abstract |
The object of the present invention is to provide a rubber composition having high breaking strength, excellent in bead durability without the generation of rubber cracking during mounting and demounting of the rim, and excellent in fuel efficiency. n The present invention relates a rubber composition for a chafer comprising:n (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 rubber composition for a chafer is at least 280%. |