| 摘要 |
PURPOSE:To prevent the generation of a chemicophysical change by light and to improve a long-term preservable property by compounding a light absorbent into a transparent substrate or forming a light absorptive layer thereon and specifying the light transmittance in the wavelength region below the wavelength of the laser beam to be used. CONSTITUTION:The light absorbent is compounded into the transparent substrate 11 or the light absorptive layer is formed thereon to confine the light transmittance in the wavelength region below the wavelength of the laser beam to be used to about <=30%. Org. dyes, such as indolenine cyanine dyes and copper phthalocyanine tetrasulfonic acid having the light absorption region in the wavelength region below the wavelength of the laser beam to be used are adequate as the light absorbent. Whether these org. dyes are used by compounding the same into the transparent substrate material or are used as the light absorptive layer by forming the film thereon on the transparent substrate as the method of using these org. dyes is determined by the characteristics of the org. dyes to be used. Then, the constant irradiation of a recording layer 12 with unnecessary rays is obviated. The generation of the chemicophysical change by light is prevented in this way and the long-term preservable property is improved. |
