| 摘要 |
<p>A process for preparing a catalyst component, comprising a Mg compound a Ti compound and an electron donor compound (ED) selected from alcohol, glycols, esters, ketones, amines, amides, nitriles, alkoxysilanes and aliphatic ethers as essential compounds, comprising two or more steps of reaction involving the use of at least one of said essential compounds as fresh reactant alone or in a mixture in which it constitutes the main component, said process being characterized by the fact that in the last of said one or more reaction steps the essential compound used as a fresh reactant is the ED compound.</p> |
