| 摘要 |
PROBLEM TO BE SOLVED: To produce the subject polymer having a sufficiently high catalyst activity even when the amount of an alumoxane used is small and a narrow distribution of molecular weight and excellent in mechanical characteristics, processability and abrasion resistance by using a specific catalyst containing a rare earth element-containing compound, the alumoxane, etc. SOLUTION: A conjugated diene-based compound is polymerized by using a catalyst consisting essentially of (A) a compound containing a rare earth element of 57-71 atomic number (preferably a carboxylic salt such as a versatic salt of neodymium) or a reactional product of the compound with a Lewis base, (B) an alumoxane, (C) an organoaluminum compound represented by the formula AlR1R2R3 (R1 and R2 are each H or a 1-10C hydrocarbon; R3 is a 1-10C hydrocarbon) (preferably triethylaluminum, etc.), and (D) a reactional product of a metal halide (preferably copper chloride, etc.), with the Lewis base (preferably acetylacetone, etc.). The content of cis-1,4-bonds in the objective polymer is preferably >=90% and the ratio of weight-average molecular weight/number- average molecular weight thereof is preferably <=3.5.
|
