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Return to Abstracts of Patents Return to Abstracts of Patents 1250-1499 Patent Abstracts1388. ------. [I. G. FARBENINDUSTRIE, A. G.] Polymerizing Olefins. British Patent 498,526, Jan. 10, 1939. Chem. Abs., vol. 33, 1939, p. 4351. Gases containing more than 30% and preferably 40% or more of olefins with up to 5 C atoms, mainly butylenes or amylenes or both, are polymerized with catalysts of the Friedel-Crafts type, the product being subjected to hydrogenation and a treatment with superheated steam in the presence of caustic alkali. Gases containing butylenes and propylene are especially suitable; they may be obtained by hydrogenation of C oxides. Suitable catalysts are B halides, or chlorides of Al, Zn, and Fe, or their double compounds. Polymerization may be conducted in the gas phase, or in the liquid phase under pressure or in the presence of an inert diluent. The catalyst is preferably decomposed, as soon as a polymer of desired viscosity is obtained, by treatment with H2O or dilute caustic alkali. The oils may then be fractionated. The crude products, or their fractions, are preferably 1st hydrogenated, using increased temperature and pressure and Ni catalysts, up to 5% of caustic alkali is added, and the products distilled with superheated steam. A subsequent distillation in vacuo may be effected. Products suitable as insulating oils are obtained, in addition to lower boiling fractions that can be used as benzine or diesel oils. |