| 摘要 |
<p>The present invention provides an improved chromium oxide based catalyst supported on a granular or microspherical refractory oxide for the gas phase polymerisation of at least one alpha olefin containing from 2 to 12 carbon atoms, characterised in that the supported chromium oxide based catalyst has been subjected to a sole calcination/activation step consisting of a single thermal treatment performed at a temperature ranging from 200 to 450 °C under an oxygen- containing atmosphere.</p> |
