ETHYLENE POLYMERISATION CATALYST SYSTEM.

Abstract

Catalyst system for polymerisation of ethylene comprising a porous support material, wherein the support material comprises, preferably on its surface and in its pores: (i) a quantity of a compound (a) of formula (I) wherein: Z is a moiety selected from M-X2, wherein X is selected from the group of halogens, alkyls, aryls and aralkyls and wherein M is selected from Zr, Hf and Ti; • R2 is a silane bridging moiety; • each R1, R1', R3, R3', R4, R4', R5 and R5' are hydrogen or a hydrocarbon moiety comprising 1-20 carbon atoms; and (ii) a quantity of methylaluminoxane; wherein the catalyst system comprises: • = 2.5*10"5 mol/g, preferably = 2.5*10"5 and = 10.0*10"5 mol/g, more preferably = 2.7*10"5 and = 10.0*10"5 mol/g, of M, with regard to the total weight of the catalyst system, and • = 5.0 wt%, preferably = 5.0 and = 20.0 wt%, of aluminium, with regard to the total weight of the catalyst system. Such catalyst system allows for the production of polyethylenes at high productivity and activity.

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