JP3121910B2 - Manufacturing method of optical recording disk - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical recording disk having a recording layer comprising a dye film containing a dye as a main component.

[0002]

2. Description of the Related Art In recent years, various types of optical recording disks of the write-once type and the rewritable type have been receiving attention as large-capacity information carrying media.

Some of such optical recording disks use a recording layer containing a dye as a main component. Conventionally, a so-called air sandwich structure in which an air layer is provided on a commonly used dye layer, or a reflective layer is provided on the dye layer as a structure capable of reproducing data in accordance with the Compact Disc (CD) standard. A structure provided in close contact has been proposed (Nikkei Electronics, January 23, 1989, No. 465, P107, Kinki Chemical Association Functional Dye Subcommittee, March 3, 1989, Osaka Science and Technology). Center, PROCEEDINGS SPIE-THE INTERNATIONAL SOCIETY F
OR OPTICAL ENGINEERING VOL.1078 PP80-87, "OPTICAL D
ATA STORAGE TOPICAL MEETING "17-19, JANUARY 1989 LOS
ANGELES etc.).

[0004] Dyes used in such a recording layer include:
Indolenin-based cyanine dyes are preferably used in terms of light resistance, heat resistance, water resistance and the like. Various proposals have been made for indolenine-based cyanine dyes (JP-A-59-24692, JP-A-59-5579).
No. 5, etc.).

[0005] Such a dye layer is usually formed by a spin coating method in which a coating solution containing a dye is spread and applied on a rotating substrate.

In such an optical recording disk, a laser beam is used as a recording beam or a reproducing beam. In order to record data at a high speed, it is necessary to increase a laser power required for recording. Had become a problem.

On the other hand, in order to avoid such a problem, it is conceivable to increase the sensitivity of the indolenine-based cyanine dye itself, which is an organic photofunctional material.

However, in order to increase the sensitivity, a molecular design such as introduction of a substituent is performed, and the synthesis is not successful even if the dye is synthesized according to the design. In many cases cannot be achieved.

Under such circumstances, a simple method for increasing the sensitivity of the dye film is desired.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for manufacturing a high-sensitivity optical recording disk capable of high-speed recording without increasing laser power by increasing the sensitivity of a dye film. To provide.

[0011]

The above object is achieved by the following constitutions (1) to (5). (1) In a method for manufacturing an optical recording disk having a recording layer comprising a dye film containing a dye on a substrate, the dye film uses a coating solution containing an indolenine-based cyanine dye represented by the formula (1). In addition, the dye film contains a dye-soluble solvent in which the dye is soluble and in which the solubility of the dye is higher than that of the coating solvent, unlike the coating solvent used in the coating solution. The substrate is a resin substrate, the substrate is washed with a washing solvent obtained by adding the dye-soluble solvent to the coating solvent to impregnate the substrate with the dye-soluble solvent, and the washed substrate is A method for manufacturing an optical recording disk, comprising forming a dye film and transferring the dye-soluble solvent to the dye film.

[0012]

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[In the formula (1), R ₁ and R ₂ each represent a hydrocarbon group. R ₃ and R ₄ each represent a hydrogen atom or a monovalent group, adjacent R ₃ or between adjacent R ₄ together, may form a ring respectively connected to each other. n represents 1, 2 or 3. X ₁ represents an anion. m ₁ represents a number for neutralizing the charge. However, when an internal salt is formed, m ₁ is 0. (2) In an optical recording disk having a recording layer comprising a dye film containing a dye on a substrate, the dye film is formed using a coating solution containing an indolenine-based cyanine dye represented by the formula (1). In addition, the dye film is soluble in the dye, unlike the coating solvent used in the coating solution, the solubility of the dye contains a dye-soluble solvent larger than the coating solvent, When preparing a coating solution containing the dye, the dye-soluble solvent is added to the coating solvent in an amount of 2 to 30% by weight, and the dye film contains the dye-soluble solvent. Production method.

[0014]

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[In the formula (1), R ₁ and R ₂ each represent a hydrocarbon group. R ₃ and R ₄ each represent a hydrogen atom or a monovalent group, adjacent R ₃ or between adjacent R ₄ together, may form a ring respectively connected to each other. n represents 1, 2 or 3. X ₁ represents an anion. m ₁ represents a number for neutralizing the charge. However, when an internal salt is formed, m ₁ is 0. (3) The method for manufacturing an optical recording disk according to (1) or (2), wherein the dye film is formed by spin coating. (4) The substrate has a groove, is formed by laminating a reflective layer in close contact with the recording layer made of the dye film, and forms a recording portion by irradiating recording light to the recording layer in the groove portion. The method for producing an optical recording disk according to any one of the above (1) to (3), wherein the reproduction is performed by a reproduction light. (5) The method for manufacturing an optical recording disc according to (4), wherein the recording light and the reproduction light are laser lights.

[0016]

[Specific Configuration] Hereinafter, a specific configuration of the present invention will be described in detail.

In the present invention, a recording layer comprising a dye film containing an indolenine-based cyanine dye represented by the formula (1) is formed by coating such as spin coating. Then, such a dye film contains a solvent having a higher solubility of the dye than the coating solvent, unlike the coating solvent.

For this reason, the melting point of the dye crystal in the dye film is lowered, so that the sensitivity of the dye film can be increased, and high-speed recording can be performed without increasing the laser power. In addition, since no synthetic operation such as introducing a substituent into the dye itself is required, the operation is simple.

Such an effect can be obtained only when the dye-soluble solvent as described above is contained in the dye film. The effect can be obtained by using only the coating solvent or by including a solvent that does not satisfy the above conditions. Is also not obtained.

In the present invention, the melting point of the dye crystals in the dye film is about 100 to 200 ° C., which is about 10 to 100 ° C. lower than when no dye-soluble solvent is contained.

JP-A-3-256790 discloses that a coloring matter is dissolved in a mineral acid or a mixture of a mineral acid and an alcohol, and then dried to prepare a coating solution using the solution. I have.

It is also described that by performing the above operation, the solubility of the dye is improved, and a dye film having a sufficient thickness can be provided.

However, the present invention does not use a mineral acid, but obviously has a different structure.

Further, when the method described in the above publication was carried out, as shown in Examples below, no drop in the melting point of the dye crystals in the dye film was observed, and the effect of the present invention was not sufficiently exhibited.

In the present invention, an indolenine-based cyanine dye represented by the formula (1) is used.

Equation (1) will be described. In the formula (1), R ₁ and R ₂ each represent a hydrocarbon group, particularly preferably an alkyl group. The alkyl group may have a substituent. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and the like.Examples of the substituent having a substituent include a halogen atom, an alkyl group, an aryl group, an alkoxy group,
Examples include an amino group, a heterocyclic group, a carbochelate group, and a sulfonate group.

Each of R ₁ and R ₂ is preferably an unsubstituted alkyl group.

R ₃ and R ₄ each represent a hydrogen atom or a monovalent group. Examples of the monovalent group include a substituted or unsubstituted alkyl group, an aryl group, an alkoxy group, an amino group or a heterocyclic group, a halogen atom, and the like. It may be substituted with the same substituents as those described for R ₁ and R ₂ .

The adjacent R ₃ or the adjacent R ₄ may be connected to each other to form a ring, and the formed ring is preferably a carbon ring, and particularly preferably a benzene ring.

N represents 1, 2 or 3, and particularly preferably 2.

[0031] Each R ₃ and R _4, the case of forming a benzene ring hydrogen atom or R ₃ together or R ₄ together, are preferred.

X ₁ represents an anion or a cation. Examples of the anion include ClO ₄ ⁻ , BF ₄ ⁻ , Cl ⁻ , and I ⁻ , and a quencher anion such as a bisphenyldithiol metal complex represented by Chemical Formula 5 may be used.

[0033] m ₁ represents a number to neutralize the charge, R
Due to the type of _{1 ~R 4.} For example, when R ₁ is an alkyl group substituted with a carboxylate group or a sulfonate group and R ₂ , R ₃ and R ₄ are electrically neutral groups, an inner salt is formed. Then, m ₁ is 0.

X ₁ is particularly preferably a quencher anion as shown in Chemical formula 5.

[0035]

Embedded image

In the chemical formula 5, M represents a metal, Ni, C
It is preferably u or the like. p represents a positive integer of 1 to 10.

In the present invention, the coating solvent of the dye-containing coating solution used to form the dye film has a boiling point of 30 to 2
It is preferable that the material hardly attack the substrate material at 50 ° C. and have an appropriate evaporation rate under the drying conditions for forming and drying the dye film.

Specifically, ketol type (3-hydroxy-3-methyl-2-butanone, 4-hydroxy-2-butanone, 5-hydroxy-2-pentanone, hydroxyacetone, etc.), alcohol ether type (2-hydroxy-3-pentanone, etc.) Methoxyethanol, 1-methoxy-2-propanol, 2-ethoxyethanol, 2-butoxyethanol, isopropylcellosolve, etc.), allyl alcohol (3-methyl-
3-buten-1-ol, 2-methyl-3-butene-2
-Ol, 3-buten-1-ol, allyl alcohol, 3-methyl-2-buten-1-ol, etc.), acetylenic alcohols (2-propyn-1-ol, 3,4
-Dimethyl-1-pentyn-3-ol, 1-pentyn-3-ol, 3-methyl-1-pentyn-3-ol, etc.), halogenated alcohols (2,2,2-trifluoroethanol, 2, 2,3,3,3-pentafluoro-1-propanol, 2,2,3,3,4,4,4-heptafluoro-1-butanol, 1-chloro-2-methyl-2-propanol, 2, 2,3,3-tetrafluoro-1-propanol and the like), ester alcohols (methyl lactate and the like), alkyl halides (carbon tetrachloride and the like),
Aliphatic alcohols (such as 1-propanol, 2-butanol and 1-butanol), ketones (such as methyl isobutyl ketone), ethers (such as isopropyl ether and dibutyl ether), amines (such as ethylenediamine and ethanolamine), and epoxy compounds (1,2-epoxybutane, etc.).

These coating solvents may be used alone or in combination of two or more.

The solubility of the indolenine-based cyanine dye of the formula (1) in these coating solvents is about 0.5 to 8% by weight.

The dye content in the dye-containing coating solution is about 2 to 8% by weight, preferably about 2.5 to 7% by weight.

Further, the dye-containing coating liquid may appropriately contain a binder, a dispersant, a stabilizer and the like.

In the present invention, to form a dye film using the dye-containing coating solution prepared as described above, any coating method may be used, but spin coating is preferred.

In the present invention, the dye film contains a dye-soluble solvent different from the coating solvent.

This dye-soluble solvent has a solubility of the indolenine-based cyanine dye of the formula (1) of about 4 to 25% by weight.

It is necessary that this remains on the dye film even after the optical recording disk is formed, and it is preferable that the dye film has a sufficient affinity for the dye.

Specifically, ketones (cyclohexanone, methyl ethyl ketone, acetone, 5-hydroxy-
2-pentanone, 2,6-dimethylcyclohexanone,
1,3-dimethyl-2-imidazolidinone, etc.), halogen type (chloroform, dichloromethane, orthodichlorobenzene, etc.), ether type (tetrahydrofuran, etc.), ester type (allyl acetate, etc.), ketol type (propioin, etc.) And phenols (such as o-chlorophenol), benzenes (such as toluene), and allyl or acetylene (such as 3-methyl-2-buten-1-ol).

In the present invention, a combination satisfying conditions such as solubility may be selected from the above-mentioned coating solvent and the above-mentioned soluble solvent.
For example, the following are mentioned.

Coating solvent Dye-soluble solvent (1) 3-methyl-2-buten-1-ol cyclohexanone (2) 2-ethoxyethanol (ethyl cellosolve) tetrahydrofuran (3) 2-methoxyethanol (methyl cellosolve) methyl ethyl ketone

In the present invention, in order to allow the dye-soluble solvent to remain in the dye film, a method in which the substrate is impregnated with the dye-soluble solvent and the solvent is transferred to the dye film,
When preparing a dye-containing coating solution, there is a method of adding the dye-soluble solvent to the coating solvent.

As a method for impregnating the substrate with the solvent and transferring the dye film, the substrate is usually washed with the same solvent as the coating solvent. At this time, for example, the dye-soluble solvent is added to the washing solvent. I just need.

The amount of addition at this time may be about 1 to 20% by weight of the coating solvent used as the washing solvent.

By such a method, about 0.5 to 10% by weight of the dye-soluble solvent can be left on the dye film (dry film). This method cannot be applied to a glass substrate.

As a method of adding a dye-soluble solvent during preparation of a coating solution, it is preferable to add a dye-soluble solvent during dissolution of the dye. In this case, it is also preferable to add a dye-soluble solvent to the coating solvent in advance. At the time of dissolution, the solution is agitated, for example, and it is preferable that a dye-soluble solvent be present at this time in order to incorporate the solvent into the dye.

In some cases, a dye-soluble solvent can be added after dissolution.

At this time, the amount of the dye-soluble solvent added to the coating solvent is about 2 to 30% by weight.

By employing such a method, about 1 to 15 wt% of the dye-soluble solvent can be left in the dye film (dry film).

The presence of the dye-soluble solvent in the dye film can be confirmed by gas analysis and differential scanning calorimetry (DSC). Further, its abundance can be detected by gas analysis.

By making the dye film contain a dye-soluble solvent by any of the methods described above, the sensitivity of the optical recording disk can be increased.

In the present invention, a plurality of methods can be used in combination.

FIG. 1 shows an example of an optical recording disk having a dye coating containing a dye-soluble solvent as a recording layer on a substrate as described above. FIG.
Is a partial sectional view.

The optical recording disk 1 shown in FIG. 1 is a contact type optical recording disk having a reflective layer adhered on a recording layer and capable of reproducing data in compliance with the CD standard.

As shown in the figure, the optical recording disk 1 has a recording layer 3 containing the above-described dye as a main component on the surface of a substrate 2 and is in close contact with the recording layer 3 to form a reflective layer 4 and a protective film. 5

The substrate 2 is in the form of a disk. To enable recording and reproduction from the back side of the substrate 2,
Recording light and reproduction light (semiconductor laser light having a wavelength of about 600 to 900 nm, particularly about 770 to 900 nm,
80 nm), which is substantially transparent (preferably a transmittance of 88
% Or more) using a resin or glass.

The size is about 64 to 200 mm in diameter and about 1.2 mm in thickness.

A tracking groove 23 is formed on the surface of the substrate 2 on which the recording layer 3 is formed, as shown in FIG.
The groove 23 is preferably a spiral continuous groove, having a depth of 0.1 to 0.25 μm, a width of 0.35 to 0.50 μm, and a groove pitch of 1.5 to 0.5 μm.
It is preferably 1.7 μm. With such a configuration of the groove, a good tracking signal can be obtained without lowering the reflection level of the groove portion.

Particularly, the groove width is set to 0.35 to 0.50 μm.
It is important to regulate the groove width to 0.35μ.
If it is less than m, it is difficult to obtain a sufficiently large tracking signal, and a slight offset of tracking during recording tends to increase jitter. 0.5
If the thickness exceeds 0 μm, waveform distortion of a reproduced signal is likely to occur,
This causes the cross stroke to increase.

The substrate 2 is preferably made of a resin, and is preferably made of various thermoplastic resins such as polycarbonate resin, acrylic resin, amorphous polyolefin, TPX, and polystyrene resin. And it can manufacture according to well-known methods, such as injection molding, using such a resin. The groove 23 is preferably formed when the substrate 2 is formed. After the manufacture of the substrate 2, a resin layer having the groove 23 may be formed by a 2P method or the like. In some cases, a glass substrate may be used.

As shown in FIG. 1, the recording layer 3 provided on the substrate 2 is formed by using the above-mentioned dye-containing coating solution, preferably by the spin coating method as described above. The spin coating may be performed under normal conditions, for example, by adjusting the rotation speed from 500 to 5000 rpm from the inner circumference to the outer circumference.

The thickness of the recording layer 3 thus formed is preferably in the range of 500 to 3000 ° in dry film thickness. Outside this range, the reflectivity decreases, making it difficult to perform reproduction in compliance with the CD standard.

At this time, the film thickness of the recording layer 3 in the recording track in the groove 23 is set to 1500 ° or more, especially 1500 to 3
If it is 000 °, the degree of modulation will be extremely large.

The recording layer 3 thus formed has a C
When recording a D signal, the extinction coefficient (imaginary part of the complex refractive index) k of the recording light and the reproduction light wavelength is 0.02 to 0.02.
It is preferably 0.05. When k is less than 0.02, the absorptivity of the recording layer decreases, and it is difficult to perform recording with normal recording power. On the other hand, if k exceeds 0.05, the reflectivity falls below 70%, making it difficult to perform reproduction according to the CD standard.

Further, the refractive index (the real part of the complex refractive index) n of the recording layer 3 is 2.0 to 2.6. When n <2.0, the reflectance is reduced, and the reproduced signal is reduced, so that the reproduction according to the CD standard tends to be difficult.

The dye used in the recording layer may be selected from the light-absorbing dyes, dye-quencher mixtures, and dye-quencher conjugates having n and k in the above ranges. In some cases, a new molecule can be designed and synthesized.

Further, in the recording layer 3, the values of n and k can be set to the above-mentioned values by dissolving two or more dyes. This can also improve the wavelength dependence.

As shown in FIG. 1, on the recording layer 3,
The reflection layer 4 is provided in close contact with the substrate. The reflective layer 4 is preferably made of a high-reflectance metal or alloy such as Au or Cu. The thickness of the reflective layer 4 is preferably 500 ° or more, and may be provided by vapor deposition, sputtering, or the like. The upper limit of the thickness is not particularly limited, but is preferably about 1200 ° or less in consideration of cost, production operation time, and the like. Thereby, the reflectance of the reflection layer 4 alone becomes 9
0% or more, the reflectance of the unrecorded portion of the medium through the substrate is
60% or more, especially 70% or more, is obtained.

As shown in FIG. 1, on the reflection layer 4,
A protective film 5 is provided. The protective film 5 is made of, for example, various resin materials such as an ultraviolet curable resin, and is usually 0.5 to 100 μ
It may be formed to a thickness of about m. The protective film 5 may be in the form of a layer or a sheet. The protective film 5 may be formed by an ordinary method such as spin coating, gravure coating, spray coating, dipping, or the like.

The optical recording disk of the present invention is not limited to a contact type optical recording disk as shown in the figure, but may be any optical disk having a recording layer containing a dye.

Examples of such a disk include a pit-formed optical recording disk having an air sandwich structure.
A similar effect can be obtained by applying the present invention.

[0080]

The present invention will be specifically described below with reference to examples.

Example 1 A diameter 12 having a spiral continuous groove 23 was formed.
A polycarbonate resin substrate 2 having a thickness of 0 mm and a thickness of 1.2 mm was produced by injection molding. At this time, the groove 23 was formed with a depth of 1600 °, a width of 0.45 μm, and a pitch of 1.6 μm.

The above polycarbonate resin substrate was washed by mixing 3 wt% of cyclohexanone with a washing solvent 1-chloro-2-methyl-2-propanol.

Thereafter, a dye of the formula (6) was used as an indolenine-based cyanine dye, and this was converted to 3-methyl-2-butene-
It was dissolved in 1-ol at 3 wt% and applied to the above substrate by spin coating.

The solubility of the dye of formula 6 in cyclohexanone was 20% by weight, and the solubility in 3-methyl-2-buten-1-ol was 4% by weight.

[0085]

Embedded image

The rotation speed at this time was adjusted between 500 and 5000 rpm from the inner circumference to the outer circumference.

After forming the dye film in this manner, 6
Dry at 0 ° C. for 1 hour. At this time, the film thickness (dry film thickness) of the recording layer 3 in the groove was 1500 °.

The melting point of the dye film was about 142 ° C.

Further, on this recording layer 3, an Au film was formed to a thickness of 1000 ° by sputtering to form a reflective layer 4,
Further, after applying an ultraviolet curable resin containing an oligoester acrylate, it was cured by ultraviolet to form a protective film 5 having a thickness of 5 μm.
1 was created.

Optical recording disk No. 2 was prepared in the same manner as in optical recording disk No. 1, except that 3-methyl-2-buten-1-ol containing no cyclohexanone was used as a solvent for washing the substrate. . At this time, the melting point of the dye film was 207 ° C.

Each of the optical recording disks No. 1 and No. 2 was recorded with a laser, and the optimum recording sensitivity was calculated by an asymmetry method. At a wavelength of 784 nm, the recording power of the optical recording disk No. 2 was 6. In contrast to 5 mW, the recording power of the optical recording disk No. 1 was reduced by 0.5 mW.

When gas analysis of the dye film was performed on the optical recording disks No. 1 and No. 2, 0.3 μg of cyclohexanone was detected per optical recording disk No. 1. This detection amount is about 3% by weight based on the total weight of the dye film. In contrast, optical recording disks
In No. 2, cyclohexanone was not detected.

Example 2 The polycarbonate resin substrate of Example 1 was replaced with 3-methyl-2
-Washed with buten-1-ol.

Thereafter, the same dye as in Example 1 was used, and this was mixed with 10% by weight of cyclohexanone in 3-methyl-2.
-Buten-1-ol to prepare a 3 wt% coating solution.

Using this, spin coating was performed in the same manner as in Example 1, and drying was performed in the same manner to obtain a recording layer 3 having a film thickness (dry film thickness) of 1500 ° in the groove.

Further, in the same manner as in Example 1, a reflective layer 4 and a protective film 5 were provided, and an optical recording disk No. 21 was produced.

Incidentally, the melting point of the dye film was about 140 ° C.

In optical recording disk No. 21, except that the coating liquid does not contain cyclohexanone,
Similarly, an optical recording disk No. 22 (same as the optical recording disk No. 2 of Example 1) was prepared.

Each of the optical recording disks No. 21 and No. 22 was recorded with a laser, and the optimum recording sensitivity was calculated by an asymmetry method.
The recording power of the optical recording disk No. 22 was 6.5 mW, while the recording power of the optical recording disk No. 21 was reduced by 0.5 mW.

The optical recording disks No. 21 and No. 22
In the optical recording disk No. 21, 0.5 μg of cyclohexanone was detected per optical disk. This detection amount is about 5% by weight based on the total weight of the dye film. On the other hand, no cyclohexanone was detected in the optical recording disk No. 22.

In the optical recording disk No. 2 (same as No. 22), the dye was pretreated according to the method described in JP-A-3-256790. 25 was created.

Dye C is 35% HCl: 3-methyl-2
-Buten-1-ol = 1: 1 (volume ratio) mixed solvent 1
It is obtained by dissolving the same dye in 0 ml and drying it with an evaporator.

At this time, the melting point of the dye film was about 208 ° C.

As described above, in the optical recording disk No. 25 prepared according to the method described in JP-A-3-256790, no cyclohexanone was detected in the dye film and no decrease in the melting point was observed. Correspondingly, the recording power could not be reduced.

[0105]

According to the present invention, a dye film having high sensitivity can be obtained. As a result, high-speed recording can be performed without increasing the power of the laser.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing an optical recording disk of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical recording disk 2 Substrate 23 Groove 3 Recording layer 4 Reflective layer 5 Protective film 6 Pit part

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsuko Mika 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation (56) References JP-A-2-16083 (JP, A) JP-A-2 -202484 (JP, A) JP-A-61-239443 (JP, A) JP-A-2-147286 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/26 G11B 7/24

Claims (5)

(57) [Claims] 1. A method for manufacturing an optical recording disk having a recording layer comprising a dye film containing a dye on a substrate, wherein the dye film is a coating solution containing an indolenine-based cyanine dye represented by the formula (1): And the dye film contains a dye-soluble solvent in which the dye is soluble and the solubility of the dye is larger than the coating solvent, unlike the coating solvent used in the coating solution. Wherein the substrate is a resin substrate, the substrate is washed with a washing solvent obtained by adding the dye-soluble solvent to the coating solvent, and the substrate is impregnated with the dye-soluble solvent, A method for producing an optical recording disk, comprising: forming the dye film on the substrate; and transferring the dye-soluble solvent to the dye film. Embedded image [In the formula (1), R ₁ and R ₂ each represent a hydrocarbon group. R ₃ and R ₄ each represent a hydrogen atom or a monovalent group, adjacent R ₃ or between adjacent R ₄ together, may form a ring respectively connected to each other. n is 1,
Represents 2 or 3. X ₁ represents an anion. m ₁ represents a number for neutralizing the charge. However, when an internal salt is formed, m ₁ is 0. ] 2. An optical recording disk having a recording layer comprising a dye film containing a dye on a substrate, wherein the dye film is formed by using a coating solution containing an indolenine-based cyanine dye represented by the formula (1). Formed, and the dye film contains the dye-soluble solvent in which the dye is soluble and the solubility of the dye is larger than the coating solvent, unlike the coating solvent used in the coating solution. An optical recording disk, wherein, when preparing a coating solution containing the dye, the dye-soluble solvent is added to the coating solvent in an amount of 2 to 30% by weight, and the dye film contains the dye-soluble solvent. Manufacturing method. Embedded image [In the formula (1), R ₁ and R ₂ each represent a hydrocarbon group. R ₃ and R ₄ each represent a hydrogen atom or a monovalent group, adjacent R ₃ or between adjacent R ₄ together, may form a ring respectively connected to each other. n is 1,
Represents 2 or 3. X ₁ represents an anion. m ₁ represents a number for neutralizing the charge. However, when an internal salt is formed, m ₁ is 0. ] 3. The method according to claim 1, wherein the dye film is formed by spin coating. 4. The recording section, wherein the substrate has a groove and is formed by laminating a reflection layer in close contact with the recording layer made of the dye film, and irradiates recording light to the recording layer in the groove section. 4. The method for manufacturing an optical recording disk according to claim 1, wherein the optical disk is formed by using a reproducing light. 5. The method according to claim 4, wherein the recording light and the reproduction light are laser light.