Lubricating oil composition

Abstract

The present disclosure provides a lubricating oil composition comprising a major amount of an oil of lubricating viscosity and one or more nitrogen-containing additives having the following formula (I): [Formula 1] TIFF2025505822000013.tif54165 In the formula, R 1 is a functional group containing 10 to 250 carbon atoms, R 2 and R 3 is independently a functional group containing 2 to 20 carbon atoms.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims the benefit of U.S. Provisional Application No. 63 / 312,122, filed on 21 February 2022, which is incorporated herein by reference in its entirety.

[0002] Areas of this disclosure This disclosure relates to a lubricating oil composition for an internal combustion engine equipped with a transmission utilizing a wet clutch mechanism. [Background technology]

[0003] Modern lubricants are often formulated according to the strict specifications set by the original equipment manufacturer. To meet these requirements, carefully selected lubricating additives are blended with a base oil of lubricating viscosity. Typical lubricating oil compositions may include, for example, dispersants, detergents, antioxidants, anti-wear agents, rust inhibitors, corrosion inhibitors, anti-foaming agents, and / or friction modifiers.

[0004] The set of additives included in a lubricating oil composition or engine oil composition is determined by the specific application or use. For example, motorcycle engine oil lubricates both the engine and the transmission, which has gears and a wet clutch mechanism, and as a result, the drivetrain is affected by the engine oil. In contrast, while passenger cars may have dry or wet clutches, the drivetrain is usually not affected by the engine oil.

[0005] Furthermore, wet clutches are often made from cellulose fibers and / or aramid fibers, which take into account the design of the motorcycle engine oil. For example, zinc dithiophosphate (ZnDTP) is widely used as a conventional anti-wear additive in engine oil. However, the use of ZnDTP in motorcycles presents challenges because it can form sludge in the porous components of paper clutches, which can cause blockages. Blockages can lead to reduced cooling by the oil and reduced cooling of the clutch material.

[0006] In some applications (e.g., automatic transmission fluids), ZnDTP is largely reduced and replaced with sulfur-phosphorus additives. However, completely removing ZnDTP from motorcycle engine oil is still not practical. Furthermore, when wet paper clutches are used, low sulfate ash or s-ash is generally desirable. For these and other reasons, engine oils specially formulated for motorcycles are required. [Overview of the project]

[0007] In one embodiment, the present invention relates to a lubricating oil composition comprising a main amount of oil with lubricating viscosity and one or more nitrogen-containing additives having the following formula: [ka] In the formula, R 1 However, it is a functional group containing 10 to 250 carbon atoms, and R 2 and R 3 This invention relates to a lubricating oil composition in which the functional group independently contains 2 to 20 carbon atoms.

[0008] In another embodiment, the present invention provides a method for increasing the coefficient of friction of a wet clutch, comprising contacting a metal surface with a lubricating oil composition comprising an oil of a major amount of lubricating viscosity and one or more nitrogen-containing additives having the following formula: [ka] In the formula, R 1 It is a functional group containing 10 to 250 carbon atoms, and R 2 The present invention relates to a method wherein R3 is independently a functional group containing 2 to 20 carbon atoms. [Modes for carrying out the invention]

[0009] definition The following terms are used throughout the present specification and have the following meanings unless otherwise indicated.

[0010] The term "major amount" of an oil of lubricating viscosity refers to that the amount of the base oil is at least 40% by weight of the lubricating oil composition. In some embodiments, "major amount" refers to an amount of base oil of more than 50% by weight, more than 60% by weight, more than 70% by weight, more than 80% by weight, or more than 90% by weight of the lubricating oil composition.

[0011] In the following description, all numerical values disclosed herein are approximate values, regardless whether the term "about" or "approximately" is used in connection therewith. They may have a variation of 1%, 2%, 5%, or in some cases 10 to 20%.

[0012] The term "succinimide" is understood in the art to include many of the amide, imide, and amidine species that can be formed by the reaction of succinic anhydride with an amine. However, the main product is succinimide, and this term is generally accepted to mean the product of the reaction of succinic acid (or substituted succinic acid) or an anhydride with an amine. Substituted succinimides are disclosed in numerous references and are well known in the art. Certain basic types of succinimides and related materials encompassed by the term "succinimide" in the art are taught in U.S. Patent Nos. 2,992,708; 3,018,291; 3,024,237; 3,100,673; 3,219,666; 3,172,892; and 3,272,746.

[0013] The present disclosure relates to a lubricant additive composition and its formulation in a lubricating oil composition specifically designed for engines found in motorcycles. The composition(s) leads to a reduction in sulfated ash and / or maintain a high coefficient of friction related to the clutch torque capacity of wet clutches.

[0014] In another aspect, the present disclosure relates to a novel composition that is particularly useful as a lubricating additive for engines using wet clutch mechanisms, such as engines of motorcycles, construction machinery, and / or industrial machinery.

[0015] Lubricating oil compositions comprising the lubricating additive can maintain high levels of engine oil performance, such as excellent wet clutch friction characteristics, excellent anti-wear properties, and / or reduced sulfate ash levels. The lubricating oil composition can exhibit improved anti-wear performance even when using low levels of conventional anti-wear additives such as ZnDTP.

[0016] Furthermore, the lubricating oil composition comprising the lubricating additive can prevent misfire caused by catalyst poisoning for exhaust gas regulations and / or fouling of spark plugs while maintaining a high coefficient of friction so as not to reduce the clutch torque transmission capacity of the wet clutch. In addition, the lubricating oil composition can maintain low levels of sulfated ash (s-ash) and phosphorus, which are generally desirable for motorcycle engines.

[0017] In one embodiment, the present invention provides a lubricating oil composition comprising a base oil of lubricating viscosity and a nitrogen-containing additive. In some embodiments, the lubricating oil composition contains less than about 900 ppm of zinc. In some embodiments, the lubricating oil composition contains a reduced amount of sulfated ash, for example from about 0.3 wt% to about 1.2 wt%, based on the total amount of the lubricating oil composition.

[0018] The lubricating oil composition of the present application generally has an SAE viscosity grade of 0W-16, 0W-20, 0W-30, 5W-30, 10W-30, 0W-40, 5W-40, 10W-40, 15W-40, 0W-50, 5W-50, 10W-50, 20W-40, 20W-50, or 10W-60.

[0019] The lubricating oil composition generally has a viscosity index of greater than about 120, or greater than about 135, or greater than about 150, or greater than about 180, or greater than about 200, up to about 270 or more.

[0020] When it comes to engine oil that lubricates not only the engine but also the transmission, additional considerations can be important. For example, high kinematic viscosity at low temperatures can lead to poor starting performance, while at high temperatures, high kinematic viscosity is necessary to prevent gear wear and pitting corrosion. Viscosity index is an important factor not only for fuel economy but also for starting performance and transmission durability. Lubricating viscosity base oil

[0021] The lubricating oil compositions disclosed herein generally comprise at least one base oil of lubricating viscosity. Any base oil known to those skilled in the art can be used as the lubricating oil of the viscosities disclosed herein. Several base oils suitable for preparing lubricating oil compositions are described in Mortier et al., “Chemistry and Technology of Lubricants,” 2nd Edition, 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 DVBrock, Lubrication Engineering, Vol. 43, pages 184-5, (1987), all of which are incorporated herein by reference.

[0022] Generally, the amount of base oil in a lubricating oil composition is the "main amount" of oil with the lubricating viscosity defined above.

[0023] In certain embodiments, the base oil is or comprises any natural or synthetic lubricating base oil fraction. Some non-limiting examples of synthetic oils include oils such as polyalphaolefins or PAOs, prepared from the polymerization of at least one alpha-olefin, such as ethylene, or from hydrocarbon synthesis procedures using carbon monoxide and hydrogen gas, such as the Fischer-Tropsch process.

[0024] In some embodiments, the base oil has a kinematic viscosity at 100°C of about 2.5 centistokes (cSt) to about 40 cSt, for example, about 4 centistokes (cSt) to about 30 cSt, about 5 cSt to about 16 cSt, about 6 cSt to about 15 cSt, about 2.5 cSt to about 35 cSt, about 2.5 cSt to about 30 cSt, about 2.5 cSt to about 25 cSt, about 4 cSt to about 25 cSt, about 4 cSt to about 20 cSt, about 5 cSt to about 40 cSt, about 5 cSt to about 35 cSt, about 6 cSt to about 40 cSt, or about 6 cSt to about 30 cSt. The kinematic viscosity of the base oil or lubricating oil composition disclosed herein may be measured according to ASTM D445, a standardization protocol shown by ASTM International and incorporated herein by reference.

[0025] In some embodiments, the base oil is or comprises a base stock or a blend of base stocks. In further embodiments, the base stock is produced using a variety of different processes, including but not limited to distillation, solvent purification, hydrogenation, oligomerization, esterification, and repurification. In some embodiments, the base stock comprises repurified stock. In further embodiments, the repurified stock is substantially free of material introduced by manufacturing, contamination, or prior use.

[0026] In some embodiments, the base oil comprises one or more base stocks from groups I to V as specified in American Petroleum Institute (API) Publication 1509, Fourteen Edition, December 1996 (i.e., API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils) (incorporated herein by reference). The API guidelines define base stocks as lubricating components that can be produced using a variety of different processes. Base stocks of groups I, II, and III are mineral oils, each having a specific range of saturation amounts, sulfur content, and viscosity index. Base stocks of group IV are polyalphaolefins (PAOs). Base stocks of group V comprise all other base stocks not included in groups I, II, III, or IV.

[0027] In some embodiments, the base oil comprises one or more base stocks from groups I, II, III, IV, and V, including any combination thereof. In other embodiments, the base oil comprises one or more base stocks from groups II, III, and IV, including any combination thereof.

[0028] The base oil may include natural oils of lubricating viscosity, synthetic oils of lubricating viscosity, and / or mixtures thereof. In some embodiments, the base oil includes base stocks obtained by isomerization of synthetic waxes and slack waxes, as well as hydrocracking base stocks produced by hydrocracking (rather than solvent extraction) the aromatic and polar components of crude oil. In other embodiments, the base oil of lubricating viscosity includes natural oils, e.g., animal oils, vegetable oils, mineral oils (e.g., liquid petroleum and paraffinic, naphthenic, or mixed paraffin-naphthenic solvent-treated or acid-treated mineral oils), coal or shale-derived oils, and combinations thereof. Some non-limiting examples of animal oils include bone oil, lanolin, fish oil, lard, dolphin oil, seal oil, shark oil, tallow oil, and whale oil. Some non-exclusive examples of vegetable oils include castor oil, olive oil, peanut oil, rapeseed oil, corn oil, sesame oil, cottonseed oil, soybean oil, sunflower oil, safflower oil, hemp oil, linseed oil, tung oil, oyster oil, jojoba oil, and meadowfoam oil. Such oils may be partially or fully hydrogenated.

[0029] In some embodiments, synthetic oils of lubricating viscosity include hydrocarbon oils and / or halo-substituted hydrocarbon oils, such as polymerized and copolymerized olefins, alkylbenzenes, polyphenyls, alkylated diphenyl ethers, alkylated diphenyl sulfides, and their derivatives, analogs, and homologs. In other embodiments, synthetic oils include alkylene oxide polymers, interpolymers, copolymers, and their derivatives, where terminal hydroxyl groups may be modified by esterification, etherification, etc. In further embodiments, synthetic oils include esters of dicarboxylic acids and various alcohols. In certain embodiments, synthetic oils include C5-C 12 Examples include monocarboxylic acids and esters produced from polyols and polyol ethers. In further embodiments, examples of synthetic oils include trialkyl phosphate oils such as tri-n-butyl phosphate and tri-iso-butyl phosphate.

[0030] In some embodiments, examples of synthetic oils with lubricating viscosity include silicone-based oils (such as polyalkyl-, polyaryl-, polyalkoxy-, polyaryloxysiloxane oils, and silicate oils). In other embodiments, examples of synthetic oils include liquid esters of phosphorus-containing acids, high molecular weight tetrahydrofurans, and polyalphaolefins.

[0031] Base oils derived from the hydrogen isomerization of waxes may also be used alone or in combination with the aforementioned natural and / or synthetic base oils. Such wax isomerized oils are produced by hydrogen isomerizing natural or synthetic waxes or mixtures thereof on a hydrogen isomerization catalyst.

[0032] In further embodiments, the base oil comprises poly-alpha-olefins (PAOs). Generally, poly-alpha-olefins can be derived from alpha-olefins having about 2 to about 40, about 4 to about 20, or about 6 to about 16 carbon atoms. Non-limiting examples of suitable poly-alpha-olefins include those derived from octene, decene, or mixtures thereof. These poly-alpha-olefins may have viscosities of about 2 cSt to about 40 cSt at 100°C, for example, about 2 cSt to about 30 cSt, about 2 cSt to about 20 cSt, about 2 cSt to about 12 cSt, about 3 cSt to about 40 cSt, about 3 cSt to about 30 cSt, about 3 cSt to about 20 cSt, about 3 cSt to about 12 cSt, or about 4 to about 10 centistokes. In some cases, poly-alpha-olefins may be used with other base oils, such as mineral oils.

[0033] In further embodiments, the base oil comprises a polyalkylene glycol or a polyalkylene glycol derivative, where the terminal hydroxyl groups of the polyalkylene glycol or its derivative may be modified by esterification, etherification, acetylation, etc. 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, etc.), monocarboxylic acid esters and polycarboxylic acid esters of polyalkylene glycols, and combinations thereof. In some cases, the polyalkylene glycol or polyalkylene glycol derivative may be used with other base oils such as poly-alpha-olefins and mineral oil.

[0034] In further embodiments, the base oil includes any esters of dicarboxylic acids (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, etc.) and various alcohols (e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol, etc.). Non-limiting examples of these esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelaate, diisodecyl azelaate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, and 2-ethylhexyl diester of linoleic acid dimer.

[0035] In further embodiments, the base oil comprises hydrocarbons 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. Further processing may be required to make these hydrocarbons useful as base oils. For example, the hydrocarbons can be dewaxed, hydrogen-isomerized, and / or hydrocrackened using methods known to those skilled in the art.

[0036] In further embodiments, the base oil includes unrefined oil, refined oil, re-refined oil, or mixtures thereof. Unrefined oil is oil obtained directly from natural or synthetic sources without further refining. Non-limiting examples of unrefined oil include shale oil obtained directly from retort extraction (dry distillation) operations, petroleum obtained directly from primary distillation, and ester oil obtained directly from esterification processes and used without further processing. Refined oil is similar to unrefined oil, except that the former is further processed by one or more refining processes to improve one or more properties. Many such refining processes are known to those skilled in the art, such as solvent extraction, secondary distillation, acid or base extraction, filtration, and leaching. Re-refined oil is obtained by applying a process similar to that used to obtain refined oil to refined oil. Such re-refined oil is also known as recycled oil or reprocessed oil and is often further processed by processes aimed at removing spent additives and oil decomposition products. Nitrogen-containing additives

[0037] The lubricating oil composition of the present invention comprises one or more nitrogen-containing additives as described herein. In one embodiment, the nitrogen-containing additive is a reaction product of succinimide and thiophosphate or an acid ester.

[0038] The succinimide in the reaction may contain an alkyl group, a cyclic group, an aromatic group, or a heteroatom-containing group, or may be substituted with any of the foregoing. Suitable examples of the functional group include 2-ethoxyethanol, 2(2-ethoxyethoxy)ethanol, 2-cyclohexyloxyethanol, 2-phenoxyethanol, and ethoxylated alkylphenol.

[0039] The succinimide reacts with a thiophosphate ester and the bis form thereof (i.e., bis-succinimide) or forms a salt. The reaction product can be represented by Formula I shown below:

Chemical Formula

[0040] The nitrogen-containing additive may be present in an amount of about 0.5% by weight to about 5.0% by weight, for example, about 0.7% by weight to about 4.5% by weight, about 1.0% by weight to about 4.0% by weight, about 1.0% by weight to about 3.5% by weight, based on the total weight of the lubricating oil composition.

[0041] In some embodiments, the nitrogen-containing additive may be present in an amount that provides about 100 ppm to about 5000 ppm of phosphorus, for example, about 100 ppm to about 4000 ppm, or about 1000 ppm to about 3000 ppm of phosphorus, based on the total weight of the lubricating oil composition.

[0042] Succinimide may be prepared by any known method, such as those described in U.S. Patent Publication No. 20180034635 and U.S. Patent No. 7,091,306 (incorporated herein by reference).

[0043] Exemplary examples, substituted succinimides (e.g., alkyl-substituted succinimides) can be obtained as products of the reaction between alkyl-substituted succinic anhydride and polyamines. In lubricating oil applications, succinic anhydride is usually substituted at the alpha position with an alkyl chain such as polyisobutylene (PIBSA) or a PIBSA-type moiety. In one embodiment, R 1 R is a polyisobutenyl substituent derived from polyisobutene, where the polyisobutenyl substituent has 10 to 250 carbon atoms. In some embodiments, R 1 It has a molecular weight in the range of approximately 120 to approximately 3000, for example, approximately 700 to approximately 2500, approximately 800 to approximately 2000, and approximately 900 to approximately 1500.

[0044] For lubricating oil applications, polyalkylene polyamines may be particularly useful. However, other polyamines suitable for the present invention may be used. Polyamines can react with alkyl-substituted succinic anhydride to produce mono-succinimide, bis-succinimide, tris-succinimide, or mixtures thereof, depending on the molar ratio.

[0045] Suitable polyamines may have a linear or branched structure and may be cyclic, acyclic, or a combination thereof. In some embodiments, polyalkylene polyamines may be used to prepare bissuccinimide dispersants. Such polyalkylene polyamines typically contain about 2 to about 12 nitrogen atoms and about 2 to 24 carbon atoms. Particularly suitable polyalkylene polyamines include those having the formula:H2N-(R'NH)xH (wherein R' is a linear or branched alkylene group having 2 or 3 carbon atoms, and x is 1 to 9). Representative examples of suitable polyalkylene polyamines include diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), and heavier polyalkylene amines (HPA).

[0046] In some embodiments, the polyamine may contain a cyclic group. Specific examples include N,N'-bis-(2-aminoethyl)piperazine) (bisAEP), N-[(2-aminoethyl)2-aminoethyl]piperazine) (PEEDA), 1-(2-aminoethyl)-4-[(2-aminoethyl)amino]ethyl]-piperazine) (AEPEEDA), and 1-[2-[[2-[(2-aminoethyl)amino]ethyl]amino]ethyl]-piperazine) (PEDETA).

[0047] Many of the polyamines suitable for use in the present invention are commercially available, and others can be prepared by methods well known in the art. For example, methods for preparing amines and their reactions are described in detail below: Sidgewick's "The Organic Chemistry of Nitrogen," Clarendon Press, Oxford, 1966; Noller's "Chemistry of Organic Compounds," Saunders, Philadelphia, 2nd Ed., 1957; and Kirk-Othmer's "Encyclopedia of Chemical Technology," 2nd Ed., Volume 2, pp. 99-116.

[0048] Generally, substituted succinic anhydride is reacted with polyamine at temperatures of approximately 130°C to 220°C (e.g., 140°C to 200°C, 145°C to 175°C, etc.). The reaction may be carried out under an inert atmosphere such as nitrogen or argon. Generally, a suitable molar charge of polyamine to substituted succinic anhydride is approximately 0.35:1 to approximately 1:1 (e.g., 0.4:1 to 0.75:1). As used herein, “molar charge of polyamine to substituted succinic anhydride” means the ratio of the number of moles of polyamine to the number of succinic groups in the succinic anhydride reaction product.

[0049] In general, the synthesis of thiophosphate esters is well known. For example, thiophosphate esters can be prepared by treating phosphorus pentasulfide with a stoichiometric excess of alcohol. This reaction is usually carried out in a non-reactive solvent while removing the liberated hydrogen sulfide.

[0050] The molar charge ratio (CMR) of polyamine to dithiophosphate can be important to ensure the correct reaction product. In some embodiments, the CMR of polyamine to dithiophosphate ester is about 1:1. In some embodiments, an excess of dithiophosphate ester is used so that the molar charge ratio of polyamine to acid ester is about 1:2. Other CMRs may also result in desirable nitrogen-containing additives. Other additives

[0051] The lubricating oil composition may further contain additives or modifiers (hereinafter referred to as "additives") that can impart or improve any desired properties of the lubricating oil composition to the extent that it matches the components and properties of the lubricating composition described above. Any additive known to those skilled in the art may be used in the lubricating oil compositions disclosed herein. Several suitable additives are described in Mortier et al., “Chemistry and Technology of Lubricants,” 2nd Edition. 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, additives can be selected from the group consisting of antioxidants, anti-wear agents, cleaning agents, rust inhibitors, anti-emulsifiers, friction modifiers, multifunctional additives, viscosity index improvers, pour point depressants, foam inhibitors, metal deactivators, dispersants, corrosion inhibitors, lubricity improvers, thermal stability improvers, anti-fogging additives, anti-icing agents, dyes, markers, antistatic agents, biocides, and combinations thereof. Certain additives are multifunctional and can be classified into multiple categories.

[0052] Generally, the concentration of each additive in a lubricating oil composition, when used, may range from about 0.001% to about 10% by weight, about 0.01% to about 5% by weight, or about 0.1% to about 2.5% by weight, based on the total weight of the lubricating oil composition. Furthermore, the total amount of additives in a lubricating oil composition may range from about 0.001% to about 20% by weight, about 0.01% to about 10% by weight, or about 0.1% to about 5% by weight, based on the total weight of the lubricating oil composition.

[0053] Cleansing agent Any cleaning agent suitable for the present invention may be used. Several suitable cleaning agents are described in Mortier et al., “Chemistry and Technology of Lubricants,” 2nd Edition, 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.

[0054] Suitable cleaning agents include oil-soluble hyperbasic sulfonates, non-sulfonate-containing phenates, sulfide phenates, salixalates, salicylates, saligenin, complex cleaning agents and naphthenic acid cleaning agents, as well as other oil-soluble alkylhydroxybenzoates of metals, particularly alkali or alkaline earth metals (e.g., barium, sodium, potassium, lithium, calcium, and magnesium). The most commonly used metals are calcium and magnesium, both of which can be found in cleaning agents used in lubricants, and in mixtures of calcium and / or magnesium with sodium.

[0055] wear-resistant agent Optionally, the lubricating oil compositions disclosed herein may contain one or more anti-wear agents. The anti-wear agents reduce wear on metal parts. Suitable anti-wear agents include zinc dithiophosphate (ZnDTP) or zinc dihydrocarbyl dithiophosphate (ZDDP) having the following structure: Zn[SP(=S)(OR1)(OR2)]2, where R1 and R2 are the same or different hydrocarbyl groups having 1 to 18 (e.g., 2 to 12) carbon atoms and including groups such as alkyl, alkenyl, aryl, arylalkyl, alkaryl, and alicyclic groups. Particularly preferred as R1 and R2 groups are alkyl groups having 2 to 8 carbon atoms (e.g., alkyl groups may be ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, and 2-ethylhexyl). To obtain oil solubility, the total number of carbon atoms (i.e., R1 + R2) is at least 5. Therefore, zinc dihydrocarbyl dithiophosphate may contain zinc dialkyldithiophosphate. Zinc dialkyldithiophosphate is primary, secondary, or a combination thereof. ZDDP or ZnDTP may be present in the lubricating oil composition at a concentration of 1.5% by weight or less (e.g., 0.1-1.0% by weight, or 0.3-1.0% by weight).

[0056] Dispersant Optionally, the lubricating oil compositions disclosed herein may further contain dispersants. Dispersants retain insoluble substances in the oil that result from oxidation during engine operation in the suspension, thus preventing sludge aggregation and precipitation or deposition on metal parts. Useful dispersants herein include nitrogen-containing ashless (metal-free) dispersants known to be effective in reducing deposit formation when used in gasoline and diesel engines. Suitable dispersants include hydrocarbyl succinimide, mixed esters / amides of hydrocarbyl succinimide and hydrocarbyl-substituted succinic acid, hydroxy esters of hydrocarbyl-substituted succinic acid, Mannich condensation products of hydrocarbyl-substituted phenol, formaldehyde, and polyamines. Condensation products of polyamines and hydrocarbyl-substituted phenyl acids are also suitable. Mixtures of these dispersants can also be used.

[0057] Basic nitrogen-containing ashless dispersants are well-known lubricant additives, and methods for their preparation are extensively described in the patent literature. Preferred dispersants are alkenyl succinimides and succinimides, where the alkenyl substituent is preferably a long chain of more than 40 carbon atoms. These materials are readily produced by reacting hydrocarbyl-substituted dicarboxylic acid materials with molecules containing amine functional groups. Examples of preferred amines are polyamines such as polyalkylene polyamines, hydroxy-substituted polyamines, and polyoxyalkylene polyamines. As is well known in the art, the dispersants may be post-treated (e.g., with boronating agents, ethylene carbonates, or cyclic carbonates). Nitrogen-containing ashless (metal-free) dispersants are basic and contribute to the TBN of the lubricant composition to which they are added without introducing additional sulfate ash. The dispersant may be present in the lubricating oil composition at a concentration of 0.1 to 10% by weight (e.g., 0.5 to 8, 0.7 to 7, 0.7 to 6, 0.7 to 6, 0.7 to 5, 0.7 to 4% by weight) based on the active substance level. Nitrogen from the dispersant is present at a concentration of more than 0.0050 to 0.30% by weight (e.g., more than 0.0050 to 0.10%, 0.0050 to 0.080%, 0.0050 to 0.060%, 0.0050 to 0.050%, 0.0050 to 0.040%, and more than 0.0050 to 0.030% by weight) based on the weight of the dispersant in the finished oil.

[0058] Antioxidant Optionally, the lubricating oil compositions disclosed herein may further include antioxidants that can reduce or prevent oxidation of the base oil. Any antioxidant known to those skilled in the art may be used in the lubricating oil compositions. Non-limiting examples of suitable antioxidants include amine antioxidants (e.g., alkyldiphenylamine, phenyl-alpha-naphthylamine, alkyl or aralkyl-substituted phenyl-alpha-naphthylamine, alkylated p-phenylenediamine, tetramethyl-diaminodiphenylamine, etc.) and phenolic antioxidants (e.g., 2-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 2,4,6-tri-tert-butylphenol, 2,6 Examples of antioxidants include di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol, 4,4'-methylenebis-(2,6-di-tert-butylphenol), 4,4'-thiobis(6-di-tert-butyl-o-cresol), sulfur-based antioxidants (e.g., dilauryl-3,3'-thiodipropionate, sulfur-phenol-based antioxidants, etc.), phosphorus-based antioxidants (e.g., phosphates, etc.), certain molybdenum complexes, oil-soluble copper compounds, and combinations thereof. The amount of antioxidant may vary from about 0.01% to about 10% by weight, about 0.05% to about 5% by weight, or about 0.1% to about 3% by weight, based on the total weight of the lubricating oil composition. Several suitable antioxidants are described in Leslie R. Rudnick, “Lubricant Additives: Chemistry and Applications,” New York. Marcel Dekker, Chapter 1, pages 1-28 (2003), which are incorporated herein by reference.

[0059] In particular, the molybdenum complex formed as a reaction product of molybdenum oxysulfide and monosuccinimide undergoes oxidative decomposition and NO x It is effective in preventing degradation caused by [unspecified factor]. The molybdenum complex may be present in the lubricating oil composition in an amount that provides about 500 ppm or less of molybdenum, for example, about 400 ppm or less, for example, about 300 ppm or less.

[0060] Suitable molybdenum succinimide complexes are described, for example, in U.S. Patent No. 8,076,275, which is incorporated herein by reference. These complexes are prepared by a process comprising reacting an acidic molybdenum compound with an alkyl or alkenyl succinimide.

[0061] Pour point depressant The lubricating oil compositions disclosed herein may optionally contain a pour point depressant capable of lowering the pour point of the lubricating oil composition. Any pour point depressant known to those skilled in the art may be used in the lubricating oil composition. Non-limiting examples of suitable pour point depressants include polymethacrylates, alkyl acrylate polymers, alkyl methacrylate polymers, di(tetra-paraffinphenol)phthalates, tetra-paraffinphenol condensates, chlorinated paraffin-naphthalene condensates, and combinations thereof. In some embodiments, the pour point depressant includes ethylene-vinyl acetate copolymers, chlorinated paraffin-phenol condensates, polyalkylstyrenes, and the like. The amount of pour point depressant may vary from about 0.01% to about 10% by weight, about 0.05% to about 5% by weight, or about 0.1% to about 3% by weight, based on the total weight of the lubricating oil composition. Several suitable pour point depressants are described in Mortier et al., “Chemistry and Technology of Lubricants,” 2nd Edition, 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.

[0062] Antiemulsifier The lubricating oil compositions disclosed herein may optionally contain an antiemulsifier that can promote oil-water separation in the lubricating oil composition when exposed to water or vapor. Any antiemulsifier known to those skilled in the art may be used in the lubricating oil composition. Non-limiting examples of suitable antiemulsifiers include anionic surfactants (e.g., alkylnaphthalene sulfonates, alkylbenzene sulfonates, etc.), nonionic alkoxylated alkylphenol resins, alkylene oxide polymers (e.g., polyethylene oxide, polypropylene oxide, ethylene oxide block copolymers, propylene oxide, etc.), oil-soluble acid esters, polyoxyethylene sorbitan esters, and combinations thereof. The amount of antiemulsifier may vary from about 0.01% to about 10% by weight, about 0.05% to about 5% by weight, or about 0.1% to about 3% by weight, based on the total weight of the lubricating oil composition. Several suitable antiemulsifiers are described in Mortier et al., “Chemistry and Technology of Lubricants,” 2nd Edition, London, Springer, Chapter 6, pages 190-193 (1996), which are incorporated herein by reference.

[0063] Anti-foaming agent The lubricating oil compositions disclosed herein may optionally contain antifoaming agents or defoaming agents capable of disrupting foam in the oil. Any antifoaming agents or defoaming agents known to those skilled in the art may be used in the lubricating oil compositions. Non-limiting examples of suitable defoaming agents include silicone oils or polydimethylsiloxanes, fluorosilicones, alkoxylated fatty acids, polyethers (e.g., polyethylene glycol), branched polyvinyl ethers, alkyl acrylate polymers, alkyl methacrylate polymers, polyalkoxyamines, and combinations thereof. The amount of defoaming agent may vary from about 0.0001% by weight to about 0.50% by weight, from about 0.001% by weight to about 0.1% by weight, and from about 0.1% by weight to about 0.05% by weight, based on the total weight of the lubricating oil composition. Several suitable antifoaming agents are described in Mortier et al., “Chemistry and Technology of Lubricants,” 2nd Edition, London, Springer, Chapter 6, pages 190-193 (1996), which are incorporated herein by reference.

[0064] Corrosion inhibitor The lubricating oil compositions disclosed herein may optionally contain corrosion inhibitors that can reduce corrosion. Any corrosion inhibitor known to those skilled in the art may be used in the lubricating oil compositions. Non-limiting examples of suitable corrosion inhibitors include dodecyl succinic acid semi-esters or amides, phosphate esters, thiophosphates, alkylimidazolines, sarcosines, and combinations thereof. The amount of corrosion inhibitor may vary from about 0.01% to about 5% by weight, about 0.03% to about 3% by weight, or about 0.05% to about 1% by weight, based on the total weight of the lubricating oil composition. Several suitable corrosion inhibitors are described in Mortier et al., “Chemistry and Technology of Lubricants,” 2nd Edition, London, Springer, Chapter 6, pages 193-196 (1996), which is incorporated herein by reference.

[0065] Extreme pressure agent The lubricating oil compositions disclosed herein may optionally contain extreme pressure (EP) agents capable of preventing seizing of metal surfaces sliding under extreme pressure conditions. Any extreme pressure agent known to those skilled in the art can be used in the lubricating oil compositions. Generally, extreme pressure agents are compounds that can chemically bond with metals to form a surface film that prevents welding of irregularities between opposing metal surfaces 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, completely or partially esterified esters of trivalent or pentavalent phosphorus acids, sulfurized olefins, dihydrocarbyl polysulfides, Diels-Alder sulfide adducts, dicyclopentadiene sulfides, sulfurized or cosulfurized mixtures of fatty acid esters and monounsaturated olefins, fatty acids, cosulfurized blends of fatty acid esters and alpha-olefins, functionally substituted dihydrocarbyl polysulfides, thia-aldehydes, thia-ketones, epithio compounds, sulfur-containing acetal derivatives, cosulfurized blends of terpenes and acyclic olefins, polysulfide olefin products, amine salts of phosphate esters or thiophosphate esters, and combinations thereof. Diallyl dithiophosphate zinc, described as an anti-wear agent, is also frequently used as an extreme pressure agent. The amount of extreme pressure additive may vary from about 0.01% to about 5% by weight, about 0.05% to about 3% by weight, or about 0.1% to about 1% by weight, based on the total weight of the lubricating oil composition. Several suitable extreme pressure additives are 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.

[0066] Rust inhibitor The lubricating oil compositions disclosed herein may optionally contain rust inhibitors capable of suppressing corrosion of iron metal surfaces. Any rust inhibitor known to those skilled in the art may be used in the lubricating oil compositions. 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 produced from tall oil fatty acids, oleic acid, linoleic acid, etc.), alkenyl succinic acids containing 10 or more carbon atoms in an alkenyl group (e.g., tetrapropenyl succinic acid, tetradecenyl succinic acid, hexadecenic acid, etc.); long-chain alpha,omega-dicarboxylic acids having molecular weights in the range of 600 to 3000 daltons, and combinations thereof. The amount of rust inhibitor may vary from about 0.01% to about 10% by weight, about 0.05% to about 5% by weight, or about 0.1% to about 3% by weight, based on the total weight of the lubricating oil composition.

[0067] Other non-limiting examples of suitable rust inhibitors include nonionic polyoxyethylene surfactants such as polyoxyethylene lauryl ether, polyoxyethylene higher alcohol ether, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene octyl stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitol monostearate, polyoxyethylene sorbitol monooleate, and polyethylene glycol monooleate. Further 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 bisulfonic acids, partially carboxylic acid esters of polyhydric alcohols, and phosphate esters.

[0068] Multifunctional additives In some embodiments, the lubricating oil composition includes at least one multifunctional additive. Some non-limiting examples of suitable multifunctional additives include oxymolybdenum dithiocarbamate sulfide, oxymolybdenum organophosphodithioate sulfide, oxymolybdenum monoglyceride, oxymolybdenum diethylate amide, amine-molybdenum complex compounds, and sulfur-containing molybdenum complex compounds.

[0069] Viscosity modifier In certain embodiments, the lubricating oil composition includes at least one viscosity modifier. Some non-limiting examples of suitable viscosity modifiers include polymethacrylic polymers, ethylene-propylene copolymers, styrene-isoprene copolymers, hydrated styrene-isoprene copolymers, polyisobutylene, and dispersant-type viscosity modifiers.

[0070] metal deactivator In some embodiments, the lubricating oil composition includes at least one metal deactivator. Some non-limiting examples of suitable metal deactivators include disalicylidenepropylenediamine, triazole derivatives, thiadiazole derivatives, and mercaptobenzimidazole.

[0071] Additive concentrate The additives disclosed herein may be in the form of additive concentrates having two or more additives. The additive concentrate may contain a suitable diluent, for example, a hydrocarbon oil of a suitable viscosity. Such diluents can be selected from the group consisting of natural oils (e.g., mineral oils), synthetic oils, and combinations thereof. Some non-limiting examples of mineral oils include paraffinic oils, naphthenic oils, asphaltic oils, and combinations thereof. Some non-limiting examples of synthetic base oils include polyolefin oils (especially hydrogenated-alpha-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 light hydrocarbon oil, either natural or synthetic. Typically, the diluent oil may have a viscosity of about 13 centistokes to about 35 centistokes at 40°C.

[0072] Generally, it is desirable that the diluent readily solubilizes lubricating oil-soluble additives and provides an oil additive concentrate that readily dissolves in the lubricating base oil stock or fuel. Furthermore, it is desirable that the diluent does not introduce any undesirable properties, such as high volatility and high viscosity, as well as impurities such as heteroatoms, into the lubricating base oil stock, and ultimately into the finished lubricating oil or fuel.

[0073] This application further provides an oil-soluble additive concentrate composition comprising an inert diluent and an oil-soluble additive composition according to this application in an amount of 2.0% to 90% by weight, preferably 10% to 50% by weight, based on the total concentrate.

[0074] A lubricating oil composition containing the above-mentioned additives may be used in a method for improving fuel economy in an internal combustion engine, which includes lubricating the engine with the lubricating oil composition containing the additives and operating the engine.

[0075] The following embodiments are presented to illustrate the embodiments, but are not intended to limit this application to the specific embodiments described. Unless otherwise indicated, all parts and percentages are by weight. All numerical values ​​are approximate. Where a numerical range is given, it should be understood that embodiments outside that range may still be included within the scope of this application. Specific details described in each embodiment should not be construed as essential features. [Examples]

[0076] The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0077] The preparation of PIB-substituted nitrogen-containing additives (Examples 1-4) is disclosed herein. Examples 1-4 differ only in the amount of starting material used, as summarized in Table 1.

[0078] Example 1 100 g (35.6 mmol) of 1000 MW PIB bis-succinimide (nitrogen content = 2.0 wt%) prepared from triethylenetetramine was placed in a three-necked round-bottom flask. The round-bottom flask was equipped with an overhead stirrer, thermocouple, dropping funnel, and nitrogen inlet. The flask was then placed in thermal contact with a heating mantle and the temperature was raised to 80°C. Next, 9.14 g (35.6 mmol) of dialkyldithiophosphate was added to the flask through a dropping funnel over 2.0 hours. The temperature was then raised to 100°C and maintained for 2.0 hours. The reaction mixture was used without purification.

[0079] Example 2 99.06 g (35.4 mmol) of 1000 MW PIB bis-succinimide (nitrogen content = 2.0 wt%) prepared from triethylenetetramine was placed in a three-necked round-bottom flask. The round-bottom flask was equipped with an overhead stirrer, thermocouple, dropping funnel, and nitrogen inlet. The flask was then placed in thermal contact with a heating mantle and the temperature was raised to 80°C. Next, 12.58 g (35.4 mmol) of dialkyldithiophosphate was added to the flask through a dropping funnel over 2.0 hours. The temperature was then raised to 100°C and maintained for 2.0 hours. The reaction mixture was used without purification.

[0080] Example 3 91.0 g (32.5 mmol) of 1000 MW PIB bis-succinimide (nitrogen content = 2.0 wt%) prepared from triethylenetetramine was placed in a three-necked round-bottom flask. The round-bottom flask was equipped with an overhead stirrer, thermocouple, dropping funnel, and nitrogen inlet. The flask was then placed in thermal contact with a heating mantle and the temperature was raised to 80°C. Next, 16.6 g (65.0 mmol) of dialkyldithiophosphate was added to the flask through a dropping funnel over 2.0 hours. The temperature was then raised to 100°C and maintained for 2.0 hours. The reaction mixture was used without purification.

[0081] Example 4 100.3 g (35.8 mmol) of 1000 MW PIB bis-succinimide (nitrogen content = 2.0 wt%) prepared from triethylenetetramine was placed in a three-necked round-bottom flask. The round-bottom flask was equipped with an overhead stirrer, thermocouple, dropping funnel, and nitrogen inlet. The flask was then placed in thermal contact with a heating mantle and the temperature was raised to 80°C. Next, 25.5 g (71.9 mmol) of dialkyldithiophosphate was added to the flask through a dropping funnel over 2.0 hours. The temperature was then raised to 100°C and maintained for 2.0 hours. The reaction mixture was used without purification. [Table 1]

[0082] Comparative Example 1 (Table 5) is an API SN class 5W-30 motorcycle engine oil. Examples A-D (Table 5) are test oils formulated using the reaction products of Examples 1, 2, 3, and 4 (Table 1). For these samples, the amount of ZnDTP used in Comparative Example 1 was reduced in favor of the nitrogen-containing additives of Examples 1, 2, 3, and 4. The phosphorus content, an indicator of the amount of added anti-wear agent, was standardized to the same level.

[0083] The SAE number 2 wet clutch test (JASO M348:2012) specified in the 4-stroke motorcycle engine oil standard (JASO T903:2016) was performed using each test oil (Examples A to D and Comparative Example 1), and evaluated in comparison with JASO reference oils (JATRE-A16 and B16).

[0084] Clutch system friction characteristics Friction tests were conducted using an SAE No. 2 clutch testing machine with test oil and JASO reference oils JAFRE-A16 and B16. The friction plates were immersed in the oil at a specified temperature and frictionally engaged with the steel plates. The coefficient of dynamic friction (μ) corresponding to the rotational speed experienced by the plates was measured. d ), stopping time (ST), and static friction coefficient (μ s Measurements were taken regarding ).

[0085] The dynamic friction coefficient relates to the frictional force when the clutch is engaged. The stopping time is the time it takes for the wet clutch to synchronize. The static friction coefficient relates to the transmission torque capacity of the wet clutch.

[0086] By measuring these values, the friction characteristics of the test oils (Examples A-D and Comparative Example 1) and JASO reference oils JAFRE-A16 and B16 were evaluated. The tests were prepared and conducted in accordance with JASO M348:2012,3.2 and JASO M348:2012,3.3.

[0087] Dynamic friction test The dynamic friction test was conducted according to JASO M348:2012,3.3.1 (with a slight modification to the number of test cycles to 1,000). The test results for the coefficient of dynamic friction are summarized in Table 2 below. [Table 2] [Table 3]

[0088] Static friction tests were conducted according to JASO M348:2012 3.3.2. In dynamic friction tests, characteristics were measured at 10, 50, and 100 test cycles, and then every 100 cycles thereafter, up to a maximum of 1,000 cycles. The test results for the static friction coefficient are summarized in Table 3. Table 3 (Static friction coefficient)

[0089] The results shown in Tables 2 and 3 demonstrate that the test oils A to D, using the compounds of Examples 1 to 4 of the present invention, significantly increase the dynamic and static friction coefficients compared to Comparative Example 1.

[0090] Stop time The stopping time (ST) in a dynamic friction test is defined as the period from the point when 30% of the set pressure is applied to a rotational speed of 200 minutes. -1 The period ends as follows. The results of the downtime are summarized in Table 4. [Table 4] The results shown in Table 4 demonstrate that Examples A to D, using the additive of the present invention, have shorter stop times than Comparative Example 1. [Table 5-1] [Table 5-2]

[0091] The performance characteristics of Examples A to D and Comparison 1 are summarized in Table 5.

[0092] As shown in Table 5, Examples A to D demonstrate the effectiveness of Examples 1 to 4 of the invention in reducing sulfate ash content compared to Comparative Example 1. Similarly, the dynamic friction index (DFI), static friction index (SFI), and stopping time index (STI) as defined in JASO T903:2016 are higher than those of Comparative Example 1, indicating better results in terms of wear resistance. From these results, it can be inferred that the wet clutch does not slip, power is transmitted firmly, and shifts are performed quickly. This makes it suitable for motorcycle engine oils that simultaneously lubricate a transmission with an internal combustion engine and a built-in wet clutch.

[0093] It will be understood that various modifications can be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but rather as illustrative examples of preferred embodiments. For example, the functions described above and implemented for operation are for illustrative purposes only. Those skilled in the art will be able to implement other configurations and methods without departing from the scope and spirit of this application. Furthermore, those skilled in the art will be able to conceive of other modifications within the scope and spirit of the claims appended herein. In connection with the present invention, the following is further disclosed. [1] A lubricating oil composition comprising an oil with a major lubricating viscosity and one or more nitrogen-containing additives having the following formula, [ka] In the formula, R 1 is a functional group containing 10 to 250 carbon atoms; and R 2 and R 3 The lubricating oil composition wherein each of the following is an independent functional group containing 2 to 20 carbon atoms. [2] The lubricating oil composition according to [1], wherein the phosphorus content provided by one or more nitrogen-containing additives is about 50 ppm to about 5000 ppm based on the total amount of the lubricating oil composition. [3] Furthermore, the lubricating oil composition according to [1] further comprises at least one dispersion additive. [4] The lubricating oil composition according to [3], wherein the at least one dispersant additive is an ashless succinimide or a succinimide boride dispersant. [5] The lubricating oil composition according to [1], wherein the amount of sulfate ash is about 0.3% by weight to about 1.2% by weight based on the total weight of the lubricating oil composition. [6] R 2 or R 3 The lubricating oil composition described in [1], wherein the primary alkyl hydrocarbon is C3-C18. [7] The lubricating oil composition according to [6], wherein the primary alkyl hydrocarbon is 2-ethylhexyl. [8] R 2 or R 3 The lubricating oil composition described in [1], wherein the C3-C12 secondary alkyl hydrocarbon is present. [9] The lubricating oil composition according to [8], wherein the secondary alkyl hydrocarbon is a mixture of 2-butyl and 4-methyl-2-pentyl.

[10] The lubricating oil composition according to [1], wherein the lubricating oil composition contains less than about 900 ppm of zinc.

[11] A method for increasing the friction coefficient of a wet clutch, comprising contacting a metal surface with a lubricating oil composition comprising an oil of a major amount of lubricating viscosity and one or more nitrogen-containing additives having the following formula:

change

[12] The method according to

[11] , wherein the amount of phosphorus provided by one or more nitrogen-containing additives is about 50 ppm to about 5000 ppm based on the total amount of the lubricating oil composition.

[13] The method according to

[11] , wherein the composition further comprises at least one dispersant additive.

[14] The method according to

[13] , wherein the at least one dispersant additive is an ashless succinimide or a succinimide boride dispersant.

[15] The method according to

[11] , wherein the amount of sulfated ash is about 0.3% by weight to about 1.2% by weight based on the total weight of the lubricating oil composition.

[16] R 2 or R 3 The method described in

[15] , wherein the primary alkyl hydrocarbon is C3-C18.

[17] The method according to

[16] , wherein the primary alkyl hydrocarbon is 2-ethylhexyl.

[18] R 2 or R 3 The method according to

[11] , wherein the mixture is a mixture of secondary alkyl hydrocarbons.

[19] The method according to

[18] , wherein the mixture of secondary alkyl hydrocarbons is 2-butyl and 4-methyl-2-pentyl.

[20] The method according to

[11] , wherein the wet clutch comprises cellulose fibers and / or aramid fibers.

Claims

1. A lubricating oil composition comprising an oil with a major lubricating viscosity and one or more nitrogen-containing additives having the following formula, 【Chemistry 1】 In the formula, R １ is a functional group containing 10 to 250 carbon atoms; and R ２ and R ３ The lubricating oil composition wherein each of the functional groups independently contains 2 to 20 carbon atoms.

2. The lubricating oil composition according to claim 1, wherein the phosphorus content provided by one or more nitrogen-containing additives is 50 ppm to 5000 ppm based on the total amount of the lubricating oil composition.

3. Furthermore, the lubricating oil composition according to claim 1, comprising at least one dispersion additive.

4. The lubricating oil composition according to claim 3, wherein the at least one dispersant additive is an ashless succinimide or a succinimide boride dispersant.

5. The lubricating oil composition according to claim 1, wherein the amount of sulfate ash is 0.3% to 1.2% by weight based on the total weight of the lubricating oil composition.

6. R ２ or R ３ The lubricating oil composition according to claim 1, wherein the C3 to C18 primary alkyl hydrocarbon is present.

7. The lubricating oil composition according to claim 6, wherein the primary alkyl hydrocarbon is 2-ethylhexyl.

8. R ２ or R ３ The lubricating oil composition according to claim 1, wherein the C3 to C12 secondary alkyl hydrocarbon is present.

9. The lubricating oil composition according to claim 8, wherein the secondary alkyl hydrocarbon is a mixture of 2-butyl and 4-methyl-2-pentyl.

10. The lubricating oil composition according to claim 1, wherein the lubricating oil composition contains less than 900 ppm of zinc.

11. A method for increasing the coefficient of friction of a wet clutch, comprising contacting a metal surface with a lubricating oil composition comprising an oil of a major amount of lubricating viscosity and one or more nitrogen-containing additives having the following formula: 【Chemistry 2】 wherein R １ is a functional group containing 10 to 250 carbon atoms, R ２ and R3 are each independently a functional group containing 2 to 20 carbon atoms, and the above method.

12. The method according to claim 11, wherein the amount of phosphorus provided by one or more nitrogen-containing additives is 50 ppm to 5000 ppm based on the total amount of the lubricating oil composition.

13. The method according to claim 11, wherein the composition further comprises at least one dispersant additive.

14. The method according to claim 13, wherein the at least one dispersant additive is an ashless succinimide or a succinimide boride dispersant.

15. The method according to claim 11, wherein the amount of sulfated ash is 0.3% to 1.2% by weight based on the total weight of the lubricating oil composition.

16. R ２ or R ３ The method according to claim 15, wherein the primary alkyl hydrocarbon is C3 to C18.

17. The method according to claim 16, wherein the primary alkyl hydrocarbon is 2-ethylhexyl.

18. R ２ or R ３ The method according to claim 11, wherein the mixture is a mixture of secondary alkyl hydrocarbons.

19. The method according to claim 18, wherein the mixture of secondary alkyl hydrocarbons is 2-butyl and 4-methyl-2-pentyl.

20. The method according to claim 11, wherein the wet clutch comprises cellulose fibers and / or aramid fibers.

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