Patent ID: 6303683
Filing Date: 2001-10-16
Classification: C08K,C08L

Abstract:
A liquid solventless synthetic rubber-based composition comprising:(a) a low number average molecular weight rubber selected from the group consisting of polybutadiene comprising from about 75% to about 92% cis-1,4 units, a copolymer comprising butadiene units and from about 27 wt % to about 45 wt % pentadiene units, and mixtures thereof,(b) a high number average molecular weight rubber comprising isobutylene units and not more than about 6 wt % isoprene units, said high number average molecular weight rubber being present in an amount of from about 0.5 parts to about 4 parts by weight based on the weight of low number average molecular weight rubber,(c) sulfur,(d) a vulcanization accelerator, and(e) an active fillerwherein the sulfur, the accelerator, and the active filler are each present in the form of a powder with a particle size of from about 5 .mu.m to about 85 .mu.m.