| 摘要 |
The instant invention pertains to a process for preparing an ethylene homo- or copolymer in the presence of a supported chromium catalyst by slurry loop polymerization or copolymerization, whereby the resulting polymer powder has an increased powder density, in which the supported chromium catalyst has a chromium content of from 0.01 to 5 wt.-%, based on the element in the finished catalyst, and shows a particle size distribution measured according to ISO 13320-2009 comprising two main fractions one of which having a d 50 of from 15 to 40 µm and the other having a d 50 of from 45 to 80 µm said catalyst being further characterized by the fact that less than 10% wt of its catalyst particles has diameter lower than 20 µm. |
