Patent ID: 6576321
Filing Date: 2003-06-10
Classification: G11B,Y10T

Abstract:
An optical recording medium comprising at least a recording layer and a metal reflective layer on a transparent substrate having a groove, wherein the recording layer comprises an azaporphyrin metal complex dye with 1 to 4 meso-nitrogen atoms represented by formula (1) as a main component; recording and/or reproduction can be conducted using a laser beam with a wavelength of &lgr;1 and also with a laser beam with a wavelength of &lgr;2 shorter than &lgr;1; the recording layer has a refractive index n of 2.0 or more at &lgr;1 and 1.8 or more at &lgr;2 as well as an attenuation coefficient k of 0.04 to 0.20 at &lgr;1 and 0.30 or less at &lgr;2; and the groove in the transparent substrate has a pitch of 0.70 to 0.85 &mgr;m, a half-value width of 0.20 to 0.35 &mgr;m and an inclination angle of 45 to 65Â°: wherein X1 to X3 independently represent nitrogen or CH; R1 to R8 are independently selected from the group consisting of hydrogen, halogen, substituted or unsubstituted alkyl with 1 to 12 carbon atoms, substituted or unsubstituted aryl with 6 to 20 carbon atoms, hydroxyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, amino or alkylamino, nitro, cyano, carboxy, substituted or unsubstituted carboxylate, substituted or unsubstituted carboxamide, alkylthio, arylthio, sulfonic, substituted or unsubstituted sulfonate, substituted or unsubstituted sulfonamide, substituted or unsubstituted silyl and siloxy; and the central metal M represents transition metal which may be charged to have a cationic salt structure.