Process for polymerizing conjugated diolefin

摘要: PURPOSE: To provide a process for polymerizing conjugated diolefin whereby (co)polymer having narrow mol.wt. distribution is obtd. at high productivity even when catalyst system contg. group 3B metal used by using specific system. CONSTITUTION: A polymerized comprising compd. (A) of metal, an organoaluminum (B) represented AlR R (wherein and are each hydrocarbon group; H or group), aluminoxane (C), (D) least one halogen atom. neodymium the most suitable as carboxylate pref., 2-ethylhexanoate versatate being still pref. The component D halogenated (alkyl)aluminum AlXn 3-n X halogen; 1-8C n 1-2) organohalogen