Patent ID: 8557935

Claim:
A method of producing a bimodal polyethylene comprising contacting ethylene and C 3 to C 10 α-olefins with a bimetallic catalyst compound produced by a method comprising contacting: (a) a modified Ziegler-Natta catalyst made by contacting: (i) a Ziegler-Natta catalyst comprising a Group 4, 5 or 6 transition metal; with (ii) a modifier, wherein the modifier is diethylaluminum ethoxide or a compound or mixture of compounds described by the formula AlX n R 3-n , wherein Al is aluminum, X is a halide, and R is independently selected from the group consisting of C 1 to C 20 alkyls, C 1 to C 20 alkoxides, C 1 to C 20 alkylamides, and combinations thereof, and n is 0 to 3; and (b) a metallocene catalyst compound to form a bimetallic catalyst; wherein the molar ratio of aluminum from the modifier to Group 4, 5 or 6 transition metal is less than 2:1.