Lubricating engine oils for hybrid or plug-in hybrid electric vehicles

Abstract

The present application relates to a lubricating oil composition for hybrid or plug-in hybrid electric vehicles. The composition may include a base oil and a ZnDTP derived from a mixture of C3 and C8 alcohols.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63 / 307,376, filed February 7, 2022, which is incorporated herein by reference.

[0002] The present disclosure relates to lubricating oil compositions for hybrid or plug-in hybrid electric vehicles. [Background technology]

[0003] Modern lubricants are often formulated according to strict specifications set by original equipment manufacturers. To meet the strict specifications, carefully selected lubricant additives are blended together with a base oil of lubricating viscosity. A typical lubricant composition may include, for example, dispersants, detergents, antioxidants, antiwear agents, rust inhibitors, corrosion inhibitors, antifoam agents, and / or friction modifiers. The particular application or use (e.g., hybrid vehicles) determines the set of additives that go into the lubricant composition.

[0004] Hybrid and / or plug-in hybrid vehicles typically rely on two distinctly different types of power technologies: an internal combustion engine and an electric motor. The internal combustion engine drives the vehicle primarily at high speeds. The electric motor drives the vehicle at lower speeds and can also assist the internal combustion engine when additional power is required. The key to a hybrid vehicle is to distribute power from the engine and motor in a balanced manner as vehicle speed increases.

[0005] One of the distinctive aspects of a hybrid / plug-in hybrid electric vehicle is that its engine typically operates at a much lower temperature compared to a conventional internal combustion engine, especially when the hybrid / plug-in hybrid vehicle is only driven short distances.

[0006] In general, the differences between hybrid / plug-in hybrid electric vehicles and conventional motor vehicles are so significant that new engine oils designed specifically for hybrid / plug-in hybrid electric engines are required. Summary of the Invention

[0007] In one embodiment, the present invention comprises a lubricating oil composition for a hybrid or plug-in hybrid electric vehicle, the lubricating oil composition comprising a base oil and a ZnDTP derived from a mixture of C3 and C8 alcohols.

[0008] In another aspect, the invention includes a method for improving performance of a hybrid or plug-in hybrid electric vehicle, the method comprising lubricating the hybrid or plug-in hybrid electric vehicle with a lubricating oil composition comprising a base oil and a ZnDTP derived from a mixture of a C3 alcohol and a C8 alcohol. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 oil of lubricating viscosity refers to an amount of base oil that is at least 40 wt% of the lubricating oil composition. In some embodiments, "major amount" refers to an amount of base oil that is greater than 50 wt%, greater than 60 wt%, greater than 70 wt%, greater than 80 wt%, or greater than 90 wt% of the lubricating oil composition.

[0011] The term "internal combustion engine" refers to any engine in which combustion of a fuel occurs with an oxidizer in a combustion chamber that is a component of the working fluid flow circuit. Internal combustion engines are used in hybrid vehicles and often operate at lower temperatures than internal combustion engines in conventional vehicles.

[0012] The present disclosure provides lubricant compositions designed for use in hybrid or plug-in hybrid electric vehicles. In one aspect, the lubricant compositions of the present invention can improve the fuel efficiency of hybrid or plug-in hybrid electric engines. In another aspect, the lubricant compositions can improve boundary friction control at the lower engine operating temperatures typically found in hybrid or plug-in hybrid electric vehicles.

[0013] In yet another aspect, the present disclosure provides a lubricating oil composition comprising a phosphorus / sulfur-containing additive, the lubricating oil composition providing high fuel economy while maintaining good oxidation performance. Fuel economy and oxidation performance are often considered trade-offs when formulating lubricants.

[0014] Oil of lubricating viscosity The lubricating oil composition disclosed herein generally comprises 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 preparing lubricating oil compositions are described in Mortier et al., "Chemistry and Technology of Lubricants", 2nd Edition, London, Springer, Chapters 1 and 2 (1996), A. Sequeria, Jr., "Lubricant Base Oil and Wax Processing", New York, Marcel Decker, Chapter 6, (1994), and DV Brock, Lubrication Engineering, Vol. 43, pages 184-5, (1987), all of which are incorporated herein by reference.

[0015] Generally, the amount of base oil in a lubricating oil composition will be a "major amount" of oil of lubricating viscosity as defined above.

[0016] 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 a hydrocarbon synthesis procedure using carbon monoxide and hydrogen gas, such as the Fischer-Tropsch process.

[0017] In some embodiments, the base oil has a kinematic viscosity of from about 2.5 centistokes (cSt) to about 20 cSt, from about 4 centistokes (cSt) to about 20 cSt, or from about 5 cSt to about 16 cSt at 100° C. The kinematic viscosity of the base oil or lubricant compositions disclosed herein can be measured according to ASTM D445, which is incorporated by reference.

[0018] In other embodiments, the base oil is or comprises a base stock or a blend of base stocks. In further embodiments, the base stocks are produced using a variety of different processes, including, but not limited to, extraction, solvent refining, hydrotreating, oligomerization, esterification, and rerefining. In some embodiments, the base stock comprises a rerefined stock. In further embodiments, the rerefined stock is substantially free of materials introduced by manufacture, contamination, or previous use.

[0019] In some embodiments, the base oil comprises one or more base stocks in one or more of Groups I-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), which is incorporated herein by reference. The API guidelines define base stocks as lubricant components that can be produced using a variety of different processes. Groups I, II, and III base stocks are mineral oils, each having a specific range of saturates, sulfur content, and viscosity index. Group IV base stocks are polyalphaolefins (PAOs). Group V base stocks include all other base stocks not included in Groups I, II, III, or IV.

[0020] In some embodiments, the base oil comprises one or more base stocks in Group I, II, III, IV, V, or combinations thereof. In other embodiments, the base oil comprises one or more base stocks in Group II, III, IV, or combinations thereof.

[0021] 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 stocks obtained by isomerization of synthetic wax and slack wax, and hydrocracked 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, such as animal oils, vegetable oils, mineral oils (e.g., liquid petroleum oils and solvent-treated or acid-treated mineral oils of paraffinic, naphthenic, or mixed paraffinic-naphthenic origin), oils derived from coal or shale, and combinations thereof. Some non-limiting examples of animal oils include bone oil, lanolin, fish oil, lard oil, dolphin oil, seal oil, shark oil, tallow oil, and whale oil. Some non-limiting 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, oiticica oil, jojoba oil, and meadowfoam oil. Such oils may be partially or fully hydrogenated.

[0022] In some embodiments, synthetic oils of lubricating viscosity include hydrocarbon oils and halo-substituted hydrocarbon oils, such as polymerized and copolymerized olefins, alkylbenzenes, polyphenyls, alkylated diphenyl ethers, alkylated diphenyl sulfides, and derivatives, analogs, and congeners thereof. In other embodiments, synthetic oils include alkylene oxide polymers, interpolymers, copolymers, and derivatives thereof, where the terminal hydroxyl groups can be modified by esterification, etherification, and the like. In further embodiments, synthetic oils include esters of dicarboxylic acids with various alcohols. In certain embodiments, synthetic oils include C5-C 12 Included are esters made from monocarboxylic acids and polyols and polyol ethers. In a further embodiment, the synthetic oils include trialkyl phosphate ester oils, such as tri-n-butyl phosphate and tri-iso-butyl phosphate.

[0023] In some embodiments, synthetic oils of lubricating viscosity include silicon-based oils (such as polyalkyl-, polyaryl-, polyalkoxy-, polyaryloxy-siloxane oils and silicate oils), hi other embodiments, synthetic oils include liquid esters of phosphorus-containing acids, polymeric tetrahydrofurans, polyalphaolefins, and the like.

[0024] Base oils derived from the hydroisomerization of wax can also be used, either alone or in combination with the aforementioned natural and / or synthetic base oils. Such wax isomerate oils are produced by hydroisomerizing natural or synthetic waxes or mixtures thereof over a hydroisomerization catalyst.

[0025] In further embodiments, the base oil comprises a poly-alpha-olefin (PAO). Generally, the poly-alpha-olefin can be derived from an alpha-olefin having from about 2 to about 30, from about 4 to about 20, or from about 6 to about 16 carbon atoms. Non-limiting examples of suitable poly-alpha-olefins include those derived from octene, decene, mixtures thereof, and the like. These poly-alpha-olefins can have a viscosity of from about 2 to about 15, from about 3 to about 12, or from about 4 to about 8 centistokes at 100° C. In some cases, the poly-alpha-olefins can be used with other base oils, such as mineral oils.

[0026] In further embodiments, the base oil comprises a polyalkylene glycol or a polyalkylene glycol derivative, where the terminal hydroxyl group of the polyalkylene glycol 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.), mono- and polycarboxylic acid esters of polyalkylene glycols, and combinations thereof. In some cases, the polyalkylene glycol or polyalkylene glycol derivatives can be used with other base oils, such as poly-alpha-olefins and mineral oils.

[0027] In further embodiments, the base oil comprises any of the 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.) with 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 azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, 2-ethylhexyl diester of linoleic acid dimer, etc.

[0028] In a further embodiment, the base oil comprises hydrocarbons prepared by the Fischer-Tropsch process, in which a Fischer-Tropsch catalyst is used to prepare hydrocarbons from a gas containing hydrogen and carbon monoxide. These hydrocarbons may require further processing to be used as base oils. For example, the hydrocarbons may be dewaxed, hydroisomerized, and / or hydrocracked using methods known to those skilled in the art.

[0029] In further embodiments, the base oil comprises unrefined oil, refined oil, re-refined oil, or mixtures thereof. Unrefined oil is oil obtained directly from natural or synthetic sources without further refining treatment. Non-limiting examples of unrefined oil include shale oil obtained directly from retorting operations, petroleum obtained directly from primary distillation, and ester oil obtained directly from esterification processes and used without further treatment. Refined oils are similar to unrefined oils, except that the former have been further treated by one or more refining processes to improve one or more properties. Many such refining processes, such as solvent extraction, secondary distillation, acid or base extraction, filtration, percolation, etc., are known to those skilled in the art. Re-refined oils are obtained by applying processes to refined oils similar to those used to obtain refined oils. Such re-refined oils are also known as reclaimed or reprocessed oils, and are often further treated by processes aimed at removing spent additives and oil breakdown products.

[0030] Phosphorus / Sulfur-containing Additives The lubricating oil composition of the present invention comprises one or more phosphorus / sulfur-containing additives. In one embodiment, the one or more phosphorus / sulfur-containing additives comprise zinc dithiophosphate (ZnDTP), also known as zinc dihydrocarbyl dithiophosphate (ZDDP). These phosphorus / sulfur-containing compounds are derived from mixtures of C3 and C8 alcohols. Without being limited by theory, it is believed that the particular combination of alcohols described herein provides the desired performance characteristics shown in the examples.

[0031] Generally, the phosphorus / sulfur-containing additive is present in the lubricating oil composition in an amount necessary to provide the desired performance benefits. The lubricating oil composition of the present invention may include a phosphorus / sulfur-containing additive present in the lubricating oil composition in an amount of from about 100 to about 2000 ppm, e.g., from about 200 to about 1900 ppm, from about 300 to about 1800 ppm, from about 400 to about 1700 ppm, from about 500 to about 1600 ppm, from about 600 to about 1500 ppm, from about 100 to about 1900 ppm, from about 100 to about 1800 ppm, from about 100 to about 1700 ppm, from about 100 to about 1600 ppm, from about 100 to about 1500 ppm, from about 200 to about 2000 ppm, from about 200 to about 1800 ppm, from about 200 to about 1700 ppm, from about 200 to about 1600 ppm, from about It may be present in an amount to provide phosphorus of 200 to about 1500 ppm, about 300 to about 2000 ppm, about 300 to about 1900 ppm, about 300 to about 1700 ppm, about 300 to about 1600 ppm, about 300 to about 1500 ppm, about 400 to about 2000 ppm, about 400 to about 1900 ppm, about 400 to about 1800 ppm, about 400 to about 1600 ppm, about 400 to about 1500 ppm, about 500 to about 2000 ppm, about 500 to about 1900 ppm, about 500 to about 1800 ppm, about 500 to about 1700 ppm, and about 500 to about 1500 ppm.

[0032] Suitable zinc dithiophosphates (ZnDTPs) can have the formula: [ka] In the formula, R 1 and R 2 is an alkyl group having 3 or 8 carbon atoms, R 1 or R 2 At least one of R 1 or R 2 At least one of the alkyl groups has 8 carbon atoms. Specific examples of the alkyl group include an n-propyl group, an isopropyl group, an n-octyl group, an isooctyl group, a 2-octyl group, a 3-octyl group, a 4-octyl group, a methylheptyl group, a 2-ethylhexyl group, a dimethylhexyl group, a cyclohexylethyl group, an ethylcyclohexyl group, and a vinylhexyl group.

[0033] Zinc dithiophosphate is a coordination compound that can be synthesized from phosphorodithioic acid that can prepare metal salt.Examples of dihydrocarbyl phosphorodithioic acid and zinc salts, and the process for preparing such acids and salts are disclosed in, for example, U.S. Patent Nos. 4,101,428, 4,215,067, 4,263,150, and 4,495,075.These patents are incorporated herein by reference for such disclosure.

[0034] Phosphorodithioic or dithiophosphoric acids are typically prepared by reaction of phosphorus pentasulfide with an alcohol or phenol, or a mixture of alcohols and / or phenols. The reaction requires at least 4 moles of alcohol or phenol per mole of phosphorus pentasulfide and may be carried out within a temperature range of about 50°C to about 200°C. Thus, the preparation of O,O-di-(isopropyl / 2-ethylhexyl) phosphorodithioic acid involves reacting phosphorus pentasulfide with a mixture of at least 4 moles of isopropanol and 2-ethylhexanol at about 100°C for up to 5 hours. Hydrogen sulfide is liberated and the residue is the specified acid. The preparation of the zinc salt of this acid can be carried out by reaction with zinc oxide in the presence of a promoter (e.g., acetic acid) at elevated reaction temperatures and extended reaction periods.

[0035] When derived from an alkyl alcohol, the zinc dithiophosphate can also be referred to as a zinc dialkyldithiophosphate. Depending on the nature of the alcohol, the zinc dialkyldithiophosphate can be a primary or secondary zinc dialkyldithiophosphate, or a mixture thereof.

[0036] The R group (i.e., R 1 , R 2etc.) are derived from a mixture of alcohols having either 3 or 8 carbon atoms. The mixture contains a specific ratio of C3 alcohols to C8 alcohols. Suitable ratios may range from about a 95 / 5 molar ratio of C3 alcohol to C8 alcohol to about 5 / 95 C3 alcohol to C8 alcohol, for example, a 90 / 10 ratio of C3 alcohol to C8 alcohol, an 85 / 15 ratio of C3 alcohol to C8 alcohol, an 80 / 20 ratio of C3 alcohol to C8 alcohol, a 75 / 25 ratio of C3 alcohol to C8 alcohol, a 70 / 30 ratio of C3 alcohol to C8 alcohol, a 60 / 40 ratio of C3 alcohol to C8 alcohol, a 50 / 50 ratio of C3 alcohol to C8 alcohol, a 40 / 60 ratio of C3 alcohol to C8 alcohol, a 30 / 70 ratio of C3 alcohol to C8 alcohol, a 25 / 75 ratio of C3 alcohol to C8 alcohol, a 20 / 80 ratio of C3 alcohol to C8 alcohol, or a 10 / 90 ratio of C3 alcohol to C8 alcohol.

[0037] Other properties of the lubricating oil composition As one skilled in the art will readily recognize, the viscosity of the base oil will depend on the application. Thus, the viscosity of the base oil for use herein will typically range from about 2 to about 2000 centistokes (cSt) at 100 degrees Celsius (°C). Generally, the base oils used individually as engine oils will have a kinematic viscosity range of about 2 cSt to about 30 cSt at 100°C, preferably about 3 cSt to about 16 cSt, and most preferably about 4 cSt to about 12 cSt, and will be selected or blended to produce the desired grade of engine oil, e.g., 0W, 0W-8, 0W-12, 0W-20, 0W-30, 0W-40, 0W-50, 0W-60, 0W-70, 0W-80, 0W-90, 0W-110, 0W-120, 0W-130, 0W-140, 0W-150, 0W-160, 0W-170, 0W-180, 0W-190, 0W-200, 0W-210, 0W-220, 0W-230, 0W-240, 0W-250, 0W-260, 0W-270, 0W-280, 0W-290, 0W-300, 0W-310, 0W-320, 0W-330, 0W-340, 0W-350, 0W-360, 0W-370, 0W-380, 0W-390, 0W-400, 0W-410, 0W-420, 0W-430, 0W-440, 0W-45 Lubricating oil compositions having SAE viscosity grades such as 0W-16, 0W-20, 0W-30, 0W-40, 0W-50, 0W-60, 5W, 5W-20, 5W-30, 5W-40, 5W-50, 5W-60, 10W, 10W-20, 10W-30, 10W-40, 10W-50, 15W, 15W-20, 15W-30, 15W-40, 30, 40, and the like will be provided.

[0038] Other Additives To the extent consistent with the components and properties of the lubricating oil composition described above, the lubricating oil composition may further include additives capable of imparting or improving any desired properties of the lubricating oil composition. Any additive known to those skilled in the art may be used in the lubricating oil composition disclosed herein. Some 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, the additives may be selected from the group consisting of antioxidants, antiwear agents, detergents, rust inhibitors, demulsifiers, friction modifiers, multifunctional additives, viscosity index improvers, pour point depressants, antifoam agents, metal deactivators, dispersants, corrosion inhibitors, lubricity improvers, thermal stability improvers, anti-fog additives, anti-icing agents, dyes, markers, static dissipative agents, biocides, and combinations thereof.

[0039] Dispersants Optionally, the lubricating oil composition disclosed herein may further comprise a dispersant. Dispersants keep oil-insoluble materials resulting from oxidation during engine operation in suspension, thus preventing sludge flocculation and precipitation or deposition on metal parts. Dispersants useful 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 succinimides, mixed esters / amides of hydrocarbyl-substituted succinic acids, hydroxyesters of hydrocarbyl-substituted succinic acids, and Mannich condensation products of hydrocarbyl-substituted phenols, formaldehyde, and polyamines. Condensation products of polyamines and hydrocarbyl-substituted phenyl acids are also suitable. Mixtures of these dispersants may also be used.

[0040] Basic nitrogen-containing ashless dispersants are well-known lubricating oil 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 long-chain, greater than 40 carbon atoms. These materials are easily prepared by reacting hydrocarbyl-substituted dicarboxylic acid materials with molecules containing amine functionality. Examples of suitable amines are polyamines, such as polyalkylene polyamines, hydroxy-substituted polyamines, and polyoxyalkylene polyamines. As is known in the art, dispersants can be post-treated (e.g., using boronating agents, ethylene carbonate, or cyclic carbonates). Nitrogen-containing ashless (metal-free) dispersants are basic and contribute to the TBN of the lubricating oil composition to which they are added without introducing additional sulfated ash. The dispersant may be present at 0.1-10 wt% (e.g., 0.5-8, 0.7-7, 0.7-6, 0.7-6, 0.7-5, 0.7-4 wt%) of the lubricating oil composition based on the actives level. Nitrogen from the dispersant is present at 0.0050-0.30 wt% or more (e.g., 0.0050-0.10 wt%, 0.0050-0.080 wt%, 0.0050-0.060 wt%, 0.0050-0.050 wt%, 0.0050-0.040 wt%, 0.0050-0.030 wt%) based on the weight of the dispersant in the finished oil.

[0041] Antioxidants Optionally, the lubricating oil composition disclosed herein can further comprise an additional antioxidant that can reduce or prevent oxidation of the base oil. Any antioxidant known to a person skilled in the art can be used in the lubricating oil composition. Non-limiting examples of suitable antioxidants include amine-based antioxidants (e.g., alkyldiphenylamines, phenyl-alpha-naphthylamines, alkyl or aralkyl substituted phenyl-alpha-naphthylamines, alkylated p-phenylenediamines, tetramethyl-diaminodiphenylamines, etc.), phenol-based antioxidants (e.g., 2-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 2,4,6-tri-tert-butylphenol, 2,5 ... ,6-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), etc.), sulfur-based antioxidants (e.g., dilauryl-3,3'-thiodipropionate, sulfurized phenol-based antioxidants, etc.), phosphorus-based antioxidants (e.g., phosphites, etc.), zinc dithiophosphate, oil-soluble copper compounds, and combinations thereof. The amount of antioxidant can vary from about 0.01% to about 10% by weight, for example, from about 0.05% to about 5% by weight, or from about 0.1% to about 3% by weight, based on the total weight of the lubricating oil composition. Some suitable antioxidants are 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.

[0042] Friction modifiers The lubricating oil composition disclosed herein can optionally include a friction modifier that can reduce friction between moving parts.Any friction modifier known to those skilled in the art can be used in the lubricating oil composition.Non-limiting examples of suitable friction modifiers include fatty carboxylic acids; derivatives of fatty carboxylic acids (e.g., alcohols, esters, borate esters, amides, and metal salts); monoalkyl-, dialkyl-, or trialkyl-substituted phosphoric or phosphonic acids; derivatives of monoalkyl-, dialkyl-, or trialkyl-substituted phosphoric or phosphonic acids (e.g., esters, amides, and metal salts); monoalkyl-, dialkyl-, or trialkyl-substituted amines; monoalkyl-, dialkyl-, or trialkyl-substituted amides, and combinations thereof. In some embodiments, the friction modifier may be an aliphatic amine, an ethoxylated aliphatic amine, an aliphatic carboxylic acid amide, an ethoxylated aliphatic ether amine, an aliphatic carboxylic acid, a glycerol ester, an aliphatic carboxylic acid ester amide, an aliphatic imidazoline, or an aliphatic tertiary amine, wherein the aliphatic or aliphatic group contains more than about 8 carbon atoms to render the compound suitably oil soluble.

[0043] The amount of friction modifier may vary from about 0.01% to about 10% by weight, from about 0.05% to about 5% by weight, or from about 0.1% to about 3% by weight, based on the total weight of the lubricating oil composition. Some suitable friction modifiers are described in Mortier et al., "Chemistry and Technology of Lubricants", 2nd Edition, London, Springer, Chapter 6, pages 183-187 (1996) and Leslie R. Rudnick, "Lubricant Additives: Chemistry and Applications", New York, Marcel Dekker, Chapters 6 and 7, pages 171-222 (2003).

[0044] The lubricating oil composition of the present invention preferably further contains a molybdenum compound in an amount to provide about 10 to 2500 ppm of molybdenum to the lubricating oil composition. Because these compounds provide sulfated ash and may have a sulfur content, the amount of these compounds is controlled taking into account the various component contents and desired properties.

[0045] The molybdenum compound can function as a friction modifier, an antioxidant, and an antiwear agent in the lubricating oil composition of the present invention, and further imparts increased high-temperature lubricity to the lubricating oil composition. The content of the molybdenum compound in the lubricating oil composition of the present invention is preferably 10 to 2,500 ppm in terms of molybdenum element content. Examples of the molybdenum compound include sulfur-containing oxymolybdenum succinimide complex compounds, sulfurized oxymolybdenum dithiocarbamate, sulfurized oxymolybdenum dithiophosphoric acid, amine-molybdenum complex compounds, oxymolybdenum diethylate amide, and molybdenum monoglyceride.

[0046] Pour Point Depressants The lubricating oil compositions disclosed herein may optionally include a pour point depressant capable of lowering the pour point of the lubricating oil composition. Any pour point depressant known to one skilled in the art may be used in the lubricating oil composition. Non-limiting examples of suitable pour point depressants include polymethacrylic acid, alkyl acrylate polymers, alkyl methacrylate polymers, di(tetra-paraffinic phenol) phthalate, condensates of tetra-paraffinic phenol, condensates of chlorinated paraffins with naphthalene, and combinations thereof. In some embodiments, the pour point depressant includes ethylene-vinyl acetate copolymers, condensates of chlorinated paraffins with phenols, polyalkylstyrenes, and the like. The amount of pour point depressant may vary from about 0.01 wt % to about 10 wt %, from about 0.05 wt % to about 5 wt %, or from about 0.1 wt % to about 3 wt %, based on the total weight of the lubricating oil composition. Some 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.

[0047] Demulsifier The lubricating oil composition disclosed herein may optionally include a demulsifier that can promote oil-water separation in the lubricating oil composition exposed to water or steam. Any demulsifier known to those skilled in the art may be used in the lubricating oil composition. Non-limiting examples of suitable demulsifiers include anionic surfactants (e.g., alkyl naphthalene sulfonates, alkyl benzene sulfonates, etc.), nonionic alkoxylated alkylphenol resins, polymers of alkylene oxides (e.g., polyethylene oxide, polypropylene oxide, block copolymers of ethylene oxide and propylene oxide, etc.), esters of oil-soluble acids, polyoxyethylene sorbitan esters, and combinations thereof.

[0048] The amount of demulsifier can vary from about 0.01% to about 10%, from about 0.05% to about 5%, or from about 0.1% to about 3% by weight based on the total weight of the lubricating oil composition. Some suitable demulsifiers are described in Mortier et al., "Chemistry and Technology of Lubricants", 2nd Edition. London, Springer, Chapter 6, pages 190-193 (1996), which is incorporated herein by reference.

[0049] Foam inhibitor The lubricating oil compositions disclosed herein may optionally include an antifoaming agent or defoamer capable of destroying foam in the oil. Any antifoaming agent or defoamer known to one of ordinary skill in the art may be used in the lubricating oil composition. Non-limiting examples of suitable defoamers include silicone oils or polydimethylsiloxanes, fluorosilicones, alkoxylated fatty acids, polyethers (e.g., polyethylene glycols), branched polyvinyl ethers, alkyl acrylate polymers, alkyl methacrylate polymers, polyalkoxyamines, and combinations thereof. In some embodiments, the defoamer comprises glycerol monostearate, polyglycol palmitate, trialkyl monothiophosphate, esters of sulfonated ricinoleic acid, benzoylacetone, methyl salicylate, glycerol monooleate, or glycerol dioleate. The amount of defoamer may vary from about 0.01% to about 5% by weight, from about 0.05% to about 3% by weight, or from about 0.1% to about 1% by weight, based on the total weight of the lubricating oil composition. Some 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 is incorporated herein by reference.

[0050] Corrosion Inhibitors The lubricating oil compositions disclosed herein may optionally include a corrosion inhibitor capable of reducing corrosion. Any corrosion inhibitor known to one skilled in the art may be used in the lubricating oil composition. Non-limiting examples of suitable corrosion inhibitors include half esters or amides of dodecyl succinic acid, phosphate esters, thiophosphoric acids, alkyl imidazolines, sarcosines, and combinations thereof. The amount of corrosion inhibitor may vary from about 0.01 wt.% to about 5 wt.%, from about 0.05 wt.% to about 3 wt.%, or from about 0.1 wt.% to about 1 wt.%, based on the total weight of the lubricating oil composition. Some 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.

[0051] Extreme Pressure Agent The lubricating oil composition disclosed herein may optionally contain an extreme pressure (EP) agent that can prevent the seizure of sliding metal surfaces under extreme pressure conditions. Any extreme pressure agent known to those skilled in the art may be used in the lubricating oil composition. In general, an extreme pressure agent is a compound that can chemically bond with metal to form a surface film that prevents the welding of asperities on opposing metal surfaces under high load. 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 trivalent or pentavalent acids of phosphorus, sulfurized olefins, dihydrocarbyl polysulfides, sulfurized Diels-Alder adducts, sulfurized dicyclopentadiene, sulfurized or co-sulfurized mixtures of fatty acid esters and monounsaturated olefins, co-sulfurized blends of fatty acids, fatty acid esters and alpha-olefins, functionally substituted dihydrocarbyl polysulfides, thiaaldehydes, thiaketones, epithio compounds, sulfur-containing acetal derivatives, co-sulfurized blends of terpenes and acyclic olefins, polysulfide olefin products, amine salts of phosphates or thiophosphates, and combinations thereof. The amount of extreme pressure agent may vary from about 0.01% to about 5% by weight, from about 0.05% to about 3% by weight, or from about 0.1% to about 1% by weight, based on the total weight of the lubricating oil composition. Some suitable extreme pressure agents 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.

[0052] Rust inhibitor The lubricating oil compositions disclosed herein may optionally include a rust inhibitor capable of inhibiting corrosion of ferrous metal surfaces. Any rust inhibitor known to one skilled in the art may 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 made 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 alpha, omega-dicarboxylic acids having molecular weights in the range of 600 to 3000 daltons, and combinations thereof. The amount of rust inhibitor can vary from about 0.01% to about 10% by weight, from about 0.05% to about 5% by weight, or from about 0.1% to about 3% by weight, based on the total weight of the lubricating oil composition.

[0053] Other non-limiting examples of suitable rust inhibitors include non-ionic polyoxyethylene surfactants such as polyoxyethylene lauryl ether, polyoxyethylene higher alcohol ether, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene octylstearyl 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 heavy sulfonic acids, partial carboxylic acid esters of polyhydric alcohols, and phosphoric acid esters.

[0054] Multifunctional Additives In some embodiments, the lubricating oil composition comprises at least one multifunctional additive. Some non-limiting examples of suitable multifunctional additives include sulfurized oxymolybdenum organophosphorus dithioates, oxymolybdenum monoglycerides, oxymolybdenum diethylate amides, amine-molybdenum complex compounds, and sulfur-containing molybdenum complex compounds.

[0055] 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 acid-based polymers, ethylene-propylene copolymers, styrene-isoprene copolymers, hydrated styrene-isoprene copolymers, polyisobutylene, and dispersant-type viscosity modifiers.

[0056] metal deactivator In some embodiments, the lubricating oil composition includes at least one metal deactivator. Some non-limiting examples of suitable metal deactivators include disalicylidene propylene diamine, triazole derivatives, thiadiazole derivatives, and mercaptobenzimidazole.

[0057] Additive concentrates The additives disclosed herein may be in the form of an additive concentrate having two or more additives. The additive concentrate may include a suitable diluent, such as a hydrocarbon oil of suitable viscosity. Such a diluent may 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, carboxylic acid esters (especially diester oils), and combinations thereof. In some embodiments, the diluent is a natural or synthetic light hydrocarbon oil. In general, the diluent oil may have a viscosity of about 13 centistokes to about 35 centistokes at 40°C.

[0058] In general, it is desirable for the diluent to readily solubilize the lubricant-soluble additives and provide an oil additive concentrate that is readily soluble in the lubricant base stock or fuel. Additionally, it is desirable for the diluent not to introduce any undesirable properties, including, for example, high volatility and high viscosity, as well as impurities, such as heteroatoms, into the lubricant base stock and, ultimately, into the finished lubricant or fuel.

[0059] The present application further provides an oil soluble additive concentrate composition comprising an inert diluent and 2.0% to 90% by weight, preferably 10% to 50% by weight, of an oil soluble additive composition according to the present application, based on the total concentrate.

[0060] The following examples are presented to illustrate the embodiments, but are not intended to limit the present application to the specific embodiments described. Unless otherwise indicated, all parts and percentages are by weight. All numerical values ​​are approximate. When numerical ranges are given, it should be understood that embodiments outside the described ranges may still fall within the scope of the present application. The specific details described in each example should not be construed as necessary features. EXAMPLES

[0061] The following examples are for illustrative purposes only and are not intended to be limiting in any way.

[0062] As an illustrative example, the preparation of ZnDTP from C3 / C8 alcohols (50 / 50 molar ratio) is described herein.

[0063] A 50 / 50 molar ratio mixture of C3 / C8 alcohols was prepared using 67 grams of isopropanol and 145 grams of 2-ethylhexanol. 102 grams of base oil and 110 grams of phosphorus pentasulfide were added to a 500 ml jacketed glass reactor connected to a scrubber filled with 25% sodium hydroxide solution. The reactor was equipped with a stirring system and a ventilation system. 212 grams of C3 / C8 alcohols (from above) were charged to the stirred reactor for 1.5 hours.

[0064] Since the reaction between phosphorus pentasulfide and alcohol is exothermic, it is important to maintain the reactor at 70°C (a Julabo pump was used). The reactor was blanketed with nitrogen. The liberated hydrogen sulfide was absorbed by sodium hydroxide solution in a scrubber. After the alcohol was added, the reactor was held at 70°C for 3 hours to ensure complete consumption of phosphorus pentasulfide. The resulting O,O-di-(isopropyl / 2-ethylhexyl) dithiophosphoric acid (DTPA) was a dark greenish liquid.

[0065] 240 grams of DTPA (from above) was charged to a 500 ml jacketed glass reactor followed by the promoter (0.4 grams of acetic acid). 41 grams of zinc oxide was charged to this stirred reactor while maintaining the reactor temperature below 70° C.

[0066] An additional 120 grams of DTPA was then charged to the reactor after 1 hour. Once the DTPA addition was complete, the reactor was held at 70° C. for 3 hours to complete the neutralization of the DTPA with the zinc oxide. After 3 hours, the reaction mixture was heated to approximately 98° C. and a vacuum was applied for 30 minutes to remove the water and unreacted alcohol.

[0067] The resulting crude zinc di-(isopropyl / 2-ethylhexyl) dithiophosphate (C3 / C8 ZnDTP) contained small amounts of unreacted zinc oxide and other precipitates, which were removed by filtration. ICP analysis showed that the C3 / C8 ZnDTP contained 7.0 wt% P, 7.7 wt% Zn, and 14.1 wt% S.

[0068] Lubricant samples were formulated using ZnDTP derived from a mixture of alkyl alcohols as described below.

[0069] The baseline formulation (0W-16) contains: (1) Ethylene carbonate post-treated bis-succinimide, (2) Calcium HOB carboxylate prepared in substantially the same manner as in U.S. Patent No. 8,993,499. The Ca content is adjusted to 0.16% by weight. (3) hindered phenol antioxidants, (4) PMA comb polymer, Viscoplex® 3-162 (available from Evonik Industries AG); (5) MoDTC compound in 0.07 wt. % molybdenum, Sakura-lube 525 (available from ADEKA CORPORATION); (6) Foam suppressors, (7) ZnDTP derived from various alcohols, and (8) The remainder is Group III base oil.

[0070] Table 1 summarizes the comparative examples and performance results including the alcohol used to synthesize the ZnDTP additive. Table 2 summarizes the inventive examples and performance results including the alcohol used to synthesize the ZnDTP additive. For the MTM and ISOT TAN tests, lower values ​​indicate better performance. [Table 1] [Table 2]

[0071] Evaluation of thermal stability at high temperatures Thermal stability at high temperatures was evaluated using the JIS (Japanese Industrial Standard) K2514 ISOT (Indiana Stirred Oxidation Test), which was used to determine the oxidation stability of lubricating oil compositions in the presence of copper and steel.

[0072] The ISOT test was performed under the following conditions: Amount of oil: 250mL, Test oil temperature: 165.5℃, Test duration: 96 hours of continuous operation.

[0073] The test results are determined and expressed as follows: Change in TAN (ATSM D664): Increase in TAN is determined by subtracting the initial TAN from the post-test TAN.

[0074] MTM friction test Friction performance was evaluated using a mini-traction machine (MTM). The MTM is a ball-on-disk type tribomachine that can measure the friction characteristics of lubricants under a wide range of sliding and rolling conditions by separately controlling the sliding and rolling speeds. The test specimens were a 19.05 mm diameter ball and a 46 mm diameter disk made of 52100 steel with a hardness of 720 to 780 VPN.

[0075] Friction measurements were carried out under the following conditions: Test oil temperature: 60℃ 37N applied load SRR (Sliding-Rolling Ratio) at 20%, 50% and 150% The entrainment speed of the Stribeck measurements, starting from 3000mm / s and decreasing to 2mm / s, consists of 36 data points. The measurements start at 20% SRR, followed by 50% and 150%. To simulate real engine conditions and properly pre-treat the metal surface, the above sequence was repeated 12 times, resulting in a total of 36 strip curves.

[0076] The final boundary friction results were provided according to the cumulative area calculated between the entrainment speeds of 2 and 10 mm / s in the last Stribeck curve at SRR 150% (36th) using the following equation: Boundary friction = Σ(((CoFi+CoFi+1) / 2)×abs(Log(entrainment rate i+1)-Log(entrainment rate i))) During the ceremony, Entrainment velocity i = the i-th entrainment velocity Entrainment velocity i+1 = (i+1)th entrainment velocity CoFi = friction coefficient at the ith entrainment velocity CoFi+1 = friction coefficient at the (i+1)th entrainment velocity

[0077] ISOT and MTM test results demonstrate improved boundary friction at lower operating temperatures, which indicates increased fuel economy while maintaining good oxidation stability.

[0078] It will be understood that various modifications can be made to the embodiments disclosed herein. Thus, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. For example, the functions described and implemented for operation above are for illustrative purposes only. Those skilled in the art can implement other configurations and methods without departing from the scope and spirit of the present application. Moreover, those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Claims

1. 1. A lubricating oil composition for use in a hybrid or plug-in hybrid electric vehicle, comprising: Base oil, and The lubricating oil composition comprises ZnDTP derived from a mixture of C3 and C8 alcohols.

2. 2. The lubricating oil composition of claim 1, wherein the mixture has a C3 molar percentage of 30% or greater.

3. 10. The lubricating oil composition of claim 1, further comprising a molybdenum friction modifier.

4. 4. The lubricating oil composition of claim 3, wherein the molybdenum friction modifier is a molybdenum dithiocarbamate.

5. 4. The lubricating oil composition of claim 3, wherein the molybdenum friction modifier is present in an amount providing about 10 to about 2500 ppm of molybdenum to the lubricating oil composition.

6. 2. The lubricating oil composition of claim 1, wherein the ZnDTP is present in an amount providing about 100 to about 2000 ppm phosphorus to the lubricating oil composition.

7. 10. The lubricating oil composition of claim 1, further comprising a dispersant, detergent, antiwear agent, or viscosity modifier.

8. The ZnDTP has the following structure: Zn[S-P(=S)(OR １ )(OR ２ )] ２ (In the formula, R １ and R ２ 2. The lubricating oil composition of claim 1, wherein:

9. 2. The lubricating oil composition of claim 1, wherein said mixture of C3 and C8 alcohols has a ratio of C3 alcohol to C8 alcohol ranging from about 95 / 5 to about 5 / 95.

10. 1. A method for improving performance of a hybrid or plug-in hybrid electric vehicle, comprising: lubricating a hybrid or plug-in hybrid electric vehicle with a lubricating oil composition, the lubricating oil composition comprising: Base oil, and The process includes ZnDTP derived from a mixture of C3 and C8 alcohols.

11. The method of claim 10 , wherein the mixture has a C3 mole percentage of 30% or greater.

12. The method of claim 10, wherein the lubricating oil composition further comprises a molybdenum friction modifier.

13. 13. The method of claim 12, wherein the molybdenum friction modifier is a molybdenum dithiocarbamate.

14. The method of claim 12, wherein the molybdenum friction modifier is present in an amount providing about 10 to about 2500 ppm of molybdenum to the lubricating oil composition.

15. The method of claim 10, wherein the ZnDTP is present in an amount providing about 100 to about 2000 ppm phosphorus to the lubricating oil composition.

16. 11. The method of claim 10, wherein the lubricating oil composition further comprises a dispersant, a detergent, an antiwear agent, or a viscosity modifier.

17. The ZnDTP has the following structure: Zn[S-P(=S)(OR １ )(OR ２ )] ２ (In the formula, R １ and R ２ The method of claim 10, wherein R, R and R are the same or different hydrocarbyl radicals having 3 or 8 carbon atoms.

18. 11. The method of claim 10, wherein the mixture of C3 and C8 alcohols has a ratio of C3 alcohols to C8 alcohols ranging from about 95 / 5 to about 5 / 95.

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