| 摘要 |
PURPOSE:To obtain a highly stereoregular polypropylene by gas phase polymerization in high yield by the use of a catalyst in the preliminary polymerization of liquid propylene. CONSTITUTION:First, a preliminary polymerization of liquid propylene is carried out in the presence of a catalyst consisting of a titanium halide, an organoaluminum compound, and a third component (e.g., an electron-donating compound), until approximately>=1,000 (pref.>=5,000) parts by wt, per 1 part by wt. of the titanium atom in the catalyst, of polypropylene are produced, followed by continuing main polymerization in a gas phase to obtain the objective polypropylene. Said prelimimary polymerization is recommended to be performed at-20-80 deg.C (pref. 20- 40 deg.C) for <=2 hrs. in the presence of the catalyst in an amount of 0.001-0.2g (as titanium atom) per 1l of liquid propylene. |
