| 摘要 |
<p>The invention provides a process for producing polypropylene and/or random copolymers of propylene type using a stereoregular catalyst which comprises a titanium-containing solid catalyst component (A), an organoaluminum compound (B) and if required an organosilicon compound (C), wherein ÄIÜ before carrying out homopolymerization of propylene or random copolymerization of propylene with an alpha -olefin other. than propylene, the above component (A), an organoaluminum compound (B') and if required an organosilicon compound (C') are used, and a small amount of propylene or ethylene and/or an alpha -olefin of 4 - 20 carbon atoms for pre-activation treatment is supplied to the above component (A), and ÄIIÜ a catalyst which is prepared by adding an organosilicon compound (C") to the pre-activated stereoregular catalyst in a molar ratio of 0.1 - 50 as Si/Ti, is used to produce polypropylene (propylene homopolymer) or propylene random copolymers (propylene- alpha -olefin random copolymers) with lesser formation of lump and string-like irregular shape polymers. <IMAGE></p> |
