| abstract |
The framework is the production of homopolymers and copolymers of propylene by means of a Ziegler-Natta catalyst system from (1) a titanium component made of titanium, magnesium, chlorine, a phthalic acid derivative and optionally other components, optionally applied to a support, (2) an aluminum alkyl and (3) a silicon compound as a cocatalyst. Characteristic is that as (3) a silicon compound of the composition (C 2n-1 H 4n-1 ) x Si (OR) 4-x is used, where R is a hydrocarbon radical, n from 1 to 5 and x from 1 to 3rd |