Patent ID: 6569951
Filing Date: 2003-05-27
Classification: C08F,C08L

Abstract:
An elastic-thermoplastic graft polymer prepared by a multi-stage free radical polymerization of (I) one or more monomers containing vinyl groups, and (ii) at least one molecular weight regulating compound, in the presence of (iii) at least one rubber in latex form comprising an emulsifier, wherein,in a first reaction stage of the polymerization, the ratio of monomers to the molecular weight regulating compound is from 50:1 to 400:1; in a second reaction stage of the polymerization, the ratio of monomers to the molecular weight regulating compound is from 100:1 to 800: 1; in a third reaction stage of the polymerization, the ratio of monomers to the molecular weight regulating compound is from 200:1 to 2000:1; and in at least one further reaction stage of the polymerization, the monomers, in the absence of the molecular weight regulating compound, are polymerized in the presence of the rubber, said further reaction stage occurring at a point selected from at least one of before the first stage and after the third stage, provided that the ratio of monomers to the molecular weight regulating compound in the first stage is less than or equal to the ratio of monomers to the molecular weight regulating compound in the second stage, and the ratio of monomers to the molecular weight regulating compound in the second stage is less than the ratio of monomers to the molecular weight regulating compound in the third stage.