Process for preparing an alpha-olefin polymer

Claim 1

A process for the preparation of a 1-olefin polymer by polymerization of a 1-olefin of the formula R-CH=CH 2 in which R is an alkyl group having 1 to 28 carbon atoms, or copolymerization of these olefins with one another or with ethylene at a temperature from -60 to 200°C, at a pressure from 0.5 to 60 bar, in solution, in suspension or in the gas phase, in the presence of a catalyst which consists of a metallocene as transition metal compound and an aluminoxane of the formula (II) for the linear type and/or of the formula (III) for the cyclic type, where in the formulae (II) and (III) R 11 denotes a C 1 -C 6 -alkyl group and p is an integer from 2 to 50, which comprises carrying out the polymerization in the presence of a catalyst whose transition metal component is a compound of the formula (I) in which M 1 is a metal from the group consisting of titanium, zirconium, vanadium, niobium and tantalum, R 1 and R 2 are identical or different and denote a hydrogen atom, a halogen atom, a C 1 -C 10 -alkyl group, a C 6 -C 10 -aryl group, a C 2 -C 10 -alkenyl group, a C 7 -C 40 -arylalkyl group, a C 7 -C 40 -alkylaryl group or a C 8 -C 4o -arylalkenyl group, R 3 and R 4 are identical or different and denote a mononuclear or polynuclear hydrocarbon radical which can form a sandwich structure with the central atom, R 5 denotes =BR 8 , =AtR 8 , -Ge-, -Sn-, -O-, -S-, =S=O, =S0 2 , =NR s , =PR 8 or =P(O) R 8 , in which R 8 , R 9 and R 10 are identical or different and denote a hydrogen atom, a halogen atom, a C 1 -C 10 -alkyl group, a C 6 -C 10 -aryl group, a C 2-10 -alkenyl group, a C 7 -C 40 -arylalkyl group, a C 8 -C 40 -arylalkenyl group or a C 7 -C 4o -alkylaryl group or R 8 and R 9 or R 8 and R 10 each form a ring together with the atoms linking them, M 2 denotes silicon, germanium or tin and o denotes 1, 2 or 3, R 6 and R 7 are identical or different and denote a =CR 8 R 9 group, in which R 8 and R 9 have the abovemen- tioned meaning, m and n are identical or different and denote zero, 1 or 2, where m+n is zero, 1 or 2, and if appropriate, preactivating the metallocene of the formula (I), prior to being employed in the polymerization reaction, by an aluminoxane of the formula (II) and/or (III).