Patent ID: 7094824

Claim:
A process for preparing a rubbery polymer which can be blended with thermoplastics to make leathery compositions having good heat and ultraviolet light resistance, said process comprising the steps of (1) polymerizing (a) butyl acrylate, or optionally a mixture of butyl acrylate and 2-ethylhexyl acrylate containing up to about 40% 2-ethylhexyl acrylate, (b) at least one member selected from the group consisting of methyl methacrylate, ethyl methacrylate, methyl acrylate, and ethyl acrylate, (c) optionally about 0% to about 40% of alkoxy ethyl me(acrylate), (d) acrylonitrile, and (e) a crosslinking agent; wherein about 1% to about 10% of a monomer containing reactive cure sites selected from the group consisting of hydroxyl groups, glycidyl groups, carboxylic acid groups, and unsaturated cure sites is incorporated into the rubbery polymer under emulsion polymerization conditions to produce a seed polymer containing latex; (2) adding (a) styrene, (b) additional acrylonitrile, and (c) additional crosslinking agent to the seed polymer containing latex under emulsion polymerization conditions which result in the formation of an emulsion containing the rubbery polymer; (3) recovering the rubbery polymer from the emulsion containing the rubbery polymer.