| 摘要 |
<p>A process is provided for preparing polyolefins using a new catalyst. According to this invention, .alpha. -olefins can be polymerized or copolymerized in good stereoregularity and in high activity by the use of such new catalyst. The new catalyst broadly consists of ¢A! a solid component obtained by contacting (1) a magnerium oxide, (2) an aluminum trihalide, the aluminum trihalide being used in an amount of 0.001 to 10 mol of the magnesium oxide, (3) a hydroxy compound represented by the general formula ROH wherein R is an organic radical having 1 to 20 carbon atoms, the hydroxy compound being used in an amount of 0.001 to 5 mols per mol of the magnesium oxide, and (4) a titanium halide and/or an addition product of a titanium halide and an aromatic carboxylic acid ester, the total amount of the aromatic carboxylic acid esters present in the catalyst system being not smaller than 0.05 mol based on the amount of magnesium (gram-atom) prosent in the catalyst system, the titanium content of the resulting wild compound being in the range of from 0.5 to 10% by weight and ¢B! an organometallic compound and.or an addition product of an organometallic compound and an aromatic carboxylic acid ester, the organometallic compound being an organoaluminum compound or an organozinc compound, the organometallic compound being used in an amount of 0.1 to 1000 mols per mol of titanium halide.</p> |
