Process for polymerizing vinyl chloride in aqueous suspension

Claim 1

A PROCESS FOR POLYMERIZING A MONOMERIC MATERIAL COMPOSED PREDOMINANTLY OF VINYL CHLORIDE COMPRISING THE SEQUENTIAL STEPS OF DISPERSING SAID MONOMERIC MATERIAL CONTAINING CATALYTIC QUANTITIES OF AN OIL-SOLUBLE PEROXIDE POLYMERIZATION CATALYST IN AN AQUEOUS PHASE CONSISTING ESSENTIALLY OF FROM 2 TO 4 PARTS BY VOLUME OF WATER PER PART OF MONOMER, FROM 0.02 TO 0.15 PERCENT BY WEIGHT OF SAID MONOMERIC MATERIAL OF A WATER-SOLUBLE CELLULOSE ETHER SELECTED FROM THE GROUP CONSISTING OF METHYL CELLULOSE AND METHYL HYDROXYPROPYL CELLULOSE, FROM 0.02 TO 0.15 PERCENT BY WEIGHT OF SAID MONOMERIC MATERIAL OF IONIC EMULSIFYING AGENT AND FROM 0.02 TO 0.15 PERCENT BY WEIGHT OF SAID MOMOMERIC MATERIAL OF A WATER-SOLUBLE POLYVALENT METAL SALT COAGULANT FOR SAID EMULSIFIER WHEREIN SAID METAL CATION IS OF A METAL HAVING A VALENCE GREATER THAN 1 AND MAINTAINING DISPERSION OF THE POLYMERIZING PARTICLES WITH AGITATION AT A TEMPERATURE OF FROM 25* TO 65*C. UNTIL POLYMERIZATION IS COMPLETE, TO PRODUCE SUBSTANTIALLY UNIFORM, FREE-FLOWING PARTICLES HAVING HIGH CAPACITY FOR PLASTICIZER ABSORPTION.