Patent GB-321402-A (GB)
Title: Improvements in the manufacture and production of carbon black
IPC: C09C1/54
Filed: 1928-08-03
Abstract: 321,402. Johnson, J. Y., (I. G. Farbenindustrie Akt.-Ges.). Aug. 3, 1928. Divided on 324,959. Carbon.-Carbon black is obtained by decomposing carbon monoxide, or gases containing it, under pressure and at from low to moderately elevated temperatures in the presence of iron, nickel or cobalt, or their compounds, with which are mixed activating additions comprising metal oxides other than those of the iron group, such an manganous oxide, vanadium oxide, chromic oxide, uranium oxide, zinc oxide, cadmium oxide, copper oxide and alumina, or alkalies or alkaline compounds furnishing them, such as carbonates, nitrates, or other salts, such as molybdates or tungstates. The iron, nickel and cobalt are preferably obtained by reducing their oxides. The catalysts may be used in finely divided state, if desired in conjunction with carriers, or in the form of lumps, chips, turnings, screens, wire gauze, etc. The walls of the reaction vessel may also exert a catalytic action. Gases such as hydrogen, carbon dioxide, nitrogen) nitrogen peroxide, and water vapour, or hydrocarbons such as methane, ethane and other paraffins, napthalene and olefines may be added to the carbon monoxide and have a temperature-regulating effect. The hydrocarbons may react with the carbon monoxide giving carbon black and water. The amount of these gases added may vary from about one per cent by volume up to several molecular proportions of the gas to each molecular proportion of the carbon monoxide. The carbon produced may be removed rapidly from the reaction zone by mechanical means and by maintaining a high gas velocity. Temperatures between 25‹-800‹C. but preferably between 100‹-450‹ C. and usually about 300‹-400‹ C. are employed. The pressure used is usually between about 30-250 atmospheres and preferably about 100-200 atmospheres. In an example, carbon monoxide at a pressure of 200 atmospheres and a temperature of about 400 ‹C. is passed over nickel deposited on kieselguhr which also contains a little alkali metal hydroxide. Violent evolution of heat takes place during the reaction, but by cooling, the temperature is prevented from rising substantially above 450‹C. Another catalyst employed is prepared by reducing a shaped mixture of 99 parts of cobalt oxide and one part of zinc oxide which has been obtained by precipitation from a solution containing the nitrates. The carbon black produced by the process is in a high state of dispersion and is especially adapted for preparing coloured compositions such as printing and endorsing inks and for use in the vulcanization of rubber or of polymerization products of diolefine hydrocarbons. The Provisional Specification describes the use of catalysts, other than metal carbonyls or organic compounds of metals capable of decomposing carbon monoxide. The catalysts include elements or compounds of the iron group alone or with additions, and metal oxides, more especially difficultly reducible oxides such as manganous oxide, vanadium oxide, chromic oxide and uranium oxide, and oxides of the alkaline earth metals, the oxides being used alone or in conjunction with additions. Salts such as silicates and chromates may also be used.