GB537067A - Improvements in or relating to recording blanks for use in facsimile telegraphy - Google Patents

Abstract

537,067. Inks. CREED & CO., Ltd. (Western Union Telegraph Co.). May 3, 1940, No. 7976. [Class 146 (iii)] [Also in Groups VIII, XIX and XL] Paper &c. for electrical reception of facsimile and picture records is made conductive by impregnation during manufacture with a solid solution of an electrolyte, e.g. iodides, sulphocyanides, bromides, chlorides, nitrates, or sulphates of sodium, potassium or ammonium, or organic compounds, e.g. nitrobenzene sulphonic acid, dissolved in solid aliphatic or aromatic alcohols or aldehydes or ketones, e.g. mannitol, erythritol, resorcinol, dextrose, succinic acid or partly esterified polyhydroxy compounds. An aqueous or alcoholic solution is preferably applied to the paper and the volatile content evaporated, the paper being then subjected to heat and/or pressure as by calendering. The paper may be coated with colour-changing materials as disclosed in Specifications 494,143 and 494,224, [both in Group XIX], or coated with conducting material such as carbon and then with a coating which can be "burnt off " electrically; a linseed oil ink containing a drier, e.g. resinates or linoleates of lead, cobalt or manganese may be used. Substances which may be removed electrically include lead thiocyanate, mercuric sulphide, cadmium sulphide, lead thiosulphate and titanium dioxide, the mercuric sulphate undergoing allotropic change under electrical stimulus. The covering power of a lead thiosulphate ink may be increased with zinc oxide or titanium dioxide.