| 摘要 |
PURPOSE:To adequately control the rate for formation of a boemite film and improve the adhesive strength to Al surface by using specific treating liquid at the time of treating the substrate of Al by a boemite method. CONSTITUTION:A substrate treatment layer by a boemite film is formed on the surface of Al or Al alloy in order to improve the adhesive strength of the painting film. The treating liquid used at this time is pure water such as distilled water or ion exchange water, or the liquid of 10,000-1,000,000OMEGAcm resistivity values prepd. by adding Mg salt, Ca salt, silicate, Fe salt, Na salt, K salt, org. acids, surfactants to pure water. As treatment conditions, the pH of the treating liquid is controlled to 5-13 bt org. amine, alkali compound etc. and the liquid is used by being heated to 40 deg.C or boiling temp. The boemite substrate treatment film of high adhesive strength to the Al surface is formed, and this improves the adhesive strength of paint to be coated thereon. |
