JPH05278341A - Optical recording disk - Google Patents

Abstract

PURPOSE:To obtain an optical recording disk capable of recording at a high speed without increasing laser power by a method wherein a pigment film formed by applying indolenine cyanine pigment solution dissolved in a specific solvent onto a substrate is formed. CONSTITUTION:A pigment-containing application liquid is prepared by dissolving indolenine cyanine pigment expressed by the formula I (R1, R2 represent a hydrocarbon group, R3, R4 represent a hydrogen atom, and a monovalent group, (n) represents an integer of 1-3, X1 represents an anion, and (m1) represents a number for neutralizing electric charge) in a solvent of about 30-250 deg.C in boiling point such as 3-hydroxy-3-methyl-2-butanone or the like. Further, a specific amount of a solvent which is different in class from the abovementioned solvent and dissolves about 2-2.5wt.% pigment of the formula (1) of a pigment film such as cyclohexanone or the like is added into the application liquid. The pigment-containing application liquid is applied onto a substrate formed by polycarbonate or the like with a spin coat or the like, dried, and the pigment film is laminated to make an optical recording disk.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Recently, various optical recording disks such as a write-once type and a rewritable type have been attracting attention as a large capacity information carrying medium.

Some of such optical recording disks use a recording layer containing a dye as a main component. Further, in terms of structure, a so-called air sandwich structure in which an air layer is provided on a dye layer which has been generally used in the past, or a reflective layer on the dye layer as a reproducible one that complies with the Compact Disc (CD) standard is provided. A structure provided in close contact has been proposed (Nikkei Electronics January 23, 1989 issue, No. 465, P107, Kinki Chemical Society 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.).

The dye used in such a recording layer is
From the viewpoint of light resistance, heat resistance, water resistance, and the like, indolenine cyanine dyes are preferably used. Various proposals have been made for indolenine cyanine dyes (JP-A-59-24692 and JP-A-59-5579).
No. 5).

Further, such a dye layer is usually formed by a spin coating method in which a coating liquid containing a dye is spread and coated on a rotating substrate.

Further, in such an optical recording disk, laser light is used as recording light and reproducing light, but when recording data at high speed, it is indispensable to increase the laser power required for recording. Has become a problem.

On the other hand, in order to avoid such a problem, it is possible to increase the sensitivity of the indolenine 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 carried out, and if the dye is synthesized according to it, the synthesis does not work well, or even if the dye is synthesized, the sensitivity is as designed. In many cases, it cannot be realized.

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

[0010]

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

[0011]

Such an object is achieved by the following constitutions (1) to (4). (1) In an optical recording disk having a recording layer composed of a dye film containing a dye on a substrate, the dye film is formed by using a coating liquid containing an indolenine cyanine dye represented by Chemical formula 2, The optical recording disc, wherein the dye film contains a solvent in which the dye is soluble and which has a solubility of the dye larger than that of the coating solvent, which is different from the coating solvent used for the coating liquid.

[0012]

[Chemical 2]

[In Chemical Formula 2, R ₁ and R ₂ each represent a hydrocarbon group. R ₃ and R ₄ each represent a hydrogen atom or a monovalent group, and adjacent R _{3 s} or adjacent R _{4 s} may be connected to each other to form a ring.
n represents 1, 2 or 3. X ₁ represents an anion. m
₁ represents the number for neutralizing the charge. However, m ₁ is 0 when forming an intramolecular salt. ]

(2) The optical recording disk as described in (1) above, wherein the dye film is formed by spin coating.

(3) The substrate has a groove and is constituted by laminating a reflective layer in close contact with the recording layer made of the dye film, and recording light is irradiated onto the recording layer in the groove portion for recording. (1) in which a part is formed and reproduction is performed with reproduction light.
Alternatively, the optical recording disc described in (2).

(4) The optical recording disk according to any one of (1) to (3), wherein the recording light and the reproducing light are laser light.

[0017]

[Specific Structure] The specific structure of the present invention will be described in detail below.

In the present invention, a recording layer comprising a dye film containing the indolenine cyanine dye represented by Chemical formula 2 is formed by coating such as spin coating. And, unlike such a coating solvent, such a dye film contains a solvent in which the dye has a higher solubility than the coating solvent.

For this reason, the melting point of the dye crystal in the dye film is lowered, the sensitivity of the dye film can be increased, and high-speed recording can be performed without increasing the laser power. Moreover, since the synthetic operation such as introducing a substituent into the dye itself is not required, the operation is simple.

Such an effect can be obtained only by incorporating the above dye-soluble solvent into the dye film, and the use of only the coating solvent or the inclusion of a solvent which does not satisfy the above conditions. Is not what you get.

The melting point of the dye crystals in the dye film of the present invention is about 100 to 200 ° C., which is about 10 to 100 ° C. lower than that when the dye-soluble solvent is not contained.

JP-A-3-256790 discloses that a dye is dissolved in a mineral acid or a mixed solution of a mineral acid and an alcohol and then dried to prepare a coating solution. There is.

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

However, the present invention does not use a mineral acid, but the constitution is obviously different.

Further, when the method described in the above publication was carried out, as shown in Examples described later, no melting point drop 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, the indolenine cyanine dye represented by Chemical formula 2 is used.

The chemical formula 2 will be described. In Chemical formula ₂ , R ₁ and R ₂ each represent a hydrocarbon group, and particularly preferably an alkyl group. The alkyl group may have a substituent. Specific examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. When the substituent has a substituent, the substituent is a halogen atom, an alkyl group, an aryl group, an alkoxy group, or an amino group. Group, heterocyclic group, carbochelate group, sulfonate group and the like.

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, and among these monovalent groups, those which can be substituted are: It may be substituted with the same substituents as those mentioned above for R ₁ and R ₂ .

Further, adjacent R _{3 s} or adjacent R _{4 s} may be linked to each other to form a ring, and the ring formed is preferably a carbocycle, particularly preferably a benzene ring.

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

Each of R ₃ and R ₄ is preferably a hydrogen atom, or R _{3 s} or R _{4 s} form a benzene ring.

X ₁ represents an anion or a cation. Examples of the anion include ClO ₄ ⁻ , BF ₄ ⁻ , Cl ⁻ , I ⁻ , and the like, and may be a quencher anion such as a bisphenyldithiol metal complex shown in Chemical formula 3.

[0034] m ₁ represents a number to neutralize the charge, R
Depends on the type of _{1 to} 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. When doing, m ₁ is 0.

X ₁ is particularly preferably a quencher anion as shown in Chemical formula 3.

[0036]

[Chemical 3]

In the chemical formula 3, M represents a metal, and 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 for the dye-containing coating liquid used for forming the dye film has a boiling point of 30 to 2
It is preferable that the substrate material is hard to attack the substrate material at 50 ° C. and has an appropriate evaporation rate under the drying condition when the dye film is formed and dried.

Specifically, ketol type (3-hydroxy-3-methyl-2-butanone, 4-hydroxy-2-butanone, 5-hydroxy-2-pentanone, hydroxyacetone, etc.), alcohol ether type (2- Methoxyethanol, 1-methoxy-2-propanol, 2-ethoxyethanol, 2-butoxyethanol, isopropyl cellosolve, 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.), acetylene alcohol-based (2-propyn-1-ol, 3,4
-Dimethyl-1-pentyn-3-ol, 1-pentyn-3-ol, 3-methyl-2-buten-1-ol,
3-methyl-1-pentyn-3-ol, etc., halogenated alcohols (2,2,2-trifluoroethanol, 2,2,3,3,3-pentafluoro-1-propanol, 2,2,2) 3,3,4,4,4-heptafluoro-1-butanol, 1-chloro-2-methyl-2-propanol, 2,2,3,3-tetrafluoro-1-propanol, etc.), ester alcohols ( Methyl lactate, etc.), alkyl halides (carbon tetrachloride, etc.), aliphatic alcohols (1-propanol, 2-butanol, 1-butanol, etc.), ketones (methyl isobutyl ketone, etc.), ethers (isopropyl ether, dibutyl ether, etc.) Etc.), amine-based (ethylenediamine, ethanolamine, etc.), epoxy-based (1,2-epoxybutane, etc.)
And so on.

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

The solubility of the indolenine cyanine dye of Chemical formula 2 in these coating solvents is about 0.5 to 8%.

The dye content of the dye-containing coating liquid is 2 to 8 wt%, preferably 2.5 to 7 wt%.

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

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

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

The dye-soluble solvent has a solubility of the indolenine cyanine dye of Chemical formula 2 of about 4 to 25 wt%.

Further, this material needs to remain on the dye film even after the optical recording disk is formed, and a material having a sufficient affinity for the dye is preferable.

Specifically, ketone-based compounds (cyclohexanone, methyl ethyl ketone, acetone, 5-hydroxy-
2-pentanone, 2,6-dimethylcyclohexanone,
1,3-dimethyl-2-imidazolidinone, etc.), halogens (chloroform, dichloromethane, orthodichlorobenzene, etc.), ethers (tetrahydrofuran, etc.), ester (allyl acetate, etc.), ketol (propioin, etc.) , Phenol-based (o-chlorophenol, etc.), benzene-based (toluene, etc.), acetylene-based (3-
Methyl-2-buten-1-ol etc.) and the like.

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

Coating solvent Dye-soluble solvent (1) 3-methyl-2-buten-1-ol cyclohexanone (2) 2-ethoxyethanol (ethylcellosolve) tetrahydrofuran (3) 2-methoxyethanol (methylcellosolve) methyl Ethyl ketone

In the present invention, in order to allow the dye-soluble solvent to remain in the dye film, a method of impregnating the substrate with the dye-soluble solvent and transferring the solvent to the dye film is carried out,
There is a method of adding the dye-soluble solvent to the coating solvent when preparing the dye-containing coating liquid.

As a method of impregnating the substrate with the solvent and transferring it to the dye film, the substrate is usually washed with the same solvent as the coating solvent. At this time, the dye-soluble solvent may be added to the washing solvent. Good.

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

By such a method, about 0.5 to 10% by weight of the dye-soluble solvent can be left in the dye film with respect to the entire dye film (dry film). Note that this method cannot be applied to a glass substrate.

As a method of adding the dye-soluble solvent when preparing the coating solution, it is preferable to add the dye-soluble solvent when the dye is dissolved. In this case, it is also preferable to add a dye-soluble solvent to the coating solvent in advance. The solution is stirred at the time of dissolution, and the presence of the dye-soluble solvent at this time is preferable in order to incorporate the solvent into the dye.

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

At this time, the amount of the dye-soluble solvent added to the coating solvent may be about 2 to 30 wt%.

By adopting such a method, about 1 to 15 wt% of the dye-soluble solvent can be left in the dye film with respect to the entire 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). Moreover, the amount thereof can be detected by gas analysis.

As described above, the sensitivity of the optical recording disk can be increased by incorporating the dye-soluble solvent into the dye film by any one of the methods.

Further, in the present invention, a plurality of methods can be used together.

FIG. 1 shows an example of the structure of an optical recording disk having a dye coating film containing a dye-soluble solvent as a recording layer on a substrate as described above. Figure 1
FIG. 4 is a partial cross-sectional view.

The optical recording disk 1 shown in FIG. 1 is a contact type optical recording disk which has a reflective layer in close contact with the recording layer and which is capable of reproduction corresponding to the CD standard.

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

The substrate 2 has a disk shape, and in order to enable recording and reproduction from the back side of the substrate 2,
Recording light and reproducing light (semiconductor laser light having a wavelength of about 600 to 900 nm, particularly about 770 to 900 nm, especially 7
Substantially transparent to 80 nm (preferably a transmittance of 88)
% Or more) resin or glass.

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

Grooves 23 for tracking are 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.
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 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 jitter is likely to increase due to a slight tracking offset during recording. Also 0.5
If it exceeds 0 μm, waveform distortion of the reproduced signal is likely to occur,
This will increase the black stroke.

As the material of the substrate 2, it is preferable to use a resin, and various thermoplastic resins such as polycarbonate resin, acrylic resin, amorphous polyolefin, TPX and polystyrene resin are suitable. Then, the resin can be manufactured by a known method such as injection molding. The groove 23 is preferably formed when the substrate 2 is molded. The resin layer having the groove 23 may be formed by the 2P method or the like after the substrate 2 is manufactured. A glass substrate may be used depending on the case.

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. Spin coating may be performed according to ordinary conditions by adjusting the rotation speed from 500 to 5000 rpm from the inner circumference to the outer circumference.

The recording layer 3 thus formed preferably has a dry film thickness of 500 to 3000A. Outside this range, the reflectance decreases and it becomes difficult to perform reproduction in accordance with the CD standard.

At this time, the film thickness of the recording layer 3 in the recording track in the groove 23 is 1500 A or more, particularly 1500 to 3
At 000A, the degree of modulation becomes extremely large.

The recording layer 3 thus formed is C
When recording a D signal, the extinction coefficient (imaginary part of complex refractive index) k at the wavelengths of the recording light and the reproducing light is 0.02 to
It is preferably 0.05. When k is less than 0.02, the absorptivity of the recording layer is lowered, and it is difficult to perform recording with normal recording power. Further, when k exceeds 0.05, the reflectance falls below 70%, making it difficult to perform reproduction according to the CD standard.

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

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

Further, in the recording layer 3, the values of n and k can be adjusted to values within the above range by compatibilizing two or more kinds of dyes. This can also improve the wavelength dependence.

As shown in FIG. 1, on the recording layer 3,
The reflective layer 4 is provided by directly adhering. As the reflective layer 4, it is preferable to use a high reflectance metal or alloy such as Au or Cu. The reflective layer 4 preferably has a thickness of 500 A or more, and may be formed by vapor deposition, sputtering or the like. Although the upper limit of the thickness is not particularly limited, it is preferably about 1200 A or less in consideration of cost, production work time and the like. Accordingly, the reflectance of the reflective layer 4 alone is 9
0% or more, the reflectance of the unrecorded part of the medium through the substrate is
60% or more, particularly 70% or more can be obtained.

As shown in FIG. 1, on the reflective layer 4,
The protective film 5 is provided. The protective film 5 is made of various resin materials such as an ultraviolet curable resin, and is usually 0.5 to 100 μm.
The layer may be formed to a thickness of about m. The protective film 5 may be layered or sheet-shaped. The protective film 5 may be formed by a usual method such as spin coating, gravure coating, spray coating, or dipping.

The optical recording disk of the present invention is not limited to the contact type optical recording disk as shown in the drawing, but may be any one as long as it has a recording layer containing a dye.

Examples of such a material include a pit forming type optical recording disk having an air sandwich structure,
Similar effects can be obtained by applying the present invention.

[0081]

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

Example 1 Diameter 12 in which 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 made by injection molding. At this time, the grooves 23 were formed with a depth of 1600 A, 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 in 1-chloro-2-methyl-2-propanol as a washing solvent.

Thereafter, the dye of Chemical formula 4 was used as an indolenine cyanine dye, and this was used as 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 Chemical formula 4 in cyclohexanone was 20% by weight, and the solubility in 3-methyl-2-buten-1-ol was 4% by weight.

[0086]

[Chemical 4]

At this time, the number of rotations was adjusted from 500 to 5000 rpm from the inner circumference to the outer circumference.

After the dye film is formed in this manner, 6
It was dried at 0 ° C. for 1 hour. At this time, the film thickness (dry film thickness) of the recording layer 3 in the groove was set to 1500A.

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

Further, an Au film having a thickness of 1000 A was sputtered on the recording layer 3 to form a reflective layer 4.
Further, a UV-curable resin containing an oligoester acrylate was applied and then UV-cured to form a protective film 5 having a thickness of 5 μm. The optical recording disc No. 1 as shown in FIG.
Created 1.

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 cleaning solvent for the substrate. .. At this time, the melting point of the dye film was 207 ° C.

Optical recording disks No. 1 and No. 2 were recorded with a laser, and the optimum recording sensitivity was calculated by the asymmetry method. The recording power of the optical recording disk No. 2 was 6. In contrast to 5 mW, the optical recording disk No. 1 showed a decrease in recording power of 0.5 mW.

When the gas analysis of the dye film was carried out in the optical recording disks No. 1 and No. 2, 0.3 μg of cyclohexanone was detected per disk in the optical recording disk No. 1. This detected amount is about 3 wt% with respect to the total weight of the dye film. In contrast, optical recording discs
In No. 2, cyclohexanone was not detected.

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

Thereafter, the same dye as in Example 1 was used, and this was mixed with 3-methyl-2 containing 10 wt% of cyclohexanone.
-Dissolved in 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 in the groove having a film thickness (dry film thickness) of 1500 A.

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

The melting point of the dye film was about 140.degree.

In the optical recording disk No. 21, except that cyclohexanone is not mixed in the coating solution,
Similarly, an optical recording disk No. 22 (same as the optical recording disk No. 2 of Example 1) was prepared.

Optical recording disks No. 21 and No. 22 were recorded with a laser, and the optimum recording sensitivity was calculated by the asymmetry method.
The recording power of the optical recording disk No. 22 was 6.5 mW, whereas the recording power of the optical recording disk No. 21 was decreased by 0.5 mW.

Optical recording disks No. 21 and No. 22
As a result of gas analysis of the dye film, 0.5 μg of cyclohexanone was detected per optical disc in the optical recording disc No. 21. This detected amount is about 5 wt% with respect to the total weight of the dye film. On the other hand, in the optical recording disk No. 22, cyclohexanone was not detected.

Incidentally, 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 and used in the same manner. .25 was created.

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

The melting point of the dye film at this time 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, cyclohexanone was not detected in the dye film and no melting point drop was observed. Correspondingly, the recording power could not be reduced.

[0106]

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

[Brief description of drawings]

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

[Explanation 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 Jin, 13-1 Nihonbashi, Chuo-ku, Tokyo TDC Corporation

Claims (4)

[Claims] 1. 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 liquid containing the indolenine cyanine dye represented by Chemical formula 1. Moreover, the dye film is characterized in that the dye is soluble, and unlike the coating solvent used for the coating liquid, contains a solvent in which the solubility of the dye is larger than the coating solvent. .. [Chemical 1] [In Chemical 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, and adjacent R _{3 s} or adjacent R _{4 s} are
Each may be connected to each other to form a ring. n represents 1, 2 or 3. X ₁ represents an anion. m ₁ represents a number for neutralizing the electric charge. However, m ₁ is 0 when forming an inner salt. ] 2. The optical recording disk according to claim 1, wherein the dye film is formed by spin coating. 3. The substrate has a groove and is constituted by laminating a reflective layer in close contact with a recording layer made of the dye film, and irradiating recording light to the recording layer of the groove part to record part. 3. The optical recording disk according to claim 1, wherein the optical recording disk is formed and is reproduced by reproducing light. 4. The optical recording disk according to claim 1, wherein the recording light and the reproducing light are laser light.