Chemische Werke Huls Aktiengesellschaft

Huels Aktiengesellschaft

Chemische Werke Huels Aktiengesellschaft

Karsten Flatau

Bernd Terwiesch

Lothar Hinz

A polyvinyl chloride molding composition, suitable for the manufacture of sheet stock according to the 'Luvitherm' method, consists essentially of emulsion polyvinyl chloride and 0.5-3.0% by weight of a processing aid which is a copolymer of 40-90% by weight of vinyl monomers whose corresponding homopolymers have a glass point below 0.degree. C., and of 10-60% by weight of vinyl monomers whose corresponding homopolymers have a glass transition temperature above 20.degree. C.

Polyvinyl chloride molding composition, a process for its production,

Pourable, tack-free vinyl chloride graft polymers based on ethylene-vinyl acetate copolymers and vinyl chloride, having more than 30% by weight of ethylene-vinyl acetate copolymer content, are prepared by thermally precipitating small amounts (0.5-10 wt. %) of polyvinyl chloride in the form of a latex onto the graft polymer.

Process for the production of pourable, tack-free vinyl chloride graft

Modified polyvinyl chloride is produced by suspension polymerization in the presence of monomersoluble catalysts and conventional protective colloids. After polymerization, there is added to the polymerized mixture, 0.1 to 3% by weight, based on the amount of polyvinyl chloride of the latex of a copolymer of 75-95% by weight of methyl methacrylate, 0-20% by weight of styrene, and 5-25% by weight of an acrylic acid ester of 4-8 carbon atoms in the alcohol component. Precipitation of the latex is then effected under continued agitation. Precipitation can be accomplished, for example, thermally or using coagulants. The thus-modified suspension polymer is subsequently obtained by ordinary removal by filtration and drying.

Production of polyvinyl chloride and acrylate copolymer modifier useful

Encrustations on reactor walls and associated equipment employed in the aqueous suspension polymerization of vinyl chloride and mixtures thereof with other monomers at 30.degree.-70.degree. C. are prevented by employing in the polymerization charge 0.0005 - 0.05% by weight of hydrogen peroxide, calculated on the monomer or monomers, preferably at a pH of at least 7.5, e.g., 7.5 - 8.5 when using a suspending agent which is sensitive to hydrolysis.

Process for preventing encrustations during the manufacture of polymers

The formation of polymer on the surfaces of the reactor equipment in the commercial production of polyvinyl chloride and copolymers thereof is avoided by employing equipment whose surfaces which contact the monomer are formed of substantially pure nickel.

Growing community of inventors

Haltern, Germany

Karsten Flatau