Novel vinyl suspension polymerization process halide.

摘要

@ A polyvinyl chloride having high bulk density and enhanced plasticizer absorption is produced by suspension polymerization of vinyl chloride monomer and comonomers wherein the initial suspension of ingredients is formed such that the oil phase droplets formed in the suspension are compositionally equivalent with respect to initiator, and the level of suspending agent and agitation are chosen to substantially preclude agglomeration of resin particles throughout the reaction, thereby producing resin wherein the resin grain size distribution results directly from the oil phase droplet distribution created at the start of the reaction. Seed particles of resin are introduced to the reaction mixture priorto establishing the final particle distribution. The seed particles can be formed by polymerizing a monomer such as vinyl chloride and mixtures of vinyl chloride and copolymerizable monomers in the presence of a polymeric dispersing agent, and optionally a low boiling solvent which is a nonsolvent for the resin being produced. The result of the process of the invention is a polyvinyl chloride polymer or copolymer that has high bulk density and enhanced plasticizer absorption. A further benefit of the process is that resin deposition on the interior surfaces of the reactor is essentially eliminated.