Post-chlorinated vinyl chloride polymer compositions having increased impact strength and improved processability

Claim 1

A COMPOSITION COMPRISING AN INTIMATE MIXTURE OF (A) 100 PARTS BY WEIGHT OF POST-CHLORINATED POLYVINYL CHLORIDE HAVING A DENSITY OF FROM 1.43 TO 1.65 GRAMS PER CC. AT 25* C., A HEAT DISTORTION TEMPERATURE WHICH IS AT LEAST ABOUT 20*C. HIGHER THAN THAT OF UNCHLORINATED POLYVINYL CHLORIDE, AND A HIGH HEAT STABILITY SUCH THAT IT IS NOT DEGRADED IF EXPOSED TO AIR AT 375 TO 400*F. FOR AT LEAST 10 MINUTES, AND (B) FROM ABOUT 3 TO ABOUT 15 PARTS BY WEIGHT OF A RUBBERY CHLORINATED POLYMER OF ISOBUTYLENE HAVING A CHLORINE CONTENT OF FROM ABOUT 12 TO ABOUT 32 PERCENT BY WEIGHT SELECTED FROM THE GROUP CONSISTING OF CHLORINATED HOMOPOLYMERS OF ISOBUTYLENE AND CHLORINATED COPOLYMERS OF ISOBUTYLENE AND WHICH IS OBTAINED BY THE SOLUTION CHLORINATION OF A POLYMER OF ISOBUTYLENE CONTAINING FROM 95 TO 100 PERCENT BY WEIGHT OF ISOBUTYLENE CONSTITUENT AND 0 TO 5 PERCENT BY WEIGHT OF ANOTHER MONOMER CONSTITUENT COPOLYMERIZABLE WITH ISOBUTYLENE SELECTED FROM THE GROUP CONSISTING OF STYRENE, ACRYLONITRILE, METHACRYLONITRILE, METHACRYLIC ACID, METHYL METHACRYLATE, ETHYL METHACRYLATE, BUTENE, BUTADIENE, DIMETHYL BUTADIENE, CHLOROBUTADIENE, PIPERYLENE AND ISOPRENE, SAID POLYMER OF ISOBUTYLENE HAVING A WEIGHT AVERAGE STAUDINGER MOLECULAR WEIGHT OF FROM ABOUT 8,000 TO 200,000 PRIOR TO CHLORINATION.