Rigid vinyl chloride resins and processes for their production

Claim 1

IN A PROCESS FOR POLYMERIZING VINYL CHLORIDE DISPERSED AS SMALL GLOBULES IN WATER CONTAINING SMALL AMOUNTS OF A DISPERSING AGENT AND OF A POLYMERIZATION CATALYST TO FORM A FINELY GRANULAR VINYL CHLORIDE POLYMER DISPERSION, THE IMPROVEMENT WHICH COMPRISES DISPERSING IN WATER A LIQUID MONOMER MIXTURE ESSENTIALLY COMPOSED OF VINYL CHLORIDE AND TRICHLOROETHYLENE AND CONTAINING NO MORE THAN 50 WEIGHT PERCENT OF OTHER MONOMERS FROM THE GROUP CONSISTING OF VINYL ACETATE AND ACRYLATE ESTER OF A MONOHYDROXY ALKANE CONTAINING 1 TO 18 CARBON ATOMS, THE TRICHLOROETHYLENE AMOUNTING TO 0.5% TO 5% BY WEIGHT OF THE MONOMER MIXTURE, THE MONOMER SELECTED FROM THE GROUP CONSISTING OF VINYL ACETATE AND ACRYLATE ESTER AMOUNTING TO NO MORE THAN 50% BY WEIGHT OF THE MONOMER MIXTURE, AND THE REMAINDER SUBSTANTIALLY CONSISTING OF VINYL CHLORIDE, SAID WATER CONTAINING SMALL AMOUNTS OF A WATER SOLUBLE HYDROPHILIC COLLOID DISPERSING AGENT AND OF AN ORGANIC PEROXIDE POLYMERIZATION CATALYST SOLUBLE IN THE MONOMER MIXTURE AND SUBSTANTIALLY LESS SOLUBLE IN WATER, AND MAINTAINING THE DISPERSION OF MONOMERS IN WATER AT TEMPERTURES IN THE RANGE 60*C. TO 80*C. TO FORM AN AQUEOUS DISPERSION OF FINELY GRANULAR RIGID VINYL CHLORIDE POLYMER ADAPTED TO BE FORMED BY PRESSURE INTO SHAPED ARTICLES WITHOUT ADDITION OF LIQUID PLASTICIZERS.