METHOD FOR PRODUCING METAL MATERIAL WITH CHEMICAL CONVERSION FILM

To provide a method for producing a metal material with a chemical conversion film that has excellent appearance after chemical conversion and excellent corrosion resistance after coating as evaluated by an exposure test or VDA 621-415 and other techniques and is able to be used in a wide temperature range.SOLUTION: A method for producing a metal material with a chemical conversion film, formed in or on the surface of a metal material, includes the step I in which a metal material is brought into contact with a chemical conversion agent which contains a supply source of fluorine ions, a supply source A of ions containing zirconium, a supply source B of ions containing aluminum, and 0.0001 g/L to 1.000 g/L of a water-soluble or water-dispersible polymer containing 90% by mole or more of a structural unit represented by formula (i) or a salt C thereof; and the step II in which the metal material that has been brought into contact with the chemical conversion agent is then brought into contact with an aqueous solution having a pH of 4.0 to 12.0 at least once.SELECTED DRAWING: None 【課題】化成後の外観及び塗装後の曝露試験やＶＤＡ６２１－４１５法等により評価される耐食性に優れ、且つ幅広い温度域で使用できる化成皮膜が形成された化成皮膜付き金属材料を製造する方法を提供する。【解決手段】金属材料の表面又は表面上に化成皮膜が形成された化成皮膜付き金属材料の製造方法であって、フッ素イオンの供給源と、ジルコニウムを含有するイオンの供給源Ａと、アルミニウムを含有するイオンの供給源Ｂと、下記式（ｉ）で表される構造単位をモル換算で９０％以上有する水溶性もしくは水分散性の高分子又はその塩Ｃを０．０００１ｇ／Ｌ以上１．０００ｇ／Ｌ以下と、を配合した化成処理剤に金属材料を接触させる工程Ｉと、化成処理剤を接触させた金属材料をｐＨ４．０以上１２．０以下の水溶液に少なくとも１度接触させる工程ＩＩと、を含む化成皮膜付き金属材料の製造方法である。TIFF2024084379000011.tif40170【選択図】なし