Powdered polyolefin prodn. using catalysts contg. vanadium cpds. - reacted with and activated by organo-aluminium cpds.

摘要

Powdered polyolefin having high apparents density, good fluidity, an ave. particle size diameter of up to 100 mu m and being almost free from very fine particles, are obtd. by polymerising ethylene opt. admixed with other 1-olefines, in the presence of H2, in inert liq. hydrocarbons at 50-95 degrees C 10-100 bars, pref. 20-60 bars pressure, in a continuous or discontinuous process using Ziegler catalysts. The catalysts are prepd. in the inert liq. hydrocarbon by reacting vanadyl cpds. contg. Cl atoms and alkoxy gp. with organo-Al cpds., sepg. the insoluble reaction prod. and activating with any organo-Al cpd. The powdered polyolefins obtd. i.e. polyethylene, copolymers of ethylene and propylene and/or butylene-(1) have apparent densities of 0.420-0.550 g/ml, are almost free from fine particles forming dust and are partic. suitable for injection and extrusion moulding e.g. tubes, sheets, hollow bodies etc. The molten prod. because of its compact granular structure is almost free from bubbles. The catalyst has long life and high productivity.