Abstract: Process for the preparation of a transparent, weather-resistant vinyl chloride polymer having a very high impact strength by the polymerization of vinyl chloride either together with or without other copolymerizable monomers in aqueous dispersion by the emulsion polymerization method in the presence of at least one acrylic ester copolymer. The process involves emulsion polymerizing vinyl chloride or a monomer mixture containing at least 80 percent by weight of vinyl chloride in the presence of a dispersion of at least one acrylic ester copolymer consisting of 90 to 99.7 percent by weight of at least one acrylic ester containing 3 to 16 carbon atoms in the ester group and 0.3 to 10 percent by weight of a polyfunctional monomer having at least two non-conjugated ethylenic double bonds, at least one of said double bonds being of the allyl type. The acrylic ester copolymer having a mean particle diameter of 30 to 150 nm, determined by soap titration.

Abstract: Process for the preparation of a transparent, high-impact-strength and weather-resistant vinyl chloride polymer by the polymerization of vinyl chloride either together with or without other copolymerizable monomers in aqueous dispersion by the emulsion polymerization method in the presence of at least one acrylic ester copolymer. The process involves emulsion polymerizing vinyl chloride or a monomer mixture containing at least 80 percent by weight of vinyl chloride in the presence of a dispersion of at least one acrylic ester copolymer consisting of 55 to 94.7 percent by weight of at least one acrylic ester containing 3 to 18 carbon atoms in the ester group, 35 to 5 percent by weight of .alpha.-methyl styrene and 0.3 to 10 percent by weight of a polyfunctional monomer having at least two non-conjugated ethylenic double bonds, at least one of said double bonds being of the allyl type. The acrylic ester copolymer having a mean particle diameter of 30 to 150 nm, determined by soap titration.