JP2002002118A - Optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical recording medium, which is excellent in recording sensitivity and suitable for high speed recording. SOLUTION: In the optical recording medium, which is formed by providing a recording layer, into or from which the writing and reading with laser beams can be done, on a substrate, the recording layer includes chelate coloring matters consisting of two or more different azo-based compounds in structure and metal ion having a valence of two or more so as to be selected from among the azo-based compounds.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical recording medium using a chelating dye of an azo compound and a metal in a recording layer.

[0002]

2. Description of the Related Art In recent years, optical recording using a laser has been particularly developed in order to enable recording and storage of high-density information and reproduction thereof. As a medium used for the recording, a conventionally proposed optical recording medium includes a magneto-optical recording medium, a phase-change optical recording medium, an organic dye-based optical recording medium, and the like.

Among these, the organic dye-based optical recording medium is considered to be superior in that it is inexpensive and the manufacturing process is simple. An example of the organic dye-based optical recording medium is a write-once compact disc (CD-R) in which a metal layer having a high reflectance is laminated on the organic dye layer.

Various dyes such as cyanine dyes, phthalocyanine dyes, and metal chelate dyes have been proposed and put into practical use as the dyes used in the recording layer of the CD-R. Attention has been paid to metal chelate dyes having excellent properties, and various optical recording media using dyes of this type have been proposed, including Japanese Patent Publication No. 3-818057 and JP-A-6-65514.

[0005]

In general, an optical recording medium must have high sensitivity to recording laser light, good storage stability, good light resistance, and a wide margin for recording power. , A high reflectance, and the like, and a dye used for an optical recording medium is also required to have a performance capable of realizing these. However,
It has heretofore been very difficult to satisfy these properties at the same time. Even in the case where a plurality of types of dyes are mixed and used in a combination that complements each other's weak parts, in general, the properties of low-performance dyes tend to appear strongly. The effect was insufficient for improving the performance of the optical recording medium.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to achieve this object, and as a result, have found that an azo metal chelate dye in which a plurality of azo compounds having different structures are coordinated to one metal. It has been found that the use of a recording layer can simultaneously improve a plurality of properties required for an optical recording medium.

That is, the present invention relates to an optical recording medium having a recording layer rewritable and / or readable by a laser provided on a substrate, wherein the recording layer comprises two or more azo compounds having different structures. A chelate dye composed of a metal ion having a valency or higher, wherein the azo compound is selected from the azo compounds represented by the following general formulas (I) and (II), respectively. Exists in optical recording media.

[0008]

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(Wherein, ring A represents an aromatic heterocyclic ring which may have a substituent. Ring B is an aromatic hydrocarbon ring, an aromatic heterocyclic ring, or a condensed condensed ring thereof. Represents a ring, each of which may have a substituent in addition to X. X represents a group having active hydrogen.)

[0010]

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(Wherein, ring C represents an aromatic heterocyclic ring which may have a substituent. Ring D is an aromatic hydrocarbon ring, an aromatic heterocyclic ring, or a condensed condensed ring thereof. Represents a ring, each of which may have a substituent in addition to X. X represents a group having active hydrogen.)

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The optical recording medium of the present invention using an azo metal chelate dye formed from an azo compound and a metal for the recording layer has a plurality of required performances such as good light resistance, good environmental resistance and high recording sensitivity. It has the feature that it can be satisfied at the same time.

In the general formulas (I) and (II), the ring A
And ring C are aromatic heterocycles, and these heterocycles may have a substituent. Ring A and ring C preferably have a structure in which one to three 5-membered and / or 6-membered rings are condensed, and more preferably a single ring or two condensed rings. Specifically, the following structures are mentioned.

[0014]

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R ₁ in the same ring structure may be the same or different, and may be hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl. C3-C6 cyclic alkyl such as butyl group, n-pentyl group, n-hexyl group, etc. having 1 to 6 carbon atoms, such as linear or branched alkyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group. Group, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n-pentyloxy group, n-hexyloxy group, etc. Alkoxy group, acetyl group, propionyl group, butyryl group, isoptyryl group, valeryl group, isovaleryl group, pivaloyl group, hexanoyl group,
An alkylcarbonyl group having 1 to 7 carbon atoms, such as a heptanoyl group, a vinyl group, a 1-propenyl group, an allyl group, an isopropenyl group, a 2-butenyl group, a 1,3-butadienyl group, a 1-pentenyl group, a 1-hexenyl group And C3 to C6 cyclic alkenyl groups such as a C2 to C6 linear or branched alkenyl group, cyclopentenyl group and cyclohexenyl group; and halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. , Formyl group, hydroxyl group, carboxyl group, hydroxymethyl group, hydroxyalkyl group having 1 to 6 carbon atoms such as hydroxyethyl group, methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl group, n- Butoxycarbonyl group, sec-butoxycarbonyl group, tert-butoxycarbonyl group, n-pen Tyloxycarbonyl group,
C2-C7 alkoxycarbonyl group such as n-hexyloxycarbonyl group, nitro group, cyano group, amino group, methylamino group, ethylamino group, n-propylamino group, n-butylamino group, etc. 1 to 6 alkylamino groups dimethylamino group, diethylamino group, di-n
-A dialkylamino group having 1 to 12 carbon atoms such as a propylamino group, a di-n-butylamino group or the like; a carbon number 3 such as a methoxycarbonylmethyl group, an ethoxycarbonylmethyl group, an n-propoxycarbonylmethyl group, an isopropoxycarbonylethyl group; To 7-alkoxycarbonylalkyl, methylthio, ethylthio, n-propylthio, sec-butylthio, tert-butylthio, n-pentylthio, n-hexylthio, etc. alkylthio groups having 1 to 6 carbon atoms, methylsulfonyl Group, ethylsulfonyl group, n-propylsulfonyl group, isopropylsulfonyl group, n-butylsulfonyl group, sec-butylsulfonyl group,
tert-butylsulfonyl group, n-pentylsulfonyl group,
C6-C16 which may have a C1-C6 alkylsulfonyl group substituent such as n-hexylsulfonyl group;
Aryl group having 7 to 17 carbon atoms which may have a substituent
An arylcarbonyl group of

[0016]

Embedded image —CR ₂ ＣC (CN) R ₃ (R ₂ is a hydrogen atom or a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a te
represents an alkyl group having 1 to 6 carbon atoms such as rt-butyl group, n-pentyl group, n-hexyl group, and R ₃ represents cyano group or methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl. Group, n-
Butoxycarbonyl group, sec-butoxycarbonyl group, te
rt- represents an alkoxycarbonyl group having 2 to 7 carbon atoms such as a butoxycarbonyl group, an n-pentyloxycarbonyl group and an n-hexyloxycarbonyl group. )

[0017]

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(R ₄ to R ₆ each independently represent a hydrogen atom, a nitro group, a fluorine atom, a chlorine atom, a bromine atom, a halogen atom such as an iodine atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, linear or branched alkyl group having 1 to 6 carbon atoms such as n-hexyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, A cyclic alkyl group having 3 to 6 carbon atoms such as a cyclohexyl group, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentyloxy group, represents an alkoxy group having 1 to 6 carbon atoms such as an n-hexyloxy group.)

[0019]

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(R ₇ to R ₉ each independently represent a hydrogen atom, a nitro group, a fluorine atom, a chlorine atom, a bromine atom, a halogen atom such as an iodine atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, linear or branched alkyl group having 1 to 6 carbon atoms such as n-hexyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, A cyclic alkyl group having 3 to 6 carbon atoms such as a cyclohexyl group, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentyloxy group, represents an alkoxy group having 1 to 6 carbon atoms such as an n-hexyloxy group, and L is -SCH
Represents _2- , -SO _3- . ) Trifluoromethyl, pentafluoroethyl, heptafluoro-n-propyl, heptafluoroisopropyl, perfluoro-n-butyl, perfluoro-sec-butyl, perfluoro-tert-
Butyl group, perfluoro-n-pentyl group, halogenated alkyl group having 1 to 6 carbon atoms such as perfluoro-n-hexyl group, trifluoromethoxy group, pentafluoroethoxy group, 2,2,2-trifluoroethoxy group, From 1 carbon atoms such as pentafluoroethoxy, perfluoro-n-butoxy, perfluoro-sec-butoxy, perfluoro-tert-butoxy, perfluoro-n-pentyloxy, perfluoro-n-hexyloxy 6, halogenated alkoxy, trifluoromethylthio, pentafluoroethylthio, heptafluoro-n-propylthio, heptafluoroisopropylthio, perfluoro
-n-butylthio group, perfluoro-sec-butylthio group,
And represents a halogenated alkylthio group having 1 to 6 carbon atoms such as a perfluoro-n-pentylthio group and a perfluoro-n-hexylthio group. ).

Preferred examples of the substituent R ₁ include a hydrogen atom, an unsubstituted alkyl group, a halogenated alkyl group, an alkylthio group, an unsubstituted alkoxy group, a halogenated alkoxy group, an alkenyl group, a formyl group, It is a carboxyl group, an alkylcarbonyl group, an alkoxycarbonyl group, a cyano group, a nitro group or a halogen atom.

The structure of ring A or ring C is particularly preferably a structure in which two rings represented by the following formula (V) are condensed.

Embedded image (In the formula, ring E represents an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocyclic ring which may have a substituent.) Ring E is a monocyclic 6-membered ring. Preferred and specific examples include a benzene ring, a pyridine ring, a diazine ring, and a triazine ring. As the substituent which ring E may have, R ₁
And the preferred groups are the same as those for R ₁ . Most preferably, the structure represented by the above formula (V) is a benzothiazole ring. In the general formulas (I) and (II), ring B and ring D are an aromatic hydrocarbon ring,
An aromatic heterocyclic ring or a ring in which a saturated ring is bonded thereto, and any of these may have a substituent other than X. As the aromatic hydrocarbon ring and the aromatic heterocycle, a 5- or 6-membered monocyclic or 2-condensed ring is preferable. As a ring formed by condensing a saturated ring with these, a ring formed by condensing one or two saturated 5-membered or 6-membered rings with the above-mentioned aromatic ring is exemplified. Specifically, examples of the aromatic hydrocarbon ring include a benzene ring and a naphthalene ring. As an aromatic heterocycle,

Embedded image And a pyrazole ring and a viridone ring. The ring formed by condensing a saturated ring with these aromatic rings will be described later. The ring B and the ring D are more preferably a benzene ring or a ring obtained by condensing a saturated ring with a benzene ring, and particularly the following general formula (IV)

[0023]

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The structure represented by the following formula is preferred. In the formula, the benzene ring G may have a substituent other than X and NR ₁₀ R ₁₁ . R ₁₀ and R ₁₁ each independently represent a group described below, bond to each other to form a ring, or each bond to a carbon atom constituting ring G to form a saturated ring fused to ring G . In the above case, R ₁₀ and R ₁₁ are each independently a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group And C6-C18 substituents such as alkyl, phenyl, tolyl, xylyl, and naphthyl, which may have a linear or branched substituent having 1 to 6 carbon atoms, such as n-hexyl group. Aryl group which may have a group, vinyl group, 1-propenyl group, allyl group, isopropenyl group, 2-butenyl group, 1,3-butadienyl group, 1-
A pentenyl group, a linear or branched alkenyl group having 2 to 6 carbon atoms such as a 1-hexenyl group, a cyclopentenyl group,
A cyclic alkenyl group having 3 to 6 carbon atoms such as a cyclohexenyl group, or a cyclic alkyl group which may have a substituent having 3 to 6 carbon atoms such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group or a cyclohexyl group; Represent. Such alkyl group, aryl group, alkenyl group, cyclic alkenyl group, cyclic alkyl group is a methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n -Alkoxy groups having 1 to 6 carbon atoms such as pentyloxy group, n-hexyloxy group, methoxymethoxy group, ethoxymethoxy group, propoxymethoxy group, methoxyethoxy group, ethoxyethoxy group, propoxyethoxy group, methoxypropoxy group, ethoxy An alkoxyalkoxy group having 2 to 12 carbon atoms such as a propoxy group, a methoxybutoxy group, an ethoxybutoxy group, a methoxymethoxymethoxy group, a methoxymethoxyethoxy group, a methoxyethoxymethoxy group, a methoxyethoxyethoxy group, an ethoxymethoxymethoxy group, an ethoxymethoxy Butoxy group, ethoxyethoxy methoxy group, alkoxyalkoxyalkoxy group carbon number of 3 15, such as ethoxyethoxy ethoxy group, allyloxy group, a phenyl group, a tolyl group, a xylyl group, an aryl group having 6 to 18 carbon atoms such as naphthyl group,
An aryloxy group having 6 to 18 carbon atoms such as a phenoxy group, a tolyloxy group, a xylyloxy group, a naphthyloxy group, a cyano group, a nitro group, a hydroxy group, a tetrahydrofuryl group, a methylamino group, an ethylamino group, and an n-propylamino group 1 to 6 carbon atoms such as n-butylamino group
Alkylamino group having 1 to 12 carbon atoms such as dimethylamino group, diethylamino group, di-n-propylamino group, di-n-butylamino group, methylsulfonylamino group, ethylsulfonylamino group, n-propyl 1 to 6 carbon atoms such as sulfonylamino group, isopropylsulfonylamino group, n-butylsulfonylamino group, sec-butylsulfonylamino group, tert-butylsulfonylamino group, n-pentylsulfonylamino group, n-hexylsulfonylamino group Alkylsulfonylamino group, a fluorine atom, a chlorine atom, a bromine atom, a halogen atom such as an iodine atom, a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an isopropoxycarbonyl group, an n-butoxycarbonyl group, and a sec-butoxy group Carbonyl group, tert-butoxy A C2-C7 alkoxycarbonyl group such as a bonyl group, an n-pentyloxycarbonyl group, or an n-hexyloxycarbonyl group; a methylcarbonyloxy group; an ethylcarbonyloxy group;
Propylcarbonyloxy group, isopropylcarbonyloxy group, n-butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butylcarbonyloxy group,
It may be substituted with an alkylcarbonyloxy group having 2 to 7 carbon atoms such as an n-pentylcarbonyloxy group or an n-hexylcarbonyloxy group.

Of these, particularly preferred as R ₁₀ and R ₁₁ are an unsubstituted linear or branched alkyl group or an alkyl group substituted with halogen. In the general formula (IV), the benzene ring G may have a substituent in addition to X and NR ₁₀ R ₁₁ , and examples of the substituent include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, n-
C1-C6 linear or branched alkyl groups such as butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, methoxy group, ethoxy group, n-propoxy group, isobutyl group C1-C6 alkoxy groups such as propoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n-pentyloxy group, n-hexyloxy group, fluorine atom, chlorine atom, bromine atom and iodine atom Such as halogen atom, cyano group, nitro group, hydroxy group, methylsulfonyl group, ethylsulfonyl group, n-propylsulfonyl group, isopropylsulfonyl group, n-butylsulfonyl group, sec-butylsulfonyl group, tert-butylsulfonyl group, C1-C6 alkylsulfonyl groups such as n-pentylsulfonyl group and n-hexylsulfonyl group, methoxycarbonyl group and ethoxycarbonyl group n- propoxycarbonyl group, isopropoxycarbonyl group, n- butoxycarbonyl group, sec- butoxycarbonyl group, tert- butoxycarbonyl group, n- pentyloxy group, n-
Examples thereof include an alkoxycarbonyl group having 2 to 7 carbon atoms such as a hexyloxycarbonyl group, and a thiocyanate group.

The substituent on the benzene ring G is particularly preferably an unsubstituted linear or branched alkyl group or an unsubstituted alkoxy group. In the case described above, that is, when R ₁₀ and R ₁₁ are bonded to each other to form a nitrogen-containing heterocyclic ring, the ring may be a saturated ring or a ring containing an unsaturated group. It is a ring. The size of the ring is preferably a 5- to 7-membered ring, more preferably a 5- or 6-membered ring.
It is a member ring. Specific examples include the following groups.

Embedded image In the formula, R ₁₃ represents the same group as R ₁₂ described below, and preferred groups include the same groups as R ₁₂ . General formula (IV)
In the above, when R ₁₀ and / or R ₁₁ form a ring condensed with the benzene ring G, that is, in the case described above, the ring size is preferably a 5- or 6-membered ring, and particularly preferably a 6-membered ring. In the case of a saturated ring and an unsaturated ring, a saturated ring is preferable. Specifically, the following structures are mentioned.

[0027]

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The substituent R ₁₂ on the nitrogen is hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl,
A linear or branched C1-C6 alkyl group which may have a substituent, such as an n-hexyl group, an optionally substituted alkyl group, a phenyl group, a tolyl group, a xylyl group, a naphthyl group, etc.
Represents an aryl group which may have 1 to 18 substituents, and is preferably a linear or branched alkyl group having 1 to 6 carbon atoms. Such alkyl groups or aryl groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentyloxy, n-hexyloxy, and the like. An alkoxy group having 1 to 6 carbon atoms, methoxymethoxy group, ethoxymethoxy group, propoxymethoxy group, methoxyethoxy group, ethoxyethoxy group, propoxyethoxy group, methoxypropoxy group, ethoxypropoxy group, methoxybutoxy group, ethoxybutoxy group, etc. C2 to C12 alkoxyalkoxy, methoxymethoxymethoxy, methoxymethoxyethoxy, methoxyethoxymethoxy, methoxyethoxyethoxy, ethoxymethoxymethoxy, ethoxymethoxyethoxy, ethoxyethoxymethoxy, ethoxy Shi alkoxyalkoxyalkoxy group carbon number of 3 15, such as ethoxyethoxy group, allyloxy group, a phenyl group, a tolyl group, a xylyl group, carbon atoms and naphthyl groups 6
To 18 aryl groups, phenoxy groups, tolyloxy groups, xylyloxy groups, naphthyloxy groups and other aryloxy groups having 6 to 18 carbon atoms, cyano groups, nitro groups,
C1-C6 alkylamino groups such as hydroxy group, tetrahydrofuryl group, methylamino group, ethylamino group, n-propylamino group, n-butylamino group, dimethylamino group, diethylamino group, di-n-propylamino Group, di-alkylamino group having 1 to 12 carbon atoms such as di-n-butylamino group, methylsulfonylamino group, ethylsulfonylamino group, n-propylsulfonylamino group, isopropylsulfonylamino group, n-butylsulfonylamino group, sec -Butylsulfonylamino group, tert-butylsulfonylamino group, n-pentylsulfonylamino group,
an alkylsulfonylamino group having 1 to 6 carbon atoms such as an n-hexylsulfonylamino group, a fluorine atom, a chlorine atom,
Bromine atom, halogen atom such as iodine atom, methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl group, n-butoxycarbonyl group, sec-butoxycarbonyl group, tert-butoxycarbonyl group, n-pentyl An alkoxycarbonyl group having 2 to 7 carbon atoms such as an oxycarbonyl group, an n-hexyloxycarbonyl group, a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group , Sec-butylcarbonyloxy group, tert-
It may be substituted with an alkylcarbonyloxy group having 2 to 7 carbon atoms, such as a butylcarbonyloxy group, an n-pentylcarbonyloxy group, and an n-hexylcarbonyloxy group.

Particularly preferred among these R ₁₂ are an unsubstituted linear or branched alkyl group, an alkyl group substituted with a halogen atom or an alkenyl group. To ring B or ring D, as a substituent other than X and R _12, a methyl group, an ethyl group, n- propyl group, an isopropyl group, n- butyl group, sec- butyl group, tert- butyl group, n- A linear or branched alkyl group having 1 to 6 carbon atoms such as a pentyl group, an n-hexyl group, a cyclopropyl group, a cyclobutyl group,
C3-C6 cyclic alkyl groups such as cyclopentyl group and cyclohexyl group, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n-pentyl Oxy group, n-
Alkylcarbonyl group having 1 to 7 carbon atoms such as alkoxy group having 1 to 6 carbon atoms such as hexyloxy group, acetyl group, propionyl group, butyryl group, isoptyryl group, valeryl group, isovaleryl group, pivaloyl group, hexanoyl group and heptanoyl group. Group, vinyl group, 1-propenyl group, allyl group, isopropenyl group, 2-butenyl group, 1,3-
C3-C6 linear or branched alkenyl, such as butadienyl, 1-pentenyl and 1-hexenyl, cyclopentenyl and cyclohexenyl, etc.
To 6 cyclic alkenyl groups, fluorine atoms, chlorine atoms, bromine atoms, halogen atoms such as iodine atoms, formyl groups,
Hydroxyl group, carboxyl group, hydroxymethyl group, hydroxyalkyl group having 1 to 6 carbon atoms such as hydroxyethyl group, methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl group, n-butoxycarbonyl group, sec-butoxycarbonyl group, tert-butoxycarbonyl group, n-pentyloxycarbonyl group, alkoxycarbonyl group having 2 to 7 carbon atoms such as n-hexyloxycarbonyl group, nitro group, cyano group, amino group, methylamino group, An alkylamino group having 1 to 6 carbon atoms such as an ethylamino group, an n-propylamino group, and an n-butylamino group; a dimethylamino group;
Dialkylamino group having 1 to 12 carbon atoms such as diethylamino group, di-n-propylamino group, di-n-butylamino group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, n-propoxycarbonylmethyl group, isopropoxycarbonylethyl C1-C7 alkoxycarbonylalkyl, methylthio, ethylthio, n-propylthio, sec-butylthio, tert-butylthio, n-pentylthio, n-hexylthio, etc. 6, alkylthio group methylsulfonyl group, ethylsulfonyl group, n-propylsulfonyl group, isopropylsulfonyl group, n-butylsulfonyl group, sec-
A C6-C16 aryl group which may have a C1-C6 alkylsulfonyl group substituent such as a butylsulfonyl group, a tert-butylsulfonyl group, an n-pentylsulfonyl group, or an n-hexylsulfonyl group; And an arylcarbonyl group having 7 to 17 carbon atoms which may have a group.

Of these substituents on ring B or ring D, particularly preferred are unsubstituted linear or branched alkyl groups and halogen-substituted alkyl groups. The chelate dye of the present invention has the general formula (I)
And two or more azo compounds having different structures selected from the azo compounds represented by (II) are coordinated,
It is preferable that at least one of the ring structure of ring A or ring C and the ring structure of ring B or ring D of the plurality of azo compounds differ from each other. Here, the “ring structure” means a ring corresponding to a skeleton portion in rings A to D, that is, a ring directly bonded to an azo group (not including a substituent).

For example,

Embedded image Compound represented by (i), it constituted chelate dye in (ii) and Ni ²⁺

Embedded image Is an example in which the ring structure of ring B in two azo compounds in one molecule is different (julolidine ring and benzene ring).
In other words, such a chelate dye is a combination of two or more azo compounds present in one molecule, a combination of different ring structures A, a combination of different ring structures C, a combination of ring structures A and C, a different ring structure. It means at least one of a combination of structures B, a combination of different ring structures D, or a combination of ring structures B and D. Of course, the chelate dye of the present invention may satisfy a plurality of the above combinations.

Particularly preferably, two or more azo compounds present in one molecule are all combinations represented by the general formula (II), and both rings C are condensed rings containing thiazole, that is, The following general formula (III)

[0033]

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(Wherein, ring E has the same meaning as in the above formula (V), and ring F represents an aromatic hydrocarbon ring or a ring obtained by condensing a saturated ring with these rings. Wherein X represents a group having active hydrogen), and two or more azo compounds in one molecule of the chelate dye (wherein the ring F in each azo compound is , Which do not have to have the same ring structure). Ring E is preferably a 5- or 6-membered ring, most preferably a 6-membered ring. Ring E is preferably an aromatic hydrocarbon ring. Ring F
Specific examples include a structure represented by the formula (IV). Most preferably as the chelate dye of the present invention,
The two or more azo compounds present in one molecule are all represented by the structural formula (III), and all the rings E are benzene rings or rings obtained by condensing a saturated ring with a benzene ring. It is a pigment.

In the general formulas (I) and (II), X represents -SH, -SO ₂ H, -SO ₃ H, -NH ₂ , -NHR ₁₃ , -OH, -C
_{O 2 H, -B (OH)} 2, -PO (OH) 2, -NHCOH, -NHCOR 13, -NHSO 2
It includes groups having an active hydrogen, such as R _13. Among them preferred _{are, -SO 3 H, -NH 2,} -NHR 13, -OH, -CO 2 H, -N
HCOH, -NHCOR _13, a -NHSO ₂ R _13, particularly preferred are
—SO ₃ H, —CO ₂ H, —OH, and —NHSO ₂ R ₁₃ .

Here, R ₁₃ is a methyl group, an ethyl group,
It has a linear or branched substituent having 1 to 6 carbon atoms such as n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group and n-hexyl group. Or a phenyl group which may have a substituent having 6 to 12 carbon atoms, such as an alkyl group or a phenyl group, a tolyl group, a xylyl group, and a naphthyl group, which are a fluorine atom, a chlorine atom, It may be substituted with a halogen atom such as a bromine atom and an iodine atom.

The metal ion constituting the chelate dye of the present invention is not particularly limited as long as it is divalent or higher. Here, the term “metal” refers to those located on the left side of the line connecting boron and astatine in the long-periodic table, ie, Group I (alkali metal and copper group) excluding hydrogen and Group II (alkaline earth metal and Zinc group), Group III excluding boron, Group IV excluding carbon and silicon, Group VIII (Iron group and Platinum group), and elements belonging to each subgroup a of V, VI, and VII, and antimony, bismuth, and polonium (See Iwanami Shoten Physical and Chemical Dictionary, 3rd Edition, Supplement, P339). Preferably, Mg, A
l, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Ru, R
h, Pd, In, Sn, Hf, Os, Pt, or Hg, especially C
o, Ni, Cu, Pd are particularly preferred.

The following are specific examples of the chelating dye of the present invention, but the present invention is not limited to these. In the following specific examples, for example, the following two azo compounds

[0039]

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And a chelate dye formed with Ni

[0041]

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## EQU2 ##

[0043]

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[0044]

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[0045]

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[0046]

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[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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[0055]

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[0056]

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[0057]

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[0058]

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[0059]

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In the present invention, a method for producing a chelate dye composed of two or more azo compounds having different structures and a divalent or higher valent metal ion includes the following methods: Method 1: Only azo compound P having the same structure is used. A chelate dye a having a ligand and a chelate dye b having only an azo compound Q having the same structure different from that of the azo as a ligand are dissolved in an appropriate solvent, and then dissolved at room temperature (about 1 ° C.).
5 to 30 ° C.) for 6 hours or more to perform ligand exchange (formula 1),

[0061]

[Equation 1] PMP + QMQ → PMQ
+ PMQ or Method 2: Multiple types of azo compounds (eg, P and Q)
And a compound containing a metal ion are mixed to perform a chelation reaction (formula 2)

[0062]

## EQU2 ## P + Q + M → PMQ. In the above formula 1, the method for producing a chelate dye of the present invention has been described, taking as an example the case where two types of chelate dyes a and b having the same ligand in method 1 are used. In Formula 2, the azo compound in Method 2 is
The case where two types of P and Q are used has been described as an example. However, the chelate dye in Method 1 and the azo compound in Method 2 may be used in three or more types.

In the case of the method 1, that is, when the chelate dye of the present invention is produced by a ligand exchange reaction, it is usually required
Hours or more, preferably 12 hours or more, more preferably 2 hours or more.
It is necessary to carry out the reaction for 4 hours. Specifically, the reaction solution is left at room temperature for at least 6 hours, preferably at least 12 hours, more preferably at least 24 hours. When heated, the ligand exchange reaction is expected to proceed faster than when left at room temperature. However, when heated to 100 ° C. or more, the dye may be degraded or decomposed. When the reaction time is shorter than the above range, the reaction is stopped before the reaction proceeds sufficiently. For this reason, for example, when forming (the recording layer of) an optical recording medium using the reaction solution as it is, or when a chelate dye is recovered from the reaction solution and used without purification, the obtained dye amount It is expected that the amount of the chelate dye of the present invention in the total is insufficient and its performance is not sufficiently exhibited. In addition, when only the pigment required by purification is obtained, the efficiency is poor because the proportion of the compound corresponding to the impurity is too large. Although there is no upper limit on the reaction time, it is usually sufficient that the ligand exchange reaction in the liquid reaches an equilibrium state. The optical recording medium of the present invention may use the chelate dye of the present invention whose purity has been increased by purification.
The chelate dye of the present invention obtained by the method 2, other methods may be used without purification (as a mixture). Purification can be carried out by a generally known method such as recrystallization and various types of chromatography. In the optical recording medium of the present invention, the ratio of the chelate dye of the present invention to the total amount of dyes in the recording layer is preferably at least 5 mol%, more preferably at least 10 mol%. This is the lower limit for the total of the plurality of chelating dyes in the case of an optical recording medium containing a plurality of chelating dyes of the present invention. If it is less than 5 mol%, the performance of the chelate dye of the present invention may not be sufficiently exhibited. There is no upper limit to the proportion of the chelate dye of the present invention. However, when the purified chelate dye is used for an optical recording medium, the proportion of the chelate dye obtained by any of the method 1 and the method 2 can be reduced. The upper limit is 100 mol%. When the chelate dye obtained by the method 1 is used without purification, the ratio of the chelate dye of the present invention is maximized when the ligand exchange reaction reaches an equilibrium state. It is 50 mol% or less per kind. In addition,
The recording layer of the optical recording medium of the present invention has an azo-based compound having the same structure selected from the azo-based compounds represented by the general formulas (I) and (II) as long as the performance of the present invention is not performed. Chelate dyes having only a compound as a ligand or other dyes, i.e., cyanine dyes, phthalocyanine dyes, azo dyes, triarylmethane dyes, squarylium dyes, metal-containing indoaniline dyes, etc. Good. Preferably, the proportion of the chelate dye of the present invention (when a plurality of dyes are included, the total amount thereof) accounts for 5 to 95 mol% of the total amount of dyes contained in the recording layer, and the remainder is only azo compounds having the same structure. This is the case where the chelate dye has as a ligand. More preferably, the chelate dye of the present invention is a chelate dye having 10 to 90 mol% and the remainder having only an azo compound having the same structure as a ligand. The content of the chelate dye of the present invention in the reaction solution in the dye synthesis process by the above method 1, the method 2 or other methods, or in the recording layer forming solution in the recording layer forming process of the optical recording medium is determined by liquid phase chromatography. It is only necessary to measure and manage using.

Although the optical recording medium of the present invention basically comprises a substrate and a recording layer containing a chelating dye, an undercoat layer may be provided on the substrate if necessary. As an example of a preferable layer configuration, a reflective layer and a protective layer are sequentially laminated on a recording layer to form a medium with high reflectivity, thereby providing a write-once recording medium. Such a substrate is made of, for example, an acrylic resin, a methacrylic resin, a polycarbonate resin, a resin such as a polyolefin resin (especially an amorphous polyolefin), a polyester resin, a polystyrene resin, an epoxy resin, or a glass. And those in which a resin layer made of a radiation-curable resin such as a photocurable resin is provided on glass. In terms of high productivity, cost, moisture absorption resistance and the like, injection molded polycarbonate is preferred.

From the viewpoints of chemical resistance and moisture absorption resistance, amorphous polyolefins are preferred. Further, a glass substrate is preferable in terms of high-speed response and the like. A resin substrate or a resin layer may be provided in contact with the recording layer, and a guide groove or pit for recording / reproducing light may be provided on the resin substrate or the resin layer. The thickness of the recording layer of the azo metal chelate dye formed from an azo compound and a metal in the optical recording medium of the present invention is from 10 nm to 5000
nm, preferably 70 nm to 3000 nm.

As a method for forming the recording layer, a vacuum evaporation method,
Sputtering method, doctor blade method, casting method,
The film can be formed by a generally used thin film forming method such as a spinner method and an immersion method, but the spinner method is preferable from the viewpoint of mass productivity and cost. Further, a binder can be used as necessary. As the binder, polyvinyl alcohol, polyvinylpyrrolidone, ketone resin,
Known materials such as nitrocellulose, cellulose acetate, polyvinyl butyral, and polycarbonate are used.
In this case, the chelating dye of the present invention contains 10% by weight in the recording layer.
It is preferable that it is contained above.

In the case of film formation by the spinner method, the number of rotations is 50.
0 to 15000 rpm is preferable, and after spin coating, a treatment such as heating or exposure to a solvent vapor may be performed in some cases. In order to improve the stability and light resistance of the chelate dye, a transition metal chelate compound (eg, acetylacetonate chelate, bisphenyldithiol, salicylaldehyde oxime, bisdithio-α-diketone) or the like is used as a singlet oxygen quencher in the recording layer. It may be contained, or a recording sensitivity improver such as a metal compound may be contained in order to improve the recording sensitivity. The metal-based compound is a compound in which a metal such as a transition metal is contained in the compound in the form of atoms, ions, clusters, etc., for example, an ethylenediamine-based complex, an azomethine-based complex, a phenylhydroxycyamine-based complex, a phenanthroline-based complex, Dihydroxyazobenzene-based complexes, dioxime-based complexes, nitrosoaminophenol-based complexes, pyridyltriazine-based complexes,
Organometallic compounds such as acetylacetonate-based complexes, metallocene-based complexes, and porphyrin-based complexes are exemplified.
The metal atom is not particularly limited, but is preferably a transition metal.

As a coating solvent for forming a recording layer by a coating method such as a doctor blade method, a casting method, a spinner method, and a dipping method, particularly a spinner method, a solvent that dissolves the dye of the present invention and does not attack the substrate. Anything is acceptable and is not particularly limited. For example, ketone alcohol solvents such as diacetone alcohol and 3-hydroxy-3-methyl-2-butanone, cellosolve solvents such as methyl cellosolve and ethyl cellosolve, hydrocarbon solvents such as n-hexane and n-octane, cyclohexane , Methylcyclohexane,
Hydrocarbon solvents such as ethylcyclohexane, dimethylcyclohexane, n-butylcyclohexane, tert-butylcyclohexane, and cyclooctane; ether solvents such as diisopropyl ether and dibutylether; and tetrafluoropropanol and octafluoropentanol Examples thereof include fluoroalkyl alcohol solvents, and hydroxyester solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate. In the case of the vacuum evaporation method, for example, the coloring matter of the present invention and, if necessary, the recording layer components such as other coloring matter and various additives are placed in a crucible placed in a vacuum vessel, and the inside of the vacuum vessel is vacuumed appropriately. After evacuating to about 10 ⁻² to 10 ⁻⁵ Pa with a pump, the crucible is heated to evaporate the components of the recording layer, and the recording layer is formed by vapor deposition on a substrate placed facing the crucible. A reflective layer may be formed on the recording layer, and its thickness is preferably 50 to 300 nm. As a material of the reflection layer, a material having a sufficiently high reflectance at the wavelength of the reproduction light, for example, a metal of Au, Al, Ag, Cu, Ti, Cr, Ni, Pt, Ta, Cr and Pd alone or as an alloy It can be used. Among them, Au, Al and Ag have high reflectivity and are suitable as a material for the reflective layer. In addition to these as main components, the following may be included. For example, Mg, Se, Hf, V, N
b, Ru, W, Mn, Re, Fe, Co, Rh, Ir, Cu, Zn, Cd, G
Metals and metalloids such as a, In, Si, Ge, Te, Pb, Po, Sn, and Bi can be mentioned. Among them, those containing Ag as a main component are particularly preferable in that they are inexpensive, easily reflect a high reflectance, and when a print receiving layer described later is provided, a ground white and beautiful one can be obtained. Here, the main component means one having a content of 50% or more. It is also possible to form a multilayer film by alternately stacking low-refractive-index thin films and high-refractive-index thin films with a material other than a metal, and use it as a reflective layer.
As a method of forming the reflective layer, for example, a sputtering method,
Examples include an ion plating method, a chemical vapor deposition method, and a vacuum vapor deposition method. In addition, a known inorganic or organic intermediate layer or adhesive layer may be provided on the substrate or below the reflective layer to improve the reflectance, the recording characteristics, and the adhesion. The material of the protective layer formed on the reflective layer is not particularly limited as long as it protects the reflective layer from external force.
Examples of the organic material include a thermoplastic resin, a thermosetting resin, an electron beam curable resin, and a UV curable resin. Further, as the inorganic substance, SiO ₂ , Si
N ₄ , MgF ₂ , SnO _{2 and the} like can be mentioned. A thermoplastic resin, a thermosetting resin, or the like can be formed by dissolving in an appropriate solvent, applying a coating solution, and drying.
The UV-curable resin can be formed by preparing a coating solution as it is or by dissolving it in an appropriate solvent, applying the coating solution, and irradiating with UV light to cure the resin. As the UV-curable resin, for example, acrylate resins such as urethane acrylate, epoxy acrylate, and polyester acrylate can be used.
These materials may be used singly or as a mixture, or may be used not only as a single layer but also as a multilayer film. As a method of forming the protective layer, a coating method such as a spin coating method or a casting method, a sputtering method, a chemical vapor deposition method, or the like is used as in the case of the recording layer. Among them, the spin coating method is preferable. The thickness of the protective layer is generally in the range of 0.1 to 100 μm, but is preferably 3 to 30 μm in the present invention.

The recording layer of the optical recording medium of the present invention may be provided on both sides of the substrate, or may be provided on one side. Further, a substrate may be further bonded to the reflective layer surface, or two optical recording media may be bonded to each other with the reflective layers facing each other as inner surfaces. Mirror side of substrate (surface without recording layer etc.)
In addition, an ultraviolet curable resin layer or an inorganic thin film may be formed to protect the surface and prevent dust adhesion.

It should be noted that a surface other than the recording / reproducing light incident surface is
A print receiving layer that can be written (printed) with various printers such as an ink jet or thermal transfer, or various writing tools may be provided. The recording on the optical recording medium obtained as described above is performed on a recording layer provided on both sides or one side of the substrate.
The irradiation is performed by irradiating a laser beam converged to about m, preferably a semiconductor laser beam. Thermal deformation of the recording layer, such as decomposition, heat generation, and melting, occurs due to absorption of laser light energy in the portion irradiated with the laser light.

Reproduction of recorded information is performed by reading the difference in reflectance between a portion where thermal deformation has occurred and a portion where thermal deformation has not occurred using a laser beam. Laser light used for the optical recording medium of the present invention is N ₂ , He-Cd, A
Examples thereof include r, He-Ne, ruby, semiconductor, and dye laser. Among them, a semiconductor laser is preferable because of its light weight, easy handling, and compactness.

[0072]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the present invention unless it exceeds the gist thereof. Example 1 a) Example of compound production

[0073]

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After dissolving 2 g of Compound A and 2 g of Compound B in 200 ml of methanol and filtering off insolubles, a solution of 0.4 g of nickel acetate tetrahydrate in 20 ml of methanol was stirred for 5 minutes at 25 ° C. And dropped. This further
The mixture was stirred at 25 ° C. for 1 hour, the generated solid was filtered, the solid was washed with methanol, and dried to obtain a mixture of compounds represented by the following structural formula.

[0075]

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B) Preparation Example of Recording Medium A mixture of the above compounds C, D and E (molar ratio: C: D: E =
24:50:26) 0.3 g of octafluoropentanol
It was dissolved in 10 ml and filtered through a filter having a pore size of 220 nm to obtain a dye solution. This dye solution was dropped onto a resin substrate (12 cm in diameter) made of injection-molded polycarbonate in which guide grooves were formed in advance, and applied by a spinner method. After application, at 80 ° C
Dry for 5 minutes. The maximum absorption wavelength of the coating film was 708 nm.

Next, a silver film having a thickness of 1000 ° was formed on this coating film by a sputtering method to form a reflection layer. Furthermore, an ultraviolet-curing resin is spin-coated on the reflective film, and this is irradiated with ultraviolet light to be cured, and the thickness is 5 μm.
Was formed. c) Evaluation example While rotating the recording medium at 5.6 m / s, the center wavelength was 780 n
m was irradiated at a recording power of 9.5 mW, and an EFM signal was recorded. Next, when this recorded portion was reproduced using a CD player having a center wavelength of 780 nm, a good reproduced signal was obtained. The light resistance (xenon fade meter acceleration test for 20 hours) and storage stability test (70 ° C 85% RH100) of this disc
Time) When the test was performed, no deterioration in sensitivity and recording characteristics was observed as compared with the initial stage, and the optical recording medium was extremely excellent. Example 2 b) Example of preparing recording medium 0.15 g of the compound C and 0.15 g of the compound E (both chelating dyes) were dissolved in 10 ml of octafluoropentanol and left at room temperature (about 20 ° C.) for 24 hours. An optical recording medium was prepared in the same manner as in Example 1 (b), except that the obtained dye solution was used after filtering through a filter. The ratio of the compounds C, D and E in the dye solution was 24: 50: 2
6 (molar ratio). c) Evaluation example While rotating the recording medium at 5.6 m / s, the center wavelength was 780 n
m was irradiated at a recording power of 9.5 mW, and an EFM signal was recorded. Next, when this recorded portion was reproduced using a CD player having a center wavelength of 780 nm, a good reproduced signal was obtained. The light resistance (xenon fade meter acceleration test for 20 hours) and storage stability test (70 ° C 85% RH100) of this disc
Time) When the test was performed, no deterioration in sensitivity and recording characteristics was observed as compared with the initial stage, and the optical recording medium was extremely excellent. Comparative Example 1 b) Example of preparing recording medium Optical recording was performed in the same manner as in Example 1 (b) except that 0.3 g of compound C was dissolved in 10 ml of octafluoropentanol, and a dye solution obtained by filtering through a filter was used. Created media. c) Evaluation example While rotating the recording medium at 5.6 m / s, the center wavelength was 780 n
m was irradiated at a recording power of 9.5 mW, and an EFM signal was recorded. Next, when this recording portion was reproduced using a CD player having a center wavelength of 780 nm, no signal could be read. Further, while rotating the recording medium at 5.6 m / s, a laser beam having a center wavelength of 780 nm was applied at a recording power of 1
Irradiation was performed at 2.5 mW, an EFM signal was recorded, and the recorded portion was reproduced using a CD player having a center wavelength of 780 nm. As a result, a good reproduced signal was obtained.

In the optical recording examples (c) of Examples 1 and 2, good recording was possible with a lower recording power than that of Comparative Example 1. Therefore, the optical recording medium using the compound of the present invention had good sensitivity. It can be seen that this is suitable for high-speed recording. Comparative Example 2 (b) Example of preparing a recording medium 0.3 g of the compound E was added to 10 ml of octafluoropentanol.
And an optical recording medium was prepared in the same manner as in Example 1 (b), except that a dye solution obtained by dissolving in a filter was used. (C) Evaluation example While rotating the recording medium at 5.6 m / s, the center wavelength was 780 n
m was irradiated at a recording power of 9.5 mW, and an EFM signal was recorded. Next, when this recorded portion was reproduced using a CD player having a center wavelength of 780 nm, a good reproduced signal was obtained. The light resistance (xenon fade meter acceleration test for 20 hours) and storage stability test (70 ° C 85% RH100) of this disc
Time) As a result of the test, the sensitivity and the recording characteristics were extremely deteriorated as compared with the initial stage, and recording and reproduction could not be performed.

The optical recording media of Examples 1 and 2 have better light resistance and storage stability than Comparative Example 2, indicating that they are excellent as optical recording media. Example 3 b) Example of creating a recording medium

[0080]

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The above compound F (0.15 g) and compound G (0.15 g) (both chelating dyes) were combined with octafluoropentanol 10
of the optical recording medium in the same manner as in Example 1 (b), except that the dye solution was dissolved in the same solution and left at room temperature (20 ° C.) for 24 hours. went. The maximum absorption wavelength of the coating film was 715 nm. In addition,
The ratio of F: H: G in the dye solution was 24:50:26 (molar ratio). c) Example of optical recording While the recording medium is rotated at 5.6 m / s, the center wavelength is 780n.
m was irradiated with a recording power of 12.5 mW to record an EFM signal.

Next, when the recorded portion was reproduced using a CD player having a center wavelength of 780 nm, a good reproduced signal was obtained. Comparative Example 3 b) Recording Medium Preparation Example The compound F (0.3 g) was dissolved in octafluoropentanol (10 ml). However, the solubility was low and the compound was not completely dissolved. An optical recording medium was prepared in the same manner as in Example 1 (b), except that it was used. c) Evaluation example While rotating the recording medium at 5.6 m / s, the center wavelength was 780 n
m was irradiated with a recording power of 12.5 mW to record an EFM signal.

Next, when this recording section was reproduced using a CD player having a center wavelength of 780 nm, no signal could be read. Comparative Example 4 b) Preparation of recording medium 0.3 g of the compound G was dissolved in 10 ml of octafluoropentanol, but the solubility was low and the compound was not completely dissolved. An optical recording medium was prepared in the same manner as in Example 1 (b), except that it was used. c) Evaluation example Optical recording example While rotating the above recording medium at 5.6 m / s, the center wavelength was 780n.
m was irradiated with a recording power of 12.5 mW to record an EFM signal.

Next, when this recording portion was reproduced using a CD player having a center wavelength of 780 nm, no signal could be read. It can be seen that Example 3 is superior to Comparative Examples 3 and 4 as an optical recording medium.

[0085]

According to the present invention, it is possible to provide a well-balanced optical recording medium which satisfies various required performances at a high level.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Satoru Imamura 1000 Kamoshita-cho, Aoba-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Chemical Corporation Yokohama Research Laboratory F-term (reference) 2H111 EA03 EA12 EA22 EA25 EA33 FB42 5D029 JA04 JC17 JC20

Claims (7)

[Claims] 1. An optical recording medium having a recording layer rewritable and / or readable by a laser provided on a substrate, wherein the recording layer comprises two or more azo compounds having different structures and two or more azo compounds. An optical recording medium comprising a chelate dye composed of a metal ion and wherein the azo compound is selected from the azo compounds represented by the following general formulas (I) and (II). . Embedded image (In the formula, ring A represents an aromatic heterocyclic ring which may have a substituent. Ring B represents an aromatic hydrocarbon ring, an aromatic heterocyclic ring, or a ring obtained by condensing a saturated ring with these. , May have a substituent in addition to X. X represents a group having active hydrogen.) (In the formula, ring C represents an aromatic heterocyclic ring which may have a substituent. Ring D represents an aromatic hydrocarbon ring, an aromatic heterocyclic ring, or a ring obtained by condensing a saturated ring with these. , May have a substituent other than X. X represents a group having active hydrogen.) 2. The chelating dye according to claim 1, wherein the two or more azo compounds contained in one molecule include a ring structure of ring A or ring C, and a ring structure of ring B
The optical recording medium according to claim 1, wherein at least one of the ring structures of the ring D is different from each other. 3. The optical recording medium according to claim 1, wherein at least two azo compounds contained in one molecule of the chelating dye are represented by the following general formula (III). Embedded image (Wherein, ring E represents an aromatic hydrocarbon ring which may have a substituent, or an aromatic heterocyclic ring which may have a substituent. Ring F is an aromatic hydrocarbon ring or Represents a ring obtained by condensing a saturated ring, each of which may have a substituent in addition to X. X represents a group having active hydrogen.) 4. An optical recording medium, wherein the recording layer contains a plurality of the chelating dyes according to claim 1. 5. The optical recording medium according to claim 1, wherein the ratio of the chelate dye to the total amount of the dye contained in the recording layer is 5 mol% or more. 6. The method according to claim 5, wherein the ratio of the chelate dye to the total amount of the dye contained in the recording layer is 5 to 95 mol%.
The optical recording medium as described in the above. 7. The remaining dye, excluding the chelate dye, of all the dyes contained in the recording layer, has the general formula (I) and the general formula (II)
The optical recording medium according to any one of claims 1 to 6, wherein the optical recording medium is a chelate dye having, as a ligand, only an azo compound having the same structure selected from the azo compounds represented by the formula: