JPH10181206A - Optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform recording and reproduction using a laser light of short wavelength by adding a specified compound into a recording layer. SOLUTION: A recording layer contains at least one kind of azo metal chelate shown by a formula (where, M: a group 3-9 or 10 metal or an oxide or a halide thereof, A: an anion, X: a residue bonded with carbon and nitrogen atoms to form a plurality of rings, Y: a residue bonded with two carbon atoms to form an aromatic group, Z<1> , Z<2> : a hydrogen atom or a cation independently, n: an integer of 1-3, the Ring X and the ring Y may have a substituent, e.g. alkyl group, alkoxy group or amino group, independently). Since high light absorbance and reflectance are attained for wavelength of 700nm or below, recording and reproduction can be performed using a laser light in the wavelength region of 700nm or below where high density recording can be carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium, and more particularly, to irradiating a light beam to cause an optical change such as transmittance and reflectance of a recording material.
The present invention relates to an optical recording medium on which information can be recorded, reproduced, and additionally recorded.

[0002]

2. Description of the Related Art The current write-once optical disk system (WO
RM, CD-R), the oscillation wavelength of the laser used is 770.
nm to 790 nm, and the recording medium records at the above wavelength,
It is configured to be able to reproduce. In the future, it is indispensable to increase the capacity of the recording medium as the amount of information increases. Therefore, it is easily expected that the wavelength of the laser used for recording and reproduction will inevitably be shortened. Many proposals have been made for data write-once optical disks using a cyanine dye or a phthalocyanine dye as a recording material (for example, a disk using a cyanine dye as a recording material is disclosed in No., JP-A-58-56892, JP-A-58-112790,
JP-A-58-114989, JP-A-59-85791
JP-A-60-83236, JP-A-60-8984
No. 2, JP-A-61-25886, and those using a phthalocyanine dye as a recording material are described in JP-A-61-150243 and JP-A-61-177287.
JP-A-61-154888, JP-A-61-246
No. 091, JP-A-62-39286, JP-A-63-3
No. 7791, JP-A-63-39888, etc.), but a recording material which is excellent in light resistance and storage stability and which can be recorded and reproduced by an optical pickup using a laser of 700 nm or less is still being developed. It has not been done yet.

The current CD-R disk system is also configured so that recording and reproduction can be performed at a laser oscillation wavelength of 770 nm to 790 nm. In this system, as in the above, it is essential to increase the capacity and shorten the recording / reproducing wavelength. In this regard, current CDs and CD-ROMs
Al is coated on the unevenness of the substrate itself.
Has a small wavelength dependence of the reflectance, so that it is possible to reproduce even if the laser wavelength is shortened in the future. However,
The CD-R uses a dye having a maximum absorption wavelength at 680 nm to 750 nm for the recording layer, and is set so as to obtain a high reflectance at 770 nm to 790 nm from the optical constant and the film thickness configuration. In this case, the reflectivity is extremely low, so that it is impossible to cope with the shortening of the laser wavelength, and information recorded and reproduced by the current CD-R system cannot be reproduced by a future system. Until now CD
Numerous proposals have been made for -R using a cyanine dye / metal reflection layer, a phthalocyanine dye / metal reflection layer, or an azo metal chelate dye / metal reflection layer as a recording material (for example, a cyanine dye / metal reflection layer is used. JP-A-1-159842, JP-A-2-42652, JP-A-2-13656 and JP-A-2-168446 each use a phthalocyanine dye as a recording material. Japanese Patent Laid-Open No. 1-1765
No. 85, JP-A-3-215466, JP-A-4-113
886, JP-A-4-226390, JP-A-5-12
No. 72, JP-A-5-171052, JP-A-5-116
456, JP-A-5-69860, JP-A-5-139
Nos. 044-46186, and those using an azo metal chelate dye as a recording material are described in JP-A-4-46186.
JP-A-4-141489, JP-A-4-36088
And Japanese Unexamined Patent Application Publication No. 5-279580), however, no solution has been found to solve such a problem.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above situation, and has a high density optical disk using a semiconductor laser having an oscillation wavelength shorter than that of the conventional system. It provides a recording material for optical recording media with excellent light resistance and storage stability that can be applied to systems, and a CD-ROM that can be recorded and played back with the current system and can be played back even in the next-generation high-density optical disk system. It is an object to provide a recording material for an R medium.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that by providing a recording layer containing a dye having a specific structure as a main component, a high-density semiconductor laser having an oscillation wavelength of 700 nm or less can be used. It is found that it can be applied to optical disc systems, and furthermore, it is possible to obtain a high reflectance even in the wavelength region of 700 nm or less by using this dye in combination with an organic dye currently used as a recording material for CD-R. Have been found possible, and the present invention has been completed.

That is, according to the present invention, first, a recording layer is provided directly or via an undercoat layer on a substrate, and if necessary, a reflection layer and a protective layer are further provided thereon. An optical recording medium is provided, wherein the recording layer contains at least one azo metal chelate compound represented by the following general formula (I) in the recording layer.

Embedded image (Wherein, M, A, X, Y, Z ¹ , Z ² and n each represent the following: M: 3, 4, 5, 6, 7, 8, 9) Or a metal atom of Group 10 or an oxide or halide thereof, A: an anion, X: a residue which forms a heterocyclic ring together with the carbon atom and nitrogen atom to which it is bonded, Y: A residue which forms an aromatic group together with two carbon atoms bonded thereto; Z ¹ and Z ² each independently represent a hydrogen atom or a cation; n: an integer of 1 to 3; Each independently may have a substituent such as an alkyl group, an alkoxy group, an amino group, a substituted amino group, a hydroxyl group, a halogen atom, a nitro group, a cyano group, a methyl trifluoride group, a carboxyl group, etc.) The recording layer may include at least one of the compounds represented by the general formula (I). The optical recording medium according to the first aspect, comprising a seed and an organic dye having a maximum absorption wavelength at 680 nm to 750 nm is provided. Thirdly, there is provided the optical recording medium according to the second aspect, wherein the organic dye having the maximum absorption wavelength at 680 nm to 750 nm is at least one of a cyanine dye, a phthalocyanine dye, and a tri (di) arylmethane compound. . Fourthly, there is provided the optical recording medium according to any one of the first to third aspects, wherein the recording layer is recorded by a laser beam having a wavelength of 630 to 720 nm. Fifthly, there is provided the optical recording medium according to any one of the first to fourth aspects, wherein the reflection layer is made of aluminum or gold. Sixthly, there is provided the optical recording medium according to any one of the first to fifth aspects, wherein the protective layer is made of an ultraviolet curable resin.

The optical recording medium of the present invention has the general formula (I)
Since the recording layer containing at least one azo metal chelate compound represented by the formula (1) is provided, recording and reproduction can be performed with a laser beam in a wavelength region of 700 nm or less, and light resistance and storage stability are excellent. In another aspect,
A recording layer comprising a mixture of at least one of the compounds represented by the general formula (I) and an organic dye having a maximum absorption wavelength at 680 to 750 nm is used as a CD-R medium in the current system. The described information can be reproduced even in the next generation high-density optical disk system.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The optical recording medium of the present invention is characterized in that the recording layer contains at least one azo metal chelate compound represented by the following general formula (I).

Embedded image

First, the above general formula (I) used in the present invention
Explaining the azo metal chelate compound represented by the following formula, in the general formula (I), M is a group 3, group 4, 5
Represents a metal atom of group 6, 6, 7, 8, 9 or 10, or an oxide or halide thereof, A represents an anion, X represents a carbon atom and a nitrogen atom to which it is bonded. Represents a residue that forms a heterocyclic ring with
Y represents a residue which forms an aromatic group together with the two carbon atoms to which it is bonded, Z ¹ and Z ² each independently represent a hydrogen atom or a cation, and n is an integer of 1 to 3 It is. Ring X and ring Y each independently have a substituent such as an alkyl group, an alkoxy group, an amino group, a substituted amino group, a hydroxyl group, a halogen atom, a nitro group, a cyano group, a methyl trifluoride group, and a carboxyl group. You may.

Specific examples of M in the general formula (I) include group 3 atoms such as Sc and Y, and groups 4 such as Ti, Zr and Hf.
Group atom, group V atom such as V, Nb, Ta, etc., Cr, Mo, W
Group 6 atom such as Mn, Tc, Re, etc., Fe,
Group 8 atoms such as Co, Ni, Ru, Rh, Pd, Os, Ir, and Pt; Group 9 atoms such as Cu, Ag, and Au; Zn, C
Examples thereof include Group 10 atoms such as d and Hg, and their oxides or halides such as fluoride, chloride, bromide, and iodide.

Further, specific examples of A include anions as shown in Table 1.

[Table 1]

Specific examples of the ring X include heterocycles shown in Table 2.

[Table 2]

Specific examples of the ring Y include aromatic rings such as a benzene ring and a naphthalene ring. As described above, ring X and ring Y each independently represent an alkyl group, an alkoxy group, an amino group, a substituted amino group, a hydroxyl group,
It may have a substituent such as a halogen atom, a nitro group, a cyano group, a methyl trifluoride group, a carboxy group and the like.

The basic structural formulas of the ligands in the azo metal chelate compound represented by the general formula (I) are shown in Table 3 below.
The results are shown in (1) to 3- (4).

[0015]

[Table 3- (1)]

[0016]

[Table 3- (2)]

[0017]

[Table 3- (3)]

[0018]

[Table 3- (4)]

Specific examples of the azo metal chelate compound represented by the general formula (I) of the present invention include, for example, Table 4
(1) to 4- (6).

[0020]

[Table 4- (1)]

[0021]

[Table 4- (2)]

[0022]

[Table 4- (3)]

[0023]

[Table 4- (4)]

[0024]

[Table 4- (5)]

[0025]

[Table 4- (6)]

As described above, the recording layer mainly contains a mixture of at least one compound represented by the above general formula (I) and an organic dye having a maximum absorption wavelength at 680 to 750 nm. As a result, the CD-R recording medium can be recorded and reproduced by the current system and can be reproduced only by the next-generation system. In this case, as the dye having the maximum absorption wavelength at 680 to 750 nm, a cyanine dye (particularly, a cyanine dye of pentamethine), a phthalocyanine dye, and an azo metal chelate dye are preferable.

Preferred examples of the cyanine dye include those represented by the following general formula (II).

Embedded image In the formula, R ¹ and R ² are an alkyl group having 1 to 3 carbon atoms, R ³ and R ⁴
Represents a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and Z ³ represents an acid anion. Note that the aromatic ring may be condensed with another aromatic ring, or may be substituted with an alkyl group, a halogen atom, an alkoxy group, or an acyl group.

Preferred examples of the phthalocyanine dye include those represented by the following formula (III-1) or (III-2).

Embedded image In the formula, M ¹ is Ni, Pd, Cu, Zn, Co, Mn, F
e, TiO or VO, X ^{5 to} X ⁸ each independently represent -OR or -SR at the substitution position α-position, and R represents an optionally substituted linear, branched or alicyclic group having 3 to 12 carbon atoms. Represents an alkyl group or an aryl group which may be substituted. Substituents on the benzene ring other than X ^{5 to} X ⁸ are a hydrogen atom or a halogen atom.

[0029]

Embedded image In the formula, M ² represents Si, Ge, In, or Sn by X ^{9 to} X
¹² is each independently -OR or -SR at the substitution position α.
R is an optionally substituted straight chain having 3 to 12 carbon atoms,
A branched or alicyclic alkyl group or an aryl group which may be substituted, wherein Y ⁵ and Y ⁶ are —OSiR ⁵ R
⁶ R ⁷ , —OCOR ⁵ R ⁶ R ⁷ , or —OPOR ⁵ R ⁶ R ⁷ , and R ^{5 to} R ⁷ each independently represent an alkyl group or an aryl group having 1 to 10 carbon atoms. Substituents on the benzene ring other than X ^{9 to} X ¹² are a hydrogen atom or a halogen atom.

Preferred examples of the tri (di) arylmethane compound include one or more compounds represented by the following general formula (IV).

Embedded image In the formula, R ¹³ and R ¹⁸ each independently represent a hydroxyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted amino group, and R ¹¹ , R ¹² , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ ,
R ¹⁹ and R ²⁰ each independently represent a hydrogen atom or a halogen atom; R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁵ each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a substituted or unsubstituted alkoxy group; , A substituted or unsubstituted amino group, a carboxyl group, or a sulfo group.

When the at least one dye represented by the general formula (I) of the present invention and the at least one dye represented by the general formulas (II) to (IV) are used in combination, the weight composition ratio is as follows: Dye of the present invention / [dye of (II) to (IV)] = 10/1
00 to 90/100, preferably 40/100 to 20 /
100. When both dyes are used in combination, the thickness of the recording layer is 500 to 5 μm, preferably 1000 to 50 μm.
00 °.

Next, the configuration of the recording medium of the present invention will be described. FIG. 1 is a diagram showing an example of a layer configuration applicable to the recording medium of the present invention, which is an example of a write-once optical disc. The recording layer 2 is provided on the substrate 1 via an undercoat layer 3 if necessary.
And, if necessary, a protective layer 4. Further, a hard coat layer 5 can be provided below the substrate 1 as needed. FIG. 2 is a diagram showing another example of a layer structure applicable to the recording medium of the present invention, which is an example of a CD-R medium. A reflective layer 6 is provided on the recording layer 2 having the configuration shown in FIG. The recording medium of the present invention is shown in FIG.
And an air sandwich structure in which the recording layer (organic thin film layer) having the structure shown in FIG. 2 is inwardly sealed with another substrate through a space, or a laminated structure in which the substrate is adhered through a protective layer. You may.

Next, the required characteristics of the constituent layers and the constituent materials thereof will be described. 1) Substrate As a necessary characteristic of the substrate, when recording / reproducing is performed from the substrate side, the substrate must be transparent to the laser beam to be used. As the substrate material, for example, polyester, acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, plastic such as polyimide, glass, ceramic, metal or the like can be used. Note that a guide groove or guide pit for tracking, and a preformat such as an address signal may be formed on the surface of the substrate.

2) Recording Layer The recording layer is capable of causing some optical change by irradiation with a laser beam and recording information by the change.
The recording layer must contain at least one compound represented by the general formula (I). In forming the recording layer, one or two compounds represented by the general formula (I) may be used. It may be used in combination of more than one kind. Further, these dyes can be used by mixing or laminating them with other organic dyes, metals, and metal compounds in order to improve optical characteristics, recording sensitivity, and signal characteristics. Other organic dyes in this case include polymethine dyes, naphthalocyanine-based, phthalocyanine-based, squarylium-based, croconium-based, pyrylium-based, naphthoquinone-based, anthraquinone (indanthrene) -based, xanthene-based, triphenylmethane-based, and azulene-based , A tetrahydrocholine-based, a phenanthrene-based, a triphenothiazine-based dye, and a metal complex compound. Examples of metals and metal compounds include In, Te, Bi, Se, Sb, Ge, and S.
Examples thereof include n, Al, Be, TeO ₂ , SnO, As, and Cd, and each of them can be used in the form of dispersion mixing or lamination. Further, various materials such as a polymer material, for example, an ionomer resin, a polyamide resin, a vinyl resin, a natural polymer, silicone, a liquid rubber, or a silane coupling agent may be dispersed and mixed in the dye, For improvement purposes, they can be used together with stabilizers (e.g. transition metal complexes), dispersants, flame retardants, lubricants, antistatic agents, surfactants, plasticizers and the like.

The recording layer is formed by vapor deposition, sputtering, C
It can be carried out by usual means such as VD or solvent application. When using the coating method, the above dye or the like is dissolved in an organic solvent, and spray, roller coating,
It can be performed by a conventional coating method such as dipping or spin coating. Examples of the organic solvent used include alcohols such as methanol, ethanol, and isopropanol; ketones such as acetone, methyl ethyl ketone and cyclohexanone; amides such as N, N-dimethylacetamide and N, N-dimethylformamide; and sulfoxides such as dimethyl sulfoxide. , Tetrahydrofuran, dioxane, diethyl ether, ethers such as ethylene glycol monomethyl ether, esters such as methyl acetate, ethyl acetate, chloroform, methylene chloride, dichloroethane, carbon tetrachloride, aliphatic halogenated carbons such as trichloroethane,
Aromatics such as benzene, xylene, monochlorobenzene and dichlorobenzene, or methoxyethanol;
Cellsolves such as ethoxyethanol, and hydrocarbons such as hexane, pentane, cyclohexane, and methylcyclohexane. The thickness of the recording layer is 100
Å-10 μm, preferably 200Å-2000Å is suitable.

3) Undercoating layer The undercoating layer is used to improve adhesiveness, a barrier against water or gas, improve storage stability of the recording layer, improve reflectivity, protect the substrate from a solvent, guide grooves and guides. It is used for forming pits and preformats. For the purpose of the polymer material, for example, ionomer resin, polyamide, vinyl resin, natural resin, natural polymer, silicone, various polymer compounds such as liquid rubber and silane coupling agent and the like can be used,
In addition to the above-mentioned polymer materials, inorganic compounds such as SiO ₂ , MgF ₂ , SiO, TiO ₂ , Z
nO, TiN, SiN, etc., and further, a metal or semimetal such as Zn, Cu, Ni, Cr, Ge, Se, A
u, Ag, Al and the like can be used. For the purpose, a metal such as Al, Au, Ag or the like, or an organic thin film having a metallic luster such as a methine dye or a xanthene-based dye can be used. Cured resin, thermosetting resin, thermoplastic resin, or the like can be used. The thickness of the undercoat layer is 0.
The thickness is suitably from 01 to 30 μm, preferably from 0.05 to 10 μm.

4) Reflective Layer The reflective layer can be made of a metal or semi-metal which is not easily corroded and has high reflectivity. Examples of materials include Au,
Ag, Al, Cr, Ni, Fe, Sn and the like.
Au, Ag, and Al are most preferable in terms of reflectivity and productivity. These metals and metalloids may be used alone.
More than one kind of alloy may be used. Examples of the film forming method include vapor deposition and sputtering, and the film thickness is 50 to 50.
00 °, preferably 100-3000 °.

5) Protective Layer, Hard Coat Layer on Substrate Surface The protective layer or hard coat layer on the substrate surface protects the recording layer (reflection / absorption layer) from scratches, dust, dirt, etc., and preserves the recording layer (reflection / absorption layer). It is used for the purpose of improving the stability and the reflectance. For these purposes,
The materials shown in the undercoat layer can be used. Further, SiO, SiO ₂ or the like may be used as an inorganic material, and polymethyl acrylate, polycarbonate, epoxy resin, polystyrene, polyester resin, vinyl resin, cellulose, aliphatic hydrocarbon resin, natural rubber, styrene-butadiene may be used as an organic material. Thermosoftening and heat melting resins such as resin, chloroprene rubber, wax, alkyd resin, drying oil and rosin can also be used. The most preferable of the above materials is an ultraviolet curable resin having excellent productivity. The thickness of the protective layer or the hard coat layer on the substrate surface is 0.01 to 30 μm, preferably 0.05 to 1 μm.
0 μm is appropriate.

In the present invention, a stabilizer, a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant, A plasticizer and the like can be contained.

[0040]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1 Example 1 A polymethyl methacrylate substrate having a thickness of 1.2 mm was formed with a photopolymer at a depth of 1200 ° and a half width of 0.4 μm.
m on a substrate on which a guide groove having a track pitch of 1.4 μm was formed. The chloroform solution of No. 1 was spin-coated and a recording layer having a thickness of 800 ° was provided to obtain a recording medium.

Examples 2 to 15 In Example 1, the specific compound No. Instead of 1,
Compound specific example No. 2, No. 3, No. 4, no.
5, no. 6, no. 7, no. 8, No. 9, No.
10, No. 11, No. 12, No. 13, No. 1
4, no. Except for using No. 15, the recording media of Examples 2 to 15 were obtained in the same manner as in Example 1.

Comparative Example 1 In Example 1, the specific compound No. A recording medium of Comparative Example 1 was obtained in the same manner as in Example 1, except that the compound represented by the following formula (V) was used instead of 1.

Embedded image

Using the recording media of Examples 1 to 15 and Comparative Example 1, recording was performed by irradiating light from a substrate under the following recording conditions, and then the C / N ratio and reflectivity were determined by the reproduction light at the recording position. It was measured. Table 5 shows the results. Recording condition: Laser oscillation wavelength 680 nm Recording frequency 1.25 MHz Recording linear velocity 1.2 m / sec Reproduction condition: Laser oscillation wavelength 680 nm (Examples 1 to 10, Comparative example 1) 635 nm (Examples 11 to 15) Reproduction power 0. Continuous light of 25 to 0.3 mW Scanning band width 30 KHz Light resistance test condition: Light resistance test 40,000 Lux, Xe light, 50 hours continuous irradiation Storage test 85 ° C., 85%, 720 hours

[0045]

[Table 5]

Example 16 Compound No. No. 1 was prepared on a 1.2 mm-thick injection-molded polycarbonate substrate having a guide groove with a depth of 1000 mm, a half width of 0.4 μm and a track pitch of 1.6 μm. 16 was dissolved in a mixed solution of methylcyclohexane, 2-methoxyethanol, methyl ethyl ketone, and tetrahydrofuran, and spin-coated to form a recording layer having a thickness of 1800１.
And a protective layer of 5 μm of acrylic photopolymer was further provided thereon to obtain a recording medium.

Examples 17 to 30 In Example 16, the specific compound Nos. In place of Compound No. 16, each of Compound Specific Example Nos. 17, No. 18, N
o. 19, no. 20, no. 21, no. 22, N
o. 23, no. 24, no. 25, no. 26, N
o. 27, no. 28, no. 29, no. Examples 17 to 3 were performed in the same manner as in Example 16 except that 30 was used.
0 was obtained.

Comparative Example 2 In Example 21, the specific compound No. A recording medium of Comparative Example 2 was obtained in the same manner as in Example 21 except that the compound represented by the formula (V) used in Comparative Example 1 was used instead of 21.

Using a semiconductor laser beam having an oscillation wavelength of 680 nm and a beam diameter of 1.4 μm on the recording media of Examples 16 to 30 and Comparative Example 2, an EFM signal was recorded while tracking (linear velocity: 1.4 m / sec). Reproduction was performed with continuous light of the same laser (however, Examples 23 to 30 were reproduced at an oscillation wavelength of 635 nm), and the reproduced waveform was observed. Table 6 shows the results.

[0050]

[Table 6]

Example 31 A compound represented by the following formula (VI) was placed on a 1.2 mm-thick injection-molded polycarbonate substrate having a guide groove having a depth of 1000 mm, a half width of 0.45 μm, and a track pitch of 1.6 μm. Compound specific example No. 31 and the weight ratio (1 /
1) Dissolved in a mixed solvent of methylcyclohexane, 2-methoxyethanol, methyl ethyl ketone, and tetrahydrofuran, and applied with a spinner to form a recording layer having a thickness of 1700 °, and then formed a reflective layer of 2000 ° gold by a sputtering method. Further, a protective layer having a thickness of 5 μm was formed thereon using an acrylic photopolymer to obtain a recording medium.

[0052]

Embedded image

Examples 32 to 37 In Example 31, the specific compound Nos. Compound Specific Example No. 31 in place of Compound No. 31 was used. 32, no. 33, N
o. 34, no. 35, no. 36, no. Examples 32 to 3 were performed in the same manner as in Example 31 except that 37 was used.
7 was obtained.

Examples 38 to 44 In Example 31, the specific compound No. Compound Specific Example No. 31 in place of Compound No. 31 was used. 38, no. 39, N
o. 40, no. 41, no. 42, No. 43, N
o. Recording media of Examples 38 to 44 were obtained in the same manner as in Example 31, except that Compound No. 44 was used and a compound represented by the following formula (VII) was used instead of the compound represented by the above formula (VI). Was.

[0055]

Embedded image

Examples 45 to 50 In Example 31, Compound No. Compound Specific Example No. 31 in place of Compound No. 31 was used. 45, no. 46, N
o. 47, no. 48, no. 49, no. Recording media of Examples 45 to 50 were obtained in the same manner as in Example 31, except that Compound 50 was used and a compound represented by the following formula (VIII) was used instead of the compound represented by the formula (VI). Was.

[0057]

Embedded image

Comparative Examples 3 to 5 In Example 31, the recording layers were respectively formed by the general formula (V)
Comparative Example 3 was carried out in the same manner as in Example 31 except that only the compound represented by I), only the compound represented by the general formula (VII), and only the compound represented by the general formula (VIII) were used.
To 5 recording media were obtained.

Using a semiconductor laser beam having an oscillation wavelength of 780 nm and a beam diameter of 1.6 μm on the recording media of Examples 31 to 50 and Comparative Examples 3 to 5, an EFM signal was recorded while tracking (linear velocity of 1.4 m / sec). ), The laser and an oscillation wavelength of 680 nm (Examples 41 to 50 were performed at a reproduction oscillation wavelength of 635 nm), and reproduction was performed with continuous light of a semiconductor laser having a beam diameter of 1.4 μm, and a reproduction waveform was observed. Table 7 shows the results.

[0060]

[Table 7- (1)]

[0061]

[Table 7- (2)]

[0062]

According to the optical recording medium of the present invention, the recording layer contains at least one azo metal chelate compound represented by the general formula (I). Since it has high light absorbing ability and light reflectivity, recording and reproduction can be performed with laser light in a wavelength range of 700 nm or less, which enables high-density recording, and is excellent in light resistance and storage stability.

The optical recording medium according to claim 2 is characterized in that at least one of the compounds represented by the above general formula (I) is combined with 680-7
Since the recording layer contains an organic dye having a maximum absorption wavelength at 50 nm, recording and reproduction can be performed with the current system. It becomes possible to reproduce.

The optical recording medium according to claim 3 is 680 to 750.
Since at least one of a cyanine dye, a phthalocyanine dye, and a tri (di) arylmethane compound is selected as the organic dye having a maximum absorption wavelength in nm, high-quality signal characteristics can be recorded.

In the optical recording medium of the fourth aspect, the recording layer has a wavelength of 6
Since recording is performed by a laser beam of 30 to 720 nm, a high-density write-once optical recording medium 1.6 to 1.8 times higher than an optical recording medium for 770 to 830 nm can be obtained.

In the optical recording medium according to the fifth aspect, since the reflection layer is made of aluminum or gold, high reflectivity and CD-R media with good productivity can be realized.

In the optical information recording medium according to the sixth aspect, since the protective layer is made of an ultraviolet curable resin, it is possible to form a medium with a protective layer having high productivity.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a layer configuration as a general write-once optical recording medium applicable to a recording medium of the present invention.

FIG. 2 is a diagram showing a layer configuration example for a CD-R applicable to the recording medium of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Recording layer (organic dye layer) 3 Undercoat layer 4 Protective layer 5 Hard coat layer 6 Reflective layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09B 23/00 G11B 7/24 516 G11B 7/24 516 C07D 233/88 // C07D 233/88 233/90 233/90 235 / 30 235/30 239/42 Z 239/42 263/48 263/48 263/58 263/58 285/12 E (72) Inventor Sasa No. 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd.

Claims (6)

[Claims] 1. An optical recording medium comprising a recording layer provided directly or via an undercoat layer on a substrate, and further, if necessary, a reflective layer and a protective layer provided thereon. An optical recording medium comprising at least one azo metal chelate compound represented by the general formula (I). Embedded image (Wherein, M, A, X, Y, Z ¹ , Z ² and n each represent the following: M: 3, 4, 5, 6, 7, 8, 9) Or a metal atom of Group 10 or an oxide or halide thereof, A: an anion, X: a residue which forms a heterocyclic ring together with the carbon atom and nitrogen atom to which it is bonded, Y: A residue which forms an aromatic group together with two carbon atoms bonded thereto; Z ¹ and Z ² each independently represent a hydrogen atom or a cation; n: an integer of 1 to 3; Each independently may have a substituent such as an alkyl group, an alkoxy group, an amino group, a substituted amino group, a hydroxyl group, a halogen atom, a nitro group, a cyano group, a methyl trifluoride group, and a carboxyl group.) 2. The recording layer according to claim 1, wherein the recording layer contains at least one compound represented by the general formula (I) and an organic dye having a maximum absorption wavelength at 680 nm to 750 nm. The optical recording medium according to the above. 3. The optical recording medium according to claim 2, wherein the organic dye having a maximum absorption wavelength at 680 nm to 750 nm is at least one of a cyanine dye, a phthalocyanine dye, and a tri (di) arylmethane compound. 4. The optical recording medium according to claim 1, wherein said recording layer is recorded by a laser beam having a wavelength of 630 to 720 nm. 5. The optical recording medium according to claim 1, wherein said reflection layer is made of aluminum or gold. 6. The optical recording medium according to claim 1, wherein said protective layer is made of an ultraviolet curable resin.