摘要 |
The area is the polymerization of ethylene by Phillips catalysis using (1) a supported catalyst containing chromium, phosphorus and aluminium, and (2) a cocatalyst comprising an alkyllithium, (1) having been obtained by (1.1) preparing a catalyst precursor containing chromium, phosphorus and aluminium from a silicate support, a selected chromium compound, a selected phosphorus compound and a selected aluminium compound, and then (1.2) heating the catalyst precursor in an oxygen-containing gas stream. It is a characteristic of the process that (1) has been obtained by - in each case specifically in the type and manner - first preparing (1.1) by (1.1.1) preparing a suspension first from (1.1.1.1) a finely divided silicate support and (1.1.1.2) an inert organic solvent, (1.1.2) then combining (1.1.2.1) an organochromium compound in an inert organic solvent (1.1.2.2) with (1.1.2.3) a trialkyl aluminium compound (1.1.3) then combining (1.1.3.1) the suspension resulting from (1.1.1) with (1.1.3.2) a phosphoric or phosphorous acid ester and (1.1.3.3) the product obtained from (1.1.2), finally (1.1.4) evaporating the suspension obtained in (1.1.3) to dryness, and then, secondly, (1.2) first (1.2.1) treating the precursor obtained from (1.1) with a stream of nitrogen, then (1.2.2) heating the intermediate obtained from (1.2.1) in an oxygen-containing gas stream, and (1.2.3) treating the intermediate obtained from (1.2.2) with a stream of nitrogen, and finally (1.3) suspending the product obtained from (1.2.3) in (1.3.1) an organic solvent and then (1.3.2) reacting it with an alkylboron compound, and (2) is an alkyllithium compound. |