| 摘要 |
PURPOSE:To prevent generation of exfoliation by thermal impact and humidity change and to enhance stability by providing an information medium layer, intermediate layer consisting of dielectric and reflection layer consisting of a thin metallic film successively on a transparent substrate and forming the respective layers in such a manner that the outer peripheral edge of the reflection layer is on the side inner than the outer peripheral edge of the intermediate layer. CONSTITUTION:An under coating layer 2, the information medium layer 3, the intermediate layer 4 and the reflection layer 5 are formed on the disk-shaped transparent substrate 1 made of polycarbonate except on the outermost and innermost peripheral part in such a manner that the outer peripheral edge of the reflection layer 5 is on the side inner than the outer peripheral edge of the intermediate layer 4. A protective substrate 7 made of polycarbonate is adhered via an adhesive agent 6 consisting of a UV curing resin to such laminate. Then, the adhesive strength decreases gradually from the outer periphery toward the inner periphery and the difference in the adhesive strength between the outside and inside with the outer peripheral edges of the respective layers as a boundary is decreased. The exfoliation in the outer peripheral part by the thermal impact and humidity change is thereby suppressed. |
