Boron fluoride in ethylidene fluoride for low-temperature polymerization

Claim 1

IN A CONTINUOUS POLYMERIZATION PROCESS FOR THE PREPARATION OF A COPOLYMER, THE STEPS COMPRISING CONTINUOUSLY DELIVERING TO A POLYMERIZATION REACTOR A STEAM CONSISTING OF A MAJOR PROPORTION OF ISOBUTYLENE AND A MINOR PROPORTION OF ISOPRENE: DILUTING THE MIXTURE WITH FROM 1/2 VOLUME OT 10 VOLUMES OF ETHYLIDENE DIFLUORIDE; COPOLYMERIZING THE MIXTURE OF ISOBUTYLENE AND ISOPRENE BY THE CONTINUOUS ADDITION TO THE REACTION MIXTURE OF A LIQUID STREAM OF PREVIOUSLY PREPARED POLYMERIZATION CATALYST CONSISTING OF BORON TRIFLUORIDE IN SOLUTION IN ETHYLIDENE DIFLUORIDE, MAINTAINING THE TEMPERATURE WITHIN THE RANGE BETWEEN -40* C. AND -103* C. THROUGHOUT THE ENTIRE COPOLYMERIZATION REACTION, WHEREBY THERE IS OBTAINED A SOLID COPOLYMER WHICH IS INSOLUBLE IN THE ETHYLIDENE DIFLUORIDE AND WHICH IS CHARACTERIZED BY HAVING A STAUDINGER MOLECULAR WEIGHT NUMBER ABOVE ABOUT 20.000 AND WHEREBY THE ADHENSION OF SOLID COPOLYMER PARTICLES TO THE POLYMERIZATION REACTOR WALLS IS MINIMIZED BY THE PRESENCE OF THE ETHYLIDENE DIFLOURIDE.