Blends of butadiene-acrylonitrile rubbery copolymers having a toluene-insoluble "b" gel content of from 30 to 50% and hard resinous styrene-acrylonitrile copolymers

Claim 1

THE PROCESS OF MAKING A HARD, TOUGH, THERMOPLASTIC ELASTOMER-RESIN MIXTURE WHICH COMPRISES MASTICATING AT A TEMPERATURE OF FROM 280* TO 340* F. A NORMALLY ELASTIC RUBBERY COPOLYMER OF BUTADIENE-1,3 AND ACRYLONITRILE UNTIL IT HAS A TOLUENE-INSOLUBLE "B" GEL CONTENT OF AT LEAST 30 BUT LESS THAN 50 PER CENT, SAID TOLUENE-INSOLUBLE "B" GEL BEING INCAPABLE OF CONVERSION INTO A SOLUBLE GEL BY MASTICATION, AND THEN INTIMATELY AND HOMOGENEOUSLY INCORPORATING THE RESULTING RUBBERY COPOLY-MER WITH A HARD NORMALLY INELASTIC RESINOUS THERMOPLASTIC COPOLYMER OF FROM 50 TO 85 PER CENT OF STYRENE AND CORRESPONDINGLY FROM 50 TO 15 PER CENT OF ACRYLONITRILE, SAID COPOLYMERS BEING EMPLOYED IN PROPORTIONS OF FROM 50 TO 90 PER CENT BY WEIGHT OF SAID RESINOUS COPOLYMER AND CORRESPONDINGLY FROM 50 TO 10 PER CENT BY WEIGHT OF SAID RUBBERY COPOLYMER, SAID LAST-NAMED PERCENTAGES BEING BY WEIGHT BASED ON TE SUM OF THE WEIGHTS OF SAID RESINOUS AND RUBBERY COPOLYMERS.