| 摘要 |
PURPOSE:To obtain an optical card enabling high density recording and preventing a change of written information by forming an optical recording layer contg. an org. polymethine dye on track grooves on the surface of a transparent substrate and by sticking the recording layer to a card base with a thermoplastic adhesive. CONSTITUTION:A thin film 2 (optical recording layer) is formed on track grooves 6 on a transparent substrate 1 by applying and drying a soln. prepd. by dissolving an org. polymethine dye represented by formula I in a solvent. In the formula, each of R1-R4 is H, alkyl, substd. alkyl, cycloalkyl, alkenyl, aralkyl, substd. aralkyl, aryl, substd. aryl, styryl, substd. styryl, a heterocyclic ring or a substd. heterocyclic ring, n=0, 1 or 2 and X<-> is an anionic group. A thin film 2 having 10-40% transmissivity or 11-17% reflectance to light incident from the transparent substrate side may be formed with a dye represented by formula II. The film 2 is then adhered to a card base 4 with a thermoplastic adhesive which melts at a temp. below the thermal deterioration temp. or the film 2. By this structure, an optical card having satisfactory recording characteristics is obtd. |
