| 摘要 |
PURPOSE:To effectively form a phosphate film on the surface of copper by adding a specified oxidizing agent to a phosphoric acid-base treating soln. CONSTITUTION:When a phosphate film is formed on the surface of copper or a copper alloy, an oxidizing agent is added to a phosphoric acid-base treating soln. by 0.1-10wt%, preferably 0.3-2wt% (expressed in terms of active oxygen). Persulfuric acid, chloric acid, perchloric acid or permanganate may be used as the oxidizing agent. Since the oxidizing agent is consumed in accordance with the progress of treatment, it is successively supplied so as to keep the prescribed concn. Thus, a phosphate film is effectively formed and environmental pollution is controlled at a reduced cost. |
