JPH0751673B2 - Metal chelate compound and optical recording medium using the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel metal chelate compound of a monoazo compound and a metal, and an optical recording medium using the same.

[Background technology]

Optical recording using a laser has been particularly developed in recent years because it enables high-density information recording, storage, and reproduction.

An example of optical recording is an optical disk. Generally, optical disks are formed by irradiating a thin recording layer on a circular base with a laser beam focused to about 1 μm, thereby recording high-density information.
The absorption of the irradiated laser light energy causes thermal deformation such as decomposition, evaporation, and melting in the recording layer at that point. The recorded information is reproduced by reading the difference in reflectance between the area where deformation has occurred due to the laser light and the area where it has not.

Therefore, the recording layer must efficiently absorb the energy of the laser light, and a laser absorbing dye is used for this purpose.

Various configurations of optical recording media of this type are known. For example, Japanese Patent Laid-Open Publication No. 55-97033 discloses a single layer of phthalocyanine dye on a substrate. However, phthalocyanine dyes have problems such as low sensitivity and a high decomposition point, making them difficult to deposit. Furthermore, they have extremely low solubility in organic solvents, making them unsuitable for coating by application.

Also, Japanese Patent Application Laid-Open Nos. 58-112790, 58-114989, and 59-85
Japanese Patent Application Laid-Open Nos. 791 and 60-83236 disclose recording layers containing cyanine dyes. However, while these dyes have the advantage of being highly soluble and can be coated by application, they have the drawback of being poor in light resistance. For this reason, Japanese Patent Application Laid-Open No. 59-55795 studies the addition of a quencher to the cyanine dye to improve light resistance, but the improvement is still insufficient.

Regarding these problems, Japanese Patent Application Laid-Open No. 62-30090 states:
Complexes of specific monoazo compounds with metals have been disclosed as media with improved solubility in organic solvents and improved light resistance. However, these compounds have short photosensitive wavelengths, poor sensitivity, and poor storage stability under high temperature and humidity conditions, which pose problems for their use as optical recording media.

DISCLOSURE OF THE INVENTION

The present invention relates to a compound represented by the following general formula [I]: (wherein A represents a residue which forms a heterocycle together with the carbon atom and nitrogen atom to which it is bonded, B represents a residue which forms an aromatic group together with the two carbon atoms to which it is bonded, and X represents a hydrogen atom or a cation), and a metal chelate compound, and an optical recording medium using the same.

The present invention will be described in detail below.

In the general formula [I], A represents a residue which forms a heterocycle together with the carbon atom and nitrogen atom to which it is bonded, Examples of such materials include the following:

(wherein R ¹ to R ⁸ each independently represent a hydrogen atom; a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-
an alkyl group having 1 to 6 carbon atoms, such as a butyl group, a tert-butyl group, a sec-butyl group, an n-pentyl group, or an n-hexyl group; a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a tert-butoxy group, or an sec-butyl group;
an alkoxy group having 1 to 6 carbon atoms, such as a c-butoxy group, an n-pentyloxy group, or an n-hexyloxy group; an alkylsulfonyl group having 1 to 6 carbon atoms, such as a methylsulfonyl group, an ethylsulfonyl group, an n-propylsulfonyl group, an isopropylsulfonyl group, an n-butylsulfonyl group, a tert-butylsulfonyl group, a sec-butylsulfonyl group, an n-pentylsulfonyl group, or an n-hexylsulfonyl group; an alkylcarbonyl (acetyl) group having 2 to 7 carbon atoms, such as an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a valeryl group, an isovaleryl group, a pivaloyl group, a hexanoyl group, or a heptanoyl group; a fluorine atom, a chlorine atom,
a halogen atom such as a bromine atom; a formyl group; ( ^R9 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms as defined above for ^R1 to ^R8 , and ^R10 represents a cyano group or an alkoxycarbonyl group having 2 to 7 carbon atoms, such as a methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl group, n-butoxycarbonyl group, tert-butoxycarbonyl group, sec-butoxycarbonyl group, n-pentyloxycarbonyl group, or n-hexyloxycarbonyl group); a nitro group; (The carbon atoms 11 to 13 each independently represent a hydrogen atom or a nitro group, and Z represents a single bond, _-SCH2- , _-SO2- or -S
O ₂ CH ₂ —; a trifluoromethyl group; a trifluoromethoxy group; a cyano group; an alkoxycarbonyl group having 2 to 7 carbon atoms, which is the same as defined for R ¹⁰ above;
Methoxycarbonylmethyl group, methoxycarbonylethyl group, ethoxycarbonylmethyl group, ethoxycarbonylethyl group, n-propoxycarbonylmethyl group, n-
a propoxycarbonylethyl group, an n-propoxycarbonylpropyl group, an isopropoxycarbonylmethyl group,
an alkoxycarbonylalkyl group having 3 to 7 carbon atoms, such as an isopropoxycarbonylethyl group; or a methylthio group, an ethylthio group, an n-propylthio group, an isopropylthio group, an n-butylthio group, a tert-butylthio group, a sec
In the general formula [I], B, together with the two carbon atoms to which it is bonded, forms an aromatic ring such as a benzene ring or a naphthalene ring, preferably a benzene ring. ( ^R14 is the same as defined above, and ^R23 to ^R28 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms as defined for ^R1 to ^R8 above.)

X represents a residue that forms ^-NR14R15 (wherein ^R14 and ^R15 each independently ^represent a hydrogen atom; a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-
an alkyl group having 1 to 20 carbon atoms, such as a butyl group, a tert-butyl group, a sec-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-decyl group, an n-dodecyl group, or an n-octadecyl group, preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms; an aryl group having 6 to 12 carbon atoms, such as a phenyl group, a tolyl group, a xylyl group, or a naphthyl group; an alkenyl group having 2 to 10 carbon atoms, such as a vinyl group, a 1-propenyl group, an allyl group, an isopropenyl group, a 2-butenyl group, a 1,3-butadienyl group, or a 2-pentenyl group; or a cyclopropyl group,
Cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and other groups having 3 carbon atoms
The alkyl group having 1 to 20 carbon atoms, the aryl group having 6 to 12 carbon atoms, the alkenyl group having 2 to 10 carbon atoms and the cycloalkyl group having 3 to 10 carbon atoms are exemplified by methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, tert-butoxy group, se group, and the like.
an alkoxy group having 1 to 10 carbon atoms, such as a c-butoxy group, an n-pentyloxy group, an n-hexyloxy group, an n-heptyloxy group, an n-octyloxy group, or an n-decyloxy group; a methoxymethoxy group, an ethoxymethoxy group, a propoxymethoxy group, a methoxyethoxy group, an ethoxyethoxy group, a propoxyethoxy group, or a methoxypropoxy group;
an alkoxyalkoxy group having 2 to 12 carbon atoms, such as an ethoxypropoxy group, a methoxybutoxy group, or an ethoxybutoxy group; a methoxymethoxymethoxy group, a methoxymethoxyethoxy group, a methoxyethoxymethoxy group, a methoxyethoxyethoxy group, an ethoxymethoxymethoxy group, an ethoxymethoxyethoxy group, or an ethoxyethoxymethoxy group;
an alkoxyalkoxyalkoxy group having 3 to 15 carbon atoms, such as an ethoxyethoxyethoxy group; an allyloxy group; a group having 6 carbon atoms, such as a phenyl group, a tolyl group, a xylyl group, or a naphthyl group;
aryl groups having 6 to 12 carbon atoms, such as a phenoxy group, a tolyloxy group, a xylyloxy group, or a naphthyloxy group; a cyano group; a nitro group, a hydroxy group; a tetrahydrofuryl group; alkylsulfonylamino groups having 1 to 6 carbon atoms, such as a methylsulfonylamino group, an ethylsulfonylamino group, an n-propylsulfonylamino group, an isopropylsulfonylamino group, an n-butylsulfonylamino group, a tert-butylsulfonylamino group, a sec-butylsulfonylamino group, an n-pentylsulfonylamino group, or an n-hexylsulfonylamino group; halogen atoms such as a fluorine atom, a chlorine atom, or a bromine atom; a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an isopropoxycarbonyl group, an n-butoxycarbonyl group, or a tert-butoxycarbonyl group,
an alkoxycarbonyl group having 2 to 7 carbon atoms, such as a sec-butoxycarbonyl group, an n-pentyloxycarbonyl group, or an n-hexyloxycarbonyl group; a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n
alkylcarbonyloxy groups having 2 to 7 carbon atoms, such as a-butylcarbonyloxy group, a tert-butylcarbonyloxy group, a sec-butylcarbonyloxy group, an n-pentylcarbonyloxy group, or an n-hexylcarbonyloxy group;
It may be substituted with an alkoxycarbonyloxy group having 2 to 7 carbon atoms, such as methoxycarbonyloxy, ethoxycarbonyloxy, n-propoxycarbonyloxy, isopropoxycarbonyloxy, n-butoxycarbonyloxy, tert-butoxycarbonyloxy, sec-butoxycarbonyloxy, n-pentyloxycarbonyloxy, or n-hexyloxycarbonyloxy. Furthermore, the aryl groups having 6 to 12 carbon atoms and the aryl groups having 3 to 12 carbon atoms, as represented by ^R14 and ^R15 , may be substituted with an alkoxycarbonyloxy group having 2 to 7 carbon atoms, such as methoxycarbonyloxy, ethoxycarbonyloxy, n-propoxycarbonyloxy, isopropoxycarbonyloxy, n-butoxycarbonyloxy, tert-butoxycarbonyloxy, sec-butoxycarbonyloxy, n-pentyloxycarbonyloxy, or n-hexyloxycarbonyloxy.
The cycloalkyl group of 10 may be substituted with an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a sec-butyl group, an n-pentyl group, or an n-hexyl group, or a vinyl group; an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a sec-butyl group, an n-pentyl group, or an n-hexyl group; an alkyl group having 1 to 6 carbon atoms, such as a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a tert-butoxy group, a sec-butoxy group, an n-pentyloxy group, or an n-hexyloxy group;
an alkoxy group; a halogen atom such as a fluorine atom, a chlorine atom, or a bromine atom; a nitro group; a cyano group; a methylsulfonyl group, an ethylsulfonyl group, or an n-propylsulfonyl group,
isopropylsulfonyl group, n-butylsulfonyl group,
alkylsulfonyl groups having 1 to 6 carbon atoms, such as a tert-butylsulfonyl group, a sec-butylsulfonyl group, an n-pentylsulfonyl group, or an n-hexylsulfonyl group; a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an isopropoxycarbonyl group, an n-butoxycarbonyl group, a tert-butoxycarbonyl group, a sec-butylsulfonyl group, an n-pentylsulfonyl group, or an n-hexylsulfonyl group;
C2 carbon atoms such as c-butoxycarbonyl, n-pentyloxycarbonyl, and n-hexyloxycarbonyl groups
and a thiocyanate group.

In the general formula [I], X is a hydrogen atom or Na ⁺ , L
Inorganic cations such as i ⁺ and K ⁺ or N ⁺ (C ₄ H ₉ (n)) ₄ , It represents a cation such as an organic cation such as

One embodiment of the preferred compound of the present invention is a compound represented by the following general formula [II]: (wherein ring Y represents a residue forming an aromatic ring having 6 to 12 carbon atoms such as a benzene ring, a naphthalene ring, an anthracene ring or a phenanthrene ring, which may have a substituent as defined above for ^R1 to ^R8 , or a heterocycle having one or more heteroatoms such as a quinoline ring, a pyridine ring, an acridine ring or a carbazole ring, and rings B and X are as defined above), and a metal.

Among the compounds represented by the formula [II], the compound represented by the following general formula [III] (wherein ring D may have one or more substituents selected from an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom, a nitro group, a cyano group, an alkylsulfonyl group having 1 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 7 carbon atoms, and a thiocyanato group, as defined for residue B above; and R ¹⁴ , R ¹⁵ , X, and Y are as defined above.) are preferred, and among the compounds represented by formula [III], metal chelate compounds of a monoazo compound represented by the formula:
The following general formula [IV]: One embodiment of the preferred compound in the present invention is a compound represented by the following general formula [IV]: (wherein ring C may have a substituent as defined above for R ¹ to R ⁸ , and ring D, R ¹⁴ , R ¹⁵ and X are as defined above), and a metal chelate compound thereof.

Among the compounds represented by the formula [IV], compounds represented by the following general formula [V] are further included. (wherein R ¹⁶ to ^{R 19} each independently represent a hydrogen atom, an alkyl group having ¹ to ⁶ carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylsulfonyl group having 1 to 6 carbon atoms, an alkylcarbonyl (acetyl) group having 2 to 7 carbon atoms, a halogen atom, a formyl group, or the like, which are as defined for R 1 to R 8 above. ( ^R9 and ^R10 are as defined above), a nitro group, (R ¹¹ to ^{R 13} are as defined above), a trifluoromethyl group, a trifluoromethoxy group, or a cyano group; R
²⁰ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom or a nitro group as defined for the residue B; R ²¹ and R ²² each independently represent an alkyl group having 1 to 6 carbon atoms or an alkoxyalkyl group having 2 to 6 carbon atoms; and X has the same meaning as defined above. (In the formula, R ¹⁶ and R ²⁰ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom; n
a metal chelate compound of a monoazo compound represented ^{by the} following general formula [VII]: (wherein R ¹⁶ and R ²⁰ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having ¹ to ⁶ carbon atoms, or a halogen atom; and R ⁹ , R ¹⁰ , ^{R 21} , R ²² and ^X are as defined above); ( ^R9 and ^R10 are as defined above), a trifluoromethyl group or a cyano group, ^R20 represents a hydrogen atom or an alkoxy group having 1 to 6 carbon atoms, ^R21 and ^R22 each independently represent an alkyl group having 1 to 6 carbon atoms, and X is as defined above; or a metal chelate compound of a monoazo compound and a metal, wherein ^R16 and ^R17 represent a hydrogen atom, and ^R18 to ^R20
Preferably used are metal chelate compounds of a monoazo compound and a metal, each of which independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom.

Further, another embodiment of the preferred compound of the present invention is
The following general formula [XI] (wherein R ¹ , R ² , R ¹⁴ , R ¹⁵ , D and X are as defined above) and a metal chelate compound.

Among the compounds represented by the formula [VI], compounds represented by the following general formula [XII] (wherein R ¹⁶ , R ¹⁷ , R ²⁰ to R ²² and X are as defined above) and a metal chelate compound thereof is preferred.

In the present invention, specific examples of the azo compound that forms a complex with a metal include the following.

In the present invention, the metal that forms a chelate with the monoazo compound is not particularly limited as long as it is a metal that can generally form a complex with the monoazo compound.
Transition elements such as Ni, Co, Fe, Ru, Rh, Pd, Os, Ir, and Pt are preferred, and Ni or Co is particularly preferred.

Next, a method for producing the metal chelate compound of the monoazo compound of the present invention will be described.

The metal chelate compound of the monoazo compound of the present invention can be prepared, for example, by the method described in Furukawa, Analytica Chimica Acta 140 (1982) 281-289.
That is, the compound represented by the general formula [XIII] or the general formula [XIV] can be synthesized in accordance with the description of the compound represented by the general formula [XIII] or the general formula [XIV] (wherein R ¹ , R ² and ring C are as defined above) is diazotized in a conventional manner to obtain an amino compound represented by the following general formula [XV]: (wherein R ¹⁴ , R ¹⁵ , X and ring D are as defined above) to obtain a monoazo compound represented by the general formula [IV] or [XI], and then the monoazo compound and a metal salt are reacted with water and/or dioxane, tetrahydrofuran, acetone,
The metal chelate compound of the present invention can be produced by reacting in an organic solvent such as ethanol.

Examples of anions of the metal salts used in the production of the metal chelate compounds include SCN ⁻ , SbF ₆ ⁻ , Cl ⁻ , Br ⁻ , F ⁻ , ClO ₄ ⁻ , BF ₄ ⁻ ,
PF ₆ ^- , CH ₃ COO ^- , TiF ₆ ^2- , SiF ₆ ^2- , ZrF ₆ ^2- , Monovalent or divalent anions such as BF ₄ ⁻ , ...
PF ₆ ⁻ and CH ₃ COO ⁻ are preferably used.

Next, the optical recording medium of the present invention will be described.

The optical recording medium of the present invention is basically composed of a substrate and a recording layer containing the metal chelate compound of the monoazo compound, and if necessary, an undercoat layer can be provided on the substrate. In addition, as a preferred layer structure, a metal reflective layer such as gold or aluminum and a protective layer are provided on the recording layer to make it a medium with high reflectivity, and it can be used for write-once CDs.
It can be a media.

The substrate in the present invention may be either transparent or opaque to the laser beam used. Materials for the substrate include supports of general recording materials such as glass, plastic, paper, and metal plates or foils.
Plastics are preferably used from various viewpoints, such as acrylic resin, methacrylic resin, vinyl acetate resin, vinyl chloride resin, nitrocellulose, polyethylene resin, polypropylene resin, polycarbonate resin, polyimide resin, epoxy resin, and polysulfone resin, but injection-molded polycarbonate resin substrates are particularly preferred from the viewpoints of high productivity, cost, and moisture absorption resistance.

The recording layer containing the chelate compound of a monoazo compound and a metal in the optical recording medium of the present invention has a thickness of 100 Å to 150 Å.
It is preferably 5 μm, and more preferably 1000 Å to
It is 3 μm.

The film can be formed by a commonly used thin film formation method such as vacuum deposition, sputtering, doctor blade, casting, spinner method, or immersion method, but the spinner method is preferred from the viewpoints of mass productivity, cost, etc.

A binder can also be used if necessary. Known binders such as polyvinyl alcohol, polyvinylpyrrolidone, ketone resin, nitrocellulose, cellulose acetate, polyvinyl butyral, and polycarbonate can be used. When forming a film using the spinner method, the rotation speed is preferably 500 to 5,000 rpm, and after spin coating, treatment such as heating or exposure to solvent vapor can be performed as necessary.

In order to improve the stability and light resistance of the recording layer, a transition metal chelate compound (e.g., acetylacetonate chelate, bisphenyldithiol, salicylaldehyde oxime, bisdithio-α
-diketones, etc.), and further, dyes of the same type or dyes of other types, such as triarylmethane dyes, azo dyes, cyanine dyes, squarylium dyes, metal chelate compounds of monoazo compounds, and nickel-indoaniline dyes, can be used in combination.

Examples of the coating solvent when forming the recording layer by a coating method such as a doctor blade method, a casting method, a spinner method, or a dipping method, particularly a spinner method, include tetrafluoropropanol, octafluoropentanol, tetrachloroethane, bromoform, dibromoethane, diacetone alcohol, ethyl cellosolve, xylene, 3-hydroxy-
3-methyl-2-butanone, chlorobenzene, cyclohexanone, methyl lactate, and the like, which have a boiling point of 120 to 160°C, are preferably used.

Among these, for injection-molded polycarbonate resin substrates, which are highly productive, inexpensive, and have excellent moisture absorption resistance, solvents that can be suitably used without damaging the substrate include diacetone alcohol, 3-hydroxy-3-methyl-2-methylpropional, and 2-methylpropional.
Ketone alcohol solvents such as butanone; cellosolve solvents such as methyl cellosolve and ethyl cellosolve; perfluoroalkyl alcohol solvents such as tetrafluoropropanol and octafluoropentanol; methyl lactate,
Examples include hydroxy ester solvents such as methyl isobutyrate.

The recording layer of the optical recording medium of the present invention may be provided on both sides of the substrate or on only one side.

Recording on the recording medium obtained as described above is carried out by irradiating the recording layer provided on one or both sides of the substrate with laser light, preferably semiconductor laser light, focused to about 1 μm. In the area irradiated with the laser light, thermal deformation of the recording layer, such as decomposition, evaporation, or melting, occurs due to absorption of laser energy. Therefore, the recorded information can be reproduced by reading the difference in reflectance between the area where thermal deformation occurs due to the laser light and the area where no thermal deformation occurs.

The laser light used for recording and playback on the optical recording medium of the present invention includes _N2 , He-Cd, Ar, He-Ne, ruby, semiconductor, and dye lasers, but semiconductor lasers are particularly preferred because of their light weight, ease of handling, and compactness.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing showing the infrared absorption spectrum of the metal chelate compound in Example 3.

FIG. 2 is a drawing showing the infrared absorption spectrum of the metal chelate compound in Example 6.

FIG. 3 is a drawing showing the infrared absorption spectrum of the metal chelate compound in Example 7.

FIG. 4 is a drawing showing the infrared absorption spectrum of the metal chelate compound in Example 8.

FIG. 5 is a drawing showing the infrared absorption spectrum of the azo compound used in the synthesis of the metal chelate compound in Example 12.

FIG. 6 is a drawing showing the infrared absorption spectrum of the metal chelate compound in Example 12.

7 and 8 are graphs showing the visible absorption spectrum of the metal chelate compound of Example 12 in solution and in the form of a thin coated film, respectively.

FIG. 9 is a drawing showing the infrared absorption spectrum of the metal chelate compound in Example 13.

FIG. 10 is a drawing showing the infrared absorption spectrum of the metal chelate compound in Example 16.

FIG. 11 is a graph showing the visible absorption spectrum of the metal chelate compound in Example 20 in a chloroform solution.

FIG. 12 is a drawing showing the infrared absorption spectrum of the metal chelate compound in Example 20.

FIG. 13 is a graph showing the visible absorption spectrum of the coating film of the metal chelate compound in Example 20.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples as long as the gist of the invention is not exceeded.

Example 1 (a) Preparation of a compound having the following structural formula 2-amino-6-methylbenzothiazole represented by the formula:
Disperse 12g (0.02 mol) of the mixture in 10ml of 98% sulfuric acid and dissolve for 5-10 minutes.
The mixture was stirred at 5°C, 10 ml of glacial acetic acid was added, and the mixture was further cooled to 5°C or below. Nitrosylsulfuric acid prepared from 1.68 g of sodium sulfite and 9.5 ml of 98% sulfuric acid was added and the mixture was stirred for 30 minutes.
The reaction mixture was stirred at 0-5°C for 1 hour.
At the same time, the following structural formula 5.02 g (0.02 mol) of the aniline sulfonic acid derivative represented by the formula (I) was dispersed in 200 ml of methanol, and the mixture was added dropwise with stirring. After further stirring at 5°C or below for 3 hours,
The reaction mixture was filtered to obtain 7.06 g of red crystals represented by the following structural formula:
obtained.

Next, 0.4 g of the azo compound obtained above was dissolved in 100 ml of methanol at room temperature, and 0.36 g of a 40% aqueous solution of Ni( _BF4 ) ₂ was added. Then, 50 ml of a pH 7 buffer solution (phosphate-based) was added to adjust the pH to 7. After stirring for approximately 1 hour, the solution was filtered and washed with water. The resulting powder was stirred in 100 ml of methanol at room temperature for approximately 30 minutes, filtered, washed with methanol, washed with water, and dried to obtain 0.37 g of a black crystalline nickel chelate compound represented by the following structural formula:

The absorption spectrum of this compound in chloroform solution is λ
_Max 646nm, 598nm (molecular extinction coefficient; ε = 10.6 × 10 ⁴ , 10.0
×10 ⁴ ).

The results of elemental analysis were as follows:

(b) Example of Production of Optical Recording Medium: 0.15 g of the chelate compound of the monoazo compound and nickel obtained in the above Production Example (a) was dissolved in 7.5 g of octafluoropentanol.
The solution was dissolved in 100 ml of ethanol and filtered through a 0.22 μm filter to obtain a solution. Five ml of this solution was dropped onto a 5-inch diameter injection-molded polycarbonate resin substrate with a 700 Å deep, 0.7 μm wide groove, and coated using a spinner at 500 rpm. After coating, the substrate was dried at 60°C for 10 minutes. The maximum absorption wavelength of the coated amount was 677 nm.

Next, a 2000 Å thick film was deposited on the coating by sputtering.
A gold film was formed to form a reflective layer. After that, a UV-curable resin was spin-coated on top of the reflective layer, and then cured by UV irradiation to form a protective layer with a thickness of 10 μm, thereby producing an optical recording medium.

(c) Optical recording example While rotating the above recording medium at 1.2 m/s, a central wavelength of 780 nm was
The EFM was irradiated with a semiconductor laser beam of 1000 MHz at a recording power of 7.0 mW.
The signal was recorded. Then, when this recording was played back using a CD player with a semiconductor laser with a central wavelength of 780 nm,
A good playback signal was obtained.

Also, light resistance (Xenon Fade Meter Accelerated Test; 6
As a result of tests for storage stability (70°C, 85% RH; 500 hours) and storage stability (70°C, 85% RH; 500 hours), no deterioration in sensitivity or playback signal was observed compared to the initial state, demonstrating that the optical recording medium is extremely excellent.

Example 2 (a) Compound Production Example: The procedure of Example 1 was repeated except that 0.48 g of 40% Co( _BF4 ) ₃ aqueous solution was used instead of 0.36 g of 40% Ni( _BF4 ) ₂ aqueous solution used in Example 1, and 0.32 g of a black powder cobalt chelate compound was obtained.

The absorption spectrum of this compound in chloroform solution is λ
_{The maximum} was 648 nm (ε=10.5×10 ⁴ ).

(b) Optical Recording Medium Production Example A coating film was formed in the same manner as in Example 1, except that 0.15 g of the chelate compound of the monoazo compound and nickel obtained in Production Example (a) was used. The maximum absorption wavelength for the coating amount was:
The wavelength was 681 nm.

Next, a reflective layer and a protective layer were formed on this coating film in the same manner as in Example 1 to produce an optical recording medium.

(c) Optical Recording Example When an EFM signal was recorded on the above recording medium in the same manner as in Example 1 and reproduced, a good reproduced signal was obtained.

Furthermore, light resistance and storage stability tests were carried out in the same manner as in Example 1. As a result, no deterioration in sensitivity or reproduced signals was observed compared with the initial state, and the optical recording medium was extremely excellent.

Example 3 (a) Compound Preparation Example 2-amino-6-methoxybenzothiazole represented by the formula:
3.60 g of this compound was dissolved in 18.4 ml of 1.5% sulfuric acid at 30-35°C.
Add 59.5 ml of 40% sulfuric acid cooled to 5-0°C, and add another 45
6.78 g of 100% nitrosylsulfuric acid was added dropwise and stirred at the same temperature for 2 hours to diazotize the mixture.
The diazotized solution was added to a solution of 115 ml of water and stirred at the same temperature for 15 minutes. Add 6.18 g of the substituted aniline sulfonic acid derivative represented by the formula
A solution of 100 ml of HCl in water was added and stirred at the same temperature for 30 minutes.
The mixture was neutralized with aqueous ammonia, stirred, and coupled. The precipitated crystals were filtered and dried to give the compound of the following structural formula: As a result, 2.73 g of crystals of the azo compound represented by the formula: was obtained.

0.45 g of this azo compound was dissolved in 40 ml of methanol, and a solution of _{0.15 g} of nickel acetate Ni( _CH3COO )2.4H2O in 6 ml of methanol was added dropwise at room temperature. The mixture was stirred at the same temperature for 2 hours to obtain 0.12 g of black crystals of a nickel chelate compound represented by the following structural formula.

The physical properties of this compound are shown below. The infrared absorption (IR) spectrum is shown in Figure 1.

Physical properties Melting point: 250°C or higher λ _max (chloroform): 696,639nm ε (molecular absorption coefficient): 11.4×10 ⁴ , 9.3×10 ⁴ IR spectrum (KBr): 1600, 1530, 1300, 1280, 1220, 1190°C
m ^-1 Example 4 6.18 g of the substituted aniline sulfonic acid derivative used in Example 2
Instead of the following structural formula The compound represented by the following structural formula was obtained by the same method as in Example 3, except that 5.07 g of a substituted aniline sulfonic acid derivative represented by the following structural formula was used. Thus, 2.20 g of crystals of the azo compound represented by the formula: was obtained.

A compound having the following structural formula was prepared in the same manner as in Example 3, except that 0.30 g of this azo compound and 0.10 g of nickel acetate were used. The absorption spectrum of this compound in chloroform solution was λ _max 685 nm, 633 nm, and the molar extinction coefficient was ε = 9.0 × 10 ⁴ .
The concentration was 7.7 × 10 ⁴ .

Example 5 Instead of 2-amino-6-methoxybenzothiazole used in Example 3, 3.88 g of 2-amino-6-ethoxybenzothiazole represented by the following structural formula was used to obtain a substituted aniline sulfonic acid derivative: The same procedure as in Example 3 was repeated except that 5.07 g of the compound represented by
By producing it in the same manner as above, a compound having the following structural formula As a result, 3.20 g of crystals of the azo compound represented by the formula: was obtained.

A compound having the following structural formula was prepared in the same manner as in Example 3, except that 0.90 g of this azo compound and 0.30 g of nickel acetate were used. The absorption spectrum of this compound in chloroform solution was λ _max 687 nm, 635 nm, and the molar extinction coefficient was ε = 10.1 × 10 ⁴ .
The concentration was 8.5 × 10 ⁴ .

Example 6: In a solution of 5 ml of acetic acid and 10 ml of sulfuric acid, 3.02 g of an aminothiazole derivative represented by the formula
After adding 5.08 g of 45% nitrosylsulfuric acid at room temperature, the temperature was
The mixture was cooled to rt, and 25 ml of water was added dropwise, followed by stirring at the same temperature for 1.5 hours to effect diazotization.

On the other hand, the following structural formula The above diazotide solution was added dropwise to a solution of 4.64 g of a substituted aniline sulfonic acid derivative represented by the formula: in 100 ml of methanol at 0 to 5° C. while controlling the pH to 5 to 6 with aqueous ammonia, to carry out coupling. The precipitated crystals were filtered off and dried to obtain a compound having the following structural formula: Thus, 2.51 g of crystals of the azo compound represented by the formula: was obtained.

0.47 g of this azo compound was dissolved in 40 ml of methanol, and 0.15 g of nickel acetate Ni(CH ₃ COO) _{2.4H 2} O dissolved in 6 ml of methanol was added dropwise at room temperature. The mixture was stirred at the same temperature for 2 hours to obtain the compound with the following structural formula: The resulting solution was 0.26 g of black crystals of a nickel chelate compound represented by the formula: The physical properties of this compound are shown below.

The IR spectrum is shown in FIG.

Physical properties Melting point: 250°C or higher λ _max (chloroform): 696,639nm ε (molecular extinction coefficient): 14.6×10 ⁴ , 11.5×10 ⁴ IR spectrum (KBr): 1590, 1530, 1390, 1280, 1210, 1180,
1100, 1080 cm ^-1 Example 7 4.64 g of the substituted aniline sulfonic acid derivative used in Example 6
Instead, use the following structural formula The same procedure as in Example 4 was repeated except that 3.80 g of a substituted aniline sulfonic acid derivative represented by the following structural formula was used. Thus, 2.15 g of crystals of the diazo compound represented by the formula: was obtained.

The same procedure as in Example 6 was repeated except that 0.3 g of this azo compound and 0.1 g of nickel acetate were used, resulting in a compound of the following structural formula: The resulting solution was 0.18 g of black crystals of a nickel chelate compound represented by the formula: The physical properties of this compound are shown below.

The IR spectrum is shown in FIG.

Physical properties Melting point: 250°C or higher λ _max (chloroform): 686, 630 nm ε (molecular absorption coefficient): 12.2×10 ⁴ , 9.7×10 ⁴ IR spectrum (KBr): 1590, 1540, 1380, 1220, 1170, 1080,
1000 cm ^-1 Example 8 Cobalt acetate was used in place of nickel acetate used in Preparation Example 7.
The compound of the following structural formula was obtained by the same method as in Example 7, except that 0.10 was used. 0.18g of black crystals of a cobalt chelate compound represented by
The physical properties of this compound are shown below.

The IR spectrum is shown in FIG.

Physical properties Melting point: 250°C or higher λ _max (chloroform): 686,627nm ε (molecular absorption coefficient): 9.8×10 ⁴ , 8.7×10 ⁴ IR spectrum (KBr): 1590, 1540, 1380, 1220, 1170, 1080,
1000 cm ^-1 Example 9 The following structural formula 2.50 g of the benzothiazole derivative represented by the formula
After cooling to 0-3°C, 3.38 g of 45% nitrosylsulfuric acid was added dropwise and the mixture was stirred at the same temperature for 2 hours to effect diazotization.

On the other hand, the following structural formula and 0.25 g of urea were dissolved in 100 ml of methanol at 0-5°C.
The diazotized solution was added dropwise to the flask while controlling the pH to 5-6 with aqueous ammonia, and coupling was carried out. The precipitated crystals were filtered and dried to give the compound having the following structural formula: 0.91 g of crystals of the azo compound represented by the formula: was obtained.

0.40 g of this azo compound was dissolved in 40 ml of methanol, and 0.11 g of nickel acetate Ni(CH ₃ COO) ₂ .4H ₂ O dissolved in 5 ml of methanol was added dropwise at room temperature. The mixture was stirred at the same temperature for 2 hours to obtain the following structural formula: 0.25g of black crystals of nickel chelate compound represented by
The absorption spectrum of this compound in chloroform solution is λ _max 713nm, 665nm, and the molar extinction coefficient is ε = 5.8 × 10 ⁴ , 5.
The concentration was 2× ¹⁰⁴ .

Example 10 According to the methods of Examples 1 to 9, the metal chelate compounds shown in Table 1 were produced, and the absorption spectra (λ _max ) and molar extinction coefficients (ε) in chloroform solutions were determined.

Example 11: Instead of the azo compound-metal chelate compound used in Example 1, a complex of an azo compound and a metal shown in Table 2 was used, and the resulting solution was applied to a substrate to obtain an optical recording medium having the maximum absorption wavelength of the coating film shown in Table 2. When writing was performed on the recording medium thus obtained using a semiconductor laser as a light source, the sensitivity was good,
The light resistance and storage stability were also excellent.

Example 12 (a) Preparation of Compound A solution of 17.8 g of phosphoric acid and 1.0 g of sulfuric acid was added with the compound having the following structural formula: 2-amino-5-nitrobenzothiazole represented by the formula:
90 g of the solution was dissolved at 40-50°C, and then 6.3 ml of acetic acid was added at the same temperature. After cooling to 0-10°C, 2.43 g of acetic acid was added, and 0
6.78 g of 45% nitrosylsulfuric acid was added at ∼-5°C, and the mixture was stirred at the same temperature for 2 hours to diazotize.

On the other hand, the following structural formula The diazotized solution obtained above was added dropwise to a solution prepared by dissolving 10.1 g of a substituted aniline sulfonic acid derivative represented by the formula (I) in 500 ml of methanol at 0 to 50°C, and the solution was adjusted to pH 5 to 6 with an aqueous ammonia solution.
The resulting crystals were filtered and dried to obtain 5.94 g of black crystals of an azo compound represented by the following structural formula.

The physical properties of this compound were as follows: The IR spectrum is shown in Figure 5.

Physical properties Melting point: 219°C (decomposition) λ _max (ethanol): 578nm IR spectrum (KBr): 2960, 1590, 1520, 1340, 1300, 1240
1200, 1180, 1090 ^{cm -1} 5.94 g of the azo compound obtained above was dissolved in 200 ml of methanol.
Dissolve nickel acetate Ni(CH;COO) ₂ .4H ₂ O in 1.6 mL of HCl.
A solution of 3 g of this compound in 200 ml of methanol was added dropwise at room temperature and stirred at the same temperature for 5 hours. The precipitated crystals were filtered off.
After drying, 5.0 g of black crystals of a nickel chelate compound of an azo compound represented by the following structural formula were obtained.

The physical properties of this compound are shown below. The IR spectrum is shown in Figure 6.
and the absorption spectrum in solution (chloroform) is shown in FIG.

Physical properties Melting point: 216°C (decomposition) λ _max (chloroform): 632, 692 nm ε (molecular extinction coefficient): 12.2×10 ⁴ , 15.1×10 ⁴ IR spectrum (KBr): 2980, 1600, 1540, 1400, 1340, 1200°C
m ^-1 (b) Example of Preparation of Optical Recording Medium A 1.0% by weight solution of the nickel chelate compound of the azo compound obtained in the above Compound Preparation Example (a) in octafluoropentanol was prepared and spin-coated (at a rotation speed of 500 rpm) to obtain a 1.0% by weight solution of the nickel chelate compound of the azo compound obtained in the above Compound Preparation Example (a).
The film was coated onto a polycarbonate substrate with a diameter of 120 mm and a thickness of 1.2 mm. The maximum absorption wavelength of the coated thin film was 719 nm, as shown in Figure 8. Gold was evaporated onto this thin film to form a reflective layer. This was then hard-coated with a UV-curable resin to produce an optical recording medium.

(c) Evaluation of recording characteristics: In the reproduced waveform, an EFM signal was recorded on the prepared optical recording medium using a semiconductor laser beam with a central waveform of 780 nm. When the recording sensitivity and modulation (I _ll /I _toP ) were determined with the optimum output being where I ll becomes 0, good initial recording characteristics were obtained, with a recording sensitivity of 7.5 mW and a modulation of 70%.

Furthermore, the optical recording medium thus produced was subjected to light resistance (accelerated xeno-fade meter test: 60 hours) and storage stability tests (70°C, 85% RH: 500 hours). As a result, no deterioration in sensitivity or playback signal was observed compared to the initial state, demonstrating that the optical recording medium was extremely excellent.

Example 13 (a) 10.1 g of the substituted aniline sulfonic acid derivative used in Preparation Example 12
Instead of the following structural formula The same procedure as in Example 12 was carried out except that 9.56 g of a substituted aniline sulfonic acid derivative represented by the following structural formula was used, to obtain 4.8 g of black crystals of a nickel chelate compound represented by the following structural formula.

The physical properties of this compound are shown below. The IR spectrum is shown in Figure 9.
Shown below.

Physical properties Melting point: 280°C or higher λ _max (chloroform): 628, 688 nm ε (molecular absorption coefficient): 11.9×10 ⁴ , 15.0×10 ⁴ IR spectrum (KBr): 1600, 1540, 1400, 1340, 1210, 1120,
1080, 1000 cm ^-1 (b) Example of Preparation of Optical Recording Medium A 1.0% by weight solution of the nickel chelate compound of the azo compound obtained in the above Compound Preparation Example (a) in 3-hydroxy-3-methyl-butanone was prepared and subjected to a spinner method (rotation speed: 500 rpm).
The film was applied to a polycarbonate substrate with a diameter of 120 mm and a thickness of 1.2 mm using a laser (microwave oven). The maximum absorption wavelength of the applied thin film was 713 nm. Gold was vapor-deposited onto this thin film to form a reflective layer. This was then hard-coated with a UV-curable resin to produce an optical recording medium.

(c) Evaluation of recording characteristics In the reproduced waveform in which an EFM signal was recorded on the prepared optical recording medium using a semiconductor laser beam with a central waveform of 780 nm, the
The recording sensitivity and modulation (I ₁₁ /I _toP ) were determined in the same manner as in 2, and good initial recording characteristics were obtained, with a recording sensitivity of 7.2 mW and a modulation of 72%.

Furthermore, light resistance and storage stability tests were carried out in the same manner as in Example 12. As a result, no deterioration in sensitivity or reproduced signals was observed compared to the initial state, demonstrating that the optical recording medium was extremely excellent.

Example 14 10.1 g of the substituted aniline sulfonic acid derivative used in Example 12
Instead of the following structural formula The same procedure as in Example 12 was carried out except that 9.69 g of a 1:1 mixture of substituted aniline sulfonic acid derivatives represented by
A mixture of nickel chelate compounds represented by the following structural formula:
4.52g was obtained.

Physical properties: Melting point: 280°C or higher λ _max (chloroform): 629,688 nm ε (molecular extinction coefficient): 12.0 × 10 ⁴ , 15.2 × 10 ⁴ Example 15: 4.73 g of a cobalt chelate compound represented by the following structural formula was obtained in the same manner as in Example 12, except that 1.63 g of cobalt acetate was used instead of 1.63 g of nickel acetate used in Example 12.
I got g.

Physical properties Melting point: 243°C (decomposition) λ _max (chloroform): 632,692 nm Example 16 A compound having the following structural formula was added to a solution of 7.5 ml of acetic acid and 15 ml of sulfuric acid. 4.28 g of the aminothiazole derivative represented by the formula (I) was dissolved at 40-50°C. The solution was cooled to 0-5°C and 5 g of 45% nitrosylsulfuric acid was added.
After adding 0.8 g of ethanol, 19 ml of water was added dropwise, and the mixture was stirred at the same temperature for 2 hours to effect diazotization.

On the other hand, the following structural formula 5.06 g of the substituted aniline sulfonic acid derivative represented by the formula
The diazotized solution obtained above was added dropwise to a solution prepared by dissolving 0.3 g of the compound in 150 ml of methanol at 0 to 5°C, and coupling was carried out while controlling the pH at 5 to 6 with an aqueous ammonia solution.
The precipitated crystals were filtered off and dried to obtain 2.01 g of black crystals of an azo compound represented by the following structural formula.

0.4 g of the obtained azo compound was dissolved in 40 ml of methanol, and 0.1 g of nickel acetate Ni(CH ₃ COO) ₂ .4H ₂ O was added to 4 ml of methanol.
The solution was added dropwise to the solution at room temperature and stirred at the same temperature for 5 hours. The precipitated crystals were filtered off and dried to obtain a compound having the following structural formula: 0.1 g of black crystals of the nickel chelate compound represented by the formula (1) was obtained. The IR spectrum is shown in Figure 10.

Physical properties: Melting point: 217°C (decomposition) λ _max (chloroform): 628,676 nm Example 17: The diazo compounds shown in Table 3 were used in place of the 2-amino-5-nitrothiazole used in Example 12.
Instead of the substituted aniline sulfonic acid derivative used in
The metal chelate compounds shown in Table 4 were obtained by the same reaction procedure as in Example 12, except that the coupling components shown in the table were used and the metal salts shown in Table 3 were used instead of the nickel acetate used in Example 12.

The maximum absorption (λ _max ) of the visible absorption spectrum in a chloroform solution of each compound obtained and the maximum absorption (λ _max ) of the absorption spectrum of the coated thin film are shown in Table 4.

Example 18 (a) Preparation Example: In the same manner as in Example 12, a compound of the following structural formula was prepared. The nickel chelate compound represented by the formula: was obtained, and an optical recording medium was prepared in the same manner. The maximum absorption wavelength of the thin film formed was 723 nm.

(b) Evaluation of recording characteristics Recording was carried out in the same manner as in Example 12, and evaluation was carried out. The recording sensitivity was 6.0 mW and the modulation was 72%.

Furthermore, when a similar light resistance test was carried out, the retention of the initial characteristics after 40 hours was an extremely good 97.6%.

Example 19 (a) In the same manner as in Preparation Example 12, a compound of the following structural formula was prepared. The nickel chelate compound represented by the formula: was obtained, and an optical recording medium was prepared in the same manner. The maximum absorption wavelength of the thin film formed was 731 nm.

(b) Evaluation of recording characteristics Recording and evaluation were carried out in the same manner as in Example 12, and the recording sensitivity was 7.0 mW and the modulation was 65%.

Furthermore, when a similar light resistance test was carried out, the retention rate of the initial characteristics after 40 hours was 98.8%, which was extremely good.

Example 20 (a) Compound Preparation Example: 7.27 g of p-aminobenzaldehyde was dissolved in 1,4-dioxane 15
The mixture was dissolved in 100 ml of toluene, and 83 ml of malononitrile, 1.50 ml of piperidine, and 1.23 ml of acetic acid were added at room temperature. After stirring for 5 hours, 100 ml of methanol was added and the mixture was left standing overnight. After filtering to remove insoluble matter, the solvent of the filtrate was removed, and further filtering with toluene revealed yellow crystals of the compound represented by the following structural formula (1).
10.89g was obtained.

8.46 g of the obtained compound (1) and 9.52 g of ammonium thiocyanate were dissolved in 237.5 g of acetic acid and 12.5 g of water, and the solution was heated at 10°C with 10 g of bromine.
A solution of 25 g of acetic acid was added dropwise. After stirring for 2 hours, the mixture was left standing overnight. The reaction mixture was heated to 70°C, poured into 500 ml of hot water, and filtered while hot. Sodium carbonate was added to the filtrate to adjust the pH to 5.
The precipitated crystals were filtered, washed with water and toluene, and dried to obtain yellow crystals of the compound represented by the following structural formula (2): 7.
21 g was obtained. Molecular weight: 226.

3.39 g of the obtained compound (2) was mixed with 13.4 g of phosphoric acid and 0.745 g of sulfuric acid.
4.73 ml of acetic acid and 0.638 g of sodium sulfate were added. 1.82 g of sulfuric acid was added at a temperature of 0 to 10°C, and the mixture was stirred at -2 to -5°C.
The resulting diazotized solution was added dropwise to a solution of 22.5 g of sodium 3-diphthylaminobenzenesulfonate in 100 ml of methanol at a temperature of 0 to 5°C, and the solution was neutralized with an alkaline compound such as sodium acetate or an aqueous ammonia solution. The resulting crystals were filtered and dried to obtain 2.88 g of black-purple crystals of an azo compound represented by the following structural formula (3).

0.50 g of the obtained azo compound (3) was dissolved in 50 ml of methanol, and 10 ml of a methanol solution containing 0.13 g of nickel acetate was added thereto, followed by stirring at room temperature for 6 hours. The precipitated crystals were filtered off.
This was washed with methanol and dried to obtain 0.168 g of a black-purple crystalline nickel chelate compound.
_{The max} (in chloroform) was 681 nm (ε=1.48×10 ⁵ ) (FIG. 11), and the melting point was above 250°C.

The infrared absorption spectrum of this compound is shown in FIG.

(b) Optical Recording Medium Production Example 0.15 g of the nickel chelate azo compound obtained in Production Example (a) above was dissolved in 7.5 g of octafluoropentanol and filtered through a 0.22 μm filter to obtain a solution.
5 ml of this solution was poured into a groove 700 Å deep and 0.7 μm wide.
The solution was then dropped onto an injection-molded polycarbonate resin substrate (5 inches in diameter) and coated using a spinner at 500 rpm. After coating, the coating was dried at 60°C for 10 minutes. The maximum absorption wavelengths of the coated film were 707 nm and 643 nm.

Figure 13 shows the absorption spectrum of the coating film.

Next, a thin film of 1000 nm thick is deposited on this coating film by sputtering.
A gold film of 2000 Å was formed as a reflective layer, and then a UV-curable resin was spin-coated on top of the reflective layer and cured by UV irradiation to form a 10 μm-thick protective layer.

(c) Optical recording example While rotating the above recording medium at 1.2 m/s, a central wavelength of 780 nm was
The recording was performed with a semiconductor laser beam of 7.0 mW at a recording power of 7.0 mW.
The M signal was recorded. Then, when this recording was played back using a CD player with a semiconductor laser with a central wavelength of 780 nm,
A good playback signal was obtained.

Also, light resistance (Xenon Fade Meter Accelerated Test; 6
As a result of tests for storage stability (70°C, 85% RH; 500 hours) and storage stability (70°C, 85% RH; 500 hours), no deterioration in sensitivity or playback signal was observed compared to the initial state, demonstrating that the optical recording medium is extremely excellent.

Example 21 (a) Compound Production Example 3.39 g of the compound (2) obtained in Example 20 was dissolved in 13.4 g of phosphoric acid and 0.745 g of sulfuric acid, and the solution was added with 4.73 ml of acetic acid and 0.638 g of sodium sulfate.
1.82 g of sulfuric acid was added at 0 to 10°C, and the mixture was heated to -2 to -5°C.
Diazotization was carried out using 5.09 g of 45% nitrosylsulfuric acid at a temperature of
The obtained diazo liquid was added dropwise to a solution prepared by dissolving 33.3 g of sodium 2-dibutylaminoanisole-4-sulfonate in 100 ml of methanol at a temperature of 0 to 5°C, and the solution was neutralized with an alkaline compound such as sodium acetate or an aqueous ammonia solution. The resulting crystals were filtered and dried to obtain 2.24 g of black-purple crystals of azo compound (4) represented by the following structural formula:

0.50 g of the obtained azo compound (4) was dissolved in 50 ml of methanol, and 10 ml of a methanol solution containing 0.13 g of nickel acetate was added thereto, followed by stirring at room temperature for 6 hours. The precipitated crystals were filtered off.
This was washed with methanol and dried to obtain 0.201 g of a black purple crystalline nickel chelate compound.

The λ _max (in chloroform) of this compound is 706 nm (ε = 5.9
×10 ⁴ ) and the melting point was 250°C or higher.

(b) Optical Recording Medium Production Example 0.15 g of the nickel chelate compound obtained in Production Example (a)
A coating film was formed in the same manner as in Example 20, except that the following was used: The maximum absorption wavelengths of the coating film were 728 nm and 662 nm.

Next, a reflective layer and a protective layer were formed on this coating film in the same manner as in Example 1, to produce an optical recording medium.

(c) Optical Recording Example An EFM signal was recorded on the above recording medium in the same manner as in Example 20. When the signal was reproduced, a good reproduction signal was obtained.

Furthermore, light resistance and storage stability tests were carried out in the same manner as in Example 1. As a result, no deterioration in sensitivity or reproduced signals was observed compared to the initial state, and the optical recording medium was extremely excellent.

Example 22 (a) Preparation of a compound of the following structural formula 3.25 g of 2-amino-4-chloro-5-formylthiazole represented by the formula:
The product was diazotized using 6.78 g of 45% nitrosylsulfuric acid at a temperature of 5°C, and the resulting diazotized solution was added dropwise to a solution of 9.22 g of sodium 3-dibutylaminobenzenesulfonate in 350 ml of water at a temperature of 0 to 5°C, and neutralized with an alkaline compound such as sodium acetate or an aqueous ammonia solution. The resulting crystals were filtered and dried to obtain 5.48 g of black-purple crystals of an azo compound represented by the following structural formula (5).

2.0 g of the obtained azo compound (5) was dissolved in 100 ml of 1,4-dioxane.
and dissolved in 0.75 ml of malononitrile and piperidine at room temperature.
After stirring for 4 hours, the solvent was removed and the mixture was purified using a silica gel column to obtain 0.16 g of a dark purple crystal of an azo compound represented by the following structural formula (6).

0.16 g of the obtained azo compound (6) was dissolved in 20 ml of methanol, and 5 ml of a methanol solution containing 0.045 g of nickel acetate was added thereto, followed by stirring at room temperature for 5 hours. The precipitated crystals were filtered off.
This was washed with methanol and dried to obtain 0.021 g of a black purple crystalline nickel chelate compound.

The λ _max (in chloroform) of this compound is 722 nm (ε = 5.4
×10 ⁴ ) and the melting point was 250°C or higher.

(b) Optical recording medium production example The nickel chelate compound obtained in the above production example (a) was 0.
A coating film was formed in the same manner as in Example 20, except that 15 g was used. The maximum absorption wavelengths of the coating film were 754 nm and 587 nm.

Next, a reflective layer and a protective layer were formed on this coating film in the same manner as in Example 1, to produce an optical recording medium.

(c) Optical Recording Example When an EFM signal was recorded on the above recording medium in the same manner as in Example 20 and reproduced, a good reproduction signal was obtained.

Furthermore, light resistance and storage stability tests were carried out in the same manner as in Example 20. As a result, no deterioration in sensitivity or reproduced signals was observed compared to the initial state, demonstrating that the optical recording medium was extremely excellent.

Example 23 (a) Compound Production Example 20 2.0 g of the azo compound (5) obtained in Example 20 was dissolved in 100 ml of 1,4-dioxane, and the solution was added with 0.97 ml of ethyl cyanoacetate at room temperature.
After stirring for 4 hours, the solvent was removed and the mixture was purified using a silica gel column to obtain 0.51 g of azo compound (7) represented by the following structural formula:
obtained.

0.15 g of the obtained azo compound (7) was dissolved in 50 ml of methanol, and 10 ml of a methanol solution containing 0.132 g of nickel acetate was added thereto, followed by stirring at room temperature for 6 hours. The precipitated crystals were filtered off.
This was washed with methanol and dried to obtain 0.016 g of a black purple crystalline nickel chelate compound.

The λ _max (in chloroform) of this compound is 693 nm (ε = 1.4
×10 ⁵ ) and the melting point was 250°C or higher.

(b) Optical Recording Medium Production Example A coating film was formed in the same manner as in Example 1, except that 0.15 g of the nickel chelate compound of the disazo compound obtained in Production Example (a) was used. The maximum absorption wavelength of the coating film was 754 nm.
m and 675 nm.

Next, a reflective layer and a protective layer were formed on this coating film in the same manner as in Example 20 to produce an optical recording medium.

(c) Optical Recording Example When an EFM signal was recorded on the above recording medium in the same manner as in Example 20 and reproduced, a good reproduction signal was obtained.

Furthermore, light resistance and storage stability tests were carried out in the same manner as in Example 20. As a result, no deterioration in sensitivity or reproduced signals was observed compared to the initial state, demonstrating that the optical recording medium was extremely excellent.

Example 24 13.5 g of p-aminoacetophenone and 31.70 g of ammonium thiocyanate were dispersed in a mixture of 800 ml of glacial acetic acid and 40 ml of water, and 20 g of bromine was added to 100 ml of glacial acetic acid at 7 to 10°C while stirring.
A solution of 1,000g of ethanol dissolved in 1,000g of ethanol was added dropwise over about 1 hour. After stirring at 10°C for 2 hours, the mixture was heated and stirred at 70°C for 5 hours. The reaction mixture was filtered at 50°C or higher, and the resulting filtrate was heated to about 70°C.
The mixture was cooled and stirred while adding crystals of anhydrous sodium carbonate until the pH reached 5. The bright pale yellow crystals were filtered and dried to obtain 2-amino-5-acetylbenzothiazole 1, which has the following structural formula:
5.83g was obtained.

Next, 2.00 g (0.0105 mol) of 2-amino-5-acetylbenzothiazole obtained as described above, 0.69 g (0.0105 mol) of malononitrile, and 0.4 g of ammonium acetate were added to a mixture of 10 ml of glacial acetic acid and 5 ml of toluene, and the mixture was heated with stirring to reflux for 2 hours while distilling off toluene and water. After cooling, the mixture was added to 100 ml of ice water, and the bright yellow crystals were filtered and dried to obtain 5-amino-5-acetylbenzothiazole represented by the following structural formula:
-(2',2'-dicyano-1'-methyletheno)-2-
2.47 g of aminobenzothiazole was obtained, and the molecular weight of this compound was confirmed by mass spectrometry.

In a mixture of 8.90 g of 85% phosphoric acid and 0.5 g of 98% sulfuric acid, 1.1 g (0.0046%) of 5-(2',2'-dicyano-1'-methyletheno)-2-aminobenzothiazole obtained as described above was dissolved.
Add 3.15 g of glacial acetic acid and then 0.43 g of sodium nitrate while stirring. Cool the mixture to 0-5°C, add 1.22 g of 97% sulfuric acid, and then add 44% nitrosylsulfuric acid.
1.62 g of ethanol was added dropwise over a period of about 5 minutes.
After stirring for 1 hour, the following structural formula 2.19 g of the aniline sulfonic acid derivative represented by the formula (I) is dispersed in 100 ml of methanol, and 30 g of sodium acetate,
About 100 g of ice was added little by little over about 15 minutes while stirring at 0 to 5°C. After stirring for another 3 hours at 0 to 5°C, the reaction mixture was filtered to give reddish purple crystals of 1.33g, which are represented by the following structural formula:
I got g.

Next, 0.566 g (0.001 mol) of the azo compound obtained above
Dissolve in 100 ml of methanol and add 0.1% nickel acetate tetrahydrate.
A solution of 6 g (0.0006 mol) dissolved in 10 ml of water was added.
After stirring at about 20°C for 2 hours, the resulting crystals were filtered and dried to obtain 0.32 g of dark red crystals of a nickel chelate compound.

The absorption spectrum of this compound in chloroform is λ _max 700
nm and a molecular weight of 1190, the ε was 13.1 × 10 ⁴ .

Example 25: A solution obtained by using a chelate compound of an azo compound and a metal shown in Table 5 instead of the chelate compound of an azo compound used in Examples 20 to 24 was coated on a substrate to obtain an optical recording medium having the maximum absorption wavelength of the coating film shown in Table 5. When writing was performed on the recording medium thus obtained using a semiconductor laser as a light source, the sensitivity was good and the light resistance and storage stability were also excellent.

In addition to the compounds used in the above examples, specific examples of metal chelate azo compounds that can be suitably used in the optical recording medium of the present invention are listed in Table 6.

──────────────────────────────────────────────────── Continued from the front page (31) Priority Number: Patent Application No. 2-328425 (32) Priority Date: November 28, 1990 (33) Priority Country: Japan (JP)

Claims (2)

[Claims] Claim 1: A compound represented by the following general formula [I] (wherein A represents a residue which forms a heterocycle together with the carbon atom and nitrogen atom to which it is bonded, B represents a residue which forms an aromatic group together with the two carbon atoms to which it is bonded, and X represents a hydrogen atom or a cation), and a metal. [Claim 2] An optical recording medium having a recording layer on a substrate on which information can be written and/or read using a laser, characterized in that the recording layer contains a chelate compound of the monoazo compound of claim 1 and a metal.