Patent ID: 7709181

Claim:
An optical recording medium comprising a recording layer on a substrate and at least one of a reflective layer and an ultraviolet cured protective layer, wherein the recording layer comprises a cyanine compound represented by general formula (I) below: wherein, in the formula, ring A and ring B each represent an optionally substituted benzene or naphthalene ring; X represents O, S, Se, CR 3 R 4 , or NY; at least one of R 1 and R 2 represents a group represented by general formula (II) or (III) below and when only one of them is a group represented by general formula (II) or (III), the other represents an organic group having 1 to 30 carbon atoms; R 3 and R 4 each represents an organic group having 1 to 30 carbon atoms; Y represents a hydrogen atom or an organic group having 1 to 30 carbon atoms; at least one of Y 1 and Y 2 is a group represented by general formula (IV) below and when only one of Y 1 and Y 2 is a group represented by general formula (IV), the other represents a hydrogen atom or an organic group having 1 to 30 carbon atoms; Z represents a hydrogen atom, a halogen atom, or a cyano group; An m− represents an m-valent anion; m is an integer of 1 or 2; and p represents a coefficient to keep an electric charge neutral, wherein in general formula (II), the bond between E and G is a double or triple bond; E represents a carbon atom; G represents a carbon, oxygen, or nitrogen atom; x, y, and z each represent 0 or 1; R 5 represents a hydrogen atom, a halogen atom, an optionally halogenated alkyl group having 1 to 4 carbon atoms, or an optionally halogenated alkoxy group having 1 to 4 carbon atoms; each of R 6 , R 7 , and R 8 independently represents a hydrogen atom, a halogen atom, an optionally halogenated alkyl group having 1 to 4 carbon atoms, and R 6 and R 8 may bond to each other to form a ring system; in general formula (III), the bond between E′ and G′ is a double bond; E′ represents a carbon atom; G′ represents a carbon, oxygen, or nitrogen atom; the ring containing E′ and G′ represents a five-membered ring optionally containing (a) heteroatom(s), a six-membered ring containing (a) heteroatom(s), or a benzene, naphthalene, quinoline, isoquinoline, anthracene, or anthraquinone ring, and said ring containing E′ and G′ may be substituted with a hydroxyl group, a halogen atom, a nitro group, a cyano group, an alkyl group, or an alkoxy group; in general formula (IV), R 9 to R 17 each represent a hydrogen atom, or an optionally halogenated alkyl group having 1 to 4 carbon atoms in which (a) methylene group(s) in the chain may be replaced by ˜ O ˜ or ˜ CO ˜ ; M represents Fe, Co, Ni, Ti, Cu, Zn, Zr, Cr, Mo, Os, Mn, Ru, Sn, Pd, Rh, or Pt; and J represents a direct bond or an alkylene group having 1 to 8 carbon atoms in which (a) methylene group(s) may be replaced by ˜ O ˜ , ˜ S ˜ , ˜ CO ˜ , ˜ COO ˜ , ˜ OCO ˜ , ˜ SO 2 ˜ , ˜ NH ˜ , ˜ CONH ˜ , ˜ NHCO ˜ , ˜ N═CH ˜ , or —CH═CH ˜ .