JPH1192682A - Dipyrromethene metal chelate compound and optical recording medium using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject new compound capable of giving optical recording media suitable for high-density recording enabling recording and reproduction using short wavelength laser beams and excellent in recording capacity and durability. SOLUTION: This new compound is shown by formula I (R1 to R9 are each H, a halogen, <=20C (un)substituted alkyl or the like; M is a transition element), e.g. a compound of formula II. The compound of the formula I is obtained, for example, by reaction between 2-formyl-5-(2-thienylethen-1-yl)pyrrole and 1-formyl-3-phenylisoindole in ethanol in the presence of hydrobromic acid to form a dipyrromethene-based compound of formula III which, in turn, is reacted with an acetate or halide of a metal such as nickel, iron, copper or platinum. The other objective optical recording medium with this new compound in the recording layer thereof enables recording and record reproduction in respect of laser beams 520-690 nm in wavelength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel dipyrromethene metal chelate compound and an optical recording medium using the same, which can record and reproduce data at a higher density than before.

[0002]

2. Description of the Related Art In recent years, CD-Rs have been used as write-once optical recording media.
(CD-Recordable) has been actively developed. This is different from a conventional CD in that a user can record information and the recorded signal is a conventional CD.
Satisfies the standard, and can be played on a commercially available CD player. As one method for realizing such an optical recording medium, Japanese Patent Laid-Open Publication No. 2-42652 proposes that a light absorbing layer is provided by spin coating a dye on a substrate, and a metal reflecting layer is provided behind the light absorbing layer. Have been. Further, as disclosed in Japanese Patent Application Laid-Open No. 2-132656, by appropriately selecting the complex refractive index and the film thickness of the light absorbing layer, the signal after recording satisfies the CD standard, Commercialized as CD-R.

Further, as a next-generation optical recording medium, attention has been paid to shortening the oscillation wavelength of laser light for high-density recording.
There is a demand for an optical recording medium capable of recording and reproducing with a laser beam having a shorter wavelength than 780 nm and 830 nm, which is shorter than 630 nm and 680 nm. Optical recording media proposed in such a situation include magneto-optical recording media, phase-change recording media, chalcogen oxide optical recording media, organic dye-based optical recording media, and the like. Among these, the organic dye-based optical recording medium is considered to have an advantage in that it is inexpensive and easy in process.

The use of organic dye-based optical recording media at short wavelengths is described in JP-A-4-74690 and JP-A-5-388.
No. 78, JP-A-6-40161, JP-A-6-401
Various proposals using cyanine dyes and the like have been made in JP-A No. 40162, JP-A-6-199045, and the like, but the light resistance and the like are completely insufficient. In addition, problems specific to short-wavelength applications, for example, where small pits should be opened with a narrowed laser beam, have a large influence on the surroundings, resulting in pits with a large distribution, resulting in increased jitter and cross-talk in the radial direction. At present, there is no solution to the problem that the talk deteriorates or the pits become extremely small and a sufficient degree of modulation cannot be obtained.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel dipyrromethene metal chelate compound, and a dipyrromethene metal chelate compound which is suitable for high-density recording which can be recorded and reproduced by a short wavelength laser having a wavelength of 520 to 690 nm. An optical recording medium is provided.

[0006]

Means for Solving the Problems The present inventors have proposed an optical recording medium suitable for high-density recording which can be recorded and reproduced using a dipyrromethene metal chelate compound as an organic dye (Japanese Patent Application No. Hei 10-284). No. 9-200576). The present inventors have further studied the optical recording medium using the dipyrromethene metal chelate compound, and as a result, in the dipyrromethene metal chelate compound, by selecting a specific substituent, in addition to the recording characteristics, The present inventors have found that an optical recording medium having excellent durability can be obtained, and have completed the present invention. That is, the present invention provides a dipyrromethene metal chelate compound represented by the following general formula (1):

[0007]

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[Wherein, R _{1 to} R ₉ each independently represent a hydrogen atom,
It represents a halogen atom, a substituted or unsubstituted alkyl group having 20 or less carbon atoms, an alkoxy group, an alkenyl group, an acyl group, an alkoxycarbonyl group, an aralkyl group, an aryl group or a heteroaryl group, and M represents a transition element. In an optical recording medium having at least a recording layer and a reflective layer on a substrate, an optical recording medium containing the described dipyrromethene metal chelate compound in the recording layer, and a laser beam selected from the wavelength range of 520 to 690 nm. And an optical recording medium capable of recording and reproduction.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the dipyrromethene metal chelate compound represented by the general formula (1) of the present invention, specific examples of R _{1 to} R ₉ include a hydrogen atom; a fluorine atom, a chlorine atom, a bromine atom and a halogen atom of iodine;

[0010] Methyl group, ethyl group, n-propyl group, iso-
Propyl, n-butyl, iso-butyl, sec-butyl, t-butyl, n-pentyl, iso-pentyl, 2-methylbutyl, 1-methylbutyl, neo-pentyl, 1,
2-dimethylpropyl group, 1,1-dimethylpropyl group, cycl
o-pentyl group, n-hexyl group, 4-methylpentyl group, 3-
Methylpentyl group, 2-methylpentyl group, 1-methylpentyl group, 3,3-dimethylbutyl group, 2,3-dimethylbutyl group, 1,3-dimethylbutyl group, 2,2-dimethylbutyl group, 1,
2-dimethylbutyl group, 1,1-dimethylbutyl group, 3-ethylbutyl group, 2-ethylbutyl group, 1-ethylbutyl group, 1,2,
2-trimethylbutyl group, 1,1,2-trimethylbutyl group, 1-
Ethyl-2-methylpropyl group, cyclo-hexyl group, n-heptyl group, 2-methylhexyl group, 3-methylhexyl group,
4-methylhexyl group, 5-methylhexyl group, 2,4-dimethylpentyl group, n-octyl group, 2-ethylhexyl group, 2,
5-dimethylhexyl group, 2,5,5-trimethylpentyl group,
2,4-dimethylhexyl group, 2,2,4-trimethylpentyl group, n-octyl group, 3,5,5-trimethylhexyl group, n-nonyl group, n-decyl group, 4-ethyloctyl group, 4 -ethyl-
4,5-dimethylhexyl group, n-undecyl group, n-dodecyl group, 1,3,5,7-tetraethyloctyl group, 4-butyloctyl group, 6,6-diethyloctyl group, n-tridecyl group, 6 -Methyl-4-butyloctyl group, n-tetradecyl group, n-pentadecyl group, 3,5-dimethylheptyl group, 2,6-dimethylheptyl group, 2,4-dimethylheptyl group, 2,2,5,5 -Tetramethylhexyl group, 1-cyclo-pentyl-2,2-dimethylpropyl group, 1-cyclo-hexyl-2,2-dimethylpropyl group,
Chloromethyl group, dichloromethyl group, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group,
A substituted or unsubstituted alkyl group having 20 or less carbon atoms, such as a nonafluorobutyl group;

Methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, iso-butoxy, sec-butoxy, t-butoxy, n-pentoxy,
iso-pentoxy group, neo-pentoxy group, n-hexyloxy group, n-dodecyloxy group, methoxyethoxy group, ethoxyethoxy group, 3-methoxypropyloxy group, 3- (i
20 carbon atoms such as so-propyloxy) propyloxy group
The following substituted or unsubstituted alkoxy groups:

A vinyl group, a propenyl group, a 1-butenyl group,
iso-butenyl group, 1-pentenyl group, 2-pentenyl group, 2-
Methyl-1-butenyl group, 3-methyl-1-butenyl group, 2-methyl-2-butenyl group, 2,2-dicyanovinyl group, 2-cyano-2-
A substituted or unsubstituted alkenyl group having 20 or less carbon atoms, such as a methylcarboxylvinyl group or a 2-cyano-2-methylsulfonevinyl group;

A formyl group, acetyl group, ethylcarbonyl group, n-propylcarbonyl group, iso-propylcarbonyl group, n-butylcarbonyl group, n-pentylcarbonyl group, iso-pentylcarbonyl group, neo-pentylcarbonyl group, 2 A substituted or unsubstituted acyl group having 20 or less carbon atoms, such as -methylbutylcarbonyl group or nitrobenzylcarbonyl group;

A substituted or unsubstituted alkoxycarbonyl group having 20 or less carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, an isopropyloxycarbonyl group and a 2,4-dimethylbutyloxycarbonyl group;

Benzyl, nitrobenzyl, cyanobenzyl, hydroxybenzyl, methylbenzyl,
Dimethylbenzyl group, trimethylbenzyl group, dichlorobenzyl group, methoxybenzyl group, ethoxybenzyl group, trifluoromethylbenzyl group, naphthylmethyl group, nitronaphthylmethyl group, cyanonaphthylmethyl group, hydroxynaphthylmethyl group, methylnaphthylmethyl group, A substituted or unsubstituted aralkyl group having 20 or less carbon atoms, such as a trifluoromethylnaphthylmethyl group;

Phenyl, nitrophenyl, cyanophenyl, hydroxyphenyl, methylphenyl,
Dimethylphenyl, trimethylphenyl, dichlorophenyl, methoxyphenyl, ethoxyphenyl, trifluoromethylphenyl, N, N-dimethylaminophenyl, naphthyl, nitronaphthyl, cyanonaphthyl, hydroxynaphthyl, methyl A substituted or unsubstituted aryl group having 20 or less carbon atoms, such as a naphthyl group and a trifluoromethylnaphthyl group;

C20 or less carbon atoms such as pyrrolyl, thienyl, furanyl, oxazoyl, isoxazoyl, oxadiazoyl, imidazoyl, benzoxazoyl, benzothiazoyl, benzimidazoyl, benzofuranyl, indoyl, etc. Or a substituted or unsubstituted heteroaryl group.

Specific examples of M are not particularly limited as long as they are transition metals having the ability to form a chelate compound with a dipyrromethene compound, but may be any one of groups VIII, Ib, IIb and Ib.
Group IIa, Group IVa, Group Va, Group VIa, Group VIIa metals are preferred, preferably nickel, cobalt, iron, ruthenium, rhodium, palladium, copper, osmium, iridium, platinum, zinc and the like, In particular, copper and cobalt are preferred.

The dipyrromethene metal chelate compound represented by the general formula (1) of the present invention is not limited.
Aust. J. Chem, 1965, 11, 1835-
45, Heteroatom Chemistry, V
ol. 1,5,389 (1990), USP-4,77
4,339, USP-5, 187,288, USP-
It is produced according to the method described in US Pat. Typically, it can be produced by the following two-step reaction.

First, in the first step, a compound represented by the general formula (2) and a compound represented by the general formula (3), or a compound represented by the general formula (4) and a compound represented by the general formula (5) are prepared. In the presence of an acid catalyst such as hydrobromic acid or hydrogen chloride,
By reacting in an appropriate solvent, a dipyrromethene compound represented by the general formula (6) is obtained. Next, in the second step, a dipyrromethene compound represented by the general formula (6) is mixed with nickel, cobalt, iron, ruthenium, rhodium, palladium, copper,
The dipyrromethene metal chelate compound represented by the general formula (1) is obtained by reacting with a metal acetate or halide such as osmium, iridium, platinum, and zinc.

[0021]

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[0022]

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[0023]

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[0024]

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[0025]

Embedded image [In the formulas (2) to (6), R _{1 to} R ₉ represent the same meaning as described above. ]

Table 1 shows specific examples of the dipyrromethene metal chelate compound represented by the general formula (1) of the present invention.

[0027]

[Table 1]

[0028]

[Table 2]

The specific structure of the present invention will be described below. The optical recording medium refers to both a read-only optical read-only medium on which information is recorded in advance and an optical recording medium capable of recording and reproducing information. Here, as an example, an optical recording medium capable of recording and reproducing the latter information, in particular, an optical recording medium having a recording layer and a reflective layer on a substrate will be described. This optical recording medium has a four-layer structure in which a substrate, a recording layer, a reflective layer, and a protective layer are sequentially laminated as shown in FIG. 1, or has a laminated structure as shown in FIG. . That is, a recording layer 2 'is formed on a substrate 1', a reflective layer 3 'is provided in close contact with the recording layer 2', and a substrate 5 'is further laminated thereon via an adhesive layer 4'. ing. However, another layer may be provided below or above the recording layer 2 ', or another layer may be provided above the reflective layer.

As a material of the substrate, basically, any material may be used as long as it is transparent at the wavelength of the recording light and the reproducing light. For example, polymer materials such as acrylic resins such as polycarbonate resin, vinyl chloride resin and polymethyl methacrylate, polystyrene resins and epoxy resins, and inorganic materials such as glass are used. These substrate materials are formed into a disk shape by injection molding or the like. If necessary, guide grooves or pits may be formed on the substrate surface. Such guide grooves and pits are preferably provided at the time of molding the substrate, but may also be provided on the substrate using an ultraviolet curable resin layer. Normal C
When used as D, the thickness is about 1.2 mm and the diameter is 80
~ 120mm disc with 15mm diameter in the center
There is a hole of about mm.

In the present invention, a recording layer is provided on a substrate, and the recording layer of the present invention has a λmax of 450 to 630 nm.
It contains a dipyrromethene metal chelate compound of a dipyrromethene compound represented by the general formula (1) and a metal ion present in the vicinity. In particular, it is necessary to have an appropriate optical constant for a recording and reproducing laser wavelength selected from 520 nm to 690 nm.

The optical constant is represented by a complex refractive index (n + ki). N and k in the expression are coefficients corresponding to the real part n and the imaginary part k. Here, n is a refractive index and k is an extinction coefficient. In general, an organic dye has a feature that the refractive index n and the extinction coefficient k greatly change with respect to the wavelength λ. In consideration of this feature, by selecting an organic dye having a preferable optical constant at a target laser wavelength and forming a recording layer, a medium having high reflectance and high sensitivity can be obtained. .

According to the present invention, the optical constant required for the recording layer is such that n is 1.8 or more at the wavelength of the laser light,
And k is 0.04 to 0.40, and preferably, n
Is 2.0 or more, and k is 0.04 to 0.20. If n is smaller than 1.8, the reflectance and signal modulation required for accurate signal reading cannot be obtained, and k is 0.4.
If it exceeds 0, not only is the reflectance lowered and a good reproduction signal cannot be obtained, but also the signal is easily changed by the reproduction light, which is not suitable for practical use. In consideration of this feature, by selecting an organic dye having a preferable optical constant at a target laser wavelength and forming a recording layer, a medium having high reflectance and high sensitivity can be obtained. .

The dipyrromethene metal chelate compound of the present invention represented by the general formula (1) has a higher extinction coefficient than ordinary organic dyes, and the absorption wavelength range can be arbitrarily selected by selecting a substituent. The optical constants required for the recording layer at the wavelength of the laser light (n is 1.8 or more, and k is 0.04 to 0.40, preferably n is 2.0 or more, and k is 0 0.04 to 0.20).

The optical recording medium of the present invention has a thickness of 520 to 690 nm.
In the case of reproducing with a laser beam selected from among, it is basically possible if the reflectance is 20% or more,
A reflectance of 30% or more is preferred.

In order to improve the recording characteristics, etc., it has an absorption maximum at a wavelength of 450 to 630 nm, and has an absorption maximum of 520 to 690 nm.
It may be mixed with other dyes having a large refractive index in nm. Specifically, cyanine dyes, squarylium dyes, naphthoquinone dyes, anthraquinone dyes, porphyrin dyes, tetrapyraporphyrazine dyes, indophenol dyes, pyrylium dyes, thiopyrylium dyes, azurenium dyes, triphenyl There are methane dyes, xanthene dyes, indazulene dyes, indigo dyes, thioindigo dyes, merocyanine dyes, thiazine dyes, acridine dyes, oxazine dyes, and the like, and a mixture of a plurality of dyes may be used. . The mixing ratio of these dyes is about 0.1 to 30%.

Further, when k of the dipyrromethene metal chelate compound represented by the general formula (1) is small with respect to a recording and reproducing laser wavelength selected from 520 nm to 690 nm, the recording characteristics and the like are improved. And a wavelength of 60
You may mix with the light absorption compound which has an absorption maximum in 0-900 nm. Specifically, cyanine dyes, squarylium dyes, naphthoquinone dyes, anthraquinone dyes, porphyrin dyes, tetrapyraporphyrazine dyes, indophenol dyes, pyrylium dyes, thiopyrylium dyes, azurenium dyes, triphenyl There are methane dyes, xanthene dyes, indathrene dyes, indigo dyes, thioindigo dyes, merocyanine dyes, thiazine dyes, acridine dyes, oxazine dyes, phthalocyanine dyes, naphthalocyanine dyes, and the like. May be mixed. The mixing ratio of these dyes is about 0.1 to 30%.

When forming a recording layer, a quencher, a dye decomposition accelerator, an ultraviolet absorber, an adhesive, or the like may be mixed with the above-mentioned dye, if necessary, or a compound having such an effect. Can be introduced as a substituent of the dye.

Specific examples of the quencher include metal acetylacetonates, bisdithio-α-diketones, bisdithiols such as bisphenyldithiols, thiocatechols, salicylaldehyde oximes, and thiobisphenolates. Complexes are preferred. Also, amines are suitable.

Examples of the thermal decomposition accelerator include metal anti-knocking agents, metallocene compounds, and metal compounds such as acetylacetonate metal complexes.

Further, if necessary, a binder, a leveling agent, an antifoaming agent and the like can be used in combination. Preferred binders include polyvinyl alcohol, polyvinylpyrrolidone, nitrocellulose, cellulose acetate, ketone resin, acrylic resin, polystyrene resin, urethane resin, polyvinyl butyral, polycarbonate, polycarbonate
Olefins and the like.

When the recording layer is formed on the substrate, a layer made of an inorganic substance or a polymer may be provided on the substrate in order to improve the solvent resistance, the reflectance, the recording sensitivity and the like of the substrate.

Here, the content of the dipyrromethene metal chelate compound represented by the general formula (1) in the recording layer is 3
0% or more, preferably 60% or more. In addition, it is also preferable that it is substantially 100%.

Examples of the method for providing the recording layer include coating methods such as spin coating, spraying, casting, and dipping.
Examples include a sputtering method, a chemical vapor deposition method, and a vacuum vapor deposition method, and a spin coating method is simple and preferred.

When a coating method such as a spin coating method is used, the dipyrromethene metal chelate compound represented by the general formula (1) is dissolved in a solvent so as to be 1 to 40% by weight, preferably 3 to 30% by weight. Alternatively, a dispersed coating solution is used. At this time, it is preferable to select a solvent that does not damage the substrate. For example, alcohol solvents such as methanol, ethanol, isopropyl alcohol, octafluoropentanol, allyl alcohol, methyl cellosolve, ethyl cellosolve, and tetrafluoropropanol, hexane, heptane, octane, decane, cyclohexane, methylcyclohexane, ethylcyclohexane, and dimethylcyclohexane Aliphatic or alicyclic hydrocarbon solvents such as, toluene, xylene, aromatic hydrocarbon solvents such as benzene, carbon tetrachloride, chloroform, tetrachloroethane, halogenated hydrocarbon solvents such as dibromoethane, diethyl ether, Ether solvents such as dibutyl ether, diisopropyl ether and dioxane; ketone solvents such as acetone and 3-hydroxy-3-methyl-2-butanone; and esters such as ethyl acetate and methyl lactate. System solvent,
Water. These may be used alone,
Alternatively, a plurality of them may be used in combination.

If necessary, the dye of the recording layer may be dispersed in a polymer thin film or the like.

When a solvent that does not damage the substrate cannot be selected, a sputtering method, a chemical vapor deposition method, a vacuum vapor deposition method, or the like is effective.

The thickness of the dye layer is not particularly limited, but is preferably from 50 to 300 nm. If the thickness of the dye layer is less than 50 nm, recording cannot be performed due to large thermal diffusion, or a recording signal will be distorted and the signal amplitude will be small. On the other hand, when the film thickness is larger than 300 nm, the reflectivity decreases and the reproduction signal characteristics deteriorate.

Next, on the recording layer, preferably, a thickness of 50
A reflective layer of ~ 300 nm is formed. As a material of the reflection layer, a material having a sufficiently high reflectance at the wavelength of the reproduction light, for example, A
u, Al, Ag, Cu, Ti, Cr, Ni, Pt, T
The metals a, Cr and Pd can be used alone or as an alloy. Among them, Au, Al and Ag have high reflectivity and are suitable as a material for the reflective layer. In addition, the following may be included. For example, Mg, S
e, Hf, V, Nb, Ru, W, Mn, Re, Fe, C
o, Rh, Ir, Zn, Cd, Ga, In, Si, G
Metals and metalloids such as e, Te, Pb, Po, Sn, and Bi can be mentioned. Further, those containing Au as a main component are preferable because a reflection layer having high reflectance can be easily obtained. Here, the main component means a component having a content of 50% or more. It is also possible to form a multilayer film by alternately stacking low-refractive-index thin films and high-refractive-index thin films with a material other than a metal, and use it as a reflective layer.

As a method of forming the reflection layer, for example,
Examples include a sputtering method, an ion plating method, a chemical vapor deposition method, and a vacuum vapor deposition method. In addition, a known inorganic or organic intermediate layer or adhesive layer may be provided on the substrate or under the reflective layer to improve the reflectance, the recording characteristics, and the adhesion.

Further, the material of the protective layer on the reflective layer is not particularly limited as long as it protects the reflective layer from external force. As organic substances, thermoplastic resins, thermosetting resins,
An electron beam curable resin, a UV curable resin, and the like can be given. As the inorganic substance, SiO ₂ , Si ₃ N ₄ ,
MgF ₂ , SnO _{2 and the} like can be mentioned. Thermoplastic resin, thermosetting resin, etc. are dissolved in an appropriate solvent and a coating liquid is applied,
It can be formed by drying. The UV curable resin can be formed by preparing a coating solution as it is or by dissolving it in an appropriate solvent, applying the coating solution, and irradiating with UV light to cure the resin. UV
As the curable resin, for example, urethane acrylate,
Acrylate resins such as epoxy acrylate and polyester acrylate can be used. These materials may be used alone or as a mixture, or may be used as a multilayer film as well as a single layer.

As a method of forming the protective layer, a coating method such as a spin coating method or a casting method, a sputtering method, a chemical vapor deposition method, or the like is used as in the case of the recording layer. Of these, the spin coating method is preferable.

The thickness of the protective layer is generally from 0.1 to 100.
μm, but in the present invention, 3 to 30 μm
And more preferably 5 to 20 μm.

Printing on a label or the like can be further performed on the protective layer. Alternatively, a means such as bonding a protective sheet or a substrate to the reflective layer surface, or bonding two optical recording media with the reflective layer surfaces facing each other and facing each other may be used. Further, an ultraviolet curable resin, an inorganic thin film, or the like may be formed on the mirror side of the substrate to protect the surface or prevent adhesion of dust and the like.

The laser having a wavelength of 520 to 690 nm in the present invention is not particularly limited. For example, a dye laser capable of selecting a wavelength in a wide range of the visible region, a helium neon laser having a wavelength of 633 nm, and a recently developed wavelength of 68 can be used.
A high-power semiconductor laser near 0, 650 and 635 nm,
A harmonic conversion YAG laser having a wavelength of 532 nm may be used. According to the present invention, high-density recording and reproduction can be performed at one wavelength or a plurality of wavelengths selected from these.

[0056]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited by these examples.

Example 1 Synthesis of Pyrometene Metal Chelate Compound (1-1) 1.35 g of 2-formyl-5-((E) -phenylethen-1-yl) pyrrol and 100 ml of ethanol were added to 100 ml of ethanol. -Formyl-3- (2,
After dissolving 1.9 g of 3-diisopropylphenyl) isoindole and adding 1.18 g of 47% hydrobromic acid thereto, the mixture was stirred at room temperature for 3 hours. After concentration under reduced pressure, chloroform 300
After extraction with water, washing with water and liquid separation, the solvent was distilled off to obtain 3.0 g of a compound represented by the following structural formula (6-a).

[0058]

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Next, the formula (6-) was added to 200 ml of ethanol.
Dissolve 1.4 g of the compound represented by a) and add copper acetate 0.5
6 g was added and the mixture was stirred at reflux temperature for 2 hours. After concentration under reduced pressure, the precipitate was collected by filtration and washed with methanol and water to obtain 1.2 g of a compound represented by the following structural formula (1-1).

[0060]

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From the following analysis results, it was confirmed that the substance was the target substance.

[0062]

[Table 3]

The compound thus obtained exhibits a maximum absorption at 589 nm in a toluene solution, and has a gram extinction coefficient of 1.30 × 10 ⁵ ml / g. cm.

Example 2 Synthesis of Pyromethene Metal Chelate Compound (1-4) 2-Formyl-5-((E) -4-t-butylphenylethen-1-yl) pyrrol in 100 ml of ethanol 1.74 g and 1.9 g of 1-formyl-3- (2,3-diisopropylphenyl) isoindole were dissolved, and 1.18 g of 47% hydrobromic acid was added dropwise, followed by stirring at room temperature for 3 hours. After concentration under reduced pressure, the mixture was extracted with chloroform (300 ml), washed with water, and separated, and the solvent was distilled off to obtain 3.1 g of a compound represented by the following structural formula (6-b).

[0065]

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Next, the formula (6-) was added to 200 ml of ethanol.
1.57 g of the compound represented by b) was dissolved in
56 g was added, and the mixture was stirred at reflux temperature for 2 hours. After concentration under reduced pressure, the precipitate was collected by filtration and washed with methanol and water to obtain 1.5 g of a compound represented by the following structural formula (1-4).

[0067]

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From the following analysis results, it was confirmed that the substance was the target substance.

[0069]

[Table 4]

The compound thus obtained shows a maximum absorption at 588 nm in a toluene solution, and has a gram extinction coefficient of 1.15 × 10 ⁵ ml / g. cm.

Example 3 Synthesis of Pyromethene Metal Chelate Compound (1-10) 2-Formyl-3,4-diethyl-5-ethanol was added to 100 ml of ethanol.
1.74 g of ((E) -phenylethen-1-yl) pyrrol and 1
After dissolving 1.9 g of -formyl-3- (2,3-diisopropylphenyl) isoindole and adding 1.18 g of 47% hydrobromic acid thereto, the mixture was stirred at room temperature for 3 hours. After concentration under reduced pressure, extraction with chloroform (300 ml), washing with water and liquid separation, the solvent was distilled off, and 3.0 g of a compound represented by the following structural formula (6-c) was obtained.
I got

[0072]

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Next, the formula (6-) was added to 200 ml of ethanol.
1.57 g of the compound represented by c) was dissolved in
56 g was added, and the mixture was stirred at reflux temperature for 2 hours. After concentration under reduced pressure, the precipitate was collected by filtration and washed with methanol and water to obtain 1.6 g of a compound represented by the following structural formula (1-10).

[0074]

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From the following analysis results, it was confirmed that the substance was the target substance.

[0076]

[Table 5]

The compound thus obtained exhibits a maximum absorption at 595 nm in a toluene solution, and has a gram extinction coefficient of 1.05 × 10 ⁵ ml / g. cm.

Example 4 Synthesis of Pyromethene Metal Chelate Compound (1-12) 1.4 g of the compound represented by the formula (6-a) was dissolved in 200 ml of ethanol, and 0.76 g of cobalt acetate tetrahydrate was dissolved. Was added and stirred at reflux temperature for 4 hours. After concentration under reduced pressure, the precipitate was collected by filtration and washed with methanol and water to obtain 1.3 g of a compound represented by the following structural formula (1-12).

[0079]

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From the following analysis results, it was confirmed that the substance was the target substance.

[0081]

[Table 6]

The compound thus obtained exhibits a maximum absorption at 575 nm in a toluene solution, and has a gram extinction coefficient of 1.50 × 10 ⁵ ml / g. cm.

Example 5 Synthesis of Pyromethene Metal Chelate Compound (1-18) 1.39 g of 2-formyl-5- (2-thienylethen-1-yl) pyrrol and 1.39 g of 1-formyl- in 100 ml of ethanol After dissolving 1.32 g of 3-phenylisoindole and dropping 1.18 g of 47% hydrobromic acid, the mixture was stirred at room temperature for 3 hours.
After concentration under reduced pressure, the mixture was extracted with chloroform (300 ml), washed with water and separated, and the solvent was distilled off to obtain 2.6 g of a compound represented by the following structural formula (6-d).

[0084]

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Next, the formula (6-) was added to 200 ml of ethanol.
Dissolve 1.2 g of the compound represented by d) and add copper acetate 0.5
6 g was added and the mixture was stirred at reflux temperature for 2 hours. After concentration under reduced pressure, the precipitate was collected by filtration and washed with methanol and water to obtain 1.1 g of a compound represented by the following structural formula (1-18).

[0086]

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From the following analysis results, the product was confirmed to be the target product.

[0088]

[Table 7]

The compound thus obtained exhibits a maximum absorption at 602 nm in a toluene solution, and has a gram extinction coefficient of 1.57 × 10 ⁵ ml / g. cm.

Example 6 Synthesis of Pyromethene Metal Chelate Compound (1-22) 1.2 g of the compound represented by the formula (6-d) was dissolved in 200 ml of ethanol, and 0.56 g of zinc acetate was added. Stirred at reflux temperature for 5 hours. After concentration under reduced pressure, the precipitate was collected by filtration,
After washing with methanol and water, the following structural formula (1-22)
1.2 g of the compound represented by was obtained.

[0091]

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From the following analysis results, the product was confirmed to be the target product.

[0093]

[Table 8]

The compound thus obtained exhibits a maximum absorption at 597 nm in a toluene solution, and has a gram extinction coefficient of 1.72 × 10 ⁵ ml / g. cm.

Example 7 0.2 g of the dipyrromethene metal chelate compound (1-1) was added to dimethylcyclohexane 10%.
The dye solution was dissolved in the solution to prepare a dye solution. The substrate is made of a continuous guide groove made of polycarbonate resin (track pitch:
0.8 μm) with a diameter of 120 mmφ and a thickness of 1.2 m
m was used.

A dye solution was placed on this substrate at a rotational speed of 1500 r.
pm, and dried at 70 ° C. for 3 hours to form a recording layer. The absorption maximum of this recording layer is 602 nm, and the optical constant is n = 2.2 and k is 0.2 at 680 nm.
03, and at 650 nm, n is 2.2 and k is 0.04.
At 635 nm, n is 2.3 and k is 0.06.

Au was sputtered on this recording layer using a sputtering apparatus (CDI-900, manufactured by Balzers) to form a reflective layer having a thickness of 100 nm. Sputter gas includes
Argon gas was used. The sputtering conditions were as follows: a sputtering power of 2.5 kW and a sputtering gas pressure of 1.0 × 10 ⁻² Torr.
I went in.

Further, an ultraviolet curable resin SD-
After spin-coating No. 17 (manufactured by Dainippon Ink and Chemicals), the layer was irradiated with ultraviolet rays to form a protective layer having a thickness of 6 μm, thereby producing an optical recording medium.

An optical disk evaluation device (DDU- manufactured by Pulstec Industrial Co., Ltd.) equipped with a semiconductor laser head having a wavelength of 635 nm and a lens numerical aperture of 0.6 on the obtained optical recording medium.
1000) and a KENWOOD EFM encoder so that the linear velocity was 3.5 m / s, the laser power was 8 mW, and the shortest pit length was 0.44 μm. After recording, the signal was reproduced using an evaluation device equipped with 650 nm and 635 nm red semiconductor laser heads (the aperture of the lens was 0.6), and the reflectance, error rate, and modulation were measured. Rate 56%, error
Rate 9 cps, modulation degree 0.63, reflectivity 54% at 635 nm reproduction, error rate 10 cps, modulation degree 0.61
And all showed good values. Also, a 100-hour car
No change was observed after the light resistance test in Bonarc.

The error rate is a CD manufactured by Kenwood.
The measurement was performed using a decoder (DR3552), and the modulation was obtained by the following equation.

[0101]

(Equation 1)

Example 8 The same as Example 7 except that a disc-shaped substrate having a diameter of 120 mmφ and a thickness of 0.6 mm having a continuous guide groove (track pitch: 0.8 μm) made of polycarbonate resin was used for the substrate. To form a coating and reflection layer.

Further, an ultraviolet curable adhesive SD is provided on the reflective layer.
-301 (manufactured by Dainippon Ink and Chemicals) is spin-coated, and a polycarbonate resin is formed thereon and has a diameter of 120 mm.
An optical recording medium was prepared by placing a disc-shaped substrate having a diameter of 0.6 mm and then irradiating the substrate with ultraviolet rays.

An optical disk evaluation device (DDU-1000) manufactured by Pulstec Industrial Co., Ltd. and an EFM encoder manufactured by KENWOOD were used in the same manner as in Example 7 except that a 635 nm semiconductor laser head corresponding to a thickness of 0.6 mm was mounted on the manufactured medium. And recorded. After recording, the signal was reproduced using an evaluation device equipped with 650 nm and 635 nm red semiconductor laser heads, and the reflectance, error rate, and modulation were measured.
Error rate 10 cps, modulation degree 0.61, 635 nm
At the time of reproduction, the reflectance was 55%, the error rate was 11 cps, and the modulation degree was 0.62, all of which were good values. No change was observed even after the light resistance test in carbon arc for 100 hours.

Comparative Example 1 In Example 8, a pentamethine cyanine dye NK-2929 [1,3,3,1 ′, 3 ′, 3′-) was used in place of the dipyrromethene metal chelate compound (1-1).
Hexamethyl-2 ', 2'-(4,5,4 ', 5'-dibenzo) indodicarbocyanine perchlorate, manufactured by Japan Photographic Dye Laboratory
An optical recording medium was produced in the same manner except that the above was used.
An optical disk evaluation device (DDU-1000) manufactured by Pulstec Industrial having a 635 nm semiconductor laser head mounted on the manufactured medium in the same manner as in Example 8, and an EF manufactured by KENWOOD
Recording was performed at a linear velocity of 3.5 m / s and a laser power of 7 mW using an M encoder. After recording, 650 nm and 6
As a result of reproducing a signal using an evaluation device equipped with a 35 nm red semiconductor laser head, the reflectance was 9% at 650 nm reproduction, the error rate was 3000 cps, the modulation was 0.13,
9% reflectivity at 635 nm reproduction, error rate 2500c
The ps and the modulation degree were inferior to 0.15. Furthermore, the signal deteriorated after a light fastness test in a carbon arc for 100 hours.

[0106]

By using the dipyrromethene metal chelate compound of the present invention as a recording layer, a write-once optical recording medium capable of recording and reproducing with a laser having a wavelength of 520 to 690 nm, which has been attracting much attention as a high-density optical recording medium, can be obtained. Can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional structural view showing a conventional optical recording medium and a layer configuration of the present invention.

FIG. 2 is a sectional structural view showing a layer configuration of the optical recording medium of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Recording layer 3 Reflective layer 4 Protective layer 1 'Substrate 2' Recording layer 3 'Reflective layer 4' Adhesive layer 5 'Substrate

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Taizo Nishimoto 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsui Toatsu Chemical Co., Ltd. (72) Inventor U U 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical (72) Inventor Keisuke Takuma 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd.

Claims (3)

[Claims] 1. A dipyrromethene metal chelate compound represented by the following general formula (1). Embedded image [Wherein, R _{1 to} R ₉ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 20 or less carbon atoms,
Represents an alkoxy group, an alkenyl group, an acyl group, an alkoxycarbonyl group, an aralkyl group, an aryl group or a heteroaryl group, and M represents a transition element. ] 2. An optical recording medium having at least a recording layer and a reflective layer on a substrate, wherein the recording layer contains the dipyrromethene metal chelate compound according to claim 1. 3. The optical recording medium according to claim 2, wherein recording and reproduction can be performed with respect to a laser beam selected from a wavelength range of 520 to 690 nm.