Patent ID: 8389654
Filing Date: 2013-03-05
Classification: C08F,C08L

Abstract:
1. A process for preparing a polypropylene containing polymer composition having a tensile modulus, determined according to ISO 527-2/1 B at 1 mm/min. and 23° C., of at least 1400 MPa, comprising the following steps in any sequence: (i) preparing a polypropylene homopolymer which has a melt flow rate MFR (ii) copolymerization of propylene with an olefin comonomer to result in a polypropylene random copolymer comprising from 0.2 to 5.0 wt % of comonomer units, and (iii) copolymerization of propylene with an olefin comonomer to result in an elastomeric copolymer having an intrinsic viscosity of from 3 to 6 dl/g measured in tetraline; using a Ziegler-Natta catalyst including an electron-donor; wherein the Ziegler-Natta catalyst comprises a cocatalyst component which has been prepared by bringing together magnesium dichloride, a lower alcohol selected from methanol, ethanol or mixtures thereof, a titanium compound and an ester of phthalic acid having an alkoxy group of at least five carbon atoms.