JP2002144724A - Optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording material in an optical recording medium capable of applying to a DVD-R disk system using a semiconductor laser having an oscillation wavelength in a short wavelength and having excellent light resistance and storage stability. SOLUTION: The optical recording medium comprises a recording layer provided on a first substrate directly or via an undercoating layer, a reflecting layer, a protective layer or a second substrate further provided thereon. The medium comprises at least one type of azo metal chelate compound containing an azo compound and a bivalent or trivalent metal or its salt, represented by formula (I), (wherein a ring A is a residue for forming a cyclic ring together with a carbon atom or a nitrogen atom bonded with the ring A, or may be condensed with another aromatic ring, A ring B is a residue for forming a cyclic ring together with a carbon atom bonded with the ring B, and R', R", R''', R'''' and R''''' are respectively independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a cyano group and a nitro group).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-capacity write-once optical disc for data (large-capacity write-once compact disc, DV
D-R) is applied to large-capacity optical cards and the like.

[0002]

2. Description of the Related Art (for information recording) write-once recording media (WOR)
As the prior art M), those using a cyanine dye as a recording material are disclosed in JP-A-57-82093, JP-A-58-56892, and JP-A-58-112790.
JP, JP-A-58-114989 and JP-A-59-149899
-85791, JP-A-60-83236,
JP-A-60-89842, JP-A-61-2588
No. 6,150,243, which uses a phthalocyanine dye as a recording material.
JP, JP-A-61-177287, JP-A-61-177287
JP-A-154888, JP-A-61-24609, JP-A-62-39286, JP-A-63-37
No. 991, JP-A-63-39888 and the like.

Further, a write-once compact disc (CD-
As the prior art of R), those using a cyanine dye + metal reflective layer as a recording material are disclosed in JP-A-1-159842, JP-A-2-42652, and JP-A-2-136.
No. 56, JP-A-2-168446, etc., which use a phthalocyanine dye + metal reflective layer as a recording material are disclosed in JP-A-1-176585, JP-A-3-215466, Kaihei 4-113886
JP, JP-A-4-226390, JP-A-5-1
No. 272, JP-A-5-171052, JP-A-5-116456, JP-A-5-96860, JP-A-5-139944 and the like. Is used as a recording material in JP-A-4-46186 and JP-A-4-46186.
-141489, JP-A-4-36088, JP-A-5-279580, JP-A-7-516
No. 73, Japanese Unexamined Patent Application Publication No.
-37272, JP-A-7-71867, JP-A-8-231866, JP-A-8-295811
JP-A-9-277703, JP-A-10-277703
No. 36693.

[0004] Further, as a conventional technology of a large capacity write-once compact disc (DVD-R), one using a cyanine dye + metal reflective layer as a recording material is known as PIONEER R & D.
vol.6No.2: Development of DVD-Recordable, Basic development of DVD-R dye disk, ISOM / ODS'96: High density of recordi
ng on Dye material Disc approach for 4.7G, and those using an imidazole-based azomethine dye + metal reflective layer as a recording material are disclosed in JP-A-8-198872, JP-A-8-209012, and JP-A-8-208. 283
No. 263, for example, which uses an azo metal chelate dye + metal reflective layer as a recording material is disclosed in
These are disclosed in, for example, Japanese Patent Application Laid-Open No. 1-48588, Japanese Patent Application Laid-Open No. 11-116834, and Japanese Patent Application Laid-Open No. 11-120616.

At present, as a next-generation large-capacity optical disk, DV
Development of DR is in progress. Development of recording materials for miniaturization of recording pits,
It is necessary to develop technology such as adoption of an image compression technology represented by PEG2 and shortening of the wavelength of a semiconductor laser for reading recording pits.

Heretofore, as a semiconductor laser in the red wavelength region, a 670 nm band Al for a bar code reader and a measuring instrument has been used.
Although only GaInP laser diodes have been commercialized, red lasers are being used in the optical storage market in earnest as the density of optical disks increases. DVD
In the case of a drive, 635 nm band and 650 n
It is standardized by two wavelengths of the m-band laser diode. On the other hand, the DVD-ROM drive for reproduction only has a wavelength of ~
Commercialized at 650 nm.

[0007] Under these circumstances, the most preferable DVD-
The R media is a medium that can record and reproduce at a wavelength of 660 nm and can reproduce at a wavelength of 660 nm. However, it has excellent light resistance and storage stability,
Recording materials that can be recorded and reproduced by an optical pickup using a laser of 0 nm or less have not yet been developed.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a DVD-R disk system using a semiconductor laser having an oscillation wavelength shorter than that of a conventional system, which is superior in light resistance and storage stability. To provide a recording material in an optical recording medium.

[0009]

Means for Solving the Problems As a result of diligent studies, the present inventors have made a next-generation semiconductor using a semiconductor laser having an oscillation wavelength of 700 nm or less by forming a recording layer containing a dye having a specific structure as a main component. It has been found that an optical recording medium applicable to a high capacity optical disk system can be provided. Further, in the present invention, by limiting a part of the structure of the recording material, (1) improvement of solubility, (2) control of thermal characteristics,
(3) improvement in metal complex stability,
The present inventors have found that an optical recording medium that is easy to handle, can perform high-density recording, and has high light resistance can be provided, and has reached the present invention.

That is, the above-mentioned problem is solved by the present invention comprising (1)
"In an optical recording medium in which a recording layer is provided directly or via an undercoat layer on a first substrate, and a reflective layer, a protective layer or a second substrate is further provided, the recording medium has the general formula (I) An optical recording medium comprising at least one azo compound represented by the formula and an azo metal chelate compound composed of a divalent or trivalent metal, or a salt thereof.

[0011]

Embedded image (Wherein, ring A represents a residue which forms a heterocyclic ring together with the carbon atom or nitrogen atom to which it is bonded, and may be condensed with another aromatic ring. Represents a residue that forms an aromatic ring together with the carbon atom to which R ′, R ′, R ″, R ′ ″, R ″ ″ and R ′ ″ ″ are each independently a hydrogen atom , A halogen atom, a substituted or unsubstituted alkyl group, a cyano group or a nitro group.) "
(2) "A and B rings of the azo compound are represented by the following general formula (I
The optical recording medium according to the above (1), which is a heterocycle represented by I).

[0012]

Embedded image (Wherein R ₁ and R ₂ each independently represent a hydrogen atom, a halogen atom, a cyano group, a hydroxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxy group, an amino group R ₃ represents a substituted or unsubstituted alkylamino group, a substituted or unsubstituted dialkylamino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted alkylthio group, or a substituted or unsubstituted arylthio group. To R ₅ are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted Unsubstituted aryloxy group, substituted or unsubstituted carbamoyl group,
R ₃ and R ₄ represent a substituted or unsubstituted acyl group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted amino group; May be linked to form a ring. R ₆ and R ₇ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted phenyl group; R ₄ and R ₆ , R ₅ and R ₇ , and R ₆ and R ₇ are linked; May form a ring. ) ", (3) that the azo metal chelate compound has at least one of R ', R", R'",R""and R '""a nitro group; The optical recording medium according to the above item (1) or (2), "(4)
"The optical recording medium according to any one of (1) to (3), wherein the azo metal chelate compound has a metal atom selected from cobalt, nickel, copper, and manganese"; 5) "The refractive index n of the recording layer single layer with respect to light in the wavelength range of recording / reproducing wavelength ± 5 nm is 1.5 ≦ n ≦
3.0, and the extinction coefficient k is 0.02 ≦ k ≦ 0.20, wherein the optical recording medium according to any one of the above items (1) to (4), ” (6) “The track pitch on the first substrate is 0.7 to 0.8 μm, and the groove width is 0.20 to 0.36 μm as a half width. The optical recording medium according to any one of the items (5) "is solved.

Here, the effect of each claim is as follows. Item (1) shows the basic structure of the novel azo compound of the present invention, and Item (2) shows a heterocyclic compound. (3) indicates the optimum structure of the novel azo compound in which a part of the substituents is limited, and (4) indicates the optimum structure of the novel azo compound in which a part of the substituent is limited. Item indicates the optimum structure of the novel azo compound having a limited metal species, and item (5) indicates the optical characteristics of the novel azo compound capable of recording and reproducing with high reflectance and high modulation. The above item (6) shows the guide groove condition of the high density recording medium substrate to be applied.

In the general formula (I), the ring A represents a residue which forms a heterocyclic ring together with the carbon atom or nitrogen atom to which it is bonded, and which is condensed with another aromatic ring. Is also good. Ring B represents a residue which, together with the carbon atom to which it is attached, forms an aromatic ring, R ', R'',
R ′ ″, R ″ ″ and R ′ ″ ″ are each independently a hydrogen atom,
Represents a halogen atom, a substituted or unsubstituted alkyl group, a cyano group, or a nitro group.

In the general formula (II), R₁, R_TwoHaso
Each independently hydrogen, halogen, cyano, hydroxyl
Group, substituted or unsubstituted alkyl group, substituted or unsubstituted
Substituted aryl group, substituted or unsubstituted alkoxy
Group, amino group, substituted or unsubstituted alkylamino
Group, substituted or unsubstituted dialkylamino group, substituted
Or unsubstituted aryloxy group, substituted or unsubstituted
Alkylthio group, substituted or unsubstituted arylthio
Represents a group. Also, R_Three~ R_FiveAre independently hydrogen sources
Atom, halogen atom, nitro group, cyano group, hydroxyl group, cal
Boxyl group, substituted or unsubstituted alkyl group, substituted
Or unsubstituted phenyl group, substituted or unsubstituted
Coxy group, substituted or unsubstituted aryloxy group,
Substituted or unsubstituted carbamoyl group, substituted or unsubstituted
Substituted acyl group, substituted or unsubstituted alkoxycarbo
Nyl group, substituted or unsubstituted aryloxycarbonyl
Group, substituted or unsubstituted alkenyl group, substituted or unsubstituted
Represents an unsubstituted amino group; _ThreeAnd R_FourConnects to form a ring
It may be formed. R₆, R₇Are independently hydrogen sources
, Substituted or unsubstituted alkyl group, substituted or unsubstituted
Represents a substituted phenyl group;_FourAnd R₆, R_FiveAnd R₇, R₆
And R₇May be linked to form a ring.

Specific examples of the halogen atom include fluorine, chlorine, bromine and iodine.

Specific examples of the substituted or unsubstituted alkyl group include a methyl group, an ethyl group, an n-propyl group,
n-butyl group, n-pentyl group, n-hexyl group, n-
Primary alkyl groups such as heptyl group, n-octyl group, n-nonyl group, n-decyl group, isobutyl group, isoamyl group, 2-methylbutyl group, 2-methylpentyl group, 3-
Methylpentyl, 4-methylpentyl, 2-ethylbutyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 2
-Ethylpentyl group, 3-ethylpentyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5-methylheptyl group, 2-ethylhexyl group, 3-ethylhexyl group, isopropyl group, sec-
Butyl group, 1-ethylpropyl group, 1-methylbutyl group, 1,2-dimethylpropyl group, 1-methylheptyl group, 1-ethylbutyl group, 1,3-dimethylbutyl group,
1,2-dimethylbutyl group, 1-ethyl-2-methylpropyl group, 1-methylhexyl group, 1-ethylheptyl group, 1-propylbutyl group, 1-isopropyl-2-methylpropyl group, 1-ethyl- 2-methylbutyl group, 1
-Ethyl-2-methylbutyl group, 1-propyl-2-methylpropyl group, 1-methylheptyl group, 1-ethylhexyl group, 1-propylpentyl group, 1-isopropylpentyl group, 1-isopropyl-2-methylbutyl group,
1-isopropyl-3-methylbutyl group, 1-methyloctyl group, 1-ethylheptyl group, 1-propylhexyl group, secondary alkyl groups such as 1-isobutyl-3-methylbutyl group, neopentyl group, tert-butyl group, te
tertiary alkyl groups such as rt-hexyl group, tert-amyl group and tert-octyl group; cyclohexyl group;
Methylcyclohexyl group, 4-ethylcyclohexyl group, 4-tert-butylcyclohexyl group, 4- (2
-Ethylhexyl) cycloalkyl group such as cyclohexyl group, bornyl group, isobornyl group (adamantane group) and the like.

Further, these primary and secondary alkyl groups are
A hydroxyl group, a halogen atom, a nitro group, a carboxy group, a cyano group, a substituted or unsubstituted aryl group, may be substituted with a substituted or unsubstituted heterocyclic residue, etc.
The alkyl group may be substituted via an atom such as sulfur or nitrogen.

Examples of the alkyl group substituted via oxygen include methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, butoxyethyl, ethoxyethoxyethyl, phenoxyethyl, methoxypropyl, and ethoxy. Propyl group, piperidino group, morpholino group, and the like.Examples of the alkyl group substituted via sulfur include a methylthioethyl group, an ethylthioethyl group, an ethylthiopropyl group, a phenylthioethyl group, and the like. Examples of the alkyl group substituted through include a dimethylaminoethyl group, a diethylaminoethyl group, and a diethylaminopropyl group.

Specific examples of the substituted or unsubstituted aryl groups include phenyl, pentalenyl, indenyl, naphthyl, azulenyl, heptalenyl, biphenylenyl, phenenyl, phenanthrenyl, anthracenyl, triphenylenyl, And a pyrenyl group.

The phenyl group may be substituted with a hydroxyl group, a halogen atom, a nitro group, a carboxy group, a cyano group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic residue, etc. , Sulfur, nitrogen or the like, may be substituted with the above-mentioned alkyl group.

Specific examples of the substituted or unsubstituted alkoxy group include those in which a substituted or unsubstituted alkyl group is directly bonded to an oxygen atom. Specific examples of the alkyl group are those described above. The same can be mentioned.

Specific examples of the substituted or unsubstituted aryloxy group include those in which a substituted or unsubstituted aryl group is directly bonded to an oxygen atom. Specific examples of the aryl group are those described above. The same thing as an example can be mentioned.

Specific examples of the substituted or unsubstituted carbamoyl group include a hydrogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aryl group directly and independently bonded to the nitrogen atom of the carbamoyl group. And specific examples of the alkyl group and the aryl group include the same as the specific examples described above.

Specific examples of the above-mentioned substituted or unsubstituted acyl groups are those in which a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group is directly bonded to the carbonyl carbon atom of the acyl group. Specific examples of the alkyl group and the aryl group include the same as those described above.

Specific examples of the substituted or unsubstituted alkoxycarbonyl group include those in which a substituted or unsubstituted alkyl group is directly bonded to an oxygen atom of the alkoxycarbonyl group. Can be the same as those described above.

Specific examples of the substituted or unsubstituted aryloxycarbonyl group include those in which a substituted or unsubstituted aryl group is directly bonded to an oxygen atom of the aryloxycarbonyl group. Examples thereof include those similar to the above-described specific examples.

Specific examples of the above-mentioned substituted or unsubstituted amino group include those in which a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group is directly bonded to a nitrogen atom. Specific examples of the aryl group include those similar to the specific examples described above.

Specific examples of the heterocyclic residue include an indolyl group, a furyl group, a thienyl group, a pyridyl group, a piperidyl group, a quinolyl group, an isoquinolyl group, a piperidino group, a morpholino group, and a pyrrolyl group.

Specific examples of the amino group in which R ₁ and R ₂ are linked to form a ring include a piperidino group, a morpholino group, a pyrrolidyl group, a piperazyl group, an imidazolidyl group, a pyrazolidyl group, an indolinyl group, an isoindolinyl group, and a pyrrolyl group. , An indolyl group, an isoindolyl group, a carbazolyl group and the like.

Specific examples of the divalent or trivalent metal atom include titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zirconium, niobium, molybdenum, technenium, ruthenium, rhodium, palladium and the like. Specific examples of the metal oxide include vanadium oxide. In particular, azo metal chelate compounds of manganese, cobalt, nickel, and copper have excellent optical properties as optical recording materials.

Hereinafter, the optical recording medium of the present invention will be described with reference to the drawings. Configuration of Recording Body The recording body of the present invention is a normal write-once optical disc shown in FIG.
(A so-called air sandwich in which two sheets of FIG. 1 are bonded together or a close bonding structure) and the structure of a CD-R medium shown in FIG.

Required Properties of Each Layer and Examples of Constituent Materials The basic structure of the recording medium of the present invention is a structure in which a first substrate and a second substrate are bonded together with an adhesive via a recording layer. The recording layer may be a single layer of an organic dye layer, or may be a laminate of an organic dye layer and a metal reflective layer to increase the reflectance.
The recording layer and the substrate may be layered with an undercoat layer or a protective layer interposed therebetween, or may be formed by laminating them for improving the function. The most commonly used structure is the first substrate / recording layer (organic dye layer) / metal reflective layer / protective layer / adhesive layer / second substrate.

<Substrate> A necessary characteristic of the substrate is that it must be transparent to the laser beam used only when recording and reproduction are performed from the substrate side, and when recording and reproduction are performed from the recording layer side, the substrate is transparent. No need to be. Therefore, in the present invention, when two layers of substrates are used, the first substrate may be transparent or opaque as long as only the second substrate described in the claims is transparent. As the substrate material, for example, polyester,
Acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, plastic such as polyimide, glass, ceramic or metal can be used. When only one substrate is used, or when two substrates are used in a sandwich form, a guide groove or guide pit for tracking and a pre-address signal such as an address signal are formed on the surface of the first substrate. The format must be formed.

<Intermediate Layer> Layers provided other than the substrate, the recording layer, the reflective layer, and the protective layer, including the undercoat layer and the like, are herein referred to as intermediate layers. This intermediate layer comprises (a) improved adhesiveness, (b) a barrier against water or gas, (c) improved storage stability of the recording layer, (d) improved reflectance, and (e) substrate from solvent. And protection of recording layer, (f) guide groove, guide pit,
It is used for the purpose of forming a preformat or the like.

For the purpose of (a), various polymer materials such as ionomer resin, polyamide resin, vinyl resin, natural resin, natural polymer, silicone, liquid rubber, and silane cup A ring agent or the like can be used. For the purposes (b) and (c),
In addition to the polymer material, an inorganic compound such as SiO ₂ , M
metals such as gF ₂ , SiO, TiO ₂ , ZnO, TiN, SiN, or semimetals, for example, Zn, Cu, Ni, Cr, G
e, Se, Au, Ag, Al and the like can be used.
For the purpose of (d), a metal such as Al or Ag is used.
And the like, an organic thin film having a metallic luster, for example, methine dye,
A xanthene dye or the like can be used, and for the purposes of (e) and (f), an ultraviolet curable resin, a thermosetting resin, a thermoplastic resin, or the like can be used. The thickness of the undercoat layer is 0.01 to 30 μm, preferably 0.05 to 10 μm.
μm is appropriate.

<Recording Layer> The recording layer is capable of causing some optical change by irradiation with a laser beam and recording information by the change. This recording layer contains the dye of the present invention. In forming the recording layer, the dye of the present invention may be used alone or in combination of two or more. Further, the dye of the present invention may be mixed or laminated with other organic dyes, metals, and metal compounds for the purpose of improving optical characteristics, recording sensitivity, signal characteristics, and the like.
Examples of organic dyes include polymethine dyes, naphthalocyanine, phthalocyanine, squarylium, croconium, pyrylium, naphthoquinone, anthraquinone (indanthrene), xanthene, triphenylmethane, azulene, and tetrahydrocholine. And phenanthrene-based dyes, triphenothiazine-based dyes, metal chelate compounds, and the like. These dyes may be used alone or in combination of two or more.

Further, in the above-mentioned dye, a metal, a metal compound,
For example, In, Te, Bi, Se, Sb, Ge, Sn,
Al, Be, TeO ₂ , SnO, As, Cd and the like can be used in the form of dispersion mixing or lamination. further,
Polymer material in the dye, for example, ionomer resin,
Various materials such as polyamide-based resins, vinyl-based resins, natural polymers, silicones, and liquid rubbers, or silane coupling agents and the like may be dispersed and mixed, or a stabilizer (for example, transition Metal complex), a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant, a plasticizer, and the like.

The recording layer is formed by vapor deposition, sputtering,
It can be carried out by ordinary means such as CVD or solution coating. When the coating method is used, the dye or the like is dissolved in an organic solvent or the like, and the coating is performed by a conventional coating method such as spraying, roller coating, dipping, and spin coating.

As the organic solvent used, generally, alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, methyl ethyl ketone and cyclohexanone, N, N-dimethylformamide, N, N
-Amides such as dimethylacetamide, sulfoxides such as dimethylsulfoxide, ethers such as tetrahydrofuran, dioxane, diethyl ether, ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, chloroform, methylene chloride, dichloroethane and tetrachloride Aliphatic halogenated hydrocarbons such as carbon and trichloroethane, or aromatics such as benzene, xylene, monochlorobenzene and dichlorobenzene, cellosolves such as methoxyethanol and ethoxyethanol, and carbonization such as hexane, pentane, cyclohexane and methylcyclohexane Hydrogens and the like can be used. The thickness of the recording layer is 100 to 10 μm, preferably 200 to
Å2000Å is appropriate.

<Metal Reflective Layer> The reflective layer may be made of a metal, a semi-metal, or the like which is highly resistant to corrosion and can provide a high reflectance by itself.
Examples of materials include Au, Ag, Cr, Ni, Al, and F.
e, Sn and the like.
u, Ag, and Al are most preferred. These metals and metalloids may be used alone or as two kinds of alloys. Examples of the film forming method include vapor deposition and sputtering.
The film thickness is 50-5000 °, preferably 100-3.
000.

<Protective Layer, Hard Coat Layer on Substrate Surface> The protective layer or hard coat layer on the substrate surface (a) protects the recording layer (reflection / absorption layer) from scratches, dust, dirt, etc., (b)
It is used for the purpose of improving the storage stability of the recording layer (reflection / absorption layer) and (c) improving the reflectance. For these purposes, the materials shown in the intermediate layer can be used. In addition, as the inorganic material, SiO, SiO ₂ or the like can be used, and as the organic material, polymethyl acrylate, polycarbonate, epoxy resin, polystyrene,
Heat-softening and heat-melting resins such as polyester resin, vinyl resin, cellulose, aliphatic hydrocarbon resin, aromatic hydrocarbon resin, natural rubber, styrene-butadiene resin, chloroprene rubber, wax, alkyd resin, drying oil and rosin Can be used.

Among the above materials, the most preferred example of the protective layer or the hard coat layer on the substrate surface is an ultraviolet curable resin having excellent productivity. The thickness of the protective layer or the hard coat layer on the substrate surface is 0.01 to 30 μm, preferably 0.05 to 30 μm.
10 μm is appropriate. In the present invention, the intermediate layer,
The protective layer and the hard coat layer on the substrate surface may contain a stabilizer, a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant, a plasticizer and the like as in the case of the recording layer.

[0044]

EXAMPLES The present invention will be described more specifically with reference to the following examples. Table 1 shows examples of compounds used in this example.

[0045]

[Table 1-1]

[0046]

[Table 1-2]

Example 1 On an injection molded polycarbonate substrate having a thickness of 0.6 mm,
Depth 1750mm, half width 0.25μ with photopolymer
m, and a guide groove having a track pitch of 0.74 μm. The 1,1,2,2-tetrafluoropropanol solution of No. 1 was applied by spinner coating to a thickness of 90
A recording layer of 0 ° is formed, and then gold 12 is formed by sputtering.
After a reflective layer having a thickness of 0.6 mm was further provided thereon, and a protective layer having a thickness of 7 μm was formed thereon using an acrylic photopolymer, a thickness of 0.6
Injection-molded polycarbonate flat substrates having a thickness of 2 mm were adhered with an acrylic photopolymer to obtain a recording medium.

Examples 2 to 15 Compound No. 1 used in Example 1 Compound N instead of 1
o. A recording medium was formed in exactly the same manner as in Example 1 using each of Nos. 2 to 15.

Comparative Example 1 Compound No. 1 used in Example 1 A recording medium was formed in the same manner as in Example 1 except that the following compound (ratio -1) was used instead of 1.

[0050]

Embedded image

<Recording Conditions> A semiconductor laser beam having a laser oscillation wavelength of 658 nm and a beam diameter of 1.0 μm was used for this recording medium, and the linear velocity was 3.5 m / sec while tracking.
c. And reproduced with continuous light (reproduction power 0.7 mW) of a semiconductor laser having an oscillation wavelength of 685 nm, and a reproduction waveform was observed.

<Conditions of Light Resistance Test> 40,000 Lux and Xe light were continuously irradiated for 20 hours.

<Storage Test Conditions> 60 ° C., 90% at 60%
Left for 0 hours.

[0054]

[Table 2]

[0055]

As described above, according to the present invention, according to the present invention, a laser having a wavelength range of 700 nm or less can be obtained by using the recording medium described in the above items (1) to (4). It is possible to provide an information recording medium capable of recording and reproducing with light, and having excellent light resistance and storage stability. In addition, the recording medium according to the above (5) can provide a stable high reflectance and high modulation degree. An information recording medium capable of recording and reproduction can be provided, and an information recording medium capable of stable recording and reproduction can be provided by the recording medium described in the above item (6).

[Brief description of the drawings]

FIG. 1 is a diagram showing a general write-once optical recording medium of the present invention.

FIG. 2 is a diagram showing a configuration of an optical recording medium for CD-R of the present invention.

FIG. 3 is a diagram showing a configuration of an optical recording medium for DVD-R of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Recording layer 3 Undercoat layer 4 Protective layer 5 Hard coat layer 6 Metal reflective layer 7 Adhesive layer 8 Spacer 9 Translucent film

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 7/24 561 B41M 5/26 Y F term (Reference) 2H111 EA03 EA12 EA14 EA22 EA25 EA32 EA39 EA40 EA43 FA01 FA12 FA14 FB42 5D029 JA04 JB47 JC05 KB03 WB11 WB14 WC01

Claims (6)

[Claims] 1. An optical recording medium comprising a recording layer provided directly or via an undercoat layer on a first substrate, and further comprising a reflective layer, a protective layer or a second substrate, wherein the recording medium has a general formula An azo compound represented by (I) and a divalent or trivalent metal,
Or an optical recording medium comprising at least one azo metal chelate compound comprising a salt thereof. Embedded image (Wherein, ring A represents a residue which forms a heterocyclic ring together with the carbon atom or nitrogen atom to which it is bonded, and may be condensed with another aromatic ring. Represents a residue that forms an aromatic ring together with the carbon atom to which R ′, R ′, R ″, R ′ ″, R ″ ″ and R ′ ″ ″ are each independently a hydrogen atom , A halogen atom, a substituted or unsubstituted alkyl group, a cyano group, or a nitro group.) 2. The optical recording medium according to claim 1, wherein the rings A and B of the azo compound are heterocyclic rings represented by the following general formula (II). Embedded image (Wherein R ₁ and R ₂ each independently represent a hydrogen atom, a halogen atom, a cyano group, a hydroxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxy group, an amino group R ₃ represents a substituted or unsubstituted alkylamino group, a substituted or unsubstituted dialkylamino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted alkylthio group, or a substituted or unsubstituted arylthio group. To R ₅ are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted Unsubstituted aryloxy group, substituted or unsubstituted carbamoyl group,
R ₃ and R ₄ represent a substituted or unsubstituted acyl group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted amino group; May be linked to form a ring. R ₆ and R ₇ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted phenyl group; R ₄ and R ₆ , R ₅ and R ₇ , and R ₆ and R ₇ are linked; May form a ring. ) 3. The method according to claim 1, wherein the azo metal chelate compound is R ′,
The optical recording medium according to claim 1, wherein at least one of R ″, R ′ ″, R ″ ″, and R ′ ″ ″ is a nitro group. 4. The optical recording medium according to claim 1, wherein the metal atom of the azo metal chelate compound is selected from cobalt, nickel, copper, and manganese. 5. A recording layer having a refractive index n of 1.5 ≦ n ≦ 3.0 and a extinction coefficient k of 0.02 ≦ k ≦ 0 with respect to light in a wavelength range of ± 5 nm. The optical recording medium according to any one of claims 1 to 4, wherein 6. A track pitch on the first substrate is set at 0.
7 to 0.8 μm, and the groove width is a half width of 0.20 to 0.2 μm.
The optical recording medium according to any one of claims 1 to 5, wherein the thickness is 36 µm.