Patent ID: 6794114
Filing Date: 2004-09-21
Classification: C09B,G11B,Y10S

Abstract:
An optical recording medium comprising a substrate and a laser-writable and/or readable recording layer provided thereon, wherein said recording layer contains a chelate dye comprising two or more azo compounds having different structures and a divalent or more metal ion, wherein said azo compounds are selected from compounds represented by the following formula (I): wherein ring E may have substituent(s), C1 and C2 each represents a carbon atom, and R1 and R2 each independently represent a hydrogen atom, an alkyl group, an aryl group, an alkenyl group, a cyclic alkenyl group or a cyclic alkyl group, or R1 and R2 may be bonded to each other to form a ring, and wherein the following conditions (1), (2) or (3) may apply:(1) R1 and C1 are bonded to each other to form a saturated ring condensed with ring F, (2) R2 and C2 are bonded to each other to form a saturated ring condensed with ring F, (3) both R1 and R2, with both C1 and C2, respectively, form a saturated ring condensed with ring F, with the proviso that in at least one of said two or more azo compounds, (1), (2), or (3) applies, and wherein the chelate dye has a degree of ligand exchange of at least that obtained by mixing a chelate dye obtained by reacting one of said two or more azo compounds with said divalent or more metal ion, with another chelate dye obtained by reacting a different one of said two or more azo compounds with said divalent or more metal ion, in a solvent, thereby forming a solution, and then allowing the solution to stand at room temperature for six hours or more, thereby performing exchange of ligands.