| abstract |
A rubber composition having excellent grip resistance is provided. A rubber component is a styrene-butadiene copolymer, and 100 parts by weight of a styrene-butadiene copolymer in which the cis-1,4 bond of the microstructure of the butadiene unit is 40% by weight or more. A rubber composition comprising 100 to 90% by weight of an isobutylene unit and 0.5 to 70 parts by weight of an isobutylene polymer having a structural unit represented by 0 to 10% by weight of an isoprene bond unit in the formula (2). The isobutylene polymer has a weight average molecular weight (Mw) of 5,000 to 100,000, a molecular weight distribution (Mw / Mn) of 3.0 or less, and a styrene-butadiene content of 70% by weight or more. It is characterized by being. [Selection figure] None |