PROCESS FOR PREPARING GRAFT COPOLYMERS BY EMULSION SUSPENSION GRAFT POLYMERISATION

摘要

The present invention relates to the method for the manufacture of graft copolymers by the polymerization of a monomeric mixture comprising at least one aromatic vinyl derivative monomer and at least one acrylic or methacrylic derivative monomer in the presence of a graftable monodimensional elastomer latex, comprising the steps of first carrying out the polymerization under aqueous emulsion polymerization conditions in the presence of an initial amount of a first monodimensional elastomer latex being the major portion of the latex entering into the composition of the graft copolymer until the xy/z ratio is greater than 30%; x being the total parts by weight of said monomers, y the conversion coefficient of said monomers expressed in percent of total amount, and z the total amount of elastomer expressed in parts by weight of dry solids, and thereafter adding the remaining amount of a second monodimensional elastomer latex and completing the polymerization reaction under suspension polymerization conditions.