| 摘要 |
Prepn. of a Ziegler-Natta type catalyst based on a Ti cpd. pptd. by redn. of Ti on a Mg chloride based support (ii) includes an impregnation step comprising contacting the support with an electron donor cpd. (D3) which is free from labile hydrogen. Before the process (ii) may be heated to higher than 40 deg.C in a liq. hydrocarbon contg. less than 0.1 wt. % D1, to extract part of D1. The process may have the steps (qa) contacting (ii) with D3 (b) contacting (ii) with an organometallic cpd. (c) contacting possibly washed (ii) with Ti cpd(s). The process may have the additional step of contacting (ii) with an electron donor (D2). D3 is pref. a linear or cyclic polyfunctional cpd. or a cyclic monofunctional cpd. (ii) may contain an electron donor cpd. (D1) where (ii) is prepd. with a ppte. reaction between a dialkyl magnesium and an organic chloride in the presence of D1. D3 has a higher complexing power towards Mg chloride than D1. D2 contains a labile hydrogen.
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