GB829440A - Polymerisation catalysts - Google Patents

Abstract

A polymerization catalyst comprises the reaction product of a Group IV-VI transition metal compound with LiAOR, wherein aliphatic unsaturation is absent, A is a divalent aromatic hydrocarbon radical (preferably phenylene) and R is a monovalent hydrocarbon radical (preferably methyl or ethyl). The metal compound is preferably a halide, particularly a chloride of, preferably, titanium or vanadium, especially TiCl4. The catalyst is preferably prepared in a hydrocarbon solvent (possibly containing ether as impurity), such as benzene or its homologues, or a petroleum fraction. Etheroid monomers polymerized are, e.g., ethylene, vinyl chloride and styrene. The catalyst may be prepared in presence of the monomer as solvent. It is stated that Friedel-Crafts halides or boron halides may be added to the above catalyst. In examples, the metal compounds specified are TiCl3, TiCl4, VCl4 and CrCl3.ALSO:Compounds of formula LiAOR (where A is a divalent aromatic hydrocarbon radical, R is a monovalent hydrocarbon radical and the oxygen atom is attached to at least one aromatic carbon atom) are prepared by reaction of compounds ROAX (X=halogen, preferably Br) with Li, either in (a) diethyl ether, or (b) a hydrocarbon solvent (e.g. benzene or its homologues or a petroleum fraction), possibly adding small quantities of ether or tertiary amine to initiate the reaction. Specifically mentioned are p-methoxy- and p-ethoxy-phenyl lithium, prepared by reacting lithium with p-bromonisole and p-bromophenetole respectively.ALSO:Etheroid monomers, e.g. ethylene, vinyl chloride and styrene, are polymerized by use of a catalyst which comprises the reactive product of a Group IV, VI transition metal compound (preferably a halide, particularly a chloride of, preferably Ti or V, especially TiClx) with LiAOR, wherein aliphatic unsaturation is absent, A is divalent hydrocarbon radical (preferably phenylene) and R is a monovalent hydrocarbon radical (preferably methyl or ethyl). The solvent used in catalyst preparation may be, e.g. benzene or homologues, a petroleum fraction, or the monomer itself. It is stated that Friedel-Crafts halides may be added to the above catalyst. The polymers are purified by the use of a hydroxyl compound, e.g. water, team or an alcohol such as methanol or butanol.