| 摘要 |
<p>In the prepn. of a mixed catalyst for the polymerisation of 1-olefins of formula R3-CH=CH2, (I), (where R3 is 1-8C alkyl) by modifying an Mg halide with an electron donor and/or a cyclopolyene, contacting the modified carrier (II) obtd. with a Ti halide and mixing the catalyst component prepd. with an organic Al cpd. and a stereoregulator; improvement consists of washing the modified carrier (II) with a liq. hydrocarbon (III) at 50-150 degrees C., before contacting with the Ti halide. The catalyst is used for homo-polymerising (I) or for co-polymerising (I) with one another and/or with 6 wt.% C2H4 or for block polymerising (I) with one another and/or with 35 wt.% C2H4. The polymers contain a high isotactic proportion. Washing step increases catalyst activity, reduces fine grain proportion and increases polymer yield.</p> |
