Patent ID: 6346585
Filing Date: 2002-02-12
Classification: C08F

Abstract:
A method for preparing polyisobutylene by polymerization of isobutylene, the method comprising:contacting (a) isobutylene with (b) a catalyst comprising a partially or fully neutralized ammonium salt of a heteropolyacid, wherein the polyisobutylene contains at least about 30 percent terminal vinylidene groups, wherein said catalyst has been calcined at above 350Â° C. to about 500Â° C.; whereby the efficiency of polymerization is increased compared to the efficiency in the absence of such calcining; wherein the polyisobutylene has a {overscore (M)}w/{overscore (M)}n of at least about 9.58 and an {overscore (M)}n of about 500 to about 5000.