Patent ID: 7022795
Filing Date: 2006-04-04
Classification: C08F

Abstract:
1. A process for the preparation of propylene homopolymers having from 0.4 wt percent to 0.6 wt percent xylene soluble fraction and a halogen content of 7.8 ppm to 10.1 ppm by polymerizing propylene at from 20 to 50° C. and from 1 to 100 bar in the presence of a Ziegler-Natta catalyst system containing, as active components, wherein the process comprises a) reacting a titanium halide with a chlorine-free magnesium alkyl compound, an inorganic oxide as a carrier, a C and, as cocatalyst, b) an aluminum compound and c) a further electron donor compound, the molar ratio of the aluminum compound b) to the further electron donor compound c) in the polymerization being from 1.5:1 to 9:1.