GB877050A - Improvements in and relating to the polymerisation of olefines, catalysts for such polymerisation, crystalline materials suitable as components of the catalysts and processes for their preparation - Google Patents

Abstract

A crystalline material of aluminium, titanium and chlorine in which the titanium is substantially all in the trivalent state and the atoms of Al, Ti and Cl are present generally in proportions of 1 : 3 : 12, obtained by heating titanium tetrachloride with aluminium, (see Group III) may be employed as a component of a catalyst for the polymerization of olefines by mixing the crystalline material with an organo-metallic compound of aluminium having at least one hydrocaron radical attached to the aluminium atom, any remaining valencies being satisfied by hydrogen or halogen; the hydrocarbon radical may be alkyl, alkenyl, alkynyl, cycloalkyl, aryl or aralkyl. The organo-metallic compound and the crystalline material may be mixed in mole ratios from 1 : 10-10 : 1 and preferably from 1 : 1-4 : 1. Polymerization of ethylene and alpha olefines, e.g. propylene, butene-1 and styrene, may be effected at temperatures up to 300 DEG C. and generally from 20 DEG -100 DEG C. under pressures from 1-50 atmosphere absolute whereby the olefine may be maintained in the liquid phase. The reaction may be effected in the presence of an inert solvent which may be paraffinic, aromatic or alicyclic. According to Examples (1) powdered aluminium was refluxed with titanium tetrachloride and petroleum ether together with a small amount of fresh aluminium chloride after which petroleum ether and excess titanium tetrachloride were distilled off and the solid heated at 200 DEG C. under a pressure of 1 mm. of H9 absolute to remove remaining titanium tetrachloride. The pale purple powder resulting was suspended in petroleum ether and reacted with aluminium tripropyl at 80 DEG C. after which propylene was passed in at the same temperature. Methanol was then added and the precipitated powdery polypropylene was filtered off and boiled with methanolic hydrochloric acid to give a crystalline polymer containing less than 0,1% of ash. Methyl cyclohexane may be substituted for the petroleum ether diluent of Example 1. (3) Aluminium powder was refluxed with titanium tetrachloride in the presence of a small amount of aluminium chloride and excess titanium tetrachloride was finally driven off to leave a pale purple powder which was ball-milled before incorporation with the organo-metallic compound as in Example 1. Propylene was passed in at temperatures rising to 92 DEG C., then, after cooling, methanol was added to deactivate the catalyst. The crude polymer was filtered hot and boiled with methanolic hydrochloric acid. (4) Aluminium triethyl, dissolved in methyl cyclohexane, was added to benzene and the crystalline material of Example 3, after ball-milling, was introduced as a slurry in benzene; propylene was passed in at a temperature rising to 57 DEG C. whereby a polymer of which 22% was soluble in ether was obtained. Specifications 811,633 and 813,797 are referred to.ALSO:A crystalline material of aluminium, titanium and chlorine in which the titanium is substantially all in the trivalent state and the atoms of Al, Ti and Cl are bound together in crystal lattices and present, generally, in proportions of 1:3:12, is obtained by heating titanium tetrachloride with aluminium, preferably in the presence of an aluminium halide, and then separating from the reaction product unreacted titanium tetrachloride. The titanium tetrachloride is preferably present in amount sufficient to react with all the aluminium and the reaction is generally effected at 100-137 DEG C. A hydrocarbon diluent may be employed; for example the reaction may be effected under reflux in the presence of petroleum ether having a boiling point of at least 100 DEG C., or methyl cyclohexane. The crystalline material is stable at 250 DEG C. at 1 mm. absolute pressure and the removal of excess titanium tetrachloride reactant, for example by distillation, should not be effected above such a temperature. The crystalline material may be employed as a component of a catalyst for the polymerization of olefines by mixing the crystalline material with an organo metallic compound of aluminium having at least one hydrocarbon radical attached to the aluminium atom, any remaining valencies being satisfied by hydrogen or halogen; the hydrocarbon radical may be alkyl, alkenyl, alkynyl, cycloalkyl, aryl or aralkyl. The organo metallic compound and the crystalline material may be mixed in mole ratios from 1:10 to 10:1 and preferably from 1:1 to 4:1. Polymerization of ethylene and alpha olefines, e.g. propylene, butene-1 and styrene, may be effected at temperatures up to 300 DEG C. and generally from 20-100 DEG C. under pressures from 1-50 atmosphere absolute, whereby the olefin may be maintained in the liquid phase. The reaction may be effected in the presence of an inert solvent which may be paraffinic, aromatic or alicyclic. According to Examples (1) powdered aluminium was refluxed with titanium tetrachloride and petroleum ether together with a small amount of fresh aluminium chloride; petroleum ether and excess titanium tetrachloride were then distilled off and the solid heated at 200 DEG C. under a pressure of 1 mm. of Hg absolute to remove remaining titanium tetrachloride. The pale purple powder resulting was suspended in petroleum ether and reacted with aluminium tripropyl at 80 DEG C., after which propylene was passed in at the same temperature. On cooling methanol was added and the precipitated powdery polypropylene was filtered off and boiled with methanolic hydrochloric acid to give a crystalline polymer containing less than 0.1% of ash. Methyl cyclohexane may be substituted for the petroleum ether diluent. (3) Aluminium powder was refluxed with titanium tetrachloride in the presence of a small amount of aluminium chloride and excess titanium tetrachloride was finally driven off to leave a pale purple powder which was ball-milled before incorporation with the organo-metallic compound as in Example 1. (4) Aluminium triethyl dissolved in methyl cyclohexane was added to benzene and the crystalline material of Example 3, after ball-milling, was introduced as a slurry in benzene; propylene was passed in at a temperature rising to 57 DEG C., whereby a polymer of which 22% was soluble in ether was obtained. Specifications 811,633 and 813,797 are referred to.