JPH11129624A - Information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information recording medium (optical disk) having a dye recording layer including an organic dye having an improved light resistance without impairing recording/reproducing characteristics. SOLUTION: In the information recording medium comprising a recording layer for recording information on a base plate by a laser beam, the recording layer contains an organic dye and a radical anionic salt of a tetracyanoquinodimethane and the like represented by the following general formula (I) [wherein R<1> , R<2> , R<3> and R<4> are independently a hydrogen atom or a substituent (however, R<1> and R<2> , and R<3> and R<4> may be coupled to form an unsaturated condensed ring), M<k+> is a metal ion, metal complex ion or onium ion, 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 high energy density laser light.

[0002]

2. Description of the Related Art An information recording medium using a high energy density beam such as a laser beam has been developed and put into practical use.
This information recording medium is called an optical disk (CD), and includes a video disk, an audio disk, a large-capacity still image file and a large-capacity computer disk.
It is used as a memory. Among these optical discs, optical discs that can record information only once are:
Recordable CD (so-called CD-R) or DRAW (Dire
ct Read After Write) type, and its use is expanding with the recent spread of personal computers. A CD-R type optical disk has an advantage that necessary information can be recorded from a computer or the like using a CD-R recording device, and that the CD thus created can be reproduced by a commercially available CD player. .

[0003] A CD-R type optical disk has, as its basic structure, a disk-shaped substrate made of glass, synthetic resin, or the like, and a metal or semimetal such as Bi, Sn, In, Te provided thereon, or a cyanine-based optical disk. A recording layer made of a metal complex-based or quinone-based dye. In general, an intermediate layer made of a polymer substance is provided on the surface of the substrate on which the recording layer is provided, from the viewpoint of improving the flatness of the substrate, improving the adhesive force with the recording layer, or improving the sensitivity of the optical disc. Is often done.

[0004] Writing (recording) and reading (reproduction) of information on an optical disk is usually performed by the following method. Writing of information is performed by irradiating the optical disk with a laser beam, and the irradiated portion of the recording layer absorbs the light and locally raises the temperature, causing a physical or chemical change (for example, a pit or the like). Information) is recorded by altering its optical properties. Reading of information is also performed by irradiating the optical disk with a laser beam, and information is reproduced by detecting reflected light or transmitted light corresponding to a change in the optical characteristics of the recording layer.

As the recording material for forming the recording layer of such an information recording medium, metals and dyes are known as described above. Information recording media using dyes have advantages in the characteristics of the recording medium itself, such as high sensitivity compared to recording materials such as metals, and in addition to the fact that the recording layer can be easily formed by a coating method. It also has great advantages. However, a recording layer made of a dye generally has disadvantages such as a low reflectance, a low C / N ratio of a reproduced signal, and the like, and a drawback that the dye recording layer is easily deteriorated with time by light irradiation. doing.

As a recording layer made of a dye having improved reflectance and C / N, Japanese Patent Application Laid-Open No. 40-40382 discloses an optical disk having a recording layer made of a cyanine dye having a benzoindolenine skeleton. . As a similar recording layer, JP-A 64-40387 discloses a dicarbocyanine dye (having five methine chains) having a benzoindolenine skeleton (a structure in which a benzene ring is condensed with an indolenine skeleton). An optical disc provided with a recording layer comprising a tricarbocyanine dye having a renin skeleton (seven methine chains) is disclosed. This is because while maintaining the high reflectance of the dicarbocyanine dye having a benzoindolenine skeleton, the tricarbocyanine dye having an indolenine skeleton is used in combination with C /
N is intended to be improved.

In order to improve the reflectance, it is common practice to further provide a reflective layer on the dye recording layer. One such example is Nikkei Electronics (10
7, page 23, issued January 23, 1989).
According to this, the dye used in the recording layer of the recording medium is unknown, but the recording method is such that the dye is melted by laser absorption of the dye recording layer, and accordingly, the plastic substrate is heated and the substrate is heated. It is disclosed that the process is performed by forming a pit by swelling on the recording layer side. This reflection layer is a deposited film of gold. According to the study of the present inventor, if the cyanine dye having the benzoindolenine skeleton is used for the dye recording layer, an optical disc having a relatively high C / N and an improved reflectance can be obtained. Is done.

However, an information recording medium having such a dye recording layer is not completely satisfactory in terms of light resistance, and therefore, a singlet oxygen quencher is generally added. For example, JP-A-2-300288 discloses an optical disk having a recording layer comprising a cyanine dye and a nitroso compound as a recording layer having improved light resistance. Similarly, as a recording layer having similarly improved light fastness, a recording layer comprising a dicarbocyanine dye having a benzoindolenine skeleton (5 methine chains) and a nickel complex is provided in JP-A-4-146189. An optical disk is disclosed. These are intended to improve the light fastness of the cyanine dye by using together a nitroso compound or a nickel complex generally well known as a singlet oxygen quencher. However, a large amount of the nitroso compound is required to improve the light resistance, but the addition of the nitroso compound significantly lowers the reflectivity. Nickel complexes are environmentally undesirable compounds.

Japanese Patent Application Laid-Open No. 63-64794 proposes an optical information recording medium having a recording layer containing a cyanine dye and an electron accepting compound and having improved light fastness. As a specific example, a tricarbocyanine dye having a benzoindolenine skeleton or the like (seven methine chains) is described as a cyanine dye. Cyanoquinodimethane (TCNQ) and tetracyanoethylene have been described. However, the present inventors have found that it is not always possible to say that sufficient light fastness can be obtained even with a combination of a cyanine dye and an electron-accepting compound as described above. In particular, it was found that the light fastness after recording (archival light fastness) was not sufficient.

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 it is advantageous for high density. Therefore, the development of an optical disk for performing recording and reproduction using a laser beam having a wavelength shorter than 780 nm, which is generally used, has been promoted. For example, a write-once digital video disk (so-called DVD-R) has been developed. ) Has been proposed. The DVD-R type optical disk performs recording and reproduction by irradiating a visible laser beam (usually a laser beam having a wavelength in a range of 600 nm to 700 nm), and is compared with the above-mentioned CD-R type optical disk. It is said that higher density recording is possible.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide an information recording medium (optical disk) having a dye recording layer containing an organic dye having improved light fastness without impairing the recording / reproducing characteristics.

[0012]

According to the research of the present inventors,
The addition of a radical anion salt of a tetracyanoquinodimethane represented by the above general formula (I) to the dye recording layer made of an organic dye as an anti-fading agent, in particular, the archival light resistance is remarkably improved. Was found. That is, according to the study of the present inventor, even when a radical anion salt of the tetracyanoquinodimethanes is added in a large amount, the reflectance does not decrease, and the compound has excellent solubility in a solvent. It has been found that the addition amount can be increased, and thus the light resistance can be remarkably improved.

According to the present invention, in an information recording medium comprising a substrate and a recording layer on which information can be recorded by a laser beam, the recording layer is represented by an organic dye and the following general formula (I). And a radical anion salt of tetracyanoquinodimethanes.

[0014]

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[In the above formula, R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or a substituent (provided that R ¹ and R ² , and R ³ and R ⁴ are each linked May form an unsaturated fused ring), M ^{k +} represents a metal ion, a metal complex ion or an onium ion, and k is 1 to
Represents an integer of 10. ]

The information recording medium of the present invention preferably has the following aspects. (1) In the general formula (I), M ^{k +} represents an ammonium ion, a pyridinium ion, an anilinium ion,
It is at least one onium ion selected from the group consisting of a quinolinium ion, a morpholinium ion, and an ion represented by the following formula.

[0017]

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(2) In the above (1), M ^{k +} is at least one onium ion selected from the group consisting of ammonium ions, pyridinium ions, and anilinium ions. (3) In the general formula (I), R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aralkyl group, a cyano group, an alkylthio group, Represents an amide group, a sulfonamide group, a ureido group, an acyl group, or an alkoxycarbonyl group. (4) In the general formula (I), R ¹ and R ² , and R
^The unsaturated condensed ring formed by ³ and R ⁴ each independently represents a benzene ring, a naphthalene ring, a pyridine ring, a pyrazine ring, a thiazane ring, or a selenazan ring. (5) In the general formula (I), k is an integer of 1 to 4 (more preferably, 1 or 2). (6) The organic dye is a cyanine dye represented by the following general formula (II). General formula (II):

[0019]

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[In the formula, Z ¹ and Z ² each independently represent an atomic group necessary for forming a 5- or 6-membered nitrogen-containing heterocyclic ring, and R ¹¹ and R ¹² each independently represent an alkyl group L ¹ , L ² , L ³ , L ⁴ and L ⁵ are each independently:
Represents an optionally substituted methine group, n1 and n2 each independently represent 0 or 1, p and q each independently represent 0
Or 1, M1 represents a charge neutralizing counter ion, and m1 represents a number of 0 or more necessary to neutralize the charge in the molecule. (7) The cyanine dye represented by the general formula (II) is a compound represented by the following general formula (II-1). General formula (II-1):

[0021]

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[In the formula, Z ³ and Z ⁴ each independently represent an atomic group required for forming a benzene ring or a naphthalene ring, which may have a substituent, and R ¹³ and R ¹⁴ , R
¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent an alkyl group having 1 to 8 carbon atoms; R ¹⁹ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, Number 6
Represents an aryl group having 10 to 10 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a heterocyclic group, a halogen atom, a carbamoyl group having 1 to 8 carbon atoms, M2 ^m2- represents an anion, and m2 represents 1 or 2
Represents ]

(8) The cyanine dye represented by the general formula (II-1) is a compound represented by the following general formula (II-2) or (II-3). General formula (II-2):

[0024]

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Formula (II-3):

[0026]

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[In the formula, R ²⁰ , R ²¹ and R ²² have the same meaning as R ¹³ in the formula (II-1), and R ²³ has the same meaning as R ¹⁹ in the formula (II-1). , X represents one substituent selected from the group consisting of a hydrogen atom, a methyl group, a chlorine atom, a fluorine atom, a methoxy group, an ethoxy group, a sulfonamide group, and an ethoxycarbonyl group, and M3 represents the general formula ( M2 and m3 in II-1) have the same meanings as m2 in formula (II-1). (9) A light reflection layer is further provided on the recording layer. (10) A light reflection layer and a protective layer are further provided on the recording layer in this order.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION The information recording medium of the present invention has a recording layer containing an organic dye on a substrate, and the dye recording layer is formed of a tetracyanoquinoline represented by the following general formula (I). It is characterized by containing a radical anion salt of methanes.

[0029]

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In the above formula, R ¹ , R ² , R ³ and R
⁴ represents a hydrogen atom or a substituent each independently. Also R
¹ and R ² , and R ³ and R ⁴ may be linked to each other to form an unsaturated condensed ring. M ^{k +} represents a metal ion, a metal complex ion or an onium ion, and k represents an integer of 1 to 10.

Hereinafter, the general formula (I) which is a feature of the present invention will be described.
The radical anion salt of a tetracyanoquinodimethane represented by the following formula will be described. In the general formula (I), the radical anion salt of tetracyanoquinodimethanes comprises an anionic component (anion portion) and a cationic component (cation portion).

First, the anion portion will be described in detail. In the above formula (I), R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or a substituent. R ¹ and R
^The substituent represented by ² , R ³ and R ⁴ is a halogen atom,
Or a substituent formed by combining at least two atoms of a hydrogen atom, a carbon atom, an oxygen atom, a nitrogen atom or a sulfur atom, and specifically, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, Ring group, cyano group, nitro group, mercapto group, hydroxy group, alkoxy group, aryloxy group, alkylthio group, arylthio group, acyloxy group, amino group, alkylamino group,
Amide group, sulfonamide group, sulfamoylamino group, alkoxycarbonylamino group, alkoxysulfonylamino group, ureido group, thioureido group, acyl group, alkoxycarbonyl group, carbamoyl group, alkylsulfonyl group, alkylsulfinyl group, sulfamoyl group, Examples thereof include a carboxyl group (including a salt) and a sulfo group (including a salt). These may be further substituted with these substituents.

Examples of the substituents represented by R ^{1 to} R ⁴ will be described in more detail. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom. The alkyl group is an alkyl group having 1 to 18 carbon atoms (preferably 1 to 6 carbon atoms) which may have a linear, branched or cyclic substituent, for example, methyl, ethyl, propyl, isopropyl , T-butyl, cyclopentyl, cyclohexyl, 2-hydroxyethyl, 3-hydroxypropyl, 4-hydroxybutyl, 3-methoxypropyl, 2-aminoethyl, acetamidomethyl,
2-acetamidoethyl, carboxymethyl, 2-carboxyethyl, 2-sulfoethyl, ureidomethyl, 2
-Ureidoethyl, carbamoylmethyl, 2-carbamoylethyl, 3-carbamoylpropyl, pentyl, hexyl, octyl, decyl, undecyl, dodecyl, hexadecyl, octadecyl. The alkenyl group has 2 to 18 carbon atoms (preferably 2 to 2 carbon atoms).
6) a linear, branched or cyclic alkenyl group,
Examples include vinyl, allyl, 1-propenyl, 2-pentenyl, 1,3-butadienyl, 2-octenyl, and 3-dodecenyl.

The aryl group is an aryl group having 6 to 10 carbon atoms which may have a substituent, and examples thereof include phenyl, naphthyl, p-dibutylaminophenyl and p-methoxyphenyl. The aralkyl group is
It is an aralkyl group having 7 to 10 carbon atoms, such as benzyl. A heterocyclic group is composed of a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom.
A 6-membered saturated or unsaturated heterocyclic group, and the number of heteroatoms and the kind of element constituting the ring may be one or more. For example, furyl, benzofuryl, pyranyl, pyrrolyl, imidazolyl , Isoxazolyl, pyrazolyl, benzotriazolyl, pyridyl, pyrimidyl, pyridazinyl, thienyl, indolyl, quinolyl,
Heterocyclic groups such as phthalazinyl, quinoxalinyl, pyrrolidinyl, pyrrolinyl, imidazolidinyl, imidazolinyl, pyrazolidinyl, piperidyl, piperazinyl, indolinyl, and morpholinyl can be mentioned.

The alkoxy group is an alkoxy group which may have a substituent having 1 to 18 carbon atoms (preferably having 1 to 6 carbon atoms), for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy, -Methoxyethoxy, 2-methanesulfonylethoxy, pentyloxy,
Hexyloxy, octyloxy, undecyloxy,
Dodecyloxy, hexadecyloxy and octadecyloxy can be mentioned. The aryloxy group is an aryloxy group which may have a substituent having 6 to 10 carbon atoms, and examples thereof include phenoxy and p-methoxyphenoxy. The alkylthio group has 1 carbon atom.
To 18 (preferably 1 to 6 carbon atoms) alkylthio groups such as methylthio, ethylthio, octylthio, undecylthio, dodecylthio, hexadecylthio, and octadecylthio. The arylthio group is an arylthio group having 6 to 10 carbon atoms which may have a substituent, and examples thereof include phenylthio and 4-methoxyphenylthio. The acyloxy group is an acyloxy group having 1 to 18 carbon atoms (preferably 1 to 6 carbon atoms), and examples thereof include acetoxy, propanoyloxy, pentanoyloxy, octanoyloxy, dodecanoyloxy, and octadecanoyloxy. it can.

The alkylamino group is an alkylamino group having 1 to 18 carbon atoms (preferably 1 to 6 carbon atoms), for example, methylamino, dimethylamino, diethylamino, dibutylamino, octylamino, dioctylamino, undecyl Amino can be mentioned. The amide group is an amide group having 1 to 18 carbon atoms (preferably having 1 to 6 carbon atoms), for example, acetamido, acetylmethylamino, acetyloctylamino, acetyldecylamino, acetylundecylamino, acetyloctadecylamino, and propa. Mention may be made of noylamino, pentanoylamino, octanoylamino, octanoylmethylamino, dodecanoylamino, dodecanoylmethylamino and octadecanoylamino. The sulfonamide group is a sulfonamide group which may have a substituent having 1 to 18 carbon atoms (preferably 1 to 6 carbon atoms), for example, methanesulfonamide, ethanesulfonamide,
Mention may be made of propylsulfonamide, 2-methoxyethylsulfonamide, 3-aminopropylsulfonamide, 2-acetamidoethylsulfonamide, octylsulfonamide, and undecylsulfonamide.

The alkoxycarbonylamino group is an alkoxycarbonylamino group having 2 to 18 carbon atoms (preferably having 2 to 6 carbon atoms), for example, methoxycarbonylamino, ethoxycarbonylamino, octyloxycarbonylamino, undecyloxycarbonyl Amino can be mentioned. An alkoxysulfonylamino group is
It is an alkoxysulfonylamino group having 1 to 18 carbon atoms (preferably 1 to 6 carbon atoms), and examples thereof include methoxysulfonylamino, ethoxysulfonylamino, octyloxysulfonylamino, and undecyloxysulfonylamino. The sulfamoylamino group is an unsubstituted sulfamoylamino group and a group having 1 to 1 carbon atoms.
18 (preferably 1 to 6 carbon atoms) sulfamoylamino group, for example, methylsulfamoylamino, dimethylsulfamoylamino, ethylsulfamoylamino, propylsulfamoylamino, octylsulfamoylamino , And undecylsulfamoylamino.

The ureido group is a ureido group which may have a substituent having 1 to 18 carbon atoms (preferably having 1 to 6 carbon atoms). Examples thereof include ureido, methylureide, N,
N-dimethylureide, octylureide and undecylureide can be mentioned. The thioureido group is a thioureido group which may have a substituent having 1 to 18 carbon atoms (preferably 1 to 6 carbon atoms), for example, thioureide, methylthioureido, N, N-dimethylthioureido, octylthio Ureido and undecylthioureide. The acyl group has 1 to 18 carbon atoms.
It is an acyl group (preferably having 1 to 6 carbon atoms) such as acetyl, benzoyl, octanoyl, decanoyl, undecanoyl and octadecanoyl. The alkoxycarbonyl group is an alkoxycarbonyl group having 2 to 18 carbon atoms (preferably having 2 to 6 carbon atoms), and examples thereof include methoxycarbonyl, ethoxycarbonyl, octyloxycarbonyl, and undecyloxycarbonyl.

The carbamoyl group is a carbamoyl group which may have a substituent having 1 to 18 carbon atoms (preferably, 1 to 6 carbon atoms), for example, carbamoyl, N, N-
Dimethylcarbamoyl, N-ethylcarbamoyl, N-
Octylcarbamoyl, N, N-dioctylcarbamoyl and N-undecylcarbamoyl can be mentioned. The alkylsulfonyl group is an alkylsulfonyl group which may have a substituent having 1 to 18 carbon atoms (preferably 1 to 6 carbon atoms), for example, methanesulfonyl, ethanesulfonyl, 2-chloroethanesulfonyl, octanesulfonyl And undecanesulfonyl. The alkylsulfinyl group is an alkylsulfinyl group having 1 to 18 carbon atoms (preferably 1 to 6 carbon atoms), and examples thereof include methanesulfinyl, ethanesulfinyl, and octanesulfinyl. The sulfamoyl group is a sulfamoyl group or a carbon number of 1 to 1.
8 (preferably 1 to 6 carbon atoms) having a substituent, for example, dimethylsulfamoyl,
Examples include ethylsulfamoyl, octylsulfamoyl, dioctylsulfamoyl, and undecylsulfamoyl.

The above R ¹ and R ² or R ³ and R ⁴ are
When these are both substituents, they may be linked to each other to form an unsaturated condensed ring. Examples of the unsaturated condensed ring include a benzene ring, a naphthalene ring, a pyridine ring, a pyrazine ring, a furazane ring, a thiazane ring, and a selenazan ring. This unsaturated condensed ring may be further substituted by a substituent, and examples of the substituent include the substituents described as specific examples of R ^{1 to} R ⁴ .

R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a halogen atom, a cyano group, an alkyl group, an aralkyl group, an alkoxy group, an alkylthio group, a carbonamide group, a sulfonamide group, It is preferably a ureido group, an acyl group, or an alkoxycarbonyl group. Particularly preferably, the above R ¹ , R ² , R ³ and R ⁴
Is independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms,
It is an alkoxy group having 1 to 8 carbon atoms. Most preferably,
When R ¹ , R ² , R ³ and R ⁴ are all hydrogen atoms,
R ² and R ³ are hydrogen atoms, and R ¹ and R ⁴ are both alkyl groups (particularly methyl) or alkoxy groups (particularly methoxy). R ¹ and R ² or R ³
And a ring formed by linking R ⁴ with a benzene ring,
Preferred are a naphthalene ring, a pyrazine ring, a thiazane ring, and a selenazan ring.

Next, the cation portion will be described in detail. Examples of the cation represented by M ^{k +} include a metal ion such as a sodium ion, a potassium ion, a lithium ion, a cesium ion, a barium ion, an iron ion, and a copper ion, a metal complex ion, and an ammonium ion, a pyridinium ion, and an anilinium. Ion, quinolinium ion, morpholinium ion, an ion represented by the following formula:

[0043]

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And onium ions such as oxonium ion, sulfonium ion, phosphonium ion, selenonium ion and iodonium ion.
M ^{k +} is preferably a metal ion or an onium ion. The onium ion is preferably an ammonium ion, a pyridinium ion, an anilium ion, a quinolinium ion, a morpholinium ion, or an ion represented by the above formula 12, more preferably an ammonium ion, a pyridinium ion, Or an anilinium ion, particularly preferably an ammonium ion. k represents an integer of 1 to 10, preferably 1 to 4, particularly preferably 1 or 2.

The radical anion salt of a tetracyanoquinodimethane compound represented by the general formula (I) used in the present invention is represented by an anion part (represented by "A-") and a cation part (represented by "C-"). The preferred specific examples of "" are described below.

[0046]

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[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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[0055]

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[0056]

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[0057]

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Specific examples of the compounds (anti-fading agents) used in the present invention are shown in Table 1 below. In Table 1,
The compound example according to the present invention is obtained by combining an anion part (A) and a cation part (C). In the general formula (I), the anion part is represented by the following general formula (III). It may contain neutral tetracyanoquinodimethanes and may be an anion radical in the whole molecule. General formula (III)

[0059]

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In the formula (III), R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are R ¹ , R ² , R ³ and R ³ in the anion radical salt of tetracyanoquinodimethane represented by the general formula (I). R ⁴
And their preferred ranges are also the same.

Hereinafter, the compound I-1 according to the present invention will be described by way of examples. Compound I-1 [anion moiety (A-1) /
The compound example represented by the cation portion (C-2)] is represented by the following formula. The same applies to compound examples of the compound I-2 and thereafter.

[0062]

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[0063]

Table 1 Table 1 Compounds Compound (I) Anion part Cation Part (I) Anion part Cation part ────────────────────────────────────1A-1C- 22 A-1 C-123 A-1 C-254 A-1 C-475 A-1 C-656 A-1 C-787 A-1 C-9888 A-1 C-6 9 A-6 C-3 10 A-6 C-80 11 A-6 C-120 12 A-13 C-313 A-13 C-12 14 A-13 C-915 A-13 C-2316 A-13 C-62 17 A-17 C-318 A-17 C-78 19 A-17 C-104 20 A-26 C-2 ─────────────── ２１ 21 A-26 C-49 22 A-26 C-80 23 A-26 C-101 24 A-28 C-125 A-28 C-826 A-28 C-78 27 A-28 C-118 28 A-32 C-329 A-32 C-98 30 A-35 C-331 A-35 C-94 32 A -35 C-104 33 A-37 C-334 A-37 C-1235 A-37 C-94 36 A-37 C-9837 A-41 C-338 A-41 C-1339 A- 41 C-80 40 A-41 C-106 41 A-45 C-242 A-45 C-843 A-45 C-80 44 A-45 C-6 − ─────────────────────────

Compound I-45 [anion moiety (A-1) /
Cation moiety (C-78)]

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Compound I-46 [anion moiety (A-1) /
Cation moiety (C-14)]

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Compound I-47 [anion moiety (A-1) /
Cation part (C-98)]

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Compound I-48 [anion moiety (A-13)
/ Cation part (C-122)]

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The compound represented by the general formula (I) according to the present invention is described, for example, in J. Am. Chem. Soc., 84, 3374 (1)
962), Synthetic Organic Chemistry, Vol. 46, 638 (1988)
It can be easily synthesized according to a general synthesis method such as In addition, the following synthesis examples and methods based thereon can also be employed.

[Synthesis Example] Synthesis of Compound I-7 [Anion Part (A-1) / Cation Part (C-98)] 0.4 g of tetracyanoquinodimethane and 1.1 g of morpholine hydrochloride were dissolved in 60 mL of acetonitrile. After being left under reflux for 30 minutes, the resulting red-purple crystals were filtered off, washed with acetonitrile, and dried under reduced pressure to obtain 0.15 g of the desired product.

Compound I-45 [anion moiety (A-1)
/ Synthesis of cation moiety (C-78) 0.5 g of tetracyanoquinodimethane and 0.32 g of tetraethylammonium iodide were dissolved in 50 mL of acetonitrile, and the mixture was refluxed for 30 minutes and cooled with ice for 30 minutes. Was filtered, washed with acetonitrile, and dried under reduced pressure to obtain 0.2 g of the desired product.

The radical anion salt of a tetracyanoquinodimethane represented by the general formula (I) used in the present invention can be used alone or in combination with another known quencher. it can. A typical example of a combined quencher is disclosed in Japanese Patent Application Laid-Open No. 3-224793.
Formula (III), (IV) or (V) described in
Metal complexes, diimmonium salts, aminium salts, JP-A-2-300287 and JP-A-2-30
There may be mentioned, for example, the nitroso compounds described in JP-A No. 0288. Particularly preferred as a combined quencher is a metal complex (for example, PA-1006).
(Manufactured by Mitsui Toatsu Fine Co., Ltd.) or diimmonium salts (for example, IRG-023 and IRG-022 (all manufactured by Nippon Kayaku Co., Ltd.)), and most preferably diimmonium salts. These quenchers can be used in combination of two or more depending on the purpose.

The addition amount of the radical anion salt of the tetracyanoquinodimethane represented by the above general formula (I) is preferably in the range of 1 to 100 parts by weight based on 100 parts by weight of the organic dye. The range is more preferably from 50 to 50 parts by weight, particularly preferably from 1 to 25 parts by weight, and most preferably from 1 to 10 parts by weight. Further, the addition amount of the quencher is preferably in the range of 1 to 100 parts by weight, more preferably in the range of 1 to 50 parts by weight, based on 100 parts by weight of the organic dye,
It is particularly preferably in the range of 1 to 25 parts by weight, and most preferably in the range of 1 to 10 parts by weight.

Next, the organic dye used in the present invention will be described. Examples of usable organic dyes include, for example, cyanine dyes, merocyanine dyes, phthalocyanine dyes, oxonol dyes, pyrylium dyes, thiopyrylium dyes, triarylmethane dyes, polymethine dyes, squarium dyes, and azurenium dyes Pigment,
Examples include naphthoquinone dyes, anthraquinone dyes, indophenol dyes, indoaniline dyes, aminium / diimmonium dyes, and pyran dyes.

In the present invention, it is preferable to use a symmetric or asymmetric cyanine dye represented by the following general formula (II).

[0075]

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In the formula, Z ¹ and Z ² each independently represent an atom group necessary for forming a 5- or 6-membered nitrogen-containing heterocyclic ring. R ¹¹ and R ¹² each independently represent an alkyl group.
L ¹ , L ² , L ³ , L ⁴ and L ⁵ each independently represent a methine group which may be substituted. n1 and n2 each independently represent 0 or 1. p and q each independently represent 0 or 1. M1 represents a charge neutralizing counter ion, and m1 represents a number of 0 or more necessary to neutralize the charge in the molecule.

The cyanine dye represented by formula (II) used in the present invention will be described in detail below. In the above formula (II), Z ¹ and Z ² each independently represent an atom group necessary for forming a 5- or 6-membered nitrogen-containing heterocyclic ring. p and q each independently represent 0 or 1. Preferably, p and q are both 0. The nucleus formed by Z ¹ or Z ² includes a 3,3-dialkylindolenine nucleus, a 3,3-dialkylbenzoindolenine nucleus,
Thiazole nucleus, benzothiazole nucleus, naphthothiazole nucleus, thiazoline nucleus, oxazole nucleus, benzoxazole nucleus, naphthoxazole nucleus, oxazoline nucleus, selenazole nucleus, benzoselenazole nucleus, naphthoselenazole nucleus, selenazoline nucleus, tellurazole nucleus, benzotellurazole Nucleus, naphthotellurazole nucleus, tellrazoline nucleus, imidazole nucleus, benzimidazole nucleus, naphthymidazole nucleus, pyridine nucleus, quinoline nucleus, isoquinoline nucleus, imidazo [4,5-b] quinoxalin nucleus, oxadiazole nucleus, thiadiazole nucleus, tetrazole A nucleus, and a pyrimidine nucleus. The 5- or 6-membered nitrogen-containing heterocyclic ring mentioned here may have a substituent (may be a substituent atom), if possible.

Examples of the above substituent include a halogen atom or a substituent composed of a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom and a hydrogen atom. Specifically, halogen atoms, alkyl groups, alkenyl groups, aryl groups, aralkyl groups, heterocyclic groups, cyano groups, nitro groups, mercapto groups, hydroxy groups, alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, acyloxy groups Group, amino group, alkylamino group,
Carbonamide group, sulfonamide group, sulfamoylamino group, alkoxycarbonylamino group, alkoxysulfonylamino group, ureido group, thioureido group, acyl group, alkoxycarbonyl group, carbamoyl group, sulfonyl group, sulfinyl group, sulfamoyl group, carboxyl Groups (including salts) and sulfo groups (including salts). These may be further substituted with these substituents.

Examples of the above substituents will be described in more detail. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom. As the alkyl group, a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms (more preferably 1 to 8 carbon atoms) is preferable. For example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, 2-hydroxyethyl, 4
-Carboxybutyl, hexyl, and octyl. The alkenyl group may have 2 to 18 carbon atoms.
A straight-chain, branched-chain or cyclic alkenyl group (more preferably 2 to 8 carbon atoms) is preferable, and examples thereof include vinyl, allyl, 1-propenyl, 2-pentenyl, 1,3-butadienyl, and 2-octenyl.

The aryl group is preferably an aryl group having 6 to 10 carbon atoms, for example, phenyl, naphthyl, 4
-Carboxyphenyl, 3-carboxyphenyl, 3,
Examples include 5-dicarboxyphenyl, 4-methanesulfonamidophenyl, and 4-butanesulfonamidophenyl. As the aralkyl group, a compound having 7 to 7 carbon atoms
Preferred are 10 aralkyl groups, such as benzyl and phenethyl. As a heterocyclic group,
It is preferably a 5- to 6-membered saturated or unsaturated heterocyclic group composed of a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, and the number of heteroatoms constituting the ring and the kind of element are 1 One or more, for example,
Oxazole ring, benzoxazole ring, 5-carboxybenzoxazole ring, thiazole ring, imidazole ring, pyridine ring, sulfolane ring, furan ring, thiophene ring, pyrazole ring, pyrrole ring, chroman ring, and coumarin ring.

The alkoxy group may have 1 to 18 carbon atoms.
An alkoxy group having 1 to 8 carbon atoms is more preferable, and examples thereof include methoxy, ethoxy, propoxy, and butoxy. As the aryloxy group, an aryloxy group having 6 to 10 carbon atoms is preferable,
For example, phenoxy, p-methoxyphenoxy and the like can be mentioned. As the alkylthio group, one having 1 carbon atom
To 18 (more preferably 1 to 8 carbon atoms) alkylthio groups are preferable, and examples thereof include methylthio and ethylthio. The arylthio group has 6 to 6 carbon atoms.
Preferred are 10 arylthio groups, such as phenylthio. As the acyloxy group, an acyloxy group having 1 to 18 (more preferably 1 to 8) carbon atoms is preferable, and examples thereof include acetoxy, propanoyloxy, pentanoyloxy and octanoyloxy.

The alkylamino group may have 1 to 1 carbon atoms.
Preferred is an alkylamino group having 8 (more preferably 1 to 8 carbon atoms), for example, methylamino, dimethylamino,
Diethylamino, dibutylamino, and octylamino can be mentioned. As the carbonamido group, a carbonamido group having 1 to 18 carbon atoms (more preferably, 1 to 8 carbon atoms) is preferable. For example, acetamido, propanoylamino, pentanoylamino, octanoylamino, octanoylmethylamino, And benzamide. As the sulfonamide group, a sulfonamide group having 1 to 18 carbon atoms (more preferably, 1 to 8 carbon atoms) is preferable.
Examples thereof include ethanesulfonamide, propylsulfonamide, butanesulfonamide, and benzenesulfonamide. As the alkoxycarbonylamino group,
An alkoxycarbonylamino group having 1 to 18 carbon atoms (more preferably 1 to 8 carbon atoms) is preferable, and examples thereof include methoxycarbonylamino and ethoxycarbonylamino. As the alkoxysulfonylamino group, an alkoxysulfonylamino group having 1 to 18 carbon atoms (more preferably 1 to 8 carbon atoms) is preferable, and examples thereof include methoxysulfonylamino and ethoxysulfonylamino.

The sulfamoylamino group is preferably sulfamoylamino or a sulfamoylamino group which may have a substituent having 1 to 18 carbon atoms (more preferably 1 to 8 carbon atoms). , Methylsulfamoylamino, dimethylsulfamoylamino, ethylsulfamoylamino, propylsulfamoylamino, and octylsulfamoisamino. As the ureido group, an ureido group which may have a substituent having 1 to 18 carbon atoms (more preferably, 1 to 8 carbon atoms) is preferable, and examples thereof include ureide, methylureide, N, N-dimethylureide, and octyl. Ureido can be mentioned. As the thioureido group, a thioureido group which may have a substituent having 1 to 18 carbon atoms (more preferably 1 to 8 carbon atoms) is preferable. For example, thioureido, methylthioureido, N, N-dimethylthioureido, And octylthioureido. The acyl group is preferably an acyl group having 1 to 18 carbon atoms (more preferably 1 to 8 carbon atoms), and examples thereof include acetyl, benzoyl and propanoyl. As the alkoxycarbonyl group, an alkoxycarbonyl group having 1 to 18 carbon atoms (more preferably 1 to 8 carbon atoms) is preferable, and examples thereof include methoxycarbonyl, ethoxycarbonyl and octyloxycarbonyl.

The carbamoyl group may have 1 to 18 carbon atoms.
A carbamoyl group (more preferably having 1 to 8 carbon atoms) which may have a substituent is preferable, and examples thereof include carbamoyl, N, N-dimethylcarbamoyl and N-ethylcarbamoyl. As the sulfonyl group,
A sulfonyl group having 1 to 18 carbon atoms (more preferably 1 to 8 carbon atoms) is preferable, and examples thereof include methanesulfonyl, ethanesulfonyl and benzenesulfonyl. As the sulfinyl group, a sulfinyl group having 1 to 18 carbon atoms (more preferably 1 to 8 carbon atoms) is preferable,
For example, methanesulfinyl, ethanesulfinyl and octanesulfinyl can be mentioned. As the sulfamoyl group, sulfamoyl and a sulfamoyl group which may have a substituent having 1 to 18 carbon atoms (more preferably, 1 to 8 carbon atoms) are preferable. For example, sulfamoyl, dimethylsulfamoyl, ethylsulfamoyl ,
Butylsulfamoyl, octylsulfamoyl and phenylsulfamoyl can be mentioned.

It is preferred that Z ¹ and Z ² are each independently a 3,3-dialkylindolenine nucleus or a 3,3-dialkylbenzoindolenine nucleus which may have a substituent. More preferably, both Z ¹ and Z ² are a 3,3-dialkylindolenin nucleus or a 3,3-dialkylbenzoindolenine nucleus which may have a substituent.

R ¹¹ and R ¹² each represent an alkyl group. The alkyl group represented by R ¹¹ and R ¹² is a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 18 carbon atoms (preferably 1 to 8 carbon atoms),
The substituent has the same meaning as the example of the substituent of the nitrogen-containing heterocycle, and the preferred range is also the same. Preferably, it is an unsubstituted alkyl group, or an alkyl group substituted with an aryl group, a halogen atom, a hydroxy group, an alkoxy group, an acyloxy group, a carbonamide group, a sulfonamide group, an oxycarbonyl group, a carboxyl group, or a sulfo group. . Examples of these are methyl, ethyl,
Propyl, butyl, isobutyl, 2-ethylhexyl,
Octyl, benzyl, 2-phenylethyl, 2-hydroxyethyl, 3-hydroxypropyl, 2-carboxyethyl, 3-carboxypropyl, 4-carboxybutyl, carboxymethyl, 2-methoxyethyl, 2- (2
-Methoxyethoxy) ethyl, 2-sulfoethyl, 3-
Sulfopropyl, 3-sulfobutyl, 4-sulfobutyl, 2- (3-sulfopropoxy) ethyl, 2-hydroxy-3-sulfopropyl, 3-sulfopropoxyethoxyethyl, 2-acetoxyethyl, carbomethoxymethyl, and 2-methane Sulfonylaminoethyl and the like can be mentioned.

The methine groups represented by L ¹ , L ² , L ³ , L ⁴ and L ⁵ may be the same or different and represent a methine group which may have a substituent. The details of the substituent are the same as the examples of the substituent of the nitrogen-containing heterocyclic ring, and the preferred range is also the same. Further, the substituents may be connected to each other to form a 5- to 7-membered ring, or a ring may be formed with an auxiliary chromophore. Here, as the 5- to 7-membered ring formed by connecting substituents, for example, a cyclopentene ring, a 1-dimethylaminocyclopentene ring, a 1-diphenylaminocyclopentene ring, a cyclohexene ring,
-Chlorocyclohexene ring, isophorone ring, 1-morpholinocyclopentene ring, and cycloheptene ring. n1 and n2 each independently represent 0 or 1.

M1 represents a charge balancing counter ion. M1 may be a cation or an anion. Examples of the cation include alkali metal ions such as sodium ion, potassium ion and lithium ion, and organic ions such as tetraalkylammonium ion and pyridinium ion.

The anion may be either an inorganic anion or an organic anion, such as a halogen anion (eg, a fluorine ion, a chloride ion, a bromine ion, an iodine ion), a sulfonate ion (eg, a methanesulfonic acid ion). , Trifluoromethanesulfonate ion,
Methyl sulfate ion, p-toluenesulfonic acid ion, p
-Chlorobenzenesulfonic acid ion, 1,3-benzenedisulfonic acid ion, 1,5-naphthalenedisulfonic acid ion, 2,6-naphthalenedisulfonic acid ion, etc.), sulfate ion, thiocyanate ion, perchlorate ion, tetrafluoroborate Ion, picrate ion,
Acetate ion, metal complex ion: for example

[0090]

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And a phosphate ion (for example, hexafluorophosphate ion, a phosphate ion represented by the following formula:

[0092]

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The following can be mentioned. Preferably, the anion is monovalent or divalent. m1 represents a number (0 or more, preferably 0 to 4) necessary for balancing the electric charge, and is 0 when a salt is formed in the molecule. The compound represented by formula (II) may form a bis-type structure by combining two kinds on any carbon atom.

The cyanine dye represented by the general formula (II) is
It is preferably a cyanine dye represented by the following general formula (II-1).

[0095]

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In the formula, Z ³ and Z ⁴ each independently represent an atomic group necessary for forming an optionally substituted benzene ring or naphthalene ring. R ¹³ , R ¹⁴ , R ¹⁵ , R
¹⁶ , R ¹⁷ and R ¹⁸ each independently represent an alkyl group having 1 to 8 carbon atoms. R ¹⁹ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, an aralkyl group having 7 to 10 carbon atoms,
A 10-aryl group, a C1-C8 alkoxy group, a heterocyclic group, a halogen atom, and a C1-C8 carbamoyl group are shown. If possible, these may further have a substituent. M2 ^m2- represents an anion, and m2 represents 1 or 2.

Preferred combinations of the formula (II-I) will be described below. Z ³ and Z ⁴ each independently represent an atomic group necessary for forming an unsubstituted benzene ring or a naphthalene ring, or an unsubstituted alkyl group having 1 to 3 carbon atoms, a halogen atom, R ¹³ and R ¹⁴ are each an unsubstituted or a fluorine atom, for forming a benzene ring substituted with one or two groups selected from an alkoxy group, a sulfonamide group, and an alkoxycarbonyl group. or an alkyl group having 1 to 6 carbon atoms substituted with an alkoxy group, R ^15,
R ¹⁶ , R ¹⁷ and R ¹⁸ are each independently an unsubstituted alkyl group having 1 to 6 carbon atoms, and R ¹⁹ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent. , A phenyl group, a benzyl group, a pyridyl group, a pyrimidyl group, a benzoxazole group or a halogen atom, and M2 is a perchlorate ion, a hexafluorophosphate ion, or a metal complex ion represented by the following formula:

[0098]

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Is as follows.

In the most preferred combination of the formula (II-I), Z ³ and Z ⁴ each independently represent an atomic group necessary for forming an unsubstituted benzene ring or a naphthalene ring, or a methyl group. A chlorine atom, a fluorine atom, a methoxy group, an ethoxy group, a sulfonamide group, and an atomic group for forming a benzene ring substituted with one or two groups selected from ethoxycarbonyl groups,
R ¹³ and R ¹⁴ are each independently an unsubstituted alkyl group (particularly preferably, a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group), and R ¹⁵ , R ¹⁶ , R ¹⁷ , and R ¹⁸ is each independently a methyl group or an ethyl group,
R ¹⁹ is a hydrogen atom, a methyl group, an ethyl group, a chlorine atom, or a bromine atom.

The cyanine dye represented by the general formula (II-1) is particularly preferably a compound represented by the following general formula (II-2) or (II-3), and most preferably the compound represented by the general formula (II-1) -3).

[0102]

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[0103]

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In the formula, R ²⁰ has the same meaning as R ¹³ in the above formula (II-1) (and the preferred range is also the same), and R ²¹ and R ²² are respectively the same as those in the above formula (II-1) )
There same meaning as R ¹⁵ in (and preferred ranges thereof are also the same), R ²³ is synonymous with R ¹⁹ (also the preferable ranges thereof are also the same) in ,, the formula (II-1), X is , A hydrogen atom, a methyl group, a chlorine atom, a fluorine atom, a methoxy group, an ethoxy group, a sulfonamide group, and an ethoxycarbonyl group, and M3 represents M2 and m3 in the general formula (II-1). Has the same meaning as m2 in formula (II-1), and the preferred range is also the same.

Specific examples of the compound represented by formula (II) [including formulas (II-1), (II-2) and (II-3)] used in the present invention are described below. However, the present invention is not limited to these.

[0106]

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[0107]

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[0108]

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[0109]

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[0110]

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[0111]

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[0112]

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[0113]

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The compound represented by the general formula (II) is
FM Hemer, Heterocyclic Compounds-Cyanine Soy and And
Related Compounds (Heterocyclic Compounds)
-Cyanine Dyes and Related Compounds), John Wiley & Sons, New York, London, 1964; Heterocyclic Compounds, by D.M. Sturmer Special topics in
Heterocyclic chemistry
(ounds-Specialtopics in heterocyclic chemistry)
, Chapter 18, Section 14, 482-515, John Wiley & Sons
New York, London, 1977; "Rod's Chemistry of Carbon Compounds (Rodd '
s Chemistry of Carbon Compounds) '' 2nd.Ed.vol.IV, p
artB, 1977, Chapter 15, Chapters 369-422
Page, Elsevir Science Publishing Company Inc.
It can be synthesized based on the method described in a company publication, New York, and the like.

The compounds represented by formula (II) can be used in combination of two or more depending on the purpose. Further, any dye conventionally known as a recording material for an information recording medium may be used in combination. For example, cyanine dyes other than the dyes used in the present invention, phthalocyanine dyes, pyrylium-thiopyrylium dyes, azurenium-based dyes,
Squarylium dyes, metal complex salt dyes such as Ni and Cr, naphthoquinone / anthraquinone dyes, indophenol dyes, indoaniline dyes, triphenylmethane dyes, triallylmethane dyes, aminium / diimmonium dyes and Nitroso compounds and the like can be mentioned.

The information recording medium of the present invention has a recording layer containing an organic dye and a radical anion salt of a tetracyanoquinodimethane represented by the general formula (I) (anti-fading agent) provided on a substrate. It becomes. The information recording medium of the present invention is a so-called CD-R type information recording medium or DVD.
-It can be configured as an R-type information recording medium. C
When configured as a DR type information recording medium, an organic dye and the general formula (I) are formed on a disc-shaped transparent substrate on which a pre-groove having a track pitch of 1.4 to 1.6 μm is formed. It is preferable to provide a recording layer containing a radical anion salt of tetracyanoquinodimethanes. When a DVD-R type information recording medium is configured, a disc-shaped transparent substrate on which a pre-groove having a track pitch of 0.6 to 0.9 μm is formed is provided with an organic dye and the general formula (I). It is preferable that a recording layer containing a radical anion salt of a tetracyanoquinodimethane represented is provided. In any of the information recording media of the above embodiments, a light reflecting layer is preferably provided on the recording layer, and a protective layer is preferably provided on the light reflecting layer.

It is preferable that the DVD-R type information recording medium is specifically configured in the following two forms. (1) A disc-shaped transparent substrate having a track pitch of 0.6 to 0.9 μm and a thickness of 0.6 ± 0.1 mm on a surface on which the pre-groove is provided, Two laminated bodies provided with a recording layer containing an organic dye and a radical anion salt of a tetracyanoquinodimethane represented by the general formula (I) are joined so that each recording layer is on the inside. Information recording medium.

(2) Track pitch is 0.6 to 0.9 μm
m pregroove formed, thickness 0.6 ± 0.1
A recording layer containing an organic dye and a radical anion salt of a tetracyanoquinodimethane represented by the general formula (I) is provided on the surface of the transparent disk-shaped transparent substrate having a thickness of 2 mm on the side where the pregroove is provided. An information recording medium comprising: a laminated body formed as described above; and a disc-shaped transparent substrate having substantially the same diameter as a substrate of the laminated body, and the respective recording layers are on the inside. In addition,
In the information recording medium of the above embodiment, it is preferable that a reflective layer is further provided on the recording layer, and a protective layer (a layer formed by an adhesive) is further provided on the reflective layer. Is preferred.

A method for manufacturing the information recording medium of the present invention will be described. The CD-R type information recording medium of the present invention can be manufactured, for example, by the following method. Note that a DVD-R type information recording medium can also be manufactured basically in the same manner as a CD-R type. Hereinafter, a method for manufacturing a CD-R type information recording medium will be mainly described.

The substrate can be arbitrarily selected from various materials used as a substrate of a conventional information recording medium. Examples of the substrate material include glass; polycarbonate; acrylic resins such as polymethyl methacrylate; vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymer; epoxy resins; amorphous polyolefin and polyester; You may use them together. Note that these materials can be used in the form of a film or a rigid substrate.
Among the above materials, polycarbonate is preferred from the viewpoints of moisture resistance, dimensional stability, cost, and the like. As these materials, materials that can transmit laser light are selected, and the transmittance is preferably 70 to 100%. A CD-R type information recording medium has a thickness of 1.2 mm and a diameter of 120 m.
m and a DVD-R type information recording medium, a 0.6 mm thick and 120 mm diameter transparent substrate or a 0.6 mm thick and 80 mm diameter transparent substrate are used.

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, and preventing deterioration of the recording layer. Examples of the material of the undercoat layer include polymethyl methacrylate, acrylic acid,
Methacrylic acid copolymer, styrene / maleic anhydride copolymer, polyvinyl alcohol, N-methylol acrylamide, styrene / vinyl toluene copolymer, chlorosulfonated polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide And high molecular substances such as 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 formed by dissolving or dispersing the above substances in an appropriate solvent to prepare a coating solution, and then applying the coating solution to the substrate surface by a coating method such as spin coating, dip coating, or extrusion coating. can do.
The thickness of the undercoat layer is generally in the range of 0.005 to 20 μm, preferably in the range of 0.01 to 10 μm.

It is preferable to form tracking grooves or irregularities (pre-grooves) representing information such as address signals 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 after further placing the substrate on this coating solution layer, the coating 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 to 10
It is in the range of 0 μm, preferably in the range of 0.1 to 50 μm.

The depth of the pre-groove provided on the substrate is preferably in the range of 300 to 2000 °, and the half width is preferably in the range of 0.2 to 0.9 μm. Further, the depth of the pre-groove layer is set to 1500 to 20
By setting it in the range of 00 °, the sensitivity can be improved without substantially lowering the reflectance, which is particularly preferable. Therefore, such an optical disk (an optical disk in which a recording layer and a reflective layer of a dye are formed on a deep pre-groove substrate) has high sensitivity, so that recording can be performed with a low laser power, and thereby an inexpensive semiconductor laser can be used. There is an advantage that the semiconductor laser can be used or the service life of the semiconductor laser can be extended.

A dye recording layer is provided on the substrate. The dye recording layer contains an organic dye and a radical anion salt of a tetracyanoquinodimethane represented by the general formula (I) (anti-fading agent). The recording layer is formed by dissolving the organic dye, the anti-fading agent represented by the general formula (I), and, if desired, a quencher or a binder in a solvent to prepare a coating solution. Is applied to the surface of the substrate to form a coating film and then dried.

Solvents for the dye layer coating solution include esters such as butyl acetate and cellosolve acetate; ketones such as methyl ethyl ketone, cyclohexanone and methyl isobutyl ketone; chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane and chloroform; dimethylformamide Hydrocarbons such as cyclohexane; ethers such as tetrahydrofuran, ethyl ether and dioxane; alcohols such as ethanol, n-propanol, isopropanol, n-butanol and diacetone alcohol; 2,2,3,3-tetrafluoropropanol Fluorine solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and propylene glycol monomethyl ether; It can be mentioned. The above solvents can be used alone or in combination of two or more in consideration of the solubility of the dye 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, examples of the binder include natural organic high-molecular substances such as gelatin, cellulose derivatives, dextran, rosin and rubber; and hydrocarbon-based substances such as polyethylene, polypropylene, polystyrene and polyisobutylene. Resin, polyvinyl chloride, polyvinylidene chloride, vinyl resin such as polyvinyl chloride / polyvinyl acetate copolymer, acrylic resin such as polymethyl acrylate, polymethyl methacrylate, polyvinyl alcohol, chlorinated polyethylene, epoxy resin, Synthetic organic polymers such as butyral resins, rubber derivatives, and initial condensates of thermosetting resins such as phenol / formaldehyde resins can be given. 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 5 parts by weight or less, based on 1 part by weight of the dye. The concentration of the coating solution thus prepared is generally in the range of 0.01 to 10% by weight, preferably 0.1 to 10% by weight.
It is in the range of 1-5% 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.

It is preferable that a light reflecting layer is provided on the recording layer for the purpose of improving the reflectance at the time of reproducing information. The light-reflective substance that is the material of the light-reflective layer is a substance having a high reflectance with respect to laser light.
Mg, Se, Y, Ti, Zr, Hf, V, Nb, Ta,
Cr, Mo, W, Mn, Re, Fe, Co, Ni, R
u, Rh, Pd, Ir, Pt, Cu, Ag, Au, Z
n, Cd, Al, Ga, In, Si, Ge, Te, P
Metals such as b, Po, Sn, and Bi and semimetals or stainless steel can be mentioned. Of these, preferred are Cr, Ni, Pt, Cu, Ag, Au, A
l and stainless steel. These substances may be used alone, or in combination of two or more kinds, or may be used as an alloy. Particularly preferably, it is Au. The light reflecting layer can be formed on the recording layer by, for example, vapor deposition, sputtering, or ion plating of the light reflecting substance. The thickness of the light reflecting layer is generally in the range of 10 to 300 nm, preferably 5 to 300 nm.
0 to 200 nm.

It is preferable to provide a protective layer on the light reflecting layer for the purpose of physically and chemically protecting the recording layer and the like. This protective layer can also 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 moisture resistance. Examples of the material used for the protective layer include Si
Examples include inorganic substances such as O, 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, it can also be formed by preparing a coating solution as it is or by dissolving it in an appropriate solvent, applying the coating solution, and irradiating with UV light to cure. These coating solutions further contain an antistatic agent, an antioxidant,
Various additives such as a V absorbent may be added according to the purpose. The thickness of the protective layer is generally in the range from 0.1 to 100 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 arranged such that the recording layer is on the inside, and an adhesive or the like may be applied. By using and joining, a recording medium of a bonding type can also be manufactured. Alternatively, an air sandwich type recording medium is manufactured by joining a substrate having the above configuration to at least one of the two disk-shaped substrates via a ring-shaped inner spacer and a ring-shaped outer spacer. I can do it.

The CD-R type information recording medium can be manufactured by the above method. Since the obtained information recording medium has a high reflectance of about 80%, it can be reproduced by a commercially available CD player. Therefore, it is possible to obtain an optical disk having high reflectance and excellent light resistance.

Further, the two laminates having a recording layer, a reflective layer, and, if desired, a protective layer provided on the substrate, produced as described above, were bonded with an adhesive so that each recording layer was on the inside. By bonding, a DV with two recording layers
A DR information recording medium can be manufactured. Further, by bonding one laminated body obtained as described above and a disc-shaped protective substrate having a diameter substantially the same as that of the substrate of the laminated body with an adhesive such that the recording layer is on the inside, one side is obtained. A DVD-R type information recording medium having only a recording layer can be manufactured.

The optical information recording method is performed, for example, as follows using the information recording medium of the present invention. First, recording light such as semiconductor laser light is irradiated from the substrate side while rotating the information recording medium at a predetermined constant linear speed (1.2 to 14 m / sec in the case of a CD format) or a predetermined constant angular speed. I do. By this light irradiation, the irradiated portion of the recording layer absorbs the light and locally raises the temperature, and physical or chemical changes occur to change its optical characteristics, thereby recording information. . 500n as recording light
A semiconductor laser beam having an oscillation wavelength in the range of m to 850 nm is used. The wavelength of the laser beam used is preferably in the range from 500 nm to 800 nm.
In a CD-R type information recording medium, the wavelength of the laser beam is 750 to 850 nm (more preferably,
It is preferably in the range of 770 to 795 nm, especially 775 to 790 nm. Alternatively, in a DVD-R type information recording medium, the wavelength of the laser beam is 600 to 70.
0 nm (more preferably, 620 to 680 nm, particularly 6 nm
(30 to 645 nm). Reproduction of the information recorded as described above can be performed by irradiating a semiconductor laser beam from the substrate side while rotating the information recording medium at a predetermined linear speed, and detecting the reflected light. It should be noted that the information recording medium of the present invention is capable of recording / reproducing not only 1 × speed in the case of the above-mentioned normal CD format but also 4 × speed or higher.

[0136]

EXAMPLES Examples and comparative examples of the present invention will be described below. However, these examples do not limit the present invention.

Example 1 The cyanine dye [II-1]
6] and a radical anion salt of a tetracyanoquinodimethanes according to the present invention or a conventional nitroso compound a shown in Table 2 as an anti-fading agent.
-It was dissolved in a solvent of tetrafluoropropanol to prepare a coating solution for forming a recording layer (concentration of the coating solution: 2.5% by weight). The addition amount of the anti-fading agent was 10% by weight based on the cyanine dye.

[0138]

Embedded image

The obtained coating solution was applied to a polycarbonate substrate having a diameter of 120 mm and a thickness of 1.2 mm to a thickness of about 140 nm.
(Within the groove). As a substrate, a spiral pre-groove (groove pitch 1.7 μm) is used in advance.
m, a groove width of 0.4 μm and a groove depth of 0.16 μm) formed by injection molding were used.

Next, a light reflecting layer made of gold was further sputtered on the recording layer to a thickness of about 100 nm.
A protective layer made of a photopolymer (UV
A curing agent SD-220, Dainippon Ink and Chemicals, Inc.) was applied so as to have a thickness of 5 μm, and was cured by irradiating UV light to produce an information recording medium (optical disk) according to the present invention.

[Evaluation as Information Recording Medium] The obtained optical disc was subjected to 3T at a wavelength of 780 nm and a linear velocity of 1.2 m / s using an OMT2000 (manufactured by Pulstec) evaluation machine.
And 11T EFM signal from laser power 5mW to 1
Recording was performed by shaking to 5 mW, and thereafter, the signal was reproduced at a laser power of 0.5 mW, and the modulation and groove reflectivity of 3T and 11T at the optimum power were measured.

The Xe lamp (140,000 lux) is
Irradiation was performed for a period of time (h), 24 hours (h), or 36 hours (h). Thereafter, the degree of modulation and groove reflectivity of the recording / reproducing signal were examined, and light resistance was evaluated. Table 2 shows the evaluation results.

[0143]

[Table 2]

[0144]

[Table 3]

From the results shown in Table 2, when the anti-fading agent according to the present invention was added, the recording / reproducing characteristics were all excellent and the deterioration of the performance after irradiation with a Xe lamp was extremely small. It can be seen that the optical disc has significantly improved light resistance.

[Example 2] In Example 1, cyanine dyes II-1 and II were used instead of cyanine dye [II-16].
-24, II-40, II-57, II-68, and II-7
The information recording medium according to the present invention was prepared in the same manner except that 0 was replaced by an equal weight, and a radical anion salt of a tetracyanoquinodimethane represented by the general formula (I) according to the present invention was used as an anti-fading agent. Produced. And the first embodiment
The same test as in Example 1 was performed.

[0147]

By using the compound represented by the general formula (I) (anti-fading agent) according to the present invention together with an organic dye in the dye recording layer, high light resistance can be obtained even after recording without impairing recording / reproduction. An information recording medium having the property can be manufactured.

[Procedure amendment]

[Submission date] January 21, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0057

[Correction method] Change

[Correction contents]

[0057]

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[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0066

[Correction method] Change

[Correction contents]

Compound I-47 [anion moiety (A-1) /
Cation part (C-98)]

Embedded image

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0067

[Correction method] Change

[Correction contents]

Compound I-48 [anion moiety (A-13)
/ Cation part (C-122)]

Embedded image

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 00106

[Correction method] Change

[Correction contents]

[0106]

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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.
An information recording medium, wherein the recording layer contains an organic dye and a radical anion salt of a tetracyanoquinodimethane represented by the following general formula (I). Embedded image [In the above formula, R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or a substituent (provided that R ¹ and R
² and R ³ and R ⁴ may be linked together to form an unsaturated condensed ring), M ^{k +} represents a metal ion, a metal complex ion or an onium ion, and k is an integer of 1 to 10. Represent. ] 2. The method according to claim 1, wherein M ^{k +} is at least one onium ion selected from the group consisting of ammonium ions, pyridinium ions, anilinium ions, quinolinium ions, morpholinium ions, and ions represented by the following formula. Item 2. An information recording medium according to Item 1. Embedded image 3. The above R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, an alkoxy group, a cyano group, an alkylthio group, a carbonamide group, a sulfonamide. The information recording medium according to claim 1, which represents a group, a ureido group, an acyl group, or an alkoxycarbonyl group. 4. The unsaturated condensed ring formed by R ¹ and R ² , and R ³ and R ⁴ is each independently a benzene ring, a naphthalene ring, a pyridine ring, a pyrazine ring, a thiazane ring, or a selenazan ring. The information recording medium according to claim 1 or 2, wherein 5. The information recording medium according to claim 1, wherein the organic dye is a cyanine dye represented by the following general formula (II). General formula (II): [Wherein, Z ¹ and Z ² each independently represent an atomic group necessary for forming a 5- or 6-membered nitrogen-containing heterocyclic ring;
¹¹ and R ¹² represents an alkyl group independently, L ^1, L
² , L ³ , L ⁴ and L ⁵ each independently represent a methine group which may be substituted, and n1 and n2 each independently represent 0.
Or p, q and q each independently represent 0 or 1, M1 represents a charge neutralizing counter ion, and m1 represents a number of 0 or more necessary to neutralize the charge in the molecule. ] 6. The information recording medium according to claim 5, wherein the cyanine dye is a compound represented by the following general formula (II-1). General formula (II-1): [Wherein, Z ³ and Z ⁴ each independently represent an atomic group necessary for forming a benzene ring or a naphthalene ring which may have a substituent, and R ¹³ , R ¹⁴ , and R ¹⁵ , R ¹⁶ , R
¹⁷ and R ¹⁸ each independently represent an alkyl group having 1 to 8 carbon atoms, R ¹⁹ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms,
Represents an aralkyl group having 7 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a heterocyclic group, a halogen atom, a carbamoyl group having 1 to 8 carbon atoms;
2 ^m2- represents an anion, and m2 represents 1 or 2. ] 7. The information recording medium according to claim 1, further comprising a light reflection layer on the recording layer.