Patent ID: 6444765
Filing Date: 2002-09-03
Classification: B01J,C08F

Abstract:
A process for polymerizing olefins to form a polyolefin product which comprises:(a) preparing a catalyst system by premixing a first organoaluminum selected from the group consisting of triisobutyaluminum and triethylaluminum with a supported catalyst comprising a support and an organometallic compound comprising zirconium and at least one boraaryl ligand, wherein the catalyst system has an aluminum:zirconium ratio greater than about 100:1 when the first organoaluminum is triisobutyaluminum and the catalyst system has an aluminum:zirconium ratio less than about 20:1 when the first organoaluminum is triethylaluminum; and (b) polymerizing an olefin in the presence of the catalyst system, an activator and a second organoaluminum, wherein the second organoaluminum is different from the first organoaluminum; wherein the polyolefin product is a bimodal molecular weight distribution polyolefin.