Abstract:
The present invention relates to an improved solution process for the formation of substantially gel-free copolymers and terpolymers of isobutylene and one or more dienes having an Mn of about less than 500,000, a mole % unsaturation of about 8 to about 45, and a polydispersity value of about 3 to about 30, wherein the mixture of isobutylene and diene monomers and a cosolvent are contacted with a catalyst at polymerization conditions (-50. degree. -to 100. degree. C. ) wherein the improvement includes a hydrocarbon soluble catalyst being formed from the reaction product of a material of the formula: R. sub. m AlX. sub. 3-m wherein m is an integer of from 1 to 3 inclusive, R is the same or different alkyl radical of straight or branched chain structure of from 1 to 7 carbons and X is the same or different halogen selected from the group consisting of chlorine and bromine, and a halogen containing material which is Y moles of halogen, halogen acid, or mixed halogen per mole of aluminum compound wherein the halogen is selected from the group consisting of chlorine and bromine, wherein the molar ratio of the formed catalyst to the monomer is critical by selecting at about 0. 0001 to about 0. 001 in order to obtain the desired elastomeric co- and terpolymers.