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.

A comb copolymer viscosity modifier may be made by polymerization comprising at least, or consisting essentially of, the following monomers: (a) (optionally from 7.0 wt % to 18 wt %, by repeat units, of) a hydrogenated polybutadiene-based (alk)acrylate ester macromonomer; (b) (optionally from 33 wt % to 64 wt %, by repeat units, of) a C.sub.3-C.sub.8alkyl (alk)acrylate ester monomer; (c) a C.sub.12-C.sub.24 alkyl (alk)acrylate ester monomer; and (d) (optionally from 3.0 wt % to 25 wt %, by repeat units, of) H-endcapped, C.sub.1-C.sub.18 alkyl-endcapped, or C.sub.6-C.sub.20 aryl-, aralkyl-, or alkaryl-endcapped C.sub.2-C.sub.6 oxyalkyl or C.sub.2-C.sub.6 oligo(alkylene glycol)-based (alk)acrylate ester monomer, wherein repeat units based on monomer (c) and/or monomer (d) comprise at least 21.0 wt % (and optionally up to 35.0 wt %) of repeat units of the comb copolymer viscosity modifier. Lubricant compositions comprising the comb copolymer viscosity modifier, as well as uses thereof and methods for modifying viscosity and dispersancy, are also contemplated.

A comb copolymer viscosity modifier may be made by polymerization comprising at least, or consisting essentially of, the following monomers: (a) (optionally from 7.0 wt % to 18 wt %, by repeat units, of) a hydrogenated polybutadiene-based (alk)acrylate ester macromonomer; (b) (optionally from 33 wt % to 64 wt %, by repeat units, of) a C.sub.3-C.sub.8alkyl (alk)acrylate ester monomer; (c) a C.sub.12-C.sub.24 alkyl (alk)acrylate ester monomer; and (d) (optionally from 3.0 wt % to 25 wt %, by repeat units, of) H-endcapped, C.sub.1-C.sub.18 alkyl-endcapped, or C.sub.6-C.sub.20 aryl-, aralkyl-, or alkaryl-endcapped C.sub.2-C.sub.6 oxyalkyl or C.sub.2-C.sub.6 oligo(alkylene glycol)-based (alk)acrylate ester monomer, wherein repeat units based on monomer (c) and/or monomer (d) comprise at least 21.0 wt % (and optionally up to 35.0 wt %) of repeat units of the comb copolymer viscosity modifier. Lubricant compositions comprising the comb copolymer viscosity modifier, as well as uses thereof and methods for modifying viscosity and dispersancy, are also contemplated.

A lubricating oil composition for an internal combustion engine, the composition including: a lubricating base oil comprising at least one mineral base oil or at least one synthetic base oil or any combination thereof, the lubricating base oil having a kinematic viscosity at 100° C. of 4.0 to 4.5 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 on the basis of the total mass of the composition; and optionally (C) a viscosity index improver in an amount of less than 1 mass % on the basis of the total mass of the composition.

A lubricating oil composition for an internal combustion engine, the composition including: a lubricating base oil comprising at least one mineral base oil or at least one synthetic base oil or any combination thereof, the lubricating base oil having a kinematic viscosity at 100° C. of 4.0 to 4.5 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 on the basis of the total mass of the composition; and optionally (C) a viscosity index improver in an amount of less than 1 mass % on the basis of the total mass of the composition.

A lubricating composition including a polymer blend of a modified styrene-maleic anhydride copolymer and poly(meth)acrylate copolymer effective to maintain a pumpable fluid at low temperatures.

A lubricating composition including a polymer blend of a modified styrene-maleic anhydride copolymer and poly(meth)acrylate copolymer effective to maintain a pumpable fluid at low temperatures.

An aqueous coating agent composition includes (A) a curable resin in the form of an aqueous emulsion, (B) a surfactant, (C) solid particles, (D) one or more nitrogen-containing heterocyclic compounds, and (E) water. In various embodiments, component (C) includes a solid lubricant, and for reasons of environmental regulations, component (D) includes 1,3-dimethyl-2-imidazolidinone.