US Patent 7816478 Polyethylene thick film and process for preparing polyethylene

A thick film and process to prepare polyethylene useful for the film are disclosed. Ethylene is polymerized in two reaction zones with a C6-C10 α-olefin in the presence of a catalyst system comprising an activator, a supported bridged zirconium complex, and a supported non-bridged zirconium complex. The process yields medium density to linear low density polyethylene having a melt index from 0.20 to 1.0 dg/min. Thick films from the polyethylene have a superior combination of high impact strength and high modulus.