| 摘要 |
PURPOSE:To establish a countermeasure to prolong the service life of copper discoloring preventive solution consisting of acidic solution of inorganic acid and/or organic acid contg. a benzotriazole derivative of 5-methyl-1H- benzotriazole, etc., as a coloring preventive. CONSTITUTION:Copper discoloring preventive solution is provided characterized in that an EDTA chelate agent is added to acidic solution (optionally including a pH buffer) of inorganic acid and/or organic acid contg. as a discoloring preventive a benzotriazole derivative of 5-methyl-1H-benzotriazole and/or 5,6-dimethyl-1 H-benzotriazole. The EDTA chelate agent may be added during use. The EDTA chelate agent is dissolved in liquid so that copper may be stabilized in the copper discoloring preventive solution, preventing the benzotriazole derivative from being adsorbed on the surface of silver. The specified example: 2.5g/l potassium pyrophosphate, 50mg/l, 5-methyl-1H-benzotriazole, 1g/l EDTA, and pH 4-6. |
