GB865317A - A process for the polymerisation of ethylenically unsaturated hydrocarbons - Google Patents

Abstract

Olefins are polymerized in the presence of a three-component catalyst as in the parent Specification, except that a solid titanium chloride component is used in place of the titanium tetrachloride, the other components being an alkali metal and aluminium trichloride. The solid titanium chloride may be the dichloride, trichloride or a mixture and the alkali metal may be sodium or potassium. Titanium tetrachloride may also be present as a further catalyst component in a quantity up to 50 mol per cent of the titanium chloride used. The solid titanium chloride may be prepared by reduction of the tetrachloride with, e.g. hydrogen and organo-aluminium compounds. The olefin may be ethylene, propylene, butylene, isoprene, butadiene or alkenyl benzeners such as styrene and copolymers of these may be made. The polymerization is preferably carried out in a liquid such as heptane or octane and in the presence of a finely-divided substance such as the halides of alkali and alkaline earth metals, powdered carborundum, glass and sand or preformed polymers. Specification 820,965 also is referred to.ALSO:A catalyst for use in the polymerization of olefins comprises the reaction product of aluminium trichloride and an alkali metal and a solid titanium chloride component in the form of a suspension in an organic solvent, such as heptane. The solid titanium chloride may be the dichloride or trichloride or a mixture thereof, and the alkali metal may be sodium or potassium. Titanium tetrachloride may be present as a further catalyst component in a quantity up to 50% mol. of the titanium chloride used. To reduce titanium tetrachloride to TiCl3 and/or TiCl2, there may be used in organic media aluminium alkyls, aluminium halogen alkyls (e.g. aluminium diethyl monochloride) or the reaction product of aluminium trichloride and an alkali metal. Resultant precipitates may be separated and eluted, e.g. with heptane. The molar ratio of alkali metal to AlCl3 is preferably between 0.1:1 and 1.5:1 and the alkali metal may be in the form of an alloy. There may also be incorporated into the catalyst suspension a finely-divided inert substance such as the halides of the alkali metals and alkaline earth metals, powdered carborundum, glass, sand or preformed polymers. Specification 820,965 is referred to.