| abstract |
The present invention relates to a process for preparing isobutene-cyclodiene copolymers having a number-average molecular weight of at least 100,000 and an unsaturation of 1 30 % by mol, characterized in that polymerization is carried out without gelation by reacting 75 99.5 % by weight of an isobutene and 0.5 25 % by weight of a cyclodiene or a mixture of cyclodiene as reaction materials, in a polar reaction solvent of 1 10 times by weight with respect to the reaction materials, wherein a catalyst solution of 0.02 2 % by weight in the polar solvent is used in the amount of 0.2 2 times by weight with respect to the reaction materials, at a reaction temperature of -100 -85 ~C, thereby obtaining a copolymer, and then removing the residual catalyst activity at a temperature of -100 -25 ~C. |