| 摘要 |
PROBLEM TO BE SOLVED: To provide a technology for forming a protection film, capable of sufficiently suppressing the deterioration of the reflectance of a surface including silver, by an electrolytic method.SOLUTION: An electrolytic solution is used for forming a protection film, for protecting a surface containing silver from the deterioration of optical performances, by an electrolytic method. The electrolytic solution includes: 0.03-6.0 g/L of zinc; and hydroxide ions; wherein the ratio of the molar concentration of the hydroxide ions to the molar concentration of zinc, (M/M), is ≥75, and the concentration of nitric acid ions in the electrolytic solution is ≤0.05 g/L. |
