GB830742A - Polymerisation process - Google Patents

Abstract

Catalysts for the polymerization of ethylene (see Group IV (a)) are formed by mixing lithium borohydride with a titanium, zirconium or vanadium halide, e.g. a chloride such as the tri- or tetra-chloride, and preferred molar ratios are specified. The catalyst formation is preferably effected in an inert medium such as pentane, hexane, cyclohexane, tetrahydronaphthalene, decahydronaphthalene, paraffins, benzene, xylene, dichlorobenzene, chlorinated naphthalene, petroleum ether or mixtures thereof. After polymerization the catalysts may be destroyed with ethanol, hydrochloric acid or ethanolic hydrochloric acid. Specification 827,464 also is referred to.ALSO:Ethylene is polymerized with a catalyst formed by mixing lithium borohydride with a titanium, zirconium or vanadium halide, e.g. a chloride such as the tri- or tetrachloride, and preferred molar ratios of the catalyst components are specified. The catalyst formation and the polymerization are preferably effected in the absence of oxygen, carbon dioxide and water and desirably in an inert medium such as pentane, hexane, cyclohexane, tetrahydronaphthalene, decahydronaphthalene, the higher paraffins, benzene, xylene, dichlorobenzene, chlorinated naphthalene, sodium dried petroleum ether or mixtures thereof. The polymerization may be batchwise or continuous and optionally the catalyst may be formed in situ. In examples ethylene is added intermittently, and catalysts are destroyed and the products purified with ethanol, hydrochloric acid or ethanolic hydrochloric acid. The products are linear and may be formed into films, fibres or moulded articles. Specification 827,464 also is referred to.