Melamine-based compounds for lubricating compositions

Abstract

To provide an alternative copper corrosion inhibitor which provides performance comparable to tolyltriazole and is compatible with lubricant formulations for transmission fluids, axle fluids, differential fluids, tractor fluids, industrial gear fluids, and / or other gear-type applications.SOLUTION: Melamine-based compounds are suitable as a corrosion inhibitor for transmission fluids (manual, automatic, dual-clutch, or electric), axle fluids, differential fluids, tractor fluids, industrial gear fluids, and / or lubricating fluids for other gear-type applications. The melamine-based compounds are in the form of oil-soluble hydrocarbyl-substituted melamine derivatives comprising the reaction product of a hydrocarbyl-substituted succinic anhydride reacted with melamine under conditions effective in forming a hydrocarbyl-substituted melamine polycarboxylic acid or anhydride compound.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to melamine-based compounds suitable for lubricant additives, particularly melamine-based compounds suitable as corrosion inhibitors, and lubricating compositions containing such melamine-based compounds to achieve improved copper corrosion performance.

Background Art

[0002] Transmissions (manual, automatic, dual clutch, and / or electric), axles, differentials, and / or industrial gears generally require lubricants that provide specific performance characteristics suitable for the desired application. Typically, lubricants for such applications may require fluids that meet one or more performance characteristics such as, for example, extreme pressure, anti-wear, friction, and / or copper corrosion, although only some of the general requirements for such fluids may be suggested. To achieve performance, various additives may be included in the lubricant. For example, such lubricants often contain oil-soluble copper corrosion inhibitors such as triazole to protect metals such as copper from corrosion.

[0003] Tril-triazole (e.g., methyl-substituted benzotriazole) is a common copper corrosion inhibitor that provides good copper corrosion performance in transmission fluids, axle fluids, differential fluids, tractor fluids, and / or industrial gear fluids, suggesting some applications that generally contain tril-triazole. Copper corrosion can be evaluated by extending the test at 150 °C for up to 168 hours according to ASTM D130 and / or more extreme versions of ASTM D130. Copper corrosion is measured by visual discoloration evaluation and / or the amount of copper leaching in the lubricant. Tril-triazole hardly discolors in such fluids and can provide effective corrosion inhibition with low levels of copper leaching, but the use of tril-triazole may be undesirable for several reasons. It has been difficult to find alternative copper corrosion inhibitors that provide performance comparable to tril-triazole and are compatible with lubricant formulations for transmission fluids, axle fluids, differential fluids, tractor fluids, industrial gear fluids, and / or other gear type applications.

SUMMARY OF THE INVENTION

[0004] In one approach or embodiment, a corrosion inhibitor in the form of an oil-soluble hydrocarbyl-substituted melamine derivative is described herein, and in some aspects, it has the structure of Formula I,

[0005]

CHEMICAL FORMULA

[0006] In other approaches or embodiments, the corrosion inhibitor of the previous paragraph includes any combination of other features or embodiments. These other features or embodiments are as follows: the hydrocarbyl substituent of the succinimide group or the dicarboxylic acid - amide group is a C12 - C30 hydrocarbyl group, and / or the hydrocarbyl substituent of the succinimide group or the dicarboxylic acid - amide group is a C12 - C24 hydrocarbyl group, and / or the corrosion inhibitor has from about 5 weight percent to about 25 weight percent nitrogen, and / or the corrosion inhibitor is a reaction product of a hydrocarbyl - substituted succinic acid or anhydride and melamine, with a molar excess of the hydrocarbyl - substituted succinic acid or anhydride over melamine, and / or the molar ratio of the hydrocarbyl - substituted succinic acid or anhydride to melamine is from about 1.1:1 to about 4:1, and / or the molar ratio of the hydrocarbyl - substituted succinic acid or anhydride to melamine is from about 1.1:1 to about 3:1, and / or one of R1, R2, and R3 is independently either a hydrocarbyl - substituted succinimide group or a hydrocarbyl - substituted dicarboxylic acid - amine group, and the remaining two of R1, R2, and R3 are -NH2 groups, and / or two of R1, R2, and R3 are independently either a hydrocarbyl - substituted succinimide group or a hydrocarbyl - substituted dicarboxylic acid - amine group, and the remaining one of R1, R2, and R3 is an -NH2 group, and / or the oil - soluble hydrocarbyl - substituted melamine derivative has the following structure,

[0007]

Table 1

[0008] wherein each R group is independently a C12 - C30 hydrocarbyl group, and / or a lubricating composition containing from about 0.1 to about 0.5 weight percent of the corrosion inhibitor exhibits less than about 100 ppm of copper after being tested for 168 hours at 150 °C in accordance with ASTM D130, including one or more of the foregoing.

[0009] In another approach or embodiment, a method for preparing an oil-soluble hydrocarbyl-substituted melamine derivative corrosion inhibitor is described herein. In one aspect, the method includes reacting a hydrocarbyl-substituted succinic acid or anhydride with melamine, with a molar excess of the hydrocarbyl-substituted succinic acid or anhydride relative to the melamine.

[0010] In another approach or embodiment, the method for preparing the oil-soluble hydrocarbyl-substituted melamine derivative corrosion inhibitor of the preceding paragraph includes any combination of other method steps, features, or embodiments. These other steps, features, or embodiments are: the hydrocarbyl substituent is a C12 - C30 hydrocarbyl group, and / or the hydrocarbyl substituent is a C12 - C24 hydrocarbyl group, and / or 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 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 the formed corrosion inhibitor has from about 5 to about 25 weight percent nitrogen, and / or the reaction conditions include a temperature of from about 50°C to about 200°C (in other approaches, 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 approaches, from about 4 to about 16 hours, and in a further approach, from about 6 to about 12 hours), and / or the formed oil-soluble hydrocarbyl-substituted melamine derivative has the structure of formula I,

[0011] [Chemical formula] Wherein each of R1, R2, and R3 is independently -NH2, a hydrocarbyl-substituted succinimide group, or a hydrocarbyl-substituted dicarboxylic acid-amide group, and one or two of R1, R2, and R3 are independently either a hydrocarbyl-substituted succinimide group or a hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining R1, R2, and R3 are independently either -NH2 or a hydrocarbyl-substituted dicarboxylic acid-amide, and / or one of R1, R2, and R3 is independently either a hydrocarbyl-substituted succinimide group or a hydrocarbyl-substituted dicarboxylic acid-amine group, and the remaining two of R1, R2, and R3 are -NH2 groups, and / or two of R1, R2, and R3 are independently either a hydrocarbyl-substituted succinimide group or a hydrocarbyl-substituted dicarboxylic acid-amine group, and / or the remaining one of R1, R2, and R3 is an -NH2 group, and / or the oil-soluble hydrocarbyl-substituted melamine derivative includes one of the following structures

[0012]

Table 2

[0013] In another embodiment or approach, the present disclosure includes a driveline lubricating composition comprising any embodiment of the corrosion inhibitor as described above in the summary of the invention. In one aspect, the driveline lubricating composition of the present disclosure comprises one or more base oils of lubricating viscosity and an oil-soluble hydrocarbyl-substituted melamine derivative having the structure of Formula I,

[0014]

Chemical formula

[0015] In still other embodiments, the lubricating composition described in the preceding paragraph may include one or more of the other features or embodiments in any combination. These other features or embodiments are as follows: the hydrocarbyl substituent of the succinimide group or the dicarboxylic acid-amide group is a C12-C30 hydrocarbyl group, and / or the oil-soluble hydrocarbyl-substituted melamine derivative is a reaction product of a hydrocarbyl-substituted succinic acid or anhydride and melamine, with a molar excess of the hydrocarbyl-substituted succinic acid or anhydride over melamine, and / or the molar ratio of the hydrocarbyl-substituted succinic acid or anhydride to melamine is from about 1.1:1 to about 4:1, and / or one of R1, R2, and R3 is independently either a hydrocarbyl-substituted succinimide group or a hydrocarbyl-substituted dicarboxylic acid-amine group, and the remaining two of R1, R2, and R3 are -NH2 groups, and / or two of R1, R2, and R3 are independently either a hydrocarbyl-substituted succinimide group or a hydrocarbyl-substituted dicarboxylic acid-amine group, and the remaining one of R1, R2, and R3 is an -NH2 group, and / or the oil-soluble hydrocarbyl-substituted melamine derivative has the following structure,

[0016]

Table 3

[0017] Wherein each R group is independently a C12-C30 hydrocarbyl group, and / or the lubricating composition does not contain a triazole additive or a derivative thereof, and / or the lubricating composition does not contain water, and / or the lubricating composition has a kinematic viscosity at 100°C of about 3 to about 10 cSt, and / or the lubricating composition has less than about 215 ppm of copper after testing in accordance with ASTM D130 at 150°C for 168 hours, and / or the oil-soluble hydrocarbyl-substituted melamine derivative provides about 5 to about 1100 ppm of nitrogen to the lubricating composition, and / or contains about 0.01 to about 0.5 weight percent of the oil-soluble hydrocarbyl-substituted melamine derivative, and / or the lubricating composition may further contain less than about 1 weight percent of an alkylated diphenylamine, including one or more of the foregoing.

[0018] In other approaches or embodiments, methods of lubricating drive line components are described herein. In one aspect, the method includes lubricating a drive line component with any of the embodiments of the lubricating compositions described herein. In another embodiment, the method includes a lubricating composition that includes one or more base oils of lubricating viscosity and an oil-soluble hydrocarbyl-substituted melamine derivative having the structure of Formula I,

[0019]

Chemical formula

[0020] In yet another approach or embodiment, the use of a corrosion inhibitor in the form of an oil-soluble hydrocarbyl-substituted melamine derivative for lubricating a driveline and, in some embodiments, for lubricating a driveline substantially free of triazole additives or derivatives thereof is described herein, and in a further embodiment, the use has less than about 215 ppm of copper after testing in accordance with ASTM D130 at 150 °C for 168 hours.

[0021] Other embodiments of the disclosure will be apparent to those of ordinary skill in the art in view of the specification and practice of the invention disclosed herein. The following definitions are provided to clarify the meaning of certain terms used herein.

Best Mode for Carrying Out the Invention

[0022] In one approach, in one embodiment, a melamine-based compound suitable as a corrosion inhibitor for a lubricating composition, particularly for a transmission fluid (e.g., manual, automatic, dual clutch, or electric), axle fluid, differential fluid, tractor fluid, industrial gear fluid, and / or other gear type applications, is disclosed herein. The melamine-based compounds of the disclosure, in other approaches or embodiments, in one approach, are reaction products of a hydrocarbyl-substituted succinic acid or anhydride (e.g., an alkenyl succinic acid or anhydride) reacted with melamine under conditions effective to form a hydrocarbyl-substituted melamine-based succinimide or acid / amide compound, in the form of an oil-soluble hydrocarbyl-substituted melamine derivative.

[0023] In one exemplary approach or embodiment, suitable reaction conditions for forming the melamine compounds herein can include a reaction temperature of from about 50°C to about 200°C (in other approaches, 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 approaches from about 4 to about 16 hours, and in yet further approaches from about 6 to about 12 hours). The reaction conditions can 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 can include, for example, C12 - C30 alkenyl succinic acid or anhydride (preferably C12 - C24 alkenyl succinic acid or anhydride, or most preferably C12 - C16 alkenyl succinic acid or anhydride), and more specifically, suitable reactants can include C20 - C24 alpha olefins reacted with maleic acid or anhydride, hexadecenyl succinic acid or anhydride, dodecenyl succinic acid or anhydride, combinations thereof, and similar hydrocarbyl succinic acids or anhydrides, but are not limited thereto. In yet further approaches, the hydrocarbyl substituted succinic acid or anhydride reactant can also be tetrapropenyl alkenyl succinic acid or anhydride, n - dodecyl alkenyl succinic acid or anhydride. In yet another approach, polyisobutylene substituted acids or anhydrides (e.g., PIBSA) can also be suitable as starting reactants, preferably polyisobutylene having a number average molecular weight of up to about 450, in other approaches up to about 1000, or up to about 1500, or up to about 2500 (or any range therebetween).

[0024] In one approach or embodiment, the oil - soluble hydrocarbyl - substituted melamine derivatives of the present disclosure suitable as corrosion inhibitors have the structure of Formula I,

[0025]

Chemical formula

[0026] [Chemical formula]

[0027] In other approaches, one of R1, R2, and R3 is independently either a hydrocarbyl-substituted succinimide group or a hydrocarbyl-substituted dicarboxylic acid-amide group. In a further approach, two of R1, R2, and R3 are independently either a hydrocarbyl-substituted succinimide group or a hydrocarbyl-substituted dicarboxylic acid-amide group. In either case, the remaining R1, R2, and R3 groups are either hydrocarbyl-substituted dicarboxylic acid-amide groups or -NH2 groups, preferably -NH2 groups. In a further approach or embodiment, the hydrocarbyl substituent (e.g., the hydrocarbyl group of the R1, R2, and / or R3 moieties (i.e., the R group in the above formula II or III)) is a C12 - C30 hydrocarbyl group, preferably the hydrocarbyl substituent is a C12 - 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.

[0028] As described above, the oil-soluble hydrocarbyl-substituted melamine derivatives of the present specification can be prepared in a reaction having a molar excess of a hydrocarbyl-substituted succinic acid or anhydride reactant over a melamine reactant. In one embodiment, this molar excess is reflected in a molar ratio of hydrocarbyl-substituted succinic acid or anhydride reactant to melamine reactant of from about 1.1:1 to about 4:1, and in another embodiment, the molar ratio of hydrocarbyl-substituted succinic acid or anhydride reactant to melamine reactant is from about 1.1:1 to about 3:1, and in a further embodiment, the molar ratio is from about 2.0:1 to about 3.0:1.

[0029] When the melamine derivatives of the present specification 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 can provide 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, preferably from about 25 to about 80 ppm nitrogen, more preferably from about 30 to about 75 ppm nitrogen to the lubricant at a treatment rate of from about 0.01 to about 0.5 weight percent in the fluid. 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,

[0030]

Table 4

[0031] wherein each R group is a hydrocarbyl substituent as described above and is independently a C12 - C30 hydrocarbyl group, preferably a C12 - C24 hydrocarbyl group, most preferably a C12 hydrocarbyl group, a C16 hydrocarbyl group, a C20 hydrocarbyl group, a C24 hydrocarbyl group, or any mixture thereof.

[0032] As described above, the melamine derivatives of the present specification are corrosion inhibitors in lubricants, particularly for lubricating compositions suitable for transmission fluids (manual, automatic, dual clutch, or electric), axle fluids, differential fluids, tractor fluids, industrial gear fluids, and / or other gear type applications, and are particularly suitable as corrosion inhibitors for such lubricating compositions containing melamine-based corrosion inhibitors. In one approach or embodiment, such a lubricating composition may contain from about 0.01 to about 0.5 weight percent (preferably from about 0.02 to about 0.1 weight percent, more preferably from about 0.03 to about 0.08 weight percent) of the melamine derivatives of the present specification. When using this melamine derivative, the lubricating composition of the present specification may exhibit less than about 215 ppm of copper leaching after testing at 150 °C for 168 hours in accordance with a modified version of ASTM D130 (preferably less than 100 ppm of copper, more preferably less than about 80 ppm of copper). The compositions of the present specification having such an amount of melamine derivative may also exhibit copper discoloration grades of 4a - 4b. Most surprisingly, the lubricating compositions of the present specification can achieve such low copper leaching levels and discoloration grades in compositions substantially free of conventional tolyltriazole additives, which means that the compositions of the present specification have less than 0.1 weight percent of tolyltriazole additive, less than about 0.05 weight percent of tolyltriazole additive, less than about 0.01 weight percent of tolyltriazole additive, or preferably have no functional and / or detectable amount of tolyltriazole additive.

[0033] The lubricating compositions of the present specification may include the above-described melamine-based corrosion inhibitor in combination with other additives suitable for the above lubricant uses. This additional additive may include, in some embodiments, one or more of a phosphorus antiwear additive, a sulfur antiwear additive, an antioxidant (including amine-based antioxidants), a viscosity modifier, and a synthetic or mineral-based oil to provide a kinematic viscosity (ASTM D445) of about 3 to about 10 cSt at 100°C. Preferably, the lubricant has a minimal level of water (e.g., less than about 0.5 weight percent, less than about 0.1 weight percent, or less than 0.05 weight percent), and preferably contains no water or contains water at undetectable levels.

[0034] Base oil Suitable base oils for use in the lubricating compositions according to the present disclosure can be mineral oils, animal oils, vegetable oils, synthetic oils, or mixtures thereof.

[0035] Natural oils may include animal and vegetable oils (e.g., castor oil, lard oil), and mineral oils such as liquid petroleum and paraffinic, naphthenic, or mixed paraffin-naphthenic solvent-treated or acid-treated mineral lubricating oils. Mineral oils can 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 oil, olive oil, peanut oil, corn oil, soybean oil, and linseed oil, and mineral lubricating oils such as liquid petroleum and paraffinic, naphthenic, or mixed paraffin-naphthenic solvent-treated or acid-treated mineral lubricating oils. Such oils may be partially or fully hydrogenated if desired. Oils derived from coal or shale may also be suitable. Additionally, oils derived from the gas liquefaction process may also be suitable. The base oil may have a kinematic viscosity at 100°C of about 2 to about 15 cSt as measured by ASTM D2270-10.

[0036] Useful synthetic lubricating oils include hydrocarbon oils such as polymerized, oligomerized, or interpolymerized olefins (e.g., polybutylene, polypropylene, propylene isobutylene copolymer); poly(1-hexene), poly(1-octene), trimers or oligomers of 1-decene such as poly(1-decene) (such materials are often referred to as α-olefins), and mixtures thereof; alkyl-benzenes (e.g., dodecylbenzene, tetradecylbenzene, dinonylbenzene, di-(2-ethylhexyl)-benzene); polyphenyls (e.g., biphenyl, terphenyl, alkylated polyphenyls); diphenylalkanes, alkylated diphenylalkanes, alkylated diphenyl ethers and alkylated diphenyl sulfides, and their derivatives, analogs and homologs, or mixtures thereof. Polyalphaolefins are typically hydrogenated materials.

[0037] Other synthetic lubricating oils include polyol esters, diesters, liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, and diethyl ester of decanephosphonic acid), or polymeric tetrahydrofuran. Synthetic oils may be produced by the Fischer-Tropsch reaction and may typically be hydrogenated isomerized Fischer-Tropsch hydrocarbons or waxes. In one embodiment, the oil may be prepared by a Fischer-Tropsch gas-liquid synthesis procedure, as well as other gas-liquid oils.

[0038] The base oil or base oil of lubricating viscosity used in the compositions 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 of Groups I-V of base oils specified in the American Petroleum Institute (API) base oil compatibility guidelines. The groups of these base oils are as follows.

[0039] [Table 5]

[0040] Groups I, II, and III are mineral oil process feeds. The Group IV base oils contain synthetic molecular species produced by the polymerization of olefinically unsaturated hydrocarbons. Polyalphaolefins (PAOs), which are API Group IV base oils, typically are derived from monomers having 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, and the like. PAOs can have a kinematic viscosity of 2 to 15, or 3 to 12, or 4 to 8 cSt at 100 °C when measured by ASTM D2270-10. Examples of suitable PAO viscosities include 4 cSt at 100 °C and 6 cSt at 100 °C, and both. Many Group V base oils are also true synthetic products and may include diesters, polyol esters, polyalkylene glycols, alkylated aromatics, polyphosphate esters, polyvinyl ethers, and / or polyphenyl ethers, but may also be natural oils such as vegetable oils. Group III base oils are derived from mineral oils, but it should be noted that due to the rigorous treatment these fluids undergo, their physical properties become very similar to those of some true synthetic oils. Thus, oils derived from Group III base oils can be referred to as synthetic fluids in the industry. Suitable oils can be derived from hydrocracked, hydrogenated, hydrofinished, virgin, refined, and re-refined oils, and mixtures thereof.

[0041] Virgin oils are those derived from natural, mineral, or synthetic sources without or with little further refining treatment. Refined oils are similar to virgin oils except that they have been treated in one or more refining steps that can result in the improvement of one or more properties. Examples of suitable refining techniques are solvent extraction, secondary distillation, acid or base extraction, filtration, osmosis, and the like. Oils refined to a quality suitable for food use may or may not be useful. Edible oils may sometimes be referred to as white oils. In some embodiments, the lubricating oil composition does not contain edible oil or white oil.

[0042] The refined oil is also known as recycled oil or reprocessed oil. These oils are obtained in the same or similar processes as the refined oil. In many cases, these oils are additionally processed by techniques aimed at removing used additives and oil decomposition products.

[0043] The base oil, in combination with an additive composition as disclosed in the embodiments of this specification, provides a lubricating fluid for transmissions, axles, tractors, or industrial gears. Thus, the base oil can be present in the lubricating fluid in an amount exceeding 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 exceeding about 85% by weight, based on the total weight of the lubricating fluid, and may be selected from any of a suitable synthetic oil, natural oil, or a mixture thereof having a suitable lubricating viscosity.

[0044] Suitable lubricant compositions for transmissions, axles, differentials, tractors, or industrial gears of this specification may include additive components within the ranges listed in Table 2.

[0045]

Table 6

[0046] The percentages of the above components represent the weight percentages of the components based on the weight of the total lubricating oil composition. The balance of the lubricating oil composition consists of one or more base oils. The additives used when formulating the compositions described in this specification can be blended with the base oil individually or in various partial combinations. However, it may be suitable to use an additive concentrate (i.e., an additive plus a diluent such as a hydrocarbon solvent) to blend all of the components simultaneously.

[0047] The lubricating compositions described herein can be formulated to provide lubrication for various applications, suitable load-carrying capabilities, and improved copper corrosion. The lubricating fluids according to the present disclosure can be used in transmission fluids, axle fluids, differential fluids, tractor fluids, industrial gear fluids, and fixed gear boxes. Gear types can include, but are not limited to, spur, spiral, worm, rack and pinion, involute, bevel, helical, planetary, and hypoid gears, as well as limited slip applications, and differentials. The driveline lubricating compositions disclosed herein are also suitable for use in automatic or manual transmissions, including step automatic transmissions, continuously variable transmissions, semi-automatic transmissions, automated manual transmissions, toroidal transmissions, and dual clutch transmissions. The driveline lubricating compositions of this specification are particularly suitable for use in axles, transfer cases, differentials, such as straight differentials, rotary differentials, limited slip differentials, clutch type differentials, and locking differentials, etc.

[0048] Optional additives In other approaches, lubricants containing such additives as described above may also contain one or more optional components, provided that such components and their amounts do not affect the performance characteristics as described in the above paragraphs. These optional components are described in the following paragraphs.

[0049] Phosphorus-containing compounds The lubricant compositions of this specification may contain one or more phosphorus-containing compounds that can impart anti-wear advantages to the fluid. The one or more phosphorus-containing compounds can be present in the lubricating oil composition in an amount in the range of about 0 wt% to about 5 wt%, or about 0.01 wt% to about 4 wt%, or about 0.05 wt% to about 3 wt%, or about 0.1 wt% to about 3 wt% of the lubricating oil composition. The phosphorus-containing compounds can provide up to 500 ppm of phosphorus, or about 3 to about 100 ppm of phosphorus, or 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.

[0050] One or more phosphorus-containing compounds may include an ashless phosphorus-containing compound. Examples of suitable phosphorus-containing compounds include, but are not limited to, thiophosphates, dithiophosphates, phosphates, phosphate esters, phosphate esters, phosphites, phosphonates, phosphorus-containing carboxylic acid esters, ethers, or amide salts thereof, and mixtures thereof. Phosphorus-containing antiwear agents are fully described by European Patent No. 0612839.

[0051] It should be noted that the terms phosphonate and phosphite are often used interchangeably in the lubricant industry. For example, dibutyl hydrogen phosphonate may sometimes be referred to as dibutyl hydrogen phosphite. It is within the scope of the present invention for the lubricant composition of the present invention to include a phosphorus-containing compound that may be referred to as either a phosphite or a phosphonate.

[0052] In any of the above phosphorus-containing compounds, the compound may have from about 4 to about 8 weight percent phosphorus, or from about 5 to about 6 weight percent phosphorus.

[0053] In some embodiments, the ashless phosphorus-containing compound may be a dialkyldithiophosphate ester, amyl acid phosphate, diamyl acid phosphate, dibutyl hydrogen phosphate, dimethyloctadecyl phosphate, salts thereof, and mixtures thereof.

[0054] The ashless phosphorus-containing compound may have the formula:

[0055]

Chemical formula

[0056] 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'', where R'' is C 18 and the phosphorus-containing compound is present in an amount that supplies 3 to 50 ppm or 3 to 20 ppm of phosphorus to the lubricating 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'', where R'' is oleyl, and the phosphorus-containing compound is present in an amount that supplies 3 to 50 ppm or 3 to 20 ppm of phosphorus to the lubricating composition.

[0057] 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 the phosphorus-containing compound is present in an amount that supplies 3 to 50 ppm of phosphorus to the lubricant composition.

[0058] 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 the phosphorus-containing compound is present in an amount that supplies 3 to 50 ppm (ppm) of phosphorus to the lubricant composition.

[0059] In yet 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 one or more phosphorus-containing compounds are present in an amount that supplies 3 to 50 ppm of phosphorus to the lubricant composition.

[0060] 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, and R'' is C 18 and one or more phosphorus-containing compounds are present in an amount that supplies 3 to 50 ppm of phosphorus to the lubricant composition.

[0061] Antiwear agent The lubricant composition may also include other antiwear agents that are phosphorus-free compounds. Examples of such antiwear agents include boric acid esters, boric acid epoxides, thiocarbamate compounds (e.g., thiocarbamate esters, alkylene-bonded thiocarbamates, and bis(S-alkyldithiocarbamyl) disulfides, thiocarbamate amides, thiocarbamic acid ethers, alkylene-bonded thiocarbamates, and bis(S-alkyldithiocarbamyl) disulfides, and mixtures thereof), sulfurized olefins, tridecyl adipate, titanium compounds, and long-chain derivatives of hydroxycarboxylic acids such as tartrate derivatives, tartramide, tartrimide, citrate, and mixtures thereof. Suitable thiocarbamate compounds are molybdenum dithiocarbamates. Suitable tartrate derivatives or tartrimides may contain an alkyl-ester group where the total number of carbon atoms on the alkyl group can be at least 8. The tartrate derivative or tartrimide may contain an alkyl-ester group where the total number of carbon atoms on the alkyl group can be at least 8. The antiwear agent may, in one embodiment, include citrate salts. Additional antiwear agents may be present in an amount ranging from about 0 wt% to about 5 wt%, or about 0.01 wt% to about 4 wt%, or about 0.05 wt% to about 3 wt%, or about 0.1 wt% to about 3 wt% of the lubricating oil composition.

[0062] Sulfur-containing compound The lubricant compositions of the present disclosure may also contain sulfur-containing compounds provided for extreme pressure performance as long as the lubricating compositions herein contain the amounts and profiles described herein.

[0063] A variety of sulfur-containing extreme pressure agents are suitable, including sulfurized animal or vegetable fats or oils, sulfurized animal or vegetable fatty acid esters, complete or partial esterified esters of trivalent or pentavalent acids of phosphorus, sulfurized olefins (see, for example, 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, for example, 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 Pat. No. 1,162,334), functional group-substituted dihydrocarbyl polysulfides (see, for example, U.S. Pat. No. 4,218,332), and polysulfide olefin products (see, for example, U.S. Pat. No. 4,795,576).

[0064] One suitable class of extreme pressure agents has the formula: Ra-S x-A polysulfide composed of one or more compounds represented by -Rb, where Ra and Rb are hydrocarbyl groups, each of which may contain 1 to 18, or in other approaches, 3 to 18 carbon atoms, and x can be 2 to 8, typically 2 to 5, particularly 3. In some approaches, x is an integer from 3 to 5, and about 30 to about 60 percent of x is an integer of 3 or 4. The hydrocarbyl group can 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 mainly or completely composed of tri-, tetra-, and pentasulfides) can be used. Examples of other useful dihydrocarbyl polysulfides include diamyl polysulfide, dinonyl polysulfide, didodecyl polysulfide, and dibenzyl polysulfide.

[0065] Another suitable class of extreme pressure agents is sulfurized isobutene made by reacting an olefin such as isobutene with sulfur. Sulfurized isobutene (SIB), particularly sulfurized polyisobutylene, typically has a sulfur content of about 10 to about 55 wt%, desirably about 30 to about 50 wt%. A variety of other olefins or unsaturated hydrocarbons, such as isobutene dimer or trimer, can be used to form sulfurized olefin extreme pressure agents. Various methods for preparing sulfurized olefins have been disclosed in the prior art. See, for example, U.S. Patent No. 3,471,404 to Myers, U.S. Patent No. 4,204,969 to Papay et al., U.S. Patent No. 4,954,274 to Zaweski et al., U.S. Patent No. 4,966,720 to DeGonia et al., and U.S. Patent No. 3,703,504 to Horodysky et al., each of which is incorporated herein by reference.

[0066] A method for preparing a sulfurized olefin that includes the method disclosed in the foregoing patent involves the formation of a material typically referred to as an "adduct" and reacting an olefin with a sulfur halide, such as sulfur monochloride. The adduct is then reacted with a sulfur source to provide the sulfurized olefin. The quality of the sulfurized olefin is generally measured by various physical properties such as, for example, viscosity, sulfur content, halogen content, weight loss in a copper corrosion test. U.S. Patent No. 4,966,720 relates to sulfurized olefins useful as extreme pressure additives in lubricating oils and a two-step reaction for their preparation.

[0067] In some embodiments, the extreme pressure agent is present in the lubricating composition in an amount up to about 3.0 wt% or up to about 5.0 wt%. In other embodiments, the extreme pressure agent is present in an amount of about 0.05 wt% to about 0.5 wt% based on the total weight of the lubricant composition. In other embodiments, the extreme pressure agent is present in an amount of about 0.1 wt% to about 3.0 wt% based on the total weight of the lubricant composition. In other embodiments, the extreme pressure agent is present in an amount of about 0.6 wt% to about 1 wt% based on the total weight of the lubricant composition.

[0068] Antioxidant The lubricating oil compositions herein may also optionally contain one or more antioxidants. Antioxidant compounds are known and include, for example, phenates, phenate sulfides, sulfurized olefins, phosphosulfurized terpenes, sulfurized esters, aromatic amines, alkylated diphenylamines (e.g., nonyldiphenylamine, di-nonyldiphenylamine, octyldiphenylamine, di-octyldiphenylamine), phenyl-alpha-naphthylamine, alkylated phenyl-alpha-naphthylamine, hindered non-aromatic amines, phenols, hindered phenols, oil-soluble molybdenum compounds, polymeric antioxidants, or mixtures thereof. The antioxidant compounds may be used alone or in combination.

[0069] The hindered phenol antioxidant may contain a secondary butyl group and / or a tertiary butyl group as a steric hindrance group. The phenol group may be further substituted with a hydrocarbyl group and / or a crosslinking group bonded 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, Irganox® L-135 available from BASF or an adduct product derived from 2,6-di-tert-butylphenol and an alkyl acrylate, where 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 and may include Ethanox® 4716 available from Albemarle Corporation.

[0070] One particularly useful antioxidant includes nonyldiphenylamine and dinonyldiphenylamine. In one embodiment, the lubricating oil composition may contain one or more of these diphenylamines present in an amount up to about 1 wt%.

[0071] One or more antioxidants may be present in the range of about 0 wt% to about 3 wt%, or about 0.1 wt% to about 1 wt%, or about 0.1 wt% to about 0.5 wt% of the lubricating oil composition.

[0072] Dispersant The lubricant composition may include one or more selected dispersants or mixtures thereof. The dispersant does not contain a metal that forms ash before being mixed into the lubricating oil composition and typically does not contribute to any ash when added to the lubricant, and is thus often known as an ashless dispersant. Ashless dispersants are characterized by polar groups attached to relatively high molecular or weight hydrocarbon chains. Typical ashless dispersants include N-substituted long-chain alkenyl succinimides. N-substituted long-chain alkenyl succinimides have a polyisobutylene (PIB) substituent with a number average molecular weight in the range of about 800 to about 2500 when determined by gel permeation chromatography (GPC) using polystyrene (having a number average molecular weight of 180 to about 18,000) as a calibration standard. The PIB substituent used in the dispersant typically has a viscosity of about 2100 to about 2700 cSt at 100 °C as determined using ASTM D445-18. Succinimide dispersants and methods for their preparation are disclosed, for example, in U.S. Patent No. 7,897,696 and U.S. Patent No. 4,234,435, which are incorporated herein by reference. Succinimide dispersants are typically imides formed from polyamines, typically poly(ethylene amines). The dispersant may include two succinimide moieties bonded by a polyamine. The polyamine can be tetraethylene pentaamine (TEPA), triethylene tetraamine (TETA), pentaethylene hexaamine (PEHA), other higher nitrogen ethylenediamine species, and / or mixtures thereof. The polyamine can be a mixture of linear, branched, and cyclic amines. The PIB substituent may be bonded to each succinimide moiety.

[0073] In some embodiments, the lubricant composition includes at least one polyisobutylene succinimide dispersant derived from polyisobutylene having a number average molecular weight in the range of about 350 to about 5000, or about 500 to about 3000 when measured by the GPC method described above. The polyisobutylene succinimide can be used alone or in combination with other dispersants.

[0074] In some embodiments, the PIB, if included, may have a content of more than 50 mol%, more than 60 mol%, more than 70 mol%, more than 80 mol%, or more than 90 mol% of terminal double bonds. Such PIB is also referred to as highly reactive PIB (“HR-PIB”). HR-PIB having a number average molecular weight in the range of about 800 to about 5000 is suitable for use in embodiments of the present disclosure. Conventional non-highly reactive PIB typically has a content of less than 50 mol%, less than 40 mol%, less than 30 mol%, less than 20 mol%, or less than 10 mol% of terminal double bonds.

[0075] HR-PIB having a number average molecular weight in the range of about 900 to about 3000, as measured by the above GPC method, may be suitable. Such HR-PIB can be commercially available or synthesized by the polymerization of isobutene in the presence of a non-chlorinated catalyst such as boron trifluoride as described in U.S. Patent No. 4,152,499 and U.S. Patent No. 5,739,355. When used in the aforementioned thermal ene reaction, HR-PIB can result in a higher conversion rate in the reaction and less precipitate formation due to its increased reactivity.

[0076] In some embodiments, the lubricant composition includes at least one dispersant derived from polyisobutylene succinic anhydride. In some embodiments, the dispersant may be derived from polyalphaolefin (PAO) succinic anhydride.

[0077] One class of suitable dispersants can be Mannich bases. Mannich bases are materials formed by the condensation of higher molecular weight alkyl-substituted phenols, polyalkylene polyamines, and aldehydes such as formaldehyde. Mannich bases are described in more detail in U.S. Patent No. 3,634,515.

[0078] A suitable class of dispersants may also be high molecular weight esters or semi-ester amides.

[0079] The dispersant can also be post-treated by conventional methods by reaction with any of various agents. Among these agents are boron, urea, thiourea, dimercaptothiadiazole, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleic anhydride, nitriles, epoxides, carbonates, cyclic carbonates, hindered phenolic esters, and phosphorus compounds. U.S. Patent No. 7,645,726, U.S. Patent No. 7,214,649, and U.S. Patent No. 8,048,831 describe some suitable post-treatment methods and post-treatment products.

[0080] Suitable boron compounds useful for forming the dispersants herein include any boron compound or mixture of boron compounds capable of introducing boron-containing species into the ashless dispersant. Any organic or inorganic boron compound capable of undergoing such reactions can be used. Thus, boron oxide, boron oxide hydrates, boron trifluoride, boron tribromide, boron trichloride, HBF4 boronic acids, such as boric acid (e.g., alkyl-B(OH)2, or aryl-B(OH)2), boric acid (i.e., H3BO3), tetraboric acid (i.e., H2B5O7), metaboric acid (i.e., HBO2), ammonium salts of such boronic acids, and esters of such boronic acids can be used. The use of complexes of boron trihalides with ethers, organic acids, inorganic acids, or hydrocarbons is a convenient means of introducing boron reactants into the reaction mixture. Such complexes are known and are exemplified by boron trifluoride-diethyl ether, boron trifluoride-phenol, boron trifluoride-phosphoric acid, boron trichloride-chloroacetic acid, boron tribromide-dioxane, and boron trifluoride-methylethyl ether.

[0081] Suitable phosphorus compounds for forming the dispersant in this specification include phosphorus compounds or mixtures of phosphorus compounds that can introduce phosphorus-containing species into the ashless dispersant. For this reason, any organic or inorganic phosphorus compound capable of undergoing such reactions can be used. Thus, such inorganic phosphorus compounds can be used as inorganic phosphorus oxides including inorganic phosphoric acids and their hydrates. Typical organic phosphorus compounds include complete esters and partial esters of phosphoric acid, such as mono-, di-, and triesters of phosphoric acid, thiophosphoric acid, dithiophosphoric acid, trithiophosphoric acid, and tetrathiophosphoric acid; mono-, di-, and triesters of phosphorous acid, thiophosphorous acid; dithiophosphorous acid and trithiophosphorous acid; trihydrocarbylphosphine oxides; trihydrocarbylphosphine sulfides; mono- and dihydrocarbylphosphonates (RPO(OR’)(OR’’), where R and R’ are hydrocarbyl and R’’ is a hydrogen atom or a hydrocarbyl group), and their mono-, di-, and trithio analogs; mono- and dihydrocarbylphosphinites (RP(OR’)(OR’’), where R and R’ are hydrocarbyl and R’’ is a hydrogen atom or a hydrocarbyl group), and their mono- and dithio analogs, etc. Thus, such compounds can be, for example, phosphorous acid (H3PO3, sometimes represented as H2(HPO3) and sometimes called ortho-phosphorous acid or phosphonic acid), phosphoric acid (H3PO4, sometimes called orthophosphoric acid), hypophosphoric acid (H4P2O6), metaphosphoric acid (HPO3), pyrophosphoric acid (H4P2O7), hypophosphorous acid (H3PO2, sometimes called phosphinic acid), pyrophosphorous acid (H4P2O5, sometimes called pyrophosphonic acid), phosphinous acid (H3PO), tripolyphosphoric acid (H5P3O 10 ), tetrapolyphosphoric acid (H5P4O 13) can be used as, for example, trimeta - phosphoric acid (H3P3O9), phosphorus trioxide, phosphorus tetraoxide, phosphorus pentoxide, etc. Partial or total sulfur analogs such as phosphorotetrathioic acid (H3PS4), phosphoromonothioic acid (H3PO3S), phosphorodithioic acid (H3P2S2), phosphorotrithioic acid (H3POS3), sesquisulfide of phosphorus, heptasulfide of phosphorus, and phosphorus pentasulfide (P2S5, P4S 10 (also sometimes referred to as such) etc. can also be used for the formation of the dispersant for the present disclosure. Inorganic phosphorus halide compounds such as PCl3, PBr3, POCl3, PSCl3, etc. can also be used.

[0082] Similarly, such organic phosphorus compounds can be used as mono -, di -, and tri - esters of phosphoric acid (e.g., trihydrocarbyl phosphate, dihydrocarbyl hydrogen phosphate, monohydrocarbyl diphosphate, and mixtures thereof), mono -, di -, and tri - esters of phosphorous acid (e.g., trihydrocarbyl phosphite, dihydrocarbyl hydrogen phosphite, monohydrocarbyl diphosphite, and mixtures thereof), esters of phosphonic acid (both "primary", RP(O)(OR)2, and "secondary", R2P(O)(OR)), esters of phosphinic acid, phosphoryl halides (e.g., RP(O)Cl2 and R2P(O)Cl), phosphite halides (e.g., (RO)PCl2 and (RO)2PCl), phosphate halides (e.g., ROP(O)Cl2 and (RO)2P(O)Cl), tertiary pyrophosphate esters (e.g., (RO)2P(O)-O-P(O)(OR)2), and total sulfur analogs or partial sulfur analogs of any of the aforementioned organic phosphorus compounds, etc. 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. Halophosphines (e.g., tetrahalohydrocarbylphosphines, trihalodihydrocarbylphosphines, and dihalotrihydrocarbylphosphines) and halophosphines (monohalophosphines and dihalophosphines) can also be used.

[0083] The lubricant in this specification may include a mixture of one or more of the above boronated and phosphorylated dispersants combined with a non-boronated and non-phosphorylated dispersant.

[0084] In one embodiment, the lubricating oil composition may include at least one boronated dispersant, where the dispersant is a reaction product of an olefin copolymer or a reaction product of an olefin copolymer having succinic anhydride and at least one polyamine. The ratio of PIBSA:polyamine can be 1:1 to 10:1, or 1:1 to 5:1, or 4:3 to 3:1, or 4:3 to 2:1. Particularly useful dispersants have a polyisobutenyl group of PIBSA having a number average molecular weight (molecular weight, Mn) in the range of about 500 to 5000 as measured by the above GPC method and a (B) polyamine having the general formula H2N(CH2) m -[NH(CH2) m n -NH2, where m ranges from 2 to 4 and n ranges from 1 to 2.

[0085] ​In addition to the above, the dispersant may be post-treated with an aromatic carboxylic acid, an aromatic polycarboxylic acid, or an aromatic anhydride, and all carboxylic acid or anhydride groups are directly bonded to the aromatic ring. Such carboxyl-containing aromatic compounds may be selected from 1,8-naphthalene acid or anhydride and 1,2-naphthalenedicarboxylic acid or anhydride, 2,3-naphthalenedicarboxylic acid or anhydride, naphthalene-1,4-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, phthalic anhydride, pyromellitic anhydride, 1,2,4-benzenetricarboxylic anhydride, diphenic acid or anhydride, 2,3-pyridinedicarboxylic acid or anhydride, 3,4-pyridinedicarboxylic acid or anhydride, 1,4,5,8-naphthalenetetracarboxylic acid or anhydride, perylene-3,4,9,10-tetracarboxylic anhydride, pyrenedicarboxylic acid or anhydride, etc. The molar amount of this post-treatment component reacted per mole of polyamine may be in the range of about 0.1:1 to about 2:1. The typical molar ratio of this post-treatment component to polyamine in the reaction mixture may be in the range of about 0.2:1 to about 2:1. Another molar ratio of this post-treatment component to polyamine that may be used is in the range of 0.25:1 to about 1.5:1. This post-treatment component may be reacted with other components at a temperature in the range of about 140 °C to about 180 °C.

[0086] Alternatively, or in addition to the above post-treatment, the dispersant may be post-treated with a non-aromatic dicarboxylic acid or anhydride. The non-aromatic dicarboxylic acid or its anhydride may have a number average molecular weight of less than 500 when measured by the above GPC method. Suitable carboxylic acids or their anhydrides may include, but are not limited to, acetic acid or anhydride, oxalic acid and anhydride, malonic acid and anhydride, succinic acid and anhydride, alkenyl succinic acid and anhydride, glutaric acid and anhydride, adipic acid and anhydride, pimelic acid and anhydride, 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-tetrahydronaphthalene acid and anhydride, etc.

[0087] The non-aromatic carboxylic acid or anhydride is reacted in a molar ratio with the polyamine in the range of about 0.1 to about 2.5 moles per mole of polyamine. Typically, the amount of non-aromatic carboxylic acid or anhydride used will be proportional to the number of secondary amino groups in the polyamine. Thus, reacting about 0.2 to about 2.0 moles of non-aromatic carboxylic acid or anhydride per secondary amino group in Component B with the other components can provide a dispersant according to embodiments of the present disclosure. Another molar ratio of non-aromatic carboxylic acid or anhydride to the polyamine that can be used may be in the range of 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 at a temperature in the range of about 140 °C to about 180 °C.

[0088] The active substance weight percentage of alkenyl or alkyl succinic anhydride can be measured using chromatographic techniques. This method is described in columns 5 and 6 of U.S. Patent No. 5,334,321. The conversion percentage of polyolefin is calculated from the active ingredient percentage using the formulas in columns 5 and 6 of U.S. Patent No. 5,334,321.

[0089] The TBN of a suitable boron oxide dispersant can be about 10 to about 65 mg KOH / gram when oil-free, which is equivalent to a TBN of about 5 to about 30 mg KOH / gram when measured on a dispersant sample containing about 50% diluent oil.

[0090] Typically, the above-mentioned dispersant is provided in the lubricant at about 4.5 to about 10 weight percent, and in other approaches at about 4.5 to about 8 weight percent, and in still other approaches at about 4.5 to about 7.7 weight percent.

[0091] Viscosity index improver The lubricant composition of the present specification may also optionally contain one or more viscosity index improvers. Suitable viscosity index improvers may include polyolefins, olefin copolymers, ethylene / propylene copolymers, polyisobutene, hydrogenated styrene-isoprene polymers, styrene / maleic acid ester copolymers, hydrogenated styrene / butadiene copolymers, hydrogenated isoprene polymers, alpha-olefin maleic anhydride copolymers, polymethacrylates, polyacrylates, polyalkylstyrenes, hydrogenated alkenylaryl conjugated diene copolymers, or mixtures thereof. The viscosity index improver may include star polymers, and suitable examples are described in U.S. Patent Application Publication No. 20120101017(A1), which is incorporated herein by reference.

[0092] The lubricating oil composition herein may optionally contain one or more dispersant viscosity index improvers in addition to or instead of the viscosity index improver. Suitable viscosity index improvers may include functionalized polyolefins, such as ethylene-propylene copolymers functionalized with the reaction product of an acylating agent (such as maleic anhydride) and an amine, polymethacrylates functionalized with an amine, or esterified maleic anhydride-styrene copolymers reacted with an amine.

[0093] The total amount of the viscosity index improver and / or the dispersant viscosity index improver may be about 0 wt% to about 10 wt%, about 0.1 wt% to about 8 wt%, or about 0.1 wt% to about 6 wt% of the lubricating oil composition.

[0094] In some embodiments, the viscosity index improver is a polyolefin or olefin copolymer having a number average molecular weight of from about 10,000 to about 500,000, from about 50,000 to about 200,000, or from 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 from about 40,000 to about 500,000, from about 50,000 to about 200,000, or from about 50,000 to about 150,000. In some embodiments, the viscosity index improver is a polymethacrylate having a number average molecular weight of from about 10,000 to about 500,000, from about 50,000 to about 200,000, or from about 50,000 to about 150,000.

[0095] Other optional additives The other additives can be selected to perform one or more functions required of the lubricant composition. Further, one or more of the foregoing additives can be multifunctional and can provide additional functions in addition to the functions described herein, or can provide other functions. The other additives can be added in addition to the additives specified in the present disclosure and / or can include one or more of metal deactivators, viscosity index improvers, ashless TBN boosters, antiwear agents, corrosion inhibitors, rust inhibitors, dispersants, dispersant viscosity index improvers, extreme pressure agents, antioxidants, foam inhibitors, demulsifiers, emulsifiers, pour point depressants, seal swell agents, and mixtures thereof. Typically, a fully formulated lubricating oil contains one or more of these additives.

[0096] Suitable metal deactivators include derivatives of benzotriazole (typically tolyltriazole), dimercaptothiadiazole derivatives, 1,2,4-triazole, benzimidazole, 2-alkyldithiobenzimidazole, or 2-alkyldithiobenzothiazole; foam suppressants including copolymers of ethyl acrylate and 2-ethylhexyl acrylate and optionally vinyl acetate; demulsifiers including trialkyl phosphate, polyethylene glycol, polyethylene oxide, polypropylene oxide, and (ethylene oxide - propylene oxide) polymers; pour point depressants including esters of maleic anhydride - styrene, polymethacrylate, polyacrylate, or polyacrylamide may be mentioned.

[0097] Suitable foam suppressants include silicon-based compounds such as siloxane.

[0098] Suitable pour point depressants may include polymethyl methacrylate or mixtures thereof. The pour point depressant may be present in an amount sufficient to provide from about 0 wt% to about 1 wt%, from about 0.01 wt% to about 0.5 wt%, or from about 0.02 wt% to about 0.04 wt% based on the final weight of the lubricating oil composition.

[0099] Antifoaming agents / surfactants may also be included in the fluid according to the present invention. Various agents for such applications are known. Copolymers of ethyl acrylate and hexyl ethyl acrylate, for example, PC-1244 available from Solutia can be used. In other embodiments, silicone fluids such as 4% DCF may be included. Mixtures of antifoaming agents may also be present in the lubricant composition.

[0100] The terms "gear oil", "gear fluid", "gear lubricant", "base gear lubricant", "lubricating oil", "lubricant composition", "lubricating composition", "lubricant", and "lubricating fluid" refer to the final lubricating product that includes a major amount of base oil and a minor amount of additive composition as contemplated herein. Such gear fluids are used, for example, in transmissions (manual, automatic, dual clutch, or electric) and / or gear differentials in extreme pressure conditions such as those of transmission and gear drive components having metal-to-metal contact.

[0101] As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl group" is used in its ordinary meaning well known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly bonded to the remainder of the molecule and having predominantly hydrocarbon characteristics. Each hydrocarbyl group is independently selected from hydrocarbon substituents, and a substituted hydrocarbon substituent contains one or more of halo group, hydroxyl group, alkoxy group, mercapto group, nitro group, nitroso group, amino group, pyridyl group, furyl group, imidazolyl group, oxygen, and nitrogen, and two or less non-hydrocarbon substituents are present per ten carbon atoms in the hydrocarbyl group.

[0102] As used herein, the term "percent by weight" or "wt%" or "weight percent" means the percentage expressed with respect to the total weight of the composition of the listed components, unless expressly stated otherwise. All percentages herein are weight percentages unless otherwise specified. As used herein, "free of" means that the amount of such component is less than about 0.1 weight percent, less than 0.05 weight percent, less than 0.01 weight percent, or absent altogether.

[0103] As used herein, the terms "soluble", "oil-soluble", or "dispersible" may indicate that a compound or additive is soluble, soluble, miscible, or suspendable in oil in any proportion, but not necessarily so. However, the foregoing terms mean that they are soluble, suspendable, soluble, or stably dispersible in oil to an extent sufficient to exert their intended effects, for example, in an environment where oil is used. Further, if desired, incorporating other additives may also make it possible to incorporate higher levels of specific additives.

[0104] As used herein, the term "alkyl" refers to straight-chain, branched-chain, cyclic, and / or substituted saturated chain moieties of from about 1 to about 200 carbon atoms. As used herein, the term "alkenyl" refers to straight-chain, branched-chain, cyclic, and / or substituted saturated chain moieties of from about 3 to about 30 carbon atoms. As used herein, the term "aryl" refers to monocyclic and polycyclic aromatic compounds containing alkyl, alkenyl, alkylaryl, amino, hydroxyl, alkoxy, halo substituents, and / or heteroatoms, for example, but not limited to, nitrogen and oxygen.

[0105] As used herein, molecular weight is measured by gel permeation chromatography (GPC) using commercially available polystyrene standards (having an Mn of about 180 to about 18,000 as calibration standards). The molecular weight (Mn) of any embodiment herein can be determined using gel permeation chromatography (GPC) equipment obtained from Waters or similar equipment, and data processed with Waters Empower Software or similar software. The GPC equipment can be provided with a Waters separation module and a Waters refractive index detector (or any optional similar equipment). The GPC operating conditions can include a guard column, four Agilent PL gel columns (length 300 × 7.5 mm, particle size 5 μm, and pore diameters in the range of 100 to 10,000 Å), and a column temperature of about 40 °C. Unstabilized HPLC grade tetrahydrofuran (THF) can be used as the solvent at a flow rate of 1.0 mL / min. The GPC equipment can be calibrated with commercially available polystyrene (PS) standards having a narrow molecular weight distribution in the range of 500 to 380,000 g / mol. The calibration curve can be extrapolated for samples having masses less than 500 g / mol. The sample and PS standards can be dissolved in THF and prepared at a concentration of 0.1 to 0.5 weight percent and used without filtration. GPC measurements are also described in U.S. Patent No. 5,266,223, which is incorporated herein by reference. The GPC method additionally provides molecular weight distribution information. See also, for example, W.W. Yau, J.J. Kirkland, and D.D. Bly, "Modern Size Exclusion Liquid Chromatography", John Wiley and Sons, New York, 1979, which is incorporated herein by reference.

[0106] Throughout this disclosure, terms such as "comprises," "includes," "contains," etc. are considered to be open-ended and should be understood to include any element, step, or ingredient not explicitly recited. The phrase "consisting essentially of" means including any explicitly recited element, step, or ingredient, and any additional element, step, or ingredient that does not materially affect the basic and novel aspects of the invention. This disclosure also contemplates that any composition described using the terms "comprises," "includes," "contains" should be construed as also including a disclosure of the same composition "consisting essentially of" or "consisting of" its specifically recited components.

Examples

[0107] The following examples illustrate exemplary embodiments of the present disclosure. In these examples, as well as elsewhere in this application, all ratios, parts, and percentages are by weight unless otherwise indicated. It is intended that these examples be presented for illustrative purposes only and not be intended to limit the scope of the invention disclosed herein.

Examples

[0108] An alkenyl succinic anhydride (alkenyl succinic anhydride, ASA, for example, Table 3 below) was dissolved in dimethyl sulfoxide at about 100 °C, melamine was added at about 100 °C, and then the reaction mixture was stirred for about 5 hours to prepare an oil-soluble hydrocarbyl-substituted melamine derivative. Then, ice water was added to the mixture, the brown precipitate was collected, then this was dissolved in tert-butyl methyl ether, filtered, and then concentrated on a rotary evaporator. Then, the concentrated sample was dried in an oven at 75 °C overnight to obtain a viscous brown liquid. The alkenyl succinic anhydride (ASA) reactants used in this example are described in Table 3 below, and the reaction conditions with melamine are described in Table 4 below.

[0109]

Table 7

[0110]

Table 8

[0111] Example 2 Lubricants containing the reaction products of Table 4 from Example 1 were prepared and evaluated for long-term copper corrosion in accordance with ASTM D130 (at 150 °C for 168 hours). Each of the lubricants of the present invention in this example contained about 0.035 weight percent of one of the reaction products of Table 4 from Example 1, as well as the same amount of the same additive package (e.g., dispersant, antifoaming agent, friction modifier, antioxidant, detergent, and antiwear agent), viscosity modifier, and Group III base oil to form Transmission Lubricants 1-4 of the present invention having a kinematic viscosity of about 5 cSt at 100 °C (ASTM D445). The lubricants of the present invention are specified in Table 5 below, along with the results of the long-term copper corrosion test of ASTM D130 (e.g., visual copper discoloration and copper leaching). Comparative lubricants containing the same amounts and the same additive package, viscosity modifier, and Group III base oil but without a corrosion inhibitor were also tested for long-term copper corrosion and are shown in Table 5 below for comparison.

[0112]

Table 9

[0113] As shown in Table 5 above, the lubricant of the present invention containing the melamine derivative of the present disclosure showed copper discoloration comparable to or better than that of the comparative lubricant and lower copper leaching than the comparative lubricant. The lubricant of this example did not contain any tolyltriazole additive or its derivative.

[0114] Example 3 Similar to Example 2, additional lubricants of the present invention containing the reaction products of Table 4 from Example 1 were prepared and evaluated for long-term copper corrosion in accordance with ASTM D130 (at 150 °C for 168 hours). Each lubricant of the present invention of this example contained one of the reaction products of Table 4 from Example 1 at about 0.035 weight percent, as well as the same amount of the same additive package (including dispersant, antifoaming agent, friction modifier, antioxidant, detergent, and antiwear agent), viscosity modifier, and Group III base oil to form Transmission Lubricants 5 - 8 of the present invention having a kV100 (ASTM D445) of about 5 cSt. The lubricants of the present invention of this example are specified in Table 6 below, along with the results of the ASTM D130 long-term copper corrosion test (e.g., visual copper discoloration and copper leaching). Comparative lubricants containing the same amounts and the same additive package, viscosity modifier, and Group III base oil but no corrosion inhibitor were also tested for long-term copper corrosion and are shown in Table 6 below for comparison.

[0115]

Table 10

[0116] As shown in Table 6 above, the lubricant of the present invention containing the melamine derivative of the present disclosure showed copper discoloration comparable to or better than that of the comparative lubricant and lower copper leaching than the comparative lubricant. The lubricant of this example also did not contain any tolyltriazole additive or its derivative.

[0117] As used in this specification and the appended claims, it should be noted that the singular forms "a", "an", and "the" include plural referents unless explicitly and clearly limited to one referent. Thus, for example, a reference to "an antioxidant" includes two or more different antioxidants. As used herein, the term "comprising" and its grammatical variants are intended to be non-limiting such that the listing of items in a list does not exclude other similar items that may be substituted or added to the items in the list.

[0118] For the purposes of this specification and the appended claims, unless otherwise indicated, all amounts, percentages, or ratios used in this specification and the claims, and all numbers representing other values, are to be understood as being modified in all instances by the term "about". Thus, unless indicated to the contrary, the numerical parameters set forth in the following specification and the appended claims are approximations that may vary depending upon the desired properties sought to be obtained by the present disclosure. 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 be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0119] It should be understood that each component, compound, substituent, or parameter disclosed herein is disclosed for use alone or in combination with one or more of any other component, compound, substituent, or parameter disclosed herein.

[0120] It should be further understood that each range disclosed herein is to be construed as a disclosure of each specific value within the disclosed range having the same number of significant digits. Thus, for example, a range of 1 to 4 is to be construed as a distinct disclosure of not only the values 1, 2, 3, and 4, but also any range of such values.

[0121] It should be further understood that each lower limit of each range disclosed herein is to be construed as being disclosed in combination with each upper limit of each range and each specific value within each range for the same component, compound, substituent, or parameter disclosed herein. Accordingly, the present disclosure should be construed as a disclosure of all ranges derivable by combining each lower limit of each range with each upper limit of each range, or with each specific value within each range, or by combining each upper limit of each range with each specific value within each range. That is, it should also be further understood that any range between the endpoint values within a broad range is also contemplated herein. Accordingly, the range of 1 to 4 also means ranges such as 1 to 3, 1 to 2, 2 to 4, 2 to 3, etc.

[0122] Furthermore, the specific amounts / values of components, compounds, substituents, or parameters disclosed in the detailed description or examples should be construed as a disclosure of either the lower or upper limit of a range, and thus, in combination with any other lower or upper limit or specific amount / value within the range for the same component, compound, substituent, or parameter disclosed elsewhere in the present application, can form a range for that component, compound, substituent, or parameter.

[0123] Although specific embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are not presently contemplated or that cannot presently be contemplated by the applicants or other persons of ordinary skill in the art may arise. Accordingly, the filed claims and the claims 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 hydrocarbyl-substituted melamine derivative having the structure of Formula I, 【Chemical 1】 In the formula, R １ , R ２ , and R ３ each independently represents -NH ２ , a hydrocarbyl-substituted succinimide group, or a hydrocarbyl-substituted dicarboxylic acid-amide group, and one or two of R １ , R ２ , and R ３ independently represent either the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining R １ , R ２ , and R ３ independently represent either the -NH ２ or a hydrocarbyl-substituted dicarboxylic acid-amide, a corrosion inhibitor.

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-C30 hydrocarbyl group, preferably a C12-C24 hydrocarbyl group.

3. The corrosion inhibitor according to Claim 1, wherein the corrosion inhibitor has from about 5 weight percent to about 25 weight percent nitrogen.

4. The corrosion inhibitor according to Claim 1, wherein the corrosion inhibitor is a reaction product of a hydrocarbyl-substituted succinic acid or anhydride and melamine, with a molar excess of the hydrocarbyl-substituted succinic acid or anhydride relative to the melamine, preferably a molar ratio of the hydrocarbyl-substituted succinic acid or anhydride to the melamine of from about 1.1:1 to about 4:1, preferably from about 1.1:1 to about 3:

1.

5. R １ , R ２ , and R ３ of which one is independently either said hydrocarbyl-substituted succinimide group or hydrocarbyl-substituted dicarboxylic acid-amine group, and R １ , R ２ , and R ３ of which the remaining two are -NH ２ groups. The corrosion inhibitor according to claim 1.

6. R １ , R ２ , and R ３ of which two are independently either the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amine group, and R １ , R ２ , and R ３ of which the remaining one is the —NH ２ group. The corrosion inhibitor according to claim 5.

7. The oil-soluble hydrocarbyl-substituted melamine derivative has one or more of the following structures, 【Table 1】 wherein each R group thereof is independently a C12-C30 hydrocarbyl group, the corrosion inhibitor according to Claim 1.

8. A lubricating composition containing from 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 in accordance with ASTM D130, the corrosion inhibitor according to Claim 1.

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

10. The method according to Claim 9, wherein the hydrocarbyl substituent is a C12-C30 hydrocarbyl group, preferably a C12-C24 hydrocarbyl group.

11. The method according to Claim 9, 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, preferably from about 1.1:1 to about 3:

1.

12. The method according to Claim 9, wherein the formed corrosion inhibitor has from about 5 to about 25 weight percent nitrogen.

13. The formed oil-soluble hydrocarbyl-substituted melamine derivative has the structure of Formula I, [Chemical Formula 2] wherein R １ , R ２ , and R ３ each independently is -NH ２ , a hydrocarbyl-substituted succinimide group, or a hydrocarbyl-substituted dicarboxylic acid-amide group, and one or two of R １ , R ２ , and R ３ independently is either the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amide group, and the remaining R １ , R ２ , and R ３ each independently is either the -NH ２ or a hydrocarbyl-substituted dicarboxylic acid-amide, the method according to claim 9.

14. R １ 、R ２ 、and R ３ of which one is independently either the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amine group, and R １ 、R ２ 、and R ３ of the remaining two are -NH ２ groups, and / or two of R １ 、R ２ 、and R ３ are independently either the hydrocarbyl-substituted succinimide group or the hydrocarbyl-substituted dicarboxylic acid-amine group, and the remaining one of R １ 、R ２ 、and R ３ is the -NH ２ group, the method according to claim 13.

15. The oil-soluble hydrocarbyl-substituted melamine derivative has one or more of the following structures, 【Table 2】 wherein each R group is independently a C12-C30 hydrocarbyl group, the method according to claim 9.

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