| 摘要 |
The invention relates to a process for the preparation of finely divided polymers of alpha -monoolefins by polymerisation in liquid i-butane - in which the monomer to be polymerised is in dissolved form and the finely divided polymer formed is in suspended form - by means of a Ziegler catalyst system comprising 1) a vanadium-containing catalyst component and 2) a metal compound carrying hydrocarbon groups, characterised in that the vanadium-containing catalyst component 1) is the solid-phase product (VII) obtained by 1.1) first bringing 1.1.1) a finely divided, porous, inorganic oxide (I) having a certain specification and 1.1.2) a solution (II) as obtained on combining (IIa) a lower alcohol and (IIb) a vanadium trihalide, into contact with one another to form a dispersion (III), and evaporating this dispersion to a dry consistency - formation of a solid-phase intermediate (IV) - and 1.2) then 1.2.1) bringing the solid-phase intermediate (IV) obtained from step 1.1) and 1.1.2) an aluminium compound (V) having hydrocarbon groups dissolved in an organic solvent into contact with one another to form a dispersion (VI), and in this way isolating, with the solid-phase product (VII) resulting as the dispersed components, the novel vanadium-containing catalyst component 1). This is distinguished, inter alia, by the fact that it is capable of giving polymers having particularly good morphological properties.
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