Catalyst for ethylene polymerisation - by reacting magnesium allyl chloride and dialkyl ether, ageing, treating with dialkyl sulphite and reacting with titanium chloride

摘要

High density ethylene homo- and copolymers are prepd. by polymerising ethylene, opt. together with up to 10 mole % 3-6C olefin, in a hydrocarbon medium, at 4-40 atmos. and 60-100 degrees C., opt. in the presence of hydrogen, using a solid catalyst activated by an alkyl-aluminium cpd. The solid catalyst is prepd. by (a) reacting 1 g. atom magnesium with at least 2, esp. 2.2-10 moles allyl chloride, and 1.75-3 moles dialkyl ether at 30-100 degrees C., (b) ageing the solid prod. for at least 10, esp. 24-150 hrs., at 30-140 esp. 50-80 degrees C., (c) treating the aged prod. with at least 0.2, esp. 0.7-4 moles dialkyl sulphate per g. atom Mg, (d) reacting with 0.5-10, esp. 1-5 moles Ti TiClx(OR)y (where x is 2-4; y is 0.2; x + y is 4; and OR is a group derived from an alkylene oxide) for 1-25 hrs. at -20 to +140 degrees C., and (e) recovering the solid prod.