Patent ID: 7799722

Claim:
A catalytic solution obtained by a process comprising the following steps: (a) contacting a solution of methylalumoxane (MAO) in an aromatic first solvent with a solution in a second solvent comprising at least one alumoxane different from methylalumoxane or at least one organo-aluminium compound of formula H j AlU 3-j or H j Al 2 U 6-j , where the U substituents, same or different, are hydrogen atoms, halogen atoms, or hydrocarbon group containing from 2 to 20 carbon atoms, optionally containing silicon or germanium atoms, with the proviso that at least one U is different from halogen and at least one U is different from hydrogen, and j ranges from 0 to 1, being also a non-integer number; (b) adding to the solution formed in step a, an alifatic third solvent having a boiling point higher than the aromatic first solvent and second solvent provided the second solvent is an aromatic solvent or the second solvent has a boiling point lower than the aromatic first solvent; (c) solubilizing a metallocene compound in the solution obtained in step a or in step b; and (d) substantially removing aromatic solvents, thereby forming a final solution having a molar concentration of the metallocene compound and a content of aromatic solvents; wherein the content of the aromatic solvents in the final solution obtained in step d) is lower than 2% by weight, the molar concentration of the metallocene compound in the final solution obtained in step d) ranges from 1·10 −5 to 1·10 −1 mol/l, and a molar ratio between methylalumoxane and the organo-aluminium compound or a molar ratio between methylalumoxane and the alumoxane used in step a) ranges from 10:1 to 1:10.