| 摘要 |
PURPOSE:To economically manufacture an Al material having superior external appearance and excellent in corrosion resistance and weatherability, by applying anodic oxidation treatment to an Al or Al-alloy base material and then by forming an electrodeposition coated film of high relative-specular glossiness and a pear skin-like electrodeposition coated film of low relative-specular glossiness. CONSTITUTION:Anodic oxidation treatment is applied to an Al or Al-alloy base material to form an anodic oxidation film on the surface of the above base material. Subsequently, anodic electrodeposition is applied by using a coating bath for anodic electrodeposition in which resin content of limited water solubility and water-insoluble resin content are not added, so that an electrodeposition coated film of >=20% 60 deg. relative-specular glossiness is formed on the above anodic oxidation film. Then, anodic electrodeposition is applied by using a coating bath for anodic electrodeposition prepared by adding resin content of limited water solubility or water-insoluble resin content having compatibility dissimilar to that of water-soluble resin content to the above water-soluble resin content, by which a pear skin-like electrodeposition coated film of <=8% 60 deg. relative-specular glossiness is further formed on the above-mentioned electrodeposition coated film of high relative-specular glossiness. By this method, the Al or Al-alloy material in which inorganic texture is provided and die marks, etc., on the base material are covered and which has superior external appearance and excellent corrosion resistance and weatherability can be obtained.
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