Catalyst for polymerizing alpha -olefins

摘要

A catalyst for polymerizing alpha -olefins composed of a titanium composition formed by heating a co-comminuted mixture of a magnesium halide and a complex of an aluminum halide and a carboxylic acid ester of the formula R1COOR2, with titanium tetra-chloride; and an organic aluminum compound of the formula AlR3mH3-m; and optionally added thereto at least one component selected from an alkyl aluminum halide of the formula AlR4nX3-n; a carboxylic acid ester of the formula R5COOR6; and its complex formed with an aluminum halide; is disclosed.