Patent ID: 7504352

Claim:
A process for forming a propylene polymerization catalyst which comprises: forming a combination of titanium tetrachloride, a magnesium-containing compound that can be converted to magnesium dihalide and an internal electron donor in an aromatic hydrocarbon solvent, with the proviso that, the magnesium-containing compound cannot be a magnesium dialkoxide when the internal donor is a halo phthaloyl derivative, and bringing that combination, as modified by the proviso clause, to elevated temperature to form an intermediate product; washing the intermediate product with an aromatic hydrocarbon solvent at elevated temperature to produce a washed product and a supernatant followed by decantation of the supernatant therefrom; treating the washed product with titanium tetrachloride in an aromatic hydrocarbon solvent to form a treated product and a supernatant followed by heating of the treated product and supernatant, decantation of the supernatant therefrom, and washing of the treated product with an aromatic hydrocarbon solvent at elevated temperature to produce a washed product and a supernatant followed by decantation of the supernatant therefrom; treating the washed product with titanium tetrachloride in an aromatic hydrocarbon solvent at least one more time, to form a treated product and a supernatant followed by heating of the treated product and supernatant, decantation of the supernatant therefrom, and washing of the treated product with an aromatic hydrocarbon solvent at elevated temperature to produce a washed product and a supernatant followed by decantation of the supernatant therefrom; and addition of an aliphatic hydrocarbon solvent to the washed treated product with decantation of the solvent therefrom to form a doubly washed product which can be used as a propylene polymerization catalyst.