JP2007045147A - Optical recording medium, optical recording material and metal complex compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical recording medium capable of recording and/or reproducing high density optical information using a short-wavelength laser light. <P>SOLUTION: The optical recording medium capable of recording and/or reproducing high density optical information using a short-wavelength laser light having a wave length of 350-530 nm comprises a recording layer formed on the substrate and containing a metal complex compound, wherein the metal complex compound is composed of a cyclic β-diketone azo compound represented by formula [I] or formula [II] and a divalent metal ion coordinated to the cyclic β-diketone azo compound. In formula [I] or formula [II], a ring A is a nitrogen-containing heteroaromatic ring. X, Y and Z in formula [I], and X' and Y' in formula [II] are independently respectively any one sort chosen from a carbon atom, an oxygen atom, a sulfur atom and a nitrogen atom that may have substituents, and form a five members ring or six members ring with a β-diketone structure. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical recording medium and the like, and more particularly, to an optical recording medium and the like excellent in light resistance that can be applied to a blue laser.

At present, various optical recording media such as CD-R / RW, DVD-R / RW, and MO can store a large amount of information, and are easily accessible at random like DVD-RAM. It is widely recognized and widely used as an external storage device. Among these, the write-once optical recording media CD-R and DVD-R are low cost and easy to manufacture as an organic dye-based optical recording medium provided with a recording layer containing an organic dye compound. In that respect, it is considered to have an advantage.
In general, in the case of an optical recording medium marketed as a CD-R, DVD-R, etc., for example, in the case of a CD-R, a DVD-DVD is suitable for recording / reproducing information with a laser beam having a wavelength of about 780 nm. In the case of -R, it is designed to be suitable for recording / reproducing information with a laser beam having a wavelength of about 600 nm to 700 nm. As such a recording dye for CD-R and DVD-R, for example, an azo compound is used (see Patent Document 1, Patent Document 2, and Patent Document 3).

International Publication No. 91/018950 JP 09-277703 A JP 2001-271001 A

On the other hand, it is desired to increase the recording density of the medium by increasing the amount of information handled. In particular, in recent years, optical recording media capable of recording / reproducing information with high density by using laser light having a short oscillation wavelength such as blue laser light, which has been remarkably developed, are being proposed.
In response to such a request, a conventional optical recording medium that optically records and reproduces information using a relatively long wavelength laser beam attempts to record and reproduce information using a shorter wavelength laser beam. However, there is a problem that the reflectivity is lowered and it is difficult to perform sufficient recording / reproduction.

  For example, in the optical recording medium described in Patent Document 1, an azo compound having a coupler component of an N, N-dialkylaniline skeleton is used as a recording dye. By having such an N, N-dialkylaniline skeleton, a dye having a very large molar extinction coefficient tends to be obtained. However, the absorption spectrum of the azo metal chelate compound solution that is a complex of such an azo compound and a metal is observed when λmax is 500 nm or more. For this reason, the absorption spectrum of the coating film containing a dye composed of such a metal-containing azo complex compound is hardly observed near the laser wavelength of 405 nm and tends to be less sensitive to blue laser light. There's a problem.

  In the optical recording medium described in Patent Document 2, an azo compound having a pyridone skeleton coupler component is used as a recording dye. The absorption spectrum of such an azo compound is known to have λmax on the shorter wavelength side, but the absorption spectrum of a metal chelate compound of a azo compound having a benzothiazole or thiazole skeleton as a diazo component and a metal is Absorption near the laser wavelength of 405 nm is small.

  Further, in Patent Document 3, a metal-containing azo complex compound, which is a complex of an azo compound having a chain β-diketone skeleton containing a β-ketoester or the like as a coupler component and a metal, has absorption spectrum absorption on the short wavelength side. It has been reported to be observed. However, azo compounds having such a chain β-diketone skeleton as a coupler component have problems to be improved in production such as low yield during synthesis, difficulty in solidification, or low product purity. There is a problem that further examination is required.

  Furthermore, the present inventors have developed a blue light having a laser wavelength of 350 nm to 530 nm by using a metal azo chelate dye of a metal and an azo compound having a diazo component such as isoxazole and a coupler component such as pyridone whose absorption is observed on the short wavelength side. It was reported that the region has absorption (Japanese Patent Application No. 2005-95905). However, as the investigation further proceeds, this azo compound has a limitation in the optimum combination of the coupler component and the diazo component, so the molecular design is limited, and it is difficult to further shorten the wavelength due to the molecular structure. It has also been found that the light resistance of azo compounds using isoxazole as the diazo component needs to be further improved.

As described above, the present invention solves the problem which has been highlighted when developing an optical recording medium on which high-density optical information is recorded and / or reproduced using blue laser light having a short wavelength. It was made.
That is, an object of the present invention is to provide an optical recording medium capable of recording and / or reproducing high-density optical information using a short wavelength laser beam.
Another object of the present invention is to provide an optical recording material capable of recording optical information using a short wavelength laser beam.
Furthermore, another object of the present invention is to provide a metal complex compound useful as an optical recording material.

As a result of intensive studies, the present inventors have found that diazo compounds having a cyclic β-diketone structure as a coupler component exhibit high-sensitivity absorption on the short wavelength side, and have completed the present invention based on such findings.
Thus, according to the present invention, there is provided a substrate, and a recording layer provided on the substrate directly or via another layer and capable of recording and / or reproducing information by being irradiated with light. The layer includes an azo compound having a coupler component having a cyclic β-diketone structure and a diazo component having a nitrogen-containing heteroaromatic ring structure, and a metal complex compound composed of a metal ion coordinated with the azo compound. A recording medium is provided.

  Here, in the optical recording medium to which the present invention is applied, the azo compound constituting the metal complex compound contained in the recording layer includes a coupler component having a cyclic β-diketone structure and a diazo component having a nitrogen-containing heteroaromatic ring structure. Although it will not be limited if it is a compound which has, from a viewpoint of stability of a compound and the ease of synthesis | combination, as a coupler structure, a 5-membered ring-a 7-membered ring are preferable. Among these, a cyclic β-diketone azo compound represented by the following general formula [I] or general formula [II] is preferable. By including such a cyclic β-diketone azo compound in the recording layer, an optical recording medium capable of recording and / or reproducing high-density optical information using a short wavelength laser beam can be obtained.

(In General Formula [I] or General Formula [II], Ring A is a nitrogen-containing heteroaromatic ring. X, Y, Z in General Formula [I] and X ′, Y ′ in General Formula [II] Are each independently any one selected from a carbon atom, an oxygen atom, a sulfur atom, and a nitrogen atom that may have a substituent, and these have a 5- or 6-membered ring together with a β-diketone structure. Form.)
As the coupler component in the cyclic β-diketone azo compound, those having a cyclic β-diketone structure having a saturated or unsaturated 5-membered to 7-membered hydrocarbon ring or heterocyclic condensed ring are preferable.

Further, as the diazo component, those having a nitrogen-containing heteroaromatic ring structure consisting of a 5-membered or 6-membered monocyclic ring or a 5-membered or 6-membered 2-condensed ring are preferable.
Further, as the metal ion, a divalent metal ion selected from Group 7A, Group 8, Group 1B and Group 2B of the periodic table is preferable, and in particular, at least one selected from nickel, cobalt, zinc, copper, and manganese. Metal ions are preferred.

  An optical recording medium to which the present invention is applied includes a complex compound of an azo compound having such a cyclic β-diketone structure and a metal, and a recording layer is provided, thereby using a laser beam having a wavelength of 350 nm to 530 nm, Information can be recorded.

Further, according to the present invention, a metal-containing cyclic β-compound composed of an azo compound having a coupler component having a cyclic β-diketone structure and a diazo component having a nitrogen-containing heteroaromatic ring structure, and a metal ion coordinated by the azo compound. An optical recording material containing a diketone azo compound and other components as required is provided.
In addition, in a metal complex compound composed of an azo compound having a cyclic β-diketone structure bonded to an azo group and a nitrogen-containing heteroaromatic ring and a divalent metal ion, the cyclic β-diketone structure includes Meldrum's acid, tetron Those having any one skeleton selected from acid, barbituric acid, thiobarbituric acid, hydroxycoumarin, hydroxycarbostyril, pyrazolidinedione, indandione, cyclohexanedione and diketopyrimidine are preferred.

  According to the present invention, an optical recording medium capable of recording and / or reproducing high-density optical information using a short wavelength laser beam is provided.

Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the invention. Also, the drawings used are used to describe the present embodiment and do not represent the actual size.
Moreover, in this Embodiment, R < ₁ > -R < ₂₅ > defined by the structural formula mentioned later may have a substituent as needed. However, in this case, the “substituent” in the description “substituent”, “may be substituted”, and “may have a substituent” described later includes, for example, a carboxyl group, a sulfonic acid group, etc. The water-soluble group is not contained.

(Azo compound)
The cyclic β-diketone azo compound used in the present embodiment (hereinafter sometimes simply referred to as “azo compound”) includes a coupler component having a cyclic β-diketone structure and a diazo component having a nitrogen-containing heteroaromatic ring structure. Although it will not be limited if it is a compound which has, as mentioned above, it is preferable that it has a structure represented by the following general formula [I] or general formula [II]. Here, in the general formula [I] or [II], the nitrogen-containing heteroaromatic ring on the left side of the azo group (—N═N—) is generally referred to as a diazo component, and the cyclic β-diketone structure on the right side is a coupler. Called ingredients. These structures are keto-enol tautomeric structures. For example, the structure of the general formula [I] can have the following structures. In the text, the keto-enol tautomeric structure is coordinated in the form of -O- when the enol hydrogen atom is removed when forming a complex with a metal ion. Therefore, the enol type is unified.

(Coupler component)
First, the coupler component will be described.
X, X ′, Y, Y ′ and Z in the coupler component of the azo compound represented by the general formula [I] or [II] may each independently have a substituent other than a hydrogen atom. Represents any one of good carbon atom, oxygen atom, sulfur atom, nitrogen atom represented by N—R ₁ , C═O, C═S, C═NR ₂ , and 5-membered ring structure together with β-diketone structure Alternatively, a 6-membered cyclic β-diketone structure is formed. Here, R ₁ is represented by a hydrogen atom, a linear or branched alkyl group, a cyclic alkyl group, an aralkyl group, an aryl group, a heterocyclic group, an acyl group represented by —COR ₃ , or —NR ₄ R _5. Any one of the following amino groups. R ₂ represents a hydrogen atom, a linear or branched alkyl group, or an aryl group. R ₃ represents a hydrocarbon group or a heterocyclic group. R ₄ and R ₅ represent a hydrogen atom, a hydrocarbon group or a heterocyclic group. In addition, these alkyl chain parts and the alkyl chain part of the aralkyl group may be substituted with the same substituent as the above-mentioned substituted alkyl chain.

  Specific examples of the cyclic β-diketone structure include, for example, cyclohexanedione, meldrum acid, cyclopentadione, pyrazolidinedione, tetronic acid, tetramic acid, barbituric acid, thiobarbituric acid, indandione, 4-hydroxy- Examples include α-pyrone, 4-hydroxy-α-pyridone, 4-hydroxycoumarin, and a structure representing 4-hydroxycarbostyril.

  Here, the combinations and arrangements selected as X, X ′, Y, Y ′, and Z are not particularly limited. However, when each is connected by a single bond, for example, the structures shown below are exemplified.

  When X, X ', Y, Y' and Z represent a carbon atom, it may further have an alkyl chain as a substituent other than a hydrogen atom. In this case, the alkyl chain may be one kind, two kinds of the same kind, or a combination of different kinds. Further, it may be cyclic at the tip of the carbon atom to form a spiro ring. As an example of such a structure, as shown below, an example in which an alkyl chain is introduced as a substituent when X and Z are oxygen atoms and Y is a carbon atom is shown.

  The alkyl chain as a substituent preferably has about 1 to 16 carbon atoms. When the length of the alkyl chain as a substituent is excessively long, the product tends to be difficult to solidify, and the gram extinction coefficient representing the absorbance per unit weight tends to decrease.

When X, X ′, Y, Y ′, and Z are a carbon atom or a nitrogen atom represented by N—R ₁ , the adjacent bonds may be a single bond or a double bond. . Examples of the structure having an unsaturated bond include the following structures.

Further, when X, X ′, Y, Y ′ and Z are carbon atoms, a nitrogen atom represented by N—R ₁ , and C═NR ₂ , adjacent ones are condensed with each other to form saturated or unsaturated carbonized carbon. A hydrogen ring or a heterocyclic ring may be formed. Examples of such a structure include the following structures.

  Among these condensed structures, preferred structures are saturated or unsaturated 5-membered to 7-membered hydrocarbon rings or heterocyclic rings, and particularly preferred are adjacent X, X ′, Y and Y ′. Z is a carbon atom, and a 6-membered saturated or unsaturated hydrocarbon ring is formed.

  Particularly preferable structures as such a structure represented by X, X ′, Y, Y ′, and Z are cyclohexanedione, meldrum acid, cyclopentadione, pyrazolidinedione, tetronic acid, tetramic acid, shown below, Examples include barbituric acid, thiobarbituric acid, indandione, 4-hydroxy-α-pyrone, 4-hydroxy-α-pyridone, diketopyrimidine, 4-hydroxycoumarin, and 4-hydroxycarbostyril.

(Diazo component)
Next, the diazo component will be described.
In general formula [I] or general formula [II], ring A in the diazo component represents a nitrogen-containing heteroaromatic ring formed together with the carbon atom and nitrogen atom to which ring A is bonded. The structure of the nitrogen-containing heteroaromatic ring may be a monocyclic ring or a condensed ring as long as it has a nitrogen atom at a coordinateable position. As an aromatic ring, the nitrogen-containing heteroaromatic ring shown below is mentioned, for example.

D _{1 to} D ₉ in the nitrogen-containing heteroaromatic ring described above are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a cyclic alkyl group having 3 to 9 carbon atoms. , An aralkyl group having 7 to 12 carbon atoms, or an acyl group represented by —COR ₃ .

  In these structures, the ring A structure is preferably a 5-membered to 6-membered monocyclic or bicondensed nitrogen-containing heteroaromatic ring from the viewpoint of absorption wavelength and solubility. Particularly preferred among these are isoxazole, triazole, oxazole, thiadiazole, pyrazole, pyridine, pyrimidine, imidazole, thiazole, isothiazole, benzothiazole, benzisoxazole, benzoxazole, and benzimidazole.

  In general formula [I] and general formula [II], ring A may have any substituent except a hydrogen atom. Examples of these substituents include the following. For example, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-heptyl group, etc. A chain or branched alkyl group; an optionally substituted cyclic alkyl group having 3 to 18 carbon atoms, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group; a substituted vinyl group, a propenyl group, a hexenyl group, etc. A linear or branched alkenyl group having 2 to 18 carbon atoms which may be substituted; a cyclic alkenyl group having 3 to 18 carbon atoms which may be substituted, such as a cyclopentenyl group or a cyclohexenyl group; a 2-thienyl group, Saturated or unsaturated heterocyclic group which may be substituted such as 2-pyridyl group, 4-piperidyl group, morpholino group; phenyl group, tolyl group, xylyl group Aryl group having 6 to 18 carbon atoms such as mesityl group and naphthyl group; aralkyl group having 7 to 20 carbon atoms such as benzyl group and phenethyl group; methoxy group and ethoxy group A linear or branched alkoxy group having 1 to 18 carbon atoms which may be substituted, such as a group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, etc .; propenyloxy A straight chain or branched alkenyloxy group having 3 to 18 carbon atoms which may be substituted, such as a group, butenyloxy group, pentenyloxy group; methylthio group, ethylthio group, n-propylthio group, n-butylthio group, sec- Examples of the substituted or unsubstituted alkylthio group having 1 to 18 carbon atoms, such as a butylthio group and a tert-butylthio group. It is.

Furthermore, other specific examples include halogen atoms such as fluorine atom, chlorine atom, bromine atom, nitro group, cyano group, mercapto group, hydroxy group, formyl group, acyl group represented by —COR ₃ ; —NR ₄ An amino group represented by R ₅ ; an acylamino group represented by —NHCOR ₆ ; a carbamate group represented by —NHCOOR ₇ ; a carboxylic acid ester group represented by —COOR ₈ ; an acyloxy group represented by —OCOR ₉ Carbamoyl group represented by -CONR ₁₀ R ₁₁ ; sulfonyl group represented by -SO ₂ R ₁₂ ; sulfinyl group represented by -SOR ₁₃ ; sulfamoyl group represented by -SO ₂ NR ₁₄ R ₁₅ ; Examples thereof include a sulfonic acid ester group represented by SO ₃ R ₁₆ ; a sulfonamide group represented by —NHSO ₂ R ₁₇ . The bonding position of these substituents is not particularly limited, and the number of substituents can be from unsubstituted to plural. When it has a plurality of substituents, it may be the same or different.

Here, in the substituents described above, R ₃ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₂ , R ₁₃ , R ₁₆ , R ₁₇ represent a hydrocarbon group or a heterocyclic group, and R ₄ , R ₅ , R ₁₀ , R ₁₁ , R ₁₄ , and R ₁₅ represent any one of a hydrogen atom, a hydrocarbon group, and a heterocyclic group. These may be substituted as necessary.

Examples of such hydrocarbon groups represented by R _{3 to} R ₁₇ include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, and an n-to group. C1-C18 straight chain or branched alkyl group such as ptyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, etc., C3-C18 cyclic alkyl group, vinyl group, propenyl A straight chain or branched alkenyl group having 2 to 18 carbon atoms such as a hexenyl group, a cyclic alkenyl group having 3 to 18 carbon atoms such as a cyclopentenyl group or a cyclohexenyl group, a benzyl group, a phenethyl group, etc. C6-C18 aryl groups, such as a C7-C20 aralkyl group, a phenyl group, a tolyl group, a xylyl group, a mesityl group, are mentioned. The alkyl chain part and the aryl group part of these groups may be further substituted with a substituent which the alkyl chain part of R _{2 to} R ₅ described later may have.

The heterocyclic group represented by R _{3 to} R ₁₇ is a saturated heterocyclic ring such as 4-piperidyl group, morpholino group, 2-morpholinyl group, piperazyl group; 2-furyl group, 2-pyridyl group, 2-thiazolyl. And aromatic heterocycles such as 2-quinolyl group. These may contain a plurality of heteroatoms, may further have a substituent, and may have any bonding position. As the heterocyclic ring, a 5-membered to 6-membered saturated heterocyclic ring, a 5-membered to 6-membered monocyclic ring, and a 2-fused aromatic heterocyclic ring thereof are preferable structures.

Next, the above-mentioned acyl group, amino group, acylamino group, carbamate group, carboxylic acid ester group, acyloxy group, carbamoyl group, sulfonyl group, sulfinyl group, sulfamoyl group, sulfonic acid ester group, sulfonamide group are specifically described. The compound structure is illustrated.
Examples of the acyl group (—COR ₁₁ ) include functional groups having the following structures.

Examples of the amino group (—NR ₁₂ R ₁₃ ) include functional groups having the following structures.

Examples of the acylamino group (—NHCOR ₁₄ ) include functional groups having the following structures.

Examples of the carbamate group (—NHCOOR ₁₅ ) include functional groups having the following structure.

Examples of the carboxylic acid ester group (—COOR ₁₆ ) include functional groups having the following structures.

Examples of the acyloxy group (—OCOR ₁₇ ) include functional groups having the following structures.

Examples of the carbamoyl group (—CONR ₁₈ R ₁₉ ) include functional groups having the following structures.

Examples of the sulfonyl group (—SO ₂ R ₂₀ ) include functional groups having the following structures.

Examples of the sulfinyl group (—SOR ₂₁ ) include functional groups having the following structures.

Examples of the sulfamoyl group (—SO ₂ NR ₂₂ R ₂₃ ) include functional groups having the following structures.

Examples of the sulfonate group (—SO ₃ R ₂₄ ) include functional groups having the following structures.

Examples of the sulfonamide group (—NHSO ₂ R ₂₅ ) include functional groups having the following structures.

In the general formula [I] or [II] described above, a linear or branched alkyl group, a cyclic alkyl group, a linear or branched alkenyl group, a cyclic alkenyl group, a linear or branched alkoxy group as a substituent. The linear or branched alkylthio group and the alkyl chain portion of the alkyl group represented by R _{3 to} R ₁₇ may further have a substituent. Examples of such substituents include alkoxy having 1 to 10 carbon atoms such as methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, and tert-butoxy group. Groups: methoxymethoxy groups, ethoxymethoxy groups, propoxymethoxy groups, ethoxyethoxy groups, propoxyethoxy groups, methoxybutoxy groups, etc., alkoxyalkoxy groups having 2 to 12 carbon atoms; methoxymethoxymethoxy groups, methoxymethoxyethoxy groups, methoxy groups An alkoxyalkoxyalkoxy group having 3 to 15 carbon atoms such as ethoxymethoxy group and ethoxyethoxymethoxy group; an aryloxy group having 6 to 12 carbon atoms such as phenoxy group, tolyloxy group, xylyloxy group and naphthyloxy group; Group, vinyloki Alkenyloxy group having a carbon number of 2 to 12 carbon atoms such group and the like.

  Further, as other substituents, heterocyclic groups such as 2-thienyl group, 2-pyridyl group, 4-piperidyl group, morpholino group; cyano group; nitro group; hydroxyl group; mercapto group; methyl mercapto group, ethyl mercapto group Alkylthio groups such as amino group, N, N-dimethylamino group, N, N-diethylamino group and the like, alkylamino groups having 1 to 10 carbon atoms; methylsulfonylamino group, ethylsulfonylamino group, n-propylsulfonyl An alkylsulfonylamino group having 1 to 6 carbon atoms such as an amino group; a halogen atom such as a fluorine atom, a chlorine atom, or a bromine atom; an alkylcarbonyl group such as a methylcarbocarbonyl group, an ethylcarbonyl group, or an isopropylcarbonyl group; a methoxycarbonyl group; Ethoxycarbonyl group, n-propoxycarbonyl group, isopropyl C2-C7 alkoxycarbonyl groups such as xyloxycarbonyl, n-butoxycarbonyl; methylcarbonyloxy, ethylcarbonyloxy, n-propylcarbonyloxy, isopropylcarbonyloxy, n-butylcarbonyloxy A C2-C7 alkylcarbonyloxy group such as methoxycarbonyloxy group, ethoxycarbonyloxy group, n-propoxycarbonyloxy group, isopropoxycarbonyloxy group, n-butoxycarbonyloxy group, etc. Examples thereof include an alkoxycarbonyloxy group having 7 carbon atoms.

Although it does not specifically limit as a substituent which the ring A in a diazo component has, From points, such as the ease of a synthesis | combination and the solubility to a coating solvent, as a preferable thing, a hydrogen atom, carbon number 1-carbon number is preferable. 12 linear or branched alkyl groups, C3-C10 cyclic alkyl groups, C2-C12 linear or branched alkenyl groups, C7-C18 aralkyl groups, carbon A linear or branched alkoxy group having 1 to 12 carbon atoms, a linear or branched alkylthio group having 1 to 12 carbon atoms, an aryl group having 6 to 18 carbon atoms, a saturated or unsaturated heterocyclic group , halogen atom, a nitro group, a cyano group, a mercapto group, hydroxy group, formyl group, acyl group represented by -COR _11, an amino group represented by _-NR 4 _{R 5;} reed represented by -NHCOR ₆ A carbamoyl group represented by _-CONR 10 _{R 11;;} acyloxy group represented by -OCOR _9; carboxylic acid ester group represented by -COOR _8; carbamate group represented by -NHCOOR _7; amino group -SO ₂ sulfonic acid ester group represented by -SO _{3 R 16;;} sulfamoyl group represented by -SO _{2 NR} 14 _{R 15;} sulfinyl group represented by -SOR _13; sulfonyl group represented by R ₁₂ -NHSO ₂ And a sulfonamide group represented by R ₁₇ .

The molecular weight of the azo compound represented by the general formula [I] or [II] is preferably 1000 or less, and particularly preferably 700 or less. If the molecular weight is excessively large, the Gram extinction coefficient decreases, and the absorption becomes small relative to the amount of the dye, which is not preferable.
Preferable examples of the azo compound represented by the general formula [I] or the general formula [II] include the following compounds ((1) to (189)).

(metal)
Next, a metal that forms a metal-containing cyclic β-diketone azo compound that is a metal complex compound by coordination with an azo compound represented by the general formula [I] or [II] will be described.
The metal that forms a metal-containing cyclic β-diketone azo compound by coordination with the azo compound represented by the general formula [I] or [II] is not particularly limited as long as it has the ability to form a coordination with the azo compound. These may be transition elements or typical elements, and their oxidation numbers are not limited. In addition, the ratio of the metal to the azo compound in the metal-containing cyclic β-diketone azo compound is not particularly limited, and a complex may be formed including a counter ion having a charge in addition to the azo compound and the metal. Examples of such metals include metals selected from Group 7A, Group 8, 1B, and 2B of the periodic table. Among these, nickel, cobalt, copper, iron, zinc, manganese, platinum, palladium and the like are preferable.

(Metal complex compound)
As described above, the azo compound represented by the general formula [I] or the general formula [II] coordinates with a metal having coordination ability with the azo compound to form a metal complex compound. In a complex structure formed by an azo compound and a metal, a preferable structure is a divalent transition because the azo compound is likely to be a tridentate ligand having a (−1) -valent charge, and thus the complex is easily formed. A structure in which the metal 1 is coordinated at a ratio of the azo compound 2 (6-coordinate structure) is preferable. Among these, a coordination structure with a divalent transition metal such as nickel, cobalt, copper, iron, zinc, or manganese is particularly preferable. Further, a metal-containing cyclic β-diketone azo compound in which a plurality of types of azo compounds are coordinated to a metal as a ligand may be used, and the recording layer may contain a plurality of types of metal-containing cyclic β-diketone azo compounds.

  Examples of such metal complex compounds include those shown below. That is, a metal having as a ligand an azo compound comprising a Meldrum acid coupler component and a diazo component selected from isoxazole, benzisoxazole, pyrazole, triazole, imidazole, benzimidazole, thiazole, benzothiazole thiadiazole, and pyridine. Complex compound: An azo compound comprising a tetronic acid coupler component and a diazo component selected from isoxazole, benzisoxazole, pyrazole, triazole, imidazole, benzimidazole, thiazole, benzothiazole thiadiazole, and pyridine as a ligand. Metal complex compound; hydroxycoumarin coupler component and isoxazole, benzisoxazole, pyrazole, triazole, imidazole, benzimidazole, thiazole, A metal complex compound having a azo compound consisting of a diazo component selected from zothiazole thiadiazole and pyridine as a ligand; a hydroxycarbostyryl coupler component, and isoxazole, benzisoxazole, pyrazole, triazole, imidazole, benzimidazole, A metal complex compound having an azo compound consisting of a diazo component selected from thiazole, benzothiazole thiadiazole and pyridine as a ligand; selected from an indandion coupler component and isoxazole, benzisoxazole, pyrazole, triazole, benzimidazole A metal complex compound having a azo compound as a ligand, a barbituric acid coupler component, and isoxazole, benzisoxazole, pyrazole, triazole A metal complex compound having a azo compound as a ligand comprising a diazo component selected from benzimidazole; a thiobarbituric acid coupler component, and a diazo component selected from isoxazole, benzisoxazole, pyrazole, triazole, and benzimidazole And metal complex compounds having an azo compound consisting of Thus, there is a possibility that the wavelength, absorbance, and solubility of the absorption band of the metal complex compound can be adjusted to desired ones by appropriately combining the diazo component and the coupler component.

(Optical recording medium)
Next, an optical recording medium to which this embodiment is applied will be described. The optical recording medium to which the present embodiment is applied includes at least a metal-containing cyclic β-diketone azo compound in which a metal is coordinated to a substrate and an azo compound represented by the general formula [I] or [II] And a recording layer containing simply “metal-containing cyclic β-diketone azo compound”. If necessary, an undercoat layer, a reflective layer, a protective layer, and the like may be further provided.

  FIG. 1 is a diagram for explaining a first embodiment (in this example, a CD-R is shown) of an optical recording medium 100 to which the present embodiment is applied. An optical recording medium 100 shown in FIG. 1 includes a substrate 10 made of a light transmissive material having guide grooves 11 and an information recording layer 20 provided on the substrate 10. The information recording layer 20 includes a recording layer 21, and a reflective layer 22 and a protective layer 23 stacked on the recording layer 21 in order. In the optical recording medium 100, information is recorded and / or reproduced by laser light emitted from the substrate 10 side. For convenience of explanation, in the optical recording medium 100, the side where the protective layer 23 is present is the upper side, the side where the substrate 10 is present is the lower side, and the surfaces of each layer corresponding to these directions are the upper and lower surfaces of each layer, respectively. It is said.

(Substrate 10)
Various materials can be used for the substrate 10 as long as the material is basically transparent at the wavelengths of recording light and reproducing light. Specific examples include resins such as acrylic resins, methacrylic resins, polycarbonate resins, polyolefin resins (particularly amorphous polyolefins), polyester resins, polystyrene resins, and epoxy resins; and glass. Moreover, the structure which provided the resin layer which consists of radiation curable resins, such as photocurable resin, on glass is mentioned. Among these, from the viewpoints of high productivity, cost, moisture absorption resistance, etc., the polycarbonate resin used in the injection molding method, and from the viewpoints of chemical resistance and moisture absorption resistance, amorphous polyolefin is preferable. Furthermore, glass is preferable from the viewpoint of high-speed response and the like. When the resin substrate 10 is used, or when the substrate 10 provided with a resin layer on the side in contact with the recording layer 21 (upper side) is used, a guide groove or pit for recording / reproducing light may be formed on the upper surface. Good. Examples of the shape of the guide groove include a concentric shape and a spiral shape based on the center of the optical recording medium 100. When forming spiral guide grooves, the groove pitch is preferably about 0.2 μm to 1.2 μm.

(Recording layer 21)
The recording layer 21 is formed directly on the upper side of the substrate 10 or on the upper side of an undercoat layer or the like provided on the substrate 10 as necessary, and is formed of an azo compound represented by the general formula [I] or the general formula [II]. Metal-containing cyclic β-diketone azo compounds coordinated with metals are included. Examples of the method for forming the recording layer 21 include various commonly used thin film forming methods such as a vacuum deposition method, a sputtering method, a doctor blade method, a casting method, a spin coating method, and an immersion method. From the viewpoint of mass productivity and cost, the spin coating method is preferable, and from the viewpoint of obtaining the recording layer 21 having a uniform thickness, the vacuum evaporation method or the like is more preferable than the coating method. In the case of film formation by a spin coating method, the rotation speed is preferably 500 rpm to 15000 rpm. Further, if necessary, after spin coating, a treatment such as heating or application to solvent vapor may be performed.

  When the recording layer 21 is formed by a coating method such as a doctor blade method, a casting method, a spin coating method, or a dipping method, the coating solvent used for dissolving the metal-containing cyclic β-diketone azo compound and coating the substrate 10 is as follows. Any solvent that does not erode the substrate 10 is not particularly limited. Specifically, for example, ketone alcohol solvents such as diacetone alcohol and 3-hydroxy-3-methyl-2-butanone; cellosolv solvents such as methyl cellosolve and ethyl cellosolve; chain forms such as n-hexane and n-octane Hydrocarbon solvents: Cyclic hydrocarbon solvents such as cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, n-butylcyclohexane, tert-butylcyclohexane, cyclooctane; tetrafluoropropanol, octafluoropentanol, hexafluorobutanol, etc. Examples include perfluoroalkyl alcohol solvents; hydroxycarboxylic acid ester solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate.

When using the vacuum evaporation method, for example, the metal-containing cyclic β-diketone azo compound and, if necessary, recording layer components such as other dyes and various additives are put in a crucible installed in a vacuum vessel, After evacuating the inside of this vacuum vessel to about 10 ⁻² Pa to 10 ⁻⁵ Pa with an appropriate vacuum pump, the crucible is heated to evaporate the recording layer components, and vapor deposition is performed on the substrate placed facing the crucible. Thereby, the recording layer 21 is formed.

  In addition to the metal-containing cyclic β-diketone azo compound, the recording layer 21 includes various additives such as transition metal chelate compounds (for example, acetylacetonate chelate, for the purpose of improving stability and light resistance). A singlet oxygen quencher such as bisphenyldithiol, salicylaldehyde oxime, bisdithio-α-diketone), or a recording sensitivity improver such as a metal compound to improve recording sensitivity. Also good. Here, the metal compound refers to a compound in which a metal such as a transition metal is included in the compound in the form of atoms, ions, clusters, etc., for example, ethylenediamine complex, azomethine complex, phenylhydroxyamine complex, phenanthroline complex. Organic metal compounds such as dihydroxyazobenzene complex, dioxime complex, nitrosoaminophenol complex, pyridyltriazine complex, acetylacetonate complex, metallocene complex, and porphyrin complex. Although it does not specifically limit as a metal atom, It is preferable that it is a transition metal.

  The recording layer 21 may be used in combination with a plurality of metal-containing cyclic β-diketone azo compounds as required. Furthermore, in addition to the metal-containing cyclic β-diketone azo compound, other types of dyes may be used in the recording layer 21 as necessary. Other dyes are not particularly limited as long as they have appropriate absorption mainly in the oscillation wavelength region of the recording laser light. Further, it is used for CD-R and the like, and is used for dyes suitable for recording and reproduction using near-infrared laser light having an oscillation wavelength in the wavelength band of 770 to 830 nm, DVD-R and the like, and 620 to 690 nm. By including in the recording layer 21 a dye suitable for recording / reproduction using a red laser beam having an oscillation wavelength in the wavelength band in combination with the metal-containing cyclic β-diketone azo compound, a plurality of types belonging to different wavelength bands It is also possible to manufacture an optical recording medium 100 that supports recording / reproduction using the above laser beam.

  Other dyes other than metal-containing cyclic β-diketone azo compounds include metal-containing azo dyes, benzophenone dyes, phthalocyanine dyes, naphthalocyanine dyes, cyanine dyes, azo dyes, squarylium dyes, metal-containing India Examples include aniline dyes, triarylmethane dyes, merocyanine dyes, azurenium dyes, naphthoquinone dyes, anthraquinone dyes, indophenol dyes, xanthene dyes, oxazine dyes, and pyrylium dyes.

  Furthermore, a binder, a leveling agent, an antifoaming agent, etc. can also be used together as needed. Preferable binders include polyvinyl alcohol, polyvinyl pyrrolidone, nitrocellulose, cellulose acetate, ketone resin, acrylic resin, polystyrene resin, urethane resin, polyvinyl butyral, polycarbonate, polyolefin and the like.

  The film thickness of the recording layer 21 is not particularly limited because a suitable film thickness varies depending on the recording method or the like. However, since a certain amount of film thickness is required to enable recording, usually at least It is 1 nm or more, preferably 5 nm or more. However, if it is too thick, there is a possibility that recording cannot be performed satisfactorily, and it is usually 300 nm or less, preferably 200 nm or less, more preferably 100 nm or less.

  The reflective layer 22 is formed on the recording layer 21. The thickness of the reflective layer 22 is preferably 50 nm to 300 nm. As the material of the reflective layer 22, a material having a sufficiently high reflectance at the wavelength of the reproduction light, for example, a metal such as Au, Al, Ag, Cu, Ti, Cr, Ni, Pt, Ta, Pd, alone or an alloy Can be used. Among these, Au, Al, and Ag have high reflectivity and are suitable as the material for the reflective layer 22. In addition to these metals as main components, other materials may be added. Here, the main component means one having a content of 50% or more.

  Examples of materials other than the main component include Mg, Se, Hf, V, Nb, Ru, W, Mn, Re, Fe, Co, Rh, Ir, Cu, Zn, Cd, Ga, In, Si, Mention may be made of metals and semi-metals such as Ge, Te, Pb, Po, Sn, Bi, Ta, Ti, Pt, Pd, Nd. Among them, those containing Ag as a main component are particularly preferable because they are low in cost, easily produce high reflectivity, and obtain a beautiful white background when a print receiving layer described later is provided.

  For example, an alloy containing about 0.1 atomic% to 5 atomic% of one or more selected from Au, Pd, Pt, Cu, and Nd in Ag has high reflectivity, high durability, high sensitivity, and low cost. It is preferable. Specifically, for example, an AgPdCu alloy, an AgCuAu alloy, an AgCuAuNd alloy, an AgCuNd alloy, or the like. As a material other than the metal, a low refractive index thin film and a high refractive index thin film can be alternately stacked to form a multilayer film, and this can be used as the reflective layer 22.

  Examples of the method for forming the reflective layer 22 include sputtering, ion plating, chemical vapor deposition, and vacuum vapor deposition. Also, a known inorganic or organic intermediate layer or adhesive layer may be provided on the substrate 10 or under the reflective layer 22 in order to improve reflectivity, improve recording characteristics, improve adhesion, or the like. it can.

  The protective layer 23 is formed on the reflective layer 22. The material of the protective layer 23 is not particularly limited as long as it protects the reflective layer 22 from external force. Examples of the material of the organic substance include a thermoplastic resin, a thermosetting resin, an electron beam curable resin, and an ultraviolet curable resin.

Examples of the inorganic substance include silicon oxide, silicon nitride, MgF ₂ and SnO ₂ . When a thermoplastic resin, a thermosetting resin, or the like is used, the protective layer 23 can be formed by applying a coating solution prepared by dissolving in a suitable solvent on the reflective layer 22 and drying it. When an ultraviolet curable resin is used, it is directly applied on the reflective layer 22, or a coating solution prepared by dissolving in an appropriate solvent is applied on the reflective layer 22 and cured by irradiation with ultraviolet light. Thus, the protective layer 23 can be formed.

  As the ultraviolet curable resin, for example, acrylate resins such as urethane acrylate, epoxy acrylate, and polyester acrylate can be used. These materials may be used alone or as a mixture of plural kinds. Further, the protective layer may be formed as a single layer or a multilayer.

  As a method for forming the protective layer 23, as with the recording layer 21, a coating method such as a spin coating method and a casting method, a sputtering method, a chemical vapor deposition method, and the like are used. Among these, a spin coating method is preferable. The film thickness of the protective layer 23 is generally 0.1 μm or more, preferably 3 μm or more because a certain amount of thickness is required to fulfill its protective function. However, if it is too thick, not only the effect does not change, but also the formation of the protective layer 23 may take time and the cost may increase, so it is usually 100 μm or less, preferably 30 μm or less.

  As described above, as the layer structure of the optical recording medium 100, the structure in which the substrate 10, the recording layer 21, the reflective layer 22, and the protective layer 23 are stacked in this order has been described as an example. You may take. For example, another substrate may be bonded to the upper surface of the protective layer 23 in the layer structure of the above example or to the upper surface of the reflective layer 22 by omitting the protective layer 23 from the layer structure of the above example. The substrate at this time may be the substrate itself without any layers, or may have an arbitrary layer such as a reflective layer on the bonded surface or the opposite surface. Further, two optical recording media having the same layer structure as above and an optical recording medium in which the protective layer is omitted from the layer structure in the above example, with the upper surfaces of the respective protective layers and / or reflective layers facing each other. You may stick together.

Next, a second embodiment of the optical recording medium will be described.
FIG. 2 is a diagram for explaining a second embodiment (in this example, a film surface incident type medium) of an optical recording medium 200 to which the present embodiment is applied. Portions common to the optical recording medium 100 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  An optical recording medium 200 shown in FIG. 2 includes a substrate 30 having a predetermined guide groove 31 and an information recording layer 40 provided on the substrate 30. The information recording layer 40 includes a reflective layer 42, a recording layer 41 and a protective film 43 laminated on the reflective layer 42 in order. In the optical recording medium 200, information is recorded / reproduced by a laser beam irradiated from the protective coating 43 side.

  The protective film 43 may be a film or a sheet-like material bonded with an adhesive, and is formed by using a material similar to that of the above-described protective layer 23 (FIG. 1), applying a coating liquid for film formation, and curing or You may form by drying. The thickness of the protective film 43 is generally 0.1 μm or more, preferably 3 μm or more because a certain degree of thickness is required to fulfill its protective function. However, if it is too thick, not only the effect does not change, but also the formation of the protective film 43 may take time and the cost may increase, so it is usually 300 μm or less, preferably 200 μm or less. Incidentally, the layers such as the recording layer 41 and the reflective layer 42 can usually be the same as those used in the optical recording medium 100 (FIG. 1). However, in this layer structure, the substrate 30 does not need to be transparent, and therefore, in addition to the above-described materials, opaque resin, ceramic, metal (including alloy), and the like are used. Even in such a layer structure, an arbitrary layer may be provided between the above-described layers as necessary as long as the characteristics of the present invention are not impaired.

  Incidentally, as one means for increasing the recording density of the optical recording media 100 and 200, there is a case where the numerical aperture (NA) of the objective lens is increased. Thereby, the light spot condensed on the information recording surface can be miniaturized. However, when the numerical aperture (NA) of the objective lens is increased, the aberration of the light spot due to the warp of the optical recording medium 100, 200 tends to increase when the laser beam is irradiated for recording / reproducing. In some cases, a good recording / reproducing signal cannot be stably obtained. Such aberration tends to increase as the film thickness of the transparent substrate or the protective film through which the laser beam is transmitted increases. Therefore, in order to reduce the aberration, it is preferable to make the substrate and the protective film as thin as possible. However, since the substrates 10 and 30 usually require a certain thickness to ensure the strength of the optical recording media 100 and 200, in this case, the structure of the optical recording medium 200 (the substrate 30, the reflective layer 42, the recording layer 41, It is preferable to employ an optical recording medium 200) having a basic layer structure which is a protective coating 43). Since the protective film 43 of the optical recording medium 200 can be easily made thinner than when the substrate 10 of the optical recording medium 100 is thinned, the optical recording medium 200 is preferably used.

  However, even in the structure of the optical recording medium 100 (the optical recording medium 100 having a basic layer structure including the substrate 10, the recording layer 21, the reflective layer 22, and the protective layer 23), the recording / reproducing laser beam is transparent. By reducing the thickness of the substrate 10 to about 50 μm to 300 μm, it becomes possible to use it with reduced aberrations. In addition, after the formation of other layers, an ultraviolet curable resin layer, an inorganic thin film, etc. are used for the purpose of protecting the surface and preventing dust from adhering to the recording / reproducing laser light incident surface (usually the lower surface of the substrate 10) The surface of the recording / reproducing laser beam is not incident (usually the upper surface of the reflective layer 22 or the protective layer 23) using various printers such as ink jet and thermal transfer or various writing tools. A print-receiving layer that can be filled and printed may be provided.

  In the optical recording media 100 and 200 to which the present embodiment is applied, the laser light used for recording / reproducing information is preferably as short as possible from the viewpoint of realizing high-density recording, but in particular, the wavelength is from 350 nm to 530 nm. The laser beam is preferable. Typical examples of such laser light include laser light having center wavelengths of 405 nm, 410 nm, and 515 nm.

  Laser light having a wavelength of 350 nm to 530 nm can be obtained by using blue or green 515 nm high-power semiconductor laser light having a wavelength of 405 nm or 410 nm. In addition, for example, (a) a semiconductor laser beam capable of continuous oscillation having a fundamental oscillation wavelength of 740 nm to 960 nm, and (b) a solid capable of continuous oscillation having a fundamental oscillation wavelength of 740 nm to 960 nm excited by the semiconductor laser beam. It can also be obtained by converting the wavelength of any laser light of the laser light by a second harmonic generation element (SHG).

SHG may be any piezoelectric element that lacks inversion symmetry, but KDP, ADP, BNN, KN, LBO, compound semiconductors, and the like are preferable. As a specific example of the second harmonic, in the case of semiconductor laser light having a fundamental oscillation wavelength of 860 nm, 430 nm which is a harmonic of the fundamental oscillation wavelength, and in the case of solid laser light excited by semiconductor laser light, Cr-doped And 430 nm of a double wave from the LiSrAlF ₆ crystal (basic oscillation wavelength 860 nm).

  When recording information on the optical recording media 100 and 200 to which the present embodiment is applied, in the case of the optical recording medium 100, the substrate 10 is transmitted from the substrate 10 side to the recording layer 21, and In the case of the optical recording medium 200, the recording layer 41 is transmitted through the protective coating 43 from the protective coating 43 side, and is usually irradiated with laser light focused to about 0.4 μm to 0.6 μm. The portions of the recording layers 21 and 41 that are irradiated with the laser light undergo thermal deformation such as decomposition, heat generation, and melting by absorbing the energy of the laser light, so that the optical characteristics change. When the information recorded on the recording layers 21 and 41 is reproduced, the recording layers 21 and 41 are irradiated with laser beams having lower energy (usually from the same direction as during recording). In the recording layers 21 and 41, by reading the difference between the reflectivity of the portion where the optical characteristics change (that is, the portion where information is recorded) and the reflectivity of the portion where the change does not occur, Playback is performed.

  Hereinafter, the present embodiment will be described more specifically based on examples. However, the present embodiment is not limited to these examples as long as the gist thereof is not exceeded.

(Synthesis method)
The method for synthesizing the metal-containing cyclic β-diketone azo compound is not particularly limited, but usually, the following synthesis method may be mentioned. That is, first, an aromatic heterocyclic amine is diazotized by adding sodium nitrite or nitrosylsulfuric acid in an acidic solution to synthesize a diazo component. Next, this diazo component is dropped into a solution in which the coupler component is dissolved at around 0 ° C. to synthesize an azo compound. Subsequently, a metal salt solution is dropped into a solution in which the synthesized azo compound is dissolved in an appropriate solvent to synthesize a metal complex compound. In the following example, a structure in the case of synthesizing a 2: 1 metal complex compound of a diazo compound and a divalent metal ion is shown.

Example 1
(A) Synthesis example
Stirring 2.45 g of 3-amino-5-methylisoxazole represented by the following structural formula [1] (0.025 mol, manufactured by Tokyo Chemical Industry Co., Ltd.) in a solution of 25 ml of acetic acid, 8.5 ml of propionic acid and 1 ml of concentrated sulfuric acid. Dissolve and cool to 0-5 ° C. Here, 8.85 g of 43% nitrosylsulfuric acid was added dropwise so as to keep the temperature at 10 ° C. or lower to prepare a diazo solution. On the other hand, 5 g of 1,3-diethyl-2-thiobarbituric acid (0.025 mol-Aldrich product) represented by the following [2], 7.5 g of sodium acetate and 1 g of urea in 100 ml of methanol and 20 ml of water are represented in another container. The solution was stirred and dissolved, adjusted to pH 5 with hydrochloric acid, and cooled to 0 ° C to 5 ° C.

  To this solution, the above-mentioned diazo solution was added dropwise at 5 ° C. or lower while maintaining pH 4 to pH 5 with a 14% aqueous ammonia solution. After completion of dropping, the mixture was stirred for 30 minutes and the reaction solution was filtered. The filtrate was suspended in 500 ml of water in order to remove inorganic salts, stirred for about 30 minutes, and then filtered. Further, the filtrate was suspended in 200 ml of methanol, stirred, filtered, and heated and dried in vacuum to obtain 6.847 g of azo compound (yield 88.5%). MS measurement (EI) of this azo compound was performed, and m / z = 309 corresponding to the target compound was confirmed (Exemplary Compound (115)).

Further, when ¹ H-NMR (CDCl ₃ (δ = ppm) MHz) of the exemplary compound (115) was measured, 1.31 (6H, t, 1,3N—CH ₂ CH ₃ ), 2.46 (3H , S, 5′- CH ₃ ), 4.55 (4H, m, 1,3N— CH ₂ CH ₃ ), 6.51 (1H, s, 4′-H), and a peak consistent with the target compound Met. Illustrative compound (115) in chloroform had a λmax of 383.5 nm and a molar extinction coefficient of 3.9 × 10 ⁴ . In FIG. 3, the solution spectrum of exemplary compound (115) is shown.

Next, 1.86 g (0.006 mol) of Exemplified Compound (115) was dissolved in 46 ml of tetrahydrofuran by stirring and filtered so as not to mix insoluble matter, and then 0.896 g (0.0036 mol) of nickel acetate was added to the filtrate. ) / Methanol 15 ml solution was added dropwise. The reaction solution was stirred for 1 hour and then evacuated with an evaporator to evaporate the solvent to precipitate a solid, added with 50 ml of water, stirred and filtered. The filtrated product was washed with isopropyl ether and dried by heating in vacuum to obtain 1.66 g (yield 81.7%) of a compound represented by the following structural formula [3] (metal complex compound (1)) And).
The metal complex compound (1) had a λmax of 428 nm in chloroform and a molar extinction coefficient of 5.4 × 10 ⁴ . FIG. 4 shows the spectrum of the metal complex compound (1) solution.

(B) Evaluation of optical recording medium The above-mentioned metal complex compound (1) was dissolved in octafluoropentanol and adjusted to 1 wt%. A solution obtained by filtering this was dropped onto an injection-molded polycarbonate resin substrate having a diameter of 120 mm and a thickness of 0.6 mm, applied by spinner method (500 rpm), and dried at 100 ° C. for 30 minutes after application. The maximum absorption wavelength (λmax) of this coating film was 427.5 nm. FIG. 5 shows the spectrum of the coating film coated with the metal complex compound (1).

  Using a light resistance tester (manufactured by Toyo Seiki Seisakusho Co., Ltd .: Suntest XLS +), a section of the disk coated with the metal complex compound (1) was irradiated with an Xe lamp at 63 ° C. and 550 mW for 40 hours. Thereafter, the absorbance at λmax before irradiation with the Xe lamp and the absorbance at λmax after irradiation with the Xe lamp were respectively measured with an ultraviolet ray measuring device, and the absorbance of λmax after irradiation with the Xe lamp with respect to the absorbance at λmax before irradiation with the Xe lamp was measured. The ratio (%) of absorbance was 55.1%. In addition, light resistance is so favorable that the numerical value of a light absorbency is large.

  Further, on the coating film thus formed, Ag or the like is formed by a sputtering method as necessary to form a reflective layer, and an ultraviolet curable resin is applied by spin coating or the like and cured by ultraviolet irradiation. Thus, a protective layer can be formed to obtain an optical recording medium. This optical recording medium can be recorded and reproduced by a semiconductor laser beam having a center wavelength of 405 nm, for example, from the value of λmax of the coating film. That is, it can be seen that the metal-containing cyclic β-diketone azo compound is a compound having an effective structure for blue laser light recording.

(Optical recording medium preparation method and recording example)
The aforementioned metal complex compound (1) was dissolved in tetrafluoropropanol and adjusted to 0.9 wt%. A solution obtained by filtering this was dropped onto an injection-molded polycarbonate resin substrate having a diameter of 120 mm and a thickness of 0.6 mm having a groove with a track pitch of 400 nm, a groove width of 220 nm, and a groove depth of 60 nm, and applied by a spinner method. The application was performed by increasing the rotational speed from 800 rpm to 7000 rpm over 13 seconds and holding at 7000 rpm for 2 seconds. Further, it was dried at 75 ° C. for 18 minutes to obtain a recording layer. Next, a silver alloy film was formed to a thickness of 120 nm by a sputtering method to form a reflective layer. Thereafter, a protective coating agent made of a UV curable resin was applied by a spinner method, and UV light was irradiated to form a protective layer having a thickness of 5 μm. Furthermore, an optical recording medium for evaluation was prepared by adhering a polycarbonate substrate having a thickness of 0.6 mm to the surface having the protective layer using a delayed curable adhesive.

(C) Recording Example 8T mark / 8T space with laser light having a wavelength of 405 nm (numerical aperture NA = 0.65) while rotating the optical recording medium for evaluation described above at a linear velocity of 6.61 m / sec. Single frequency signals were recorded on the grooves. T is a reference clock period corresponding to a frequency of 65 MHz. As the recording pulse strategy, the number of divided pulses is nT (n-1), the head recording pulse width is 2T, the subsequent recording pulse width is 0.5T, the bias power is 3.0 mW, the reproduction power is 0.4 mW, and the recording power is variable. It was. As a result, a signal having a modulation degree of 51% was recorded at 7.5 mW. It is considered that the modulation degree becomes larger by optimizing the recording conditions such as the pulse strategy.

(Example 2)
(A) Synthesis example
2-aminothiazole represented by the following structural formula [4] (0.035 mol, manufactured by Tokyo Chemical Industry Co., Ltd.) is dissolved in 50 ml of acetic acid, 35 g of phosphoric acid, and 5 g of concentrated sulfuric acid with stirring and dissolved at 0 ° C. to 5 ° C. Cooled to. Here, 12.39 g of 43% nitrosylsulfuric acid was added dropwise so as to maintain the temperature at 10 ° C. or lower to prepare a diazo solution. On the other hand, 5.3 g of the compound represented by the following [5] (1.05 equivalent—manufactured by Tokyo Chemical Industry Co., Ltd.), 10.5 g of sodium acetate and 1.4 g of urea are placed in 140 ml of methanol and 35 ml of water in a separate container. The solution was dissolved, adjusted to pH 5 with hydrochloric acid, and cooled to 0 ° C to 5 ° C.

The above diazo solution was added dropwise to this solution at 5 ° C. or lower while maintaining the pH at 4 to 5 with a 14% aqueous ammonia solution. After completion of dropping, the mixture was stirred for 30 minutes and the reaction solution was filtered. The filtered product was suspended in 500 ml of water in order to remove inorganic salts, and stirred and filtered for about 30 minutes. Further, the filtrate was suspended in 150 ml of methanol, stirred, filtered, and heated and dried in vacuo to obtain 6.458 g of azo compound (yield 72.3%). This azo compound had λmax in chloroform of 384.5 nm and a molar extinction coefficient of 1.7 × 10 ⁴ .

MS measurement (EI) of this azo compound was performed, and m / z = 255 consistent with the target compound was confirmed. ^{When 1} H-NMR (CDCl ₃ (δ = ppm) MHz) was measured, 1.83 (6H, s, 2,2-CH ₃ ), 7.12 (1H, d, 5′-H), 7 .55 (1H, d, 4′-H) and 13.76 (1H, s, 6-OH), which were peaks consistent with the target compound (Exemplary Compound (116)).

After 1.53 g (0.006 mol) of the compound represented by the exemplified compound (116) is stirred and dissolved in 28 ml of tetrahydrofuran and filtered so as not to mix insoluble matter, 0.9 g of nickel acetate tetrahydrate is added to the filtrate. A (0.0036 mol) / methanol 16 ml solution was added dropwise. The reaction was stirred for 1 hour and then filtered to remove the product. The obtained solid was washed with water and heat-dried in vacuum to obtain 1.552 g (yield 91.2%) of a compound represented by the following structural formula [6] (metal complex compound (2)) And). The compound of the metal complex exemplified compound (141) had a wavelength of λmax of 420.5 nm in chloroform and a molar extinction coefficient of 3.9 × 10 ⁴ .

(B) Evaluation of optical recording medium
The metal complex compound (2) was dissolved in octafluoropentanol and adjusted to 1 wt%. A solution obtained by filtering this was dropped onto an injection-molded polycarbonate resin substrate having a diameter of 120 mm and a thickness of 0.6 mm, applied by a spinner method, and dried at 100 ° C. for 30 minutes after application. The maximum absorption wavelength (λmax) of this coating film was 423.5 nm. FIG. 6 shows the spectrum of the coating film coated with the metal complex compound (2).

  The optical recording medium was prepared as follows. Using a light resistance tester (manufactured by Toyo Seiki Seisakusho Co., Ltd .: Suntest XLS +), a section of the disk coated with the metal complex compound (2) was used at 63 ° C. and 550 mW in the same manner as in Example 1. When the light resistance was evaluated by irradiation for 40 hours, it was 97.2%.

  The aforementioned metal complex compound (2) was dissolved in tetrafluoropropanol and adjusted to 0.9 wt%. A solution obtained by filtering this was dropped onto an injection-molded polycarbonate resin substrate having a diameter of 120 mm and a thickness of 0.6 mm having a groove with a track pitch of 400 nm, a groove width of 220 nm, and a groove depth of 60 nm, and applied by a spinner method. The application was performed by increasing the rotational speed from 800 rpm to 7000 rpm over 13 seconds and holding at 7000 rpm for 2 seconds. Further, it was dried at 75 ° C. for 18 minutes to obtain a recording layer. Next, a silver alloy film was formed to a thickness of 120 nm by a sputtering method to form a reflective layer. Thereafter, a protective coating agent comprising a UV curable resin was applied by a spinner method, and UV light was irradiated to form a protective layer having a thickness of 5 μm. Furthermore, an optical recording medium for evaluation was prepared by adhering a polycarbonate substrate having a thickness of 0.6 mm to the surface having the protective layer using a delayed curable adhesive.

(C) Recording example
While rotating the optical recording medium for evaluation described above at a linear velocity of 6.61 m / sec, a single frequency signal of 8T mark / 8T space with a laser beam having a wavelength of 405 nm (numerical aperture NA = 0.65 of the objective lens). Was recorded on the groove. T is a reference clock period corresponding to a frequency of 65 MHz. As the recording pulse strategy, the number of divided pulses is nT (n-1), the head recording pulse width is 2T, the subsequent recording pulse width is 0.5T, the bias power is 3.0 mW, the reproduction power is 0.4 mW, and the recording power is variable. It was. As a result, a signal having a modulation degree of 51% was recorded at 6.5 mW. It is considered that the modulation degree becomes larger by optimizing the recording conditions such as the pulse strategy.

(Example 3)
(A) Synthesis example
1.53 g (0.006 mol) of Exemplified Compound (116) synthesized in Example 2 was dissolved in 28 ml of tetrahydrofuran by stirring and filtered so as not to mix insoluble matter, and then 0.9 g (0) of cobalt acetate was added to the filtrate. .0036 mol) / methanol 16 ml solution was added dropwise. The reaction was stirred for 1 hour and then filtered to remove the product. The obtained solid was washed with water and heat-dried in vacuum to obtain 1.22 g (yield 71.6%) of a compound represented by the following structural formula [7]. This compound had λmax in chloroform of 417.5 nm and a molar extinction coefficient of 3.3 × 10 ⁴ (referred to as metal complex compound (3)).

(B) Evaluation of optical recording medium
The metal complex compound (3) was dissolved in octafluoropentanol and adjusted to 1 wt%. A solution obtained by filtering this was dropped onto an injection mold polycarbonate resin substrate having a diameter of 120 mm and a thickness of 0.6 mm, applied by a spinner method, and dried at 100 ° C. for 30 minutes after application. The maximum absorption wavelength (λmax) of this coating film was 420.5 nm. FIG. 7 shows the spectrum of the coating film coated with the metal complex compound (3).

  Using a light resistance tester (manufactured by Toyo Seiki Seisakusho Co., Ltd .: Suntest XLS +), a section of the disk coated with this metal complex compound (3) was used at 63 ° C. and 550 mW in the same manner as in Example 1. When the light resistance was evaluated by irradiation for 40 hours, it was 94.1%.

(Optical recording medium preparation method and recording example)
The aforementioned metal complex compound (3) was dissolved in tetrafluoropropanol and adjusted to 0.9 wt%. A solution obtained by filtering this was dropped onto an injection-molded polycarbonate resin substrate having a diameter of 120 mm and a thickness of 0.6 mm having a groove with a track pitch of 400 nm, a groove width of 220 nm, and a groove depth of 60 nm, and applied by a spinner method. The application was performed by increasing the rotational speed from 800 rpm to 7000 rpm over 13 seconds and holding at 7000 rpm for 2 seconds. Further, it was dried at 75 ° C. for 18 minutes to obtain a recording layer. Next, a silver alloy film was formed to a thickness of 120 nm by a sputtering method to form a reflective layer. Thereafter, a protective coating agent made of a UV curable resin was applied by a spinner method, and UV light was irradiated to form a protective layer having a thickness of 5 μm. Furthermore, an optical recording medium for evaluation was prepared by adhering a polycarbonate substrate having a thickness of 0.6 mm to the surface having the protective layer using a delayed curable adhesive.

(C) Recording Example 8T mark / 8T space with laser light having a wavelength of 405 nm (numerical aperture NA = 0.65) while rotating the optical recording medium for evaluation described above at a linear velocity of 6.61 m / sec. Single frequency signals were recorded on the grooves. T is a reference clock period corresponding to a frequency of 65 MHz. As the recording pulse strategy, the number of divided pulses is nT (n-1), the head recording pulse width is 2T, the subsequent recording pulse width is 0.5T, the bias power is 3.0 mW, the reproduction power is 0.4 mW, and the recording power is variable. It was. As a result, a signal having a modulation degree of 48.4% was recorded at 6.4 mW. It is considered that the modulation degree becomes larger by optimizing the recording conditions such as the pulse strategy.

(Example 4 to Example 151)
Hereinafter, after synthesizing Exemplified Azo Compound (115) to Exemplified Azo Compound (189) by the same method as the synthesis method described above, it is further converted into a metal complex, and the absorption spectrum of the coating film prepared in the same manner as in Example 1 is obtained. It was measured. The maximum absorption wavelength and molar extinction coefficient of these metal complex compounds in solution (chloroform), and the maximum absorption wavelength of the coating film (the coating solvent is selected from octafluoropentanol or tetrafluoropropanol as appropriate) are measured. . Moreover, the light resistance test of these coating films was done. The results are shown in Tables 1 to 7 together with Examples 1 to 3.

  The wavelength of the metal-containing cyclic β-diketone azo compound is determined by a combination of a diazo component, a coupler component, and a metal ion. If the same coupler component and metal are used, a longer wavelength compound can be formed by using a longer diazo component. Similarly, if the same diazo component and metal are used, a long-wavelength metal-containing cyclic β-diketone azo compound can be synthesized even if a longer-wavelength coupler component is used. Although the order of these changes depending on the substituents and the like, the following order is generally seen when illustrated in the range of the examples.

  Although it varies depending on the combination with the coupler component and the type of metal, as a general trend, the light resistance is highly derived from the diazo component, and the lower wavelength diazo component isoxazole and triazole tend to be lower. In the case of thiazole or benzothiazole having a longer wavelength, a better light fastness is obtained. Therefore, these light-resistant compounds can be synthesized by using a shorter coupler component and a diazo component having a longer wavelength. In addition to the combination of the diazo component and the coupler component, a compound suitable for the target wavelength can be synthesized depending on the substituent of the diazo component and the type of metal. As described above, for example, the metal-containing cyclic β-diketone azo compound shown in Table 1 can cover a wide range of wavelengths from 368.5 nm to 482 nm.

  Further, on the coating film thus formed, Ag or the like is formed by a sputtering method as necessary to form a reflective layer, and an ultraviolet curable resin is applied by spin coating or the like and cured by ultraviolet irradiation. Thus, a protective layer can be formed to obtain an optical recording medium. This optical recording medium can be recorded and reproduced by a semiconductor laser beam having a center wavelength of 405 nm, for example, from the value of λmax of the coating film. That is, the metal-containing cyclic β-diketone azo compound composed of the azo compound represented by the general formula [I] or the general formula [II] and a metal is a compound having a structure effective for blue laser light recording. I understand.

  From the results shown in Tables 1 to 7, the light resistance of the metal complex compound tends to be influenced by the type of diazo component, coupler component or metal ion. For example, when isoxazole is used as a diazo component (Examples 1, 5, 8, 23 to 27, 38, and 41), the maximum value of light resistance remains at 65.2%. In addition, the light resistance in the case of Example 2 and Example 3 using the same metal complex compound as the coupler component exceeds 90%, whereas the metal complex compound having a coupler component different from these is used. In the case of Example 8, it remains at 42.9%. Furthermore, the light resistance of Example 27 using the metal complex compound with Zn ion is 65.2% of the light resistance of Example 25 using the metal complex compound with Co ion for the same azo compound. Decrease to 1.7%.

  In addition, about a metal complex compound with low light resistance, other light metal complex compounds with favorable light resistance, for example, the organic pigment compound etc. which are conventionally used for CD-R etc., are mixed, and light resistance light is mixed. It is possible to improve the practical level of the optical recording medium.

  For metal complex compounds with low light resistance, it is also effective to include compounds having a singlet oxygen quencher effect (for example, acetylacetonate chelate, bisphenyldithiol, salicylaldehyde oxime, bisdithio-α-diketone, etc.) Is.

(Comparative Example 1)
For comparison, the compound [8] shown below was synthesized and evaluated as an optical recording medium.
(A) Production example
From 2-amino-6-methylbenzothiazole (Tokyo Chemicals Co., Ltd.) represented by the following structural formula [8] and 1-n-butyl-3-cyano-4-methyl-6-hydroxy-2-pyridone The following compound [9] was synthesized. Compound [9] had a λmax in chloroform of 453.5 nm and a molar extinction coefficient of 3.2 × 10 ⁴ .

This compound [9] was metallized with nickel acetate to obtain the following compound [10]. Compound [10] had a λmax in chloroform of 524 nm and a molar extinction coefficient of 7.4 × 10 ⁴ .

(B) Optical recording medium example
This compound [10] was dissolved in octafluoropentanol and adjusted to 1 wt%. However, the solubility was low and there was a half unsolved residue. This was filtered, and the resulting solution was dropped onto an injection mold polycarbonate resin substrate having a diameter of 120 mm and a thickness of 0.6 mm, applied by spinner method (500 rpm), and dried at 100 ° C. for 30 minutes after application. The maximum absorption wavelength (λmax) of this coating film was 542.5 nm. However, it can be seen that there is little absorption at the wavelength of 405 nm, and recording cannot be expected with respect to the laser beam having the center wavelength of 405 nm.

  FIG. 8 shows an absorption spectrum of the compound [10]. In addition, it overlapped with the spectrum of the nickel complex (Example 15) which used Meldrum's acid as a coupler component. As shown in FIG. 8, the compound [10] has a different coupler component even if it is a metal-containing azo compound using the same benzothiazole as the diazo component, compared with the complex compound of Example 15 having a large absorption at 405 nm. This indicates that the dye compound is insufficient for blue laser light recording.

(Comparative Example 2)
For comparison, the compound [11] shown below was synthesized and evaluated as an optical recording medium.
(A) Production example
2-Amino-5-methyl-1,3,4-thiadiazole (Tokyo Kasei Co., Ltd.) was diazotized in a similar manner and coupled under the same conditions as in Example 1 to synthesize the following compound [11]. did. Compound [11] had a λmax of 409.5 nm and a molar extinction coefficient of 3.0 × 10 ⁴ in chloroform.

This compound [11] was metallized with nickel acetate in the same manner as in Comparative Example 1 to synthesize the following compound [12]. Compound [12] had a λmax in chloroform of 494 nm and a molar extinction coefficient of 7.1 × 10 ⁴ in chloroform. FIG. 9 shows an absorption spectrum of the compound [12]. In addition, it overlapped with the spectrum of the nickel complex (Example 32) which used barbituric acid as a coupler component. As shown in FIG. 9, it can be seen that Compound [12] is a dye compound that is insufficient for blue laser light recording as compared with the metal complex compound of Example 32 having a large absorption at 405 nm.

(B) Example of optical recording medium This compound [12] was dissolved in octafluoropentanol and adjusted to 1 wt%, but the solubility was low and hardly dissolved. This was filtered, and the resulting solution was dropped onto an injection mold polycarbonate resin substrate having a diameter of 120 mm and a thickness of 0.6 mm, applied by spinner method (500 rpm), and dried at 100 ° C. for 30 minutes after application. However, the absorption spectrum of the coating film could not be obtained due to poor solubility.
From the above results, it is clear that when a pyridone skeleton is used as the coupler component, 1,3,4-thiadiazole is sufficiently long as the diazo component, and the benzothiazole and thiazole as described above cannot be used.

(Comparative Example 3)
For comparison, an azo compound was synthesized using a chain β-diketone coupler component.
(A) Production example
Stirring 1.4 g of 2-amino-4-methylthiazole represented by the following structural formula [13] (0.013 mol-Tokyo Kasei Co., Ltd.) in a solution of 6 ml of acetic acid, 2 ml of propionic acid and 1.3 ml of concentrated sulfuric acid. Dissolve and cool to 0-5 ° C. Here, 4.6 g of 43% nitrosylsulfuric acid was added dropwise so as to maintain the temperature at 10 ° C. or lower to prepare a diazo solution.

  On the other hand, in another container, 2.8 g of tenoyl trifluoroacetone represented by the following chemical formula [14] (1 equivalent—Tokyo Kasei Co., Ltd.), 4.3 g of sodium acetate, 0.43 g of urea, 50 ml of methanol and 5 ml of water. It was dissolved in, adjusted to pH 11 with 20% NaOH aqueous solution, and cooled to 0 ° C to 5 ° C. To this solution, the aforementioned diazo solution was added dropwise at 5 ° C. or lower while maintaining the pH at 10 with an aqueous ammonia solution. After completion of dropping, the mixture was stirred for 30 minutes and the reaction solution was filtered. The filtrate was poured into water and concentrated hydrochloric acid was added dropwise to acidify the solution to precipitate the reaction product. This was filtered, washed with water, and dried by heating in vacuo to obtain 0.96 g of a compound represented by the following chemical formula [15] in a yield of 21%.

FIG. 10 shows an absorption spectrum of the chemical formula [15]. The compound represented by the chemical formula [15] had λmax in chloroform of 399.5 nm and a molar extinction coefficient of 1.0 × 10 ⁴ . Thus, it can be seen that the yield of the compound represented by the chemical formula [15] is low and the molar extinction coefficient is also low.

(Comparative Example 4)
For comparison, the compound [16] shown below having the same absorption at λmax was evaluated as an optical recording medium.
A cyanine dye having a structural formula represented by [16] below (Nippon Photosensitive Dye Research Laboratories NK-1204) had a λmax of 407.5 nm and a molar extinction coefficient of 8.2 × 10 ^{4 in} chloroform. It was. The solution spectrum is shown in FIG.

This compound [16] is dissolved in octafluoropentanol, adjusted to 1 wt% and filtered, and the resulting solution is dropped onto an injection-molded polycarbonate resin substrate having a diameter of 120 mm and a thickness of 0.6 mm, It was applied (500 rpm) by a spinner method and dried at 100 ° C. for 30 minutes after the application. The maximum absorption wavelength (λmax) of this coating film was 371.5 nm. This spectrum is shown in FIG.
As apparent from comparison with the spectrum of the solution FIG. 11, the spectrum of the coating film is significantly deformed. This could not be observed visually, but may be partially crystallized on the disk surface.
When the dye used sections of the coated discs was evaluated the rate of absorbance lambda _max in the same manner as in Example 1 (light resistance), was 18%.

(Comparative Example 5)
For the same comparison, the compound [17] shown below was evaluated as an optical recording medium.
In 2- [2-furan-2-yl] vinyl] -4,6-bis- (trichloromethyl) -1,3,5-triazine (Tokyo Kasei Co., Ltd.) represented by the following [17] in chloroform Λmax was 375 nm, and the molar extinction coefficient was 3.5 × 10 ⁴ .

  This compound [17] is dissolved in methyl lactate, adjusted to 1 wt%, filtered, and the resulting solution is dropped onto an injection-molded polycarbonate resin substrate having a diameter of 120 mm and a thickness of 0.6 mm, and spinner method (500 rpm) and dried at 100 ° C. for 30 minutes. However, the substrate surface was clouded and crystallized, and a good spectrum could not be obtained.

  As is apparent from the results of Comparative Example 4 and Comparative Example 5, even if the dye has absorption in the same region, the ease of forming a coating film and light resistance required as an optical recording medium are greatly different. . In general, crystallization during the formation of a coating film tends to be more pronounced with smaller molecules or molecules with higher planarity, but the metal-containing azo complex compound used in the examples of the present invention has two molecules of azo dye. And one metal ion, and has a three-dimensionally bulky molecular structure, so that it is difficult to crystallize on the substrate surface. Moreover, the light resistance is improved by forming a complex as compared with the azo dye alone. From the above, it is clear that the present invention is very useful as a dye for an optical recording medium.

  From the above, it can be seen that the coupler component having a cyclic β-diketone structure has a better reaction yield and a higher molar extinction coefficient than the chain β-diketone structure. The reason for this is that when the coupler component has a cyclic structure, the active methylene group, which is a reactive site, is immobilized, so that the reactivity is improved and the product tends to have a more planar structure, so that the conjugated system is extended. It may be easier.

(Example 152)
In order to evaluate the recording and reproducing characteristics of the optical recording medium obtained in Example 1, the system conforms to the HD DVD-R standard Ver1.0 defined by the DVD Forum, and the PRSNR (Partial Response) in the standard is used. SNR) was evaluated.
Evaluation was performed on the obtained optical recording medium using a tester (ODU-1000 manufactured by Pulstec) with a laser wavelength of 405 nm and NA (numerical aperture) of 0.65, a linear velocity of 6.61 m / s, and a shortest mark length of 204 nm. The recording power was optimized so that the maximum value of PRSNR was obtained.
As a result, the recording mechanism was a Low To High type, and the optimum recording power was 7.8 mW. The PRSNR of the optical recording medium was 32.8, which was much higher than the standard PRSNR value of 15.

(Example 153 to Example 198)
An optical recording medium was produced under the same conditions as in Example 152 except that the compounds shown in Tables 8 to 10 were used as the dye, and evaluation was performed in the same manner as in Example 152. Since the recording sensitivity and recording characteristics depend on the thickness of the dye thin film and the recording method, the concentration of the coating solution (0.9 to 1.2% by weight) and the spin rate are obtained so that good recording characteristics can be obtained. The program of the coat, the groove shape of the disk, the recording pulse width, etc. were optimized at the appropriate time.

  Table 8 to Table 10 show the optimum recording power and PRSNR values of Example 153 to Example 198 together with the result of Example 152. As is apparent from Tables 8 to 10, in many examples, even in the HD DVD-R standard, the sensitivity was 10 mW or less and PRSNR = 15. The recording mechanism was a Low To High type.

  The values of recording sensitivity and recording characteristics vary depending on the structure of the dye, the spectral shape, the thermal decomposition start temperature of the dye, the type of metal forming the complex, and the like. For example, the values are longer using the same coupler component as in Example 153. When comparing with the wavelength-converted example 157, the PRSNR was decreased in the example 157. For this reason, when λmax of the coating film of the dye deviates more than 405 nm, there is a tendency that the recording characteristics are deteriorated. This is because the recording principle is the Low To High type, and it is considered that a certain amount of absorption is required for the recording wavelength. Therefore, it is apparent that a coupler component that absorbs shorter wavelengths is required to improve the recording characteristics.

It is a figure explaining 1st Embodiment (CD-R) of the optical recording medium to which this Embodiment is applied. It is a figure explaining 2nd Embodiment (film surface incident type medium) of the optical recording medium to which this Embodiment is applied. It is a solution spectrum of exemplary compound (115). It is a spectrum of a metal complex compound (1) solution. It is a spectrum of the coating film which apply | coated metal complex compound (1). It is a spectrum of the coating film which apply | coated metal complex compound (2). It is a spectrum of the coating film which apply | coated metal complex compound (3). It is an absorption spectrum of the compound [10] (solid line) and the complex compound of Example 15 (broken line). It is an absorption spectrum of the compound [12] (solid line) and the complex compound of Example 32 (broken line). It is an absorption spectrum of chemical formula [15]. It is an absorption spectrum of compound [16]. It is an absorption spectrum of the coating film of compound [16].

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,30 ... Board | substrate, 11,31 ... Guide groove, 20, 40 ... Information recording layer, 21, 41 ... Recording layer, 22, 42 ... Reflective layer, 23 ... Protective layer, 43 ... Protective film, 100, 200 ... Optical recoding media

Claims (10)

A substrate,
A recording layer provided on the substrate directly or via another layer and capable of recording and / or reproducing information by being irradiated with light;
The recording layer is
An optical recording medium comprising an azo compound having a coupler component having a cyclic β-diketone structure and a diazo component having a nitrogen-containing heteroaromatic ring structure, and a metal complex compound composed of a metal ion coordinated with the azo compound . The optical recording medium according to claim 1, wherein the azo compound is a cyclic β-diketone azo compound represented by the following general formula [I] or general formula [II].

(In General Formula [I] or General Formula [II], Ring A is a nitrogen-containing heteroaromatic ring. X, Y, Z in General Formula [I] and X ′, Y ′ in General Formula [II] Are each independently any one selected from a carbon atom, an oxygen atom, a sulfur atom, and a nitrogen atom that may have a substituent, and these have a 5- or 6-membered ring together with a β-diketone structure. Form.)   The optical recording medium according to claim 1, wherein the coupler component has a cyclic β-diketone structure having a saturated or unsaturated 5-membered to 7-membered hydrocarbon ring or heterocyclic condensed ring.   2. The optical element according to claim 1, wherein the diazo component has a nitrogen-containing heteroaromatic ring structure composed of a 5-membered or 6-membered monocyclic ring, or a 5-membered or 6-membered bicondensed ring. recoding media.   2. The optical recording medium according to claim 1, wherein the metal ion is a metal ion selected from Group 7A, Group 8, 1B, and 2B of the periodic table.   2. The optical recording medium according to claim 1, wherein the metal ions are ions of at least one metal selected from nickel, cobalt, zinc, copper, and manganese.   The optical recording medium according to claim 1, wherein the light is laser light having a wavelength of 350 nm to 530 nm.   It includes an azo compound having a coupler component having a cyclic β-diketone structure and a diazo component having a nitrogen-containing heteroaromatic ring structure, and a metal-containing cyclic β-diketone azo compound composed of a metal ion coordinated with the azo compound. An optical recording material.   A metal complex compound composed of an azo compound having a cyclic β-diketone structure bonded to an azo group and a nitrogen-containing heteroaromatic ring and a divalent metal ion.   The cyclic β-diketone structure is any one selected from meldrum acid, tetronic acid, barbituric acid, thiobarbituric acid, hydroxycoumarin, hydroxycarbostyril, pyrazolidinedione, indandione, cyclohexanedione and diketopyrimidine. The metal complex compound according to claim 9, which has a seed skeleton.

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