Patent ID: 8592515
Filing Date: 2013-11-26
Classification: C08C,C08K,C08L,Y10T

Abstract:
1. A rubber composition comprised of, based upon parts by weight per 100 parts by weight of rubber (phr): (A) elastomers comprised of: (B) about 5 to about 20 phr of naphthenic rubber processing oil having a Tg in a range of from about 80 to about 90° C.; (C) about 40 to about 110 phr of reinforcing filler comprised of: (D) coupling agent having a moiety reactive with hydroxyl groups contained on the surface of said precipitated silica and another moiety interactive with at least one of said elastomers, wherein said coupling agent is comprised of a bis-(3-ethoxysilylpropyl) polysulfide material having an average of from about 2 to about 4 connecting sulfur atoms in the polysulfide bridge; wherein said polybutadiene rubber is a cis 1,4-polybutadiene rubber which has a microstructure comprised of about 96 to about 98 percent cis 1,4-isomeric units, about 1 to about 3 percent trans 1,4-isomeric units and about 0.3 to about 1 percent vinyl 1,2-content; a number average molecular weight (Mn) in a range of from about 230,000 to about 250,000 with a heterogeneity index (Mw/Mn) in a range of from about 1.5/1 to about 2/1, and a Tg in a range of from about −104 to about −109° C.; wherein said functionalized styrene/butadiene rubber (SBR) has a bound styrene content in a range of from about 10 to about 50, or about 10 to about 30, percent based on the SBR and a vinyl content in a range of from about 35 to about 45 percent based on the SBR and contained in its polybutadiene portion.