Continuous polymerization process

Claim 1

AN AQUEOUS SUSPENSION PROCESS FOR THE POLYMERIZATION OF VINYL CHLORIDE INTO GRANULAR POLYVINYL CHLORIDE COMPRISING CONTINUOUSLY FEEDING VINYL CHLORIDE MONOMER INTO A REACTION ZONE WHEREIN IS MAINTAINED THROUGHOUT THE POLYMERIZATION A POLYMERIZATION MIXTURE INCLUDING (A) VINYL CHLORIDE MONOMER AND POLYVINYL CHLORIDE IN THE WEIGHT PROPORTIONS OF POLYMER:MONOMER OF FROM ABOUT 3:1 TO ABOUT 5:1, (B) FROM ABOUT 0.1 TO 3 PERCENT OF AN OIL-SOLUBLE POLYMERIZATION CATALYST, (C) AT LEAST ABOUT 150 PARTS TO 400 PARTS OF WATER PER 100 PARTS OF THE POLYVINYL CHLORIDE PLUS THE VINYL CHLORIDE MONOMER, AND (D) AT LEAST ONE WATER-SOLUBLE SUSPENSION AGENT; MAINTAINING THE POLYMERIZATION MIXTURE AT A TEMPERATURE OF FROM ABOUT 0*C. TO ABOUT 70*C.; CONTINUOUSLY WITHDRAWING FROM SAID REACTION ZONE A PORTION OF THE POLYMERIZATION MIXTURE AND SUBJECTING IT TO A TWO-STAGE SEPARATION, THE FIRST STAGE CONSISTING IN DIVIDING THE SAID POLYMERIZATION MIXTURE INTO TWO PORTIONS, A FIRST PORTION COMPRISING A PREDOMINANTLY AQUEOUS LIQUID, HAVING MINOR AMOUNTS OF VINYL CHLORIDE MONOMER AND FINELY DIVIDED POLYVINYL CHLORIDE SUSPENDED THEREIN, AND A SECOND PORTION COMPRISING A SLURRY OF LARGER POLYVINYL CHLORIDE PARTICLES AND MINOR AMOUNTS OF VINYL CHLORIDE MONOMER AND AQUEOUS SOLUTION, RECYCLING AT LEAST PART OF THE SAID FIRST PORTION TO THE REACTION ZONE, AND SEPARATING THE LARGER POLYVINYL CHLORIDE PARTICLES FROM SAID SECOND PORTION, AND RECYCLING AT LEAST PART OF THE REMAINING LIQUID PORTION TO THE REACTION ZONE.