abstract |
A very active catalyst system for olefin polymerization consists of a co-catalyst, preferably an aluminoxane, and a metallocene of the formula I <IMAGE> in which preferably M<1> denotes Zr or Hf, R<1> and R<2> denote halogen or alkyl, R<3> denotes alkyl, R<4> to R<10> denote alkyl or hydrogen and R<11> denotes a (subst.) alkylene or hetero atom bridge. |