JP2002079755A - Optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical recording medium and a recording material employed for the same, capable of being applied for a DVD-R disc system employing a semiconductor laser having an oscillating wavelength in a short wave length and excellent in resistance to light as well as storage stability. SOLUTION: The optical recording medium consisting of a recording layer provided on a substrate contains in the recording medium at least one kind of an azo metal chelate compound, shown in a general formula (I) while consisting of an azo compound and a metal, metal oxide or the salt of the same. (In the formula, a circle A represents a residue forming a heterocycle integrated with a nitrogen atom having a carbon atom, connected to the circle A, and an active hydrogen, the circle B shows a remaining group forming an aromatic group integrated with two carbon atoms connected to the circle B while X shows a group having no active hydrogen).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-capacity write-once optical disc for data (large-capacity write-once compact disc, DV
D-R) is applied to large-capacity optical cards and the like.

[0002]

2. Description of the Related Art (for information recording) write-once recording media (WOR)
As the prior art M), those using a cyanine dye as a recording material are disclosed in JP-A-57-82093, JP-A-58-56892, and JP-A-58-112790.
JP, JP-A-58-114989 and JP-A-59-149899
-85791, JP-A-60-83236,
JP-A-60-89842, JP-A-61-2588
No. 6,150,243, which uses a phthalocyanine dye as a recording material.
JP, JP-A-61-177287, JP-A-61-177287
JP-A-154888, JP-A-61-24609, JP-A-62-39286, JP-A-63-37
No. 991, JP-A-63-39888 and the like.

Further, a write-once compact disc (CD-
As the prior art of R), those using a cyanine dye + metal reflective layer as a recording material are disclosed in JP-A-1-159842, JP-A-2-42652, and JP-A-2-136.
No. 56, JP-A-2-168446, etc., which use a phthalocyanine dye + metal reflective layer as a recording material are disclosed in JP-A-1-176585, JP-A-3-215466, Kaihei 4-113886
JP, JP-A-4-226390, JP-A-5-1
272, JP-A-5-171052, JP-A-5-116456, JP-A-5-96860, JP-A-5-139944, JP-A-5-139
No. 044, which uses an azo metal chelate dye and a metal reflective layer as a recording material,
-46186, JP-A-4-141489,
JP-A-4-36088, JP-A-5-27958
0, JP-A-7-51673, and JP-A-7-1
These are disclosed in JP-A-61069, JP-A-7-37272, JP-A-7-71867, JP-A-8-231866, JP-A-8-295811 and the like.

[0004] Further, as a prior art of a large capacity write-once compact disc (DVD-R), a disc using a cyanine dye + metal reflective layer as a recording material is known as ISOM / O.
DS'96: High density of recording on Dye materi
al Disc approach for 4.7G, which is disclosed in JP-A-10-235999, which uses an azomethine dye + metal reflective layer as a recording material is disclosed in JP-A-8-198872 and JP-A-8-198872. JP-A-8-209012, JP-A-8-283263, JP-A-10-2
No. 73484, etc., which use an azo metal chelate dye + metal reflective layer as a recording material are disclosed in Japanese Examined Patent Publication No. 5-67438, Japanese Patent Application Laid-Open Nos. 7-161069 and 8-156408. JP-A-8-231
866, JP-A-8-332772, JP-A-9-58123, JP-A-9-175031, JP-A-9-193545, JP-A-9-274
732, JP-A-9-277703, JP-A-10-6644, JP-A-10-6650,
JP-A-10-6651 and JP-A-10-36693
JP, JP-A-10-44606, JP-A-10-44606
JP-A-58828, JP-A-10-86519, JP-A-10-149584, JP-A-10-1572
No. 93, JP-A-10-157300, JP-A-10-157301, JP-A-10-157302
JP, JP-A-10-181199, JP-A-10-181199
JP-A-181201, JP-A-10-181203, JP-A-10-181206, JP-A-10-1
No. 88340, JP-A-10-188341,
JP-A-10-188358, JP-A-10-208
No. 303, JP-A-10-214423, JP-A-10-228671, JP-A-10-36693
JP, JP-A-11-12483, JP-A-11-124
No. 28865, JP-A-11-42858, JP-A-11-102537, JP-A-11-1168
No. 34, JP-A-11-166125, JP-A-11-120616, JP-A-11-130970
JP, JP-A-11-138999, JP-A-11-138999
-134708, JP-A-11-138999, JP-A-11-151861, JP-A-11-1
No. 51862, Japanese Patent Application Laid-Open No. 11-208111,
JP-A-11-213442, JP-A-2000-36
Japanese Patent Application Laid-Open No. 10-86 discloses a recording material using a dye and a metal reflection layer as a recording material.
517, JP-A-10-93788, JP-A-10-226172, JP-A-10-244758
JP, JP-A-10-287819, JP-A-10-287819
-297103, JP-A-10-309871, JP-A-10-309872, JP-A-11-1
No. 29624 and the like.

At present, as a next-generation large-capacity optical disk, DV
Development of DR is in progress. Development of recording materials for miniaturization of recording pits,
It is necessary to develop technology such as adoption of an image compression technology represented by PEG2 and shortening of the wavelength of a semiconductor laser for reading recording pits.

Heretofore, as a semiconductor laser in the red wavelength region, a 670 nm band Al for a bar code reader and a measuring instrument has been used.
Although only GaInP laser diodes have been commercialized, red lasers are being used in the optical storage market in earnest as the density of optical disks increases. DVD
In the case of a drive, 635 nm band and 650 n
It is standardized by two wavelengths of the m-band laser diode. On the other hand, the DVD-ROM drive for reproduction only has a wavelength of ~
Commercialized at 650 nm.

[0007] Under these circumstances, the most preferable DVD-
The R media is a medium that can record and reproduce at a wavelength of 630 to 670 nm. However, 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 670 nm or less has not yet been developed.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a DVD-R disk system using a semiconductor laser having an oscillation wavelength shorter than that of a conventional system, which is superior in light resistance and storage stability. It is an object of the present invention to provide an optical recording medium and a recording material used therein.

[0009]

Means for Solving the Problems As a result of intensive studies, the present inventors have made it possible to use a semiconductor laser having an oscillation wavelength of 670 nm or less by forming a recording layer containing a dye having a specific structure as a main component. The present inventors have found that an optical recording medium applicable to a high capacity optical disk system can be provided, and have reached the present invention.

That is, the above-mentioned problem is solved by the present invention comprising (1)
"In an optical recording medium having a recording layer provided on a substrate, an azo compound represented by the general formula (I)
An optical recording medium characterized by containing at least one kind of azo metal chelate compound composed of a metal oxide or a salt thereof,

[0011]

Embedded image Wherein ring A represents the residue which, together with the carbon atom to which it is attached and the nitrogen atom having an active hydrogen, forms a heterocycle, and ring B which represents the residue to which it is attached. Represents a residue that forms an aromatic group with two carbon atoms,
X represents a group having no active hydrogen. ) ", (2)
"The optical recording medium according to the above (1), wherein the azo metal chelate compound is represented by the following general formula (II):

[0012]

Embedded image Wherein the ring A is taken from the group consisting of pyrrole, imidazole, pyrazole, triazole, tetrazole, indole, isoindole, benzimidazole, indazole, purine, perimidine together with the carbon and nitrogen atoms to which it is attached. M represents a metal or metal oxide, R ₁ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and R _{2 to} R ₅ represent a selected heterocyclic ring-forming residue. Each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group,
Hydroxyl group, carboxy group, amino group, substituted or unsubstituted alkyl group, substituted or unsubstituted aryl group, substituted or unsubstituted heterocyclic residue, substituted or unsubstituted alkylcarbonyl group, substituted or unsubstituted arylcarbonyl Group, substituted or unsubstituted alkyloxycarbonyl group, substituted or unsubstituted aryloxycarbonyl group, substituted or unsubstituted alkylsulfonyl group,
Substituted or unsubstituted arylsulfonyl group, substituted or unsubstituted alkylthiooxy group, substituted or unsubstituted arylthiooxy group, substituted or unsubstituted alkyloxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted Alkylamino group, substituted or unsubstituted arylamino group, substituted or unsubstituted alkylcarbonylamino group, substituted or unsubstituted arylcarbonylamino group, substituted or unsubstituted alkylcarbamoyl group, substituted or unsubstituted arylcarbamoyl Represents an unsubstituted or substituted alkenyl group, and n represents 2 or 3. Also, R ₂ and R ₃ , R ₃
And R ₄ , or R ₄ and R ₅ may be linked to form a ring. ) ", (3)" the optical recording medium according to the above (1) or (2), wherein the azo metal chelate compound has a divalent or trivalent metal valence " (4) The optical recording according to any one of (1) to (3), wherein the azo metal chelate compound has a metal atom selected from manganese, cobalt, nickel, and copper. Medium, "(5)" the azo metal chelate compound, wherein the A ring is an imidazole residue, the optical recording medium according to any one of the above items (1) to (4) ", (6) “The optical recording medium according to any one of the above (1) to (5), wherein the metal atom is nickel in the azo metal chelate compound”; The azo metal chelate compound is represented by the following general formula (III): That the first (1)
The optical recording medium according to any one of the items (6) to (6),

[0013]

Embedded image (Wherein, R ₆ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, and R ₇ and R ₈ each independently represent a hydrogen atom, a cyano group, a substituted or unsubstituted alkyl group, Represents an unsubstituted aryl group, and R ₉ and R ₁₀ are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxy group, an amino group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted Aryl group, substituted or unsubstituted heterocyclic residue, substituted or unsubstituted alkylcarbonyl group, substituted or unsubstituted arylcarbonyl group, substituted or unsubstituted alkyloxycarbonyl group, substituted or unsubstituted aryloxycarbonyl group A substituted or unsubstituted alkylsulfonyl group, a substituted or unsubstituted arylsulfonyl group Group, substituted or unsubstituted alkylthiooxy group, substituted or unsubstituted arylthiooxy group, substituted or unsubstituted alkyloxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylamino group, substituted or unsubstituted alkylamino group, Unsubstituted arylamino group, substituted or unsubstituted alkylcarbonylamino group, substituted or unsubstituted arylcarbonylamino group, substituted or unsubstituted alkylcarbamoyl group, substituted or unsubstituted arylcarbamoyl group, substituted or unsubstituted Represents an alkenyl group, and R ₈
And R ₉ or R ₉ and R ₁₀ may be linked to form a ring. ) ", (8)" the refractive index n of the recording layer single layer with respect to light in the wavelength range of recording / reproducing wavelength ± 5 nm is 1.5 ≦ n ≦
3.0, and the extinction coefficient k is 0.02 ≦ k ≦ 0.2, wherein the optical recording medium according to any one of the above items (1) to (7) ”, (9) "In the thermogravimetric analysis of organic dyes, the slope of weight loss with respect to temperature in the main weight loss process is 2
% / ° C. or more, the optical recording medium according to any one of the above items (1) to (8) ”, (10)
"By thermogravimetric analysis of organic dyes, the total weight loss in the main weight loss process was 3
The optical recording medium according to any one of the above items (1) to (9), wherein the temperature is 0% or more and the weight-loss start temperature is 350 ° C. or less. The track pitch is 0.7 to 0.8 μm, the groove width is half width,
The optical recording medium according to any one of the above items (1) to (10), wherein the thickness is 0.20 to 0.36 μm.

The effect of each claim is as follows. The above item (1) is a novel azo metal having no active hydrogen in the ligand substituent and active hydrogen in the heterocyclic ring. This is a basic configuration of an optical recording medium using a chelate compound, wherein the item (2) shows the optimum structure of the item (1), and the item (3) contains a specific metal species. FIG. 4 shows the optimum structures of the above-mentioned items (1) and (2) used, wherein the item (4) is the above-mentioned items (1) to (3) using an optimum metal species. (5) shows the optimal structure of the above (1) to (4) using an optimal heterocyclic ring, and (6) )) Is the said (1) using the optimal metal
And (5) showing the optimized structure of the azo metal chelate compound, and (8) shows the optimized structure of the azo metal chelate compound. The optical characteristics of the azo metal chelate compound capable of recording and reproducing with high reflectivity and high modulation are shown. The above items (9) and (10) are azo metals capable of high density recording with low jitter. It shows the optical characteristics of the chelate compound, and the above item (11) shows the conditions for the substrate guide groove for high density media to be applied.

In the general formula (I), the ring A represents a residue which forms a heterocyclic ring together with the carbon atom to which it is bonded and the nitrogen atom having an active hydrogen;
The ring represents a residue which, together with the two carbon atoms to which it is attached, forms an aromatic, and X represents a group having no active hydrogen. Examples of the ring A include pyrrole, imidazole, pyrazole, triazole, tetrazole, indole, isoindole, benzimidazole, indazole, purine, perimidine and the like. X is a group having an active hydrogen conventionally used, for example, -OH,
Rather than —COOH, —SO ₃ H, NHSO ₂ R (R is an alkyl group, etc.), NH ₂ or the like, it is selected from a substituent having no active hydrogen such as a carboxylate group.

In the above general formula (II), the ring A together with the carbon atom and the nitrogen atom to which it is bonded, pyrrole, imidazole, pyrazole, triazole, tetrazole, indole, isoindole, benzimidazole, indazole, Represents a residue forming a heterocyclic ring selected from the group consisting of purines and perimidines, M represents a metal or metal oxide, and R ₁ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. , R _{2 to} R ₅ each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxy group, an amino group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted group. A heterocyclic residue, a substituted or unsubstituted alkylcarbonyl group, a substituted or unsubstituted Reel carbonyl group, substituted or unsubstituted alkyloxycarbonyl group, substituted or unsubstituted aryloxycarbonyl group, substituted or unsubstituted alkylsulfonyl group, substituted or unsubstituted arylsulfonyl group, substituted or unsubstituted alkylthiooxy group A substituted or unsubstituted arylthiooxy group, a substituted or unsubstituted alkyloxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted alkylamino group, a substituted or unsubstituted arylamino group, a substituted or unsubstituted Represents a substituted alkylcarbonylamino group, a substituted or unsubstituted arylcarbonylamino group, a substituted or unsubstituted alkylcarbamoyl group, a substituted or unsubstituted arylcarbamoyl group, a substituted or unsubstituted alkenyl group, It represents 2 or 3. R ₂ and R ₃ , R ₃ and R ₄ , or R ₄ and R ₅
May be linked to form a ring.

Specific examples of the halogen atom include fluorine, chlorine, bromine and iodine.

Specific examples of the substituted or unsubstituted alkyl group include a methyl group, an ethyl group, an n-propyl group,
n-butyl group, n-pentyl group, n-hexyl group, n-
Primary alkyl groups such as heptyl group, n-octyl group, n-nonyl group, n-decyl group, isobutyl group, isoamyl group, 2-methylbutyl group, 2-methylpentyl group, 3-
Methylpentyl, 4-methylpentyl, 2-ethylbutyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 2
-Ethylpentyl group, 3-ethylpentyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5-methylheptyl group, 2-ethylhexyl group, 3-ethylhexyl group, isopropyl group, sec-
Butyl group, 1-ethylpropyl group, 1-methylbutyl group, 1,2-dimethylpropyl group, 1-methylheptyl group, 1-ethylbutyl group, 1,3-dimethylbutyl group,
1,2-dimethylbutyl group, 1-ethyl-2-methylpropyl group, 1-methylhexyl group, 1-ethylheptyl group, 1-propylbutyl group, 1-isopropyl-2-methylpropyl group, 1-ethyl- 2-methylbutyl group, 1
-Ethyl-2-methylbutyl group, 1-propyl-2-methylpropyl group, 1-methylheptyl group, 1-ethylhexyl group, 1-propylpentyl group, 1-isopropylpentyl group, 1-isopropyl-2-methylbutyl group,
1-isopropyl-3-methylbutyl group, 1-methyloctyl group, 1-ethylheptyl group, 1-propylhexyl group, secondary alkyl groups such as 1-isobutyl-3-methylbutyl group, neopentyl group, tert-butyl group, te
tertiary alkyl groups such as rt-hexyl group, tert-amyl group and tert-octyl group; cyclohexyl group;
Methylcyclohexyl group, 4-ethylcyclohexyl group, 4-tert-butylcyclohexyl group, 4- (2
-Ethylhexyl) cycloalkyl group such as cyclohexyl group, bornyl group, isobornyl group (adamantane group) and the like.

Furthermore, these primary and secondary alkyl groups are
A hydroxyl group, a halogen atom, a nitro group, a carboxy group, a cyano group, a substituted or unsubstituted aryl group, may be substituted with a substituted or unsubstituted heterocyclic residue, etc.
The alkyl group may be substituted via an atom such as sulfur or nitrogen.

Examples of the alkyl group substituted via oxygen include methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, butoxyethyl, ethoxyethoxyethyl, phenoxyethyl, methoxypropyl, and ethoxy. Propyl group, piperidino group, morpholino group, and the like.Examples of the alkyl group substituted via sulfur include a methylthioethyl group, an ethylthioethyl group, an ethylthiopropyl group, a phenylthioethyl group, and the like. Examples of the alkyl group substituted through include a dimethylaminoethyl group, a diethylaminoethyl group, and a diethylaminopropyl group.

Specific examples of the substituted or unsubstituted aryl group include phenyl, pentalenyl, indenyl, naphthyl, azulenyl, heptalenyl, biphenylenyl, phenenyl, phenanthrenyl, anthracenyl, triphenylenyl, And a pyrenyl group.

Specific examples of the substituted or unsubstituted heterocyclic residue include an indolyl group, a furyl group, a thienyl group,
Examples include a pyridyl group, a piperidyl group, a quinolyl group, an isoquinolyl group, a piperidino group, a morpholino group, and a pyrrolyl group.

Specific examples of the substituted or unsubstituted alkylcarbonyl group include those in which a substituted or unsubstituted alkyl group is directly bonded to a carbon atom of the carbonyl group. Specific examples of the alkyl group include The same ones as those in the above-described specific example can be given.

Specific examples of the substituted or unsubstituted arylcarbonyl group include those in which a substituted or unsubstituted aryl group is directly bonded to a carbon atom of the carbonyl group. Specific examples of the aryl group include: The same ones as those in the above-described specific example can be given.

Specific examples of the substituted or unsubstituted alkyloxycarbonyl group include those in which a substituted or unsubstituted alkyl group is directly bonded to the oxygen atom of the oxycarbonyl group. Examples thereof include those similar to the specific examples described above.

Specific examples of the substituted or unsubstituted aryloxycarbonyl group include those in which a substituted or unsubstituted aryl group is directly bonded to the oxygen atom of the oxycarbonyl group. Examples thereof include those similar to the specific examples described above.

Specific examples of the substituted or unsubstituted alkylsulfonyl group include those in which a substituted or unsubstituted alkyl group is directly bonded to a sulfur atom of the sulfonyl group. Specific examples of the alkyl group include The same ones as those in the above-described specific example can be given.

Specific examples of the substituted or unsubstituted arylsulfonyl group include those in which a substituted or unsubstituted aryl group is directly bonded to a sulfur atom of the sulfonyl group. Specific examples of the aryl group include: The same ones as those in the above-described specific example can be given.

Specific examples of the above-mentioned substituted or unsubstituted alkylthioxy group include those in which a substituted or unsubstituted alkyl group is directly bonded to a sulfur atom, and specific examples of the alkyl group are those described above. Examples are the same as in the example.

Specific examples of the substituted or unsubstituted arylthioxy group include those in which a substituted or unsubstituted aryl group is directly bonded to a sulfur atom. Specific examples of the aryl group are those described above. The same thing as a specific example is mentioned.

Specific examples of the above-mentioned substituted or unsubstituted alkyloxy group may be those in which a substituted or unsubstituted alkyl group is directly bonded to an oxygen atom, and specific examples of the alkyl group are those described above. Examples are the same as in the example.

Specific examples of the substituted or unsubstituted aryloxy group include those in which a substituted or unsubstituted aryl group is directly bonded to an oxygen atom, and specific examples of the aryl group are those described above. Examples are the same as in the example.

Specific examples of the above-mentioned substituted or unsubstituted alkylamino group may be those in which a substituted or unsubstituted alkyl group is directly bonded to a nitrogen atom, and specific examples of the alkyl group are those described above. Examples are the same as in the example.

Specific examples of the substituted or unsubstituted arylamino group include those having a substituted or unsubstituted aryl group directly bonded to a nitrogen atom. Specific examples of the aryl group are those described above. Examples are the same as in the example.

Specific examples of the substituted or unsubstituted alkylcarbonylamino group include those in which a substituted or unsubstituted alkyl group is directly bonded to a carbon atom of the carbonylamino group. Examples thereof include those similar to the specific examples described above.

Specific examples of the substituted or unsubstituted arylcarbonylamino group include those in which a substituted or unsubstituted aryl group is directly bonded to a carbon atom of the carbonylamino group. Examples thereof include those similar to the specific examples described above.

Specific examples of the substituted or unsubstituted alkylcarbamoyl group include those in which a hydrogen atom or a substituted or unsubstituted alkyl group is directly and independently bonded to the nitrogen atom of the carbamoyl group. Specific examples of the alkyl group include the same as those described above.

Specific examples of the substituted or unsubstituted arylcarbamoyl group include those in which a hydrogen atom or a substituted or unsubstituted aryl group is directly and independently bonded to the nitrogen atom of the carbamoyl group. Specific examples of the aryl group include the same as those described above.

Specific examples of the divalent or trivalent metal atom include titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zirconium, niobium, molybdenum, technenium, ruthenium, rhodium, palladium and the like. Specific examples of the metal oxide include vanadium oxide. In particular, azo metal chelate compounds of manganese, cobalt, nickel, and copper have excellent optical properties as optical recording materials. Further, the azo metal chelate compound of nickel is particularly excellent in storage stability in addition to optical properties, and can provide an extremely stable optical recording medium. With respect to heterocyclic residues, imidazole residues are particularly excellent in optical properties, storage stability, and thermal decomposition properties,
An extremely stable optical recording medium can be provided.

The structure of the azo metal chelate compound having the most excellent characteristics in the present invention is the structure described in the above formula (III). In the general formula (III), R ₆ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, R ₇ and R ₈ each independently represent a hydrogen atom,
A cyano group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and R ₉ and R ₁₀ are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxy group, an amino group, Substituted or unsubstituted alkyl group, substituted or unsubstituted aryl group, substituted or unsubstituted heterocyclic residue, substituted or unsubstituted alkylcarbonyl group, substituted or unsubstituted arylcarbonyl group, substituted or unsubstituted alkyl An oxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted alkylsulfonyl group, a substituted or unsubstituted arylsulfonyl group,
Substituted or unsubstituted alkylthiooxy group, substituted or unsubstituted arylthiooxy group, substituted or unsubstituted alkyloxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylamino group, substituted or unsubstituted Arylamino group, substituted or unsubstituted alkylcarbonylamino group, substituted or unsubstituted arylcarbonylamino group, substituted or unsubstituted alkylcarbamoyl group, substituted or unsubstituted arylcarbamoyl group, substituted or unsubstituted alkenyl group Represents R ₈ and R ₉ or R ₉ and R ₁₀ may be linked to form a ring. Examples of the substituent are the same as those described above.

The azo metal chelate compound of the present invention is characterized in that an azo compound composed of a heterocyclic residue having an active hydrogen and a coupler having no active hydrogen acts on a metal to form a recording material for an optical recording medium. It is a stable chelate compound that can be used. BACKGROUND ART A heterocyclic azo metal chelate compound used in an optical recording medium known as a conventional technique is composed of a coupler having active hydrogen and a heterocyclic residue having no active hydrogen group. The differences are shown below.

[0042]

Embedded image

[0043]

Embedded image

Hereinafter, the configuration of the recording medium will be described.
Items necessary for forming the recording layer include optical characteristics and thermal characteristics. The condition required for the optical characteristics is that the recording / reproducing wavelength has a large absorption band on the shorter wavelength side with respect to the recording / reproducing wavelength of 630 nm to 690 nm, and the recording / reproducing wavelength is near the long wavelength end of the absorption band. is there. This means that it has a large refractive index and an extinction coefficient at the recording / reproducing wavelength of 630 nm to 690 nm.

Specifically, the refractive index n of the recording layer single layer with respect to light in the wavelength region near the long wavelength near the recording / reproducing wavelength is 1.5 or more and 3.0 or less, and the extinction coefficient k is 0.02 or more. 0.2
It is preferably within the following range. When n is less than 1.5, it is difficult to obtain a sufficient optical change, so that the recording modulation degree becomes low, which is not preferable. When n exceeds 3.0, the wavelength dependency becomes too high. Therefore, an error occurs even in the recording / reproducing wavelength region, which is not preferable. When k is less than 0.02, the recording sensitivity deteriorates, which is not preferable. When k exceeds 0.2, it is difficult to obtain a reflectance of 50% or more, which is not preferable.

The condition required for the thermal characteristics is that the weight loss in the main weight loss process in thermogravimetric analysis must be sharp with respect to the temperature. This is because the organic material film is decomposed in the main weight reduction process, causing a decrease in film thickness and a change in optical constant, thereby forming a recording portion in an optical sense. Therefore, when the weight loss in the main weight loss process is gentle with respect to the temperature, the recording portion is formed over a wide temperature range, which is extremely disadvantageous when a high-density recording portion is formed. For the same reason, the use of a material having a plurality of weight loss processes is also disadvantageous for high density. In the present invention, among several weight loss processes, the one with the largest weight loss rate is referred to as the main weight loss process.

In the present invention, the slope of the weight loss is determined as follows. As shown in FIG. 1, an organic material having a mass m0 was placed in a nitrogen atmosphere at 10 ° C./min. To raise the temperature. As the temperature rises, the mass decreases little by little, and the straight line a-
b shows a weight loss line, and when a certain temperature is reached, a sharp weight loss occurs, and a weight loss occurs substantially along a straight line cd. If the temperature is further increased, the abrupt weight loss ends and the weight decreases substantially along the straight line ef. Now, let the temperature at the intersection of the straight line ab and the straight line cd be T1
(° C.), the residual weight with respect to the initial mass m0 is m1 (%),
The temperature at the intersection of the straight line cd and the straight line ef is T2
(° C.) and the residual weight based on the initial mass m0 is m2 (%). The weight loss start temperature is T1, the weight loss end temperature is T2, and the slope of the weight loss is (m1-m2) (%) / (T2
-T1) (° C.), and the weight loss rate with respect to the initial weight is represented by (m1-m2) (%).

Based on the above definition, the recording material used for the optical information recording medium preferably has a weight loss gradient of 2% / ° C. or more in the main weight loss process. When a recording material having a slope of the weight loss of less than 2% / ° C. is used, the spread of the recording portion becomes large, and it becomes difficult to form a short recording portion, which is not suitable for an information recording medium. .

The weight loss rate in the main weight loss process is as follows:
It is preferably at least 30%. If it is less than 30%, there is a possibility that good recording modulation and recording sensitivity cannot be obtained. Further, the condition required for the thermal characteristics is that the weight start temperature T
1 must be in a certain temperature range. Specifically, the weight loss starting temperature is 350 ° C. or less, preferably 200 ° C.
It is desirable to be in the range of -350 ° C. If the temperature at which the weight loss starts is 350 ° C. or higher, the power of the recording laser beam becomes high, which is not practical. If the temperature is 200 ° C. or lower, the recording stability deteriorates such as reproduction deterioration.

The conditions required for the substrate shape are that the track pitch on the substrate is 0.7 to 0.8 μm and the groove width is a half value width of 0.20 to 0.36 μm. The substrate usually has a guide groove having a depth of 1000 to 2500 °. The track pitch is usually 0.7 to 1.0 μm, but preferably 0.7 to 0.8 μm for high capacity applications. The groove width is preferably from 0.18 to 0.36 μm in half width. 0.
If it is less than 18 μm, it may be difficult to obtain a sufficient tracking error signal intensity. 0.36 μm
Is not preferable because the recording portion tends to spread laterally when recording is performed.

Hereinafter, the optical recording medium of the present invention will be described with reference to the drawings. Configuration of Recording Body The recording body of the present invention is a normal write-once optical disc shown in FIG.
(A so-called air sandwich in which two sheets of FIG. 2 are bonded together or a close bonding structure) and the structure of a CD-R medium shown in FIG.

Required Properties of Each Layer and Examples of Constituent Materials The structure of the recording medium of the present invention is as shown in FIG. 4 in which a first substrate and a second substrate (protective substrate) are bonded together with an adhesive via a recording layer. Basic structure. The recording layer may be a single layer of an organic dye layer, or may be a laminate of an organic dye layer and a metal reflective layer to increase the reflectance. The recording layer and the substrate may be layered with an undercoat layer or a protective layer interposed therebetween, or may be formed by laminating them for improving the function. The most commonly used structure is the first substrate / recording layer (organic dye layer) / metal reflective layer / protective layer / adhesive layer / second substrate.

<Substrate> A necessary characteristic of the substrate is that the substrate must be transparent to the laser beam used only when recording and reproduction are performed from the substrate side, and when recording and reproduction are performed from the recording layer side, the substrate is transparent. No need to be. Therefore, in the present invention, when two layers of substrates are used, the first substrate may be transparent or opaque as long as only the second substrate described in the claims is transparent. As the substrate material, for example, polyester,
Acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, plastic such as polyimide, glass, ceramic or metal can be used. When only one substrate is used, or when two substrates are used in a sandwich form, a guide groove or guide pit for tracking and a pre-address signal such as an address signal are formed on the surface of the first substrate. The format must be formed.

<Intermediate Layer> Layers provided other than the substrate, the recording layer, the reflective layer, and the protective layer, including the undercoat layer and the like, are herein referred to as intermediate layers. This intermediate layer comprises (a) improved adhesiveness, (b) a barrier against water or gas, (c) improved storage stability of the recording layer, (d) improved reflectance, and (e) substrate from solvent. And protection of recording layer, (f) guide groove, guide pit,
It is used for the purpose of forming a preformat or the like.

For the purpose of (a), various polymer materials such as ionomer resins, polyamide resins, vinyl resins, natural resins, natural polymers, silicones, liquid rubbers, etc .; A ring agent or the like can be used. For the purposes (b) and (c),
In addition to the polymer material, an inorganic compound such as SiO ₂ , M
metals such as gF ₂ , SiO, TiO ₂ , ZnO, TiN, SiN, or semimetals, for example, Zn, Cu, Ni, Cr, G
e, Se, Au, Ag, Al and the like can be used.
For the purpose of (d), a metal such as Al or Ag is used.
And the like, an organic thin film having a metallic luster, for example, methine dye,
A xanthene dye or the like can be used, and for the purposes of (e) and (f), an ultraviolet curable resin, a thermosetting resin, a thermoplastic resin, or the like can be used. The thickness of the undercoat layer is 0.01 to 30 μm, preferably 0.05 to 10 μm.
μm is appropriate.

<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 contains the dye of the present invention. In forming the recording layer, the dye of the present invention may be used alone or in combination of two or more. Further, the dye of the present invention may be mixed or laminated with other organic dyes, metals, and metal compounds for the purpose of improving optical characteristics, recording sensitivity, signal characteristics, and the like.
Examples of organic dyes include polymethine dyes, naphthalocyanine, phthalocyanine, squarylium, croconium, pyrylium, naphthoquinone, anthraquinone (indanthrene), xanthene, triphenylmethane, azulene, and tetrahydrocholine. And phenanthrene-based dyes, triphenothiazine-based dyes, metal chelate compounds, and the like. These dyes may be used alone or in combination of two or more.

Further, a metal, a metal compound,
For example, In, Te, Bi, Se, Sb, Ge, Sn,
Al, Be, TeO ₂ , SnO, As, Cd and the like can be used in the form of dispersion mixing or lamination. further,
Polymer material in the dye, for example, ionomer resin,
Various materials such as polyamide-based resins, vinyl-based resins, natural polymers, silicones, and liquid rubbers, or silane coupling agents and the like may be dispersed and mixed, or a stabilizer (for example, transition Metal complex), a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant, a plasticizer, and the like.

The recording layer is formed by vapor deposition, sputtering,
It can be carried out by ordinary means such as CVD or solution coating. When the coating method is used, the dye or the like is dissolved in an organic solvent or the like, and the coating is performed by a conventional coating method such as spraying, roller coating, dipping, and spin coating.

As the organic solvent to be used, generally, alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, methyl ethyl ketone and cyclohexanone, N, N-dimethylformamide, N, N
-Amides such as dimethylacetamide, sulfoxides such as dimethylsulfoxide, ethers such as tetrahydrofuran, dioxane, diethyl ether, ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, chloroform, methylene chloride, dichloroethane and tetrachloride Aliphatic halogenated hydrocarbons such as carbon and trichloroethane, or aromatics such as benzene, xylene, monochlorobenzene and dichlorobenzene, cellosolves such as methoxyethanol and ethoxyethanol, and carbonization such as hexane, pentane, cyclohexane and methylcyclohexane Hydrogens and the like can be used. The thickness of the recording layer is 100 to 10 μm, preferably 200 to
Å2000Å is appropriate.

<Metal Reflective Layer> The reflective layer may be made of a metal, a semi-metal, or the like, which can provide a high reflectance by itself and is hardly corroded.
Examples of materials include Au, Ag, Cr, Ni, Al, and F.
e, Sn and the like.
u, Ag, and Al are most preferred. These metals and metalloids may be used alone or as two kinds of alloys. Examples of the film forming method include vapor deposition and sputtering.
The film thickness is 50-5000 °, preferably 100-3.
000.

<Protective Layer, Hard Coat Layer on Substrate Surface> The protective layer or hard coat layer on the substrate surface (a) protects the recording layer (reflection / absorption layer) from scratches, dust, dirt, etc., (b)
It is used for the purpose of improving the storage stability of the recording layer (reflection / absorption layer) and (c) improving the reflectance. For these purposes, the materials shown in the intermediate layer can be used. In addition, as the inorganic material, SiO, SiO ₂ or the like can be used, and as the organic material, polymethyl acrylate, polycarbonate, epoxy resin, polystyrene,
Heat-softening and heat-melting resins such as polyester resin, vinyl resin, cellulose, aliphatic hydrocarbon resin, aromatic hydrocarbon resin, natural rubber, styrene-butadiene resin, chloroprene rubber, wax, alkyd resin, drying oil and rosin Can be used.

Among the above materials, the most preferable example of the protective layer or the hard coat layer on the substrate surface 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 30 μm.
10 μm is appropriate. In the present invention, the lower intermediate layer, the protective layer, and the substrate surface hard coat layer each include a stabilizer, a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant, a plasticizer, and the like as in the case of the recording layer. Can be contained.

[0063]

EXAMPLES The present invention will be described more specifically with reference to the following examples. Table 1 shows examples of compounds used in this example.

[0064]

[Table 1-1]

[0065]

[Table 1-2]

[0066]

[Table 1-3]

Example 1 On a 0.6 mm thick injection molded polycarbonate substrate,
Depth 1750mm, half width 0.25μ with photopolymer
m, and a guide groove having a track pitch of 0.74 μm. The 1,1,2,2-tetrafluoropropanol solution of No. 1 was applied by spinner coating to a thickness of 90
A recording layer of 0 ° is formed, and then gold 12 is formed by sputtering.
After a reflective layer having a thickness of 0.6 mm was further provided thereon, and a protective layer having a thickness of 7 μm was formed thereon using an acrylic photopolymer, a thickness of 0.6
Injection-molded polycarbonate flat substrates having a thickness of 2 mm were adhered with an acrylic photopolymer to obtain a recording medium.

Examples 2 to 13 Compound No. 1 used in Example 1 Compound N instead of 1
o. Recording media were formed in exactly the same manner as in Example 1 using each of Nos. 2 to 20.

Comparative Example 1 Compound No. 1 used in Example 1 A recording medium was formed in the same manner as in Example 1 except that the following compound (ratio -1) was used instead of 1.

[0070]

Embedded image

<Recording Conditions> A semiconductor laser beam having a laser oscillation wavelength of 658 nm and a beam diameter of 1.0 μm was used for this recording medium, and an EFM signal (linear velocity of 3.
5 m / sec. ) Was recorded and reproduced with continuous light (reproduction power 0.7 mW) of a semiconductor laser having an oscillation wavelength of 685 nm, and a reproduction waveform was observed.

<Conditions for Light Resistance Test> A 40,000 Lux, Xe light was continuously irradiated for 20 hours.

<Storage test conditions> 60 ° C., 90% at 60%
Left for 0 hours.

[0074]

[Table 2]

[0075]

As described above, according to the present invention, according to the present invention, a laser having a wavelength range of 670 nm or less can be obtained by the recording medium described in the above items (1) to (7). It is possible to provide an information recording medium capable of recording and reproducing with light, and having excellent light resistance and storage stability. In addition, the recording medium according to the above (8) can provide a stable high reflectance and high modulation. An information recording medium capable of recording and reproduction can be provided, and an information recording medium capable of high-density recording with low jitter can be provided by the recording medium described in the above items (9) and (10). With the recording medium described in the item 11), an information recording medium capable of performing stable recording and reproduction can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a main weight loss process of an organic material and a method of obtaining a weight loss rate.

FIG. 2 is a diagram showing a general write-once optical recording medium of the present invention.

FIG. 3 is a diagram showing a configuration of an optical recording medium for CD-R of the present invention.

FIG. 4 is a diagram showing a configuration of an optical recording medium for DVD-R of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Recording layer 3 Undercoat layer 4 Protective layer 5 Hard coat layer 6 Metal reflective layer 7 Protective substrate 8 Adhesive layer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsutomu Sato 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Tatsuya Tomura 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Inside Ricoh Company (72) Inventor Noboru Sasa 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company (72) Inventor Somu 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh F Terms (reference) 2H111 EA03 EA12 EA22 EA25 EA40 FB16 FB23 FB25 FB42 5D029 JA04 JC05 KB03 WB14 WC01

Claims (11)

[Claims] 1. An optical recording medium comprising a recording layer provided on a substrate, wherein the recording medium contains at least an azo compound represented by the general formula (I) and an azo metal chelate compound comprising a metal, a metal oxide or a salt thereof. An optical recording medium characterized by containing one kind. Embedded image Wherein ring A represents the residue which, together with the carbon atom to which it is attached and the nitrogen atom having an active hydrogen, forms a heterocycle, and ring B which represents the residue to which it is attached. Represents a residue that forms an aromatic group with two carbon atoms,
X represents a group having no active hydrogen. ) 2. The optical recording medium according to claim 1, wherein the azo metal chelate compound is represented by the following general formula (II). Embedded image Wherein the ring A is taken from the group consisting of pyrrole, imidazole, pyrazole, triazole, tetrazole, indole, isoindole, benzimidazole, indazole, purine, perimidine together with the carbon and nitrogen atoms to which it is attached. M represents a metal or metal oxide, R ₁ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and R _{2 to} R ₅ represent a selected heterocyclic ring-forming residue. Each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group,
Hydroxyl group, carboxy group, amino group, substituted or unsubstituted alkyl group, substituted or unsubstituted aryl group, substituted or unsubstituted heterocyclic residue, substituted or unsubstituted alkylcarbonyl group, substituted or unsubstituted arylcarbonyl Group, substituted or unsubstituted alkyloxycarbonyl group, substituted or unsubstituted aryloxycarbonyl group, substituted or unsubstituted alkylsulfonyl group,
Substituted or unsubstituted arylsulfonyl group, substituted or unsubstituted alkylthiooxy group, substituted or unsubstituted arylthiooxy group, substituted or unsubstituted alkyloxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted Alkylamino group, substituted or unsubstituted arylamino group, substituted or unsubstituted alkylcarbonylamino group, substituted or unsubstituted arylcarbonylamino group, substituted or unsubstituted alkylcarbamoyl group, substituted or unsubstituted arylcarbamoyl Represents an unsubstituted or substituted alkenyl group, and n represents 2 or 3. Also, R ₂ and R ₃ , R ₃
And R ₄ , or R ₄ and R ₅ may be linked to form a ring. ) 3. The azo metal chelate compound according to claim 1, wherein the valence of the metal is divalent or trivalent.
Or the optical recording medium according to 2. 4. The optical recording medium according to claim 1, wherein the metal atom of the azo metal chelate compound is selected from manganese, cobalt, nickel, and copper. 5. The optical recording medium according to claim 1, wherein the A ring of the azo metal chelate compound is an imidazole residue. 6. The optical recording medium according to claim 1, wherein the metal atom of the azo metal chelate compound is nickel. 7. The optical recording medium according to claim 1, wherein the azo metal chelate compound is represented by the following general formula (III). Embedded image (Wherein, R ₆ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, and R ₇ and R ₈ each independently represent a hydrogen atom, a cyano group, a substituted or unsubstituted alkyl group, Represents an unsubstituted aryl group, and R ₉ and R ₁₀ are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxy group, an amino group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted Aryl group, substituted or unsubstituted heterocyclic residue, substituted or unsubstituted alkylcarbonyl group, substituted or unsubstituted arylcarbonyl group, substituted or unsubstituted alkyloxycarbonyl group, substituted or unsubstituted aryloxycarbonyl group A substituted or unsubstituted alkylsulfonyl group, a substituted or unsubstituted arylsulfonyl group Group, substituted or unsubstituted alkylthiooxy group, substituted or unsubstituted arylthiooxy group, substituted or unsubstituted alkyloxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylamino group, substituted or unsubstituted alkylamino group, Unsubstituted arylamino group, substituted or unsubstituted alkylcarbonylamino group, substituted or unsubstituted arylcarbonylamino group, substituted or unsubstituted alkylcarbamoyl group, substituted or unsubstituted arylcarbamoyl group, substituted or unsubstituted Represents an alkenyl group, and R ₈
And R ₉ or R ₉ and R ₁₀ may be linked to form a ring. ) 8. A recording layer having a refractive index n of 1.5 ≦ n ≦ 3.0 and an extinction coefficient k of 0.02 ≦ k ≦ 0 with respect to light in a wavelength range of ± 5 nm. The optical recording medium according to any one of claims 1 to 7, wherein 9. The optical recording medium according to claim 1, wherein, in the thermogravimetric analysis of the organic dye, the slope of the weight loss with respect to the temperature in the main weight loss process is 2% / ° C. or more. . 10. The thermogravimetric analysis of the organic dye shows that the total weight loss in the main weight loss step is 30% or more and the weight loss start temperature is 350%.
The optical recording medium according to any one of claims 1 to 9, wherein the temperature is lower than or equal to ° C. 11. A track pitch on a substrate is 0.7 to 0.7.
0.8 μm, the groove width is half width, 0.20 to 0.3
The optical recording medium according to any one of claims 1 to 10, wherein the thickness is 6 µm.