Abstract: A perfluoropolyether hard disk lubricant having a UV curable functional end group that may be UV cured at a rapid rate with a Xenon excimer lamp. The perfluoropolyether preferably has at least one UV curable functional end group. In one embodiment, the UV curable end group comprises an acrylate.

Abstract: The invention provides a lubricant oil composition useful for reduction in friction loss and improvement in fuel economy in internal combustion engines, particularly, a lubricant oil composition for internal combustion engines exhibiting an excellent friction reducing effect even in a diesel engine equipped with EGR accompanied with an increase in soot content in oil. The invention is a lubricant composition for internal combustion engines comprising a lubricant base oil consisting of a mineral oil and/or synthetic oil or the like incorporated with 1 wt % or more, based on the total weight of the lubricant oil composition, a nonionic surfactant with alkylene oxide added thereto consisting of at least one compound having an HLB value of 15 or more and a molecular weight of 900 or more, and a friction reducing method for internal combustion engines using this lubricant oil composition.

Abstract: A two-cycle engine lubricant comprising from about 10% to about 30% low ash detergent inhibitor; from about 10% to about 45% bio-based ester selected from the group consisting of castor oil, a synthetic polyol-based ester and mixtures thereof; from about 14% to about 37% polyalphaolefin; from about 7% to about 18% synthetic ester; from 2% to about 10% surfactant; and from about 2% to about 5% pour point depressant; by weight of the lubricant. Optionally, the subject two-cycle lubricant can also comprise up to about 20 weight percent solvent, such as Stoddard solvent, to improve miscibility of the lubricant with gasoline fuel. The subject lubricant can be pre-packaged with gasoline for use with small engines not equipped for direct lubricant injection. A method for making the subject lubricant composition so as to resist subsequent separation of the components into layers is also disclosed.

Abstract: This invention relates to an aqueous composition comprising water, a surfactant or thickener, and at least one metal-free thiophosphorus acid ester, at least one amine salt of the thiophosphorus acid ester, or a mixture thereof, wherein the thiophosphorus acid ester contains at least one hydrocarbyl terminated oxyalkylene group, at least one hydrocarbyl terminated polyoxyalkylene group, or a mixture thereof. The aqueous compositions have improved antiwear/extreme pressure properties and improved antioxidation properties. In these compositions, the thiophosphorus acid esters and their salts act as antiwear agents and rust inhibitors.

Abstract: The object of the present invention is to provide a cutting oil composition excellent in solubility, lubricity, cutting properties, antirust ability, safety, and washing ability and reduced in foaming, and for that purpose, an N-acylamino acid having a long chain acyl group and/or a salt thereof, or an N-alkylamino acid having a long chain alkyl group and/or a salt thereof is used concurrently with an alkylalkylene oxide and/or an acylalkylene oxide.

Abstract: A lubricating oil comprising a major amount of at least one of Group II, III, and IV base oil and a minor amount of 3,5-di-t-butyl 4-hydroxy phenol propionate. A method of making this lubricating oil and a method of lubricating a natural gas engine with this lubricating oil.

Abstract: The present invention provides a composition for cutting or abrasive working operations that comprises at least one lubricious additive and at least one hydrofluorocarbons. The present invention also provides a method for cutting or abrasive working.

Abstract: The invention relates to a chain lubricant for conveyor and transport systems which is comprised of water, surfactants, disinfecting agents as well as conventional auxiliary agents and additives. According to the invention, an anionic surfactant is used as the surfactant and chlorine dioxide is used as the disinfecting agent.

Abstract: An internal or an external combustion engine which has at least one surface coated with a lubricant made up of vegetable-based products. The products preferably include a base oil containing primarily mono, di and triglycerides and free fatty acids, 5-30% by volume hydroxy fatty acids and 5-10% of the oil additives by volume of animal or vegetable waxes.

Abstract: Lubricant compositions are used on conveying systems in the beverage industry during the filling of containers with dairy products or other beverages. An antimicrobial conveyor lubricant composition according to the invention includes alkyl alkoxylated phosphate ester, antimicrobial agent comprising at least one of quaternary ammonium antimicrobial agent and protonated amine antimicrobial agent, extreme pressure additive, water, and neutralizing agent in an amount sufficient to provide a use solution having a pH in the range of about 4 to about 9. The composition can include an extreme pressure additive and/or a corrosion inhibitor. A method for using an antimicrobial lubricant composition is provided.

Abstract: A composition useful as a well lubricant, solvent, emulsifier, and performance extender for corrosion inhibitors in high velocity gas, oil or water drilling, production or gathering applications, that is preferably formed by the reaction and distillation of a tall oil fatty acid with a fatty alkanolamide, preferably in the presence of methyl ester of fatty acids, and most preferably when further reacted and distilled with an emulsifier such as coconut oil diethanolamide or distilled tall oil amide of aminoethylpiperazine. The fatty acids and oils useful in the invention can range from C8 to C24, with C12, C14, C16, C18 and C20 fatty acids and oils being most preferred. The presence of methyl ester is preferred because it functions as a foam suppressant, diluent and amine scavenger during distillation.

Abstract: The invention relates to engine oil compositions with reduced deposit-formation tendency which contain between 0.05 and 10% by weight, in relation to the total weight of the engine oil composition, of an alkyl alkoxylate of formula (I), in which R 1 , R 2 and R 3 independently are hydrogen or a hydrocarbon rest with up to 40 carbon atoms; R 4 is hydrogen, a methyl or ethyl rest; L is a linking group; n is a whole number between 4 and 40; A is an alkoxy group with between 2 and 25 recurring units derived from ethylene oxide, propylene oxide and/or butylene oxide and comprises homopolymers and statistical copolymers of at least two of the above compounds; and z is 1 or 2. The nonpolar part of compound (I) of the formula (II) contains at least 9 carbon atoms. The invention also relates to the preparation of such engine oils and to the use of alkyl alkoxylates of formula (I) for the reduction of deposit formation.

Abstract: Lubricating oil compositions providing superior soot dispersing characteristics, which contain a combination of a high molecular weight dispersant and a soot dispersant comprising a linked aromatic oligomer.

Abstract: A lubricant composition for a surface treatment of a steel filament comprises at least one specified compound as a lubricant component and a rubber-steel filament composite body is prepared by using a steel filament treated with the lubricant composition.

Abstract: Secondary alcohol esters of hydroxyacids, e.g., ricinoleate esters of secondary alcohols, are prepared by reacting an ester of a hydroxyacid with a secondary alcohol, in the presence of an organometallic transesterification catalyst. Under these reaction conditions, a high proportion of the starting ester of a hydroxyacid is converted into a secondary alcohol ester of the hydroxyacid, while minimizing the formation of by-products including estolide. The product esters and composition containing same may be used as a lubricity agent or as a friction modifier in a lubricant composition.

Abstract: An extreme pressure industrial gear lubricant having enhanced oxidative and thermal stability, lower pour point, and higher viscosity index relative to petroleum-based lubricants is comprised of a poly-&agr;-olefin, a polyol ester, a polybutene oligomer, an antioxidant, and an extreme pressure additive.

Abstract: A lubricating oil composition which exhibits improved fuel economy and fuel economy retention which contains keto-amide and keto-ester friction modifiers formed by reaction or trans-esterification of alkyl acetoacetates. The trans-esterified products are also novel compositions of matter.

Abstract: A lubricant composition is provided. The lubricant composition includes a machinery lubricant and an antimicrobially effective amount of an antimicrobial agent. The antimicrobial agent exhibits a partition coefficient between water and the machinery lubricant of between about 0.01 and about 1,000, and the lubricant composition provides at least a two log reduction in bacteria in water in about two weeks or at least a two log reduction in mold and yeast in water in about one month from a concentration of bacteria of between 105 and 106 CFU/ml and a mold and yeast concentration of between about 105 and 106 CFU/ml. Methods for manufacturing and using a lubricant composition are provided. A method for manufacturing a lubricant composition is provided.

Abstract: Lubricating solutions are used on conveying systems in the beverage industry during the filling of containers with dairy products or other beverages.

Abstract: A lubricant is provided which has a hardness in the range 0.1-10 N/mm at all temperatures in the range 15-40° C. The lubricant consists of at least one full ester of a glycol with a fatty acid, e.g. ethylene glycol dilaurate, optionally mixed with a minor amount of a fatty acid such as stearic acid, and/or a minor amount of a partial ester of a glycol with a fatty acid. The lubricant is useful in the production of press-formed components, and particularly in techniques for converting aluminium sheet to adhesively bonded aluminium structures.

Abstract: The present invention is to provide a rolling bearing suitable for the use under a high temperature, high speed, high load and high vibration condition, having a good rust-preventive performance and the excellent flaking life without a hazard to a human body. A rolling bearing is described, comprising an inner race, an outer race and rolling elements, with a grease composition comprising, as the main components, a base oil, a thickener and at least one kind of a rust-preventive additive made from a naphthenate or a succinic acid derivative, packed in a bearing space formed by at least the inner race, the outer race and the rolling elements, said at least one kind of a rust-preventive additive is present in an amount of 0.1 to 10% by weight based on the total amount of the grease composition.

Abstract: A water-dispersible cooling and lubricating composition effective for use as a metal working fluid or a metal removal fluid. The composition comprises an oil and water emulsion prepared from a pre-emulsion concentrate having a high concentration of crude, degummed vegetable oil which can be combined with esters of such vegetable oil. The metal working fluid composition of the present invention is prepared by mixing the crude vegetable oil with alkyl esters as an antigumming agent, a corrosion inhibitor, a surfactant, a saponifier, a buffer, and a preservative to form a pre-emulsion concentrate. In a preferred embodiment of the invention, the pre-emulsion concentrate further comprises a fragrance. To form the desired metal working fluid composition of the present invention, the pre-emulsion concentrate is mixed with water to form a stable metal working fluid composition of the present invention.

Abstract: Fatty ether compounds and a process for their production is disclosed. The compounds possess low viscosity and low temperature melting point properties and may be used as viscosity modifiers in the creation of cosmetics and complete vegetable oil based biodegradable fluids such as hydraulic fluids and dielectric fluids. Formation of these fatty ether compounds is by reaction of the appropriate hydroxy fatty acid or lactone with a nucleophilic alcohol in the presence of an acid catalyst to produce fatty ether esters. Following their formation, the fatty ether esters may be recovered for subsequent use, or in the alternative, they may either be hydrolyzed to produce fatty ether acids or transesterified with a different nucleophilic alcohol in the presence of an acid catalyst to produce alternate ester variants.

Abstract: The present invention relates to at least simply unsaturated polyolefins with a number mean molecular weight in the range of 400 to 1,500 dalton and a dispersibility of M.sub.W /M.sub.N <1.2, obtained through catalytic dimerization from at least simply unsaturated olefin-oligomers, as well as to the method for their production. The present invention further relates to derivatives of these polyolefins which can be obtained by functionalizing at least a double link of the polyolefin. The invention also relates to the use of polyolefins and/or functionalization products as additives for fuels or lubricants.

Abstract: Described are products suitable as lubricant and fuel additives which are obtainable by reacting a polyunsaturated polymer, for example polybutadiene, polyisoprene, ring-opening polymerised polycyclooctenamer or polynorbomene, with at least one enophilic compound of the groups of the dihydrocarbyidithiophosphoric acids, dihydrocarbylmonothiophosphoric acids, dihydrocarbylphosphoric acids or mercaptans.

Abstract: Synthetic biodegradable lubricants and functional fluids containing 45-94 wt. % of an ester of a C.sub.5 -C.sub.10 acid as the base oil, 5-18% of a polyol ester of a C.sub.12 -C.sub.28 acid as a lubricity additive, and 1-35 wt. % of an additive package for lubricants and functional fluids.

Abstract: Disclosed is a refrigerator oil composition comprising at least one base oil selected from mineral oils and synthetic oils, and at least one hydroxy-fatty acid derivative selected from (A) hydroxy-fatty acids or their condensates, (B) metal salts or amine salts of hydroxy-fatty acids or their condensates, and (C) esters of hydroxy-fatty acids. The composition has an excellent lubricating property, while specifically improving the lubricity between aluminium materials and steel materials. This is effective for preventing such materials from being seized and worn, and is suitable as a lubricating oil in refrigerators using hydrogen-containing Flon refrigerants, such as R134a, that do not cause environmental pollution.

Abstract: A lubricating oil composition for internal combustion engines which comprises a base oil, (a) an ashless dispersant containing boron, (b) a metallic detergent, and optionally (c) at least one selected from a group consisting of esters of aromatic carboxylic acids having hydroxyl group and hydroxy compounds and compounds containing boron which are derived from the esters, wherein a ratio [B]/[M] of a content of boron [B] in the composition in % by weight to a total content of metals [M] derived from the detergent in the composition in % by weight is not less than 0.15, and a sulfated ash content in the composition is not more than 1.5% by weight. The lubricating oil composition has a low ash content, does not show adverse effects on the performance of apparatuses for exhaust gas treatment, and exhibits excellent resistance to coking and oxidation stability.

Abstract: A lubricant composition capable of improving the fuel economy of an internal combustion engine and comprising a base oil as a major component and from about 2 to about 15 wt. %, based on the weight of composition, of a fuel economy improving additive having a viscosity greater than the viscosity of the bulk lubricant and being selected such that the lubricant is characterized by (1) a positive deviation from that of a theoretical line when the elastohydrodynamic (EHD) film thickness thereof is plotted against entrainment speed on a log basis, and by (2) a traction coefficient under both hydrodynamic and mixed lubrication conditions which is lower than it would have been if the fuel economy improving additive were not present in the lubricant is disclosed.

Abstract: A magnet wire insulation material having combined therewith a magnet wire winding lubricant having the formula of ##STR1## where n is from about 0 to about 26, m is from about 1 to about 35 and R is a hydrogen atom or any alkyl or acyl radical or a ##STR2## radical, and R.sup.1 is a hydrogen atom or an alkyl or an acyl radical and a magnet wire having superimposed on a base insulation material a coating of a lubricant having the formula of ##STR3## where n is from about 0 to about 26, m is from about 0 to about 35 and R is a hydrogen atom or any alkyl or acyl radical or a ##STR4## radical, and R.sup.1 is a hydrogen atom or an alkyl or an acyl radical.

Abstract: A lubricating oil composition comprises (A) a base oil, (B) a 3-methyl-5-tert-butyl-4-hydroxyphenyl substituted fatty acid ester in an amount of 0.1-5 percent by mass and (C) an auxiliary component, said auxiliary component being one member of the group of (a) a nitrogen-containing compound in an amount of 0.001-1 percent by mass, (b) a sulfur and/or phosphorus-containing compound in an amount of 0.1-5.0 percent by mass or (c) a phenolic compound in an amount of 0.1-5.0 percent by mass. This composition features the combination with a base oil of these specified components whereby there is provided synergistic effect conducive to inhibition or prevention of both oxidation and sludge formation while in use under elevated temperature conditions over extended periods of time.

Abstract: Ester base stocks for two-cycle gasoline engine lubricant compositions are disclosed which produce lower amounts of observable smoke in the exhaust emitted as a result of combustion in a two-cycle gasoline engine, require no miscibility-enhancing solvents, have a viscosity of 3.0 cSt to 20.0 cSt at 100.degree. C. and a smoke index of at least 75. Some of the esters are biodegradable.

Abstract: A lube oil composition that inhibits lubricant viscosity increase and dispersancy decrease is described. The composition includes an oil of lubricating viscosity and a mixture of specified functionalized derivatives of pentaerythritol tetrakis 3-mercaptopropionate and amine antioxidants.

Abstract: A drilling fluid additive for use during drilling and excavating applications, the additive comprises a mixture of an oil, an ester alcohol, nonionic surfactant and polypropylene glycol; and a method for manufacturing a drilling fluid additive comprising the step of admixing an oil, an ester alcohol, a nonionic surfactant, and a polypropylene glycol.

Abstract: The vegetable oil based lubricant of the present invention is derived primarily from plants, a renewable resource. It is readily biodegradable via .alpha.- and .beta.-oxidation utilizing microbes naturally present in the environment and is non-toxic to flora and fauna. The vegetable based lubricant of the invention includes a mono-, di- and trigycerol base oil making up the majority of the composition, a vegetable oil additive containing hydroxy fatty acids and a liquid vegetable wax. Additional antioxidants derived from natural vegetable or petroleum sources may be used. The base oil is primarily derived from the families Cruciferae, Leguminosae or Compositae. The vegetable oil additive is principally derived from castor or lesquerella and the vegetable wax from jojoba or meadowfoam. The invention is suitable for use in internal combustion engines and in total loss applications. The invention is designed as a total composition for its applications and is not an additive to petroleum lubricants.

Abstract: Synthetic biodegradable lubricants and functional fluids containing 45-94 wt. % of an ester of a C.sub.5 -C.sub.10 acid as the base oil, 5-18% of a polyol ester of a C.sub.12 -C.sub.28 acid as a lubricity additive, and 1-35 wt. % of an additive package for lubricants and functional fluids.

Abstract: Lubricant or lubricant concentrate on mineral oil and/or synthetic oil basis having improved lubricating properties, in particular improved load bearing, sliding and corrosion inhibiting properties, which containsa) one or more mineral oils and/or synthetic oils as base oil andb) at least one compound A containing in its molecule at least one quaternary carbon atom and at least one ester bond and/or ether bond, as well asc) further usual additives.

Abstract: A lubricant composition capable of improving the fuel economy of an internal combustion engine and comprising a base oil as a major component and from about 2 to about 15 wt. %, based on the weight of composition, of a fuel economy improving additive having a viscosity greater than the viscosity of the bulk lubricant and being selected such that the lubricant is characterized by (1) a positive deviation from that of a theoretical line when the elastohydrodynamic (EHD) film thickness thereof is plotted against entrainment speed on a log basis, and by (2) a traction coefficient under both hydrodynamic and mixed lubrication conditions which is lower than it would have been if the fuel economy improving additive were not present in the lubricant is disclosed.

Abstract: The frictional durability of lubricating oils, including power transmitting fluids and in particular automatic transmission fluids, are improved by incorporating a combination of low potency friction modifiers, ashless and/or metal-containing antioxidants, and oil-soluble phosphorus-containing compounds.

Abstract: A biodegradable lubricant which is prepared from: about 60-99% by weight of at least one biodegradable synthetic ester base stock which comprises the reaction product of: a branched or linear alcohol having the general formula R(OH).sub.n, wherein R is an aliphatic or cyclo-aliphatic group having from about 2 to 20 carbon atoms and n is at least 2; and mixed acids comprising about 30 to 80 molar % of a linear acid having a carbon number in the range between about C.sub.5 to C.sub.12, and about 20 to 70 molar % of at least one branched acid having a carbon number number in the range between about C.sub.5 to C.sub.13 ; wherein the ester base stock exhibits the following properties: at least 60% biodegradation in 28 days as measured by the Modified Sturm test; a pour point of less than -25.degree. C; and a viscosity of less than 7500 cps at -25.degree. C; about 1 to 20% by weight lubricant additive package; and about 0 to 20% of a solvent.

Abstract: The present invention provides a composition for dispersing oil slicks comprising a twin tail surfactant or mixture of twin tail surfactants having the general formula: ##STR1## wherein R.sub.1 and R.sub.3 may be the same or different alkyl or alkenyl groups; R.sub.2 is H or OH; and x is from 1 to about 20.

Abstract: An improved lubricant is provided by combining ester lubricants with alkylated polyaromatic lubricants. This combination provides a lubricant that exhibits the oxidation/varnish control of alkylated naphthenics, while at the same time providing the high temperature stability of the ester-type lubricants. A wide variety of ester lubricants can be used such as polyol esters, dimeracid esters and the like. Preferably, the alkylated aromatic lubricant has a viscosity greater than 25 up to 220 cSt measured at 40.degree. C. Greases can also be formed using this combination.

Abstract: A biodegradable lubricant which is prepared from: about 60-99% by weight of at least one biodegradable synthetic ester base stock which comprises the reaction product of: a branched or linear alcohol having the general formula R(OH).sub.n, wherein R is an aliphatic or cyclo-aliphatic group having from about 2 to 20 carbon atoms and n is at least 2; and mixed acids comprising about 30 to 80 molar % of a linear acid having a carbon number in the range between about C.sub.5 to C.sub.12, and about 20 to 70 molar % of at least one branched acid having a carbon number in the range between about C.sub.5 to C.sub.10 and wherein no more than 10% of the branched acids used to form the biodegradable synthetic ester base stock contains a quaternary carbon; wherein the ester base stock exhibits the following properties: at least 60% biodegradation in 28 days as measured by the Modified Sturm test; a pour point of less than -25.degree. C.; a viscosity of less than 7500 cps at -25.degree. C.

Abstract: A lubricating agent contains at least one alkylene oxide derivative having an alkylene oxide group and an ester moiety or an ammonium salt moiety, which is represented by the following general formula (1), (2), (3) or (4):R.sup.1 --O--(R.sup.2 O).sub.m --R.sup.3 --COO--R.sup.4 (1)R.sup.1 O--(R.sup.2 O).sub.m --R.sup.3 --COONH.sub.3 --R.sup.4 (2)R.sup.4 --OCO--R.sup.3 --O--(R.sup.2 O).sub.m --R.sup.3 --COO--R.sup.4 (3)R.sup.4 --NH.sub.3 OCO--R.sup.3 --O--(R.sup.2 O).sub.m --R.sup.3 --COONH.sub.3 --R.sup.4 (4)wherein R.sup.1 is a hydrocarbon group having 1 to 26 carbon atoms or a hydrogen atom, R.sup.2 is a hydrocarbon group having 1 to 6 carbon atoms, R.sup.3 is a hydrocarbon group having 1 to 26 carbon atoms, R.sup.4 is a hydrocarbon or fluorocarbon group having 1 to 26 carbon atoms, and m is from 1 to 12.

Abstract: A method of maintaining and servicing air conditioning systems and compositions therefor are provided whereby newer, more environmentally friendly R-134a refrigerant gas is substituted for the older R-12 and R-22 types. In addition, a method of flushing and internal lubrication of the system is presented, along with a new flush solvent and a new lubricant composition for use with an R-134a refrigerant gas.

Abstract: The present invention is directed to provide an engine oil composition which fully exploits the performance of molybdenum dithiocarbamate (MoDTC), restricts degradation of MoDTC itself, and has a high MoDTC residual property even at the time of degradation, hence providing low friction and low wear for a long time, and which results in savings in fuel consumption. It is also directed to an engine oil composition having a high coefficient of friction and an extreme-pressure property under fluid lubricating conditions arising from extreme-pressures, in order to solve various problems encountered in friction. The engine oil compositions according to the present invention comprise a specific MoDTC, a specific zinc dithiophosphate and a base oil for engine oil as the essential components, and specific polyglycerin half esters may be further added.

Abstract: A biodegradable synthetic ester base stock which comprises a blend of the following base stocks: (A) the reaction product of: (1) a branched or linear alcohol having the general formula R(OH).sub.n, wherein R is an aliphatic or cyclo-aliphatic group having from about 2 to 20 carbon atoms and n is at least 2; and (2) mixed acids comprising about 30 to 80 molar % of a linear acid having a carbon number in the range between about C.sub.5 to C.sub.12, and about 20 to 70 molar % of at least one branched acid having a carbon number in the range between about C.sub.5 to C.sub.10 and wherein no more than 10% of the branched acids used to form the biodegradable synthetic ester base stock contains a quaternary carbon; wherein the ester base stock exhibits the following properties: at least 60% biodegradation in 28 days as measured by the Modified Sturm test, a pour point of less than -25.degree. C.; and a viscosity of less than 7500 cps at -25.degree. C.

Abstract: A biodegradable lubricant which is prepared from: about 60-99% by weight of at least one biodegradable synthetic ester base stock which comprises the reaction product of: a branched or linear alcohol having the general formula R(OH).sub.n, wherein R is an aliphatic or cyclo-aliphatic group having from about 2 to 20 carbon atoms and n is at least 2; and mixed acids comprising about 30 to 80 molar % of a linear acid having a carbon number in the range between about C.sub.5 to C.sub.12, and about 20 to 70 molar % of at least one branched acid having a carbon number in the range between about C.sub.5 to C.sub.10 and wherein no more than 10% of the branched acids used to form the biodegradable synthetic ester base stock contains a quaternary carbon; wherein the ester base stock has an oxygen to carbon ratio of between about 0.15:1 to 0.3:1 and exhibits the following properties: at least 60% biodegradation in 28 days as measured by the Modified Sturm test; a pour point of less than -25.degree. C.

Abstract: A lubricating oil composition which comprises one or more base oils of the group consisting of (A) a mineral oil having a kinematic viscosity of 5-200 m.sup.2 /s at 40.degree. C. and an aromatics content of less than 15 percent by weight, (B) an olefinic polymer of 2-16 carbon atoms or its hydride having a number-average molecular weight of 250-4,000, and (C) an alkylbenzene having 1-4 alkyl groups of 1-40 carbon atoms and a total carbon number of said alkyl groups in the range of 6-40, said base oil or oils being blended with a 3-methyl-5-tert-butyl-4-hydroxyphenyl-substituted fatty acid ester in an amount of 0.1-5.0 percent by weight based on total composition. The inventive lubricant composition having such a base oil in combination with the specified fatty acid ester provides a synergistic effect conducive to inhibition or prevention of both oxidation and sludge formation while in use under elevated temperature conditions over extended periods of time.

Abstract: The present invention provides a lubricating oil composition which comprises in combination with a base oil:(A) a 3-methyl-5-tert-butyl-4-hydroxyphenyl substituted fatty ester of the formula ##STR1## where R.sup.1 is a C.sub.1 -C.sub.6 alkylene group, and R.sup.2 is a C.sub.1 -C.sub.24 alkyl or alkenyl group;(B) a N-p-alkylphenyl-.alpha.-naphthyl amine of the formula ##STR2## where R.sup.3 is a C.sub.1 -C.sub.6 alkyl group; and (C) a p,p'-dialkyldiphenyl amine of the formula ##STR3## where R.sup.4 and R.sub.5 each are a C.sub.1 -C.sub.16 alkyl group. The various components (A)-(C) as combined with a mineral or synthetic base oil are surprisingly conducive to both oxidation stability and sludge inhibiting performance under elevated temperature conditions over extended periods of service life.