| 摘要 |
471,922. Photographic developing and fixing agents. I. G. FARBENINDUSTRIE AKT.-GES. March 13, 1936, No. 7638. Convention date, March 13, 1935. [Class 98 (ii)] A developing or fixing agent in solid or dissolved form for use with silver salt emulsions contains a soluble pyrophosphate or metaphosphate in order to avoid the formation of a white deposit of calcium sulphite or sulphate &c., on the emulsion during treatment owing to the use of hard water for the developing &c. baths. Formulae are given for metal-hydroquinone developers containing sodium pyrophosphate, and a hypo fixing bath containing sodium pyro- or meta-phosphate. The latter may be in the form of tri- or hexametaphosphate. |
