摘要 |
A multistage process for obtaining an heterophasic propylene polymer comprising the following steps: step a) contacting under polymerization conditions propylene and optionally ethylene or one or more alpha olefins in the presence of a catalysts system, supported on a porous organic polymer, comprising: ii) one or more metallocene compounds of formula (I) wherein: M is an atom of a transition metal; p is an integer from 0 to 3; X, same or different, is a hydrogen atom, a halogen atom, or a hydrocarbon group; L is a divalent bridging group; R<SUP>1</SUP>, is a linear or branched, saturated or unsaturated C<SUB>1</SUB>-C<SUB>20</SUB>-alkyl radical; R<SUP>2 </SUP>is a branched C<SUB>1</SUB>-C<SUB>20</SUB>alkyl radical; T, equal to or different from each other, is a moiety of formula (IIIa) or (IIIb): wherein: the atom marked with the symbol * bonds the atom marked with the same symbol in the compound of formula (I); R<SUP>5</SUP>-R<SUP>13</SUP>, equal to or different from each other, are hydrogen atoms or hydrocarbon groups; ii) an alumoxane or a compound capable of forming an alkyl metallocene cation; and optionally iii) an organo aluminium compound; step b) contacting, under polymerization conditions, in a gas phase, ethylene and one or more alpha olefins and optionally a non-conjugated diene, in the presence of the polymer obtained in step a) and optionally in the presence of an additional organo aluminium compound.
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