2-SUBSTITUTED BISINDENYLMETALLOCENES,PROCESS FOR THEIR PREPARATION,AND THEIR USE AS CATALYSTS IN THE POLYMERIZATION OF OLEFINS

摘要

The metallocenes of the formula I according to the invention …… in which the substituents have the following preferred meanings: M<1> is Zr or Hf, R<1> and R<2> are alkyl or halogen, R<3> and R<4> are hydrogen, R<5> and R<6> are alkyl or haloalkyl, -(CR<8>R<9>)m-R<7>-(CR<8>R<9>)n- is a chain with one or more than one members in which R<7> can also be a (substituted) hetero atom, and m + n is zero or 1, form, together with aluminoxanes as cocatalysts, a highly effective catalyst system for the preparation of polyolefins having a high molecular weight.