Patent ID: 6506845
Filing Date: 2003-01-14
Classification: C08F,Y10S

Abstract:
A method of preparing a rubber substrate, comprising:first-polymerizing 50 to 95 parts by weight of either an aliphatic conjugated diene monomer or a mixture of an aliphatic conjugated diene monomer and a copolymerizable ethylenically unsaturated monomer, thereby forming a core having a gel content of 5 to 70 wt %; and second-polymerizing the core with 5 to 50 parts by weight of one or more monomers comprising an aliphatic conjugated diene monomer to form an outer layer on the core, thereby forming a rubber substrate comprising the core and the outer layer, wherein the parts of the monomers in the first and second polymerizations are based on 100 parts by weight of total monomers used in both of the first and second polymerizations.