| 摘要 |
PURPOSE:To rapidly carry out reversal processing, to lower fog, and to improve contrast, by using a specified thiol derivative together with an oxidant in the bleach step of a reversal development process. CONSTITUTION:To a bleach solution containing as an oxidant, an inorganic ferric or ceric salt, and as anions, sulfate or nitrate ions is added dimethylaminoethanthiol of formula I in which A1 is H, hydroxy, or formula II; R1 and R2 are H, CH3, C2H5; R3 is 1-4C alkylene optionally substituted by OH, SCH3, or carboxy; B is H or -S-R6-A2; A2 is H, OH, or formula II; A1 and A2 are not simultaneously H; and R6 is as R3. Or it may be added to a development stop solution. This processing is carried out rapidly, and yet it does not affect the steps following bleaching adversely. This bleach solution is low in toxicity to man and the like, and suitable to microfilms. |
