JP2003305958A - Optical recording medium, and method and apparatus for optical recording by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical recording medium which can be applied to a writing once DVD disc system using a semiconductor laser having an oscillation wavelength as a short wavelength in comparison with a conventional optical recording medium. <P>SOLUTION: For the optical recording medium having a recording layer on a substrate, (i) a formazan metal chelated compound comprising a formazan compound and a metal, (ii) a squalirium metal chelated compound comprising a squalirium compound and the metal and (iii) a pentamethine cyanin compound are provided in the recording medium. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium, an optical recording method using the same, and an optical recording apparatus.

[0002]

2. Description of the Related Art Currently, write-once type DVD media are being developed as next-generation large-capacity optical disks. As an elemental technology for improving the recording capacity, it is necessary to develop a recording material for reducing the size of recording pits, adopt an image compression technology represented by MPEG2, and shorten the wavelength of a semiconductor laser for reading recording pits. . Until now, semiconductor lasers in the red wavelength range have been used for barcode readers and measuring instruments.
Although only the 70 nm band AlGaInP laser diode was commercialized, a red laser is being used in earnest in the optical storage market as the density of optical discs increases. In the case of DVD drive, 630 as a light source
It is standardized by the wavelength of the laser diode in the 690 nm band. On the other hand, a read-only DVD-ROM drive has been commercialized with a wavelength of about 650 nm. The most preferable write-once type DVD media in such a situation is a wavelength of 630 to 6
It is a medium capable of recording and reproducing at 90 nm. To date, various dye-based materials have been proposed for the recording layer.
However, these materials are designed so that the long wavelength end of the absorption band of the absorption spectrum of the dye film becomes the recording / reproducing wavelength as shown in FIG. 1 in order to obtain the high reflectance which is a characteristic of the dye-based media. Therefore, there is a problem that the wavelength dependence is large. On the other hand, it is known that the oscillation wavelength of a semiconductor laser used for a recordable DVD drive or the like varies depending on the usage environment. Especially when placed in a high temperature environment, the oscillation wavelength shifts to a long wavelength,
There is a problem that the absorption coefficient k of the dye material used in the recording layer becomes small and the recording sensitivity becomes insufficient.

[0003]

DISCLOSURE OF THE INVENTION The present invention is an optical recording medium applicable to a write-once type DVD disk system using a semiconductor laser having an oscillation wavelength at a shorter wavelength than that of a conventional optical recording medium, and particularly, it depends on the recording wavelength. It is an object of the present invention to provide an optical recording medium having reduced properties, an optical recording method using the optical recording medium, and an optical recording apparatus.

[0004]

As a result of various investigations, the present inventors have found that a mixture of a formazan metal chelate compound and a squarylium metal chelate compound (maximum absorption wavelength of 500 to 500) which is a recording material for a conventional write-once type DVD medium. 6
It has been found that an optical recording medium having less dependence on the wavelength shift of a semiconductor laser can be obtained by adding a pentamethinecyanine compound having a specific structure (maximum absorption wavelength of 650 to 750 nm) to a (50 nm) material. Has been completed. That is, according to the present invention, the following optical recording medium, optical recording method and optical recording device are provided. (1) In an optical recording medium in which a recording layer is provided on a substrate, (i) a formazan metal chelate compound containing a formazan compound and a metal, (ii) a squarylium metal chelate compound containing a squarylium compound and a metal in the recording layer And (iii) an optical recording medium containing a pentamethine cyanine compound. (2) The maximum absorption wavelength of the absorption spectrum of the film of the formazan metal chelate compound and the squarylium metal chelate compound is 500 to 650 nm, and the maximum absorption wavelength of the absorption spectrum of the film of the pentamethinecyanine compound is 6
50-750 nm, The optical recording medium as described in (1) above. (3) The weight ratio of the formazan metal chelate compound to the squarylium metal chelate compound is 10:90 to 5
0:50, and the content of the pentamethine cyanine compound was 0.50 with respect to the total amount of the formazan metal chelate compound and the squarylium metal chelate compound.
5 to 5% by weight, The optical recording medium as described in (1) or (2) above. (4) The formazan metal chelate compound comprises a formazan compound represented by the following general formula (I) and / or the following general formula (II) and a metal.
The optical recording medium according to any one of (3).

[Chemical 6] (In the formula, ring A is a substituted or unsubstituted 5 containing a nitrogen atom.
Represents a member ring or a 6-membered ring, Z represents an atomic group that gives the ring A, and the nitrogen-containing heterocycle may be condensed with another ring,
A is an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkylcarbonyl group which may have a substituent, an arylcarbonyl which may have a substituent Group, an alkenyl group which may have a substituent, a heterocyclic group which may have a substituent, or an alkoxycarbonyl group which may have a substituent, and B has a substituent. Represents an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group)

[Chemical 7] (In the formula, ring B and ring C may be substituted with a nitrogen atom.
Or an unsubstituted 5- or 6-membered ring, Z₁, Z₂Haso
The atomic groups that give ring B and ring C, respectively, are shown below.
A ring may be condensed with another ring,₁, A₂Is it
An alkyl group which may have a substituent and a substituent
Optionally substituted aryl group, optionally substituted
Alkyl carbonyl group, which may have a substituent
Carbonyl group, alkeny optionally having substituents
Group, a heterocyclic group which may have a substituent or a substituent
Represents an alkoxycarbonyl group which may have,
B₁, B₂Each is an alkyle which may have a substituent.
Group, an alkenylene group which may have a substituent or a substituent
Represents an arylene group which may have a substituent, W is -C
H ₂-Or-SO₂Indicates-, and n is an integer of 0 or 1.
) (5) The metal component of the formazan metal chelate compound is
Vanadium, manganese, iron, cobalt, nickel, copper,
Is a metal selected from zinc and palladium, or
Characterized by being an oxide or halide of the metal
The optical recording medium according to any one of (1) to (4) above.
body. (6) The squarylium metal chelate compound is generally the following
Before being characterized by being a compound represented by formula (III)
The optical recording medium according to any one of (1) to (5).

[Chemical 8] [In the formula, R ₁ and R ₂ may be the same or different and each represents a hydrogen atom, an aliphatic group which may have a substituent, an aralkyl group which may have a substituent or a substituent. Represents an optionally substituted aryl group or a heterocyclic group which may have a substituent, M represents a metal atom having a coordination ability, m represents an integer of 2 or 3, and X represents An aryl group which may have a substituent, a heterocyclic group which may have a substituent, or Z
₃ = CH- (in the formula, Z ₃ represents a heterocyclic group which may have a substituent)] (7) X in the general formula (III) is represented by the following general formula (IV). The optical recording medium as described in (6) above, which is

[Chemical 9] (In the formula, R ₃ and R ₄ may be the same or different and each represents an aliphatic group which may have a substituent, or
₃ and R ₄ may combine with an adjacent carbon atom to form a carbocycle or a heterocycle, and R ₅ has a hydrogen atom, an optionally substituted aliphatic group, or a substituent. Represents an optionally substituted aralkyl group or an aryl group which may have a substituent, R _{6 to} R ₉ may be the same or different, and a halogen atom or an aliphatic group which may have a substituent. , An aralkyl group which may have a substituent, an aryl group which may have a substituent, a nitro group, a cyano group or an alkoxy group which may have a substituent, and are two adjacent to each other. The groups may combine with each other to form a ring which may have a substituent) (8) The above (6) or (6), wherein M in the general formula (III) is aluminum. (7) The optical recording medium as described above. (9) The optical recording medium as described in any of (1) to (8) above, wherein the pentamethinecyanine compound is a compound represented by the following general formula (V).

[Chemical 10] (In the formula, R_TenIs a hydrogen atom, a fat which may have a substituent
Represents an aliphatic group or a halogen atom, R₁₁And R₁₂Is the same
May be different and may have a substituent
Indicates a group, Q^-Is I^-, ClO_Four ^-, BF_Four ^-, PF₆ ^-, S
bF₆ ^-Or TsO ^-Indicates) (10) For light in the wavelength range of recording / reproducing wavelength ± 5 nm
Since the refractive index n of the single recording layer is 1.5 ≦ n ≦ 3.0,
Characteristic is that the extinction coefficient k is 0.02 ≦ k ≦ 0.3
The optical recording medium according to any one of (1) to (9) above. (11) Having a reflective layer, which is composed of gold, silver, copper and al
A metal selected from the group consisting of minium or a combination of the metals
Any of the above (1) to (10), which is gold
An optical recording medium described therein. (12) The track pitch on the substrate is 0.7 to 0.8 μ
m, and the groove width is a half-value width at 0.18 to 0.40 μm
Any of the above (1) to (11), characterized in that
The optical recording medium according to 1. (13) It is possible to record at a recording wavelength of 600 to 720 nm.
Any of the above (1) to (12), characterized in that
The optical recording medium according to 1. (14) The optical recording according to any one of (1) to (13) above.
Recording on a recording medium at a recording wavelength of 600 to 720 nm
An optical recording method characterized by: (15) The optical recording according to any one of (1) to (13) above.
An optical recording device equipped with a recording medium.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The optical recording medium of the present invention has, in its recording layer, (i) a formazan metal chelate compound comprising a formazan compound and a metal, (ii) a squarylium metal chelate compound comprising a squarylium compound and a metal, and (Iii) It contains a pentamethine cyanine compound. In this case, various conventionally known compounds can be used as the formazan compound, but at least one selected from compounds represented by the following general formulas (I) and (II) is preferably used.

[Chemical 11]

[Chemical 12]

In the above formula, ring A, ring B and ring C each represent a substituted or unsubstituted nitrogen-containing 5-membered ring or 6-membered ring,
Z, Z ₁ and Z ₂ each represent an atomic group providing ring A, ring B and ring C. Such an atomic group may include a hetero atom in addition to the carbon atom. Further, the hetero atom includes a nitrogen atom (-N-) and a sulfur atom (-S).
-), Oxygen atom (-O-), selenium atom (-Se-) and the like are included.

Another ring D may be condensed with each of ring A, ring B and ring C. The ring D in this case includes a carbocycle and a heterocycle. In the case of a carbocycle, the number of carbon atoms constituting the ring is 6 to 20, preferably 6 to 10. Specific examples thereof include a benzene ring, a naphthalene ring, a cyclohexane ring and the like. On the other hand, in the case of a heterocycle, the number of ring-constituting atoms is 5 to 20, preferably 5 to 14, and more preferably 5 to 6. Specific examples thereof include a pyrrolidine ring, a thiazole ring, an imidazole ring, an oxazole ring,
Examples thereof include a pyrazole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a quinoline ring, an indoline ring and a carbazole ring.

Specific examples of the ring A, ring B and ring C are thiazole ring, imidazole ring, thiadiazole ring, oxazole ring, triazole ring, pyrazole ring,
Examples thereof include an oxadiazole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring and a triazine ring.

Specific examples of the substituents bonded to ring A, ring B and ring C are, independently of each other, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, an amino group,
A carbamoyl group, an alkyl group which may have a substituent, an aryl group which may have a substituent, a heterocyclic group which may have a substituent, an alkoxy which may have a substituent Group, aryloxy group optionally having substituent (s), alkylthio group optionally having substituent (s), arylthio group optionally having substituent (s), alkylamino optionally having substituent (s) Group, an arylamino group which may have a substituent, an alkoxycarbonyl group which may have a substituent, an aryloxycarbonyl group which may have a substituent, and which may have a substituent Good alkylcarboxamide group, arylcarboxamide group optionally having substituents, alkylcarbamoyl group optionally having substituents, arylcarbamoyl group optionally having substituents, substituted Alkenyl which may have a, optionally substituted alkyl sulfamoyl group, and the like.

In the above general formulas (I) and (II),
A, A ₁ and A ₂ each represent an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkylcarbonyl group which may have a substituent, and a substituent. The arylcarbonyl group which may have, the alkenyl group which may have a substituent, the heterocyclic group which may have a substituent, or the alkoxycarbonyl group which may have a substituent are shown. In this case, the alkyl group and the alkenyl group include chain and cyclic groups. The alkyl group preferably has 1 to 15 carbon atoms, and more preferably 1 to 8 carbon atoms. The alkenyl group preferably has 2 to 8 carbon atoms, and more preferably 2 to 6 carbon atoms.

In the above general formula (I), B is an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an aryl group which may have a substituent. Indicates. In this case, the alkyl group and the alkenyl group include chain and cyclic groups. The carbon number of the alkyl group is preferably 1 to 15, more preferably 1
And the number of carbon atoms of the alkenyl group is preferably 2
8, more preferably 2-6. The aryl group preferably has 6 to 18 carbon atoms, and more preferably 6 to 14 carbon atoms.

In the general formula (II), B ₁ and B ₂ are
Each of them represents an alkylene group which may have a substituent, an alkenylene group which may have a substituent or an arylene group which may have a substituent. In this case, the alkylene group and alkenylene group include chain and cyclic groups. In the alkylene group, the carbon number thereof is preferably 1 to 15, more preferably 1 to 8. In the alkenylene group, the carbon number thereof is preferably 2-8, more preferably 2-6. In the arylene group, the carbon number thereof is preferably 6-18, more preferably 6-14.

Specific examples of the above-mentioned alkyl groups preferably include those having 1 to 15 carbon atoms, and examples thereof include methyl group, ethyl group, n-propyl group, n-butyl group, and n.
-Pentyl group, n-hexyl group, n-heptyl group, n-
Linear alkyl groups such as octyl group, n-nonyl group and n-decyl group, isobutyl group, isoamyl group, 2-methylbutyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 2 -Ethylbutyl group, 2-
Methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 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-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, 1-isobutyl-3-methylbutyl group, neopentyl group, tert-butyl group, tert-hexyl group,
branched alkyl groups such as tert-amyl group and tert-octyl group, cyclohexyl group, 4-methylcyclohexyl group, 4-ethylcyclohexyl group, 4-tert-
Butylcyclohexyl group, 4- (2-ethylhexyl)
Examples thereof include cycloalkyl groups such as a cyclohexyl group, a bornyl group, an isobornyl group and an adamantyl group, and among them, those having 1 to 8 carbon atoms are preferable. Examples of the alkylene group include those obtained by removing one hydrogen atom from the above alkyl group.

Each of the above-mentioned alkyl groups may be substituted with a hydroxyl group, a halogen atom, a nitro group, a carboxyl group, a cyano group or the like, or may have a specific substituent (for example, a halogen atom). Alternatively, it may be substituted with a nitro group), and may be substituted with an aryl group, a heterocyclic group or the like. Further, it may be substituted with another hydrocarbon group such as the above alkyl group through a hetero atom such as oxygen, sulfur or nitrogen.

Examples of the alkyl group substituted with another hydrocarbon group through oxygen include methoxymethyl group, methoxyethyl group, ethoxymethyl group, ethoxyethyl group, butoxyethyl group, ethoxyethoxyethyl group and phenoxyethyl group. , An alkyl group substituted with an alkoxy group such as a methoxypropyl group and an ethoxypropyl group, an aryloxy group and the like. These alkoxy group and aryloxy group may have a substituent.

The alkyl group substituted with another hydrocarbon group through sulfur is substituted with an alkylthio group such as a methylthioethyl group, an ethylthioethyl group, an ethylthiopropyl group, a phenylthioethyl group or an arylthio group. And an alkyl group. These alkylthio group and arylthio group may have a substituent.

Examples of the alkyl group substituted with another hydrocarbon group through nitrogen include alkylamino groups such as dimethylaminoethyl group, diethylaminoethyl group, diethylaminopropyl group, phenylaminomethyl group and arylamino groups. Examples include substituted alkyl groups. These alkylamino group and arylamino group may have a substituent.

Specific examples of the alkenyl group preferably have 2 to 8 carbon atoms, for example, vinyl group, allyl group, 1-propenyl group, methacryl group, crotyl group, 1
-Butenyl group, 3-butenyl group, 2-pentenyl group, 4
-Pentenyl group, 2-hexenyl group, 5-hexenyl group, 2-heptenyl group, 2-octenyl group and the like. Examples of the substituent of the alkenyl group include those similar to the case of the above alkyl group. Specific examples of the aryl group include, for example, phenyl group, naphthyl group, anthranyl group, fluorenyl group, phenalenyl group, phenanthranyl group, triphenylenyl group, pyrenyl group and the like. Examples of the alkylene group and the alkenylene group include those obtained by removing one hydrogen atom from the above alkyl group and alkenyl group. Examples of the arylene group include the above aryl group with one hydrogen atom removed.

The aryl group and arylene group may have an alkyl group, an alkenyl group, a hydroxyl group, a halogen atom, a nitro group, a carboxyl group, a cyano group, a trifluoromethyl group, or a specific substituent (for example, (It may be substituted with a halogen atom or a nitro group)
Aryl group, which may have a specific substituent (eg, may be substituted with a halogen atom or a nitro group) may be substituted with a heterocyclic group, and an atom such as oxygen, sulfur or nitrogen may be substituted. It may be substituted with the above alkyl group or the like. Here, examples of the alkyl group and aryl group are the same as those described above, and examples of the halogen atom are the same as those described below.

Specific examples of the heterocyclic group include furyl group, thienyl group, pyrrolyl group, benzofuranyl group, isobenzofuranyl group, benzothienyl group, indolinyl group, isoindolinyl group, carbazolyl group, pyridyl group, piperidyl group, quinolyl group. Group, isoquinolyl group, oxazolyl group, isoxazolyl group, thiazolyl group, isothiazolyl group, imidazolyl group, pyrazolyl group, benzimidazolyl group, pyrazyl group, pyrimidinyl group, pyridazinyl group, quinoxalinyl group and the like. The heterocyclic group may have a hydroxyl group, an alkyl group, a halogen atom, a nitro group, a carboxyl group, a cyano group, or a specific substituent (for example, it may be substituted with a halogen atom or a nitro group). Aryl group, optionally substituted by a heterocyclic group which may have a specific substituent (eg, may be substituted by a halogen atom or a nitro group), and a hetero atom such as oxygen, sulfur or nitrogen It may be substituted with a hydrocarbon group such as the above alkyl group via an atom. Here, as specific examples of the alkyl group, aryl group and heterocyclic group, the above-mentioned specific examples can be mentioned.

Specific examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms. The alkoxy group which may have a substituent may be one having an alkyl group which may have a substituent directly bonded to an oxygen atom. Specific examples of the alkyl group and the substituent include the above-mentioned specific examples. The aryloxy group which may have a substituent may be one having an aryl group which may have a substituent directly bonded to an oxygen atom. Specific examples of the aryl group and the substituent include the above-mentioned specific examples. The alkylthio group which may have a substituent may be one in which an alkyl group which may have a substituent is directly bonded to a sulfur atom. Specific examples of the alkyl group and the substituent include the above-mentioned specific examples. The arylthio group which may have a substituent may be one in which an aryl group which may have a substituent is directly bonded to a sulfur atom. Specific examples of the aryl group and the substituent include the above-mentioned specific examples. The alkylamino group which may have a substituent may be one having an alkyl group which may have a substituent directly bonded to a nitrogen atom.
Specific examples of the alkyl group and the substituent include the above-mentioned specific examples. Further, the alkyl groups are bonded to each other and include a piperidino group containing an oxygen atom, a nitrogen atom, or the like,
A ring may be formed such as a morpholino group, a pyrrolidinyl group, a piperazinyl group, an indolinyl group and an isoindolinyl group. The arylamino group which may have a substituent may be one having an aryl group which may have a substituent directly bonded to a nitrogen atom. Specific examples of the aryl group and the substituent include the above-mentioned specific examples.

The alkylcarbonyl group which may have a substituent may be any one in which an alkyl group which may have a substituent is directly bonded to the carbon atom of the carbonyl group. Specific examples of the alkyl group and the substituent include the above-mentioned specific examples. The arylcarbonyl group which may have a substituent may be one having an aryl group which may have a substituent directly bonded to the carbon atom of the carbonyl group. Specific examples of the aryl group and the substituent include the above specific examples. The alkoxycarbonyl group which may have a substituent may be one having an alkyl group which may have a substituent directly bonded to an oxygen atom (—O—). Specific examples of the alkyl group and the substituent include the above-mentioned specific examples. The aryloxycarbonyl group which may have a substituent may be one having an aryl group which may have a substituent directly bonded to an oxygen atom (—O—). Specific examples of the aryl group and the substituent include the above specific examples. The alkylcarboxamide group which may have a substituent may be one in which an alkyl group which may have a substituent is directly bonded to a carbon atom of the carboxamide. Specific examples of the alkyl group and the substituent include the above-mentioned specific examples. The arylcarboxamide group which may have a substituent may be one in which an aryl group which may have a substituent is directly bonded to a carbon atom of the carboxamide. Specific examples of the aryl group and the substituent include the above specific examples.

The alkylcarbamoyl group which may have a substituent may be one in which an alkyl group which may have a substituent is directly bonded to the nitrogen atom of the carbamoyl group. Specific examples of the alkyl group and the substituent include the above-mentioned specific examples. Further, the alkyl groups may be bonded to each other to form a ring containing an oxygen atom, a nitrogen atom and the like, such as a piperidino group, a morpholino group, a pyrrolidinyl group, a piperazinyl group, an indolinyl group and an isoindolinyl group. The arylcarbamoyl group which may have a substituent may be one in which an aryl group which may have a substituent is directly bonded to the nitrogen atom of the carbamoyl group. Specific examples of the aryl group and the substituent include the above specific examples. The alkylsulfamoyl group which may have a substituent may be one in which an alkyl group which may have a substituent is directly bonded to the nitrogen atom of the sulfamoyl group. Specific examples of the alkyl group and the substituent include the above-mentioned specific examples.

The metal component in the formazan metal chelate may be any metal or metal compound capable of forming a chelate with formazan, and examples thereof include titanium, vanadium, chromium, manganese, iron, cobalt, nickel,
Copper, zinc, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium and oxides and halides of these metals are included. In the present invention, vanadium, manganese, iron, cobalt, nickel, copper, zinc, and palladium are particularly preferable as the formazan-chelating metal component, and the present invention using a formazan metal chelate compound containing these metals is preferable. The optical recording medium (1) has excellent optical characteristics. Among the halides, chloride is preferably used.

Specific examples of the formazan metal chelate compounds represented by the above general formulas (I) and (II) are shown in Tables 1 to 4. In the table below, Ph represents phenyl.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

[Table 3]

[0029]

[Table 4]

Next, the squarylium metal compound will be described in detail. As the squarylium compound used in the present invention, various conventionally known compounds can be used. The optical recording medium of the present invention has a recording / reproducing wavelength of 600 to 720n.
It is preferable to use a laser beam of m, but among the squarylium metal chelate compounds, those represented by the following general formula (III) are preferable from the optical characteristics at this wavelength.

[Chemical 13]

In the above formula, R ₁ and R ₂ may be the same or different and each is a hydrogen atom, an aliphatic group which may have a substituent, an aralkyl group which may have a substituent, The aryl group which may have a substituent or the heterocyclic group which may have a substituent is shown. M represents a metal atom having a coordination ability. m represents an integer of 2 or 3. X represents an aryl group which may have a substituent, a heterocyclic group which may have a substituent, or Z ₃ = CH- (Z ₃ represents a heterocyclic group which may have a substituent. Represents).

As X in the general formula (III), a nitrogen-containing cyclic group represented by the following general formula (IV) is preferable.

[Chemical 14]

In the above formula, R ₃ and R ₄ may be the same or different and each represents an aliphatic group which may have a substituent, or R ₃ and R ₄ are bonded to each other to form a carbon ring. Alternatively, it may form a heterocycle. R ₅ represents a hydrogen atom, an aliphatic group which may have a substituent, an aralkyl group which may have a substituent, or an aryl group which may have a substituent.
R _{6 to} R ₉ are a hydrogen atom, a halogen atom, an aliphatic group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent, A nitro group, a cyano group or an alkoxy group which may have a substituent is shown. In R _{6 to} R ₉ , two adjacent groups may be bonded to each other to form a carbocycle or a heterocycle which may have a substituent. Aliphatic groups include alkyl and alkenyl groups. Moreover, these alkyl groups and alkenyl groups may be chain-like or cyclic. In this aliphatic group, when it is chain-like, it preferably has 1 to 6 carbon atoms, and when it is cyclic,
Those having 3 to 8 carbon atoms are preferable.
Specific examples of the aliphatic group include, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, 1-methylbutyl group. , 2-
Methylbutyl group, tert-pentyl group, hexyl group,
Cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, vinyl group, allyl group, 1-propenyl group, methacryl group, crotyl group, 1-butenyl group, 3-butenyl group, 2- Examples thereof include a pentenyl group, a 4-pentenyl group, a 2-hexenyl group, a 5-hexenyl group, a 2-heptenyl group and a 2-octenyl group. The alkyl group portion in the alkoxy group may be a chain or cyclic alkyl group. In the case of a chain, those having 1 to 6 carbon atoms are preferable, and in the case of a ring, those having 3 to 8 are preferable. Specific examples of the alkyl group include those mentioned above. Examples of the aralkyl group include an aralkyl group having a carbon number of 7 to 15, and examples thereof include a benzyl group, a phenethyl group, a phenylpropyl group, and a naphthylmethyl group. The aryl group preferably has 6 to 18 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, an anthryl group, and an azulenyl group.

Examples of the halogen atom include chlorine atom, bromine atom, fluorine atom and iodine atom. The aralkyl group, the aryl group, the alkoxy group, the substituent of the aromatic ring or the heterocyclic group, for example, a hydroxyl group, a carboxyl group,
Halogen atom, alkyl group, alkoxy group, nitro group,
A substituted or unsubstituted amino group and the like can be mentioned. Examples of the halogen atom, alkyl group and alkoxy group are the same as those mentioned above. These substituents have 1 in the molecule.
It can be one or more. Examples of the substituent of the aliphatic group or the alkyl group include a hydroxyl group, a carboxyl group, a halogen atom and an alkoxy group. Examples of the halogen atom and the alkoxy group are the same as those mentioned above. These substituents can be one or more in the molecule. Examples of the substituent of the amino group include 1 to 2 alkyl groups which may be the same or different, and the alkyl group in this case includes the same ones as described above.

As the metal atom M, various conventionally known metals having a coordination ability with respect to a squarylium compound are used. For example, aluminum, zinc, copper, iron, nickel, chromium, cobalt, manganese, iridium, vanadium. , Titanium, and the like, and in particular, the optical recording medium of the present invention using a squarylium metal chelate compound of aluminum has excellent optical characteristics.

In R _{6 to} R ₉ , the carbon ring formed by the bonding of two adjacent groups includes an aromatic ring having 6 to 14 carbon atoms such as a benzene ring, and 3 to 3 carbon atoms such as cyclohexane. Ten aliphatic rings are included.

In the general formula (III), the heterocyclic ring in the heterocyclic group and the heterocyclic ring formed by combining R ₃ and R ₄ include, for example, nitrogen atom, oxygen atom and sulfur atom. A 5- or 6-membered monocyclic aromatic or aliphatic heterocyclic ring containing at least one selected atom, a bicyclic or tricyclic condensed with a 3- to 8-membered ring, a nitrogen atom, an oxygen atom, and a sulfur atom. And a condensed aromatic or aliphatic heterocycle containing at least one atom selected from among the above, more specifically, a pyridine ring, a pyrazine ring,
Pyrimidine ring, pyridazine ring, quinoline ring, isoquinoline ring, phthalazine ring, quinazoline ring, quinoxaline ring,
Naphthyridine ring, cinnoline ring, pyrrole ring, pyrazole ring, imidazole ring, triazole ring, tetrazole ring, thiophene ring, furan ring, thiazole ring, oxazole ring, indole ring, isoindole ring, indazole ring, benzimidazole ring, benztriazole ring ,
Benzothiazole ring, benzoxazole ring, purine ring, carbazole ring, pyrrolidine ring, piperidine ring, piperazine ring, morpholine ring, thiomorpholine ring, homopiperidine ring, homopiperazine ring, tetrahydropyridine ring, tetrahydroquinoline ring, tetrahydroisoquinoline ring, Tetrahydrofuran ring, tetrahydropyran ring,
Examples thereof include a dihydrobenzofuran ring and a tetrahydrocarbazole ring.

The heterocyclic group of Z _{3 in} the general formula (III) includes indoline-2-ylidene, benz [e] indoline-2-ylidene, 2-benzothiazolinylidene, naphtho [2,1-]. d] thiazole-2 (3H) -ylidene, naphtho [1,2-d] thiazole-2 (1H) -ylidene, 1,4-dihydroquinoline-4-ylidene,
1,2-dihydroquinoline-2-ylidene, 2,3-dihydro-1H-imidazo [4,5-d] quinoxaline-
2-ylidene, 2-benzoselenazolinylidene and the like can be mentioned.

The alicyclic carbon ring formed by combining R ₃ and R ₄ preferably has 3 to 8 carbon atoms, and may be saturated or unsaturated. , Cyclopropane ring, cyclobutane ring, cyclopentane ring, cyclohexane ring, cycloheptane ring,
Examples thereof include a cyclooctane ring, a cyclopentene ring, a 1,3-cyclopentadiene ring, a cyclohexene ring and a cyclohexadiene ring.

The reaction formulas for the general method for producing the compound of the general formula (III) are shown below. Here, the compound represented by the general formula (III) may be referred to as the compound (III). The same applies to compounds having other formula numbers. (1) Reaction formula (1-a)

[Chemical 15]

(2) Reaction formula (1-b)

[Chemical 16]

(3) Reaction formula (1-c)

[Chemical 17]

(4) Reaction formula (1-d)

[Chemical 18]

In the above formula, R ₁ , R ₂ , X, M and m have the same meanings as defined above, and Y represents a hydrogen atom, potassium, sodium or the like. Me represents a methyl group.

The production of the compound according to the above reaction formula (1-a) is shown below. Compound (VII) is compound (V)
And 0.5 to 2 times the molar amount of compound (VI), if necessary, in the presence of a base in a solvent at room temperature to 40 ° C. for 30 minutes to 15 hours to obtain. As the base, for example, an inorganic base such as potassium carbonate, sodium carbonate or potassium hydroxide or an organic base such as triethylamine or sodium methoxide is used. As the solvent, for example, methanol, ethanol, dimethylformamide or the like is used.

The production of the compound according to the above reaction formula (1-b) is shown below. Compound (VIII) is converted to compound (VI
I) in an alkaline solvent or in an acidic solvent at room temperature to 4
It is obtained by reacting at 0 ° C. for 30 minutes to 15 hours. As the alkaline solvent, for example, a potassium carbonate aqueous solution, a sodium carbonate aqueous solution, a potassium hydroxide aqueous solution, or the like is used. The acidic solvent is, for example, 50% hydrochloric acid.
% Volume / volume of dimethylsulfoxide aqueous solution, hydrochloric acid 5
A 0% volume / volume dimethylformamide aqueous solution or the like is used.

The production of the compound according to the above reaction formula (1-c) is shown below. Compound (IX) is compound (VIII)
And 0.5 to 2 times the molar amount of X-H, if necessary, 0.5 to
1 at 80 to 120 ° C. in a solvent in the presence of a 2-fold molar base.
Obtained by reacting for ~ 15 hours. As the solvent, for example, only an alcohol solvent having 2 to 8 carbon atoms such as ethanol, propanol, isopropanol, butanol, octanol or the like, or a mixed solvent of the alcohol solvent and benzene, toluene or xylene (alcohol 50 volume / volume% Above) is used. As the base, for example, an organic base such as quinoline, triethylamine, pyridine or the like, or an inorganic base such as potassium carbonate, potassium hydrogencarbonate, sodium hydrogencarbonate or the like is used.

The production of the compound according to the above reaction formula (1-d) is shown below. Compound (III) is compound (IX)
And 0.5 to 2 times the molar M ^{m +} , if necessary, 0.5
It can be obtained by reacting in a solvent at room temperature to 120 ° C. for 1 to 15 hours in the presence of ˜2 times mol of acetic acid. As the raw material for giving M ^{m +} , for example, aluminum trisacetylacetonate, aluminum trisethylacetoacetate, aluminum isoproxide, aluminum sec-butoxide, aluminum ethoxide, aluminum chloride, copper chloride, copper acetate, nickel acetate, etc. are used. To be Examples of the solvent include halogen solvents such as chloroform and dichloromethane, aromatic solvents such as toluene and xylene, tetrahydrofuran, and methyl-tert-.
An ether solvent such as butyl ether and an ester solvent such as ethyl acetate are used.

Specific examples of the compound represented by the general formula (III) are shown in Tables 5 to 7.

In the table below, nPr represents n-propyl, iPr represents isopropyl, nBu represents n-butyl, and Ph represents phenyl.

[Table 5]

[Table 6]

[Table 7]

Next, the pentamethine cyanine compound will be described. As the pentamethine cyanine compound used in the present invention, various conventionally known compounds can be used. The optical recording medium of the present invention has a conventional maximum absorption wavelength of 5
By adding a pentamethinecyanine compound having a maximum absorption wavelength of 650 to 750 nm to a mixed dye material of formazan metal chelate and squarylium metal chelate having a wavelength of 00 to 650 nm, the dependency on the wavelength shift of the semiconductor LD is reduced. However, as the structure of pentamethinecyanine, those represented by the following general formula (V) are particularly preferable.

[Chemical 19] In the above formula, R ₁₀ represents a hydrogen atom, an aliphatic group which may have a substituent, or a halogen atom. R ₁₁ and R ₁₂ may be the same or different and each represents an aliphatic group which may have a substituent. Q ⁻ is I ⁻ , ClO ₄ ⁻ , BF ₄ ⁻ , PF
Anions such as ₆ ⁻ , SbF ₆ ⁻ and TsO ⁻ are shown. The aliphatic group which may have a substituent has 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms. The aliphatic group includes an alkyl group and an alkenyl group. Further, the alkyl group or alkenyl group may be chain or cyclic. Furthermore, this aliphatic group may contain a hetero atom such as an oxygen atom, a nitrogen atom, or a sulfur atom in its main chain. Specific examples of the substituents include the various ones shown for the general formula (I).

Specific examples of the compound represented by the general formula (V) are shown in Tables 8 to 10.

In the table below, nHex represents n-hexyl, iBu represents isobutyl, and nPr represents n-hexyl.
Represents propyl.

[Table 8]

[0054]

[Table 9]

[0055]

[Table 10]

The mixing ratio of the formazan metal chelate compound and the squarylium metal chelate compound in the recording layer is preferably 10:90 to 50:50 by weight, and the pentamethinecyanine compound is further contained in the recording layer. 0.5 to 5% (weight% based on the total amount of the formazan metal chelate compound and the squarylium metal chelate compound) is preferably contained. When the squarylium metal chelate compound is in the above range, the formazan metal chelate compound works effectively and high light resistance can be obtained. Further, when the squarylium metal chelate compound is in the above range, a high reflectance is obtained, which is preferable. 500-6
A mixture of a formazan metal chelate compound having an absorption maximum at 50 nm and a squarylium metal chelate compound similarly having an absorption maximum at 500 to 650 nm is further added to the mixture.
By adding a pentamethinecyanine compound having an absorption maximum at 0 to 750 nm (near the recording / reproducing wavelength) in the above range, the recording sensitivity is lowered with respect to the wavelength fluctuation of the recording laser while maintaining the basic characteristics of the write-once type DVD media.
So-called wavelength dependence is reduced.

Next, optical properties and light resistance are listed as items necessary for constituting the recording layer of the optical recording medium of the present invention. As an optical characteristic, a recording and reproducing wavelength of 600
It is preferable to have a large absorption band on the short wavelength side with respect to 720 nm and to have the recording / reproducing wavelength in the vicinity of the long wavelength end of the absorption band. This is a recording / reproducing wavelength of 600 to 720.
It has a large refractive index and extinction coefficient in nm. Specifically, the refractive index n of the recording layer single layer for light in the wavelength region of recording / reproducing wavelength ± 5 nm is 1.5 or more and 3.0 or less, and the extinction coefficient k is 0.02 or more and 0.3 or less. It is preferably in the range. When n is 1.5 or more, a sufficient optical change can be obtained, and the recording modulation degree becomes high, which is preferable, and when n is 3.0 or less, the wavelength dependence does not become high and recording Even in the reproduction wavelength region, a reproduction error is unlikely to occur, which is preferable. Further, when k is 0.02 or more, recording sensitivity is improved, and when k is 0.3 or less, reflectance of 50% or more is easily obtained, which is preferable.
Further, since the larger the extinction coefficient, the larger the refractive index n, the log ε (ε is the molar extinction coefficient) is preferably 5 or more. Further, as the light resistance, it is preferable that it has reproduction stability of 1,000,000 times or more repeatedly and fastness that does not fade when left indoors. Substrates typically have a depth of 1000-250
It has a 0Å guide groove. Track pitch is usually
It is 0.7 to 1.0 μm, but it is 0.
It is preferably 7 to 0.8 μm. The groove width is preferably 0.18 to 0.40 μm in full width at half maximum. 0.18
When the thickness is at least μm, a sufficient tracking error signal strength can be easily obtained, which is preferable. Further, when it is 0.40 μm or less, the recording portion is not likely to spread laterally when recording, which is preferable.

Next, the structure of the optical recording medium of the present invention will be described. FIG. 2 is a diagram showing an example of a layer structure applicable to the optical 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 with the undercoat layer 3 interposed as necessary, and the protective layer 4 is further provided as necessary. In addition, a hard coat layer 5 may be formed under the substrate 1 if necessary.
Can be provided.

FIG. 3 is a diagram showing an example of another type of layer structure applicable to the optical recording medium of the present invention, which is an example of a CD-R medium. A reflective layer 6 is formed on the recording layer 2 having the structure shown in FIG.
Is provided.

FIG. 4 is a diagram showing an example of the layer structure of another type (for DVD-R) applicable to the optical recording medium of the present invention. In this case, the protective layer 4 having the structure of FIG. A layer 8 and a protective substrate 7 are provided. That is, the optical recording medium of the present invention is
An air sandwich structure in which the recording layer (organic thin film layer) having the structure shown in FIGS. 2 and 3 is placed inside and sealed with another substrate through a space, or is bonded through a protective layer A laminated structure can also be used.

When the optical recording medium of the present invention is applied as a write-once type DVD medium, the structure of the recording medium is as follows:
The basic structure is a structure in which the substrate (1) and the second substrate (hereinafter, sometimes referred to as the first substrate and the second substrate) are bonded to each other with an adhesive via a recording layer. The recording layer may be a single layer of organic dye,
A laminate of an organic dye layer and a metal reflective layer may be used to enhance the reflective layer. A layer between the recording layer and the substrate may be formed via an undercoat layer or a protective layer, or may be laminated to improve the function. Most commonly used is the first substrate / organic dye layer / metal reflective layer / protective layer / adhesive layer / second substrate structure.

<Substrate> As a necessary characteristic of the substrate, it must be transparent to the laser beam used only when recording and reproducing from the substrate side, and when recording and reproducing from the recording layer side, the substrate is transparent. No need. Therefore, in the present invention, when two substrates are used in a sandwich form, for example, if only one substrate (second substrate) is transparent, the other substrate (first substrate) may be transparent or opaque. . As the substrate material, for example, polyester, acrylic resin, polyamide, polycarbonate resin, polyolefin resin,
Phenolic resin, epoxy resin, plastic such as polyimide, glass, ceramic or metal can be used. If only one layer of substrate is used, the surface of the substrate is used. If two substrates are used in a sandwich form, the surface of the first substrate is used. A format may be formed.

<Recording Layer> The recording layer causes some kind of optical change upon irradiation with laser light, and information can be recorded by the change, and the recording layer contains the dye mixture characterized by the above-mentioned present invention. It is necessary to contain [a mixture of a formazan metal chelate compound, a squarylium metal chelate compound, and a pentamethinecyanine metal chelate compound]. In forming the recording layer, the dyes which are the features of the present invention may be used singly or in combination. Further, in addition to the above-mentioned dyes which are the features of the present invention, they may be mixed or laminated with other organic dyes for the purpose of improving optical characteristics, recording sensitivity, signal characteristics and the like. Examples of such other organic dyes include polymethine dyes, naphthalocyanine dyes, phthalocyanine dyes, croconium dyes, pyrylium dyes, naphthoquinone dyes, anthraquinone (indanthrene) dyes, xanthene dyes, triphenylmethane dyes, azulene dyes, Tetrahydrocholine type, phenanthrene type,
Examples thereof include triphenothiazine dyes and metal chelate compounds. These dyes may be used alone or in combination of two or more. In the dye, a metal or a metal compound such as In, Te, Bi, Se, Sb, Ge,
It is also possible to use Sn, Al, Be, TeO ₂ , SnO, As, Cd, etc. in the form of a dispersion mixture or a laminated layer.

Further, a polymer material such as, for example,
Ionomer resin, polyamide resin, vinyl resin,
Various materials such as natural polymers, silicones, liquid rubbers, or silane coupling agents may be dispersed and mixed, or stabilizers (for example, transition metal complexes), dispersants, flame retardants for the purpose of improving properties. , A lubricant, an antistatic agent, a surfactant, a plasticizer and the like can be used together.

The recording layer is formed by vapor deposition, sputtering, C
It can be carried out by a conventional means such as VD or solution coating. When using a coating method, the dye mixture or the like is dissolved in an organic solvent or the like, spraying, roller coating,
It is carried out by a conventional coating method such as dipping and spin coating. As the organic solvent used, alcohols such as methanol, ethanol, isopropanol and 2,2,3,3-tetrafluoropropanol are generally used, ketones such as acetone, methyl ethyl ketone and cyclohexanone, N, N-dimethylformamide, N, N- are used. Amides such as dimethylacetamide, sulfoxides such as dimethyl sulfoxide, tetrahydrofuran, dioxane, diethyl ether, ethers such as ethylene glycol monomethyl ether, methyl acetate,
Esters such as ethyl acetate, aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethane, carbon tetrachloride, trichloroethane, benzene, xylene,
Aromatic compounds such as monochlorobenzene and dichlorobenzene,
Examples thereof include cellosolves such as methoxyethanol and ethoxyethanol, hydrocarbons such as hexane, pentane, cyclohexane and methylcyclohexane. The thickness of the recording layer is preferably 100 Å to 10 μm, more preferably 200 Å to 2000 Å.

<Undercoat layer> The undercoat layer is (a) improved in adhesiveness, (b) barrier for water or gas, (c) improved storage stability of the recording layer, (d) improved reflectance, (E) It is used for the purpose of protecting the substrate and the recording layer from a solvent, and (f) forming guide grooves, guide pits, preformats, etc.
For the purpose of (a), various polymeric materials such as ionomer resins, polyamide resins, vinyl resins, natural resins, natural polymers, silicones, liquid rubbers, and various silane coupling agents are used. For the purpose of (b) and (c), an inorganic compound such as SiO ₂ , MgF ₂ , Si may be used in addition to the above-mentioned polymer material.
O, TiO ₂ , ZnO, TiN, SiN, etc., and also metal or semimetal, such as Zn, Cu, Ni, Cr, G
e, Se, Au, Ag, Al or the like can be used.
For the purpose of (d), a metal such as Al or Ag, or an organic thin film having a metallic luster such as a methine dye or a xanthene-based dye can be used, and for the purposes of (e) and (f). In contrast, UV curable resin, thermosetting resin,
A thermoplastic resin or the like can be used. The thickness of the undercoat layer is preferably 0.01 to 30 μm, more preferably 0.
05-10 μm is suitable.

<Metal Reflective Layer> Examples of the material of the metal reflective layer include metals and semi-metals which have a high reflectance and are hardly corroded, and specific examples thereof include Au, Ag, and
Cr, Ni, Al, Fe, Sn, Cu and the like can be mentioned, but Au, Ag, Al and Cu are most preferable from the viewpoint of reflectance and productivity, and these metals and semimetals may be used alone. Two or more kinds of alloys may be used. Examples of the method for forming the film of the metal reflective layer include vapor deposition and sputtering, and the film thickness is preferably 50 to 5000Å, more preferably 1
It is from 00 to 3000Å.

<Protective Layer, Substrate Surface Hard Coat Layer> The protective layer or the substrate surface hard coat layer is (a) protection of the recording layer (reflection / absorption layer) from scratches, dust and dirt, and (b) recording layer ( It is used for the purpose of improving the storage stability of the (reflection absorption layer) and (c) improving the reflectance. For these purposes, the materials shown for the undercoat layer can be used.
Further, SiO, SiO ₂ or the like can be used as the inorganic material, and polymethyl acrylate, polycarbonate, epoxy resin, polystyrene, polyester resin, vinyl resin, cellulose, aliphatic hydrocarbon resin, aromatic hydrocarbon resin, or the like can be used as the organic material. It is also possible to use natural rubber, styrene-butadiene resin, chloroprene rubber, wax, alkyd resin, drying oil, heat-softening resin such as rosin, heat-melting resin, and UV-curing resin. The most preferable example of the above-mentioned materials for the protective layer or the substrate surface hard coat layer is an ultraviolet curable resin having excellent productivity. The thickness of the protective layer or the hard coat layer on the substrate surface is preferably 0.01.
-30 μm, more preferably 0.05-10 μm is suitable.

In the present invention, the undercoat layer, the protective layer, and the substrate surface hard coat layer are the same as in the case of the recording layer, such as a stabilizer, a dispersant, a flame retardant, a lubricant, an antistatic agent, and a surfactant. , A plasticizer, etc. can be contained.

<Protective Substrate> When the protective substrate is irradiated with laser light from the protective substrate side, it must be transparent to the laser light used, and when used as a simple protective plate,
Transparency does not matter. The usable materials are exactly the same as the above-mentioned substrate materials, and plastics such as polyester, acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, polyimide, or glass, ceramics, metal, etc. should be used. You can

<Adhesive, Adhesive Layer> Any material can be used as long as it can adhere two recording media. From the viewpoint of productivity, an ultraviolet-curable or hot-melt adhesive is preferable.

[0072]

EXAMPLES The present invention will now be described in detail with reference to examples.

Example 1 Compound Examples A-9, B- were formed on a 0.6 mm thick injection-molded polycarbonate substrate having a guide groove with a groove depth of 1750 Å, a half width of 0.25 μm and a track pitch of 0.74 μm.
4 and C-10 (see Table 11 for mixing ratio)
Dissolve in 2,3,3-tetrafluoropropanol,
The solution was applied to a spinner to form an organic dye layer having a thickness of 1000 Å, and then a reflective layer of gold 1300 Å was provided by a sputtering method, and a protective layer of 5 μm was provided thereon by an acrylic photopolymer. Further, an injection molded polycarbonate substrate having a thickness of 0.6 mm was adhered with an acrylic photopolymer to obtain an optical recording medium.

Examples 2 to 10 An optical recording medium was formed in exactly the same manner as in Example 1 except that the dye mixtures having the combinations shown in Table 11 were used.

Comparative Example 1 Except that the dyes in the combinations shown in Table 11 were used,
An optical recording medium was formed exactly as in Example 1. However,
The optical recording medium of Comparative Example 1 does not contain a pentamethinecyanine compound.

<Recording conditions> An oscillation wavelength of 6 was recorded on each recording medium.
Using a semiconductor laser beam of 58 nm and a beam diameter of 1.0 μm, recording is performed while tracking (linear velocity 3.5 m / sec), and reproduction is performed by continuous light (reproduction power 0.7 mW) of a semiconductor laser having an oscillation wavelength of 658 nm. The waveform was observed.
Further, the same recording / reproducing was performed with a semiconductor laser having an oscillation wavelength of 670 nm. The evaluation results are shown in Table 11.

[0077]

[Table 11]

[0078]

As described above, according to the present invention, 600 to
It is possible to provide an information recording medium which is capable of recording and reproducing with a laser beam in the wavelength range of 720 nm and has excellent light resistance and storage stability. In particular, it is possible to provide an optical recording medium less dependent on the wavelength shift of the semiconductor LD, as compared with the case of using a mixture of only the formazan metal chelate compound and the squarylium metal chelate compound. Further, according to the present invention, it is possible to provide an optical recording medium capable of recording and reproducing with stable high reflectance and high modulation. Furthermore, according to the present invention, an optical recording medium capable of stable recording and reproduction can be provided. Furthermore, by using the optical recording medium of the present invention, it is possible to provide a novel optical recording method and recording apparatus by limiting the recording wavelength.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between an absorption spectrum of a dye mixture used in a recording layer and a recording / reproducing wavelength.

2A to 2D are diagrams showing a typical write-once type optical recording medium.

3A to 3C are diagrams showing the configuration of an optical recording medium for CD-R.

4A to 4C are diagrams showing the configuration of an optical recording medium for DVD-R.

[Explanation of symbols]

1 substrate 2 recording layers 3 subbing layer 4 protective layer 5 Hard coat layer 6 Metal reflective layer 7 Protective board 8 Adhesive layer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G11B 7/24 561 C09B 23/00 L // C09B 23/00 50/00 50/00 50/06 50 / 06 57/00 Z 57/00 B41M 5/26 Y (72) Inventor Mune Noguchi 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. (72) Tsutomu Sato 1 Nakamagome, Ota-ku, Tokyo 3-6, Ricoh Co., Ltd. (72) Inventor Tatsuya Tomura 1-3-6 Nakamagome, Ota-ku, Tokyo In-house (72) Ricoh Co., Ltd. Yasunobu Ueno 1-3-6 Nakamagome, Ota-ku, Tokyo No. In stock company Ricoh (72) Inventor Toru Yashiro 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh company (72) Inventor Tomomi Iwami 1-3-6 Nakamagome, Ota-ku, Tokyo Stock company Inside Ricoh (72) Akio Shimizu Ikuo Shimizu 2-3, Daikyo-cho, Yokkaichi-shi, Mie Kyowa Yuka Co., Ltd. Yokkaichi Laboratory (72) Inventor Motoharu Kinugasa 2-chome, Daikyo-cho, Yokkaichi-shi, Mie Yokkaichi Laboratory, Kyowa Yuka Co., Ltd. (72) Inventor Hiroshi Toyota, 3-3 Okyo-cho, Yokkaichi-shi, Mie Kyowa Yuka Co., Ltd. Yokkaichi Laboratory (72) Inventor Shiho Yamada 2-3-3, Okyo-cho, Yokkaichi-shi, Mie Yokkaichi Kyowa Co., Ltd. F-term in the laboratory (reference) 2H111 EA03 EA12 EA22 EA25 EA31 FA12 FA23 FB42 FB43 FB48 4H056 CA01 CC02 CC08 CE03 DD03 FA06 5D029 JA04 JC04 JC06 MA13 WB11 WB14 5D090 AA01 BB03 CC01 KK06

Claims (15)

[Claims] 1. An optical recording medium comprising a recording layer provided on a substrate, wherein the recording layer comprises (i) a formazan metal chelate compound comprising a formazan compound and a metal, and (ii) a squarylium metal comprising a squarylium compound and a metal. An optical recording medium comprising a chelate compound and (iii) a pentamethinecyanine compound. 2. The maximum absorption wavelength of the absorption spectrum of the film of the formazan metal chelate compound and the squarylium metal chelate compound is 500 to 650 nm, and the maximum absorption wavelength of the absorption spectrum of the film of the pentamethine cyanine compound is 650 to 750 nm. The optical recording medium according to claim 1, wherein 3. A weight ratio of the formazan metal chelate compound to the squarylium metal chelate compound is 10: 9.
0 to 50:50, and the content of the pentamethine cyanine compound is 0.5 to 5% by weight based on the total amount of the formazan metal chelate compound and the squarylium metal chelate compound. Claim 1
Or the optical recording medium according to 2. 4. The formazan metal chelate compound comprises
General formula (I) and / or represented by the following general formula (II)
Claims comprising a formazan compound and a metal
Item 4. The optical recording medium according to any one of Items 1 to 3. [Chemical 1] (In the formula, ring A is a substituted or unsubstituted 5 containing a nitrogen atom.
Represents a member ring or a 6-membered ring, and Z represents an atomic group giving ring A.
However, another ring may be condensed with the nitrogen-containing heterocycle,
A is an alkyl group which may have a substituent or has a substituent.
Optionally substituted aryl group, optionally substituted
Alkyl carbonyl group, which may have a substituent
Carbonyl group, alkeny optionally having substituents
Group, a heterocyclic group which may have a substituent or a substituent
Represents an alkoxycarbonyl group which may have, B is
Optionally substituted alkyl group, having a substituent
May have an alkenyl group or a substituent
Indicates an aryl group) [Chemical 2] (In the formula, ring B and ring C may be substituted with a nitrogen atom.
Or an unsubstituted 5- or 6-membered ring, Z₁, Z₂Haso
The atomic groups that give ring B and ring C, respectively, are shown below.
A ring may be condensed with another ring,₁, A₂Is it
An alkyl group which may have a substituent and a substituent
Optionally substituted aryl group, optionally substituted
Alkyl carbonyl group, which may have a substituent
Carbonyl group, alkeny optionally having substituents
Group, a heterocyclic group which may have a substituent or a substituent
Represents an alkoxycarbonyl group which may have,
B₁, B₂Each is an alkyle which may have a substituent.
Group, an alkenylene group which may have a substituent or a substituent
Represents an arylene group which may have a substituent, W is -C
H ₂-Or-SO₂Indicates-, and n is an integer of 0 or 1.
) 5. The metal component of the formazan metal chelate compound is a metal selected from vanadium, manganese, iron, cobalt, nickel, copper, zinc and palladium, or an oxide or halide of the metal. The optical recording medium according to any one of claims 1 to 4, wherein 6. The optical recording medium according to claim 1, wherein the squarylium metal chelate compound is a compound represented by the following general formula (III). [Chemical 3] [In the formula, R ₁ and R ₂ may be the same or different and each represents a hydrogen atom, an aliphatic group which may have a substituent, an aralkyl group which may have a substituent or a substituent. Represents an optionally substituted aryl group or a heterocyclic group which may have a substituent, M represents a metal atom having a coordination ability, m represents an integer of 2 or 3, and X represents An aryl group which may have a substituent, a heterocyclic group which may have a substituent, or Z
₃ = CH- (in the formula, Z ₃ represents a heterocyclic group which may have a substituent)] 7. X in the general formula (III) is represented by the following general formula (I
The optical recording medium according to claim 6, which is a group represented by V). [Chemical 4] (In the formula, R ₃ and R ₄ may be the same or different and each represents an aliphatic group which may have a substituent, or
₃ and R ₄ may combine with each other to form a carbon ring or a heterocycle, and R ₅ may have a hydrogen atom, an optionally substituted aliphatic group, or a substituent. An aralkyl group or an aryl group which may have a substituent is shown, R _{6 to} R ₉ may be the same or different, and a halogen atom, an aliphatic group which may have a substituent and a substituent are An aralkyl group which may have, an aryl group which may have a substituent, a nitro group, a cyano group or an alkoxy group which may have a substituent, and two adjacent groups are mutually May combine to form a ring which may have a substituent) 8. The optical recording medium according to claim 6, wherein M in the general formula (III) is aluminum. 9. The pentamethine cyanine compound is one of the following:
Contract characterized by being a compound represented by general formula (V)
The optical recording medium according to any one of claims 1 to 8. [Chemical 5] (In the formula, R_TenIs a hydrogen atom, a fat which may have a substituent
Represents an aliphatic group or a halogen atom, R₁₁And R₁₂Is the same
May be different and may have a substituent
Indicates a group, Q^-Is I^-, ClO_Four ^-, BF_Four ^-, PF₆ ^-, S
bF₆ ^-Or TsO ^-Indicates) 10. The recording layer single layer has a refractive index n of 1.5 ≦ n ≦ 3.0 and a extinction coefficient k of 0.02 ≦ k ≦ 0. 3. The optical recording medium according to claim 1, wherein the optical recording medium is 3. 11. A reflective layer, which is a metal selected from gold, silver, copper, and aluminum, or is an alloy of the metals. An optical recording medium according to item 1. 12. The track pitch on the substrate is 0.7 to.
It is 0.8 μm, and the groove width is a half value width of 0.18 to 0.4.
The optical recording medium according to claim 1, wherein the optical recording medium has a thickness of 0 μm. 13. The optical recording medium according to claim 1, wherein recording is possible at a recording wavelength of 600 to 720 nm. 14. An optical recording method for recording on the optical recording medium according to claim 1 at a recording wavelength of 600 to 720 nm. 15. An optical recording device equipped with the optical recording medium according to claim 1.