Patent ID: 6998448

Claim:
A tire having at least one component of a rubber composition comprised of, (A) 100 phr of elastomers comprised of: (1) about 30 to about 70 phr of a styrene/butadiene elastomer composite (SBR Composite) as a composite of styrene/butadiene copolymer rubber (SBR-1) and a functional styrene/butadiene copolymer rubber (SBR-2) which contains at least one silanol and/or siloxy group, with associated pendent hydroxyl and/or alkoxy groups, as a part of the (SBR-2) elastomer chain to thereby provide said elastomer with at least two segments thereof (SBR-2A and SBR-2B) with the silicon atom of said silanol and/or siloxy group between said segments, wherein said SBR Composite is thereby comprised of a polymodal molecular weight distribution comprised about 35 to about 55 weight percent thereof of said (SBR-1) having a number average molecular weight (Mn) in a range of about 200,000 to about 300,000 and, about 65 to about 35 weight percent thereof of said (SBR-2) having a number average molecular weight (Mn) in a range of about 400,000 to 550,000; wherein said SBR Composite contains from zero to a maximum of ten weight percent of at least one additional styrene/butadiene copolymer segment (SBR-3) appended to said silicon atom having an number average molecular weight (Mn) of greater than 550,000; and based on 100 parts by weight of elastomer (phr) (2) at least 30 phr of cis 1,4-polybutadiene rubber, and (3) from zero to about 15 phr of at least one additional diene-based elastomer selected from cis 1,4-polyisoprene rubber, 3,4-polyisoprene rubber and trans 1,4-polybutadiene rubber, and (B) about 35 to about 100 phr of particulate reinforcement comprised of: (1) about 35 to about 85 phr of aggregates of precipitated silica comprised of a plurality of individual elementary silica particles, wherein said silicas particles contain hydroxyl groups thereon; (2) from zero to about 15 phr of carbon black, (C) a coupling agent as bis(3-triethoxysilylpropyl) polysulfide having an average of from 2 to 2.5 connecting sulfur atoms in its polysulfidic bridge to the exclusion of a bis(3-trialkoxysilylalkyl) polysulfide having an average connecting sulfur atoms greater than 3 in its polysulfidic bridge.