PNEUMATIC TIRE COMPOSED OF NEW RUBBER COMPOUND AS SIDE WALL

摘要

PURPOSE:To enable both weather and flex cracking resistance to be improved by allowing a side wall section to be made of rubber compound which includes the stated amount of medium vinyl type diene polymer that consists of the state amount of bonded vinyl aromatic compound and of diene. CONSTITUTION:The side wall section of rubber compound which contains medium vinyl diene polymer at least 20wt%. The medium vinyl type diene polymer includes the amount of vinyl bonding of from 15-60% in regard to diene constituent, and whole polymer is composed of bonded vinyl aromatic compound of from 0-20wt% and of diene of from 80-10wt%. Copolymer of diene monopolymer such as 1.3 butadiene combined with the vinyl aromatic compound is used as the medium vinyl type dien polymer. This configuration enables hysteresis loss to be minimized and also enables both weather and flex cracking resistance to be improved.