Rubber composition, useful as a tire tread rubber for a pneumatic tire, comprises a rubber copolymer and a hydrogenated styrene-butadiene copolymer

摘要

Rubber composition (I), comprises a rubber copolymer (Ia), made up of an aromatic-vinyl, in which a diene compound is polymerized with a polymerization initiator to give polystyrene; and a hydrogenated styrene-butadiene copolymer (Ib), converted into polystyrene, where the styrene is present at 10-70 wt.% and the double bond (25-50%) in the butadiene is hydrogenated and the weight ratio of (Ia) and (Ib) is 100:10-200. Rubber composition (I), comprises a rubber copolymer (Ia) (having molecular weight of 3x10 5-3x10 6), made up of an aromatic-vinyl compound containing a diene compound, polymerized with a polymerization initiator (containing lithium) to give polystyrene compound; and a hydrogenated styrene-butadiene copolymer (Ib) (having molecular weight of 5x10 3-2x10 5), converted into polystyrene compound, where the styrene is present at 10-70 wt.% and the double bonds (25-50%) in the butadiene portion is hydrogenated, (Ia) and (Ib) have a weight ratio of 100:10-200 and the molecular weight is measured by gel-permeation chromatography. An independent claim is included for a pneumatic tire, comprising (I), useful as a tire rubber tread.