Patent attributes
A method for the preparation of copolymers of ethylene and α-olefins having a fraction (%) of the molecular weight component of >1,000,000 of less than 6% comprises polymerising ethylene and an α-olefin in the presence of a supported polymerisation catalyst system comprising (a) a transition metal compound (b) a porous support material, and (c) an activator characterized in that the support material has been (i) dried at a temperature in the range 0° C. to 195° C. in an inert atmosphere, and (ii) treated with an organometallic compound. The resultant supported catalyst systems show improved productivity and allow for control of the resultant polymer properties. Particularly preferred supported catalyst systems are those comprising metallocene complexes.