JPH1192479A - Optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject medium allowing the recording and reproduction with a short-wavelength laser and suitable for high-density recording by including a metal chelate compound derived from a specific compound and a metal ion in a recording layer. SOLUTION: The objective medium is produced by including an azapyrromethene metal chelate compound derived from an azapyrromethene compound of the formula I (R1 to R6 are each H, etc.), and a metal ion in a recording layer. The compound of the formula I can be produced by reacting a compound of the formula II with a compound of the formula III in acetic acid. An azapyrromethene metal chelate compound coordinated with the corresponding metal is produced e.g. by reacting the compound of the formula I with baron trifluoride, etc. The medium enables the recording and reproduction with a laser light having a wavelength of 520-690 nm and preferably has a reflectance of >=30% measured from the substrate side. The recording layer preferably has a refractive index of >=2.0 and an extinction coefficient of 0.04-0.20 at the wavelength of the laser light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an azapyrromethene metal chelate compound and an optical recording medium using the same, which allows higher density recording and reproduction 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 an azapyrromethene metal chelate compound and a compound containing the same.
An object of the present invention is to provide an optical recording medium suitable for high-density recording that can record and reproduce with a short wavelength laser having a wavelength of 520 to 690 nm.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, completed the present invention. That is, the present invention relates to an azapyrromethene metal chelate compound obtained from an azapyrromethene compound represented by the following general formula (1) and a metal ion in an optical recording medium having at least a recording layer and a reflective layer on a substrate. An optical recording medium containing

[0007]

Embedded image [Wherein, R _{1 to} R ₆ each independently represent 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, wherein R ₁ and R ₂ , R ₂ and R ₃ , R ₄ and R ₅ or R
₅ and R ₆ may be bonded to each other to form an aromatic ring fused to a pyrrole ring. ]

An optical recording medium according to the above, wherein the azapyrromethene metal chelate compound is a compound represented by the following general formula (2):

[0009]

Embedded image [Wherein, R _{1 to} R ₆ represent the same meaning as described above, and M represents a transition element. ]

An optical recording medium according to the above, wherein the azapyrromethene metal chelate compound is a compound represented by the following general formula (3):

[0011]

Embedded image [Wherein, R _{1 to} R ₆ represent the same meaning as described above. ]

[0012] The optical recording medium according to any one of [1] to [3], wherein recording and reproduction are possible with respect to a laser beam selected from the wavelength range of 520 to 690 nm, and the recording layer has a refractive index of 1.8 at the laser wavelength. Above, and the extinction coefficient is 0.04 to 0.40
The optical recording medium according to any one of-, wherein the reflectance measured from the substrate side to the laser light selected from the wavelength range of 520 to 690 nm is 20% or more. An azapyrromethene metal chelate compound represented by the following general formula (4):

[0013]

Embedded image [Wherein, R _{7 to} R ₁₄ each independently represent 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. ]

An azapyrromethene metal chelate compound represented by the following general formula (5):

[0015]

Embedded image [Wherein, R _{7 to} R ₁₄ represent the same meaning as described above. ].

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION In the azapyrromethene metal chelate compound of the present invention represented by the general formula (1) and a metal ion, specific examples of R _{1 to} R ₁₄ include a hydrogen atom; A halogen atom of bromine or iodine;

Methyl, ethyl, n-propyl, 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;

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, benzoimidazoyl, benzofuranyl, indoyl, etc. Or a substituted or unsubstituted heteroaryl group.

The metal forming a chelate compound together with the azapyrromethene compound represented by the general formula (1) is not particularly limited as long as it is generally a metal capable of forming a chelate compound with the azapyrromethene compound. 9, 10 (VIII), 11 (Ib), 1
Group 2 (Group IIb), Group 3 (Group IIIa), Group 4 (Group IVa),
Group 5 (Group Va), Group 6 (Group VIa), Group 7 (Group VIIa) metals, preferably nickel, cobalt,
Transition elements such as iron, ruthenium, rhodium, palladium, copper, osmium, iridium, platinum, and zinc are exemplified.

The azapyrromethene compound represented by the general formula (1) of the present invention and the azapyrromethene metal chelate compound are not limited. Chem. So
c, 590-599 (1943), Heteroaat.
om Chemistry, Vol. 4,6,603-
608 (1993) and the like. Typically, it can be produced by the following two-step reaction.

First, in the first step, a compound represented by the general formula (6) and a compound represented by the general formula (7), or a compound represented by the general formula (8) and a compound represented by the general formula (9) Is reacted in acetic acid to obtain an azapyrromethene compound represented by the general formula (1). Next, in the second step, an azapyrromethene compound represented by the general formula (1) and a metal triacetate such as boron trifluoride, nickel, cobalt, iron, ruthenium, rhodium, palladium, copper, osmium, iridium, platinum, zinc, By reacting with a halide, an azapyrromethene metal chelate compound in which the corresponding metal is coordinated is obtained.

[0028]

Embedded image

[0029]

Embedded image

[0030]

Embedded image

[0031]

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

Table 1 shows specific examples of the metal chelate of the azapyrromethene compound represented by the general formula (1) of the present invention, exemplifying the respective substituents in the general formulas (2) to (5). The compound numbers in the table are combinations of the formula numbers and the serial numbers. For example, 2-1 indicates the first example of the compound of the formula (2).

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

[Table 3]

[0036]

[Table 4]

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 an azapyrromethene metal chelate compound of a metal ion and an azapyrromethene compound represented by the general formula (1) present nearby. 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, organic dyes are characterized in 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 at least 1.8 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 azapyrromethene metal chelate compound represented by the general formula (1) according to the present invention is more effective than ordinary organic dyes.
Since the extinction coefficient is high 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 an extremely useful compound that satisfies the condition that n is 2.0 or more and k is 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.

Further, 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 azapyrromethene metal chelate compound represented by the general formula (1) is small with respect to the recording and reproducing laser wavelength selected from 520 nm to 690 nm, it is necessary to improve the recording characteristics. , Wavelength 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 the 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 metals such as acetylacetonate, bisdithio-α-diketone and bisphenyldithiol, and other bisdithiols, thiocatechol, salicylaldehyde oxime, and thiobisphenolate. Complexes are preferred. Also, amines are suitable.

Examples of the thermal decomposition accelerator include metal antiknocking 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, polyolefin 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 azapyrromethene metal chelate compound represented by the general formula (1) in the recording layer is as follows:
It is at least 30%, preferably at least 60%. In addition, it is also preferable that it is substantially 100%.

The method for providing the recording layer includes, for example, a coating method such as a spin coating method, a spray method, a casting method, and a dipping method;
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, 1 to 40% by weight, preferably 3 to 30% by weight of the azapyrromethene metal chelate compound represented by the general formula (1) is used.
A coating solution dissolved or dispersed in a solvent is used so that the solvent is preferably selected so as not to 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 can be used by dispersing it 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 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.

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 for 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.

A label or the like can be further printed on the protective layer.

Alternatively, a protective sheet or a substrate may be bonded to the reflective layer surface, or two optical recording media may be bonded with the reflective layer surfaces facing each other.

On the mirror surface of the substrate, an ultraviolet curable resin, an inorganic thin film or the like may be formed to protect the surface or prevent adhesion of dust and the like.

The laser having a wavelength of 520 to 690 nm referred to 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.

[0067]

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

Example 1 Among the azapyrromethene metal chelate compounds represented by the general formula (1), 0.2 g of the compound (2-1) shown in Table 1 was dissolved in 10 ml of dimethylcyclohexane, and a dye solution was prepared. Was prepared. The substrate is made of polycarbonate resin and has a continuous guide groove (track pitch: 0.8 μm) with a diameter of 120 mmφ and a thickness of 1.
A 2 mm disc 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 620 nm, and the optical constants are n = 2.2 and k = 0.2 at 680 nm.
06, n is 2.3 and k is 0.07 at 650 nm.
At 635 nm, n is 2.4 and k is 0.07.

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.

The obtained optical recording medium is equipped with a semiconductor laser head having a wavelength of 635 nm and a lens numerical aperture of 0.6, and an optical disk evaluation device (DDU- manufactured by Pulstec Industrial Co., Ltd.).
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, signals were reproduced using an evaluation device equipped with 650 nm and 635 nm red semiconductor laser heads (the numerical aperture of the lens was 0.6), and the reflectance, error rate, and modulation were measured. The value was shown.

Next, an optical disk evaluation device (DDU) manufactured by Pulstec Industrial equipped with a 680 nm semiconductor laser head
-1000) and KENWOOD EFM encoder, linear velocity 1.4m / s, laser power 10m
W was recorded so that the shortest pit length was 0.60 μm.
The recorded medium was stored at 680 nm, 650 nm and 635 nm.
A signal was reproduced using an optical disk evaluation device (DDU-1000) manufactured by Pulstec Industrial equipped with a nm red semiconductor laser head, and the reflectance, the error rate, and the modulation were measured. All exhibited good values.

As described above, this medium was able to perform recording and reproduction favorably with a plurality of laser wavelengths.

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

[0076]

(Equation 1)

Example 2 The same as Example 1 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 and an EFM encoder manufactured by KENWOOD were used in the same manner as in Example 1 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.

[Examples 3 to 48] The azapyrromethene metal chelate compounds (2-2 to 2-13, 3
-1 to 3-13, 4-1 to 4-11, 5-1 to 5-1
An optical recording medium was produced in the same manner as in Example 2 except that 1) was used.

In the same manner as in Example 2, 635 n
m Optical disk evaluation device (DDU-1000) manufactured by Pulstec Industrial equipped with a semiconductor laser head and KENW
Recording was performed using an OOD EFM encoder. After recording, the signal was reproduced using an evaluation device equipped with 650 nm and 635 nm red semiconductor laser heads, and the reflectance,
As a result of measuring the error rate and the degree of modulation, all of them showed good values.

Comparative Example 1 In Example 2, a pentamethine cyanine dye NK-2929 [1,3,3,1 ′, 3 ′, 3 ′) was used in place of the azapyrromethene metal chelate compound (2-1).
-Hexamethyl-2 ', 2'-(4,5,4 ', 5'-dibenzo) indodicarbocyanine perchlorate, manufactured by Japan Photographic Dye Laboratories
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 and a EF manufactured by KENWOOD equipped with a 635 nm semiconductor laser head mounted on the manufactured medium in the same manner as in Example 2.
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 low, the error rate was large, and the modulation was small. Furthermore, the signal deteriorated during long-time reproduction.

Comparative Example 2 In Comparative Example 1, NK29
29 instead of the trimethine cyanine dye NK79 [1,3,
3,1 ′, 3 ′, 3′-Hexamethyl-2 ′, 2′-indodicarbocyanine iodide, manufactured by Japan Photographic Dye Laboratories]. An optical disk evaluation device (DD manufactured by Pulstec Industrial Co., Ltd.) equipped with a 635 nm semiconductor laser head on the manufactured medium in the same manner as in Example 2.
U-1000) and KENWOOD EFM encoder, linear velocity 3.5 m / s, laser power 7 m
W recorded. After recording, the signal was reproduced using an evaluation device equipped with 650 nm and 635 nm red semiconductor laser heads. As a result, the waveform was distorted, and the error rate was large.
The degree of modulation was also small. Furthermore, the signal deteriorated during long-time reproduction.

The above Examples 1-48 and Comparative Examples 1-2
, The optical constant of the recording layer and each medium were 635 nm
Table 2 shows the reflectivity, error rate, and modulation factor when recording at 650 and 635 nm.

[0085]

[Table 5]

[0086]

[Table 6]

[0087]

[Table 7]

[0088]

[Table 8]

[0089]

[Table 9]

[0090]

[Table 10]

[0091]

[Table 11]

Example 49 Synthesis of Compound (4-1) 1-Formyl-3- (2,4-diisopropyl) in 100 ml of acetic acid
2.78 g of phenylisoindole and 5-nitroso-2,
2.86 g of 4-diphenylpyrrole was dissolved and refluxed for 30 minutes. After cooling to room temperature, drain into 600 ml of water,
After salting out, the compound represented by the following structural formula (1-a) 5.
2 g were obtained.

[0093]

Embedded image

Next, the formula (1-) was added to 500 ml of ethanol.
Dissolve 2.54 g of the compound of a) and add
91 g was added, and the mixture was stirred at reflux temperature for 3 hours. After cooling,
The solvent was distilled off under reduced pressure, and the residue was purified by column (eluent; toluene: hexane = 1: 1) to obtain 2.3 g of a compound represented by the following structural formula (4-1).

[0095]

Embedded image

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

[0097]

[Table 12]

The compound thus obtained exhibits a maximum absorption at 636.5 nm in a toluene solution, and has a gram extinction coefficient of 0.80 × 10 ⁵ ml / g. cm.

Example 50 Synthesis of Compound (4-4) 1.2 g of the compound represented by the formula (1-a) was dissolved in 500 ml of ethanol, 0.43 g of zinc acetate was added, and the mixture was refluxed for 6 hours. Stirred. After cooling, the solvent was distilled off under reduced pressure, and the residue was purified by column (eluent; toluene: hexane = 1: 1) to obtain 1.1 g of a compound represented by the following structural formula (4-4).

[0100]

Embedded image

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

[0102]

[Table 13]

The compound thus obtained exhibits a maximum absorption at 625.5 nm in a toluene solution, and has a gram extinction coefficient of 1.17 × 10 ⁵ ml / g. cm.

[0104]

According to the present invention, by using an azapyrromethene metal chelate compound of an azapyrromethene compound and a metal ion as a recording layer, 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. It is possible to provide a recordable optical recording medium on which recording and reproduction can be performed.

[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

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C09B 55/00 G11B 7/24 516 G11B 7/24 516 C09K 3/00 108D // C09K 3/00 108 B41M 5/26 Y (72) Invention Person Taizo Nishimoto 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside of Mitsui Toatsu Chemicals Co., Ltd. (72) Inventor U. Tsukahara 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsui Toatsu Chemicals Co., Ltd. 1190 Kasama-cho, Sakae-ku, Yokohama, Japan Mitsui Toatsu Chemical Co., Ltd.

Claims (8)

[Claims] In an optical recording medium having at least a recording layer and a reflective layer on a substrate, an azapyrromethene metal chelate compound obtained from an azapyrromethene compound represented by the following general formula (1) and a metal ion is contained in the recording layer. Optical recording medium containing. Embedded image [Wherein, R _{1 to} R ₆ each independently represent 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, wherein R ₁ and R ₂ , R ₂ and R ₃ , R ₄ and R ₅ or R
₅ and R ₆ may be bonded to each other to form an aromatic ring fused to a pyrrole ring. ] 2. An azapyrromethene metal chelate compound,
The optical recording medium according to claim 1, which is a compound represented by the following general formula (2). Embedded image [Wherein, R _{1 to} R ₆ represent the same meaning as described above, and M represents a transition element. ] 3. An azapyrromethene metal chelate compound,
The optical recording medium according to claim 1, which is a compound represented by the following general formula (3). Embedded image [Wherein, R _{1 to} R ₆ represent the same meaning as described above. ] 4. The optical recording medium according to claim 1, wherein recording and reproduction can be performed with respect to a laser beam selected from a wavelength range of 520 to 690 nm. 5. The optical recording medium according to claim 1, wherein at a laser wavelength, the recording layer has a refractive index of 1.8 or more and an extinction coefficient of 0.04 to 0.40. 6. The optical recording medium according to claim 1, wherein the reflectance of the laser light selected from the wavelength range of 520 to 690 nm measured from the substrate side is 20% or more. 7. An azapyrromethene metal chelate compound represented by the following general formula (4). Embedded image [Wherein, R _{7 to} R ₁₄ each independently represent 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. ] 8. An azapyrromethene metal chelate compound represented by the following general formula (5). Embedded image [Wherein, R _{7 to} R ₁₄ represent the same meaning as described above. ]