PROCESS FOR THE PRODUCTION OF POLYVINYL CHLORIDE GRAFT COPOLYMERS

摘要

A process for the production of polyvinyl chloride graft copolymers from ethylene/vinyl acetate copolymers and vinyl chloride by graft polymerization in the aqueous phase consisting essentially of adding a water-soluble, free-radical-forming polymerization catalyst to an aqueous dispersion of an ethylene/vinyl acetate copolymer optionally containing additional emulsifiers and/or dispersion stabilizers, heating said dispersion to the polymerization temperature, adding vinyl chloride gas above said agitated heated dispersion at such rate that the pressure is below the saturation pressure of vinyl chloride at the polymerization temperature, and recovering said polyvinyl chloride grafted copolymer. The said process results in non-tacky powdery products, which can be processed to give transparent molded articles, especially sheets and non-rigid foils.