The lubricating oil composition of the present invention contains a base oil, a 2,6-di-tert-butylphenol (A), and at least one compound (B) selected from a benzotriazole compound and a sorbitan compound.

One aspect of the present invention is a refrigerating machine including a refrigerant circulation system including a compressor, a condenser, an expansion mechanism, and an evaporator, and the refrigerant circulation system being filled with a refrigerant and a refrigerating machine oil, wherein the refrigerating machine oil contains: a first base oil having a compatible region with the refrigerant in a range of a temperature of 30 C. or lower and an oil ratio of 1 to 80% by mass; and a second base oil having a kinematic viscosity at 40 C. lower than the first base oil and having a narrower compatible region with the refrigerant than the first base oil.

A lubricating oil composition having greater than 50 wt % of a base oil and 0.1 wt % to 20 wt %, both based on the total weight of the lubricating oil composition, of a dispersant viscosity modifier obtainable by: A) reacting: a) at least one of a lactone of formula (I) or a derivative thereof: ##STR00001##
wherein X is oxygen, and R is an optionally substituted hydrocarbylene group having from 1 to 20 carbon atoms; and b) at least one compound selected from amines, alcohols and oxazolines; and B) reacting the reaction product of step A) onto an acylated olefin copolymer obtainable by acylating a copolymer of ethylene and one or more C.sub.3-C.sub.10 alpha-olefins having a number average molecular weight of 5,000 to 200,000 g/mol as measured by GPC, with an acylating agent. Methods employing the lubricating oil compositions and uses of the lubricating compositions as engine oils are also described.

Methods of lubricating food processing equipment that include applying a food grade, high temperature lubricant composition to the food processing equipment are described. The composition includes a polyol polyester base oil that is a reaction product of at least one neopentyl polyhydric alcohol and at least one monocarboxylic acid. Also described are methods of preparing a food grade, high temperature composition comprising reacting at least one neopentyl polyhydric alcohol and at least one monocarboxylic acid. The composition may be a lubricant composition. Additionally, the invention provides a food grade, high temperature lubricant composition comprising a polyol polyester base oil that is a reaction product of at least one neopentyl polyhydric alcohol and at least one monocarboxylic acid.

This disclosure provides a method for improving or maintaining antioxidant performance of a lubricating oil in an engine or other mechanical component lubricated with the lubricating oil by using as the lubricating oil a formulated oil. The formulated oil has a composition including a lubricating oil base stock as a major component, and at least one functionalized quercetin antioxidant, as a minor component. The at least one functionalized quercetin antioxidant is soluble in the lubricating oil. Antioxidant performance is improved or maintained as compared to antioxidant performance achieved using a lubricating oil containing a phenolic or aminic antioxidant, as determined by Lubricant Oxidation Test as described herein or Catalytic Oxidation Test as described herein. This disclosure also relates to lubricating oils having at least one functionalized quercetin antioxidant. The lubricating oils are useful as passenger vehicle engine oils (PVEO), commercial vehicle engine oils (CVEO), and other mechanical industrial applications.

The present invention relates to a lubricating composition containing (a) an oil of lubricating viscosity; and (b) a compound selected from the group consisting of: (i) an ester-containing heterocycle; (ii) an amide-containing heterocycle; and (iii) a pyrimidine, wherein the ester-containing heterocycle and the amide-containing heterocycle have a hydrocarbyl group containing 6 to 40 carbon atoms. The invention further provides for a method of supplying an internal combustion engine with the lubricating composition.

The present invention relates to a lubricating composition containing (a) an oil of lubricating viscosity; and (b) a compound selected from the group consisting of: (i) an ester-containing heterocycle; (ii) an amide-containing heterocycle; and (iii) a pyrimidine, wherein the ester-containing heterocycle and the amide-containing heterocycle have a hydrocarbyl group containing 6 to 40 carbon atoms. The invention further provides for a method of supplying an internal combustion engine with the lubricating composition.

A lubricating oil composition having greater than 50 wt % of a base oil and 0.1 wt % to 20 wt %, both based on the total weight of the lubricating oil composition, of a dispersant viscosity modifier obtainable by: A) reacting: a) at least one of a lactone of formula (I) or a derivative thereof:

##STR00001##

wherein X is oxygen, and R is an optionally substituted hydrocarbylene group having from 1 to 20 carbon atoms; and b) at least one compound selected from amines, alcohols and oxazolines; and B) reacting the reaction product of step A) onto an acylated olefin copolymer obtainable by acylating a copolymer of ethylene and one or more C.sub.3-C.sub.10 alpha-olefins having a number average molecular weight of 5,000 to 200,000 g/mol as measured by GPC, with an acylating agent. Methods employing the lubricating oil compositions and uses of the lubricating compositions as engine oils are also described.

The present invention relates to a refrigerator oil containing a polyvinyl ether-based compound (A) containing a structural unit (a1) having a methoxy group in a side chain thereof in an amount of 30 mol % or more and 100 mol % or less on a basis of 100 mol % of the whole amount of structural units excluding a terminal structural unit in a molecular structure thereof, a refrigerator oil composition containing the refrigerator oil, and a production method of the refrigerator oil.

A lubricating oil including a lubricating oil base stock as a major component, and one or more lubricating oil additives having at least one protected active group, as a minor component. The one or more lubricating oil additives having at least one protected active group are converted into one or more lubricating oil additives having at least one unprotected active group in the lubricating oil in-service in an engine or other mechanical component. Compositions including one or more lubricating oil additives having at least one protected active group. A method for improving solubility of one or more lubricating oil additives in a lubricating oil. A method for improving oxidative stability of a lubricating oil and extending performance life of one or more lubricating oil additives. A method for improving friction control in an engine or other mechanical component lubricated with a lubricating oil.