| abstract |
Abstract of the Disclosure Process for the preparation of an olefin polymer A very active catalyst system for olefin polymerization is composed of an aluminoxane and a metallocene of the formula I (I) in which, preferably, M1 is Zr or Hf, R1 and R2 are alkyl or halogen, R3 and R4 are hydrogen, R5 and R6 are alkyl or haloalkyl, -(CR8R8)m-R7-(CR8R9n- is a single-membered or multimembered chain in which R7 may furthermore be a (substituted) hetero atom, m+n is zero or 1 and R10 is hydrogen The catalyst system gives polymers having high stereospecificity and a high melting point. |