| 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, where a compound of the formula I is <IMAGE> where M<1> is Zr or Hf, R<1> and R<2> are (C1-C3)-alkyl or chlorine, R<3> is hydrogen, F, Cl, -OR<7>, -NR<7>R<8>, -P(O)R<7>R<8>, -P(OR<7>)2 or SR <7 > , with the proviso that at least one of the radicals R<3> is other than hydrogen, R<4> is a radical <IMAGE> and m plus n is zero or 1.i |