Discoloration resistance and a rubber composition having excellent flex crack resistance and a pneumatic tire using the same for sidewall rubber

摘要

PROBLEM TO BE SOLVED: To provide a rubber composition which is enhanced in weather resistance/discoloration resistance and flex cracking resistance performances, and a pneumatic tire having a sidewall comprised of the rubber composition.;SOLUTION: The rubber composition comprises 40-75 wt% of a diene rubber and, dispersed therein, 25-60 wt% of at least one butyl rubber selected from the group consisting of a butyl rubber, a halogenated butyl rubber and a rubber obtained by halogenating a copolymer of a 4-7C isomonoolefin with a para-alkylstyrene and is obtained by dynamically crosslinking them by adding 0.05-5 pts. wt. of an amine compound together with a dynamic crosslinking agent to 100 pts. wt. of the rubber components, kneading the resultant mixture and discharging at a temperature of 140°C or higher. The pneumatic tire has the sidewall comprised of the rubber composition.;COPYRIGHT: (C)2005,JPO&NCIPI