Preactivated catalyst for producing alpha -olefin polymers

摘要

A preactivated catalyst for producing alpha -olefin polymers is provided, which is obtained by the steps which comprises: reacting an organoaluminum compound (O-Al1) with an electron donor (ED1) to obtain a reaction product (I); reacting (I) with TiCl4 to obtain a solid product (II); reacting (II) with an electron donor (ED2) and an electron acceptor to obtain a solid product (III); combining (III) with an organoaluminum compound (O-Al2) and a reaction product (RP) of an organoaluminum (O-Al3) with an electron donor (ED3) (III), (O-Al2) and (PP) being referred to as catalyst components), and in this combination, subjecting a part or the whole of the catalyst components to polymerization treatment with an alpha -olefin at least in the presence of (III) and said (O-Al2) to obtain a preliminarily activated catalyst; and polymerizing an alpha -olefin in the presence of the catalyst. According to this catalyst, even in the case of gas phase polymerization, the resulting polymer has a uniform particle size; the catalyst employed has not only a high stability but also a high activity whereby the advantages of gas phase polymerization can be fully exhibited; and further it is possible to easily control the stereoregularity of polymer.