| 摘要 |
<p>A photocatalytic element comprising a titanium oxide film disposed on a major surface of a transparent substrate and having a photocatalytic function and a physical thickness of 50 to 500 nm; and a primary film interposed between the transparent substrate and the titanium oxide film, composed of two layers, and having a total physical thickness of 40 to 200 nm. The layer adjoining the transparent substrate, of the primary film, has at least a function of blocking the gas and impurities which are to be discharged or eluded at least from the transparent substrate. The layer adjoining the titanium oxide, of the primary film, has a larger refractive index than that of the layer adjoining the transparent substrate. The primary film suppresses the dependence of the color tone on the thickness of the titanium oxide film to a small value, so that the visible light reflected light color tone and the visible light transmitted light color tone, when observed at least in one direction, of one primary surface of the transparent substrate, are within such ranges where the chromaticness indices a* and b* of the L*a*b* color specification system are within ± 5.</p> |
