JPS63191689A - Production of information recording medium - Google Patents

Abstract

PURPOSE:To facilitate preparing a coating liquid for forming a recording layer and prevent a substrate from being dissolved by the coating liquid, by using a fluorinated nitrile compound as a solvent for preparing the coating liquid. CONSTITUTION:A fluorinated nitrile compound is an organic compound containing at least one fluorine atom and a cyano group in one molecule thereof, and may be any such compound capable of serving as a solvent for a coloring matter. The coloring matter may be any one conventionally known as a recording material for an information recording medium. The fluorinated nitrile compound used as the solvent ensures high solubilities of the coloring matters therein, so that a coating liquid for forming a recording layer can be easily prepared. The compound does not dissolve a substrate constituted of a plastic material such as a polycarbonate, so that the substrate will not be dissolved in the coating process.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a method for manufacturing an information recording medium on which information can be written and/or read using a high energy density laser beam.

[Technical Background of the Invention] In recent years, information recording media that use high energy density beams such as laser light have been developed and put into practical use. This information recording medium is, for example, an optical disc such as a video disc or an audio disc, a large-capacity still image file, a large-capacity computer disk memory, an optical card, a micro image recording medium, an ultra-micro image recording medium, or a micro image recording medium. It is applied to facsimiles, original plates for phototypesetting, etc.

An information recording medium basically consists of a transparent substrate made of plastic, glass, etc., and a recording layer provided thereon. Materials for the recording layer include Bi, Sn, In, and T.
Metals or semimetals such as e, and pigments of cyanine type, metal complex type, guinone type, etc. are known.

Information is written on an information recording medium by, for example, irradiating the recording medium with a laser beam.
The irradiated portion of the recording layer absorbs the light and locally increases in temperature, resulting in a physical or chemical change that changes its optical properties, thereby recording information. Information is also read from a recording medium by irradiating the recording medium with a laser beam, and the information is reproduced by detecting reflected or transmitted light depending on changes in the optical characteristics of the recording layer.

Recently, as a disk structure for protecting the recording layer, a recording layer is provided on at least one of the two disk-shaped substrates, and the recording layer is located inside the two disk-shaped substrates. Also, an air sandwich structure has been proposed in which a ring-shaped inner spacer and a ring-shaped outer spacer are joined to form a space. In information recording media with such a structure, the recording layer is not in direct contact with the outside air, and information is recorded and reproduced using laser light that passes through the substrate. It will not be damaged or have dust attached to its surface, which will not interfere with recording or reproducing information.

Information recording media that use dyes as recording materials have excellent properties such as high sensitivity, as well as manufacturing advantages such as the ability to easily form a recording layer on a substrate using a coating method. It has great advantages.

Most dyes, such as cyanine dyes, generally have low solubility, and when preparing coating solutions, halogenated hydrocarbons such as dichloromethane and dichloroethane are usually used as solvents with high solubility for dyes.

However, plastic substrates have poor solvent resistance to these halogenated hydrocarbon solvents, and when the coating liquid is applied, the substrate surface dissolves, causing irregularities such as tracking groups provided on the substrate surface. disappear or
There are problems such as a decrease in the reflectance of the recording layer due to the mixing of the substrate material into the recording layer. In order to solve this problem, for example, Japanese Patent Application Laid-open No. 59-217241 describes that a plastic substrate is previously subjected to insolubilization treatment in a halogenated hydrocarbon solvent.

[Summary of the Invention] An object of the present invention is to provide a method for manufacturing an information recording medium using a novel solvent.

Another object of the present invention is to provide a method for forming a recording layer on a substrate by the cloth method without dissolving the substrate when manufacturing an information recording medium.

A further object of the present invention is to provide a method for easily manufacturing an information recording medium.

The above object is a method for manufacturing an information recording medium in which a recording layer on which information can be written and/or read by a laser is provided on a substrate, in which a dye is dissolved in a solvent containing a fluorine-substituted nitrile compound. This can be achieved by the method for manufacturing an information recording medium of the present invention, which comprises preparing a coating liquid, and then applying the coating liquid onto a substrate and drying it to form a recording layer.

That is, the present invention uses a fluorine-substituted nitrile compound as a solvent for preparing a coating solution for forming a recording layer using a dye as a recording material, thereby facilitating the preparation of the coating solution and dissolving the substrate with the coating solution. This is to prevent

In the present invention, the fluorine-substituted nitrile compound used as a solvent has a high solubility for dyes such as cyanine dyes, so that a coating liquid for forming a recording layer can be easily prepared. Furthermore, since this compound is insoluble in a substrate made of a plastic material such as polycarbonate, the substrate will not dissolve during the coating process.

Therefore, according to the present invention, a high-performance information recording medium can be manufactured without causing problems such as disappearance of groups on the substrate surface and decrease in reflectance of the recording layer, which have been problems in the past. Further, since there is no need to previously perform insolubilization treatment on the substrate with respect to a solvent, the manufacturing process of the recording medium does not become complicated and the manufacturing cost does not increase.

[Structure of the Invention] An information recording medium can be manufactured, for example, by the method of the present invention as described below.

The substrate used in the present invention can be arbitrarily selected from various materials used as substrates for conventional information recording media. Optical properties, flatness, processability of the substrate,
In terms of ease of handling, stability over time, and manufacturing cost,
Examples of substrate materials include acrylic resins such as cell cast polymethyl methacrylate and injection molded polymethyl methacrylate; vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymers; epoxy resins; and polycarbonate resins, amorphous polyolefins, and polyesters. ;
Mention may be made of glasses such as soda-lime glass and ceramics.

The method of the present invention is particularly effective when the substrate material is a plastic material, and among these, it can be suitably applied when it is polycarbonate, polymethyl methacrylate, epoxy resin, amorphous polyolefin, polyester, or polyvinyl chloride. In addition, from the viewpoint of dimensional stability, transparency, flatness, etc., preferred are:
These are polymethyl methacrylate, polycarbonate resin, epoxy resin, amorphous polyolefin, polyester and glass. Note that these materials can be used in the form of a film or as a rigid substrate.

The surface of the substrate on which the recording layer is provided has improved flatness,
For the purpose of improving adhesive strength and preventing deterioration of the recording layer, an undercoat layer may be provided. Examples of materials for the undercoat layer include polymethyl methacrylate, acrylic acid/methacrylic acid copolymer, styrene/anhydride. Maleic acid copolymer, polyvinyl alcohol, N-methylol acrylamide, styrene sulfonic acid copolymer, styrene/vinyltoluene, 1141, chlorosulfonated polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, Polymer substances such as vinyl acetate/vinyl chloride copolymer, ethylene/vinyl acetate copolymer, polyethylene, polypropylene, polycarbonate; organic substances such as silane coupling agents; and inorganic oxides (Sio2.A120 etc.), inorganic Fluoride (MgF
Examples include inorganic substances such as 2).

In the case of a glass substrate, in order to prevent adverse effects on the recording layer due to alkali metal ions and alkaline earth metal ions liberated from the substrate, wood-philic groups such as styrene ψ maleic anhydride copolymer and/or maleic anhydride are added. Preferably, a subbing layer consisting of a polymer having # groups is provided.

The undercoat layer can be formed by, for example, preparing a coating solution by dissolving or dispersing the above substances in an appropriate solvent, and then applying this coating solution to the substrate surface by a coating method such as spin code, dip coating, or extrusion coating. It can be formed by The layer thickness of the undercoat layer is generally 0.005 to 20
gm, preferably o, oi to lOpm.

Further, a pre-groove layer may be provided on the substrate (or undercoat R) for the purpose of forming tracking grooves or unevenness representing information such as address signals.As a material for the pre-groove layer, acrylic acid A mixture of at least one type of monoester, diester, triester, and tetraester (or oligomer) and a photopolymerization initiator can be used.

The pre-groove layer is formed by first coating a mixture of the above acrylic ester and polymerization initiator on a precisely made matrix (stamper), then placing the substrate on top of this coating solution layer. , the substrate and the liquid phase are fixed by curing the liquid layer by irradiating ultraviolet rays through the substrate or the matrix.
Next, by peeling the substrate from the mother mold, a substrate provided with a pregroove layer is obtained. The thickness of the pregroove layer is generally in the range of O,OS to 100 μm, preferably in the range of 0.1 to 50 pm. If the substrate material is plastic, the groups may be provided directly on the substrate by injection molding, extrusion molding, or the like.

Note that the fluorine-substituted nitrile compound used as a solvent in the present invention is not only insoluble in the plastic substrate, but also almost insoluble in this pre-groove layer material, so it is not necessary to provide the recording layer directly on the substrate. Similar effects can be obtained not only when the recording layer is provided on the pregroove layer.

A recording layer is provided on the substrate (or pregroove layer, etc.).

The recording layer is a layer consisting essentially only of a dye, or a layer consisting of a dye and a binder containing the dye dispersed therein.

As the dye in the present invention, any dye conventionally known as a recording material for information recording media can be used. For example, cyanine dyes, phthalocyanine dyes, biryllium/thiopyrylium dyes, azulenium dyes, squarylium dyes, metal complex dyes such as Nf and Cr, naphthoquinone-anthraquinone dyes, indophenol dyes, and indoaniline dyes. dye,
triphenylmethane dyes, triallylmethane dyes,
Examples include aminium-based and diimmonium-based dyes and nitroso compounds.

Margin below Among these, dyes with a high absorption rate for light in the near-infrared region of 700 to 900 nm are preferred, since 11 semiconductor lasers that emit near-infrared light are used in practical use as lasers for recording and reproduction. .

Examples include: i) Cyanine dye: [11(GHx)2N-(OHmaroOH) 5-CH-◆
N(CH3)2 C04- (however, n is 2 or 3
(However, R is a hydrogen atom or N(CH3)2) [4] A-(OH-OH). -〇H-8, and R
is an alkyl group or a counter ion; in some cases, a chlorine atom, an alkyl group, an alkoxy group, or an aryl group may be present in the benzene ring or naphthalene ring, and n is an integer of 0 to 3) (However, R is an alkyl group, and X is a halogen atom.) (However, R is a substituted or unsubstituted alkyl group, alkoxy group, aralkyl group, or alkenyl group, and X is a hydrogen atom or a halogen atom. ), Y is halogen, perchlorate, substituted or unsubstituted benzenesulfonate, paratoluenesulfonate, methylsulfate, ethylsulfate, benzenecarboxylate, methylcarboxylate or trifluoromethylcarboxylate, and n is O~ is an integer of 3) (but
R1, R2 and R3 are each substituted or unsubstituted alkyl groups, and may be the same or different from each other,
X- is a perhalogen ion, a toluenesulfonic acid ion or an alkyl sulfonic acid ion, and n is an integer of O to 3.

A halogen atom is present in at least one of the 4th, 5th, 6th, and 7th positions of the indolenine ring, and further halogen atoms may optionally be present in other positions, and further optionally benzene The ring may be substituted with an alkyl group, an alkoxy group, a hydroxy group, a carboxy group, an allyl group, or an alkylcarbonyl group) (However, A1 and A2 are each a hydrogen atom or a substituent, and Z represents a member heterocycle. R1 and R4 are each a hydrogen atom or a substituent, R5 is a substituent or may form a six-membered heterocycle with Z, and x- is an anion. and n is 0~
(an integer of 2) Below the margin [11] Φ-L='l' (X-) @ (However, Φ and ! are indole ring residues and thiazole ring residues, respectively, which may be fused with an aromatic ring. , an oxazole ring residue, a selenazole ring residue, an imidazole ring residue or a pyridine ring residue, and L is a linking group for forming monocarbocyanine, dicarbocyanine, tricarbocyanine or tetracarbocyanine, X- is an anion, m is O or l) ii) squarylium dye: 1ii) azulenium dye: (Tatashi, R1 to R2, R2, !l: R3, R3 to R4
, R1, R2, 11i3 when at least one of the combinations of R4 and R5, R5 and R6, and R6 and R7 forms a whole ring of substituted or unsubstituted heterocycles or aliphatic rings and does not form a linear ring. ．． R4, R5, R6 and R7 are each a hydrogen atom, a halogen atom or a monovalent organic residue; =R2, R3
4. At least one combination of R4, R5, R5 and R6, and R6 and R7 may form a substituted or unsubstituted aromatic ring, and A is a divalent organic residue bonded via a double bond. group, and Z- is an anionic residue. Note that at least one carbon atom constituting the azulene ring may be replaced with a nitrogen atom to form an azaazulene ring.) ii) Indophenol dye: (However, X and Y are each a hydrogen atom.

an alkyl group, an acylamino group, an alkoxy group, or a halogen atom, R1, R2, and R3 are each a hydrogen atom, a substituted or unsubstituted alkyl group, an aryl group, a heterocycle, or a cyclohexyl group of CI""C20,
A is -NHCO- or 100NH-) ■) Metal complex dye: (However, R1-R4 are each an alkyl group or an aryl group, and M is a divalent transition metal atom) (However, R1 and R2 are each an alkyl group or a halogen atom, and M is a divalent transition metal atom) (R3)n (R')
n (where RI and R2 are each a substituted or unsubstituted alkyl group or aryl group, and R3 is an alkyl group, a halogen atom, or a substituted or unsubstituted alkyl group or aryl group), and M is a transition metal atom, n is the 0th necessary cation, M is Ni, C
u.

Co, Pd or Pt, n is 1 or 2) (Catl is a cation necessary to neutralize the complex salt, M is Ni, Cu, Co, Pd or pt, , n is 1 or 2 and is a child or methyl group, n is an integer from 1 to 4, and A is a quaternary ammonium group) with spaces below (however, X+ and xl are a nitro group and /
or a halogen atom, nl and R2 are each an integer of 1 to 3, and R1 and R2 are each an amino group, a monoalkylamino group, a dialkylamino group,
an acetylamine group, a benzoylamino group (including substituted benzoylamino groups), and xl and X2. n+ and R2
and R1 and R2 may be the same or different from each other, M is a Cr or co atom, and Y is hydrogen, sodium, potassium, ammonium, aliphatic ammonium (including substituted aliphatic ammonium) or aliphatic ammonium. i) Naphthoquinone-based, anthraquinone-based dye: (R is a hydrogen atom, an alkyl group, an allyl group, an amine group, or a substituted amino group)
(However, R is a hydrogen atom, an alkyl group, an allyl group, an amino group, or a substituted amine group) (However, R is a hydrogen atom, an alkyl group, an allyl group, an amino group, or a substituted amine group) (However, or a halogen is an atom, and n is 0 to
It is an integer of lO) Below is a blank space (However, it is a halogen atom) NH2O, etc. can be mentioned.

Among these dyes, the method of the present invention can be particularly preferably applied to cyanine dyes. In addition,
These dyes may be used alone or as a mixture of two or more, and when cyanine dyes are used, the above metal complex dyes or aminium/diimmonium dyes may be used together as a quencher. good.

The recording layer can be formed by dissolving the dye and, if desired, a binder in a solvent to prepare a coating solution, then applying this coating solution to the surface of the substrate to form a coating film, and then drying the coating solution. can.

The solvent for preparing the coating solution, which is a characteristic requirement of the present invention, includes:
A nitrile compound at least partially substituted with fluorine is used.

Examples of fluorine-substituted nitrile compounds used in uninventions include:
For example, general formula (■): A-CM (I) (where A is a substituted or unsubstituted alkyl group or aryl group having 1 to 20 carbon atoms, and at least one hydrogen atom is substituted with fluorine) ) can be mentioned.

In the above general formula CI), in addition to the fluorine atom, substituents on A include a chlorine atom, a bromine atom, a nitro group, a hydroxyl group,
Examples include substituted or unsubstituted alkyl groups and phenyl groups. Further, the molecular weight of the compound is preferably 400 or less.

Specific examples thereof include the following compounds.

CH2F0M, CF30N.

However, the fluorine-substituted nitrile compound used in the present invention is not limited to the above compounds.

- Any organic compound containing at least one fluorine atom and a cyano group in its molecule as long as it can be used as a solvent for the dye can be used.

In the present invention, the above-mentioned fluorine-substituted nitrile compound may be used alone as a solvent, or may be used in combination with other solvents as a mixed solvent.

Examples of such solvents include toluene, xylene, ethyl acetate, butyl acetate, cellosolve acetate, methyl ethyl ketone, dichloromethane 21.2-dichloroethane, chloroform, dimethyl formamide, methyl isobutyl ketone, cyclohexanone, cyclohexane, tetrahydrofuran, ethyl ether, dioxane. , ethanol, n-propatol, inpropatol, n-butanol, and the like, which can dissolve the dye.

Note that when the fluorine-substituted nitrile compound is solid at room temperature, it is used as a mixed solvent with the above solvent.

The coating solution also contains antioxidants, UV absorbers, plasticizers,
Various additives such as lubricants may be added depending on the purpose.

When a binder is used, examples of the binder include natural organic polymer substances such as gelatin, cellulose derivatives, dextran, rosin, and rubber; hydrocarbon resins such as polyethylene, polypropylene, polystyrene, and polyisobutylene, and polyvinyl chloride. , polyvinylidene chloride, polyvinyl chloride-polyvinyl acetate copolymer, and other vinyl resins.

Synthetic organic polymers such as initial condensates of acrylic resins such as polymethyl acrylate and polymethyl methacrylate, polyvinyl alcohol, chlorinated polyethylene, epoxy resins, butyral resins, rubber derivatives, and thermosetting resins such as phenol/formaldehyde resins. Can list substances.

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

When using a binder as a material for the recording layer.

The ratio of dye to binder is generally between 0.01 and 99% (
It is preferably in the range of 1°0 to 95% (weight ratio). In addition, when the solvent is a mixture of a fluorine-substituted nitrile compound and another solvent, the fluorine-substituted nitrile compound generally accounts for 5 to 95% ( It is preferably used in a range of 30 to 90% (weight ratio). The concentration of the coating liquid thus prepared is generally in the range of 0.01 to io% (weight ratio), preferably in the range of 0.1 to 5% (weight ratio).

The recording layer may be a single layer or a multilayer, but the layer thickness is generally 0.
．． It is in the range of 0.01 to 104 m, preferably 0.02 to 104 m.
It is in the lpm range. Furthermore, the recording layer may be provided not only on one side of the substrate but also on both sides.

Furthermore, on the recording layer, there is a S/N ratio when reproducing information.
A reflective layer may be provided for the purpose of improving the ratio and improving the sensitivity during recording.

The light-reflective substance that is the material of the reflective layer is a substance that has a high reflectance to laser light, and examples thereof include Mg, Se,
, Y, Ti, Zr, Hf, ■, Nb, Ta, Cr, Mo
, W, Mn, Re, Fe, Co, Ni, R
u, Rh, Pd, Ir.

Pt, Cu, Ag, Au, Zn,
Cd, An, Ga, In, Si, G
Mention may be made of metals and metalloids such as e, Te, Pb, Po, Sn, Bi, etc. Among these, the preferred one is A! ;L, Cr and Ni.

These substances may be used alone, or in combination of two or more or as an alloy.

The reflective layer can be formed by, for example, depositing the above-mentioned light-reflecting substance,
It can be formed on the recording layer by taring or ion blating.

The thickness of the reflective layer is generally in the range of 100 to 3000 mm.

Note that the reflective layer may be provided between the substrate and the recording layer, and in this case, information is recorded and reproduced from the recording layer side (the side opposite to the substrate).

Further, a protective layer may be provided on the recording layer (or the reflective layer) for the purpose of physically and chemically protecting the recording layer. It may also be provided on the other side for the purpose of increasing scratch resistance and moisture resistance.

Examples of materials used for the protective layer include SiO, 5i0
2. Inorganic substances such as MgF2.5n02: thermoplastic resin,
Examples include organic substances such as thermosetting resins and UV curable resins.

The protective layer can be formed, for example, by laminating a film obtained by extrusion of plastic onto the recording layer (or silver salt layer or reflective layer) and/or onto the substrate via an adhesive layer. Alternatively, it may be provided by vacuum deposition, sputtering, or coating methods.
In the case of a thermoplastic resin or a thermosetting resin, it can also be formed by dissolving these in an appropriate solvent to prepare a coating liquid, then applying this coating liquid and drying it. In the case of a UV curable resin, it can also be formed by preparing a coating liquid as it is or by dissolving it in an appropriate solvent, applying this coating liquid, and curing it by irradiating it with UV light. Various additives such as antistatic agents, antioxidants, and UV absorbers may be further added to these coating liquids depending on the purpose.

The thickness of the protective layer is generally in the range from 0.1 to 1004 m.

In the present invention, the information recording medium may be a single board having the above-mentioned structure, or alternatively, two substrates having the above-mentioned structure may be placed facing each other so that the recording layer is on the inside, and adhesive or the like is used. By joining, a laminated type recording medium can also be manufactured. Alternatively, an air sandwich type recording medium is manufactured by using a substrate having the above configuration as at least one of two disc-shaped substrates and joining them via a ring-shaped inner spacer and a ring-shaped outer spacer. You can also.

Examples and comparative examples of the present invention are described below. However, each of these does not limit the present invention.

[Example 1] Cyanine dye (the above structural formula [5]: 2 g was mixed with trifluoroacetonitrile (structural formula: GF3G
A coating solution (concentration: 2% by weight) was prepared by dissolving it in 100 cc of N).

A disc-shaped polycarbonate substrate with a tracking guide (outer diameter: 130 mm, inner diameter: 15 mm, thickness:
1.2mm, track pitch = 1.374m, group depth: 800 A recording layer having a film thickness of 0.06 lumen was formed.

In this way, an information recording medium consisting of a substrate and a recording layer was manufactured.

[Example 2] In Xi Example 1, pentafluorocarbon F was used as the solvent.
) An information recording medium consisting of a substrate and a recording layer was manufactured by performing the same treatment as in Example 1 except for using the following.

[Comparative Example 1] An information recording medium consisting of a substrate and a recording layer was manufactured by performing the same treatment as in Example 1 except that dichloroethane was used as the solvent.

A recording/reproduction characteristic test was conducted on each of the obtained information recording media. As a result, the recording medium (Examples 1 and 2) manufactured by the method of the present invention using a fluorine-converted nitrile compound as a solvent was able to measure recording and reproducing characteristics along groups on the substrate surface. On the other hand, in the recording medium manufactured by the conventional method (Comparative Example 1), the recording and reproducing characteristics could not be measured because the groups disappeared due to dissolution of the substrate surface.

[Examples 3 and 4] In Examples 1 and 2, a nickel complex salt dye (the above structural formula [21]: is added as a quencher to each coating liquid in equimolar amounts as the cyanine dye) to prepare a coating liquid. An information recording medium consisting of a substrate and a recording layer was manufactured by performing the same treatment as in Examples 1 and 2 except for the above.

[Example 5.6] In Examples 1 and 2, a coating solution was prepared by further adding diimmonium dye (structural formula: % formula %) as a quencher to each coating solution in an equimolar amount as the cyanine dye. An information recording medium consisting of a substrate and a recording layer was manufactured by performing the same treatment as in Examples 1 and 2, respectively.

[Example 7.8 In Examples 1 and 2, the same treatment as in Examples 1 and 2 was carried out, respectively, except that a cyanine dye (J: structural formula [9]: % formula %) was used as the dye. By performing the above steps, an information recording medium consisting of a substrate and a recording layer was manufactured.

[Example 9.10] In Examples 1 and 2, an information recording medium consisting of a substrate and a recording layer was manufactured by performing the same treatment as in Examples 1 and 2, respectively, except that cyani was used as the dye. did.

L Example 11.12] In Examples 1 and 2, the substrate was treated in the same manner as in Examples 1 and 2, respectively, except for using squarylium dye (the above structural formula [13]: An information recording medium comprising a recording layer and a recording layer was manufactured.

When a recording/reproducing characteristic test was conducted on each of the information recording media of Examples 3 to 12, in each case, groups on the substrate surface remained without disappearing, and the recording/reproducing characteristics could be measured along these groups. .

Claims (1)

[Claims] 1. Writing information on the substrate by laser and/or
Alternatively, in a method for manufacturing an information recording medium provided with a readable recording layer, a coating solution is prepared by dissolving a dye in a solvent containing a fluorine-substituted nitrile compound, and then the coating solution is coated on a substrate and dried. A method for manufacturing an information recording medium, comprising forming a recording layer by: 2. The above fluorine-substituted nitrile compound has the general formula (I): A-CN(I) (where A is a substituted or unsubstituted alkyl group or aryl group having 1 to 20 carbon atoms, and at least one 2. The method for producing an information recording medium according to claim 1, which is a compound represented by the following formula (in which hydrogen atoms are substituted with fluorine). 3. The method for producing an information recording medium according to claim 1, wherein the solvent consists only of a fluorine-substituted nitrile compound. 4. The above dye is a cyanine dye, a phthalocyanine dye, pyrylium, a thiopyrylium dye, a squarylium dye, an azulenium dye, an indophenol dye, an indoaniline dye, a triphenylmethane dye, a quinone dye, aminium, Claim 1, characterized in that it is at least one type of dye selected from the group consisting of diimmonium dyes and metal complex dyes.
Method for manufacturing the information recording medium described in Section 1. 5. The method for producing an information recording medium according to claim 4, wherein the dye is a cyanine dye or a mixture of a cyanine dye and another dye. 6. The method for manufacturing an information recording medium according to claim 1, wherein the substrate is made of a plastic material. 7. The substrate according to claim 6, wherein the substrate is made of a type of polymer compound selected from the group consisting of polycarbonate, polymethyl methacrylate, epoxy resin, amorphous polyolefin, polyester, and polyvinyl chloride. Method for manufacturing information recording media. 8. The method for manufacturing an information recording medium according to claim 7, wherein the substrate is made of polycarbonate.