摘要 |
<p>There are disclosed new solid catalyst-forming components for use in preparing catalysts for the stereoregular polymerization of alpha-olefins containing at least 3 carbon atoms, mixtures of alpha-olefins with one another and/or with ethylene, said components being obtained by reacting (a) at least one hydrocarbon-soluble halogenated Ti compound; (b) a product comprising a Mg dihalide obtained by decomposition of an adduct of at least a Mg dihalide and an electron-donor compound present in the adduct in an amount of at least 0.5 mole per mole of Mg dihalide, the decomposition product being characterized in that, in its X-rays powder spectrum, instead of the diffraction line of maximum intensity which appears in the X-rays powder spectrum of the normal Mg dihalide, a halo appears whose intensity maximum is shifted with respect to said line, and (c) an electron-donor compound which does not contain active hydrogen atoms. The electron-donor compound (c) can be reacted with (a) or combined with (b) before the reaction of (a) and (b). Methods for preparing the new catalyst-forming components, catalysts obtained therefrom, and use of the catalysts for the production of crystalline homo- and co-polymers of the alpha-olefins are also disclosed.</p> |