Terpolymer rubber of styrene, isoprene and butadiene

Claim 1

A linear styrene, isoprene, butadiene terpolymer rubber (SIBR) which is comprised of (1) about 6 to about 40 weight percent bound styrene; (2) about 20 to about 65 weight percent bound isoprene; and (3) about 10 to about 50 weight percent bound butadiene and is characterized by having a single glass transition temperature (Tg) which is in the range of about -10° C. to -75° C. a heterogeneity index in the range of about 1.5 to about 2.4 and a ML4(100) viscosity in the range of about 70 to about 100, and further characterized in that at least 98 percent of its styrene is contained in sequential styrene units of 5 or less, and at least 75 percent of its styrene is contained in sequential styrene units of 2 or less and the bound butadiene structure contains about 8 to about 40 percent 1,2-vinyl units with the remainder being essentially composed of 1,4-configured units, the said bound isoprene structure contains about 8 to about 50 percent 3,4-vinyl units with the remainder being essentially 1,4-configured units with less than about 2 percent 1,2-configured units and the sum of the said percent 1,2-vinyl units of the bound butadiene and the percent 3,4 units of the bound isoprene is in the range of about 20 to about 90.