Lubricant compositions comprising a base oil, one or more antioxidants selected from a group consisting of N-α-naphthyl-N-phenylamine antioxidants and diphenylamine antioxidants; and a sulfur-containing additive comprising up to seven carbon atoms exhibit outstanding oxidative stability and non-corrosion properties. The N-α-naphthyl-N-phenylamine antioxidants plus diphenylamine antioxidants in total may be present from about 0.2 wt % to about 0.8 wt %, based on the total weight of the lubricant composition. The sulfur provided by the sulfur-containing additive may be present from about 50 ppm to about 1000 ppm by weight, based on the total weight of the lubricant composition.

A lubricant additive capable of imparting various functions to a lubricant base oil contains an ester compound (A) represented by formula (1) and an ester compound (B) represented by formula (2). (A):(B) being a mass ratio of the ester compound (A) to the ester compound (B) is 99:1 to 80:20.

The present invention provides an application of nano copper in a cutting fluid. The nano copper is self-dispersible nano copper with an organic long-carbon chain, wherein the surface of copper metal is coated with a long carbon chain organic matter, and the long chain organic matter is dialkyl dithiophosphoric acid (HDDP) and a derivative thereof. In the present invention, the nano copper substitutes functional additives which comprises one or more of a preservative, an anti-rust agent, a sterilizing agent, a compression-resisting agent and a lubricant to solve the technical problems of the existing fluid in the prior art being unable to simultaneously have efficient anti-corrosion, anti-rust, compression-resistant, lubricating and sterilizing properties as well as the variety, the relatively high amount, the high cost and the limited selection of added additives.

A lubricant additive capable of imparting various functions to a lubricant base oil contains an ester compound (A) represented by formula (1) and an ester compound (B) represented by formula (2). (A):(B) being a mass ratio of the ester compound (A) to the ester compound (B) is 99:1 to 80:20.

A universal additive for fuel and lubricants contains C2-C4 alcohols, carbamide, boric acid, acrylic compounds, and water. The additive allows for more complete combustion of liquid and solid fuels, as well as reduced fuel consumption and fewer harmful emissions. In lubricating oil compositions, the additive reduces wear on the friction surfaces of engines, and also reduces fuel consumption.

The present invention addresses a problem of providing a grease composition containing a urea-based thickener and capable of appropriately maintaining the kinematic friction force in lubrication parts. The grease composition contains a base oil (A) and a urea-based thickener (B), wherein the base oil (A) has a kinematic viscosity at 40° C. of 100 mm.sup.2/s or more, and the particles containing the urea-based thickener (B) in the grease composition satisfy the following requirement (I). Requirement (I): the area-based arithmetic average particle diameter of the particles is 2.0 μm or less, as measured by a laser diffraction/scattering method.

The present invention provides an application of nano copper in a cutting fluid. The nano copper is self-dispersible nano copper with an organic long-carbon chain, wherein the surface of copper metal is coated with a long carbon chain organic matter, and the long chain organic matter is dialkyl dithiophosphoric acid (HDDP) and a derivative thereof. In the present invention, the nano copper substitutes functional additives which comprises one or more of a preservative, an anti-rust agent, a sterilizing agent, a compression-resisting agent and a lubricant to solve the technical problems of the existing fluid in the prior art being unable to simultaneously have efficient anti-corrosion, anti-rust, compression-resistant, lubricating and sterilizing properties as well as the variety, the relatively high amount, the high cost and the limited selection of added additives.

The present invention relates to provision of an extreme pressure agent-containing grease composition using, as a thickener, a urea-based thickener, the grease composition being excellent in both torque transmitting efficiency and leakage prevention performance and also excellent in wear resistance and load resistance. The grease composition contains a base oil (A), a urea-based thickener (B), and an extreme pressure agent (C), wherein particles containing the urea-based thickener (B) in the grease composition satisfies the following requirement (I): Requirement (I): an arithmetic average particle diameter of the particles on an area basis as measured by the laser diffraction/scattering method is 2.0 μm or less, and the extreme pressure agent (C) is at least one selected from an organic metal-based extreme pressure agent, a sulfur-based extreme pressure agent, a phosphorus-based extreme pressure agent, and a sulfur-phosphorus-based extreme pressure agent.

A lubricating oil composition for a transmission, the composition including: (A) a lubricant base oil comprising a mineral base oil and/or a synthetic base oil; and (B) a poly(meth)acrylate having a weight average molecular weight of no more than 25,000, wherein the composition has a kinematic viscosity at 100° C. of 2.5 to 4.9 mm.sup.2/s.

A composite material comprising a plurality of polymer chains fixed to a base and swelled with a mixture which contains a salt and a hydrogen bond-donating compound and has a melting point maintained at 100° C. or less.