JP2002086918A - Optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording material of an optical recording medium with excellent light resistance and storage stability being applicable to a DVD-R disc system in which a semiconductor laser with an oscillation wave length in shorter wave length in comparison with the conventional system. SOLUTION: In the optical recording medium provided with a recording layer 2 on a base sheet 1, the optical recording medium is characterized by incorporating at least one kind of azo metal chelate compound consisting of an azo compound in which tetrazole ring residue or triazole ring residue and an aromatic ring residue are respectively bonded on one end of an N-N double bond and on the other end and a metal, a metal oxide or its salt in the recording layer 2.

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
DR).

[0002]

2. Description of the Related Art At present, as a next-generation large-capacity optical disk, D
VD-R is under development. The elemental technologies for improving the recording capacity include recording material development for miniaturizing recording pits,
It is necessary to develop technology such as adoption of image compression technology represented by PEG2 and shortening of the wavelength of a semiconductor laser for reading recorded pits. Until now, semiconductor lasers in the red wavelength range have been used for bar code readers and measuring instruments.
Although only the 1GaInP laser diode has been commercialized, the red laser is being used in the optical storage market in earnest as the density of optical disks increases. DV
In the case of D 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. Under such circumstances, the most preferable DVD-R media has a wavelength of 630 to 670.
It is a medium that can record and reproduce in nm. However, a recording material which is excellent in light resistance and storage stability and can be recorded and reproduced by an optical pickup using a laser of 670 nm or less has not yet been developed.

[0003]

According to the present invention, there is provided a light-emitting device which is superior in light resistance and storage stability to a DVD-R disk system using a semiconductor laser having an oscillation wavelength at a shorter wavelength than the conventional system. It is an object to provide a recording material for a recording medium.

[0004]

Means for Solving the Problems The present inventors have studied the means for solving the above problems, and as a result, by adopting a recording layer containing a dye having a specific structure as a main component, the oscillation wavelength is 670 nm or less. The present invention has been found to be applicable to a next-generation large-capacity optical disk system using a semiconductor laser, and has completed the present invention.

Hereinafter, means for solving the problems of the present invention will be described. The first aspect of the present invention is to provide an optical recording medium having a recording layer provided on a substrate, wherein the recording layer has a tetrazole ring residue or a triazole ring residue at one end of a nitrogen-nitrogen double bond, and an aromatic residue at the other end. 1. An optical recording medium comprising an azo compound having an aromatic ring residue and at least one azo metal chelate compound comprising a metal, a metal oxide or a salt thereof.

A second aspect of the present invention is characterized in that the structure of the azo compound is an azo metal chelate compound comprising an azo compound represented by the following general formula (I) and a metal, a metal oxide or a salt thereof. It is on the first optical recording medium.

Embedded image (Wherein, R _{1 to} R ₇ are the same as described above)

A third aspect of the present invention is that the azo compound has a structure
The first optical recording medium is characterized in that the first optical recording medium is an azo compound represented by the following general formula (II) and an azo metal chelate compound comprising a metal, a metal oxide or a salt thereof.

Embedded image (Wherein, R _{1 to} R ₈ are the same as described above)

A fourth aspect of the present invention is the first to third optical recording media, wherein the valence of the metal of the azo metal chelate compound is divalent or trivalent. A fifth aspect of the present invention resides in the first to fourth optical recording media, wherein the metal atom of the azo metal chelate compound is selected from the group consisting of cobalt, nickel, copper and manganese.

A sixth aspect of the present invention is that a single layer of the recording layer has a refractive index n of 1.5 ≦ for light in a wavelength range of recording / reproducing wavelength ± 5 nm.
n ≦ 3.0 and the extinction coefficient k is 0.02 ≦ k ≦ 0.2
The first to fifth optical recording media are characterized in that: According to a seventh aspect of the present invention, there is provided the optical recording medium according to any one of the first to sixth aspects, wherein the slope of the weight loss with respect to the temperature in the main weight loss process is 2% / ° C. or more in thermogravimetric analysis of the organic dye. The eighth aspect of the present invention is a thermogravimetric analysis of the organic dye, wherein the total weight loss in the main weight loss process is 30% or more and the weight loss start temperature is 350 ° C.
The first to seventh optical recording media are characterized by the following. A ninth aspect of the present invention is that the track pitch on the substrate is 0.7 to 0.8 μm, and the groove width is a half value width of 0.18.
In the first to eighth optical recording media, the thickness is 0.36 μm.

Hereinafter, specific substituents of the azo compounds of formulas (I) and (II) will be exemplified. Specific examples of the halogen atom include fluorine, chlorine, bromine and iodine. Specific examples of the alkyl group include a methyl group, an ethyl group,
n-propyl group, n-butyl group, n-pentyl group, n-
Primary alkyl group such as hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, isobutyl group, isoamyl group, 2-methylbutyl group, 2-methylpentyl group, 3-methylpentyl group , 4-methylpentyl, 2-ethylbutyl, 2-methylhexyl, 3-
Methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 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 group such as 1-isobutyl-3-methylbutyl group, neopentyl group, tert-butyl group, tert-hexyl group, tert-amyl group, t
tertiary alkyl groups such as tert-octyl group, cyclohexyl group, 4-methylcyclohexyl group, 4-ethylcyclohexyl group, 4-tert-butylcyclohexyl group,
Examples thereof include cycloalkyl groups such as 4- (2-ethylhexyl) cyclohexyl group, bornyl group, and isobornyl group (adamantane group).

The primary and secondary alkyl groups are a hydroxyl group,
It may be substituted with a halogen atom, a nitro group, a carboxy group, a cyano group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic residue, and the like, and via an atom such as oxygen, sulfur, or nitrogen. The alkyl group may be substituted. Examples of the alkyl group substituted through oxygen include a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group, a butoxyethyl group, an ethoxyethoxyethyl group, a phenoxyethyl group, a methoxypropyl group, an ethoxypropyl group, As an alkyl group in which a piperidino group, a morpholino group, etc. are substituted via sulfur, a methylthioethyl group, an ethylthioethyl group, an ethylthiopropyl group, a phenylthioethyl group, etc. are substituted via nitrogen. Examples of the alkyl group include a dimethylaminoethyl group, a diethylaminoethyl group, and a diethylaminopropyl group.

Specific examples of the aryl group include a phenyl group,
Examples include a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, a biphenylenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a triphenylenyl group, a pyrenyl group, and the like.

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 alkylcarbonyl group are those in which a substituted or unsubstituted alkyl group is directly bonded to a carbon atom of the carbonyl group. Specific examples of the alkyl group include the aforementioned specific examples. be able to.

Specific examples of the arylcarbonyl group are those in which a substituted or unsubstituted aryl group is directly bonded to a carbon atom of the carbonyl group. Specific examples of the aryl group include the specific examples described above. be able to.

Specific examples of the alkyloxycarbonyl group may be those in which a substituted or unsubstituted alkyl group is directly bonded to the oxygen atom of the oxycarbonyl group. Specific examples of the alkyl group are those described above. Can be mentioned. Specific examples of the aryloxycarbonyl group include:
It is sufficient that a substituted or unsubstituted aryl group is directly bonded to the oxygen atom of the oxycarbonyl group, and specific examples of the aryl group include the specific examples described above.

Specific examples of the alkylsulfonyl group include those in which a substituted or unsubstituted alkyl group is directly bonded to a sulfur atom of the sulfonyl group. Specific examples of the alkyl group include the aforementioned specific examples. be able to.

Specific examples of the arylsulfonyl group include those in which a substituted or unsubstituted aryl group is directly bonded to the sulfur atom of the sulfonyl group. Specific examples of the aryl group include the above-mentioned specific examples. be able to.

Specific examples of the silyl group include those in which a silicon atom is a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, three of which are selected in any combination. What is necessary is just to be bonded, and specific examples of the alkyl group and the aryl group include the specific examples described above.

Specific examples of the alkylthioxy group may be those in which a substituted or unsubstituted alkyl group is directly bonded to a sulfur atom, and specific examples of the alkyl group include the aforementioned specific examples. .

Specific examples of the arylthioxy group may be those in which a substituted or unsubstituted aryl group is directly bonded to a sulfur atom. Specific examples of the aryl group include the above-mentioned specific examples. it can.

Specific examples of the alkyloxy group may be those in which a substituted or unsubstituted alkyl group is directly bonded to an oxygen atom, and specific examples of the alkyl group include the aforementioned specific examples. .

Specific examples of the aryloxy group may be those in which a substituted or unsubstituted aryl group is directly bonded to an oxygen atom, and specific examples of the aryl group include the aforementioned specific examples. .

Specific examples of the alkylamino group may be those in which a substituted or unsubstituted alkyl group is directly bonded to a nitrogen atom, and specific examples of the alkyl group include the aforementioned specific examples. .

Specific examples of the arylamino group may be those in which a substituted or unsubstituted aryl group is directly bonded to a nitrogen atom. Specific examples of the aryl group include the above-mentioned specific examples. .

Specific examples of the alkylcarbonylamino group may be those in which a substituted or unsubstituted alkyl group is directly bonded to a carbon atom of the carbonylamino group. Specific examples of the alkyl group are those described above. Can be mentioned.

Specific examples of the arylcarbonylamino group include those in which a substituted or unsubstituted aryl group is directly bonded to a carbon atom of the carbonylamino group. Specific examples of the aryl group are those described above. Can be mentioned.

Specific examples of the alkylcarbamoyl group include:
It is sufficient that a hydrogen atom or a substituted or unsubstituted alkyl group is directly and independently bonded to the nitrogen atom of the carbamoyl group, and specific examples of the alkyl group include the aforementioned specific examples.

Specific examples of the arylcarbamoyl group include:
It is sufficient that a hydrogen atom or a substituted or unsubstituted aryl group is directly and independently bonded to the nitrogen atom of the carbamoyl group, and specific examples of the aryl group include the specific examples described above.

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

The characteristics necessary for forming the recording layer of the recording medium include optical characteristics and thermal characteristics. These characteristics will be described below.

Optical characteristics The condition required for the optical characteristics is a recording / reproducing wavelength of 630n.
It is necessary to have a large absorption band on the short wavelength side with respect to m to 690 nm and the recording / reproducing wavelength to be near the long wavelength end of the absorption band. This is the recording / reproducing wavelength of 630.
It means having a large refractive index and an extinction coefficient in the range of nm to 690 nm. Specifically, the refractive index n of the recording layer single layer with respect to light in the wavelength range near the long wavelength near the recording / reproducing wavelength is 1.5 or more and 3.0 or less, and the extinction coefficient k is 0.0 or less.
It is preferably in the range of 2 or more and 0.2 or less. When n is less than 1.5, it is difficult to obtain a sufficient optical change, so that the recording modulation degree is low, which is not preferable. When n is more than 3.0, the wavelength dependency becomes too high. However, an error occurs even in the recording / reproducing wavelength region, which is not preferable. If k is less than 0.02, the recording sensitivity deteriorates, which is not preferable.
If the ratio exceeds 50, it is difficult to obtain a reflectance of 50% or more, which is not preferable.

Thermal Characteristics The condition required thermally is that the weight loss in the main weight loss process in thermogravimetric analysis must be steep with respect to the temperature. This is because the organic material film is decomposed in the main weight reduction process, causing a decrease in film thickness and a change in optical constant, thereby forming a recording portion in an optical sense. Therefore, when the weight loss in the main weight loss process is gentle with respect to the temperature, this is formed over a wide temperature range, which is extremely disadvantageous when a high-density recording portion is formed. For the same reason, the use of a material having a plurality of weight loss processes is also disadvantageous for high density. In the present invention, among several weight loss processes, the one with the largest weight loss rate is referred to as the main weight loss process. In the present invention, the slope of the weight loss is determined as follows.

As shown in FIG. 1, an organic material having a mass M0 was placed in a nitrogen atmosphere at 10 ° C./min. To raise the temperature. As the temperature rises, the mass decreases by a small amount, and the straight line a-
b shows a weight loss line, and when a certain temperature is reached, a sharp weight loss occurs, and a weight loss occurs substantially along a straight line cd. If the temperature is further increased, the abrupt weight loss ends and the weight decreases substantially along the straight line ef. Now, let the temperature at the intersection of the straight line ab and the straight line cd be T1
(° C.), the residual weight with respect to the initial mass M0 is m1 (%),
The temperature at the intersection of the straight line cd and the straight line ef is T2
(° C.) and the residual weight based on the initial mass M0 is m2 (%). The raw material start temperature is T1, the weight loss end temperature is T2, and the slope of the weight loss is (m1-m2) (%) / (T2
-T1) (° C.), and the weight loss rate with respect to the initial weight is represented by (m1-m2) (%).

Based on the above definition, the recording material used for the optical information recording medium preferably has a weight loss gradient of 2% / ° C. or more in the main weight loss process. When a recording material having a slope of the weight loss of less than 2% / ° C. is used, the spread of the recording portion becomes large, and it becomes difficult to form a short recording portion, which is not suitable for an information recording medium.
Further, the weight reduction rate in the main weight loss process is preferably 30% or more. If it is less than 30%, there is a possibility that good recording modulation and recording sensitivity cannot be obtained.

Further, the condition required for the thermal characteristics is that the weight start temperature T1 must be within a certain temperature range. Specifically, it is desirable that the temperature at which the weight loss starts is 350 ° C. or lower, preferably in the range of 200 to 350 ° C. If the temperature at which the weight loss starts is 350 ° C. or higher, the power of the recording laser beam becomes high, which is not practical. If the temperature is 200 ° C. or lower, the recording stability deteriorates such as reproduction deterioration.

The conditions required for the substrate shape are as follows: the track pitch on the substrate is 0.7 to 0.8 μm, and the groove width is a half value width of 0.18 to 0.36 μm. The substrate usually has a guide groove with a depth of 1000 to 2500 °. The track pitch is usually 0.7 to 1.0 μm, but preferably 0.7 to 0.8 μm for high capacity applications. The groove width is
The half width is preferably 0.18 to 0.36 μm. 0.18
If it is less than μm, it may be difficult to obtain a sufficient tracking error signal intensity. On the other hand, if the thickness exceeds 0.36 μm, the recording portion tends to spread laterally when recording, which is not preferable.

Next, the configuration of the recording medium of the present invention will be described.
The recording medium of the present invention is an ordinary write-once optical disc.
(A so-called air sandwich in which two sheets of FIG. 3 are bonded or a close bonding structure may be used), or a structure of a CD-R medium shown in FIG.
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 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 a first substrate / organic dye layer / metal reflective layer / protective layer / adhesive layer / second substrate structure.

Substrate A required 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 the substrate does not need to be transparent when recording and reproduction are performed from the recording layer side. . Therefore, in the present invention, when only one layer of the substrate is used, the first transparent or opaque is not required as long as only the second substrate is transparent. As a substrate material, for example, plastic such as polyester, acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, and polyimide, glass, ceramic, or metal can be used. When only one layer of the substrate is used, or when two substrates are used in the form of a sandwich, guide grooves and guide pits for tracking on the surface of the first substrate and pre-formatting of address signals and the like are described. 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 the recording layer,
(F) Used for forming guide grooves, guide pits, preformats, and the like. For the purpose of the above (a), polymer materials, for example, various polymer materials such as ionomer resins, polyamide resins, vinyl resins, natural resins, natural polymers, silicones, liquid rubbers, and silane coupling agents And the above (b) and (c)
For the purpose of, inorganic compounds other than the polymer material,
For example, SiO ₂ , MgF ₂ , SiO, TiO ₂ , ZnO,
Metals such as TiN and SiN, or metalloids such as Zn, C
u, Ni, Cr, Ge, Se, Au, Ag, Al and the like can be used. For the purpose (d), a metal such as Al or Ag, or an organic thin film having a metallic luster such as a methine dye or a xanthene dye can be used. For example, an ultraviolet curable resin, a thermosetting resin, a thermoplastic resin, or the like can be used. The thickness of the undercoat layer is suitably 0.01 to 30 μm, preferably 0.05 to 10 μm.

Recording Layer The recording layer is capable of causing some optical change upon irradiation with a laser beam and recording information by the change. The recording layer contains the dye of the present invention. It is necessary to use the dye of the present invention in forming the recording layer.
Species or a combination of two or more species may be used. 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-based, phthalocyanine-based, squarylium-based, croconium-based, pyrylium-based, naphthoquinone-based, anthrequinone (indanthrene) -based, xanthene-based, triphenylmethane-based, azulene-based, and tetreline. Examples thereof include hydrocholine-based, phenanthrene-based, triphenothiazine-based dyes, and metal chelate compounds, and the above-described dyes may be used alone or in combination of two or more.

In the dye, a metal or a metal compound such as In, Te, Bi, Se, Sb, Ge, Sn, A
1, Be, TeO ₂ , SnO, As, Cd and the like can be used in the form of dispersion mixing or lamination. Further, various materials such as an ionomer resin, a polyamide resin, a vinyl resin, a natural polymer, silicone, a liquid rubber, or a silane coupling agent may be dispersed and mixed in the dye. Alternatively, it can be used together with a stabilizer (for example, a transition metal complex), a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant, a plasticizer, and the like for the purpose of improving properties.

The recording layer is formed by vapor deposition, sputtering, C
It can be carried out by ordinary means such as VD or solution application. 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 to be used, generally, alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, methyl ethyl ketone and cyclohexanone, N, N-dimethylformamide,
Amides such as N, N-dimethylacetamide, sulfoxides such as dimethyl sulfoxide, ethers such as tetrahydrofuran, dioxane, diethyl ether, ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, chloroform, methylene chloride, dichloroethane , Carbon tetrachloride, aliphatic halogenated hydrocarbons such as trichloroethane, or aromatics such as benzene, xylene, monochlorobenzene, dichlorobenzene, cellosolves such as methoxyethanol, ethoxyethanol, hexane, pentane, cyclohexane,
Hydrocarbons such as methylcyclohexane can be used. The thickness of the recording layer is suitably 100 to 10 μm, preferably 200 to 2000 μm.

Metal Reflective Layer The reflective layer is made of a metal, a semi-metal, or the like, which can provide a high reflectance by itself and is hardly corroded. Examples of the material include Au, Ag, and the like.
Although Cr, Ni, Al, Fe, Sn and the like can be mentioned, Au, Ag, and Al are most preferable in terms of reflectance and productivity. These metals and metalloids may be used alone.
It may be a kind of alloy. Examples of the film forming method include vapor deposition and sputtering, and the film thickness is 50 to 5000.
{, Preferably 100-3000}.

Protective Layer, Hard Coat Layer on Substrate Surface The protective layer or hard coat layer on the substrate surface is composed of (a) a recording layer
(B) protects the radiation absorbing layer) from scratches, dust, dirt, etc.
Improvement of storage stability of recording layer (reflection / absorption layer), (c) reflection
It is used for the purpose of improving the rate. For these purposes
Then, the material shown in the intermediate layer can be used.
You. Further, as the inorganic material, SiO, SiO _TwoAlso use
Can be polymethyl acrylate, as organic material,
Polycarbonate, epoxy resin, polystyrene, poly
Ester resin, vinyl resin, cellulose, aliphatic hydrocarbon
Resin, aromatic hydrocarbon resin, natural rubber, styrene pig
Diene resin, chloroprene rubber, wax, alkyd
Uses heat-softening and hot-melt resins such as resin, drying oil and rosin
Can be. Protective layer or substrate surface of the above materials
The most preferable example for the surface hard coat layer is excellent productivity.
UV curable resin. Protective layer or substrate surface
The film thickness of the coating layer is 0.01 to 30 μm, preferably 0.05
10 to 10 μm is appropriate. In the present invention, the lower intermediate
Layer, protective layer, and hard coat layer on the substrate
As well as stabilizers, dispersants, flame retardants, lubricants, antistatic
Agents, surfactants, plasticizers and the like.

[0046]

Embodiments of the present invention will be described below.

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 were formed. 1, a 1,1,2,2-tetrafluoropropanol solution was applied by spinner coating to a thickness of 900
The recording layer of Å is formed, and then gold
After a reflective layer of 0 ° was provided, and a 7 μm protective layer of an acrylic photopolymer was further provided thereon, the thickness was 0.6 m.
m of the injection-molded polycarbonate flat substrate was bonded with an acrylic photopolymer to obtain a recording medium.

Examples 2 to 13 In Example 1, Compound No. In place of Compound No. 1, Compound Example Nos. Using 2 to 13, a recording medium was formed in exactly the same manner as in Example 1.

Comparative Example 1 Compound Example No. 1 was 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.

Embedded image

The recording materials of Examples 1 to 13 and Comparative Example 1 were subjected to an evaluation test under the following recording conditions and weather resistance test conditions.
Shows the evaluation results.

[0051]

[Table 1]

[0052]

[Table 2]

<Evaluation Results>

[Table 3]

Example 14 On a 0.6 mm thick injection molded polycarbonate substrate,
Depth 1750mm, half width 0.25μ with photopolymer
m, and a guide groove having a track pitch of 0.74 μm was formed. 14, a 1,1,2,2-tetrafluoropropanol solution 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 15 to 26 In Example 14, the compound No. Compound No. 14 shown in Table 4 below in place of Compound No. 14 Using Nos. 15 to 26, a recording medium was formed in exactly the same manner as in Example 1.

Comparative Example 2 In Example 14, Compound Example No. A recording medium was formed in the same manner as in Example 1 except that the following compound (ratio-2) was used instead of 14.

Embedded image

An evaluation test was performed on the recording materials of Examples 14 to 26 and Comparative Example 2 under the recording conditions and weathering test conditions described above.
Table 6 below shows the evaluation results.

[0058]

[Table 4]

[0059]

[Table 5]

[0060]

[Table 6]

[0061]

Advantages of the Invention Claims 1 to 4 An information recording medium capable of recording and reproducing with a laser beam having a wavelength range of 670 nm or less and having excellent light resistance and storage stability was provided. 2. Claim 5 An information recording medium capable of recording and reproducing with a stable high reflectance and a high modulation degree can be provided. 3. Claims 6 and 7 An information recording medium capable of high-density recording with low jitter can be provided. 4. Claim 8 An information recording medium capable of stable recording and reproduction can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a main weight loss process of an organic material and a method of obtaining a weight loss rate.

FIGS. 2A to 2D are diagrams illustrating a normal write-once optical recording medium.

FIGS. 3A to 3C are diagrams illustrating a configuration of a medium for CD-R.

FIGS. 4A to 4D are diagrams illustrating a configuration of a DVD-R medium.

[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 Protective substrate 8 Adhesive layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H111 EA03 EA12 EA25 EA40 EA43 EA48 FA01 FA12 FA14 FA15 FA37 FB42 FB60 5D029 JA04 JC05 JC13 WB14 WB17 WC01

Claims (9)

[Claims] In an optical recording medium comprising a recording layer provided on a substrate, a tetrazole ring residue or a triazole ring residue is provided at one end of a nitrogen = nitrogen double bond in the recording layer, and an aromatic residue is provided at the other end. An optical recording medium comprising an azo compound having a ring residue bonded and at least one azo metal chelate compound comprising a metal, a metal oxide or a salt thereof. 2. The azo compound has a structure represented by the following general formula (I):
The optical recording medium according to claim 1, wherein the optical recording medium is an azo metal chelate compound composed of an azo compound represented by the formula and a metal, a metal oxide or a salt thereof. Embedded image (Wherein, R _{1 to} R ₃ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic residue, a formyl group,
Substituted or unsubstituted alkylcarbonyl group, substituted or unsubstituted arylcarbonyl group, substituted or unsubstituted alkyloxycarbonyl group, substituted or unsubstituted aryloxycarbonyl group, substituted or unsubstituted alkylsulfonyl group, substituted or unsubstituted Substituted arylsulfonyl group, substituted or unsubstituted silyl group, nitro group, phthaloyl group, substituted or unsubstituted alkylthioxy group, substituted or unsubstituted arylthioxy group, R
_{4 to} R ₇ each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxy group, an amino group, a carbamoyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted group. Substituted heterocyclic residue, substituted or unsubstituted alkyloxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylthioxy group, substituted or unsubstituted arylthioxy group, substituted or unsubstituted alkyl Amino group, substituted or unsubstituted arylamino group, substituted or unsubstituted alkyloxycarbonyl group, substituted or unsubstituted aryloxycarbonyl group, substituted or unsubstituted alkylcarbonylamino group, substituted or unsubstituted arylcarbonylamino Group, substituted or unsubstituted alkyl carb Represents a bamoyl group, a substituted or unsubstituted arylcarbamoyl group, or a substituted or unsubstituted alkenyl group. R ₄ and R ₅ , R ₅ and R ₆ , or R ₆
And R ₇ may be linked to form a ring. ) 3. An azo compound having a structure represented by the following general formula (I)
2. The optical recording medium according to claim 1, which is an azo metal chelate compound comprising the azo compound represented by I) and a metal, a metal oxide or a salt thereof. Embedded image (Wherein, R _{1 to} R ₃ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic residue, a formyl group,
Substituted or unsubstituted alkylcarbonyl group, substituted or unsubstituted arylcarbonyl group, substituted or unsubstituted alkyloxycarbonyl group, substituted or unsubstituted aryloxycarbonyl group, substituted or unsubstituted alkylsulfonyl group, substituted or unsubstituted A substituted arylsulfonyl group, a substituted or unsubstituted silyl group, a nitro group, a phthaloyl group, a substituted or unsubstituted alkylthioxy group, a substituted or unsubstituted arylthioxy group, R
_{4 to} R ₈ each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxy group, an amino group, a carbamoyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted group. Substituted heterocyclic residue, substituted or unsubstituted alkyloxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylthioxy group, substituted or unsubstituted arylthioxy group, substituted or unsubstituted alkyl Amino group, substituted or unsubstituted arylamino group, substituted or unsubstituted alkyloxycarbonyl group, substituted or unsubstituted aryloxycarbonyl group, substituted or unsubstituted alkylcarbonylamino group, substituted or unsubstituted arylcarbonylamino Group, substituted or unsubstituted alkyl carb Represents a bamoyl group, a substituted or unsubstituted arylcarbamoyl group, or a substituted or unsubstituted alkenyl group. R ₅ and R ₆ , R ₆ and R ₇ , or R ₇
And R ₈ may be linked to form a ring. 4. The azo metal chelate compound according to claim 1, wherein the valence of the metal is divalent or trivalent.
The optical recording medium according to any one of the above. 5. The optical recording medium according to claim 1, wherein the metal atom of the azo metal chelate compound is selected from the group consisting of cobalt, nickel, copper and manganese. 6. A recording layer having a refractive index n of 1.5 ≦ n ≦ 3.0 and a extinction coefficient k of 0.02 ≦ k ≦ 0. The optical recording medium according to claim 1, wherein the number is 2. 7. The optical recording medium according to claim 1, wherein, in thermogravimetric analysis of the organic dye, a slope of a weight loss with respect to a temperature in a main weight loss process is 2% / ° C. or more. . 8. The thermogravimetric analysis of the organic dye, the total weight loss in the main weight loss process is 30% or more, and the temperature at which the weight loss starts is 350 ° C.
The optical recording medium according to claim 1, wherein: 9. The track pitch on the substrate is 0.7-0.
8 μm, and the groove width is a half width, 0.18 to 0.36 μm.
The optical recording medium according to any one of claims 1 to 8, wherein m is m.