GB313561A - - Google Patents

Abstract

313,561. Horn, R. June 14, 1928, [Convention date]. Inkless printing by chemical reaction.-Paper which may be written and drawn upon electrolytically, either by machine or by hand, suitable for the transfer of pictures and for use with recording electric currents &c., is obtained by impregnating absorbent paper with an aqueous or alcoholic, neutral or alkaline solution of an organic nitroso, nitro, amine, hydroxylamine, or quinine compound which on passage of an electric current with an anode of silver, copper, lead iron, nickel, aluminium, or an alloy of these metals with each other or with zinc or tin, produces with ions derived from such anode, but without the presence of a catalyst, a sparingly soluble organic metal compound or a lake, or with an insoluble anode, or one rendered passive, produces, by oxidation, sparingly soluble pigments. A carrier electrolyte and, in the latter case, catalysts may be added and the paper may be impregnated with a salt of a metal the oxide of which acts as a mordant. The paper may be subsequently washed in an aqueous, alkaline, or acid bath. In an example, paper is impregnated first with 1 gram of dimethylglyoxime dissolved in 100 c. cs. of alcohol and then with 3 grams of sodium chloride and 2 grams of ammonium chloride dissolved in 100 c. cs. of water, a nickel anode being used. An example of the use of an alizarin derivative with a copper anode, is described, and with an insoluble anode or one rendered passive with concentrated nitric acid, aniline salts, gallocyanine, leuco gallocyanine and their derivatives may be used, with vanadium pentoxide as a suitable catalyst.