Patent ID: 6242067
Filing Date: 2001-06-05
Classification: C09B,G11B,Y10S,Y10T

Abstract:
An optical recording medium capable of writing and reading operation with light having a wavelength of up to 690 nm, comprising a recording layer containing at least one chelate compound of a metal with a dye of the following formula (I): ##STR19##wherein each of X.sub.1 and X.sub.2 is independently a group having active hydrogen; each of R.sub.1 and R.sub.2 is independently selected from the group consisting of hydrogen, alkyl, aralkyl, aryl, and alkenyl groups, and R.sub.1 and R.sub.2, taken together, may form a ring; each of R.sub.3, R.sub.4, and R.sub.5 is independently a monovalent group selected from the group consisting of hydrogen, alkyl, halogen, hydroxyl, carboxyl, carboxylic ester, sulfone, sulfonic ester, sulfamoyl, sulfonamide, carbamoyl, amide, amino, aryl, acyl, alkoxy, and alkenyl groups, and R.sub.3 and R.sub.4, taken together, may form a ring, or each pair of (R.sub.1 and R.sub.4) and (R.sub.2 and R.sub.5), taken together, may form a ring; each of R.sub.6, R.sub.7, R.sub.8, and R.sub.9 is independently a monovalent group selected from the group consisting of hydrogen, halogen, hydroxyl, carboxyl, sulfone, aryl, acyl, sulfonamide, amide, cyano, nitro, mercapto, thiocyano, amino, alkylthio, alkylazomethine, carboxylic ester, carbamoyl, sulfonic ester, sulfamoyl, alkyl, alkoxy, aralkyl, and alkenyl groups, and each pair of (R.sub.6 and R.sub.7), (R.sub.7 and R.sub.8), and (R.sub.8 and R.sub.9), taken together, may form a ring;with the proviso that in any one of the cases where (i) all R.sub.3 to R.sub.9 are hydrogen, (ii) R.sub.7 is a nitro group, (iii) R.sub.3 and R.sub.4 form a benzene ring, and all R.sub.5 to R.sub.9 are hydrogen, (iv) all R.sub.3 to R.sub.7 are hydrogen, and R.sub.8 and R.sub.9 form a benzene ring, (v) R.sub.7 is a halogen atom, and R.sub.3 to R.sub.6, R.sub.8 and R.sub.9 are monovalent groups as listed above, and (vi) R.sub.8 is a nitro group, sulfamoyl group or halogen atom, and R.sub.3 to R.sub.7 and R.sub.9 are monovalent groups as listed above; R.sub.1 and R.sub.2 are independently hydrogen, aralkyl, aryl or alkenyl groups, or one of R.sub.1 and R.sub.2 is an alkyl group and the other is hydrogen, aralkyl, aryl or alkenyl group, and R.sub.1 and R.sub.2, taken together, may form a ring.