Rubber composition for tire tread for low temperature performance and wet traction

A rubber composition comprised of, based on parts by weight per 100 parts by weight elastomer (phr):

• (A) 100 parts by weight of a combination of conjugated diene-based elastomers comprised of:
• (1) about 10 to about 50 phr of an organic solvent polymerization prepared high Tg styrene/butadiene elastomer having a Tg in a range of from about −40° C. to about −30° C. with a styrene content in a range of from about 30 to about 35 weight percent wherein said high Tg S-SBR is extended with from about 10 to about 38 parts by weight per 100 parts of said high Tg styrene/butadiene elastomer of triglyceride vegetable oil,
• (2) about 10 to about 50 phr of aqueous emulsion polymerization prepared styrene/butadiene elastomer having a Tg in a range of from about −65° C. to about −45° C. with a styrene content in a range of from about 15 to about 30 weight percent, and
• (3) about 20 to about 60 phr of cis 1,4-polybutadiene rubber having a cis 1,4-isomeric content of at least about 95 percent and having a Tg in a range of from about −100° C. to about −108° C.,
• (B) about 50 to about 250 phr of rubber reinforcing filler comprised of precipitated silica and rubber reinforcing carbon black containing from about 2 to about 10 phr of said rubber reinforcing carbon black, wherein said precipitated silica is comprised of at least one of:
• (1) pre-hydrophobated precipitated silica comprised of precipitated silica pre-hydrophobated with an alkoxyorganomercaptosilane or bis(3-triethoxysilylpropyl) polysulfide containing an average of from about 2 about 4 connecting sulfur atoms in its polysulfidic bridge to form a composite thereof,
• (2) precipitated silica having a nitrogen surface area in a range of from about 140 to about 220 m2/g together with a silica coupler having a moiety reactive with hydroxyl groups on said precipitated silica and another different moiety interactive with said diene-based elastomers,
• (3) precipitated silica having a nitrogen surface area in a range of from about 90 to about 130 m2/g together with a silica coupler having a moiety reactive with hydroxyl groups on said precipitated silica and another different moiety interactive with said diene-based elastomers,
• (C) about 5 to about 45 phr of traction promoting resin comprised of at least one of terpene, coumarone indene and styrene-alphamethylstyrene resins having a softening point within a range of from about 60° C. to about 150° C.