Melamine-based compounds for lubricating compositions

Abstract

In one embodiment, the melamine-based compounds are suitable as corrosion inhibitors for lubricating compositions, in particular for lubricating oils for transmission oils (manual, automatic, dual clutch or electric), axle fluids, differential oils, tractor oils, industrial gear oils, and / or other gear-based applications. The melamine-based compound is in the form of an oil-soluble hydrocarbyl-substituted melamine derivative comprising the reaction product of reacting a hydrocarbyl-substituted succinic anhydride with melamine under conditions effective to form a hydrocarbyl-substituted melamine polycarboxylic acid or anhydride compound.

Description

Technical Field

[0001] The present invention relates to melamine-based compounds suitable for use as lubricant additives, in particular melamine-based compounds suitable as corrosion inhibitors, and lubricating compositions comprising such melamine-based compounds for achieving improved copper corrosion performance. Background Art

[0002] Transmissions (manual, automatic, dual clutch and / or electric), axles, differentials and / or industrial gears often require lubricants that provide specific performance characteristics suitable for the desired application. Typically, lubricants used in such applications may require, for example, that the fluid meet one or more performance characteristics of extreme pressure, wear resistance, friction and / or copper corrosion to indicate some common requirements for such fluids. Various additives may be included in the lubricant to achieve performance. For example, such lubricants often include oil-soluble copper corrosion inhibitors, such as triazoles, to protect metals such as copper from corrosion.

[0003] Tolyltriazole (e.g., methyl substituted benzotriazole) is a common copper corrosion inhibitor that has good copper corrosion performance for transmission fluids, axle fluids, differential oils, tractor oils, and / or industrial gear oils, which indicates some of the applications that often include tolyltriazole. Copper corrosion can be evaluated according to ASTM D130 and / or a more extreme version of ASTM D130 by extending the test to 168 hours at 150°C. Copper corrosion is measured by visual tarnishing rating and / or the amount of copper leached from the lubricant. Although tolyltriazole can provide effective corrosion inhibition (almost no tarnishing and low copper leaching in such fluids), the use of tolyltriazole may be undesirable for a number of reasons. It has been a challenge to find an alternative copper corrosion inhibitor that performs comparable to tolyltriazole and is compatible with lubricant formulations for transmission fluids, axle fluids, differential oils, tractor oils, industrial gear oils, and / or other gear type applications. Summary of the invention

[0004] In one method or embodiment, described herein is a corrosion inhibitor in the form of an oil-soluble hydrocarbyl-substituted melamine derivative, and in one aspect, has a structure of Formula I wherein R1, R2 and R3 are each independently -NH2, a hydrocarbyl-substituted succinimide group or a hydrocarbyl-substituted dicarboxylic acid-amide group, and wherein one or two of R1, R2 and R3 are independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining R1, R2 and R3 are independently the -NH2 or the hydrocarbyl-substituted dicarboxylic acid-amide group.

[0005] In other methods or embodiments, the corrosion inhibitor of the previous paragraph includes other features or embodiments in any combination. These other features or embodiments include one or more of the following: wherein the hydrocarbyl substituent of the succinimide group or the dicarboxylic acid-amide group is a C12 to C30 hydrocarbyl group; and / or wherein the hydrocarbyl substituent of the succinimide group or the dicarboxylic acid-amide group is a C12 to C24 hydrocarbyl group; and / or wherein the corrosion inhibitor has about 5 weight percent to about 25 weight percent nitrogen; and / or wherein the corrosion inhibitor is the reaction product of a hydrocarbyl-substituted succinic acid or anhydride and melamine in a molar excess of the hydrocarbyl-substituted succinic acid or anhydride relative to the melamine; and / or wherein the molar ratio of the hydrocarbyl-substituted succinic acid or anhydride to the melamine is about 1.1 :1 to about 4:1; and / or wherein the molar ratio of the hydrocarbyl-substituted succinic acid or anhydride to the melamine is from about 1.1:1 to about 3:1; and / or wherein one of R1, R2 and R3 is independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining two of R1, R2 and R3 are the -NH2 group; and / or wherein two of R1, R2 and R3 are independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining one of R1, R2 and R3 is the -NH2 group; and / or wherein the oil-soluble hydrocarbyl-substituted melamine derivative has one or more of the following structures wherein each of the R groups thereof is independently a C12 to C30 hydrocarbon group; and / or a lubricating composition comprising about 0.1 to about 0.5 weight percent of the corrosion inhibitor exhibits less than about 100 ppm of copper after testing at 150° C. for 168 hours according to ASTM D130.

[0006] In another method or embodiment, a method of preparing an oil-soluble hydrocarbyl-substituted melamine derivative corrosion inhibitor is described herein. In one aspect, the method comprises reacting a hydrocarbyl-substituted succinic acid or anhydride with melamine in a molar excess of the hydrocarbyl-substituted succinic acid or anhydride relative to the melamine.

[0007] In another method or embodiment, the method of preparing the oil-soluble hydrocarbyl-substituted melamine derivative corrosion inhibitor of the preceding paragraph includes the other method steps, features or embodiments in any combination. These other steps, features or embodiments include one or more of the following: wherein the hydrocarbyl substituent is a C12 to C30 hydrocarbyl group; and / or wherein the hydrocarbyl substituent is a C12 to C24 hydrocarbyl group; and / or wherein the molar ratio of the hydrocarbyl-substituted succinic acid or anhydride to the melamine is from about 1.1:1 to about 4:1; and / or wherein the molar ratio of the hydrocarbyl-substituted succinic acid or anhydride to the melamine is from about 1.1:1 to about 3:1; and / or wherein the corrosion inhibitor formed has from about 5 to about 25 weight percent nitrogen; and / or wherein the reaction conditions include a temperature of from about 50°C to about 200°C (in other methods, from about 50°C to about 150°C or from about 100°C to about 200°C), and a reaction time of from about 1 to about 20 hours (in other methods, from about 4 to about 16 hours, and in further methods, from about 6 to about 12 hours) and / or wherein the oil-soluble hydrocarbyl-substituted melamine derivative formed has the structure of Formula I wherein R1, R2 and R3 are each independently -NH2, a hydrocarbyl-substituted succinimide group or a hydrocarbyl-substituted dicarboxylic acid-amide group, and wherein one or two of R1, R2 and R3 are independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining R1, R2 and R3 are independently the -NH2 or the hydrocarbyl-substituted dicarboxylic acid-amide group; and / or wherein one of R1, R2 and R3 is independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group wherein the oil-soluble hydrocarbon-substituted melamine derivative has one or more of the following structures:

[0008] In another embodiment or method, the present invention includes a powertrain lubricating composition comprising any embodiment of the corrosion inhibitor described in the Summary of the Invention above. In one aspect, the powertrain lubricating composition of the present invention includes one or more base oils of lubricating viscosity; an oil-soluble hydrocarbyl-substituted melamine derivative having a structure of Formula I

[0009]

[0010] wherein R1, R2 and R3 are each independently -NH2, a hydrocarbyl-substituted succinimide group or a hydrocarbyl-substituted dicarboxylic acid-amide group, and wherein one or two of R1, R2 and R3 are independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining R1, R2 and R3 are independently the -NH2 or the hydrocarbyl-substituted dicarboxylic acid-amide group; and in some embodiments, wherein the powertrain lubricating composition is substantially free of a methylbenzotriazole additive or a derivative thereof (as further defined herein).

[0011] In another embodiment, the lubricant composition described in the preceding paragraph may include any combination of one or more other features or embodiments. These other features or embodiments may include one or more of the following: wherein the hydrocarbyl substituent of the succinimide group or the dicarboxylic acid-amide group is a C12 to C30 hydrocarbyl group; and / or wherein the oil-soluble hydrocarbyl-substituted melamine derivative is a reaction product of a hydrocarbyl-substituted succinic acid or anhydride and melamine in a molar excess of the hydrocarbyl-substituted succinic acid or anhydride relative to the melamine; and / or wherein the molar ratio of the hydrocarbyl-substituted succinic acid or anhydride to the melamine is from about 1.1:1 to about 4:1; and / or wherein one of R1, R2 and R3 is independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining two of R1, R2 and R3 are the -NH2 group; and / or wherein two of R1, R2 and R3 are independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining one of R1, R2 and R3 is the -NH2 group; and / or wherein the oil-soluble hydrocarbyl-substituted melamine derivative has one or more of the following structures wherein the R groups thereof are each independently a C12 to C30 hydrocarbon group; and / or wherein the lubricating composition is free of a methylbenzotriazole additive or a derivative thereof; and / or wherein the lubricating composition is free of water; and / or wherein the lubricating composition has a kV100 viscosity of about 3 to about 10 cSt; and / or wherein the lubricating composition has less than about 215 ppm copper after testing at 150°C for 168 hours according to ASTM D130; and / or wherein the oil-soluble hydrocarbon-substituted melamine derivative provides about 5 to about 1100 ppm of nitrogen to the lubricating composition; and / or comprises about 0.01 to about 0.5 weight percent of the oil-soluble hydrocarbon-substituted melamine derivative; and / or wherein the lubricating composition further comprises less than about 1 weight percent of an alkylated diphenylamine.

[0012] In another method or embodiment, a method of lubricating a driveline component is described herein. In one aspect, the method comprises lubricating the driveline component with any embodiment of the lubricating composition described herein. In another embodiment, wherein the method comprises a lubricating composition comprising one or more base oils of lubricating viscosity; an oil-soluble hydrocarbyl-substituted melamine derivative having a structure of Formula I wherein R1, R2 and R3 are each independently -NH2, a hydrocarbyl-substituted succinimide group or a hydrocarbyl-substituted dicarboxylic acid-amide group, and wherein one or two of R1, R2 and R3 are independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining R1, R2 and R3 are independently the -NH2 or the hydrocarbyl-substituted dicarboxylic acid-amide group; and / or wherein the lubricating composition is prepared according to ASTM D130 has less than about 215 ppm copper after testing at 150°C for 168 hours; and / or wherein the hydrocarbyl substituent of the succinimide group or the dicarboxylic acid-amide group is a C12 to C30 hydrocarbyl group; and / or wherein the oil-soluble hydrocarbyl-substituted melamine derivative is the reaction product of a hydrocarbyl-substituted succinic acid or anhydride and melamine in a molar excess of the hydrocarbyl-substituted succinic acid or anhydride relative to the melamine; and / or wherein the molar ratio of hydrocarbyl-substituted succinic anhydride to melamine is from about 1.1:1 to about 4:1; and / or wherein one of R1, R2 and R3 is independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining two of R1, R2 and R3 are the -NH 2 group; and / or wherein two of R1, R2 and R3 are independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining one of R1, R2 and R3 is the -NH2 group; and / or wherein the kV100 viscosity of the lubricating composition is from about 3 to about 10 cSt; and / or wherein the oil-soluble hydrocarbyl-substituted melamine derivative provides from about 5 to about 1100 ppm of nitrogen to the lubricating composition; and / or wherein the lubricating composition comprises from about 0.01 to about 0.5 weight percent of the oil-soluble hydrocarbyl-substituted melamine derivative; and / or wherein the lubricating composition further comprises less than about 1 weight percent of an alkylated diphenylamine; and / or wherein the powertrain is an automatic transmission.

[0013] In another method or embodiment, described herein is the use of any embodiment of a corrosion inhibitor in the form of an oil-soluble hydrocarbyl-substituted melamine derivative for lubricating a powertrain system, in some embodiments, for lubricating a powertrain system, wherein the powertrain lubricating composition is substantially free of a methylbenzotriazole additive or a derivative thereof, and in another embodiment, has less than about 215 ppm copper after testing at 150° C. for 168 hours according to ASTM D130.

[0014] Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein.The following term definitions are provided to clarify the meaning of certain terms used herein. DETAILED DESCRIPTION

[0015] In one approach, disclosed herein are melamine-based compounds that are suitable, in one embodiment, as corrosion inhibitors for lubricating compositions, particularly for transmission oils (e.g., manual, automatic, dual clutch, or electric), axle fluids, differential oils, tractor oils, industrial gear oils, and / or lubricating oils for other gear-type applications. In other approaches or embodiments, the melamine-based compounds of the present invention are in the form of oil-soluble hydrocarbyl-substituted melamine derivatives, which, in one approach, are the reaction products of a hydrocarbyl-substituted succinic acid or anhydride (e.g., an alkenyl succinic acid or anhydride) and melamine under conditions effective to form a hydrocarbyl-substituted melamine-based succinimide or acid / amide compound (which is also referred to as a succinyl heterocyclic imide compound).

[0016] In one exemplary method or embodiment, suitable reaction conditions for forming the melamine compounds herein may include a reaction temperature of about 50° C. to about 200° C. (in other methods, about 50° C. to about 150° C., or about 100° C. to about 200° C.) and a reaction time of about 1 to about 20 hours (in other methods, about 4 to about 16 hours, and in further methods, about 6 to about 12 hours). The reaction conditions may also include a molar excess of the hydrocarbyl-substituted succinic acid or anhydride reactant (e.g., alkenyl succinic acid or anhydride) relative to the melamine reactant. Suitable hydrocarbyl-substituted succinic acid or anhydride reactants may include, for example, C12 to C30 alkenyl succinic acid or anhydride (preferably C12 to C24 alkenyl succinic acid or anhydride, or most preferably C12 to C16 alkenyl succinic acid or anhydride), more specifically, suitable reactants include, but are not limited to, C20-C24 alpha-olefins reacted with maleic acid or anhydride, hexadecene succinic acid or anhydride, dodecene succinic acid or anhydride, combinations thereof, and similar hydrocarbyl succinic acids or anhydrides. In other methods, the hydrocarbyl-substituted succinic acid or anhydride reactant may also be tetrapropenyl alkenyl succinic acid or anhydride, n-dodecene succinic acid or anhydride. In another alternative process, polyisobutylene substituted acids or anhydrides (e.g., PIBSA) may also be suitable as the starting reactant, preferably polyisobutylene having a number average molecular weight of up to about 450, and in other processes, polyisobutylene having a number average molecular weight of up to about 1000, or up to about 1500, or up to about 2500 (or any range therebetween).

[0017] In one method or embodiment, the oil-soluble hydrocarbyl-substituted melamine derivatives of the present invention suitable for use as corrosion inhibitors have the structure of Formula I Wherein R1, R2 and R3 are each independently -NH2, a hydrocarbyl-substituted succinimide group (i.e., Formula II below) or a hydrocarbyl-substituted dicarboxylic acid-amide group (i.e., Formula III below). In one method, one or two of R1, R2 and R3 are independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining R1, R2 and / or R3 are the -NH2 group or the hydrocarbyl-substituted dicarboxylic acid-amide group. In another method, one or two of R1, R2 and R3 are independently the hydrocarbyl-substituted succinimide group, and the remaining R1, R2 and / or R3 are the hydrocarbyl-substituted dicarboxylic acid-amide group. The hydrocarbyl-substituted succinimide group may have a structure of Formula II and the hydrocarbyl-substituted dicarboxylic acid-amide group may have a structure of Formula III (wherein ~ represents a bond to the central melamine portion): In other methods, one of R1, R2 and R3 is independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and in further methods, two of R1, R2 and R3 are independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group. In either case, the remaining R1, R2 and R3 groups are the hydrocarbyl-substituted dicarboxylic acid-amide groups or the -NH2 groups, and preferably the -NH2 groups. In further methods or embodiments, the hydrocarbyl substituent (e.g., the hydrocarbyl group of the R1, R2 and / or R3 moiety (i.e., the R group of the above formula II or III)) is a C12 to C30 hydrocarbyl group, preferably the hydrocarbyl substituent is a C12 to C24 hydrocarbyl group, and most preferably a C12 hydrocarbyl group, a C16 hydrocarbyl group, a C20 hydrocarbyl group, a C24 hydrocarbyl group or any mixture thereof.

[0018] As described above, the oil-soluble hydrocarbyl-substituted melamine derivatives herein can be prepared in a reaction in which the hydrocarbyl-substituted succinimide acid or anhydride reactant is in molar excess relative to the melamine reactant. In one embodiment, the molar excess is reflected in a molar ratio of the hydrocarbyl-substituted succinimide acid or anhydride reactant to the melamine reactant of from about 1.1:1 to about 4:1, in another embodiment, a molar ratio of the hydrocarbyl-substituted succinimide acid or anhydride reactant to the melamine reactant of from about 1.1:1 to about 3:1, and in yet another embodiment, a molar ratio of from about 2.0:1 to about 3.0:1.

[0019] When the melamine derivatives herein are formed in a reaction with a molar excess of hydrocarbyl-substituted succinic anhydride under the above conditions, the resulting melamine derivatives have from about 5 to about 25 weight percent nitrogen and a treat rate in the liquid of from about 0.01 to about 0.5 weight percent, capable of providing from about 5 ppm to about 1100 ppm nitrogen, from about 10 to about 800 ppm nitrogen, from about 10 to about 200 ppm nitrogen, from about 25 to about 100 ppm nitrogen, and preferably from about 25 to about 80 ppm nitrogen to the lubricant, and more preferably from about 30 to about 75 ppm nitrogen to the lubricant. In other embodiments, the oil-soluble hydrocarbyl-substituted melamine derivatives formed in a reaction with a molar excess of hydrocarbyl-substituted succinic anhydride under the above conditions have one or more of the following structures: wherein each R group thereof is a hydrocarbyl substituent as discussed above, and is independently a C12 to C30 hydrocarbyl group, preferably a C12 to C24 hydrocarbyl group, and most preferably a C12 hydrocarbyl group, a C16 hydrocarbyl group, a C20 hydrocarbyl group, a C24 hydrocarbyl group, or any mixture thereof.

[0020] As described above, the melamine derivatives herein are particularly suitable as corrosion inhibitors in lubricants, particularly corrosion inhibitors for lubricating compositions suitable for transmission oils (manual, automatic, dual clutch or electric), axle fluids, differential oils, tractor oils, industrial gear oils and / or other gear type applications, and for such lubricating compositions including melamine-based corrosion inhibitors. In one method or embodiment, such lubricating compositions may contain about 0.01 to about 0.5 weight percent of the melamine derivatives herein (preferably about 0.02 to about 0.1 weight percent, more preferably about 0.03 to about 0.08 weight percent). Using such melamine derivatives, the lubricant compositions herein may show less than about 215 ppm of copper leaching (preferably less than 100 ppm of copper, more preferably less than about 80 ppm of copper) after testing at 150° C. for 168 hours according to a modified version of ASTM D130. Compositions herein having such amounts of melamine derivatives may also exhibit a copper tarnishing rating of 4a to 4b. Most surprisingly, the lubricating compositions herein can achieve such low copper leaching levels and rust ratings in compositions that are substantially free of prior art methylbenzotriazole additives, meaning that the compositions herein have less than 0.1 weight percent methylbenzotriazole additives, less than about 0.05 weight percent methylbenzotriazole additives, less than about 0.01 weight percent methylbenzotriazole additives, or preferably no functional amount and / or no detectable amount of methylbenzotriazole additives.

[0021] The lubricating composition herein may include a combination of the above-mentioned melamine-based corrosion inhibitor and other additives suitable for the above-mentioned lubricant applications. The other additives may include one or more of a phosphorus antiwear additive, a sulfur antiwear additive, an antioxidant (including an ammonia antioxidant), a viscosity modifier, and a synthetic base oil or a mineral base oil to provide a kV100 viscosity (ASTM D445) of about 3 to about 10 cSt in some embodiments. Preferably, the lubricant has a negligible amount of water (e.g., about 0.5 weight percent or less, about 0.1 weight percent or less, or 0.05 weight percent or less), preferably, no water or an undetectable amount of water.

[0022] Base oil

[0023] Suitable base oils for use in the lubricating composition of the present invention may be mineral oils, animal oils, vegetable oils, synthetic oils or mixtures thereof.

[0024] Natural oils may include animal oils and vegetable oils (such as castor oil, lard), and mineral oils such as liquid petroleum, and paraffin oil, naphthenic oil or paraffin-naphthenic mixed type solvent-treated or acid-treated mineral lubricating oils. Mineral oils may include oils obtained by drilling or from plants and animals or any mixture thereof. For example, such oils may include but are not limited to castor oil, lard, olive oil, peanut oil, corn oil, soybean oil and linseed oil, and mineral lubricating oils, such as liquid petroleum, and paraffin oil, naphthenic oil or paraffin-naphthenic mixed type solvent-treated or acid-treated mineral lubricating oils. If necessary, these oils may be partially or completely hydrogenated. Oils from coal or shale may also be suitable. In addition, oils extracted from gas-to-liquid process are also suitable. According to ASTM D2270-10 measurement, the kinematic viscosity of base oil at 100°C is about 2 to 15cSt.

[0025] Useful synthetic lubricating oils may include hydrocarbon oils such as polymerized, oligomeric or copolymerized olefins (e.g., polybutene, polypropylene, propylene-isobutylene copolymers); trimers or oligomers of poly(1-hexene), poly(1-octene), 1-decene, such as poly(1-decene), these materials are generally referred to as alpha-olefins, and mixtures thereof; alkylbenzenes (e.g., dodecylbenzene, tetradecylbenzene, dinonylbenzene, di-(2-ethylhexyl)-benzene); polyphenylenes (e.g., biphenyl, terphenyl, alkylated polyphenylenes); diphenylalkanes, alkylated diphenylalkanes, alkylated diphenyl ethers and alkylated diphenyl sulfides and derivatives, analogs and homologs thereof or mixtures thereof. Polyalphaolefins are typically hydrogenated materials.

[0026] Other synthetic lubricating oils include polyol esters, diesters, liquid esters of phosphorus-containing acids (such as tricresol phosphate, trioctyl phosphate and diethyl ester of decanephosphonic acid) or polymerized tetrahydrofuran. Synthetic oils can be produced by Fischer-Tropsch reactions, typically Fischer-Tropsch hydrocarbons or waxes of hydrogen isomerization. In one embodiment, the oil can be prepared by Fischer-Tropsch gas-to-liquids synthesis procedures and other natural gas synthetic oils.

[0027] The base oil or base oil with lubricating viscosity used in the composition herein can be a single base oil or a mixture of two or more base oils. One or more base oils can be selected from any base oil in Class IV specified in the Base Oil Interchangeability Guidelines of the American Petroleum Institute (API). These base oil groups are as follows:

[0028] Table 1: Base oil types

[0029] I, II and III are mineral oil processing raw materials. IV group base oil contains synthetic molecular substances, which are produced by the polymerization reaction of olefinic unsaturated hydrocarbons. API IV group base oil, polyalphaolefins (PAOs), are generally derived from monomers with 4 to 30, or 4 to 20, or 6 to 16 carbon atoms. Examples of PAOs that can be used in the present invention include those derived from octene, decene, mixtures thereof, etc. According to ASTM D2270-10, the kinematic viscosity of PAO at 100°C can be 2 to 15cSt, or 3 to 12cSt, or 4 to 8cSt. Suitable PAO viscosity examples include 4cSt at 100°C and 6cSt at 100°C, and mixtures thereof. Many V group base oils are also true synthetic products, and may include diesters, polyol esters, polyalkylene glycols, alkylated aromatics, polyphosphates, polyethylene ethers and / or polyphenylene ethers, etc., but may also be natural oils, such as vegetable oils. It should be noted that although the III group base oils are derived from mineral oils, the rigorous processing that these fluids undergo makes their physical properties very similar to some true synthetic oils. Therefore, oils derived from the III group base oils may be referred to as synthetic oils in the industry. Suitable oils may be derived from hydrocracking, hydrogenation, hydrofining, unrefined, refined and re-refined oils and mixtures thereof.

[0030] Unrefined oil refers to oil derived from natural, mineral or synthetic sources without or almost without further purification treatment. Refined oils are similar to unrefined oils, except that they have been subjected to one or more purification steps, which may improve one or more properties. Examples of suitable purification techniques are solvent extraction, secondary distillation, acid or base extraction, filtration, percolation, etc. Oils refined to edible quality may or may not be useful. Edible oils may also be referred to as white oils. In some embodiments, the lubricating oil composition does not contain edible oils or white oils.

[0031] Re-refined oils are also called reclaimed oils or reprocessed oils. These oils are obtained similarly to refined oils using the same or similar processes. Typically, these oils are additionally treated by techniques designed to remove spent additives and oil breakdown products.

[0032] The base oil is mixed with the additive composition disclosed in the embodiments herein to provide a lubricating fluid for a transmission, an axle, a tractor or an industrial gear. Therefore, the base oil may be present in the lubricating fluid in an amount greater than about 80% by weight, based on the total weight of the lubricating fluid. In some embodiments, the base oil may be present in the lubricating fluid in an amount greater than about 85% by weight, based on the total weight of the lubricating fluid, and may be selected from any suitable synthetic oil or natural oil or mixture thereof having a suitable lubricating viscosity.

[0033] Suitable transmission, axle, differential, tractor or industrial gear lubricant compositions herein may include additive components within the ranges listed in Table 2.

[0034] Table 2: Suitable powertrain or gear fluid compositions

[0035] The percentages of the above components represent the weight percentage of each component based on the weight of the total lubricating oil composition. The remainder (balance) of the lubricating oil composition consists of one or more base oils. The additives used to formulate the compositions described herein can be incorporated into the base oils individually or in various sub-combinations. However, it may be appropriate to use an additive concentrate (i.e., additives plus a diluent, such as a hydrocarbon solvent) to mix all components simultaneously.

[0036] The lubricating compositions described herein can be formulated to provide lubrication, adequate load-bearing capacity, and improved copper corrosion performance for a variety of applications. The lubricating fluids according to the present invention can be used in transmission oils, axle fluids, differential oils, tractor oils, industrial gear oils, and stationary gearboxes. Gear types can include, but are not limited to, spur gears, helical gears, worm gears, rack and pinion gears, involute gears, bevel gears, helical gears, planetary gears, and hypoid gears, as well as limited slip applications and differentials. The powertrain lubricating compositions disclosed herein are also suitable for automatic or manual transmissions, including stepped automatic transmissions, continuously variable transmissions, semi-automatic transmissions, mechanical automatic transmissions, toroidal transmissions, and dual clutch transmissions. The powertrain lubricant compositions herein are particularly suitable for axles, transfer cases, differentials, such as straight differentials, steering differentials, limited slip differentials, clutch differentials, and locking differentials, etc.

[0037] Optional additives

[0038] In other methods, the lubricant including the above-mentioned additives may also include one or more optional components, as long as these components and their amounts do not affect the performance characteristics described in the above paragraphs. These optional components are described in the following paragraphs.

[0039] Phosphorus compounds

[0040] The lubricant composition of the present invention may include one or more phosphorus-containing compounds, which may provide anti-wear benefits to the fluid. The one or more phosphorus-containing compounds may be present in the lubricant composition in an amount ranging from about 0 wt % to about 5 wt %, or from about 0.01 wt % to about 4 wt %, or from about 0.05 wt % to about 3 wt %, or from about 0.1 wt % to about 3 wt % of the lubricant composition. The phosphorus-containing compound may provide up to 500 ppm of phosphorus, or from about 3 to about 100 ppm of phosphorus, or from about 4 to about 20 ppm of phosphorus, or up to 50 ppm of phosphorus, or up to 20 ppm of phosphorus to the lubricant composition.

[0041] One or more phosphorus-containing compounds may include ashless phosphorus-containing compounds. Examples of suitable phosphorus-containing compounds include, but are not limited to, thiophosphates, dithiophosphates, phosphates, esters of phosphoric acid, phosphate esters, phosphites, phosphonates, phosphorus-containing carboxylates, ethers or their amide salts and mixtures thereof. Phosphorus-containing antiwear agents are more fully described in European Patent 0612839.

[0042] It should be noted that in the lubricant industry, the terms phosphonate and phosphite are often used interchangeably. For example, dibutyl hydrogen phosphonate is often referred to as dibutyl hydrogen phosphite. Within the scope of the present invention, the lubricant composition of the present invention includes a phosphorus-containing compound, which may be referred to as a phosphite or a phosphonate.

[0043] In any of the above phosphorus-containing compounds, the compound can have from about 4 to about 8 weight percent phosphorus, or from about 5 to about 6 weight percent phosphorus.

[0044] In some embodiments, the ashless phosphorus-containing compound may be a dialkyl dithiophosphate, amyl acid phosphate, diamyl phosphate, dibutyl hydrogen phosphonate, dimethyloctadecyl phosphonate, salts thereof, and mixtures thereof.

[0045] The ashless phosphorus-containing compound may have the formula: wherein R1 is S or O; R2 is –OR, –OH or –R”; R3 is –OR”, –OH or SR”’C(O)OH; R4 is –OR”; R”’ is a C1 to C3 branched or straight alkyl chain; and R” is a C1 to C 18 When the phosphorus-containing compound has the structure shown in Formula XIV, the compound can have from about 8 to about 16 weight percent phosphorus.

[0046] In some embodiments, the lubricating composition comprises a phosphorus-containing compound of Formula XIV, wherein R1 is O; R2 is H; R3 and R4 are each OR", wherein R" is C 18 ; wherein the phosphorus-containing compound is present in an amount that provides 3-50 ppm phosphorus or 3-20 ppm phosphorus to the lubricant composition. In other embodiments, the lubricating composition comprises a phosphorus-containing compound of Formula XIV, wherein R1 is O; R2 is H; R3 and R4 are each OR", wherein R" is oleyl; and wherein the phosphorus-containing compound is present in an amount that provides 3-50 ppm phosphorus or 3-20 ppm phosphorus to the lubricant composition.

[0047] In some embodiments, the lubricant composition comprises a phosphorus-containing compound of Formula XIV, wherein R1 is S; R2 is -OR", R3 is SR"'COOH; R4 is -OR", R"' is a C3 branched alkyl chain; R" is C4; and wherein the phosphorus-containing compound is present in an amount providing 3-50 ppm phosphorus to the lubricant composition.

[0048] In another embodiment, the lubricant composition comprises a phosphorus-containing compound of Formula XIV, wherein R1 is O; R2 is -OH; R3 is -OR" or -OH; R4 is -OR"; R" is C5; and wherein the phosphorus-containing compound is present in an amount to provide 3-50 ppm phosphorus to the lubricant composition.

[0049] In another embodiment, the lubricant composition comprises a phosphorus-containing compound of Formula XIV, wherein R1 is O; R2 is OR", R3 is H; R4 is -OR", R" is C4; and wherein the one or more phosphorus-containing compounds are present in an amount to provide 3-50 ppm phosphorus to the lubricant composition.

[0050] In other embodiments, the lubricant composition comprises a phosphorus-containing compound of Formula XIV, wherein R1 is O; R2 is -R"; R3 is -OCH3 or -OH; R4 is -OCH3; R" is C 18 ; and wherein the one or more phosphorus-containing compounds are present in an amount to provide 3-50 ppm phosphorus to the lubricant composition.

[0051] Antiwear Agents

[0052] Lubricant composition can also include the antiwear agent of non-phosphorus-containing compound.The example of this type of antiwear agent includes boric acid ester, borate / ester epoxide, thiocarbamate / ester compound (including thiocarbamate / ester, alkylene coupled thiocarbamate / ester and bis (S-alkyl dithiocarbamoyl) disulfide, thiocarbamic acid amide, thiocarbamic acid ether (thiocarbamic ethers), alkylene coupled thiocarbamate / ester and bis (S-alkyl dithiocarbamoyl) disulfide, and mixture thereof), olefin sulfide, tridecyl adipate, titanium compound and hydroxycarboxylic acid long chain derivative, for example tartrate / salt derivative, tartrate amide, tartrimide, citrate / salt and mixture thereof.Suitable thiocarbamate / ester compound is dithiocarbamic acid platinum.Suitable tartrate derivative or tartrimide can contain alkyl ester group, wherein the sum of carbon atoms on alkyl can be at least 8. The tartaric acid derivative or tartarimide may contain an alkyl ester group, wherein the sum of the carbon atoms on the alkyl group may be at least 8. In one embodiment, the antiwear agent may include a citrate. The additional antiwear agent may be present in an amount ranging from about 0 wt % to about 5 wt %, or from about 0.01 wt % to about 4 wt %, or from about 0.05 wt % to about 3 wt %, or from about 0.1 wt % to about 3 wt %, based on the weight of the lubricating oil composition.

[0053] Sulfur compounds

[0054] The lubricant compositions of the present invention may also contain sulfur-containing compounds for providing extreme pressure performance, so long as the lubricant compositions herein include the amounts and formulations described herein.

[0055] Various sulfur-containing extreme pressure agents are suitable, including sulfurized animal or vegetable fats or oils, sulfurized animal or vegetable fatty acid esters, fully or partially esterified esters of trivalent or pentavalent acids of phosphorus, sulfurized olefins (see, e.g., U.S. Pat. Nos. 2,995,569; 3,673,090; 3,703,504; 3,703,505; 3,796,661; 3,873,454; 4,119,549; 4,119,550; 4,147,640; 4,191,659; 4,240,958; 4,344,854; 4,472,306; and 4,711,736), dihydrocarbyl polysulfides (see, e.g., U.S. Pat. Nos. 2,237,625; 2,237,627; 2,527,948; 2,695,316; 3,022,351; 3,308,166; 3,392,201; 4,564,709; and British 1,162,334), functionally substituted dihydrocarbyl polysulfides (see, e.g., U.S. Pat. No. 4,218,332), and polysulfide olefin products (see, e.g., U.S. Pat. No. 4,795,576).

[0056] One class of suitable extreme pressure agents is polysulfides composed of one or more compounds represented by the formula: Ra-S x -Rb, wherein Ra and Rb are hydrocarbyl groups, each of which may contain 1 to 18 carbon atoms, in other methods, 3 to 18 carbon atoms, and x may be 2 to 8, typically 2 to 5, and particularly 3. In some methods, x is an integer from 3 to 5, and about 30% to about 60% of x is an integer of 3 or 4. The hydrocarbyl group may be of various types, such as alkyl, cycloalkyl, alkenyl, aryl or aralkyl. Tertiary alkyl polysulfides such as di-tert-butyl trisulfide, and mixtures containing di-tert-butyl trisulfide (e.g., mixtures consisting mainly or entirely of trisulfide, tetrasulfide and pentasulfide) may be used. Examples of other useful dihydrocarbyl polysulfides include diamyl polysulfide, dinonyl polysulfide, didodecyl polysulfide and dibenzyl polysulfide.

[0057] Another suitable extreme pressure agent is sulfurized isobutylene prepared by reacting an olefin (such as isobutylene) with sulfur. Sulfurized isobutylene (SIB), particularly sulfurized polyisobutylene, typically has a sulfur content of about 10 to about 55 weight percent, ideally about 30 to about 50 weight percent. Various other olefins or unsaturated hydrocarbons, such as isobutylene dimers or trimers, can be used to form sulfurized olefin extreme pressure agents. Various methods for preparing sulfurized olefins are disclosed in the prior art. For example, see U.S. Pat. No. 3,471,404 to Myers; U.S. Pat. No. 4,204,969 to Papay et al.; U.S. Pat. No. 4,954,274 to Zaweski et al.; U.S. Pat. No. 4,966,720 to DeGonia et al.; and U.S. Pat. No. 3,703,504 to Horodysky et al., each of which is incorporated herein by reference.

[0058] Methods for preparing sulfurized olefins, including those disclosed in the above patents, generally involve forming a material, generally referred to as an "adduct," in which an olefin is reacted with a sulfur halide (e.g., sulfur monochloride). The adduct is then reacted with a sulfur source to provide a sulfurized olefin. The quality of the sulfurized olefin is generally measured by various physical properties, including viscosity, sulfur content, halogen content, and copper corrosion test weight loss. U.S. Pat. No. 4,966,720 relates to a two-stage reaction for sulfurized olefins used as extreme pressure additives in lubricating oils and their preparation.

[0059] In some embodiments, the content of the extreme pressure agent in the lubricating composition is up to about 3.0wt% or up to about 5.0wt%. In other embodiments, the extreme pressure agent is present in an amount of 0.05wt% to about 0.5wt% based on the total lubricant composition. In other embodiments, the extreme pressure agent is present in an amount of about 0.1wt% to about 3.0wt% based on the total lubricant composition. In other embodiments, the extreme pressure agent is present in an amount of about 0.6wt% to about 1wt% based on the total lubricant composition.

[0060] Antioxidants

[0061] The lubricating oil composition of the present invention may also optionally contain one or more antioxidants. Antioxidant compounds are known and include, for example, phenates, phenate sulfides, sulfided olefins, phosphorus sulfided terpenes, sulfided esters, aromatic amines, alkylated diphenylamines (e.g., nonyldiphenylamine, dinonyldiphenylamine, octyldiphenylamine, dioctyldiphenylamine), phenyl α-naphthylamine, alkylated phenyl α-naphthylamine, hindered non-aromatic amines, phenols, hindered phenols, oil-soluble molybdenum compounds, macromolecular antioxidants, or mixtures thereof. Antioxidant compounds may be used alone or in combination.

[0062] The hindered phenol antioxidant may contain a sec-butyl and / or tert-butyl group as a sterically hindering group. The phenol group may be further substituted with a hydrocarbon group and / or a bridging group connected 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, for example, 2,6-di-tert-butylphenol available from BASF. or an addition product derived from 2,6-di-tert-butylphenol and an alkyl acrylate, wherein the alkyl group may contain from about 1 to about 18, or from about 2 to about 12, or from about 2 to about 8, or from about 2 to about 6, or about 4 carbon atoms. Another commercially available hindered phenol antioxidant may be an ester, which may include the esters available from Albemarle Corporation

[0063] One particularly useful antioxidant includes nonyldiphenylamine and dinonyldiphenylamine. In one embodiment, the lubricating oil composition may include one or more of these diphenylamines present in an amount up to about 1 wt%.

[0064] One or more antioxidants may be present in an amount from about 0 wt % to about 3 wt %, or from about 0.1 wt % to about 1 wt %, or from about 0.1 wt % to about 0.5 wt %, based on the weight of the lubricating oil composition.

[0065] Dispersants

[0066] The lubricant composition may include one or more selected dispersants or mixtures thereof. Dispersants are often referred to as ashless dispersants because they do not contain ash-forming metals prior to mixing into the lubricating oil composition and do not typically produce any ash when added to the lubricant. Ashless dispersants are characterized by polar groups attached to relatively high molecular weight hydrocarbon chains. Typical ashless dispersants include N-substituted long chain alkenyl succinimides. The N-substituted long chain alkenyl succinimides include polyisobutylene (PIB) substituents having a number average molecular weight in the range of about 800 to about 2500 as determined by gel permeation chromatography (GPC) using polystyrene (number average molecular weight of 180 to about 18,000) as a calibration reference. The viscosity of the PIB substituent used in the dispersant is typically about 2100 to about 2700 cSt at 100°C, which is determined using ASTM D445-18. Succinimide dispersants and their preparation are disclosed in, for example, U.S. Patent Nos. 7,897,696 and 4,234,435, which are incorporated herein by reference. Succinimide dispersants are typically imides formed by polyamines, typically poly(ethyleneamine). Dispersants can include two succinimide moieties connected by polyamines. Polyamines can be tetraethylenepentamine (TEPA), triethylenetetramine (TETA), pentaethylenehexamine (PEHA), other higher nitrogen ethylenediamine materials and / or mixtures thereof. Polyamines can be a mixture of straight chain, branched chain and cyclic amines. PIB substituents can be connected to each succinimide moiety.

[0067] In some embodiments, the lubricant composition comprises at least one polyisobutylene succinimide dispersant derived from polyisobutylene, wherein the polyisobutylene has a number average molecular weight of from about 350 to about 5000, or from about 500 to about 3000, as measured by the GPC method described above. The polyisobutylene succinimide can be used alone or in combination with other dispersants.

[0068] In some embodiments, when PIB is included, the content of terminal double bonds can be greater than 50 mol%, greater than 60 mol%, greater than 70 mol%, greater than 80 mol%, or greater than 90 mol%. Such PIB is also referred to as highly reactive PIB ("HR-PIB"). HR-PIB having a number average molecular weight of about 800 to about 5000 is suitable for embodiments of the present invention. Conventional non-highly reactive PIBs typically have a terminal double bond content of less than 50 mol%, less than 40 mol%, less than 30 mol%, less than 20 mol%, or less than 10 mol%.

[0069] HR-PIB having a number average molecular weight of about 900 to about 3000 as measured by the above-mentioned GPC method may be suitable. Such HR-PIB is commercially available or may be synthesized by polymerization of isobutylene in the presence of a non-chlorinated catalyst such as boron trifluoride, as described in U.S. Pat. Nos. 4,152,499 and 5,739,355. When used in the above-mentioned thermal ene reaction, HR-PIB may result in higher conversion in the reaction and lower deposit formation due to increased reactivity.

[0070] In some embodiments, the lubricant composition comprises at least one dispersant derived from polyisobutylene succinic anhydride. In some embodiments, the dispersant may be derived from polyalphaolefin (PAO) succinic anhydride.

[0071] One type of suitable dispersant may be a Mannich base. A Mannich base is a material formed by the condensation of a relatively high molecular weight alkyl-substituted phenol, a polyalkylene polyamine, and an aldehyde such as formaldehyde. Mannich bases are described in more detail in U.S. Pat. No. 3,634,515.

[0072] A suitable class of dispersants may be high molecular weight esters or half ester amides.

[0073] The dispersant may also be post-treated by conventional methods of reaction with any of a variety of agents. These agents include boron, urea, thiourea, dimercaptothiadiazoles, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleic anhydride nitrile, epoxides, carbonates, cyclic carbonates, hindered phenol esters, and phosphorus compounds. U.S. Patent Nos. 7,645,726; 7,214,649; and 8,048,831 describe some suitable post-treatment methods and post-treated products.

[0074] Suitable boron compounds that can be used to form the dispersant herein include any boron compound or mixture of boron compounds that can introduce boron-containing materials into the ashless dispersant. Any organic or inorganic boron compound that can carry out this reaction can be used. Therefore, boron oxide, boron oxide hydrate, boron trifluoride, boron tribromide, boron trichloride, HBF4, boric acids such as boronic acid (e.g., alkyl-B(OH)2 or aryl-B(OH)2), boric acid (boricacid, i.e., H3BO3), tetraboric acid (i.e., H2B5O7), metaboric acid (i.e., HBO2), ammonium salts of these boronic acids, and esters of these boronic acids can be used. The use of complexes of trihalogenated boron with ethers, organic acids, inorganic acids, or hydrocarbons is a convenient method for introducing boron reactants into the reaction mixture. Such complexes are known and examples are boron trifluoride-diethyl ether, boron trifluoride-phenol, boron trifluoride-phosphoric acid, boron trichloride-chloroacetic acid, boron tribromide-dioxane and boron trifluoride-methyl ethyl ether.

[0075] Suitable phosphorus compounds for forming dispersants herein include phosphorus compounds or mixtures of phosphorus compounds that can introduce phosphorus-containing materials into ashless dispersants. Therefore, any phosphorus compound capable of such a reaction may be used, whether organic or inorganic. Therefore, inorganic phosphorus compounds such as inorganic phosphoric acid and inorganic phosphorus oxides, including their hydrates, may be used. Typical organophosphorus compounds include full and partial esters of phosphorus-containing acids, such as monoesters, diesters and triesters of phosphoric acid, thiophosphoric acid, dithiophosphoric acid, trithiophosphoric acid and tetrathiophosphoric acid; monoesters, diesters and triesters of phosphorous acid, thiophosphorous acid and thiophosphorous acid; dithiophosphorous acid and trithiophosphorous acid; trialkylphosphine oxides; trialkylphosphine sulfides; monoalkylphosphonic acid esters and dialkylphosphonic acid esters (RPO(OR′)(OR″), wherein R and R′ are hydrocarbon groups and R″ is a hydrogen atom or a hydrocarbon group) and their monothio, dithio and trithio analogs; monoalkylphosphonic acid esters and dialkylphosphonic acid esters (RP(OR′)(OR″), wherein R and R′ are hydrocarbon groups and R″ is a hydrogen atom or a hydrocarbon group) and their monothio and dithio analogs; and the like. Thus, such compounds as phosphorous acid (H3PO3, sometimes described as H2(HPO3), sometimes referred to as orthophosphorous acid or phosphonic acid), phosphoric acid (H3PO4, sometimes referred to as orthophosphoric acid), hypophosphorous acid (H4P2O6), metaphosphoric acid (HPO3), pyrophosphoric acid (H4P2O7), hypophosphorous acid (H3PO2, sometimes referred to as phosphinic acid), pyrophosphorous acid (H4P2O5, sometimes referred to as pyrophosphonic acid), triphosphonic acid (H3PO), tripolyphosphoric acid (H5P3O 10 ), tetrapolyphosphate (H5P4O 13), trimetaphosphoric acid (H3P3O9), phosphorus trioxide, phosphorus tetroxide, phosphorus pentoxide, etc. Some or all sulfur analogs, such as tetrathiophosphoric acid (phosphorotetrathioic acid, H3PS4), monothiophosphoric acid (phosphoromonothioic acid, H3PO3S), dithiophosphoric acid (H3P2S2), trithiophosphoric acid (H3POS3), tetraphosphorus trisulfide, phosphorus heptasulfide and phosphorus pentasulfide (P2S5, sometimes called P4S 10 ), can also be used to form the dispersant of the present invention. Inorganic phosphorus halides can also be used, such as PCl3, PBr3, POCl3, PSCl3, etc.

[0076] Likewise, such organophosphorus compounds as monoesters, diesters and triesters of phosphoric acid (e.g., trialkyl phosphates, monoacid dialkyl phosphates, diacid monoalkyl phosphates, and mixtures thereof), monoesters, diesters and triesters of phosphites (e.g., trialkyl phosphites, dialkyl hydrogen phosphites, diacid alkyl phosphites, and mixtures thereof), phosphonates (including both "primary" RP(O)(OR)2 and "secondary" R2P(O)(OR)), phosphinates, phosphonyl halides (e.g., RP(O)Cl2 and R2P(O)(OR)), and phosphinyl halides (e.g., RP(O)Cl2 and R2P(O)(OR)). The present invention also includes phosphites (e.g., (RO)PCl2 and (RO)2PCl), phosphites (e.g., (RO)PCl2 and (RO)2PCl), phosphites (e.g., ROP(O)Cl2 and (RO)2P(O)Cl), tertiary pyrophosphates (e.g., (RO)2P(O)—O—P(O)(OR)2), and all or part of the sulfur analogs of any of the above organophosphorus compounds, and the like, wherein each hydrocarbyl group contains up to about 100 carbon atoms, or up to about 50 carbon atoms, or up to about 24 carbon atoms, or up to about 12 carbon atoms. Halophosphine halides (e.g., hydrocarbyl phosphorus tetrahalides, dihydrocarbyl phosphorus trihalides, and trihydrocarbyl phosphorus dihalides) and phosphine halides (monohalogenated and dihalogenated phosphine) are also useful.

[0077] The lubricants herein may include a mixture of one or more of the boronated dispersants and phosphated dispersants described above with non-borated dispersants and non-phosphated dispersants.

[0078] In one embodiment, the lubricating oil composition may include at least one boronated dispersant, wherein the dispersant is the reaction product of an olefin copolymer, or a reaction product of an olefin copolymer and succinic anhydride; and at least one polyamine. The ratio of PIBSA to polyamine may be from 1:1 to 10:1, or from 1:1 to 5:1, or from 4:3 to 3:1, or from 4:3 to 2:1. A particularly useful dispersant comprises a polyisobutylene group of PIBSA having a number average molecular weight (Mn) in the range of about 500 to 5000, as determined by the GPC method described above, and (B) having the general formula H2N(CH2) m—[NH(CH2) m ] n —NH2 polyamines, wherein m is in the range of 2 to 4 and n is in the range of 1 to 2.

[0079] In addition to the above, the dispersant can also be post-treated with aromatic carboxylic acids, aromatic polycarboxylic acids or aromatic anhydrides, wherein all carboxylic acid or anhydride groups are directly attached to the aromatic ring. Such carboxyl-containing aromatic compounds can be selected from 1,8-naphthalene dicarboxylic acid or anhydride and 1,2-naphthalene dicarboxylic acid or anhydride, 2,3-naphthalene dicarboxylic acid or anhydride, naphthalene-1,4-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, phthalic anhydride, pyromellitic anhydride, 1,2,4-trimethylbenzene dicarboxylic acid or anhydride, biphenyl dicarboxylic acid or anhydride, 2,3-pyridine dicarboxylic acid or anhydride, 3,4-pyridine dicarboxylic acid or anhydride, 1,4,5,8-naphthalene tetracarboxylic acid or anhydride, perylene-3,4,9,10-tetracarboxylic anhydride, pyrene dicarboxylic acid or anhydride, etc. The number of moles of the post-treatment component reacted per mole of polyamine can be in the range of about 0.1:1 to about 2:1. A typical molar ratio of the post-treatment component to the polyamine in the reaction mixture can be about 0.2:1 to about 2:1. Another molar ratio of the post-treatment component to the polyamine that can be used can be in the range of 0.25:1 to about 1.5:1. Such a post-treatment component can react with the other components in the temperature range of about 140°C to about 180°C.

[0080] As an alternative or supplement to the above-mentioned post-treatment, the dispersant can be post-treated with a non-aromatic dicarboxylic acid or anhydride. The number average molecular weight of the non-aromatic dicarboxylic acid or anhydride can be less than 500, as measured by the above-mentioned GPC method. Suitable carboxylic acids or their anhydrides can include but are not limited to acetic acid or anhydride, oxalic acid and anhydride, malonic acid and anhydride, succinic acid and anhydride, alkenylsuccinic acid and anhydride, glutaric acid and anhydride, adipic acid and anhydride, pimelic acid and anhydride, suberic acid and anhydride, azelaic acid and anhydride, sebacic acid and anhydride, maleic acid and anhydride, fumaric acid and anhydride, tartaric acid and anhydride, glycolic acid and anhydride, 1,2,3,6-tetrahydronaphthoic acid and anhydride, etc.

[0081] The non-aromatic carboxylic acid or anhydride reacts with the polyamine at a molar ratio of about 0.1 to about 2.5 moles of non-aromatic carboxylic acid or anhydride per mole of polyamine. Typically, the amount of non-aromatic carboxylic acid or anhydride used is related to the number of secondary amino groups in the polyamine. Therefore, about 0.2 to about 2.0 moles of non-aromatic carboxylic acid or anhydride relative to each secondary amino group in component B can be reacted with other components to provide a dispersant according to an embodiment of the present invention. Another molar ratio of non-aromatic carboxylic acid or anhydride to polyamine that can be used can be 0.25:1 to about 1.5:1 moles per mole of polyamine. The non-aromatic carboxylic acid or anhydride can react with the other components in a temperature range of about 140° to about 180°C.

[0082] The active ingredient weight percent of alkenyl or alkyl succinic anhydride can be determined using chromatographic techniques. This method is described in U.S. Pat. No. 5,334,321, columns 5 and 6. The percent conversion of the polyolefin is calculated from the active ingredient percentage (% actives) using the equation in columns 5 and 6 of U.S. Pat. No. 5,334,321.

[0083] Suitable boronated dispersants may have a TBN of about 10 to about 65 mg KOH / gram of composition on an oil-free basis, which is comparable to a TBN of about 5 to about 30 mg KOH / gram of composition if measured on a sample of the dispersant containing about 50% diluent oil.

[0084] Typically, the dispersant is present in the lubricant in an amount of about 4.5 to about 10 weight percent, in other methods, about 4.5 to about 8 weight percent, and in still other methods, about 4.5 to about 7.7 weight percent.

[0085] Viscosity Index Improver

[0086] The lubricant composition herein may also optionally include one or more viscosity index improvers. Suitable viscosity index improvers may include polyolefins, olefin copolymers, ethylene / propylene copolymers, polyisobutylene, hydrogenated styrene-isoprene polymers, styrene / maleic ester copolymers, hydrogenated styrene / butadiene copolymers, hydrogenated isoprene polymers, alpha-olefin-maleic anhydride copolymers, polymethacrylates, polyacrylates, polyalkylstyrenes, hydrogenated alkenyl aryl conjugated diene copolymers or mixtures thereof. Viscosity index improvers may include star polymers, suitable examples of which are described in U.S. Publication No. 20120101017A1, which is incorporated herein by reference.

[0087] In addition to or in place of a viscosity index improver, the lubricating oil composition herein may optionally include one or more dispersant viscosity index improvers. Suitable viscosity index improvers may include functionalized polyolefins, for example, ethylene-propylene copolymers functionalized with the reaction product of an acylating agent (such as maleic anhydride) and an amine; polymethacrylates functionalized with amines or esterified maleic anhydride-styrene copolymers reacted with amines.

[0088] Viscosity Index Improvers and / or Dispersants The total amount of viscosity index improvers may be from about 0 wt % to about 10 wt %, from about 0.1 wt % to about 8 wt %, from about 0.1 wt % to about 6 wt %, based on the weight of the lubricating oil composition.

[0089] In some embodiments, the viscosity index improver is a polyolefin or olefin copolymer having a number average molecular weight of about 10,000 to about 500,000, about 50,000 to about 200,000, or about 50,000 to about 150,000. In some embodiments, the viscosity index improver is a hydrogenated styrene / butadiene copolymer having a number average molecular weight of about 40,000 to about 500,000, about 50,000 to about 200,000, or about 50,000 to about 150,000. In some embodiments, the viscosity index improver is a polymethacrylate having a number average molecular weight of about 10,000 to about 500,000, about 50,000 to about 200,000, or about 50,000 to about 150,000.

[0090] Other optional additives

[0091] Other additives can be selected to perform one or more functions required for lubricant composition. In addition, one or more in the additive can be multifunctional, and provide the function except the function specified herein. Other additives can be additives outside the specified additive of the present invention, and / or can comprise one or more in metal deactivator, viscosity index improver, ashless TBN reinforcing agent, antiwear agent, corrosion inhibitor, rust inhibitor, dispersant, dispersion viscosity index improver, extreme pressure agent, antioxidant, foam inhibitor, demulsifier, emulsifier, pour point depressant, seal expansion agent and composition thereof. Usually, the lubricating oil prepared fully will contain one or more in these additives.

[0092] Suitable metal deactivators may include benzotriazole (typically methylbenzotriazole), dithiothiadiazole derivatives, 1,2,4-triazole, benzimidazole, 2-alkyldithiobenzimidazole or 2-alkylthiobenzothiazole derivatives; foam inhibitors including copolymers of ethyl acrylate and 2-ethylhexyl acrylate and optionally vinyl acetate; demulsifiers including trialkyl phosphates, polyethylene glycol, polyethylene oxide, polypropylene oxide and (ethylene oxide-propylene oxide) polymers; pour point depressants including esters of maleic anhydride-styrene, polymethacrylates, polyacrylates or polyacrylamides.

[0093] Suitable suds suppressors include silicon-based compounds, for example siloxanes.

[0094] Suitable pour point depressants may include polymethyl methacrylate or mixtures thereof.The pour point depressant may be present in an amount sufficient to provide about 0 wt% to about 1 wt%, about 0.01 wt% to about 0.5 wt%, or about 0.02 wt% to about 0.04 wt%, based on the final weight of the lubricating oil composition.

[0095] Defoamers / surfactants may also be included in the fluids according to the present invention. Various agents are known for such use. Copolymers of ethyl acrylate and hexyl ethyl acrylate may be used, such as PC-1244 commercially available from Solutia. In other embodiments, silicone fluids may be included, such as 4% DCF. Mixtures of defoamers may also be present in the lubricant composition.

[0096] The terms "gear oil", "gear fluid", "gear lubricant", "base gear lubricant", "lubricating oil", "lubricant composition", "lubricating composition", "lubricant" and "lubricating fluid" refer to a finished lubricating product that contains a major amount of base oil and a minor amount of the additive composition discussed herein. Such gear oils are used in extreme pressure situations, such as in transmissions and gear transmission components with metal-to-metal contact situations, such as in transmissions (manual, automatic, dual clutch or electric) and / or gear differentials.

[0097] As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl group" is used in its ordinary sense, which is well known to those skilled in the art. Specifically, it refers to a group whose carbon atoms are directly attached to the remainder of the molecule and is predominantly hydrocarbon in nature. Each hydrocarbyl group is independently selected from a hydrocarbon substituent and a substituted hydrocarbon substituent containing one or more of a halogen group, a hydroxyl group, an alkoxy group, a thiol group, a nitro group, a nitroso group, an amino group, a pyridyl group, a furanyl group, an imidazolyl group, oxygen and nitrogen, and wherein no more than two non-hydrocarbon substituents are present for every ten carbon atoms in the hydrocarbyl group.

[0098] As used herein, unless otherwise expressly stated, the term "weight percent" or "wt%" or "% by weight" refers to the percentage of the component by weight of the entire composition. Unless otherwise stated, all percentage figures herein are weight percentages. As used herein, free of means less than about 0.1 weight percent, less than about 0.05 weight percent, less than about 0.01 weight percent, or no functional amount of such components.

[0099] The terms "soluble", "oil-soluble" or "dispersible" as used herein may, but do not necessarily, mean that a compound or additive is soluble, dissolvable, miscible or capable of being suspended in oil in various proportions. However, the above terms do mean that they are, for example, soluble, suspendable, dissolvable or stably dispersible in oil to a sufficient extent to exert their intended effect in the environment in which the oil is used. In addition, if desired, the additional incorporation of other additives may also allow the incorporation of higher levels of a particular additive.

[0100] As used herein, the term "alkyl" refers to a straight chain, branched chain, cyclic and / or substituted saturated chain portion of about 1 to about 200 carbon atoms. As used herein, the term "alkenyl" refers to a straight chain, branched chain, cyclic and / or substituted unsaturated chain portion of about 3 to about 30 carbon atoms. As used herein, the term "aryl" refers to monocyclic and polycyclic aromatic compounds, which may include alkyl, alkenyl, alkylaryl, amino, hydroxyl, alkoxy, halogen substituents and / or heteroatoms, including but not limited to nitrogen and oxygen.

[0101] As used herein, molecular weight is determined by gel permeation chromatography (GPC) using commercially available polystyrene standards (Mn of about 180 to about 18,000 as a calibration reference). The molecular weight (Mn) of any embodiment herein can be determined using a gel permeation chromatography (GPC) instrument obtained from Waters or a similar instrument and data processed using Waters Empower Software or similar software. The GPC instrument can be equipped with a Waters Separations Module and a Waters Refractive Index detector (or similar optional equipment). GPC operating conditions may include a guard column, 4 Agilent PL gel columns (length 300 x 7.5 mm; particle size 5 μ, pore size range ), the column temperature is about 40°C. Unstabilized HPLC grade tetrahydrofuran (THF) can be used as a solvent with a flow rate of 1.0 mL / min. The GPC instrument can be calibrated with commercially available polystyrene (PS) standards having a narrow molecular weight distribution range of 500-380,000 g / mol. The calibration curve can be extrapolated to samples with a mass of less than 500 g / mol. Samples and PS standards can be dissolved in THF, prepared at a concentration of 0.1-0.5 weight percent, and used without filtration. GPC measurements are also described in US 5,266,223, which is incorporated herein by reference. The GPC method also provides molecular weight distribution information; for example, see WW Yau, JJ Kirkland and DD Bly, "Modern Size Exclusion Liquid Chromatography", John Wiley and Sons, New York, 1979, which is also incorporated herein by reference.

[0102] It should be understood that throughout the present invention, the terms "comprising", "including", "containing", etc. are considered to be open-ended, including any elements, steps or ingredients not explicitly listed. The phrase "essentially consisting of..." means including any explicitly listed elements, steps or ingredients, as well as any other elements, steps or ingredients that do not materially affect the fundamental and novel aspects of the present invention. The present invention also contemplates that any composition described using the terms "comprising", "including", "containing" should also be interpreted as including the disclosure of the same composition "essentially consisting of" or "consisting of" its specifically listed ingredients. Example

[0103] The following examples illustrate exemplary embodiments of the present invention. In these examples, and elsewhere in this application, unless otherwise stated, all ratios, parts and percentages are calculated by weight. These examples are only for illustrative purposes and are not intended to limit the scope of the present invention disclosed herein.

[0104] Example 1

[0105] Oil-soluble hydrocarbyl-substituted melamine derivatives are prepared as follows: alkenyl succinic anhydride (ASA, as shown in Table 3 below) is dissolved in dimethyl sulfoxide at about 100°C, melamine is added at about 100°C, and the reaction mixture is stirred for about 5 hours. Thereafter, ice water is added to the mixture, and the brown precipitate is collected, which is then dissolved in tert-butyl methyl ether, filtered, and then concentrated on a rotary evaporator. The concentrated sample is then dried overnight in an oven at 75°C to obtain a viscous brown liquid. The alkenyl succinic anhydride (ASA) reactants used in this example are listed in Table 3 below, and the reaction conditions with melamine are listed in Table 4 below.

[0106] Table 3: Alkenyl Succinic Anhydride (ASA) Reactants ASA describe A <![CDATA[C that reacts with maleic anhydride 20-24 α-olefin mixture (estimated to be 400 g / mol)]]> B Hexadecene (C16) succinic anhydride (322.5 g / mol) C Dodecenyl (C12) succinic anhydride (266.38 g / mol)

[0107] Table 4: Reaction conditions

[0108] Example 2

[0109] Lubricants including the reaction products from Table 4 of Example 1 were prepared and evaluated for extended copper corrosion according to ASTM D130 (168 hours at 150°C). Each of the inventive lubricants of this example included about 0.035 weight percent of one of the reaction products from Table 4 of Example 1 and the same amount of the same additive package (e.g., dispersant, defoamer, friction modifier, antioxidant, detergent, and antiwear agent), viscosity modifier, and Group III base oil to form inventive transmission lubricants 1-4 (ASTM D445) having a kV100 of about 5 cSt. The inventive lubricants and the results of the extended copper corrosion test of ASTM D130 (e.g., visual copper rust and copper leaching) are listed in Table 5 below. A comparative lubricant including the same amount and the same additive package, viscosity modifier, and Group III base oil but without a corrosion inhibitor was also tested for extended copper corrosion and compared as shown in Table 5 below.

[0110] Table 5

[0111] As shown in Table 5 above, the inventive lubricants including the inventive melamine derivatives exhibited comparable or better copper corrosion and lower copper leaching than the comparative lubricants. The lubricant of this example did not include any tolyltriazole additive or derivatives thereof.

[0112] Example 3

[0113] As in Example 2, additional inventive lubricants including the reaction products from Table 4 of Example 1 were prepared and evaluated for extended copper corrosion according to ASTM D130 (168 hours at 150°C). Each of the inventive lubricants of this Example included about 0.035 weight percent of one of the reaction products from Table 4 of Example 1 and the same amount of the same additive package (including dispersants, defoamers, friction modifiers, antioxidants, detergents, and antiwear agents), viscosity modifiers, and Group III base oils to form inventive transmission lubricants 5-8 (ASTM D445) having a kV100 of about 5 cSt. The inventive lubricants of this Example and the results of the extended copper corrosion test of ASTM D130 (e.g., visual copper rust and copper leaching) are listed in Table 6 below. A comparative lubricant including the same amount and the same additive package, viscosity modifier, and Group III base oil but without a corrosion inhibitor was also tested for extended copper corrosion, as shown in Table 6 below for comparison.

[0114] Table 6

[0115] As shown in Table 6 above, the inventive lubricants including the inventive melamine derivatives exhibited comparable or better copper corrosion and lower copper leaching than the comparative lubricants. The lubricants of this example also did not include any tolyltriazole additives or derivatives thereof.

[0116] It should be noted that as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless expressly and unambiguously limited to one referent. Thus, for example, reference to "an antioxidant" includes two or more different antioxidants. As used herein, the term "comprising" and its grammatical variations are intended to be non-limiting, and thus recitation of items in a list does not exclude other similar items that can be substituted or added to the listed items.

[0117] For purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing quantities, percentages or ratios, as well as other numerical values ​​used in the specification and claims should be understood as being modified by the word "about" in all cases. Therefore, unless otherwise indicated, the numerical parameters set forth in the following specification and the appended claims are approximate and may vary depending on the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0118] It should be understood that each component, compound, substituent or parameter disclosed herein should be interpreted as being used alone or in combination with one or more of each of the other components, compounds, substituents and parameters disclosed herein.

[0119] It is further understood that each range disclosed herein should be interpreted as disclosing each specific value within the disclosed range having the same numerical value as significant figures. Thus, for example, a range from 1 to 4 should be interpreted as explicitly disclosing the values ​​1, 2, 3, and 4 and any range of these values.

[0120] It is further understood that each lower limit of each scope disclosed herein should be interpreted as being disclosed in combination with each upper limit value of each scope disclosed herein for the same component, compound, substituent or parameter and each specific value in each scope. Therefore, the present invention should be interpreted as being disclosed to all scopes, which are obtained by combining each lower limit value of each scope with each upper limit value of each scope or with each specific value in each scope, or by combining each upper limit value of each scope with each specific value in each scope. That is to say, it can also be further understood that any scope between the endpoint values ​​in a wide range is also discussed herein. Therefore, a scope of 1 to 4 also means a scope of 1 to 3, 1 to 2, 2 to 4, 2 to 3, etc.

[0121] In addition, the specific amounts / values ​​of components, compounds, substituents or parameters disclosed in the specification or examples should be interpreted as disclosure of the lower or upper limits of the range and can therefore be combined with any other lower or upper limits or specific amounts / values ​​of the range disclosed elsewhere in the application for the same components, compounds, substituents or parameters to form the range of the components, compounds, substituents or parameters.

[0122] Although specific embodiments have been described, applicants or other persons skilled in the art may recognize alternatives, modifications, variations, improvements, and substantial equivalents that are not currently foreseeable or may not be foreseeable. Therefore, the appended claims as filed and as they may be amended are intended to cover all such alternatives, modifications, variations, improvements, and substantial equivalents.

Claims

1. A corrosion inhibitor in the form of an oil-soluble hydrocarbon-substituted melamine derivative having a structure of formula I wherein R1, R2 and R3 are each independently -NH2, a hydrocarbyl-substituted succinimide group or a hydrocarbyl-substituted dicarboxylic acid-amide group, and wherein one or two of R1, R2 and R3 are independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining R1, R2 and R3 are independently the -NH2 or the hydrocarbyl-substituted dicarboxylic acid-amide group. 2 . The corrosion inhibitor according to claim 1 , wherein the hydrocarbyl substituent of the succinimide group or the dicarboxylic acid-amide group is a C12 to C30 hydrocarbyl group.

3. The corrosion inhibitor according to claim 2, wherein the hydrocarbyl substituent of the succinimide group or the dicarboxylic acid-amide group is a C12 to C24 hydrocarbyl group.

4. The corrosion inhibitor of claim 1, wherein the corrosion inhibitor has about 5 weight percent to about 25 weight percent nitrogen.

5. The corrosion inhibitor of claim 1, wherein the corrosion inhibitor is the reaction product of a hydrocarbyl-substituted succinic acid or anhydride and melamine in a molar excess of the hydrocarbyl-substituted succinic acid or anhydride relative to the melamine.

6. The corrosion inhibitor of claim 5, wherein the molar ratio of the hydrocarbyl-substituted succinic acid or anhydride to the melamine is from about 1.1:1 to about 4:

1.

7. The corrosion inhibitor of claim 5, wherein the molar ratio of the hydrocarbyl-substituted succinic acid or anhydride to the melamine is from about 1.1:1 to about 3:

1.

8. The corrosion inhibitor according to claim 1, wherein one of R1, R2 and R3 is independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining two of R1, R2 and R3 are the -NH2 group.

9. The corrosion inhibitor according to claim 7, wherein two of R1, R2 and R3 are independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining one of R1, R2 and R3 is the -NH2 group.

10. The corrosion inhibitor according to claim 1, wherein the oil-soluble hydrocarbon-substituted melamine derivative has one or more of the following structures: wherein the R groups thereof are each independently a C12 to C30 hydrocarbon group.

11. The corrosion inhibitor of claim 1 , wherein a lubricating composition including about 0.1 to about 0.5 weight percent of the corrosion inhibitor exhibits less than about 100 ppm copper after testing at 150°C for 168 hours according to ASTM D130.

12. A method of preparing an oil-soluble hydrocarbyl-substituted melamine derivative corrosion inhibitor, the method comprising reacting a hydrocarbyl-substituted succinic acid or anhydride with melamine in a molar excess of the hydrocarbyl-substituted succinic acid or anhydride relative to the melamine.

13. The method of claim 12, wherein the hydrocarbyl substituent is a C12 to C30 hydrocarbyl group.

14. The method of claim 13, wherein the hydrocarbyl substituent is a C12 to C24 hydrocarbyl group.

15. The method of claim 12, wherein the molar ratio of the hydrocarbyl-substituted succinic acid or anhydride to the melamine is from about 1.1:1 to about 4:

1.

16. The method of claim 12, wherein the molar ratio of the hydrocarbyl-substituted succinic acid or anhydride to the melamine is from about 1.1:1 to about 3:

1.

17. The method of claim 12, wherein the corrosion inhibitor formed has about 5 to about 25 weight percent nitrogen.

18. The method according to claim 12, wherein the oil-soluble hydrocarbon-substituted melamine derivative formed has a structure of formula I wherein R1, R2 and R3 are each independently -NH2, a hydrocarbyl-substituted succinimide group or a hydrocarbyl-substituted dicarboxylic acid-amide group, and wherein one or two of R1, R2 and R3 are independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining R1, R2 and R3 are independently the -NH2 or the hydrocarbyl-substituted dicarboxylic acid-amide group.

19. The method of claim 18, wherein one of R1, R2 and R3 is independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining two of R1, R2 and R3 are the -NH2 group.

20. The method of claim 18, wherein two of R1, R2 and R3 are independently the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining one of R1, R2 and R3 is the -NH2 group.

21. The method according to claim 18, wherein the oil-soluble hydrocarbon-substituted melamine derivative has one or more of the following structures: Preferably, the R groups thereof are each independently a C12 to C30 hydrocarbon group.

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