Patent GB-976097-A (GB)
Title: Process for producing a reduced transition metal halide,polymerization catalysts containing it and process for the polymerization of ª-olefins with such catalysts
IPC: C08F4/64
Filed: 1961-11-23
Abstract: A reduced transition metal halide is produced by reacting a transition metal halide, i.e. the chloride, bromide or iodide of titanium, zirconium, vanadium, molybdenum or chromium, the metal of which is exhibiting its maximum valency, with a reducing metal selected from beryllium, magnesium, zinc, calcium, strontium, barium, indium, thallium, aluminium and gallium, to form a halide of such metal, the reaction being carried out in the presence of a complexing agent which forms with such metal halide a complex which is soluble in the complexing agent.  The complexing agents may be diaryl ethers, amides, ketones, carboxylic esters, phenols or alkyl phenols, nitro-containing compounds and nitrile-containing compounds, organosulphur compounds or organophosphorus compounds.  The preferred transition metal halide is titanium tetrachloride and the preferred reducing metal is aluminium which may be employed in the form of a metal alloy, e.g. with magnesium. In a preferred embodiment 0.9 to 2 times the stoichiometric quantity of aluminium required to reduce the titanium tetrachloride to the trichloride in accordance with the equation Al+3TiCl4-->Alcl3+3TiCl3, is used, diphenyl ether being the reaction medium.  The aluminium trichloride formed complexes with the diphenyl ether and this complex can be removed by filtering the hot reaction mixture, leaving behind solid titanium trichloride which may be used as a catalyst component for polymerizing alpha-olefines.  In the titanium tetrachloride reduction reaction 1 to 30% mol. of the titanium tetrachloride may be replaced by one of the other transition metal halides. In Example 1, titanium tetrachloride is reduced with aluminium powder in the presence of anhydrous aluminium trichloride and a eutectic mixture of diphenyl ether and biphenyl.ALSO:Crystalline polymers of alpha-olefines are formed using a catalyst containing a reduced transition metal halide formed by reacting a transition metal halide, i.e. the chloride, bromide or iodide of titanium, zirconium, vanadium, molybdenum or chromium, the metal of which is exhibiting its maximum valency, with one of the following reducing metals: beryllium, magnesium, zinc, calcium, strontium, barium, indium, thallium, aluminium or gallium, to form a halide of such metal, the reaction being carried out in the presence of a complexing agent which forms with such metal halide a complex which is soluble in the complexing agent.  The complexing agents may be diaryl ethers, amides, ketones, carboxylic esters, phenols or alkyl phenols, nitro-containing compounds and nitrile-containing compounds, organosulphur compounds or organophosphorus compounds. The preferred transition metal halide is titanium tetrachloride, however, from 1 to 30 mole per cent of the TiCl4 can be replaced by another transition metal halide and the preferred reducing metal is aluminium which may be employed in the form of a metal alloy.  In the polymerization reaction the reduced transition metal halide is used in conjunction with at least one component selected from (a) a metal from Group Ia, II and IIIa, Large's Periodic Table, alkyl and hydride derivatives of such metals and complex metal hydrides of aluminium and alkali metal, (b) organoaluminium halides RmAlXn and R3Al2X3 where R is a lower alkyl, cycloalkyl, phenyl or tolyl radical, X is chlorine or bromine and "m" and "n" are integers whose sum equals the valence of aluminium; (c) a polymeric reaction product of aluminium and a methylene halide.  Monomers specified are propylene, butenes, styrene, 3-methyl -1- butene, 4-methyl -1- pentene, allylbenzene and vinylcyclohexane.