GB817308A - Novel catalyst composition, preparation and use thereof - Google Patents

Abstract

A catalyst for the polymerization of olefins comprises (i) an organo-metallic compound of a metal of Group IIIb, e.g. tri-ethyl aluminium, (ii) a halide of a metal of Groups IVa, Va, VIa, VIIa or VIII, e.g. titanium tetrachloride, and (iii) a chlorine-substituted organic compound, e.g. carbon tetrachloride or trichloroethylene. The catalyst is prepared by independently adding the organo-metallic compound and the inorganic metal halide to the chlorine-substituted organic compound in the absence of air and moisture, whereby a red liquid complex is formed. A stable liquid catalyst is obtained by also having a hydrocarbon, e.g. hexane, present when the starting materials are independently mixed. The presence of the hydrocarbon is unnecessary when the chlorine-substituted organic compound is carbon tetrachloride. Preferred chlorine-substituted organic compounds may be aliphatic or aromatic and include methylene dichloride, chloroform, carbon tetrachloride, trichloroethylene, tetrachloroethylene, tetrachloroethane, pentachloroethane and chlorobenzene. Some preferred metal compounds of Group IIIb are trimethyl aluminium, triethyl aluminium, tri-isobutyl aluminium, aluminium tri-n-hexyl, trimethyl indium, diethyl aluminium fluoride, ethyl aluminium dihydride. The preferred inorganic metal chlorides are titanium tetrachloride, zirconium tetrachloride and ferric chloride. The polymers produced by the catalysts may be derived from substituted or unsubstituted olefins including vinyl compounds and organic compounds having at least one ethylenic carbonto-carbon double bond, including both acyclic and alicyclic compounds.ALSO:Vinyl-type compounds, i.e. compounds having at least one ethylenic carbon-to-carbon double bond, including both acyclic and alicyclic compounds, are polymerized at a temperature of -100 DEG to 200 DEG C., preferably at -20 DEG to 100 DEG C., in the presence of a catalyst comprising (i) an organo-metallic compound of a metal of Group IIIb, e.g. tri-ethyl aluminium, (ii) a halide of a metal of Groups IVa, Va, VIa, VIIa or VIII, e.g. titanium tetrachloride, and (iii) a chlorine-substituted organic compound, e.g. carbon tetrachloride or trichlorethylene (see Group III). The catalysts are liquid and stable, although stability may be further improved by adding n-hexane. Hence polymerization may be effected in a homogeneous liquid phase and so is easier to control, can be carried out in a simplified apparatus, and the polymer does not become occluded within the catalyst and may be freed from catalyst by simple washing. Vinyl-type compounds which may be polymerized include aliphatic mono-olefins of up to 20 DEG C. atoms, e.g. ethylene, aliphatic polyolefins such as conjugated dienes, e.g. butadiene, halogen-substituted olefins, e.g. vinyl chloride, alkoxy and aryl substituted olefins, e.g. vinyl ethly ether, and monomers containing any combination of halogen, alkoxy and aryl substituents, e.g. phenyltrifluoroethylene. The polymerization is preferably carried out between -20 DEG and 65 DEG C., under pressures of 1-1000 atmospheres and ethylene may be polymerized at room temperature and atmospheric pressure by simply passing it through the catalyst in an open vessel. Examples describe the polymerization of: (Ex. 2-4) trifluorochloroethylene, (Ex. 11) ethylene, (Ex. 12) propylene, (Ex. 14) isobutylene, (Ex. 15) 2-olefins, (Ex. 16, 17) copolymerization of ethylene and propylene, (Ex. 18) butadiene-1,3, (Ex. 19) vinyl chloride, (Ex. 20) styrene, (Ex. 21) vinyl isobutyl ether, (Ex. 22, 23) ethylene, (Ex. 24) 1,1,3-trifluorobutadiene.