Electric Determination of the Etching Potency of Ferric Chloride Solutions

• Published in: Bulletin of the Technical Association of Graphic Arts of Japan Vol. 4; no. 7; pp. 62 - 67
• Main Author: Miyaki, Satoshi
• Format: Journal Article
• Language: English; Japanese
• Published: The Japanese Society of Printing Science and Technology 1961; 社団法人 日本印刷学会
• ISSN: 0040-0874; 2185-1263
• DOI: 10.11413/nig1958.4.62

As in used ferric chloride etching solution there exist not only Fe3+, but also Fe2+ and Cu2+, the solution will form a redox electrode and its etching potency should be determined by the ratio of molar concentration of Fe3+ and Fe2+([Fe3+]/[Fe2+]) in the solution. According to the principle of the Fe3+-Fe2+ redox electrode, the [Fe3+]/[Fe2+], that is the etching potency of the solution, is expected to be evaluated by measuring the redox potential of the solution. Because of lack of the detailed informations about this subject, a series of experiments was made along this line. Number of known sample solutions prepared by mixing FeCl2 with FeCl3 solution in different proportions, and the actual FeCl3 etching solutions exhausted to various degrees were also examined. They were almost all certified to conform to the principle of the redox electrode, and a prospect for the possibility of evaluating the etching potency by measurement of the electric potential was made sure. Actual procedures of the electric determination were also discussed.