The present invention relates to copolymers, to a method for the preparation of these copolymers, to the use of these copolymers for reducing wear in a lubricant composition, to lubricant compositions comprising these copolymers, and to the use of these lubricant compositions as an automatic transmission fluid, a continuously variable transmission fluid, an engine oil, a gear oil, or a hydraulic oil.

The invention provides a lubricating composition containing an antiwear agent and an oil of lubricating viscosity. The invention further relates to the use of the lubricating composition in an internal combustion engine, or a driveline device.

To provide a lubricating oil composition achieving both of high traction coefficient and excellent low temperature fluidity at a higher level and having a high flash point, which contains a naphthene-based synthetic oil (a) having a flash point of 140 C. or higher, and an ester (b) having 5 to 32 carbon atoms and having a branched chain, wherein the content of the naphthene-based synthetic oil (a) based on the total amount of the composition is 35% by mass or more and less than 80% by mass, a method for producing the lubricating oil composition, and a continuously variable transmission using the lubricating oil composition.

Disclosed is a lubricating oil composition capable of inhibiting vibrations or noises generated between a pulley and a chain or between a pulley and a belt in a CVT or the like, while increasing an intermetallic friction coefficient, the composition containing a base oil, an alkaline earth metal-based detergent (A), a phosphite ester (B1), a phosphate ester amine salt (B2), an acidic phosphate ester (B3), an aliphatic monoamine (C1), and an aromatic monoamine (C2).

The present invention relates to a lubricating oil composition and a continuously-variable transmission filled with the lubricating oil composition. The present invention also relates to a friction control method for a continuously-variable transmission, the method using the lubricating oil composition. This lubricating oil composition is characterized by containing: (A) a base oil; (B) a diamine; (C) a glycolic acid amide; and (D) a phosphorous ester. With this lubricating oil composition, it is possible to provide different wear characteristics between different parts, so in a preferable embodiment of the present invention, the lubricating oil composition is suitably used as a lubricating oil for variable transmissions, in particular, metal-belt continuously-variable transmissions.

Provided is a mineral base oil having a kinematic viscosity at 40 C. of 4.0 mm.sup.2/s or more and less than 6.0 mm.sup.2/s, a kinematic viscosity at 100 C. of 1.0 mm.sup.2/s or more and less than 2.0 mm.sup.2/s, and a flash point of 140 C. or higher. A lubricating oil composition containing the mineral base oil has a high flash point while having a low viscosity and thus having excellent fuel-saving performance when used as a driving system oil and the like.

A lubricating oil composition including greater than 50 wt. % of a base oil; a reaction product of a hydrocarbyl acid phosphate and a nitrogen containing compound; and an oil soluble hydrocarbyl borate. A method for reducing gear scuffing in a transmission including a step of lubricating the transmission with the above-mentioned lubricating oil composition and a method of operating a transmission including steps of lubricating said transmission with the lubricating oil composition described above and operating the transmission, are also described.

This invention provides A methacrylic copolymer (C) comprising 25 to 35 mass % of a methyl methacrylate unit (A), and 75 to 65 mass % of an alkyl methacrylate ester unit (B) containing an alkyl group having 10 to 36 carbon atoms, the methacrylic copolymer having (a) a weight average molecular weight of 10,000 to 500,000, (b) a molecular weight distribution (Mw/Mn) of 1.01 to 1.60, (c) a triad syndiotacticity (rr) of 65% or more, and (d) a solubility of 5.0 mass % or more at 0 C. in at least one lubricant base oil (D) selected from the group consisting of API groups III, III+, and IV.

A constant velocity joint having a boot constructed from a thermoplastic polyether ester as the boot material. The boot includes a lubricating grease composition for lubricating the constant velocity joint, the lubricating grease composition comprising calcium lignin sulfonate.

The invention discloses a lubricating grease with thixotropy and a preparation method thereof. The lubricating grease comprises a polyurea/high base number calcium sulfonate composite thickener, colloidally dispersed calcium carbonate solid particles in the form of calcite, a calcium borate or calcium borate composite, and a calcium soap of fatty acid having 12 to 24 carbon atoms. The above components are uniformly dispersed in an oil phase medium. The content of high base number calcium sulfonate in the lubricating grease is less than 22 wt %, and the lubricating grease has a worked cone penetration of 295 or less.