| 摘要 |
PROBLEM TO BE SOLVED: To produce a filter for an air conditioner having a semipermanental antifungal property and deodorizing property by utilizing a photocatalytic function of TiO2 . SOLUTION: A stainless steel sheet containing 0.1-0.6% Ti is used as a base stock and a TiO2 concentrated surface layer is provided on a surface. Moreover, the stainless steel sheet containing 0.3-0.7% Cu and/or 0.4-3.0% Mo may be used. The TiO2 concentrated surface layer is formed by a bright annealing in which the material is heated at 850-1000 deg.C in a H2 gas atmosphere having -40 to -65 deg.C dew-point or a H2 -N2 mixed gas atmosphere containing >=90vol% H2 . After subjecting to the bright annealing, the sheet may be subjected to dip treatment with a mixed acid soln. containing 0.5-5% hydrofluoric acid and 5-20% nitric acid to precipitate the Cu having the antifungal property. In this way, the filter hardly causing a generation of fungi and malodor over a long period of time is obtained. Moreover, an antifungal function is supplemented with a precipitated Cu even if photoirradiation is low when the stainless steel base stock containing the Cu is used. |
