| 摘要 |
PROBLEM TO BE SOLVED: To allow the surface of a base material to sufficiently exhibit the effects of water cleanability, rainfall cleanability or the like and to enable the prevention of contamination or self-purification therein by forming a photosemiconductor-contg. layer contg. no Cu atoms on the surface of a base material and making the surface to be the highly hydrophilic one in accordance with the photoexcitation of the photosemiconductor. SOLUTION: On the surface of a base material, a photosemiconductor-contg. layer contg. no Cu atoms is formed desirably to a film thickness of about <=0.4 μm. As this photosemiconductor, anatase-type or rutile-type titanium oxide, tin oxide, ZnO, Bi2O3, WO3, Fe2O3, SrTiO3 or the like is used, the contg. layer is moreover incorporated with solid superstrong acid such as silica, sulfuric acid-carried Al2O3 or the like, silicone or the like, and its film thickness is controlled to about <=0.4 μm, desirably to about 0.2 μm in particular. At the time of providing this photosemiconductor-contg. layer on the surface of a base material composed of a Cu alloy such as bronze, brass or the like, the surface of the base material is provided with a layer preventing the diffusion of Cu such as silica, an acrylic resin or the like. |
