A radical-curable adhesive composition containing a rubber (a) having one or more (meth)acryloyl groups within a single molecular chain, a polymerizable monomer (b) having both an epoxy group and a (meth)acryloyloxy group in the molecule, and a radical polymerization initiator (c). The rubber (a) is preferably a polymer of a monomer containing at least acrylonitrile.

A radical-curable adhesive composition containing a rubber (a) having one or more (meth)acryloyl groups within a single molecular chain, a polymerizable monomer (b) having both an epoxy group and a (meth)acryloyloxy group in the molecule, and a radical polymerization initiator (c). The rubber (a) is preferably a polymer of a monomer containing at least acrylonitrile.

A viscosity index improver comprising a copolymer having a unit (a) derived from a maleimide monomer and a unit (b) derived from a macromonomer, wherein viscosity measured by the following method is 8000 mPa.Math.s or less. Viscosity measurement method: A solution composed of 78 mass % of a Group III base oil (viscosity index: 122, kinematic viscosity at 40° C.: 19.6 mm.sup.2/s) on the American Petroleum Institute (API) classification and 22 mass % of the copolymer is measured with a viscometer (TVB-10 manufactured by Toki Sangyo Co., Ltd., rotor: SPINDLE No. M3, rotation speed: 6 rpm) at 25° C.

A viscosity index improver comprising a copolymer having a unit (a) derived from a maleimide monomer and a unit (b) derived from a macromonomer, wherein viscosity measured by the following method is 8000 mPa.Math.s or less. Viscosity measurement method: A solution composed of 78 mass % of a Group III base oil (viscosity index: 122, kinematic viscosity at 40° C.: 19.6 mm.sup.2/s) on the American Petroleum Institute (API) classification and 22 mass % of the copolymer is measured with a viscometer (TVB-10 manufactured by Toki Sangyo Co., Ltd., rotor: SPINDLE No. M3, rotation speed: 6 rpm) at 25° C.

A viscosity index improver comprising a copolymer having a unit (a) derived from a maleimide monomer and a unit (b) derived from a macromonomer, wherein viscosity measured by the following method is 8000 mPa.Math.s or less. Viscosity measurement method: A solution composed of 78 mass % of a Group III base oil (viscosity index: 122, kinematic viscosity at 40° C.: 19.6 mm.sup.2/s) on the American Petroleum Institute (API) classification and 22 mass % of the copolymer is measured with a viscometer (TVB-10 manufactured by Toki Sangyo Co., Ltd., rotor: SPINDLE No. M3, rotation speed: 6 rpm) at 25° C.

A vinyl-based comb copolymer includes a polyisobutylene-based macromonomer unit and a vinyl-based monomer unit. A polyisobutylene-based macromonomer has at least 0.8 (meth)acryloyl groups represented by a specific formula at one end of a main chain per molecule, and is copolymerized with a vinyl-based monomer. A method for producing the vinyl-based comb copolymer includes copolymerizing the polyisobutylene-based macromonomer with the vinyl-based monomer. A viscosity index improver includes the comb copolymer. A lubricating oil composition includes the comb copolymer.

A vinyl-based comb copolymer includes a polyisobutylene-based macromonomer unit and a vinyl-based monomer unit. A polyisobutylene-based macromonomer has at least 0.8 (meth)acryloyl groups represented by a specific formula at one end of a main chain per molecule, and is copolymerized with a vinyl-based monomer. A method for producing the vinyl-based comb copolymer includes copolymerizing the polyisobutylene-based macromonomer with the vinyl-based monomer. A viscosity index improver includes the comb copolymer. A lubricating oil composition includes the comb copolymer.

Provided is an a solid electrolyte composition including: an inorganic solid electrolyte; a particle binder that includes a polymer and has an average particle size of 5 nm to 10 μm, the polymer including a component that includes a binding site represented by Formula (H-1) or (H-2) at a side chain and has a C log P value of 4 or lower and a molecular weight of lower than 1000; and a dispersion medium. A solid electrolyte-containing sheet, an electrode sheet for an all-solid state secondary battery, and an all-solid state secondary battery that include layer formed of the solid electrolyte composition are also provided. In addition, method of manufacturing the particle binder, the solid electrolyte-containing sheet, and the all-solid state secondary battery are provided.

Selected comb polymers contain specified amounts of macromonomer and nitrogen-containing (meth)acrylates. Lubricant compositions can contain such comb polymers. The selected comb polymers can be used as solubilizers in lubricant compositions, especially in engine oil (EO) compositions.

The invention relates to a poly alkyl(meth)acrylate polymer comprising a combination of polybutadiene-based monomers having different average molecular weight, lubricant compositions comprising the polymer, a method for manufacturing the polymer and the use of the polymer as a viscosity index improver in a lubricating oil composition.