| abstract |
(57) [Summary] [Structure] (A) Formula R 1 n TiX 1 4-n (In the formula, R 1 is a substituted or unsubstituted cyclopentadienyl group, X 1 is a halogen group, and n is 1, A titanium compound represented by the formula (2,3), (B) alumoxane, and (C) a formula R 2 m AlX 2 3 -m (wherein R 2 is a hydrocarbon group having 1 to 10 carbon atoms). And X 2 represents a halogen group, and m is a number of 1 to 3), and a catalyst system comprising an organoaluminum compound represented by the formula (3) is used. [Effect] It is possible to produce a polybutadiene having a high cis-1,4-structure with a high polymerization activity and an appropriate amount of a 1,2-vinyl structure. |