Heat treatment of ziegler-natta catalysts to increase polymer molecular weight in solution polymerization

摘要

The present invention provides a novel catalyst preparation method to substantially increase the polymer molecular weight in the high temperature solution process. The method utilizes mixing and heating a mixture of Aluminum alkyl/dialkyl Magnesium with a chlorinating compound, prior to reacting with Transition metal and a second Aluminum alkyl activator. This novel catalyst preparation method is designed to significantly increase the molecular weight in ethylene - alpha-olefin copolymerization by about 80% without any significant loss in activity.