JP2002283721A - Optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical recording medium using a recording material which is applicable to a high density optical recording system using a semiconductor laser having an oscillation wavelength in a short wavelength and is excellent in light resistance and reservation stability compared with a conventional optical recording medium. SOLUTION: In this optical recording medium, a light absorbing layer is provided on a substrate, and the light absorbing layer comprises a nitrogen- containing compound or phosphorus-containing compound which has a specific metal tetrazaporphyrin compound and an N atom capable of coordinating with the metal tetrazaporphyrin compound as a main component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium,
More specifically, by irradiating a light beam, the optical properties of the recording material, such as transmittance and reflectance, are changed.
The present invention relates to an optical recording medium on which information can be recorded, reproduced, and additionally recorded.

[0002]

2. Description of the Related Art At present, as a next-generation large-capacity optical disk, D
VD-R is under development. Elemental technologies for improving the recording capacity include recording material development for miniaturizing recording pits, M
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 recorded pits. Until now, the red wavelength laser has been used for bar code readers and measuring instruments in the 670 nm band.
Only an lGaInP laser diode has been commercialized.

However, with the increase in the density of optical disks, red lasers are being used in the optical storage market in earnest. In the case of a DVD drive, the light source is standardized at two wavelengths of a 635 nm band and a 650 nm band laser diode. For high-density recording, it is preferable that the recording wavelength is shorter.
35 nm is preferred.

On the other hand, a read-only DVD-ROM drive is commercialized at a wavelength of 650 nm. Under these circumstances, the most preferable DVD-R media has a wavelength of ~ 635.
A medium (DVD-R) that can record and play back at nm and can play back even at wavelengths up to 650 nm, has excellent light resistance and storage stability, and can record and play back with an optical pickup using laser light at 650 nm or less. A new recording material is desired.

A large-capacity write-once compact disc (DVD
-R) include those using a cyanine dye / metal reflective layer as a recording material, those using another dye / metal reflective layer as a recording material, and tetraazaporphyrin (porphyrazine) dye / metal reflective layer. Is used as a recording material (for example, JP-A-9-169166).

[0006] Among them, the tetraazaporphyrin compound is a compound having a cyclic plane, poor solubility, and difficult to form a film by a solvent coating method. Furthermore, even if the compound is improved in solubility until a film can be formed, the compound has a planar structure, so that the film spectrum due to association between molecules becomes Boolean, the light absorption at the recording / reproducing wavelength is large, and the refractive index is further increased. Has a disadvantage that a high reflectance cannot be obtained.

The present inventors have developed a high-density optical disk system using a semiconductor laser having an oscillation wavelength of 700 nm or less by using a tetraazaporphyrin compound and a recording layer mainly composed of a compound coordinated to the compound. The inventors have found that the present invention is applicable and completed the present invention.

[0008]

Accordingly, the present invention provides a recording material having excellent light resistance and storage stability applicable to a high-density optical disk system using a semiconductor laser having an oscillation wavelength shorter than the conventional wavelength range. It is an object of the present invention to provide an optical recording medium using the same.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, the above problems can be solved by employing the following technical means. (1) In an optical recording medium in which a light absorbing layer is provided on a substrate, the light absorbing layer is formed of the following general formula (Ia, Ib, I-
c, Id) a metal tetraazaporphyrin compound (I) and a nitrogen-containing compound or a P-containing N-atom-containing compound capable of coordinating with the metal tetraazaporphyrin compound.
An optical recording medium comprising a phosphorus-containing compound having an atom as a main component.

Embedded image (Wherein, X _{1 to} X ₄ each represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted alkoxy group, Or a substituted or unsubstituted phenyloxy group, Y _{1 to} Y ₄ are each a hydrogen atom,
Represents a 5-membered heterocyclic ring containing a halogen atom, substituted or unsubstituted one or more nitrogen atoms. The 5-membered heterocyclic ring may be condensed with another aromatic ring or a heterocyclic ring, and the 5-membered heterocyclic ring may be a nitrogen atom. An atom is bonded to the tetraazaporphyrin ring. However, at least one of Y _{1 to} Y ₄ is represented by the following general formula (II) or (III):

Embedded image

Embedded image Wherein Z _{1 to} Z ₄ are each a substituted or unsubstituted carbon atom which forms a hetero 5-membered ring together with a carbon atom or a nitrogen atom bonded thereto. An atom or a nitrogen atom, and this 5-membered heterocyclic ring may be condensed with another aromatic ring. Z _{1 to} Z ₄ are not all nitrogen atoms, and Z _{5 to} Z ₇ are a carbon atom or nitrogen atom of a substituted or unsubstituted form a heterocyclic 5-membered ring together with the carbon atom or nitrogen atom are, Z ₁
-Z ₄ are not all nitrogen atoms and are bonded to the tetraazaporphyrin ring at the nitrogen atom;
R '''' independently represents a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, an alkoxy group, an aryloxy group, a carboxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group. Represents a group or a substituted or unsubstituted acyl group. ) M represents a divalent metal, a trivalent or tetravalent substituted metal atom or a metal oxide. (2) The optical recording medium according to the above (1), wherein the nitrogen-containing compound is a compound having a -N = or -N <group. (3) The optical recording medium according to (1) or (2), wherein the nitrogen-containing compound is an imidazole derivative, a benzimidazole derivative, or a thiazole derivative. (4) The above-mentioned (1), wherein the phosphorus-containing compound is a compound having a -P = group, -PH- group or -PPh- group (where Ph means a phenyl group).
An optical recording medium according to claim 1. (5) The phosphorus-containing compound is (A) ₂ -P- (CH ₂ ) _n
-P- (A) ₂ (wherein A represents a substituted or unsubstituted aryl group, and n represents an integer of any one of 2 to 6). The optical recording medium according to the above (1) or (4). (6) The metal tetraazaporphyrin compound (I)
The number of d-orbital electrons of the central metal ion of 0, 1, 2, 3,
The optical recording medium according to any one of (1) to (5), wherein the optical recording medium is 4, 5, 6, 7, or 10. (7) The central metal ion of the metal tetraazaporphyrin compound (I) is Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Zn ²⁺ or C
The optical recording medium according to any one of the above (1) to (6), which is d ²⁺ . (8) When the metal tetraazaporphyrin compound (I) is represented by the general formula (Ia), (Ib), (Ic) or (I
The optical recording medium according to any one of the above (1) to (7), comprising at least one of -d). (9) The track pitch of the substrate is 0.7 to 0.8 μm
The optical recording medium according to any one of (1) to (8), wherein the half width of the groove is 0.18 to 0.36 μm. (10) The optical recording medium as described in any one of (1) to (9) above, wherein the reflective layer having a reflective layer is made of gold, silver, copper, aluminum, or an alloy of these metals. . (11) The optical recording medium according to any one of (1) to (10), wherein a recording wavelength is 720 to 600 nm.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The optical recording medium according to the present invention is an optical recording medium having a light absorbing layer provided on a substrate, wherein the light absorbing layer has the following general formula (I)
-A, Ib, Ic, Id):

Embedded image (Wherein, X _{1 to} X ₄ each represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted alkoxy group, Or a substituted or unsubstituted phenyloxy group, Y _{1 to} Y ₄ are each a hydrogen atom,
Represents a 5-membered heterocyclic ring containing a halogen atom, substituted or unsubstituted one or more nitrogen atoms. The 5-membered heterocyclic ring may be condensed with another aromatic ring or a heterocyclic ring, and the 5-membered heterocyclic ring may be a nitrogen atom. An atom is bonded to the tetraazaporphyrin ring. However, at least one of Y _{1 to} Y ₄ is represented by the following general formula (II) or (III):

Embedded image

Embedded image (Wherein, Z _{1 to} Z ₄ are each a substituted or unsubstituted carbon or nitrogen atom forming a 5-membered heterocyclic ring together with the carbon atom or nitrogen atom to which they are bonded, and The ring and another aromatic ring may be fused, Z _{1 to} Z ₄ are not all nitrogen atoms, and Z _{5 to} Z ₇ are taken together with the carbon atom or nitrogen atom to which they are respectively bonded. A substituted or unsubstituted carbon atom or a nitrogen atom forming a 5-membered heterocyclic ring, and all of Z _{1 to} Z ₄ are not nitrogen atoms and are bonded to the tetraazaporphyrin ring at the nitrogen atom. , R ′ to R ″ ″ are each independently:
Hydrogen atom, halogen atom, nitro group, cyano group, hydroxyl group, alkoxy group, aryloxy group, carboxy group,
Represents a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group, or a substituted or unsubstituted acyl group. ), Wherein M is a divalent metal, trivalent or 4
Represents a valent substituted metal atom or a metal oxide. )) And a nitrogen-containing compound having an N atom or a phosphorus-containing compound having a P atom capable of coordinating with the metal tetraazaporphyrin compound. .

The metal tetraazaporphyrin compound (I) used in the present invention may be any one capable of forming a film by a solvent coating method. Specific examples of the substituents bonded to the tetraazaporphine skeleton Are, for example, hydrogen, unsubstituted alkyl group, unsubstituted cycloalkyl group, unsubstituted alkoxy group, unsubstituted aryl group, unsubstituted aryloxy group, halogen, nitro group, cyano group , A heterocyclic residue, a thioalkyl group, a thioaryl group and the like.

In particular, the number of d-orbital electrons of the central metal ion of the metal tetraazaporphyrin compound (I) is 0, 1, 2, or
3,4,5,6,7,10 tetraazaporphyrins are more preferable because they can easily coordinate with a nitrogen-containing compound having an N atom or the phosphorus-containing compound. It is particularly preferable that the central metal ion of the metal tetraazaporphyrin compound (I) is at least one ion selected from Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Zn ²⁺ and Cd ²⁺ .

Further, a preferable structure in the tetraazaporphyrin skeleton is represented by the above general formula (Ia, I-
b, Ic, and Id). The above general formulas Ia, Ib, Ic or I-
In d, X _{1 to} X ₄ each represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted alkoxy group, Or a substituted or unsubstituted phenyloxy group; Y _{1 to} Y ₄ each represent a hydrogen atom, a halogen atom, or a substituted or unsubstituted 5-membered heterocyclic ring containing at least one nitrogen atom; The 5-membered ring may be fused to another tetra-azaporphyrin ring at the nitrogen atom,
_At least one of _{1 to} Y ₄ contains a 5-membered heterocyclic ring represented by the above general formula (II) or (III), M is a divalent metal, a trivalent or tetravalent substituted metal atom, Represents a metal oxide or two hydrogen atoms.

In the general formula (II), Z ₁ to
Z ₄ is a substituted or unsubstituted carbon or nitrogen atom which forms a 5-membered heterocyclic ring together with the carbon or nitrogen atom to which it is bonded, and the 5-membered heterocyclic ring and another aromatic ring are It may be condensed, and Z _{1 to} Z ₄ are not all nitrogen atoms. In the above general formula (III), Z _{5 to} Z ₇ each represent a substituted or unsubstituted carbon atom or nitrogen which forms a 5-membered heterocyclic ring together with the carbon atom or nitrogen atom bonded thereto. Atoms, Z _1-
All of Z ₄ are not nitrogen atoms and are bonded to the tetraazaporphyrin ring at the nitrogen atom.

Further, in the above general formula (I), R′〜
R '''' is independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, an alkoxy group, an aryloxy group, a carboxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group, Represents a substituted or unsubstituted acyl group.

More specifically, X _{1 to} X ₄ in the general formula (I)
Alkyl group means a monovalent, linear, branched or cyclic aliphatic hydrocarbon group, for example, a methyl group,
Ethyl group, n-propyl group, n-butyl group, isobutyl group, n-pentyl group, neopentyl group, isoamyl group,
2-methylbutyl group, n-hexyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 2-ethylbutyl group, n-heptyl group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 2-ethylpentyl group,
3-ethylpentyl group, n-octyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5-methylheptyl group, 2-ethylhexyl group, 3
-Ethylhexyl group, n-nonyl group, n-decyl group, n
A primary alkyl group such as a dodecyl group, an isopropyl group, s
ec-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-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, 1-isobutyl-3-
Secondary alkyl groups such as methylbutyl group, tert-butyl group, tert-hexyl group, tert-amyl group, te
tertiary alkyl groups such as rt-octyl group, cyclohexyl group, 4-methylcyclohexyl group, 4-ethylcyclohexyl group, 4-tert-butylcyclohexyl group, 4
And cycloalkyl groups such as-(2-ethylhexyl) cyclohexyl group, bornyl group, isobornyl group, and adamantane group. These alkyl groups may be substituted with a substituent such as halogen.

Examples of the unsaturated alkyl group include an ethylene group, a propylene group, a butylene group, a hexene group, an octene group, a dodecene group, a cyclohexene group and a butylhexene group. Further, these primary and secondary alkyl groups 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 or a substituted or unsubstituted heterocyclic residue,
Further, it may be substituted with the above-mentioned alkyl group via an atom such as oxygen, sulfur, or nitrogen.

Examples of the alkyl group substituted through oxygen include methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, butoxyethyl, ethoxyethoxyethyl, phenoxymethyl, methoxymethyl Propyl group, ethoxypropyl group,
Piperidino group, morpholino group and the like, and examples of the alkyl group substituted via sulfur include, for example,
Examples include a methylthioethyl group, an ethylthioethyl group, an ethylthiopropyl group, and a phenylthioethyl group. Furthermore, examples of the alkyl group substituted via nitrogen include a dimethylaminoethyl group, a diethylaminoethyl group, and a diethylaminopropyl group.

The aryl group of X _{1 to} X _{4 in} the general formula (I) means a monovalent aromatic hydrocarbon group. Specific examples of the aryl group include, for example, a phenyl group and a pentalenyl group. , Indenyl group, naphthyl group, heptalenyl group,
Biphenylyl group, as-indacenyl group, s-indacenyl group, acenaphthalenyl group, fluorenyl group, phenalenyl group, phenanthranyl group, anthranyl group, fluoracenyl group, acephenanthrenyl group, aceanthrylene group, triphenylenyl group, pyrenyl group, chrysenyl And naphthacenyl groups. Further, these aryl groups may be substituted with, for example, a hydroxyl group, a halogen atom, a nitro group, a carboxy group, a cyano group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic residue, The alkyl group may be substituted through an atom such as oxygen, sulfur, or nitrogen.

The above-mentioned alkoxy group may be any one in which a substituted or unsubstituted alkyl group is directly bonded to an oxygen atom. Specific examples of such a substituted or unsubstituted alkyl group include the above-mentioned specific examples. Can be.

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

The thermophysical properties of the compounds Ia to Id can be determined by using a thermogravimetrically decomposed compound having a decomposition temperature of 350 ° C. or less or a total weight loss of 30% or more in the main weight loss process. In addition, recording with high sensitivity and low jitter becomes possible.
If the thermal decomposition temperature exceeds 350 ° C., the recording sensitivity is poor, and the jitter characteristics are degraded even when recording at a high power. In addition, a thermophysical dye having a total weight loss of less than 30% in the main weight loss process also deteriorates jitter characteristics.

As the nitrogen-containing compound containing an N atom used in the present invention, those having a -N = or -N <group are preferable, and imidazole derivatives, benzimidazole derivatives and thiazole derivatives are particularly preferable. However, the present invention is not limited to these. Among these, a compound containing an N atom in a heterocycle is preferable because it has a high effect of preventing the association of the tetraazaporphyrin compound (I) and is excellent in light resistance and heat resistance. Further, from the viewpoint of maintaining the thermal stability of the light absorbing layer, it is preferable that the nitrogen-containing compound also has a melting point of 150 ° C. or higher. If the melting point is lower than 150 ° C., the characteristics (particularly, optical characteristics) of the light absorbing layer are likely to change in a high-temperature and high-humidity environment.

Preferred specific examples of such a nitrogen-containing compound include, for example, n-butylamine, n-hexylamine, tert-butyl-amine, pyrrole, pyrrolidine, pyridine, piperidine, purine, pyrimidine, pyridazine, triazine, imidazole, benz. Imidazole, 5,6-dimethylbenzimidazole, 2,5,6
-Trimethylbenzimidazole, naphthoimidazole, 2-methylnaphthoimidazole, quinoline, isoquinoline, quinoxaline, benzquinoline, phenanthridine, indoline, carbazole, norharman, thiazole, benzthiazole, benzoxazole, benztriazole, 7-azaindole, tetrahydro Quinoline, triphenylimidazole, phthalimide, benzoisoquinoline-5,10-dione, triazine, pyrimidine, 5-chlorotriazole, ethylenediamine, azobenzene, trimethylamine, phthalhydrazide, 1,3-diiminoisoindoline, oxazole,
Polyimidazole, polybenzimidazole, polythiazole and the like can be mentioned.

Similarly, the phosphorus-containing compound containing P used in the present invention includes -P = group,> PH group or> PPh
Compounds having a group (where Ph means a phenyl group), more specifically (A) ₂ -P- (CH ₂ ) _n -P-
(A) ₂ (wherein, A represents a substituted or unsubstituted aryl group, and n represents an integer of 2 to 6), but is not limited thereto. Not something. Among these, the effect of preventing the association of the tetraazaporphyrin compound (I) is high, and the light resistance,
A compound containing an N atom in a heterocyclic ring is preferred from the viewpoint of excellent heat resistance. Further, similarly, from the viewpoint of maintaining the thermal stability of the light absorbing layer, the phosphorus-containing compound has a melting point of 15%.
Those at 0 ° C. or higher are preferred. When the melting point is lower than 150 ° C., the characteristics (particularly, optical characteristics) of the light absorbing layer under a high temperature and high humidity environment.
Is likely to change.

Preferred specific examples of such phosphorus-containing compounds include, for example, tri-n-butylphosphine, tri-
n-hexylphosphine, tri-n-octylphosphine, triphenylphosphine, diethylphenylphosphine, tris (4-methoxyphenyl) phosphine, chlorodiphenylphosphine, triisopropylphosphite, triphenylphosphite, trisdiethylaminophosphite, 2- Chloro-1,2,3, dioxaphosphorane, benzenephosphonous dichloride, trimethylolpropane phosphite, 2-chloro-4H-
1,2,3, -benzodioxaphosphorin-4one,
2-cyanoethyl-N, N diisopropylchlorophosphoramidate, 2,2′bis (diphenylphosphino) -1,1′binaphthyl, 1,2-bis (diphenylphosphino) ethane, 1,3-bis (diphenyl Phosphino) propane, 1,4-bis (diphenylphosphino) butane, 1,2bis (di (m-methoxyphenyl)
Examples thereof include phosphino) ethane, 1,2 bis (di (p-chlorophenyl) phosphino) ethane, and 1,3 bis (di (m-ethylphenyl) phosphino) propane.

A film (light-absorbing layer) comprising the compound (I) and the nitrogen-containing compound or the phosphorus-containing compound coordinated with the compound (I) dissolves these two compounds in a solvent, It is easily obtained by coating on a substrate as a coating liquid. The mixing ratio between the compound (I) and the nitrogen-containing compound or the phosphorus-containing compound is 1 in molar ratio.
/ 2 to 2/1 (ratio of compound (I) / nitrogen-containing compound or the phosphorus-containing compound) is preferred. Molar ratio is 1
If the ratio is less than / 2, the dye concentration in the film is low, so that the absorbance per unit film of the light absorbing layer is apt to decrease, and a good refractive index cannot be obtained. Conversely, when the molar ratio exceeds 2/1. In this case, the effect of adding the nitrogen-containing compound or the phosphorus-containing compound cannot be sufficiently obtained.

Examples of the solvent for preparing the coating solution include known organic solvents, for example, alcohols, cellosolves, hydrocarbon solvents, ketones and ethers.

The optical recording medium according to the present invention is composed of various components, such as a substrate (1), a recording layer (2), an undercoat layer (3), a metal reflection layer ( 6), protective layer (4), substrate surface hard coat layer (5),
There are a protective substrate (7), an adhesive layer (8) and the like. The optical recording medium according to the present invention is an optical recording medium having various layer structures by arbitrarily combining various components according to the respective applications, including a two-layer structure in which the components include a substrate and a recording layer. Can be configured. For example, as such an optical recording medium, for example, a normal write-once optical recording medium as shown in FIGS. 1A to 1D, and FIGS. 2A to 2C
The medium configuration for CD-R as shown in FIG.
To (c) as the media configuration for DVD-R.

The necessary components of the optical recording medium according to the present invention will be described below. (Substrate) The substrate used for the optical recording medium according to the present invention must be transparent to the laser used only when recording and reproduction are performed from the substrate side. However, the substrate does not necessarily have to be transparent. As the substrate material, for example, plastic such as polyester, acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, polyimide, glass, ceramic, or metal can be used. Note that a guide groove for tracking, a guide pit, and a preformat such as an address signal may be formed on the surface of the substrate.

(Recording Layer) The recording layer of the optical recording medium according to the present invention causes some optical change by irradiation with a laser beam, and records information by the change. It is necessary that the recording medium contains a dye that can be used in the present invention, and the recording layer may be used alone or in combination of two or more kinds. Further, such a dye may be used by mixing or laminating with another organic dye and a metal or a metal compound for the purpose of improving optical characteristics, recording sensitivity, signal characteristics, and the like. Examples of such organic dyes include polymethine dyes,
Naphthalocyanine, phthalocyanine, squarylium, croconium, pyrylium, naphthoquinone, anthraquinone (indanthrene), xanthene, triphenylmethane, azulene, tetrahydrocholine, phenanthrene, and triphenothiazine dyes And metal complex compounds.

Examples of metals or metal compounds include:
For example, In, Te, Bi, Se, Sb, Ge, Sn, A
l, Be, TeO ₂ , SnO, As, Cd and the like, and each of them can be used in the form of dispersion mixing or lamination. Further, various materials such as a polymer material such as an ionomer resin, a polyamide resin, a vinyl resin, a natural polymer, silicone, and a liquid rubber or a silane coupling agent may be dispersed and mixed in the dye,
For the purpose of improving properties, 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 can be used together.

The recording layer can be formed by a usual method such as vapor deposition, sputtering, CVD or solvent application. When the coating method is used, the above-mentioned dye or the like can be dissolved in an organic solvent, and the coating can be 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,
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, aromatics such as benzene, xylene, monochlorobenzene, dichlorobenzene, cellosolves such as methoxyethanol and ethoxyethanol, hexane, pentane, cyclohexane, methylcyclohexane, etc. And the like. The thickness of the recording layer is generally 100 ° to 10 μm.
m, preferably 200 to 2000 degrees.

(Undercoating Layer) The undercoating layer is formed by, for example, improving adhesion, disposing a barrier such as water or gas, improving storage stability of the recording layer, improving reflectance, protecting the substrate from a solvent, It is used for the purpose of forming guide grooves, guide pits, preformats, and the like. The thickness of the undercoat layer is, for example, about 0.01 to 30 μm, preferably 0.05 to 30 μm.
About 10 to 10 μm is appropriate. For the purpose of improving the adhesiveness, a polymer material, for example, an ionomer resin,
Polyamide resin, vinyl resin, natural resin, natural polymer,
Various polymer compounds such as silicone and liquid rubber, and
A silane coupling agent or the like can be used. For the purpose of disposing a barrier such as water or gas, or improving the storage stability of the recording layer, an inorganic compound such as SiO, MgF, SiO
₂ , TiO, ZnO, TiN, SiN, etc., and a metal or metalloid such as Zn, Cu, Ni, Cr, G
e, Se, Au, Ag, Al and the like can be used. For the purpose of improving the reflectance, a metal, for example, Al, Au, Ag, or the like, or an organic thin film having a metallic luster, for example, a methine dye or a xanthene-based dye can be used. Furthermore, protection of the substrate from solvents, guide grooves,
For the purpose of forming guide pits, preformats, and the like, an ultraviolet curable resin, a thermosetting resin, a thermoplastic resin, or the like can be used.

(Metal Reflective Layer) As the metal reflective layer, a metal, a semi-metal, or the like, which can provide a high reflectance by itself, is used. Examples of such a material include Au,
Ag, Cr, Ni, Al, Fe, Sn and the like can be mentioned. From the viewpoint of reflectivity and productivity, Au, Ag, and Al are particularly preferable. These metals and metalloids may be used alone or as two kinds of alloys. As the film forming method, a conventional method such as vapor deposition and sputtering can be used, and the film thickness is generally about 50 to 5000 °, preferably 1 to 500 °.
It is about 00-3000 °.

(Protective Layer and Hard Coat Layer on Substrate Surface) Protection
Layer and substrate surface hard coat layer is a recording layer (reflective absorption layer)
The recording layer (reflection)
With the aim of improving the storage stability of the absorption layer) and the reflectance.
Used as For these purposes,
The materials shown for the layers can be used. Also, inorganic materials
As, for example, SiO, SiO _TwoAlso use
Can be. Further, as the organic material, for example, polymer
Chill acrylate, polycarbonate, epoxy resin,
Polystyrene, polyester resin, vinyl resin, cellulose
Base, aliphatic hydrocarbon resin, natural rubber, styrene butadi
Ene resin, chloroprene rubber, wax, alkyd tree
Thermo-softening or hot-melting resin such as fat, drying oil and rosin
Can also be used. Particularly preferred examples of the above materials
As an example, mention UV curable resin with excellent productivity
Can be. The thickness of the protective layer or the substrate surface hard coat layer is
Generally, about 0.01 to 30 μm, preferably 0.0
About 5 to 10 μm is appropriate. In the present invention,
The undercoat layer, protective layer and hard coat layer on the substrate
As with recording layers, stabilizers, dispersants, flame retardants, lubricants,
It can contain antistatic agent, surfactant, plasticizer, etc.
it can.

(Protective Substrate) When the protective substrate is irradiated with laser light from the protective substrate side, it must be transparent to the laser light used. When used as a mere protective plate, transparency does not matter. As a usable substrate material, it is completely the same as the substrate material, and uses a plastic such as polyester, acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, polyimide, or glass, ceramic, or metal. be able to.

(Adhesive and Adhesive Layer) As the adhesive, 2
Any material can be used as long as it can bond two recording media, and from the viewpoint of productivity, an ultraviolet curable or hot melt adhesive is preferable.

[0039]

EXAMPLES The optical recording medium according to the present invention will be described in more detail with reference to examples. Specific examples of the metal tetraazaporphyrin compound (I) that can be used in the present invention include the following compounds. However, the present invention is not limited to the specific examples, and it goes without saying that any compound included in the general formula (I) can be used in the present invention.

[0040]

Embedded image

[0041]

[Table 1]

Example 1 The above compound No. Tetraazaporphyrin and benzimidazole represented by No. 2 were dissolved in chloroform in an equimolar ratio, and spin-coated on a glass substrate to obtain a light absorbing layer.

(Examples 2, 3, and 4) Compound N in Example 1
o. No. 2 instead of No. 2. 4, 5 and 8, with benzthiazole, 1, 1 instead of benzimidazole, respectively
Spin coating was performed in the same manner as in Example 1 using 3-diiminoisoindoline and phthalimide, respectively, to obtain a light absorbing layer.

(Comparative Example 1) 2
Was dissolved in chloroform and spin-coated on a glass substrate to obtain a light absorbing layer.

Table 2 below shows the measurement results of the absorption coefficient of the film at the maximum absorption wavelength (λmax) and the refractive index at 635 nm of the light absorbing layers obtained in Examples 1 to 4 and Comparative Example 1.

[0046]

[Table 2]

(Embodiment 5) A depth of 1750 ° and a half width of 0.
The above Compound No. was placed on a 0.6 mm thick injection molded polycarbonate substrate having a guide groove with a track pitch of 22 μm and a track pitch of 0.74 μm. 5 and 2,5-dimethylbenzimidazole were mixed at a molar ratio of 1: 1. This was dissolved in a mixed solvent of methylcyclohexane, 2-methoxyethanol, methyl ethyl ketone, and tetrahydrofuran, and applied with a spinner to form an organic dye layer having a thickness of 1100 mm. Was formed. Next, gold was formed to a thickness of 1600 ° by a sputtering method to form a reflective layer. Further, a protective layer of acrylic photopolymer having a thickness of 7 μm was provided thereon to produce an optical recording medium.

(Examples 6 and 7) In Example 5, the recording layer was replaced with Compound Example No. In place of No. 5, respectively. 10, 13
And an optical recording medium was obtained in exactly the same manner as in Example 5.

(Comparative Examples 2, 3, and 4) No. 5, only No. 5 No. 10 only, 13
Only as in Example 5, a recording medium was obtained.

(Reproduction conditions) An oscillation wavelength of 63
Using a semiconductor laser of 5 nm and a beam diameter of 0.9 μm,
The EFM signal is recorded while tracking, and (linear speed 3.
5 m / sec) The laser and oscillation wavelength 635 nm
, And the modulation and the reflectance were measured. The results are shown in Table 3 below.

[0051]

[Table 3]

Example 8 Compound No. 1 shown in Table 1 above was used. 2
Of tetraazaporphyrin and tri-n-butylphosphine were dissolved in chloroform in an equimolar ratio, and spin-coated on a glass substrate to obtain a light absorbing layer.

(Examples 9, 10, 11) In Example 1, the compound No. No. 2 instead of No. 2 respectively. 4,
5 and 8, using triphenylphosphine, diethylphenylphosphine and chlorodiphenylphosphine instead of tri-n-butylphosphine, respectively.
A light absorbing layer was obtained by spin coating in the same manner as in Example 1.

(Comparative Example 5) Only 2 was dissolved in chloroform and spin-coated on a glass substrate to obtain a light absorbing layer.

Table 4 below shows the results of measurement of the absorption coefficient of the film at the maximum absorption wavelength (λmax) and the refractive index at 635 nm of the light absorbing layers obtained in Examples 8 to 11 and Comparative Example 5.

[0056]

[Table 4]

Example 12 The above Compound No. was placed on a 0.6 mm thick injection molded polycarbonate substrate having a guide groove with a depth of 1750 °, a half width of 0.22 μm and a track pitch of 0.74 μm. 5 and diethylphenylphosphine in a molar ratio of 1: 1 were dissolved in a mixed solvent of methylcyclohexane, 2-methoxyethanol, methyl ethyl ketone and tetrahydrofuran, and applied with a spinner to form an organic dye layer having a thickness of 1100 °. And then
Gold was formed to a thickness of 1600 ° by a sputtering method to form a reflective layer. Further, a protective layer of acrylic photopolymer having a thickness of 7 μm was provided thereon to produce an optical recording medium.

(Examples 13 and 14) The recording layer of Example 12 was replaced with Compound No. No. 5 instead of No. 5 respectively. 1
Using 0 and 13, a recording medium was obtained in the same manner as in Example 12.

(Comparative Examples 6, 7, and 8) No. 5, only No. 5 No. 10 only, 1
A recording medium was obtained in the same manner as in Example 12, except that the recording medium was only 3.

<Reproduction conditions> Using a semiconductor laser having an oscillation wavelength of 635 nm and a beam diameter of 0.9 μm on the recording medium thus obtained, an EFM signal was recorded while tracking (linear velocity: 3.5 m / sec). Reproduction was performed with continuous light of a semiconductor laser having an oscillation wavelength of 657 nm, and modulation and reflectance were measured. The evaluation results are shown in Table 5 below.

[0061]

[Table 5]

[0062]

As described above, according to the present invention, 700 nm
It has become possible to provide an optical recording medium that can be recorded and reproduced with laser light in the following wavelength ranges, has excellent jitter characteristics, has high reflectance, and has excellent light resistance and storage stability.

[Brief description of the drawings]

FIGS. 1A to 1D are explanatory diagrams showing a normal write-once optical recording medium.

FIGS. 2A to 2C are explanatory diagrams showing the configuration of a medium for CD-R.

FIGS. 3A to 3C are explanatory diagrams showing a medium configuration for a DVD-R.

[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 (72) Inventor Tsutomu Sato 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Noboru 1-3-6 Nakamagome, Ota-ku, Tokyo Share Inside Ricoh Company (72) Inventor Yasunobu Ueno 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company (72) Inventor Somu 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh F Terms (reference) 2H111 EA03 EA12 EA40 EA48 FA01 FA12 FA14 FA23 FA30 FA33 FB42 GA07 5D029 JA04 MA13 WB14 WC01 WD10

Claims (11)

[Claims] 1. An optical recording medium comprising a substrate and a light absorbing layer provided on a substrate, wherein the light absorbing layer has the following general formula (Ia, I-
b, Ic, Id) a metal tetraazaporphyrin compound (I) and a nitrogen-containing compound having an N atom or a phosphorus-containing compound having a P atom which can be coordinated to the metal tetraazaporphyrin compound An optical recording medium characterized by comprising: Embedded image (Wherein, X _{1 to} X ₄ each represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted alkoxy group, Or a substituted or unsubstituted phenyloxy group, Y _{1 to} Y ₄ are each a hydrogen atom,
Represents a 5-membered heterocyclic ring containing a halogen atom, substituted or unsubstituted one or more nitrogen atoms. The 5-membered heterocyclic ring may be condensed with another aromatic ring or a heterocyclic ring, and the 5-membered heterocyclic ring may be a nitrogen atom. An atom is bonded to the tetraazaporphyrin ring. However, at least one of Y _{1 to} Y ₄ is represented by the following general formula (II) or (III): Embedded image Wherein Z _{1 to} Z ₄ are each a substituted or unsubstituted carbon atom which forms a hetero 5-membered ring together with a carbon atom or a nitrogen atom bonded thereto. An atom or a nitrogen atom, and this 5-membered heterocyclic ring may be condensed with another aromatic ring. Z _{1 to} Z ₄ are not all nitrogen atoms, and Z _{5 to} Z ₇ are a carbon atom or nitrogen atom of a substituted or unsubstituted form a heterocyclic 5-membered ring together with the carbon atom or nitrogen atom are, Z ₁
To Z ₄ are not all nitrogen atoms, but are bonded to the tetraazaporphyrin ring at the nitrogen atom;
R '''' independently represents a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, an alkoxy group, an aryloxy group, a carboxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group. Represents a group or a substituted or unsubstituted acyl group. ) M represents a divalent metal, a trivalent or tetravalent substituted metal atom or a metal oxide. ) 2. The method according to claim 1, wherein the nitrogen-containing compound is -N = or -N <.
The optical recording medium according to claim 1, wherein the optical recording medium is a compound having a group. 3. The optical recording medium according to claim 1, wherein the nitrogen-containing compound is an imidazole derivative, a benzimidazole derivative or a thiazole derivative. 4. The method according to claim 1, wherein the phosphorus-containing compound is -P = group, -PH
The optical recording medium according to claim 1, wherein the optical recording medium is a compound having a-group or a -PPh- group (where Ph means a phenyl group). 5. The method according to claim 1, wherein the phosphorus-containing compound is (A) ₂ -P-
(CH ₂ ) _n -P- (A) ₂ (wherein A represents a substituted or unsubstituted aryl group, and n represents an integer of any one of 2 to 6). The optical recording medium according to claim 1, wherein: 6. The metal tetraazaporphyrin compound (I) has a central metal ion having a d-orbital electron number of 0, 1,
The optical recording medium according to any one of claims 1 to 5, wherein the optical recording medium is 2, 3, 4, 5, 6, 7 or 10. 7. The metal tetraazaporphyrin compound (I) has a central metal ion of Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Z
The optical recording medium according to any one of claims 1 to 6, wherein the optical recording medium is n2 ⁺ or Cd2 ⁺ . 8. The compound of formula (Ia), (Ib) or (I-) wherein the metal tetraazaporphyrin compound (I) is
The optical recording medium according to any one of claims 1 to 7, comprising at least one of c) and (Id). 9. The track pitch of the substrate is 0.7 to 0.7.
0.8 μm, groove half width 0.18 to 0.36 μm
The optical recording medium according to claim 1, wherein: 10. When the reflective layer has a reflective layer, the reflective layer is made of gold, silver,
The optical recording medium according to any one of claims 1 to 9, wherein the optical recording medium is copper, aluminum, or an alloy of these metals. 11. The optical recording medium according to claim 1, wherein a recording wavelength is from 720 to 600 nm.