| 摘要 |
PROBLEM TO BE SOLVED: To provide a clear standard as oxidation-reduction potential in terms of photographic properties, with respect to the remaining amount of an oxidizing agent used for bleaching or the remaining amount of sulfurous acid used for neutralizing it. SOLUTION: In the method for manufacturing photographic paper, a reference electrode and a platinum electrode are put in pulp slurry after a bleaching step, the unreacted remainder of an oxidizing agent for bleaching is neutralized by adding sulfurous acid in such a way that the potential E of the platinum electrode defined as mentioned below is set in the range of 300≤E≤900 (mV) expressed in terms of 50°C and pH 4, and then the pulp slurry is immediately transferred without concentrating to a solid concentration of≥25 mass% to a paper-making step, where paper is made. The potential of the platinum electrode represents (relative potential to the reference electrode measured with the platinum electrode)+(reference electrode potential determined by the kind of the reference electrode). COPYRIGHT: (C)2005,JPO&NCIPI
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