JP2006248180A - Trimethine-based compound and optical recording medium using this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a write-once type optical recording medium that permits recording and reproduction with a short wavelength laser of 520 to 690 nm, has superior moisture and heat resistance and is suitable for high density and high speed recording. <P>SOLUTION: A trimethine compound containing anion components expressed by formula (I) is provided. In the formula (I), X, Y represent each an alkyl group which may have a substituent independently, an alkenyl group which may have a substituent, an aryl group which may have a substituent, a metallocenyl group which may have a substituent, and a heterocycle expressed by formula (II). X and Y may be combined to form a ring. In the formula (II), the ring (A) represents the heterocycle which may have a substituent containing a nitrogen atom with which the ring A is combined and a carbonyl group. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical recording medium using a trimethine compound and capable of recording and reproducing at a higher density than before.

  A CD-R using an organic dye as a recording material is widely known as a medium capable of recording and reproducing data such as images, videos, and sounds. At present, with the increase in the amount of data to be handled, it is desired that an optical recording medium capable of recording and reproducing a large volume compared with a CD-R is desired. In particular, a DVD-R using an organic dye as a recording material is similar to a CD-R. It has been developed and commercialized.

  In DVD-R, in order to perform high-density recording, the transmission wavelength of laser light is near 630 nm to 680 nm and shorter than in the case of CD-R. Examples of dyes for such organic dye-based optical recording media for short wavelengths include trimethine compounds, azo compounds, porphyrin compounds, indigo compounds, dioxazine compounds, coumarin compounds, perylene compounds, naphtholactam compounds, triphenylmethane compounds, subphthalocyanines. Compounds, dibenzopyran compounds, dipyrromethene compounds and the like have been proposed.

Among these, trimethine compounds have been studied because they are excellent in optical properties and can cope with higher density.
The trimethine compound is composed of a cation having a trimethine structure and an anion that is a counter ion thereof. Examples of the anion that is a counter ion include halogen anions such as iodine, bromine, and chlorine; perchlorate anion, chlorate anion, and thiocyanate. Inorganic anions such as acid anion, phosphorus hexafluoride anion, antimony hexafluoride anion, boron tetrafluoride anion; organic sulfonate anions such as benzenesulfonate anion, toluenesulfonate anion, trifluoromethanesulfonate anion, etc. These are disclosed in Japanese Patent Laid-Open Nos. 2001-209969, 2001-322354, 2000-108510, 2000-168233, 10-235999, 10 -337959 It has been described in an equal.
However, the trimethine compound using the above anions has a problem that the storage stability of the recording against moisture and heat in the air (hereinafter sometimes referred to as “moisture and heat resistance”) is insufficient.
JP 2001-209969 A JP 2001-322354 A JP 2000-108510 A JP 2000-168233 A JP-A-10-235999 JP 10-337959 A

  The object of the present inventor is to enable recording and reproduction with a short-wavelength laser having a wavelength of 520 to 690 nm, excellent heat and humidity resistance, and high recording properties that are good not only at standard recording speed but also at high speed recording. The object is to provide a density optical recording medium.

  As a result of diligent investigations to solve the above problems, the present inventors have excellent heat and humidity resistance by using a trimethine compound having a specific structure, and in addition to standard recording speed as well as high speed recording. It has been found that a high-density optical recording medium having good recording characteristics can be obtained, and the present invention has been completed.

That is, the present invention
[1] A trimethine compound containing an anion component represented by the following general formula (I):

(In the formula, X and Y each independently have an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an aryl group which may have a substituent, and a substituent. Represents a good metallocenyl group and a heterocyclic ring represented by the following general formula (II), and X and Y may combine to form a ring.)

(In the formula, ring A represents a nitrogen atom to which it is bonded and a heterocyclic ring which may have a substituent, including a carbonyl group.)
[2] The trimethine compound according to [1] represented by the following general formula (III):

(Wherein R _{1 to} R ₁₄ each independently have a hydrogen atom, a halogen atom, a formyl group, a hydroxy group, a cyano group, a nitro group, an amino group, an alkyl group that may have a substituent, or a substituent. An alkoxy group which may have a substituent, an acyl group which may have a substituent, an alkenyl group which may have a substituent, a hydroxyalkyl group which may have a substituent, an alkoxycarbonyl group which may have a substituent , An alkylamino group which may have a substituent, a dialkylamino group which may have a substituent, an alkoxycarbonylalkyl group which may have a substituent, an alkylthio group which may have a substituent, a substituent An alkylsulfonyl group which may have a group, an alkylcarbonylamino group which may have a substituent, R ₂ and R ₃ , R ₃ and R ₄ , R ₄ and R ₅ , R ₁₀ and R ₁₁ , R ₁₁ and R _2, R ₁₂ and R ₁₃ are bonded to an aromatic hydrocarbon ring which may have a substituent, or a nitrogen atom, an oxygen atom, may form a heterocyclic ring containing a sulfur atom. The R ₆ and R ₇ and R ₈ and R ₉ may combine to form a 5- to 6-membered ring, R _{15 to} R ₁₇ represent a hydrogen atom, a halogen atom, or an alkyl group which may have a substituent, and X, Y represents the same meaning as in the general formula (I).)
[3] The trimethine compound according to [1] or [2], comprising an anionic component of any one of the following formulas (Ia) to (Id):

[4] An optical recording medium having at least a recording layer containing an organic dye and a reflective layer on a substrate, wherein at least one trimethine compound according to any one of [1] to [3] is used as the organic dye An optical recording medium,
It is about.

  By using the novel trimethine compound of the present invention as a recording layer, recording and reproduction can be performed with a laser having a wavelength of 520 to 690 nm, excellent heat and humidity resistance, and good not only for standard recording speed but also for high speed recording. It is possible to provide a high-density optical recording medium having excellent recording characteristics.

Hereinafter, the present invention will be described in detail.
The trimethine compound of the present invention is a trimethine compound containing an anionic component represented by the following general formula (I):

(In the formula, X and Y each independently have an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an aryl group which may have a substituent, and a substituent. Represents a good metallocenyl group and a heterocyclic ring represented by the following general formula (II), and X and Y may combine to form a ring.)

(In the formula, ring A represents a nitrogen atom to which it is bonded and a heterocyclic ring which may have a substituent, including a carbonyl group.)
More specifically, a trimethine compound represented by the following general formula (III):

(Wherein R _{1 to} R ₁₄ each independently have a hydrogen atom, a halogen atom, a formyl group, a hydroxy group, a cyano group, a nitro group, an amino group, an alkyl group that may have a substituent, or a substituent. An alkoxy group which may have a substituent, an acyl group which may have a substituent, an alkenyl group which may have a substituent, a hydroxyalkyl group which may have a substituent, an alkoxycarbonyl group which may have a substituent , An alkylamino group which may have a substituent, a dialkylamino group which may have a substituent, an alkoxycarbonylalkyl group which may have a substituent, an alkylthio group which may have a substituent, a substituent An alkylsulfonyl group which may have a group, an alkylcarbonylamino group which may have a substituent, R ₂ and R ₃ , R ₃ and R ₄ , R ₄ and R ₅ , R ₁₀ and R ₁₁ , R ₁₁ and R _2, R ₁₂ and R ₁₃ are bonded to an aromatic hydrocarbon ring which may have a substituent, or a nitrogen atom, an oxygen atom, may form a heterocyclic ring containing a sulfur atom. The R ₆ and R ₇ and R ₈ and R ₉ may combine to form a 5- to 6-membered ring, R _{15 to} R ₁₇ represent a hydrogen atom, a halogen atom, or an alkyl group which may have a substituent, and X, Y represents the same meaning as in the general formula (I).)
It is.

  Hereinafter, the trimethine compound containing an anionic component represented by the following general formula (I) and the trimethine compound represented by the following general formula (III) will be described more specifically as the trimethine compound in the present invention.

(In the formula, X and Y each independently have an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an aryl group which may have a substituent, and a substituent. Represents a good metallocenyl group and a heterocyclic ring represented by the following general formula (II), and X and Y may combine to form a ring.)

(In the formula, ring A represents a nitrogen atom to which it is bonded and a heterocyclic ring which may have a substituent, including a carbonyl group.)

(Wherein R _{1 to} R ₁₄ each independently have a hydrogen atom, a halogen atom, a formyl group, a hydroxy group, a cyano group, a nitro group, an amino group, an alkyl group that may have a substituent, or a substituent. An alkoxy group which may have a substituent, an acyl group which may have a substituent, an alkenyl group which may have a substituent, a hydroxyalkyl group which may have a substituent, an alkoxycarbonyl group which may have a substituent , An alkylamino group which may have a substituent, a dialkylamino group which may have a substituent, an alkoxycarbonylalkyl group which may have a substituent, an alkylthio group which may have a substituent, a substituent An alkylsulfonyl group which may have a group, an alkylcarbonylamino group which may have a substituent, R ₂ and R ₃ , R ₃ and R ₄ , R ₄ and R ₅ , R ₁₀ and R ₁₁ , R ₁₁ and R _2, R ₁₂ and R ₁₃ are bonded to an aromatic hydrocarbon ring which may have a substituent, or a nitrogen atom, an oxygen atom, may form a heterocyclic ring containing a sulfur atom. The R ₆ and R ₇ and R ₈ and R ₉ may combine to form a 5- to 6-membered ring, R _{15 to} R ₁₇ represent a hydrogen atom, a halogen atom, or an alkyl group which may have a substituent, and X, Y represents the same meaning as in the general formula (I).)

  In the trimethine compound containing an anion component represented by the general formula (I) of the present invention, the trimethine compound is formed from an anion component and a cation component and contains at least an anion component represented by the general formula (1). Good. The cationic component is not particularly limited as long as it has a trimethine structure.

  In the anion component represented by the general formula (I), X and Y may each independently have an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a substituent. An aryl group, a metallocenyl group which may have a substituent, and a heterocyclic ring represented by the general formula (II) are represented. X and Y may combine to form a ring.

Specific examples of X and Y include, for example, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, t-butyl group, n-pentyl group, 2-methylbutyl group, 1-methylbutyl group, neo-pentyl group, 1,2-dimethylpropyl group, cyclo-pentyl group, n-hexyl group, 4-methylpentyl group, 3-methylpentyl group, 2-methylpentyl group 1-methylpentyl group, 3,3-dimethylbutyl group, 2,3-dimethylbutyl group, 1,3-dimethylbutyl group, 2,2-dimethylbutyl group, 1,2-dimethylbutyl group, 1,1 -Dimethylbutyl group, 3-ethylbutyl group, 2-ethylbutyl group, 1-ethylbutyl group, 1,2,2-trimethylbutyl group, 1,1,2-trimethylbutyl group, 1-ethyl Ru-2-methylpropyl group, cyclo-hexyl group, n-heptyl group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 2,4-dimethylpentyl group, n-octyl group, 2-ethylhexyl group, 2,5-dimethylhexyl group, 2,5,5-triethylpentyl group, 2,4-dimethylhexyl group, 2,2,4-trimethylpentyl group, n-nonyl group 3,5,5-trimethylhexyl group, n-decyl group, 4-ethyloctyl group, 4-ethyl-4,5-dimethylhexyl group, n-undecyl group, n-dodecyl group, 1,3,5, 7-tetramethyloctyl group, 4-butyloctyl group, 6,6-diethyloctyl group, n-tridecyl group, 6-methyl-4-butyloctyl group, 6,6-diethyloctyl Group, n-tetradecyl group, n-pentadecyl group, 3,5-dimethylheptyl group, 2,6-dimethylheptyl group, 2,4-dimethylheptyl group, 2,2,5,5-tetramethylhexyl group, 1 A linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, such as -cyclo-pentyl-2,2-dimethylpropyl group, 1-cyclo-hexyl-2,2-dimethylpropyl group;
Chloromethyl group, dichloromethyl group, fluoromethyl group, trifluoromethyl group, 2,2,2-trifluoroethyl group, pentafluoroethyl group, heptafluoroisopropyl group, heptafluoro-n-propyl group, 2,2, 3,3,3-pentafluoropropyl group, nonafluoro-n-butyl group, nonafluoro-tert-butyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, 2,2,3, 4,4,4-hexafluorobutyl group, perfluoroisopentyl group, 2,2,3,3,4,4,5,5-octafluoropentyl group, heptafluoro-sec-pentyl group, perfluorohexyl Groups, perfluoroisohexyl groups, perfluoroheptyl groups, perfluorooctyl groups, perfluorocyclohexyl groups, 4-trifluoromethylcyclohexyl groups and the like halogenoalkyl groups;
Alkoxyalkyl groups such as methoxyethyl group, ethoxyethyl group, iso-propyloxyethyl group, 3-methoxypropyl group, 2-methoxybutyl group;
An alkoxycarbonylalkyl group having 3 to 7 carbon atoms such as a methoxycarbonylmethyl group, an ethoxycarbonylmethyl group, an n-propoxycarbonylmethyl group, an isopropoxycarbonylethyl group, a phenoxycarbonyl group;
Alkenyl groups such as vinyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, cyclopentenyl group, cyclohexenyl group;
Phenyl group, 4-methylphenyl group, 4-tert-butylphenyl group, biphenyl group, 4-trifluoromethylphenyl group, 4-methoxyphenyl group, 4-chlorophenyl group, 4-fluorophenyl group, naphthalen-1-yl Group, an aryl group such as naphthalen-2-yl group;
Examples thereof include metallocenyl groups such as a ferrocenyl group, a titanocenyl group, a chronocenyl group, and a ruthenocenyl group.

  Moreover, the following structure is mentioned as a preferable specific example of the following general formula (II).

(In the formula, ring A represents a nitrogen atom to which it is bonded and a heterocyclic ring which may have a substituent, including a carbonyl group.)

In the above formula, all Zs may be the same or different. As a specific example,
Hydrogen atom; halogen atom such as fluorine atom, chlorine atom, bromine atom; formyl group; hydroxyl group; carboxyl group; cyano group; nitro group;
Methyl, trifluoromethyl, ethyl, pentafluoroethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, cyclo Propyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, 1,2,2-trimethylbutyl group, 1,1,2-trimethylbutyl group, 1-ethyl-2-methylpropyl group, cyclo-hexyl group, n-heptyl Group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 2,4-dimethylpentyl group, n-octyl group, 2-ethylhexyl group, 2,5-dimethylhexyl Group, 2,5,5-triethylpentyl group, 2,4-dimethylhexyl group, 2,2,4-trimethylpentyl group Alkyl group having 1 to 8 carbon atoms;
Methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, tert-butoxy group, sec-butoxy group, n-pentyloxy group, iso-pentyloxy group, n-hexyloxy group, n- An alkoxy group having 1 to 8 carbon atoms such as an octyloxy group, a methoxymethoxy group, an ethoxyethoxy group, and a 3- (iso-propyloxy) propyloxy group;
An acyl group having 2 to 7 carbon atoms such as acetyl group, propiol group, butyryl group, isobutyryl group, valeryl group, isovaleryl group, pivaloyl group, hexanoyl group, heptanoyl group;
An alkenyl group having 2 to 6 carbon atoms such as vinyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, cyclopentenyl group, cyclohexenyl group;
A hydroxyalkyl group having 1 to 6 carbon atoms such as a hydroxymethyl group and a hydroxyethyl group;
Methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl group, n-butoxycarbonyl group, tert-butoxycarbonyl group, sec-butoxycarbonyl group, n-pentyloxycarbonyl group, n-hexyloxycarbonyl group An alkoxycarbonyl group having 2 to 7 carbon atoms, such as
An alkylamino group having 1 to 6 carbon atoms such as a methylamino group, an ethylamino group, an n-propylamino group, and an n-butylamino group;
A dialkylamino group having 2 to 8 carbon atoms such as a dimethylamino group, a diethylamino group, a di-n-propylamino group, a di-n-butylamino group;
An alkoxycarbonylalkyl group having 3 to 7 carbon atoms such as a methoxycarbonylmethyl group, an ethoxycarbonylmethyl group, an n-propoxycarbonylmethyl group, an isopropoxycarbonylethyl group, a phenoxycarbonyl group;
An alkylthio group having 1 to 6 carbon atoms such as methylthio group, ethylthio group, n-propylthio group, tert-butylthio group, sec-butylthio group, n-pentylthio group, n-hexylthio group;
Methylsulfonyl group, trifluoromethylsulfonyl group, ethylsulfonyl group, pentafluoroethylsulfonyl group, n-propylsulfonyl group, isopropylsulfonyl group, n-butylsulfonyl group, tert-butylsulfonyl group, sec-butylsulfonyl group, n- An alkylsulfonyl group having 1 to 6 carbon atoms such as a pentylsulfonyl group and an n-hexylsulfonyl group;
Methylcarbonylamino group, ethylcarbonylamino group, n-propylcarbonylamino group, isopropylcarbonylamino group, n-butylcarbonylamino group, tert-butylcarbonylamino group, sec-butylcarbonylamino group, n-pentylcarbonylamino group, etc. And an alkylcarbonylamino group having 2 to 6 carbon atoms.

Further, when X and Y are bonded to form a ring, they may be bonded via a coupler as described below.
-CH ₂ CH ₂ CH _2- , -CHCH ₃ CH ₂ CH _2- , -CH ₂ CHCH ₃ CH _2- , -CH ₂ CH ₂ CH ₂ CH _2- , -CHCH ₃ CH ₂ CH ₂ CH ₂ -,- An alkylene group having 1 to 6 carbon atoms such as CH ₂ CHCH ₃ CH ₂ CH _2- , -CH ₂ CH ₂ CH ₂ CH ₂ CH _2- , -CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH _2- ;
-CCl ₂ CCl ₂ CCl _2- , -CClCCl ₃ CCl ₂ CCl _2- , -CCl ₂ CClCCl ₃ CCl _2- , -CCl ₂ CCl ₂ CCl ₂ CCl _2- , -CClCCl ₃ CCl ₂ CCl ₂ CCl ₂ -,- _{CCl 2 CClCCl 3 CCl 2 CCl 2} -, - CCl 2 CCl 2 CCl 2 CCl 2 CCl 2 -, - CCl 2 CCl 2 CCl 2 CCl 2 CCl 2 CCl 2 -, - CF 2 CF 2 CF 2 -, - CFCF 3 CF ₂ CF _2- , -CF ₂ CFCF ₃ CF _2- , -CF ₂ CF ₂ CF ₂ CF _2- , -CFCF ₃ CF ₂ CF ₂ CF _2- , -CF ₂ CFCF ₃ CF ₂ CF _2- , -CF Examples thereof include perhalogenoalkylene groups having 1 to 6 carbon atoms such as ₂ CF ₂ CF ₂ CF ₂ CF ₂ -and -CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ CF _2- .

In the trimethine compound represented by the general formula (III), R _{1 to} R ₁₄ may each independently have a hydrogen atom, a halogen atom, a formyl group, a hydroxy group, a cyano group, a nitro group, an amino group, or a substituent. A good alkyl group, an alkoxy group which may have a substituent, an acyl group which may have a substituent, an alkenyl group which may have a substituent, a hydroxyalkyl group which may have a substituent, a substituted group An alkoxycarbonyl group which may have a group, an alkylamino group which may have a substituent, a dialkylamino group which may have a substituent, an alkoxycarbonylalkyl group which may have a substituent, a substituent Represents an alkylthio group which may have a substituent, an alkylsulfonyl group which may have a substituent, and an alkylcarbonylamino group which may have a substituent.

Here, specifically, R _{1 to} R ₁₄ are each independently a hydrogen atom, a halogen atom, a formyl group, a hydroxy group, a cyano group, a nitro group, an amino group, or a carbon group that may have a substituent. An alkyl group having 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms which may have a substituent, an acyl group having 2 to 7 carbon atoms which may have a substituent, and 2 carbon atoms which may have a substituent -6 alkenyl groups, optionally substituted hydroxyalkyl groups having 1 to 6 carbon atoms, optionally substituted alkoxycarbonyl groups having 2 to 7 carbon atoms, and optionally substituted. An alkylamino group having 1 to 6 carbon atoms, a dialkylamino group having 2 to 8 carbon atoms which may have a substituent, an alkoxycarbonylalkyl group having 3 to 7 carbon atoms which may have a substituent, and a substituent; Having a C1-C8 alkylthio group, which may have a substituent Alkyl sulfonyl group having 1 to 6 carbon atoms, a an optionally substituted alkyl carbonyl amino group having 2 to 6 carbon atoms.

More specifically, R _{1 to} R ₁₄ are each independently a hydrogen atom, a halogen atom, a formyl group, a hydroxy group, a cyano group, a nitro group, an amino group, an alkyl group having 1 to 8 carbon atoms, or an alkyl group having 1 to 8 carbon atoms. An alkoxy group having 2 to 7 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 7 carbon atoms, and an alkylamino having 1 to 6 carbon atoms. Group, C2-C8 dialkylamino group, C3-C7 alkoxycarbonylalkyl group, C1-C8 alkylthio group, C1-C6 alkylsulfonyl group, C2-C6 alkylcarbonyl Represents an amino group.

Here, specific examples of the substituent of the trimethine compound containing the anionic component of the general formula (I) and R _{1 to} R ₁₄ of the trimethine compound of the general formula (III) include, for example, a hydrogen atom; a fluorine atom, a chlorine atom, Halogen atom such as bromine atom; formyl group; hydroxyl group; cyano group; nitro group; amino group;
Methyl, trifluoromethyl, ethyl, pentafluoroethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, cyclo Propyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, 1,2,2-trimethylbutyl group, 1,1,2-trimethylbutyl group, 1-ethyl-2-methylpropyl group, cyclo-hexyl group, n-heptyl Group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 2,4-dimethylpentyl group, n-octyl group, 2-ethylhexyl group, 2,5-dimethylhexyl Group, 2,5,5-triethylpentyl group, 2,4-dimethylhexyl group, 2,2,4-trimethylpentyl group Alkyl group having 1 to 8 carbon atoms;
Methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, tert-butoxy group, sec-butoxy group, n-pentyloxy group, iso-pentyloxy group, n-hexyloxy group, n- An alkoxy group having 1 to 8 carbon atoms such as an octyloxy group, a methoxymethoxy group, an ethoxyethoxy group, and a 3- (iso-propyloxy) propyloxy group;
An acyl group having 2 to 7 carbon atoms such as acetyl group, propiol group, butyryl group, isobutyryl group, valeryl group, isovaleryl group, pivaloyl group, hexanoyl group, heptanoyl group;
An alkenyl group having 2 to 6 carbon atoms such as vinyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, cyclopentenyl group, cyclohexenyl group;
A hydroxyalkyl group having 1 to 6 carbon atoms such as a hydroxymethyl group and a hydroxyethyl group;
Methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl group, n-butoxycarbonyl group, tert-butoxycarbonyl group, sec-butoxycarbonyl group, n-pentyloxycarbonyl group, n-hexyloxycarbonyl group An alkoxycarbonyl group having 2 to 7 carbon atoms, such as
An alkylamino group having 1 to 6 carbon atoms such as a methylamino group, an ethylamino group, an n-propylamino group, and an n-butylamino group;
A dialkylamino group having 2 to 8 carbon atoms such as a dimethylamino group, a diethylamino group, a di-n-propylamino group, a di-n-butylamino group;
An alkoxycarbonylalkyl group having 3 to 7 carbon atoms such as a methoxycarbonylmethyl group, an ethoxycarbonylmethyl group, an n-propoxycarbonylmethyl group, an isopropoxycarbonylethyl group, a phenoxycarbonyl group;
An alkylthio group having 1 to 6 carbon atoms such as methylthio group, ethylthio group, n-propylthio group, tert-butylthio group, sec-butylthio group, n-pentylthio group, n-hexylthio group;
Methylsulfonyl group, trifluoromethylsulfonyl group, ethylsulfonyl group, pentafluoroethylsulfonyl group, n-propylsulfonyl group, isopropylsulfonyl group, n-butylsulfonyl group, tert-butylsulfonyl group, sec-butylsulfonyl group, n- An alkylsulfonyl group having 1 to 6 carbon atoms such as a pentylsulfonyl group and an n-hexylsulfonyl group;
Methylcarbonylamino group, ethylcarbonylamino group, n-propylcarbonylamino group, isopropylcarbonylamino group, n-butylcarbonylamino group, tert-butylcarbonylamino group, sec-butylcarbonylamino group, n-pentylcarbonylamino group, etc. And an alkylcarbonylamino group having 2 to 6 carbon atoms.

In addition, R ₂ and R ₃ , R ₃ and R ₄ , R ₄ and R ₅ , R ₁₀ and R ₁₁ , R ₁₁ and R ₁₂ , R ₁₂ and R ₁₃ may be bonded and have a substituent. An aromatic hydrocarbon ring or a heterocyclic ring containing a nitrogen atom, an oxygen atom, or a sulfur atom may be formed, but as a specific example of forming an aromatic hydrocarbon ring that may have a substituent, for example, The following formula is mentioned.

In the formula, R _{18 to} R ₂₁ may each independently have a hydrogen atom, a halogen atom, a formyl group, a hydroxy group, a cyano group, a nitro group, an amino group, an alkyl group that may have a substituent, or a substituent. A good alkoxy group, an acyl group which may have a substituent, an alkenyl group which may have a substituent, a hydroxyalkyl group which may have a substituent, an alkoxycarbonyl group which may have a substituent, An alkylamino group which may have a substituent, a dialkylamino group which may have a substituent, an alkoxycarbonylalkyl group which may have a substituent, an alkylthio group which may have a substituent, a substituent Represents an alkylsulfonyl group which may have a substituent and an alkylcarbonylamino group which may have a substituent.

More specifically, R _{18 to} R ₂₁ each independently have a hydrogen atom, a halogen atom, a formyl group, a hydroxy group, a cyano group, a nitro group, an amino group, or a substituent having 1 to 8 carbon atoms. An alkyl group, an optionally substituted alkoxy group having 1 to 8 carbon atoms, an optionally substituted acyl group having 2 to 7 carbon atoms, and an optionally substituted carbon group having 2 to 6 carbon atoms An alkenyl group, an optionally substituted hydroxyalkyl group having 1 to 6 carbon atoms, an optionally substituted alkoxy group having 2 to 7 carbon atoms, an optionally substituted carbon number An alkylamino group having 1 to 6 carbon atoms, a dialkylamino group having 2 to 8 carbon atoms which may have a substituent, an alkoxycarbonylalkyl group having 3 to 7 carbon atoms which may have a substituent, and a substituent; Or having an alkylthio group having 1 to 8 carbon atoms and a substituent. There alkylsulfonyl group having 1 to 6 carbon atoms, a an optionally substituted alkyl carbonyl amino group having 2 to 6 carbon atoms.

More specifically, R _{18 to} R ₂₁ are each independently a hydrogen atom, a halogen atom, a formyl group, a hydroxy group, a cyano group, a nitro group, an amino group, an alkyl group having 1 to 8 carbon atoms, or an alkyl group having 1 to 8 carbon atoms. An alkoxy group having 2 to 7 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 7 carbon atoms, and an alkylamino having 1 to 6 carbon atoms. Group, C2-C8 dialkylamino group, C3-C7 alkoxycarbonylalkyl group, C1-C8 alkylthio group, C1-C6 alkylsulfonyl group, C2-C6 alkylcarbonylamino Represents a group, and specific examples thereof include those described above.

  Moreover, the following formula is mentioned as a specific example in the case of combining and forming a heterocyclic ring.

R ₆ and R ₇ and R ₈ and R ₉ may combine to form a 5- to 6-membered ring. Specific examples in which R ₆ and R ₇ and R ₈ and R ₉ are combined to form a 5- to 6-membered ring include a cyclopentyl group, a cyclohexyl group, a tetrahydrofuran group, and a tetrahydropyran group.

R _{15 to} R ₁₇ represent a hydrogen atom, a halogen atom, or an alkyl group that may have a substituent, and more specifically, R _{15 to} R ₁₇ may have a hydrogen atom, a halogen atom, or a substituent. represents an alkyl group having 1 to 8 carbon atoms, more specifically _R 15 _{to R 17} represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms.

Specific examples of R _{15 to} R ₁₇ include, for example, hydrogen atom; halogen atom such as fluorine atom, chlorine atom, bromine atom, methyl group, trifluoromethyl group, ethyl group, pentafluoroethyl group, n-propyl group, Isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, 1,2,2-trimethylbutyl group 1,1,2-trimethylbutyl group, 1-ethyl-2-methylpropyl group, cyclo-hexyl group, n-heptyl group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5 -Methylhexyl group, 2,4-dimethylpentyl group, n-octyl group, 2-ethylhexyl group, 2,5-dimethylhexyl Group, 2,5,5-triethyl pentyl group, 2,4-dimethyl hexyl group, an alkyl group having 1 to 8 carbon atoms such as 2,2,4-trimethylpentyl group.

  X and Y represent the same meaning as in the general formula (I).

  Moreover, as an anion component of the trimethine compound of this invention, the anion component represented by following formula (Ia)-(Id) is mentioned as a preferable thing, The trimethine compound of this application is shown by following formula (I- The trimethine compound which consists of an anion component in any one of a)-(Id) is mentioned as a preferable thing.

  Although the preferable specific example of the trimethine compound which has an anion component of general formula (I) of this invention and the trimethine compound of general formula (III) is shown below, the range of the compound is not limited to these.

  The trimethine compound of the present invention is not particularly limited. For example, the indolenium compound represented by the general formula (IV) and the dianyl compound represented by the following formula (a) are condensed using a dehydrating organic acid in the presence of a fatty acid salt. To obtain a trimethine compound of the following general formula (V).

(IV)
(In the formula, R _{18 to} R ₂₄ have the same meaning as R _{1 to} R ₁₄ in the general formula (III)).

(A)

(In the formula, R _{1 to} R ₁₇ have the same meaning as R _{1 to} R ₁₇ in the general formula (III)).

In the above condensation reaction, examples of the fatty acid salt include sodium acetate, potassium acetate, potassium acetate, sodium propionate, and potassium propionate.
Such a fatty acid salt is usually used in an amount of about 0.1 to 5 mol, preferably about 0.5 to 2 mol, per mol of the compound represented by formula (IV).
Examples of the dehydrating organic acid include acetic anhydride, propionic anhydride, butyric anhydride, and γ-butyllactone.
Such dehydrating organic acid is usually used in an amount of about 10 to 100 mol, preferably about 20 to 50 mol, per 1 mol of the compound represented by formula (V).
The proportion of the compound represented by the general formula (V) and the compound represented by the formula (a) is usually about 0.2 to 1.5 mol, preferably 0.4 to 0, per 1 mol of the former. About 7 moles are used.

The above reaction normally proceeds suitably at about 10 to 150 ° C., preferably at room temperature to 120 ° C., and is generally completed in about several minutes to 3 hours.
After the reaction, for example, water, methanol, ethanol, n-propanol, iso-propanol, n-butanol or other poor solvent is injected, or water, methanol, ethanol, n-propanol, iso-propanol, n-butanol, etc. The target product can be easily isolated from the reaction mixture by discharging to a poor solvent.

  The trimethine compound of the general formula (V) is converted into an aprotic solvent such as DMF (N, N-dimethylformamide), DMAC (N, N-dimethylacetamide), DMSO (dimethylsulfoxide), DMI (1,3-dimethyl- 2-imidazolidinone) in the presence of alkali, NaOH, KOH, etc., in the presence of 5-50 ° C., preferably 10-30 ° C. for several minutes to 3 hours, and corresponding to the following general formula (VI ) Is produced.

(In the formula, R _{1 to} R ₁₇ have the same meaning as R _{1 to} R ₁₇ in the general formula (III)).

  After the reaction, the target trimethine hydroxy compound can be easily obtained by discharging into water.

  The aprotic solvent is used in an amount of 1 to 20 times, preferably 5 to 10 times the volume of the trimethine compound of the general formula (V).

  The alkali amount is 1 to 10 mol, preferably about 3 to 5 mol, relative to the trimethine compound of the general formula (V).

  The trimethine hydroxy form of the general formula (VI) is dissolved in a polar solvent such as acetone, ethyl acetate, THF, methylene chloride, chloroform, methanol, ethanol, n-propanol and represented by the following general formula (VII). And the corresponding trimethine compound represented by the general formula (III) can be produced by reacting at 5 to 50 ° C., preferably 10 to 30 ° C. for several minutes to 3 hours.

(In the formula, X and Y are the same as those in the general formula (I)).

A specific configuration of the optical recording medium in the present invention will be described below.
The optical recording medium refers to both a reproduction-only optical reproduction medium in which information is recorded in advance and an optical recording medium in which information can be recorded and reproduced. However, here, as an example, an optical recording medium that can record and reproduce the latter information, particularly an optical recording medium having a recording layer and a reflective layer on a substrate will be described. The optical recording medium of the present invention has a bonding structure as shown in FIG. That is, the recording layer 2, the reflective layer 3, and the protective layer (or adhesive layer) 4 are formed on the transparent resin substrate 1 having the lands 7 and the grooves 6, and in some cases, the substrate 5 is further formed thereon. Provided. However, another layer may be provided below or on the recording layer 2, and another layer may be provided on the reflective layer 3. Here, in order to be compatible with an existing DVD, a disk-shaped substrate having a thickness of 0.6 mm, an outer diameter of 120 mmΦ, and an inner diameter of 15 mmφ is bonded.

Next, the required characteristics of each layer constituting the recording medium of the present invention and its constituent materials will be described.
In addition, in the following description, although the case where the trimethine compound of general formula (III) is used as a compound of this application for convenience is demonstrated, it is not limited to this at all.

1) Substrate The material of the substrate may be basically transparent at the wavelengths of recording light and reproducing light. For example, an acrylic resin such as polycarbonate resin, vinyl chloride resin or polymethyl methacrylate, a polymer material such as polystyrene resin or epoxy resin, or an inorganic material such as glass is used. These substrate materials are formed into a disk shape by an injection molding method or the like. The substrate surface may have pregrooves and prepits representing recording positions, and prepits for partial reproduction-only information. These pregrooves and prepits are usually transferred and applied from a stamper master during substrate production by an injection molding method or the like. Moreover, you may produce by the laser cutting method (prelight) and 2P (Photo Polymer) method.

  The groove pitch of the substrate is 0.7 μm to 1.0 μm, and the groove depth is 100 nm to 200 nm, preferably 140 nm to 185 nm. The groove width is 0.25 μm to 0.40 μm, preferably 0.30 μm to 0.35 μm. When the groove depth is less than 100 nm, it tends to be difficult to obtain a push-pull signal amplitude for tracking. When the groove depth exceeds 200 nm, the transfer process at the time of injection molding is not practical for production. Further, when the groove width is less than 0.25 μm, the crosstalk tends to deteriorate, and when it exceeds 0.4 μm, the transfer process at the time of injection molding is not practical in production. These groove shapes are obtained from a diffracted light analysis by He-Cd laser irradiation or a profile such as AFM.

2) Recording layer In the present invention, a recording layer is provided on a substrate, and the recording layer of the present invention contains a trimethine compound represented by the general formula (III) having a λmax of around 450 nm to 630 nm. Among them, an appropriate optical constant for the recording and reproducing laser wavelength selected from 520 nm to 690 nm (the optical constant is expressed by a complex refractive index (n + ki). N and k in the formula are a real part n and an imaginary part. It is necessary to have a coefficient corresponding to k, where n is a refractive index and k is an extinction coefficient.

  In general, organic dyes are characterized in that the refractive index n and the extinction coefficient k greatly change with respect to the wavelength λ. When n is less than 1.8, the reflectivity and signal modulation necessary for accurate signal reading cannot be obtained, and even if k exceeds 0.40, the reflectivity decreases and a good reproduction signal is obtained. Not only is the signal easily changed by the reproduction light, but it is not suitable for practical use. In consideration of this feature, an organic dye having a preferable optical constant at a target laser wavelength is selected and a recording layer is formed, so that a medium having high reflectance and high sensitivity can be obtained. .

  The trimethine compound represented by the general formula (III) used in the present invention has a higher extinction coefficient than a normal organic dye, and the absorption wavelength range can be arbitrarily selected by selecting a substituent. Required for the recording layer (n is 1.8 or more and k is 0.04 to 0.40, preferably n is 2.0 or more and k is 0.04 to 0.4. 20) is satisfied.

  In addition, the trimethine compound represented by the general formula (III) is moderately accelerated by the heat generated during recording laser irradiation, has high sensitivity during high-speed recording, and suppresses deterioration of pit jitter due to thermal interference sufficiently low. Therefore, it has good recording characteristics not only at standard recording speed but also at high speed recording.

  Further, the trimethine compound represented by the general formula (III) is a very useful compound because of high storage stability of recording against moisture and heat in the air.

  In the recording layer of the present invention, preferably, one type of trimethine compound represented by the general formula (III) is used as the recording layer. However, in order to improve the recording characteristics, two or more types may be mixed, You may mix and use pigments other than a trimethine compound.

  The mixing ratio of the trimethine compound in the case of using a mixture of two or more trimethine compounds represented by the general formula (III) is not particularly limited. For the above reasons, the optical constant n is 1.8 or more, preferably 2 It is preferable that the mixing be performed so that the k is 0.04 or more and k is 0.04 to 0.40, preferably 0.04 to 0.20.

  Examples of the dye other than the trimethine compound of the present invention that may be used as a mixture include dyes having an absorption maximum at a wavelength of 450 nm to 630 nm and a large refractive index at 520 nm to 690 nm. Specifically, azo dyes, squarylium dyes, naphthoquinone dyes, anthraquinone dyes, porphyrin dyes, azaporphyrin dyes, tetrapyraporphyrazine dyes, indophenol dyes, pyrylium dyes, thiopyrylium dyes, Azurenium dyes, triphenylmethane dyes, xanthene dyes, indanthrene dyes, indigo dyes, thioindigo dyes, merocyanine dyes, thiazine dyes, acridine dyes, oxazine dyes, etc. It may be mixed. The mixing ratio of these pigments is about 0.1 to 30%.

  Further, when the k for the recording and reproducing laser wavelength selected from 520 nm to 690 nm of the trimethine compound represented by the general formula (III) is small, the wavelength is 600 nm to 900 nm in order to improve the recording characteristics. May be mixed with a light-absorbing compound having an absorption maximum. Specifically, azo dyes, squarylium dyes, naphthoquinone dyes, anthraquinone dyes, porphyrin dyes, azaporphyrin dyes, tetrapyraporphyrazine dyes, indophenol dyes, pyrylium dyes, thiopyrylium dyes, azurenium Dyes, triphenylmethane dyes, xanthene dyes, indanthrene dyes, indigo dyes, thioindigo dyes, merocyanine dyes, thiazine dyes, acridine dyes, oxazine dyes, phthalocyanine dyes, naphthalocyanine dyes Or a mixture of a plurality of pigments. The mixing ratio of these pigments is about 0.1 to 30%.

  When forming the recording layer, if necessary, a quencher, a dye decomposition accelerator, an ultraviolet absorber, an adhesive, an endothermic decomposition compound, or the like is mixed, or a compound having such an effect is represented by the general formula ( It can also be introduced as a substituent of the trimethine compound represented by III).

  Specific examples of quenchers include acetylacetonate compounds, bisdithio-α-diketone compounds, bisdithiol compounds such as bisphenyldithiol compounds, thiocatechol compounds, salicylaldehyde oxime compounds, thiobisphenolate compounds Metal complexes such as compounds are preferred. Amine compounds are also suitable.

  Examples of the thermal decomposition accelerator include metal compounds such as metal anti-knock agents, metallocene compounds, and acetylacetonate metal complexes.

  Furthermore, a binder, a leveling agent, an antifoaming agent, etc. can also be used together as needed. Preferred binders include polyvinyl alcohol, polyvinyl pyrrolidone, nitrocellulose, cellulose acetate, ketone resin, acrylic resin, polystyrene resin, urethane resin, polyvinyl butyral, polycarbonate, polyolefin and the like.

  When the recording layer is formed on the substrate, a layer made of an inorganic substance or a polymer may be provided on the substrate in order to improve the solvent resistance, reflectance, recording sensitivity, etc. of the substrate.

  Examples of the method for providing the recording layer include spin coating, spraying, casting, dipping, and other coating methods, sputtering, chemical vapor deposition, and vacuum vapor deposition. The spin coating method is simple and preferable.

  When a coating method such as spin coating is used, a coating solution in which the trimethine compound represented by the general formula (III) is dissolved or dispersed in a solvent so as to be 1 to 40% by weight, preferably 3 to 30% by weight. In this case, it is preferable to select a solvent that does not damage the substrate. Specific examples include alcohols (including alkoxy alcohols such as keto alcohols and ethylene glycol monoalkyl ethers), ketones, esters, ethers, aromatics, and alkyl halides.

  Of these, the alcohol type is particularly preferable. Among alcohols, alkoxy alcohols and keto alcohols are preferable. In the alkoxy alcohol system, the alkoxy moiety preferably has 1 to 4 carbon atoms, the alcohol moiety preferably has 1 to 5 carbon atoms, more preferably 2 to 5 carbon atoms, and the total number of carbon atoms is 3 It is preferably ˜7. Specifically, ethylene glycol monoalkyl ether (cellosolve) such as ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (also referred to as ethyl cellosolve, ethoxyethanol), butyl cellosolve, 2-isopropoxy-1-ethanol, etc. And 1-methoxy-2-propanol, 1-methoxy-2-butanol, 3-methoxy-1-butanol, 4-methoxy-1-butanol, 1-ethoxy-2-propanol and the like. Examples of keto alcohols include diacetone alcohol. Furthermore, fluorinated alcohols such as 2,2,3,3-tetrafluoropropanol can also be used.

  Moreover, you may make a coating liquid contain a binder, a dispersing agent, a stabilizer, etc. suitably.

  If necessary, the dye of the recording layer can be dispersed in a polymer thin film or the like.

  In addition, when a solvent that does not damage the substrate cannot be selected, a sputtering method, a chemical vapor deposition method, a vacuum vapor deposition method, or the like is effective.

  The film thickness of the dye layer is not particularly limited, but the film thickness on the guide grooves (grooves) of the substrate is preferably in the range of 30 nm to 150 nm, and the film thickness between the guide grooves (lands) of the substrate is 10 nm to A range of 80 nm is preferred. If the thickness of the groove exceeds 150 nm, the shortest pit is crushed, which is not preferable. On the other hand, when the thickness is smaller than 30 nm, good recording sensitivity and recording modulation degree cannot be obtained. It is particularly preferable that the film thickness on the land is as thin as possible. The film thickness of these recording layers can be controlled by using a mixture of a plurality of the above organic solvents.

3) Reflective layer A reflective layer having a thickness of preferably 50 nm to 300 nm is formed on the recording layer. As a material for the reflective layer, a material having a sufficiently high reflectance at the wavelength of the reproduction light, for example, Au, Al, Ag, Cu, Ti, Cr, Ni, Pt, Ta, and Pd metal may be used alone or as an alloy. Is possible. Among these, Au, Al, and Ag have high reflectivity and are suitable as the material for the reflective layer. Other than this, the following may be included. For example, Mg, Se, Hf, V, Nb, Ru, W, Mn, Re, Fe, Co, Rh, Ir, Zn, Cd, Ga, In, Si, Ge, Te, Pb, Po, Sn, Bi, etc. And metals and metalloids. In addition, a material containing Au as a main component is preferable because a reflective layer having a high reflectance can be easily obtained. Here, the main component means that the content is 50% or more. It is also possible to form a multilayer film by alternately stacking a low refractive index thin film and a high refractive index thin film using a material other than metal, and use it as a reflective layer.

  Examples of the method for forming the reflective layer include sputtering, ion plating, chemical vapor deposition, and vacuum vapor deposition. In addition, a known inorganic or organic intermediate layer or adhesive layer may be provided on the substrate or below the reflective layer in order to improve reflectivity, recording characteristics, and adhesion.

  The reflectance is not particularly limited as long as the signal can be reproduced, but is preferably 30% or more and less than 65%, and more preferably 45% or more and less than 60%.

4) Protective layer The material of the protective layer on the reflective layer is not particularly limited as long as it protects the reflective layer from external force. Examples of the organic substance include a thermoplastic resin, a thermosetting resin, an electron beam curable resin, and an ultraviolet curable resin. Examples of inorganic substances include SiO ₂ , Si ₃ N ₄ , MgF ₂ , SnO _{2 and the} like. A thermoplastic resin, a thermosetting resin, etc. can be formed by dissolving in an appropriate solvent, applying a coating solution, and drying. The ultraviolet curable resin can be formed by preparing a coating solution as it is or by dissolving in an appropriate solvent, and then applying the coating solution and curing it by irradiating with ultraviolet rays. As the ultraviolet curable resin, for example, acrylate resins such as urethane acrylate, epoxy acrylate, and polyester acrylate can be used. These materials may be used alone or in combination, and may be used not only as a single layer but also as a multilayer film.

  As a method for forming the protective layer, a coating method such as a spin coating method and a casting method, a sputtering method, a chemical vapor deposition method, and the like are used as in the recording layer. Among these, a spin coating method is preferable.

  The thickness of the protective layer is generally in the range of 0.1 μm to 100 μm, but in the present invention, it is 3 μm to 30 μm, more preferably 5 μm to 20 μm.

  A label or the like can be further printed on the protective layer. Alternatively, a protective sheet or substrate may be bonded to the reflective layer surface, or two optical recording media may be bonded to each other with the reflective layer surfaces facing each other. Further, an ultraviolet curable resin, an inorganic thin film, or the like may be formed on the mirror surface side of the substrate in order to protect the surface and prevent adhesion of dust and the like.

  The laser having a wavelength of 520 nm to 690 nm in the present invention is not particularly limited. For example, a dye laser capable of selecting a wavelength over a wide range in the visible light region, a helium neon laser having a wavelength of 633 nm, a high output around wavelengths 680, 650, and 635 nm. Examples thereof include a semiconductor laser and a harmonic conversion YAG laser having a wavelength of 532 nm. In the present invention, high-density recording and reproduction are possible at one wavelength or a plurality of wavelengths selected from these.

  Examples of the present invention will be shown below, but the present invention is not limited thereto.

[Production Example 1]
Production of Trimethine Compound Under a nitrogen atmosphere, 13.9 g of N, N′-diphenylformamidine was added to 45.0 g of acetic anhydride and cooled to 20 ° C. After 37.0 g of a compound represented by the following structural formula (A) was added dropwise at 20 ° C., the mixture was reacted at 45 to 50 ° C. for 1.5 hours. After adding 60 ml of methanol and stirring at 30 ° C. for 30 minutes, the mixture was stirred at 60 to 65 ° C. for 1 hour, and the pressure was gradually reduced to distill off the solvent. 135 ml of methanol was added to 25 ° C., 11.1 g of 70% perchloric acid was added dropwise, and the mixture was reacted at the same temperature for 1 hour. After adding 135 ml of water and stirring for 15 minutes, the crystals were collected by filtration, washed with water, dried and then recrystallized in ethanol to obtain 20.6 g of a compound represented by the following structural formula (B).

The compound thus obtained showed an absorption maximum at 582.0 nm in an acetone solution, and the gram extinction coefficient was 1.34 × 10 ⁵ ml / g · cm.

Production of Trimethine Compound (Compound 22) 5.0 g of the trimethine compound (Structural Formula (B)) of Production Example 1 was dissolved in 50 ml of dimethylformamide, 10 g of 10% aqueous sodium hydroxide solution was added at room temperature, and then at room temperature. Stir for 30 minutes. This reaction solution was added to 600 ml of ice water with stirring. The produced crystals were filtered, washed with water, dissolved in 50 ml of acetone, a solution prepared by dissolving 2.6 g of the following structural formula (C) in 5 ml of acetone was added at room temperature, and the mixture was stirred at room temperature for 30 minutes. After concentrating the reaction solution, 10 ml of water was added and stirred for 30 minutes. The produced crystal was filtered, washed with water, and dried to obtain 5.9 g of a compound represented by the following structural formula (Compound 22).

The compound thus obtained showed an absorption maximum at 582.0 nm in an acetone solution, and the gram extinction coefficient was 1.37 × 10 ⁵ ml / g · cm.

From the following analysis results, it was confirmed to be the target product.
Elemental analysis _{(C 37 H 49 N 4 F} 3 O 10 S 2)

FAB-MS (posi) (m / z): 533
FAB-MS (nega) (m / z): 297

Production of Trimethine Compound (Compound 27) 5.0 g of the trimethine compound (Structural Formula (B)) of Production Example 1 was dissolved in 50 ml of dimethylformamide, 10 g of 10% aqueous sodium hydroxide solution was added at room temperature, and then at room temperature. Stir for 30 minutes. This reaction solution was added to 600 ml of ice water with stirring. The produced crystals were filtered and washed with water, and then dissolved in 50 ml of acetone. After adding a solution of 2.4 g of trifluoromethylsulfonimide in 5 ml of acetone at room temperature, the mixture was stirred at room temperature for 30 minutes. After concentrating the reaction solution, 10 ml of water was added and stirred for 30 minutes. The produced crystals were filtered, washed with water, and dried to obtain 5.8 g of a compound represented by the following structural formula (Compound 27).

The compound thus obtained showed an absorption maximum at 582.0 nm in an acetone solution, and the gram extinction coefficient was 1.18 × 10 ⁵ ml / g · cm.

From the following analysis results, it was confirmed to be the target product.
Elemental analysis _{(C 35 H 45 N 3 F} 6 O 8 S 2)

FAB-MS (posi) (m / z): 533
FAB-MS (nega) (m / z): 280

[Production Example 2]
Production of Trimethine Compound In a nitrogen atmosphere, 5.7 g of N, N′-diphenylformamidine was added to 14.7 g of acetic anhydride and cooled to 15 ° C. A solution of compound 12.6 represented by the following structural formula (D) dissolved in 6 g of acetic anhydride was added to the above mixed solution and reacted at 100 ° C. for 5 hours. After standing to cool, 15 ml of methanol was added and stirred at 65 ° C. for 30 minutes, and the solvent was distilled off. 40 ml of methanol was added, and a 70% aqueous perchloric acid solution was added dropwise at 30 ° C. and reacted for 1 hour. 40 ml of water was added, and the mixture was stirred at 15 ° C. for 1 hour, filtered and washed with water. The obtained crystals were refluxed with 70 ml of methanol, cooled, filtered, washed and dried to obtain 7.8 g of a compound represented by the following structural formula (E).

The compound thus obtained showed an absorption maximum at 566.0 nm in an acetone solution, and the gram extinction coefficient was 2.74 × 10 ⁵ ml / g · cm.

Production of Trimethine Compound (Compound 46) 5.0 g of the trimethine compound (Structural Formula (E)) of Production Example 2 was dissolved in 50 ml of dimethylformamide, and 11 g of 10% aqueous sodium hydroxide solution was added at room temperature. Stir for 30 minutes. This reaction solution was added to 600 ml of ice water with stirring. The produced crystals are filtered, washed with water, dissolved in 50 ml of acetone, and after adding a solution of 2.9 g of hexafluoropropane-1,3-disulfonimide in 5 ml of acetone at room temperature, 30 minutes at room temperature. Stir. After concentrating the reaction solution, 10 ml of water was added and stirred for 30 minutes. The produced crystal was filtered, washed with water, and dried to obtain 6.2 g of a compound represented by the following structural formula (Compound 46).

The compound thus obtained showed an absorption maximum at 566.0 nm in an acetone solution, and the gram extinction coefficient was 2.35 × 10 ⁵ ml / g · cm.

From the following analysis results, it was confirmed to be the target product.
Elemental analysis _{(C 28 H 27 N 5 F} 6 O 8 S 2)

FAB-MS (posi) (m / z): 447
FAB-MS (nega) (m / z): 292

[Production Example 3]
Synthesis of Trimethine Compound In a nitrogen atmosphere, 10.4 g of N, N′-diphenylformamidine was added to 32.5 g of acetic anhydride and cooled to 20 ° C. After 27.7 g of the compound represented by the formula (F) was added dropwise at 20 ° C., the mixture was reacted at 45 to 50 ° C. for 2 hours. After adding 40 ml of methanol and stirring at 60 to 65 ° C. for 1 hour, the pressure was gradually reduced and the solvent was distilled off. 90 ml of methanol was added to 25 ° C., and 7.85 g of 70% perchloric acid was added dropwise, followed by reaction at the same temperature for 1 hour. After adding 90 ml of water and stirring for 30 minutes, the crystals were collected by filtration, washed with water and dried to obtain 26.4 g of a compound represented by the following structural formula (G).

The compound thus obtained showed an absorption maximum at 593.0 nm in an acetone solution, and the gram extinction coefficient was 1.42 × 10 ⁵ ml / g · cm.

Production of Trimethine Compound (Compound 92) 3.0 g of the trimethine compound (Structural Formula (G)) of Production Example 3 was dissolved in 30 ml of dimethylformamide, and 5.6 g of 10% aqueous sodium hydroxide solution was added at room temperature. The reaction was allowed for 5 hours. After completion of the reaction, the reaction solution was discharged into 600 g of ice water, filtered, washed with water and dried to obtain 2.3 g of a compound represented by the following structural formula (H).

  After dissolving 2.0 g of the compound represented by the structural formula (H) in 60 ml of acetone and adding a solution of 1.1 g of the compound represented by the following structural formula (C) in 10 ml of acetone at room temperature, The reaction was allowed for 5 hours. After the reaction solution was concentrated, 40 ml of water was added and stirred for 30 minutes. The obtained crystals were filtered, washed with water, and dried to obtain 2.3 g of a compound represented by the following structural formula (Compound 92).

The compound thus obtained showed an absorption maximum at 593.5 nm in an acetone solution, and the gram extinction coefficient was 1.00 × 10 ⁵ ml / g · cm.

From the following analysis results, it was confirmed to be the target product.
Elemental analysis _{(C 35 H 41 N 4 F} 3 O 12 S 2)

FAB-MS (posi) (m / z): 533
FAB-MS (nega) (m / z): 297

Production of Trimethine Compound (Compound 97) 3.0 g of the trimethine compound (Structural Formula (G)) of Production Example 3 was dissolved in 30 ml of dimethylformamide, and 5.6 g of 10% aqueous sodium hydroxide solution was added at room temperature. The reaction was allowed for 5 hours. After completion of the reaction, the reaction solution was discharged into 600 g of ice water, filtered, washed with water and dried to obtain 2.3 g of a compound represented by the following structural formula (H).

  After dissolving 2.0 g of the compound represented by the structural formula (H) in 60 ml of acetone and adding a solution of 1.0 g of trifluoromethanesulfonimide in 5 ml of acetone at room temperature, the mixture was reacted for 1.5 hours. . After the reaction solution was concentrated, 40 ml of water was added and stirred for 30 minutes. The obtained crystals were filtered, washed with water and dried, and purified with 62.5 ml of water / methanol (4/1) to obtain 2.3 g of a compound represented by the following structural formula (compound 97).

The compound thus obtained showed an absorption maximum at 593.0 nm in an acetone solution, and the gram extinction coefficient was 0.93 × 10 ⁵ ml / g · cm.

From the following analysis results, it was confirmed to be the target product.
Elemental analysis _{(C 33 H 37 N 3 F} 6 O 10 S 2)

FAB-MS (posi) (m / z): 533
FAB-MS (nega) (m / z): 280

[Production Example 4]
Synthesis of Trimethine Compound In a nitrogen atmosphere, 24.1 g of dimethylformamide was cooled to 10 ° C., and 12.7 g of phosphorus oxychloride was added dropwise at the same temperature, followed by reaction at 20 ° C. for 1 hour. A solution of 21.5 g of the compound represented by the following structural formula (I) and 20 ml of dimethylformamide was added dropwise at 20 ° C., and reacted at 35 ° C. for 1 hour. The reaction solution was discharged into 100 g of ice water, 72 g of 20% aqueous sodium hydroxide solution was added, and the mixture was stirred at 85 ° C. for 30 minutes. The mixture was extracted with 200 ml of toluene, washed with water and concentrated to obtain 17.7 g of a compound represented by the following structural formula (J).

  Under a nitrogen atmosphere, 7.84 g of the compound represented by the above structural formula (J) and 8.68 g of the compound represented by the following structural formula (K) were dissolved in 50 ml of acetic anhydride, and 2.88 g of methanesulfonic acid was added at 80 ° C. It reacted for 1.5 hours. After adding 50 ml of methanol and stirring at 60 to 65 ° C. for 1 hour, the pressure was gradually reduced and the solvent was distilled off. 75 ml of methanol was added to 25 ° C., and 4.76 g of 70% perchloric acid was added dropwise, followed by reaction at the same temperature for 1 hour. The reaction solution was discharged into 150 ml of water and stirred for 30 minutes, and then the crystals were collected by filtration, washed with water and dried to obtain 14.8 g of a compound represented by the following structural formula (L).

The compound thus obtained showed an absorption maximum at 587.5 nm in an acetone solution, and the gram extinction coefficient was 1.51 × 10 ⁵ ml / g. cm.

Production of Trimethine Compound (Compound 111) 4.0 g of the trimethine compound (Structural Formula (L)) of Production Example 4 was dissolved in 40 ml of dimethylformamide, 8 g of 10% aqueous sodium hydroxide solution was added at room temperature, and then at room temperature. Stir for 30 minutes. This reaction solution was added to 400 ml of ice water with stirring. The generated crystals were filtered and washed with water, and then dissolved in 30 ml of acetone. After adding a solution of 2.0 g of trifluoromethylsulfonimide in 10 ml of acetone at room temperature, the mixture was stirred at room temperature for 30 minutes. After concentrating the reaction solution, 30 ml of water was added and stirred for 30 minutes. The produced crystal was filtered, washed with water, and dried to obtain 5.1 g of a compound represented by the following structural formula (Compound 111).

The compound thus obtained showed an absorption maximum at 587.5 nm in an acetone solution, and the gram extinction coefficient was 1.14 × 10 ⁵ ml / g · cm.

From the following analysis results, it was confirmed to be the target product.
Elemental analysis _{(C 34 H 41 N 3 F} 6 O 9 S 2)

FAB-MS (posi) (m / z): 533
FAB-MS (nega) (m / z): 280

[Production Example 5]
Synthesis of Trimethine Compound 50 g of a compound represented by the following structural formula (M) and 22.0 g of N, N′-diphenylformamidine were added to 200.0 g of acetic anhydride under a nitrogen atmosphere, and then 1.5 to 45-50 ° C. Reacted for hours. After adding 250 ml of methanol and stirring at 30 ° C. for 30 minutes, the mixture was stirred at 60 to 65 ° C. for 1 hour, and the pressure was gradually reduced to distill off the solvent. After adding 400 ml of methanol to 25 ° C. and adding 18.8 g of 70% perchloric acid dropwise, the mixture was reacted at the same temperature for 1 hour. After adding 400 ml of water and stirring for 15 minutes, the crystals were collected by filtration, washed with water, dried and then recrystallized in ethanol to obtain 65.7 g of a compound represented by the following structural formula (N).

The compound thus obtained showed an absorption maximum at 584.0 nm in an acetone solution, and the gram extinction coefficient was 1.90 × 10 ⁵ ml / g · cm.

Production of Trimethine Compound (Compound 113) 5.0 g of the trimethine compound (Structural Formula (N)) of Production Example 5 was dissolved in 50 ml of dimethylformamide, and 11 g of 10% aqueous sodium hydroxide solution was added at room temperature. Stir for 30 minutes. This reaction solution was added to 600 ml of ice water with stirring. The produced crystals were filtered and washed with water, and then dissolved in 50 ml of acetone. After adding a solution of 2.8 g of trifluoromethylsulfonimide in 14 ml of acetone at room temperature, the mixture was stirred at room temperature for 30 minutes. After concentrating the reaction solution, 50 ml of water was added and stirred for 30 minutes. The produced crystal was filtered, washed with water, and dried to obtain 6.2 g of a compound represented by the following structural formula (compound 113).

The compound thus obtained showed an absorption maximum at 584.0 nm in an acetone solution, and the gram extinction coefficient was 1.38 × 10 ⁵ ml / g · cm.

From the following analysis results, it was confirmed to be the target product.
Elemental analysis _{(C 35 H 33 N 3 F} 6 O 4 S 2)

FAB-MS (posi) (m / z): 457
FAB-MS (nega) (m / z): 280

Production of Trimethine Compound (Compound 114) The reaction and treatment were conducted in the same manner as in Example 7 except that 2.8 g of trifluoromethylsulfonimide of Example 7 was changed to 2.9 g of the compound represented by the following structural formula (C). The compound 6.2g shown by the following structural formula (compound 114) was obtained.

The compound thus obtained showed an absorption maximum at 584.5 nm in an acetone solution, and the gram extinction coefficient was 1.28 × 10 ⁵ ml / g · cm.

From the following analysis results, it was confirmed to be the target product.
Elemental analysis _{(C 37 H 37 N 4 F} 3 O 6 S 2)

FAB-MS (posi) (m / z): 457
FAB-MS (nega) (m / z): 297

Production of Trimethine Compound (Compound 120) The reaction and treatment were conducted in the same manner as in Example 7 except that 2.8 g of trifluoromethylsulfonimide of Example 7 was changed to 2.9 g of hexafluoropropane-1,3-disulfonimide. 6.3 g of a compound represented by the following structural formula (Compound 120) was obtained.

The compound thus obtained showed an absorption maximum at 584.0 nm in an acetone solution, and the gram extinction coefficient was 1.44 × 10 ⁵ ml / g · cm.

From the following analysis results, it was confirmed to be the target product.
Elemental analysis _{(C 36 H 33 N 3 F} 6 O 4 S 2)

FAB-MS (posi) (m / z): 457
FAB-MS (nega) (m / z): 292

[Production Example 6]
Synthesis of Trimethine Compound In a nitrogen atmosphere, 6.0 g of a compound represented by the following structural formula (O) and 6.9 g of a compound represented by the following structural formula (P) were dissolved in 50 ml of acetic anhydride, and 2.6 g of methanesulfonic acid was dissolved. The mixture was further reacted at 80 ° C. for 1.5 hours. After adding 50 ml of methanol and stirring at 60 to 65 ° C. for 1 hour, the pressure was gradually reduced and the solvent was distilled off. 100 ml of methanol was added to 25 ° C., 4.3 g of 70% perchloric acid was added dropwise, and the mixture was reacted at the same temperature for 1 hour. The reaction solution was discharged into 300 ml of water and stirred for 30 minutes, and then the crystals were collected by filtration, washed with water and dried to obtain 14.2 g of a compound represented by the following structural formula (Q).

The compound thus obtained showed an absorption maximum at 575.5 nm in an acetone solution, and the gram extinction coefficient was 1.69 × 10 ⁵ ml / g. cm.

Production of Trimethine Compound (Compound 131) 3.0 g of the trimethine compound (Structural Formula (Q)) of Production Example 6 was dissolved in 60 ml of dimethylformamide, and 6.0 g of a 10% aqueous sodium hydroxide solution was added at room temperature. For 1.5 hours. This reaction solution was added to 900 ml of ice water with stirring. The produced crystals were filtered and washed with water, and then dissolved in 100 ml of acetone. After adding a solution of 1.5 g of trifluoromethylsulfonimide in 5 ml of acetone at room temperature, the mixture was stirred at room temperature for 1 hour. After concentrating the reaction solution, 50 ml of water was added and stirred for 30 minutes. The produced crystal was filtered, washed with water, and dried to obtain 3.6 g of a compound represented by the following structural formula (Compound 131).

The compound thus obtained showed an absorption maximum at 575.5 nm in an acetone solution, and the gram extinction coefficient was 1.24 × 10 ⁵ ml / g · cm.

From the following analysis results, it was confirmed to be the target product.
Elemental analysis _{(C 31 H 30 N 4 F} 6 O 6 S 2)

FAB-MS (posi) (m / z): 452
FAB-MS (nega) (m / z): 280
[Production Example 7]

Synthesis of Trimethine Compound In a nitrogen atmosphere, 19.0 g of a compound represented by the following structural formula (R) and 7.0 g of N, N′-diphenylformamidine were added to 60.0 g of acetic anhydride, followed by 1 at 45-50 ° C. Reacted for 5 hours. After adding 80 ml of methanol and stirring at 60 to 65 ° C. for 1 hour, the pressure was gradually reduced and the solvent was distilled off. 130 ml of methanol was added to 25 ° C., and 5.7 g of 70% perchloric acid was added dropwise, followed by reaction at the same temperature for 1 hour. After adding 150 ml of water and stirring for 30 minutes, the crystal was collected by filtration, washed with water and dried to obtain 20.1 g of a compound represented by the following structural formula (S).

The compound thus obtained showed an absorption maximum at 587.5 nm in an acetone solution, and the gram extinction coefficient was 1.71 × 10 ⁵ ml / g · cm.

Production of Trimethine Compound (Compound 205) 3.0 g of the trimethine compound (Structural Formula (S)) of Production Example 7 was dissolved in 30 ml of dimethylformamide, and 6.6 g of 10% aqueous sodium hydroxide solution was added at room temperature. For 1 hour. This reaction solution was added to 500 ml of ice water with stirring. The produced crystals are filtered, washed with water, dissolved in 80 ml of acetone, a solution prepared by dissolving 1.5 g of hexafluoropropane-1,3-disulfonimide in 10 ml of acetone at room temperature is added, and then at room temperature for 1 hour. Stir. After concentrating the reaction solution, 50 ml of water was added and stirred for 30 minutes. The generated crystals were filtered, washed with water, and dried to obtain 3.5 g of a compound represented by the following structural formula (Compound 205).

The compound thus obtained showed an absorption maximum at 587.5 nm in an acetone solution, and the gram extinction coefficient was 1.37 × 10 ⁵ ml / g · cm.

From the following analysis results, it was confirmed to be the target product.
Elemental analysis _{(C 42 H 45 N 3 F} 6 O 4 S 2)

FAB-MS (posi) (m / z): 541
FAB-MS (nega) (m / z): 292

  The trimethine compound 13 described in Table I was added to tetrafluoropropanol on an injection-molded polycarbonate substrate having a spiral groove (pitch = 0.74 um, depth = 165 nm, width = 0.33 um) having a thickness of 0.6 mm and a diameter of 120 mmΦ. (20 g / l), and the film was formed by spin coating so that the film thickness on the grooves was approximately 80 nm and the film thickness between the grooves was 20 nm. After drying at 80 ° C. for 2 hours, an AgPdCu reflective film is formed with a film thickness of 80 nm using a sputtering apparatus (CDI-900) manufactured by Balzers, and on this reflective layer, UV curable resin: SD17 (Dainippon Ink) After being coated and UV cured, a 0.6 mm thick polycarbonate substrate was laminated thereon as described above, and an optical recording medium was produced by bonding with UV light using a KZ8681 radical polymerization adhesive manufactured by JSR.

  Disc tester DDU1000 manufactured by Pulstec Industrial Co., Ltd .: wavelength = 661 nm, NA = 0.60, linear velocity = 3.5 m / s (DVD-R standard recording velocity), linear velocity = 14 m / second. Each DVDR-compatible EFM + signal was recorded at s (4 times the DVD-R standard recording speed) and linear velocity = 28 m / s (8 times the DVD-R standard recording speed). Recording conditions were recorded by adjusting the pulse conditions described in the DVD-R standard (ver. 2.0) at high speeds of 1 ×, 4 ×, and 8 ×, respectively, so as to be optimal for each pit. Jitter measurement was performed on these recording parts at a standard DVD speed. In the DVDR medium shown in this example, a wide power window was confirmed with a good jitter value at any of 1 × speed, 4 × speed, and 8 × speed.

  Further, the above optical recording medium was subjected to a reliability test at 80 ° C. and 85% RH for 500 hours. Even after the reliability test, a wide power window was confirmed with a good jitter value at any of 1 ×, 4 ×, and 8 × speeds.

[Examples 13 to 24]
An optical recording medium was produced in the same manner as in Example 12 except that the trimethine compounds described in Table I were used as appropriate.

  When these optical recording media were evaluated in the same manner as in Example 12, a wide power window could be confirmed with a good jitter value at any of 1 × speed, 4 × speed, and 8 × speed.

  Further, the above optical recording medium was subjected to a reliability test at 80 ° C. and 85% RH for 500 hours. Even after the reliability test, a wide power window was confirmed with a good jitter value at any of 1 ×, 4 ×, and 8 × speeds.

[Comparative Example 1]
Using the trimethine compound of Production Example 5 (Structural Formula (N)), an optical recording medium was produced in the same manner as in Example 12, and the same evaluation was performed. A wide power window was confirmed with good jitter values at 1x, 4x, and 8x speeds, but after a reliability test at 80 ° C and 85% RH for 500 hours, the signal deteriorated and good signal characteristics were obtained. I couldn't.

Table I shows the results of jitters and modulation factors of 1 × speed, 4 × speed, and 8 × speed measured before and after the reliability test at 80 ° C. and 85% RH 500 hours in Examples 12 to 24 and Comparative Example 1. It was. In the DVD-R medium shown in this example, good jitter and modulation degree were confirmed at any of 1 × speed, 4 × speed, and 8 × speed before and after the reliability test.
<Table-I>

  By using the trimethine compound of the present invention as a recording layer, it is possible to provide a write-once type optical recording medium that can be recorded and reproduced with a laser of 520 to 690 nm and is excellent in wet heat resistance and suitable for high-density and high-speed recording. Become.

It is a cross-sectional structure diagram showing a conventional optical recording medium and a layer structure of the present invention.

Explanation of symbols

1 Substrate 2 Recording layer 3 Reflective layer 4 Adhesive layer 5 Substrate

Claims (4)

The trimethine compound containing the anion component shown by the following general formula (I).
(In the formula, X and Y each independently have an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an aryl group which may have a substituent, and a substituent. Represents a good metallocenyl group and a heterocyclic ring represented by the following general formula (II), and X and Y may combine to form a ring.)
(In the formula, ring A represents a nitrogen atom to which it is bonded and a heterocyclic ring which may have a substituent, including a carbonyl group.) The trimethine compound according to claim 1, which is represented by the following general formula (III).
(Wherein R _{1 to} R ₁₄ each independently have a hydrogen atom, a halogen atom, a formyl group, a hydroxy group, a cyano group, a nitro group, an amino group, an alkyl group that may have a substituent, or a substituent. An alkoxy group which may have a substituent, an acyl group which may have a substituent, an alkenyl group which may have a substituent, a hydroxyalkyl group which may have a substituent, an alkoxycarbonyl group which may have a substituent , An alkylamino group which may have a substituent, a dialkylamino group which may have a substituent, an alkoxycarbonylalkyl group which may have a substituent, an alkylthio group which may have a substituent, a substituent An alkylsulfonyl group which may have a group, an alkylcarbonylamino group which may have a substituent, R ₂ and R ₃ , R ₃ and R ₄ , R ₄ and R ₅ , R ₁₀ and R ₁₁ , R ₁₁ and R _2, R ₁₂ and R ₁₃ are bonded to an aromatic hydrocarbon ring which may have a substituent, or a nitrogen atom, an oxygen atom, may form a heterocyclic ring containing a sulfur atom. The R ₆ and R ₇ and R ₈ and R ₉ may combine to form a 5- to 6-membered ring, R _{15 to} R ₁₇ represent a hydrogen atom, a halogen atom, or an alkyl group which may have a substituent, and X, Y represents the same meaning as in the general formula (I).) The trimethine compound according to claim 1 or 2, comprising an anionic component of any one of the following formulas (Ia) to (Id).
  An optical recording medium having at least a recording layer containing an organic dye and a reflective layer on a substrate, wherein at least one trimethine compound according to any one of claims 1 to 3 is used as the organic dye. Optical recording medium.