Improvements in and relating to photographic developers

Abstract

Abstract 299,751. Merejkovsky, B. June 29, 1927. Developing.-To a developing composition containing (1) a polyphenol having two or more OH groups and not being an amine (such as hydroquinone or pyrogallol), and (2) hydroxylamine sulphonic acid or nitrilo sulphonic acid or salts thereof, there is added a very small quantity of a primary diamine or a secondary amine, as an accelerator, i.e., organic products containing the groups NH or (NH2)2, such as for example piperidine, methylaniline, methylpara-amido-phenol, amidol or the like. Two specific hydroquinone developing compositions are given. Reference is made to Specification 255,925.

Inventors

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