Process from polymerising ethylene in the gas phase

摘要

A process for the polymerisation of olefins in the gas phase is carried out in the presence of a supported constrained geometry catalyst. The process involves a prepolymerisation step which may be performed in-situ. The catalyst may for example comprise a constrained geometry metallocene complex supported on silica and used in the presence of an activator. The prepolymerisation step enables the activity of the catalyst to be improved.