The disclosed technology provides alkylphenol-containing detergent having at least one unit (a) of an alkyl-substituted phenol wherein the alkyl group is derived from oligomers of an olefin compound containing 3 to 8 carbon atoms, wherein the polyolefin-derived alkyl group comprises at least 30 mol percent of an olefin with 4 or more carbon atoms. The invention further relates to a method of lubricating a mechanical device with the lubricant composition.

A lubricating oil composition including a base oil (A) containing an olefin-based polymer (A1), a viscosity index improver (B), and an imide-based dispersant (C), in which a first olefin-based polymer (A1-1) having a kinematic viscosity at 100° C. of 3.0 mm.sup.2/s or more is contained as the olefin-based polymer (A1), a second olefin-based polymer (A1-2) having a kinematic viscosity at 100° C. of less than 3.0 mm.sup.2/s is not contained as the olefin-based polymer (A1), a content of a resin component (B1) derived from the viscosity index improver (B) is 0.01% by mass or more based on a total amount of the lubricant composition, and a content of nitrogen atoms derived from the imide-based dispersant (C) is 0.06% by mass or more based on the total amount of the lubricant composition.

A lubricating oil composition for an internal combustion engine includes: a lubricant base oil including at least one mineral base oil, at least one synthetic base oil, or any combination thereof, and having a kinematic viscosity at 100° C. of 3.0 to 4.0 mm.sup.2/s and a NOACK evaporation loss at 250° C. of no more than 15 mass %; (A) a calcium-containing metallic detergent in an amount of no less than 1000 mass ppm and less than 2000 mass ppm in terms of calcium; (B) a magnesium-containing metallic detergent in an amount of 100 to 1000 mass ppm in terms of magnesium; (G) a zinc dialkyl dithiophosphate in an amount of no less than 600 mass ppm in terms of phosphorus; and optionally (C) a viscosity index improver in an amount of no more than 5 mass %.

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.

Disclosed is a lubricating composition including a base oil, a surfactant system and a phase-change material, especially water. The lubricating composition according to the invention is used to lubricate engines, especially for a vehicle. It has improved thermal performances compared to lubricating compositions of prior art. It also reduces clogging of the engine parts.

A method for inhibiting adsorption of α-olefin in a lubricant composition to a metal surface is disclosed. The lubricant composition comprises any of oils of Group III, Group IV and polyisobutylenes classified into Group V according to the API base oil classification or a mixture thereof as a base oil, and the α-olefin coexisting in an amount of 1% by mass or less based on the total amount of the composition. The method comprises adding a sarcosinic acid derivative, an aspartic acid derivative or a diethanolamine derivative, or a mixture thereof to the lubricant composition.

A method for inhibiting adsorption of α-olefin in a lubricant composition to a metal surface is disclosed. The lubricant composition comprises any of oils of Group III, Group IV and polyisobutylenes classified into Group V according to the API base oil classification or a mixture thereof as a base oil, and the α-olefin coexisting in an amount of 1% by mass or less based on the total amount of the composition. The method comprises adding a sarcosinic acid derivative, an aspartic acid derivative or a diethanolamine derivative, or a mixture thereof to the lubricant composition.

Provided is a lubricating oil composition to be used in an internal combustion engine having a sliding mechanism including a piston ring and a liner, the lubricating oil composition including: a base oil; (A) a poly(meth)acrylate; and (B) an organic molybdenum compound, in which: (A) the poly(meth)acrylate contains a polymer (A1) including a repeating unit derived from a (meth)acrylate represented by the following formula (1) and having a mass-average molecular weight of from 1,000 to 500,000; and a content of (B) the organic molybdenum compound in a total amount of the composition is from 0.01 mass % to 0.2 mass % in terms of a molybdenum atom: wherein R.sup.1 represents a hydrogen atom or a methyl group, and X represents a hydrogen atom, a hydrocarbon group having 1 to 60 carbon atoms, or a functional group-containing hydrocarbon group having 1 to 60 carbon atoms.

A lubricating oil composition for an internal combustion engine including: (A) a lubricant base oil having a kinematic viscosity at 100° C. of 2 to 5 mm.sup.2/s; (B) a metallic detergent in an amount of 500 to 2500 mass ppm in terms of Ca and 100 to 1000 mass ppm in terms of Mg, on the basis of the total mass of the composition, the metallic detergent including both (B1) a Ca-containing metallic detergent and (B2) a Mg-containing metallic detergent; (C) a boron-containing additive in an amount of 50 to 1000 mass ppm in terms of boron on the basis of the total mass of the composition, wherein the boron-containing additive is oil-soluble or oil-dispersible and is stable in oil, and wherein the boron-containing additive may compose at least a part of the component (B); and (D) an oil-soluble organic Mo compound in an amount of 100 to 2000 mass ppm in terms of Mo on the basis of the total mass of the composition, wherein a mass ratio (MB/Mg) of boron content of the composition (MB) to Mg content of the composition (Mg) is 0.5 to 10.

A lubricating oil composition for an internal combustion engine including: (A) a lubricant base oil having a kinematic viscosity at 100° C. of 2 to 5 mm.sup.2/s; (B) a metallic detergent in an amount of 500 to 2500 mass ppm in terms of Ca and 100 to 1000 mass ppm in terms of Mg, on the basis of the total mass of the composition, the metallic detergent including both (B1) a Ca-containing metallic detergent and (B2) a Mg-containing metallic detergent; (C) a boron-containing additive in an amount of 50 to 1000 mass ppm in terms of boron on the basis of the total mass of the composition, wherein the boron-containing additive is oil-soluble or oil-dispersible and is stable in oil, and wherein the boron-containing additive may compose at least a part of the component (B); and (D) an oil-soluble organic Mo compound in an amount of 100 to 2000 mass ppm in terms of Mo on the basis of the total mass of the composition, wherein a mass ratio (MB/Mg) of boron content of the composition (MB) to Mg content of the composition (Mg) is 0.5 to 10.