Patent ID: 7244795

Claim:
A process of polymerizing olefins comprising contacting, in a reactor: (a) ethylene and at least one comonomer selected from the group consisting of C 4 to C 8 alpha olefins; and (b) a supported catalyst system comprising a metallocene catalyst compound activated by methylaluminoxane, and a support material, the methylaluminoxane being present on the range of from 3 to 7.7 mmole methylaluminoxane per gram of support material, the metallocene being present in the range of from 0.04 to 0.1 mmole metallocene per gram of support material; wherein the process produces a polyethylene copolymer having a bulk density of at least 0.30 gram/cubic centimeter; and wherein the support material is silica having an average particle size ranging from 10 to 40 μm, and wherein the metallocene catalyst compound is a substituted bis-cyclopentadienyl zirconocene catalyst compound comprising at least one fluoride or fluorine containing leaving group.