Patent ID: 6841633
Filing Date: 2005-01-11
Classification: C08F

Abstract:
1. A process for the preparation of a lower α-alkene polymerisation heterogeneous solid catalyst comprising mixing a hydrated magnesium chloride derived procatalyst, a cocatalyst comprising an organoaluminium compound and a selectivity control agent comprising an ester or ether, wherein the procatalyst is obtained by: i) refluxing hydrated magnesium chloride with an aliphatic alcohol in the mole ratio of 0.5-1:10-20 in a hydrocarbon and/or halohydrocarbon solvent to form magnesium chloride alcoholate followed by dehydration of the reaction mixture; ii) reaction of the resulting magnesium chloride alcoholate with an activated carbonyl compound in the presence of a hydrocarbon and/or halohydrocarbon solvent in the mole ratio of 0.5-1:10-20 at 30-160° C. to generate insitu an internal electron donor ester component of a magnesium chloride ester complex precursor optionally followed by dehydration of the reaction mixture; iii) reaction of the resulting magnesium chloride ester complex precursor comprising the internal electron donor ester component generated insitu, with titanium tetrahalide optionally in the presence of a hydrocarbon and/or hydrocarbon solvent at 30-130° C. followed by isolating the resulting procatalyst; the mole ratio of the aluminium to titanium being 10-300:1 and that of the selectivity control agent to the titanium being 10-100:1.