Patent ID: 8232340

Claim:
A rubber composition for a chafer comprising: (A) a diene rubber comprising (A1) 10 to 60% by mass of a butadiene rubber containing 2.5 to 20% by mass of a 1,2-syndiotactic polybutadiene crystal, (A2) 5 to 50% by mass of a tin-modified butadiene rubber polymerized with a lithium initiator and having 50 to 3000 ppm content of tin atoms, 5 to 50% by mass of vinyl bond amount and a molecular weight distribution of at most 2.0, and (A3) 20 to 75% by mass of a diene rubber other than the butadiene rubber (A1) and the tin-modified butadiene rubber (A2); and (B) 5 to 30 parts by mass of silica (B) based on 100 parts by mass of the diene rubber components, wherein elongation at break of the vulcanized rubber composition for a chafer is at least 280%, complex modulus E* of the same is not less than 5.7, and loss tangent tan δ of the same is not more than 0.120, and index of rim chafing property of a tire for passenger cars and light trucks which tire is composed of the chafer using the vulcanized rubber composition for a chafer is not less than 85.