RUBBER COMPOSITION CONTAINING STYRENE/BUTADIENE ELASTOMER AND SILICA REINFORCEMENT AND TIRE

A rubber composition is disclosed containing, based on parts by weight per 100 parts by weight of the rubber (phr), (A) conjugated diene-based elastomers comprising: (1) from 40 to 90 phr, alternately 60 to 80 phr, of a styrene/butadiene elastomer having a molecular weight profile comprising a weight average molecular weight (Mw) in a range of from 500,000 to 800,000, with the low molecular weight content having a weight average molecular weight (Mw) of up to 150,000 being limited to a maximum of seven weight percent of the styrene/butadiene elastomer, and (2) from 60 to 10 phr of at least one additional conjugated diene-based elastomer; (B) from 40 to 150 phr of a filler comprising a combination of carbon black and silica together with a coupling agent having a moiety reactive or interactive with hydroxyl groups on the silica and another different moiety reactive or interactive with the diene-based elastomers. Also, a tire comprising this rubber composition is disclosed.