Polymerisation process

摘要

A process for the copolymerisation of ethylene and an alpha-olefin having 7 to 10 carbon atoms in a fluidised bed gas phase reactor in the presence of a single site polymerisation catalyst comprises operating the process in condensed mode and wherein the amount of said alpha-olefin is maintained below that at which substantial condensation in the reactor occurs. The preferred alpha-olefin is 1-octene and the preferred single site polymerisation catalyst is a metallocene complex. By use of the process conditions of the present invention, higher alpha-olefins may be successfully employed in a gas phase process provided the amount of higher alpha-olefin comonomer is maintained below that at which substantial condensation occurs: Such operation is also dependent upon the operation temperature and the boiling point of the higher alpha-olefin and the process is particularly advantageous when performed in the presence of catalysts able to incorporate high levels of comonomers at low comonomer inventories.