METHOD FOR COLORING A SURFACE OF COPPER OR COPPER PLATING ARTICLES

摘要

This method is used for coloration of the surface of copper or copper plated body by the evaporation of a coloring agent containing ammonium group of over one kind in the closed vessel. The methods of evaporation are a natural evaporation with saturation of ammonia solution, a forced evaporation with super saturation of the mixed solution of ammonia solution and alkaline solution, and a forced evaporation of the mixed solution of an ammonium salt and alkaline solution. This process provides a homogeneous and high adherency, and low production cost with simple equipments and evaporating process. The optimum concentration of coloring agents is 14 to 28%.