| 摘要 |
PURPOSE:To improve the adhesiveness of Al or Al alloy surfaces without using anything which will give harmful effect upon human body by dipping Al or Al alloy in the aqueous nitric acid solution of the specific concentration. CONSTITUTION:Al or Al alloy is dipped in an aqueous nitric acid solution of 30- 80wt% or the aqueous solution comprising adding one or more kinds of heavy metal salts, corrosion inhibitors, sulfuric acid, phosphoric acid or fluorine compounds according to need to this solution, whereby the natural oxide films on the surfaces are removed. The above treatment improves the adhesiveness between the Al or Al alloy surfaces and paints, adhesives and resins. |
