| abstract |
The present invention discloses a rubbery polymer having improved properties, which is comprised of an inner core and an outer shell, wherein the inner core is comprised of a polymeric structure having repeat units which are derived from (a) butyl acrylate, (b) a member selected from the group consisting of methyl methacrylate, ethyl methacrylate, methyl acrylate, and ethyl acrylate, (c) optionally, an alkoxy ethyl acrylate or an alkoxy ethyl methacrylate, (d) acrylonitrile, (f) a cross-linking agent, and (g) a monomer containing reactive cure sites, wherein the outer core is comprised of a polymeric structure having repeat units which are derived from (d) acrylonitrile, (e) styrene, and (f) additional cross-linking agent, wherein the outer core is void of repeat units which are derived from methyl methacrylate. |