Verfahren zur Polymerisation von Olefinen unter Verwendung von Koordinationskatalysatoren

摘要

Polymerization catalysts are prepared by reacting aluminium trisalkenyls of formula wherein each of R1, R2 and R3 is hydrogen or a hydrocarbon radical, wherein any two R groups may be cyclised and at least one R is a hydrocarbon radical with transition metal halides, especially those of metals of Group IVa, Va and VIa such as titanium, zirconium, vanadium, chromium, molybdenum and tungsten. Preferred halides are chlorides, bromides, oxyhalides and alkoxyhalides. The catalyst may be formed in the presence of a hydrocarbon diluent. The preferred molar ratio of reactants is 0.5 to 10 of aluminium trisalkenyl to 1 of transition metal halide.ALSO:The invention comprises organometallic aluminium compounds free of conjugated, non-aromatic unsaturation and having the formula wherein each of R1, R2 and R3 is hydrogen or a hydrocarbon radical, wherein any two R groups may be cyclized and at least one R is a hydrocarbon radical. Compounds specified are trisdihydromyrcenyl aluminium, trisdihydrophellandryl aluminium and trisdihydro-2-phenyl-butadienyl aluminium. They may be prepared (a) by reacting the corresponding alkenyl halide with an aluminium magnesium alloy; (b) by reacting aluminium hydrides or lithium aluminium hydrides with the corresponding diolefin, the aluminium alkenyl being obtained from the lithium aluminium alkenyl by reaction with aluminium chloride; (c) by reacting unoxidized finely-divided aluminium with hydrogen and the corresponding diolefin in the presence of an aluminium trialkyl; and (d) by exchange reaction between aluminium trialkyl and a diolefin. The compounds of the invention may be used in the polymerization of ethylene (see Groups III and IV(a)).ALSO:Ethylene is polymerized in the presence of a catalyst (see Group III) prepared by reacting a halide, oxyhalide or alkoxyhalide of a group IVa, Va or VIa of the Periodic Table with an aluminium trialkenyl of formula where each of R1, R2 and R3 is hydrogen or a hydrocarbon radical, wherein two R substituents may be cyclized, and at least one R is a hydrocarbon radical. Two substituents may be cyclized to form a ring structure. Aluminium trialkenyls specified include trishydromyrcenyl aluminium, trisdihydrophenandryl aluminium and trisdihydro - 2 - phenyl butadienyl aluminium (see Group IV (b)]