The Photographic Implications of the Chemistry of Quinone^*

* This research was supported by the United States Air Force under Contract No. AF 18(600).371 monitored by the Office of Scientific Research. Reproduction in whole or in part is permitted for any purpose of The United States Government.

Abstract

The data obtained in the investigation of the chemistry of quinone were used in conjunction with sensitometric data to relate fog, accelerated, contagious, infectious and superadditive development. Latensification and desensitization were studied. The photographic experiments have been summarized and discussed. It was concluded that hydroxyhydroquinone or its precursors were the prime cause of development fog and aerial fog. It was also suggested that hydroxyhydroquinone is the cause of accelerated, contagious and infectious development. It was further shown that the best anti-foggants against hydroxyhydroquinone were the superadditive components of developers, namely Phenidone and Elon. It was suggested that Phenidone and Elon react with hydroxyhydroquinone to form a powerful non-fogging developer. Furthermore, it appeared from the data that benzotriazole also reacted with hydroxyhydroquinone to form a non-fogging compound, whereas 6-nitrobenzimidazole was merely strongly adsorbed to fogged areas and thus inhibited development, it was shown that Fremy's salt, potassium nitrosodisulphonate, may be used to give reproducible latensification without aerial drying. This suggested that the usual latensifying agents must be aerially oxidized to free radicals before they latensify. This also explained the irreproducibility of latensification by perborate and metabisulphite. The work on latensification led to experiments which showed that inhibition by the products of development in paraphenylenediamine developers was due to the destruction of latent image and small development centres by the semiquinone and the diimine of the paraphenylenediamine. It was found that Wurster's Slue and methylpyridinium iodide could desensitize exposed film. It was also found that a dilute solution of Wurster’s Blue could completely desensitize unexposed film.

Notes

* This research was supported by the United States Air Force under Contract No. AF 18(600).371 monitored by the Office of Scientific Research. Reproduction in whole or in part is permitted for any purpose of The United States Government.