Provided are a lubricating oil composition containing (A) a specific amide compound and (B) a metal-based detergent, wherein the content of the metal-based detergent (B) as converted in terms of metal atom is, based on the total amount of the composition, more than 300 ppm by mass and 1,000 ppm by mass or less, and having a high intermetallic friction coefficient and excellent clutch anti-shudder performance; and a lubrication method and a transmission using the composition.

The invention provides a lubricating composition comprising an oil of lubricating viscosity and synergistic mixture of a functionalized ethylene-α-olefin copolymer, a poly(meth)acrylate block polymer having a substantially oil soluble block and a substantially oil insoluble block. The invention also provides a method of lubricating a mechanical device using such a lubricating composition.

A continuous process for producing a polyurea concentrate or powder. The process includes combing at least one amine and an isocyanate in the presence of a liquid diluent or a base oil in a rotor stator mixer. The concentrate comprises a polyurea in a base oil wherein the concentration of from about 20 weight percent to about 50, or 40 or 35 or 30 weight percent of polyurea based on total weight of grease thickener. The powder has particle size of 2 to 400 microns. This concentrate or powder can then be formulated by grease manufacturers to the desired final properties without the need for handling of the isocyanate and amine raw materials.

A lubricating oil composition for hydraulic oils including 10 to 99% by mass of a lubricant base oil (A) with a kinematic viscosity at 100° C. of 1 to 14 mm.sup.2/s, a viscosity index of 100 or more, and a pour point of 0° C. or lower, and 90 to 1% by mass of a liquid random copolymer (B) of ethylene and α-olefin prepared using a specific catalyst, wherein the total amount of (A) and (B) is 100% by mass, and having a kinematic viscosity at 100° C. of 10 to 300 mm.sup.2/s.

Disclosed is a lubricating oil composition. The lubricating oil composition contains a lubricating base oil including mineral base oil, 4 to 15 mass % of an ester compound of a monovalent or polyvalent aliphatic carboxylic acid and a monovalent or polyvalent aliphatic alcohol, 400 to 1200 mass ppm of zinc dialkyl dithiophosphate in terms of a phosphorus element, 500 to 3000 mass ppm of a calcium-based detergent in terms of a calcium element, and 50 to 1000 mass ppm of a boron-modified succinimide-based dispersant in terms of a boron element, on the basis of the total amount of the lubricating oil composition.

A lubricating composition comprises an oil of lubricating viscosity, a metal-free pre-ceramic polymer and one or more co-additives. The metal-free pre-ceramic polymer comprises a plurality of repeat units which do not contain oxygen. The pre-ceramic polymers provide the lubricating oil composition with antiwear properties. Also described is a method of lubricating an internal combustion engine and the use of a lubricating oil composition containing a pre-ceramic polymers to inhibit wear in an internal combustion engine.

A lubricating oil composition for automobile gears, including a lubricant base oil and a liquid random copolymer of ethylene and α-olefin(s), the liquid random copolymer being produced using a specific catalyst, wherein the lubricating oil composition has a kinematic viscosity at 100° C. of 7 to 30 mm.sup.2/s, and wherein the lubricant base oil consists of a mineral oil having a kinematic viscosity at 100° C. of 2 to 10 mm.sup.2/s, a viscosity index of 105 or more and a pour point of −10° C. or lower, and/or a synthetic oil having a kinematic viscosity at 100° C. of 1 to 10 mm.sup.2/s, a viscosity index of 120 or more and a pour point of −30° C. or lower.

The present invention provides a lubricating oil composition comprising a polymer for improving viscosity, the composition suppressing viscosity increase in low temperature and having an excellent low-temperature property, and having low viscosity decrease caused by shearing. The present invention is a lubricating oil composition containing from 30 to 90% by weight of a liquid random copolymer (A) of ethylene and α-olefin produced by a specific method, and 10 to 70% by weight of a lubricating oil base consisting of one or more components selected from specific synthetic oil (B) or mineral oil (C) (note that the sum total of the components (A), (B) and (C) is 100% by weight).

Provided is a lubricating oil composition for a gas engine, comprising a base oil (A), a calcium-based detergent (B), and an alkenyl succinimide (C), wherein a content of calcium atoms is 0.09 to 0.17 mass % based on the total amount of the lubricating oil composition, the component (C) comprises a non-boron-modified alkenyl bis-succinimide (C1), and a content of boron atoms derived from the component (C) is less than 0.02 mass % based on the total amount of the lubricating oil composition.

A comb copolymer viscosity modifier may be made by polymerization comprising at least, or consisting essentially of, the following monomers: (a) a hydrogenated polybutadiene-based (alk)acrylate ester macromonomer (which repeat units may comprise from 7.0 wt % to 18 wt % of the repeat units of the comb copolymer viscosity modifier); (b) a C.sub.3-C.sub.8 alkyl (alk)acrylate ester monomer (which repeat units may comprise from 40 wt % to 71 wt % or from 45 wt % to 64 wt % of the repeat units of the comb copolymer viscosity modifier); and (c) a C.sub.12-C.sub.24 alkyl (alk)acrylate ester monomer, wherein repeat units based on the C.sub.12-C.sub.24 alkyl (alk)acrylate ester monomer comprise at least 21.0 wt % (and optionally up to 35.0 wt %) of repeat units of the comb copolymer viscosity modifier. Lubricant compositions comprising the comb copolymer viscosity modifier, as well as uses thereof and methods for modifying viscosity, are also contemplated herein.