| 摘要 |
PURPOSE:To decrease moisture permeability resistance and to prevent the generation of warpage at and under a higher temp. and higher humidity by adhering a transparent moisture-proof film on the side, where a recording layer is not provided, of a transparent synthetic resin substrate provided with the recording layer on one side. CONSTITUTION:A reflecting film 3 consisting of aluminum, etc. and a protective film 4 are formed on the recording layer 2 of the transparent synthetic resin substrate 1 consisting of polymethyl methacrylate, etc. The transparent moisture-proof film 5 is thereupon adhered to the side where the layer 2 is not formed. The film 5 is constituted by forming a thin transparent amorphous film layer 53 consisting of the compsn. contg. SiO2, B2O3, BaO, Al2O3 at (SiO2):(B2O3): (BaO+Al2O3)=2-4:1-2:0.3-1 molar ratio on a thin transparent film 52 consisting of the magnesium oxide formed on a transparent synthetic resin film 51 made of polyacrylonitrile, etc. The side thereof where the layer 53 is not formed is adhered. |
