JPH048585A - Manufacture of information recording medium - Google Patents

Abstract

PURPOSE:To prevent the crystallization of a dye to form a uniform layer by a method wherein a coating liquid prepared by dissolving the dye in a solvent containing a specific fluorinated alcohol is applied on a substrate and dried to form a recording layer on which information can be written by a laser light. CONSTITUTION:A coating liquid is prepared by dissolving a dye in a solvent containing a fluorinated alcohol of 99wt.% or more purity, shown by a general formula (I) (A is F(CnF2n) or H(CnF2n), and (n) is an integer of 1-3). The coating liquid is applied on a substrate and dried to form a recording layer on which information can be written by a laser light. For the solvent for preparing the coating liquid, a fluorinated alcohol of 99wt.% or more purity is used. Since a normal low-purity fluorinated alcohol contains impurities, a dye recording layer formed by using such a fluorinated alcohol generates crystallization depending on the combination of a dye, a solvent, a coating condition and the like at the time of forming the dye layer. However, by using a high-purity fluorinated alcohol containing remarkably little impurity as the solvent, a recording layer made of a dye having little possibility of crystallization can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a method of manufacturing an information recording medium on which information can be written 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 disk such as a video disk or an audio disk, a large-capacity still image file, a large-capacity computer disk memory, an optical card, a micro image recording medium, a super 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 BiSn, In,
Metals or semimetals such as Te; and dyes such as cyanine, metal complex, and quinone are known.

Information is written on the 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.

Information recording media that use dyes as recording materials have excellent properties such as high sensitivity, as well as the ability to easily form a recording layer on a substrate using a coating method. It has the above major advantages. Many 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 that have high solubility for dyes. however,
Plastic substrates have poor solvent resistance to these halogenated hydrocarbon solvents, and when the coating solution is applied, the substrate surface dissolves, causing irregularities such as tracking groups on the substrate surface to disappear. In addition, there are problems such as a decrease in the reflectance of the recording layer due to mixing of the substrate material into the recording layer.

As a method to solve such problems, JP-A-63-1
No. 59090 discloses the use of fluorinated alcohol as a solvent for dissolving the dye. It is stated that this makes it possible to dissolve any dye, to easily prepare a dye coating solution, and to coat a dye recording layer without dissolving the surface of a plastic substrate.

[Object of the Invention] The above-mentioned fluorinated alcohol generally 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 fluorinated alcohol does not dissolve substrates made of plastic materials such as polycarbonate, the substrates do not dissolve or swell during the coating process. Therefore, an information recording medium can be manufactured without causing problems such as disappearance of groups on the substrate surface and reduction in reflectance of the recording layer, which have been problems in the past. However, according to studies conducted by the present inventors, it has been found that depending on the dye used, the solvent, coating conditions, etc., the dye in the formed dye recording layer crystallizes during formation or over time. did.

An object of the present invention is to provide a method for manufacturing an information recording medium using a highly purified fluorinated alcohol containing extremely few impurities as a solvent.

Another object of the present invention is to provide a method for forming a recording layer made of a dye that hardly crystallizes on a substrate by a coating 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.

[Summary of the Invention] The present invention provides the following general formula (I) having a purity of 99% by weight or more: A-CH2OH(I) [where A is F(C,F2.,) or H(C,F2.
o), and n is an integer from 1 to 3] After preparing a coating solution by dissolving a dye in a solvent containing a fluorinated alcohol represented by the following formula, the coating solution is coated on a substrate and dried to form a laser beam. A method of manufacturing an information recording medium comprises forming a recording layer on which information can be written.

Preferred embodiments of the method for manufacturing an information recording medium of the present invention are as follows.

1) A method for producing the above information recording medium, characterized in that the method comprises only the above solvent or fluorinated alcohol.

2) The information record characterized in that the content of the fluorinated alcohol having a larger number of carbon atoms than the fluorinated alcohol in the fluorinated alcohol is 0.5% by weight or less based on the entire fluorinated alcohol. Method of manufacturing media.

3) The content of aldehydes in the fluorinated alcohol is 0.5Ji% based on the total fluorinated alcohol.
The method for manufacturing the information recording medium described above, characterized by the following.

4) The content of metal ions in the fluorinated alcohol is
The method for producing the above-mentioned information recording medium, characterized in that the weight is 1100 pp or less.

5) The above dye is a cyanine dye, a phthalocyanine dye, biryllium, a thiopyrylium dye, a squarylium dye, an azulenium dye, an indophenol dye, an indoaniline dye, a triphenylmethane dye, a quinone dye, aminium, The above method for producing an information recording medium, characterized in that the dye is at least one dye selected from the group consisting of diimmonium dyes and metal complex dyes.

6) The method for producing the information recording medium, wherein the dye is a cyanine dye or a mixture of a cyanine dye and another dye.

7) The method for manufacturing the information recording medium, wherein the substrate is made of a plastic material.

8) The method for manufacturing the information recording medium, wherein the substrate is made of polycarbonate, polymethyl methacrylate, or amorphous polyolefin.

9) The method for manufacturing the information recording medium, wherein the substrate is made of polycarbonate.

10) The method for manufacturing the information recording medium, further comprising forming a reflective layer on the recording layer.

11) The method for manufacturing the information recording medium, which further comprises forming a reflective layer and a protective layer in this order on the recording layer.

[Effects of the Invention] The present invention uses a highly purified fluorinated alcohol with a purity of 99% or more as a solvent for preparing a coating solution for forming a recording layer using a dye as a recording material. In addition to the effects of using conventional fluorinated alcohols, which facilitate preparation and prevent the coating solution from dissolving the substrate,
Furthermore, crystallization of the dye, which tends to occur during formation of the dye recording layer or over time after formation, can be prevented, and a uniform layer can be formed.

[Detailed Description 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. Examples of substrate materials include acrylic resins such as polymethyl methacrylate; vinyl chloride resins such as polyvinyl chloride; 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 the substrate material 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 and amorphous polyolefin. 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,
An undercoat layer may be provided for the purpose of improving adhesive strength and preventing deterioration of the recording layer. Examples of materials for the undercoat layer include polymethyl methacrylate, acrylic acid/methacrylic acid copolymer, styrene/maleic anhydride copolymer, polyvinyl alcohol, N-methylolacrylamide, styrene/sulfonic acid copolymer, and styrene/vinyl. Toluene copolymer, chlorosulfonated polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, vinyl acetate/vinyl chloride copolymer, ethylene/vinyl acetate copolymer, polyethylene,
Polymer substances such as polypropylene and polycarbonate; organic substances such as nitrogen coupling agents; and inorganic oxides (Si02, A11203, etc.), inorganic fluorides (MgF
Examples include inorganic substances such as 2).

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

The undercoat layer is formed by, for example, dissolving or dispersing the above substances in a suitable solvent to prepare a coating solution, and then applying this coating solution to the substrate surface using a coating method such as spin code, dip coating, or extrusion coating. can do. The layer thickness of the undercoat layer is generally o, oos ~ 20
It is in the range of μm, preferably in the range of 0.01 to 10 μm.

Further, a pregroove layer may be provided on the substrate (or undercoat layer) for the purpose of forming tracking grooves or irregularities representing information such as address signals. As the 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 pre-groove layer is formed by first coating a mixture of the above acrylic ester and polymerization initiator on a precisely made matrix (stambar), then placing the substrate on top of this coating layer. Then, the liquid layer is cured by irradiation with ultraviolet rays through the substrate or the matrix, thereby fixing the substrate and the liquid phase.

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 0.05 to 100 μm, preferably in the range of 0.1 to 50 μm. If the substrate material is plastic, the groups may be provided directly on the substrate by injection molding, extrusion molding, or the like.

An intermediate layer may be provided on the substrate (or the pregroove layer, etc.) to improve sensitivity and the like.

Preferred materials for the intermediate layer are polymethyl methacrylate, nitrocellulose, chlorinated polypropylene, chlorinated polyethylene, fluororesin, and polycarbonate.

Note that the fluorine-containing compound used as a solvent in the present invention is not only insoluble in the plastic substrate, but also almost insoluble in the pregroove layer material and the intermediate layer material. Similar effects can be obtained not only when the recording layer is provided directly but also when the recording layer is provided on the break loop 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 that disperses the dye.

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, pyrylium/thiopyrylium dyes, azulenium dyes, squarylium dyes, metal complex dyes with Ni, Cr, etc., naphthoquinone/anthraquinone dyes, indophenol dyes, and indoaniline. dyes,
triphenylmethane dyes, triallylmethane dyes,
Examples include aminium-based and diimmonium-based dyes and nitroso compounds.

Margins Below Among these, dyes with a high absorption rate for light in the near-infrared region of 700 to 900 nm are preferred, since semiconductor lasers that emit near-infrared light have been put to practical use as recording and reproducing lasers.

Preferred examples include: i) Cyanine dye: [13(CH3)2N-(CH=CH)s-CD-''N
(CH3)2CILL (however, n is 2 or 3) (however, R is a hydrogen atom or N(C:H3)2) [4] Φ"-L = '4'(X"-
) I/- (where Φ and ! are each an indolenine ring residue, a thiazole ring residue, an oxazole ring residue, a selenazole ring residue, an imidazole ring residue, a pyridine ring, which may have an aromatic ring fused thereto) residue, thiazolopyrimidine ring residue or imidazoquinoxaline ring residue, shi is a linking group for forming monocarbocyanine, dicarbocyanine, tricarbocyanine or tetracarbocyanine, It is an m-valent anion, where m is 1
or 2, and further x'a- may be substituted on Φ, L or double to form an inner salt, or Φ, or L and flat may be further connected to form a ring. Examples of specific compounds represented by the above general formula include a) to k) below.

Margin below [f] ClO4’ [Cl CIO” [91 C1○.

CIO' H3 ii) Squarylium dye: [j] ClO4゜[k] CIO,' jii) Azulenium dye: may be formed into an azaazulene ring. ) iv) Indophenol dye: (Tatashi, R1 and R2, R2 and R3, R3 and R4, R4
and R5, R5 and R6, and at least one combination of R6 and R7 to form a substituted or unsubstituted heterocycle or aliphatic ring, and when the ring is not formed, R1, R2R3, R4R5, R6 and R7 are each a hydrogen atom, a halogen atom, or m organic residues, or R1 and R2, R3 and R4, R4 and R5, RS
and R6 and at least one combination of R6 and R7 may form a substituted or unsubstituted aromatic ring, A is a divalent organic residue bonded via a double bond, and Z- is It is an anionic residue. Note that at least one carbon atom constituting the azulene ring is replaced with a nitrogen atom (X and Y are each a hydrogen atom, an alkyl group, an acylamino group, an alkoxy group, or a halogen atom, and RI, R2, and R3 are each hydrogen atom, substituted or unsubstituted alkyl group of c5 to c2o,
is an aryl group, a heterocycle or a cyclohexyl group, and A
is -NHCO- or -(:0NH-) V) 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) (However, [Cat] is a cation necessary to make the complex salt neutral, and M is Ni, (Cu, Co, Pd or pt, and n is 1 or 2) (However, R1 and R2 are each a substituted or unsubstituted alkyl group or aryl group, and R3 is an alkyl group, a halogen atom, or N-R5 group (wherein R4 and R5 are each a substituted or unsubstituted alkyl group or aryl group), M is a transition metal atom,
n is an integer from 0 to 3) (where, [Cat] is a cation necessary to neutralize the complex salt, M is Ni, Cu, Co, Pd, or pt, and n is 1 or 2) or a methyl group, n is an integer from 1 to 4, and A
is a quaternary ammonium group) and R2 are each 1 to
is an integer of 3, R1 and R2 are each an amino group,
A monoalkylamino group, a dialkylamino group, an acetylamino group, a henshylamino group (including a substituted henshylamino group), 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 alicyclic atom. vi) naphthoquinone-based, anthraquinone-based dyes (wherein xl and x2 are respectively nitro groups and/or) λ rogen atoms, (R is a hydrogen atom, an alkyl group, an allyl group, an amino group or a substituted amino group) (R is a hydrogen atom, an alkyl group, an allyl group,
amino group or substituted amino group) (wherein X is a halogen atom).

Among these dyes, cyanine dyes are particularly suitable for use in the method of the present invention. In addition,
These dyes may be used alone or as a mixture of two or more. Further, when a cyanine dye is used, the metal complex dye or the aminium/diimmonium dye described above may be used together as a quencher.

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 fluorinated alcohol having a purity of 99% by weight or more is used. As the fluorinated alcohol, the following general formula (I)
: A-CH2OH(I) [However, A is F (CnF2n) or H(C,F2
n), where n is an integer of 1 to 3]. Specific examples thereof include the following compounds.

H-CF2-C:F2-C:1 (20H, H-CF2-
CF2-CF2-C)120H1cF3-G:H20H Particularly preferably H-(:F2-CF2-C11208
There is.

In the present invention, it is necessary to use a fluorinated alcohol having a purity of 99% by weight or more as a solvent. Ordinary low-purity fluorinated alcohols contain impurities, and dye recording layers formed using such fluorinated alcohols may undergo crystallization depending on the combination of the dye, solvent, coating conditions, etc. during the formation of the dye layer. This may occur. This is presumed to be caused by the following impurities.

For example, fluorinated alcohol (2,2,3,3-tetrafluoro-1-propatol) is produced as shown in the following formula.

CFz-CFz + C1130)1 →H-CF2-
GF2-CH20H At this time, 10F2 obtained by the above formula
In addition to the compound represented by -CF2-(:820H, H-(CF2-CF2)m-CH2 compounds in which m is 2 or 3 are produced as by-products. A certain aldehyde is produced.Furthermore, metal ions such as Ni and Fe from the catalyst used or the production container are mixed into the obtained fluorinated alcohol.In this way, the obtained fluorinated alcohol contains more than the target compound. It contains compounds with a large molecular weight and a large number of carbon atoms, and in some cases, compounds with a small molecular weight, aldehydes, carboxylic acids, and metal ions.

Therefore, it is desirable that the fluorinated alcohol used in the present invention contains substantially or almost no alkaline earth metal ions, and the metal ions are preferably 1100 pp or less by weight based on the entire fluorinated alcohol. The content of aldehydes is preferably 0.5% by weight or less. Furthermore, since it is desirable not to contain a fluorinated alcohol having a larger number of carbon atoms than the target compound, the content of the fluorinated alcohol having a larger number of carbon atoms than the fluorinated alcohol represented by the general formula (1) is generally It is preferable that the amount is 0.5% by weight or less based on the total alcohol, and it is particularly preferable that it is not included.

For example, the boiling point of 2,2,3,3-tetrafluoro-1-propanol obtained from the above reaction formula is 108.5 to 10.
Preferably, the temperature is in the range of 9.5°C. Also, m is 2 or 3
0.5 by weight of fluorinated alcohol with a large number of carbon atoms
It is preferable that the content is less than % by weight, and it is especially preferable that it is not contained at all.

The fluorinated alcohol having a purity of 99% by weight or more according to the present invention can be produced by a conventional method such as further distillation of a fluorinated alcohol of ordinary purity.

In the present invention, it is preferable to use only the above-mentioned high-purity fluorinated alcohol as a solvent, but the following solvents may also be used in combination with this.

Examples of such solvents include toluene, xylene, ethyl acetate, butyl acetate, cellosolve acetate, methyl ethyl ketone, dichloromethane, 1,2-dichloroethane, chloroform, dimethyl formamide, methyl isobutyl ketone, cyclohexanone, cyclohexane, tetrahydrofuran, ethyl ether, Dioxane, ethanol, n-propanol, isopropanol, n-butanol and the like can be mentioned.

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 ceratin, cellulose derivatives, dextran, rosin, and rubber; hydrocarbon resins such as polyethylene, polypropylene, polystyrene, and polyisobutylene, and polyvinyl chloride. , vinyl resins such as polyvinylidene chloride, polyvinyl chloride/polyvinyl acetate copolymers, acrylic resins such as polymethyl acrylate and polymethyl methacrylate, polyvinyl alcohol, chlorinated polyethylene, epoxy resins, butyral resins, rubber derivatives ,
Examples include synthetic organic polymeric substances such as initial condensates of thermosetting resins such as phenol-formaldehyde resins.

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 a binder is used as a material for the recording layer, the ratio of dye to binder is generally 0.01 to 99% (weight ratio).
It is preferably in the range of 1.0 to 95% (weight ratio). In addition, when the solvent is a mixture of fluorinated alcohol and other solvents, the fluorinated alcohol generally accounts for 5 to 95% of the total solvent (weight ratio ), preferably in the range of 30 to 90% (weight ratio). The concentration of the coating solution prepared in this way is generally 0.01~
10% (weight ratio), preferably 0.1 to 5
% (overlapping 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 10 μm, preferably 0.02 to 10 μm.
It is in the range of 1 μm. 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, M
o, W, Mn, Re.

Fe, Co, Ni, Ru, Rh, Pd, Ir, Pt, C
u, Ag, Au, Zn1Cd, All.

Ga, In, Si, Ge, Te, Pb, Po.

Mention may be made of metals and metalloids such as Sn and Bi. Among these, preferred are Al1, 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 on the recording layer by, for example, vapor deposition, sputtering, or ion-blating the above-mentioned light-reflective material.

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

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).

Furthermore, a protective layer may be provided on the recording layer (or reflective layer) for the purpose of physically and chemically protecting the recording layer and the like. This protective layer may also be provided on the side of the substrate where the recording layer is not provided for the purpose of increasing scratch resistance and moisture resistance.

Examples of materials used for the protective layer include Sio, SiO
2. Inorganic substances such as MgF2 and SnO2; thermoplastic resins,
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 methods such as vacuum deposition, sputtering, and coating.

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 of 0.1 to 100 μm.

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.

Next, a method for recording information on the obtained information recording medium will be described.

Without rotating the information recording medium obtained as described above, a laser beam is irradiated onto the pregroove from the substrate side to record information such as an EFM signal of CD format.

While rotating the information recording medium at a constant linear velocity (for example, 1.2 to 2.8 m/sec) or a constant angular velocity, a laser beam is irradiated from the substrate side to the pregroove to transmit a signal to the recording layer on the group. Recording is done. Generally, a semiconductor laser beam having an oscillation wavelength in the range of 750 to 850 nm is used as the recording light.

Reproduction of information recorded as described above can be performed by irradiating semiconductor laser light from the substrate side while rotating the recording medium at the same constant linear velocity as described above, and detecting the reflected light.

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

[Example 1] Cyanine dye (above structural formula [4] -[d]: 17
2.2, containing 99% by weight or more of pure 2.2,3.3-tetrafluoro-1-propatol, and 1.7 parts by weight of the following dye (IRG-023, manufactured by Nippon Kayaku ■). 3.
3-tetrafluoro-1-propatol (structural formula: )I
CF2CF2CH20H) was dissolved in 150 parts by weight to prepare a coating liquid.

A disc-shaped polycarbonate substrate with a tracking guide (outer diameter: 120 mm, inner diameter = 15 mm, thickness:
1.2 mm, track pitch: 1.6 μm, group depth: 800
The coating was finished by increasing the rotation to 0rp- and the layer thickness was 130.
A 0X recording layer was formed.

Au is sputtered onto the recording layer to a layer thickness of 1000X.
A reflective layer was formed.

An ultraviolet curable resin (product name=3070, ■
A protective layer with a thickness of 2 μm was formed by applying UV rays (high-pressure mercury lamp: 80 W/cm) using a spin code method.

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

The obtained information recording medium was left at 80° C. and 80% RH for 10 days, and then the optical disk surface was visually inspected.
Then, a recording/reproduction test was conducted as described below.

The information recording medium was recorded using semiconductor laser light with a wavelength of 780 nm at a constant linear velocity of 1.3 m/sec and a recording power of 7.0 m.
W, modulation frequency 196kHz (duty -45%
) signals were recorded. And the recorded signal is 0.5m
Reproduction was performed with a reproduction power of W, and the C/N during reproduction was measured using a spectrum analyzer (TR4135: manufactured by Atopan Test Co., Ltd.).

As a result of the above, the optical disc obtained in Example 1 showed no abnormality such as crystallization in the recording layer, and the recorded signal was
/N = 50 (dB).

Claims (1)

[Claims] The following general formula ( I
): A-CH_2OH(I) [However, A is F(C_nF_2_n) or H(C_
nF_2_n), where n is an integer from 1 to 3] After preparing a coating solution by dissolving a dye in a solvent containing a fluorinated alcohol represented by A method of manufacturing an information recording medium, comprising forming a recording layer on which information can be written.