Isobutylene polymerization process

A process for producing viscous polyisobutylene having a number average molecular weight about 1,900-5,000 which comprises continuously contacting an olefin stream comprising isobutylene at a temperature of -25.degree. to 52.degree. C. at sufficient pressure to maintain the feed in liquid phase with a chlorided alumina in at least one reaction zone to form a polyisobutylene product and continuously withdrawing the polyisobutylene product from the reaction zone.

A process for producing viscous polyisobutylene having a number average molecular weight greater than about 1,250 which comprises contacting an olefin stream feed comprising isobutylene with a halided alumina, at a temperature of about -25.degree. to 52.degree. C. at sufficient pressure to maintain the feed in a liquid phase, wherein the halided alumina contains randomly substituted halogen atoms bonded directly to aluminum atoms, produced by contacting an alumina at a temperature of about 100.degree. C. to 600.degree. C. with a gaseous haliding agent.