| 摘要 |
<p>Polymerization and copolymerization is carried out in the presence of an improved transition metal based catalyst. The catalyst is obtained by activating with an organometallic compound, the solid product which results from the reaction of a halogen containing transition metal compound with an alkoxy metal compound of the formula Xm-nM(OR)n wherein M is at least one metal selected from the elements of Groups Ia, IIa, IIb, IIIa and VIIb of the Periodic Table, X is a monovalent inorganic radical, R is a monovalent hydrocarbon radical, m is the valence of M and n is an integer such that 1 </= n </= m.</p> |
