Patent ID: 7326756

Claim:
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 1 arid R 2 are identical or different, and are one of a hydrogen atom, a C 1 -C 10 alkyl group, a C 1 -C 10 alkoxy group, a C 6 -C 10 aryl group, a C 6 -C 10 aryloxy group, a C 2 -C 10 alkenyl group, a C 7 -C 40 arylalkyl group, a C 7 -C 40 alkylaryl group, a C 8 -C 40 arylalkenyl group, or a halogen atom, or a conjugated diene which is optionally substituted with one or more hydrocarbyl, tri(hydrocarbyl)silyl groups or hydrocarbyl, tri(hydrocarbyl)silylhydrocarbyl groups, said diene having up to 30 atoms not counting hydrogen; the radicals R 3 , R 4 , and R 10 are identical or different and have the meanings stated for R 5 and R 6 , or two adjacent R 10 radicals are joined together to form a ring; R 5 and R 6 are identical or different, and are one of a hydrogen atom, a halogen atom, a C 1 -C 10 alkyl group, which may be halogenated, a C 6 -C 10 aryl group, which may be halogenated, a C 2 -C 10 alkenyl group, a C 7 -C 40 arylalkyl group, a C 7 -C 40 alkylaryl group, a C 8 -C 40 arylalkenyl group, a —NR 2 , —SR′, —OR′, —OSiR 3 ′ or —PR 2 ′ radical, wherein: R′ is one of a halogen atom, a C 1 -C 10 alkyl group, or a C 6 -C 10 aryl group: —B(R 14 )—, —Al(R 14 )—, —Ge—, —Sn—, —O—, —S—, —SO—, —SO 2 —, —N(R 14 )—, —CO—, —P(R 14 )—, or —P(O)(R 14 )—; wherein: R 14 , R 15 and R 16 are identical or different and are a hydrogen atom, a halogen atom, a C 1 -C 20 branched or linear alkyl group, a C 1 -C 20 fluoroalkyl or silaalkyl group, a C 6 -C 30 aryl group, a C 6 -C 30 fluoroaryl group, a C 1 -C 20 alkoxy group, a C 9 -C 20 alkenyl group, a C 7 -C 40 arylalkyl group, a C 8 -C 40 arylalkenyl group, a C 7 -C 40 alkylaryl group, or R 14 and R 15 , together with the atoms binding them, form a cyclic ring; M 2 is one or more carbons, silicon, germanium or tin; 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.