A lubricating oil composition including: a lubricating base oil; (A) a dispersant poly(meth)acrylate compound having a weight average molecular weight of 30,000 to 200,000 in an amount of 1 to 10 mass % on the basis of the total mass of the composition; and (B) a non-dispersant poly(meth)acrylate compound having a weight average molecular weight of 15,000 to 100,000 in an amount of no more than 15 mass % on the basis of the total mass of the composition, wherein the ratio MA/MB of the amount MA of the component (A) to the amount MB of the component (B) is 0.05 to 1; and the ratio MwB/MwA of the weight average molecular weight MwB of the component (B) to the weight average molecular weight MwA of the component (A) is 0.05 to 2.

There is disclosed an antifoam component for a mechanical device which includes a fluorinated poly(acrylate) copolymer. The antifoam component has improved foam performance and thermal stability in finished fluids, such as driveline fluids.

A lubricant composition comprising: (i) silver or gold nanoparticles, each of which is encapsulated by a layer of alkylthiol or alkylamine molecules; (ii) palladium or platinum nanoparticles, each of which is encapsulated by a layer of alkylthiol or alkylamine molecules; and (iii) a fluid in which components (i) and (ii) are present. Further described are methods for applying the lubricant composition onto a mechanical device for which lubrication is beneficial, with resulting improvement in friction and wear reduction and/or corrosion inhibition.

There is disclosed an antifoam component for a mechanical device which includes a fluorinated poly(acrylate) copolymer. The antifoam component has improved foam performance and thermal stability in finished fluids, such as driveline fluids.

Disclosed is a lubricating oil composition for gear oil, comprising a lubricating base oil having a kinematic viscosity at 40 C. of 140 to 350 mm.sup.2/s, a copolymer of an -olefin and an ester monomer having a polymerizable unsaturated bond, a performance additive containing phosphorus and sulfur, and a poly(meth)acrylate pour-point depressant.

The present invention provides a grease composition for constant velocity joints, which includes a lubricating base oil, a thickener including a nitrogen-containing compound, a triglyceride, a diester, and a boron nitride, wherein a total content of the triglyceride and the diester is 1 to 5 mass % based on a total amount of the grease composition, and a mass ratio of a content of the triglyceride to a content of the diester (triglyceride/diester) is 0.3 to 1.5.

Provided are; a lubricating oil composition excellent in fuel saving performance, seizure resistance, wear resistance, fatigue lifetime and shear stability, which contains a base oil (A), an olefin polymer (B) having a number average molecular weight of 1,000 or more and 12,000 or less, and a specific sulfur compound (C) and wherein the content of all sulfur atoms based on the total amount of the composition is 1.2% by mass or more and 2.5% by mass or less; and a lubrication method using the lubricating oil composition.

A grease composition including: a base oil; a thickener; a zinc sulfonate; a polysulfide; an overbased calcium sulfonate; and triphenyl phosphite, in which a proportion of the zinc sulfonate with respect to a total mass of the base oil and the thickener is 0.030 mass % to 0.045 mass % in terms of a zinc content, a proportion of the polysulfide with respect to the total mass of the base oil and the thickener is 0.16 mass % to 0.24 mass % in terms of a sulfur content, a proportion of the overbased calcium sulfonate with respect to the total mass of the base oil and the thickener is 0.010 mass % to 0.015 mass % in terms of a calcium content, and a proportion of the triphenyl phosphite with respect to the total mass of the base oil and the thickener is 0.24 mass % to 0.36 mass %.

To provide a lubricating oil composition for internal combustion engines, which can realize low friction in both internal combustion engines equipped with a DLC and internal combustion engines not equipped with a DLC. [Solution] a lubricating oil composition for internal combustion engines, which is characterized in that the lubricating oil composition for internal combustion engines is a composition obtained by blending a molybdenum dithiocarbamate (MoDTC) and a polyalkylene glycol (PAG) in a base oil, the weight average molecular weight of the polyalkylene glycol is 2750-4500 and the content of the polyalkylene glycol is not less than 0.05 mass % and less than 10 mass % relative to the total mass of the composition.

An axle oil composition having enhanced fuel efficiency and low viscosity is provided, wherein the axle oil composition contains 40 to 70 wt % of poly alpha olefin (PAO) synthetic oil; 5 to 35 wt % of an oil soluble poly alkylene glycol (OSP) synthetic oil; 15 to 20 wt % of an ester-based viscosity modifier; 0.05 to 0.5 wt % of calcite; and 5 to 20 wt % of additive, wherein the axle oil composition having enhanced fuel efficiency and low viscosity has average kinematic viscosity at 100 C. of 11.5 to 13.5 cSt and average kinematic viscosity at 40 C. of 65 to 75 cSt and forms an oil film having a thickness of 85 to 96 nm even at low viscosity, largely improving durability and fuel efficiency of a vehicle.