Patent ID: 7071246

Claim:
A rubber composition comprising: (1) a rubbery polymer; (2) from 1 to 30 parts per hundred parts of rubber by weight of pre-crosslinked polymer particles, wherein the pre-crosslinked polymer particles have a mean particle size as determined by light scattering which is within the range of 30 nm to 500 nm, wherein the pre-crosslinked polymer is comprised of repeat units that are derived from at least one monomer selected from the group consisting of acrylate monomers, acrylonitrile monomers, and vinyl halide monomers, wherein the pre-crosslinked polymer is in the form of core-shell particles having a core and a shell; and wherein the pre-crosslinked polymer has a glass transition temperature which is within the range of 30° C. to 200° C.; and (3) 10 to 150 parts per hundred parts of rubber by weight of a filler selected from the group consisting of carbon black and silica.