A gear fluid composition for lubricating a driveline including organic sulfide compounds effective to achieve passing friction, extreme pressure, and copper corrosion.

A lubricant composition comprising an oil of lubricating viscosity and an N-hydrocarbyl-substituted γ-aminoester or γ-aminothioester, wherein the N-hydrocarbyl substituent comprises a hydrocarbyl group of at least 3 carbons atoms, with a branch at the 1 or 2 position of the hydrocarbyl chain, provides exhibits basicity and good seal performance.

A lubricant composition comprising an oil of lubricating viscosity and an N-hydrocarbyl-substituted γ-aminoester or γ-aminothioester, wherein the N-hydrocarbyl substituent comprises a hydrocarbyl group of at least 3 carbons atoms, with a branch at the 1 or 2 position of the hydrocarbyl chain, provides exhibits basicity and good seal performance.

The present invention concerns a friction piece (10) suitable for operating in a lubricated medium at a temperature higher than 200° C. The piece (10) comprises a metal surface (12) and an external coating (14) composed of tungsten carbide doped with nitrogen WC(N) with an atomic ratio of nitrogen between 5 and 12%. The invention also relates to a mechanical system (1) comprising such a piece (10). The invention also relates to a method for implementing such a piece (10).

The present invention concerns a friction piece (10) suitable for operating in a lubricated medium at a temperature higher than 200° C. The piece (10) comprises a metal surface (12) and an external coating (14) composed of tungsten carbide doped with nitrogen WC(N) with an atomic ratio of nitrogen between 5 and 12%. The invention also relates to a mechanical system (1) comprising such a piece (10). The invention also relates to a method for implementing such a piece (10).

The present invention provides a grease composition for electrical contacts, including: a thickener; a base oil; and an organic sulfur compound, wherein the organic sulfur compound is a compound having no heterocycle containing nitrogen in a molecule thereof.

Disclosed is a lubricating oil composition containing a base oil, a viscosity index improver, a molybdenum-based friction modifier, a boron-containing dispersant, and at least two extreme-pressure additives selected from a sulfur-based extreme-pressure additive, a phosphorous-based extreme-pressure additive and a sulfur/phosphorus-based extreme-pressure additive, or a sulfur/phosphorus-based extreme-pressure additive. The base oil is a synthetic oil having a kinematic viscosity at 100° C. of 3 mm.sup.2/s or more and 10 mm.sup.2/s or less, the viscosity index improver is a resin having a number average molecular weight (Mn) of 1,000 or more and 10,000 or less, the mass ratio of boron atoms (B) contained in the boron-containing dispersant to molybdenum atoms (Mo) contained in the molybdenum-based friction modifier, [(B)/(Mo)] is 1 or more and 5 or less, and the mass ratio of sulfur atoms (S) to phosphorus atoms (P) contained in the extreme-pressure additive(s), [(S)/(P)] is 10 or more and 20 or less.

A lubricating oil composition for a sliding guide surface, which includes a lubricant base oil, an acid phosphate ester mixture having a structure represented by the following Formula (1) and including an acid phosphate monoester and an acid phosphate diester, and an aliphatic monoamine, and which satisfies a predetermined condition A or condition B, is provided. In Formula (1), each of R.sup.1 and R.sup.2 represents a hydrogen atom or a saturated or unsaturated straight-chain aliphatic hydrocarbon group having from 1 to 30 carbon atoms, and R.sup.1 and R.sup.2 are not simultaneously hydrogen atoms.
(R.sup.1O)(R.sup.2O)(HO)P═O  (1)

A lubricating oil composition for a sliding guide surface, which includes a lubricant base oil, an acid phosphate ester mixture having a structure represented by the following Formula (1) and including an acid phosphate monoester and an acid phosphate diester, and an aliphatic monoamine, and which satisfies a predetermined condition A or condition B, is provided. In Formula (1), each of R.sup.1 and R.sup.2 represents a hydrogen atom or a saturated or unsaturated straight-chain aliphatic hydrocarbon group having from 1 to 30 carbon atoms, and R.sup.1 and R.sup.2 are not simultaneously hydrogen atoms.
(R.sup.1O)(R.sup.2O)(HO)P═O  (1)

Lubricating compositions comprising a thiol-carboxylic adduct that is the reaction product of a thiol and carboxylic acid and/or a carboxylic acid derivative. The lubricating composition also comprises an antiwear agent. Methods of lubricating an internal combustion engine comprise contacting the internal combustion engine with a lubricating composition comprising a thiol-carboxylic adduct that is the reaction product of a thiol and carboxylic acid and/or a carboxylic acid derivative. Methods of reducing lubricant oxidation and/or corrosion in an internal combustion engine with a lubricating composition comprising a thiol-carboxylic adduct that is the reaction product of a thiol and carboxylic acid and/or a carboxylic acid derivative. The use of a comprising a thiol-carboxylic adduct that is the reaction product of a thiol and carboxylic acid and/or a carboxylic acid derivative to reduce lubricant oxidation and/or corrosion in an internal combustion engine.