| 摘要 |
PURPOSE:To enhance reading sensitivity, a C/N ratio and raw preservability in a case using recording and reading light such as semiconductor laser by providing a recording layer containing a specific light absorbing dye on a substrate. CONSTITUTION:A recording layer containing a light absorbing dye represented by formula (phi<+> and psi are respectively an indolenine ring residue, a benzoindolenine ring residue or a dibenzoindolenine ring resin but not together a 4,5-benzoindolenine ring residue, L is a connection group for forming a monocarbocyanine dye or a dicarbocyanine dye, X<-> is an anion and m is 0 or 1) is formed on a substrate. When this recording layer is irradiated with semiconductor laser recording beam with a wavelength of 750nm while rotated at 1800rpm, sensitivity is 1X10<-2>(nsec)<-1> or more and C/N and the reflectivity through the substrate are respectively 50dB or more and 30dB or more and a C/N ratio after preservation for 500hr at 60 deg.C after writing is high to show preservability. |
