PRODUCTION OF VINYL CHLORIDE RESIN

摘要

PURPOSE:To produce the titled resin having a high bulk density and a low fish eye content, by adding a specified nonionic surfactant to vinyl chloride or its mixture with a copolymerizable monomer and polymerizing this monomer or monomer mixture in two stages under specified conditions. CONSTITUTION:100pts.wt. vinyl chloride monomer or mixture thereof with a copolymerizable monomer and 0.001-0.1pt.wt. nonionic surfactant of an HLB value of 6-14 [e.g., polyoxyethylene alkyl (phenyl) ether] and water in an amount to provide a water to monomer ratio of 0.8-1.0 are fed to a polymeriza tion reactor equipped with a reflux condenser in the vapor phase of polymeriza tion or outside the polymerization vessel and polymerized (stage 1) at 40-75 deg.C to a conversion <=50wt%. The reaction mixture in stage 1 and polymerized (stage 2) completely while water in an amount not exceeding the volume shrink age occurring with the progress of polymerization is continuously or intermittent ly purged so that the water to monomer ratio at the end of the polymerization may be 1.0-1.4.