JPH1081069A - Optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize excellent light resistance and highly sensitive and favorable record reproducing characteristics by a method wherein a recording layer containing specified azo-metal complex-based coloring matter is provided. SOLUTION: A recording layer contains azo metal-complex-based coloring matter obtained by reacting azo compound represented by the formula with metal compound. In the formula, Q1 represents a group of atoms necessary for the formation of an aromatic ring together with two carbon atoms, Z represents a group having active hydrogen, A represents carbon atom or heteroatom, Q2 represents a group of a atoms necessary for the formation of an aromatic ring together with two carbon atoms and A, Q3 represents a group of atoms necessary for the formation of an aromatic ring together with carbon atom, nitrogen atom and A and the aromatic ring completed by Q2 and the aromatic ring completed by Q3 from condensed rings. As a result, excellent characteristics such as high recording sensitivity and small jitter and the like are realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical recording medium using an azo metal complex dye for a recording layer.

[0002]

2. Description of the Related Art The inventors of the present invention have proposed a C (Compact Disc) standard as a recordable optical recording medium conforming to the CD (Compact Disk) standard.
D-R (write-once compact disc) has been developed.
In recent years, further high-density optical recording media have been desired, and one of them is to increase the recording wavelength of CD-R from the existing
Next-generation CD-Rs and DVs with shorter wavelengths from 0 to 635 nm
DR (write-once digital video disc) and the like have been proposed. However, as a result of the development proceeding up to 780 nm, almost no dyes satisfying various properties such as light fastness, solubility and recording sensitivity on the short wavelength side such as 680 nm to 635 nm are known. An additional requirement that cannot be ignored is compatibility with current standards. In other words, if the medium recorded by the current recording machine is at least short-wavelength and cannot be read at least, there is a problem that the accumulation of past information cannot be used simply and quickly. Therefore, it is important for the short wavelength recording layer to be developed in the future to comply with the standard at the current wavelength of 780 nm, that is, satisfy the so-called Orange Book standard, and at the same time, have the same characteristics from 680 nm to 635 nm as the current standard. Will be.

In order to realize this most practically, a proper amount of a dye having good characteristics in the current standard and having no large absorption on the short wavelength side is mixed and the characteristics are satisfied at both wavelengths. There is a way to do it. In this case, it is necessary to sufficiently examine the recording characteristics in the mixed system.

Although the recording wavelength is also important, a particularly important and difficult characteristic is the light resistance of the dye for the recording layer. Until now, some metal complex dyes have been mainly disclosed as high lightfast dyes. For example, as disclosed in JP-A-59-55795, there is an example in which a light-fast cyanine dye is combined with a metal complex quencher to improve the light fastness. However, this system has the drawback that the solubility in a coating solvent used during spin coating is significantly reduced, and that the stabilizer itself is decomposed and deteriorated. In addition, examples of those having high light resistance include azo-based metal complex dyes (Japanese Patent Publication No. 7-51682) and formazan nickel complex dyes (JP-A-60-254038 and JP-A-62-1449).
No. 97). Certainly, these metal complex dyes are excellent in light resistance, but generally have low recording sensitivity, relatively low solubility, and have the disadvantage that they are dissolved only in a specific solvent. Considering recording and reproduction at a short wavelength of 680 nm to 635 nm, the absorption wavelength of the formazan nickel metal complex dye is too long, and it is considered that this skeleton can no longer cope with the short wavelength.

With respect to phthalocyanine dyes which have long been known as high lightfast dyes, it is still difficult to avoid the above-mentioned disadvantages, and it is considered impossible to develop them as dyes for short-wavelength dye recording layers. As described above, 680 nm to 63
Dye having desired recording / reproducing characteristics even when used in a mixed system with a dye having absorption at the longer wavelength side, especially when used in a mixed system with a dye having a short wavelength of 5 nm. There is a strong need for a skeleton.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is, first, to provide a high-sensitivity optical recording medium having excellent light resistance and good recording / reproducing characteristics at a wavelength of about 680 nm to 635 nm. . Second, it is an object of the present invention to provide a high-sensitivity optical recording medium capable of performing good recording and reproduction even at a wavelength of about 780 nm and having recording and reproduction characteristics conforming to the Orange Book standard.

[0007]

This and other objects are achieved by the present invention which is defined below as (1) to (6). (1) An optical recording medium having a recording layer containing an azo metal complex dye obtained by reacting an azo compound represented by the following formula (I) with a metal compound.

[0008]

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[In the formula (I), Q ₁ represents an atom group necessary for forming an aromatic ring together with two carbon atoms.
Z represents a group having active hydrogen. A represents a carbon atom or a hetero atom. Q ₂ represents an atomic group necessary for forming an aromatic ring together with two carbon atoms and A, Q ₃ represents an atomic group necessary for forming an aromatic ring together with a carbon atom, a nitrogen atom and A, The aromatic ring completed by Q ₂ and Q
_The aromatic ring completed in ₃ forms a condensed ring. (2) The central metal of the azo metal complex dye is Co, M
n, Ti, V, Ni, Cu, Zn, Mo, W, Ru, F
e, Pd, Pt or Al, wherein the azo compound is represented by the following formula (Ia):

[0010]

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[In the formula (Ia), R ₁ , R ₂ , R ₃ and R ₄ each represent a hydrogen atom, a halogen atom, an amino group, an alkyl group, an alkoxy group, an aryloxy group, an acyl group, an aryl group, a carbamoyl group Or an alkoxycarbonyl group, which may be the same or different. R ₁ and R ₂ , R ₂ and R _3, and R ₃ and R ₄ may be bonded to each other to form a condensed ring. Z is -O
_{H, -SH, -NH 2, -COOH} , -CONH 2, -
It represents an SO ₂ NH ₂ or -SO ₃ H. R ₅ , R ₆ , R
₇ , R ₈ , R ₉ and R ₁₀ each represent a hydrogen atom, a halogen atom, a nitro group, a cyano group or an alkyl group, which may be the same or different. (3) An optical recording medium having a recording layer containing an azo metal complex dye obtained by reacting an azo compound represented by the following formula (II) with a metal compound. Formula (II) Q ¹ -N = N-Q ² [In the formula (II), Q ¹ represents an 8-quinolyl group;
² represents a 2-imidazolyl group, and nitrogen at position 1 of the 2-imidazolyl group has active hydrogen. (4) The central metal of the azo metal complex dye is Co, M
The optical recording medium according to the above (3), which is n, Ni, Cu, Zn, Mo, Fe or Pd. (5) The above (1) to (1) to wherein the recording layer further contains a light-absorbing dye having optical characteristics different from those of the azo metal complex dye.
The optical recording medium according to any one of (4). (6) The optical recording medium according to the above (5), wherein the light absorbing dyes having different optical characteristics are phthalocyanine dyes.

[0012]

The azo metal complex dye used in the present invention is obtained by coordinating an azo compound represented by the formula (I), preferably the formula (Ia), with a metal. And a coordination bond with a nitrogen atom forming a condensed aromatic ring together with a carbon atom adjacent to a carbon atom in the aromatic ring. For this reason, Tokuho 7-5
The complex itself has a relatively distorted coordination structure as compared to the azo metal complex-based dye disclosed in Japanese Patent No. 1682, which coordinates to the central metal at the nitrogen atom adjacent to the carbon atom in the aromatic ring to which the azo group is bonded. It is considered that this leads to an improvement in solubility. At the same time, the distorted coordination structure enhances the thermal decomposability, and it is considered that even metal complex dyes generally considered to have low recording sensitivity cause relatively high recording sensitivity. Although a theoretical explanation cannot be given, it is considered that this distorted structure leads to an unexpected effect of improving jitter characteristics when used in a mixed dye system.

H. Hoshino, T. Yotsuyanagi, Buns
eki Kagaku, 31 , E435 (1982) states that 2- (8-quinolylazo) -5-N, N-diethylaminophenol (in the formula (II), R ₁ , R ₃ -R ₁₀ = H, R ₂ = −N (C
_{2 H 5) 2, Z =} -OH) is disclosed. But,
This is only used as a metal analysis reagent by reversed-phase partition liquid chromatography, and there is no suggestion of using it for the recording layer of an optical recording medium.

The azo metal complex dye used in the present invention is obtained by coordinating an azo compound represented by the formula (II) with a metal, and the central metal is a nitrogen atom of a quinoline ring and a coordination bond. To form The azo group is located at the 8-position of the quinoline ring [see formula (IIa) described below], and the nitrogen atom is located at a position adjacent to the carbon atom adjacent to the carbon atom to which the azo group is bonded. For this reason, Japanese Patent Publication No. 7-51682 and Japanese Patent Publication No. 7-7
No. 1867, No. 7-71868, No. 7-71
No. 869 discloses a coordination structure in which the complex itself is relatively distorted as compared with an azo metal complex-based dye which coordinates to a central metal at a nitrogen atom adjacent to a carbon atom in an aromatic ring to which an azo group is bonded. It is considered that this leads to improvement in solubility. At the same time, the distorted coordination structure enhances the thermal decomposability, and it is considered that even metal complex dyes generally considered to have low recording sensitivity cause relatively high recording sensitivity. Although a theoretical explanation cannot be given, it is considered that this distorted structure leads to an unexpected effect of improving jitter characteristics when used in a mixed dye system.

In addition, "Shozo Shibata, Masamichi Furuk
awa and Ryozo Nakashima, Analytica Chimica Acta, 8
1 (1976) 131-141 "shows 2- (8-quinolylazo) -4,5-diphenylimidazole which is one kind of the azo compound represented by the formula (II). It has been shown to be used as a colorimetric reagent. However, in the above document, 2- (8-quinolylazo) -4,
There is no suggestion to use a metal complex of 5-diphenylimidazole in the recording layer of an optical recording medium.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The optical recording medium of the present invention has a recording layer containing an azo metal complex dye. As such an azo metal complex dye, first, an azo compound represented by the formula (I) is reacted with a metal compound. What was obtained is mentioned.

Describing the formula (I), Q ₁ represents an atomic group necessary for forming an aromatic ring together with two carbon atoms. The aromatic ring completed by Q ₁ may be a carbocyclic or heterocyclic ring, and may be a monocyclic or polycyclic ring. In the case of a polycyclic ring, it may be a condensed polycyclic ring or a ring assembly. Examples of such an aromatic ring include a benzene ring, a naphthalene ring, a pyridine ring, a thiazole ring, a benzothiazole ring, an oxazole ring, a benzoxazole ring, a quinoline ring, an imidazole ring, a pyrazine ring, and a pyrrole ring. A ring and a naphthalene ring are preferred, and a benzene ring is particularly preferred.

Z represents a group having active hydrogen, and specific examples thereof include the same as those in formula (Ia).

The aromatic ring completed in Q ₁ may further have a substituent in addition to Z and an azo group, such an alkyl group, an alkoxy group, a nitro group, a cyano group, Examples include a halogen atom, an aryl group, an aryloxy group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, and an amino group.

A represents a carbon atom or a heteroatom such as O, N and S, and is preferably a carbon atom.

Q ₂ represents a group of atoms necessary for forming an aromatic ring together with two carbon atoms and A, and the aromatic ring completed by Q ₂ is the same as the aromatic ring completed by Q ₁ And specific examples include the same. Of these, a benzene ring is preferred.

Q ₃ represents a group of atoms necessary for forming an aromatic ring together with a carbon atom, a nitrogen atom and A. The nitrogen-containing aromatic ring completed by Q ₃ may be a single ring or a condensed polycyclic ring. You may. Specific examples of such a nitrogen-containing aromatic ring include a pyridine ring, a thiazole ring, a benzothiazole ring, an oxazole ring, a benzoxazole ring, a quinoline ring, an imidazole ring, a pyrazine ring, and a pyrrole ring. preferable.

The aromatic ring completed by Q ₂ and the aromatic ring completed by Q ₃ form a condensed ring. Examples of such a condensed ring include a quinoline ring, a benzothiazole ring and a benzoxazole ring. And preferably a quinoline ring.

The condensed aromatic ring completed by Q ₂ and Q ₃ may further have a substituent in addition to the azo group. Examples of such a substituent are those exemplified for Q _1. The same can be mentioned.

Among the azo compounds of the formula (I), those of the formula (Ia) are preferred. To explain the formula (Ia), R _{1 to} R ₄ each represent a hydrogen atom, a halogen atom, an amino group, an alkyl group, an alkoxy group, an aryloxy group, an acyl group, an aryl group, a carbamoyl group or an alkoxycarbonyl group. May be the same or different.

Examples of the halogen atom represented by R _{1 to} R ₄ include a fluorine atom, a chlorine atom and a bromine atom.

The amino groups represented by R _{1 to} R ₄ include
Those having a substituent are preferred, but may be unsubstituted. The substituted amino group is particularly preferably a dialkylamino group. In this case, the alkyl portion of the dialkylamino group preferably has 1 to 12 carbon atoms, more preferably 1 to 4 carbon atoms, and may be linear or branched. The two alkyl groups in the dialkylamino group may be the same or different. R ₁
Specific examples of the amino group represented by to R _4, an amino group, but also include such methylamino group, dimethylamino group, diethylamino group, dipropylamino group, dibutylamino group, methylethylamino group, methyl isopropyl Preferred are an amino group, ethyl isopropyl amino group, methyl butyl amino group, ethyl butyl amino group, isopropyl butyl amino group and the like.

The alkyl group represented by R _{1 to} R ₄ is preferably one having a total of 1 to 12 carbon atoms, and may be linear or branched. Or a compound having a cycloalkyl group. Further, it may have a substituent, such a halogen atom (fluorine atom, chlorine atom, etc.)
Are preferred. As the alkyl group represented by R _{1 to} R ₄ , an alkyl group which may have a straight-chain or branched substituent having a total of 1 to 4 carbon atoms is particularly preferable. Group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-
Examples thereof include a butyl group and a trifluoromethyl group.

The alkoxy group represented by R _{1 to} R ₄ is preferably one having a total carbon number of the alkyl portion of _{1 to 4} , and may be substituted with a halogen atom (such as a fluorine atom). Specific examples of such an alkoxy group include:
Methoxy, ethoxy, propoxy, butoxy,
And a pentafluoropropoxy group.

The aryloxy group represented by R _{1 to} R ₄ may further have a substituent, for example, a phenoxy group is preferred.

As the acyl group represented by R _{1 to} R ₄ ,
Examples include an acetyl group, a propionyl group, and a butyryl group. Among them, an acetyl group and the like are preferable.

The aryl group represented by R _{1 to} R ₄ may further have a substituent, for example, a phenyl group and an (o-, m-, p-) tolyl group.

The carbamoyl group represented by R _{1 to} R ₄ may further have a substituent, for example, a carbamoyl group, a methylaminocarbonyl group, a dimethylaminocarbonyl group and the like.

Examples of the alkoxycarbonyl group represented by R _{1 to} R ₄ include a methoxycarbonyl group and an ethoxycarbonyl group.

R ₁ and R ₂ , R ₂ and R ₃ and R ₃ and R ₄
May be bonded to each other to form a condensed ring. In this case, the condensed ring is preferably a carbon ring, particularly preferably a benzene ring. Among them, it is preferable that R ₃ and R ₄ combine to form a benzene ring.

As the combination of R _{1 to} R ₄ , R ₁ , R ₃
And R ₄ is preferably a hydrogen atom, an alkyl group, an alkoxy group or a chlorine atom, and R ₂ is preferably a substituted amino group, an alkyl group, an alkoxy group or an aryloxy group. Particularly, R ₂ is preferably a substituted amino group, and especially R ₂ is a substituted amino group, and R ₁ , R ₃ and R ₄
Is preferably a hydrogen atom.

Z is --OH, --SH, --NH ₂ , --COO
H, -CONH _2, represents -SO ₂ NH ₂ or -SO ₃ H, in particular -OH is preferred.

R _{5 to} R ₁₀ each represent a hydrogen atom, a halogen atom, a nitro group, a cyano group or an alkyl group, which may be the same or different.

Examples of the alkyl group represented by R _{5 to} R ₁₀ include the same as the alkyl group represented by R _{1 to} R ₄ , and include a straight-chain or branched alkyl group having a total of 1 to 4 carbon atoms. Are preferred, and specific examples include a methyl group, an ethyl group, and a propyl group.

As a combination of R _{5 to} R ₁₀ , R ₆ and R _{8 to} R ₁₀ are each a hydrogen atom, a halogen atom, an alkyl group and the like, and R ₅ and R ₇ are a hydrogen atom, a nitro group and a cyano group. , A combination such as a trifluoromethyl group is preferable,
Particularly, a combination in which R _{5 to} R ₁₀ are a hydrogen atom is preferable.

As the azo compound represented by the formula (Ia), R
₁ , R ₃ and R ₄ are each a hydrogen atom, R ₂ is a substituted amino group, R _{5 to} R ₁₀ are each a hydrogen atom, and Z is —O
H is preferred.

The central metal of the azo metal complex dye obtained by coordinating the azo compound represented by the formula (I), particularly the formula (Ia), is Co, Mn, Ti, V, Ni, Cu, Zn, M
o, W, Ru, Fe, Pd, Pt and Al are preferred. V, Mo, and W are oxide ions such as VO ²⁺ ,
_{^{VO 3+, MoO 2 +, MoO}} 3+, may become a form of WO ^3+. Co, Cu, Ni, M
n is preferable, and Co, Ni, and particularly Co is preferable.

The azo compound of the formula (I), preferably of the formula (Ia), is a tridentate ligand. Therefore, when the coordination number of the central metal is 4 or more, other ligands may be coordinated in addition to the azo compound. Examples of such other ligands include a chlorine atom, a water molecule, and hydroxo, and these other ligands are derived from a raw material, a reaction solvent, and the like.

The group of the azo compound represented by the formula (I), preferably the formula (Ia) is an acid anion (for example, Z = -OH
Coordinated to the metal in the form of ^a) - -O when the.

In the case where the azo metal complex dye has an electric charge, the counter ions include chloride ion (Cl ⁻ ), bromide ion (Br ⁻ ), iodide ion (I ⁻ ), and tetrafluoroborate ion ( BF ₄ ⁻ ), hexafluorophosphate ion (PF ₆ ⁻ ), tetraphenylborate ion (B
^{_{(C 6 H 5) 4 -}} ), perchlorate ion (ClO ₄ ^-), tungstate ions (WO ₄ ^2-), acetylacetone anion _{(CH 3 COCH = C (CH} 3) O -) and the like, Preferably, chloride ion (Cl ⁻ ), tetrafluoroborate ion (BF ₄ ⁻ ), hexafluorophosphate ion (PF ₆ ⁻ ),
Examples include perchlorate ion (ClO ₄ ⁻ ) and acetylacetone anion (CH ₃ COCH = C (CH ₃ ) O ⁻ ), and particularly, tetrafluoroborate ion (BF ₄ ⁻ ) and hexafluorophosphate ion (PF ₆ ^- ), Perchlorate ion (ClO ₄ ⁻ ) and acetylacetone anion (CH ₃ COCH = C (CH ₃ ) O ⁻ ) are preferred.

Such an azo metal complex-based dye is obtained by coordinating an azo compound represented by the formula (Ia):
For example, there is one represented by the following formula (Ib).

[0047]

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In the formula (Ib), R _{1 to} R ₁₀ correspond to the formula (Ia)
Are those ones synonymous in, Z ₁ is ^{-O -,} -S -,
_{^{-COO -, -CONH -, -SO 2}} NH - or -S
O ₃ ^- represents a. M ₁ represents a central metal, and L represents another ligand. n is 1 or 2. m is usually 0 or 1-3
Is an integer. X represents a counter ion, and x is a number for maintaining charge balance.

Hereinafter, specific examples of the azo metal complex-based dye used in the present invention will be shown by a combination of an azo compound used to obtain the azo metal complex-based dye, a central metal, and a counter ion.
The azo compound is shown by a combination of R _{1 and the} like in the formula (Ib).

[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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[0060]

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[0061]

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[0062]

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[0063]

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[0064]

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[0065]

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[0066]

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[0067]

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[0068]

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The azo compound used in the present invention is H. Hoshin
o, T. Yotsuyanagi, Bunseki Kagaku, 31 , E435 (1982)
, S. Shibata, M. Furukawa, R. Nakashima, Anal. Ch
Acta, 81 , 131 (1976) and the references cited therein can be synthesized.

The compound was identified by mass spectrometry, ¹ H-
It can be performed by a nuclear magnetic resonance spectrum, an infrared absorption spectrum, or the like.

The azo metal complex dye can be obtained by reacting the azo compound with a metal salt in a non-aqueous solvent such as alcohol (methanol, ethanol, etc.) or ketone (acetone, etc.). Metal salts include chlorides (eg, cobalt chloride, zinc chloride, chromium chloride,
Manganese chloride, iron chloride, vanadium oxytrichloride, etc.) or acetate (eg, nickel acetate, copper acetate, etc.) acetylacetonate complex salt (acetylacetonatocobalt (III) salt, etc.)
Are generally used. The complexing reaction is carried out at room temperature (15 ° C.
Although the reaction proceeds instantaneously at a temperature of about 30 ° C.), the reaction is usually performed at a temperature of about room temperature to about 100 ° C. for about 3 minutes to 1.5 hours. The formation of such a complex can be confirmed by the coloration of the solution. It can be obtained as a solid by crystallization, and this can be identified by a visible ultraviolet absorption spectrum, an infrared absorption spectrum, a mass spectrum, or the like.

When the azo metal complex dye obtained as described above has a counter ion, it has a counter ion (for example, Cl ⁻ , CH ₃ COO ^−, etc.) derived from the metal salt of the synthesis raw material. After salt exchange, ClO ₄ ⁻ , BF ₄ ⁻ ,
Conversion to PF ₆ ^- or the like is preferred. For salt exchange, perchlorate (sodium perchlorate, ammonium perchlorate, magnesium perchlorate, etc.), tetrafluoroborate (sodium tetrafluoroborate, ammonium tetrafluoroborate, etc.), hexafluorophosphoric acid Using a salt (potassium hexafluorophosphate, ammonium hexafluorophosphate, etc.), the above-mentioned azo metal complex dye is added to a solution (0.5 to 4% by weight) in which these salts are dissolved in a solvent such as methanol or ethanol. It can be carried out, for example, by adding and stirring such that the quantitative ratio of the dye to the salt (molar ratio of dye / salt) is 1 / 0.5 to 1/2. Then, crystallization may be performed thereafter.

Identification of this compound can be carried out by means of visible ultraviolet absorption spectrum, mass spectrum, X-ray fluorescence measurement and the like.

The following shows a synthesis example.

Synthesis Example 1 Synthesis of Dye No. I-186 Azo compound: 2- (8-quinolylazo) -5- (N, N
Synthesis of -diethylamino) phenol 3.5 ml of concentrated sulfuric acid was diluted with 16 ml of water, and 2.88 g (20 mmol) of pale yellow 8-aminoquinoline was dissolved to obtain an orange aqueous solution. This was cooled to 5 ° C. or less in an ice bath while sodium nitrite 1.40 dissolved in 15 ml of water.
g (20 mmol) was added slowly with stirring to effect diazotization. With the addition of the aqueous solution of sodium nitrite, a red insoluble material precipitated. When about 90% of the solution was added, the reaction solution became green, and when the entire amount was added, the solution became a black-brown solution without insoluble matter. Stirring was continued for another 30 minutes.

3.30 g (20 mmol) of 3-diethylaminophenol was dissolved in 6 ml of ethanol, and the solution was gradually added to the above aqueous solution of diazonium salt while cooling to 3 to 5 ° C. for coupling. The reaction solution became reddish brown, and the insoluble diazonium salt gradually disappeared to form a uniform solution as a whole. After adding the whole amount, the mixture was stirred in an ice bath for 1 hour.

A precipitate was precipitated by adding sodium acetate,
This was collected by suction filtration, and the ethanol-soluble component was extracted. The solution was concentrated to dryness using a rotary evaporator, and further dried under vacuum to obtain green crystals having a metallic luster (62.5% yield). Mass spectrometry value (M ⁺ ): 32
0

Synthesis of Co Complex 0.25 g (0.8 mmol) of the above azo compound was dissolved in 5 ml of methanol, and 0.1 ml of cobalt chloride hexahydrate was added thereto.
2 g (0.5 mmol) was added and the mixture was stirred for 5 minutes. The liquid instantly turned reddish purple. To the methanol solution was added 30 ml of water to precipitate a complex, which was collected by suction filtration. The crude product was washed with a small amount of water and dried under hot vacuum at 60 ° C. for 1 hour. 0.13 g with a dark green metallic luster (yield 52
%) Co complex was obtained. When the fluorescent X-ray measurement was performed on this complex, the molar ratio Cl / Co of the cobalt atom and the chlorine atom in one molecule was 1.09, and it was confirmed that one Cl ⁻ per molecule of the complex was present.

Synthesis Example 2 Synthesis of Dye No. I-1 Dye No. I-186 obtained in Synthesis Example 1 (counter ion Cl ⁻ )
0.12 g was dissolved in 5 ml of methanol, and 0.1 g (1.0 mmol) of ammonium tetrafluoroborate was added thereto, followed by stirring for 5 minutes. To the methanol solution was added 30 ml of water to precipitate a complex, which was collected by suction filtration. The crude was washed with a small amount of water and vacuum dried at 60 ° C. overnight. Column purification was performed using alumina (developing solvent: ethanol), the target component was dried by an evaporator, and dried under vacuum at 60 ° C. overnight. It has a dark green metallic luster.
06 g of the desired product was obtained. Further, the fluorescent X-ray measurement confirmed that the molar ratio F / Co of the cobalt atom to the fluorine atom was 4.10, and it was confirmed that one BF ₄ ⁻ was present per one molecule of the complex.

Synthesis Example 3Synthesis of Dye No. I-2 Dye No. I-186 obtained in Synthesis Example 1 (counter ion Cl^- )
With potassium hexafluorophosphate as starting material
BF of Synthesis Example 2 except that it is used as a replacement reagent. _Four ^-Same as salt
PF₆ ^-The desired product as a salt was obtained.

Synthesis Example 4 Synthesis of Dye No. I-3 Dye No. I-186 obtained in Synthesis Example 1 (counter ion Cl ⁻ )
Was used as a starting material, in addition to use of sodium perchlorate monohydrate as a reagent for the salt exchange is BF ₄ Synthesis Example 2 ^- to obtain the desired compound is a salt ^- ClO ₄ in the same manner as the salt.

Synthesis Example 5 Synthesis of Ni Complex of Dye No. I-5 0.61 g (1.9 mmol) of the azo compound of Synthesis Example 1 was dissolved in 20 ml of ethanol, and 0.30 g of nickel acetate tetrahydrate was added thereto. (1.2 mmol) and refluxed at 80 ° C. for 1 hour. The solution turned reddish purple. 5
The complex was precipitated by adding 0 ml of water and collected by suction filtration. The crude product was washed with a small amount of water and dried under hot vacuum at 60 ° C. for 1 hour. 0.35 g (57% yield) of Ni complex having a black metallic luster was obtained.

[0083] BF ₄ ^- Synthesis of Ni complex salts (counter ions CH ₃ COO ^-) 0.34g
Was dissolved in 5 ml of methanol, and 0.1 g (1.0 mmol) of ammonium tetrafluoroborate was added thereto, followed by stirring for 5 minutes. To the methanol solution was added 30 ml of water to precipitate a complex, which was collected by suction filtration. The crude was washed with a small amount of water and vacuum dried at 60 ° C. overnight. Column purification was performed using alumina (developing solvent, ethanol), and the target component was dried using an evaporator and dried under vacuum at 60 ° C. overnight. 0.18 g of the target product having a black metallic luster was obtained. Further, the fluorescent X-ray measurement confirmed that the molar ratio F / Ni of the nickel atom and the fluorine atom was 4.02, and it was confirmed that one BF ₄ ⁻ was present per one molecule of the complex.

Synthesis Example 6 Synthesis of Dye No. I-32 Azo compound: 2- (8-quinolylazo) -5- (N, N
Synthesis of -dimethylamino) benzoic acid 3.5 ml of concentrated sulfuric acid was diluted with 16 ml of water, and 2.88 g (20 mmol) of pale yellow 8-aminoquinoline was dissolved to obtain an orange aqueous solution. This was cooled to 5 ° C. or less in an ice bath while sodium nitrite 1.40 dissolved in 15 ml of water.
g (20 mmol) was added slowly with stirring to effect diazotization. With the addition of the aqueous solution of sodium nitrite, a red insoluble material precipitated. When about 90% of the solution was added, the reaction solution became green, and when the entire amount was added, the solution became a black-brown solution without insoluble matter. Stirring was continued for another 30 minutes.

Water 5 ml, dioxane 10 ml, ethanol 1
3.30 g (20 mmol) of 3- (N, N-dimethylamino) benzoic acid was dissolved in 0 ml of the mixture, and 4.30 g (77 mmol) of potassium hydroxide was added to make the mixture alkaline. This was gradually added to the above aqueous solution of diazonium salt while cooling to 3 to 8 ° C. to perform coupling. The reaction solution became reddish brown, and after adding the whole amount, the mixture was stirred in an ice bath for 1 hour, and a black paste-like insoluble material was precipitated.

The whole was neutralized by adding sodium acetate, the solid was collected by suction filtration, and the ethanol-soluble component was extracted. The solution was concentrated to dryness using a rotary evaporator, and further dried under vacuum to obtain black-brown crystals (yield 6).
3.0%). Mass spec (M ⁺ ): 321

Synthesis of Ni Complex The above azo compound (0.60 g, 1.9 mmol) was dissolved in ethanol (20 ml), and nickel acetate tetrahydrate (0.10 g) was added thereto.
30 g (1.2 mmol) was added and stirred for 5 minutes. The liquid instantly turned reddish purple. A complex was precipitated by adding 50 ml of water to the ethanol solution and collected by suction filtration. The crude product was washed with a small amount of water and dried under hot vacuum at 60 ° C. for 1 hour. 0.41 g having a black metallic luster (68 in yield)
%) Of a Ni complex.

[0088] BF ₄ ^- to afford the desired product in the same manner as in the synthesis of the salt ^- BF ₄ in Synthesis Example 5 of a salt.

Synthesis Example 7 Synthesis of Dye No. I-187 The target compound was obtained in the same manner as in Synthesis Example 1 except that the azo compound of Synthesis Example 6 was used.

Synthesis Example 8 Synthesis of Dye No. I-33 Dye No. I-187 obtained in Synthesis Example 7 was used, and the others were the same as in Synthesis Example 2 to obtain the desired product.

Synthesis Example 9 Synthesis of Dye No. I-188 Azo compound: 2- (5-nitro-8-quinolylazo)-
Synthesis of 5- (N, N-diethylamino) phenol Concentrated hydrochloric acid (11.6 ml) was diluted with water (20 ml) to dissolve yellow 5-nitro-8-aminoquinoline (3.8 g, 20 mmol). 10 ml of 2-methoxyethanol was added to completely dissolve 5-nitro-8-aminoquinoline. While cooling this to below 5 ° C in an ice bath,
1.40 g of sodium nitrite dissolved in 15 ml of water (20
mmol) was added slowly with stirring to effect diazotization.
After the dropwise addition of sodium nitrite, stirring was continued for 30 minutes.

A mixture of 10 ml of water and 20 ml of ethanol
Dissolve 3.30 g (20 mmol) of diethylaminophenol and further add 4.0 g (100 mmol) of sodium hydroxide.
l) was added to make it alkaline. This was gradually added to the above diazonium aqueous solution while cooling to 3 to 8 ° C. to perform coupling. After adding the whole amount, stirring was continued for 1 hour. The whole was neutralized by adding sodium acetate, and the precipitated solid was collected by suction filtration to extract an ethanol-soluble component. The solution was concentrated to dryness using a rotary evaporator, and further dried under vacuum at 60 ° C. to obtain black crystals. Mass spec (M ⁺ ): 365

The desired product was obtained in the same manner as in Synthesis Example 1 except that the above azo compound was used.

Synthesis Example 10 Synthesis of Dye No. I-12 Dye No. I-188 obtained in Synthesis Example 9 was used, and the others were the same as in Synthesis Example 2 to obtain the desired product.

Synthesis Example 11 Synthesis of Dye No. I-189 Azo compound: 2- (8-quinolylazo) -5- (N, N
Synthesis of -diethylamino) aniline 3.5 ml of concentrated sulfuric acid was diluted with 16 ml of water to dissolve 2.88 g (20 mmol) of 8-aminoquinoline. While cooling this in an ice bath to 5 ° C. or lower, 1.40 g (20 mmol) of sodium nitrite dissolved in 15 ml of water was gradually added with stirring to effect diazotization. After adding the whole amount, stirring was continued for 30 minutes.

3.28 g (20 mmol) of 3-diethylaminoaniline was dissolved in 10 ml of methanol, and the solution was gradually added to the above aqueous solution of diazonium salt while cooling at 3 to 5 ° C. for coupling. 1 hour after adding the whole amount,
Stir in an ice bath.

The mixture was neutralized by adding sodium hydroxide, diluted with water, and then salted out for salting out. The precipitated precipitate was collected by suction filtration, and the ethanol-soluble component was extracted. The solution was concentrated to dryness using a rotary evaporator, and further dried under vacuum to obtain crystals having a green metallic luster (yield: 58.3%). Mass spec (M ⁺ ): 319

Synthesis of Co complex 0.25 g (0.8 mmol) of the above azo compound was dissolved in 5 ml of ethanol, and 0.1 ml of cobalt chloride hexahydrate was added thereto.
2 g (0.5 mmol) was added and 30
Stirred for minutes. The solution turned reddish purple. To the ethanol solution was added 30 ml of water to precipitate a complex, which was collected by suction filtration. The crude product was washed with a small amount of water and dried under vacuum at 60 ° C. for 1 hour. 0.18 with dark green metallic luster
g of Co complex was obtained.

Synthesis Example 12 Synthesis of Dye No. I-8 Dye No. I-189 obtained in Synthesis Example 11 was used, and the others were obtained in the same manner as in Synthesis Example 2 to obtain the desired product.

Synthesis Example 13 Synthesis of Dye No. I-190 Azo compound: 2- (7-chloro-8-quinolylazo)-
Synthesis of 5- (N, N-diethylamino) -6-methylphenol To a mixture of concentrated sulfuric acid (11.5 ml), water (20 ml) and dioxane (15 ml) was added 3.58 g of 7-chloro-8-aminoquinoline (20%).
mmol) and completely dissolved the solid while heating at 60 ° C. While cooling this in an ice bath to 5 ° C or less, 15 ml of water
1.40 g (20 mmol) of sodium nitrite dissolved in water was gradually added with stirring to effect diazotization. After adding the whole amount, stirring was continued for 30 minutes.

3.58 g (20 mmol) of 2-methyl-3-diethylaminophenol was dissolved in 10 ml of ethanol, and this was gradually added to the above aqueous solution of diazonium salt while cooling at 3 to 5 ° C. to perform coupling. After adding the whole amount, the mixture was stirred in an ice bath for 1 hour.

The mixture was neutralized by adding sodium hydroxide, and the precipitated solid was collected by suction filtration to extract an ethanol-soluble component. This solution was concentrated to dryness using a rotary evaporator, and further dried under vacuum to obtain crystals having a black metallic luster (yield 71%). Mass spec (M ⁺ ): 367

Using the above azo compound, a Co complex (counter ion Cl ⁻ ) was obtained in the same manner as in Synthesis Example 1.

Synthesis Example 14 Synthesis of Dye No. I-82 Dye No. I-190 was used as a starting material, and sodium perchlorate monohydrate was used as a reagent for salt exchange. ₄ ^- to obtain the desired compound is a salt.

Other exemplified compounds were synthesized in the same manner as described above and identified in the same manner.

The azo metal complex dye of the present invention has a melting point (m
p) is 150-320 ° C and λmax (in ethanol) is in the range of 480-620 nm.

When these azo metal complex dyes are used in the recording layer of an optical recording medium, they may be used alone or in combination of two or more. When two or more compounds having different coordination numbers of azo compounds or different kinds of ligands are obtained in the synthesis process, they may be used as they are without separation.

These dyes have a wavelength of 635 nm or 6 nm.
The real part n of the complex refractive index at 50 nm is 2.00 to 2.40, and the imaginary part k is 0.01 to 0.40. The dyes n and k are measured by forming a dye film on a predetermined transparent substrate to a thickness of about the recording layer of an optical recording medium, for example, a thickness of about 40 to 100 nm under the same conditions as the recording layer, and measuring. A sample for measurement was prepared, and then the sample for measurement at 635 nm or 65 nm was prepared.
The reflectance and the transmittance at 0 nm were measured, and from these measured values, for example, Kyoritsu Zensho “Optics” Kozo Ishiguro P168
178 is calculated. The reflectance is the reflectance of the measurement sample through the substrate or the reflectance from the dye film side, and is measured by specular reflection (about 5 °).

These compounds have a sufficient solubility in an organic solvent, and have a high solubility in a coating solvent which does not attack a polycarbonate resin (PC) generally used as a substrate material of an optical recording medium.

The azo metal complex dyes used in the present invention include those obtained by reacting an azo compound represented by the formula (II) with a metal compound. Formula (II) Q ¹ −N = N−Q ²

To explain the formula (II), Q ¹ is 8-
Represents an quinolyl group, and the 8-quinolyl group may further have a substituent in addition to the azo group. Examples of such a substituent include a halogen atom, a nitro group, a cyano group, an amino group, an amide group, Examples include a sulfonamide group, a carbamoyl group, a sulfamoyl group, an alkoxy group, an alkoxycarbonyl group, an acyloxy group, and an alkyl group.

The halogen atom in this case includes a fluorine atom, a chlorine atom, a bromine atom and the like.

The amino group preferably has a substituent, and the substituted amino group is particularly preferably a dialkylamino group. In this case, the alkyl portion of the dialkylamino group preferably has 1 to 12 carbon atoms, more preferably 1 to 4 carbon atoms, and may be linear or branched. Specific examples of the amino group include an amino group and a methylamino group, and a dimethylamino group, a diethylamino group, a dipropylamino group, a dibutylamino group, and the like are preferable. The total carbon number of the amino group is preferably from 0 to 8.

The amide group may have an alkyl group or an aryl group, and examples thereof include an acetamido group, a propionylamino group, a butyrylamino group and a benzamide group. The total number of carbon atoms of the amide group is preferably 2 to 7.

The sulfonamide group may have an alkyl group or an aryl group, and examples thereof include a methylsulfonylamino group, an ethylsulfonylamino group, and a phenylsulfonylamino group. The total carbon number of the sulfonamide group is preferably 1 to 6.

The carbamoyl group may further have a substituent, for example, a carbamoyl group, a methylaminocarbonyl group, a dimethylaminocarbonyl group and the like. The carbamoyl group preferably has 1 to 5 carbon atoms.

The sulfamoyl group may further have a substituent, for example, a sulfamoyl group, a methylaminosulfonyl group, a dimethylaminosulfonyl group and the like. The total carbon number of the sulfamoyl group is preferably 0 to 4.

The alkoxy group is preferably one having a total of 1 to 4 carbon atoms in the alkyl portion, and may be substituted with a halogen atom (such as a fluorine atom). Specific examples of such an alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a pentafluoropropoxy group.

Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group. The total carbon number of the alkoxycarbonyl group is preferably 2-5.

Examples of the acyloxy group include an acetyloxy group and a propionyloxy group. The total carbon number of the acyloxy group is preferably 2 to 5.

The alkyl group is preferably one having a total of 1 to 12 carbon atoms, and may be linear or branched, and in some cases, may have a cycloalkyl group or a cycloalkyl group. You may. Further, it may have a substituent, and such a substituent is preferably a halogen atom (such as a fluorine atom or a chlorine atom). As the alkyl group, particularly, an alkyl group having a total of 1 to 4 carbon atoms which may have a linear or branched substituent is preferable, and specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group , N-butyl group, isobutyl group, s-butyl group, t-butyl group, trifluoromethyl group and the like.

As the 8-quinolyl group represented by Q ¹ , unsubstituted one is preferable, and when it has a substituent, among the above, a halogen atom, a nitro group, an alkyl group and the like are preferable.

When two or more substituents are present, these substituents may be the same or different. The number of the above substituents is preferably 0 to 2.

In the formula (II), Q ² represents a 2-imidazolyl group, and the nitrogen at the 1-position of the 2-imidazolyl group [see formula (IIa) described later] has active hydrogen. The 2-imidazolyl group may further have a substituent at the 4-position and / or 5-position [see formula (IIa) described below] in addition to the azo group. Examples of such a substituent include an alkyl group and an alkoxy group. Group, nitro group, cyano group, halogen atom, aryl group,
Examples include an aryloxy group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, and an amino group.

[0125] alkyl group in this case, an alkoxy group, a halogen atom, an alkoxycarbonyl group, a carbamoyl group, specific examples of the amino group include the same groups at the Q ^1. However, the alkyl group may be an aralkyl group such as a benzyl group or a phenethyl group, and the aralkyl group preferably has 7 to 10 carbon atoms.

The aryl group may further have a substituent, for example, a phenyl group, (o
-, M-, p-) tolyl group and the like. The total carbon number of the aryl group is preferably 6 to 10.

The aryloxy group may further have a substituent, and is preferably, for example, a phenoxy group. The total carbon number of the aryloxy group is preferably from 6 to 10.

Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group. Among them, an acetyl group is preferred. The total carbon number of the acyl group is preferably 2 to 5.

In the 2-imidazolyl group represented by Q ² , adjacent substituents may be bonded to each other to form a ring, and examples of such a ring include a benzene ring.

The 2-imidazolyl group represented by Q ² preferably has a substituent at the 4-position and / or 5-position, and more preferably at both of these positions. As the substituent, a phenyl group, (o-, m-, p-) chlorophenyl group, (o
-, M-, p-) bromophenyl group, (o-, m-, p
-) Tolyl group, aryl group such as (o-, m-, p-) butylphenyl group and the like are preferable, and phenyl group is particularly preferable. When there are substituents at both the 4-position and 5-position, each substituent may be the same or different.

The center metal of the azo metal complex dye obtained by coordinating the azo compound represented by the formula (II) is Co, M
n, Ni, Cu, Zn, Mo, Fe, and Pd are preferred.
Among them, Mo is an oxide ion, for example, MoO ₂ ⁺ , Mo
It may be in the form of O ³⁺ . As the central metal, Co, Cu, Ni, and Mn are more preferable, and further, C is preferable.
o, Ni, particularly Ni is preferred.

The azo compound represented by the formula (II) is a tridentate ligand, and usually forms a 1: 1 complex or a 1: 2 complex (metal: ligand) with a metal. Therefore, when the coordination number of the central metal is 4 or more, other ligands may be coordinated in addition to the azo compound. Examples of such other ligands include a chlorine atom, a water molecule, and hydroxo, and these other ligands are derived from a raw material, a reaction solvent, and the like.

The group of the azo compound represented by the formula (II) coordinates to the metal in the form of an acid anion in which the active hydrogen of the imidazolyl group represented by Q ² has been dissociated.

When the azo metal complex dye has an electric charge, the counter ion includes chloride ion (Cl ⁻ ), bromide ion (Br ⁻ ), iodide ion (I ⁻ ), tetrafluoroborate ion ( BF ₄ ⁻ ), hexafluorophosphate ion (PF ₆ ⁻ ), tetraphenylborate ion (B
^{_{(C 6 H 5) 4 -}} ), perchlorate ion (ClO ₄ ^-), tungstate ions (WO ₄ ^2-), acetylacetone anion _{(CH 3 COCH = C (CH} 3) O -) and the like, Preferably, chloride ion (Cl ⁻ ), tetrafluoroborate ion (BF ₄ ⁻ ), hexafluorophosphate ion (PF ₆ ⁻ ),
A perchlorate ion (ClO ₄ ⁻ ) is exemplified, and a tetrafluoroborate ion (BF ₄ ⁻ ), a hexafluorophosphate ion (PF ₆ ⁻ ), and a perchlorate ion (ClO ₄ ⁻ ) are particularly preferable.

Examples of the structure of such an azo metal complex dye include the following. This compound is obtained by using 2- (8-quinolylazo) -4,5-diphenylimidazole as an azo compound represented by the formula (II) and producing N
i in is coordinated, counterion ClO ₄ ^- is the the thing (exemplified dye No. II-3 below).

[0136]

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Hereinafter, specific examples of the azo metal complex-based dye used in the present invention will be shown by a combination of an azo compound used for obtaining the azo metal complex-based dye, a central metal, and a counter ion.
The azo compound is represented by a combination of R ^{1 and the} like in the following formula (IIa).

[0138]

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[0139]

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[0140]

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[0141]

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[0142]

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[0143]

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[0144]

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[0145]

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[0146]

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[0147]

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[0148]

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[0149]

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[0150]

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The azo compound used in the present invention is "Shozo Sh
ibata, Masamichi Furukawa and Ryozo Nakashima, Ana
lytica Chimica Acta, 81 (1976) 131-141 "and the references cited therein.

The compound was identified by mass spectrometry, ¹ H-
It can be performed by a nuclear magnetic resonance spectrum, an infrared absorption spectrum, or the like.

The azo metal complex dye can be obtained by reacting the azo compound with a metal salt in a non-aqueous solvent such as alcohol (methanol, ethanol, etc.) or ketone (acetone, etc.). Metal salts include chlorides (eg, cobalt chloride, zinc chloride, chromium chloride,
Manganese chloride, iron chloride, vanadium oxytrichloride, etc.), acetates (eg, nickel acetate, copper acetate, etc.), acetylacetonato complex salts (acetylacetonatocobalt (III) salts, etc.) are generally used. The complexing reaction is carried out at room temperature (15
(30 ° C. to 30 ° C.), but it usually proceeds instantaneously at a temperature of about room temperature to about 100 ° C. for 3 minutes to 1.
The reaction may be performed for about 5 hours. The formation of such a complex can be confirmed by the coloration of the solution. It can be obtained as a solid by crystallization, and this can be identified by a visible ultraviolet absorption spectrum, an infrared absorption spectrum, a mass spectrum, or the like.

When the azo metal complex-based dye obtained as described above has a counter ion, it has a counter ion (eg, Cl ⁻ , CH ₃ COO ^−, etc.) derived from the metal salt of the raw material for synthesis. After salt exchange, ClO ₄ ⁻ , BF ₄ ⁻ ,
Conversion to PF ₆ ^- or the like is preferred. For salt exchange, perchlorate (sodium perchlorate, ammonium perchlorate, magnesium perchlorate, etc.), tetrafluoroborate (sodium tetrafluoroborate, ammonium tetrafluoroborate, etc.), hexafluorophosphoric acid Using a salt (potassium hexafluorophosphate, ammonium hexafluorophosphate, etc.), the above-mentioned azo metal complex dye is added to a solution (0.5 to 4% by weight) in which these salts are dissolved in a solvent such as methanol or ethanol. It can be carried out, for example, by adding and stirring such that the quantitative ratio of the dye to the salt (molar ratio of dye / salt) is 1 / 0.5 to 1/2. Then, crystallization may be performed thereafter.

[0155] The product can be identified by a visible ultraviolet absorption spectrum, a mass spectrum, X-ray fluorescence measurement, or the like.

The following shows a synthesis example.

Synthesis Example 15 Synthesis of Dye No. II-1 Azo compound: Synthesis of 2- (8-quinolylazo) -4,5- (diphenylimidazole 2.7 ml of concentrated sulfuric acid was diluted with 20 ml of water to give pale yellow 8 2.88 g (20 mmol) of aminoquinoline were dissolved to give an orange aqueous solution, which was cooled to below 5 ° C. in an ice bath, while sodium nitrite 1.40 dissolved in 15 ml of water.
g (20 mmol) was added slowly with stirring to effect diazotization. With the addition of the aqueous solution of sodium nitrite, a red insoluble material precipitated. When about 90% of the solution was added, the reaction solution became green, and when the entire amount was added, the solution became a black-brown solution without insoluble matter. Stirring was continued for another 30 minutes.

50 ml of a 20% aqueous sodium hydroxide solution, 2
4.4 g of 4,5-diphenylimidazole (2 g) was added to a mixture of 50 ml of 0% aqueous sodium carbonate solution and 70 ml of ethanol.
0 mmol) was dissolved and gradually added to the above aqueous solution of diazonium salt while cooling to 3 to 5 ° C. to perform coupling. The reaction solution became reddish brown, and after adding the whole amount, was stirred for 1 hour in an ice bath.

After 1 hour, the precipitated solid was collected by suction filtration and washed with water several times. Further, extraction was performed with ethanol, and the soluble component was concentrated to dryness using a rotary evaporator. Further, it was dried by heating under vacuum to obtain brown crystals. Mass spec (M ⁺ ): 375, melting point (mp): 252 ° C.

Synthesis of Ni Complex (Dye No. II-1) 0.3 g (0.8 mmol) of the above azo compound was dissolved in 5 ml of ethanol, and 0.1 g of nickel chloride (0.8
mmol) and stirred for 5 minutes. The liquid instantly turned blue-violet. To the ethanol solution was added 30 ml of water to precipitate a complex, which was collected by suction filtration. The crude product was washed with a small amount of water and dried under hot vacuum at 60 ° C. for 1 hour. 0.18 g (52% yield) of a nickel complex having a dark green metallic luster was obtained. X-ray fluorescence measurement of this complex revealed that the molar ratio of nickel atoms to chlorine atoms in one molecule was Cl.
/ Ni is 1.05 and one Cl ⁻ per complex molecule.
Was confirmed to be present.

Synthesis Example 16 Synthesis of Dye No. II-2 Dye No. II-1 (counter ion Cl ⁻ ) obtained in Synthesis Example 1
18 g was dissolved in 5 ml of ethanol, and 0.1 g (1.0 mmol) of ammonium tetrafluoroborate was added thereto, followed by stirring for 5 minutes. To the ethanol solution was added 30 ml of water to precipitate a complex, which was collected by suction filtration. The crude was washed with a small amount of water and vacuum dried at 60 ° C. overnight. Alumina (Developing solvent dichloromethane: ethanol =
Column purification was performed in 2: 1), and the target component was dried using an evaporator and dried under vacuum at 60 ° C. overnight. 0.
07 g of the desired product were obtained. In addition, the fluorescent X-ray measurement confirmed that the molar ratio F / Ni of the nickel atom and the fluorine atom was 4.08, and that one BF ₄ ⁻ was present per one molecule of the complex.

Synthesis Example 17 Synthesis was carried out in the same manner as in the Ni complex of Synthesis Example 1, except that cobalt chloride was used as the synthetic metal salt of Dye No. II-5 . X-ray fluorescence measurement of this complex confirmed that the molar ratio Cl / Co of cobalt atom and chlorine atom in one molecule was 1.02, and one molecule of complex contained one Cl ^−. Was done.

Synthesis Example 18 Synthesis of Dye No. II-7 Dye No. II-5 (counter ion Cl ⁻ ) obtained in Synthesis Example 3 and sodium perchlorate monohydrate were prepared in the same manner as in Synthesis Example 2. ClO ₄ ^- to give the salt. It was confirmed that one ClO ₄ ^- was present in one molecule of the complex.

Other dyes can be synthesized in the same manner as described above.

The λ max of these azo metal complex dyes is 5
20-630 nm (measured in ethanol), melting point (mp) 210-320 ° C.

When these azo metal complex dyes are used in the recording layer of an optical recording medium, they may be used alone or in combination of two or more. When two or more compounds having different coordination numbers of azo compounds or different kinds of ligands are obtained in the synthesis process, they may be used as they are without separation. In the present invention, the azo metal complex dye represented by the formula (I) and the azo metal complex dye represented by the formula (II) may be used in combination.

Further, these dyes have a wavelength of 635 nm or 6 nm.
The real part n of the complex refractive index at 50 nm is 2.00 to 2.50, and the imaginary part k is 0.01 to 0.50.

The dyes n and k are determined by forming a dye film on a predetermined transparent substrate to a thickness of about the recording layer of an optical recording medium, for example, about 40 to 100 nm under the same conditions as the recording layer. Then, a measurement sample was prepared, and then the reflectance and transmittance at 635 nm or 650 nm of the measurement sample were measured. From these measured values, for example, according to Kyoritsu Zensho “Optics” Kozo Ishiguro P168-178, It is calculated. The reflectance is the reflectance of the measurement sample through the substrate or the reflectance from the dye film side, and is measured by specular reflection (about 5 °).

Such an azo metal complex dye has a sufficient solubility in an organic solvent and has a high solubility in a coating solvent which does not corrode a polycarbonate resin (PC) generally used as a substrate material of an optical recording medium. Become.

A recording layer using such an azo metal complex dye is particularly suitable for a write-once optical recording disk (CD-R or DV).
DR). Such a recording layer is preferably formed using a dye-containing coating solution.
In particular, it is preferable to use a spin coating method in which a coating solution is spread and applied on a rotating substrate. In addition, gravure coating, spray coating, dipping, or the like may be used.
The application solvent will be described later.

After the spin coating as described above, the coating film is dried if necessary. The thickness of the recording layer formed in this way is appropriately set according to the target reflectance and the like, but is usually about 400 to 3000 A.

The content of the pigment in the coating solution is preferably 0.05 to 10% by weight. Since the azo metal-containing complex dye has good solubility, a coating solution having such a content can be easily prepared. Specifically, the azo metal complex dyes of the present invention mainly show good solubility in polar solvents, and include ketones such as alcohols, cellosolves or alkoxy alcohols, diacetone alcohols, ketones such as cyclohexanone, and the like. ,
It is dissolved in a fluorinated alcohol such as 2,3,3-tetrafluoropropanol in an amount of 0.5 to 10% by weight. In particular, it is dissolved in ethyl cellosolve or 2,2,3,3-tetrafluoropropanol, which is a suitable coating solvent when applied to a polycarbonate disk substrate, to form a high-quality spin-coated film in a short time. It is possible.

The coating liquid may contain a binder, a dispersant, a stabilizer and the like as appropriate.

The recording layer of the optical recording medium of the present invention may contain other types of light absorbing dyes in addition to the azo metal complex dyes. Examples of such a dye include a phthalocyanine dye, a cyanine dye, a metal complex dye different from the above, a styryl dye, a porphyrin dye, an azo dye different from the above, and a formazan metal complex.

Therefore, in such a case, the recording layer may be coated by including such a dye in the coating solution.

In particular, according to the present invention, recording and reproduction can be performed at two wavelengths of a short wavelength of about 680 to 635 nm and a conventional wavelength of about 780 nm, and recording and reproduction can be performed separately for these two wavelengths. . In this case, the present invention is suitable for a recording and reproducing method of CD-RII in which recording is performed with a conventional wavelength light of about 780 nm and reproduction is performed with two wavelengths of a short wavelength and a conventional wavelength light of about 780 nm. In such a configuration, it is preferable to use a dye having different optical characteristics such as absorption characteristics in addition to the azo metal complex dye of the present invention in the recording layer. As such a combination, an azo metal complex-based dye of the present invention is used for a short wavelength, and another type of light absorbing dye is used for a long wavelength, and conversely, an azo metal complex-based dye is used for a long wavelength. age,
There are other types of light absorbing dyes for short wavelengths,
Usually, the former combination is preferably used. In such a case, it is preferable that a dye having an absorption maximum (λ _max ) of about 680 to 750 nm is contained in addition to the azo metal complex dye of the present invention, and a dye having such an absorption maximum (λ _max ) is used. What is necessary is just to select and use from the said dyes. Among them, phthalocyanine dyes and pentamethine cyanine dyes are usually used.

In particular, when the azo metal complex dye is used for a recording layer of CD-RII of the type which performs recording and reproduction at two wavelengths as described above, the real part n of the complex refractive index at 650 nm is 1.
It is preferable that the imaginary part is 8 to 2.6 and the imaginary part is 0.02 to 0.20. On the other hand, as the dye to be combined with this, 78
The real part n of the complex refractive index at 0 nm is 1.8 to 2.6, and the imaginary part k
Is 0.02 to 0.30, particularly 0.02 to 0.15 when used for a laminated recording layer, and the half width of the absorption spectrum of the thin film, that is, the half width of the spectrum line near λmax is 170 nm or less. And preferably 150 nm or less. There is no particular lower limit for the half width,
Usually it is 50 nm. By using a material having such a half-value width, the reflectance and the degree of modulation in the short wavelength region are sufficient without affecting the absorption characteristics of the azo metal complex dye used in combination. On the other hand, the half width is 170 nm.
If the wavelength exceeds the above range, the absorption edge is applied to the wavelength region of the short-wavelength laser, and the reflectance in the short-wavelength region is reduced. The half value width was determined by preparing a sample in which a dye film was formed on a transparent substrate so that the transmittance T at the absorption maximum λmax was 25% or less, and measuring the absorption spectrum of this sample. For example, to explain according to the absorption spectrum of FIG. 1, the transmittance T _{1 at} λmax and the transmittance T ₂ which becomes substantially constant without depending on the shift of the wavelength when the wavelength is shifted to the longer wavelength side are obtained. T ₂ and the bottom of the depth of half the width △ lambda half width of up to T ₁ as baseline (base). The thickness of the dye film of the sample is usually 500 to 1500 A (50 to 150 nm).
It is about.

The above n and k were obtained in the same manner as above, with the measurement wavelengths being 650 nm and 780 nm, respectively.

The dye is particularly preferably a phthalocyanine dye represented by the formula (III).

[0180]

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In the formula (III), M represents a central atom.
X ₁ , X ₂ , X ₃ and X ₄ each represent a halogen atom, which may be the same or different. p
1, p2, p3 and p4 are each 0 or an integer of 1 to 4, and p1 + p2 + p3 + p4 is 0 to 15. Y
₁ , Y ₂ , Y ₃ and Y ₄ each represent an oxygen atom or a sulfur atom, which may be the same or different. Z ₁ , Z ₂ , Z ₃ and Z ₄ each represent an alkyl group having 4 or more carbon atoms, an alicyclic hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic group, which may be the same or different, Is also good. q1, q2, q3, and q4 are each 0 or an integer of 1 to 4; they do not become 0 at the same time; q1 + q2 + q3 + q4 is 1 to 8;

The formula (III) is described in more detail.
In (II), M represents a central atom. The central atom represented by M includes a hydrogen atom (2H) or a metal atom. At this time, as the metal atom, the periodic tables 1 to 14
Group (1A to 7A group, 8 group, 1B to 4B group), and specifically, Li, Na, K, M
g, Ca, Ba, Ti, Zr, V, Nb, Ta, Cr,
Mo, W, Mn, Tc, Fe, Co, Ni, Ru, R
h, Pd, Os, Ir, Pt, Cu, Ag, Au, Z
n, Cd, Hg, Al, In, Tl, Si, Ge, S
n, Pb, etc., especially Li, Na, K, Mg, Ca, Ba,
Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn,
Tc, Fe, Co, Ni, Ru, Rh, Pd, Os, I
r, Pt, Cu, Ag, Au, Cd, Hg, Al, I
n, Tl, Si, Ge, Sn, and Pb. Among them, Al, Si, Ge, Zn, Cu, Pd, Ni,
Fe, Co, etc. are preferred, and in particular, Cu, Pd, Ni, F
e, Co, VO, etc. are preferred in terms of stability over time.

These metal atoms may be in the form of VO or the like, such as V, etc.
Like Ge, Co, Fe, and the like, ligands such as an ether group, an ester group, pyridine, and derivatives thereof may be further coordinated above and below or on one of the metal atoms.
A preferred example of Si will be described later.

X _{1 to} X ₄ each represent a halogen atom;
Halogen atoms include F, Cl, Br, I and the like. Particularly, Br and F are preferable.

P1, p2, p3 and p4 are each 0 or an integer of 1 to 4, and p1 + p2 + p3 + p4 is 0 to 0.
15 and preferably 0-10.

X _{1 to} X ₄ may be the same or different. When p 1, p 2, p 3, and p 4 are each an integer of 2 or more, X ₁ and X ₂ , X ₃ and X ₃ X ₄
They may be the same or different.

Y _{1 to} Y ₄ each represent an oxygen atom or a sulfur atom, and particularly preferably an oxygen atom. Y _{1 to} Y
₄ are usually the same, but may be different. Z
_{1 to} Z ₄ each represent an alkyl group having 4 or more carbon atoms, an alicyclic hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic group,
These may be the same or different.

Each of q1, q2, q3 and q4 is 0 or an integer of 1 to 4, and they are not simultaneously 0, and q1 + q2 + q3 + q4 is 1 to 8, preferably 2 to 6.

The bonding position of Y _{1 to} Y _{4 to} the phthalocyanine ring is preferably the 3-position and / or the 6-position (see the following structural formula) of the phthalocyanine ring, and it is preferable that at least one such bond is contained. preferable.

[0190]

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Z₁ ~ Z_Four As the alkyl group represented by
Those having 4 to 16 carbon atoms are preferred and are linear
May also have a branch, but also have a branch
Is preferred. It may have a substituent, and the substituent
As a halogen atom (F, Cl, Br, I, etc.)
And preferably F, Br, etc.). Such an
Specific examples of the alkyl group include nC_Four H₉ , I-C_Four H
₉ -, S-C_Four H₉ -, T-C_Four H₉ -, NC_Five H₁₁
−, (CH_Three )_Two CHCH_Two CH_Two −, (CH_Three )_Three C
CH_Two −, (C_Two H_Five )_Two CH-, C_Two H_Five C (CH
_Three )_Two -, NC_Three H₇ CH (CH_Three )-, NC₆ H
₁₃−, (CH_Three )_Two CHCH_Two CH_Two CH _Two −, (CH
_Three )_Three C-CH_Two -CH_Two -, NC_Three H₇ CH (CH
_Three ) CH_Two-, NC_Four H₉ CH (CH_Three )-, NC₇
 H_Fifteen-, [(CH_Three )_Two CH]_Two-CH-, nC_Four H
₉ CH (CH_Three ) CH_Two −, (CH_Three )_Two CHCH_Two C
H (CH_Three ) CH_Two -, NC₈ H₁₇−, (CH_Three )_Three 
CCH_Two CH (CH_Three ) CH_Two −, (CH_Three )_Two CHC
H (i-C_Four H₉ )-, NC_Four H₉ CH (C_Two H_Five )
CH_Two -, NC₉ H₁₉-, CH_Three CH_Two CH (CH
_Three ) CH_Two CH (CH_Three ) CH_Two CH_Two −, (CH_Three )
_Two CHCH_Two CH_Two CH_Two CH (CH_Three ) CH_Two −, N
-C_Three H₇ CH (CH_Three ) CH_Two CH (CH_Three ) CH_Two 
-, NC_TenH_{twenty one}−, (CH_Three )_Three CCH_Two CH_Two C
(CH_Three )_Two CH_Two -, NC₁₁H_{twenty three}-, NC₁₂H_{twenty five}
-, NC₁₃H₂₇-, NC₁₄H₂₉-, NC_FifteenH
₃₁-, NC₁₆H₃₃-, CHF_Two CF_Two CH_Two -, CF
_Three CH_Two -, CF_Three CF_Two CH_Two CH_Two−, (CF_Three )_Two
 (CH_Three ) C-CH_Two -, NC_Four F₉ -, I-C_Four 
F₉ -, S-C_Four F₉ -, T-C_Four F₉ -Etc.
You.

Examples of the alicyclic hydrocarbon group represented by Z _{1 to} Z ₄ include a cyclohexyl group and a cyclopentyl group, and a cyclohexyl group is preferred. These may further have a substituent, and examples of such a substituent include an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an aralkyl group, a halogen atom, a nitro group, a carboxyl group, an ester group, and an acyl group. Group, amino group, amide group, carbamoyl group, sulfonyl group, sulfamoyl group, sulfo group, sulfino group, arylazo group, alkylthio group, arylthio group and the like. Among them, an alkyl group having 1 to 5 carbon atoms (for example, methyl Group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-
Butyl group, n-pentyl group, iso-pentyl group, ne
o-pentyl group, tert-pentyl group, 1-methylbutyl group), alkoxy group (for example, methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group), An aryl group (eg, phenyl, tolyl, biphenyl, naphthyl), a halogen atom (eg, F,
Cl, Br, I, preferably F, Br) and the like are preferred.
The substitution position of these substituents is preferably one or both of the adjacent positions of the bonding position of Y _{1 to} Y ₄ , and preferably contains at least one such substitution.

The aromatic hydrocarbon group represented by Z _{1 to} Z ₄ may be a single ring, a group having a condensed ring, or a group having a substituent. Further, the total number of carbon atoms is preferably 6 to 20. Specific examples include a phenyl group and a naphthyl group, and a phenyl group is preferable. These may further have a substituent, and examples of such a substituent include the same as those exemplified for the alicyclic hydrocarbon group, and preferable ones are also the same. The same applies to the preferred substitution position, which is preferably the ortho position of the bonding position of Y _{1 to} Y ₄ , and preferably contains at least one ortho substitution.

The heterocyclic groups represented by Z _{1 to} Z ₄ include:
It may be a single ring or one having a condensed ring, and a compound having a hetero atom of oxygen, nitrogen, sulfur or the like, particularly oxygen or nitrogen, is preferred. Specific examples include a pyridyl group, a furanone-yl group, a pyrazyl group, a pyrazolidyl group, a piperidinone-yl group, a quinoxalyl group, a pyranone-yl group, a thiophenetrion-yl group, and the like.
Furanone-yl groups and the like are preferred. These heterocyclic groups are
The compound may further have a substituent, and examples of the substituent include those exemplified for the alicyclic hydrocarbon group and the aromatic hydrocarbon group, and preferable examples are also the same. In particular, when a carbon atom is present adjacent to the bonding position of Y _{1 to} Y ₄ , it is preferable to have a substituent at such an adjacent position.

Z _{1 to} Z ₄ are preferably an alicyclic hydrocarbon group or an aromatic hydrocarbon group, more preferably a cyclohexyl group or a phenyl group, and particularly preferably at least one of the bonding positions of Y ₁ to Y _4. Are preferably those having a substituent (particularly the above-mentioned preferred substituent) at the adjacent position.

Specific examples of such phthalocyanine dyes
Are shown below, but the present invention is not limited to these.
Absent. A specific example is X of the following formula (IIa) [Formula 13]₁₁~
X₁₄, X _Fifteen~ X₁₈, X₁₉~ X_{twenty two}, X_{twenty three}~ X₂₆And M
And X₁₁~ X₁₄Etc. are all H
When it is H, and when it is a substituent,
The display of H is omitted. The phthalocyanine ring
, 3rd, 6th, 4th, and 5th positions are equivalent,
When a substituent is present on any one of these
They are merely representative examples.

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[0198]

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[0199]

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[0200]

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[0201]

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[0202]

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[0203]

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[0204]

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[0205]

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[0206]

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[0207]

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[0208]

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[0209]

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[0210]

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[0211]

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The following formula (IV) wherein the central atom is Si
The phthalocyanine dye represented by formula (1) is also preferable.

[0213]

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In the formula (IV), A ₁ , A ₂ , A ₃ and A ₄ each represent a hydrogen atom or an alkyl group, which may be the same or different. A _f1 and A _f2
Each represents a fluorinated alkyl group, which may be the same or different. R _f1 , R _f2 , R _f3 and R _f4 represent a fluorinated alkyl group, which may be the same or different. r1, r2, r3 and r4 are each 0
Or, they are integers of 1 to 4, and they do not become 0 at the same time, and r1 + r2 + r3 + r4 = 1 to 16.

The alkyl group represented by A _{1 to} A ₄ is preferably one having 1 to 3 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group and an isopropyl group.
A _{1 to} A ₄ are usually preferably the same.

The fluorinated alkyl groups represented by A _f1 and A _f2 are preferably those having 1 to 6 carbon atoms, and may be linear or branched. Further, it is more preferable not to be a perfluoro group. Examples of such a fluorinated alkyl group include CHF ₂ CF ₂ CH ₂ —, (CF ₃ )
₂ (CH ₃ ) C—CH ₂ —, CF ₃ —CH ₂ —, CF ₃
—CF ₂ —CH ₂ —CH ₂ — and the like. A _f1 , A
Preferably, _f2 is usually the same.

The fluorinated alkyl group represented by R _{f1 to} R _f4 is preferably one having 1 to 6 carbon atoms, and may be linear or branched. Further, it is preferable that it is not a perfluoro group. Examples of such a fluorinated alkyl group include CHF ₂ CF ₂ CH ₂ —, (CF ₃ ) ₂
(CH ₃ ) C—CH ₂ —, CF ₃ CH ₂ —, CF ₃ CF
₂ CH ₂ CH ₂ — and the like. Preferably, R _{f1 to} R _f4 are usually the same. r1 to r4 are 0 or 1 to 4
Which are not simultaneously 0 but 1
~ 16. r1 to r4 are each preferably 1 or 2, and particularly preferably r1 = r2 = r3 = r4 = 1.
It is. When r1 to r4 are 2 or more, each R _f1
, Each R _f2 , each R _f3 , and each R _f4 may be the same or different.

As described above, the bonding position of the oxygen atom to the phthalocyanine ring is preferably the 3-position and / or the 6-position of the phthalocyanine ring, and it is preferable that at least one such bond is included.

Specific examples of such phthalocyanine dyes are shown below, but the present invention is not limited to these. Specific examples include A _{1 to} A ₄ , A _f1 , and A _{1 in the following} formula (IVa).
_{f2, X 31 ~X 34, X} 35 ~X 38, X 39 ~X 42, X 43 ~X 46
Is used when X _{31 to} X _{34 and the} like are all H, and when it is a substituent, only H itself is shown and H is omitted. In addition, the 3-position, the 6-position, the 4-position and the 5-position of the phthalocyanine ring are equivalent to each other, and when any of these has a substituent, only a typical example is shown.

[0220]

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[0221]

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The phthalocyanine dyes described above are disclosed in
3-313760, JP-A-63-301261, E
The compound can be synthesized with reference to the method described in P675489 or the like.

The melting points (mp) of these dyes are 60 to 40.
0 ° C.

These phthalocyanine-based dyes
Tables 1 and 2 show n and k at 80 nm. These n and k are obtained when the thickness of the dye film is 80 nm. Further, the half width of the absorption spectrum of the dye thin film was determined as described above.
(Thin film) is also shown.

[0225]

[Table 1]

[0226]

[Table 2]

These phthalocyanine compounds may be used alone or in combination of two or more.

Specific examples of the coating solvent used in the present invention include alcohols (including alkoxy alcohols such as keto alcohols and ethylene glycol monoalkyl ethers), aliphatic hydrocarbons, ketones and esters. System, ether system, aromatic system, alkyl halide system and the like.

Of these, alcohols and aliphatic hydrocarbons are preferred. Among alcohols, alkoxy alcohols and keto alcohols are preferred.
In the alkoxy alcohol system, the alkoxy moiety preferably has 1 to 4 carbon atoms, and the alcohol moiety has 1 to 5 carbon atoms, more preferably 2 to 5 carbon atoms, and the total carbon atom is 3 To 7 is preferable.
Specifically, ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (also referred to as ethyl cellosolve, ethoxyethanol), butyl cellosolve, 2-isopropoxy-1-
Ethylene glycol monoalkyl ether (cellosolve) such as ethanol, 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, a fluorinated alcohol such as 2,2,3,3-tetrafluoropropanol can also be used.

Examples of the aliphatic hydrocarbon system include n-hexane, cyclohexane, methylcyclohexane, ethylcyclohexane, cyclooctane, dimethylcyclohexane, n-octane, iso-propylcyclohexane,
T-butylcyclohexane and the like are preferable, and among them, ethylcyclohexane and dimethylcyclohexane are preferable.

The ketones include cyclohexanone.

In the present invention, alkoxy alcohols such as ethylene glycol monoalkyl ether are particularly preferable. Among them, ethylene glycol monoethyl ether, 1-methoxy-2-propanol and 1-methoxy-
2-butanol and the like are preferable, and a mixed solvent thereof is also preferable. Examples thereof include a combination of ethylene glycol monoethyl ether and 1-methoxy-2-butanol.

The azo metal complex dyes and phthalocyanine dyes of the present invention may be used in combination of two or more kinds so as to satisfy the above n and k.

The ratio of the metal complex dye of the present invention to another dye such as a phthalocyanine dye in the recording layer of the optical recording medium for recording and reproducing at two wavelengths is determined by the ratio of the azo metal complex dye of the present invention to the azo metal complex dye of the present invention. The molar ratio of other dyes is 90/10 to 10 /
Preferably it is 90.

Therefore, such a mixed type recording layer may be applied using a coating solution containing such a dye at a predetermined ratio.

In the case of recording and reproducing at two wavelengths, a recording layer in which a layer of the azo metal complex dye of the present invention and a layer of another dye are laminated may be used. The order of lamination may be appropriately selected, and the thickness per layer is usually 400 to 2
It may be about 500 A (40 to 250 nm). Such a laminated recording layer may be applied using a coating solution containing each dye.

In the case of such a laminated recording layer having a two-layer structure, a recording layer lower layer (first recording layer) corresponding to a short wavelength containing an azo metal complex dye is provided on the substrate side, and the lower layer is formed thereon. It is preferable to provide a recording layer upper layer (second recording layer) corresponding to 780 nm containing another dye such as the above phthalocyanine dye. In this case, the lower layer of the recording layer is preferably thinner than the upper layer of the recording layer, and the ratio of the thickness of the lower layer to the upper layer of the recording layer is preferably such that the lower layer / upper layer is 1/10 to 1/1.

As an optical recording disk having such a recording layer corresponding to two wavelengths or a short wavelength, on a substrate,
2 and 3 show examples of the configuration. 2 and 3 are partial sectional views. Referring to FIG. 2, the optical recording disk 1 shown in FIG. 2 is a contact type optical recording disk having a reflective layer adhered on a recording layer and capable of reproducing data in compliance with the CD standard. As shown in the drawing, the optical recording disk 1 has a recording layer 3 containing the azo metal complex-based dye of the present invention on the surface of a substrate 2 and is in close contact with the recording layer 3 to form a reflective layer (reflective film) 4 and a protective layer. It has a film (protective layer) 5.

The recording layer 3 is a two-wavelength compatible type of the above-mentioned mixed type or laminated type using an azo metal complex dye and another dye, and a short wavelength compatible type mainly containing an azo metal complex dye. It is.

The substrate 2 is in the form of a disk. To enable recording and reproduction from the back side of the substrate 2,
Recording light and reproduction light (wavelength of about 500 to 900 nm, especially about 500 to 700 nm,
About 690 nm, especially about 635-680 nm laser light and about 680-900 nm laser light, especially about 680-780 nm laser light and about 770-900 nm, especially about 770-830 nm.
Substantially transparent (preferably at a transmittance of 8) for semiconductor laser light of a certain degree, in particular 635-650 nm and 780 nm.
(8% or more) using a resin or glass. The size is about 64 to 200 mm in diameter and about 1.2 mm in thickness.

As shown in FIG. 2, a tracking groove 23 is formed on the recording layer 3 forming surface of the substrate 2.
The groove 23 is preferably a spiral continuous groove having a depth of 0.1 to 0.25 μm, a width of 0.35 to 0.60 μm for a mixed type and a short wavelength type,
In the case of a laminated type, it is preferable that the groove pitch is 0.35 to 0.80 μm and the groove pitch is 1.5 to 1.7 μm. With such a configuration of the groove, a good tracking signal can be obtained without lowering the reflection level of the groove. Particularly, the groove width is 0.35 to 0.80.
It is important to regulate the groove width to 0.35 μm or 0.35 to 0.60 μm. If the groove width is less than 0.35 μm, it is difficult to obtain a tracking signal of a sufficient magnitude,
Due to the slight offset of tracking when recording,
Jitter tends to be large. Also, as the groove width increases, waveform distortion tends to occur.

For the material of the substrate 2, it is preferable to use a resin, and various thermoplastic resins such as polycarbonate resin, acrylic resin, amorphous polyolefin, TPX, and polystyrene resin are suitable. And it can manufacture according to well-known methods, such as injection molding, using such a resin. The groove 23 is preferably formed when the substrate 2 is formed. After the manufacture of the substrate 2, a resin layer having the groove 23 may be formed by a 2P method or the like. In some cases, a glass substrate may be used.

As shown in FIG. 2, the recording layer 3 provided on the substrate 2 is formed by using the above-mentioned dye-containing coating solution, preferably by spin coating, as described above. The spin coating may be performed under normal conditions, for example, by adjusting the number of revolutions from 500 to 5000 rpm from the inner circumference to the outer circumference.

The thickness of the recording layer 3 thus formed is 50% in dry film thickness for the mixed type and the short wavelength type.
It is preferably from 0 to 3000 A (50 to 300 nm). Outside of this range, the reflectivity decreases, making it difficult to perform reproduction conforming to the CD standard. At this time, groove 2
The thickness of the recording layer 3 in the recording track 3 is 1000A.
(100 nm) or more, especially 1300-3000 A (130
３００300 nm), the degree of modulation becomes extremely large.

In the case of the laminated type, as described above,
400 to 2500 A (40 to 250 n
m) is preferable. Thereby, good reproduction can be performed. The thickness of the recording layer 3 in the recording track in the groove 23 is 500 A (50 nm) or more, especially 50 A.
It is preferably from 0 to 800 A (50 to 80 nm).
Further, as described above, when the azo metal complex-based dye of the present invention is contained in the lower layer as a two-layer structure, the upper and lower layers are formed as described above to obtain a CD-RII. Recording and reproduction can be performed satisfactorily.

The recording layer 3 formed in this manner is
If the recording layer is of a wavelength-compatible dye-mixing type, then 6
At 35 to 650 nm, n = 1.8 to 2.3, k = 0.
N = 1.8-2 at 780 nm.
5, it is preferable that k = 0.03 to 0.15. Further, when the recording layer is of a laminated type corresponding to two wavelengths, 6
From 35 to 650 nm, n = 1.8 to 2.3, k =
0.02 to 0.20, n = 1.8 at 780 nm
2.6, and k is preferably 0.02 to 0.15. By controlling n and k in this manner, good recording and reproduction can be performed at two wavelengths. In particular, at a conventional wavelength of about 780 nm, recording and reproduction in accordance with the Orange Book standard can be performed.

When the device is of a type having a short wavelength of about 635-650 nm, the extinction coefficient (imaginary part of the complex refractive index) k of the recording light and the reproduction light wavelength is 0-0.20.
It is preferred that If k exceeds 0.20, a sufficient reflectance cannot be obtained. Further, the refractive index (real part of the complex refractive index) n of the recording layer 3 is preferably 1.8 or more. If n is less than 1.8, the modulation degree of the signal is too small. n
The upper limit of is not particularly limited, but is usually about 2.6 for convenience in the synthesis of the dye compound.

The recording layers n and k are determined by preparing a recording sample on a predetermined transparent substrate to a thickness of, for example, about 40 to 100 nm under actual conditions, producing a measurement sample, The reflectance is determined by measuring the reflectance of the measurement sample through the substrate or the reflectance from the recording layer side. In this case, the reflectance is measured by specular reflection (about 5 °) using the recording / reproducing light wavelength. Also, the transmittance of the sample is measured. And from these measurements, for example,
According to Kyoritsu Zensho "Optics" Kozo Ishiguro P168-178,
What is necessary is just to calculate n and k.

Incidentally, n and k of such a recording layer are as follows.
Depending on the dye used, the values correspond to the aforementioned n and k of each dye.

As shown in FIG. 2, on the recording layer 3,
The reflection layer 4 is provided in close contact with the substrate. The reflective layer 4 is preferably made of a high-reflectance metal or alloy such as Au, Cu, Al, Ag, and AgCu. The thickness of the reflection layer 4 is 50
It is preferably 0 A or more, and the layer may be formed by vapor deposition, sputtering or the like. The upper limit of the thickness is not particularly limited.
It is preferable that it is not more than about. Thereby, the reflection layer 4
The reflectance alone is 90% or more, and the reflectance through the substrate in the unrecorded portion of the medium is sufficient. The conventional wavelength of about 780 nm of the two-wavelength compatible type has a reflectance of 60% or more, particularly 70%
The above is obtained.

As shown in FIG. 2, on the reflective layer 4,
A protective film 5 is provided. The protective film 5 is made of, for example, various resin materials such as an ultraviolet curable resin, and is usually 0.5 to 100 μm.
It may be formed to a thickness of about m. The protective film 5 may be in the form of a layer or a sheet. The protective film 5 may be formed by an ordinary method such as spin coating, gravure coating, spray coating, dipping, or the like.

For recording or additional recording on the optical recording disk 1 having such a configuration, for example, 650 nm or 780 nm
The recording light of nm is irradiated in a pulse shape through the substrate 2 to change the light reflectance of the irradiated portion. When the recording light is irradiated, the recording layer 3 absorbs the light and generates heat, and at the same time, the substrate 2 is also heated. As a result, in the vicinity of the interface between the substrate 2 and the recording layer 3, the material of the recording layer such as a dye is melted or decomposed, and pressure is applied to the interface between the recording layer 3 and the substrate 2 to deform the bottom and side walls of the groove. Sometimes.

Referring to FIG. 3, the optical recording disk 6 shown in FIG. 3 has a reflective layer adhered on a recording layer, a protective film is provided on the reflective layer, This is a contact type optical recording disk which can be reproduced by a commercially available DVD player. As shown in the figure, the optical recording disk 6 has a recording layer 8 containing the azo metal complex dye of the present invention on the surface of a substrate 7, and is in close contact with the recording layer 8 to form a reflection layer (reflection film) 9, Having a film (protective layer) 10 and a protective film 10 for two disks
Has an adhesive layer 11 inside.

The substrate 7 is disk-shaped. In order to enable recording and reproduction from the back side of the substrate 7,
Recording light and reproduction light (wavelength of about 500 to 900 nm, especially about 500 to 680 nm, especially 635 to
It is preferable to use a resin or glass which is substantially transparent (preferably at least 88% in transmittance) to a laser beam of about 680 nm, particularly 635 to 650 nm. Also,
The size is about 64-200 mm in diameter and about 0.6 mm in thickness.

As shown in FIG. 3, a tracking groove 78 is formed on the surface of the substrate 7 on which the recording layer 8 is formed.
The groove 78 is preferably a spiral continuous groove, having a depth of 0.04 to 0.15 μm, a width of 0.20 to 0.45 μm, and a groove pitch of 0.74 to
It is preferably 0.80 μm. With such a configuration of the groove, a good tracking signal can be obtained without lowering the reflection level of the groove portion. In particular, it is important to restrict the groove width to 0.20 to 0.45 μm. If the groove width is less than 0.20 μm, it is difficult to obtain a tracking signal of a sufficient magnitude, and a slight offset in tracking during recording. As a result, jitter tends to increase. 0.45μ
If m is exceeded, waveform distortion of the reproduced signal is likely to occur, causing an increase in cross stroke.

The substrate 7 is preferably made of a resin, and various thermoplastic resins such as polycarbonate resin, acrylic resin, amorphous polyolefin, TPX, and polystyrene resin are suitable. And it can manufacture according to well-known methods, such as injection molding, using such a resin. The groove 78 is preferably formed when the substrate 7 is formed. After the manufacture of the substrate 7, a resin layer having the groove 23 may be formed by a 2P method or the like. In some cases, a glass substrate may be used.

As shown in FIG. 3, the recording layer 8 provided on the substrate 7 is formed by using the above-mentioned dye-containing coating solution, preferably by the spin coating method as described above. Spin coating may be performed according to ordinary conditions, for example, by adjusting the number of revolutions from 500 to 5000 rpm from the inner circumference to the outer circumference.

The thickness of the recording layer 8 thus formed is 400 to 2000 A (40 to 200 nm) in terms of dry film thickness.
It is preferable that Outside this range, the reflectivity decreases, and it becomes difficult to perform reproduction with a commercially available DVD player. At this time, the thickness of the recording layer 8 in the recording track in the groove 78 is set to 400 A (40 nm) or more, especially 600
When it is set to A2000 A (60 to 200 nm), the degree of modulation becomes extremely large.

The recording layer 8 thus formed is
When a signal is recorded in a tan wavelength compatible type of about 35 to 650 nm, the extinction coefficient (imaginary part of the complex refractive index) k of the recording light and the reproduction light wavelength is 0.02.
０．２0.20 is preferred. When k is less than 0.02, the absorptivity of the recording layer decreases, and it is difficult to perform recording with normal recording power. On the other hand, if k exceeds 0.20, the reflectance becomes low, and it is difficult to perform reproduction by a commercially available DVD player. The refractive index (the real part of the complex refractive index) n of the recording layer 3 is 2.0 to 2.6.
Becomes When n <2.0, the reflectance is reduced, and the reproduction signal is small, so that reproduction by a commercially available DVD player tends to be difficult. When n> 2.6, it is difficult to synthesize a dye.

As shown in FIG. 3, on the recording layer 8,
The reflection layer 9 is provided in direct contact. The reflective layer 9 is preferably made of a metal or alloy having high reflectivity such as Au, Cu, Al, Ag, and AgCu. The thickness of the reflective layer 9 is 400A
It is preferable that the thickness be as described above. Also, there is no particular upper limit on the thickness,
Considering cost, production work time, etc., the thickness is 1200
It is preferably about A or less. Thus, the reflectivity of the reflective layer 9 alone is 90% or more, and the reflectivity of the medium through the unrecorded portion of the substrate is sufficient.

As shown in FIG. 3, on the reflection layer 9,
A protective film 10 is provided. The protective film 10 is made of various resin materials such as an ultraviolet curable resin, for example, usually 0.5 to 10
The layer may be formed to a thickness of about 0 μm. The protective film 10 may be in the form of a layer or a sheet. The protective film 10
It may be formed by a usual method such as spin coating, gravure coating, spray coating, and dipping.

As shown in FIG. 3, with the protective films 10 of the two disks inside, the adhesive layer 11 is placed between the protective films 10.
Layer. The adhesive layer 11 may be made of various adhesive resin materials such as a thermoplastic resin, an ultraviolet-curable resin, a thermosetting resin, and an anaerobic-curable resin. Good. The adhesive 11 may be in the form of a layer or a sheet. The adhesive layer 11 may be formed by a usual method such as spin coating, gravure coating, spray coating, or the like. After providing the adhesive layer 11, the adhesive layers 11 of the two disks may be bonded together.

For recording or additional recording on the optical recording disk 6 having such a configuration, recording light of, for example, 635 nm is irradiated in a pulse form through the substrate 7 to change the light reflectance of the irradiated portion. When the recording light is irradiated, the recording layer 8 absorbs the light and generates heat, and at the same time, the substrate 7 is also heated. As a result, in the vicinity of the interface between the substrate 7 and the recording layer 8, the material of the recording layer such as a dye is melted or decomposed, and pressure is applied to the interface between the recording layer 8 and the substrate 7 to deform the bottom and side walls of the groove. Sometimes.

[0264]

EXAMPLES Hereinafter, the present invention will be described in more detail by showing specific examples of the present invention. Example 1 Among the illustrated azo metal complex dyes, I-1 of 2
A dye film was formed on a polycarbonate substrate (120 mm in diameter, 1.2 mm in thickness) by spin coating using a wt% 2-ethoxyethanol solution, and the transmission spectrum and reflection spectrum of the thin film sample were measured. The thickness (dry film thickness) of the dye film was 500 A (50 nm). The result is shown in FIG.

FIG. 4 shows that this compound was 700 to 500 nm
It can be seen that a high reflectivity is exhibited in a wide wavelength range. This shows that the pigment is compatible with a commercially available CD player or a commercially available DVD player in this wavelength region.

Example 2 The thin film sample of Example 1 was examined for light resistance. The light resistance was measured by measuring the initial transmittance T ₀ , further irradiating a xenon lamp (xenon fade meter manufactured by Shimadzu Corporation) with an 80,000 lux, measuring the transmittance T after irradiation, and (100−T) ×
The dye remaining rate (%) was calculated and determined at 100 / (100-T ₀ ). When the dye remaining ratio after irradiation for 100 hours was examined, it was about 95%.

From this, it was found that Dye No. I-1 had sufficient light fastness.

Example 3 An optical recording disk was manufactured using the same dye No. I-1 as in Example 1 as a dye for a recording layer. First, a pre-groove (depth 0.10 μm, width 0.42 μm, groove pitch 0.8
A recording layer containing a dye was formed on a polycarbonate resin substrate having a diameter of 120 mm and a thickness of 0.6 mm having a thickness of 900 μm (90 nm) by spin coating. In this case, a 2-wt% 2-ethoxyethanol solution was used as a coating solution. Next, an Au reflection film is formed on this recording layer to a thickness of 850 A by a sputtering method, and a transparent protective layer (5 μm thick) of an ultraviolet curable acrylic resin is formed.
) Formed. Two protective layers of the disk samples formed in the same manner were adhered to the inner side with an adhesive to form a disk. This is designated as disk sample No. 1.

In Disk Sample No. 1, a 2.0 wt% 2-ethoxyethanol solution was prepared using an azocobalt complex dye having the following structure disclosed in Japanese Patent Publication No. 7-51682, and the recording layer was formed using the solution. A disk sample No. 2 was prepared in the same manner except for forming.

[0270]

Embedded image

The optical recording disk thus manufactured was subjected to 8/16 modulation of a signal at a linear velocity of 1.2 m / sec with respect to the disk samples No. 1 and No. 2 using a laser (oscillation wavelength: 635 nm). The signal is recorded, and the optimum recording power (P ₀ )
Jitter was measured. The optimum recording power means a range where the asymmetry is 0% with an evaluation machine (manufactured by Pulstec) used for recording evaluation. Table 3 shows the results. With respect to jitter, deterioration of jitter when light was irradiated under the same conditions as in Example 2 was also evaluated.

[0272]

[Table 3]

As is clear from Table 3, 7-51
It can be seen that the azocobalt complex dye of the present invention has a lower optimum recording power, that is, higher recording sensitivity than the azocobalt complex dye disclosed in JP-A-682. Also, it is understood that the jitter characteristics of the reproduced signal are excellent.

Example 4 An optical recording disk was prepared using the same dye No. I-1 as in Example 1 as a dye for a recording layer. First, a pre-groove (depth 0.16 μm, width 0.48 μm, groove pitch 1.6)
A recording layer containing a dye was formed to a thickness of 2000 A (200 nm) by a spin coating method on a polycarbonate resin substrate having a diameter of 120 mm and a thickness of 1.2 mm. In this case, a 2-wt% 2-ethoxyethanol solution was used as a coating solution. Next, an Au reflection film is formed on this recording layer to a thickness of 850 A by a sputtering method, and a transparent protective layer (5 μm thick) of an ultraviolet curable acrylic resin is formed.
) Formed. This is designated as disk sample No. 3.

In disk sample No. 3, an azocobalt complex dye having the following structure (comparative dye used in disk sample No. 2 of Example 3) disclosed in Japanese Patent Publication No. 7-51682 was used. A disc sample No. 4 was prepared in the same manner except that a 2-ethoxyethanol solution was prepared and a recording layer was formed using the solution.

Signals were recorded at a linear velocity of 1.2 m / sec using a laser (oscillation wavelength: 650 nm) with respect to the disk samples No. 3 and No. 4 of the optical recording disk manufactured in this manner. Recording power (P ₀ ), jitter (Jitt)
er) was measured. The asymmetry of the optimum recording power was -2 with the evaluator (Pulstec) used for recording evaluation.
% Means the range. Table 4 shows the results. With respect to jitter, deterioration of jitter when light was irradiated under the same conditions as in Example 2 was also evaluated.

[0277]

[Table 4]

[0278] As is clear from Table 4, 7-51
It can be seen that the azocobalt complex dye of the present invention has a lower optimum recording power, that is, higher recording sensitivity than the azocobalt complex dye disclosed in JP-A-682. Also, it is understood that the jitter characteristics of the reproduced signal are excellent.

Example 5 In the disk sample No. 3 of Example 4, the dye No. I-1 and the phthalocyanine dye A were used as dyes for the recording layer.
-152, a 2 wt% 2-ethoxyethanol solution of these mixed dyes (molar ratio of dye No. I-1 / phthalocyanine dye A-52 = 30/70) was prepared, thereby forming a recording layer. An optical recording disk was prepared in the same manner except that the layers were layered. This is designated as disk sample No. 5.

Disk sample No. 6 was prepared in the same manner as disk sample No. 5 except that the molar ratio of dye No. I-1 / phthalocyanine dye A-52 was 50/50.
Was prepared.

In this disk sample No. 6, instead of Dye No. I-1, an azocobalt complex dye of Chemical Formula 23 disclosed in Japanese Examined Patent Publication No. 7-51682 (Example 3)
Disk sample No. 7 was prepared in the same manner except that the comparative dye used for disk sample No. 2 was used.

As in Example 4, recording was performed on these disk samples using a 780 nm laser beam in accordance with the Orange Book standard.
The degree of modulation (I ₁₁₎ at the time of reproduction using a 0 nm laser beam
Mod) and jitter (Jitter) were measured. Table 5 shows the results.

[0283]

[Table 5]

As is clear from Table 5, the azocobalt complex dye of the present invention absorbs not only when the dye is used alone in the optical recording layer but also on the longer wavelength side for the purpose of achieving compatibility with 780 nm of the Orange Book standard. When used in a mixed system with a dye, for example, a phthalocyanine dye, and reproduction was performed on the short wavelength side near 650 nm, excellent characteristics were exhibited without deterioration in modulation and jitter. on the other hand,
It was found that the azo metal complex-based dye of the type used as a comparative dye increased the jitter of the reproduced signal and also had a smaller modulation factor than the dye of the present invention.
In addition, it was found that the dye of the present invention can obtain desired characteristics with a smaller mixing amount than the azo metal complex dye of the type used as a comparative dye.

Further, the degree of modulation and the jitter of each disk sample recorded at 780 nm as described above when reproduced using a 780 nm laser beam were measured. As a result, disk sample No. 5 using the dye of the present invention was obtained. Has a modulation degree of 68%, a jitter of 19 ns, and disk sample No. 6.
In this case, the modulation was 70% and the jitter was 20 ns. In contrast, Sample No. 7 using the comparative dye had a modulation factor of 62% and a jitter of 42 ns, indicating that the dye of the present invention had better characteristics.

Further, recording (linear speed: 1.2 m / sec) was performed on each disk sample using a 650 nm laser beam, and reproduction was performed using a 650 nm laser beam. As a result, disk sample No. 5 of the present invention was obtained. In No. 6, good reproduction could be performed, and the modulation degree and jitter were also good. On the other hand, the characteristics of the comparative disk sample No. 7 were inferior to those of the disk sample of the present invention.

Each disc sample recorded using a 650 nm laser beam was reproduced with a 780 nm laser beam.
5, No. 6, good reproduction can be performed.
Jitter points were also good. On the other hand, the characteristics of the comparative disk sample No. 7 were inferior to those of the disk sample of the present invention.

As described above, the disc sample No.
It can be seen that Nos. 5 and 6 can be favorably used as an optical recording disk compatible with two wavelengths.

Example 6 In each of disk samples No. 5, No. 6, and No. 7 of Example 5, phthalocyanine dye A-3 was used in place of phthalocyanine dye A-52, and 1 Disc samples No. 8, No. 9, and No. 10 were prepared in the same manner except that a 2 wt% solution using -methoxy-2-butanol was prepared and a dye film was formed to form a recording layer.

The characteristics of disk samples No. 8 to No. 10 were examined in the same manner as in Example 5. As a result, disk samples No. 8 and No. 9 were equal to or more than disk samples No. 5 and No. 6, respectively. Good characteristics were obtained.
On the other hand, disc sample No. 10 is disc sample No.
It showed only the same properties as 7.

In this, recording was performed at 780 nm and 650 nm was recorded.
modulation (I ₁₁ Mod) and jitter (J
Table 6 shows the measurement results of itter).

[0292]

[Table 6]

Example 7 In each of disk samples No. 5, No. 6, and No. 7 of Example 5, phthalocyanine dye A-1 was used instead of phthalocyanine dye A-52, and 1 Disc samples No. 11, No. 12, and No. 13 were prepared in the same manner except that a 2 wt% solution using -methoxy-2-butanol was prepared to form a dye film to form a recording layer.

The characteristics of disk sample Nos. 11 to 13 were examined in the same manner as in Example 5. As for disk sample Nos. 11 and 12, disk sample Nos.
Good characteristics equivalent to or better than No. 5 and No. 6 were obtained. On the other hand, disc sample No. 13 is disc sample No.
It showed only the same properties as 7.

In this, recording was performed at 780 nm and 650 nm was recorded.
modulation (I ₁₁ Mod) and jitter (J
Table 7 shows the measurement results of itter).

[0296]

[Table 7]

As described above, the azo metal complex-based dyes of the present invention represented by Dye No. I-1 are compared with known azo metal complex-based dyes for optical recording layers represented by comparative dyes. It is excellent in its recording sensitivity and jitter characteristics. Also,
It has been found that even when used in combination with other light absorbing dyes, it has unexpected characteristics such as the jitter of the reproduced signal does not deteriorate.

Example 8 Disk sample No. 1 of Example 3, disk sample No. 3 of Example 4, and disk sample No. of Example 5
5, No. 6, disk sample No. 8 and No. 6 of Example 6
9. In the disk samples No. 11 and No. 12 of Example 7, instead of Dye No. I-1, Dye No. I
-2, I-3, I-7, I-8, I-9, I-28, I
-32, I-53, I-65, I-79, I-107,
I-143 and I-193, respectively, or dye No.
When two or more of these dyes including I-1 were used in combination, other disk samples were prepared in the same manner, and the characteristics were examined in the same manner as in Examples 3 to 7. According to the structure, Disk sample No.1, No.3, No.5, No.
6, No. 8, No. 9, No. 11, and No. 12 showed the same characteristics. Further, for the dyes of the present invention other than Dye No. I-1, light resistance was examined in the same manner as in Example 2,
It was found to exhibit the same good light fastness as Dye No. I-1.

Example 9 A recording layer having a thickness of 50 nm was formed on the same polycarbonate resin substrate as in Example 4 by using a 2,2,3,3, -tetrafluoropropanol solution of 2% by weight of dye No. I-1. A lower layer was formed, and an upper layer of a recording layer having a thickness of 100 nm was formed using a 1.5 wt% solution of dye A-3 in ethylcyclohexane. Thereafter, a disk sample was prepared in the same manner as in Example 4.

The disk sample thus manufactured
When the characteristics of No. 14 were examined in the same manner as in Example 5, the same good results as the samples of the present invention of Examples 5 to 7 were shown. Among them, recording was performed at 780 nm and 650 nm was recorded.
modulation (I ₁₁ Mod) and jitter (J
itter) was as follows: I ₁₁ Mod = 66% Jitter = 20 ns

Example 10 Of the azo metal complex dyes exemplified above, No. II-2-2
A dye film was formed on a polycarbonate substrate (120 mm in diameter, 1.2 mm in thickness) by spin coating using a wt% 2-ethoxyethanol solution, and the transmission spectrum and reflection spectrum of the thin film sample were measured. The thickness (dry film thickness) of the dye film was 500 A (50 nm). The result is shown in FIG.

As shown in FIG. 5, this compound was 700 to 500 nm
It can be seen that a high reflectivity is exhibited in a wide wavelength range. This indicates that the pigment is compatible with a commercially available CD player or a commercially available DVD player in this wavelength region.

Incidentally, n and k at 650 nm obtained as described above were n = 2.25 and k = 0.10.

Example 11 The light resistance of the thin film sample of Example 10 was examined. The light fastness was measured by measuring the initial transmittance T _0, and a xenon lamp (Xenon fade meter manufactured by Shimadzu Corporation) of 80,000 lux.
And the transmittance T after the irradiation is measured, and (100-T)
Dye residual ratio (%) was calculated and examined at × 100 / (100−T ₀ ). When the dye remaining ratio after irradiation for 100 hours was examined, it was about 95%.

From this, it was found that Dye No. II-2 had sufficient light fastness.

Example 12 An optical recording disk was prepared using the same dye No. II-2 as in Example 10 as a dye for a recording layer. First, a pre-groove (depth 0.10 μm, width 0.42 μm, groove pitch 0.
On a polycarbonate resin substrate having a diameter of 120 mm and a thickness of 0.6 mm having a thickness of 80 μm), a recording layer containing a dye was formed to a thickness of 900 A (90 nm) by spin coating. In this case, a 2-wt% 2-ethoxyethanol solution was used as a coating solution. Next, an Au reflection film is formed on this recording layer to a thickness of 850 A by a sputtering method, and a transparent protective layer (5 μm thick) of an ultraviolet curable acrylic resin is formed.
) Formed. The two protective layers formed in the same manner were adhered to the inner side with an adhesive to form a disk.
This is designated as Disk Sample No. 21.

In disk sample No. 21, an azocobalt complex dye disclosed in Japanese Patent Publication No. 7-51682 (comparative dye used in disk sample No. 2 of Example 3) was used. A disc sample No. 22 was prepared in the same manner except that an ethanol solution was prepared and a recording layer was formed using the ethanol solution.

The optical recording disk manufactured in this manner was subjected to a laser beam (oscillation wavelength: 635 nm) at a linear speed of 3.9 m / sec with respect to the disk samples No. 21 and No. 22 of the optical recording disk.
A / 16 modulated signal was recorded, and the optimum recording power (P ₀ ) and jitter (Jitter) were measured. The optimum recording power means a range where the asymmetry is 0% with an evaluation machine (manufactured by Pulstec) used for recording evaluation. Table 8 shows the results. With respect to jitter, deterioration of jitter when light was irradiated under the same conditions as in Example 11 was also evaluated.

[0309]

[Table 8]

[0310] As is clear from Table 8, 7-51
It can be seen that the azocobalt complex dye of the present invention has a lower optimum recording power, that is, higher recording sensitivity than the azocobalt complex dye disclosed in JP-A-682. Also, it is understood that the jitter characteristics of the reproduced signal are excellent.

Example 13 An optical recording disk was produced using the same dye No. II-2 as in Example 10 as a dye for a recording layer. First, a pre-groove (depth 0.16 μm, width 0.48 μm, groove pitch 1.
A recording layer containing a dye having a thickness of 2000 A (200 nm) was formed on a polycarbonate resin substrate having a diameter of 120 mm and a thickness of 1.2 mm having a thickness of 6 μm) by spin coating. In this case, a 2-wt% 2-ethoxyethanol solution was used as a coating solution. Next, an Au reflective film is formed on this recording layer to a thickness of 850 A by a sputtering method, and a transparent protective layer (5 μm thick) of an ultraviolet curable acrylic resin is formed.
m) formed. This is designated as Disk Sample No. 23.

In disk sample No. 23, an azocobalt complex dye disclosed in Japanese Patent Publication No. 7-51682 (comparative dye used in disk sample No. 2 of Example 3) was used. A disc sample No. 24 was prepared in the same manner except that an ethanol solution was prepared and a recording layer was formed using the ethanol solution.

Signals were recorded at a linear velocity of 1.2 m / sec using a laser (oscillation wavelength: 650 nm) with respect to the disk samples No. 23 and No. 24 of the optical recording disk thus manufactured. Recording power (P ₀ ), jitter (Ji
ter) was measured. The optimum recording power means a range in which the asymmetry is -2% with an evaluator (manufactured by Pulstec) used for recording evaluation. Table 9 shows the results.
With respect to jitter, deterioration of jitter when light was irradiated under the same conditions as in Example 2 was also evaluated.

[0314]

[Table 9]

[0315] As is clear from Table 9, 7-51
It can be seen that the azocobalt complex dye of the present invention has a lower optimum recording power, that is, higher recording sensitivity than the azocobalt complex dye disclosed in JP-A-682. Also, it is understood that the jitter characteristics of the reproduced signal are excellent.

Example 14 In the disk sample No. 23 of Example 13, Dye No. II-2 and a phthalocyanine dye A-52 were used as dyes for the recording layer, and 2 wt% 2-ethoxy of the mixed dye was used. An ethanol solution (molar ratio of dye No. II-2 / phthalocyanine dye A-52 = 30/70) was prepared, and an optical recording disk was prepared in the same manner except that a recording layer was formed. This is designated as Disk Sample No. 25.

Also, disc sample No. 25 was prepared in the same manner as disc sample No. 25 except that the molar ratio of dye No. II-2 / phthalocyanine dye A-52 was 50/50.
No. 26 was produced.

Also, in this disk sample No. 26, Japanese Patent Publication No. 7-51682 was used instead of Dye No. II-2.
Disc Sample No. 27 was prepared in the same manner except that the azocobalt complex dye disclosed in Japanese Patent Application Laid-Open No. H10-209 (comparative dye used in Disc Sample No. 2 of Example 3) was used.

On these disk samples, recording was performed according to the Orange Book standard using a 780 nm laser beam in the same manner as in Example 13;
The degree of modulation (I) when reproduced using a 50 nm laser beam
₁₁ Mod) and jitter (Jitter) were measured. Table 10 shows the results.

[0320]

[Table 10]

As is clear from Table 10, the azocobalt complex dye of the present invention absorbs not only when the dye alone is used in the optical recording layer but also on the longer wavelength side for the purpose of compatibility with the Orange Book standard of 780 nm. When used in a mixed system with a dye, for example, a phthalocyanine dye, and reproduction was performed on the short wavelength side near 650 nm, excellent characteristics were exhibited without deterioration in modulation and jitter. On the other hand, it was found that an azo metal complex dye of the type used as a comparative dye increased the jitter of the reproduced signal and also had a smaller degree of modulation than the dye of the present invention. In addition, it was found that the dye of the present invention can obtain desired characteristics with a smaller mixing amount than the azo metal complex dye of the type used as a comparative dye.

Further, when the degree of modulation and jitter of each disk sample recorded at 780 nm as described above were reproduced using a 780 nm laser beam, the disk sample No. 25 using the dye of the present invention was measured. The modulation degree is 67%, the jitter is 20 ns, and the disk sample No.
In No. 26, the modulation was 71% and the jitter was 19 ns.
In contrast, Sample No. 27 using the comparative dye had a modulation factor of 62% and a jitter of 42 ns, indicating that the dye of the present invention had better characteristics.

Further, recording (linear speed: 1.2 m / sec) was performed on each disk sample using a laser beam of 650 nm, and reproduction was performed by a laser beam of 650 nm. As a result, disk sample No. 25 of the present invention was obtained. In No. 26, good reproduction could be performed, and the degree of modulation and jitter were also good. On the other hand, the characteristics of the comparative disk sample No. 27 were inferior to those of the present invention.

Each disc sample recorded using a 650 nm laser beam was reproduced with a 780 nm laser beam.
In Nos. 25 and 26, good reproduction could be performed, and the degree of modulation and jitter were also good. On the other hand, the characteristics of the comparative disk sample No. 27 were inferior to those of the disk sample of the present invention.

As described above, the disc sample No.
It can be seen that No. 25 and No. 26 can be used favorably as an optical recording disk compatible with two wavelengths.

Example 15 Disc samples No. 25, No. 26 and N of Example 14
o. In each of 27, the phthalocyanine dye A-5
The phthalocyanine dye A-3 was used in place of 2, and 1-methoxy-2-butanol was used as a coating solvent.
Disc samples No. 28, No. 29 and No. 28 were prepared in the same manner except that a dye solution was formed and a recording layer was formed by preparing a wt% solution.
30 were produced.

When the characteristics of the disk samples No. 28 to No. 30 were examined in the same manner as in Example 14, the disk sample Nos. 28 and 29 were equal to or more than the disk samples No. 25 and No. 26, respectively. Good characteristics were obtained. On the other hand, disk sample No. 30 showed only the same characteristics as disk sample No. 27.

In this, recording was performed at 780 nm and 650 nm was recorded.
modulation (I ₁₁ Mod) and jitter (J
Table 11 shows the measurement results of itter).

[0329]

[Table 11]

Example 16 Disk samples of Example 14 No. 25, No. 26, N
o. In each of 27, the phthalocyanine dye A-5
The phthalocyanine dye A-1 was used in place of 2, and 1-methoxy-2-butanol was used as a coating solvent.
Disc samples No. 31, No. 32, and No. 32 were prepared in the same manner except that a recording solution was formed by forming a dye film by preparing a wt% solution.
33 were produced.

The characteristics of the disk samples Nos. 31 to 33 were examined in the same manner as in Example 14. As a result, the disk samples No. 31 and No. 32 were as good as or better than the disk samples No. 25 and No. 26, respectively. Characteristics were obtained. On the other hand, disk sample No. 33 showed only the same characteristics as disk sample No. 27.

In this, recording was performed at 780 nm and 650 nm was recorded.
modulation (I ₁₁ Mod) and jitter (J
Table 12 shows the measurement results of itter).

[0333]

[Table 12]

As described above, the azo metal complex dye of the present invention represented by Dye No. II-2 is compared with a known azo metal complex dye for an optical recording layer represented by a comparative dye. It is excellent in its recording sensitivity and jitter characteristics. Also,
It has been found that even when used in combination with other light absorbing dyes, it has unexpected characteristics such as the jitter of the reproduced signal does not deteriorate.

Example 17 Disk sample No. 21 of Example 12, disk sample No. 23 of Example 13, disk sample Nos. 25 and 26 of Example 14, disk sample No. 28 of Example 15, No. 29, disk sample of Example 16
In each of No. 31 and No. 32, dyes No. II-3, No. II-4, No.
II-6, No. II-13, No. II-44, No. II-63,
Various disk samples were prepared using each of No. II-71 or in combination of two or more of these dyes including dye No. II-2.
When the characteristics were examined in the same manner as in the case of No. 16, disc samples No. 21, No. 23, No. 25, N
The characteristics equivalent to o. 26, No. 28, No. 29, No. 31, and No. 32 were shown. Further, the light resistance of the dye of the present invention other than the dye No. 2 was examined in the same manner as in Example 11, and it was found that the dye had the same good light resistance as the dye No. II-2.

Example 18 A recording layer having a thickness of 50 nm was formed on the same polycarbonate resin substrate as in Example 13 by using a 2% by weight solution of dye No. II-2 in 2,2,3,3-tetrafluoropropanol. A lower layer was formed, and an upper layer of a recording layer having a thickness of 100 nm was formed using a 1.5 wt% solution of dye A-3 in ethylcyclohexane. Thereafter, a disk sample was prepared in the same manner as in Example 13.

The disk sample thus manufactured
When the characteristics of No. 34 were examined in the same manner as in Example 14, the same good results as those of the samples of the present invention of Examples 14 to 16 were shown. Among them, the modulation factor (I ₁₁ Mod) and jitter when recording at 780 nm and reproducing at 650 nm were as follows. I ₁₁ Mod = 68% Jitter = 22 ns

Comparative Example In the disk sample No. 23 of Example 13, the dye
Instead of No. II-2, compounds a, b, c,
Three kinds of disk samples were prepared in the same manner as in the above, and the reflectance of the disk before recording at 650 nm was measured. As a result, the reflectance was low in all cases.

[0339]

Embedded image

From these results, it is found that the compounds a to d having a pyrrole ring, a pyrazole ring, a 1,2,4-triazole ring or a 1,2,3-triazole ring are similar to those of the present invention.
All were found to be unsuitable as dyes for optical recording layers.

Example 19 The λ max of the azo metal complex dye of the present invention used in Examples 5 to 9 and 14 to 18 was determined in the same manner as in Examples 1 and 10. Further, n and k at 650 nm were determined in the same manner as described above. Table 13 shows the results.

[0342]

[Table 13]

[0343]

According to the present invention, an azo metal complex dye excellent in solubility and light resistance is used as a light absorbing dye, and an optical recording medium excellent in characteristics such as high recording sensitivity and small jitter can be obtained. . Also, when mixed with a dye having absorption on the long wavelength side and used as a dye for an optical recording layer corresponding to two wavelengths, unlike known azo metal complex dyes, the mixing greatly deteriorates jitter. Thus, it is possible to realize an unexpected characteristic such as absence of an optical recording medium and realize a characteristic optical recording medium of a two-wavelength compatible type with excellent characteristics.

[Brief description of the drawings]

FIG. 1 is a graph illustrating a method for obtaining a half width of an absorption spectrum of a thin film of a phthalocyanine dye in the present invention.

FIG. 2 is a partial sectional view showing an example of the optical recording disk of the present invention.

FIG. 3 is a partial sectional view showing another example of the optical disk of the present invention.

FIG. 4 is a graph showing a transmission spectrum and a reflection spectrum of an azo metal complex dye used in the present invention.

FIG. 5 is a graph showing a transmission spectrum and a reflection spectrum of an azo metal complex dye used in the present invention.

[Explanation of symbols]

 1,6 Optical recording disk 2,7 Substrate 23,78 Groove 3,8 Recording layer 4,9 Reflective layer 5,10 Protective film 11 Adhesive layer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masahiro Shinkai 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Corporation (72) Inventor Sumiko Kitagawa 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Inside the corporation

Claims (6)

[Claims] 1. An optical recording medium having a recording layer containing an azo metal complex dye obtained by reacting an azo compound represented by the following formula (I) with a metal compound. Embedded image [In the formula (I), Q ₁ represents an atom group necessary for forming an aromatic ring together with two carbon atoms. Z represents a group having active hydrogen. A represents a carbon atom or a hetero atom. Q ₂ represents an atomic group necessary for forming an aromatic ring together with two carbon atoms and A, Q ₃ represents an atomic group necessary for forming an aromatic ring together with a carbon atom, a nitrogen atom and A, and aromatic ring completed by Q _2, to form a fused ring with an aromatic ring completed by Q _3. ] 2. The azo metal complex dye has a central metal of C
o, Mn, Ti, V, Ni, Cu, Zn, Mo, W, R
2. The optical recording medium according to claim 1, wherein the azo compound is u, Fe, Pd, Pt or Al, and the azo compound is represented by the following formula (Ia). Embedded image [In the formula (Ia), R ₁ , R ₂ , R ₃ and R ₄ each represent a hydrogen atom, a halogen atom, an amino group, an alkyl group, an alkoxy group, an aryloxy group, an acyl group, an aryl group, a carbamoyl group or an alkoxycarbonyl group. Represents a group, which may be the same or different. R ₁
And R ₂ , R ₂ and R _3, and R ₃ and R ₄ may be bonded to each other to form a condensed ring. Z is -OH, -SH,-
NH ₂ , —COOH, —CONH ₂ , —SO ₂ NH _2, or —SO ₃ H. R ₅ , R ₆ , R ₇ , R ₈ , R ₉
And R ₁₀ are each a hydrogen atom, a halogen atom, a nitro group,
Represents a cyano group or an alkyl group, which may be the same or different. ] 3. An optical recording medium having a recording layer containing an azo metal complex dye obtained by reacting an azo compound represented by the following formula (II) with a metal compound. Formula (II) Q ¹ -N = N-Q ² [In the formula (II), Q ¹ represents an 8-quinolyl group;
² represents a 2-imidazolyl group, and nitrogen at position 1 of the 2-imidazolyl group has active hydrogen. ] 4. The method according to claim 1, wherein the central metal of the azo metal complex dye is C.
4. The optical recording medium according to claim 3, wherein the medium is o, Mn, Ni, Cu, Zn, Mo, Fe or Pd. 5. The optical recording medium according to claim 1, wherein the recording layer further contains a light-absorbing dye having optical characteristics different from those of the azo metal complex dye. 6. The optical recording medium according to claim 5, wherein said light absorbing dyes having different optical characteristics are phthalocyanine dyes.