Patent ID: 6903170

Claim:
A process which comprises polymerizing ethylene and, optionally, an alpha-olefin comonomer in the presence of a supported, activated metallocene catalyst and triisobutylaluminum to produce an ethylene polymer or copolymer; wherein the supported, activated catalyst is made by: (a) treating silica with a silane compound in an amount effective to reduce the surface hydroxyl content of the silica; (b) treating the product from step (a) with an organoboron compound; and (c) combining the product from step (b) with a Group 4 metallocene complex and an alumoxane such that the aluminum to Group 4 metal (Al/M) molar ratio is within the range of about 20 to about 2000; and wherein the triisobutylaluminum is added to the reactor in an amount within the range of about 10 to about 1000 moles of triisobutylaluminum per mole of Group 4 metal.