| 摘要 |
PURPOSE:To lower toxicity and to meet the demand of pollution control and to improve bleaching speed by using a ferric salt as a bleaching agent and incorporating a specified compd. in a bleaching or bleach-fixing bath. CONSTITUTION:A ferric salt is used as a bleaching agent used for bleaching or bleach-fixing treatment following the color developing treatment, and the bleaching or bleach-fixing bath contains a compd. or at least of its tautomers represented by the formula in which X is N or C-R; R, R<1>-R<3> are each H, alkyl, carboxy, sulfo, or alkyl; R<4>, R<5> are each H, alkyl, acyl, or both may form a linked ring; and n is 0-5. Since such a compd. has high bleach accelerating effect, it can execute sufficient removal of silver in a short time in combination with a comparatively weak bleaching agent, such as ferric salt, and it exerts no adverse effect on photographic characteristics, such as color development, sensitivity, and staining characteristics, and since it is stable for a long time in the processing bath, maintenance of the bath is made easy.
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