摘要 |
A process for the preparation of homopolymers and copolymers of alpha -monoolefins by means of a Ziegler-Natta catalyst system comprising (1) a halide of trivalent titanium, (2) an oxygen compound (ester) having a specific formula and (3) an aluminum-alkyl, the titanium halide (1) and the oxygen compound (2) being milled together before use, wherein the catalyst system employed contains, as a further component, (4) a phenolic compound of the formula <IMAGE> where R3 is C1-C6-alkyl, R4 is hydrogen or C1-C6-alkyl, p is an integer from 0 to 5 and q is an integer from 1 to 5. |