GB948620A - Improvements in polymerisation and catalyst therefor - Google Patents

Abstract

An anhydrous titanium-containing composition in which more than 50 wt. per cent of the titanium is in the trivalent state is made by heating a mixture of TiCl4, an organic solvent therefore and metallic aluminium until the reaction is complete and thereafter cooling to cause separation of the composition. In Examples 1 and 2, the solvent is kerosene or mineral spirits and block homogeneous crystals were obtained in which the Ti values were essentially trivalent, the product being characterized by an X-ray diffraction pattern.ALSO:A polymerization catalyst system for ethylenically unsaturated monomers is prepared by forming an anhydrous titanium-containing composition in which more than 50 wt. per cent of the titanium is in the trivalent state by heating a mixture of TiCl4, or organic solvent therefor and A1 until the ensuing reaction is substantially complete and cooling to cause separation of said composition, the latter then being mixed with one or more organo-compounds of A1 or of a metal of Groups IA, IIB, IIIB, Specified ethylenically unsaturated hydrocarbon monomers which may also be copolymerized are ethylene, propylene, butene-1, pentene-1 and 4-methylpentene-1. In examples, propylene is polymerised with said catalyst system the organo metallic compound being aluminium tri-methyl, -ethyl or i-butyl, lithium n-butyl, sodium n-or i-aryl, or cadmium diphenyl (optionally mixed with cadmium diethyl); 4-methylpentene-1 is polymerized, the organometallic compound being isobutyl aluminium.