JPH11321108A - Information recording medium and novel oxonol compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information recording medium (optical disk) having high stability of sufficiently maintaining recording characteristics for a long period with excellent recording/reproducing characteristics or particularly high stability even in a light resistance and preservation durability. SOLUTION: The laser recording information recording medium comprises a recording layer containing an oxonol compound (containing novel oxonol compound) represented by formula, [wherein R<1> and R<2> are each a substituent, X<k+1> is a cation, p and q are each an integer of 0 to 4, (wherein p+q>=1), if p and q are all 2 or more, two R<1> and/or the two R<2> are each bonded to one another and may form a condensed ring together with a benzene ring, and k is an integer of 1 to 10].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording medium on which information can be written using a laser beam having a high energy density, and a novel dye compound which can be advantageously used for manufacturing the information recording medium. It is.

[0002]

2. Description of the Related Art An information recording medium (optical disc) on which information can be recorded only once by a laser beam is also called a write-once CD (so-called CD-R), and is widely used, for example, as a disc memory for a computer. . This CD-R
Type optical disk is a transparent disk-shaped substrate made of a hard material such as polymer or glass, and a Te,
It has a basic structure from a recording layer capable of recording information with a laser beam composed of a metal or semimetal such as In, or a dye such as cyanine, metal complex, or quinone. Usually, a reflective layer made of a highly reflective material such as gold and a protective layer made of a polymer are sequentially provided on the recording layer in a laminated state.

[0003] Writing (recording) of information on a CD-R type optical disk is usually performed by irradiating a recording layer of the optical disk with a laser beam having a wavelength near 780 nm. Due to this laser irradiation, the irradiated portion of the recording layer absorbs the light and locally raises the temperature, causing a physical or chemical change (for example, generation of pits or the like), and the optical characteristics of the recording layer are changed. By changing, information is recorded. On the other hand, reading (reproduction) of information is also usually performed by irradiating the recording layer of the optical disk with laser light having the same wavelength as the recording laser light, and a portion of the recording layer where optical characteristics have changed (such as pit generation). The information is reproduced by detecting the difference in the reflectance of the laser beam between the portion (recorded portion due to) and the portion that does not change (unrecorded portion).

A recording layer using a dye as a recording material does not require the use of a vapor deposition method as in the case of the production of a metal recording layer, and can be easily formed by coating, which is advantageous in terms of production cost. Further, it has advantages such as higher sensitivity than the metal recording layer. However, the dye recording layer generally has problems such as low stability over time against heat or light. Therefore, development of a dye recording layer capable of maintaining stable performance against heat or light over a long period of time is desired, and dye recording layers made of various dye recording materials have been proposed.

[0005] For example, Japanese Patent Application Laid-Open No. Sho 63-209995 discloses an information recording medium in which a dye recording layer using an oxonol dye as a recording material is provided on a substrate. This publication states that the use of this dye can maintain stable recording / reproducing characteristics for a long period of time.

In recent years, an information recording medium having a higher recording density has been demanded. In order to increase the recording density, it is effective to reduce the diameter of the laser beam to be irradiated, and it is also effective to reduce the diameter of the laser beam with a shorter wavelength.
It is theoretically known that the use of laser light having a short wavelength is advantageous for increasing the density. Therefore, the development of an optical disc for recording and reproducing using a laser beam having a wavelength shorter than 780 nm, which is generally used in the past, is being promoted. For example, a write-once digital video disc (so-called DVD-R) has been developed. ) Has been proposed.
DVD-R type optical discs use visible laser light (usually 6
By irradiating laser light having a wavelength in the range of 00 nm to 700 nm), recording and reproduction are performed, and higher-density recording can be performed as compared with the above-described CD-R type optical disk. .

[0007]

According to the study of the present inventors, an information recording medium using an oxonol dye having a specific chemical structure described in JP-A-63-209995 as a recording material. Is excellent in heat storage and durability (repeated reproduction), but may have poor reproduction when exposed to light such as sunlight for a long time. It turned out not. In addition, the information recording medium using this oxonol dye, compared with the information recording medium using a conventionally known cyanine dye as a recording material, has a problem such as a low reflectance and a low degree of modulation and a high jitter. It has been found that there is a point to be improved in the recording and reproducing characteristics.

The main object of the present invention is to provide information having excellent recording / reproducing characteristics and high stability so that the recording characteristics can be sufficiently maintained for a long period of time, particularly high stability in light resistance and storage durability. It is to provide a recording medium (optical disk). Another object of the present invention is to provide a novel oxonol dye which can be advantageously used for producing an information recording medium having the above-mentioned high performance.

[0009]

According to the research of the present inventors,
When a dye compound (oxonol compound) having a specific chemical structure is used as a recording material of an information recording medium using laser light as information recording means, the recording / reproducing characteristics are superior to conventional ones, and light resistance and storage durability are also improved. It has been found that an information recording medium having further improved storage stability can be obtained.

According to the present invention, there is provided an information recording medium comprising a substrate and a recording layer on which information can be recorded by a laser beam, wherein the recording layer is a dye represented by the following general formula (I-1): An information recording medium comprising a compound (oxonol compound).

[0011]

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[Wherein, R ¹ and R ² each independently represent a substituent, X ^{k +} represents a cation, and p and q each independently represent an integer of 0 to 4 (provided that p + q ≧ 1) ), When p and q are each 2 or more, two R ¹ and / or two R ² are connected to each other to form a condensed ring together with a benzene ring to which each is bonded. And k represents an integer of 1 to 10. ]

The present invention particularly relates to the following general formula (II-1):
There is also a novel oxonol compound represented by the formula (1) and an information recording medium using laser light as an information recording means using the oxonol compound as a recording material.

[0014]

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Wherein R ⁷ and R ⁸ are each independently an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, An aryl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 18 carbon atoms, an acyl group having 2 to 18 carbon atoms, an alkylsulfonyl group having 1 to 18 carbon atoms, and 6 to 1 carbon atoms
8, an arylsulfonyl group, an alkylsulfinyl group having 1 to 18 carbon atoms, an alkoxycarbonyl group having 2 to 18 carbon atoms, an aryloxycarbonyl group having 7 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, Aryloxy group having 6 to 18 carbon atoms, 1 to 1 carbon atom
An alkylthio group having 8 carbon atoms, an arylthio group having 6 to 10 carbon atoms, an acyloxy group having 2 to 18 carbon atoms, a sulfonyloxy group substituted with a hydrocarbon group having 1 to 18 carbon atoms, A carbamoyloxy group optionally substituted with a hydrocarbon group, an amino group optionally substituted with a hydrocarbon group having 1 to 18 carbon atoms, even an amino group optionally substituted with a hydrocarbon group having 1 to 18 carbon atoms A good amide group, a ureido group optionally substituted by a hydrocarbon group having 1 to 18 carbon atoms, a carbamoyl group optionally substituted by a hydrocarbon group having 1 to 18 carbon atoms,
18, a sulfamoyl group optionally substituted with a hydrocarbon group, a halogen atom, a hydroxyl group, a mercapto group, a nitro group, a cyano group, a carboxyl group, a sulfo group, or 4
Represents a 7 to 7-membered heterocyclic group (these substituents may be further substituted with any of the above-mentioned substituents, and the alkyl group contained in these substituents may be linear, branched, or X ^{k +} represents a cation, p and q each independently represent an integer of 0 to 4 (provided that p + q ≧ 1), and p and q each represent 2 or more. In some cases, two R ⁷ and / or two R ⁸
May be linked to each other to form a condensed ring together with the benzene ring to which each is attached, and k is 1
Represents an integer of 10 to 10. ]

The information recording medium and the oxonol compound of the present invention preferably have the following aspects. (1) An information recording medium, wherein in formula (I-1), X ^{k +} is a quaternary ammonium ion. (2) An information recording medium in which k is 1 to 4 in the general formula (I-1). (3) An information recording medium in which k is 2 in the general formula (I-1). (4) An information recording medium wherein X ^{k +} is an onium ion represented by the following general formula (I-2) in the general formula (I-1).

[0017]

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[Wherein, R ³ and R ⁴ each independently represent a substituent, and R ⁵ and R ⁶ each independently represent an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an aryl group or a heterocyclic group. R ³ and R ⁴ , R ³ and R ⁵ , R ⁴
And R ⁶ and / or R ⁵ and R ⁶ may be linked to each other to form a ring, and r and s each independently represent 0 to
Represents an integer of 4. ]

(5) In the oxonol compound of the general formula (II-1), X ^{k +} is an ion represented by the following general formula (II-2).

[0020]

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Wherein R ⁹ and R ¹⁰ are each independently an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, An aryl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 18 carbon atoms, an acyl group having 2 to 18 carbon atoms, an alkylsulfonyl group having 1 to 18 carbon atoms, and 6 to 6 carbon atoms
18 arylsulfonyl groups, alkylsulfinyl groups having 1 to 18 carbon atoms, alkoxycarbonyl groups having 2 to 18 carbon atoms, aryloxycarbonyl groups having 7 to 18 carbon atoms, alkoxy groups having 1 to 18 carbon atoms, Aryloxy group having 6 to 18 carbon atoms, 1 to 1 carbon atom
An alkylthio group having 18 carbon atoms, an arylthio group having 6 to 10 carbon atoms, an acyloxy group having 2 to 18 carbon atoms, a sulfonyloxy group substituted with a hydrocarbon group having 1 to 18 carbon atoms, A carbamoyloxy group optionally substituted with a hydrocarbon group, an amino group optionally substituted with a hydrocarbon group having 1 to 18 carbon atoms, even an amino group optionally substituted with a hydrocarbon group having 1 to 18 carbon atoms A good amide group, a ureido group optionally substituted by a hydrocarbon group having 1 to 18 carbon atoms, a carbamoyl group optionally substituted by a hydrocarbon group having 1 to 18 carbon atoms,
18, a sulfamoyl group optionally substituted with a hydrocarbon group, a halogen atom, a hydroxyl group, a mercapto group, a nitro group, a cyano group, a carboxyl group, a sulfo group, or 4
Represents a 7-membered heterocyclic group (these substituents may be further substituted by any of the above-mentioned substituents,
The alkyl group contained in these substituents may be linear, branched or cyclic), R ¹¹ and R ¹² are each independently an alkyl group having 1 to 18 carbon atoms, An alkenyl group having 2 to 18 atoms, 2 carbon atoms
-18 alkynyl group, aralkyl group having 7-18 carbon atoms, aryl group having 6-18 carbon atoms, or 4-7
Represents a membered heterocyclic group (these groups are further represented by R
⁹ and may be substituted with substituents corresponding to R ^10), R ⁹ and R ^10, R ⁹ and R ^11, R ¹⁰ and R ^12, and / or R ¹¹ and R ¹² are each connected to one another It may form a 4- to 7-membered ring, and r and s each independently represent an integer of 0 to 4. ]

(6) An information recording medium in which a reflective layer is provided on a recording layer. (7) An information recording medium in which a reflective layer and a protective layer are provided on a recording layer in this order.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The information recording medium of the present invention is characterized by using an oxonol compound (a dye compound) represented by the following general formula (I-1) as a recording material.

[0024]

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The dye compound of formula (I-1) comprises an anionic component (simply an anion portion) and a cationic component (simply a cation portion) as dye components.

First, the anion portion (color component) will be described. Examples of the substituent represented by R ¹ and R ² in the general formula (I-1) include the following.

A substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 18 carbon atoms (preferably having 1 to 8 carbon atoms) (eg, methyl, ethyl, propyl, isopropyl, n- Butyl, isobutyl, sec-
Butyl, t-butyl, cyclohexyl, methoxyethyl, ethoxycarbonylethyl, cyanoethyl, diethylaminoethyl, hydroxyethyl, chloroethyl, acetoxyethyl, trifluoromethyl, etc.); having 2 to 18 carbon atoms (preferably having 2 to 8 carbon atoms) An alkenyl group (eg, vinyl and the like); an alkynyl group having 2 to 18 carbon atoms (preferably 2 to 8 carbon atoms) (eg, ethynyl and the like); 6 to 18 carbon atoms (preferably 6 to 6 carbon atoms)
10) substituted or unsubstituted aryl groups (eg, phenyl, 4-methylphenyl, 4-methoxyphenyl, 4-
Carboxyphenyl, 3,5-dicarboxyphenyl and the like; C7-18 (preferably C7-C8)
12) a substituted or unsubstituted aralkyl group (eg, benzyl, carboxybenzyl, etc.);

A substituted or unsubstituted acyl group having 2 to 18 carbon atoms (preferably 2 to 8 carbon atoms) (eg, acetyl, propionyl, butanoyl, chloroacetyl, etc.); 1 carbon atom
8) a substituted or unsubstituted alkyl or arylsulfonyl group (eg, methanesulfonyl, p-toluenesulfonyl, etc.); an alkylsulfinyl group having 1 to 18 carbon atoms (preferably 1 to 8 carbon atoms) (eg, methane Sulfinyl, ethanesulfinyl, octanesulfinyl and the like); having 2 to 18 carbon atoms (preferably having 2 to 2 carbon atoms)
8) an alkoxycarbonyl group (eg, methoxycarbonyl, ethoxycarbonyl, etc.);

An aryloxycarbonyl group having 7 to 18 (preferably 7 to 12) carbon atoms (eg, phenoxycarbonyl, 4-methylphenoxycarbonyl,
4-methoxyphenylcarbonyl, etc.);
18 (preferably 1 to 8 carbon atoms) substituted or unsubstituted alkoxy group (eg, methoxy, ethoxy, n-butoxy, methoxyethoxy, etc.); 6 to 18 carbon atoms
(Preferably 6 to 10 carbon atoms) a substituted or unsubstituted aryloxy group (eg, phenoxy, 4-methoxyphenoxy, etc.); an alkylthio group having 1 to 18 carbon atoms (preferably 1 to 8 carbon atoms) (Eg, methylthio, ethylthio, etc.); an arylthio group having 6 to 10 carbon atoms (preferably, 1 to 8 carbon atoms) (eg, phenylthio, etc.);

A substituted or unsubstituted acyloxy group having 2 to 18 carbon atoms (preferably having 2 to 8 carbon atoms) (eg, acetoxy, ethylcarbonyloxy, cyclohexylcarbonyloxy, benzoyloxy, chloroacetyloxy, etc.); A substituted or unsubstituted sulfonyloxy group having 1 to 18 atoms (preferably 1 to 8 carbon atoms) (eg, methanesulfonyloxy, etc.);
To 18 (preferably 2 to 8 carbon atoms) substituted or unsubstituted carbamoyloxy groups (eg, methylcarbamoyloxy, diethylcarbamoyloxy, etc.);

Unsubstituted amino group or 1 carbon atom
To 18 (preferably 1 to 8 carbon atoms) substituted amino group (eg, methylamino, dimethylamino, diethylamino, anilino, methoxyphenylamino, chlorophenylamino, pyridylamino, methoxycarbonylamino, n-butoxycarbonylamino, phenoxycarbonyl) Amino, phenylcarbamoylamino, ethylthiocarbamoylamino, methylsulfamoylamino, phenylsulfamoylamino, ethylcarbonylamino, ethylthiocarbonylamino, cyclohexylcarbonylamino, benzoylamino, chloroacetylamino, methanesulfonylamino, benzenesulfonylamino etc);

An amide group having 1 to 18 carbon atoms (preferably 1 to 8 carbon atoms) (eg, acetamido, acetylmethylamide, acetyloctylamide, etc.); 1 to 18 carbon atoms (preferably 1 carbon atom) To 8) substituted or unsubstituted ureido groups (eg, unsubstituted ureido, methylureide, ethylureido, dimethylureide, etc.); substituted or unsubstituted 1 to 18 carbon atoms (preferably 1 to 8 carbon atoms); A substituted carbamoyl group (eg, unsubstituted carbamoyl, methylcarbamoyl, ethylcarbamoyl,
n-butylcarbamoyl, t-butylcarbamoyl, dimethylcarbamoyl, morpholinocarbamoyl, pyrrolidinocarbamoyl, etc.); an unsubstituted sulfamoyl group or 1 to 18 carbon atoms (preferably 1 to 1 carbon atoms)
8) substituted sulfamoyl groups (eg, methylsulfamoyl, phenylsulfamoyl, etc.); halogen atoms (eg,
Hydroxyl group; mercapto group; nitro group; cyano group; carboxyl group; sulfo group; heterocyclic group (eg, oxazole ring, benzoxazole ring, thiazole ring, benzothiazole ring, imidazole ring, benzimidazole) Ring, indolenine ring, pyridine ring, morpholine ring, piperidine ring, pyrrolidine ring, sulfolane ring, furan ring, thiophene ring, pyrazole ring, pyrrole ring, chroman ring, coumarin ring and the like).

The substituents represented by R ¹ and R ² are preferably an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an amino group, a halogen atom, a hydroxyl group, a nitro group and a cyano group. Particularly preferred are an alkyl group, an alkoxy group, an amino group and a halogen atom.

P and q each independently represent an integer of 0 to 4, and at least one of p and q represents an integer of 1 or more. When p and / or q represent an integer of 2 or more, a plurality of substituents represented by R ¹ and / or a plurality of R
^The substituents represented by ² may be the same or different from each other, or may be linked to each other to form a condensed ring (unsaturated condensed ring) together with a benzene ring. The fused ring is preferably a carbocyclic ring, and particularly preferably a fused aromatic ring with a benzene ring to which R ¹ and R ² are bonded.

Next, the cation portion will be described. X ^{k +}
Examples of the cation represented by, for example, hydrogen ion, or sodium ion, potassium ion, lithium ion,
Calcium ion, iron ion, metal ion such as copper ion, metal complex ion, ammonium ion, pyridinium ion, oxonium ion, sulfonium ion,
Examples thereof include a phosphonium ion, a selenonium ion, and an iodonium ion. X ^{k +} is preferably other than a cyanine dye. Preferably, the fourth
Grade ammonium ion.

The quaternary ammonium is generally a tertiary amine (eg, trimethylamine, triethylamine, tributylamine, triethanolamine, N-methylpyrrolidine, N-methylpiperidine, N, N-dimethylpiperazine, triethylenediamine, N, N ', N'
-Tetramethylethylenediamine, etc.) or a nitrogen-containing heterocycle (pyridine ring, picoline ring, 2,2'-bipyridyl ring, 4,4'-bipyridyl ring, 1,10-phenanthroline ring, quinoline ring, oxazole ring, thiazole ring, N-methylimidazole ring, pyrazine ring, tetrazole ring, etc.) can be obtained by alkylation (by Menshkin reaction), alkenylation, alkynylation or arylation.

The quaternary ammonium ion represented by X ^{k +} is preferably a quaternary ammonium ion composed of a nitrogen-containing heterocyclic ring, and particularly preferably a quaternary pyridinium ion.

K represents an integer of 1 to 10, preferably 1
To 4, particularly preferably 2.

The cation represented by X ^{k +} is most preferably an onium ion represented by the following general formula (I-2). These compounds are generally prepared by subjecting 2,2'-bipyridyl or 4,4'-bipyridyl to a Mensutkin reaction with a halide having a desired substituent (see, for example,
-148162) or JP-A-51-1
It can be easily obtained by an arylation reaction according to the methods described in JP-A-6675 and JP-A-1-96171.

[0040]

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[Wherein, R ³ and R ⁴ each independently represent a substituent, and R ⁵ and R ⁶ each independently represent an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an aryl group or a heterocyclic group. R ³ and R ⁴ , R ³ and R ⁵ , R ⁴
And R ⁶ and / or R ⁵ and R ⁶ may be linked to each other to form a ring, and r and s each independently represent 0 to
Represents an integer of 4. ]

Examples of the substituents corresponding to R ³ and R ⁴ in the general formula (I-2) include the substituents corresponding to R ¹ and R ² described above.

The alkyl group represented by R ⁵ and R ⁶ in the formula (I-2) is preferably a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, more preferably 1 to 8 carbon atoms. Is a substituted or unsubstituted alkyl group. These may be linear, branched or cyclic. Examples of these include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-hexyl, cyclohexyl, cyclopropyl, and the like.

Examples of the substituent of the alkyl group include the following. A substituted or unsubstituted alkenyl group having 2 to 18 carbon atoms (preferably 2 to 8 carbon atoms) (eg, vinyl); substituted or unsubstituted alkenyl group having 2 to 18 carbon atoms (preferably 2 to 8 carbon atoms) A substituted alkynyl group (eg, ethynyl); a substituted or unsubstituted aryl group having 6 to 10 carbon atoms (eg, phenyl, naphthyl); a halogen atom (eg, F, Cl, Br, etc.); A substituted or unsubstituted alkoxy group having 18 (preferably 1 to 8 carbon atoms) (eg, methoxy, ethoxy); a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms (eg, phenoxy, p-methoxy) Phenoxy); having 1 to 18 carbon atoms (preferably having 1 to carbon atoms)
8) a substituted or unsubstituted alkylthio group (eg, methylthio, ethylthio); a substituted or unsubstituted arylthio group having 6 to 10 carbon atoms (eg, phenylthio); 2 to 18 carbon atoms (preferably, carbon atom) 2-8) substituted or unsubstituted acyl groups (eg, acetyl, propionyl);

A substituted or unsubstituted alkylsulfonyl or arylsulfonyl group having 1 to 18 carbon atoms (preferably 1 to 8 carbon atoms) (eg, methanesulfonyl, p-toluenesulfonyl);
(Preferably 2 to 8 carbon atoms) substituted or unsubstituted acyloxy group (eg, acetoxy, propionyloxy); 2 to 18 carbon atoms (preferably 2 to 8 carbon atoms)
8) a substituted or unsubstituted alkoxycarbonyl group (eg, methoxycarbonyl, ethoxycarbonyl); a substituted or unsubstituted aryloxycarbonyl group having 7 to 11 carbon atoms (eg, naphthoxycarbonyl); an unsubstituted amino group Or a substituted amino group having 1 to 18 (preferably 1 to 8) carbon atoms (eg, methylamino, dimethylamino, diethylamino, anilino, methoxyphenylamino, chlorophenylamino, pyridylamino, methoxycarbonylamino, n- Butoxycarbonylamino, phenoxycarbonylamino, methylcarbamoylamino, ethylthiocarbamoylamino, phenylcarbamoylamino, acetylamino, ethylcarbonylamino, ethylthiocarbamoylamino, cyclohexylcarbonyl Mino, benzoylamino, chloroacetyl amino, methylsulfonylamino);

A substituted or unsubstituted carbamoyl group having 1 to 18 carbon atoms (preferably 1 to 8 carbon atoms) (eg, unsubstituted carbamoyl, methylcarbamoyl, ethylcarbamoyl, n-butylcarbamoyl, t-butylcarbamoyl) Dimethylcarbamoyl, morpholinocarbamoyl, pyrrolidinocarbamoyl); an unsubstituted sulfamoyl group or a substituted sulfamoyl group having 1 to 18 (preferably 1 to 8 carbon atoms) (eg, methylsulfamoyl, phenylsulfamo) Moyl); cyano group; nitro group; carboxy group; hydroxyl group; heterocyclic group (eg, oxazole ring, benzoxazole ring, thiazole ring, benzothiazole ring, imidazole ring, benzimidazole ring, indolenine ring, pyridine ring, piperidine ring , A pyrrolidine ring, Ruhorin ring, sulfolane ring,
Furan ring, thiophene ring, pyrazole ring, pyrrole ring,
Chroman ring, coumarin ring).

The alkenyl group represented by R ⁵ and R ⁶ is preferably a substituted or unsubstituted alkenyl group having 2 to 18 carbon atoms, more preferably 2 to 8 carbon atoms.
Is a substituted or unsubstituted alkenyl group, for example,
Vinyl, allyl, 1-propenyl, 1,3-butadienyl and the like. As the substituent for the alkenyl group, those mentioned above as the substituent for the alkyl group are preferable.

The alkynyl group represented by R ⁵ and R ⁶ is preferably a substituted or unsubstituted alkynyl group having 2 to 18 carbon atoms, more preferably 2 to 8 carbon atoms.
Is a substituted or unsubstituted alkynyl group, for example,
Ethynyl, 2-propynyl and the like can be mentioned. As the substituent for the alkynyl group, those described above as the substituent for the alkyl group are preferable.

The aralkyl group represented by R ⁵ and R ⁶ is preferably a substituted or unsubstituted aralkyl group having 7 to 18 carbon atoms, and examples thereof include benzyl and methylbenzyl.

The aryl group represented by R ⁵ and R ⁶ is preferably a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, and examples thereof include phenyl and naphthyl. As the substituent of the aryl group, those described above as the substituent of the alkyl group are preferable. In addition, alkyl groups (eg, methyl and ethyl) are also preferred substituents.

The heterocyclic group represented by R ⁵ and R ⁶ is
It is a 5- or 6-membered saturated or unsaturated heterocyclic ring composed of a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, and examples thereof include an oxazole ring, a benzoxazole ring, a thiazole ring, and a benzothiazole. Ring, imidazole ring, benzimidazole ring, indolenine ring,
Examples include a pyridine ring, a piperidine ring, a pyrrolidine ring, a morpholine ring, a sulfolane ring, a furan ring, a thiophene ring, a pyrazole ring, a pyrrole ring, a chroman ring, and a coumarin ring. The heterocyclic group may be substituted, and in this case, the substituent is preferably an alkyl group or the substituents described above for the alkyl group.

In the general formula (I-1), the cation moiety is particularly preferably a cation represented by the following general formula (I-3) or (I-4).

[0053]

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[Wherein, R ¹³ and R ¹⁴ have the same meanings as the substituents represented by R ³ and R ⁴ , respectively, and their preferred ranges are also the same. R ¹⁵ and R ¹⁶ have the same meanings as the substituents represented by R ⁵ and R ⁶ described above, respectively, and their preferred ranges are also the same. r and s each independently represent an integer of 0 to 4, and when r and s are 2 or more, a plurality of R ¹³ and R ¹⁴ may be the same or different from each other. ]

[0055]

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[Wherein, R ¹⁷ and R ¹⁸ have the same meanings as the substituents represented by R ³ and R ⁴ , respectively, and the preferred ranges thereof are also the same. R ¹⁷ and R
^18, preferably also forming a carbocyclic or heterocyclic ring linked to each other, particularly preferably a R ¹⁷ R
^{In this case, 18} forms a condensed aromatic ring with the pyridine ring to which they are respectively bonded. r and s each independently represent an integer of 0 to 4, and when r and s are 2 or more, a plurality of R
¹⁷ and R ¹⁸ may be the same or different from each other. ]

The anion part (denoted by [A-]) and the cation part (“B-”) of the dye compound represented by formula (I-1)
) Are specifically described below.

[0058]

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[0059]

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[0060]

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[0061]

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[0062]

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[0063]

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[0064]

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[0065]

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[0066]

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[0067]

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[0068]

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[0069]

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[0070]

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[0071]

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[0072]

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[0073]

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[0074]

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[0075]

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[0076]

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[0077]

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[0078]

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[0079]

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[0080]

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[0081]

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Preferred specific examples of the oxonol compound used in the present invention are shown in Tables 1 to 6 below. In each table, the compound examples are shown in the form of a combination of an anion part and a cation part. That is, taking Compound No. 1 as an example, the compound of Compound No. 1 is represented by [anion part (A-1) / cation part (B-21)], and this compound example is represented by the following formula. It is a compound shown.

[0083]

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[0084]

[Table 1]

[0085]

[Table 2]

[0086]

[Table 3]

[0087]

[Table 4]

[0088]

[Table 5]

[0089]

[Table 6]

The compound represented by the general formula (I-1) or (II-
3-oxo-2,3 dihydrobenzothiophene-1,1- which is the skeleton of the oxonol compound represented by 1)
The dioxy skeleton is referred to as “Chemica Scripta”.
a Scripta) ", Vol. 6,184-192
(1974) and "Soy and Pigments"
s and Pigments ", Vol. 11,37
-46 (1989). The conversion to oxonol compounds is described in FM Hamer, "Heterocyclic Compounds-Cyanin Heterocyclic Compounds-Cyanin
edyes and Related Compounds) "by John Wiley
John Wiley & Sons, New York, London, 1964, pp. 244-247.
Page, and pages 463 to 482.

Next, synthesis examples of the oxonol compounds represented by the general formulas (I-1) and (II-1) will be described.

First, synthesis examples of 3-oxo-2,3-dihydrobenzothiophene derivatives (A, B, C, and D) will be described.

[0093]

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[Synthesis of Compound A] 4-Bromophenylmercaptoacetic acid (12.3 g, 0.050 mol) was dissolved in chlorobenzene (50 mL), and phosphorus trichloride (5.7) was dissolved.
mL, 0.065 mol) was added dropwise, and the mixture was stirred at 40 ° C for 2 hours. After cooling to room temperature, aluminum chloride (7.4 g, 0.055 mol) was added portionwise to the reaction solution, and
Stirred for hours. The reaction solution was poured into ice water (250 mL), and the obtained crude crystals were repeatedly recrystallized from methanol and acetonitrile to obtain 5.1 g of Compound A. This corresponds to 45% of the theoretical yield. ¹ H-NMR (CDCl ₃ ): 7.9 (s, 1 H),
7.6 (d, 1H), 7.2 (d, 1H), 3.8
(S, 2H)

[Synthesis of Compound B] In the above synthesis example,
5.9 g of compound B was obtained by the same operation except that 4-methylphenylmercaptoacetic acid (9.1 g, 0.050 mol) was used instead of 4-bromophenylmercaptoacetic acid. This corresponds to 72% of the theoretical yield. ¹ H-NMR (CDCl ₃ ): 7.6 (s, 1H),
7.3 (m, 2H), 3.8 (s, 2H), 2.4
(S, 3H)

[Synthesis of Compound C and Compound D] In the above synthesis example, instead of 4-bromophenylmercaptoacetic acid, 3,4-dichlorophenylmercaptoacetic acid (11.
(8 g, 0.050 mol) by the same operation except that 6.0 g of an isomer mixture of compound C and compound D was obtained. The obtained isomer mixture was repeatedly fractionated and recrystallized with chloroform to obtain 2.0 g of compound C and 1.0 g of compound C.
Compound D was obtained. These correspond to a theoretical yield of 18
% And 9%. (Compound C) ¹ H-NMR (CDCl ₃ ): 7.8 (s, 1 H),
7.5 (s, 1H), 3.8 (s, 2H) (Compound D) ¹ H-NMR (CDCl ₃ ): 7.6 (d, 1H),
7.3 (d, 1H), 3.9 (s, 2H)

Next, 3-oxo-2,3-dihydrobenzothiophene-1,1-dioxy derivatives (E, F, G,
And H) are shown below.

[0098]

Embedded image

[Synthesis of Compound E] Compound A (2.3 g,
(0.010 mol) was dissolved in methylene chloride (70 mL), perbenzoic acid (3.47 g, 0.020 mol) was added in portions, and the mixture was stirred at room temperature for 2 hours. The reaction solution was concentrated under reduced pressure, and the obtained crude crystals were purified by silica gel column chromatography (developing solvent: methylene chloride) to obtain 1.7 g of a compound E as a white powder. This corresponds to 65% of the theoretical yield. ¹ H-NMR (CDCl ₃ ): 8.2 (s, 1H),
8.1 (d, 1H), 7.8 (d, 1H), 4.1
(S, 2H)

[Synthesis of Compound F] In the above synthesis example,
1.4 g of compound F was obtained by the same operation except that compound B (1.6 g, 0.010 mol) was used instead of compound A. This corresponds to 70% of the theoretical yield. ¹ H-NMR (CDCl ₃ ): 7.8 (m, 3H),
4.1 (s, 2H), 2.5 (s, 3H)

[Synthesis of Compound G] In the above synthesis example,
2.8 g of compound G was obtained by the same operation except that compound C (3.0 g, 0.014 mol) was used instead of compound A. This corresponds to 80% of the theoretical yield. ¹ H-NMR (CDCl ₃ ): 8.1 (s, 2H),
4.2 (s, 2H)

[Synthesis of Compound H] In the above synthesis example,
2.8 g of compound H was obtained by the same operation except that compound D (3.0 g, 0.014 mol) was used instead of compound A. This corresponds to 80% of the theoretical yield. ¹ H-NMR (CDCl ₃ ): 8.0 (d, 1 H),
7.8 (d, 1H), 4.2 (s, 2H)

[1,1′-bisisobutyl-4,4′-
Synthesis of bipyridinium dibromide] 4,4'-Dipyridyl (7.8 g, 0.050 mol) and isobutyl bromide (27.4 g, 0.20 mol) are dissolved in dimethylformamide (20 mL) and heated to 90 ° C. Heated. 90
After stirring at 8 ° C. for 8 hours, the yellow precipitate was filtered off and ethanol (9%) was added.
0 mL). Triethylamine (2.2 mL, 0.016 mol) was added dropwise to the suspension, and the mixture was stirred at room temperature for 1 hour. The obtained yellow precipitate was collected by filtration and washed with ethanol to obtain 2.1 g of 1,1′-bisisobutyl-4,4′-bipyridinium dibromide. This corresponds to 10% of the theoretical yield. ¹ H-NMR (D ₂ O): 9.1 (d, 4H), 8.5
(D, 4H), 4.5 (d, 4H), 2.4 (m, 2
H), 1.1 (d, 12H)

[1,1′-bis (1-phenylethyl)
Synthesis of -4,4'-bipyridinium dibromide] In the above synthesis example, 12.9 g was obtained by the same operation except that 1-phenylethyl bromide (37 g, 0.20 mol) was used instead of isobutyl bromide. Of (1,1′-bis (1-phenylethyl) -4,4′-bipyridinium dibromide, corresponding to 49% of the theoretical yield. ¹ H-NMR (DMSO-d ₆ ): 9.7 ( d, 4
H), 8.8 (d, 4H), 7.7 (d, 4H), 7.
5 (m, 6H), 6.4 (q, 2H), 2.1 (d, 6
H)

[Synthesis of 1,1′-bisallyl-4,4′-bipyridinium dibromide] In the above synthesis example, allyl bromide (24.2) was used instead of isobutyl bromide.
g, 0.20 mol) in the same manner as above.
7.5 g of 1,1′-bisallyl-4,4′-bipyridinium dibromide were obtained. This corresponds to 88% of the theoretical yield. ¹ H-NMR (DMSO-d ₆ ): 9.4 (d, 4
H), 8.8 (d, 4H), 6.1 (m, 2H), 5.
5 (m, 4H), 5.4 (d, 4H)

[Synthesis of 1,1′-bis (2,6-diethylphenyl) -4,4′-bipyridinium dichloride]
1,1′-bis (2,4-dinitrophenyl) -4,
4'-bipyridinium dichloride (5.6 g, 0.01
0 mol) and 2,6-diethylaniline (6.6 g, 0.
(044 mol) was dissolved in 70% ethanol (30 mL), and the mixture was heated under reflux for 8 hours and then the solvent was distilled off. The obtained yellow solid was suspended in water (90 mL) and stirred at room temperature for 1 hour. After filtering off a white-yellow solid, the aqueous layer was evaporated under reduced pressure, and the obtained yellow solid was washed with ethyl acetate to give 4.4 g of 1,1′-bis (2,6-diethyl). Phenyl) -4,4'-bipyridinium dichloride was obtained. This corresponds to 89% of the theoretical yield. ¹ H-NMR (D ₂ O): 9.6 (d, 4H), 9.1
(D, 4H), 7.3 to 7.7 (m, 6H), 2.3
(Q, 8H), 1.1 (t, 12H)

[Synthesis of 1,1′-bis (2-isopropoxyphenyl) -4,4′-bipyridinium dichloride] In the above synthesis example, 2-isopropoxyaniline (3. 7 g, 0.
024 mol), and then 3.5 g was obtained in the same manner as described above.
(1,1'-bis (2-isopropoxyphenyl)-
4,4'-Bipyridinium dichloride was obtained. This corresponds to 70% of the theoretical yield. ¹ H-NMR (D ₂ O): 9.3 (d, 4H), 8.8
(D, 4H), 7.8 (m, 4H), 7.5 (d, 2
H), 7.3 (dd, 2H), 4.9 (m, 2H),
1.3 (d, 12H).

[Synthesis of Oxonol Compound of Compound No. 17] Compound E (1.3 g, 5.0 mmol) and N,
N'-1,3-Pentadien-1-yl-5-ylidenedianiline hydrochloride (0.71 g, 2.5 mmol) was dissolved in dimethylformamide (8 mL), and triethylamine (1.1 mL, 7.8) was added under ice cooling. Mmol) was added dropwise. After stirring at room temperature for 3 hours, water (40 m
When L) was added, yellow crystals of the oxonol compound of Compound No. 17 precipitated. The crystals were collected by filtration and dried to obtain 1.6 g of an oxonol compound of Compound No. 17. This corresponds to 93% of the theoretical yield. ¹ H-NMR (DMSO-d ₆ ): 7.2 to 8.0
(M, 9H), 6.5 (dd, 2H), 3.1 (q, 6
H), 1.2 (t, 9H) λ _max : 650 nm (in methanol)

[Synthesis of Oxonol Compound of Compound No. 11] Oxonol compound of Compound No. 17 (0.35
g, 0.51 mmol) in methanol (30 mL) and stirred at room temperature for 30 minutes. 1,
1′-Bisisobutyl-4,4′-bipyridinium dibromide (0.13 g, 0.30 mmol) was added, and the mixture was stirred at room temperature for 4 hours. The resulting precipitate was collected by filtration, washed with methanol, and dried to obtain 0.33 g of an oxonol compound of Compound No. 11. This corresponds to 90% of the theoretical yield. ¹ H-NMR (DMSO-d ₆ ): 9.4 (d, 2
H), 8.8 (d, 2H), 7.2 to 8.0 (m, 9
H), 6.5 (dd, 2H), 4.5 (d, 2H),
2.4 (m, 1H), 0.9 (d, 6H) _λmax : 650 nm (in methanol)

[Synthesis of oxonol compound of compound No. 26] Compound F (1.0 g, 5.0 mmol) and N,
N'-1,3-Pentadien-1-yl-5-ylidenedianiline hydrochloride (0.71 g, 2.5 mmol) was dissolved in dimethylformamide (8 mL), and triethylamine (1.1 mL, 7.8) was added under ice cooling. Mmol) was added dropwise. After stirring at room temperature for 3 hours, methanol (60 mL) was added to the reaction solution, and then concentrated hydrochloric acid (1 mL) was added dropwise. After stirring at room temperature for 2 hours, the crystals were collected by filtration and dried to obtain 1.1 g of an oxonol compound of Compound No. 27. This corresponds to 98% of the theoretical yield. ¹ H-NMR (DMSO-d ₆ ): 7.7 (d, 2
H), 7.6 (m, 4H), 7. s4 (d, 2H),
7.1 (s, 1H), 6.6 (dd, 2H), 2.5
(S, 6H) λ _max : 644 nm (in methanol)

[Synthesis of Oxonol Compound of Compound No. 25] Oxonol compound of Compound No. 26 (0.23
g, 0.51 mmol) in methanol (30 mL), and then triethylamine (0.07 mL, 0.5
(1 mol) was added dropwise and stirred at room temperature for 30 minutes. 1,1′-bis (2,6-diethylphenyl)-
4,4′-bipyridinium dichloride (0.15 g,
0.30 mmol) and stirred at room temperature for 4 hours.
The resulting precipitate was collected by filtration, washed with methanol, and dried to obtain 0.27 g of an oxonol compound of Compound No. 25. This corresponds to 80% of the theoretical yield. ¹ H-NMR (DMSO-d ₆ ): 9.6 (d, 2
H), 9.1 (d, 2H), 7.3 to 7.7 (m, 11
H), 7.1 (s, 1H), 6.6 (dd, 2H),
2.5 (s, 6H), 2.3 (q, 4H), 1.1
(T, 6H) λ _max : 644 nm (in methanol)

[Synthesis of Oxonol Compound of Compound No. 80] Compound G (2.0 g, 8.0 mmol) and N,
N′-1,3-pentadien-1-yl-5-ylidenedianiline hydrochloride (1.1 g, 3.9 mmol) is dissolved in dimethylformamide (15 mL), and triethylamine (1.7 mL, 12 mmol) is cooled under ice-cooling. Was added dropwise. After stirring at room temperature for 6 hours, water (80 mL) was added to the reaction solution.
Was added to precipitate green crystals. After filtering the crystals, the crystals were dissolved in methanol (40 mL), and then 1,1′-bisallyl-4,4′-bipyridinium dibromide (0.8%).
(3 g, 2.0 mmol) was added and stirred at room temperature for 8 hours. The obtained green precipitate was collected by filtration, washed with methanol, and dried to obtain 1.1 g of an oxonol compound of Compound No. 80. This corresponds to 69% of the theoretical yield. ¹ H-NMR (DMSO-d ₆ ): 7.2 to 8.0
(M, 9H), 6.5 (dd, 2H), 3.1 (q, 6
H), 1.2 (t, 9H ) λ max: 648nm ( in methanol)

[Synthesis of Oxonol Compound of Compound No. 90] Compound H (2.0 g, 8.0 mmol) and N,
N′-1,3-pentadien-1-yl-5-ylidenedianiline hydrochloride (1.1 g, 3.9 mmol) is dissolved in dimethylformamide (15 mL), and triethylamine (1.7 mL, 12 mmol) is cooled under ice-cooling. Was added dropwise. After stirring at room temperature for 6 hours, water (80 mL) was added to the reaction solution.
Was added to precipitate green crystals. After filtering the crystals, the crystals were dissolved in methanol (40 mL), and then 1,1′-bis (2-isopropoxyphenyl) -4,4′-bipyridinium dichloride (0.99 g, 2.0 mmol) was added. And stirred at room temperature for 8 hours. The resulting green precipitate was collected by filtration, washed with methanol, and dried to obtain 1.2 g of an oxonol compound of Compound No. 90. This is the theoretical yield of 7
Equivalent to 8%. ¹ H-NMR (DMSO-d ₆ ): 7.2 to 8.0
(M, 9H), 6.5 (dd, 2H), 3.1 (q, 6
H), 1.2 (t, 9H ) λ max: 648nm ( in methanol)

[Synthesis of Oxonol Compound of Compound No. 100] Compound F (2.0 g, 10 mmol) and N,
N′-1,3-pentadien-1-yl-5-ylidenedianiline hydrochloride (2.9 g, 10 mmol) was dissolved in dimethylformamide (30 mL), and triethylamine (2.8 mL, 20 mmol) was added under ice cooling. ) Was added dropwise. After stirring at room temperature for 1 hour, methanol (5
(0 mL), purple crystals precipitated. After the crystals were collected by filtration, they were dissolved in dimethylformamide (4 mL), and then 3-oxo-2,3-dihydrobenzothiophene-
1,1-dioxy (1.8 g, 10 mmol) and triethylamine (1.4 mL, 10 mmol) were added,
Stir at room temperature for 3 hours. Add methanol (60
mL) was added, followed by dropwise addition of concentrated hydrochloric acid (1.8 mL). After stirring at room temperature for 2 hours, the crystals were collected by filtration and dried. The crystals were dissolved in methanol (30 mL), tetramethylammonium bromide (1.5 g, 10 mmol) was added, and the mixture was stirred at room temperature for 8 hours. The resulting purple precipitate was collected by filtration, washed with methanol, and dried to obtain 1.3 g of an oxonol compound of Compound No. 100. This corresponds to 26% of the theoretical yield. ¹ H-NMR (DMSO-d ₆ ): 7.2 to 8.0
(M, 9H), 6.5 (dd, 2H), 3.1 (q, 6
H), 1.2 (t, 9H) λ _max : 644 nm (in methanol)

[Synthesis of Oxonol Compound of Compound No. 105] In the above synthesis example, 1,1′-bis (1-phenylethyl) -4,4′-bipyridinium dibromide (2.6) was used instead of tetramethylammonium bromide.
g, 5.0 mmol) to obtain 2.6 g of an oxonol compound of Compound No. 105 in the same manner as described above. This corresponds to 42% of the theoretical yield. ¹ H-NMR (D ₂ O): 9.3 (d, 4H), 8.8
(D, 4H), 7.8 (m, 4H), 7.5 (d, 2
H), 7.3 (dd, 2H), 4.9 (m, 2H),
1.3 (d, 12H) λ _max : 643 nm (in methanol)

The compound of the present invention represented by the general formula (I-1), particularly the oxonol compound represented by the general formula (II-1) may be used alone or in combination of two or more. Good. Alternatively, the compound according to the present invention may be used in combination with a dye compound conventionally known as a dye compound for an information recording medium. Such known dye compounds include oxonol dyes, cyanine dyes, phthalocyanine dyes, pyrylium, thiopyrylium dyes, azurenium dyes, squalilium dyes, naphthoquinone dyes, and triphenyl other than those specified in the present invention. Methane pigments and triallylmethane pigments can be mentioned.

The information recording medium of the present invention has the general formula (I)
-1), in particular, a recording layer containing a dye compound represented by the general formula (II-1) is provided on a substrate. In the information recording medium of the present invention, it is preferable that a reflective layer is further provided on the recording layer, and a protective layer is further provided on the reflective layer.

The information recording medium of the present invention can be manufactured, for example, by the following method.

The substrate can be arbitrarily selected from various materials used as a substrate of a conventional information recording medium. As the substrate material, for example, glass; polycarbonate; acrylic resin such as polymethyl methacrylate;
Examples thereof include polyvinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymer; epoxy resins; amorphous polyolefins and polyesters. These may be used in combination, if desired. Note that these materials can be used in the form of a film or a rigid transparent substrate. Among the above materials, polycarbonate is preferred from the viewpoints of moisture resistance, dimensional stability, cost, and the like.

An undercoat layer may be provided on the surface of the substrate on which the recording layer is provided, for the purpose of improving flatness, improving adhesive strength, preventing deterioration of the recording layer, and the like. As the material of the undercoat layer, for example, polymethyl methacrylate, acrylic acid / methacrylic acid copolymer, styrene / maleic anhydride copolymer, polyvinyl alcohol, N-methylolacrylamide, styrene / vinyltoluene copolymer,
Chlorsulfonated polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester,
Examples include polymeric substances such as polyimide, vinyl acetate / vinyl chloride copolymer, ethylene / vinyl acetate copolymer, polyethylene, polypropylene, and polycarbonate; and surface modifiers such as silane coupling agents.

The undercoat layer is prepared by dissolving or dispersing the above substances in an appropriate solvent to prepare a coating solution, and then applying this coating solution to the surface of the substrate using a coating method such as spin coating, dip coating, or extrusion coating. By applying to
Can be formed. The thickness of the undercoat layer is generally 0.00
In the range of 5 to 20 μm, preferably 0.01 to 10
It is in the range of μm.

Further, it is preferable that irregularities (pre-grooves) representing information such as tracking grooves or address signals are formed on the substrate (or undercoat layer). This pregroove is preferably formed directly on the substrate when injection molding or extrusion molding of a resin material such as polycarbonate.

The pre-groove may be formed by providing a pre-groove layer. As a material for the pregroove layer, a mixture of at least one monomer (or oligomer) of acrylic acid monoester, diester, triester and tetraester and a photopolymerization initiator can be used. The formation of the pre-groove layer is performed, for example, by first forming a precisely formed master (stamper).
A mixture of the above-mentioned acrylate and the polymerization initiator is applied thereon, and the substrate is further placed on the application liquid layer.Then, the application layer is cured by irradiating ultraviolet rays through the substrate or the matrix. To fix the substrate and the coating layer. Next, it can be obtained by peeling the substrate from the matrix. The thickness of the pregroove layer is generally 0.05
１００100 μm, preferably 0.1-50 μm
m.

The depth of the pre-groove is preferably in the range of 300 to 2,000 angstroms, and the half width of the pre-groove is preferably in the range of 0.2 to 0.9 μm. The depth of the pre-groove layer is set to 1500
By setting the range to 2,000 Å, the sensitivity can be improved without substantially lowering the reflectance, which is particularly preferable. Therefore, such an optical disk (a recording layer comprising a dye compound represented by the general formula (I-1), particularly a dye compound represented by the general formula (II-1) on a deep pregroove substrate, and a reflection layer An optical disk having a layer formed thereon has a high sensitivity, so that recording can be performed with a low laser power, thereby making it possible to use an inexpensive semiconductor laser or extend the service life of the semiconductor laser.

On the surface of the substrate (or the undercoat layer) (if a pregroove is formed, on the surface), the dye compound represented by the formula (I-1) according to the present invention is provided. ,
In particular, a recording layer comprising a dye compound represented by the general formula (II-1) is provided.

The recording layer may contain various compounds known as a singlet oxygen quencher in order to further improve the light resistance. Representative examples of the quencher include metal complexes, diimmonium salts, aminium salts represented by general formulas (III), (IV) and (V) described in JP-A-3-224793.
There may be mentioned, for example, the nitroso compounds disclosed in JP-A No. 0287 and JP-A-2-300288.

The formation of the recording layer is performed according to the general formula (I-
A dye compound represented by 1), in particular, an oxonol compound represented by the general formula (II-1) and, if desired, a quencher and a binder are added, and the mixture is dissolved in a solvent to prepare a coating solution. The coating is performed by applying a coating solution to the surface of the substrate (or the surface of the undercoat layer) to form a coating film and then drying the coating film.

Solvents for the coating solution for forming the dye recording layer include esters such as butyl acetate and cellosolve acetate; ketones such as methyl ethyl ketone, cyclohexanone and methyl isobutyl ketone;
Chlorinated hydrocarbons such as dichloroethane and chloroform; amides such as dimethylformamide; hydrocarbons such as cyclohexane; ethers such as tetrahydrofuran, ethyl ether and dioxane; ethanol, n-propanol, isopropanol, n-butanol and diacetone alcohol. Alcohols such as 2,2,3,3-tetrafluoropropanol; and glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and propylene glycol monomethyl ether. The above solvents can be used alone or in combination of two or more in consideration of the solubility of the compound used. Various additives such as an antioxidant, a UV absorber, a plasticizer, and a lubricant may be further added to the coating solution according to the purpose.

When a binder is used in the dye recording layer, examples of the binder include natural organic polymers such as gelatin, cellulose derivatives, dextran, rosin, and rubber;
And polyethylene, polypropylene, polystyrene,
Hydrocarbon resins such as polyisobutylene; vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl chloride / polyvinyl acetate copolymer; acrylic resins such as polymethyl acrylate and polymethyl methacrylate; polyvinyl alcohol; Synthetic organic polymers such as chlorinated polyethylene, epoxy resins, butyral resins, rubber derivatives, and initial condensates of thermosetting resins such as phenol / formaldehyde resins can be mentioned. When a binder is used in combination as a material for the recording layer, the amount of the binder used is generally 10 parts by weight or less, preferably 1 part by weight or less, more preferably 0.1 part by weight, based on 1 part by weight of the dye. Part or less. The concentration of the coating solution thus prepared is generally in the range of 0.01 to 10% by weight, preferably in the range of 0.1 to 5% by weight.

Examples of the coating method include a spray method, a spin coating method, a dip method, a roll coating method, a blade coating method, a doctor roll method, and a screen printing method.

The recording layer may be a single layer or a multilayer. The thickness of the recording layer is generally in the range from 20 to 500 nm, preferably in the range from 50 to 300 nm. The recording layer may be provided not only on one side of the substrate but also on both sides.

A reflective layer is usually provided on the recording layer for the purpose of improving the reflectivity during information reproduction. The light-reflective substance that is the material of the reflection layer is a substance having a high reflectance to laser light, and examples thereof include Mg, Se,
Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo,
W, Mn, Re, Fe, Co, Ni, Ru, Rh, P
d, Ir, Pt, Cu, Ag, Au, Zn, Cd, A
1, Ga, In, Si, Ge, Te, Pb, Po, S
Metals and semimetals such as n and Bi or stainless steel can be mentioned. Preferred among these are metals such as Cr, Ni, Pt, Cu, Ag, Au, Al and stainless steel. These substances may be used alone, or in combination of two or more kinds, or as an alloy.

The reflective layer is formed, for example, by depositing the above-mentioned reflective substance.
It can be formed on the recording layer by sputtering or ion plating. The thickness of the reflective layer is generally in the range of 10 to 300 nm, preferably in the range of 50 to 200 nm.

It is preferable that a protective layer is provided on the reflective layer for the purpose of physically and chemically protecting the recording layer and the like. This protective layer may be provided on the side of the substrate on which the recording layer is not provided for the purpose of improving the scratch resistance and the moisture resistance. As a material used for the protective layer, for example,
Examples include inorganic substances such as SiO, SiO ₂ , MgF ₂ , SnO ₂ , and Si ₃ N _4, and organic substances such as thermoplastic resins, thermosetting resins, and UV curable resins.

The protective layer can be formed, for example, by laminating a film obtained by extrusion of a plastic on an adhesive layer and / or on a substrate. Alternatively, it may be provided by a method such as vacuum deposition, sputtering, or coating. In the case of a thermoplastic resin or a thermosetting resin, they can also be formed by dissolving these in an appropriate solvent to prepare a coating solution, applying the coating solution, and drying. In the case of a UV-curable resin, without using a solvent, or after dissolving in an appropriate solvent to prepare a coating solution, apply this coating solution,
It can also be formed by irradiating UV light and curing. In these coating solutions, an antistatic agent,
Various additives such as antioxidants and UV absorbers may be added according to the purpose. The thickness of the protective layer is generally 0.1 to 10
It is in the range of 0 μm.

The information recording medium of the present invention may be a single plate having the above-described configuration, or two substrates having the above-mentioned configuration may be faced each other such that the recording layer is on the inside, and an adhesive or the like may be used. By bonding using, a bonding type information recording medium can also be manufactured. Alternatively, by using a substrate having the above configuration on at least one of the two disk-shaped substrates, by joining via a ring-shaped inner spacer and a ring-shaped outer spacer,
An air sandwich type recording medium can be manufactured.

The information recording medium of the present invention can be manufactured by the above-mentioned method, but is an information recording medium (optical disk) having an extremely high reflectance and excellent recording / reproducing characteristics, and has a light resistance. Has also improved. Since the information recording medium of the present invention has a high reflectance of about 70%, for example, when manufactured as a CD-R type optical disk, it can be reproduced by a commercially available CD player. Therefore, an optical disk having high reflectance and excellent light resistance can be obtained.

[0138] The information recording method is performed, for example, as follows using the above-mentioned information recording medium. First, the information recording medium is set at a constant linear speed (1.2 to 14 m
/ Sec) or rotating at a constant angular speed, or 2
A recording light such as a semiconductor laser beam is irradiated from the substrate side while rotating at a high speed of twice or more. By this light irradiation, a cavity is formed at the interface between the recording layer and the reflective layer (the cavity is formed by deforming the recording layer or the reflective layer, or by deforming both layers), or the substrate is thinned. It is considered that information is recorded when the refractive index is changed due to deformation of the recording layer or discoloration of the recording layer or a change in the association state. As the recording light, a semiconductor laser beam having an oscillation wavelength in the range of 500 nm to 850 nm is used. The wavelength of this laser beam is preferably 500 nm or more,
It is 800 nm or less. The wavelength of the laser beam suitable for CD-R is preferably in the range of 770 to 790 nm.

The information recorded as described above is reproduced by rotating the information recording medium at the same constant linear speed as above.
Alternatively, it can be performed by irradiating a semiconductor laser beam having the same wavelength as at the time of recording from the substrate side while rotating at a high speed of 2 × or more, and detecting the reflected light.

[0140]

EXAMPLES Examples and comparative examples of the present invention will be described below.

[Example 1] 3 g of the oxonol dye compound (Compound No. 1) according to the present invention was
Dissolve in 100 mL of 3-tetrafluoropropanol,
A coating liquid for forming a recording layer was obtained. Spiral pre-groove (track pitch: 1.7 μm, groove width: 0.4 μm, groove depth: 0.16 μm)
Polycarbonate transparent substrate (diameter: 120 mm, thickness: 1.2 mm) manufactured by injection molding on which is formed
On the pre-groove surface of by spin coating,
A dye recording layer was formed. The thickness of the dye recording layer was about 200 nm in the pre-groove.

Next, silver (Ag) was sputtered on the dye recording layer to form a metal reflection layer having a thickness of about 100 nm. Further, a UV-curable resin (UV-curing agent SD-22)
0, Dainippon Ink and Chemicals, Inc. was applied, and a protective layer having a thickness of 5 μm was formed by irradiating ultraviolet rays to obtain an information recording medium according to the present invention (hereinafter, referred to as a sample of the present invention).

[Examples 2 to 18] In Example 1, instead of the oxonol dye compound (Compound No. 1),
An information recording medium according to the present invention (sample of the present invention) was obtained in the same manner as in Example 1, except that the same amount of the oxonol dye compound according to the present invention shown in Table 7 was used.

Comparative Example 1 The procedure of Example 1 was repeated, except that the following oxonol dye compound (Compound No. 1) was used in place of the conventionally known cyanine dye compound (Comparative Compound A). An information recording medium for comparison was obtained in the same manner as in Example 1.

[0145]

Embedded image

Comparative Example 2 The procedure of Example 1 was repeated, except that the following oxonol dye compound (Comparative Compound B) was used in place of the oxonol dye compound (Compound No. 1). Thus, an information recording medium for comparison was obtained.

[0147]

Embedded image

Reference Example 1 The procedure of Example 1 was repeated, except that the following oxonol dye compound (Reference Compound C) was used in the same amount instead of the oxonol dye compound (Compound No. 1). Thus, an information recording medium for comparison was obtained.

[0149]

Embedded image

[Evaluation of Information Recording Medium] (1) Degree of Modulation The information recording medium was irradiated with a semiconductor laser beam having a wavelength of 780 nm, and while tracking the pregroove, the recording laser power at a constant linear velocity of 1.4 m / sec. Was varied in the range of 4 to 9 mW, and 3T and 11T EFM signals were recorded.
Reproduction was performed with a laser power of 0.5 mW, and the modulation degrees of 3T and 11T at the optimum recording power were determined. (2) Reflectance The reflectance of the pre-groove (non-recording area) at the above-mentioned optimum recording power at the time of reproduction was determined.

(3) Light fastness The information recording medium recorded as described above has a Xe lamp (1
(40,000 lux) for 18 hours or 36 hours, and the degree of modulation and reflectance after irradiation were measured in the same manner as described above. Further, the presence or absence of color of the information recording medium after irradiation was visually inspected from the following viewpoints. AA: No fading. BB: The color has faded but the color remains, which is within the allowable range. CC: Little color remains. Table 7 shows the obtained evaluation results.

[0152]

[Table 7]

From the results shown in Table 7 above, the information recording media (optical disks) of Examples 1 to 17 having the recording layer containing the oxonol compound represented by the general formula (I-1) of the present invention were Compared with a comparative optical disc having a recording layer containing a cyanine dye (Comparative Example 1), the change in the degree of modulation is remarkably small even after irradiation with a Xe lamp, and the light resistance is high. You can see that In particular, the optical disk according to the present invention (Examples 1 to 14) using an oxonol compound having the general formula (I-3) or (I-4) as a cation moiety as a recording material has surprisingly excellent light resistance. It can be seen that it has. Also,
Compared with a comparative optical disk (Comparative Example 2 or Reference Example 1) having a recording layer using an oxonol compound having no aromatic ring, both the degree of modulation and the reflectance are higher, and the recording characteristics are significantly improved. I understand.

[0154]

By using the oxonol compound represented by the general formula (I-1) of the present invention, it is possible to obtain an information recording medium having a remarkably improved light fastness while maintaining a high degree of modulation and reflectance. Can be obtained.

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[Procedure amendment]

[Submission date] June 17, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

Embedded image [Wherein, R ¹ and R ² each independently represent a substituent;
^{k +} represents a cation, and p and q each independently represent 0 to
Represents an integer of 4 (provided that p + q ≧ 1), and when each of p and q is 2 or more, two R ¹ and / or two R ² are connected to each other, Each may form a condensed ring together with the benzene ring to which they are attached, and k represents an integer of 1 to 10].

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claim 5

[Correction method] Change

[Correction contents]

Embedded image [Wherein, R ⁷ and R ⁸ each independently represent a group having 1 to 1 carbon atoms.
8 alkyl groups, alkenyl groups having 2 to 18 carbon atoms,
An alkynyl group having 2 to 18 carbon atoms, 6 to 1 carbon atoms
8 aryl groups, aralkyl groups having 7 to 18 carbon atoms,
An acyl group having 2 to 18 carbon atoms, an alkylsulfonyl group having 1 to 18 carbon atoms, an arylsulfonyl group having 6 to 18 carbon atoms, an alkylsulfinyl group having 1 to 18 carbon atoms, and having 2 to 18 carbon atoms Alkoxycarbonyl group, aryloxycarbonyl group having 7 to 18 carbon atoms, alkoxy group having 1 to 18 carbon atoms, 6 carbon atoms
To 18 aryloxy groups, C1 to C18 alkylthio groups, C6 to C10 arylthio groups, C2 to C18 acyloxy groups, C1 to C1
A sulfonyloxy group substituted with a hydrocarbon group having 8 carbon atoms, a carbamoyloxy group optionally substituted with a hydrocarbon group having 1 to 18 carbon atoms, or a carbamoyloxy group substituted with a hydrocarbon group having 1 to 18 carbon atoms. Good amino group, 1 to 18 carbon atoms
An amide group which may be substituted with a hydrocarbon group, an ureido group which may be substituted with a hydrocarbon group having 1 to 18 carbon atoms, or an amide group which may be substituted with a hydrocarbon group having 1 to 18 carbon atoms. A good carbamoyl group, a sulfamoyl group optionally substituted with a hydrocarbon group having 1 to 18 carbon atoms, a halogen atom, a hydroxyl group, a mercapto group, a nitro group, a cyano group, a carboxyl group, a sulfo group, or a 4- to 7-membered Represents a heterocyclic group (these substituents may be further substituted with any of the above-mentioned substituents, and the alkyl group contained in these substituents may be any of linear, branched or cyclic X ^{k +} represents a cation, p and q each independently represent an integer of 0 to 4 (provided that p + q ≧ 1), and p and q each represent 2 or more. In case Represents two R ⁷ and / or two R ^7
8 may be linked to each other to form a condensed ring together with the benzene ring to which each is attached, and k represents an integer of 1 to 10].

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

[0014]

Embedded image

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0053

[Correction method] Change

[Correction contents]

[0053]

Embedded image

Claims (7)

[Claims] An information recording medium comprising a substrate and a recording layer on which information can be recorded by a laser beam is provided.
The information recording medium, wherein the recording layer contains a dye compound represented by the following general formula (I-1): [Wherein, R ¹ and R ² each independently represent a substituent;
^{k +} represents a cation, and p and q each independently represent 0-4
(Where p + q ≧ 1), and when p and q are each 2 or more, two R ¹ and / or two R ² are connected to each other, and May form a condensed ring together with the benzene ring to which it is attached, and k represents an integer of 1 to 10.] 2. The information recording medium according to claim 1, wherein X ^{k +} is a quaternary ammonium ion. 3. The information recording medium according to claim 1, wherein X ^{k +} is an onium ion represented by the following general formula (I-2). Embedded image [Wherein, R ³ and R ⁴ each independently represent a substituent;
⁵ and R ⁶ are each independently an alkyl group, an alkenyl group,
Represents an alkynyl group, an aralkyl group, an aryl group or a heterocyclic group, wherein R ³ and R ⁴ , R ³ and R ⁵ , R ⁴ and R ⁶ , and / or R ⁵ and R ⁶ are connected to each other to form a ring; R and s each independently represent an integer of 0-4. ] 4. The information recording medium according to claim 1, wherein a reflective layer is further provided on the recording layer. 5. An oxonol compound represented by the general formula (II-1): [Wherein, R ⁷ and R ⁸ each independently represent a group having 1 to 1 carbon atoms.
8 alkyl groups, alkenyl groups having 2 to 18 carbon atoms,
An alkynyl group having 2 to 18 carbon atoms, 6 to 1 carbon atoms
8 aryl groups, aralkyl groups having 7 to 18 carbon atoms,
An acyl group having 2 to 18 carbon atoms, an alkylsulfonyl group having 1 to 18 carbon atoms, an arylsulfonyl group having 6 to 18 carbon atoms, an alkylsulfinyl group having 1 to 18 carbon atoms, and having 2 to 18 carbon atoms Alkoxycarbonyl group, aryloxycarbonyl group having 7 to 18 carbon atoms, alkoxy group having 1 to 18 carbon atoms, 6 carbon atoms
To 18 aryloxy groups, C1 to C18 alkylthio groups, C6 to C10 arylthio groups, C2 to C18 acyloxy groups, C1 to C1
A sulfonyloxy group substituted with a hydrocarbon group having 8 carbon atoms, a carbamoyloxy group optionally substituted with a hydrocarbon group having 1 to 18 carbon atoms, or a carbamoyloxy group substituted with a hydrocarbon group having 1 to 18 carbon atoms. Good amino group, 1 to 18 carbon atoms
An amide group which may be substituted with a hydrocarbon group, an ureido group which may be substituted with a hydrocarbon group having 1 to 18 carbon atoms, or an amide group which may be substituted with a hydrocarbon group having 1 to 18 carbon atoms. A good carbamoyl group, a sulfamoyl group optionally substituted with a hydrocarbon group having 1 to 18 carbon atoms, a halogen atom, a hydroxyl group, a mercapto group, a nitro group, a cyano group, a carboxyl group, a sulfo group, or a 4- to 7-membered Represents a heterocyclic group (these substituents may be further substituted with any of the above-mentioned substituents, and the alkyl group contained in these substituents may be any of linear, branched or cyclic X ^{k +} represents a cation, p and q each independently represent an integer of 0 to 4 (provided that p + q ≧ 1), and p and q are each 2 or more. in case of Two of R ⁷ and / or two R
⁸ may be linked to each other to form a condensed ring together with the benzene ring to which they are attached, and k represents an integer of 1 to 10]. 6. The oxonol compound according to claim 5, wherein X ^{k +} is an ion represented by the following general formula (II-2): [Wherein, R ⁹ and R ¹⁰ each independently represent a carbon atom of 1 to
18 alkyl groups, alkenyl groups having 2 to 18 carbon atoms, alkynyl groups having 2 to 18 carbon atoms, 6 carbon atoms
To 18 aryl groups, aralkyl groups having 7 to 18 carbon atoms, acyl groups having 2 to 18 carbon atoms, and 1 to 1 carbon atoms
8 alkylsulfonyl groups, arylsulfonyl groups having 6 to 18 carbon atoms, alkylsulfinyl groups having 1 to 18 carbon atoms, alkoxycarbonyl groups having 2 to 18 carbon atoms, aryloxycarbonyl groups having 7 to 18 carbon atoms An alkoxy group having 1 to 18 carbon atoms, 6 carbon atoms
To 18 aryloxy groups, C1 to C18 alkylthio groups, C6 to C10 arylthio groups, C2 to C18 acyloxy groups, C1 to C1
A sulfonyloxy group substituted with a hydrocarbon group having 8 carbon atoms, a carbamoyloxy group optionally substituted with a hydrocarbon group having 1 to 18 carbon atoms, or a carbamoyloxy group substituted with a hydrocarbon group having 1 to 18 carbon atoms. Good amino group, 1 to 18 carbon atoms
An amide group which may be substituted with a hydrocarbon group, an ureido group which may be substituted with a hydrocarbon group having 1 to 18 carbon atoms, or an amide group which may be substituted with a hydrocarbon group having 1 to 18 carbon atoms. A good carbamoyl group, a sulfamoyl group optionally substituted with a hydrocarbon group having 1 to 18 carbon atoms, a halogen atom, a hydroxyl group, a mercapto group, a nitro group, a cyano group, a carboxyl group, a sulfo group, or a 4- to 7-membered Represents a heterocyclic group (these substituents may be further substituted with any of the above-mentioned substituents, and the alkyl group contained in these substituents may be any of linear, branched or cyclic) a may be) is, each independently R ¹¹ and R ^12, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, carbon atoms 7-18 aralkyl group, an aryl group or a 4-7-membered heterocyclic ring group, having 6 to 18 carbon atoms (more these groups, substituted by a substituent which corresponds to R ⁹ and R ¹⁰ of the R ⁹ and R ¹⁰ , R ⁹ and R ¹¹ , R ¹⁰ and R ¹² , and / or R ¹¹ and R ¹²
May be linked to each other to form a 4- to 7-membered ring,
And s each independently represent an integer of 0 to 4]. 7. An information recording medium in which a recording layer on which information can be recorded by a laser beam is provided on a substrate,
An information recording medium, wherein the recording layer contains the oxonol compound according to any one of claims 5 and 6.