In a fluid bearing lubricating oil, a viscosity index improver including polymethacrylate is added to an ester oil-based base oil.

In a fluid bearing lubricating oil, a viscosity index improver including polymethacrylate is added to an ester oil-based base oil.

A lubricant composition comprising (a) an oil having a kinematic viscosity at 100 C. of 2.2 to 3.7 mm.sup.2/s; at least one borate ester having an alkyl group of 4 to 18 carbon atoms in an amount to provide 25 to 150 parts per million by weight boron to the composition; and (c) at least one phosphorus ester in an amount to provide 150 to 650 parts per million by weight phosphorus to the composition, wherein the kinematic viscosity at 100 C. of the lubricant composition is less than or equal to 4.7 mm.sup.2/s, provides wear resistance to a needle bearing in an automatic transmission.

A lubricating oil composition may contain a base oil (A) and a dispersant-type viscosity index improver (B), in which the nitrogen atom content based on the solid content of the dispersant-type viscosity index improver (B) is 0.50 to 1.50% by mass, and the weight-average molecular weight (Mw) thereof is 100,000 or more, and the content in terms of the solid content based on the total amount of the composition of the dispersant-type viscosity index improver (B) is more than 0.05% by mass and less than 5.0% by mass. The lubricating oil composition may exert excellent wear resistance in a state contaminated with soot.

Disclosed herein is a method of pretreatment of a metallic substrate for a subsequent metal cold forming process. The method includes at least steps (1) and (2), namely providing at least one substrate having at least one surface at least partially made of at least one metal (step (1)), contacting the at least one surface of the substrate provided in step (1) with an aqueous lubricant composition (B) (step (2)), where the aqueous lubricant composition (B) includes besides water at least constituents (b1) to (b4) and optionally (b5).

Further disclosed herein are a pretreated metallic substrate obtained by the method, a method of cold forming of a metallic substrate, and an aqueous lubricant composition (B).

The present invention relates to novel uses of corrosion inhibitors in fuels and lubricants.

The present invention provides a viscosity index improver having an excellent viscosity index improving effect, a lubricant composition having excellent low-temperature viscosity in which the viscosity reduction due to long-term use is small, and a method for producing the lubricant composition. A viscosity index improver of the present invention contains a copolymer (A) containing, as monomer units, an alkyl (meth)acrylate (a) whose alkyl group contains 5 or more carbon atoms, and an alkyl (meth)acrylate (b) whose alkyl group contains 1 to 4 carbon atoms, wherein the alkyl group of the alkyl (meth)acrylate (a) whose alkyl group contains 5 or more carbon atoms has a molar-average carbon number (Q) of 29 or more, and the alkyl (meth)acrylate (b) whose alkyl group contains 1 to 4 carbon atoms is contained as a monomer unit in an amount of 38 to 75% by weight based on the weight of the copolymer (A).

The present invention relates to novel uses of corrosion inhibitors in fuels and lubricants.

A stable lubricant emulsion composition for use in engine and gear applications is provided. The emulsion includes a base petroleum oil, an aqueous salt solution that functions as a friction/wear modifier, and a polymeric non-ionic surfactant composition having a hydrophilic-lipophilic balance value in the range of 2.5 to 7 and an average molecular weight in the range of 1,000 to 3,000. The surfactant composition may include a polyester surfactant, a PIB succinimide surfactant, a PIB amine surfactant, or a mixture thereof.

The present invention relates to novel uses of corrosion inhibitors in fuels and lubricants.