Process for the preparation of homopolymers and copolymers of propene by means of a Ziegler-Natta catalyst system

摘要

The invention relates to the preparation of polymers of propene by means of a Ziegler-Natta catalyst system comprising (1) a titanium component based on a finely divided, shape-providing silica gel and containing magnesium, chlorine and a benzenecarboxylic acid derivative in addition to titanium, (2) an aluminium component and (3) a silane component, characterised in that a titanium component (1) is used which is obtained by (1.1) first (I) preparing a support material from (Ia) a silica gel, (Ib) an organomagnesium compound and (Ic) a gaseous chlorinating agent by (1.1.1) at first reacting (Ia) with (Ib), (1.1.2) then passing (Ic) into the product from (1.1.1) and isolating (I), (1.2) then preparing a solid-phase intermediate from (I), (II) an alkanol, (III) titanium tetrachloride and (IV) a phthalic acid derivative by (1.2.1) first reacting (I) with (II), (1.2.2) subsequently introducing (III) into the product from (1.2.1), with the proviso that (IV) is also introduced during (1.2.1) or (1.2.2), (1.3) then extracting the solid product from (1.2) with titanium tetrachloride or a mixture of titanium tetrachloride and ethylbenzene, and (1.4) finally washing the solid product from (1.3) with a liquid hydrocarbon.