| abstract |
A highly effective catalyst system for the polymerisation of olefins is composed of a co-catalyst, preferably an aluminoxane, and a metallocene of the formula I, <IMAGE> in which M<1> is preferably Zr or Hf, R<1> and R<2> are preferably alkyl or halogen, R<5> is preferably hydrogen or alkyl, R<3> and R<4> are preferably alkyl, it also being possible for R<3>, R<4> and R<5> to be halogenated, -(CR<7>R<8>)m-R<6>-(CR<7>R<8>)n- is preferably a chain having one or more than one members in which R<6> can also be a (substituted) heteroatom, and m + n is preferably zero or 1. |