| 摘要 |
PURPOSE:To enable the long-term storage of a replenisher for a bleaching bath contg. metallic complex salt of org. acid and bromate and to provide superior bleaching power by separating the replenisher into a replenisher contg. the metallic complex salt of org. acid and a replenisher contg. the bromate and by mixing them immediately before replenishment. CONSTITUTION:A replenisher A contg. metallic complex salt of org. acid consisting of aminopolycarboxylic acid, org. phosphonic acid or the like and metallic ion such as Fe<+++> and a replenisher B contg. bromate and adjusted to 3-12, especially 4-8pH with NaOH or acetic acid are stored in different storage tanks until they are added to a bleaching bath. A soln. overflowing from a bleaching tank may be recovered and used as the replenisher A as it is or after supplying the insufficient component. Since the amount of bromate in the recovered soln. is small, the influence is slight. The pH of the replenisher B is kept at said value to improve the stability. Thus, the shelf stability of the replenishers is improved, rapid fixing and long-term continuous use of a bleaching bath are enabled, and imperfect recoloring, defective desilvering, etc. are prevented. |
