[Technical Problem] An object is to provide a sliding system which can achieve both the reduced friction and the enhanced wear resistance by means of a novel combination of a sliding film and a lubricant oil.

[Solution to Problem] The sliding system of the present invention comprises: a pair of sliding members having sliding surfaces that can relatively move while facing each other; and a lubricant oil interposed between the sliding surfaces facing each other. At least one of the sliding surfaces comprises a coating surface of a crystalline chromium carbide film. The lubricant oil contains an oil-soluble molybdenum compound that has a chemical structure of a trinuclear of Mo. When the chromium carbide film as a whole is 100 at %, the chromium carbide film contains 40-75 at % of Cr. The chromium carbide film in contact with the lubricant oil containing a Mo-trinuclear appears to react with the Mo-trinuclear adsorbed during the sliding to generate a layered structural body (boundary film) similar to MoS.sub.2 on the surface, thereby developing a considerably low friction property.

A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil composition is formulated to be resistant to turbocharger deposit formation in the boosted internal combustion engine, as shown by its ability to ensure a TCO Temperature Increase of less than 9.0% as measured using the 2015 version of the General Motors dexos1® Turbocharger Coking Test. The lubricating oil composition may also have a low NOACK volatility, as measured by the method of ASTM D-5800 at 250° C.

A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil composition is formulated to be resistant to turbocharger deposit formation in the boosted internal combustion engine, as shown by its ability to ensure a TCO Temperature Increase of less than 9.0% as measured using the 2015 version of the General Motors dexos1® Turbocharger Coking Test. The lubricating oil composition may also have a low NOACK volatility, as measured by the method of ASTM D-5800 at 250° C.

The present invention relates to a compound of the Formula I:

##STR00001##

and a lubricating composition containing and a method for preparing the same. In Formula I, R.sub.1-R.sub.5 and R.sub.6-R.sub.10 are independently selected from the group consisting of hydrogen, hydrocarbyl groups and hydrocarbyl groups containing heteroatoms, such that the total carbon atoms from Q.sub.1 and Q.sub.2 is from 6 to 166 carbon atoms, and molybdate anion (Y) is a binuclear sulfur-containing dianion selected from the group consisting of [Mo.sub.2S.sub.8O.sub.2].sup.2−, [Mo.sub.2S.sub.9O].sup.2−, and [Mo.sub.2S.sub.10].sup.2.

The present invention relates to lubricating compositions comprising a compound of Formula I:

##STR00001##

wherein R.sub.1-R.sub.4 and R.sub.5-R.sub.8 are independently selected from the group consisting of hydrocarbyl groups and hydrocarbyl groups containing heteroatoms, such that the total carbon atoms from counterions Q.sub.1 and Q.sub.2 is from 8 to 76, and molybdate anion (Y) is a binuclear sulfur-containing dianion selected from the group consisting of [Mo.sub.2S.sub.8O.sub.2].sup.2−, [Mo.sub.2S.sub.9O].sup.2−, [Mo.sub.2S.sub.10].sup.2−, and mixtures thereof, and are present in the lubricating composition in an amount sufficient to provide about 100-15,000 ppm molybdenum.

The present invention relates to lubricating compositions comprising a compound of Formula I:

##STR00001##

wherein R.sub.1-R.sub.4 and R.sub.5-R.sub.8 are independently selected from the group consisting of hydrocarbyl groups and hydrocarbyl groups containing heteroatoms, such that the total carbon atoms from counterions Q.sub.1 and Q.sub.2 is from 8 to 76, and molybdate anion (Y) is a binuclear sulfur-containing dianion selected from the group consisting of [Mo.sub.2S.sub.8O.sub.2].sup.2−, [Mo.sub.2S.sub.9O].sup.2−, [Mo.sub.2S.sub.10].sup.2−, and mixtures thereof, and are present in the lubricating composition in an amount sufficient to provide about 100-15,000 ppm molybdenum.

The present invention relates to a multifunctional lubricant composition which serves as a base oil for lubrication or as an additive for lubrication, including, with respect to 100 parts by mass of phosphorus compound (A) having a specific structure specified in the Description, 26 parts by mass to 43 parts by mass of phosphorus compound (B) having a specific structure specified in the Description, 0 parts by mass to 1.3 parts by mass of phosphorus compound (C) having a specific structure specified in the Description, and a total of 0 parts by mass to 1.3 parts by mass of triphenyl phosphate and tricresyl phosphate.

The present invention relates to a multifunctional lubricant composition which serves as a base oil for lubrication or as an additive for lubrication, including, with respect to 100 parts by mass of phosphorus compound (A) having a specific structure specified in the Description, 26 parts by mass to 43 parts by mass of phosphorus compound (B) having a specific structure specified in the Description, 0 parts by mass to 1.3 parts by mass of phosphorus compound (C) having a specific structure specified in the Description, and a total of 0 parts by mass to 1.3 parts by mass of triphenyl phosphate and tricresyl phosphate.

Disclosed are lubricating compositions and base oils for motor vehicles, specifically for engines, gearboxes, or vehicle axle assemblies. The lubricating composition contains an oil-soluble polymer that is a specific polyalkyl glycol or a specific polyalkylene glycol (PAG). Also described is use of the lubricating composition for reducing fuel consumption in a vehicle provided with an engine, an axle assembly, or a gearbox that are lubricated using the lubricating composition or the specific PAG.

The invention provides a grease composition for rolling bearings of automotive electrical equipment or automotive auxiliaries, containing a base oil that includes as an essential component an alkyldiphenyl ether oil; a diurea thickener represented by formula (1); an anti-flaking additive including an organic sulfonate rust inhibitor and a load carrying additive; and an antioxidant. In the formula (1), R.sup.2 is a bivalent aromatic hydrocarbon group having 6 to 15 carbon atoms; and one of R.sup.1 or R.sup.3 represents cyclohexyl group and the other represents cyclohexyl group, an alkyl group having 8 to 22 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms. ##STR00001##