Process for the protection and authentification of deeds, cheques or any other documents, printed or manuscript, or any other objects

摘要

305,028. Bayle, E., George, H., and MachÚ, A. Jan. 28, 1928, [Convention date]. Records.-Phonograph records are marked, in order to enable frauds to be detected, with an ink containing an indicator whose colour depends on its ionic state and which can be changed by treatment with different reagents, together with a mixture to render the indicator immune against atmospheric agents; alternatively, the coloured material may be incorporated in the material of the record. In an example, a violet ink is prepared by mixing together the chloro-zincic derivative of the bromo-ethylate of hexamethyl- and pentamethylmonoethylp-rosaniline, the sodium salt of otoluidine-dia.zo - bi - 1-naphthylamine-4-sulphonic acid, sodium dihydrogen orthophosphate, soda, glycerine, and a thin printing-ink varnish. The colour is changed as follows:-to green, by treatment with hydrochloric acid; to blue-green, by treatment with glycocol, salt, and hydrochloric acid; to blue-grey by treatment with hydrochloric acid and potassium biphthalate; to indigo, by treatment with sodium citrate and hydrochloric acid; and to violet, by treatment with boric acid and borax. One or more of the indicator materials may be incorporated in the reagent instead of adding them all to the ink.