Provided is a lubricant composition having small shear rate dependence of its apparent viscosity. The lubricant composition includes a perfluoropolyether as a base oil, and fluorine resin particles as a thickener. The lubricant composition further includes a fluorine-containing polymer having a tetrafluoroethylene structure under a state in which the polymer is dissolved in the perfluoropolyether.

A lubricating fluid comprising a base oil, which utilizes carboxylic esters of carboxyl di-end-capped-polyethylene glycols, or a mixture thereof with carboxylic esters of carboxyl di-end-capped-polytetramethylene glycols, to improve low temperature performance, as well as minimize elastohydrodynamic shear strength, and enables the production of high efficiency fluids with enhanced low temperature properties for machines or machine elements that operate in the elastohydrodynamic regime in lubrication.

This invention is directed to intramolecular crosslinked polymer chains, commonly known also as single-chain polymer nanoparticles (SCPNs), with high resistance to mechanochemical bond scission and to uses thereof in solution.

This application relates to copolymer compositions and copolymerization processes, as well as to lubricating oil compositions comprising such copolymer compositions as viscosity index improvers, and base oil. The copolymer compositions may be made using two different metallocene catalysts: one capable of producing high molecular weight copolymers; and one suitable for producing lower molecular weight copolymers having at least a portion of vinyl terminations, and the copolymer compositions produced thereby. Copolymer compositions may comprise (1) a first ethylene copolymer fraction having high molecular weight, exhibiting branching topology, and having relatively lower ethylene content (based on the weight of the first ethylene copolymer fraction); and (2) a second ethylene copolymer fraction having low molecular weight, exhibiting linear rheology, and having relatively higher ethylene content (based on the weight of the second ethylene copolymer fraction). Lubricating oil compositions comprising such copolymer compositions may exhibit superior viscosity properties.

The instant disclosure generally relates to lubricating compositions having an oil of lubricating viscosity and a mixed dispersant additive package. The mixed dispersant additive package can include an acylated poly(1-olefin)-based dispersant and a poly-isobutylene succinimide dispersant where the ratio of the acylated poly(1-olefin)-based dispersant to the polyisobutylene succinimide dispersant in the lubricating composition is from 3:1 to 1:3.

Compositions are obtained by mixing at least one oligomer A1, which is obtained by copolymerizing at least two monomers functionalized by diol functions with at least one second monomer, with at least one compound A2 having at least two boron ester functions. The compositions exhibit very varied rheological properties depending on the proportion of the compounds A1 and A2 used. A composition is also obtained by mixing at least one lubricating oil with such a composition of associative and exchangeable polymers, and the use of this composition to lubricate a mechanical part.

Provided are a lubricating oil composition used in a diesel engine equipped with a forced-induction compressor, containing a base oil (A) containing a poly-α-olefin (A1), and a viscosity index improver (B) having an SSI (shear stability index) of 20 or less, having a distillation amount of a light fraction of 496° C. or less in a gas chromatography distillation test of less than 80% by volume, having a high retention of the effect of suppressing the formation of deposits that may occur inside the compressor, and being capable of retaining a high efficiency of the compressor for a long period of time, in the use thereof in a diesel engine equipped with a forced-induction compressor having an outlet temperature of the compressor becoming a high temperature reaching 190° C. or more, and a method for using the lubricating oil composition.

A lubricant oil composition for automotive gears includes a lubricant base oil including a mineral oil having a kinematic viscosity at 100° C. of 2.0 to 6.5 mm.sup.2/s, a viscosity index of not less than 105 and a pour point of not more than −10° C., and/or a synthetic oil having a kinematic viscosity at 100° C. of 1.0 to 6.5 mm.sup.2/s, a viscosity index of not less than 120 and a pour point of not more than −30° C.; and an ethylene/α-olefin copolymer having an ethylene content of 55 to 85 mol %, a kinematic viscosity at 100° C. of 10 to 200 mm.sup.2/s, a molecular weight distribution of not more than 2.2, and a melting point in the range of −30° C. to −60° C. The lubricant oil composition for automotive gears has a kinematic viscosity at 100° C. of 4.0 to 9.0 mm.sup.2/s.

A continuous process for producing a polyurea concentrate or powder. The process includes combing at least one amine and an isocayante 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

Provided are a lubricating oil composition containing a mineral oil (1) having a kinematic viscosity at 100° C. of 2.5 mm.sup.2/s or more and 5 mm.sup.2/s or less, and a polymethacrylate (2) having a functional group containing an oxygen atom in the molecule while having a specific structural unit, which satisfies both high viscosity index and high shear stability, and a lubrication method and a transmission using the lubricating oil composition.