DYESTUFF MIXTURE FOR OPTICAL RECORDING LAYER

摘要

PURPOSE: To obtain a recording layer wherein recording information on a photo-CD disk can be kept stable for a long period of time by a method wherein a dye mixture contains a metallized azo dye having specific index of refraction and structure, and at least one kind of second dye. CONSTITUTION: An optical recording element has a transparent supporting body carrying a recording layer coated with a light reflecting layer. That is, the recording layer contains such a dye mixture as follows: a real index of refraction of at least 1.8 in the 780 to 790 nm region of the spectra; an imaginary index (k) between 0.3 and 0.02 in the 780 to 790 nm region of the spectra; a metallized azo dye comprising an azo group linking a substituted 3-hydroxy- pyridine nucleus to a phenyl nucleus wherein the phenyl nucleus has an alkoxy or thioether substituent at its 2-position; and at least second dye.