Process for preparing a polypropylene molding composition.

摘要

Copolymerisation of propylene with ethylene or a 1-olefin of the formula R-CH = CH-R in the presence of a catalyst comprising a metallocene of the formula I

in which M<1> is titanium, zirconium, hafnium, vanadium, niobium or tantalum, and an aluminoxane gives a polypropylene moulding composition containing syndiotactic polymer chains in high yield. This moulding composition has a very high molecular weight, a very narrow molecular weight distribution and very high syndiotacticity. Mouldings produced from the moulding composition have high transparency, flexibility and tear strength and excellent surface gloss.