Patent Number: 8,877,857

Title: Polar group-containing copolymer, rubber composition and studless tire

Abstract: The present invention provides a polar group-containing copolymer which can provide a rubber composition and a winter tire achieving the abrasion resistance, performance on ice, and handling stability on dry roads in a balanced manner. The present invention relates to a polar group-containing copolymer obtainable by copolymerizing a conjugated diene compound and a polar group-containing vinyl compound, wherein the polar group-containing vinyl compound is a compound that has a polymerizable unsaturated bond and a polar group, wherein any one of carbon atoms forming the polymerizable unsaturated bond and a carbon atom linked to the polar group are connected to each other via at least one carbon atom, and wherein a cis content of the double bond portion of the conjugated diene compound in the polar group-containing copolymer is 80 mol % or more.

Inventors: Tokimune; Ryuichi (Kobe, JP), Hochi; Kazuo (Kobe, JP), Terakawa; Katsumi (Kobe, JP)

Assignee: Sumitomo Rubber Industries, Ltd.

International Classification: C08F 36/04 (20060101); C08L 7/00 (20060101)

Expiration Date: 2019-11-04 0:00:00