GB814837A - Improvements in the production of polymers from olefinically unsaturated hydrocarbons - Google Patents

Abstract

A crystalline catalyst suitable for use in the polymerization of olefinically unsaturated hydrocarbons is made by reacting aluminium with a titanium halide in the presence of a halogen-containing aliphatic compound and optionally aluminium chloride and/or a halogen such as chlorine, bromine, or iodine, or a halogen hydracid e.g. hydrochloric acid. The reaction may be carried out at temperatures between room and 100 DEG C. After the reaction any excess halogen compound is distilled off and the catalyst separated with the aid of an organic precipitant such as dimethylcyclohexane. Specified titanium halides are the tetrachloride, tetrabromide, and trichloride. The halogen-containing compound may be ethyl chloride or bromide, propyl or butyl chloride, methylene chloride, ethylene chloride, ethylene bromide, chloroform, trichlorethane, or carbon tetrachloride. In the preparation of the catalyst generally 1 mol. of titanium halide is reacted with 2 to 8 mols. of aluminium and the aluminium chloride when present is used in an amount up to 5 times the amount of the halide. Specification 781,837 is referred to.ALSO:Olefinically unsaturated hydrocarbons are polymerized, e.g continuously in the absence of any halogen-containing aliphatic compound in the presence of a catalyst obtained by the reaction of aluminium with a titanium halide in the presence of a halogen-containing aliphatic compound and optionally aluminium chloride, and/or a halogen or halogen hydracid. In the preparation of the catalyst any excess halogen compound is removed. Hydrocarbons mentioned are ethylene, propylene, butylene, isobutylene, and mixtures, and butadiene, isoprene, and styrene. The polymerization may be effected in the presence of diluents such as pentane, octane, cyclohexane, gasoline, or aromatic hydrocarbons, and at temperatures between - 120 DEG and 200 DEG C. The titanium halide used in the preparation of the catalyst may be titanium tetrachloride, titanium tetra-bromide, or titanium trichloride. The halogen-containing compound may be ethyl chloride or bromide, propyl or butyl chloride, methylene chloride, ethylene chloride, ethylene bromide, chloroform, trichlorethane, or carbon tetrachloride. The polymer may be purified by washing with methanolic hydrochloric acid, water, or tetrahydrofurane, and made into films, foils, fibres, or threads. Specification 781,837 is referred to.