| 摘要 |
PURPOSE:To obtain an optical recording medium having an absorption band on the longer wavelength side and being stable to heat and light, by incorporating at least one specified diazulenium salt compound into a recording layer. CONSTITUTION:An optical recording medium has a recording layer on a substrate, the recording layer being composed of an organic thin film comprising at least one diazulenium salt compound of formula I, II or III, wherein each of R1-R7 and R1'-R7' is hydrogen, a halogen, or a univalent organic residue, or at least one of combination of Rn with Rn+1 and Rn' with Rn+1' (n=1-6) may form a substd. or unsubstd. condensed ring, A is a univalent organic residue, and n(-) is an anion residue. The optical recording medium makes it possible to obtain high recording and reproduction characteristics by using a long wavelength oscillating semiconductor laser, to form a favorable pit shape end to obtain a high C/N. In addition, the recording medium has high stability to heat and light and excellent preservability. |
