Rubber composition for reinforcing bead of tires which contains butadiene rubber with syndiotactic crystals, carbon black, sulfur and sulfenamide accelerator

摘要

A rubber composition suitable for reinforcing beads of tires, having high hardness, high durability and high aging resistance, which comprises a rubber component containing 30 to 70% by weight of a butadiene rubber containing syndiotactic crystals, 60 to 75 parts by weight of a carbon black having a specified iodine adsorption number and a specified oil absorption, 1 to 2 parts by weight of sulfur and 2 to 4 parts by weight of a sulfenamide accelerator, respectively, per 100 parts by weight of the rubber component, wherein the total amount of sulfur and the sulfenamide accelerator is from 3 to 5 parts by weight.