The present invention relates to a lubricant composition, and more particularly to a lubricant composition, which includes an ethylene-alphaolefin oligomer and an alkylated phosphonium compound, thus realizing energy reduction and an increased endurance life, and which is thus suitable for use in gear oil. The lubricant composition of the present invention includes a base oil, a liquid olefin copolymer, and an alkylated phosphonium compound.

The lubricating oil composition of the present invention contains, together with a base oil, a viscosity index improver (A) including a comb-shaped polymer (A1), a detergent dispersant (B) including an alkali metal borate (B1) and an organometallic compound (B2) containing a metal atom selected from an alkali metal atom and an alkaline earth metal atom, and a friction modifier (C) including a molybdenum-containing friction modifier, with the total content of an alkali metal atom and an alkaline earth metal atom being 2,000 mass ppm or less. The lubricating oil composition of the present invention has excellent detergency, fuel saving properties, and LSPI-preventing properties.

The lubricating oil composition of the present invention contains, together with a base oil, a viscosity index improver (A) including a comb-shaped polymer (A1), a detergent dispersant (B) including an alkali metal borate (B1) and an organometallic compound (B2) containing a metal atom selected from an alkali metal atom and an alkaline earth metal atom, and a friction modifier (C) including a molybdenum-containing friction modifier, with the total content of an alkali metal atom and an alkaline earth metal atom being 2,000 mass ppm or less. The lubricating oil composition of the present invention has excellent detergency, fuel saving properties, and LSPI-preventing properties.

The purpose of the present invention is to provide a lubricant composition which can be applied as a gear oil for a high-output and high-speed gear mechanism, and whereby fuel saving as well as further wear resistance in a bearing of a pinion gear can be realized while maintaining excellent durability, seizure resistance, and stability are maintained. A lubricant composition containing a Fischer-Tropsch-derived base oil, a poly alpha-olefin, and an ester compound, and further containing an unsaturated fatty acid and/or a partial ester compound of an unsaturated fatty acid and a polyol, wherein the partial ester compound of an unsaturated fatty acid includes a monoester compound of an unsaturated fatty acid and a polyol in a ratio of 50% by mass with respect to the total amount of the partial ester compound, and the SAE viscosity grade of the lubricant composition is 75W-85 or lower.

The purpose of the present invention is to provide a lubricant composition which can be applied as a gear oil for a high-output and high-speed gear mechanism, and whereby fuel saving as well as further wear resistance in a bearing of a pinion gear can be realized while maintaining excellent durability, seizure resistance, and stability are maintained. A lubricant composition containing a Fischer-Tropsch-derived base oil, a poly alpha-olefin, and an ester compound, and further containing an unsaturated fatty acid and/or a partial ester compound of an unsaturated fatty acid and a polyol, wherein the partial ester compound of an unsaturated fatty acid includes a monoester compound of an unsaturated fatty acid and a polyol in a ratio of 50% by mass with respect to the total amount of the partial ester compound, and the SAE viscosity grade of the lubricant composition is 75W-85 or lower.

A lubricating oil composition for a sliding guide surface, which exhibits excellent low friction properties and extreme pressure properties so as to enable high precision machining in a machine tool, is disclosed.

A lubricating oil composition for a sliding guide surface, which exhibits excellent low friction properties and extreme pressure properties so as to enable high precision machining in a machine tool, is disclosed.

A grease composition for resin lubrication, the grease composition to be applied to a sliding surface made of resin, the grease composition containing: a fluorine-based base oil (a kinematic viscosity at 40° C. of 300 mm.sup.2/s or higher) and a synthetic hydrocarbon oil as base oils; a fluorine-based thickener, and a lithium soap thickener or a lithium complex soap thickener as thickeners; and a fluorine-based surfactant and an extreme pressure additive as additives; and a resin sliding member (slide switch) having a sliding surface made of resin, the sliding surface provided by application with the grease composition.

A grease composition for resin lubrication, the grease composition to be applied to a sliding surface made of resin, the grease composition containing: a fluorine-based base oil (a kinematic viscosity at 40° C. of 300 mm.sup.2/s or higher) and a synthetic hydrocarbon oil as base oils; a fluorine-based thickener, and a lithium soap thickener or a lithium complex soap thickener as thickeners; and a fluorine-based surfactant and an extreme pressure additive as additives; and a resin sliding member (slide switch) having a sliding surface made of resin, the sliding surface provided by application with the grease composition.

An ionic liquid composition having the following generic structural formula:

##STR00001##

wherein Z is N or P, and R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently selected from hydrogen atom and hydrocarbon groups having one to four carbon atoms with optional interconnection to form a cyclic group that includes Z, and wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are all hydrocarbon groups when Z is P, and X.sup.− is a phosphorus-containing or carboxylate anion, particularly an organophosphate, organophosphonate, or organophosphinate anion, or a thio-substituted analog thereof containing hydrocarbon groups with at least three carbon atoms. Also described are lubricant compositions comprising the above ionic liquid and a base lubricant, wherein the ionic liquid is dissolved in the base lubricant. Further described are methods for applying the ionic liquid or lubricant composition onto a mechanical device for which lubrication is beneficial, with resulting improvement in friction reduction, wear rate, and/or corrosion inhibition.