Patent ID: 7682679

Claim:
An optical information recording medium, comprising: a substrate having translucency; an optical recording layer comprising a light-absorbing material formed of a dye that absorbs a laser beam; and a light reflection layer reflecting the laser beam, wherein the optical information recording medium has (i) a main information area for recording main information that is optically readable by irradiating the laser beam on the optical recording layer, and (ii) a sub-information area separated from the main information area for recording sub-information of a type different from that of the main information by irradiating the laser beam on the optical recording layer, said light-absorbing material in the optical recording layer having absorption peaks at a wavelength of 350 to 500 nm and at a wavelength of 640 to 680 nm and/or 750 to 830 nm, wherein the light-absorbing material comprises an oxacyanine dye of chemical formula 2 and an azo dye of chemical formula 3: wherein Z1 and Z2 each represent a group of atoms necessary for forming a five or six-membered aromatic ring and nitrogen-containing heterocyclic ring, which may include a substituent; R represents a hydrogen atom, halogen, or aliphatic group, an aromatic group, or a heterocyclic ring group; R10 and R11 each represent any one of methyl group, ethyl group, propyl group, butyl group, pentyl group, and hexyl group, respectively; X represents an ion necessary for neutralizing electrical charges in a molecule; n1 and n2 each represent numbers of alkyl chains, which are represented by an integer of 1 to 20, wherein ring A represents a heterocyclic ring formed together with a carbon atom and a nitrogen atom to which the ring A is bonded; Ring B represents an aromatic ring that may be substituted or condensed; X represents a group that can contain active hydrogen which is a metal complex obtained by one molecule of a divalent positive metal ion (M 2+ ) to two molecules of this azo dye.