Industrial lubricant

Abstract

To provide a lubricating composition and a method for lubrication for a transmission, a gearbox, or clutches to protect from wear and to prolong service life of devices.SOLUTION: A lubricating composition for a transmission, a gearbox, and / or clutches includes a mixture of compounds providing to the fluids (i) a base oil having a lubricating viscosity, (ii) a certain amount of phosphorus provided from three phosphorus compounds: (iia) a first phosphorus compound including ashless dialkyl dithiophosphate or salts thereof, (iib) a second phosphorus compound including aminoalkyl phosphonate or cyclic derivatives thereof, and (iic) a third phosphorus compound including a hydrocarbyl phosphonate monoester, and (iii) a certain amount of nitrogen provided from nitrogen-containing polyisobutylene succinimide.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to industrial lubricants, and more particularly to lubricating compositions for transmissions, gearboxes, and / or clutches. [Background technology]

[0002] Industrial gearboxes and transmissions are essential components of a wide variety of large machines, such as mining equipment, oil rigs, material handling systems, and equipment used in manufacturing plant operations, to name just a few applications. These gear systems operate under harsh conditions, high loads, high temperatures, and / or extreme pressures, often leading to increased wear and tear, reduced efficiency, and premature failure. Efficient lubrication of these gear systems protects against wear and extends the life of the equipment.

[0003] As original equipment manufacturer (OEM) requirements evolve, traditional industrial gear and transmission lubricants often fail to provide adequate protection and durability under more demanding operating conditions and the wider range of end-use applications required by newer requirements and applications. Existing products often face challenges related to roller bearing protection, gear wear, material compatibility, and / or fall short when attempting to balance wear protection with the higher friction applications (e.g., clutches and / or clutch brakes) often required in such new applications. For example, newer transmission and gearbox lubricating compositions are periodically required to simultaneously achieve several important properties, including one or more of wear protection, extreme pressure protection, corrosion reduction, and / or friction performance. Such new lubricants often must simultaneously meet or exceed multiple performance tests, including wear protection as measured by the four-ball wear test (ASTM D4172), extreme pressure properties according to the four-ball load wear index (ASTM D2783), friction performance as measured according to a high frequency reciprocating rig (HFRR), and achieving low copper corrosion (ASTM D130). Formulating a lubricant to meet one or two of these performance tests tended to cause the others to fail, so it was previously difficult to design transmission and gearbox lubricants that could simultaneously meet all four requirements. Summary of the Invention

[0004] In one approach or embodiment, a lubricating composition is provided herein, the lubricating composition configured to lubricate, for example, a transmission, a gearbox, and / or a clutch. In an aspect, the lubricating composition comprises at least (i) a base oil of lubricating viscosity, and (ii) an amount of phosphorus provided from three phosphorus compounds, the three phosphorus compounds comprising: (iia) a first phosphorus compound comprising an ashless dialkyldithiophosphate of Formula I, or a salt thereof:

[0005] [ka] (wherein R1 and R2 are independently a C3-C8 linear or branched alkyl group, and R3 is hydrogen or a methyl group), (iib) a second phosphorus compound comprising an aminoalkylphosphonate of formula II or a cyclic derivative thereof:

[0006] [ka] wherein R4 and R5 are independently a C1-C4 straight chain or branched alkyl group, and R6 and R7 are independently a C1-C4 hydroxyalkyl group, and (iic) a third phosphorus compound comprising a hydrocarbyl phosphonate monoester of formula III:

[0007] [ka] (Wherein R8 is C 12 ~C 30 and R is a hydrocarbyl group, and R is a methyl group, an ethyl group, a propyl group, or an isopropyl group), wherein the first phosphorus compound, the second phosphorus compound, and the third phosphorus compound collectively provide about 30 ppm to about 200 ppm of phosphorus to the lubricating composition; and (iii) an amount of nitrogen provided by a nitrogen-containing polyisobutylene succinimide, the polyisobutylene succinimide having a number average molecular weight of the polyisobutylene substituent of about 500 to about 2500 g / mol as determined by gel permeation chromatography using polystyrene as a standard, and providing about 30 ppm to about 105 ppm weight percent of nitrogen to the lubricating composition.

[0008] In other approaches or embodiments, the lubricating composition of the preceding paragraph may include other features or embodiments in any combination, including one or more of the following: the first phosphorus compound is 3-[[bis(2-methylpropoxy)phosphinothioyl]thio]-2-methyl-propanoic acid, and / or the first phosphorus compound provides from about 5 to about 75 ppm of phosphorus to the lubricating composition, and / or the second phosphorus compound is N,N-bis(2-hydroxyethyl)aminomethylphosphonic acid diethyl ester, and / or the second phosphorus compound provides from about 10 to about 65 ppm of phosphorus to the lubricating composition; and / or the third phosphorus compound is methyl octadecylphosphonate; and / or the third phosphorus compound provides from about 5 to about 40 ppm of phosphorus to the lubricating composition; and / or the first phosphorus compound provides from about 5 ppm to about 75 ppm of phosphorus to the lubricating composition, the second phosphorus compound provides from about 10 to about 65 ppm of phosphorus to the lubricating composition, and the third phosphorus compound provides from about 5 to about 40 ppm of phosphorus to the lubricating composition; and / or the lubricating composition has an average wear scar of about 0.5 mm or less according to ASTM D4172 (40 kgf), a load wear index of about 46 or greater according to ASTM D2783, a coefficient of friction of greater than about 0.128 when measured using a high frequency reciprocating rig (HFRR) using a 400 gram load, 20 Hz, and 80°C for 3 minutes, and and / or about 30 to about 45 weight percent of the total phosphorus is provided by the first phosphorus compound, about 35 to about 40 weight percent of the total phosphorus is provided by the second phosphorus compound, about 20 to about 30 weight percent of the total phosphorus is provided by the third phosphorus compound, and / or greater than 50 weight percent of the phosphorus is provided by the sum of the second phosphorus compound and the third phosphorus compound, and / or the lubricating composition has a KV100 of about 5 to about 60 cSt, and / or the lubricating composition has a ratio of phosphorus from the three phosphorus compounds to nitrogen from the nitrogen-substituted long-chain alkenyl succinimide of about 1:1 to about 2.2:1, and / or the nitrogen-substituted long-chain alkenyl succinimide comprises a compound having the structure of Formula IV:

[0009] [ka] In the formula, R 10 is a polyisobutylene having a number average molecular weight of about 500 to about 1200 g / mol, and R 11 and R 12 are independently divalent C1-C6 alkylene, and R 13 and R 14 are independently hydrogen, a C1-C6 alkyl group, or together with the N to which they are attached form a 5- or 6-membered ring, optionally fused with one or more aromatic or non-aromatic rings, where n is an integer from 0 to 8; and / or R 13 and R 14 together with the N to which they are attached to form a succinimide moiety of formula V,

[0010] [ka] and / or R 11 and R 12 Each of is a C2 alkylene and n is an integer of 2.

[0011] In another approach or embodiment, provided herein is a method of lubricating a transmission, gearbox, and / or clutch. In an aspect, the method includes lubricating a transmission, gearbox, and / or clutch component with a lubricating composition, the lubricating composition comprising: (i) a base oil of lubricating viscosity; and (ii) an amount of phosphorus provided by three phosphorus compounds, the three phosphorus compounds including: (iia) a first phosphorus compound comprising an ashless dialkyldithiophosphate of Formula I, or a salt thereof:

[0012] [ka] (wherein R1 and R2 are independently a C3-C8 linear or branched alkyl group, and R3 is hydrogen or a methyl group), (iib) a second phosphorus compound comprising an aminoalkylphosphonate of formula II or a cyclic derivative thereof:

[0013] [ka] wherein R4 and R5 are independently a C1-C4 straight chain or branched alkyl group, and R6 and R7 are independently a C1-C4 hydroxyalkyl group, and (iic) a third phosphorus compound comprising a hydrocarbyl phosphonate monoester of formula III:

[0014] [ka] (Wherein R8 is C 12 ~C 30 and R is a hydrocarbyl group, and R is a methyl, ethyl, propyl, or isopropyl group), wherein the first phosphorus compound, the second phosphorus compound, and the third phosphorus compound collectively provide about 30 ppm to about 200 ppm of phosphorus to the lubricating composition; and (iii) an amount of nitrogen provided by a nitrogen-containing polyisobutylene succinimide, the polyisobutylene succinimide having a number average molecular weight of the polyisobutylene substituent of about 500 to about 2,500 g / mol as determined by gel permeation chromatography using polystyrene as a standard, and providing about 30 ppm to about 105 ppm weight percent of nitrogen to the lubricating composition.

[0015] In still further approaches or embodiments, the method described in the preceding paragraph may include other features, steps, or embodiments in any combination, including one or more of the following: the first phosphorus compound is 3-[[bis(2-methylpropoxy)phosphinothioyl]thio]-2-methyl-propanoic acid, and / or the first phosphorus compound provides from about 5 to about 75 ppm of phosphorus to the lubricating composition, and / or the second phosphorus compound is N,N-bis(2-hydroxylethyl)aminomethylphosphonic acid diethyl ester, and / or the second phosphorus compound provides from about 10 to about 65 ppm of phosphorus to the lubricating composition; and / or the third phosphorus compound is methyl octadecylphosphonate; and / or the third phosphorus compound provides about 5 to about 40 ppm of phosphorus to the lubricating composition; and / or the first phosphorus compound provides about 5 ppm to about 75 ppm of phosphorus to the lubricating composition, the second phosphorus compound provides about 10 to about 65 ppm of phosphorus to the lubricating composition, and the third phosphorus compound provides about 5 to about 40 ppm of phosphorus to the lubricating composition; and / or the lubricating composition has an average wear scar of about 0.5 mm or less according to ASTM D4172 (40 kgf), a load wear index of about 46 or greater according to ASTM D2783, a coefficient of friction of greater than about 0.128 when measured using a high frequency reciprocating rig (HFRR) using a 400 gram load, 20 Hz, and 80°C for 3 minutes, and a wear index of about 0.5 mm or less according to ASTM D2783. and / or about 30 to about 45 weight percent of the total phosphorus is provided by the first phosphorus compound, about 35 to about 40 weight percent of the total phosphorus is provided by the second phosphorus compound, and about 20 to about 30 weight percent of the total phosphorus is provided by the third phosphorus compound; and / or greater than 50 weight percent of the phosphorus is provided by the sum of the second phosphorus compound and the third phosphorus compound; and / or the lubricating composition has a KV100 of about 5 to about 60 cSt; and / or the lubricating composition has a ratio of phosphorus from the three phosphorus compounds to nitrogen from the nitrogen-substituted long-chain alkenyl succinimide of about 1:1 to about 2.2:1; and / or the nitrogen-substituted long-chain alkenyl succinimide comprises a compound having the structure of Formula IV:

[0016] [ka] In the formula, R 10 is a polyisobutylene having a number average molecular weight of about 500 to about 1200 g / mol, and R 11 and R 12 are independently divalent C1-C6 alkylene, and R 13 and R 14 are independently hydrogen, a C1-C6 alkyl group, or together with the N to which they are attached form a 5- or 6-membered ring, optionally fused with one or more aromatic or non-aromatic rings, where n is an integer from 0 to 8; and / or R 13 and R 14 together with the N to which they are attached to form a succinimide moiety of formula V,

[0017] [ka] and / or R 11 and R 12 Each of is a C2 alkylene and n is an integer of 2.

[0018] In yet another approach or embodiment, also described herein is the use of any embodiment of the lubricating composition described above in the Summary of this Invention to lubricate a transmission, gearbox, and / or clutch and achieve an average wear scar of about 0.5 mm or less according to ASTM D4172 (40 kgf), a load wear index of about 46 or greater according to ASTM D2783, a coefficient of friction of greater than about 0.128 as measured using a high frequency reciprocating rig (HFRR) using a 400 gram load, 20 Hz, and 80°C for 3 minutes, and a copper corrosion tarnish rating of 2b or better when evaluated at 100°C for 3 hours according to ASTM D130.

[0019] Other embodiments of the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. The following definitions are provided to clarify the meaning of certain terms used herein. DETAILED DESCRIPTION OF THE INVENTION

[0020] Disclosed herein are lubricating compositions suitable for gear fluid, transmission fluid, power transmission fluid, and / or driveline applications that simultaneously achieve good performance in wear, extreme pressure, friction, and copper corrosion. In one approach or embodiment, the lubricating compositions herein comprise a base oil of lubricating viscosity, an amount of phosphorus selected from three specific phosphorus compounds, and an amount of nitrogen provided by a specific nitrogen-containing polyisobutylene succinimide. In this approach, the three phosphorus-containing compounds provide a total of about 30 ppm to about 200 ppm of phosphorus to the lubricating composition, and the nitrogen-containing polyisobutylene succinimide provides about 30 to about 105 ppm of nitrogen. As shown in the examples below, only when all four compounds (e.g., three phosphorus compounds and a nitrogen-containing polyisobutylene succinimide) are included together in a lubricant does the lubricant pass all four performance tests for wear (ASTM D4172), extreme pressure (ASTM D2783), friction (HFRR), and copper corrosion (ASTM D130) appropriate for an industrial gear lubricant.

[0021] In one approach or embodiment, the three phosphorus-containing compounds of the lubricants herein include (1) an ashless dialkyldithiophosphate, (2) an aminoalkylphosphonate, and (3) a hydrocarbylphosphonate monoester. The first phosphorus compound of the lubricant is an ashless dialkyldithiophosphate of Formula I, or a salt thereof:

[0022] [ka] wherein R1 and R2 are independently a C3-C8 straight or branched alkyl group, and R3 is hydrogen or a methyl group. The second phosphorus compound of the lubricants herein is an aminoalkylphosphonate or cyclic derivative thereof of Formula II:

[0023] [ka] wherein R4 and R5 are independently C1-C4 straight or branched alkyl groups, and R6 and R7 are independently C1-C4 hydroxyalkyl groups. The third phosphorus compound of the lubricants herein is a hydrocarbyl phosphonate monoester of Formula III:

[0024] [ka] In the formula, R8 is C 12 ~C 30 is a hydrocarbyl group, and R9 is a methyl group, an ethyl group, a propyl group, or an isopropyl group.

[0025] In another approach or embodiment, the nitrogen-containing polyisobutylene succinimide of the lubricants herein is a polyisobutylene-substituted succinimide having a number average molecular weight of the polyisobutylene substituent of from about 500 to about 2500 g / mol, and more specifically, a nitrogen-substituted long chain alkenyl succinimide comprising one or more compounds having the structure of Formula IV:

[0026] [ka] In the formula, R 10 is a polyisobutylene having a number average molecular weight of about 500 to about 2,500 g / mol (in other approaches, about 500 to about 1,200 g / mol), and R 11 and R 12 are independently divalent C1-C6 alkylene, and R 13 and R 14are each independently hydrogen, C1-C6 alkyl, or together with the N to which they are attached form a 5- or 6-membered ring optionally fused to one or more aromatic or non-aromatic rings, and n is an integer from 0 to 8.

[0027] Each of the phosphorus and nitrogen compounds is discussed further below.

[0028] First phosphorus compound In one approach or embodiment, the first phosphorus compound of the lubricating compositions and methods herein is an acid thiophosphate or thiophosphate ester, such as an ashless, amine-free dialkyldithiophosphate ester or a sulfur-containing phosphate ester. The first phosphorus compound comprises about 8 to about 10 weight percent phosphorus, providing the lubricating composition with about 7 ppm to about 75 ppm phosphorus (in another approach, about 10 ppm to about 50 ppm phosphorus, in a further approach, about 15 ppm to about 40 ppm, and in yet another approach, about 20 ppm to about 30 ppm phosphorus). In an alternative approach, the lubricating compositions herein comprise about 0.01 weight percent to about 0.075 weight percent of the first phosphorus compound (in another approach, about 0.015 weight percent to about 0.05 weight percent, in a further approach, about 0.02 weight percent to about 0.04 weight percent, or in yet another approach, about 0.03 weight percent to about 0.04 weight percent of the first phosphorus compound).

[0029] In other approaches or embodiments, the first phosphorus compound provides phosphorus to the lubricating composition in an amount ranging from at least about 7 ppm, at least about 10 ppm, at least about 12 ppm, at least about 15 ppm, or at least about 20 ppm to about 75 ppm or less, about 70 ppm or less, about 60 ppm or less, about 50 ppm or less, about 40 ppm or less, or about 30 ppm or less (or any range between such endpoints). In yet other approaches, the treat rate of the first phosphorus compound in the lubricating oil composition ranges from at least about 0.01 weight percent, at least about 0.02 weight percent, at least about 0.03 weight percent to about 0.075 weight percent or less, about 0.07 weight percent or less, about 0.06 weight percent or less, about 0.05 weight percent or less, or about 0.04 weight percent or less (or any range between such endpoints).

[0030] The acid thiophosphate, thiophosphate ester, or sulfur-containing phosphate ester of the first phosphorus compound may have one or more sulfur-phosphorus bonds. In one embodiment, the sulfur-containing phosphate ester may be an acid thiophosphate, a thiophosphate ester, a thiophosphoric acid, or a salt thereof. The thiophosphate ester may be a dithiophosphate ester. In some more specific approaches, the acid thiophosphate or thiophosphate ester may have the structure of Formula II or a salt thereof:

[0031] [ka] wherein R1 and R2 are each independently a linear or branched C1-C10 hydrocarbyl group, and R is a C1-C10 linear or branched carboxyl group, or a C1-C10 linear or branched alkyl alkanoate group. More specifically, R1 and R2 are each a C3-C8 linear or branched alkyl group, and R is derived from 2-methylpropionic acid, such that the first phosphorus compound (or salt thereof) has the structure of Formula Ia:

[0032] [ka] wherein R1 and R2 are independently a C3-C8 straight or branched alkyl group (preferably each a branched C4 group), and R3 is -H or -CH3 (preferably a methyl group). In some approaches or embodiments, the first phosphorus product is preferably 3-[[bis(2-methylpropoxy)phosphinothioyl]thio]-2-methyl-propanoic acid.

[0033] Second phosphorus compound In one approach or embodiment, the second phosphorus compound of the lubricating compositions and methods herein comprises an aminoalkylphosphonate, such as an aminoalkylphosphonic acid dialkyl ester or a cyclic derivative thereof. In another approach or embodiment, the second phosphorus compound comprises from about 11 to about 13 weight percent phosphorus, providing the lubricating composition with from about 10 ppm to about 65 ppm phosphorus (from about 12 ppm to about 50 ppm phosphorus in another approach, from about 14 ppm to about 30 ppm in a further approach, or from about 14 ppm to about 25 ppm phosphorus). In an alternative approach, the lubricating compositions herein comprise from about 0.01 weight percent to about 0.05 weight percent of the second phosphorus compound (from about 0.011 weight percent to about 0.04 weight percent in another approach, from about 0.012 weight percent to about 0.03 weight percent in a further approach, or from about 0.014 weight percent to about 0.02 weight percent of the second phosphorus compound).

[0034] In other approaches or embodiments, the second phosphorus compound provides phosphorus to the lubricating composition in an amount ranging from at least about 10 ppm, at least about 12 ppm, at least about 14 ppm, or at least about 15 ppm to about 65 ppm or less, about 60 ppm or less, about 50 ppm or less, about 40 ppm or less, or about 30 ppm or less (or any range between such endpoints). In yet other approaches, the treat rate of the second phosphorus compound in the lubricating oil composition may range from at least about 0.01 weight percent, at least about 0.012 weight percent, or at least about 0.014 weight percent to about 0.05 weight percent or less, about 0.04 weight percent or less, about 0.03 weight percent or less, or about 0.02 weight percent or less (or any range between such endpoints).

[0035] In an approach or embodiment, the second phosphorus compound is an aminoalkylphosphonate or a cyclic derivative thereof of Formula II:

[0036] [ka] In the formula, R4 and R5 are independently a C1 to C4 linear or branched alkyl group, and R6 and R7 are independently a C1 to C4 hydroxyalkyl group.

[0037] This second phosphorus compound can be prepared from a phosphite, formaldehyde, and an amine. An exemplary reaction scheme for forming the second phosphorus compound using diethyl phosphite, diethanolamine, and formaldehyde as exemplary reactants is shown below.

[0038] [ka]

[0039] As shown, this reaction scheme utilizes an intermediate compound, and the resulting aminoalkylphosphonate may also contain a residual amount of this intermediate (e.g., about 20 weight percent or less, about 10 weight percent or less, about 5 weight percent or less, about 2 weight percent or less, about 1 weight percent or less, or no detectable amount). Water is a by-product of this reaction and is not shown in the above scheme. Other compounds of Formula II can be prepared in a similar manner using appropriate reactants.

[0040] In some approaches, the compounds of formula II herein may also include cyclic derivatives thereof, such as those of formula IIa below, where R' is a C1-C4 alkylene group.

[0041] [ka]

[0042] In some approaches, the second phosphorus compound is N,N-bis(2-hydroxylethyl)aminomethylphosphonic acid diethyl ester, and in other embodiments, comprises greater than about 50 weight percent N,N-bis(2-hydroxylethyl)aminomethylphosphonic acid diethyl ester, greater than about 20 weight percent of the cyclized product of N,N-bis(2-hydroxylethyl)aminomethylphosphonic acid diethyl ester, and less than about 20 weight percent of the diethyl(hydroxymethyl)phosphonate intermediate. In a further approach, the second phosphorus compound can comprise about 50 to about 60 weight percent N,N-bis(2-hydroxylethyl)aminomethylphosphonic acid diethyl ester, about 20 to about 30 weight percent of the cyclized N,N-bis(2-hydroxylethyl)aminomethylphosphonic acid diethyl ester, and less than about 20 weight percent of the diethyl(hydroxymethyl)phosphonate intermediate.

[0043] Third Phosphorus Compound The third phosphorus compound of the lubricating compositions and methods herein is a hydrocarbyl phosphonate monoester. In one approach, the third phosphorus compound comprises about 7 to about 10 weight percent phosphorus, providing the lubricating composition with about 5 ppm to about 40 ppm phosphorus (in another approach, about 8 ppm to about 30 ppm phosphorus, in a further approach, about 10 to about 25 ppm, or in yet another approach, about 12 ppm to about 20 ppm phosphorus). In an alternative approach, the lubricating compositions herein comprise about 0.01 weight percent to about 0.04 weight percent of the third phosphorus compound (in another approach, about 0.011 weight percent to about 0.03 weight percent, in a further approach, about 0.012 weight percent to about 0.02 weight percent, or in yet another approach, about 0.014 weight percent to about 0.02 weight percent of the third phosphorus compound).

[0044] In other approaches or embodiments, the third phosphorus compound provides phosphorus to the lubricating composition in an amount ranging from at least about 5 ppm, at least about 10 ppm, at least about 12 ppm, or at least about 15 ppm to about 40 ppm or less, about 35 ppm or less, about 25 ppm or less, or about 20 ppm or less (or any range between such endpoints). In yet other approaches, the treat rate of the third phosphorus compound in the lubricating oil composition may range from at least about 0.01 weight percent, at least about 0.011 weight percent, at least about 0.012 weight percent, at least about 0.014 weight percent, or at least about 0.015 weight percent to about 0.04 weight percent or less, about 0.035 weight percent or less, about 0.03 weight percent or less, about 0.025 weight percent or less, or about 0.02 weight percent or less (or any range between such endpoints).

[0045] In some approaches, the hydrocarbyl phosphonate monoester comprises one or more compounds having the structure of Formula III:

[0046] [ka] wherein the hydrocarbyl moiety R8 is a linear or branched C12 to C30 hydrocarbyl chain (alternatively, a C12 to C24 hydrocarbyl chain or a C12 to C20 hydrocarbyl chain), and the monoester moiety R9 is a linear or branched C1 to C4 alkyl group, preferably a methyl group, an ethyl group, a propyl group, or an isopropyl group.

[0047] Exemplary phosphonic acid compounds include methyl hydrocarbyl phosphonic acid, ethyl hydrocarbyl phosphonic acid, propyl hydrocarbyl phosphonic acid, butyl hydrocarbyl phosphonic acid, and isobutyl hydrocarbyl phosphonic acid, in each case preferably wherein the hydrocarbyl group is linear and saturated or contains one or more olefinic double bonds, each of which is preferably an internal double bond. Other suitable compounds include those in which the hydrocarbyl group attached to the phosphorus atom contains 16 to 20 carbon atoms or 18 to 20 carbon atoms. Particularly suitable phosphonic acid monoester compounds may be ethyl octadecyl phosphonic acid or methyl octadecyl phosphonic acid. Other examples of suitable phosphonic acid monoesters include, but are not limited to, compounds such as methyl triacontylphosphonic acid, methyl triacotenylphosphonic acid, methyl eicosylphosphonic acid, methyl hexadecylphosphonic acid, methyl hexadecenylphosphonic acid, methyl tetracontenylphosphonic acid, methyl hexacontylphosphonic acid, methyl dodecylphosphonic acid, methyl dodecenylphosphonic acid, ethyl triacontylphosphonic acid, ethyl triacotenylphosphonic acid, ethyl eicosylphosphonic acid, ethyl hexadecylphosphonic acid, ethyl hexadecenylphosphonic acid, ethyl tetracontenylphosphonic acid, ethyl hexacontylphosphonic acid, ethyl dodecylphosphonic acid, ethyl dodecenylphosphonic acid, and mixtures thereof.Preferably, the third phosphorus compound is methyl octadecylphosphonate.

[0048] Nitrogen-containing polyisobutylene succinimide The nitrogen-containing polyisobutylene succinimides of the lubricating compositions and methods herein comprise one or more succinimide compounds derived from polyisobutylene having a number average molecular weight of at least about 500, or in another approach, from about 500 to about 2,500 g / mol, as determined by gel permeation chromatography using polystyrene as a standard. The nitrogen-containing polyisobutylene succinimides herein contain from about 1.6 to about 2.1 weight percent nitrogen, providing the lubricating composition with from about 20 to about 105 ppm nitrogen (or, in another approach, from about 30 ppm to about 90 ppm nitrogen, or in a further approach, from about 40 to about 80 ppm, or in yet another approach, from about 50 ppm to about 75 ppm nitrogen). In an alternative approach, the lubricating compositions herein include from about 0.2 weight percent to about 0.5 weight percent of the nitrogen-containing polyisobutylene succinimide (in another approach, from about 0.25 weight percent to about 0.45 weight percent; in a further approach, from about 0.3 weight percent to about 0.4 weight percent; or in yet another approach, from about 0.32 weight percent to about 0.38 weight percent of the nitrogen-containing polyisobutylene succinimide).

[0049] In other approaches or embodiments, the nitrogen-containing polyisobutylene succinimide provides the lubricating composition with an amount of nitrogen ranging from at least about 30 ppm, at least about 40 ppm, or at least about 50 ppm to about 105 ppm or less, about 100 ppm or less, about 90 ppm or less, about 80 ppm or less, or 70 ppm or less (or any range between such endpoints). In yet other approaches, the treat rate of the nitrogen-containing polyisobutylene succinimide in the lubricating oil composition may range from at least about 0.2 weight percent, at least about 0.25 weight percent, at least about 0.3 weight percent, or at least about 0.35 weight percent to about 0.5 weight percent or less, about 0.45 weight percent or less, about 0.4 weight percent or less, or about 0.38 weight percent or less (or any range between such endpoints).

[0050] In one approach, the nitrogen-containing polyisobutylene succinimide is a nitrogen-substituted long chain alkenyl succinimide comprising one or more compounds having the structure of Formula IV:

[0051] [ka] In the formula, R 10 is a polyisobutylene having a number average molecular weight of about 500 to about 2,500 g / mol (or, by other approaches, about 500 to about 2,200 g / mol, or about 800 to about 2,000 g / mol, or about 800 to about 1,500 g / mol, or about 800 to about 1,000 g / mol, or any range between such stated endpoints) using gel permeation chromatography and polystyrene as the standard; 11 and R 12 are independently divalent C1-C6 alkylene, and R 13 and R 14 are each independently hydrogen, C1-C6 alkyl, or together with the N to which they are attached form a 5- or 6-membered ring optionally fused to one or more aromatic or non-aromatic rings, where n is an integer from 0 to 8.

[0052] In another approach, R of Formula IV 13 and R 14 together with the N to which they are attached to form a succinimide moiety of formula V to form the nitrogen-containing polyisobutylene succinimide bissuccinimide compounds herein:

[0053] [ka]

[0054] In yet another approach, R of compounds of formula IV and formula V 11 and R 12 Each of is a C2 alkylene and n is an integer of 2.

[0055] Such succinimide compounds and their preparation are known and are disclosed, for example, in U.S. Patent Nos. 7,897,696 and 4,234,435, which are incorporated herein by reference. The alkenyl or hydrocarbyl substituent of the succinimide can be prepared from polymerizable monomers containing from about 2 to about 16, or from about 2 to about 8, or from about 2 to about 6 carbon atoms. Succinimide compounds are typically imides formed from polyamines, typically poly(ethyleneamines).

[0056] In one approach, preferred amines for the nitrogen-containing succinimide can be selected from polyamines and hydroxylamines. Examples of polyamines that can be used include, but are not limited to, diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), and higher homologs such as pentaethylamine hexamine (PEHA). In some approaches, so-called polyamine bottoms products and / or heavy polyamines can be used, which are mixtures of polyalkylene-polyamines containing small amounts of lower polyamine oligomers such as TEPA and PEHA (pentaethylenehexamine), but primarily containing oligomers with six or more nitrogen atoms, two or more primary amines per molecule, and more extensive branching than conventional polyamine mixtures. In one approach, the polyamine bottoms products and / or heavy polyamines preferably contain polyamine oligomers containing seven or more nitrogen atoms per molecule and two or more primary amines per molecule.

[0057] In some embodiments, polyisobutylene (PIB) is a preferred reactant when included in the nitrogen-containing polyisobutylene succinimides herein and may have a terminal double bond content of 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 in the range of about 800 to about 5000 as determined by GPC is suitable for use in embodiments of the present disclosure. Conventional PIB typically has 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%.

[0058] HR-PIB having a number average molecular weight in the range of about 500 to about 2,500 g / mol, as determined by GPC using polystyrene as a standard, may be suitable, with about 500 to about 1,500 or about 800 to about 1,000 being preferred. Such HR-PIB is commercially available or can be synthesized by polymerization of isobutene 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 aforementioned thermal ene reaction, HR-PIB can result in higher conversion rates and less precipitate formation in the reaction due to its increased reactivity. A suitable method is described in U.S. Pat. No. 7,897,696. In one embodiment, the present disclosure further includes at least one nitrogen-containing polyisobutylene succinimide derived from polyisobutylene succinic anhydride ("PIBSA"). The PIBSA may have an average of about 1.0 to about 2.0 succinic acid moieties per polymer.

[0059] In some approaches, some of the nitrogen-containing polyisobutylene succinimides in the lubricating compositions and methods herein may not include any post-treatment, such as post-treatment with 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. In other embodiments, the nitrogen-containing polyisobutylene succinimides in the lubricating compositions herein may be post-treated by conventional methods by reaction with any of a variety of post-treating agents. If post-treated, suitable post-treating agents include 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. (See, e.g., U.S. Pat. Nos. 7,645,726, 7,214,649, 8,048,831, and 5,241,003, all of which are incorporated by reference in their entirety.)

[0060] When post-treated with boron, the boron compound used as the post-treating reagent can be selected from boron oxide, boron halide, boric acid, and esters of boric acid in an amount to provide from about 0.1 atomic percentage of boron per mole of nitrogen composition to about 20 atomic percentages of boron for each atomic percentage of nitrogen used. When treated, any nitrogen-containing polyisobutylene succinimide post-treated with boron can contain from about 0.05 weight percent to about 2.0 weight percent, or in other approaches, from about 0.05 weight percent to about 0.7 weight percent, of boron, based on the total weight of the boron-containing nitrogen-containing polyisobutylene succinimide.

[0061] In other approaches, if used, carboxylic acids can also be used as post-treating reagents and can be saturated or unsaturated mono-, di-, or poly-carboxylic acids. Examples of carboxylic acids include, but are not limited to, maleic acid, fumaric acid, succinic acid, and naphthalic diacids (e.g., 1,8-naphthalic diacid). Anhydrides can also be used as post-treating reagents and can be selected from the group consisting of mono-unsaturated anhydrides (e.g., maleic anhydride), alkyl- or alkylene-substituted cyclic anhydrides (e.g., succinic anhydride or glutamic anhydride), and aromatic carboxylic anhydrides (including naphthalic anhydrides, e.g., 1,8-naphthalic anhydride).

[0062] In one embodiment, if used, the process for post-treating the nitrogen-containing polyisobutylene succinimide herein comprises first forming a succinimide product as described above, and then further reacting the succinimide product with a post-treating agent, such as a boron compound, such as boric acid. In some cases, the nitrogen-containing polyisobutylene succinimide herein can be post-treated with more than one post-treating agent. For example, the nitrogen-containing polyisobutylene succinimide can be post-treated with a boron compound, such as boric acid, and also with an anhydride, such as maleic anhydride and / or 1,8-naphthalic anhydride.

[0063] base oil In one approach, suitable base oils for use in the lubricating compositions or gear fluids herein include mineral oils, synthetic oils, and re-refined oils, including all common mineral oil base stocks. Mineral oils can be naphthenic or paraffinic. Mineral oils can be refined by conventional methods using acids, alkalis, and other agents such as clay or aluminum chloride, or can be extracted oils produced by solvent extraction using solvents such as phenol, sulfur dioxide, furfural, or dichlorodiethyl ether. Mineral oils can be hydrotreated or hydrofinished, dewaxed by a cooling or catalytic dewaxing process, or hydrocracked (such as the Yubase® family of hydrocracked base oils from SK Innovation Co., Ltd. (Seoul, Korea)). Mineral oils can be produced from natural crude oil sources or composed of isomerized wax materials or residues from other refining processes.

[0064] The base oil, or base oils of lubricating viscosity used in the compositions herein, can be selected from any base oil suitable for driveline or gear oil applications. Examples include base oils in Groups I through V, as designated by the American Petroleum Institute (API) Base Oil Interchangeability Guidelines. These three base oil groups are as follows:

[0065] [Table 1]

[0066] Groups I, II, and III are mineral oil process stocks and may be preferred for the driveline or gear fluids of this application. It should be noted that although Group III base oils are derived from mineral oils, the rigorous processing these fluids undergo results in their physical properties being very similar to some true synthetic oils, such as PAOs. Therefore, oils derived from Group III base oils may be referred to in the industry as synthetic fluids. Suitable oils may be derived from hydrocracked, hydrogenated, hydrofinished, unrefined, refined, and rerefined oils, as well as mixtures thereof. In some approaches, the base oil may be a blend of Group I and Group II oils, which may be about 0% to about 100% Group I oil, about 0% to about 100% Group II oil, about 0% to about 100% Group III oil, or various blends of Group I and II, Group I and III, or Group II and III oil blends.

[0067] Unrefined oils are derived from natural, mineral, or synthetic sources with little or no further purification processing. Refined oils are similar to unrefined oils except that they have been treated with one or more purification steps, which may result in the improvement of one or more properties. Examples of suitable purification techniques include 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 called white oils. In some embodiments, the lubricating oil composition does not include edible oils or white oils.

[0068] Re-refined oils are also known as reclaimed or reprocessed oils. These oils are obtained similarly to refined oils using the same or similar processes. Often, these oils are additionally processed by techniques directed to the removal of spent additives and oil breakdown products.

[0069] Mineral oils may include oils obtained by drilling, 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, as well as mineral lubricating oils, such as liquid petroleum oils and solvent- or acid-treated mineral lubricating oils of the paraffinic, naphthenic, or mixed paraffinic-naphthenic types. Such oils may be partially or fully hydrogenated, if desired. Oils derived from coal or shale may also be useful.

[0070] The major amount of base oil included in the gear fluids herein may be selected from the group consisting of Group I, Group II, Group III, and combinations of two or more of the foregoing, where the major amount of base oil is other than the base oil resulting from the provision of additive components or viscosity index improvers in the composition. In another embodiment, the major amount of base oil included in the lubricating composition may be selected from the group consisting of Group I, Group II, and combinations of two or more of the foregoing, where the major amount of base oil is other than the base oil resulting from the provision of additive components or viscosity index improvers in the composition.

[0071] The base oil can also be any of the synthetic base oils. Useful synthetic lubricating oils can include hydrocarbon oils, such as polymerized, oligomerized, or interpolymerized olefins (e.g., polybutylene, polypropylene, propylene-isobutylene copolymers); 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, as well as their derivatives, analogs, and homologs, or mixtures thereof. Polyalphaolefins are typically hydrogenated materials.

[0072] Other synthetic lubricating oils include polyol esters, diesters, liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, and diethyl ester of decane phosphonic acid), or polymeric tetrahydrofurans. Synthetic oils may be produced by the Fischer-Tropsch reaction and are typically hydroisomerized Fischer-Tropsch hydrocarbons or waxes. In one embodiment, oils may be prepared by the Fischer-Tropsch gas-to-liquid synthesis procedure, as well as other gas-to-liquid oils.

[0073] The amount of base oil of lubricating viscosity in the compositions herein can be the remainder remaining after subtracting the total amount of performance additives from 100% by weight. For example, the oil of lubricating viscosity can be present in the final fluid in a "major amount," such as greater than about 50%, greater than about 60%, greater than about 70%, greater than about 80%, greater than about 85%, greater than about 90%, or greater than 95% by weight.

[0074] Suitable transmission or gear lubricant compositions herein may contain additive components in the ranges listed in Table 2 below.

[0075] [Table 2]

[0076] The percentages of each component above represent the weight percent of each component, based on the total weight of the final additive or lubricating oil composition. The remainder of the lubricating oil composition consists of one or more base oils or solvents. The additives used in formulating the compositions described herein can be blended into the base oil or solvent individually or in various subcombinations. However, it may be preferred to blend all of the components simultaneously using an additive concentrate (i.e., additives plus a diluent such as a hydrocarbon solvent).

[0077] In one approach or embodiment, the lubricating compositions herein contain from about 30 ppm to about 200 ppm total phosphorus from all three phosphorus compounds (in other approaches, a total of about 40 ppm to about 150 ppm total phosphorus, or about 50 to about 100 ppm total phosphorus, or about 50 ppm to about 80 ppm total phosphorus). In a further approach, the lubricating compositions herein contain from about 7 ppm to about 75 ppm phosphorus provided by a first phosphorus compound, from about 10 ppm to about 65 ppm phosphorus provided by a second phosphorus compound, and from about 5 ppm to about 40 ppm phosphorus provided by a third phosphorus compound. In an alternative approach, from about 30 to about 45 weight percent of the total phosphorus is provided by the first phosphorus compound, from about 35 to about 40 weight percent of the total phosphorus is provided by the second phosphorus compound, and from about 20 to about 30 weight percent of the total phosphorus is provided by the third phosphorus compound. In yet another optional approach, the lubricating compositions herein contain greater than 50 weight percent phosphorus, combining the phosphorus provided by the second and third phosphorus compounds with the remaining phosphorus provided by the first phosphorus compound. However, as shown by the following examples, the presence of three phosphorus compounds is not sufficient to achieve acceptable wear, extreme pressure, friction, and copper corrosion performance. Only when further comprising the specific nitrogen-containing polyisobutylene succinimide disclosed herein does the lubricating composition achieve passing performance in all four performance tests. To this end, the lubricating compositions herein also contain, in some embodiments, from about 30 to about 105 ppm nitrogen from the nitrogen-containing polyisobutylene succinimide embodiment, and in other embodiments, have a weight ratio of phosphorus from the three phosphorus compounds to nitrogen from the nitrogen-containing polyisobutylene succinimide of from about 1:1 to about 2.2:1.

[0078] In any embodiment or approach herein, such combination of three phosphorus compounds and nitrogen-containing polyisobutylene succinimide provides a lubricating composition that achieves an average wear scar of about 0.5 mm or less (preferably about 0.48 mm or less, more preferably about 0.45 mm or less, or about 0.42 mm or less) according to ASTM D4172 (40 kgf, 75°C, 1800 rpm, 60 minutes), while simultaneously achieving a Load Wear Index (LWI) of 46 or greater (preferably 48 or greater, more preferably 50 or greater) according to ASTM D2783, while simultaneously achieving a coefficient of friction of about 0.125 or greater (preferably about 0.128 or greater) when tested in a High Frequency Reciprocating Rig (HFRR) as further described herein (when tested at 400 g load, 20 Hz, 80°C for 3 minutes), and while simultaneously achieving a copper corrosion rating of 2b or greater (e.g., 2b, 2a, 1b, or 1a) when tested at 100°C for 3 hours according to ASTM D130. The lubricating compositions herein achieve such performance even at low viscosities, having a KV100 of about 5 to about 60 cSt (preferably about 5 to about 66, about 8 to about 55 cSt, about 8 to about 40 cSt, about 8 to about 30 cSt, about 8 to about 20 cSt, or about 8 to about 15 cSt), as measured at 100°C using ASTM D445.

[0079] As used herein, the coefficient of friction was measured at 80°C using a high-frequency reciprocating rig (HFRR), such as that from PCS Instruments, using the test conditions generally described in SAE paper 982503 (except for the measurement temperature noted above). This test measures the coefficient of friction of a sample using an SAE 52100 metal ball and an SAE 52100 metal disk. The ball was oscillated across the disk at a frequency of 20 Hz over a 1 mm path while applying a 400 gram load. Each sample was tested in the HFRR for 3 minutes, and the data from the last 2 minutes was averaged to determine the coefficient of friction. As shown in the examples, higher coefficients of friction are preferred for the lubricants herein, with coefficients of friction of about 0.128 or greater (preferably about 0.128 to about 0.148 or about 0.128 to about 0.135) being preferred.

[0080] The lubricating compositions disclosed herein can be used to lubricate machine parts such as gears, transmissions, or gearbox components. The lubricating fluids disclosed herein can be used in gear applications such as industrial gear applications, automotive gear applications, axles, and fixed gearboxes. 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 lubricating compositions disclosed herein are also suitable for automatic or manual transmissions, including step automatic transmissions, continuously variable transmissions, semi-automatic transmissions, automated manual transmissions, toroidal transmissions, and dual-clutch transmissions.

[0081] Optional Additives In another approach, lubricants containing such additives as described above may also contain one or more optional ingredients, as long as such ingredients and their amounts do not affect the performance characteristics as described in the preceding paragraphs. These optional ingredients are described in the following paragraphs.

[0082] Other phosphorus-containing compounds The lubricant compositions herein may contain the mentioned phosphorus compounds and one or more other phosphorus-containing compounds that may impart antiwear benefits to the fluid, so long as the above amounts are met. The one or more other phosphorus-containing compounds may be present in the lubricant composition in an amount ranging from about 0 wt. % to about 15 wt. %, or from about 0.01 wt. % to about 10 wt. %, or from about 0.05 wt. % to about 5 wt. %, or from about 0.1 wt. % to about 3 wt. % of the lubricant composition. The optional other phosphorus-containing compounds may provide the lubricant composition with up to 5000 ppm phosphorus, or from about 50 to about 5000 ppm phosphorus, or from about 300 to about 1500 ppm phosphorus, or up to 600 ppm phosphorus, or up to 900 ppm phosphorus.

[0083] The one or more other phosphorus-containing compounds may comprise ashless phosphorus-containing compounds.Suitable examples of phosphorus-containing compounds include, but are not limited to, thiophosphates, dithiophosphates, phosphates, phosphoric acid esters, phosphate esters, phosphites, phosphonates, phosphorus-containing carboxylic acid esters, ethers, or amide salts thereof, and mixtures thereof.Phosphorus-containing antiwear agents are more fully described in EP 0612839.

[0084] It should be noted that the terms phosphonate and phosphite are often used interchangeably in the lubricant industry. For example, dibutyl hydrogen phosphonate is sometimes referred to as dibutyl hydrogen phosphite. It is within the scope of the present invention that the lubricant compositions of the present invention include phosphorus-containing compounds that may be referred to as either phosphites or phosphonates.

[0085] In any of the above phosphorus-containing compounds, the compound can have from about 5 weight percent to about 20 weight percent phosphorus, or from about 5 weight percent to about 15 weight percent phosphorus, or from about 8 weight percent to about 16 weight percent phosphorus, or from about 6 weight percent to about 9 weight percent phosphorus.

[0086] Another type of phosphorus-containing compound is an ashless (metal-free) phosphorus-containing compound. In some embodiments, the ashless phosphorus-containing compound may be a dialkyldithiophosphate ester, amyl acid phosphate, diamyl acid phosphate, dibutyl hydrogen phosphate, dimethyl octadecyl phosphate, salts thereof, and mixtures thereof. The ashless phosphorus-containing compound may have the following formula:

[0087] [ka] 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-C3 branched or straight chain alkyl chain, and R" is a C1-C18 hydrocarbyl chain. 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.

[0088] In some embodiments, the lubricant composition comprises a phosphorus-containing compound of Formula XIV, where R1 is S, R2 is —OR″, R3 is SR′″COOH, R4 is —OR″, R′″ is a C3 branched alkyl chain, and R″ is C4, and the phosphorus-containing compound is present in an amount providing 80 to 900 ppm of phosphorus to the lubricant composition.

[0089] In another embodiment, the lubricant composition comprises a phosphorus-containing compound of Formula XIV, where R1 is O, R2 is —OH, R3 is —OR″ or —OH, R4 is —OR″, and R″ is C5, and the phosphorus-containing compound is present in an amount providing 80 to 1500 ppm of phosphorus to the lubricant composition.

[0090] In yet another embodiment, the lubricant composition comprises phosphorus-containing compounds of Formula XIV, where R1 is O, R2 is OR″, R3 is H, R4 is —OR″, and R″ is C4, and the one or more phosphorus-containing compounds are present in an amount providing 80 to 1550 ppm of phosphorus to the lubricant composition.

[0091] In another embodiment, the lubricant composition comprises a phosphorus-containing compound of Formula XIV, where R1 is O, R2 is —R″, R3 is —OCH3 or —OH, R4 is —OCH3, and R″ is C18, and the one or more phosphorus-containing compounds are present in an amount providing 80 to 850 ppm of phosphorus to the lubricant composition.

[0092] In some embodiments, the phosphorus-containing compound has the structure shown in Formula XIV and provides from about 80 ppm to about 4500 ppm of phosphorus to the lubricant composition. In other embodiments, the phosphorus-containing compound is present in an amount to provide from about 150 ppm to about 1500 ppm of phosphorus, or from about 300 ppm to about 900 ppm of phosphorus, or from about 800 ppm to 1600 ppm of phosphorus, or from about 900 ppm to about 1800 ppm of phosphorus to the lubricant composition.

[0093] Other anti-wear agents The lubricant composition may also contain other antiwear agents that are phosphorus-free compounds. Examples of such antiwear agents include boric acid esters, boric acid epoxides, thiocarbamate compounds (including 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 hydroxylcarboxylic acids, such as tartrate derivatives, tartramide, tartrimide, citrate, and mixtures thereof. A suitable thiocarbamate compound is molybdenum dithiocarbamate. A suitable tartrate derivative or tartrimide may contain an alkyl-ester group, where the total number of carbon atoms on the alkyl group may be at least 8. The tartrate derivatives or tartrimides may contain alkyl-ester groups, where the total number of carbon atoms on the alkyl group may be at least 8. The antiwear agent may, in one embodiment, comprise a citrate salt. The additional antiwear agent may be present in a range including from about 0 wt. % to about 15 wt. %, or from about 0.01 wt. % to about 10 wt. %, or from about 0.05 wt. % to about 5 wt. %, or from about 0.1 wt. % to about 3 wt. % of the lubricating oil composition.

[0094] Other extreme pressure agents The lubricant compositions of this disclosure may also contain other extreme pressure agents. The extreme pressure agents may contain sulfur, and may contain at least 12 wt. % sulfur. In some embodiments, the extreme pressure agents added to the lubricating oil are sufficient to provide the lubricant composition with at least 350 ppm sulfur, 500 ppm sulfur, 760 ppm sulfur, about 350 ppm to about 2,000 ppm sulfur, about 2,000 ppm to about 30,000 ppm sulfur, about 2,000 ppm to about 4,800 ppm sulfur, or about 4,000 ppm to about 25,000 ppm sulfur.

[0095] A wide variety of 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 (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 Patent No. 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). Other suitable examples include organosulfur compounds selected from sulfurized olefins, sulfur-containing aminoheterocyclic compounds, 5-dimercapto-1,3,4-thiadiazoles, polysulfides having a majority of S3 and S4 sulfides, sulfurized fatty acids, sulfurized branched olefins, organic polysulfides, and mixtures thereof.

[0096] In some embodiments, the extreme pressure agent is present in the lubricating composition in an amount of 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 from about 0.05 wt % to about 1.5 wt %, based on the total weight of the lubricating composition. In other embodiments, the extreme pressure agent is present in an amount of from about 0.1 wt % to about 3.0 wt %, based on the total weight of the lubricating composition. In other embodiments, the extreme pressure agent is present in an amount of from about 0.6 wt % to about 1.3 wt %, based on the total weight of the lubricating composition.

[0097] One suitable class of extreme pressure agents are polysulfides composed of one or more compounds represented by the formula: Ra-Sx-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; x may range from 2 to 8, typically from 2 to 5, and particularly 3. In some approaches, x is an integer from 3 to 5, with about 30 to about 60 percent of the x's being the integer 3 or 4. The hydrocarbyl groups may be of a wide variety of 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 composed primarily or entirely of tri-, tetra-, and pentasulfides) may be used. Examples of other useful dihydrocarbyl polysulfides include diamyl polysulfide, dinonyl polysulfide, didodecyl polysulfide, and dibenzyl polysulfide.

[0098] Another suitable class of extreme pressure agents is sulfurized isobutene, which is prepared 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% by weight, desirably about 30 to about 50% by weight. A wide 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. 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.

[0099] Methods for preparing sulfurized olefins, including those disclosed in the aforementioned patents, generally involve the formation of a material typically referred to as an "adduct," by 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 viscosity, sulfur content, halogen content, copper corrosion test weight loss, etc. U.S. Pat. No. 4,966,720 relates to sulfurized olefins useful as extreme pressure additives in lubricating oils and a two-step reaction for their preparation.

[0100] antioxidants 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-naphthylamines, alkylated phenyl-alpha-naphthylamines, 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.

[0101] The hindered phenol antioxidant may contain a secondary butyl group and / or a tertiary butyl group as a steric hindering group. The phenol group may be further substituted with a hydrocarbyl group and / or a bridging group connecting 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, 4-butyl-2,6-di-tert-butylphenol, or 4-dodecyl-2,6-di-tert-butylphenol. In one embodiment, the hindered phenol antioxidant can be an ester and can include, for example, Irganox® L-135 available from BASF or an addition product derived from 2,6-di-tert-butylphenol and an alkyl acrylate, where the alkyl group can 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 can be an ester and can include Ethanox® 4716 available from Albemarle Corporation.

[0102] Useful antioxidants may include diarylamines and phenols. In one embodiment, the lubricating oil composition may contain a mixture of diarylamines and phenols, with each antioxidant present in an amount sufficient to provide up to about 5 wt. % antioxidant, based on the weight of the lubricant composition. In one embodiment, the antioxidant may be a mixture of about 0.3 to about 1.5 wt. % diarylamines and about 0.4 to about 2.5 wt. % phenols, based on the weight of the lubricant composition.

[0103] Examples of suitable olefins that can be sulfurized to form sulfurized olefins include propylene, butylene, isobutylene, polyisobutylene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene, octadecene, nonadecene, eicosene, or mixtures thereof. In one embodiment, hexadecene, heptadecene, octadecene, nonadecene, eicosene, or mixtures thereof, as well as their dimers, trimers, and tetramers, are particularly useful olefins. Alternatively, the olefin can be a Diels-Alder adduct of a diene, such as 1,3-butadiene, and an unsaturated ester, such as butyl acrylate.

[0104] Another class of sulfurized olefins includes sulfurized fatty acids and their esters. The fatty acids are often derived from vegetable or animal oils and typically contain from about 4 to about 22 carbon atoms. Examples of suitable fatty acids and their esters include triglycerides, oleic acid, linoleic acid, palmitoleic acid, or mixtures thereof. Often, the fatty acids are derived from lard oil, tall oil, peanut oil, soybean oil, cottonseed oil, sunflower seed oil, or mixtures thereof. The fatty acids and / or esters may be mixed with an olefin, such as an α-olefin.

[0105] The one or more antioxidants may be present in the range of from about 0% to about 20%, or from about 0.1% to about 10%, or from about 1% to about 5% by weight of the lubricating oil composition.

[0106] Dispersants Dispersants contained in the lubricant composition may include, but are not limited to, an oil-soluble polymeric hydrocarbon backbone having functional groups capable of associating with particles to be dispersed. Typically, dispersants contain amine, alcohol, amide, or ester polar moieties attached to the polymer backbone, often through a bridging group. Dispersants may be selected from Mannich dispersants such as those described in U.S. Pat. Nos. 3,634,515, 3,697,574, and 3,736,357; ashless succinimide dispersants such as those described in U.S. Pat. Nos. 4,234,435 and 4,636,322; amine dispersants such as those described in U.S. Pat. Nos. 3,219,666, 3,565,804, and 5,633,326; Koch dispersants such as those described in U.S. Pat. Nos. 5,936,041, 5,643,859, and 5,627,259; and polyalkylene succinimide dispersants such as those described in U.S. Pat. Nos. 5,851,965, 5,853,434, and 5,792,729.

[0107] In some embodiments, the additional dispersant may be derived from polyalphaolefin (PAO), succinic anhydride, olefin maleic anhydride copolymer. As an example, the additional dispersant may be described as poly-PIBSA. In another embodiment, the additional dispersant may be derived from an anhydride grafted onto an ethylene-propylene copolymer. Another additional dispersant may be a high molecular weight ester or half-ester amide.

[0108] When present, the additional dispersant can be used in an amount sufficient to provide up to about 10% by weight, based on the final weight of the lubricating oil composition. Alternative amounts of dispersant that can be used can be from about 0.1% to about 10% by weight, or from about 0.1% to about 10% by weight, or from about 3% to about 8% by weight, or from about 1% to about 6% by weight, based on the final weight of the lubricating oil composition.

[0109] thickener The lubricant compositions herein may also optionally contain one or more thickeners. Suitable additives 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 thickener may include a star polymer; suitable examples are described in U.S. Patent Application Publication No. 20120101017(A1), incorporated herein by reference.

[0110] The total amount of thickener can be from about 0% to about 20%, from about 0.1% to about 15%, from about 0.1% to about 12%, or from about 0.5% to about 10%, from about 3% to about 20%, from about 3% to about 15%, from about 5% to about 15%, or from about 5% to about 10% by weight of the lubricating oil composition.

[0111] In some embodiments, the thickening agent 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 thickening agent 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 thickening agent 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.

[0112] 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 comprising a major amount of a base oil and a minor amount of an additive composition, as discussed herein. Such gear fluids are intended for use in extreme pressure conditions, such as in transmissions and gear-driven components having metal-to-metal contact, in transmissions and / or limited-slip differentials.

[0113] As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl group" is used in its ordinary sense, as is well known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly attached to the remainder of the molecule and having a predominantly hydrocarbon character. Each hydrocarbyl group is independently selected from hydrocarbon substituents, where the substituted hydrocarbon substituents contain one or more of halo, hydroxyl, alkoxy, mercapto, nitro, nitroso, amino, pyridyl, furyl, imidazolyl, oxygen, and nitrogen, and no more than two non-hydrocarbon substituents are present for every 10 carbon atoms in the hydrocarbyl group.

[0114] As used herein, the term "percent by weight" or "% by weight (wt%)" means the percentage that the listed component represents relative to the weight of the entire composition, unless otherwise specified. All percentages herein are by weight unless otherwise specified.

[0115] The terms "soluble," "oil-soluble," or "dispersible" as used herein may, but do not necessarily, indicate that a compound or additive is soluble, dissolvable, miscible, or suspendable in oil in all proportions. However, the terms do mean that they are soluble, suspendable, dissolvable, or stably dispersible in oil to a sufficient degree to exert their intended effect in the environment in which the oil is used, for example. Furthermore, if desired, the incorporation of other additives may also allow for the incorporation of higher levels of the specific additive.

[0116] As used herein, the term "alkyl" refers to straight, branched, cyclic, and / or substituted saturated chain moieties of about 1 to about 200 carbon atoms. As used herein, the term "alkenyl" refers to straight, branched, cyclic, and / or substituted saturated chain moieties of about 3 to about 30 carbon atoms. As used herein, the term "aryl" refers to mono- and polycyclic aromatic compounds that may contain alkyl, alkenyl, alkylaryl, amino, hydroxyl, alkoxy, halo substituents, and / or heteroatoms such as, but not limited to, nitrogen and oxygen.

[0117] As used herein, molecular weight is measured by gel permeation chromatography (GPC) using commercially available polystyrene standards (having Mn of about 180 to about 18,000 as calibration standards). The molecular weight (Mn) of any embodiment herein may be determined using a gel permeation chromatography (GPC) instrument from Waters or similar instrumentation, and data processed with Waters Empower Software or similar software. The GPC instrument may be equipped with a Waters Separation Module and a Waters Refractive Index Detector (or similar optional instrumentation). GPC operating conditions may include a guard column, four Agilent PLgel columns (300 x 7.5 mm long, 5 μm particle size, and pore sizes ranging from 100 to 10,000 Å), and a column temperature of about 40°C. Unstabilized HPLC-grade tetrahydrofuran (THF) may be used as the solvent at a flow rate of 1.0 mL / min. GPC instruments can be calibrated with commercially available polystyrene (PS) standards with narrow molecular weight distributions ranging from 500 to 380,000 g / mol. Calibration curves can be extrapolated for samples with masses less than 500 g / mol. Samples and PS standards can be dissolved in THF, prepared at concentrations of 0.1 to 0.5 weight percent, and used without filtration. GPC measurements are also described in U.S. Pat. No. 5,266,223, which is incorporated herein by reference. The GPC method additionally provides molecular weight distribution information. See, for example, W.W. Yau, J.J. Kirkland, and D.B. Ly, "Modern Size Exclusion Liquid Chromatography," John Wiley and Sons, New York, 1979, which is incorporated herein by reference.

[0118] Throughout this disclosure, the terms "comprises," "includes," "contains," and the like are considered open-ended and should be understood to include any element, step, or ingredient not expressly recited. The phrase "consisting essentially of" means including any explicitly recited element, step, or ingredient, as well as any additional elements, steps, or ingredients that do not materially affect the basic and novel aspects of the invention. This disclosure also contemplates that any composition described using the terms "comprises," "includes," or "contains" should also be interpreted as including a disclosure of the same composition "consisting essentially of" or "consisting of" the specifically recited ingredient. [Example]

[0119] 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 are presented for illustrative purposes only and are not intended to limit the scope of the inventions disclosed herein. As used herein, references to any ASTM or other standardized test in the examples, descriptions, and / or claims refer to the version of the test publicly available at the time of this application, unless otherwise clear from the context of its use.

[0120] Example 1 Lubricating compositions containing the following phosphorus and nitrogen compounds were evaluated for wear, extreme pressure, coefficient of friction, and copper corrosion. Phosphorus Compound A: 3-[[bis(2-methylpropoxy)phosphinothioi]thio]-2-methyl-propionic acid (containing about 8 to about 10 phosphorus atoms), having the following structure:

[0121] [ka] Phosphorus compound B: N,N-bis(2-hydroxyethyl)aminomethylphosphonic acid diethyl ester (containing about 11 to about 13% by weight of phosphorus) having the following structure:

[0122] [ka] Phosphorus compound C: methyl octadecylphosphonate (containing about 7 to about 10% by weight of phosphorus), having the following structure:

[0123] [ka] Nitrogen compound D: 1,1'-((ethane-1,2-diylbis(azanediyl))bis(ethane-2,1-diyl))bis(pyrrolidine-2,5-dione), in which each succinimide is substituted with polyisobutylene (containing about 1.6 to about 2.1 wt. % nitrogen) having a number average molecular weight of about 950, and having the following structure:

[0124] [ka]

[0125] Compounds A, B, C, and / or D were incorporated into lubricating compositions in the weight percent amounts shown in Table 3 below. Each lubricant also contained the same additive package of detergents, dispersants, corrosion inhibitors, antioxidants, and antifoam agents. Each lubricant also contained an API Group I base oil to achieve a KV100 of about 13 to about 15 cSt.

[0126] [Table 3]

[0127] As used herein, the 4-ball wear test was performed according to ASTM D4172 using a 40 kg load, 75°C, and 1800 rpm for 60 minutes. Reported results are the average wear scar diameter (mm). The 4-ball LWI extreme pressure test was performed according to ASTM D2783, and the Load Wear Index (LWI) was reported. High-Frequency Reciprocating Rig (HFRR) friction coefficient was performed at 400 g load, 20 Hz, and 80°C for 3 minutes, and the friction coefficient was reported (as described in SAE paper 982503, incorporated herein by reference, except using 80°C). Copper corrosion was determined according to ASTM D130, testing at 100°C for 3 hours, and the reported rating was determined by a comparator chart.

[0128] As shown in Table 3 above, comparative samples B through I, which contained only one, two, or three of the above compounds, failed one or more of the performance tests (indicated by underlining). Only when all four of compounds A, B, C, and D were included in the lubricant was the fluid able to pass all of the performance tests.

[0129] In the case of fluids containing nitrogen compounds but no phosphorus compounds (e.g., Comparative Example B), the fluid performed poorly in terms of wear scar. In the case of fluids containing nitrogen compounds but only one of the phosphorus compounds (e.g., Comparative Examples C, D, or E), the fluid performed poorly in terms of wear scar, extreme pressure, and / or friction. In the case of fluids containing nitrogen compounds with only two phosphorus compounds (e.g., Comparative Examples F, G, or H), the fluid failed wear, extreme pressure, and / or friction. In the case of fluids containing all three phosphorus compounds but no nitrogen compounds (e.g., Comparative Example I), the fluid failed extreme pressure and copper corrosion. The inventive sample containing all three phosphorus and nitrogen compounds was the only fluid capable of passing each of the four performance tests.

[0130] 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, a reference to an "antioxidant" includes two or more different antioxidants. As used herein, the term "comprises" and grammatical variations thereof are intended to be open-ended, such that the recitation of items in a list does not exclude other similar items that may be substituted for or added to the listed items.

[0131] For purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing quantities, percentages, or proportions, and other numerical values ​​used in the specification and claims should be understood in all instances to be modified by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and 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 at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0132] It is understood that each component, compound, substituent, or parameter disclosed herein should be construed as disclosed for use alone or in combination with one or more of any and all other components, compounds, substituents, or parameters disclosed herein.

[0133] It is further understood that each range disclosed herein should 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 should be construed as an explicit disclosure of not only the values ​​1, 2, 3, and 4, but also any range of such values.

[0134] It should be further understood that each lower limit of each range disclosed herein should be interpreted 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. Thus, the present disclosure should be interpreted as a disclosure of all ranges derived by combining each lower limit of each range with each upper limit of each range, or each specific value within each range, or by combining each upper limit of each range with each specific value within each range. In other words, it should also be understood that any range between the endpoints within a broad range is also contemplated herein. Thus, a range of 1 to 4 also means ranges of 1 to 3, 1 to 2, 2 to 4, 2 to 3, etc.

[0135] Furthermore, a specific amount / value of a component, compound, substituent, or parameter disclosed in the details or examples should be construed as disclosing either a lower or upper limit of a range and, therefore, can be combined with any other lower or upper limit or specific amount / value in a range for the same component, compound, substituent, or parameter disclosed elsewhere in this application to form a range for that component, compound, substituent, or parameter.

[0136] While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents may occur that are not presently anticipated or presently unforeseeable to Applicants or others skilled in the art. Accordingly, the appended claims as filed, and the appended claims as they may be amended, are intended to cover all such alternatives, modifications, variations, improvements, and substantial equivalents.

Claims

1. 1. A lubricating composition comprising: (i) a base oil of lubricating viscosity; and (ii) an amount of phosphorus provided by three phosphorus compounds, the three phosphorus compounds being: (iia) a first phosphorus compound comprising an ashless dialkyldithiophosphate of Formula I, or a salt thereof: 【Chemical 1】 In the formula, R １ and R ２ are independently a C3 to C8 linear or branched alkyl group, and R ３ is a hydrogen or methyl group, providing about 5 to about 75 ppm of phosphorus to the lubricating composition; (iib) a second phosphorus compound comprising an aminoalkylphosphonate or a cyclic derivative thereof of formula II: 【Chemistry 2】 In the formula, R ４ and R ５ are independently a C1 to C4 linear or branched alkyl group, and R ６ and R ７ a second phosphorus compound, which is independently a C1-C4 hydroxyalkyl group, providing about 10 to about 65 ppm of phosphorus to the lubricating composition; and (iic) a third phosphorus compound comprising a hydrocarbyl phosphonate monoester of formula III: 【Chemistry 3】 In the formula, R ８ is C １２ ~C ３０ is a hydrocarbyl group, R ９ a third phosphorus compound that is a methyl group, an ethyl group, a propyl group, or an isopropyl group, providing about 5 to about 40 ppm of phosphorus to the lubricating composition; an amount of phosphorus, wherein the first phosphorus compound, the second phosphorus compound, and the third phosphorus compound collectively provide about 30 ppm to about 200 ppm of phosphorus to the lubricating composition; and (iii) an amount of nitrogen provided by a nitrogen-containing polyisobutylene succinimide having a number average molecular weight of the polyisobutylene substituent of about 500 to about 2500 g / mol as determined by gel permeation chromatography using polystyrene as a standard, and providing about 30 ppm to about 105 ppm weight percent nitrogen to the lubricating composition.

2. 2. The lubricating composition of claim 1, wherein the first phosphorus compound is 3-[[bis(2-methylpropoxy)phosphinothioyl]thio]-2-methyl-propanoic acid, and / or the second phosphorus compound is N,N-bis(2-hydroxylethyl)aminomethylphosphonic acid diethyl ester, and / or the third phosphorus compound is methyl octadecylphosphonate.

3. 10. The lubricating composition of claim 1, wherein the lubricating composition exhibits an average wear scar of about 0.5 mm or less according to ASTM D4172 (40 kgf), a load wear index of about 46 or greater according to ASTM D2783, a coefficient of friction of greater than about 0.128 when measured using a high frequency reciprocating rig (HFRR) using a 400 gram load, 20 Hz, and 80°C for 3 minutes, and a copper corrosion tarnish rating of 2b or better when evaluated at 100°C for 3 hours according to ASTM D130.

4. 2. The lubricating composition of claim 1, wherein about 30 to about 45 weight percent of total phosphorus is provided by the first phosphorus compound, about 35 to about 40 weight percent of total phosphorus is provided by the second phosphorus compound, and about 20 to about 30 weight percent of total phosphorus is provided by the third phosphorus compound.

5. 10. The lubricating composition of claim 1, wherein greater than 50 weight percent of the phosphorus is provided by the second phosphorus compound combined with the third phosphorus compound.

6. 2. The lubricating composition of claim 1, wherein the lubricating composition has a ratio of phosphorus from the three phosphorus compounds to nitrogen from the nitrogen-substituted long chain alkenyl succinimide of about 1:1 to about 2.2:

1.

7. The nitrogen-substituted long chain alkenyl succinimides include compounds having the structure of Formula IV: 【Chemistry 4】 During the ceremony, R １０ is a polyisobutylene having a number average molecular weight of about 500 to about 1200 g / mol; R １１ and R １２ are independently divalent C １ ~C ６ is alkylene, R １３ and R １４ each independently represents hydrogen, C １ ~C ６ alkyl groups or, together with the N to which they are attached, form a 5- or 6-membered ring, optionally fused with one or more aromatic or non-aromatic rings; 2. The lubricating composition of claim 1, wherein n is an integer from 0 to 8.

8. R １３ and R １４ together with the N to which they are attached to form a succinimide moiety of formula V: 【Chemistry 5】 The lubricant composition of claim 7.

9. 1. A method of lubricating a transmission, gearbox, and / or clutch, the method comprising: lubricating a transmission, gearbox, and / or clutch with a lubricating composition; The lubricating composition comprises: (i) a base oil of lubricating viscosity; and (ii) an amount of phosphorus provided by three phosphorus compounds, the three phosphorus compounds being: (iia) a first phosphorus compound comprising an ashless dialkyldithiophosphate of Formula I, or a salt thereof: 【Chemistry 6】 In the formula, R １ and R ２ are independently a C3 to C8 linear or branched alkyl group, and R ３ is a hydrogen or methyl group, providing about 5 to about 75 ppm of phosphorus to the lubricating composition; (iib) a second phosphorus compound comprising an aminoalkylphosphonate or a cyclic derivative thereof of formula II: 【Chemistry 7】 In the formula, R ４ and R ５ are independently a C1 to C4 linear or branched alkyl group, and R ６ and R ７ a second phosphorus compound, which is independently a C1-C4 hydroxyalkyl group, providing about 10 to about 65 ppm of phosphorus to the lubricating composition; and (iic) a third phosphorus compound comprising a hydrocarbyl phosphonate monoester of formula III: 【Chemistry 8】 In the formula, R ８ is C １２ ~C ３０ is a hydrocarbyl group, R ９ a third phosphorus compound which is a methyl group, an ethyl group, a propyl group, or an isopropyl group, providing about 5 to about 40 ppm of phosphorus to the lubricating composition; an amount of phosphorus, wherein the first phosphorus compound, the second phosphorus compound, and the third phosphorus compound collectively provide about 30 ppm to about 200 ppm of phosphorus to the lubricating composition; and (iii) an amount of nitrogen provided by a nitrogen-containing polyisobutylene succinimide, the polyisobutylene succinimide having a number average molecular weight of the polyisobutylene substituent of from about 500 to about 2,500 g / mol as determined by gel permeation chromatography using polystyrene as a standard, and providing from about 30 ppm to about 105 ppm weight percent nitrogen to the lubricating composition.

10. 10. The method of claim 9, wherein the first phosphorus compound is 3-[[bis(2-methylpropoxy)phosphinothioyl]thio]-2-methyl-propanoic acid, and / or the second phosphorus compound is N,N-bis(2-hydroxylethyl)aminomethylphosphonic acid diethyl ester, and / or the third phosphorus compound is methyl octadecylphosphonate.

11. 10. The method of claim 9, wherein the lubricating composition exhibits an average wear scar of about 0.5 mm or less according to ASTM D4172 (40 kgf), a load wear index of about 46 or greater according to ASTM D2783, a coefficient of friction of greater than about 0.128 when measured using a high frequency reciprocating rig (HFRR) using a 400 gram load, 20 Hz, and 80°C for 3 minutes, and a copper corrosion tarnish rating of 2b or better when evaluated at 100°C for 3 hours according to ASTM D130.

12. 10. The method of claim 9, wherein about 30 to about 45 weight percent of the total phosphorus is provided by the first phosphorus compound, about 35 to about 40 weight percent of the total phosphorus is provided by the second phosphorus compound, and about 20 to about 30 weight percent of the total phosphorus is provided by the third phosphorus compound.

13. 10. The method of claim 9, wherein greater than 50 weight percent of the phosphorus is provided by the second phosphorus compound combined with the third phosphorus compound.

14. 10. The method of claim 9, wherein the lubricating composition has a ratio of phosphorus from the three phosphorus compounds to nitrogen from the nitrogen-substituted long chain alkenyl succinimide of about 1:1 to about 2.2:

1.

15. The nitrogen-substituted long chain alkenyl succinimides include compounds having the structure of Formula IV: 【Chemistry 9】 During the ceremony, R １０ is a polyisobutylene having a number average molecular weight of about 500 to about 1200 g / mol; R １１ and R １２ are independently divalent C １ ~C ６ is alkylene, R １３ and R １４ each independently represents hydrogen, C １ ~C ６ alkyl groups or, together with the N to which they are attached, form a 5- or 6-membered ring, optionally fused with one or more aromatic or non-aromatic rings; n is an integer from 0 to 8; Preferably, R １３ and R １４ together with the N to which they are attached to form a succinimide moiety of formula V: 【Chemistry 10】 10. The method of claim 9.

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