Patent ID: 9273197
Filing Date: 2016-03-01
CPC Classification: B60C,C08K,C08L,Y10T

Claim Text:
1. A rubber composition for a sidewall, comprising: a rubber component containing: at least one of a 1,2-syndiotactic polybutadiene crystal-containing butadiene rubber and a butadiene rubber synthesized in the presence of a rare-earth catalyst; a terminally modified butadiene rubber polymerized in the presence of a lithium initiator; and an isoprene-based rubber; at least one of a carbon black having a nitrogen adsorption specific surface area of 25 to 120 m zinc oxide; and a C5 petroleum resin, wherein the rubber component has: a combined amount of the 1,2-syndiotactic polybutadiene crystal-containing butadiene rubber and the butadiene rubber synthesized in the presence of a rare earth catalyst of 5 to 60% by mass; an amount of the terminally modified butadiene rubber polymerized in the presence of a lithium initiator of 7 to 60% by mass; and an amount of the isoprene-based rubber of 20 to 70% by mass, each based on 100% by mass of the rubber component, and the rubber composition has: a combined amount of the carbon black having a nitrogen adsorption specific surface area of 25 to 120 m an amount of the zinc oxide of 3.6 to 16 parts by mass, each per 100 parts by mass of the rubber component.