摘要 |
A surface treatment method for tin-free steel, which comprises applying a water solution, containing a polymer obtained from one or two or more kinds of monomers of unsaturated carboxylic acids, on to the surface of a steel sheet having a metallic chromium layer formed thereon and having a film, mainly consisting of hydrated chromic oxide, formed on the above layer, and then conducting heating and drying. The coating of tin-free steel obtained by this method is excellent in adhesiveness and is most suitable for bonded cans requiring high-temperature treatment. |