CYANINE DYE MIXTURE TO BE USED AS OPTICAL RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To bring λmax in a near infrared radiation region (680-780nm) by a method wherein a specified cyanine dye mixture, which is thermally stable to a laser writing and dissolves in an organic solvent for spin coating, is employed. SOLUTION: A cyanine dye mixture for using in an optical disc recording medium has a structure represented by a formula, in which R represents a 4-methoxycarbonyl-benzyl group, X<-> represents an acid anion and (n) represents an integer of 2 or 3. This cyanine dye mixture is suitable for use as a near infrared absorbing organic dye useful as the optical disc recording medium.