Patent ID: 6747103
Filing Date: 2004-06-08
Classification: C08F,C08L,Y10S

Abstract:
A nucleated high-stiffness propylene polymer composition obtained by homopolymerization or copolymerization of propylene in the presence of a catalyst system comprising a catalyst component, a cocatalyst component, and an external donor, the procatalyst component of the catalyst system containing magnesium, titanium, halogen and an electron donor, said catalyst being modified by polymerizing it with a vinyl compound of the formula wherein R1 and R2 together form a 5 or 6 membered saturated or unsaturated or aromatic ring in the presence of a cocatalyst and a strongly coordinating external donor of at least one compound of formula III or formula IV as follows:R4R5C(COMe)2â€ƒâ€ƒ(III) wherein R4 and R5 are the same or different and are a linear, branched or cyclic aliphatic or an aromatic hydrocarbon group; andR1nR2mSi(R3O)4âˆ’nâˆ’mâ€ƒâ€ƒ(IV) wherein R1 and R2 can be the same or different and they stand for a linear, branched or cyclic aliphatic, or aromatic hydrocarbon group;R3is methyl or ethyl; n is an integer 0 to 3; m is an integer 0 to 3; and n+m is 1 to 3, with the proviso that the coordinating effect of the donor is stronger than that of a donor of formula (IV) wherein R1 is methyl, R3 is methyl and R2 is a cyclohexyl group.