| 摘要 |
PURPOSE:To obtain a film having excellent corrosion resistance, hydrophilicity and the adhesion of a paint coated film by using an aq. basic soln. contg. peroxoborate in a treatment for forming a hydroxide film on the surface of an Al metal. CONSTITUTION:Al or an Al alloy is treated in an aq. basic soln. contg. peroxoborate (for example, by dipping or spraying) to form a hydroxide film on the surface of the Al or Al alloy. NaOH, etc. are used to adjust adequately the concn. of an oxidizing agent for the peroxoborate such as Na metaborate peroxyhydrate (NaBO2.H2O2.3H2O) or Na tetraborate peroxyhydrate (Na2B4O7. H2O2.9H2O), etc. and to make the treating soln. basic, by which the soln. is adjusted to correct pH. The treating time is made adequate as well. The problem in environmental pollution in a waste treatment, etc. is obviated according to the above-mentioned method. |
