| abstract |
Provided is an aluminum or aluminum alloy material having a surface treatment coating film on a surface of a substrate formed by an aluminum or aluminum alloy. The aluminum or aluminum alloy material has: a substrate formed by an aluminum or aluminum alloy; and a first protective layer and a second protective layer in the order on a surface of the substrate, wherein the first protective layer is a conversion coating film including vanadium and at least one or more types of metals selected from titanium, zirconium, and hafnium, the second protective layer is an organic coating film having a composition that includes (1) a chitosan derivative and a solubilizing agent, (2) a modified polyvinyl alcohol formed by graft polymerization of a hydrophilic polymer to a side chain of polyvinyl alcohol, and (3) a water-soluble crosslinking agent. |