Patent ID: 6191241
Filing Date: 2001-02-20
Classification: C07F,C08F,Y10S

Abstract:
A process for the preparation of a high-melting polyolefin by homo- or copolymerization of one or more monomers from the group consisting of .alpha.-olefins having 2 or more C atoms in the presence of an organometallic catalyst which can be activated by a cocatalyst, which comprises employing as the organometallic catalyst a metallocene compound or .pi. complex compound of the formula ##STR66##in whichCpI and CpII are two identical or different carbanions having a cyclopentadienyl-containing structure, in which one to all the H atoms can be substituted by identical or different radicals from the group consisting of linear or branch C.sub.1 -C.sub.20 -alkyl, which can be monosubstituted to completely substituted by halogen, mono- to trisubstituted by phenyl or mono- to trisubstituted by vinyl, C.sub.6 -C.sub.12 -aryl, halogenoaryl having 6 to 12 C atoms, organometallic substituents, including silyl, trimethylsilyl or ferrocenyl, or one or two can be replaced by D and A,D denotes a donor atom, which can additionally carry substituents and has at least one free electron pair in its bond state,A denotes an acceptor atom, which can additionally carry substituents and has an empty orbital capable of accepting a pair of electrons in its bond state,wherein D and A are linked by a reversible coordinate bond such that the donor group assumes a positive charge and the acceptor group assumes a negative charge,M represents a transition metal of sub-group III, IV, V or VI of the Periodic Table of the Elements, including the lanthanides and actinides,X denotes one anion equivalent andn denotes the number zero, one, two, three or four, depending on the charge of M,ora .pi. complex compound, or metallocene compound of the formula ##STR67##in which.pi.I and .pi.II represent different charged or electrically neutral .pi. systems which can be fused with one or two unsaturated or saturated five- or six-membered rings,D denotes a donor atom, which is a substituent of .pi.I or part of the .pi. system of .pi.I and has at least one free electron pair in its bond state,A denotes an acceptor atom, which is a substituents of .pi.II or part of the .pi. system of .pi.II and has an empty orbital capable of accepting a pair of electrons in its bond state,wherein D and A are linked by a reversible coordinate bond such that the donor group assumes a positive charge and the acceptor group assumes a negative charge, and where at least one of D and A is part of the associated .pi. system,wherein D and A in their turn can carry substituents,wherein each .pi. system and each fused-on ring system can contain one or more D or A or D and A andwherein .pi.I and .pi.II in the non-fused or in the fused form, one to all the H atoms of the .pi. system independently of one another can be substituted by identical or different radicals from the group consisting of linear or branched C.sub.1 -C.sub.20 -alkyl, which can be monosubstituted to completely substituted by halogen, mono- to trisubstituted by phenyl or mono- to trisubstituted by vinyl, C.sub.6 -C.sub.12 -aryl, halogenoaryl having 6 to 12 C atoms, organometallic substituents, including silyl, trimethylsilyl or ferrocenyl, or one or two can be replaced by D and A, so that the reversible coordinate D.fwdarw.A bond (i) is formed between D and A which are both parts of the .pi. system or the fused-on ring system, or (ii) of which D or A is part of the .pi. system and in each case the other is substituent of the non-fused .pi. system or the fused-on ring system, or (iii) both D and A are such substituents, and in the case of (iii) at least one additional D or A or both is (are) parts of the .pi. system or the fused-on ring system,M and X have the above meanings andn denotes the number zero, one, two, three or four, depending on the charges of M and those of .pi.-I and .pi.-II.