A lubricating oil composition excellent in the wear resistance and a refrigerator oil composition excellent in the oxidation stability using the lubricating oil composition are provided by a lubricating oil composition containing a base oil (A) and a phosphine derivative (B) having one or more oxygen atom in a molecule.

The present invention relates to a lubricating composition containing: an oil of lubricating viscosity, a non-borated dispersant, a detergent, and an antiwear package comprising (a) a derivative of a hydroxycarboxylic acid, (b) an amine salt of a phosphoric acid ester, and (c) a phosphite having at least one hydrocarbyl group with 4 or more carbon atoms. The invention further provides for a method of lubricating a driveline device application by employing a lubricating composition containing the antiwear package.

A composition obtained by reacting an O,O-dialkyldithiophosphoric acid with a hydroxyalkyl acrylate or a hydroxyalkyl methacrylate, and reacting the product thereof with a dialkylphosphite provides good antiwear protection.

Provided are a lubricating oil composition having a high intermetallic friction coefficient and having excellent clutch anti-shudder performance of excellent initial clutch anti-shudder performance and a long clutch anti-shudder lifetime, and a lubrication method and a transmission using the lubricating oil composition. The lubricating oil composition contains an amide compound (A) having a specific structure, a metal-based detergent (B), and at least one phosphorus acid ester (C) selected from an acid phosphate ester and an acid phosphite ester; and the lubrication method and the transmission use the lubricating oil composition.

There is disclosed an antifoam component for a mechanical device which includes a poly(acrylate) copolymer. The antifoam component has improved foam performance in finished fluids utilizing dibutyl hydrogen phosphite compounds, such as driveline fluids. A lubricating composition comprising a) at least one oil of lubricating viscosity; and b) an antifoam component comprising a poly(acrylate) copolymer. The poly(acrylate) copolymer, b) may include (i) from about 30 wt % up to about 99 wt % of a (meth)acrylate monomer having C.sub.1 to C.sub.4 alkyl esters of (meth)acrylic acid; and (ii) from about 1 wt % up to about 70 wt % of a fluorinated (meth)acrylate monomer.

A dielectric fluid is provided comprising a natural bio-sourced oil and one or more compounds selected from the group consisting of phosphite compounds. It has been discovered that addition of one or more compounds selected from the group consisting of phosphite compounds to dielectric fluids comprising oil impart a stabilizing effect that reduces, inhibits or prevents formation of stray gases in the dielectric fluid during ordinary use.

A dielectric fluid is provided comprising an oil and one or more compounds selected from the group consisting of phosphite compounds. It has been discovered that addition of one or more compounds selected from the group consisting of phosphite compounds to dielectric fluids comprising oil impart a stabilizing effect that reduces, inhibits or prevents formation of stray gases in the dielectric fluid during ordinary use.

Provided is a lubricating oil composition containing a mineral base oil (A) having a temperature gradient |Dt| of a distillation temperature between two points of a distillation amount of 2.0% by volume and a distillation amount of 5.0% by volume in a distillation curve of 6.8 C./% by volume or less, and an antioxidant (B) containing an amine-based antioxidant (B1), a phenol-based antioxidant (B2), and a phosphorus-based antioxidant (B3), wherein the content of the component (B3) is 0.06 to 1.0% by mass based on the total amount of the lubricating oil composition. The lubricating oil composition is a long-life lubricating oil composition that maintains excellent oxidation stability even for long-term use in a high-temperature environment, and has a high effect of suppressing the generation of sludge for a long period of time.

The instant disclosure is directed to a method of lubricating a sump-lubricated, high efficiency, gasoline-fueled internal combustion engine. Said method involves supplying to the engine a lubricating composition comprising an oil of lubricating viscosity, an anti-wear agent, an ashless antioxidant, a metal-containing detergent, an ashless polyolefin dispersant, and (f) a polymeric viscosity modifier. The disclosure further provides a method of operating a high efficiency sump-lubricated gasoline-fueled internal combustion engine while maintaining or improving at least one of durability, deposit control, oxidation control, fuel economy, and resistance to knock and stochastic pre-ignition.

A lubricating oil composition for a push-belt continuously variable transmission includes: (A) a lubricant base oil including at least one wax-isomerized base oil, and having a specific kinematic viscosity and a specific viscosity index; (B) a poly(meth)acrylate having a specific weight average molecular weight; (C) a boron-containing succinimide compound; (D) a borate ester compound; and (E) an overbased calcium detergent, wherein the composition has a kinematic viscosity at 40 C. of no more than 25 mm.sup.2/s; a viscosity index of no less than 180; and the ratio of a boron content to a calcium content of 0.5 to 1.5.