PURPOSE: A rubber composition which has excellent hysteresis loss characteristics, etc., obtained by mixing an oil-extended butadiene copolymer containing vinyl-bonded butadiene units and a bound vinyl aromatic compound with a diene rubber, and oil-extending the mixture.
CONSTITUTION: A butadiene copolymer containing vinyl-bonded butadiene units in an amount of 35W80wt% based on the butadiene part and 25W50wt% bound vinyl aromatic compound is oil-extended with an extender oil in an amount of at least 30wt% of the total oil to give a Mooney viscosity of 20W100. A diene rubber is mixed with this oil-extended butadiene copolymer in an amount of at least 30wt% excluding the oil component based on the diene rubber. This mixture is further oil-extended to give a total extender oil content of 55W200pts. wt. based on 100pts.wt. rubber component excluding the oil, thus producing an objective rubber composition having a ratio of dynamic moduli of elasticity of the vulcanizate at 100°C to the one at 20°C of 0.2 or higher.
TSUTSUMI FUMIO
SAKAKIBARA MITSUHIKO
FUJINAGA YOSHIHISA
OOSHIMA NOBORU
JAPAN SYNTHETIC RUBBER CO LTD
| JPS5770134A | 1982-04-30 | |||
| JPS4730903A |