| 摘要 |
PROBLEM TO BE SOLVED: To obtain a non-cyanide non-ammonia type silver platting liquid having high stability with which a silver plating film of good physical properties can be formed, by using a water-soluble sulfur-contg. org. compd. having two monosulfide groups in the molecule as a chelating agent. SOLUTION: The plating liquid consists of an aq. soln. containing a water-soluble silver salt, a water-soluble sulfur-contg. org. compd. having two monosulfide groups in the molecule, and a reducing agent. By compounding the sulfur-contg. org. compd., silver ions in a bath sufficiently form complexes to give good stability of the plating liquid. The sulfur-contg. org. compd. is preferably selected from compds. having two monosulfide groups in the molecule and one or more kinds of hydroxyl groups, carboxyl groups, sulfonate groups, amino groups, phosphonate groups, mercapto groups in the molecule and having 2-8C bivalent hydrocarbon groups between the two monosulfide groups, or their alkali metal salts, ammonium salts or the like.
|
