| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for easily forming, on a surface of a noble-metal base, a strong and dense protection film having excellent adhesion to the noble-metal base and having durability so that a user can wear it frequently in daily life without any special care, while having excellent corrosion resistance and keeping the effects over a long period.SOLUTION: A silica glass film having a thickness of 0.2-1.0 μm is formed by applying, to a surface of a noble-metal base, a composition for forming glass coating formed mainly of polysilazane under an inert gas atmosphere, such as argon, and holding the noble-metal base with the composition for glass coating formation applied thereon, at a temperature lower than the melting point of the noble-metal base in an atmosphere in the presence of water vapor. |
