Process for producing alpha -olefin polymers

摘要

A process for producing highly crystalline alpha -olefin polymers of good particle form with high yield is provided, which comprises polymerizing alpha -olefin in the presence of a preactivated catalyst obtained by reacting a reaction product (I) of organoaluminum compound (A1) with electron donor (B1), with TiCl4 to obtain a solid product (II); further reacting (II) with electron donor (B2) and electron acceptor to obtain a solid product (III); during or/and after the reaction step for obtaining (II) or/and during or/and after the reaction step for obtaining (III), subjecting (II) or (III), to polymerization treatment with alpha -olefin; and combining the resulting final solid product with organo-aluminum compound (A2) and a reaction product (G) of organo-aluminum compound (A3) with electron donor (B3) to obtain a preactivated catalyst; and preferably, in this combination, further subjecting a part or the total of the catalyst to polymerization treatment with alpha -olefin in the presence of the final solid product and (A2) to obtain another preactivated catalyst. The catalyst has a superior storage stability and heat stability.