Patent ID: 6166160
Filing Date: 2000-12-26
Classification: C08F

Abstract:
A process for preparing a deodorized rubbery polymer which comprises the steps of (1) polymerizing in a first stage (a) butyl acrylate, (b) at least one member selected from the group consisting of methyl methacrylate, ethyl methacrylate, methyl acrylate and ethyl acrylate, (c) acrylonitrile and (d) a crosslinking agent under emulsion polymerization conditions to produce a seed polymer containing latex, wherein said polymerization is initiated with a redox initiator system, wherein the redox initiator system is comprised of a free radical generator and a reducing agent selected from the group consisting of sodium bisulfite, sodium metabisulfite, sodium dithionate, sodium formaldehyde sulfoxylate, ascorbic acid and triethanol amine; (2) adding (a) styrene, (b) additional acrylonitrile, (c) additional crosslinking agent and (d) additional free radical generator to the seed polymer containing latex under emulsion polymerization conditions which result in the formation of an emulsion containing the rubbery polymer; and (3) recovering the rubbery polymer from the emulsion containing the rubbery polymer.