Milling isobutylene-multiolefin copolymer synthetic rubber prior to curing

Claim 1

IN A PROCESS FOR PREPARING A SOLID PLASTIC CURABLE HYDROCARBON INTERPOLYMER OF A MAJOR PROPORTION OF ISOBUTYLENE WITH A MINOR PROPORTION OF AN ALIPHATIC MULTI-OLEFIN HAVING FROM 4 TO 14 INCLUSIVE CARBON ATOMS PER MOLECULE AT A TEMPERATURE WITHIN THE RANGE BETWEEN -40*C. AND -164*C. IN THE PRESENCE OF A POLYMERIZATION CATALYST COMPRISING A FRIEDEL-CRAFTS ACTIVE METAL HALIDE IN SOLUTION IN A LOW FREEZING NON-COMPLEX FORMING SOLVENT, THE STEP OF MILLING THE CURABLE POLYMER IN THE ABSENCE OF A VULCANIZATION AID AT A TEMPERATURE WITHIN THE RANGE BETWEEN 150*C. AND 200*C. FOR TIME INTERVALS FROM 5 MINUTES TO 30 MINUTES UNDER MILLING PRESSURES GREAT ENOUGH TO EFFECT A RAPID BREAKDOWN OF CAUTCHOUC AND THEREAFTER CURING THE POLYMER IN THE PRESENCE OF A VULCANIZATION AID, THE MILLING STEP SERVING TO PREVENT THE DEVELOPMENT OF BLISTERS UPON SUBSEQUENT CURING.