JP2008047222A - Method of manufacturing optical information recording medium, and optical information recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an optical information recording medium by which a recording layer compatibly having high speed recording characteristics and archival performance (durability) is formed by using a coating liquid stable in long time preservation and repetitive utilization and having excellent productivity, and to provide an optical information recording medium applicable to a write-once type DVD disk system. <P>SOLUTION: The recording layer is formed on a light transmissible substrate by a coating method using a coating liquid which is formed by dissolving a cyanine compound (e.g. a cyanine compound having a PF<SB>6</SB><SP>-</SP>as an anion) having a specified structure and a squarylium metal chelate compound (e.g. a squarylium metal chelate compound having Al as a center metal) having a specified structure in a dehydrated solvent and whose pH is maintained at ≥5.5 and a reflection layer, a protective layer, an adhesive layer and a cover layer are sequentially provided to manufacture the optical information recording medium, which is applied to the write-once type DVD disk system and the like. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a large-capacity optical recording medium capable of recording and reproducing information by irradiating a light beam, and additionally recording, and in particular, durability and recording characteristics comprising a cyanine compound and a squarylium metal chelate compound. The present invention relates to a method for producing an optical information recording medium having an excellent recording layer with good productivity and an optical information recording medium obtained thereby.

  In recent years, recordable DVDs (DVD + RW, DVD + R, DVD-R, DVD-RW, DVD-RAM, etc.) have been put into practical use in addition to optical recording media such as read-only DVD-ROMs. These DVD + R, DVD + RW, etc. are positioned on the extension of conventional recordable CD-R, CD-RW (recordable compact disc) technology, and are recorded to ensure playback compatibility with playback-only DVDs. The density (track pitch, signal mark length) and substrate thickness are designed to meet the DVD conditions from the CD conditions.

  For example, in the case of DVD + R, an information recording substrate having an optical recording layer provided by spin coating a dye on a substrate and a metal reflective layer behind it is formed in the same shape via a bonding material as in CD-R. A configuration in which the substrate is bonded is adopted. In this case, a dye material is used for the optical recording layer. CD-R is characterized by having a high reflectivity (65%) that satisfies the CD standard. In order to obtain a high reflectivity in the above configuration, the light absorption layer has a recording / reproducing light wavelength. It is necessary to satisfy a specific complex refractive index, and a dye material is used because the light absorption property of the dye is suitable for such a requirement. The same applies to DVDs.

  However, conventional CD-R dyes (for example, pentamethine cyanine dyes, phthalocyanine dyes, etc.) have a large wavelength dependence as a recording material, and have recording / reproduction characteristics at a wavelength of 650 nm, which is near the light absorption wavelength of DVD. Can not be satisfied. That is, in the case of the above-mentioned dye for CD-R, recording / reproduction becomes difficult because the absorption coefficient k at 650 nm is large and the reflectance is low. In the case of a DVD drive, the light source is standardized with a wavelength of a semiconductor laser in the 630 to 690 nm band. In addition, a read-only DVD-ROM drive is commercialized at a wavelength of about 650 nm.

  Therefore, a technique for adjusting the absorption band wavelength by combining dyes used as recording materials has been proposed. For example, an optical recording medium provided with a light absorption layer containing both a tetraazaporphyrin compound and a phthalocyanine compound (see Patent Document 1), a phthalocyanine dye and a trimethine cyanine dye or a trimethine indolenine cyanine dye. An optical recording medium having a recording layer (see Patent Document 2) or an optical recording medium having a recording layer containing a metal complex of an azo compound and a phthalocyanine dye (see Patent Document 3) is known.

Furthermore, with the recent increase in write-once recording speed of DVD media, recording materials have also been improved, and squarylium compounds and cyanine compounds have been proposed.
As the squarylium compound, for example, a metal complex-type squarylium compound (see Patent Documents 4 and 5) suitable for a recordable DVD recording material has been proposed. Further, as the cyanine compound, for example, a cyanine compound suitable for a recordable DVD recording material comprising a cyanine compound cation and an anion (see Patent Documents 6 and 7), or a cyanine compound cation and a phosphorous hexafluoride anion. A cyanine compound (see Patent Document 8) suitable for write-once CD / DVD recording materials has been proposed.
In order to improve the moisture resistance of the optical recording medium, organic dyes (phthalocyanine dyes, cyanine dyes) using 2,2,3,3-tetrafluoro-1-propanol (TFP) having a pH of 6.0 or more as a solvent. It has been proposed to form a recording film (see Patent Document 9).

However, when used as a recording material for DVD, it is difficult to achieve both high-speed recording characteristics and archival performance (durability) in any of the recording materials.
That is, a recording material (for example, a cyanine compound) having a low thermal decomposition temperature and a high decomposition speed is suitable for high-speed recording, but such a material is likely to deteriorate in heat resistance and moisture resistance. It is. Therefore, it is generally employed to combine a recording material having a high decomposition rate and a durable recording material and to mix two or more dye materials. However, when two or more kinds of dyes are mixed, there are the following problems.
When a recording layer is formed (film formation) by a coating method (for example, spin coating) using a coating solution obtained by dissolving two or more types of dye materials in a solvent, for example, a cyanine dye having an ionic structure and a chelate structure are used. When a squalene compound or the like is mixed, there is a problem that an interaction such as an exchange reaction is likely to occur in the coating solution, the composition varies due to a chemical change, and desired recording characteristics cannot be obtained. For example, the cyanine compound cationic and hexafluorophosphate anions ^- if a combination of cyanine compound composed of (PF ₆ ion) and squarylium metal chelate compounds, PF ₆ ^- ions ion is highly reactive, de-chelate such squarylium metal chelate compound There is a problem that it is easy to cause.

Japanese Patent Laid-Open No. 9-169166 JP-A-9-66671 JP 11-48612 A WO2002-050190 JP 2004-244342 A Japanese Patent No. 3698708 Japanese Patent No. 3659922 Japanese Patent No. 2594443 JP-A-7-137448

  The present invention contains a cyanine compound consisting of a cyanine cation and an anion and a metal complex-type squarylium compound in a solvent, and there is no exchange reaction or chemical change for each composition even for long-term storage and repeated use. In a method for manufacturing an optical information recording medium that stably forms a recording layer that achieves both high-speed recording characteristics and archival performance (durability) using an excellent coating solution, and a write-once DVD disc system obtained thereby An object is to provide an applicable optical information recording medium.

  As a result of intensive studies, the present inventor has found that the above problems can be solved by the inventions described in the following (1) to (6), and has reached the present invention. Hereinafter, the present invention will be specifically described.

  (1): At least a cyanine compound represented by the following general formula (I) and a squarylium metal chelate compound represented by the following general formula (II) on a translucent substrate having grooves and / or pits formed on the surface. Is formed in a dehydrated solvent, and a recording layer is formed by a coating method using a coating solution having a pH of 5.5 or higher.

(In the formula, ring A and ring B are a benzene ring or a naphthalene ring which may have a substituent, and R1 to R4 are benzyl groups in which at least one of them may have a substituent. The remaining group that is not a benzyl group is an alkyl group having 1 to 4 carbon atoms, or a group in which R1 and R2 or R3 and R4 are linked to form a 3- to 6-membered ring, and Y1 and Y2 are each independently carbon (An ^m- represents an m-valent anion, m is an integer of 1 or 2, and p is a coefficient that keeps the charge neutral.)

(In the formula, R7 and R8 may be the same as or different from each other, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, and a substituent. R5 represents a hydrogen atom, an alkyl group which may have a substituent, or a substituent, which may be an aryl group which may have a substituent or a heterocyclic group which may have a substituent. R6 represents a halogen atom, a nitro group, a cyano group, or an alkyl group that may have a substituent, which may be an aralkyl group that may have or an aryl group that may have a substituent. Represents an aralkyl group which may have a substituent, an aryl group which may have a substituent, and an alkoxy group which may have a substituent, and R9 and R10 may be the same or May be different and have substituents R 9 and R 10 may be linked to form a ring structure, M represents a metal atom having coordination ability, and n represents an integer of 2 or 3. )

  The coating solution containing the cyanine compound and the squarylium metal chelate compound in the dehydrated solvent is maintained at a pH of 5.5 or more without causing chemical changes such as dechelation or new compounds over time. The Even if the coating solution is stored for a long time, the light absorption spectrum does not change (no composition change) and is stable, so that the properties of the cyanine compound and the metal complex-type squarylium compound can be maintained at any time. A recording layer that exhibits both high-speed recording characteristics and archival performance (durability) is formed. The coating solution is stable even when stored for a long time, and since conventional coating methods (for example, spraying, roller coating, dipping, spin coating, etc.) can be applied, the productivity is also excellent.

  (2): In the method for producing an optical information recording medium described in (1) above, the cyanine compound represented by the general formula (I) is represented by the following general formula (III), and the general formula (II) The represented squarylium metal chelate compound is represented by the following general formula (1V).

(In the formula, ring A and ring B are a benzene ring or a naphthalene ring which may have a substituent, and R1 to R4 are benzyl groups in which at least one of them may have a substituent. The remaining group that is not a benzyl group is an alkyl group having 1 to 4 carbon atoms, or a group in which R1 and R2 or R3 and R4 are linked to form a 3- to 6-membered ring, and Y1 and Y2 are each independently carbon (It is an organic group of the number 1-30.)

(In the formula, R7 and R8 may be the same as or different from each other, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, and a substituent. R5 represents a hydrogen atom, an alkyl group which may have a substituent, or a substituent, which may be an aryl group which may have a substituent or a heterocyclic group which may have a substituent. R6 represents a halogen atom, a nitro group, a cyano group, or an alkyl group that may have a substituent, which may be an aralkyl group that may have or an aryl group that may have a substituent. Represents an aralkyl group which may have a substituent, an aryl group which may have a substituent, and an alkoxy group which may have a substituent, and R9 and R10 may be the same or May be different and have substituents Or an alkyl group which may or R9 and R10 may form a ring structure linked.)

PF ₆ ^- ions cyanine compound to the anion has a small amount of heat generated during the thermal decomposition, thermal decomposition characteristics are suitable for high speed and high density recording, squarylium metal chelate compound as a central metal of Al optical characteristics and light Therefore, a recording layer that achieves both high-speed recording characteristics and archival performance (durability) and exhibits excellent performance as a write-once DVD recording material is formed.

  (3): In the method for producing an optical information recording medium according to the above (1) or (2), the solvent is dehydrated using a crystalline zeolite comprising a hydrous metal salt of a synthetic crystalline aluminosilicate. It is characterized by being.

  Crystalline zeolite (molecular sieve) composed of a hydrous metal salt of synthetic crystal alumino-silicate can be easily obtained as a commercial product, and can be easily and efficiently dehydrated. That is, the pH of the coating solution over time can be maintained at 5.5 or higher by using a solvent dehydrated using molecular sieves.

  (4): In the method for manufacturing an optical information recording medium according to any one of (1) to (3), the solvent is a fluorine-substituted alcohol.

  By using a fluorine-substituted alcohol as a solvent, a uniform and stable coating solution can be prepared. Further, the influence of humidity is small, pH change with time of the coating solution is suppressed, and a recording layer can be formed stably.

  (5): In the method for manufacturing an optical information recording medium according to any one of (1) to (4), a surplus coating liquid that has flowed out when forming the recording layer is treated with a hydrous metal of synthetic crystal aluminosilicate. A method for producing an optical information recording medium, comprising: collecting and storing in a container containing crystalline zeolite composed of salt, and forming a recording layer using the collected and stored coating solution.

  By collecting and storing the excess coating solution that has flowed and discharged into the container containing the molecular sieve, chemical changes such as oxidation reaction due to moisture absorption of the coating solution can be easily and easily prevented. By reusing, the recording layer can be formed economically without waste.

  (6): An optical information recording medium obtained by the production method according to any one of (1) to (5).

  An optical information recording medium applicable to a write-once DVD disc system in which a recording layer composed of a cyanine compound and a metal complex-type squarylium compound is formed by the production method of the present invention and has both high-speed recording characteristics and archival performance (durability) Is obtained. Of course, it can also be applied to a CD disk system.

Since the coating liquid used in the method for producing an optical information recording medium of the present invention contains a cyanine compound and a squarylium metal chelate compound in a dehydrated solvent, the composition does not cause chemical changes such as dechelation over time. There is no change and it is stable, the pH is maintained at 5.5 or higher, and the light absorption spectrum does not change. For this reason, a recording layer having both high-speed recording characteristics and archival performance (durability) is formed by a conventional coating method (for example, spin coating or spraying) at an arbitrary coating time. Even when stored for a long time, the coating solution is stable, so that the productivity is good.
Here, PF ₆ ^- using a cyanine compound and an anion when small amount of heat generated during the thermal decomposition, thermal decomposition characteristics are suitable for high speed and high density recording, whereas, squarylium metal chelate compound as a central metal Al Is excellent in optical characteristics and light resistance, and further achieves both high-speed recording characteristics and durability, and forms an excellent recording layer as a recording material for write-once DVDs.
In the present invention, the method for dehydrating the solvent used in the coating solution is not limited, but molecular sieves are preferably used because they are readily available as commercial products and can be easily and efficiently dehydrated.
Further, by using a fluorine-substituted alcohol as a solvent, a uniform coating solution that is uniform and less affected by humidity can be obtained, pH change over time can be suppressed, and a good recording layer can be formed.
Furthermore, by collecting and storing the surplus coating liquid that spilled out at the time of recording layer formation in a container containing molecular sieves to prevent chemical changes due to moisture absorption, the coating liquid can be reused to save resources. A recording layer can be formed economically.
An optical information recording medium (DVD + RW, DVD + R, DVD-R, DVD-RW, DVD-RAM) applicable to a write-once DVD disc system that achieves both high-speed recording characteristics and archival performance (durability) by the manufacturing method of the present invention. Etc.) can be provided. Of course, the present invention can also be applied to CD-R media.

  A cyanine compound comprising a cyanine cation and an anion is suitable as a recording material for high-speed recording because it has a low thermal decomposition temperature and a high decomposition rate. On the other hand, the metal complex-type squarylium compound can be applied to write-once DVD media using a semiconductor laser having an oscillation wavelength shorter than that of a conventional recording material. Is not necessarily sufficient. Therefore, the present invention focuses on the above-mentioned problem of instability of each composition in the coating solution in order to realize both high speed recording characteristics and durability by using a cyanine compound and a squarylium compound in combination. It is intended to do.

As a result of studying to solve the above problems, when a cyanine compound and a squarylium compound are mixed in a solvent, the amount of water contained in the solvent affects, causing an interaction such as an exchange reaction, dechelation, etc. It is thought that this chemical change has occurred. For example, PF ₆ ^- ions cyanine compound was anions and squarylium metal chelate compound, is dissolved in a solvent (2,2,3,3-tetrafluoropropanol) not subjected to dehydration treatment to prepare a coating solution, the coating When the pH of the liquid over time was measured, as shown in Table 1 below, it was found that the pH decreased with time and a chemical change occurred. This pH change is thought to be due to the accelerated oxidation reaction.

  Further, when the light absorption spectrum of the coating solution over time was measured, as shown in FIG. 1, it was confirmed that the light absorption spectrum also changed with the pH variation with time. It was confirmed from the change in the light absorption spectrum that a chemical change occurred in the coating solution. The light absorption spectrum was measured using a spectrophotometer.

  From the results shown in Table 1 and FIG. 1, it is considered that the light absorption spectrum does not change until the pH change of the coating solution is 5.5, and the cyanine compound and the squarylium metal chelate compound hardly change. Therefore, both the high-speed recording characteristics and the durability can be realized within a range where the state in which the light absorption spectrum does not change is maintained (pH 5.5 or more). However, after one week, the oxidation reaction is promoted, the pH change becomes smaller than 5.5, and the light absorption spectrum also changes, indicating that it is difficult to realize desired recording characteristics and durability. Based on the above results, the above-mentioned problems have been solved, and the method for producing the optical information recording medium of the present invention has been established.

  That is, the method for producing an optical information recording medium of the present invention comprises at least a cyanine compound represented by the following general formula (I) and the following general formula (I) on a translucent substrate having grooves and / or pits formed on the surface. The recording layer is formed by a coating method using a coating solution containing the squarylium metal chelate compound represented by II) in a dehydrated solvent and having a pH of 5.5 or more. .

(In the formula, ring A and ring B are a benzene ring or a naphthalene ring which may have a substituent, and R1 to R4 are benzyl groups in which at least one of them may have a substituent. The remaining group that is not a benzyl group is an alkyl group having 1 to 4 carbon atoms, or a group in which R1 and R2 or R3 and R4 are linked to form a 3- to 6-membered ring, and Y1 and Y2 are each independently carbon (An ^m- represents an m-valent anion, m is an integer of 1 or 2, and p is a coefficient that keeps the charge neutral.)

(In the formula, R7 and R8 may be the same as or different from each other, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, and a substituent. R5 represents a hydrogen atom, an alkyl group which may have a substituent, or a substituent, which may be an aryl group which may have a substituent or a heterocyclic group which may have a substituent. R6 represents a halogen atom, a nitro group, a cyano group, or an alkyl group that may have a substituent, which may be an aralkyl group that may have or an aryl group that may have a substituent. Represents an aralkyl group which may have a substituent, an aryl group which may have a substituent, and an alkoxy group which may have a substituent, and R9 and R10 may be the same or May be different and have substituents R 9 and R 10 may be linked to form a ring structure, M represents a metal atom having coordination ability, and n represents an integer of 2 or 3. )

  By adding the cyanine compound represented by the above general formula (I) and the squarylium metal chelate compound represented by the above general formula (II) to the dehydrated solvent, the prepared coating solution can be dechelated over time. No chemical change such as the above occurs, the pH fluctuation is slight, the pH is maintained at 5.5 or higher, and the light absorption spectrum does not change. If such a coating solution is used to form a film by a coating method, a recording layer having both high-speed recording characteristics and archival performance (durability) can be stably formed with good productivity. In addition, since the recording layer contains a cyanine compound and a metal complex-type squarylium compound, the features such as high-speed recording performance and reduction of recording wavelength dependency are well-balanced and compatible with write-once DVD media, etc. can do. In addition, there is no restriction | limiting in the mixing ratio of a cyanine compound and a squarylium metal chelate compound, According to the required characteristic, it can select.

  Furthermore, the cyanine compound represented by the general formula (I) is represented by the following general formula (III), and the squarylium metal chelate compound represented by the general formula (II) is represented by the following general formula (1V). It is preferable.

(In the formula, ring A and ring B are a benzene ring or a naphthalene ring which may have a substituent, and R1 to R4 are benzyl groups in which at least one of them may have a substituent. The remaining group that is not a benzyl group is an alkyl group having 1 to 4 carbon atoms, or a group in which R1 and R2 or R3 and R4 are linked to form a 3- to 6-membered ring, and Y1 and Y2 are each independently carbon (It is an organic group of the number 1-30.)

(In the formula, R7 and R8 may be the same as or different from each other, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, and a substituent. R5 represents a hydrogen atom, an alkyl group which may have a substituent, or a substituent, which may be an aryl group which may have a substituent or a heterocyclic group which may have a substituent. R6 represents a halogen atom, a nitro group, a cyano group, or an alkyl group that may have a substituent, which may be an aralkyl group that may have or an aryl group that may have a substituent. Represents an aralkyl group which may have a substituent, an aryl group which may have a substituent, and an alkoxy group which may have a substituent, and R9 and R10 may be the same or May be different and have substituents Or an alkyl group which may or R9 and R10 may form a ring structure linked.)

Ni will be represented by the general formula (III), anions of cyanine compound PF ₆ ^- in the case of ions, the amount of heat generated during the thermal decomposition is small, thermal decomposition characteristics are suitable for the higher speed and higher density recording . Further, as represented by the above general formula (IV), when the metal atom of the squarylium metal chelate compound is Al, the optical properties and light resistance are good, and it is suitable as a recording material for DVD. Therefore, a combination of the features of both forms a recording layer that exhibits excellent performance as a write-once DVD recording material.

Details of each group in the cyanine compound represented by the general formula (I) will be described below.
In the general formula (I), the substituent of the benzene ring or naphthalene ring which may have a substituent represented by ring A and ring B includes a halogen group such as fluorine, chlorine, bromine and iodine; Ethyl, propyl, isopropyl, butyl, secondary (sec-) butyl, tertiary (tert-) butyl, isobutyl, amyl, isoamyl, tertiary amyl, hexyl, cyclohexyl, heptyl, isoheptyl, tertiary heptyl, n-octyl, Alkyl groups such as isooctyl, tertiary octyl and 2-ethylhexyl; aryl groups such as phenyl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-vinylphenyl and 3-isopropylphenyl; methoxy, ethoxy , Propoxy, isopropoxy, butoxy, secondary butoxy, tertiary butoxy, etc. Alkoxy groups; methylthio, ethylthio, propylthio, isopropylthio, butylthio, secondary butylthio, alkylthio groups such as tert-butylthio; nitro group, a cyano group Ageraru.
Examples of the alkyl group having 1 to 4 carbon atoms represented by R1 to R4 include methyl, ethyl, propyl, isopropylbutyl, sec-butyl, tert-butyl, and isobutyl.
Examples of the 3- to 6-membered ring group formed by linking R1 and R2 or R3 and R4 include cyclopropane-1,1-diyl, cyclobutane-1,1-diyl, 2,4-dimethylcyclobutane-1, 1-diyl, cyclohexane-1,1-diyl, tetrahydropyran-4,4-diyl, thian-4,4-diyl, piperidine-4,4-diyl, N-substituted piperidine-4,4-diyl, morpholine- 2,2-diyl, morpholine-3,3-diyl, N-substituted morpholine-2,2-diyl, N-substituted morpholine-3,3-diyl, and the like. Examples of the substituent of ring B include those exemplified.

In the general formula (I), at least one of the groups represented by R1 to R4 is a benzyl group which may have a substituent. The number of substituents of the substituted benzyl group is 1 to 5, and examples of the substituent include halogen groups such as fluorine, chlorine, bromine and iodine; methyl, ethyl, propyl, isopropyl, butyl, sec-butyl and tert-butyl Alkyl groups such as isobutyl, amyl, isoamyl, tert-amyl, hexyl, cyclohexyl, heptyl, isoheptyl, tert-heptyl, n-octyl, isooctyl, tert-octyl, 2-ethylhexyl; halogen substituents of these alkyl groups, Alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, tert-butoxy; halogen substituents of these alkoxy groups, methylthio, ethylthio, propylthio, isopropylthio, butylthio, sec-butylthio, tert-butylthio Alkylthio group such as nitro group, Group, and the like.
When the substituent of the substituted benzyl group is large, the molar extinction coefficient of the cyanine compound is decreased, which may affect the sensitivity. Therefore, the number of substituents is preferably 1 or 2. For example, as the substituent, a hydroxyl group, a halogen group , A cyano group, a nitro group, an alkyl group having 1 to 4 carbon atoms, a halogen-substituted alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen-substituted alkoxy group having 1 to 4 carbon atoms. The substituents may be the same or different.

  Examples of the halogen group, the alkyl group having 1 to 4 carbon atoms, and the alkoxy group having 1 to 4 carbon atoms in the substituent of the substituted benzyl group include the groups described for the ring A and ring B. Examples of the halogen-substituted alkyl group having 1 to 4 carbon atoms include chloromethyl, dichloromethyl, trichloromethyl, bromomethyl, dibromomethyl, tribromomethyl, fluoromethyl, difluoromethyl, trifluoromethyl, perfluoromethyl, and perfluoromethyl. Examples include fluoropropyl and perfluorobutyl. Examples of the halogen-substituted alkoxy group having 1 to 4 carbon atoms include chloromethyloxy, dichloromethyloxy, trichloromethyloxy, bromomethyloxy, dibromomethyloxy, tribromomethyloxy, fluoromethyloxy, difluoromethyloxy, trifluoro Examples include methyloxy, perfluoropropyloxy, perfluorobutyloxy and the like.

Moreover, in the said general formula (I), as a C1-C30 organic group represented by Y1 or Y2, other than the alkyl group and aryl group which were described by the substituent of the said ring A and the ring B, for example, Alkyl groups such as cyclohexyl, cyclohexylmethyl, 2-cyclohexylethyl, nonyl, isononyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl; 4-isopropylphenyl, 4-butylphenyl, 4-isobutylphenyl, 4 Tertiary butylphenyl, 4-hexylphenyl, 4-cyclohexylphenyl, 4-octylphenyl, 4- (2-ethylhexyl) phenyl, 4-stearylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2 , 5-Dimethylphenyl, 2,6 Dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2,4-di-tert-butylphenyl, and an aryl group such as phenyl. Further, alkenyl groups such as vinyl, 1-methylethenyl, 2-methylethenyl, propenyl, butenyl, isobutenyl, pentenyl, hexenyl, heptenyl, octenyl, decenyl, pentadecenyl, 1-phenylpropen-3-yl; benzyl, phenethyl, 2-phenyl Aralkyl groups such as propan-2-yl, diphenylmethyl, triphenylmethyl, styryl, cinnamyl and the like, and those hydrocarbon groups linked by an ether bond or a thioether bond, such as 2-methoxyethyl, 3-methoxypropyl, Examples include 4-methoxybutyl, 2-butoxyethyl, methoxyethoxyethyl, methoxyethoxyethoxyethyl, 3-methoxybutyl, 2-phenoxyethyl, 2-methylthioethyl, and 2-phenylthioethyl. These groups may be substituted with the aforementioned alkoxy group, alkenyl group, nitro group, cyano group, halogen atom or the like.
Y1 and Y2 are preferably a hydrocarbon group having 1 to 8 carbon atoms, since the molar extinction coefficient of the cyanine compound becomes small and the sensitivity may be affected if the substituent is large, and the alkyl group having 1 to 8 carbon atoms is preferable. Groups are more preferred.

In the general formula (I), examples of the anion represented by An ^m- include halogen anions such as chlorine anion, bromine anion, iodine anion, and fluorine anion; perchlorate anion, chlorate anion, and thiocyanate. Inorganic anions such as anions, phosphorus hexafluoride anions, antimony hexafluoride anions, boron tetrafluoride anions; benzenesulfonate anions, toluenesulfonate anions, trifluoromethanesulfonate anions, diphenylamine-4-sulfonate anions, 2 -Organic sulfonate anions such as amino-4-methyl-5-chlorobenzenesulfonate anion, 2-amino-5-nitrobenzenesulfonate; octyl phosphate anion, dodecyl phosphate anion, octadecyl phosphate anion, phenyl phosphate anion , Nonylphenyl phosphate anion, organic phosphate anions such as 2,2-methylenebis (4,6-ditert-butylphenyl) phosphonate anion, monovalent anions, benzene disulfonate anion, naphthalene disulfonate And divalent anions such as anions.

  In addition, as a cyanine compound in this invention, a well-known cyanine compound, for example, the thing as described in the patent 2594443 specification, the patent 3659922 specification, the patent 3698708 specification, etc. can be used.

Next, details of each group in the squarylium metal chelate compound represented by the general formula (II) will be described below.
In the general formula (II), examples of the alkyl group which may have a substituent represented by R5, R6, R7 and R8 include, for example, a linear or branched carbon number of 1 to 15, preferably 1 to An alkyl group having 8 carbon atoms or a cyclic alkyl group having 3 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and a pentyl group. , Isopentyl group, 1-methylbutyl group, 2-methylbutyl group, tert-pentyl group, hexyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and the like. In addition, vinyl group, allyl group, 1-propenyl group, methacryl group, crotyl group, 1-butenyl group, 3-butenyl group, 2-pentenyl group, 4-pentenyl group, 2-hexenyl group, 5-hexenyl group, 2 A group having an unsaturated bond such as a heptenyl group and a 2-octenyl group is also included in the alkyl group in the general formula (II).

  In the general formula (II), the aralkyl group which may have a substituent represented by R5, R6, R7 and R8 is preferably an aralkyl group having 7 to 15 carbon atoms, such as a benzyl group or a phenethyl group. , Phenylpropyl group, naphthylmethyl group and the like.

  In the general formula (II), the aryl group which may have a substituent represented by R5, R6, R7 and R8 is preferably one having 6 to 18 carbon atoms, for example, a phenyl group, a naphthyl group, An anthryl group, an azulenyl group, etc. are mentioned. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

  In the general formula (II), the alkyl group moiety of the alkoxy group which may have a substituent represented by R6 can be a chain or cyclic alkyl group. In the case of a chain, those having 1 to 6 carbon atoms are preferable, and in the case of a ring, those having 3 to 8 carbon atoms are preferable. Specific examples of the alkyl group include the same alkyl groups as described above.

In the general formula (II), examples of the heterocyclic group optionally having a substituent represented by R7 and R8 include at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom. 5-membered or 6-membered monocyclic aromatic or aliphatic heterocycle, bicyclic or tricyclic fused with 3 to 8 membered ring and at least one selected from nitrogen atom, oxygen atom and sulfur atom And a condensed aromatic or aliphatic heterocyclic ring containing the above-mentioned atoms.
Specifically, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, quinoline ring, isoquinoline ring, phthalazine ring, quinazoline ring, quinoxaline ring, naphthyridine ring, cinnoline ring, pyrrole ring, pyrazole ring, imidazole ring, triazole ring, Tetrazole ring, thiophene ring, furan ring, thiazole ring, oxazole ring, indole ring, isoindole ring, indazole ring, benzimidazole ring, benztriazole ring, benzothiazole ring, benzoxazole ring, purine ring, carbazole ring, pyrrolidine ring, Piperidine ring, piperazine ring, morpholine ring, thiomorpholine ring, homopiperidine ring, homopiperazine ring, tetrahydropyridine ring, tetrahydroquinoline ring, tetrahydroisoquinoline ring, tetrahydrofuran ring, teto Hydropyran ring, dihydrobenzofuran ring, tetrahydrocarbazole ring, and the like.

  In the general formula (II), examples of the alkyl group which may have a substituent represented by R9 and R10 include the same alkyl groups as described above. The ring structure formed by linking R9 and R10 preferably includes those having 3 to 8 carbon atoms, and may be saturated or unsaturated, such as a cyclopropane ring or a cyclobutane ring. , Cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclopentene ring, 1,3-cyclopentadiene ring, cyclohexene ring, cyclohexadiene ring and the like.

  Examples of the substituent in the general formula (II) such as an alkyl group, an aralkyl group, an aryl group, an alkoxy group, and a heterocyclic group include a hydroxyl group, a carboxyl group, a halogen atom, an alkyl group, an alkoxy group, a nitro group, and a substituent. And an amino group which may have. Examples of the halogen atom, alkyl group, and alkoxy group include the same ones as described above. These substituents can be one or more in the molecule. Examples of the substituent of the amino group include one or two alkyl groups which may be the same or different, and examples of the alkyl group in this case include the same ones as described above.

  In the general formula (II), M represents a metal atom having coordination ability, and examples thereof include metals selected from aluminum, iron, cobalt, nickel, manganese, zinc, beryllium, magnesium and calcium. In particular, aluminum can be preferably used for a write-once DVD disc system in terms of optical characteristics and light resistance.

  In addition, as a squarylium metal chelate compound in this invention, a well-known compound, for example, the thing as described in WO2002-050190, Unexamined-Japanese-Patent No. 2004-244342, etc. can be used.

  In the present invention, as described above, the change in pH of the coating solution over time is suppressed, and the pH of the coating solution is maintained at 5.5 or higher, so that the coating solution needs to be in a moisture-free state (a state in which moisture is reduced to a minimum). is there. That is, it is important to use a dehydrated solvent for dissolving (or dispersing) the cyanine compound and squarylium metal chelate compound. The method for removing water in the solvent is not limited, but since it can be easily and efficiently dehydrated, a crystalline zeolite (molecular sieve) comprising a hydrous metal salt of a synthetic crystalline aluminosilicate that is readily available as a commercial product. ) Is preferably used for dehydration.

Here, as a solvent used for preparing the coating liquid, generally, alcohols such as methanol, ethanol, and isopropanol; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; amides such as N, N-dimethylformamide and N, N-dimethylacetamide Sulfoxides such as dimethyl sulfoxide; ethers such as tetrahydrofuran, dioxane, diethyl ether and ethylene glycol monomethyl ether; esters such as methyl acetate and ethyl acetate; chloroform, methylene chloride, dichloroethane, carbon tetrachloride, trichloroethane, etc. Aliphatic halogenated hydrocarbons; aromatics such as benzene, xylene, monochlorobenzene and dichlorobenzene; cellosolves such as methoxyethanol and ethoxyethanol Hexane, pentane, cyclohexane, hydrocarbons such as methylcyclohexane; 2,2,3,3-tetrafluoro-1-propanol, fluorinated alcohols such.
In particular, when a fluorine-substituted alcohol is used, the cyanine compound and squarylium metal chelate compound in the present invention are uniformly dissolved and are not easily affected by humidity, and the recording layer is stable by suppressing pH change over time of the coating solution. Formed.

  In the production method of the present invention, the recording layer is formed (film formation) by a coating method such as a spin coater. At this time, an excess coating solution is scattered and discharged, and this is collected and stored in a tank (container). In this case, the recovered coating solution can be reused to form another recording layer. At this time, in order to prevent chemical changes (oxidation reaction, etc.) due to moisture absorption of the coating liquid collected and stored in the container, a crystalline zeolite (molecular sieve) composed of a hydrous metal salt of synthetic crystalline aluminosilicate is contained in the container. It is preferable to keep.

  By the production method of the present invention, a stable recording layer containing a cyanine compound and a metal complex-type squarylium compound is formed, and high-speed recording performance, reduction of recording wavelength dependency, light resistance, etc., which are the characteristics of each, are well balanced. Thus, an optical information recording medium that can be applied to a write-once DVD medium that achieves both high-speed recording characteristics and archival performance (durability) is obtained.

Hereinafter, the configuration of the optical information recording medium of the present invention will be described using CD-R, DVD + R, and DVD-R media as examples.
FIG. 2 is a schematic sectional view showing an example of the layer structure of the optical information recording medium of the present invention.
The optical information recording medium of FIG. 2 has a layer structure in which a recording layer 2 made of a dye, a reflective layer 3, a protective layer 4, an adhesive layer 5, and a cover substrate 6 are sequentially provided on a substrate 1, and from the substrate 1 surface side. Recording / reproduction is performed by light (laser light). In the configuration of FIG. 2, an inorganic film or the like formed by sputtering or the like may be provided on and / or below the recording layer 1.
The materials used for the substrate, the dye recording layer, the reflective layer, the protective layer, the adhesive layer, and the cover substrate constituting the optical information recording medium of the present invention will be specifically described.

<Board>
The substrate used in the present invention is translucent and can be arbitrarily selected from various materials used as substrates for conventional information recording media. Examples of such substrate materials include acrylic resins such as polymethyl methacrylate, vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymers, epoxy resins, polycarbonate resins, amorphous polyolefins, polyesters, and soda lime glass. Mention may be made of glass and ceramics. In particular, polymethyl methacrylate, polycarbonate resin, epoxy resin, amorphous polyolefin, polyester, glass, and the like can be mentioned from the viewpoint of dimensional stability, transparency, and planarity. Furthermore, polycarbonate resin is preferable from the viewpoint of ease of molding.
Further, a tracking guide groove (groove) and / or guide pit (pit) may be formed on the surface, and a preformat such as an address signal may be further formed.
Note that one of the features of a recording medium that can be played back by a CD player such as DVD + R and CD-R is that track information is recorded by wobbling guide grooves or pit rows in a meandering manner. The meandering state of the guide groove can be detected from the track signal as a wobble signal, and the track information is recorded in advance on the substrate by FM modulation or phase modulation of a predetermined frequency. The track information is address information, disk rotation frequency information, and the like. When detected from the track signal, the track information is easily separated from the information data signal and has a feature of easily obtaining ROM signal compatibility.

<Recording layer>
As the material used for the recording layer, the above-mentioned cyanine compound and squarylium metal chelate compound are indispensable. In addition to these, in order to improve light resistance, optical properties, temperature and humidity resistance, etc. Other pigments can also be mixed as components.
Examples of such materials include other cyanine dyes, phthalocyanine dyes, pyrylium / thiopyrylium dyes, azurenium dyes, squalene dyes, azo dyes, formazan chelate dyes, Ni, Cr and other metals. Examples thereof include complex salt dyes, naphthoquinone dyes / anthraquinone dyes, indophenol dyes, indoaniline dyes, triphenylmethane dyes, triallylmethane dyes, aminium dyes / diimmonium dyes, and nitroso compounds.
When a coating method is used, the recording layer can be formed by dissolving the above compound in an organic solvent and using a conventional coating method such as spraying, roller coating, dipping or spin coating. As the organic solvent, the aforementioned solvents are used.
A preferable pigment film thickness is 40 to 1000 mm. This is because if the dye film thickness is thinner than this range, it is difficult to obtain the degree of signal modulation (contrast). On the contrary, if the dye film thickness is thick, the mark shapes are difficult to align and jitter is likely to increase.

<Reflective layer>
A reflective layer is provided on the recording layer for the purpose of improving the S / N ratio, the reflectance, and the sensitivity during recording. The material (light reflective substance) used for the reflective layer is a substance having a high reflectance with respect to laser light. Examples thereof include Mg, Se, Y, Ti, Zr, Hf, V, Nb, Ta, and Cr. , Mo, W, Mn, Re, Fe, Co, Ni, Ru, Rh, Pd, Ir, Pt, Cu, Ag, Au, Zn, Cd, Al, Ca, In, Si, Ge, Te, Pb, Po , Sn, Si, Nd and other metals and metalloids. Among these, Au, Al and Ag are preferable. These substances may be used alone or in combination of two or more or as an alloy. The thickness of the reflective layer is generally in the range of 100 to 3000 mm. Moreover, as a general method for forming the reflective layer, sputtering such as vacuum film forming means can be cited.

<Protective layer>
Further, a protective layer is provided on the recording layer or the reflective layer for the purpose of physically and chemically protecting the light absorption layer and the like. This protective layer may be provided on the side of the substrate where the light absorption layer is not provided for the purpose of improving scratch resistance and moisture resistance. Examples of materials used for the protective layer include inorganic substances mainly composed of SiO, SiO ₂ , MgF ₂ , SnO ₂ , ZnS, ZnO, etc., thermoplastic resins, thermosetting resins, UV curable resins. Can do. The thickness of the protective layer is generally in the range of 500 to 50 μm.

<Adhesive layer>
For example, it is provided for bonding the protective layer and the cover substrate. As the material used for the adhesive layer, an existing acrylate-based, epoxy-based, urethane-based ultraviolet curable adhesive or thermosetting adhesive can be used. Furthermore, the method of bonding with a transparent sheet may be used.

<Cover substrate>
For example, polymethyl methacrylate, polycarbonate resin, epoxy resin, amorphous polyolefin, polyester, and glass are used.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not limited to these.

(Example 1)
A substrate having a guide groove uneven pattern having a depth of about 1600 mm, a width of about 0.24 μm, and a track pitch of 0.74 μm was prepared on the surface of a polycarbonate disk having a diameter of 120 mm and a thickness of 0.6 mm.
On the other hand, a cyanine dye compound having a structure represented by the following formula (V) and a squarylium metal chelate dye compound having a structure represented by the following formula (VI) were subjected to 2,2,3,3-tetrafluoro-1- A coating solution was prepared by dissolving in propanol (2,2,3,3-tetrafluoropropanol).

[Coating solution preparation conditions]
First, dehydration treatment was performed on 2,2,3,3-tetrafluoropropanol using molecular sieves (Sakai Kogyo Co., Ltd .: 3A pellets), and then each of the above-mentioned dye compounds was dissolved in this solvent to prepare a coating solution. . The pigment concentration in the coating solution was 1.0% by weight, and the mixing ratio [(V) / (VI)] of each pigment compound was 60/40 by weight.

  On the substrate prepared above, a recording layer made of a dye having a thickness of about 80 nm was formed by spin coating using the prepared coating solution and a solution that had passed for one month.

(Example 2)
In the spin coating process using the coating liquid performed in the recording layer formation of Example 1, excess coating liquid scattered during coating film formation was collected in a tank. The collection was carried out for about one month.
Here, the molecular sieve was accommodated in the tank for collecting the coating solution, and dehydration treatment was performed so that the solvent in the coating solution did not absorb water. A recording layer was formed in the same manner as in Example 1 except that the recording layer was formed using the coating solution collected over about one month.

(Comparative Example 1)
In Example 1, except that the 2,2,3,3-tetrafluoropropanol was not dehydrated, each of the dye compounds was dissolved in the same manner as in Example 1 to prepare a coating solution.
In the same manner as in Example 1, a recording layer made of a dye having a thickness of about 80 nm was formed on the substrate by spin coating using the prepared coating solution and the solution that had passed for one month.

(Comparative Example 2)
In the spin coating process using the coating liquid carried out in the recording layer formation of Comparative Example 1, surplus coating liquid scattered during coating film formation was collected in a tank. The collection was carried out for about one month.
Here, the molecular sieve is not accommodated in the tank for collecting the coating liquid. A recording layer was formed in the same manner as in Comparative Example 1 except that the recording layer was formed using the coating solution collected over about one month.

  The light absorption spectrum and pH of the coating solutions prepared in Examples 1 and 2 and Comparative Examples 1 and 2 were measured. Regarding the light absorption spectrum, the spectrophotometer pH manufactured by Shimadzu Corporation was measured using a pH meter manufactured by Horiba. The measurement results of the light absorption spectrum are shown in FIG. 3, and the measurement results of pH are shown in Table 2 below.

  Next, an Ag alloy (Ag / In: 99.5 /) is formed on each recording layer formed on the substrate in Examples 1 and 2 and Comparative Examples 1 and 2 by sputtering using Ar as a sputtering gas. 0.5) was provided to a thickness of about 1400 mm to form a reflective layer. Further, a protective layer made of an ultraviolet curable resin is provided thereon with a thickness of about 4 μm to form a disk body, which is bonded to a polycarbonate cover substrate of the same shape with an ultraviolet curable resin adhesive to record each optical information. A medium (DVD + R in this case) was obtained.

About each optical information recording medium produced above, it evaluated on the following evaluation conditions using the disk evaluation apparatus (ODU-1000 and DDU-1000) by a Pulsock company.
[Signal recording]
DVD (8-16) signal was recorded under the conditions of wavelength: 659 nm, NA: 0.65, linear velocity: 16 × velocity (55.8 m / s). As a recording condition, a pulse emission pattern according to the DVD + R standard was adopted.
[Reproduction (jitter, reflectance)]
Reproduced with DVD-ROM player optical system (NA: 0.60, wavelength: 650nm) at 1x speed (3.5m / s), pit edge-clock jitter (σ / T) to time interval analyzer Measured. The reflectance of the reflected signal was measured. The standard values are a jitter of 9% or less and a reflectance of 45% or more. The results are shown in Table 2 below together with the pH measurement results.

From the results of Example 1 and Comparative Example 1, in the coating solution of the comparative example using the solvent not subjected to the dehydration treatment, the oxidation reaction proceeds with time, and the light absorption spectrum greatly changes as shown in FIG. On the other hand, as shown in Table 2, it can be seen that sufficient signal characteristics are not obtained. That is, the standard values of jitter (jitter) of 9% or less and reflectance of 45% or more are not satisfied. Further, from the results of Example 2 and Comparative Example 2, in the case of the comparative example in which the molecular sieve is not accommodated in the recovery tank, the oxidation reaction of the coating solution progresses over time, the pH also fluctuates, and the light absorption spectrum Has also changed significantly. Jitter is also 9% or more, the reflectance is smaller than 45% and does not satisfy the standard value, and sufficient signal characteristics are not obtained.
That is, the manufacturing method of the present invention does not change the coating solution even for long-term storage and repeated use, and can stably form a recording layer having high-speed recording characteristics and excellent durability, and is applicable to a DVD disk system. It is possible to provide a possible optical information recording medium.

It is a figure which shows the change of the light absorption spectrum in the time of the coating liquid containing a cyanine compound and a squarylium compound in the solvent which does not perform a dehydration process. It is a schematic sectional drawing which shows the layer structural example of the optical information recording medium of this invention. It is a light absorption spectrum figure of each coating liquid in Examples 1 and 2 and Comparative Examples 1 and 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Recording layer 3 Reflective layer 4 Protective layer 5 Adhesive layer 6 Cover substrate

Claims (6)

At least a cyanine compound represented by the following general formula (I) and a squarylium metal chelate compound represented by the following general formula (II) were dehydrated on a translucent substrate having grooves and / or pits formed on the surface. A method for producing an optical information recording medium, wherein a recording layer is formed by a coating method using a coating solution contained in a solvent and having a pH of 5.5 or more.

(In the formula, ring A and ring B are a benzene ring or a naphthalene ring which may have a substituent, and R1 to R4 are benzyl groups in which at least one of them may have a substituent. The remaining group that is not a benzyl group is an alkyl group having 1 to 4 carbon atoms, or a group in which R1 and R2 or R3 and R4 are linked to form a 3- to 6-membered ring, and Y1 and Y2 are each independently carbon (An ^m- represents an m-valent anion, m is an integer of 1 or 2, and p is a coefficient that keeps the charge neutral.)

(In the formula, R7 and R8 may be the same as or different from each other, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, and a substituent. R5 represents a hydrogen atom, an alkyl group which may have a substituent, or a substituent, which may be an aryl group which may have a substituent or a heterocyclic group which may have a substituent. R6 represents a halogen atom, a nitro group, a cyano group, or an alkyl group that may have a substituent, which may be an aralkyl group that may have or an aryl group that may have a substituent. Represents an aralkyl group which may have a substituent, an aryl group which may have a substituent, and an alkoxy group which may have a substituent, and R9 and R10 may be the same or May be different and have substituents R 9 and R 10 may be linked to form a ring structure, M represents a metal atom having coordination ability, and n represents an integer of 2 or 3. ) The cyanine compound represented by the general formula (I) is represented by the following general formula (III), and the squarylium metal chelate compound represented by the general formula (II) is represented by the following general formula (1V). The method of manufacturing an optical information recording medium according to claim 1, wherein

(In the formula, ring A and ring B are a benzene ring or a naphthalene ring which may have a substituent, and R1 to R4 are benzyl groups in which at least one of them may have a substituent. The remaining group that is not a benzyl group is an alkyl group having 1 to 4 carbon atoms, or a group in which R1 and R2 or R3 and R4 are linked to form a 3- to 6-membered ring, and Y1 and Y2 are each independently carbon (It is an organic group of the number 1-30.)

(In the formula, R7 and R8 may be the same as or different from each other, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, and a substituent. R5 represents a hydrogen atom, an alkyl group which may have a substituent, or a substituent, which may be an aryl group which may have a substituent or a heterocyclic group which may have a substituent. R6 represents a halogen atom, a nitro group, a cyano group, or an alkyl group that may have a substituent, which may be an aralkyl group that may have or an aryl group that may have a substituent. Represents an aralkyl group which may have a substituent, an aryl group which may have a substituent, and an alkoxy group which may have a substituent, and R9 and R10 may be the same or May be different and have substituents Or an alkyl group which may or R9 and R10 may form a ring structure linked.)   3. The method for producing an optical information recording medium according to claim 1, wherein the solvent is dehydrated using a crystalline zeolite made of a hydrous metal salt of synthetic crystalline aluminosilicate.   The method for producing an optical information recording medium according to claim 1, wherein the solvent is a fluorine-substituted alcohol.   The method for producing an optical information recording medium according to any one of claims 1 to 4, wherein an excess coating liquid splashed and discharged when forming the recording layer is a crystalline zeolite comprising a hydrous metal salt of synthetic crystalline aluminosilicate. A method for producing an optical information recording medium, comprising: collecting and storing in a container housing the recording layer, and forming a recording layer using the collected and stored coating liquid. An optical information recording medium obtained by the manufacturing method according to claim 1.

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