JP2001322356A - Optical recording medium and optical recording method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording technique, which is excellent in light resistance and storage stability, in an optical recording medium, which is applicable for an DVD-R disc system using a semiconductor laser having an oscillating wave length in a short wave length and in which a conventional squalilium coloring matter is employed. SOLUTION: In this optical recording medium, in which at least a recording layer is provided on a substrate, the recording layer includes respectively at least one kind of the squalilium compound and of an azo-metallic chelate compound consisting of a metal and an azo-compound represented by general formula (I), in which A represents a residue, which forms a heterocycle together with a carbon atom and a nitrogen atom bonding therewith, B represents a residue, which forms an aromatic ring or a heterocycle togetherwith two carbon atoms bonding therwith, and X represents a sustituent with an active hydrogen.

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 and an optical recording method capable of recording with short-wavelength light.

[0002]

2. Description of the Related Art a. (For information recording) write-once recording medium (W
ORM)

(1) Using a cyanine dye as a recording material JP-A-57-82093, 58-56892, 58-1
12790, 58-114989, 59-85791,
60-83236, 60-89842, 61-2588
6

(2) Using a phthalocyanine dye as a recording material JP-A-61-150243, 61-177287, 61
154888, 61-24609, 62-3928
6,63-37991,63-39888

B. Write-once compact disc (CD-
R) Prior art (1) Using cyanine dye + metal reflection layer as recording material JP-A-1-159842, 2-42652, 2-136
56, 2-168446

(2) Using a phthalocyanine dye + metal reflective layer as a recording material: JP-A-1-176585, 3-215466, 4-11
3886, 4-226390, 5-1272, 5-17
1052, 5-116456, 5-96860, 5-1
39044,5-139044

(3) Using an azo metal chelate dye + metal reflective layer as a recording material: Japanese Patent Application Laid-Open No. 4-46186, 4-141489, 4-361
088, 5-279580, 7-51673, 7-16
1069, 7-37272, 7-71867, 8-23
1866,8-295811

C. Large capacity write-once compact disc (D
VD-R)

(1) Using Cyanine Dye + Metal Reflective Layer as Recording Material PIONEER R & D vol. 6 No. 2, 19
96 : Development of DVD-Recordable, DVD-
Basic development of R dye disk ISOM / ODS'96, 1996 : High den
situation of recording on Dye
material Disc approach fo
r 4.7G JP-A-10-235999

(2) Using an azomethine dye + metal reflective layer as a recording material: Japanese Patent Application Laid-Open No. 8-198872, 8-209012, 8-28
3263, 10-273484

(3) Using an azo metal chelate dye + metal reflective layer as a recording material Japanese Patent Publication No. 5-67438, Japanese Patent Application Laid-Open No. 7-161069, 8-
156408, 8-231866, 8-333772
9-58123, 9-175031, 9-19354
5,9-277432,9-277703,10-66
44, 10-6650, 10-6651, 10-366
93, 10-44606, 10-58828, 10-8
6519, 10-149584, 10-157293.
10-157300, 10-157301, 10-15
7302, 10-181199, 10-181201,
10-181203, 10-181206, 10-18
8340, 10-188341, 10-188358,
10-208303, 10-214423, 10-22
8671, 11-12483, 11-28865, 11
-42858, 11-134708, 11-20811
1

(4) Using other dye + metal reflective layer as a recording material JP-A-10-86517, 10-93788, 10-2
26172,10-244752,10-28781
9,10-297103,10-309871,10-
309872

(5) Using azo metal chelate dye + other dye + metal reflection layer as recording material JP-B-7-51682, JP-A-11-34499, 11
-48612,11-105424

[0014]

At present, DVD-R is being developed as a next-generation large-capacity optical disk. As elemental technologies for improving the recording capacity, it is necessary to develop recording materials for miniaturizing recording pits, use of image compression technology represented by MPEG2, and shorten the wavelength of a semiconductor laser for reading recording pits. .

Heretofore, as a semiconductor laser in the red wavelength range, 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, the light source is standardized by the wavelength of a laser diode in the 630 to 670 nm band. On the other hand, a read-only DVD-ROM drive is commercialized at a wavelength of about 650 nm.

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.

A squarylium dye is one of the recording layers of an optical recording medium for recording and reproducing by an optical pickup using a laser having a wavelength of 630 to 670 nm. However, this dye is remarkably deteriorated in light and has poor stability. In addition, azo metal chelate dyes may be mentioned as dyes exhibiting high light resistance,
Media using this dye for the recording layer had problems such as low reflectance.

The present invention provides a DVD-ROM using a semiconductor laser having an oscillation wavelength shorter than that of the conventional system.
Provided is a recording material in an optical recording medium applicable to an R disk system, in particular, a recording material excellent in light resistance and storage stability in an optical recording medium using a conventional squarylium dye, and a recording method using the recording material. The purpose is to do.

[0019]

As a result of various studies on means for solving the above-mentioned problems, the present inventors have found that a recording layer is composed mainly of a squarylium dye mixed with a dye having a specific structure. , Oscillation wavelength 670
The present inventors have found that an optical recording medium which is applicable to a next-generation large-capacity optical disk system using a semiconductor laser of nm or less and has excellent light resistance and storage stability can be obtained.

That is, according to the present invention, in an optical recording medium having at least a recording layer provided on a substrate, the recording layer comprises a squarylium compound, an azo compound represented by the following general formula (I), and a metal. An optical recording medium comprising at least one azo metal chelate compound is provided.

Embedded image Wherein A represents a residue that forms a heterocyclic ring together with the carbon and nitrogen atoms to which it is attached, and B represents an aromatic group that is taken together with the two carbon atoms to which it is attached. Represents a residue forming a ring or a heterocyclic ring, and X represents a substituent having an active hydrogen.)

In the optical recording medium of the present invention, the recording layer contains at least one squarylium compound and at least one azo metal chelate compound composed of an azo compound represented by the general formula (I) and a metal. Thereby, optical deterioration of the squarylium compound is prevented, and an optical recording medium having excellent light resistance is obtained.

In the squarylium compound used in the optical recording medium of the present invention, the following general formula (II)

Embedded image [In the formula, R ₁ and R ₂ are the same or different and each have a hydrogen atom, an alkyl group optionally having a substituent, an aralkyl group optionally having a substituent, or a substituent. Represents an optionally substituted aryl group. Further, R ₁ and R ₂ may form a heterocyclic ring which may have a substituent together with an adjacent nitrogen atom. R ₃ is represented by the following general formula (III)
Or represent (IV):

Embedded image [Wherein, R ₄ and R ₅ are the same or different and each represent a hydrogen atom or an alkyl group, or R ₄ and R ₅ may have a substituent together with an adjacent nitrogen atom. Forming a heterocyclic ring, R ₆ , R ₇ , R ₈ and R ₉ are the same or different and are each a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent; R ₄ and R ₆ , or R ₅ and R ₇ may form a heterocycle containing a nitrogen atom together with an adjacent N—C—C, The heterocyclic ring may have a substituent.]

Embedded image [In the formula, Q ₁ represents a carbon atom or a nitrogen atom, and R ₁₀ and R ₁₁ are the same or different and each have a hydrogen atom, an alkyl group which may have a substituent, A good aryl group, an optionally substituted aralkyl group or a hydroxyl group (provided that when Q ₁ is a nitrogen atom,
₁₁ represents not present), R ₁₂ represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group or an optionally substituted aralkyl group And R ₁₃ and R ₁₄ are the same or different and each represent a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group or a halogen atom, or two carbon atoms in which R ₁₃ and R ₁₄ are adjacent to each other. Together with the atoms, they form an alicyclic hydrocarbon ring, an aromatic ring which may have a substituent or a hetero ring which may have a substituent. Or a compound represented by the following general formula (V)

Embedded image[Where Q_TwoRepresents a carbon atom or a nitrogen atom;
_FifteenIs a hydrogen atom or an optionally substituted alkyl
Group, aryl group which may have a substituent or substituent
Represents a heterocyclic group optionally having₁₆Is a hydrogen atom,
A halogen atom, an alkyl group which may have a substituent,
An alkoxy group which may have a substituent,
Optionally having an aralkyl group, may have a substituent
An aryl group, an amino group which may have a substituent or
Represents a heterocyclic group which may have a substituent. R₁₇and
R₁₈Are the same or different and may have a substituent
Represents a good alkyl group or R₁₇And R₁₈Is the adjacent carbon source
Forms an alicyclic hydrocarbon ring or heterocyclic ring
May be. However, Q_TwoIs a nitrogen atom, R₁₈Is
Does not exist. R₁₉May have a hydrogen atom or a substituent
Alkyl group, aralkyl group which may have a substituent,
Or an aryl group which may have a substituent; ₂₀
Is a halogen atom, an alkyl which may have a substituent
Group, an aralkyl group which may have a substituent,
An aryl group which may have, a trifluoromethyl group,
May have a nitro group, a cyano group, or a substituent
Represents an alkoxy group. n represents an integer of 0 to 4;
When n is 2 to 4, R_{twenty one}Are the same or different
And two Rs adjacent to each other₂₀Is adjacent
May have a substituent together with two carbon atoms
May form an aromatic ring].
preferable.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The mixing ratio of the squarylium compound and the azo metal chelate compound in the optical recording medium is 90:10 to 10:90, preferably 8 by weight.
0:20 to 15:85, more preferably 80:20 to 3
0:70. When the squarylium compound is within the above range, the azo metal chelate compound works effectively and high light resistance is obtained. When the squarylium compound is in the above range, a high reflectance can be obtained, which is preferable.

In the general formula (I), A represents a residue which forms a heterocyclic ring together with the carbon atom and nitrogen atom to which it is bonded, and B represents two carbon atoms to which it is bonded. X represents a residue forming an aromatic ring or a heterocyclic ring together with an atom, and X represents a substituent having an active hydrogen group.

Specific examples of A include thiazole ring, benzothiazole ring, imidazole ring, benzimidazole ring, thiadiazole ring, oxazole ring, benzoxazole ring, triazole ring, pyrazole ring, oxadiazole ring, pyridine ring, pyridazine ring, Residues forming a pyrimidine ring, a pyrazine ring, a triazine ring, a quinoline ring and the like can be mentioned. These nitrogen-containing heterocycles may have a substituent.

Specific examples of the substituents include a hydrogen atom, 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, Aryl group optionally having substituent (s), heterocyclic residue optionally having substituent (s), alkyloxy group optionally having substituent (s), aryloxy optionally having substituent (s) Group, alkylthio group optionally having substituent (s), arylthio group optionally having substituent (s), alkylamino group optionally having substituent (s), arylamino optionally having substituent (s) Group, an alkyloxycarbonyl group which may have a substituent, an aryloxycarbonyl group which may have a substituent, an alkylcarboxamide group which may have a substituent, Optionally have arylcarboxamido group, which may have a substituent alkylcarbamoyl group, which may have a substituent arylcarbamoyl group include an alkenyl group which may have a substituent.

The alkyl group preferably has 1 to 9 carbon atoms (linear or branched) and 3 to 14 carbon atoms (cyclic). Specific examples thereof include a methyl group, an ethyl group, an n-propyl group, n-butyl group, n-pentyl group, n-hexyl group,
n-heptyl group, n-octyl group, n-nonyl group, n-
Linear alkyl group such as 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, 3-ethyl Pentyl group, 2
-Methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5-methylheptyl group, 2-ethylhexyl group, 3-ethylhexyl group, isopropyl group, se
c-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-ethylhexyl group, 1-propylpentyl group, 1-isopropylpentyl group, 1-isopropyl-2-methylbutyl group, 1-isopropyl-3-methylbutyl group, 1-methyloctyl group, 1-propylhexyl group, 1-isobutyl-3-methylbutyl group, neopentyl group, tert-
Branched alkyl groups such as butyl group, tert-hexyl group, tert-amyl group, tert-octyl group, cyclohexyl group, 4-methylcyclohexyl group, 4-ethylcyclohexyl group, 4-tert-butylcyclohexyl group, 4- ( Cycloalkyl groups such as 2-ethylhexyl) cyclohexyl group, bornyl group, and isobornyl group (adamantyl group).

The alkyl group is substituted with a hydroxyl group, a halogen atom, a nitro group, a carboxyl group, a cyano group, an aryl group which may have a substituent, a heterocyclic residue which may have a substituent, and the like. It may be. Also oxygen,
It may be substituted with the above-mentioned alkyl group or aryl group via an atom such as sulfur or nitrogen.

Examples of the alkyl group substituted via oxygen include a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group, a butoxyethyl group, an ethoxyethoxyethyl group, a phenoxyethyl group, a methoxypropyl group, and an ethoxy group. Examples of the alkyl group in which a propyl group or the like is substituted via sulfur include an alkyl group in which a methylthioethyl group, an ethylthioethyl group, an ethylthiopropyl group, a phenylthioethyl group, or the like is substituted via nitrogen. Is a dimethylaminoethyl group, a diethylaminoethyl group, a diethylaminopropyl group or the like.

Specific examples of the aryl group include a phenyl group, a naphthyl group, an anthranyl group, a fluorenyl group, a phenalenyl group, a phenanthryl group, a triphenylenyl group, a pyrenyl group and the like.

The aryl group is substituted with a hydroxyl group, a halogen atom, a nitro group, a carboxyl group, a cyano group, an aryl group which may have a substituent, a heterocyclic residue which may have a substituent, and the like. And oxygen,
It may be substituted with the above-mentioned alkyl group via an atom such as sulfur or nitrogen or directly.

Specific examples of the heterocyclic residue include a furyl group,
Thienyl, pyrrolyl, benzofuryl, isobenzofuranyl, benzothienyl, indolinyl, isoindolinyl, carbazolyl, pyridyl, piperidyl, quinolyl, isoquinolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl Groups, imidazolyl groups, pyrazolyl groups, benzimidazolyl groups, pyrazyl groups, pyrimidinyl groups, pyridazinyl groups, quinoxalinyl groups and the like.

The heterocyclic residue includes a hydroxyl group, a halogen atom, a nitro group, a carboxyl group, a cyano group, an optionally substituted aryl group, and an optionally substituted heterocyclic residue. May be substituted with oxygen,
The alkyl group may be substituted via an atom such as sulfur or nitrogen.

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

The alkoxy group may be any one in which an alkyl group which may have a substituent is directly bonded to an oxygen atom, and specific examples of the alkyl group include the aforementioned specific examples.

The aryloxy group may be any one in which an aryl group which may have a substituent is directly bonded to an oxygen atom, and specific examples of the aryl group include the specific examples described above. .

The alkylthio group may be any one in which an alkyl group which may have a substituent is directly bonded to a sulfur atom, and specific examples of the alkyl group include the aforementioned specific examples.

The arylthio group may be any one in which an aryl group which may have a substituent is directly bonded to a sulfur atom, and specific examples of the aryl group include the aforementioned specific examples.

The alkylamino group may be any one in which an alkyl group which may have a substituent is directly bonded to a nitrogen atom, and specific examples of the alkyl group 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 arylamino group may be any one in which an aryl group which may have a substituent is directly bonded to a nitrogen atom, and specific examples of the aryl group include the aforementioned specific examples. .

An alkoxycarbonyl group is represented by O (C ＝ O)
It is sufficient that an alkyl group which may have a substituent is directly bonded to the oxygen atom. Specific examples of the alkyl group include the above-mentioned specific examples.

The aryloxycarbonyl group is represented by O (C =
It is sufficient that the aryl group which may have a substituent is directly bonded to the oxygen atom of O), and specific examples of the aryl group include the specific examples described above.

The alkylcarboxamide group may be any one in which an alkyl group which may have a substituent is directly bonded to a carbon atom of carboxysamide. Specific examples of the alkyl group include those described above. Can be mentioned.

The arylcarboxamide group may be any one in which an aryl group which may have a substituent is directly bonded to a carbon atom of carboxysamide. Specific examples of the aryl group include those described above. Can be mentioned.

The alkylcarbamoyl group may be any 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 include the above-mentioned specific examples. be able to. Further, alkyl groups are bonded to each other, and include an oxygen atom, a nitrogen atom, etc., a piperidino group, a morpholino group, a pyrrolidinyl group,
A ring may be formed like a piperazinyl group, an indolinyl group, an isoindolinyl group and the like.

The arylcarbamoyl group may be any 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 include the above-mentioned specific examples. be able to.

The alkylsulfamoyl group may be any as long as the alkyl group which may have a substituent is directly bonded to the nitrogen atom of the sulfamoyl group. Can be mentioned.

Specific examples of B include residues forming a benzene ring, a naphthalene ring, a pyridine ring, a quinoline ring and the like. These aromatic rings or hetero rings may have a substituent. Specific examples of the substituent are selected from the specific examples of the substituent of A described above.

Specific examples of the substituent having an active hydrogen group for X include a hydroxyl group, a carboxyl group, an amino group, an alkylcarboxamide group, an arylcarboxamide group, an alkylsulfonamide group, an arylsulfonamide group, a carbamoyl group and an alkylcarbamoyl group. , An arylcarbamoyl group, a sulfo group, a sulfino group, a sulfeno group, a sulfamoyl group, and a thiol group.

Specific examples of the alkylcarboxamide group, the arylcarboxamide group, the alkylcarbamoyl group and the arylcarbamoyl group include the above-mentioned specific examples.

Specific examples of the alkylsulfonamido group may be those in which an alkyl group which may have a substituent is directly bonded to the sulfur atom of the sulfonamido. Specific examples can be given.

Specific examples of the arylsulfonamide group may be any as long as the aryl group which may have a substituent is directly bonded to the sulfur atom of the sulfonamide, and specific examples of the aryl group are those described above. Specific examples can be given.

Specific examples of metal atoms include aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium and palladium. , Cobalt, nickel,
An azo metal chelate compound of copper has excellent optical properties as an optical recording material.

In the optical recording medium of the present invention, it is preferable to use a laser beam having a recording / reproducing wavelength of 600 to 720 nm. From the optical characteristics at this wavelength and the like, among the squarylium compounds, general formula (II) or general formula ( Compounds represented by V) are preferred.

Next, the definitions of the groups in formulas (II) to (V) will be described. In the definition of the groups of the general formulas (II) to (V), the alkyl moiety in the alkyl group and the alkoxy group is a linear or branched alkyl group having 1 to 6 carbon atoms or a cyclic alkyl group having 3 to 8 carbon atoms. Examples 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, ter
Examples thereof include a t-pentyl group, a hexyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group.

The aryl group and the aryl moiety of the aralkyl group include, for example, a phenyl group, a naphthyl group and an anthryl group.

Examples of the aralkyl group include aralkyl groups having 7 to 15 carbon atoms, such as benzyl, phenethyl, phenylpropyl, naphthylmethyl and benzhydryl.

Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.

The heterocyclic ring in the heterocyclic group and the heterocyclic ring formed by R ₁₃ and R ₁₄ or R ₁₇ and R ₁₈ together with adjacent (two) carbon atoms include an aromatic heterocyclic ring and an alicyclic ring. Formula heterocycles are mentioned.

As the aromatic heterocyclic ring, for example, a nitrogen atom,
A 5- or 6-membered monocyclic aromatic heterocyclic ring containing at least one atom selected from an oxygen atom and a sulfur atom;
A bicyclic or tricyclic condensed aromatic heterocyclic ring containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom in which an 8-membered ring is fused, and more specifically pyridine Ring, 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, Examples include a furan ring, a thiazole ring, an oxazole ring, an indole ring, an isoindole ring, an indazole ring, a benzimidazole ring, a benzotriazole ring, a benzothiazole ring, a benzoxazole ring, a purine ring, and a carbazole ring.

The alicyclic heterocyclic ring includes, for example, a nitrogen atom,
A 5- or 6-membered monocyclic alicyclic heterocyclic ring containing at least one atom selected from an oxygen atom and a sulfur atom;
A bicyclic or tricyclic fused 8-membered ring and a condensed alicyclic heterocyclic ring containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom, and the like, and more specifically, Pyrrolidine ring, piperidine ring, piperazine ring, morpholine ring, thiomorpholine ring, homopiperidine ring, homopiperazine ring, tetrahydropyridine ring, tetrahydroquinoline ring, tetrahydroisoquinoline ring, tetrahydrofuran ring, tetrahydropyran ring, dihydrobenzofuran ring, tetrahydrocarbazole ring And the like.

A heterocyclic ring formed by R ₁ and R ₂ , or R ₄ and R ₅ together with an adjacent nitrogen atom, and an N—C— group formed by R ₄ and R ₆ or R ₅ and R ₇ adjacent to each other;
Examples of the heterocycle formed together with C include an aromatic heterocycle containing a nitrogen atom and an alicyclic heterocycle containing a nitrogen atom.

Examples of the aromatic heterocycle containing a nitrogen atom include, for example, a 5- or 6-membered monocyclic aromatic heterocycle containing at least one nitrogen atom, and a bicyclic or tricyclic fused 3- to 8-membered ring. And a condensed aromatic heterocyclic ring containing at least one nitrogen atom, more specifically, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, a quinoline ring, an isoquinoline ring, a phthalazine ring, and a quinazoline ring. , Quinoxaline ring, naphthyridine ring, cinnoline ring, pyrrole ring,
Pyrazole ring, imidazole ring, triazole ring, tetrazole ring, thiazole ring, oxazole ring, indole ring, isoindole ring, indazole ring, benzimidazole ring, benzotriazole ring, benzothiazole ring, benzoxazole ring, purine ring, carbazole ring, etc. Is mentioned.

The alicyclic heterocyclic ring containing a nitrogen atom includes, for example, a 5- or 6-membered monocyclic alicyclic heterocyclic ring containing at least one nitrogen atom and a nitrogen atom condensed with a 3- to 8-membered ring. A condensed alicyclic heterocyclic ring containing at least one or the like;
More specifically, a pyrrolidine ring, a piperidine ring, a piperazine ring, a morpholine ring, a thiomorpholine ring, a homopiperidine ring, a homopiperazine ring, a tetrahydropyridine ring, a tetrahydroquinoline ring, a tetrahydroisoquinoline ring,
And a tetrahydrocarbazole ring.

The alicyclic hydrocarbon ring formed by R ₁₃ and R ₁₄ or R ₁₇ and R ₁₈ together with adjacent (two) carbon atoms includes those having 3 to 8 carbon atoms. It may be saturated or unsaturated, for example,
Examples include a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, a cyclopentene ring, a 1,3-cyclopentadiene ring, a cyclohexene ring, and a cyclohexadiene ring.

The aromatic ring formed by R ₁₃ and R ₁₄ together with two adjacent carbon atoms is preferably an aromatic ring having 6 to 6 carbon atoms.
14, and examples thereof include a benzene ring, a naphthalene ring, and an anthracene ring.

The substituents of the aryl group, aralkyl group, heterocyclic group, aromatic ring, heterocyclic ring containing a nitrogen atom or the same or different substituents may be the same or different and have 1-substitutable number, preferably 1-5 substituents. Groups such as hydroxyl, carboxyl, nitro, alkoxy, alkyl, aralkyl, cyano, halogen, -N = N-Ar (Ar
Represents a hydroxyl group, a carboxyl group, a nitro group, an alkoxy group, an alkyl group optionally substituted with a halogen atom, or an aryl group optionally substituted with a substituent such as a cyano group or a halogen atom. ), -CH
= CH-Ar (Ar has the same meaning as described above). Examples of the alkyl group, alkoxy group, aralkyl group, aryl group, and halogen atom include the same as those described above.

The substituents of the alkyl group or the alkoxy group may be the same or different and may have 1 to 1 substituent, preferably 1 to 3 substituents, for example, hydroxyl group, carboxyl group, nitro group, alkoxy group, aryl group, And a halogen atom. Examples of the alkoxy group, the aralkyl group, the aryl group, and the halogen atom include the same as described above.

Examples of the substituent of the amino group include the same or different and one or two substituents such as an alkyl group and an aryl group. Examples of the alkyl group and the aryl group include the same as those described above.

Hereinafter, the method for producing the squarylium compound used in the present invention will be described with reference to the compounds represented by formulas (II) and (V) as examples. Hereinafter, the compound represented by the general formula (II) or (V) may be referred to as a compound (II) or a compound (V), respectively. The same applies to compounds of other formula numbers.

Reaction formula (1-a)

Embedded image

Reaction formula (1-b)

Embedded image

Reaction formula (1-c)

Embedded image

Reaction formula (2-a)

Embedded image

Reaction formula (2-b)

Embedded image

Reaction formula (2-c)

Embedded image Compound (G) + R ₃ —H (B) → Compound (II)

[0077] [wherein, R _1, R ₂ and R ₃ have the same meanings as defined above, Y is chlorine, in a halogen atom or OR ₂₁ (wherein the bromine, .R R ₂₁ represents an alkyl group ₂₁ As the alkyl group in the definition of the general formulas (II) to (V)
And the same as the alkyl group in the above. ). ]

Reaction formula (1-a) Compound (C) is prepared by reacting compound (A) with 0.4 to 2 moles of compound (B), if necessary, in the presence of 0.4 to 2 moles of a base. In a solvent at room temperature for 1 to 4 hours. Examples of the solvent include chloroform, dichloromethane, 1,2-dichloroethane, ethyl acetate, diethyl ether, methyl-tert-butyl ether, tetrahydrofuran, toluene, benzene, dimethylformamide, dimethyl sulfoxide and the like. Examples of the base include organic bases such as quinoline, triethylamine and pyridine, and inorganic bases such as potassium hydrogen carbonate and sodium hydrogen carbonate.

Reaction Formula (1-b) The compound (D) is prepared by reacting the compound (C) in an aqueous acetic acid solution of 50 to 90% by volume at 90 to 110 ° C. for 1 to 7 hours, or 50 to 99% by weight. In trifluoroacetic acid aqueous solution or concentrated sulfuric acid at 40 to 60 ° C for 1 to 3 hours.

Reaction formula (1-c) Compound (II) is obtained by mixing compound (D) with 0.5 to 2 moles of compound (E) and, if necessary, 1.0 to 2.0 moles of base. It is obtained by reacting at 80 to 120 ° C for 1 to 15 hours in the presence. As the solvent, for example, only an alcoholic solvent having 2 to 8 carbon atoms such as ethanol, propanol, isopropanol, butanol, and octanol,
Alternatively, a mixed solvent of the alcohol-based solvent and benzene or toluene (50% by volume or more by volume of alcohol) or the like is used. As the base, for example, an organic base such as quinoline, triethylamine, pyridine or potassium carbonate,
Inorganic bases such as potassium bicarbonate and sodium bicarbonate are used.

Reaction formula (2-a) Compound (F) is obtained by replacing compound (B) with compound (E)
Can be obtained by performing the same operation as in the above reaction formula (1-a), except that

Reaction formula (2-b) Compound (G) is obtained by replacing compound (C) with compound (F)
Can be obtained by performing the same operation as in the aforementioned reaction formula (1-b), except that

Reaction formula (2-c) Compound (II) is obtained by replacing compound (D) with compound (G)
Can be obtained by performing the same operation as in the above reaction formula (1-c) except that compound (B) is used instead of compound (E).

After the reaction, the compound (II) is, for example, subjected to solvent distillation or filtration and, if necessary, further purified by a method usually used in organic synthetic chemistry (column chromatography, recrystallization or washing with a solvent, etc.). It is isolated and purified by the treatment.

Reaction formula (3-a)

Embedded image

Reaction formula (3-b)

Embedded image

Reaction formula (3-c)

Embedded image

Reaction formula (4-a)

Embedded image

Reaction formula (4-b)

Embedded image

Reaction formula (4-c)

Compound (P) + Compound (Ha) or Compound (Hb) → Compound (V)

[Wherein Q ₂ , R ₁₅ , R ₁₆ , R ₁₇ , R ₁₈ ,
R ₁₉ , R ₂₀ and n are as defined above, and X
Represents a halogen atom such as chlorine, bromine or iodine, or a tosyl group or a mesyl group, and Y has the same meaning as described above. ]

Reaction formula (3-a) Compound (J) is prepared by reacting compound (A) with 1 to 2 moles of compound (Ha) or (Hb), if necessary, in the presence of 1 to 2 moles of a base. In a solvent at 0 ° C. to room temperature for 30 minutes to 70 hours. As a solvent, chloroform, dichloromethane, 1,2-dichloroethane, ethyl acetate, diethyl ether, methyl-tert-butyl ether, tetrahydrofuran, toluene, benzene,
Examples include dimethylformamide and dimethylsulfoxide. As the base, quinoline, triethylamine,
Examples thereof include organic bases such as pyridine and inorganic bases such as potassium bicarbonate and sodium bicarbonate.

Reaction formula (3-b) Compound (K) is prepared by subjecting compound (J) to an aqueous acetic acid solution of 50 to 90 vol / vol% at 90 to 110 ° C for 1 to 7 hours, or 50 to 99 wt%. In an aqueous solution of trifluoroacetic acid at 45 to 50 ° C. for 1 to 3 hours.

Reaction formula (3-c) The compound (V) is prepared by mixing the compound (K) with 0.5 to 2 moles of the compound (L) and, if necessary, 0.5 to 2 moles of a base. It is obtained by reacting in the presence of a solvent at 80 to 120 ° C. for 1 to 15 hours. As the solvent, for example, only an alcoholic solvent having 2 to 8 carbon atoms such as ethanol, propanol, isopropanol, butanol, octanol, or a mixed solvent of the alcoholic solvent and benzene or toluene (alcohol 50 vol / vol% or more) Are used. As the base, for example, quinoline,
Organic bases such as triethylamine and pyridine or inorganic bases such as potassium carbonate, potassium hydrogen carbonate and sodium hydrogen carbonate are used.

Reaction formula (4-a) The compound (M) is the same as the reaction formula (3-a) except that the compound (L) is used instead of the compound (Ha) or (Hb).
It can be obtained by performing the same operation as in a).

Reaction formula (4-b) Compound (P) is replaced with compound (M) instead of compound (J)
Can be obtained by performing the same operation as in the aforementioned reaction formula (3-b), except that

Reaction formula (4-c) Compound (V) is obtained by replacing compound (K) with compound (P)
Can be obtained by performing the same operation as in the aforementioned reaction formula (3-c), except that the compound (Ha) or the compound (Hb) is used instead of the compound (L).

After the reaction, the compound (V) is purified, for example, by distilling off or filtering off the solvent, if necessary, by a method usually used in organic synthetic chemistry (column chromatography, recrystallization or washing with a solvent, etc.). It is isolated and purified by the treatment.

Next, as an item necessary for forming the recording layer of the optical recording medium of the present invention, optical characteristics can be raised. Conditions necessary for the optical characteristics include a recording / reproducing wavelength of 630.
It is preferable to have a large absorption band on the short wavelength side with respect to nm to 670 nm, and that the recording / reproducing wavelength be near the long wavelength end of the absorption band. This is 630n which is the recording / reproducing wavelength.
It is preferable to have a large refractive index and an extinction coefficient at m to 670 nm.

More specifically, the refractive index n of the recording layer single layer with respect to light in the wavelength region of the 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. It is preferably in the range of 3 or less. When n is 1.5 or more, a sufficient optical change can be obtained, and the recording modulation degree becomes high, which is preferable. When n is 3.0 or less, the wavelength dependency does not increase and the recording An error is less likely to occur even in the reproduction wavelength region, which is preferable. When k is 0.02 or more, it is preferable because the recording sensitivity is improved.
When it is 3 or less, it is preferable because a reflectance of 50% or more can be easily obtained.

The substrate usually has a guide groove having a depth of 1000 to 2500 °. Track pitch is usually 0.7
.About.1.0 μm, but 0.7.about.
0.8 μm is preferred. Groove width is 0.18 ~ at half width
0.40 μm is preferred. A thickness of 0.18 μm or more is preferable because sufficient tracking error signal intensity can be obtained. When the thickness is 0.40 μm or less, it is preferable that the recording portion hardly spreads laterally upon recording.

Next, the configuration of the recording medium of the present invention will be described. FIG. 1 is a diagram showing an example of a layer configuration applicable to the recording medium of the present invention, which is an example of a write-once optical disc. The recording layer 2 is provided on the substrate 1 via an undercoat layer 3 if necessary.
And, if necessary, a protective layer 4. Further, a hard coat layer 5 can be provided below the substrate 1 as needed.

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

FIG. 3 is a diagram showing an example of a layer structure of another type (for DVD-R) applicable to the recording medium of the present invention. In this case, an adhesive layer is formed on the protective layer 4 having the structure of FIG. 8 and a protection substrate 7 are provided.

That is, the recording medium of the present invention has the structure shown in FIGS.
With the recording layer (organic thin film layer) having the structure shown in (1) inside, an air sandwich structure sealed with another substrate through a space can be used, or a bonding structure bonded with a protective layer can be used. You can also.

When the recording medium of the present invention is applied to a DVD-R, the configuration of the recording medium includes a first substrate and a second substrate (hereinafter sometimes referred to as a first substrate and a second substrate).
Are bonded to each other with an adhesive via a recording layer as a basic structure. The recording layer may be a single layer of an organic dye, or a laminate of an organic dye layer and a metal reflective layer to enhance the reflective layer. 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 a first substrate / organic dye layer / metal reflective layer / protective layer / adhesive layer / second substrate structure.

<Substrate> As a necessary characteristic of the substrate, the substrate must be transparent to the laser beam used only when recording and reproduction are performed from the substrate side, and the substrate must be transparent when recording and reproduction are performed from the recording layer side. There is no. Therefore, in the present invention, when two substrates are used in a sandwich shape, for example, if only one substrate (the second substrate) is transparent, the other substrate (the first substrate) may be transparent or opaque. .

As a 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 layer of the substrate is used, on the surface of the substrate, when two substrates are used in a sandwich form, on the surface of the first substrate, guide grooves and guide pits for tracking, and address signals are provided. Etc. may be formed.

<Recording Layer> The recording layer causes some optical change by irradiation with a laser beam, and can record information by the change. The recording layer contains the above-mentioned dye mixture which is a feature of the present invention. It is necessary to contain [a mixture of a squarylium compound and a compound (I)], and the dyes characteristic of the present invention may be used singly or in combination of two or more in forming the recording layer. further,
In addition to the above-mentioned dye which is a feature of the present invention, it may be mixed or laminated with another organic dye 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, and the like.
Anthraquinone (indanthrene), xanthene,
Triphenylmethane, azulene, tetrahydrocholine, phenanthrene, triphenothiazine dyes,
And metal chelate compounds. These dyes may be used alone or in combination of two or more.

Metals and metal compounds such as I
n, Te, Bi, Se, Sb, Ge, Sn, Al, B
e, TeO ₂ , SnO, As, Cd and the like can be used in the form of dispersion mixing or lamination. Further, various materials such as an ionomer resin, a polyamide-based resin, a vinyl-based resin, a natural polymer, silicone, and a liquid rubber, or a silane coupling agent or the like may be dispersed and mixed in the pigment. Alternatively, a stabilizer (for example, a transition metal complex), a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant, a plasticizer, and the like can be used together for the purpose of improving properties.

The recording layer is formed by vapor deposition, sputtering, C
It can be carried out by ordinary means such as VD or solution application. 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 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 Carbon, aliphatic halogenated hydrocarbons such as trichloroethane, aromatics such as benzene, xylene, monochlorobenzene and dichlorobenzene, cellosolves such as methoxyethanol and ethoxyethanol, and hydrocarbons such as hexane, pentane, cyclohexane and methylcyclohexane And the like.

The thickness of the recording layer is preferably 100 to 10
μm, more preferably 200 ° to 2000 °.

<Undercoat Layer> The undercoat layer comprises (a) an improvement in adhesiveness, (b) a barrier against water or gas, (c) an improvement in storage stability of the recording layer, and (d) an improvement in reflectance. It is used for the purpose of (e) protection of the substrate and the recording layer from a solvent, and (f) formation of guide grooves, guide pits, preformats and the like.

For the purpose of (a), a polymer material such as an ionomer resin, a polyamide resin, a vinyl resin,
Various polymer substances such as natural resins, natural polymers, silicones, liquid rubbers, and silane coupling agents can be used. For the purposes (b) and (c), other than the above-mentioned polymer materials can be used. Inorganic compounds such as SiO ₂ and Mg
F ₂ , SiO, TiO ₂ , ZnO, TiN, SiN, etc., and also a metal or semimetal such as Zn, Cu, Ni, C
r, Ge, Se, Au, Ag, Al and the like can be used. For the purpose of (d), a metal such as Al,
Ag or an organic thin film having a metallic luster such as a methine dye or a xanthene dye can be used. For the purposes of (e) and (f), an ultraviolet curable resin, a thermosetting resin, a thermoplastic resin, etc. Can be used.

The thickness of the undercoat layer is preferably 0.01 to 3
0 μm, more preferably 0.05 to 10 μm is suitable.

<Metal Reflective Layer> Examples of the material of the metal reflective layer include metals and semi-metals which are highly resistant to corrosion and provide high reflectivity by themselves, and specific examples thereof include Au, Ag, and the like.
Examples thereof include Cr, Ni, Al, Fe, Sn, and Cu. Au, Ag, Al, and Cu are most preferable in terms of reflectance and productivity, and these metals and metalloids may be used alone. Alternatively, two or more alloys may be used.

Examples of the method for forming the metal reflective layer include vapor deposition and sputtering.
000 °, more preferably 100-3000 °.

<Protective Layer, Hard Coat Layer on Substrate Surface> The protective layer or hard coat layer on the substrate surface is composed of (a) protection of the recording layer (reflection / absorption layer) from scratches, dust, dirt, etc .; It is used for the purpose of improving the storage stability of the reflection / absorption layer), (c) improving the reflectance, and the like. For these purposes, the materials shown in the undercoat layer can be used.
In addition, SiO, SiO _{2 and the} like can be used as inorganic materials, and polymethyl acrylate, polycarbonate, epoxy resin, polystyrene, polyester resin, vinyl resin, cellulose, aliphatic hydrocarbon resin, aromatic hydrocarbon resin, and the like can be used as organic materials. Thermosoftening, hot-melting resins and ultraviolet curable resins such as natural rubber, styrene butadiene resin, chloroprene rubber, wax, alkyd resin, drying oil and rosin can also be used. The most preferable example of the protective layer or the substrate hard coat layer among the above materials is an ultraviolet curable resin having excellent productivity.

The film thickness of the protective layer or the hard coat layer on the substrate surface is preferably 0.01 to 30 μm, more preferably 0.1 to 30 μm.
It is suitably from 05 to 10 μm.

In the present invention, a stabilizer, a dispersant, a flame retardant, a lubricant, an antistatic agent, and a surfactant are provided on the undercoat layer, the protective layer, and the hard coat layer on the substrate surface, as in the case of the recording layer. , A plasticizer and the like.

<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.
Transparency does not matter. Usable substrate 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, ceramic or metal are used. be able to.

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

[0126]

EXAMPLES Examples and comparative examples of the present invention will be described below.
Table 1 below shows the evaluation results of the optical recording media obtained in these Examples and Comparative Examples. Examples of compounds used in Examples and Comparative Examples are those shown in Tables 2 to 6 below.

(Example 1) Compound examples A-3 and B-4 on a 0.6 mm-thick injection-molded polycarbonate substrate having a guide groove with a groove depth of 1700 °, a half width of 0.23 µm and a track pitch of 0.74 µm. (See Table 1 for the mixing ratio) was dissolved in 2,2,3,3-tetrafluoropropanol, and the solution was applied with a spinner to a thickness of 900 °.
Is formed, and then silver 13 is formed by a sputtering method.
A reflective layer having a thickness of 00 ° was provided, and a 6 μm protective layer of an acrylic photopolymer was provided thereon. 0.6m thick
m of the injection-molded polycarbonate substrate was bonded with an acrylic photopolymer to obtain an optical recording medium according to the present invention.

(Examples 2 to 10) Optical recording media according to the present invention were formed in exactly the same manner as in Example 1 by using combinations of dyes as shown in Table 1 below.

The optical recording medium of the above example was recorded under the following recording conditions, tested under the following weathering test conditions, and the evaluation results are shown in Table 1 below. <Recording conditions> An EFM signal (linear velocity: 3.5 m / sec) was recorded on this recording medium while tracking using a semiconductor laser beam having an oscillation wavelength of 658 nm and a beam diameter of 1.0 μm.
Reproduction was performed with continuous light (reproduction power 0.7 mW) of a semiconductor laser having an oscillation wavelength of 658 nm, and a reproduction waveform was observed.

Comparative Example 1 Using only the squarylium compound B-11, an optical recording medium was formed at the same time as in Example 1. <Weather resistance test conditions> Light resistance test: 40,000 Lux, Xe light, continuous irradiation for 10 hours Storage test: 50 ° C., 80%, left for 600 hours

[0131]

[Table 1]

[0132]

[Table 2]

[0133]

[Table 3]

[0134]

[Table 4]

[0135]

[Table 5]

[0136]

[Table 6]

[0137]

According to the present invention, it is possible to provide an optical recording medium capable of recording and reproducing with a laser beam having a wavelength range of 670 nm or less, and having excellent light resistance and storage stability. In particular, it has become possible to provide an optical recording medium having excellent light fastness as compared with one using a squarylium compound alone. 2) Claims 5 to 6 In addition to the first effect, an optical recording medium capable of recording and reproducing information with a stable high reflectance and a high modulation degree can be provided. 3) Claim 7 In addition to the first effect, an optical recording medium capable of performing stable recording and reproduction can be provided. 4) Claim 9 It has become possible to provide an optical recording method capable of achieving the first effect.

[Brief description of the drawings]

FIGS. 1A to 1D are schematic cross-sectional views showing the configuration of a general write-once optical recording medium applicable to the recording medium of the present invention.

FIGS. 2A to 2C are schematic cross-sectional views showing a configuration of a high-reflectivity (for CD-R) optical recording medium applicable to the recording medium of the present invention.

FIGS. 3A to 3C are schematic cross-sectional views illustrating a configuration of a large-capacity reflectance (for DVD-R) optical recording medium applicable to the recording medium of the present invention.

[Explanation of symbols]

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

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) G11B 7/24 538 G11B 7/24 561N 561 B41M 5/26 Y (72) Inventor Mune Noguchi Ota-ku, Tokyo 1-3-6 Nakamagome, Ricoh Company (72) Inventor Tsutomu Tsutomu 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor, Tatsuya Tomura 1-chome Nakamagome, Ota-ku, Tokyo No. 3-6 Inside Ricoh Company, Ltd. (72) Noboru Sasa, Inventor 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company Ltd. Yasunobu Ueno, 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company, Ltd. (72) Inventor Yasuhiro Higashi 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company, Ltd. (72) Ikuo Shimizu Yokkaichi, Mie Prefecture 2-3 Kyomachi Yukaichi Research Institute, Kyowa Yuka Co., Ltd. (72) Inventor Hiroshi Toyoda 2-3-3 Daikyocho Yokkaichi City, Mie Prefecture Kyowa Yuka Co., Ltd., Yokkaichi Research Center (72) Inventor Motoharu Kinugasa Mie Prefecture 2-3-3, Daikyocho, Yokkaichi-shi Kyowa Yuka Co., Ltd. Yokkaichi Research Laboratory (72) Inventor Shiho Yamada 2-3-3, Yokkaichi-shi, Mie Pref.Yokkaichi Co., Ltd. Yokkaichi Research Laboratory Co., Ltd. Kyowa Yuka Co., Ltd. Yokkaichi Research Laboratories 2-3-2 Daikyo-cho, Yokkaichi-shi, Mie (72) Inventor Kenji Muto 1-6-1, Otemachi, Chiyoda-ku, Tokyo Kyowa Hakko Kogyo Co., Ltd. 2H111 EA03 EA12 EA22 EA25 EA32 EA39 EA40 EA43 FA01 FA12 FA23 FB42 FB48 4H056 CA01 CC02 CC08 CE01 CE03 DD03 5D029 JA04 JC06 MA13 WB11

Claims (9)

[Claims] 1. An optical recording medium comprising at least a recording layer provided on a substrate, wherein a squarylium compound and an azo metal chelate compound comprising an azo compound represented by the following general formula (I) and a metal are contained in the recording layer. , An optical recording medium characterized by containing at least one kind of each. Embedded image Wherein A represents a residue that forms a heterocyclic ring together with the carbon and nitrogen atoms to which it is attached, and B represents an aromatic group that is taken together with the two carbon atoms to which it is attached. Represents a residue forming a ring or a heterocyclic ring, and X represents a substituent having an active hydrogen.) 2. The optical recording medium according to claim 1, wherein the weight ratio of the squarylium compound to the azo metal chelate compound is 90:10 to 20:80. 3. The method according to claim 1, wherein the metal atom of the azo metal chelate compound is
2. The material according to claim 1, wherein the material is at least one selected from the group consisting of manganese, cobalt, nickel and copper.
Or the optical recording medium according to 2. 4. A squarylium compound represented by the following general formula (I)
I)[Wherein, R₁And R_TwoAre the same or different,
A substituent, an alkyl group which may have a substituent,
Having an aralkyl group or a substituent
Represents an optionally substituted aryl group. Also, R₁And R_TwoIs next to
It may have a substituent together with the contacting nitrogen atom.
May form a heterocyclic ring. R_ThreeIs represented by the following general formula (III)
Or (IV): embedded image[Wherein, R_FourAnd R_FiveAre the same or different,
Represents an atom or an alkyl group;_FourAnd R_FiveIs adjacent
May have a substituent together with the nitrogen atom
Forming a heterocycle, R₆, R₇, R₈And R₉Are the same or
Are different from each other and may have a hydrogen atom or an
Alkyl group, alkoxy group which may have a substituent, water
Represents an acid group or a halogen atom;_FourAnd R₆,Also
Is R_FiveAnd R₇Together with the adjacent NCC
A heterocyclic ring containing a nitrogen atom may be formed.
It may have a substituent.][Where Q₁Represents a carbon atom or a nitrogen atom;_TenYou
And R₁₁Are the same or different and each represents a hydrogen atom or a substituent.
May have an alkyl group, may have a substituent
Aryl groups and aralkyl groups which may have a substituent
Or a hydroxyl group (however, Q₁Is a nitrogen atom,
₁₁Does not exist), and R₁₂Represents a hydrogen atom and a substituent
May have an alkyl group, may have a substituent
Aryl groups or aralkyl which may have a substituent
R₁₃And R₁₄Are the same or different, water
Atom, alkyl group which may have a substituent, alcohol
Represents a xy group or a halogen atom;₁₃and
R₁₄Together with two adjacent carbon atoms form an alicyclic
A hydrocarbon ring, an aromatic ring which may have a substituent or
A heterocyclic ring which may have a substituent is formed. ]]
Or a compound represented by the following general formula (V):[Where Q_TwoRepresents a carbon atom or a nitrogen atom;
_FifteenIs a hydrogen atom or an optionally substituted alkyl
Group, aryl group which may have a substituent or substituent
Represents a heterocyclic group optionally having₁₆Is a hydrogen atom,
A halogen atom, an alkyl group which may have a substituent,
An alkoxy group which may have a substituent,
Optionally having an aralkyl group, may have a substituent
An aryl group, an amino group which may have a substituent or
Represents a heterocyclic group which may have a substituent. R₁₇and
R₁₈Are the same or different and may have a substituent
Represents a good alkyl group or R₁₇And R₁₈Is the adjacent carbon source
Forms an alicyclic hydrocarbon ring or heterocyclic ring
May be. However, Q_TwoIs a nitrogen atom, R₁₈Is
Does not exist. R₁₉May have a hydrogen atom or a substituent
Alkyl group, aralkyl group which may have a substituent,
Or an aryl group which may have a substituent; ₂₀
Is a halogen atom, an alkyl which may have a substituent
Group, an aralkyl group which may have a substituent,
An aryl group which may have, a trifluoromethyl group,
May have a nitro group, a cyano group, or a substituent
Represents an alkoxy group. n represents an integer of 0 to 4;
When n is 2 to 4, R₂₀Are the same or different
And two Rs adjacent to each other₂₀Is adjacent
May have a substituent together with two carbon atoms
May form an aromatic ring].
The method according to any one of claims 1 to 3, wherein
Optical recording medium. 5. A recording layer having a refractive index n of 1.5 ≦ n ≦ 3.0 and a extinction coefficient k of 0.02 ≦ k ≦ 0.3 with respect to light in a wavelength range of ± 5 nm. The optical recording medium according to any one of claims 1 to 4, wherein: 6. A reflective layer comprising gold, silver, copper,
The optical recording medium according to any one of claims 1 to 5, wherein the optical recording medium is aluminum or an alloy of these metals. 7. The track pitch on a substrate is 0.7-0.
8 μm, and the groove width is half width, 0.18 to 0.40 μm.
The optical recording medium according to claim 1, wherein m is m. 8. The optical recording medium according to claim 1, wherein recording and reproduction can be performed at a wavelength of 600 to 720 nm. 9. An optical recording method comprising recording on the optical recording medium according to claim 1 at a recording wavelength of 600 to 720 nm.