| 摘要 |
To provide a surface treatment method for a metal base material which can be conducted prior to cathodic electrodeposition coating in order to improve the uniformity of a cathodic electrodeposition coating film, a metal material which has been treated by the surface treatment method, and a coating method using the metal material. A metal surface treatment method for a metal base material in order to improve the uniformity of a cathodic electrodeposition coating film, the method including: a surface treatment step for forming a chemical conversion film on a metal base material by contacting the metal base material with a metal surface treatment composition including zirconium and/or titanium ions and an adhesive imparting agent characterized in being at least one selected from the group consisting of (A) silicon-containing compound, (B) adhesive imparting metal ion, and (C) adhesive imparting resin; and a heating/drying step to heat and dry the metal base material, on which the chemical conversion film is formed, at 60°C to 190°C for at least 30 seconds. |
