| abstract |
Catalyst system containing: a) at least one metallocene, b) at least one Lewis base of the ** formula ** M2R3R4R5, where R3, R4 and R5 are the same or different, and mean a hydrogen atom, an alkyl group with 1 to 20 carbon atoms, halogenated alkyl with 1 to 20 carbon atoms, aryl with 6 to 40 carbon atoms, halogenated aryl with 6 to 40 carbon atoms, alkylaryl with 7 to 40 carbon atoms or arylalkyl with 7 to 40 carbon atoms, being able, if necessary, two residues, or the three residues R3, R4 and R5, to be linked through hydrocarbon units with 2 to 20 carbon atoms, and M2 represents an element of the main group V of the system periodic of the elements, c) a support d) at least one organic compound of boron and aluminum, which is constituted by units of the ** formula ** Ri1M3-O-M3R2. |