Process for preparing a Ziegler-Natta type catalyst.

摘要

The present invention relates to a process for the preparation of a catalyst of the Ziegler-Natta type comprising precipitating titanium onto a spheroidal magnesium chloride support. This process comprises (a) contacting a magnesium chloride support (A) with an electron-donor compound (B) which contains labile hydrogen, (b) contacting the support of (a) with an organometallic compound (C) which is a reducing agent for titanium, (c) washing the product of (b) with a liquid hydrocarbon and (d) contacting the product of (c) with at least one titanium compound and possibly with at least one vanadium compound used in such quantity that the molar ratio of the quantity of titanium to the quantity of vanadium is greater than 1.