Patent ID: 6559250
Filing Date: 2003-05-06
Classification: C08F

Abstract:
A method of homo- or co-polymerization of &agr;-olefin by means of using a catalyst system which comprises the following components:(1) a solid titanium catalyst produced by means of a production method comprising the following steps: (a) preparing a magnesium compound solution by dissolving a magnesium halide compound and a compound of Group IIIA of the Periodical Table in a solvent of mixture of cyclic ether, one or more alcohols, a phosphorus compound, and an organic silane; (b) precipitating solid particles by reacting said magnesium compound solution with a transition metal compound, a silicon compound, a tin compound, or the mixtures thereof; and (c) reacting said precipitated solid particles with a titanium compound and electron donors; (2) an organometallic compound of metal of Group IIIA of the Periodical Table; and (3) external electron donors comprising three or more organo-silicon compounds, wherein the melt flow rates of the homopolymers obtained from polymerization by individually using said organo-silicon compounds under the same polymerization conditions are 5 or less, 5Ëœ20, and 20 or higher, respectively.