Friction modifiers for automatic transmission oils

Abstract

A lubricating oil composition is disclosed. The composition comprises a major amount of an oil of lubricating viscosity; one or more ashless dispersants; at least one phosphorus-containing antiwear additive, wherein the at least one phosphorus-containing antiwear additive is a phosphorus-containing acid, a phosphate ester, a phosphite ester, a thiophosphate ester, or an amine salt thereof; at least one friction modifier, wherein the at least one friction modifier is a diol, an ethoxylated amine, a fatty acid ester, or an alcohol; a nitrogen-containing friction modifier having the structure wherein R1 and R2 are independently a branched C10-C25 hydrocarbyl group.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to lubricating oil compositions for automatic transmissions. BACKGROUND

[0002] There has been an industry push to change from cellulose rich wet clutch papers to aromatic polyamide rich wet clutch papers for automotive automatic transmissions. In particular, wet clutches can transmit power by means of mechanical and fluid couplings through paper wet friction plates immersed in lubricant. Paper wet friction plates typically employ composites with reinforcing fibers such as cellulose and aromatic polyamide. The ratio of cellulose to aromatic polyamide is important for the thermal and oxidative stability performance of the wet clutch.

[0003] Lubricant additives can have a large impact on wet clutch performance. Additive action is caused by their physical and chemical adsorption on the surfaces of clutch materials such as cellulose, aromatic polyamide (natural and synthetic) fibers, silica, and steel plates. High aromatic polyamide wet clutch papers provide excellent durability performance. However, aromatic polyamide fibers are costly.

[0004] Without sufficient antiwear and friction modifying additives, the engine can experience power loss, uncomfortable vibrations, and / or noise caused by wet clutch lockup in the transmission. SUMMARY

[0005] A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented by way of illustration only, and that these aspects are not intended to limit the scope of the disclosure in any way. Indeed, this disclosure can encompass a wide variety of aspects not set forth below.

[0006] In one aspect, the present disclosure relates to a lubricating oil composition comprising: (a) a major amount of an oil of lubricating viscosity; (b) one or more ashless dispersants; (c) at least one phosphorus-containing antiwear additive, wherein the at least one phosphorus-containing antiwear additive is a phosphorus-containing acid, a phosphate ester, a phosphite ester, a thiophosphate ester, or an amine salt thereof; (d) at least one friction modifier, wherein the at least one friction modifier is a diol, an ethoxylated amine, a fatty acid ester, or an alcohol; (e) a nitrogen-containing friction modifier having the structure, wherein R 1 and R 2 are independently a branched C10-C25 hydrocarbyl group.

[0007] In another aspect, the present disclosure relates to a method of improving chatter resistance comprising: lubricating a transmission with a lubricating oil composition comprising: (a) a major amount of an oil of lubricating viscosity; (b) one or more ashless dispersants; (c) at least one phosphorus-containing antiwear additive, wherein the at least one phosphorus-containing antiwear additive is a phosphorus-containing acid, a phosphate ester, a phosphite ester, a thiophosphate ester, or an amine salt thereof; (d) at least one friction modifier, wherein the at least one friction modifier is a diol, an ethoxylated amine, a fatty acid ester, or an alcohol; (e) a nitrogen-containing friction modifier having the structure, wherein R 1 and R 2 are independently a branched C10-C25 hydrocarbyl group. DETAILED DESCRIPTION

[0008] Definitions The following terms will be used throughout the specification and will have the following meanings unless otherwise indicated.

[0009] The term "major amount" of base oil refers to a case where the amount of base oil is at least 40% by weight of the lubricating oil composition. In some embodiments, the "major amount" of base oil refers to a case where the amount of base oil is greater than 50% by weight, greater than 60% by weight, greater than 70% by weight, greater than 80% by weight, or greater than 90% by weight of the lubricating oil composition.

[0010] The term "ashless" with respect to the dispersant of the lubricating oil composition means that the dispersant is substantially free of metals.

[0011] The term "total base number" or "TBN" refers to the alkalinity level expressed as mg KOH / g of a component or composition (number of milliequivalents of KOH required to neutralize 1 gram of product) that indicates the ability of the component or composition to continue to neutralize corrosive acids according to ASTM Standard No. D2896 or equivalent procedure. The term "total acid number" or "TAN" refers to the acidity level of a component or composition according to ASTM Standard No. D664 or equivalent procedure.

[0012] The present disclosure relates generally to a lubricating oil composition that provides excellent wet paper clutch friction characteristics, such as chatter resistance, and which can also maintain excellent wet clutch torque capacity and durability of wet clutch friction characteristics.

[0013] The lubricating oil composition generally comprises an oil of lubricating viscosity having a kinematic viscosity at 100°C of 2 to 12 mm 2The lubricating oil composition further comprises (a) one or more ashless dispersants; at least one phosphorus-containing antiwear additive, wherein the antiwear additive is a phosphorus-containing acid, a phosphate ester, a phosphite ester, a thiophosphate ester, or an amine salt thereof; at least one friction modifier, wherein the friction modifier is a diol, an ethoxylated amine, a fatty acid ester, or an alcohol; and a nitrogen-containing friction modifier having the following structure given by Formula I, wherein R 1 and R 2 are independently branched C10-C25 hydrocarbyl groups.

[0014] Formula 1 “Branched” herein means that the hydrocarbyl group contains at least one tertiary carbon.

[0015] Formula 1 can be prepared, for example, by reacting diethylenetriamine (DETA) with a branched carboxylic acid. In some embodiments, the hydrocarbyl group is fully saturated.

[0016] Suitable branched carboxylic acids include, for example, 2-butyloctanoic acid, 3-butyloctanoic acid, 4-butyloctanoic acid, 2-hexyldecanoic acid, 3-hexyldecanoic acid, 4-hexyldecanoic acid, 2-octyldodecanoic acid, 3-octyldodecanoic acid, 4-octyldodecanoic acid, 5-octyldodecanoic acid, and the like. Some suitable branched carboxylic acids are commercially available. These include Guerbet acids (e.g., ISOCARB 16, ISOCARB 20) commercially available from Sasol (Houston, TX).

[0017] In some embodiments, Formula 1 can undergo a simple condensation reaction to form, for example, an imidazoline given by Formula 1A, wherein R 1 and R 2 are independently branched hydrocarbyl groups, wherein each branched hydrocarbyl group has a total of 10 to 25 carbons.

[0018] Formula 1A The following sections discuss in detail the components of various embodiments of the lubricating oil composition, provide exemplary lubricating oil compositions, and disclose test results demonstrating the superior friction and anti-shudder performance achieved by the lubricating oil composition.

[0019] Oil of lubricating viscosity The lubricating oil compositions disclosed herein generally include at least one oil of lubricating viscosity. Any base oil known to those skilled in the art can be used as the oil of lubricating viscosity disclosed herein. Some base oils suitable for use in making the lubricating oil compositions are described in Mortier et al., “Chemistry and Technology of Lubricants,” 2ndEdition, London, Springer, Chapters 1 and 2 (1996); and A. Sequeria, Jr., “Lubricant Base Oil and Wax Processing,” New York, Marcel Decker, Chapter 6 (1994); and D. V. Brock, Lubrication Engineering, Vol. 43, pp. 184-185 (1987), all of which are incorporated herein by reference. Generally, the amount of base oil in the lubricating oil composition can be from 70 wt% to 99.5 wt%, based on the total weight of the lubricating oil composition. In some embodiments, the amount of base oil in the lubricating oil composition is at least 75 wt% or at least 80 wt%, and no greater than 99 wt%, or no greater than 98.5 wt%, or no greater than 98 wt%, based on the total weight of the lubricating oil composition.

[0020] In certain embodiments, the base oil is or includes any natural or synthetic lubricating base oil fraction. Some non-limiting examples of synthetic oils include oils made from the polymerization of at least one a-olefin, such as ethylene, or from hydrocarbon synthesis procedures using carbon monoxide and hydrogen, such as the Fisher-Tropsch process, such as polyalphaolefins or PAOs. In certain embodiments, the base oil includes less than 10 wt% of one or more heavy fractions, based on the total weight of the base oil. A heavy fraction refers to a lubricating oil fraction having a viscosity of at least 20 cSt at 100°C. In certain embodiments, the heavy fraction has a viscosity of at least 25 cSt or at least 30 cSt at 100°C. As an example, the heavy fraction can have a viscosity in the range of 20 cSt, 25 cSt, or 30 cSt up to 25 cSt, 30 cSt, or 35 cSt at 100°C. In further embodiments, the amount of one or more heavy fractions in the base oil is less than 10 wt%, less than 5 wt%, less than 2.5 wt%, less than 1 wt%, or less than 0.1 wt%, based on the total weight of the base oil. In further embodiments, the base oil does not include a heavy fraction.

[0021] In certain embodiments, the lubricating oil composition comprises a major amount of a base oil of lubricating viscosity. In some embodiments, the base oil has a kinematic viscosity at 100°C of at least 1.5 centistokes (cSt) or at least 2 centistokes (cSt), and no greater than 20 cSt or no greater than 16 cSt. The kinematic viscosity of the base oil or lubricating oil composition disclosed herein can be measured according to ASTM D 445, which is incorporated herein by reference.

[0022] In other embodiments, the base oil is or comprises a base stock or a blend of base stocks. In further embodiments, the base stock is manufactured using a variety of different processes including, but not limited to, distillation, solvent refining, hydroprocessing, oligomerization, esterification, and rerefming. In some embodiments, the base stock comprises a rerefmed stock. In further embodiments, the rerefmed stock should be substantially free of materials introduced by manufacturing, contamination, or prior use.

[0023] In some embodiments, the base oil comprises one or more base stock(s) in one or more of Groups I-Group V as specified in American Petroleum Institute (API) Publication 1509, Fourteenth Edition, December 1996 (i.e., API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils), which is incorporated herein by reference. The API guidelines define base stock as a lubricant component that can be manufactured using a variety of different processes. Group I, Group II, and Group III base stocks are mineral oils each having a specified range of saturates amount, sulfur content, and viscosity index. Group IV base stocks are polyalphaolefins (PAOs). Group V base stocks include all other base stocks not included in Group I, Group II, Group III, or Group IV.

[0024] In some embodiments, the base oil comprises one or more base stock(s) in Group I, Group II, Group III, Group IV, Group V, or a combination thereof. In other embodiments, the base oil comprises one or more base stock(s) in Group II, Group III, Group IV, or a combination thereof. In further embodiments, the base oil comprises one or more base stock(s) in Group II, Group III, Group IV, or a combination thereof, wherein the base oil has a kinematic viscosity at 100°C of at least 1.5 centistokes (cSt) or at least 2 cSt, and no greater than 20 cSt or no greater than 16 cSt. In some embodiments, the base oil is a mixture of a Group II base oil and a Group III base oil.

[0025] The base oil can be selected from the group consisting of natural oils of lubricating viscosity, synthetic oils of lubricating viscosity, and mixtures thereof. In some embodiments, the base oil includes base stock obtained by isomerization of waxes and slack waxes, as well as hydrocracked base stocks produced by hydrocracking of the aromatic and polar components of crude oil, rather than solvent extraction. In other embodiments, the base oil of lubricating viscosity includes natural oils such as animal oils, vegetable oils, mineral oils (e.g., liquid petroleum oils and solvent-treated or acid-treated

[0026] In some embodiments, the synthetic oil of lubricating viscosity includes hydrocarbon oils and halosubstituted hydrocarbon oils such as polymerized and interpolymerized olefins, alkylbenzenes, polyphenyls, alkylated diphenyl ethers, alkylated diphenyl sulfides, and derivatives, analogs, and homologs thereof, and the like. In other embodiments, the synthetic oil includes alkylene oxide polymers, interpolymers, copolymers, and derivatives thereof, in which terminal hydroxyl groups can be modified by esterification, etherification, and the like. In further embodiments, the synthetic oil includes esters of dicarboxylic acids with various alcohols. In certain embodiments, the synthetic oil includes esters prepared from carboxylic acids, polyols, and polyol ethers. In additional embodiments, the synthetic oil includes trialkyl phosphate oils such as tri-n-butyl phosphate and tri-iso-butyl phosphate. 12 In some embodiments, the synthetic oil of lubricating viscosity includes hydrocarbon oils and halosubstituted hydrocarbon oils such as polymerized and interpolymerized olefins, alkylbenzenes, polyphenyls, alkylated diphenyl ethers, alkylated diphenyl sulfides, and derivatives, analogs, and homologs thereof, and the like. In other embodiments, the synthetic oil includes alkylene oxide polymers, interpolymers, copolymers, and derivatives thereof, in which terminal hydroxyl groups can be modified by esterification, etherification, and the like. In further embodiments, the synthetic oil includes esters of dicarboxylic acids with various alcohols. In certain embodiments, the synthetic oil includes esters prepared from carboxylic acids, polyols, and polyol ethers. In additional embodiments, the synthetic oil includes trialkyl phosphate oils such as tri-n-butyl phosphate and tri-iso-butyl phosphate.

[0027] In some embodiments, the synthetic oil of lubricating viscosity includes hydrocarbon oils and halosubstituted hydrocarbon oils such as polymerized and interpolymerized olefins, alkylbenzenes, polyphenyls, alkylated diphenyl ethers, alkylated diphenyl sulfides, and derivatives, analogs, and homologs thereof, and the like. In other embodiments, the synthetic oil includes alkylene oxide polymers, interpolymers, copolymers, and derivatives thereof, in which terminal hydroxyl groups can be modified by esterification, etherification, and the like. In further embodiments, the synthetic oil includes esters of dicarboxylic acids with various alcohols. In certain embodiments, the synthetic oil includes esters prepared from carboxylic acids, polyols, and polyol ethers. In additional embodiments, the synthetic oil includes trialkyl phosphate oils such as tri-n-butyl phosphate and tri-iso-butyl phosphate.

[0028] Base oils derived from the hydroisomerization of waxes can also be used alone or in combination with the natural and / or synthetic base oils described above. Such wax isomerate oils are produced by the hydroisomerization of natural waxes or synthetic waxes or mixtures thereof over a hydroisomerization catalyst.

[0029] In further embodiments, the base oil comprises a poly-a-olefin (PAO). Generally, the poly-a-olefin can be derived from an a-olefin having 2 to 30, 2 to 20, or 2 to 16 carbon atoms. Non-limiting examples of suitable poly-a-olefins include those derived from octene, decene, mixtures thereof, and the like. The poly-a-olefins can have a viscosity of at least 1.5 centistokes at 100°C, and no greater than 15 centistokes, or no greater than 12 centistokes, or no greater than 8 centistokes. In some cases, the poly-a-olefins can be used with other base oils such as mineral oil, synthetic ester, or alkylated naphthalene base oils.

[0030] In further embodiments, the base oil comprises a polyalkylene glycol or a polyalkylene glycol derivative, where the terminal hydroxyl groups of the polyalkylene glycol can be modified by esterification, etherification, acetylation, and the like. Non-limiting examples of suitable polyalkylene glycols include polyethylene glycol, polypropylene glycol, polyisopropylene glycol, and combinations thereof. Non-limiting examples of suitable polyalkylene glycol derivatives include ethers of polyalkylene glycols (e.g., methyl ether of polyisopropylene glycol, diphenyl ether of polyethylene glycol, diethyl ether of polypropylene glycol, and the like), mono- and polycarboxylic acid esters of polyalkylene glycols, and combinations thereof. In some examples, the polyalkylene glycol or polyalkylene glycol derivative can be used with other base oils such as poly-a-olefins and mineral oil.

[0031] In further embodiments, the base oil comprises any one of the esters of a dicarboxylic acid (e.g., phthalic acid, succinic acid, alkyl succinic acid, alkenyl succinic acid, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acid, alkenyl malonic acid, and the like) with various alcohols (e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol, and the like). Non-limiting examples of these esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, diarachidyl sebacate, 2-ethylhexyl diester of linoleic acid dimer, and the like.

[0032] In further embodiments, the base oil comprises a hydrocarbon prepared by the Fischer-Tropsch process. The Fischer-Tropsch process uses a Fischer-Tropsch catalyst to prepare hydrocarbons from a gas containing hydrogen and carbon monoxide. These hydrocarbons can need to be further processed in order to be useful as a base oil. For example, the hydrocarbons can be dewaxed, hydroisomerized, and / or hydrocracked using methods known to those of ordinary skill in the art.

[0033] In further embodiments, the base oil comprises unrefined oil, refined oil, rerefined oil, or mixtures thereof. Unrefined oil is oil that has not been further modified or treated after recovery from a natural or synthetic source. Non-limiting examples of unrefined oil include shale oil obtained directly from retorting operations, petroleum oil obtained directly from primary distillation, and ester oil obtained directly from an esterification process and used without further treatment. Refined oil is similar to unrefined oil except that the former has been further treated by one or more purification methods to improve one or more properties. Many such purification methods are known to those of skill in the art, such as solvent extraction, secondary distillation, acid or base extraction, filtration, percolation, and the like. Rerefined oil is obtained by applying to refined oil the same methods used to obtain refined oil. Such rerefined oil is also called regenerated or reprocessed oil, and is typically additionally treated by methods aimed at removing spent additives and oil breakdown products.

[0034] Ashless dispersant The lubricating oil composition comprises at least one ashless dispersant (A). According to exemplary embodiments, the lubricating oil composition comprises one or more nitrogen-containing ashless succinimide dispersants. According to certain embodiments, the one or more nitrogen-containing ashless succinimide dispersants are unpost-treated dispersants.

[0035] Typical examples of nitrogen-containing ashless dispersants include hydrocarbyl succinimides, such as alkenyl or alkyl succinimides derived from polyolefins and derivatives thereof. The succinimides can be obtained by reaction between succinic anhydride, which is substituted by high molecular weight alkenyl or alkyl groups, and a polyalkylene polyamine containing on average at least 3 or 4 nitrogen atoms per molecule and not more than 7 or not more than 10 nitrogen atoms per molecule. In one aspect, the high molecular weight alkenyl or alkyl groups are typically polyolefins having a number average molecular weight of from about 500 to 5000, with polyisobutylene being particularly advantageous. In one aspect, the high molecular weight alkenyl or alkyl groups are typically polyolefins having a number average molecular weight of at least 500, or at least 700, or at least 800, or at least 900, or at least 950, and not more than 4000, or not more than 3000, or not more than 2000, or not more than 1050. For example, the polyolefin can have a number average molecular weight of 1000.

[0036] In some aspects, a chlorination method in which chlorine is used in the step of obtaining polybutenyl succinic anhydride by reaction between polybutene and maleic anhydride. However, with this method, although the reactivity is good, a large amount of chlorine (such as 2000 ppm) is finally left in the final succinimide product. On the other hand, if a thermal reaction in which chlorine is not involved is used, the amount of chlorine left in the final product can be kept at a very low level (such as 40 ppm or less). Furthermore, compared to conventional polybutenes (mainly polybutenes having a β-olefin structure), the use of a high reactivity polybutene (polybutene in which at least 50% has a methylvinylidene structure) is advantageous in increasing the reactivity, even if a thermal reaction method is employed. If the reactivity is high, there is less unreacted polybutene in the dispersant, and thus a dispersant having a high concentration of active components (succinimide) can be obtained. Therefore, a succinimide can be prepared by first obtaining a polybutenyl succinic anhydride by thermal reaction using a high reactivity polybutene, and then reacting the polybutenyl succinic anhydride with a polyamine. The succinimide can be used in the form of a so-called modified succinimide by further reacting with boric acid, an alcohol, an aldehyde, a ketone, an alkylphenol, a cyclic carbonate, an organic acid, or the like. Boron-containing alk(en)yl succinimides obtained by reaction with boric acid or a boron compound are particularly advantageous in terms of thermal stability and oxidation stability. Succinimides have mono-, di-, tri-, and poly-types depending on the number of imide structures per molecule, but di-types are generally used as succinimides in lubricating oil compositions.

[0037] Other examples of nitrogen-containing ashless dispersants include polymeric succinimide dispersants derived from ethylene-a-olefin copolymers (such as copolymers having a molecular weight of 1000 to 15,000) and alk(en)yl benzylamine-based ashless dispersants.

[0038] Examples of nitrogen-containing ashless dispersants are mono- and di-alk(en)yl succinimides derived from the reaction of an alk(en)yl succinic acid or anhydride with an alkylene polyamine. These compounds are generally considered to have the formula (I): wherein R1 is a substantially hydrocarbon chain having a molecular weight of 500 to 3000, i.e. R1 is a hydrocarbyl chain containing 40 to 200 carbon atoms, such as an alkenyl group; Alk is an alkylene chain having 2 to 10 or 2 to 6 carbon atoms, R2, R3 and R4 are selected from C1-C4 alkyl or alkoxy or alkyl amine or hydrogen, typically hydrogen, and x is an integer from 0 to 10, typically 0 to 3; optionally, two of the nitrogen atoms can be part of a cyclic ring; or formula (II): wherein R5and R7are both substantially hydrocarbon chains having a molecular weight of 500 to 3000, i.e., R5and R7are each a hydrocarbyl chain, such as an alkenyl chain, containing 30 to 220 carbon atoms; Alk is an alkylene chain having 2 to 10, typically 2 to 6, carbon atoms; R6is selected from C1-C4 alkyl or alkoxy or alkyl amine or hydrogen, typically hydrogen, and y is an integer from 0 to 10, typically 0 to 3; optionally, two of the nitrogen atoms can be part of a cyclic ring. In one embodiment, R1, R5, and R7are polyisobutyl groups.

[0039] In one embodiment, the actual reaction product of the alkylene or alkenylene succinic acid or anhydride with the alkylene polyamine will include a mixture of compounds including mono- and bis-succinimides. The mono- and bis-alkenyl succinimides produced can depend on the charge molar ratio of the polyamine to the succinic acid groups and the particular polyamine used. A charge molar ratio of 1 : 1 of the polyamine to the succinic acid groups can produce primarily mono-alkenyl succinimides. A charge molar ratio of 1 :2 of the polyamine to the succinic acid groups can produce primarily bis-alkenyl succinimides. Examples of succinimide dispersants include those described in, for example, U.S. Patent Nos. 3,172,892; 4,234,435; and 6,165,235, which are incorporated by reference herein in their entirety.

[0040] In one embodiment, the polyolefin from which the substituents are derived is typically a homopolymer and interpolymer of a polymerizable olefin monomer having 2 to 16 carbon atoms, typically 2 to 6 carbon atoms. The amine that reacts with the succinic acylating agent to form the carboxylic acid dispersant composition can be a monoamine or a polyamine.

[0041] In one aspect of the disclosure, the alkenyl succinimide can be prepared by reacting a polyalkylene succinic anhydride with an alkylene polyamine. The polyalkylene succinic anhydride is the reaction product of a polyalkylene, typically a polyisobutylene, and maleic anhydride. Either conventional polyisobutylenes or high methyl vinylidene polyisobutylenes can be used in the preparation of this polyalkylene succinic anhydride. Heat, chlorination, free radical, acid catalyzed, or any other method can be used in the preparation. Examples of suitable polyalkylene succinic anhydrides are heat PIBSA (polyisobutenyl succinic anhydride) as described in U.S. Patent No. 3,361,673; chlorinated PIBSA as described in U.S. Patent No. 3,172,892; a mixture of heat and chlorinated PIBSA as described in U.S. Patent No. 3,912,764; high succinic ratio PIBSA as described in U.S. Patent No. 4,234,435; polyPIBSA as described in U.S. Patent Nos. 5,112,507 and 5,175,225; high succinic ratio polyPIBSA as described in U.S. Patent Nos. 5,565,528 and 5,616,668; free radical PIBSA as described in U.S. Patent Nos. 5,286,799, 5,319,030, and 5,625,004; PIBSA made from high methyl vinylidene polybutylenes as described in U.S. Patent Nos. 4,152,499, 5,137,978, and 5,137,980; high succinic ratio PIBSA made from high methyl vinylidene polybutylenes as described in European Patent Application Publication No. EP 355 895; terpolymer PIBSA as described in U.S. Patent No. 5,792,729; sulfonic acid PIBSA as described in U.S. Patent No. 5,777,025 and European Patent Application Publication No. EP 542 380; and purified PIBSA as described in U.S. Patent No. 5,523,417 and European Patent Application Publication No. EP 602 863. The disclosure of each of these documents is incorporated herein by reference in its entirety. The polyalkylene succinic anhydride is typically a polyisobutenyl succinic anhydride. In one exemplary embodiment, the polyalkylene succinic anhydride is a polyisobutenyl succinic anhydride derived from a polyisobutylene having a number average molecular weight of at least 500, or at least 600, or at least 700, or at least 800, or at least 900, and not more than 1400, or not more than 1300, or not more than 1200, or not more than 1100, or not more than 1000.

[0042] A typical polyalkylene amine for preparing the succinimide has the formula (III): where z is an integer from 0 to 10, and Alk is an alkylene group having 2 to 10, typically 2 to 6, carbon atoms, R8, R9, and R 10selected from C1-C4 alkyl or alkoxy or alkylamines or hydrogen, typically hydrogen, and z is an integer from 0 to 10, typically 0 to 3.

[0043] Alkyleneamines include primarily methyleneamines, ethyleneamines, butyleneamines, propyleneamines, pentyleneamines, hexyleneamines, heptyleneamines, octyleneamines, other polymethyleneamines, and cyclic and higher homologs of such amines such as piperazine and aminoalkyl-substituted piperazines. They are exemplified specifically by ethylenediamine, triethylenetetramine, propylenediamine, decamethylenediamine, octamethylenediamine, dipentamethylene triamine, tripropylenetetramine, tetraethylenepentamine, trimethylenediamine, pentaethylenehexamine, dimethylenetriamine, 2-heptyl-3-(2-aminopropyl)-imidazoline, 4-methylimidazoline, N,N-dimethyl-l,3- propanediamine, l,3-bis(2-aminoethyl)imidazoline, l-(2-aminopropyl)-piperazine, 1,4-bis(2- aminoethyl)piperazine, and 2-methyl-l-(2-aminobutyl)piperazine. It is also useful to obtain higher homologs by condensing two or more of the above alkyleneamines.

[0044] Ethyleneamines are particularly useful. They are described in detail under the heading "Ethylene Amines" in Encyclopedia of Chemical Technology, Kirk-Othmer, Vol. 5, pp. 898-905 (Interscience Publishers, New York, 1950). The term "ethyleneamines" is used in a general sense to denote a class of polyamines which in most cases conform to the formula (IV): wherein a is an integer from 1 to 10. In one embodiment, a is an integer from 3 to 5. Thus, it includes, for example, ethylenediamine, diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine, pentaethylenehexamine, and the like.

[0045] It will be appreciated that the polyamines used herein typically include mixtures of polyamine products. For example, triethylenetetramine (TETA) commercially available from Huntsman is described as a mixture of linear TETA, branched TETA, bisaminoethylpiperazine (bis-AEP), and N-[(2-aminoethyl)2-aminoethyl]piperazine) or PEEDA.

[0046] Linear TETA Branched TETA Bis-AEP PEEDA Various alkenyl succinimides for use in the alkenyl succinimide composition can be prepared by conventional methods, such as disclosed in U.S. Patent Nos. 2,992,708; 3,018,250; 3,018,291; 3,024,237; 3,100,673; 3,172,892; 3,202,678; 3,219,666; 3,272,746; 3,361,673; 3,381,022; 3,912,764; 4,234,435; 4,612,132; 4,747,965; 5,112,507; 5,241,003; 5,266,186; 5,286,799; 5,319,030; 5,334,321; 5,356,552; 5,716,912, the disclosures of which are hereby incorporated by reference in their entirety for all purposes.

[0047] The term "alkenyl succinimide" also includes post-treated succinimides, such as post-treatment methods involving borate esters or ethylene carbonate disclosed in U.S. Patent No. 4,612,132 to Wollenberg et al., U.S. Patent No. 4,746,446 to Wollenberg et al., and other post-treatment methods, each of which is hereby incorporated by reference in its entirety. Carbonate-treated alkenyl succinimides are typically polyisobutylene succinimides derived from polyisobutylenes having a molecular weight of at least 500, or at least 900, or at least 1,300, or at least 2,000 and not greater than 3,000, or not greater than 2,500, or not greater than 2,400, or not greater than 2,300.

[0048] In one embodiment, the dispersant system is present in an amount of at least 1 wt%, or at least 1.5 wt%, or at least 2.0 wt% and not greater than 20 wt%, or not greater than 15 wt%, or not greater than 10 wt%, or not greater than 5.0 wt%, or not greater than 4.0 wt%, or not greater than 3.0 wt%, for example, 1.0 to 3.0 wt%, based on the total weight of the lubricating oil composition.

[0049] In another embodiment, the non-post-treated dispersant is a non-post-treated succinimide dispersant. In other embodiments, the non-post-treated succinimide dispersant is present in an amount of at least 0.3 wt%, or at least 0.5 wt%, or at least 0.6 wt% and not greater than 8 wt%, or not greater than 5 wt%, or not greater than 4 wt%, or not greater than 3.0 wt%, or not greater than 2.0 wt%, based on the total weight of the lubricating oil composition.

[0050] The various alkenyl succinimides used in the alkenyl succinimide composition can be prepared by conventional methods, such as disclosed in U.S. Patent Nos. 2,992,708; 3,018,250; 3,018,291; 3,024,237; 3,100,673; 3,172,892; 3,202,678; 3,219,666; 3,272,746; 3,361,673; 3,381,022; 3,912,764; 4,234,435; 4,612,132; 4,747,965; 5,112,507; 5,241,003; 5,266,186; 5,286,799; 5,319,030; 5,334,321; 5,356,552; 5,716,912, the disclosures of which are incorporated by reference in their entirety herein for all purposes.

[0051] The term "alkenyl succinimide" also includes post-treated succinimides, such as post-treatment methods involving boronic esters or ethylene carbonate disclosed in, for example, U.S. Patent No. 4,612,132; U.S. Patent No. 4,746,446, and other post-treatment methods, each of which is incorporated by reference herein in its entirety. Generally, the carbonate-treated alkenyl succinimide is a polybutene succinimide derived from a polybutene having a molecular weight of at least 500, or at least 600, or at least 800, or at least 900, and not greater than 3000, or not greater than 2500, or not greater than 2300.

[0052] According to exemplary embodiments, each nitrogen-containing ashless succinimide dispersant has a number average molecular weight of at least 500, at least 750, or at least 850, or at least 1000, and not greater than 1800, or not greater than 1700, or not greater than 1600, or not greater than 1500, or not greater than 1400, or not greater than 1350.

[0053] Each nitrogen-containing ashless succinimide dispersant generally has a TBN of at least 25 mg KOH / g, or at least 30 mg KOH / g, and not greater than 55 mg KOH / g, or not greater than 50 mg KOH / g.

[0054] The nitrogen content of each nitrogen-containing ashless succinimide dispersant according to exemplary embodiments ranges from 1.0 wt% to 3.0 wt%, based on the total weight of the nitrogen-containing ashless succinimide dispersant.

[0055] In one embodiment, the dispersant is not post-treated. In another embodiment, the dispersant is post-treated with a boron compound.

[0056] According to an exemplary embodiment, the one or more nitrogen-containing ashless succinimide dispersants include a boron-containing dispersant. The boron content of the nitrogen-containing ashless succinimide dispersant is in the range of 0.1 wt% to 2.0 wt%, based on the total weight of the nitrogen-containing ashless succinimide dispersant.

[0057] According to an exemplary embodiment, the one or more nitrogen-containing ashless succinimide dispersants include two dispersants. The first dispersant is a boron-modified polyisobutenyl succinimide having a polyisobutylene number average molecular weight of 1300, a nitrogen content of 1.95 wt%, a boron content of 0.63 wt%, and a TBN of 46 mg KOH / g. The second dispersant is a polyisobutenyl succinimide having a polyisobutylene number average molecular weight of 1000, a nitrogen content of 1.93 wt%, and a TBN of 35 mg KOH / g.

[0058] The lubricating oil composition generally includes less than 0.3 wt% sulfated ash, or no more than 0.1 wt% sulfated ash, based on the total weight of the lubricating oil composition.

[0059] Phosphorus-containing anti-wear additives The lubricating oil composition also includes at least one phosphorus-containing anti-wear additive compound. A variety of different phosphorus-containing anti-wear additive compounds can be used in the lubricating oil composition. However, according to an exemplary embodiment, the lubricating oil composition includes at least one phosphorus-containing anti-wear additive that is a phosphorus-containing acid, a phosphate ester, a phosphite ester, a thiophosphate ester, or an amine salt thereof. In some embodiments, the phosphorus-containing acid is phosphoric acid or phosphorous acid.

[0060] Phosphoric acid The phosphoric acid of the lubricating oil composition is generally an 85 wt% solution of inorganic phosphoric acid, H3PO4. According to an exemplary embodiment, the phosphoric acid (85 wt% solution) includes phosphorus in an amount of at least 20.0 wt%, or at least 25.0 wt%, and no more than 32.0 wt%, or no more than 30.0 wt%, based on the total weight of the phosphoric acid.

[0061] According to an exemplary embodiment, the phosphoric acid (85 wt% solution) has a total acid number (TAN) of at least 850 mg KOH / g, or at least 950 mg KOH / g, and no more than 1050 mg KOH / g, or no more than 1000 mg KOH / g.

[0062] In one embodiment, phosphoric acid (85 wt% solution) is present in an amount of 0.01 wt% to 1.0 wt%, based on the total weight of the lubricating oil composition. In other embodiments, phosphoric acid is present in an amount of at least 0.01 wt%, or at least 0.02 wt%, or at least 0.03 wt%, and not more than 0.5 wt%, or not more than 0.6 wt%, or not more than 0.7 wt%, or not more than 1.0 wt%, based on the total weight of the lubricating oil composition.

[0063] Phosphorous acid In some embodiments, the lubricating oil composition can include phosphorous acid, (HO)2PO, and / or tautomeric forms of phosphorous acid, phosphonic acid. The tautomeric forms are shown below: Acid phosphonate In certain embodiments, the phosphorus-containing anti-wear additive compound can include a mono- or diphosphonate. Examples of phosphonates include mono- and / or di- aryl phosphonates, mono- and / or di-alkyl phosphonates, mono- and / or alkyl aryl phosphonates, mono- and / or aryl alkyl phosphonates, and mono- and / or di-alkenyl phosphonates. Specific examples include monobenzyl and / or diphenyl phosphonate, monomethylphenyl and / or dimethylphenyl phosphonate, benzyl phenyl phosphonate, ethyl phenyl phosphonate, monobutyl and / or dibutyl phosphonate, ethyl butyl phosphonate, tolyl phenyl phosphonate, ethyl phenyl phenyl phosphonate, propyl phenyl phenyl phosphonate, phosphonate, diethyl phenyl phosphonate, dipropyl phenyl phosphonate, butyl phenyl phenyl phosphonate, dibutyl phenyl phosphonate, dihexyl phosphonate, di-(2-ethylhexyl) phosphonate, dioctyl phosphonate, didecyl phosphonate, dilauryl phosphonate, dimyristyl phosphonate, dipalmityl phosphonate, distearyl phosphonate, and dioleyl phosphonate.

[0064] Sulfide bonds can be included in the alkyl groups. Examples of phosphonates containing sulfides include mono- and / or di-alkyl thiophosphonates, monobutyl and / or dibutyl thiophosphonate, monohexyl and / or dihexyl thiophosphonate, mono- and / or dioctyl thiophosphonate, monodecyl and / or didecyl thiophosphonate, mono- and / or dilauryl thiophosphonate, mono- and / or dihexadecyl thiophosphonate.

[0065] According to exemplary embodiments, each mono- and / or diphosphonate has a phosphorus content of 3.0 wt% to 20.0 wt% and a sulfur content of 5.0 wt% to 15.0 wt%, based on the total weight of the phosphonate.

[0066] The lubricating oil composition can comprise phosphorus in an amount of at least 0.01 wt%, or at least 0.02 wt%, or at least 0.03 wt% and not more than 0.20 wt%, or not more than 0.1 wt%, or not more than 0.08 wt%, based on the total weight of the lubricating oil composition.

[0067] Neutral phosphonate Examples of phosphates include triaryl phosphates, trialkyl phosphates, trialkylaryl phosphates, triarylalkyl phosphates, and trialkenyl phosphates. Specific examples include triphenyl phosphate, tricumene phosphate, benzyl diphenyl phosphate, ethyl diphenyl phosphate, tributyl phosphate, ethyl dibutyl phosphate, cresyl diphenyl phosphate, xylenyl phenyl phosphate, ethyl phenyl diphenyl phosphate, di(ethyl phenyl) phenyl phosphate, propyl phenyl diphenyl phosphate, di(propyl phenyl) phenyl phosphate, triethyl phenyl phosphate, tripropyl phenyl phosphate, butyl phenyl diphenyl phosphate, di(butyl phenyl) phenyl phosphate, tributyl phenyl phosphate, trihexyl phosphate, tri(2-ethylhexyl) phosphate, trioctyl phosphate, tridecyl phosphate, tridodecyl phosphate, triisooctyl phosphate, diphenyl isodecyl phosphate, tristearyl phosphate, and trioleyl phosphate.

[0068] Phosphonite Examples of phosphites include triethyl phosphite, tributyl phosphite, triphenyl phosphite, tricumene phosphite, tri(nonyl phenyl) phosphite, tri(2-ethylhexyl) phosphite, tridecyl phosphite, tridodecyl phosphite, triisooctyl phosphite, diphenyl isodecyl phosphite, tristearyl phosphite, and trioleyl phosphite.

[0069] Sulfide bonds can be included in the alkyl groups. Examples of phosphites containing sulfides include trialkyl thio phosphites, tributyl thioethyl phosphite, trihexyl thioethyl phosphite, trioctyl thioethyl phosphite, tridecyl thioethyl phosphite, tridodecyl thioethyl phosphite, trihexadecyl thioethyl phosphite.

[0070] According to exemplary embodiments, each phosphite has a phosphorus content of 3.0 wt% to 15.0 wt%. When the phosphite contains a sulfide bond, the phosphite has a sulfur content of 5.0 wt% to 25.0 wt%, based on the total weight of the phosphite.

[0071] Phosphorous acid hydrogen ester In certain embodiments, the hydrogen phosphite is a hydrogen dialkyl phosphite, hydrogen diphenyl phosphite, hydrogen dialkyl-phenyl phosphite is preferred, but the present application is not limited thereto. Examples of hydrogen phosphites include hydrogen dibutyl phosphite, hydrogen dipentyl phosphite, hydrogen dihexyl phosphite, hydrogen dioctyl phosphite, hydrogen di-2-ethylhexyl phosphite, hydrogen didecyl phosphite, hydrogen dilauryl phosphite, hydrogen dioctadecyl phosphite, hydrogen diphenyl phosphite, and the like.

[0072] Sulfide bonds can be included in the alkyl groups. Examples of hydrogen phosphites containing sulfides include dialkylthio hydrogen phosphite, dibutylthioethyl hydrogen phosphite, dihexylthioethyl hydrogen phosphite, dioctylthioethyl hydrogen phosphite, didecylthioethyl hydrogen phosphite, didodecylthioethyl hydrogen phosphite, dihexadecylthioethyl hydrogen phosphite.

[0073] According to exemplary embodiments, each hydrogen phosphite has a phosphorus content of 3.0 wt% to 15.0 wt%. In embodiments where the hydrogen phosphite contains a sulfide bond, the hydrogen phosphite has a sulfur content of 5.0 wt% to 25.0 wt%, based on the total weight of the phosphite.

[0074] Thiophosphonate Specific examples of thiophosphates include trialkyl dithiophosphates such as tripropyl dithiophosphate, tributyl dithiophosphate, tripentyl dithiophosphate, trihexyl dithiophosphate, and trioctyl dithiophosphate; and 0,0-dialkyl dithiophosphoryl alkylene alkyl carboxylates such as Irgalube 63 (produced by BASF Corporation), Vanlube 727, and Vanlube 7611 (produced by Vanderbilt Co., Ltd.).

[0075] Amine salt Specific examples of amine salts include amine salts of acidic phosphates or amine salts of acidic phosphites. Examples of such amine salts include amine salts of monohexyl phosphate, amine salts of dihexyl phosphate, amine salts of mono-2-ethylhexyl phosphate, amine salts of di-2-ethylhexyl phosphate, amine salts of monooctyl phosphate, amine salts of dioctyl thiophosphate, amine salts of monooctyl thiophosphate, amine salts of dioctyl, amine salts of monodecyl phosphate, amine salts of monododecyl phosphate, amine salts of didodecyl phosphate, amine salts of monooctadecyl phosphate, amine salts of dioctadecyl phosphate.

[0076] The amine for making the amine salt can be represented by R5R6R7N. R5, R6, and R7are independently saturated or unsaturated aliphatic, aromatic, or aromatic aliphatic hydrocarbons having 1 to 20 carbon atoms or hydrogen. When the group is a hydrocarbon, it can be a straight chain structure or branched.

[0077] In certain embodiments, the amine salt can be represented by Formula (V): where R8is C9to C 22 hydrocarbyl, R9and R 10 are each independently C1to C4hydrocarbyl, R 11 is C 10 to C 20 hydrocarbyl, and R 12 is hydrogen or C 10 to C 20 hydrocarbyl. Examples of such amine salts are described in U.S. Patent No. 5,552,068, which is incorporated by reference herein in its entirety.

[0078] According to exemplary embodiments, each amine salt has a phosphorus content of 3.0 wt% to 15.0 wt% and a nitrogen content of 0.5 wt% to 5.0 wt%, based on the total weight of the amine salt.

[0079] Exemplary phosphorus compounds According to exemplary embodiments, the one or more phosphorus-containing antiwear additive compounds are present in an amount of 0.01 wt% to 3.0 wt%, based on the total weight of the lubricating oil composition. In other embodiments, the one or more phosphorus-containing antiwear additive compounds are present in an amount of at least 0.01 wt%, or at least 0.02 wt%, or at least 0.03 wt%, and not more than 1.0 wt%, or not more than 0.5 wt%, or not more than 0.3 wt%, or not more than 0.2 wt%, based on the total weight of the lubricating oil composition.

[0080] Friction modifier A variety of known friction modifiers can be used as the friction modifier in the lubricating oil composition of the present disclosure. The friction modifier can provide improved frictional properties, as evidenced by an increased or decreased coefficient of friction and extended coefficient of friction stability of the lubricating oil composition. Thus, the lubricating oil composition containing the friction modifier can enable the automatic transmission to avoid shudder over a relatively long period of time.

[0081] According to certain embodiments, the friction modifier in the lubricating oil composition comprises a diol. For example, the lubricating oil composition can comprise a diol compound having the following formula (VI): (VI) where R represents hydrogen, an alkyl group, or an alkenyl group. Mixtures of compounds having different alkyl or alkenyl groups can also be used. The alkyl or alkenyl groups can be straight chain or branched, and typically contain 10-30 carbon atoms.

[0082] According to other embodiments, the friction modifier in the lubricating oil composition comprises an ethoxylated amine. The ethoxylated amine can have the following formula (VII): where R represents hydrogen, an alkyl group, or an alkenyl group. Mixtures of compounds having different alkyl or alkenyl groups can also be used. The alkyl or alkenyl groups can be straight chain or branched, and typically contain 8-22 carbon atoms.

[0083] According to certain embodiments, the friction modifier in the lubricating oil composition comprises a fatty acid ester, a fatty acid amide, a fatty acid amide of a low molecular weight amino acid, and / or an alcohol. Examples of fatty acid esters include those disclosed in U.S. Patent No. 3,933,659, which is incorporated by reference herein in its entirety.

[0084] Each friction modifier is typically present in an amount of 0.01 wt% to 3 wt%, based on the total weight of the lubricating oil composition. The total amount of friction modifier present in the lubricating oil composition is typically 0.01 wt% to 5 wt%, based on the total weight of the lubricating oil composition. In exemplary embodiments, the friction modifier is present in an amount of at least 0.01 wt%, or at least 0.05 wt%, or at least 0.1 wt%, and not more than 4.0 wt%, or not more than 3.0 wt%, or not more than 2.0 wt%, based on the total weight of the lubricating oil composition.

[0085] Other Additives Optionally, the lubricating oil composition can also include at least one additive or modifier (hereinafter “additive”) that can impart or improve any desired property of the lubricating oil composition. Any additive known to one of ordinary skill in the art can be used in the lubricating oil compositions disclosed herein. Some suitable additives are described in Mortier et al., “Chemistry and Technology of Lubricants,” 2ndEdition, London, Springer, (1996); and Leslie R. Rudnick, “Lubricant Additives: Chemistry and Applications,” New York, Marcel Dekker (2003), both of which are incorporated herein by reference. In some embodiments, the at least one additive can be selected from the group consisting of antioxidants, antiwear agents, detergents, rust inhibitors, demulsifiers, multifunctional additives, viscosity index improvers, pour point depressants, foam inhibitors, metal deactivators, corrosion inhibitors, lubricity improvers, thermal stability improvers, anti-fogging additives, ice formation inhibitors, dyes, markers, static dissipative agents, biocides, and combinations thereof. The additives can also include friction modifiers and dispersants in addition to the friction modifiers and dispersants described above.

[0086] When used, the concentration of each additive in the lubricating oil composition is typically at least 0.001 wt.%, or at least 0.01 wt.%, or at least 0.1 wt.% and not more than 15 wt.%, or not more than 10 wt.%, or not more than 8 wt.%, respectively, based on the total weight of the lubricating oil composition. Further, the total amount of additives in the lubricating oil composition is typically at least 0.001 wt.%, or at least 0.1 wt.%, or at least 1 wt.% and not more than 20 wt.%, or not more than 15 wt.%, or not more than 10 wt.%, for example, 9 wt.% to 10 wt.%, based on the total weight of the lubricating oil composition.

[0087] In one embodiment, the lubricating oil composition includes a metal detergent compound. Some non-limiting examples of suitable metal detergents include sulfated or un-sulfated alkyl or alkenyl phenates, alkyl or alkenyl aromatic sulfonates, borated sulfonates, sulfated or un-sulfated metal salts of polyhydroxy alkyl or alkenyl aromatic compounds, alkyl or alkenyl hydroxy aromatic sulfonates, sulfated or un-sulfated alkyl or alkenyl naphthenates, metal salts of alkanoic acids, metal salts of alkyl or alkenyl polyacids, and chemical and physical mixtures thereof. Other non-limiting examples of suitable metal detergents include metal sulfonates, phenates, salicylates, phosphonates, thiophosphonates, and combinations thereof. The metal can be any metal suitable for making a sulfonate, phenate, salicylate, or phosphonate detergent. Non-limiting examples of suitable metals include alkaline earth metals, alkali metals, and transition metals. In some embodiments, the metal is Ca, Mg, Ba, K, Na, Li, and the like.

[0088] Some suitable detergents have been described in Mortier et al., “Chemistry and Technology of Lubricants,” 2ndEdition, London, Springer, Chapter 3, pages 75-85 (1996); and Leslie R. Rudnick, “Lubricant Additives: Chemistry and Applications,” New York, Marcel Dekker, Chapter 4, pages 113-136 (2003), both of which are incorporated herein by reference.

[0089] Generally, the amount of metal detergent is about 0.001 wt.% to about 0.5 wt.%, about 0.01 wt.% to about 0.3 wt.%, about 0.01 wt.% to about 0.2 wt.%, about 0.01 wt.% to about 0.1 wt.%, about 0.02 wt.% to about 0.5 wt.%, about 0.02 wt.% to about 0.4 wt.%, or about 0.03 wt.% to about 0.3 wt.%, based on the total weight of the lubricating oil composition.

[0090] In one embodiment, the metal detergent is a calcium sulfonate or calcium salicylate detergent having a TBN of 50 to 450 mg KOH / gm and a calcium content of 1.0 wt.% to 20 wt.%.

[0091] In another embodiment, calcium is present in the lubricating oil composition in an amount of no more than 300 wt. ppm. In other embodiments, calcium is present in the lubricating oil composition in an amount of 25 to 300, 30 to 250, 34 to 250 wt. ppm.

[0092] According to some embodiments, the lubricating oil composition includes at least one antioxidant that can reduce or prevent oxidation of the oil or base oil of lubricating viscosity. Any antioxidant known to those of ordinary skill in the art can be used in the lubricating oil composition. Non-limiting examples of suitable antioxidants include amine-based antioxidants (e.g., alkyl diphenylamine, phenyl-a-naphthylamine, alkyl or aralkyl substituted phenyl-a-naphthylamine, alkylated p-phenylenediamine, tetramethyl-diaminodiphenylamine, and the like), phenolic antioxidants (e.g., 2-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 2,4,6-tri-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol, 4,4'-methylenebis-(2,6-di-tert-butylphenol), 4,4'-thio-bis(6-di-tert-butyl-o-cresol), and the like), sulfur-based antioxidants (e.g., dilauryl-3,3'-thiodipropionate, sulfurized phenolic antioxidants, and the like), phosphorus-based antioxidants (e.g., phosphites and the like), zinc dithiophosphates, oil-soluble copper compounds, and combinations thereof. The amount of antioxidant can vary between at least 0.01 wt.%, or at least 0.05 wt.%, or at least 0.1 wt.% and not more than 10 wt.%, or not more than 5 wt.%, or not more than 3 wt.%, based on the total weight of the lubricating oil composition. Some suitable antioxidants have been described in Leslie R. Rudnick, “Lubricant Additives: Chemistry and Applications,” New York, Marcel Dekker, Chapter 1, pages 1-28 (2003), which is incorporated herein by reference.

[0093] The lubricating oil composition can optionally include at least one pour point depressant that can reduce the pour point of the lubricating oil composition. Any pour point depressant known to those of ordinary skill in the art can be used in the lubricating oil composition. Non-limiting examples of suitable pour point depressants include polymethacrylates, alkyl acrylate polymers, alkyl methacrylate polymers, di(tetraalkylphenyl) phthalates, condensates of tetraalkylphenols, condensates of chlorinated paraffins with naphthalenes, and combinations thereof. In some embodiments, the pour point depressant includes ethylene-vinyl acetate copolymers, condensates of chlorinated paraffins and phenol, polyalkylstyrenes, and the like. The amount of pour point depressant can vary from at least 0.01 wt.%, or at least 0.05 wt.%, or at least 0.1 wt.% and not more than 10 wt.%, or not more than 5 wt.%, or not more than 3 wt.%, based on the total weight of the lubricating oil composition. Some suitable pour point depressants have been described in Mortier et al., “Chemistry and Technology of Lubricants,” 2ndEdition, London, Springer, Chapter 6, pages 187-189 (1996); and Leslie R. Rudnick, “Lubricant Additives: Chemistry and Applications,” New York, Marcel Dekker, Chapter 11, pages 329-354 (2003), both of which are incorporated herein by reference.

[0094] The lubricating oil composition can also include at least one foam inhibitor or antifoam additive. Any foam inhibitor or antifoam additive known to those of ordinary skill in the art can be used in the lubricating oil composition. Non-limiting examples of suitable antifoam additives include silicone oils or polydimethylsiloxanes, fluorosilicones, alkoxylated fatty acids, polyethers (e.g., polyethylene glycol), branched polyvinyl ethers, alkyl acrylate polymers, alkyl methacrylate polymers, polyalkyloxy amines, and combinations thereof. In some embodiments, the antifoam additive includes glycerol monostearate, polyethylene glycol palmitate, trialkyl monothiophosphates, sulfonated ricinoleates, benzoyl acetone, methyl salicylate, glycerol monooleate, or glycerol dioleate. The amount of antifoam additive can vary between at least 0.0001 wt.%, or at least 0.0005 wt.%, or at least 0.001 wt.% and not more than 1 wt.%, or not more than 0.5 wt.%, or not more than 0.1 wt.%, based on the total weight of the lubricating oil composition. Some suitable antifoam additives have been described in Mortier et al., “Chemistry and Technology of Lubricants,” 2ndEdition, London, Springer, Chapter 6, pages 190-193 (1996), which is incorporated by reference herein.

[0095] The lubricating oil composition can optionally include at least one corrosion inhibitor that can reduce corrosion. Any corrosion inhibitor known to those of ordinary skill in the art can be used in the lubricating oil composition. Non-limiting examples of suitable corrosion inhibitors include half-esters or amides of dodecyl succinic acid, phosphates, thiophosphates, alkyl imidazolines, sarcosines, benzotriazoles, thiadiazoles, and combinations thereof. The amount of corrosion inhibitor can vary between at least 0.001 wt.%, or at least 0.005 wt.% and not more than 5 wt.%, or not more than 1 wt.%, or not more than 0.5 wt.%, based on the total weight of the lubricating oil composition. Some suitable corrosion inhibitors have been described in Mortier et al., “Chemistry and Technology of Lubricants,” 2ndEdition, London, Springer, Chapter 6, pages 193-196 (1996), which is incorporated by reference herein.

[0096] The lubricating oil compositions disclosed herein can optionally include at least one extreme pressure (EP) agent that can prevent seizure of sliding metal surfaces under extreme pressure conditions. Any extreme pressure agent known to those of ordinary skill in the art can be used in the lubricating oil composition. Generally, extreme pressure agents are compounds that can chemically bond with metal to form a surface film that prevents welding to asperities in the opposing metal surface under high loads. Non-limiting examples of suitable extreme pressure agents include sulfurized animal or vegetable fats or oils, sulfurized animal or vegetable fatty acid esters, fully or partially esterified esters of phosphorous tri- or penta-valent acids, sulfurized olefins, dihydrocarbyl polysulfides, sulfurized Diels-Alder adducts, sulfurized dicyclopentadiene, sulfurized or co-sulfurized mixtures of fatty acid esters and mono-unsaturated olefins, co-sulfurized blends of fatty acids, fatty acid esters, and a-olefins, functionally substituted dihydrocarbyl polysulfides, thioaldehydes, thioketones, cyclic sulfur compounds, sulfur-containing acetal derivatives, co-sulfurized blends of terpenes and acyclic olefins, polysulfide olefin products, amine salts of phosphorus esters or thiophosphorus esters, and combinations thereof. The amount of extreme pressure agent can vary between at least 0.01 wt.%, or at least 0.05 wt.%, or at least 0.1 wt.% and not more than 5 wt.%, or not more than 3 wt.%, or not more than 1 wt.%, based on the total weight of the lubricating oil composition. Some suitable extreme pressure agents have been described in Leslie R. Rudnick, “Lubricant Additives: Chemistry and Applications”, New York, Marcel Dekker, Chapter 8, pages 223-258 (2003), which is incorporated herein by reference.

[0097] In one embodiment, the lubricating oil composition is free of sulfur-based extreme pressure agents.

[0098] The lubricating oil compositions disclosed herein can optionally include at least one rust inhibitor that can inhibit corrosion of ferrous metal surfaces. Any rust inhibitor known to those of ordinary skill in the art can be used in the lubricating oil composition. Non-limiting examples of suitable rust inhibitors include oil-soluble monocarboxylic acids (e.g., 2-ethylhexanoic acid, lauric acid, myristic acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, behenic acid, cerotic acid, etc.), oil-soluble polycarboxylic acids (e.g., those prepared from tall oil fatty acids, oleic acid, linoleic acid, etc.), alkenyl succinic acids in which the alkenyl group contains 10 or more carbon atoms (e.g., tetrapropenyl succinic acid, tetradecenyl succinic acid, hexadecenyl succinic acid, etc.); long chain a, w-dicarboxylic acids having a molecular weight in the range of 600 to 3000 daltons, and combinations. The amount of rust inhibitor can vary between at least 0.01 wt.%, or at least 0.05 wt.%, or at least 0.1 wt.% and not more than 10 wt.%, or not more than 5 wt.%, or not more than 3 wt.%, based on the total weight of the lubricating oil composition.

[0099] Other non-limiting examples of suitable rust inhibitors include non-ionic polyoxyethylene surfactants such as polyoxyethylene lauryl ether, polyoxyethylene higher alcohol ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene octyl stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitol monostearate, polyoxyethylene sorbitol monooleate, and polyethylene glycol monooleate. Other non-limiting examples of suitable rust inhibitors include stearic acid and other fatty acids, dicarboxylic acids, metal soaps, fatty acid amine salts, metal salts of heavy sulfonic acids, partial carboxylic esters of polyhydric alcohols, and phosphoric acid esters.

[0100] In some embodiments, the lubricating oil composition comprises at least one multifunctional additive. Some non-limiting examples of suitable multifunctional additives include sulfurized oxymolybdenum dithiocarbamates, sulfurized oxymolybdenum organodithiophosphates, oxymolybdenum monoglycerides, oxymolybdenum diacetamides, amine-molybdenum complexes, and sulfur-containing molybdenum complexes.

[0101] In certain embodiments, the lubricating oil composition comprises at least one viscosity index improver. Some non-limiting examples of suitable viscosity index improvers include polymethacrylate-type polymers, ethylene-propylene copolymers, styrene-isoprene copolymers, hydrated styrene-isoprene copolymers, polyisobutylenes, and dispersant-type viscosity index improvers.

[0102] In some embodiments, the lubricating oil composition comprises at least one metal deactivator. Some non-limiting examples of suitable metal deactivators include disalicylidene propylenediamine, triazole derivatives, thiadiazole derivatives, and mercaptobenzimidazoles.

[0103] The additives disclosed herein can be in the form of an additive concentrate having more than one additive. The additive concentrate can comprise a suitable diluent, such as a hydrocarbon oil having a suitable viscosity. Such diluents can be selected from the group consisting of natural oils (e.g., mineral oil), synthetic oils, and combinations thereof. Some non-limiting examples of mineral oils include paraffinic-based oils, naphthenic-based oils, asphaltic-based oils, and combinations thereof. Some non-limiting examples of synthetic base oils include polyolefin oils (especially hydrogenated a-olefin oligomers), alkylated aromatics, polyalkylene oxides, aromatic ethers, and carboxylic acid esters (especially diester oils), and combinations thereof. In some embodiments, the diluent is a natural or synthetic light hydrocarbon oil. Generally, the diluent oil can have a viscosity of 13 to 35 centistokes at 40 °C.

[0104] Generally, it is desirable for the diluent to readily dissolve the lubricating oil-soluble additives and provide an oil additive concentrate that is readily soluble in an oil, oiler, or fuel having a lubricating viscosity. Further, it is desirable for the diluent to not introduce any undesirable properties, including, for example, high volatility, high viscosity, and impurities such as heteroatoms, to the oil having a lubricating viscosity and, thus, ultimately to the finished lubricant or fuel.

[0105] According to certain embodiments, the lubricating oil composition comprises an oil-soluble additive concentrate composition comprising an inert diluent, and the oil-soluble additive concentrate composition is present in an amount of at least 2.0 wt% or at least 10 wt% and not more than 90 wt% or not more than 50 wt%, based on the total weight of the lubricating oil composition.

[0106] Examples The following examples are provided to illustrate embodiments of the present disclosure, but are not intended to limit the present disclosure to the specific embodiments set forth. Unless otherwise indicated, all parts and percentages are by weight. When a range of values is given, it is to be understood that embodiments outside of that stated range can still fall within the scope of the present disclosure. The specific details described in each example are not to be construed as essential features of the present disclosure.

[0107] Lubricating oil sample Lubricating oil samples (i.e., baseline, comparative, inventive examples) were evaluated for friction performance. Each sample included a friction modifier, a succinimide dispersant, and a phosphorus-containing antiwear additive. The samples were blended with a mixture comprising Group II and Group III base oils.

[0108] Friction modifier A A 2.0 liter glass reactor was charged with 211.7 g of diethylenetriamine (2 moles) and 1056.1 g of 2-hexyldecanoic acid (4.1 moles) under nitrogen. The mixture was heated to 180°C for one hour. The reaction temperature was increased to 190°C and vacuum was applied. After 2 hours, the temperature was again increased to 200°C and the mixture was held for an additional 2.5 hours. The nitrogen content of the final product was 6.72 wt%.

[0109] Dispersant Dispersant 1 is a boron-modified polyisobutylene-based bis-succinimide having a polyisobutylene number average molecular weight of 1,300 (N: 1.95 wt%; B: 0.63 wt%).

[0110] Dispersant 2 is a polyisobutylene-based bis-succinimide having a polyisobutylene number average molecular weight of 950 (N: 1.93 wt%).

[0111] Phosphorus-containing anti-wear additive Phosphorus compound 1 is inorganic phosphoric acid, H3PO4 (P: 27.0 wt%).

[0112] Phosphorus compound 2 is diphenyl hydrogen phosphite (P: 13.3 wt%) Phosphorus compound 3 is a monoalkyl amine salt of a dialkyl phosphate (P: 8.2 wt%, N: 1.8 wt%) Friction modifier Friction modifier 1 is an ethoxylated monoalkyl amine, available from Nouryon under the trade name Ethomeen® T / 12 (N: 4.1 wt%).

[0113] Friction modifier 2 is a mixture of C16 / C18 diols.

[0114] Friction modifier 3 is the reaction product of a C20 alkenyl substituted succinic anhydride with diethylenetriamine (N: 4.6 wt%).

[0115] The samples also include other lubricant additives, including detergents, antioxidants, metal deactivators, foam inhibitors, seal swell agents, and viscosity modifiers.

[0116] JASO SAE #2 friction test The dynamic and static friction tests were performed according to the Friction Test Method for Automobiles and Automobile Automatic Transmission Fluid (defined in JASO M348.2002) by means of a SAE No. 2 tester.

[0117] Friction material FZ127-24-Y12, Steel Plate (FZ132-8Y2) Kinetic friction measurement Moment of inertia of the inertia disc: 0.343 kgm

[0118] Rotational speed: 3,600 rpm Test cycle: 30 seconds / cycle, number of tests: 5,000 cycles Static friction measurement Rotational speed: 0.7 rpm

[0119] Friction plate surface pressure: 785 MPa Test period: 3 minutes after the start of rotation Test cycle: after 1, 5, 10, 20, 50, 100, 200, 500, 1000, 2000, 3000, 4000, and 5000 cycles Measurement Static friction coefficient (μs) at the maximum torque induced at the start of rotation at 0.7 rpm and the static coefficient (μt) after 2 seconds.

[0120] Transmission torque capacity was evaluated by the μt values at 50, 500 and 5000 cycles.

[0121] Wet clutch chatter resistance performance test JASO M349-2012 Anti-shudder durability was determined by a low speed friction apparatus according to "Road vehicles Test method for anti-shudder performance of automatic transmission fluids" described in JASO M-349:2012. In this test, a positive value of friction coefficient dμ / dV indicates anti-shudder performance. Details of the test method are described below.

[0122] Friction material Cellulose disc / steel plate; paper disc / steel plate Oil amount About 150 mL Run-in condition Contact pressure: 1 MPa Oil temperature: 80°C.

[0123] Slip speed: 0.6 m / s Slip time: 30 minutes Endurance test condition Contact pressure: 1 MPa Oil temperature: 120°C.

[0124] Slip speed: 0.9 m / s Slip time: 30 minutes Rest time: 1 minute Performance measurement time interval: 6 hours Anti-shudder duration was determined by measuring the duration required for dμ / dV to reach a negative value. The longer the duration, the better the anti-shudder performance.

[0125] Table 1

[0126] The results of the LVFA anti-shudder test show that the friction modifier A (reaction product of 2-hexyldecanoic acid and diethylenetriamine) of the present application performs as well as the alkenyl succinimide friction modifier. In contrast, the baseline formulation has a relatively short anti-shudder duration.

[0127] For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges "from any lower limit to any upper limit," where such ranges are explicitly listed, are considered to be expressly stated herin, even though only a single number may be named for the lower or upper limit. Accordingly, a range including only one number, for example the number 10, is considered to be explicitly stated as being open-ended to the exclusion of only 10 itself. Likewise, a range from 0.1 (or 0.01 or 0.001, etc.) to 10 is considered to be explicitly stated, even though only the number 10 is explicitly recited as the upper limit. In other words, a range of "from 0.1 (or 0.01 or 0.001, etc.) to 10" is considered to have been explicitly recited herein. Also, the terms "first", "second", "third", etc. merely identify different elements, rather than imply a particular ordering. Likewise, unless explicitly stated otherwise, the terms "first", "second", "third", etc. are not necessarily intended to identify one element as prior or precedent to another element. The mere use of the term "first" does not necessarily mean that such element is necessarily, chronologically, precede another element to which the term "second" is used.

[0128] Likewise, the term "comprising" is to be read to mean the inclusion of any stated elements or a subset thereof, but not to the exclusion of any other elements that are not specifically stated. Likewise, the term "comprising" is to be read to mean the inclusion of any stated elements or a subset thereof, but not to the exclusion of any other elements that are not specifically stated. Also, the terms "a" and "an" are to be read as meaning "one or more" unless otherwise indicated.

[0129] The terms "a" and "an" as used herein shall be understood to encompass one or more.

[0130] Various terms have been defined above. To the extent a term used in a claim is not defined above, such term is intended to be given the broadest definition construed in accordance with the principles of patent law including but not limited to the doctrine of equivalents. Furthermore, all patents, test procedures, and other documents cited in this application are fully incorporated by reference to the extent such disclosure is not inconsistent with this application and for all jurisdictions in which such incorporation is permitted.

[0131] The foregoing description of the present disclosure illustrates and describes the present disclosure. Additionally, the disclosure shows and describes only the preferred embodiments, but as mentioned above, it is to be understood that the disclosure is capable of use in various other combinations, modifications, and environments and is capable of changes or modifications within the scope of the concepts as expressed herein, commensurate with the above teachings and / or the skill or knowledge of the relevant art. While the foregoing relates to embodiments of the present disclosure, further and additional embodiments of the present disclosure can be devised without departing from the basic scope thereof, and that scope is determined by the claims that follow, the claims being in their broadest form.

[0132] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Pronouns in the masculine form include the feminine form, and vice versa, and the singular form also includes the plural form, unless the context clearly dictates otherwise.

[0133] The embodiments described above are further intended to explain the known best mode of practicing the disclosure and to enable one skilled in the art to utilize the disclosure in such or other embodiments and with various modifications as are suited to the particular use or application. The description is not intended to limit the disclosure to the form disclosed herein. Also, it is intended that the appended claims be construed to include alternative embodiments.

Claims

1. A lubricating oil composition comprising: (a) a major amount of an oil of lubricating viscosity; (b) one or more ashless dispersants; (c) at least one phosphorus-containing antiwear additive, wherein the at least one phosphorus-containing antiwear additive is a phosphorus-containing acid, a phosphate ester, a phosphite ester, a thiophosphate ester, or an amine salt thereof; (d) at least one friction modifier, wherein the at least one friction modifier is a diol, an ethoxylated amine, a fatty acid ester, or an alcohol; (e) a nitrogen-containing friction modifier having the structure wherein R 1 and R 2 are independently a branched C10-C25alkyl group.

2. The lubricating oil composition of claim 1, comprising phosphorus in an amount of 0.01 wt % to 0.20 wt %, based on the total weight of the lubricating oil composition.

3. The lubricating oil composition of claim 1, wherein the friction modifier of (e) is present in an amount of 0.01 wt % to 1.0 wt %, based on the total weight of the lubricating oil composition.

4. The lubricating oil composition of claim 1, wherein the friction modifier of (e) is present in an amount of 0.25 wt % to 0.75 wt %, based on the total weight of the lubricating oil composition.

5. The lubricating oil composition of claim 1, wherein the one or more ashless dispersants comprise a polyisobutenyl succinimide dispersant.

6. The lubricating oil composition of claim 5, wherein the polyisobutenyl group has a number average molecular weight of about 900 to about 1400.

7. The lubricating oil composition of claim 1, wherein the nitrogen-containing friction modifier is a reaction product of 2-hexyldecanoic acid and diethylenetriamine.

8. The lubricating oil composition of claim 1, wherein the phosphorus-containing acid is phosphoric acid or phosphorous acid.

9. The lubricating oil composition of claim 1, wherein the branched hydrocarbyl group comprises at least one tertiary carbon.

10. The lubricating oil composition of claim 1, wherein at least one of the branched hydrocarbyl groups is derived from octyldodecanoic acid or hexyldecanoic acid.

11. A method of improving chatter resistance, the method comprising: lubricating a transmission with a lubricating oil composition comprising: (a) a major amount of an oil of lubricating viscosity; (b) one or more ashless dispersants; (c) at least one phosphorus-containing antiwear additive, wherein the at least one phosphorus-containing antiwear additive is a phosphorus-containing acid, a phosphate ester, a phosphite ester, a thiophosphate ester, or an amine salt thereof; (d) at least one friction modifier, wherein the at least one friction modifier is a diol, an ethoxylated amine, a fatty acid ester, or an alcohol; (e) a nitrogen-containing friction modifier having the structure wherein R 1 and R 2 are independently a branched C10-C25alkyl group.

12. The method of claim 11, wherein the lubricating oil composition comprises phosphorus in an amount of 0.01 wt % to 0.20 wt %, based on the total weight of the lubricating oil composition.

13. The method of claim 11, wherein the friction modifier of (e) comprises phosphorus in an amount of 0.01 wt % to 1.0 wt %, based on the total weight of the lubricating oil composition.

14. The method of claim 11, wherein the friction modifier of (e) is present in an amount of 0.25 wt % to 0.75 wt %, based on the total weight of the lubricating oil composition.

15. The method of claim 11, wherein the one or more ashless dispersants comprise a polyisobutenyl succinimide dispersant.

16. The method of claim 15, wherein the polyisobutenyl groups have a number average molecular weight of about 900 to about 1400.

17. The method of claim 11, wherein the nitrogen-containing friction modifier is a reaction product of 2-hexyldecanoic acid and diethylenetriamine.

18. The method of claim 1, wherein the phosphorus-containing acid is phosphoric acid or phosphorous acid.

19. The method of claim 11, wherein the branched hydrocarbyl group comprises at least one tertiary carbon.

20. The method of claim 11, wherein at least one of the branched hydrocarbyl groups is derived from octyldodecanoic acid or hexyldecanoic acid.

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