Catalyst component

Claim 1

A catalyst component which is the product of treating at least one particulate support material with at least one organomagnesium compound, at least one transition metal compound of Groups IVA, VA or VIA of the Periodic Table, at least one pacifying agent, and optionally one or more compounds selected from the group consisting of: i) an aluminium compound of the general formula: R n AlY 3 _ n wherein R, each of which may be the same or different, represents a hydrocarbyl group, or substituted hydrocarbyl group, such as alkyl, aryl, cycloalkyl, aralkyl, alkenyl or alkadienyl, n is 0, 1, 2, 3 or a fraction less than 3, and Y is a singly charged ligand such as hydride, fluoride, chloride, bromide, iodide or oxyhydrocarbyl, ii) an organometallic compound of the general formula: R 1 m MX p wherein M is a metal of Groups IA, IIA, IIB IIIB, IVA, VA or VIA of the Periodic Table, R 1 is a hydrocarbyl or a substituted hydrocarbyl group, X is a singly charged anionic ligand or a mono- dentate neutral ligand, m is an integer up to the highest valency of the metal M and p is 0 or an integer up to 2 less than the valency of the metal M, except that when M is a metal from Group VIA, p is always O, and m has a value from 2 to the highest'valency of the metal, and when M is a metal from Groups IVA or VA m has a value from 2 to the highest valency of the metal and p has a value from O to a value of 2 less than the valency of the metal M, iii) a halogen containing compound and iv) a Lewis Base compound with the proviso (i) that the at least one particulate support material is treated with the at least one organomagnesium compound, the at least one transition metal compound of Groups IVA, VA or VIA and the one or more optional compounds, where one or more is used, prior to being treated with the at least one pacifying agent, except that where (a) the at least one pacifying agent is a hydrogen halide, (b) the at least one particulate support material is treated with at least one aluminium compound of general formula RnA l Y3-n and (c) the at least one particulate support material is treated with the at least one aluminium compound of general formula R n AlY 3-n and the at least one organomagnesium compound separately, the at least one pacifying agent may be added to the at least one particulate support material after it has been treated with the at least one organomagnesium compound and the at least one aluminium compound of general formula R n AlY 3-n and before it is treated with the at least one transition metal compound of Groups IVA, VA or VIA and (ii) that where the at least one particulate support material is treated with two compounds selected from the optional compounds they are not exclusively an aluminium compound R n AlY 3-n and an organometallic compound RmMXp.