Process for preparing a catalyst component for propylene polymerization

Abstract

The invention relates to a process for preparing a polymerization catalyst component wherein a solid compound with formula Mg(OR)Clwherein x is larger than 0 and smaller than 2, and each R, independently, represents an alkyl group, said compound being obtained by reacting a Grignard compound with an alkoxy- or aryloxy-containing silane compound, is contacted with at least one activating compound selected from the group formed by internal electron donors and compounds of formula M(OR)(R), wherein M can be Ti, Zr, Hf, Al or Si, each Rand R, independently, represent an alkyl, alkenyl or aryl group, v is the valency of M and w is smaller than v, in the presence of an inert dispersant to give an intermediate reaction product, and wherein the intermediate reaction product is contacted with a halogen-containing Ti-compound. A catalyst system comprising said component shows improved performance in olefin polymerization. The invention also relates to a polymerization catalyst system comprising the catalyst component and to a process of making a polyolefin by contacting at least one olefin with a polymerization catalyst system comprising the catalyst component.