Patent ID: 7326756
Filing Date: 2008-02-05
Classification: C08F,Y10S

Abstract:
1. A process of preparing a polymer composition that comprises branched crystalline polypropylene, having a melting point Tm of 145° C. or more, said process comprising: contacting a metallocene catalyst compound represented by the formula: wherein: M is a metal of Group 4, 5, or 6 of the Periodic Table: R the radicals R R —B(R wherein: R M with a polymerization medium that comprises propylene monomers; and less than 25 volume percent diluent; and conducting polymerization of the propylene monomers at a temperature greater than 70° C. for a time sufficient to provide branched crystalline polypropylene that has from 0.0 wt % to 2.0 wt % ethylene, a branching index (g′) of 0.97 or less and a heat of fusion of 70 J/g or more, wherein diene monomer has not been added to the polymerization medium and wherein the metallocene catalyst compound is combined with propylene in the absence of hydrogen.