Patent ID: 8067328

Claim:
A polymerisation catalyst composition comprising (1) a transition metal compound having the following Formula A, wherein Z comprises a five-membered heterocyclic group, the five membered heterocyclic group containing at least one carbon atom, at least one nitrogen atom and at least one other hetero atom selected from nitrogen, sulphur and oxygen, the remaining atoms in said ring being selected from nitrogen and carbon; M is a metal from Group 3 to 11 of the Periodic Table or a lanthanide metal; E 1 and E 2 are divalent groups independently selected from (i) aliphatic hydrocarbon, (ii) alicyclic hydrocarbon, (iii) aromatic hydrocarbon, (iv) alkyl substituted aromatic hydrocarbon, (v) heterocyclic groups and (vi) heterosubstituted derivatives of said groups (i) to (v); D 1 and D 2 are donor atoms or groups; E 1 and E 2 are not linked other than through the donor atom or group D 1 ; X is an anionic group, L is a neutral donor group; n=m=1; y and z are independently zero or integers such that the number of X and L groups satisfy the valency and oxidation state of the metal M, (2) a catalyst-activating support which is a solid particulate substance, insoluble in hydrocarbons, comprising at least magnesium and aluminium atoms and hydrocarbyloxy groups containing 1 to 20 carbons atoms, the molar ratio of Mg/Al being in the range 1.0 to 300 and the molar ratio of hydrocarbyloxy groups to aluminium atoms being in the range 0.05 to 2.0, and (3) an additional activator selected from aluminium alkyl activators and boron compound activators.