JPH1153766A - Optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of a light reflecting layer made of silver or an alloy consisting essentially of silver. SOLUTION: After an organic dyestuff recording layer 2 and the light reflecting layer 3 made of silver or the alloy consisting essentially of silver are successively laminated on a substrate 1, a surface of the light reflecting layer 3 is treated by any one compound among mercaptoazaindene containing one or >=3 N in a 6-membered ring and 5-membered ring constituting indene, mercaptopyridine, mercaptopyrimidine, mercaptoazanaphthalene, mercaptobenzothiadiazole and mercaptobenzoxazole or a compound among the same with one or plural substituent groups among hydrocarbon group, ester group, aryl group, halogen group, hydroxyl group, alkoxyl group, amino group, nitro group, cyano group, acyl group, aldehyde group, carboxyl group, alkylthio group, arylthio group, aryloxy group, acyloxy group, thioester group, -NHR and -NRR' (R and R' are alkyl groups) and further a protective layer 4 is formed thereon to constitute an optical recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium, and more particularly to an optical recording medium having a light reflecting layer of silver or an alloy containing silver as a main component.

[0002]

2. Description of the Related Art Conventionally, gold or aluminum alloy has been widely used for a light reflection layer of an optical disk as an optical recording medium. Gold has high reflectivity and is chemically stable, and is therefore mainly used for write-once optical disks (such as CD-R) having an organic dye in a recording layer. However, gold is expensive, and cheaper materials are desired to reduce manufacturing costs.

On the other hand, aluminum alloys are inexpensive, have relatively high reflectivity, and are relatively chemically stable, so that read-only optical disks (CD-ROM, DVD-ROM) are used.
Etc.) and rewritable optical disks (CD-RW, DVD-R
AM, MO, etc.). However, the light reflection layer of the CD-R, which is a write-once optical disc, requires a high reflectivity sufficient to compensate for the attenuation of the light beam in the organic dye recording layer. Therefore, an aluminum alloy whose reflectivity is not as high as gold is required. Not yet used.

As a material for the light reflecting layer other than gold and aluminum alloy, silver having a reflectance equal to or higher than that of gold can be considered (see JP-A-57-212638). And silver is much cheaper than gold,
It satisfies both high reflectivity and economy, and can be applied to the light reflection layer of CD-R which is a write-once optical disc.

[0005]

However, silver is not chemically very stable, and when it is used as a light reflection layer of an optical recording medium, there is a possibility that a problem may occur in the reliability of the optical recording medium. In particular, when the optical recording medium is stored for a long period of time, a problem such as an increase in an error occurrence rate is likely to occur.

As a method for improving the chemical stability of silver, a method has been proposed in which another metal element is added to silver to form a silver alloy (for example, JP-A-61-134945).
And Japanese Patent Application Laid-Open No. 3-122845). The present inventor also produced an optical disk using these alloys and performed an environmental resistance test on it, but could not obtain sufficient performance. Further, when silver is alloyed, there is a problem that the reflectance is lowered, which is not preferable in terms of the performance of the optical recording medium.

In JP-A-6-231488 and JP-A-7-105572, the surface of a light reflecting layer formed of silver is treated with a triazinethiol compound, a triazineamine compound, a mercaptobenzimidazole compound, or the like. It is disclosed that by doing so, an optical disk having improved corrosion resistance and high reliability can be obtained. The present inventor also produced an optical recording medium in which a silver light reflecting layer was treated with these compounds and performed an environmental resistance test, but the reliability and durability were improved as compared with those without treatment. But it was still not enough.

The present invention has been made in view of such conventional problems,
Higher reflectivity than gold, and inexpensive, in an optical recording medium having silver or an alloy containing silver as a main component in the light reflection layer,
It is an object of the present invention to improve the chemical stability of silver or a silver alloy and provide an optical recording medium having excellent reliability and durability.

[0009]

According to the first aspect of the present invention, an optical recording medium is laminated on a substrate, and the surface opposite to the substrate side is formed of indene. A mercaptoazaindene containing one or three or more N atoms in a 6-membered ring and a 5-membered ring, or a hydrocarbon group, an ester group, an aryl group, a halogen group, a hydroxyl group, an alkoxyl group, an amino group , Nitro, cyano, acyl, aldehyde, carboxyl, alkylthio, arylthio, aryloxy, acyloxy, thioester, -NHR, -NRR '
(R and R 'are alkyl groups) treated with a compound in which one or more of the groups are substituted, and a light reflecting layer made of silver or an alloy containing silver as a main component.

Similarly, in the invention according to claim 2, a substrate and a surface laminated on the substrate and opposite to the substrate are coated with mercaptopyridine or a hydrocarbon group, ester, Group, aryl group, halogen group, hydroxyl group, alkoxyl group, amino group, nitro group, cyano group, acyl group, aldehyde group, carboxyl group, alkylthio group, arylthio group, aryloxy group, acyloxy group, thioester group, -NHR, -NRR '
(R and R 'are alkyl groups) treated with a compound in which one or more of the groups are substituted, and a light reflecting layer made of silver or an alloy containing silver as a main component.

In the invention according to claim 3, the substrate and the surface laminated on the substrate and opposite to the substrate are coated with mercaptopyrimidine or a hydrocarbon group, an ester group or an aryl group on the mercaptopyrimidine. Group, halogen group, hydroxyl group, alkoxyl group, amino group, nitro group, cyano group,
Acyl group, aldehyde group, carboxyl group, alkylthio group, arylthio group, aryloxy group, acyloxy group, thioester group, -NHR, -NRR '(R,
R ′ is an alkyl group), and a light reflecting layer made of silver or an alloy containing silver as a main component, which is treated with a compound in which one or more of the groups are substituted.

In the invention according to claim 4, the substrate and the surface laminated on the substrate and opposite to the substrate are coated with mercaptoazanaphthalene or mercaptoazanaphthalene with a hydrocarbon group or an ester group. , Aryl group, halogen group, hydroxyl group, alkoxyl group, amino group, nitro group, cyano group, acyl group, aldehyde group, carboxyl group, alkylthio group, arylthio group, aryloxy group, acyloxy group, thioester group, -NHR,- NRR '
(R and R 'are alkyl groups) treated with a compound in which one or more of the groups are substituted, and a light reflecting layer made of silver or an alloy containing silver as a main component.

In the invention according to claim 5, the substrate and the surface laminated on the substrate and opposite to the substrate are coated with mercaptobenzothiadiazole or mercaptobenzothiadiazole with a hydrocarbon group or an ester group. , Aryl group, halogen group, hydroxyl group, alkoxyl group, amino group,
Nitro group, cyano group, acyl group, aldehyde group, carboxyl group, alkylthio group, arylthio group, aryloxy group, acyloxy group, thioester group, -NH
A light reflection layer made of silver or an alloy containing silver as a main component, which is treated with a compound in which one or more of R and -NRR '(R and R' are alkyl groups) are substituted. It consists of.

In the invention according to claim 6, a substrate and a surface laminated on the substrate and opposite to the substrate are coated with mercaptobenzoxazole or mercaptobenzoxazole by a hydrocarbon group or an ester group. , Aryl group,
Halogen group, hydroxyl group, alkoxyl group, amino group, nitro group, cyano group, acyl group, aldehyde group, carboxyl group, alkylthio group, arylthio group, aryloxy group, acyloxy group, thioester group, -NHR,-
A light reflecting layer made of silver or an alloy containing silver as a main component, which is treated with a compound in which one or more of NRR '(R and R' are alkyl groups) are substituted. .

With such a configuration, the chemical stability of silver or an alloy containing silver as a main component, which forms the light reflection layer, is improved. The optical recording medium of the present invention can be applied to any of a read-only type, a rewritable type, and a write-once type optical recording medium. Is most effective when used as a write-once optical recording medium which is required to have high reflectivity and economic efficiency. In this case, a structure in which layers such as a protective layer, an adhesive layer, and a second substrate are sequentially stacked on the light reflecting layer may be adopted.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the structure of a write-once optical disc which is an embodiment of the optical recording medium of the present invention. On a substrate 1, an organic dye recording layer 2, a light reflection layer 3,
And the protective layer 4 are sequentially laminated.

The substrate 1 is preferably made of a material that is transparent to the recording light beam and the reproducing light beam, for example, resin or glass. Particularly, resin is preferable because it is easy to handle and inexpensive. . Specifically, for example, a polycarbonate resin, an acrylic resin, an epoxy resin, an ABS resin, or the like can be used as the resin. The shape and dimensions of the substrate are not particularly limited, but are usually disk-shaped, the thickness is usually about 0.5 to 3 mm, and the diameter is 4 mm.
It is about 0 to 360 mm. On the surface of the substrate, a predetermined pattern such as a groove or the like for pre-pits for recording information or for tracking or addressing is provided as necessary.

The dye of the dye thin film forming the organic dye recording layer 2 is not particularly limited as long as it absorbs light, for example, laser energy and changes optical properties.
Specifically, organic dyes such as cyanine dyes, squarylium dyes, croconium dyes, azurenium dyes, triarylamine dyes, anthraquinone dyes, metal-containing azo dyes, dithiol metal complex salt dyes, and indoaniline metal Complex dyes, phthalocyanine dyes,
Naphthalocyanine dyes, intermolecular CT complex dyes and the like are preferably used. These dyes can be used alone or in combination. Further, an antioxidant, a binder, and the like can be added to the dye thin film.

As a method for forming the organic dye recording layer 2, a method in which an organic dye is dissolved in an organic solvent and spin-coated on a transparent substrate 1 is preferably used, but has a sublimability like a phthalocyanine dye. For the dye, a vapor deposition method can also be used. The thickness of the dye thin film of the organic dye recording layer 2 is determined based on the wavelength used, the optical properties of the reflective layer 3 and the dye thin film in consideration of the recording sensitivity to the energy of light used for recording such as a laser, the coefficient of performance, and the like. Is appropriately selected depending on the material and the like, and is usually in the range of 120 to 150 nm.

The light reflecting layer 3 is formed of silver or an alloy containing silver as a main component. The element which forms a silver alloy when mixed with silver is not particularly limited, but for example, Al, Au, C
u, Cr, Ni, Pt, Sn, In, Pd, Ti, Fe
, Ta, W, Zn and the like. Although the composition ratio of silver in the alloy is not particularly limited, it is preferably 50 atomic% or more, and more preferably 80 atomic% or more, in order to obtain a high reflectance in the light reflecting layer. The thickness of the light reflecting layer 3 is usually 1
It is set to 0 to 200 nm. If it is thinner than this, a high reflectance cannot be obtained, and if it is thicker, no remarkable effect is exhibited.

The method of forming the light reflecting layer 3 is not particularly limited, but it is preferable to use a vapor phase growth method such as a sputtering method or a vacuum evaporation method, which can easily form a uniform film and is easy to mass-produce. In the present invention, after the light reflecting layer 3 made of silver or an alloy containing silver as a main component is formed, the surface of the light reflecting layer 3 on the side opposite to the substrate 1 is coated with a six-membered ring constituting indene and a five-membered ring. Mercaptoazaindene, mercaptopyridine, mercaptopyrimidine, mercaptoazanaphthalene (which is a generic term for mercaptoquinoline, mercaptoquinoxaline, mercaptoquinazoline) containing one or three or more N (nitrogen) in a ring, mercaptobenzothiadiazole, and , Any compound of mercaptobenzoxazole, or each of these compounds, a hydrocarbon group,
Ester group, aryl group, halogen group, hydroxyl group, alkoxyl group, amino group, nitro group, cyano group, acyl group,
One or more of aldehyde group, carboxyl group, alkylthio group, arylthio group, aryloxy group, acyloxy group, thioester group, -NHR, -NRR '(R and R' are alkyl groups) are substituted. Treat with compound.

Specific examples include compounds having the structures shown in the following chemical formulas (1) to (6).

[0023]

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[0024]

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[0025]

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[0026]

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[0027]

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[0028]

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Here, an example of the compound of claim 1 is shown in Chemical formula 1.
An example of the compound of Claim 2 is shown in Chemical Formula 2, an example of the compound of Claim 3 is shown in Chemical Formula 3, an example of the compound of Claim 4 is shown in Chemical Formula 4, and an example of the compound of Claim 5 is shown in Chemical Formula 5. An example of the compound of formula 6 is
Each is shown. The surface treatment of the light reflection layer 3 with the compound is performed by dissolving the compound in an appropriate solvent to form a treatment liquid, applying the treatment liquid on the light reflection film, and then drying. The application method is not particularly limited, but spin coating or dip coating is preferably used.

The solvent for the treatment liquid is not particularly limited, but an alcohol-based or ether-based solvent is preferred from the viewpoint of solubility of the compound and ease of handling, and examples thereof include ethanol and diethyl ether. The concentration of the compound in the solvent is usually preferably from 0.0001 to 5.0% by weight, and more preferably from 0.001 to 0.1% by weight. If the concentration is lower than this, the treatment effect of the compound on the light reflecting layer 3 is not sufficient, and if the concentration is higher than this, no remarkable improvement in the effect is observed.

The drying (volatilization) of the solvent can be performed by a spin drying method at room temperature. If necessary, drying can be promoted by heating and dehumidifying the atmosphere. By performing such a treatment, the surface of the light reflecting layer 3 made of silver or a silver alloy is coated with mercaptoazaindene, mercaptopyridine, mercaptopyrimidine,
Mercaptoazanaphthalene (which is a generic term for mercaptoquinoline, mercaptoquinoxaline, and mercaptoquinazoline), mercaptobenzothiadiazole, and any compound of mercaptobenzoxazole, or a hydrocarbon group, an ester group, an aryl group Group, halogen group, hydroxyl group, alkoxyl group, amino group, nitro group, cyano group, acyl group, aldehyde group, carboxyl group, alkylthio group, arylthio group, aryloxy group, acyloxy group, thioester group, -NHR, -NRR ' (R and R 'are alkyl groups)
A compound in which one or a plurality of groups are substituted is attached, and the chemical stability of the light reflecting layer 3 is significantly improved.

After the surface of the light reflecting layer 3 is treated by the above-described method, the protective layer 4 is formed to improve friction resistance and corrosion resistance.
A single layer or a plurality of layers are provided. The protective layer 4 is preferably composed of an organic substance in which various organic or inorganic fillers are mixed, and in particular, a substance obtained by curing a radiation-curable compound or a composition thereof by radiation such as an electron beam or ultraviolet rays. Preferably. The thickness of the protective layer is usually about 0.1 to 100 μm in total, and can be formed by a usual method such as spin coating, gravure coating, spray coating, roll coating and the like.

In the write-once optical disk having the above-described structure, an information signal is recorded by irradiating a recording light beam from the substrate 1 side to change the optical properties of the organic dye recording layer 2. On the other hand, during reproduction, it is weaker than the recording light beam,
The substrate 1 is irradiated with a reproducing light beam to the extent that the optical properties of the organic dye recording layer 2 do not change, and the recorded information signal is read based on the reflected light. This reflected light is attenuated by the organic dye recording layer 2, but the light reflecting layer 3 using silver or a silver alloy has a reflectivity similar to that of gold and obtains reflected light having an intensity that is practically acceptable. be able to.

Furthermore, since the light reflecting layer 3 has been subjected to the above-mentioned surface treatment, the reliability and durability, which have conventionally been regarded as the drawbacks of the light reflecting layer using silver or an alloy containing silver as a main component, are reduced. It shows improved reliability and durability equivalent to those of optical disks using gold for the light reflection layer. Thus, for example, even when the optical disk is stored under high temperature and high humidity for a long period of time, the error occurrence rate does not significantly increase.

The present invention is applicable to various types of optical recording media such as a read-only type and a rewritable type, in addition to the write-once type optical recording medium described above. In the case of a read-only optical recording medium, one having a protective layer, an adhesive layer, a second substrate, and the like in addition to the above-described substrate and light reflecting layer is considered. It is conceivable that the substrate has a layer such as a dielectric layer, a phase-change recording layer, a protective layer, an adhesive layer, and a second substrate in addition to the substrate and the light reflecting layer described above. In the case of a rewritable optical recording medium utilizing magnetism (such as a magneto-optical disk), an interference layer, a reproducing layer, a non-magnetic intermediate layer, a magnetic recording layer, One having a layer such as a writing layer and a protective layer is conceivable.

[Examples] In order to specifically show the effects of the present invention, examples will be described below. (Example 1) A write-once optical disc (hereinafter referred to as a “write-once optical disc”) having a cyanine organic dye in an organic dye recording layer and silver in a light reflection layer using a polycarbonate substrate having a spiral guide groove having a diameter of 120 mm and a plate thickness of 1.2 mm , A sample).

First, a cyanine dye is dissolved in an organic solvent,
After filtering through a filter to remove insolubles, the mixture was applied on a substrate by a spin coater (manufactured by Able) to form an organic dye recording layer. Subsequently, heat treatment was performed in an oven to completely remove the solvent, and then a 100 nm-thick silver light reflecting layer was formed by a DC magnetron sputtering apparatus.

Next, a structural formula represented by the following chemical formula 7

[0039]

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4-mercapto-1H-pyrazolo [3,4-d] pyrimidine represented by the following formula is dissolved in ethanol,
A solution having a concentration of 0.01% by weight was prepared and applied on the silver light reflecting film by a spin coating method. Thereafter, spin drying was performed for 10 seconds. Then, a UV-curable resin was applied by spin coating on the surface-reflected silver light-reflective film, and cured by UV irradiation to form a protective layer. The cured film thickness of the protective layer was 5 μm.

Example 2 A sample was produced in the same manner as in Example 1 except that the light reflecting layer was formed of a silver-titanium alloy (10 atomic% of titanium). (Example 3) The compound used for the surface treatment of the light reflecting layer is represented by the following structural formula

[0042]

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2-amino-6-hydroxy- represented by the formula:
A sample was prepared in the same manner as in Example 1 except that 8-mercaptopurine was used. (Example 4) The compound used for the surface treatment of the light reflection layer was represented by the following structural formula:

[0044]

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A sample was prepared in the same manner as in Example 1 except that 2-mercaptopyridine represented by the following formula was used. Example 5 A light-reflecting layer was formed of a silver-titanium alloy (titanium 10
Atomic%), a sample was prepared in the same manner as in Example 4.

Example 6 The compound used for the surface treatment of the light reflecting layer was represented by the following structural formula.

[0047]

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A sample was prepared in the same manner as in Example 1 except that 2-mercapto-4-methylpyrimidine represented by the following formula was used. Example 7 A light-reflecting layer was formed of a silver-titanium alloy (titanium 10
Atomic%), except that the sample was formed in the same manner as in Example 6.

Example 8 The compound used for the surface treatment of the light reflecting layer was represented by the following structural formula:

[0050]

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A sample was prepared in the same manner as in Example 1 except that 8-mercaptoquinoline represented by the following formula was used. (Example 9) A light-reflecting layer was formed of a silver-titanium alloy (titanium 10
Atomic%), except that the sample was formed in the same manner as in Example 8.

Example 10 The compound used for the surface treatment of the light reflecting layer was represented by the following structural formula:

[0053]

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2-mercapto-4 (3H)-represented by
A sample was prepared in the same manner as in Example 1 except that quinazolinone was used. (Example 11) The compound used for the surface treatment of the light reflecting layer is represented by the following structural formula

[0055]

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A sample was prepared in the same manner as in Example 1 except that 2-mercaptobenzothiazole was used. Example 12 A light-reflecting layer was formed of a silver / titanium alloy (titanium 1).
A sample was prepared in the same manner as in Example 11 except that the sample was formed at 0 atomic%).

(Example 13) The compound used for the surface treatment of the light reflecting layer was represented by the following structural formula:

[0058]

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A sample was prepared in the same manner as in Example 1 except that 2-mercaptobenzoxazole represented by the following formula was used. (Example 14) The light reflection layer was formed of a silver-titanium alloy (titanium 1
A sample was prepared in the same manner as in Example 13 except that the sample was formed at 0 atomic%).

Example 15 The compound used for the surface treatment of the light reflecting layer was represented by the following structural formula:

[0061]

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A sample was prepared in the same manner as in Example 1 except that 5-chloro-2-mercaptobenzothiazole represented by the following formula was used. (Example 16) The compound used for the surface treatment of the light reflecting layer is represented by the following structural formula

[0063]

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A sample was prepared in the same manner as in Example 1 except that 6-ethoxy-2-mercaptobenzothiazole was used. Comparative Example 1 A sample was produced in the same manner as in Example 1 except that the surface treatment of the light reflecting layer was not performed.

Comparative Example 2 The compound used for the surface treatment of the light reflecting layer was represented by the following structural formula:

[0066]

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The same procedure as in Example 1 was carried out except that a triazineamine compound represented by the following formula was used, water was used as a solvent, a 0.02% by weight solution was prepared, and the surface of the light reflecting layer was treated by spin coating. A sample was prepared in the same manner. (Reference Example 1) Comparative Example 1 except that the light reflecting layer was formed of gold.
A sample was prepared in the same manner as described above.

Each sample obtained as described above is
Data recording was performed. Data is transmitted and converted from the host computer by the CD writing software, and the CD recorder (CDW-900E manufactured by SONY) is used.
Recording of the EFM signal for 74 minutes. Note that C
The wavelength of the semiconductor laser used for the recording pickup of the D recorder is 780 nm, and the aperture N of the optical lens is
A is 0.50.

Next, the maximum value of the block error rate for all samples was measured by a CD signal evaluator.
The wavelength of the semiconductor laser used for the reading pickup of the CD signal evaluation device is 780 nm, and the aperture NA of the optical lens is 0.45. First, the maximum value of the initial block error rate was measured, and then each sample was allowed to stand for 1000 hours under the conditions of high temperature and high humidity (80 ° C., 85% RH). , The maximum value of the block error rate was measured. Table 1 shows the results.

[0070]

[Table 1]

In the samples of the present invention of Examples 1 to 16, the maximum value of the block error rate hardly changed before and after the high-temperature and high-humidity test. This is a result equivalent to that of the sample of Reference Example 1 having a reflective layer formed of gold. On the other hand, in Comparative Example 1 in which the surface treatment was not performed on the silver light reflecting layer, the maximum value of the block error rate after the high-temperature and high-humidity test was about 10 times that before the test.

In Comparative Example 2 in which the surface of the silver light reflecting layer was treated with a compound different from that of the present invention, although smaller than Comparative Example 1, the maximum value of the block error rate after the high-temperature and high-humidity test was also obtained. Increased about four times. From the above results, it has been clarified that the optical recording medium of the present invention has both high reflectivity and durability.

[0073]

According to the first to sixth aspects of the present invention, the chemical stability of the light reflecting layer made of silver or an alloy containing silver as a main component is improved, and a high reflectivity and a high reflectivity are obtained. There is an effect that an optical recording medium having reliability and durability can be provided at low cost. According to the seventh aspect of the present invention, silver or silver having a high reflectivity sufficient to compensate for the attenuation of the light beam due to the organic dye recording layer and excellent reliability and durability is mainly composed of silver or silver. An alloy light reflecting layer is obtained,
There is an effect that a high-performance write-once optical recording medium can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a layer configuration of a write-once optical disc according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Organic dye recording layer 3 Light reflection layer 4 Protective layer

Claims (7)

[Claims] And a mercaptoaza having one or three or more N atoms in a six-membered ring and a five-membered ring constituting indene. Indene, or the mercaptoazaindene, a hydrocarbon group, an ester group, an aryl group, a halogen group, a hydroxyl group, an alkoxyl group, an amino group,
Nitro group, cyano group, acyl group, aldehyde group, carboxyl group, alkylthio group, arylthio group, aryloxy group, acyloxy group, thioester group, -NH
A light reflecting layer made of silver or an alloy containing silver as a main component, which is treated with a compound in which one or more of R and -NRR '(R and R' are alkyl groups) are substituted. An optical recording medium comprising: 2. A substrate, and a surface laminated on the substrate and having a surface opposite to the substrate,
Mercaptopyridine or the mercaptopyridine, a hydrocarbon group, an ester group, an aryl group, a halogen group, a hydroxyl group, an alkoxyl group, an amino group, a nitro group, a cyano group,
Acyl group, aldehyde group, carboxyl group, alkylthio group, arylthio group, aryloxy group, acyloxy group, thioester group, -NHR, -NRR '(R,
R ′ is an alkyl group), and a light reflecting layer made of silver or an alloy containing silver as a main component, which is treated with a compound in which one or more of the groups are substituted. Optical recording medium. 3. A substrate, and a surface laminated on the substrate and opposite to the substrate,
Mercaptopyrimidine, or a mercaptopyrimidine, a hydrocarbon group, an ester group, an aryl group, a halogen group, a hydroxyl group, an alkoxyl group, an amino group, a nitro group, a cyano group, an acyl group, an aldehyde group, a carboxyl group, an alkylthio group, an arylthio group , Aryloxy group, acyloxy group, thioester group, -NHR, -NRR '(R and R' are alkyl groups)
An optical recording medium comprising: a light reflecting layer made of silver or an alloy containing silver as a main component, which is treated with a compound in which one or more groups are substituted. 4. A substrate, and a surface laminated on the substrate and opposite to the substrate,
Mercaptoazanaphthalene or the mercaptoazanaphthalene, a hydrocarbon group, an ester group, an aryl group, a halogen group, a hydroxyl group, an alkoxyl group, an amino group, a nitro group, a cyano group, an acyl group, an aldehyde group, a carboxyl group, an alkylthio group, Arylthio group, aryloxy group, acyloxy group, thioester group, -NHR, -N
A light reflecting layer made of silver or an alloy containing silver as a main component, which is treated with a compound in which one or more of RR ′ (R and R ′ are alkyl groups) are substituted. An optical recording medium characterized in that: 5. A substrate, and a surface laminated on the substrate and opposite to the substrate,
Mercaptobenzothiadiazole, or the mercaptobenzothiadiazole, a hydrocarbon group, an ester group, an aryl group, a halogen group, a hydroxyl group, an alkoxyl group, an amino group, a nitro group, a cyano group, an acyl group, an aldehyde group, a carboxyl group, an alkylthio group, Arylthio group, aryloxy group, acyloxy group, thioester group, -N
One of HR and -NRR '(R and R' are alkyl groups)
An optical recording medium comprising: a light reflecting layer made of silver or an alloy containing silver as a main component, which is treated with a compound in which one or more groups are substituted. 6. A substrate, and a surface laminated on the substrate and opposite to the substrate,
Mercaptobenzoxazole, or the mercaptobenzoxazole, a hydrocarbon group, an ester group, an aryl group, a halogen group, a hydroxyl group, an alkoxyl group, an amino group,
Nitro group, cyano group, acyl group, aldehyde group, carboxyl group, alkylthio group, arylthio group, aryloxy group, acyloxy group, thioester group, -NH
A light reflecting layer made of silver or an alloy containing silver as a main component, which is treated with a compound in which one or more of R and -NRR '(R and R' are alkyl groups) are substituted. An optical recording medium comprising: 7. The optical recording medium according to claim 1, wherein an organic dye recording layer is provided between the substrate and the light reflection layer.