conditions for preparing polyethers. Examples of the alkylene oxides include ethylene oxide, propylene oxide or butylene oxide. The number of alkylene oxide units in the polyether intermediate can be 10-35 or 18-27.

[0034] In one embodiment, a polyether for the lubricant can be prepared from a primary alcohol. Suitable primary alcohols for use herein may contain from 6 to 30 carbon atoms, in another embodiment 8 to 24, or 10 to 20 carbon atoms. Mixtures of alcohols are contemplated. In one embodiment, the alcohol mixture used is at least 50 wt. %, or at least 60 wt. %, or at least 80 wt. %, or at least 90 wt. % of alcohols with at least 10 aliphatic carbon atoms, or at least 12 aliphatic carbon atoms. In one embodiment, the alcohol mixture used contains no more than 5.0 wt. % of C6 and lower linear alcohol, or no more than 2 wt. % or no more than 1 wt. %.

[0035] The primary alcohol may be linear or may be branched at the α-, or β-, or higher position with the proviso that there is no more than 3 branch points or no more than 2 branch points or no more than 1 branch points. In one embodiment, a mixture of linear and branched alcohols is employed.

[0036] Examples of useful primary linear alcohols include, decanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, or mixtures thereof. In one embodiment the linear alcohol contains 10 to 30, or 10 to 25, or 12 to 22 carbon atoms (typically 10 to 22 carbon atoms).

[0037] Other exemplary primary alcohols include commercially available mixtures of alcohols. These include oxoalcohols which may comprise, for example, various mixtures of alcohols having from 8-24 carbon atoms. Of the various commercial alcohols useful herein, one 12 to 18 aliphatic carbon atoms. The alcohols in the mixture may include one or more of, for example, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, dodecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, and octadecyl alcohol. Several suitable sources of these alcohol mixtures are the technical grade alcohols sold under the name NE-ODOL ®< alcohols (Shell Oil Company, Houston, Tex.) and under the name AL-FOL ®< alcohols (Sasol, Westlake, La.), and fatty alcohols derived from animal and vegetable fats and sold commercially by, for example, Henkel, Sasol, and Emery.

[0038] In some embodiments, the alcohol includes one or more Guerbet alcohols. Guerbet alcohols may be described as alcohols made via the Guerbet reaction, which was named after Marcel Guerbet. In a Guerbet reaction, a primary aliphatic alcohol is converted to its β-alkylated dimer alcohol (i.e., a branched, primary, saturated alcohol). In some embodiments, the alcohol includes at least one compound with the structure: HO-CH2-(R1 ),,- CR2R3R4 where R1 is a alkylene group containing from 1 to 20 carbon atoms, n is either 0 or 1, and each of R2, R3 and R4 are independently hydrogen or alkyl groups containing from 1 to 20 carbon atoms. In some embodiments, n is zero, and R2 and R3 are alkyl groups, and R4 is hydrogen. In such embodiments, R2 and R3 may contain from 4 to 14, or even from 6 to 12 carbon atoms. In still further embodiments, R2 and R3 contain 6 and 8, or 10 and 12 carbon atoms. Suitable examples of the alcohol useful in the invention include 2-ethylhexanol, 2-butyloctanol, 2-hexyldecanol, 2-octyldodecanol, 2-decyltetradecanol, 2-dodecylhexadecanol, or any combination thereof. These types of alcohols are commercially available from Sasol and marketed as ISOFOL ®< alcohols. In some embodiments, the alcohol includes 2-hexyldecanol, 2-decyltetradecanol, or any combination thereof. In some embodiments, the alcohol includes 2-hexyldecanol. In some embodiments, the alcohol includes 2-decyltetradecanol.

[0039] In another embodiment, the alcohol can be an alcohol with an isoalkly group. An isoalkyl group is a group of atoms resulting from the removal of a hydrogen atom from a methyl group situated at the end of the straight chain segment of an isoalkane. Particularly useful alcohols with an isoalkyl group are those where the methyl group is attached to the penultimate carbon atom of the main chain. Exemplary alcohols of this type are isodecanol, isododecanol, isotridecanol, isotetradecanol, isopentadecanol, isohexadecanol, isoheptade-canol, isooctadecanol, isononadecanol, isoeicosanol.

[0040] In an embodiment, the polyether can be of the formula wherein R1 is hydrocarbyl group having 6 to 30 carbon atoms, R2 is hydrogen or an alkyl group having 1 to 5 carbon atoms, and R3 is hydrogen, an C1-C4 alkyl group, -C(O)R4, wherein R4 is a C1-C4 alkyl group and x is an integer from 10-40 (15-35 or 20-30 or 22-26).

[0041] In an embodiment the polyether of formula I wherein the hydrocarbyl group R1 is a linear aliphatic group from 6 to 30 carbon atoms, in another embodiment 8 to 24, or 10 to 20 carbon atoms, in yet another embodiment from 10 to 18 carbon atoms.

[0042] In an embodiment the polyether of formula I wherein the hydrocarbyl group R1 is a branched aliphatic group from 6 to 30 carbon atoms, in another embodiment 8 to 24, or 10 to 20 carbon atoms, in yet another embodiment from 10 to 18 carbon atoms.

[0043] In an embodiment the polyether of formula I wherein the hydrocarbyl group R1 is a linear aliphatic group from 6 to 30 carbon atoms, in another embodiment 8 to 24, or 10 to 20 carbon atoms, in yet another embodiment from 10 to 18 carbon atoms and R3 is hydrogen

[0044] In an embodiment the polyether of formula I wherein the hydrocarbyl group R1 is a branched aliphatic group from 6 to 30 carbon atoms, in another embodiment 8 to 24, or 10 to 20 carbon atoms, in yet another embodiment from 10 to 18 carbon atoms and R3 is hydrogen

[0045] In different embodiments the polyethers of formulae I is present in an amount ranging from 0.01 weight % to 2 weight %, or 0.02 to 1 weight %, or 0.04 to 0.6 weight %, or even 0.25 to 0.5 weight % of the lubricating composition. Typically the polyethers of formulae I is present in an amount from 0.05 to 1 weight % of the lubricating composition.

[0046] In one embodiment, the polyether is prepared from an alkylphenol. The alkyl group of the alkylphenols can be 1 to 30 carbon atoms, in another embodiment 10 to 20 carbon atoms.

[0047] In some embodiments, the polyether may comprise an oxyalkylated hydrocarbyl phenol represented by Formula II: wherein each R2 is independently hydrogen or a hydrocarbyl group of 1 to 6 carbon atoms; R3 is hydrogen, a C1-C4 alkyl group, -C(=O)R4, wherein R4 is a C1-C4 alkyl group. In some embodiments each, R5 of Formula II is a hydrocarbyl group of 1 to 24 carbon atoms; 10 to 24 (such as from 12 to 24, from 14 to 24, from 16 to 24, from 18 to 24, from 20 to 24, from 22 to 24, from 10 to 22, from 12 to 22, from 14 to 22, from 16 to 22, from 18 to 22, from 20 to 22, from 10 to 20, from 12 to 20, from 14 to 20, from 16 to 20, from 18 to 20, from 10 to 18, from 12 to 18, from 14 to 18, from 16 to 18, from 10 to 16, from 12 to 16, from 14 to 16, from 10 to 14, from 12 to 14, or from 10 to 12) carbon atoms.

[0048] The oxyalkylated hydrocarbyl phenol of Formula II is selected such that the R2 group is methyl, R3 is hydrogen, an alkyl group of 1 to 4 carbon atoms, or an acyl group represented by -C(=O)R4, R4 is an alkyl group of 1 to 4 carbon atoms; R5 is an aliphatic hydrocarbyl group having from 10 to 24 (such as from 12 to 24, from 14 to 24, from 16 to 24, from 18 to 24, from 20 to 24, from 22 to 24, from 10 to 22, from 12 to 22, from 14 to 22, from 16 to 22, from 18 to 22, from 20 to 22, from 10 to 20, from 12 to 20, from 14 to 20, from 16 to 20, from 18 to 20, from 10 to 18, from 12 to 18, from 14 to 18, from 16 to 18, from 10 to 16, from 12 to 16, from 14 to 16, from 10 to 14, from 12 to 14, or from 10 to 12) carbon atoms, n = 2 to 8 (or 3 to 5); and m = 1.

[0049] The R5 group of each of the formulae II above may be located in the para position relative to the oxyalkylated group, and the resultant formula is represented by the structure: wherein variables R2 to R5, and n, are defined previously.

[0050] In one embodiment, the oxyalkylated hydrocarbyl phenol of Formula II is selected such that the R2 group is methyl, R3 is hydrogen, an alkyl group of 1 to 4 carbon atoms, or an acyl group represented by -C(=O)R4, R4 is an alkyl group of 1 to 4 carbon atoms; R5 is an aliphatic hydrocarbyl group having from 10 to 24 (such as from 12 to 24, from 14 to 24, from 16 to 24, from 18 to 24, from 20 to 24, from 22 to 24, from 10 to 22, from 12 to 22, from 14 to 22, from 16 to 22, from 18 to 22, from 20 to 22, from 10 to 20, from 12 to 20, from 14 to 20, from 16 to 20, from 18 to 20, from 10 to 18, from 12 to 18, from 14 to 18, from 16 to 18, from 10 to 16, from 12 to 16, from 14 to 16, from 10 to 14, from 12 to 14, or from 10 to 12) carbon atoms, n = 2 to 8 (or 3 to 5); and m = 1.

[0051] In one embodiment, the oxyalkylated hydrocarbyl phenol of the present invention is represented by Formula II(b) wherein R5 can be a linear or branched aliphatic group having from 1 to 30 carbon atoms, in another embodiment 10 to 20 carbon atoms, R2 can be hydrogen or an alkyl group having 1 to 5 carbon atoms, and R3 can be hydrogen, an C1-C4 alkyl group, -C(O)R4 wherein R4 can be a C1-C4 alkyl group and n can be an integer from 10-40 (15-35 or 20-30 or 22-26) m can be an integer from 1 to 3.

[0052] The oxyalkylated group of the oxyalkylated hydrocarbyl phenol has the formula -(R10),,-, wherein R1 is an ethylene, propylene, butylene group, or mixtures thereof; and n may independently be from 1 to 50, or 1 to 20, or 1 to 10, or 2 to 5.

[0053] The oxyalkylated group of the oxyalkylated hydrocarbyl phenol may be either a homopolymer or copolymer or oligomers thereof. If the oxyalkylated group is in the form of a copolymer, or oligomer thereof, the oxyalkylated group may have either random or block architecture.

[0054] In one embodiment, the oxyalkylated group (or R1) is a propylene, or butylene group i.e., the oxyalkylated group does not require an ethylene group. If an ethylene group is present the oxyalkylate group may be a copolymer, or oligomer thereof with either propylene or butylene oxide i.e., blocks of (i) - CH2CH2O- with (ii) -CH2CH2CH2CH2O- or -CH2CH(CH3)CH2O- or -CH2CH(CH3)O-.

[0055] In one embodiment, the oxyalkylated group is based upon propylene oxide.

[0056] The oxyalkylated hydrocarbyl phenol can be prepared by reacting a hydrocarbyl substituted phenol with an alkylene oxide (typically ethylene oxide, propylene oxide or butylene oxide), optionally in the presence of a base catalyst. Typically the reaction occurs in the presence of a base catalyst.

[0057] The base catalyst may include, but is not limited to, sodium chloroacetate, sodium hydride or potassium hydroxide

[0058] The aliphatic hydrocarbyl group (also represented by R4) is linear or branched, typically with at least one branching point. The aliphatic hydrocarbyl group typically has one, although it may in some embodiments be desirable to have to R4 groups, with the second group being methyl. If a second R4 group is present and is methyl, then the oxyalkylated hydrocarbyl phenol is a cresol.

[0059] In different embodiments, the oxyalkylated hydrocarbyl phenol of the present invention is present in an amount ranging from 0.01 weight % to 5 weight %, or 0.05 to 3.5 weight %, or 0.1 to 2.5 weight % of the lubricating composition. Typically, the polyethers of formulae I is present in an amount from 0.25 to 2 weight % of the lubricating composition.

[0060] In one embodiment, the polyether is prepared from a hydrocarbyl carboxylic acid with from 8 to 24 carbon atoms, in another embodiment from 12 to 24 carbon atoms in yet another embodiment from 14-18 carbon atoms.

[0061] In some embodiments, the polyether may comprise an oxyalkylated hydrocarbyl phenol represented by Formula III: wherein the hydrocarbyl group R1 is a linear or branched aliphatic group having from 7 to 23 carbon atoms, in another embodiment 11 to 23 or 13 to17 carbon atoms R2 is hydrogen or an alkyl group having 1 to 5 carbon atoms, and R3 is hydrogen, an C1-C4 alkyl group, or -C(O)R4, R4 is a C1-C4 alkyl group and n is an integer from 10-40 (15-35 or 20-30 or 22-26) m is an integer from 1 to 3.

[0062] Examples of the oxyalkylated hydrocarbyl carboxylic acids include but are not limited to tall oil fatty acid initiated polypropyleneoxide (22-24) ester-ol, butanol initiated polypropyleneoxide (23-25) ether-tallow fatty acid ester, tallow fatty acid initiated polypropyleneoxide (22-24) ester-ol. These alkoxylates can be made from the reaction of a fatty acid such as tall oil fatty acids (TOFA) that is, the mixture of fatty acids predominately oleic and linoleic and contains residual rosin acids or tallow acid that is, the mixture of fatty acids predominately stearic, palmitic and oleic with an alcohol terminated polyether such as polypropylene glycol in the presence of an acidic catalyst, usually methane sulphonic acid. These alkoxylates can also be made from the reaction of glycerol dioleate and propylene oxide in the presence of catalyst

[0063] The lubricant in the method contains oil-soluble amine salt or amine adducts of a phosphoric acid ester, such as those taught in U.S. Pat. Nos. 5,354,484, 5,763,372, and 5,942,470. The amine salts or adducts of a phosphoric acid ester may be prepared by reacting a phosphoric acid ester with ammonia or a basic nitrogen compound, such as an amine. The salts may be formed separately, and then the salt of the phosphoric acid ester may be added to the lubricating composition. The phosphoric acid esters useful in preparing the amine salts of the present invention may be characterized by the formula; wherein R1 is hydrogen or a hydrocarbyl group, R2 is a hydrocarbyl group, and both X groups are either O or S.

[0064] A preferred method of preparing compositions containing (I) comprises reacting at least one hydroxy compound of the formula ROH with a phosphorus compound of the formula P2X5 wherein R is a hydrocarbyl group and X is O or S. The phosphorus-containing compositions obtained in this manner are mixtures of phosphorus compounds, and are generally mixtures of mono- and dihydrocarbyl-substituted phosphoric and / or dithiophosphoric acids depending on a choice of phosphorus reactant (i.e., P20 5 or P2S5). The hydroxy compound used in the preparation of the phosphoric acid esters of this invention are characterized by the formula ROH wherein R is a hydrocarbyl group. The hydroxy compound reacted with the phosphorus compound may comprise a mixture of hydroxy compounds of the formula ROH wherein the hydrocarbyl group R contains from about 1 to 40 carbon atoms. It is necessary, however, that the amine salt of the substituted phosphoric acid ester ultimately prepared is soluble in the lubricating compositions of the present invention. Generally, the R group will contain at least 2 carbon atoms, typically 4 to 40, or 6 to 39, or 6 to 18, or 8 to 18 carbon atoms. The R group may be aliphatic or aromatic such as alkyl, aryl, alkaryl, aralkyl and alicyclic hydrocarbon groups. Examples of useful hydroxy compounds of the formula ROH includes, for example, ethyl alcohol, iso-propyl, n-butyl alcohol, amyl alcohol, hexyl alcohol, 2-ethyl-hexyl alcohol, nonyl alcohol, dodecyl alcohol, stearyl alcohol, amyl phenol, octyl phenol, nonyl phenol, methyl cyclohexanol, alkylated naphtha, etc.

[0065] The preferred alcohols, ROH, are aliphatic alcohols and more particularly, primary aliphatic alcohols containing at least about 4 carbon atoms. Accordingly, examples of the preferred monohydric alcohols ROH which are useful in the present invention include, amyl alcohol, 1-octanol, 1-decanol, 1-dodecanol, 1-tetradecanol, 1-hexadecanol, 1-octadecanol, oleyl alcohol, linoleyl alcohol, linolenyl alcohol, phytol, myricyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol and behenyl alcohol. Commercial alcohols (including mixtures) are contemplated herein, and these commercial alcohols may comprise minor amounts of alcohols which, although not specified herein, do not detract from the major purposes of this invention.

[0066] The amine salts of the present invention can be prepared by reaction of the above-described phosphoric acid esters such as represented by Formula I with at least one amino compound which may be a primary amine, a secondary amine, a tertiary amine, or mixtures thereof. The amine may be aliphatic, or cyclic, aromatic or non-aromatic, Typically, aliphatic. In one embodiment the amine includes an aliphatic amine such as a tertiary-aliphatic primary amine.

[0067] Examples of suitable primary amines include ethylamine, propyl amine, butylamine, 2-ethylhexylamine, bis-(2-ethylhexyl)amine, octylamine, and dodecylamine, as well as such fatty amines as n-octylamine, n-decylamine, n-dodecyl amine, 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 0, Armeen OL, Armeen T, Armeen H T, Armeen S and Armeen S D, wherein the letter designation relates to the fatty group, such as coco, oleyl, tallow, or stearyl groups.

[0068] Examples of suitable secondary amines include dimethylamine, diethylamine, dipropylamine, dibutylamine, diamylamine, dihexylamine, diheptylamine, methylethylamine, ethylbutylamine, N-methyl-1-amino-cyclohexane, Amleen ®< 2C and ethylamylamine. The secondary amines may be cyclic amines such as piperidine, piperazine and morpholine. Examples of tertiary amines include tri-n-butylamine, tri-n-octylamine, tri-decylamine, tri-laurylamine, tri-hexadecylamine, and dimethyloleylamine (Amleen ®< DMOD).

[0069] In one embodiment the amines are in the form of a mixture. Examples of suitable mixtures of amines include (i) a tertiary alkyl primary amine with 11 to 14 carbon atoms, (ii) a tertiary alkyl primary amine with 14 to 18 carbon atoms, or (iii) a tertiary alkyl primary amine with 18 to 22 carbon atoms. Other examples of tertiary alkyl primary amines include tert-butyl amine, tert-hexyl amine, tertoctylamine (such as 1,1-dimethylhexylamine), tertdecylamine (such as 1,1-dimethyloctylamine), tertdodecylamine, tert-tetradecylamine, tert-hexadecylamine, tertoctadecylamine, tert-tetracosanyl amine, and tert-octacosanylamine.

[0070] In one embodiment a useful mixture of amines is "Primene ®< SIR" or "Primene ®< JMT." Primene ®< SIR and Primene ®< JMT (both produced and sold by Rohm & Haas) are mixtures of C11 to C14 tertiary alkyl primary amines and C18 to C22 tertiary alkyl primary amines respectively.

[0071] In one embodiment the lubricating composition contains a phosphorus compound that may be an amine salt of a phosphate hydrocarbon ester (i.e., an amine salt of a hydrocarbon ester of phosphoric acid). The amine salt of a phosphate hydrocarbon ester may be derived from an amine salt of a phosphate. The amine salt of the phosphate hydrocarbon ester may be represented by the formula: wherein R3 and R4 may be independently hydrogen or hydrocarbon typically containing 4 to 40, or 6 to 30, or 6 to 18, or 8 to 18 carbon atoms, with the proviso that at least one is a hydrocarbon group; and R5, R6 , R7 and R8 may be independently hydrogen or a hydrocarbyl group, with the proviso that at least one is a hydrocarbyl group. The hydrocarbon groups of R3 and / or R4 may be linear, branched, or cyclic. Examples of a hydrocarbon group for R3 and / or R4 include straight-chain or branched alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl.

[0072] Examples of a cyclic hydrocarbon group for R3 and / or R4 include cyclopentyl, cyclohexyl, cycloheptyl, methylcyclopentyl, dimethylcyclopentyl, methylcyclopentyl, dimethylcyclopentyl, methy lethy lcyclopenty 1, diethy 1-cyclopenty 1, methylcyclohexyl, dimethylcyclohexyl, methylethylcyclohexyl, diethylcyclohexyl, methylcycloheptyl, dimethylcycloheptyl, methylethyl-cycloheptyl, and diethylcycloheptyl.

[0073] In another embodiment, the phosphorus antiwear / extreme pressure agent can be a dithiophosphoric acid or phosphorodithioic acid. The dithiophosphoric acid may be represented by the formula (RO)2PSSH wherein each R is independently a hydrocarbyl group containing from about 3 to about 30 carbon atoms. R generally contains up to about 18, or to about 12, or to about 8 carbon atoms. Examples R 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-1-hexyl; isobutyl and n-hexyl; isobutyl and isoamyl; 2-propyl and 2-methyl-4-pentyl; isopropyl and sec-butyl; and isopropyl and isooctyl.

[0074] In one embodiment, the dithiophosphoric acid may be reacted with an epoxide or a glycol. 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. Propylene oxide is preferred. The glycols may be aliphatic glycols having from 1 to about 12, or about 2 to about 6, or 2 or 3 carbon atoms, or aromatic glycols. Glycols include ethylene glycol, propylene glycol, catechol, resorcinol, and the like. The dithiophosphoric acids, 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. The following Examples B-1 and B-2 exemplify the preparation of useful phosphorus acid esters.EXAMPLE B-1

[0075] Phosphorus pentoxide (64 grams) is added at 58° C. over a period of 45 minutes to 514 grams of hydroxypropyl O,O-di(4-methyl-2-pentyl)phosphorodi-thioate (prepared by reacting di(4-methyl-2-pentyl)-phosphorodithioic acid with 1.3 moles of propylene oxide at 25° C.). The mixture is heated at 75° C. for 2.5 hours, mixed with a diatomaceous earth and filtered at 70° C. The filtrate contains 11.8% by weight phosphorus, 15.2% by weight sulfur, and an acid number of 87 (bromophenol blue).EXAMPLE B-2

[0076] A mixture of 667 grams of phosphorus pentoxide and the reaction product of 3514 grams of diisopropyl phosphorodithioic acid with 986 grams of propylene oxide at 50° C. is heated at 85° C. for 3 hours and filtered. The filtrate contains 15.3% by weight phosphorus, 19.6% by weight sulfur, and an acid number of 126 (bromophenol blue).

[0077] Acidic phosphoric acid esters may be reacted with ammonia, an amine compound or a metallic base to form an ammonium or metal salt. The salts may be formed separately and then the salt of the phosphorus acid ester may be added to the lubricating composition. Alternately, the salts may also be formed in situ when the acidic phosphorus acid ester is blended with other components to form a fully formulated lubricating composition.

[0078] The amine salts of the phosphorus acid esters may be formed from ammonia, or an amine, including monoamines and polyamines. The amines may be primary amines, secondary amines or tertiary amines. In one embodiment, the amines are one or more of the amines described above for preparing the dithiocarbamates. Useful amines include those amines disclosed in U.S. Pat. No. 4,234,435 at Col. 21, line 4 to Col. 27, line 50.

[0079] The monoamines generally contain from 1 up to about 24 carbon atoms, or up to about 12, or up to about 6 carbon atoms. Examples of monoamines include methylamine, ethylamine, propylamine, butylamine, octylamine, and dodecylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, methyl butylamine, ethyl hexylamine, trimethylamine, tributylamine, methyl diethylamine, ethyl dibutylamine, etc.

[0080] In one embodiment, the amine may be a fatty (C4_30) amine which include n-hexylamine, n-octylamine, n-decylamine, n-dodecylamine, n-tetradecylamine, n-hexadecylamine, n-octadecylamine, oleylamine, etc. Also useful fatty amines include commercially available fatty amines such as "Armeen" amines (products available from Armak Chemicals, Chicago, Ill.), such as Armak's ArmeenC, Armeen-O, Armeen-OL, Armeen-T, Armeen-HT, Armeen S and Armeen SD, wherein the letter designation relates to the fatty group, such as cocoa, oleyl, tallow, or soya groups.

[0081] In one embodiment, the phosphorus antiwear agent may be the amine salt comprise a species represented by formula (I) or (II): or

[0082] The phosphorous amine salt is prepared or preparable by the reaction of phosphorus pentoxide with a secondary alcohol having about 3 to about 12 carbon atoms and reacting the product thereof with a hydrocarbyl amine. The hydrocarbyl amine may comprise at least one Ci-C20, C4-C18, or C6-C14 hydrocarbyl group. In the reaction to prepare the alkyl phosphate amine salt, the phosphorus pentoxide may be reacted with about 2.2 to about 3.1 moles, or about 2.3 to about 2.8 moles, or 2.4 to 2.4 per mole of P2O5, of the secondary alcohol at a temperature of about 30° C. to about 60° C.

[0083] The alkyl phosphate amine salt may comprise up to about 60 mole percent of the phosphorus atoms in mono- or di-alkyl-orthophosphate salt structures. In other embodiments, the alkyl phosphate amine salt may comprise at least about 50 to about 80, or 55 to 65 mole percent of the phosphorus atoms in an alkyl pyrophosphate salt structure.

[0084] In other embodiments, the hydrocarbyl amine can be a hindered amine represented by formula (III) R3-NR5-R4 wherein R3, R4, and R5 are independently a Cl-C30 hydrocarbyl group. In other embodiments, R3, R4, and R5 can independently be a Q-C^, C4-C18, or C6-C14 hydrocarbyl group. In another embodiment, the hindered hydrocarbyl amine may have at least one aromatic group. In other embodiments, the hydrocarbyl amine can be an aromatic amine having an alkyl group attached directly to a nitrogen atom that salts with the phosphate and wherein the nitrogen atom may optionally be further alkylated. In yet other embodiments the hydrocarbyl amine can be a tertiary alkyl amine with at least two branched alkyl groups. The at least two branched alkyl groups can independently be branched at the a or the β position. In yet other embodiments, the at least two branched alkyl groups can both be branched at the β position. In some embodiments, the alkyl group or groups of the alkylphosphate structure may comprise 4-methylpent-2-yl groups.

[0085] The corrosion inhibitor is a thiadiazole, such as a 1,3,4-thiadiazole. In embodiments, the 1,3,4-thiadiazole can include substituents at the 2 and 5 positions of the thiadiazole ring, such as, for example, alkyldisulfaneyl moieties. Such corrosion inhibitors can include those of formula wherein R1 and R2 are independently alkyl groups with 1 to 12 carbons.

[0086] In one embodiment, the corrosion inhibitor includes (i) a 2,5-bis(alkyl-dithio)-1,3,4-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-.

[0087] 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)-1,3,4-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)-1,3,4-thiadiazole, 2,5-bis(tert-nonyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-decyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-undecyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-dodecyldithio)-1,3,4-thiadiazole, or mixtures thereof.

[0088] 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)-1,3,4-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-.

[0089] In different embodiments the corrosion inhibitor is a thiadiazole. Thiadiazole corrosion inhibitors may be present alone or in mixtures with other thiadiazole 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.

[0090] The lubricant can also include other additives, such as, for example, dispersants, antioxidants, viscosity modifiers, detergents, and other antiwear agents (besides the amine(thio)phosphates above), to name a few. Those of ordinary skill in the art will understand the other additives available to employee in the lubricant.

[0091] Dispersants can include, for example, "succinimide dispersants," a species of carboxylic dispersants prepared by the reaction of a hydrocarbyl-substituted succinic anhydride or reactive equivalent thereof with an amine such as a poly(ethyleneamine); "amine dispersants," which are reaction products of relatively high molecular weight aliphatic or alicyclic halides and amines, such as polyalkylene polyamines; "Mannich dispersants," i.e., the reaction products of alkyl phenols in which the alkyl group contains at least 30 carbon atoms with aldehydes (especially formaldehyde) and amines (especially polyalkylene polyamines); and "ester dispersants," similar to the above-described succinimide dispersants except that they may be seen as having been prepared by reaction of a hydrocarbyl acylating agent and a polyhydric aliphatic alcohol such as glycerol, pentaerythritol, or sorbitol, as described in US Patent 3,381,022.

[0092] 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).

[0093] 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-dimercaptothiadiazole (DMTD), or an aromatic diacid having acid groups in 1,3 or 1,4 positions on a benzene ring (such as terepthahlic acid).

[0094] Borated dispersants are generally obtained by reacting a carboxylic (e.g., succinimide), amine or Mannich dispersant with a boron compound reagent, such as boric acid (to give "borated dispersants"). Dispersants and their method of production are well-known in the art. The borated dispersant may be further functionalized with a sulfur or phosphorus moiety. The dispersant component in the borated dispersant may be a mixture of multiple dispersants which may be of different types; optionally at least one may be a succinimide dispersant. In one embodiment the borated dispersant may be a borated polyisobutylene succinimide dispersant, in which the polyisobutylene portion thereof may have a number average molecular weight of 750 to 2200, or 750 to 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.

[0095] 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 11,500ppm or greater than or equal to about 12,000 ppm.

[0096] 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.

[0097] 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.

[0098] The dispersant can also be a grafted copolymer that is a condensation reaction product of an olefin polymer having carboxylic acid (or equivalent) functionality grafted thereon, the grafted olefin reacted with a monoamine or a polyamine which may have a single primary amino group. If the olefin polymer is an ethylene / propylene copolymer, then said polyamine is not a poly(ethylene amine).

[0099] The polymer substrate will be an olefin polymer such as that described above. The olefin polymer substrate employed in the derivatized graft copolymer will contain grafted carboxylic acid functionality or a reactive equivalent of carboxylic acid functionality (e.g., anhydride or ester). The reactive carboxylic acid functionality will typically be present as a pendant group attached by, for instance, a grafting process.

[0100] An ethylenically unsaturated carboxylic acid material is typically radically grafted onto the polymer backbone. These materials which are attached to the polymer typically contain at least one ethylenic bond (prior to reaction) and at least one, such as two, carboxylic acid (or its anhydride) groups or a polar group which is convertible into said carboxyl groups by oxidation or hydrolysis. Maleic anhydride or a derivative thereof is suitable. It grafts onto the olefin polymer, (e.g., ethylene copolymer or terpolymer) to give two carboxylic acid functionalities. Examples of additional unsaturated carboxylic materials include maleic anhydride, itaconic anhydride, or the corresponding dicarboxylic acids, such as maleic acid, fumaric acid and their esters, as well as cinnamic acid and esters thereof.

[0101] The ethylenically unsaturated carboxylic acid material may be radically grafted onto the polymer (such as the ethylene / propylene copolymer). The free-radical induced grafting of ethylenically unsaturated carboxylic acid materials may also be conducted in solvents, such as hexane or mineral oil. It may be carried out at an elevated temperature in the range of 100°C to 250°C, e.g., 120°C to 190°C, or 150°C to 180°C, e.g., above 160°C.

[0102] The free-radical initiators which may be used include peroxides, hydroperoxides, and azo compounds, typically those which have a boiling point greater than about 100°C and which decompose thermally within the grafting temperature range to provide free radicals. Representative of these free-radical initiators include azobisisobutyronitrile and 2,5-dimethyl-hex-3-yne-2,5-bis-tertiary-butyl peroxide. The initiator may be used in an amount of 0.005% to 1% by weight based on the weight of the reaction mixture solution. The grafting may be carried out in an inert atmosphere, such as under nitrogen blanketing. The resulting polymer intermediate is characterized by having carboxylic acid acylating functions within its structure.

[0103] In an alternative embodiment, the unsaturated carboxylic acid material, such as maleic anhydride, can be first condensed with a monoamine or polyamine, typically having a single primary amino group (described below) and the condensation product itself then grafted onto the polymer backbone in analogous fashion to that described above.

[0104] The amount of the reactive carboxylic acid on the polymer chain, and in particular the amount of grafted carboxylic acid on the chain is typically 0.5 to 8 weight percent, or 1 to 7 weight percent, or 1.5 to 6 weight percent, based on the weight of the polymer backbone, or in some embodiments 2 to 5 weight percent. In some embodiments the amount of the reactive carboxylic acid on the polymer chain, and in particular the amount of grafted carboxylic acid on the chain can be from about 1 to about 2, or in other embodiments from about 2 to 3, or from about 3 to 4 weight percent or 4 to 5 weight percent. These numbers represent the amount of carboxyl-containing species with particular reference to maleic anhydride as the graft material. The amounts may be adjusted to account for carboxyl-containing species having higher or lower molecular weights or greater or lesser amounts of acid functionality per molecule, as will be apparent to the person skilled in the art. The grafting may be of an extent to provide an acid functionalized polymer having a total acid number (TAN per ASTM D664) of 5 to 100, 10 to 80, or 15 to 75, or 20 to 70, or about 20 to about 60 or 65 mgKOH / g.

[0105] The acid-containing polymer is reacted with a monoamine or a polyamine typically having a single primary amino group. If the olefin polymer is an ethylene / propylene copolymer, then said polyamine is not a poly(ethyleneamine). The reaction may consist of condensation to form an imide, amide, or half-amide or amide-ester (assuming a portion of alcohol is also reacted) or an amine salt. A primary amino group will typically condense to form an amide or, in the case of maleic anhydride, an imide. It is noted that in certain embodiments the amine will have a single primary amino group, that is, it will not have two or more primary amino groups (except perhaps a very small an inconsequential amount of additional primary amino groups within the entire amine component, e.g., less than 5% or 2% or 1% or 0.5%, or 0.01 to 0.1%, especially 1% or less, such as 0.01 to 1%, of amine groups being primary). This feature will minimize the amount of crosslinking that might otherwise occur. Poly(ethyleneamine)s may generally, and in an oversimplified manner, be depicted as H2N-(C2H4-NH-)n-C2H4-NH2, where n may be, for instance, 2 through 6. These typically have on average about 2 primary amino groups, so their use is typically undesirable for functionalization of ethylene / propylene copolymers, so that any undesirable crosslinking may be minimized or avoided. In those embodiments in which the polyamine is not a poly(ethyleneamine), the amine component employed to make the condensation product will be free of or substantially free of poly(ethyleneamine), such as less than 5 percent by weight of the amine component is poly(ethyleneamine), or less than 1 percent, or 0.01 to 0.1 percent by weight.

[0106] Suitable primary amines may include aromatic amines, such as amines wherein a carbon atom of the aromatic ring structure is attached directly to the amino nitrogen. The amines may be monoamines or polyamines. The aromatic ring will typically be a mononuclear aromatic ring (i.e., one derived from benzene) but can include fused aromatic rings, such as those derived from naphthalene. Examples of aromatic amines include aniline, N-alkylanilines such as N-methylaniline, and N-butylaniline, di-(para-methylphenyl)amine, naphthylamine, 4-aminodiphenylamine, N,N-dimethylphenylenediamine, 4-(4-nitro-phenylazo)aniline (disperse orange 3), sulfamethazine, 4-phenoxyaniline, 3-nitroaniline, 4-aminoacetanilide, 4-amino-2-hydroxy-benzoic acid phenyl ester (phenyl amino salicylate), N-(4-amino-5-methoxy-2-methyl-phenyl)-benzamide (fast violet B), N-(4-amino-2,5-dimethoxy-phenyl)-benzamide (fast blue RR), N-(4-amino-2,5-diethoxy-phenyl)-benzamide (fast blue BB), N-(4-amino-phenyl)-benzamide and 4-phenylazoaniline. Other examples include para-ethoxyaniline, para-dodecylaniline, cyclohexyl-substituted naphthylamine, and thienyl-substituted aniline. Examples of other suitable aromatic amines include amino-substituted aromatic compounds and amines in which an amine nitrogen is a part of an aromatic ring, such as 3-aminoquinoline, 5-aminoquinoline, and 8-aminoquinoline. Also included are aromatic amines such as 2-aminobenzimidazole, which contains one secondary amino group attached directly to the aromatic ring and a primary amino group attached to the imidazole ring. Other amines include N-(4-anilinophenyl)-3-aminobutanamide (i.e., ϕ-NH-ϕ-NH-COCH2CH(CH3)NH2). Additional aromatic amines include aminocarbazoles, aminoindoles, aminopyrroles, aminoindazolinones, aminoperimidines, mercaptotriazoles, aminophenothiazines, aminopyridines, aminopyrazines, aminopy-rimidines, pyridines, pyrazines, pyrimidines, aminothiadiazoles, aminothiothi-adiazoles, and aminobenzotriaozles. Other suitable amines include 3-amino-N-(4-anilinophenyl)-N-isopropyl butanamide, and N-(4-anilinophenyl)-3-{(3-aminopropyl)-(cocoalkyl)amino} butanamide. Other aromatic amines which can be used include various aromatic amine dye intermediates containing multiple aromatic rings linked by, for example, amide structures. Examples include materials of the general structure □-CONH-ϕ-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.

[0107] The amine may also be non-aromatic, or in other words, an amine in which an amino nitrogen is not attached directly to a carbon atom of an aromatic ring, or in which an amine nitrogen is not a part of an aromatic ring, or in which an amine nitrogen is not a substituent on an aromatic carboxylic compound. In some instances, such non-aromatic amines may be considered to be aliphatic, or cycloaliphatic. Such amines may be straight, or branched or functionalized with some functional group. The non-aromatic amines can include monoamines having, e.g., 1 to 8 carbon atoms, such as methylamine, ethylamine, and propylamine, as well as various higher amines. Diamines or polyamines can also be used, and typically will have only a single primary amino group. Examples include dimethylaminopropylamine, diethylaminopropylamine, dibutylaminoprop-ylamine, dimethylaminoethylamine, diethylaminoethylamine, dibutylami-noethylamine, 1-(2-aminoethyl)piperidine, 1-(2-aminoethyl)pyrrolidone, N,N-dimethylethylamine; 3-(dimethylamino)-1-propylamine; O-(2-aminopropyl)-O'-(2-methoxyethyl)polypropylene glycol; N,N-dimethyldipropylenetriamine, aminoethylmorpholine, 3-morpholinopropylamine; aminoethylethyleneurea and aminopropylmorpholine.

[0108] 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.

[0109] In certain embodiments the grafted olefin polymer may have a nitrogen content, calculated using ASTM D5291, of 0.05 to 3 percent by weight, or 0.1 to 2.5, or 0.15 to 2, or 0.2 to 1.75, or 0.25 to 1.6 percent by weight.

[0110] 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.

[0111] In one embodiment the lubricant additive composition of the invention includes an aryl amine antioxidant. The aryl amine antioxidant may be a phenyl-α-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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] Sulfurized olefins are well known commercial materials, and those which are substantially nitrogen-free, that is, not containing nitrogen functionality, are readily available. The olefinic compounds which may be sulfurized are diverse in nature. They contain at least one olefinic double bond, which is defined as a non-aromatic double bond; that is, one connecting two aliphatic carbon atoms. In its broadest sense, the olefin may be defined by the formula R*1R*2C=CR*3R*4, wherein each of R*1, R*2, R*3 and R*4 is hydrogen or an organic group. In general, the R groups in the above formula which are not hydrogen may be satisfied by such groups as -C(R*5)3, -COOR*5, - COOM, -X, -YR*5 or -Ar, wherein each R 5 is independently hydrogen, alkyl, alkenyl, aryl, substituted alkyl, substituted alkenyl or substituted aryl, with the proviso that any two R 5 groups can be alkylene or substituted alkylene whereby a ring ofup to 12 carbon atoms is formed; M is one equivalent of a metal cation (preferably Group I or II, e.g., sodium, potassium, barium, calcium); X is halogen (e.g., chloro, bromo, or iodo);Y is oxygen or divalent sulfur; Ar is an aryl or substituted aryl group of up to 12 carbon atoms. Any two of R*1, R*2, R*3 and R*4 may also together form an alkylene or substituted alkylene group; i.e., the olefinic compound may be alicyclic.

[0117] One type of sulfurized olefin is prepared in accordance with the detailed teachings of U.S. Pat. No. 4,957,651. Described therein is a cosulfurized mixture of 2 or more reactants selected from the group consisting of(1) at least one fatty acid ester of a polyhydric alcohol, (2) at least one fatty acid, (3) at least one olefin, and (4) at least one fatty acid ester of a monohydric alcohol. Reactant (3), the olefin component, comprises at least one olefin. This olefin is preferably an aliphatic olefin, which usually will contain 4 to 40 carbon atoms, preferably from 8 to 36 or 12 to 18 carbon atoms. Terminal olefins, or alpha-olefins, are preferred, especially those having from 12 to 20 carbon atoms. Mixtures of these olefins are commercially available, and such mixtures are contemplated for use in this invention.

[0118] The sulfurized olefin can be prepared by reacting a single reactant or a mixture of appropriate reactants with a source of sulfur. The sulfurization reaction generally is affected at an elevated temperature, e.g., 50-350° C. or 100-200° C., with efficient agitation and often in an inert atmosphere such as nitrogen, optionally in the presence of an inert solvent. The sulfurizing agents useful in the process of the present invention include elemental sulfur, which is preferred, hydrogen sulfide, sulfur halide, sodium sulfide and a mixture of hydrogen sulfide and sulfur or sulfur dioxide. Usually, the amount of sulfur or sulfurizing agent employed calculated based on the total olefinic unsaturation of the mixture. Typically, often 0.5 to 3 moles of sulfur are employed per mole of olefinic bonds.

[0119] The olefinic compound is usually one in which each R group, above, which is not hydrogen is independently alkyl, alkenyl or aryl group. Monoolefinic and diolefinic compounds, particularly the former, are preferred, and especially terminal monoolefinic hydrocarbons; that is, those compounds in which R 3 and R 4 are hydrogen and R 1 and R 2 are alkyl or aryl, especially alkyl (that is, the olefin is aliphatic) having 1 to 30, or 1 to 16, or 1 to 8, or 1 to 4 carbon atoms. Olefinic compounds having 3 to 30 or 3 to 16 (often fewer than 9) carbon atoms can be used.

[0120] Isobutene, propylene and their dimers, trimers and tetramers, and mixtures thereof are useful as olefinic compounds for sulfurization, as are terpene compounds, that is, various isomeric terpene hydrocarbons having the empirical formula C10H1 6, as well as various synthetic and naturally occurring oxygen-containing derivatives thereof.

[0121] In one embodiment, the sulfurized organic composition is a sulfur-containing material which comprises the reaction product of a sulfur source and at least one Diels-Alder adduct, in a molar ratio of at least 0.75: 1. Generally, the molar ratio of sulfur source to Diels-Alder adduct is 0.75 to 4.0, or 1 to 2.0, or 1 to 1.8. The Diels-Alder adducts can be prepared from dienophiles having at least one carboxylic ester group represented by-C(O)O-Ro where Ro is the residue of a saturated aliphatic alcohol of up to 40 carbon atoms, the aliphatic alcohol from which -Ro is derived being a mono or polyhydric alcohol such as alkylene glycols, alkanols, aminoalkanols, alkoxy-substituted alkanols, ethanol, ethoxy ethanol, propanol, butanol, beta-diethylamino-ethanol, dodecyl alcohol, diethylene glycol, tripropylene glycol, tetrabutylene glycol, hexanol, octanol, and isooctyl alcohol. Generally, not more than two -C(O)-O-Ro groups will be present, preferably only one -C(O)-O-Ro group. Such materials can also be described as cyclohexene compounds bearing ester substituents. A preferred sulfurized olefin is sulfurized 4-carbobutoxy cyclohexene. This and other sulfurized olefins can be further treated with other materials such as an aryl phosphate, e.g., triphenyl phosphite.

[0122] Other sulfurized olefins include sulfurized vegetable oils and sulfurized lard oil (that is, sulfurized oils of animal sources generally).

[0123] The amount of the sulfurized olefin in a fully formulated lubricant will be an amount sufficient to improved the antiwear performance of the lubricant, as measured by any wellknown wear tests, as described below. Such an amount will typically be 0.05 to 1.5% or to 1% by weight, preferably 0.10 to 0.80% or 0.15 to 0.70% or 0.20 to 0.60%. In a concentrate the amounts will be approximately an order of magnitude greater, e.g., 0.5 to 15% or to 10% by weight. A concentration of0.5% sulfurized 4-carbobutoxy cyclohexene will typically impart about 5 80 ppm by weight sulfur to the lubricant, which is consistent with a low-sulfur composition. (The present specification that the composition contain less than 0.4 or 0.35 percent S, or less than 0.3 percent S, or alternatively less than 0.27 percent S, is determined based on the total sulfur from all sources, including the sulfurized olefin and, e.g., any sulfonates, sulfurized phenates, and dithiophosphates. The lubricant composition may also contain, for example, 0.05 or 0.1 to 0.4 or to 0.35 or to 0.3 or to 0.27 weight percent total sulfur.)

[0124] The lubricant additive composition can also contain a viscosity modifier. One type of viscosity modifier that may be employed is a poly(meth)acrylate polymer viscosity modifier. As used herein ranges below for the viscosity modifier are measured by GPC using polystyrene standards with a weight average molecular weight ranging from 350 to 100,000.

[0125] The lubricant additive composition in one embodiment can include a linear poly(meth)acrylate polymer with a weight average molecular weight of 5,000 to 25,000, or 8000 to 20,000.

[0126] The linear poly(meth)acrylate polymer may be present in the lubricant additive composition at about 0.1 wt % to about 5 wt %, or 0.1 wt % to 4 wt %, or 0.2 wt % to 3 wt %, or 0.5 wt % to 3 wt %, or 1.0 wt % to 4 wt %, 0.6 wt% to 4 wt%, or 0.75 wt% to 3 wt%, or 0.2 wt% to 0.75 wt%of the lubricant additive composition.

[0127] The poly(meth)acrylate polymer may be derived from a monomer composition comprising:(a) 50 wt % to 95 wt %, or 60 wt % to 80 wt % of an alkyl (meth)acrylate, wherein the alkyl group of the (meth)acrylate has 10 to 15 carbon atoms; (b) 1 wt % to 40 wt %, or 4 wt % to 35 wt % of an alkyl (meth)acrylate, wherein the alkyl group of the (meth)acrylate has 1 to 9 carbon atoms; (c) 1 wt % to 10 wt %, or 1 wt % to 8 wt % of a monomer having dispersant functionality, (d) 0 wt % to 4 wt %, or 0 wt % to 2 wt %, or 0 wt % of a vinyl aromatic monomer (typically styrene); and (e) 0 wt % to 9 wt %, or 0 wt % to 6 wt % of an alkyl (meth)acrylate, wherein the alkyl group of the (meth)acrylate has 16 to 18 carbon atoms. In one embodiment the linear polymer may contain 0 wt % to 20 wt % of 16 to 18 alkyl (meth)acrylate.

[0128] In one embodiment the linear polymer can include a poly(meth)acrylate (typically a polymethacrylate) with units derived from a mixture of alkyl (meth)acrylate ester monomers containing, (a) 8 to 24, or 10 to 18, or 12 to 15 carbon atoms in the alcohol-derived portion of the ester group and (b) 6 to 11, or 8 to 11, or 8 carbon atoms in the alcohol-derived portion of the ester group, and which have 2-(C1-4 alkyl)-substituents, and optionally, at least one monomer selected from the group consisting of (meth)acrylic acid esters containing 1 to 7 carbon atoms in the alcohol-derived portion of the ester group and which are different from (meth)acrylic acid esters (a) and (b), vinyl aromatic compounds (or vinyl aromatic monomers); and nitrogen-containing vinyl monomer; provided that no more than 60% by weight, or no more than 50% by weight, or no more than 35% by weight of the esters contain not more than 10 carbon atoms in the alcohol-derived portion of the ester group. The linear polymer of this type is described in more detail in US 6,124,249, or EP 0 937 769 A1 paragraphs

[0019] and

[0031] to

[0067] . (The "alcohol-derived portion" refers to the "-OR" portion of an ester, when written as R'C(=O)-OR, whether or not it is actually prepared by reaction with an alcohol.) Optionally, the linear polymer may further contain a third monomer. The third monomer may be styrene, or mixtures thereof. The third monomer may be present in an amount 0% to 25% of the polymer composition, or from 1% to 15% of the composition, 2% to 10% of the composition, or even from 1% to 3% of the composition.

[0129] Typically, the mole ratio of esters (a) to esters (b) in the copolymer ranges from 95:5 to 35:65, or 90: 10 to 60:40, or 80:20 to 50:50.

[0130] The esters are usually aliphatic esters, typically alkyl esters. In one embodiment the ester of (a) may be a C12-15 alkyl (meth)acrylate and the ester of (b) may be 2-ethylhexyl (meth)acrylate.

[0131] In one embodiment, the ester groups in ester (a) contain branched alkyl groups. The ester groups may contain 2 to 65%, or 5 to 60% of the ester groups having branched alkyl groups. The branched alkyl groups may be □-branched and may contain 8 to 60, or 8 to 30, or 8 to 16 carbon atoms. For examples branched alkyl groups may be derived from 2-ethylhexanol, 2-butyloctanol, 2-hexyldecanol, 2-octyldodecanol, 2-decyltetradecanol, or mixtures thereof, or commercially available alcohols such as Isofol ®< branched Guerbet alcohols available from Sasol.

[0132] The C1-4 alkyl substituents may be methyl, ethyl, and any isomers of propyl and butyl.

[0133] The weight average molecular weight of the linear poly(meth)acrylate may be 45,000 or less, or 35,000 or less, or 25,000 or less, or 8000 to 25,000, or, 10,000 to 35,000, or 12,000 to 20,000.

[0134] The linear polymer may be called a viscosity modifier, or a dispersant viscosity modifier as it may exhibit dispersant functionality. Reference to a "dispersant viscosity modifier" herein is exclusive of dispersants, which are a separate class of compounds. The linear polymer may be used as a sole viscosity modifier (or dispersant viscosity modifier) present at 0.5 wt % to 4 wt % of a linear (meth)acrylic polymer viscosity modifier having dispersant functionality, wherein the linear polymer has a weight average molecular weight of 5,000 to 25,000, or 10,000 to 20,000, and wherein oil the of lubricating viscosity has a kinematic viscosity at 100°C of 4 to 6 cSt (mm2 / s) and a viscosity index of 120 to 150.

[0135] The lubricant additive composition in one embodiment may contain only two linear polymer viscosity modifiers having dispersant functionality, wherein the linear polymer has a weight average molecular weight of 5,000 to 25,000, or 10,000 to 20,000.

[0136] In one embodiment the lubricant additive composition may comprise 0.1 wt% to 4 wt % (or 0.2 wt % to 3 wt %) of a linear (meth)acrylic polymer viscosity modifier having dispersant functionality, wherein the linear polymer has a weight average molecular weight of greater than 25,000 to 400,000 (or to 350,000) or 30,000 to 150,000. The linear (meth)acrylic polymer a weight average molecular weight of greater than 25,000 to 400,000 (or to 350,000) may be considered chemically similar to the linear (meth)acrylic polymer a weight average molecular weight of 5,000 to 25,000 except the weight average molecular weight is different.

[0137] The lubricant additive composition may comprise a linear polymer viscosity modifier having dispersant functionality comprises: 0.1 wt % to 5 wt % (or 1 wt % to 4 wt %) of a linear (meth)acrylic polymer viscosity modifier having dispersant functionality, wherein the linear polymer has a weight average molecular weight of 10,000 to 20,000; and 0.1 wt % to 4 wt % (or 1 wt % to 3 wt %) of a linear (meth)acrylic polymer viscosity modifier having dispersant functionality, wherein the linear polymer has a weight average molecular weight of greater than 20,000 to 250,000 (or 30,000 to 150,000).

[0138] As described hereinafter the molecular weight of the viscosity modifier has been determined using known methods, such as GPC analysis using polystyrene standards. Methods for determining molecular weights of polymers are well known. The methods are described for instance: (i) P.J. Flory, "Principles of star polymer Chemistry", Cornell University Press 91953), Chapter VII, pp 266-315; or (ii) "Macromolecules, an Introduction to star polymer Science", F. A. Bovey and F. H. Winslow, Editors, Academic Press (1979), pp 296-312.

[0139] Another type of viscosity modifier that may be employed is an ethylene α-olefin copolymer. The ethylene α-olefin copolymer includes those with a backbone containing 1 to 3 different α-olefin monomers (beside the ethylene monomer), in one embodiment 1 to 3 different α-olefin monomers and in yet another embodiment 1 α-olefin monomer in addition to the ethylene monomer. The α-olefin monomers include 3 to 20, and in other embodiments 3 to 12, or 3 to 10, or 3 to 6, or 3 to 4 carbon atoms, and in another embodiment 3 carbon atoms (i.e., propylene). The olefin may be an alpha olefin of the above listed number of carbon atoms.

[0140] The ethylene α-olefin copolymer will have greater than 5 percent by weight ethylene monomer units, and in some embodiments at least 10 percent and up to 90 percent, or 15 to 85, or 20 to 80, or 30 to 50 percent by weight ethylene monomer units. In certain embodiments the amount of ethylene monomer will be 30-50 weight percent; in other embodiments the amount of ethylene monomer will be 75 to 85, or 79 to 81, weight percent. Otherwise expressed, the amount of ethylene monomer may be 15 to 90 or 25 to 85 or 40 to 60 or 45 to 55 mole percent.

[0141] The ethylene olefin copolymer thus includes an ethylene monomer and at least one other co-monomer derived from an alpha-olefin having the formula H2C=CHR3, wherein R3 is a hydrocarbyl group, in one embodiment an alkyl radical containing 1 to 18, 1 to 12, 1 to 10, 1 to 6 or 1 to 3 carbon atoms. The hydrocarbyl group includes an alkyl radical that has a straight chain, a branched chain, or mixtures thereof.

[0142] Examples of suitable co-monomers include propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-l-pentene, 1-decene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene or mixtures thereof. The co-monomer may be 1-butene, propylene or mixtures thereof. Examples of α-olefin copolymers include ethylene-propylene copolymers and ethylene-1-butene copolymers and mixtures thereof.

[0143] The polymer (c) may have a kinematic viscosity at 100° C. of at least 35 or at least 50 or at least 100 or at least 500 mm2 / s at 100° C. In certain embodiments the polymer (c) may have a kinematic viscosity at 100° C. of at least about 500 or at least about 1000 mm2 / s or 1500 mm2 / s or 2000 mm2 / s, which feature will distinguish it from similar materials of much lower viscosity that might be used as base oils. The polymer may have a number average molecular weight of 1000 to 8000, or 1000 to 5000, or 1300 to 8000, or 1500 to 3000, or 1800 to 2500, or about 2000, or 2500 to 5000, or 3500 to 4500, or about 4000. Its polydispersity (Mw / Mn) may be in the range of 1.3 to 4 or 1.4 to 3 or 1.4 to 2. It may be prepared by known methods by polymerization of (typically) ethylene and an alpha olefin such as propylene using an AlCl3 or BF3 catalyst or by other known methods.

[0144] Another type of viscosity modifier is a grafted copolymer as described for the dispersant grafted copolymers above.

[0145] In one embodiment, the lubricant for the method can further contain a metal-containing detergent. The metal-containing detergent may be an overbased detergent. Overbased detergents otherwise referred to as overbased or su-perbased salts are characterized by a metal content in excess of that which would be necessary for neutralization according to the stoichiometry of the metal and the particular acidic organic compound reacted with the metal. The overbased detergent may be selected from the group consisting of non-sulfur containing phenates, sulfur containing phenates, sulfonates, salixarates, salicylates, and mixtures thereof.

[0146] The metal-containing detergent may also include "hybrid" detergents formed with mixed surfactant systems including phenate and / or sulfonate components, e.g. phenate / salicylates, sulfonate / phenates, sulfonate / salicylates, sulfonates / phenates / salicylates, as described, for example, in U.S. Pat. Nos. 6,429,178; 6,429,179; 6,153,565; and 6,281,179. Where, for example, a hybrid sulfonate / phenate detergent is employed, the hybrid detergent would be considered equivalent to amounts of distinct phenate and sulfonate detergents introducing like amounts of phenate and sulfonate soaps, respectively.

[0147] The overbased metal-containing detergent may be sodium salts, calcium salts, magnesium salts, or mixtures thereof of the phenates, sulfur-containing phenates, sulfonates, salixarates and salicylates. Overbased phenates and salicylates typically have a total base number of 180 to 450 TBN. Overbased sulfonates typically have a total base number of 250 to 600, or 300 to 500. Overbased detergents are known in the art. In one embodiment, the sulfonate detergent may be predominantly a linear alkylbenzene sulfonate detergent having a metal ratio of at least 8 as is described in paragraphs

[0026] to

[0037] of US Patent Publication 2005065045 (and granted as U.S. Pat. No. 7,407,919). The linear alkylbenzene sulfonate detergent may be particularly useful for assisting in improving fuel economy. The linear alkyl group may be attached to the benzene ring anywhere along the linear chain o fthe alkyl group, but often in the 2, 3 or 4 position of the linear chain, and in some instances, predominantly in the 2 position, resulting in the linear alkylbenzene sulfonate detergent. Overbased detergents are known in the art. The overbased detergent may be present at 0 wt % to 15 wt %, or 0.1 wt % to 10 wt %, or 0.2 wt % to 8 wt %, or 0.2 wt % to 3 wt %. For example, in a heavy duty diesel engine, the detergent may be present at 2 wt % to 3 wt % of the lubricating composition. For a passenger car engine, the detergent may be present at 0.2 wt % to 1 wt % of the lubricating composition.

[0148] Metal-containing detergents contribute sulfated ash to a lubricating composition. Sulfated ash may be determined by ASTM D874. In one embodiment, the lubricating composition of the invention comprises a metal-containing detergent in an amount to deliver at least 0.4 weight percent sulfated ash to the total composition. In another embodiment, the metal-containing detergent is present in an amount to deliver at least 0.6 weight percent sulfated ash, or at least 0.75 weight percent sulfated ash, or even at least 0.9 weight percent sulfated ash to the lubricating composition.

[0149] The lubricant can also include other antiwear agents other than amine (thio)phosphate salts discussed above.

[0150] For example, in one embodiment the lubricant can include a non-ionic phosphorus compound that is a hydrocarbyl phosphite. The hydrocarbyl-substituted phosphite of the invention includes those represented by the formula: wherein each R‴ independently is hydrogen or a hydrocarbyl group, with the proviso that at least one of the R‴ groups is hydrocarbyl.

[0151] Each hydrocarbyl group of R‴ in different embodiments contains at least about 2, or at least about 4 carbon atoms. Typically, the combined total sum of carbon atoms present on both R‴ groups is less than about 45, or is less than about 35, or is less than about 25. Examples of suitable ranges for the number of carbon atoms present on R‴ groups include about 2 to about 40, about 3 to about 24, or about 4 to about 20. Examples of suitable hydrocarbyl groups include propyl, butyl, t-butyl, pentyl, hexyl, dodecyl, butadecyl, hexadecyl, or octadecyl groups. Generally, the hydrocarbyl phosphite is soluble or at least dispersible in oil. In one embodiment the hydrocarbyl phosphite is di-butyl hydrogen phosphite or a C16-18 alkyl or di-alkyl hydrogen phosphite. A more detailed description of the non-ionic phosphorus compound is included in column 9, line 48 to column 11, line 8 of U.S. Pat. No. 6,103,673.

[0152] In one embodiment the other antiwear agent can be an amide-containing dithiophosphorus acid ester. A more detailed description for the amide-containing dithiophosphorus acid ester is found in U.S. Pat. No. 4,938,884. A description of the molecular structure is found in column 2, lines 4 to 28. Suitable examples prepared are disclosed in Examples 1 to 7 (column 8, line 45 to column 10, line 13 of U.S. Pat. No. 4,938,884). Typically, the amide-containing dithiophosphorus acid ester is prepared by the addition of dithiophosphoric acid to an acrylamide, such as acrylamide, methacrylamide, methylenebisacrylamide, or methylenebismethacrylamide. In one embodiment the amide-containing dithiophosphorus acid ester includes a methylenebisacrylamide, or methylenebismethacrylamide product prepared from prepared by the addition ofa dithiophosphoric acid to acrylamide to form an adduct; and subsequent reaction of the adduct with formaldehyde to make the methylene coupled product

[0153] The other antiwear agent can be a phosphorus containing amide. Phosphorus containing amides are prepared by the reaction of phosphorus acids, preferably a dithiophosphoric acid, with an unsaturated amide. Examples of unsaturated amides include acrylamide, N,N'-methylene bisacrylamide, methacrylamide, crotonamide, and the like. The reaction product of the phosphorus acid and the unsaturated amide may be further reacted with a linking or a coupling compound, such as formaldehyde or paraformaldehyde. The phosphorus containing amides are known in the art and are disclosed in U.S. Pat. Nos. 4,670,169, 4,770,807, and 4,876,374.

[0154] In an embodiment the other antiwear can be a dithiophosphate containing an ester functional group and can be prepared by reaction of a dithiophosphoric acid and an alpha, beta unsaturated carboxylic compound, such as an acrylic or methacrylic acid or ester. If the carboxylic acid is used, the ester can be formed, if desired, by subsequent reaction, known to those skilled in the art. The unsaturated carboxylic esters can contain 4 to 40, preferably 4 to 24, and more preferably 4 to 12 carbon atoms. Preferably, the unsaturated carboxylic ester is an allyl or vinyl ester of a carboxylic acid or an ester of an unsaturated carboxylic acid.

[0155] The vinyl ester of a carboxylic acid can be represented by the formula R6CH=CH-O(O)CR7 wherein R6 is a hydrogen or hydrocarbyl group having from 1 to 30 carbon atoms, preferably 1 to 12 carbon atoms, and more preferably hydrogen; and R7 is a hydrocarbyl group having 1 to 30 carbon atoms, preferably 1 to 12 and more preferably 1 to 8 carbon atoms. Examples of vinyl esters include vinyl acetate, vinyl 2-ethylhexanoate, vinyl butanoate, and vinyl crotonate.

[0156] In another embodiment, the unsaturated carboxylic ester is an ester of an unsaturated carboxylic acid such as maleic, fumaric, acrylic, methacrylic, itaconic, citraconic acids, and the like. In one embodiment, the ester is represented by the formula R8O-(O)C-CH=CH-C(O)ORg, wherein each Rg is independently a hydrocarbyl group having 1 to 18 carbon atoms, preferably 1 to 12 and more preferably 1 to 8 carbon atoms.

[0157] Examples of unsaturated carboxylic esters, useful in the present invention, include methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, ethyl maleate, butyl maleate, and 2-ethylhexyl maleate. The foregoing list includes mono- as well as diesters of maleic, fumaric, and citraconic acids.

[0158] The other antiwear can be, for example, a dithiophosphate. A dithiophosphate ester can be formed by reaction of a dithiophosphoric acid represented by (RO)2PSSH with an unsaturated compound. In one embodiment, the unsaturated compounds is an unsaturated carboxylic acid or ester. Examples of unsaturated carboxylic acids or anhydrides include acrylic acids or esters, methacrylate acid or esters, itaconic acid or ester, fumaric acid or esters, and maleic acid, anhydride, or esters.

[0159] The other antiwear can also be a sulfur containing phosphite. Sulfur containing phosphites can include, for example, a material represented by the formula [R1O(OR2)(S)PSC2H4(C)(O)OR4O]nP(OR5)2-n(O)H, wherein R1 and R2 are each independently hydrocarbyl groups of 3 to 12 carbon atoms, or 6 to 8 carbon atoms, or wherein R1 and R2 together with the adjacent O and P atoms form a ring containing 2 to 6 carbon atoms; R4 is an alkylene group of 2 to 6 carbon atoms or 2 to 4 carbon atoms; R5 is hydrogen or a hydrocarbyl group of 1 to about 12 carbon atoms; and n is 1 or 2. The C12-22 hydrocarbyl phosphite may be present in the lubricant composition at about 0.05 wt.% to about 1.5 wt.% of the lubricant composition, or from about 0.1 wt.% to about 1.0 wt.% of the lubricant composition.

[0160] The amount of each chemical component described is presented exclusive of any solvent or diluent oil, which may be customarily present in the commercial material, that is, on an active chemical basis, unless otherwise indicated. However, unless otherwise indicated, each chemical or composition referred to herein should be interpreted as being a commercial grade material which may contain the isomers, by-products, derivatives, and other such materials which are normally understood to be present in the commercial grade.

[0161] As used herein, the term "hydrocarbyl" refers to a group having a carbon atom directly attached to the remainder of the molecule, where the group includes at least carbon and hydrogen atoms. If the hydrocarbyl group comprises more than one carbon atom, then those carbons need not necessarily be linked to each other. For example, at least two of the carbons may be linked via a suitable element or group. In various embodiments, the term "hydrocarbyl" refers to a group having a carbon atom directly attached to the remainder of the molecule, where the group consists of carbon, hydrogen, optionally one or more heteroatoms provided the heteroatoms do not alter the predominantly hydrocarbon nature of the substituent. The heteroatom may link at least two of the carbons in the hydrocarbyl group, and optionally no more than two non-hydrocarbon substituents. Suitable heteroatoms will be apparent to those skilled in the art and include, for instance, sulphur, nitrogen, oxygen, phosphorus and silicon. Where the hydrocarbyl contains heteroatoms, optionally, no more than two heteroatoms will be present for every ten carbon atoms in the hydrocarbyl group. Suitable non-hydrocarbon substituents will also be apparent to those skilled in the art and include, for instance, halo, hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulphoxy.

[0162] Examples of hydrocarbyls within the context of the present technology therefore include: hydrocarbon groups selected from aliphatic (e.g. alkyl or alkenyl), alicyclic (e.g. cycloalkyl, cycloalkenyl, cycloalkadienyl), and aromatic groups; substituted hydrocarbon groups, selected from hydrocarbon groups defined in (i) substituted with no more than two non-hydrocarbon substituents and / or one or more hydrocarbon substituents, the non-hydrocarbon substituents being selected from the group consisting of halo, hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulphoxy; hetero-containing hydrocarbon groups, selected from hydrocarbon groups defined in (i) containing one or more heteroatom in the ring or chain, provided that the group has no more than two heteroatoms present for every ten carbon atoms in the group, the heteroatoms being selected from sulphur, nitrogen, oxygen, phosphorus and silicon. The hetero-containing hydrocarbon groups may be substituted with no more than two non-hydrocarbon substituents and / or one or more hydrocarbon substituents.

[0163] In some embodiments, the term "hydrocarbyl" refers to a group having a carbon atoms directly attached to the remainder of the molecule, where the group consists of carbon and hydrogen atoms.

[0164] It is known that some of the materials described above may interact in the final formulation, so that the components of the final formulation may be different from those that are initially added. For instance, metal ions (of, e.g., a detergent) can migrate to other acidic or anionic sites of other molecules. The products formed thereby, including the products formed upon employing the composition of the present invention in its intended use, may not be susceptible of easy description. The present invention encompasses the composition prepared by admixing the components described above.EXAMPLES

[0165] The conductive layer deposit test (CDLT) comprises printed circuit boards (PCB) containing a metal of interest (for example, copper, aluminum, gold, nickel or any combination) arranged into two separate stacked layers, five in the solution of oil and five in the vapor space. Each stack contains up to five energized circuits with the ability to measure and record resistance measurements in real-time at temperatures up to 250 °C. The formation of conducting layers results in detection of energy flow outside of the intended path. This is detected via the induced magnetic field caused by the flow of current. The fluid tested is contained within a closed, vented vessel. Temperature is measured in both the solution and vapor space via two Platinum Resistance Thermometers (PRTs). Vapor retention is controlled using a condenser. During the test, data is acquired by the data acquisition component and processed by the data processing component. Analysis at the end of the test includes resistance measurements, used oil analysis (ICP), microscopy and elemental analysis of the deposited material, e.g., via energy dispersive X-ray analysis (EDAX). Further details of this test method are disclosed in PCT Appl. WO 2021 / 247428.

[0166] Three lubricant compositions INV1, INV 2 and COMP1 were tested in the CLDT to evaluate the effects of the polyether additive in preventing conductive layer deposits. The composition of these lubricant compositions is outlined in Table 1. Table 1. Lubricant CompositionsAdditiveINV1INV2COMP1Dispersant Polymethacrylate1.401.401.402,5-bis(nonyldisulfaneyl)-1,3,4-thiadiazole.30.30.30alkyl su bstituted diphenylamine.60.60.60alkyl thiophosphate amine salt.20.20.201000Mn PIB succinimide 3.43%N; 2.83%B (oil free).35.35.351000Mn PIB succinimide 3.83%N: 0.82%B (oil free).70.70.70phosphoric acid ester amine salt.20.20.20propoxylated C12 alkyl alcohol.25.05.00polydimethylsiloxane antifoam agent20ppm20ppm20ppmstyrene / maleic anhydride copolymer0.330.330.33styrene / maleic anhydride copolymer ester0.100.100.103 cSt Group III OilBalanceBalanceBalance4 cSt Group III Oilto 100%to 100%to 100%

[0167] The results of the CLDT for the three lubricant compositions are shown in Table 2. Conducting layer deposits are formed in COMP1 in both the vapor phase and in solution over the test period of 499 hours. INV1 and INV2 containing does not form conducting layer deposits. Table 2. CLDT results.(e-axle)INV1INV2COMP1CLDTConductance (Ω -1< )Conductance (Ω -1< )Conductance (Ω -1< )VaporV17.69E-041.11E-031V28.33E-052.70E-051V35.00E-111.89E-101V44.17E-046.71E-071V55.00E-115.71E-070.005SolutionS15.00E-115.00E-115.00E+00S24.76E-043.45E-041.00E+00S36.67E-051.00E-041.00E+00S42.13E-043.85E-041.00E+00S51.89E-047.69E-051.00E+00CU_WIRE_150Vapour000Temp / °C150150150Solution86.7856.6666.1Vapour163.4626.451829.22

[0168] Furthermore, the results shown in Table 2 also show that the presence of the polyether showed an improvement in vapor phase corrosion at 150 °C as measured by the wire corrosion test disclosed in PCT application WO2021 / 155015.

[0169] The mention of any document is not an admission that such document qualifies as prior art or constitutes the general knowledge of the skilled person in any jurisdiction. Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reaction conditions, molecular weights, number of carbon atoms, and the like, are to be understood as modified by the word "about." It is to be understood that the upper and lower amount, range, and ratio limits set forth herein may be independently combined. Similarly, the ranges and amounts for each element of the invention can be used together with ranges or amounts for any of the other elements. As used herein, the expression "consisting essentially of" permits the inclusion of substances that do not materially affect the basic and novel characteristics of the composition under consideration.

Claims

1. A lubricant composition comprising: a. an oil of lubricating viscosity, b. an amine (thio)phosphate salt, c. 0.01 to 5 weight % of a polyether comprising: i.formula I: wherein R1 can be a hydrocarbyl group having 6 to 30 carbon atoms, R2 can be hydrogen or an alkyl group having 1 to 5 carbon atoms, and R3 can be hydrogen, an C1-C4 alkyl group, or -C(O)R4, and wherein R4 can be a C1-C4 alkyl group and x can be an integer from 10-40 (15-35 or 20-30 or 22-26), ii.formula II: wherein R5 can be a linear or branched aliphatic group having from 1 to 30 carbon atoms, in another embodiment 10 to 20 carbon atoms, R2 can be hydrogen or an alkyl group having 1 to 5 carbon atoms, and R3 can be hydrogen, an C1-C4 alkyl group, -C(O)R4 wherein R4 can be a C1-C4 alkyl group and n can be an integer from 10-40 (15-35 or 20-30 or 22-26) m can be an integer from 1 to 3, or iii.formula III: wherein the hydrocarbyl group R1 can be a linear or branched aliphatic group having from 7 to 23 carbon atoms, R2 can be hydrogen or an alkyl group having 1 to 5 carbon atoms, and R3 can be hydrogen, an C1-C4 alkyl group, or -C(O)R4 and wherein R4 can be a C1-C4 alkyl group and n can be an integer from 10-40 (15-35 or 20-30 or 22-26), and d. a thiadiazole.

2. The lubricant composition of claim 1, wherein the amine (thio)phosphate salt comprises: a. alkyl phosphate amine salt, b. alkyl thiophosphate amine salt, c. dialkyl dithiophosphate amine salt, d. alkyl pyrophosphate amine salt, or e. combinations of any of a), b), c) and d).

3. The lubricant composition of claim 1, wherein the hydrocarbyl group R1 can be a linear or a branched aliphatic group from 6 to 30 carbon atoms, or wherein the hydrocarbyl group R1 can be a linear aliphatic group from 6 to 30 carbon atoms and R3 can be hydrogen.

4. The lubricant composition of claim 1, wherein the thiadiazole comprises a 1,3,4-thiadiazole.

5. The lubricant composition of claim 4, wherein the 1,3,4-thiadiazole comprises substituents at the 2 and 5 position of the thiadiazole ring structure, preferably wherein the 2 and 5 position of the thiadiazole ring structure are alkyldisulfaneyl moieties.

6. The lubricant composition of claim 4, wherein the thiadiazole compound has the formula: wherein R1 and R2 are independently alkyl groups with 1 to 12 carbons.

7. The lubricant composition of claim 1, further comprising a dispersant, preferably wherein the dispersant comprises a succinimide dispersant.

8. The lubricant composition of claim 7 wherein the dispersant: comprises a polyisobutylene succinimide dispersant, a grafted olefin copolymer, or wherein the dispersant is post treated with boron, dimercaptothiadiazole, terephthalic acid, or phosphoric acid.

9. The lubricant composition of claim 7, wherein the dispersant comprises succinate ester.

10. The lubricant composition of claim 7, wherein the dispersant is post treated with polyethylene amines or dimercaptothiadiazole.

11. The lubricant composition of claim 1, further comprising an antioxidant, preferably wherein the antioxidant comprises a hindered phenolic antioxidant or a hindered amine antioxidant.

12. The lubricant composition of claim 1, further comprising a dispersant viscosity modifier, preferably wherein the dispersant viscosity modifier comprises a dispersant poly(meth)acrylate or a dispersant ethylene / propylene copolymer.

13. The lubricant composition of claim 1, further comprising a detergent.

14. The lubricant composition of claim 1, further comprising an antiwear additive, preferably wherein the antiwear additive comprises hydrocarbyl phosphite, bis-acrylamide coupled dithiophosphate ester, or dithiophosphate ester.

15. A method of minimizing electrically conductive deposits in the propulsion system of an electric or hybrid vehicle comprising applying to said propulsion system a lubricant comprising the lubricant composition of any previous claim, and operating the propulsion system.