| abstract |
A sulfur-vulcanizable rubber compound, being devoid of peroxide components, having high modulus and low hysteresis properties subsequent to vulcanization. Such compounds comprise from about 25 to 55 parts by weight of polyisoprene; and from about 75 to 45 parts by weight of a diene polymer selected from the group consisting of homopolymers of conjugated diene monomers and copolymers thereof with monoolefin monomers and EPDM terpolymers to total 100 parts by weight of rubber polymer; from about 50 to 70 parts by weight of a reinforcing filler, per 100 parts by weight wherein at least a portion of at least one of the rubber polymers is grafted with a polymeric metal salt of an α, β-ethylenically unsaturated carboxylic acid to form an uncured graft rubber copolymer and at least about 4 parts by weight of a curative selected from the group consisting of sulfur and sulfur donors, per 100 parts by weight of rubber. Pneumatic tires and structural components therefor are manufactured from rubber compounds having high modulus, low hysteresis and high compressive flex fatigue and provide run flat operation. |