GB338152A - Improvements in the manufacture and production of valuable condensation products from diolefines - Google Patents

Abstract

338,152. Johnson, J. Y., (I. G. Farbenindustrie Akt.-Ges.). May 14, 1929. Caoutchouc, synthetic.-The polymerization of diolefines is effected with at least 30 per cent of an inorganic oxygen-containing acid or an organic derivative of such an acid, and no other substance influencing the reaction is supplied. Suitable agents are sulphuric acid, phosphoric acid. benzene sulphonic acid, toluene sulphonic acid, ptoluene sulphochloride, benzene sulphochloride, or the like. Products of varying character are produced according to the conditions of the reaction: thus, with low temperature, short time of reaction or low concentration of the acid, only or semi-solid products are generally obtained, while by longer or more energetic action harder products are produced. The process may be effected below 0‹ C. and elevated pressures may be em. ployed. The products may be used as adhesives, as additions to paints and lacquers, as additions in the manufacture of rubber-like products for the manufacture of artificial materials such as films, threads. foils, bands, and moulded articles. In the examples (1) butadiene is added slowly to 68 per cent aqueous sulphuric acid at -10‹ C., the mixture being stirred at -7‹ C. until the whole is soluble in water and contains no butadiene; the reaction mixture is' then poured on to ice and volatile matter is removed by steam; the brown mass remaining is dissolved in a solvent such as cyclohexane and washed with water and dilute sodium carbonate solution; after distilling off the solvent a viscous oil is left which distills at 150-300‹ C., leaving as residue a clear resin which softens at 60‹ C, and is soluble in many solvents such as benzene, toluene, xylene, chloroform, and carbon tetrachloride, (2) butadiene is heated in a pressure vessel with aqueous solution of benzene sulphonic acid for 20 hours at 100‹ C. ; on cooling the brown viscous product is treated with steam to remove volatile matter, the viscous dark oil remaining being washed with sodiumcarbonate solution and water and dissolved in ether; the ether is evaporated and a small proportion of an oil is distilled off at 25 m.m. pressure and up to 200‹ C. the residue being a resin similar to that obtained in the first example; (3) butadiene is heated with 89 per cent phosphoric acid, the rest of the process being similar to that of the previous example.