Patent ID: 8957149
Filing Date: 2015-02-17
Classification: B60C,C08C,C08K,C08L

Abstract:
1. A method of preparing a silica reinforced rubber composition which comprises blending, based upon parts by weight per 100 parts by weight rubber (phr): (A) conjugated diene-based elastomers comprised of: (B) from about 20 to about 80 phr of rubber reinforcing filler as: (C) silica coupler for said precipitated silica having a moiety reactive with hydroxyl groups on said precipitated silica and another, different moiety interactive with said cis 1,4-polyisoprene rubber and cis 1,4-polybutadiene rubber; wherein said epoxidized natural rubber (ENR), has an epoxidation content in a range of from about 5 to about 25 percent; wherein said ENR is added to the rubber composition subsequent to the addition of both of said precipitated silica and silica coupling agent; and wherein the silica coupler is comprised of a bis(3-triethoxysilylpropyl) polysulfide having an average of from about 2.1 to about 2.6 connecting sulfur atoms in its polysulfidic bridge.