Patent ID: 8298977

Claim:
A process for preparing an active supported catalyst system that comprises the steps of: a) preparing a fluorinated support by the steps of: i) providing a support prepared from one or more porous mineral oxides; ii) optionally heating the support under inert gas; iii) functionalising the support with a solution containing an alkylating agent; iv) heating the functionalised support of step e) iii) under an inert gas and then under oxygen; v) fluorinating the support with a solution containing a fluorinating agent; b) subjecting the fluorinated support of step a) to a thermal treatment under inert gas; c) subjecting the support of step b) to a thermal treatment under oxygen; d) dissolving in an inorganic solvent a metallocene catalyst component of formula R″ s (CpR m )(CpR′ n )MQF (I) or R″ s (CpR m )XMQF (II) wherein Cp is a cyclopentadienyl group, R and R′ are each independently selected from hydrogen or hydrocarbyl having from 1 to 20 carbon atoms and two consecutive substituents can be linked together to form a ring, M is a metal group 4 of the Periodic Table, R″ is an optional bridge between the two cyclopentadienyl groups or between one cyclopentadienyl group and X, s being 0 when the bridge is absent and 1 when it is present, Q is selected from halogen, hydrogen, alkyl, cycloalkyl or alkoxy having at most 8 carbon atoms, and X comprises an heteroatom selected from groups 15 or 16 of the Periodic Table, said metallocene component being optionally pre-alkylated; e) optionally, providing an alkylating agent; f) impregnating the solution of step d) and the optional alkylating agent of step e) onto the support of step c) either simultaneously or in any order; and g) retrieving an active supported catalyst system.