JP2002321454A - Optical recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical recording material made of a compound with an optical recording material suitable for DVD-R or the like. SOLUTION: This optical recording material includes an indole compound represented by general formula (I), wherein a ring A and a ring A' each represent a benzene ring, a naphthalene ring or a pyridine ring, R1 and R1 ' each represent a halogen atom, a nitro group, a cyano group, a 1-8C alkyl group, a 1-8C alkoxy group or a 6-30C aryl-containing group, R2 and R2 ' each represent a hydrogen atom, a 1-8C alkyl group, a 1-8C alkenyl group, a 1-8C alkylthio group, a 1-8C alkoxy group, a 1-8C carbonyl group, or a 6-30C aryl-containing group, X1 and X2 each represent a hydrogen atom or a group forming a five- membered ring or a six-membered ring, Y and Y' each represent a hydrogen atom, a 1-30C organic group, Z represents a hydrogen atom, a halogen atom, a cyano group, a 1-8C alkyl group and a 6-30C aryl-containing group, r and r' each represent an integer from 0 through 2, An<n-> represents a n-th valent anion, n represents an integer of 1 or 2 and q represents a coefficient for keeping charges neutral.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording material used for an optical recording medium for recording by giving information as an information pattern by a laser or the like. The present invention relates to an optical recording material used for an optical recording medium which has high density optical recording and reproduction with a low energy laser or the like.

[0002]

2. Description of the Related Art Optical recording media are widely used because they have a large storage capacity and excellent characteristics such as recording and reproduction without contact. In write-once optical disks such as WORM, CD-R, and DVD-R, a laser is focused on a very small area of the recording layer, recording is performed by changing the properties of the recording layer, and reproduction is performed based on the difference in the amount of reflected light from the unrecorded portion. Is going.

[0003] At present, among the above-mentioned optical disks, those capable of shortening the wavelength of a semiconductor laser used for recording and reproduction and performing high-density recording have been developed. The wavelength of the semiconductor laser used for this is 380 to 830 n
m, for example, CD-R is 750-830n
m, the DVD-R is 620 nm to 660 nm, and an even higher density optical disk of 600 nm or less has been developed.

The recording layer needs to have sufficient sensitivity to a writing laser beam and sufficient recording stability to a reading laser beam. Optical disks such as DVD-Rs have the same or similar wavelengths of lasers for writing and reading, and perform writing and reading by changing the magnitude of the output. If the recording layer has low absorption at these wavelengths, sufficient recording sensitivity cannot be obtained, and if the absorption is high, recording stability such as light resistance decreases, so the recording layer needs to have an appropriate absorption intensity. It is.

At present, organic dyes such as phthalocyanine compounds, azo compounds and cyanine compounds are used in the recording layer, and these compounds have optical characteristics such as absorption wavelength, absorbance and light stability. Was not always satisfactory.

Accordingly, an object of the present invention is to provide an optical recording material comprising a compound suitable as an optical recording material for a DVD-R or the like.

[0007]

Means for Solving the Problems The present inventors have proposed a method for producing an optical recording material using an indole compound having a specific structure.
The present inventors have found that the V absorption spectrum gives an appropriate absorption as an optical recording material such as a DVD-R, and have reached the present invention.

[0008] The present invention has been made based on the above findings, and comprises an optical recording material comprising an indole compound represented by the following general formula (I): An optical recording medium characterized by forming a thin film made of the recording material.

[0009]

Embedded image

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail.

In the general formula (I) according to the present invention, R ₁ and R ₁ ′ may be the same or different;
Examples of the halogen atom represented by R ₁ and R ₁ ′ include fluorine, chlorine, bromine and iodine. Examples of the alkyl group having 1 to 8 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl and sec-butyl. , Tert-butyl, isobutyl, amyl, isoamyl, tertiary amyl, hexyl, cyclohexyl, heptyl, isoheptyl, tertiary heptyl,
Examples include n-octyl, isooctyl, tertiary octyl, and 2-ethylhexyl. Examples of the alkoxy group having 1 to 8 carbon atoms include methyloxy, ethyloxy, isopropyloxy, propyloxy, butyloxy, pentyloxy, isopentyloxy, and hexyloxy. , Heptyloxy, octyloxy, and 2-ethylhexyloxy. Examples of the aryl-containing group having 6 to 30 carbon atoms include phenyl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, and 4-vinylphenyl. , 3
-Isopropylphenyl, 4-isopropylphenyl,
4-butylphenyl, 4-isobutylphenyl, 4-tert-butylphenyl, 4-hexylphenyl, 4-cyclohexylphenyl, 4-octylphenyl, 4- (2-
Ethylhexyl) phenyl, 4-stearylphenyl,
2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2,4-di-tert-butyl Phenyl, 2,5-di-tert-butylphenyl, 2,6-di-tert-butylphenyl,
2,4-ditertiary pentylphenyl, 2,5-ditertiary amylphenyl, 2,5-ditertiary octylphenyl, 2,4
-Dicumylphenyl, cyclohexylphenyl, biphenyl, 2,4,5-trimethylphenyl, benzyl, phenethyl, 2-phenylpropan-2-yl, diphenylmethyl, triphenylmethyl, styryl, cinnamyl and the like. R ₂ and R ₂ ′ may be the same or different, and may be an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or a C 6 atom represented by R ₂ and R ₂ ′. Examples of the aryl-containing group having from 30 to 30 include the same groups as those described for R _1, and examples of the alkenyl group having 1 to 8 carbon atoms include vinyl, methylethenyl, propenyl, butenyl,
Isobutenyl, pentenyl, hexenyl, heptenyl,
Octenyl is mentioned, and the position of these double bonds is not particularly limited. Examples of the alkylthio group having 1 to 8 carbon atoms include methylthio, ethylthio, isopropylthio, propylthio, butylthio, pentylthio, isopentylthio, hexylthio, heptylthio, octylthio,
Ethylhexylthio is mentioned, and examples of the carbonyl group having 1 to 8 carbon atoms include acetyl, propionyl, octanoyl, acryloyl, methacryloyl, phenylcarbonyl, and salicyloyl.

Further, Y and Y ′ may be the same or different, and examples of the organic group having 1 to 30 carbon atoms represented by Y and Y ′ include methyl, ethyl, propyl, isopropyl, butyl, Butyl, tert-butyl, isobutyl, amyl, isoamyl, tert-amyl, hexyl, cyclohexyl, cyclohexylmethyl, 2-cyclohexylethyl, heptyl, isoheptyl, tertiary heptyl, n-octyl, isooctyl, tertiary octyl, 2-ethylhexyl, Alkyl groups such as nonyl, isononyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, peptadecyl, octadecyl, vinyl, 1-
Methylethenyl, 2-methylethenyl, propenyl, butenyl, isobutenyl, pentenyl, hexenyl, heptenyl, octenyl, decenyl, pentadecenyl, 1-
Alkenyl groups such as phenylpropen-3-yl, phenyl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-vinylphenyl, 3-isopropylphenyl, 4-isopropylphenyl, 4-
Butylphenyl, 4-isobutylphenyl, 4-tert-butylphenyl, 4-hexylphenyl, 4-cyclohexylphenyl, 4-octylphenyl, 4- (2-ethylhexyl) phenyl, 4-stearylphenyl, 2,
3-dimethylphenyl, 2,4-dimethylphenyl,
Alkylaryl groups such as 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2,4-di-tert-butylphenyl, cyclohexylphenyl, benzyl, phenethyl, Arylalkyl groups such as 2-phenylpropan-2-yl, diphenylmethyl, triphenylmethyl, styryl, cinnamyl, etc., which are interrupted by an ether bond or a thioether bond, for example, 2-methoxyethyl, 3-methoxypropyl , 4-methoxybutyl, 2-
Butoxyethyl, methoxyethoxyethyl, methoxyethoxyethoxyethyl, 3-methoxybutyl, 2-phenoxyethyl, 3-phenoxypropyl, 2-methylthioethyl, 2-phenylthioethyl, and these groups further include an alkoxy group, Alkenyl group, nitro group,
It may be substituted with a cyano group, a halogen atom or the like. Z
An alkyl group having 1 to 8 carbon atoms represented by
Examples of the aryl-containing group include the same groups as those described above for R ₁ .

In the above general formula (I), An ^n-
Examples of the anion represented by are, as monovalent, halogen anions such as chlorine anion, bromine anion, iodine anion and fluorine anion; perchlorate anion, chlorate anion, thiocyanate anion and phosphorus hexafluoride anion Inorganic anions such as chromium, antimony hexafluoride and boron tetrafluoride, organic sulfonic acid anions such as benzenesulfonic acid anion, toluenesulfonic acid anion and trifluoromethanesulfonic acid anion; octyl phosphate anion, dodecyl phosphate anion and octadecyl Organic phosphate anions such as phosphate anion, phenyl phosphate anion, nonylphenyl phosphate anion, and 2,2′-methylenebis (4,6-ditert-butylphenyl) phosphonate anion, and the like. For example, Benzene disulfonic acid anion, naphthalenedisulfonic acid anion, JP-A-60-2
And quencher anions described in JP-A-34892 and JP-A-10-45767.

Specific examples of the indole compound according to the present invention include the following. Note that, in the following examples, the dye cation is shown without the anion.

[0015]

Embedded image

[0016]

Embedded image

[0017]

Embedded image

[0018]

Embedded image

[0019]

Embedded image

[0020]

Embedded image

The indium represented by the general formula (I) according to the present invention
In the doll compound, R_TwoAnd R _Two’
These are alkyl groups having 1 to 8 carbon atoms and 6 to 30 carbon atoms.
Those selected from aryl-containing groups are those having photostability
Are preferred, and methyl or phenyl is more preferred.
New In addition, those in which ring A and ring A 'are benzene rings
Is preferred because it conforms to the DVD-R standard.

X ₁ and X ₂ are preferably hydrogen atoms because they conform to the DVD-R standard.

The compound represented by the above general formula (I) according to the present invention is obtained, for example, by reacting a cyclic compound having a corresponding structure with a bridging agent compound for introducing a trimethine chain with a reactant, It can be synthesized by performing anion exchange as needed. For example, it is synthesized by the following route.

[0024]

Embedded image

The above-mentioned compound according to the present invention is applied as a recording layer of an optical recording medium, and a known method can be used for forming the recording layer. Generally,
Lower alcohols such as methanol and ethanol; ether alcohols such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, and butyl diglycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and diacetone alcohol;
Esters such as ethyl acetate, butyl acetate, and methoxyethyl acetate; acrylates such as ethyl acrylate and butyl acrylate; fluorinated alcohols such as 2,2,3,3-tetrafluoropropanol; benzene; Hydrocarbons such as xylene, methylene dichloride,
It can be easily formed by applying a solution dissolved in an organic solvent such as chlorinated hydrocarbons such as dichloroethane and chloroform onto a substrate.

The thickness of the recording layer is usually from 0.001 to
10 μm, preferably in the range of 0.01 to 5 μm. The method for forming the recording layer is not particularly limited, and a commonly used method such as a spin coating method can be used.

When the optical recording material of the present invention is contained in a recording layer of an optical recording medium, the amount used for the recording layer is preferably 50 to 100% by weight.

In addition to the optical recording material of the present invention, the above-mentioned recording layer may contain, if necessary, other compounds used for the optical recording layer such as a cyanine compound, an azo compound, a phthalocyanine compound and a quinoline compound. It may contain resins such as polyethylene, polyester, polystyrene, polycarbonate, epoxy, urethane, etc., surfactants, antistatic agents, lubricants, flame retardants, radical scavengers, pit formation accelerators, pit control agents, dispersants , An antioxidant, a crosslinking agent, a lightfastness-imparting agent, and the like.

Further, the recording layer may contain an aromatic nitroso compound, an aminium compound, an iminium compound, a bisiminium compound, a transition metal chelate compound or the like as a quencher for singlet oxygen or the like. These are preferably used in the range of 0 to 50% by weight based on the recording layer.

The material of the substrate on which such a recording layer is provided is not particularly limited as long as it is substantially transparent to writing light and reading light. Examples thereof include polymethyl methacrylate, polyethylene terephthalate, and polycarbonate. Resin, glass, etc. are used. In addition, any shape such as a tape, a drum, a belt, and a disk can be used depending on the application.

A reflective film can be formed on the recording layer by vapor deposition or sputtering using gold, silver, aluminum, copper or the like.
A protective layer made of an ultraviolet curable resin or the like can be formed.

[0032]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Production Examples and Examples. However, the present invention is not limited at all by the following examples.

[Production Example 1] (Synthesis of p-toluenesulfonic acid salt of compound No. 1)
27.5 g of indole was placed in a reaction flask purged with nitrogen,
16.4 g of 1,1,3,3-tetramethoxypropane,
20.9 g of p-toluenesulfonic acid monohydrate and 94.1 g of diethylene glycol dimethyl ether were charged.
Stirred at 0 ° C. for 7 hours. 300m chloroform in this system
l, 200 ml of water was added, and the chloroform phase obtained by oil-water separation was dried over anhydrous sodium sulfate and concentrated to obtain a solid phase. A mixed solvent of 50 g of dimethylformamide and 100 g of methanol was added thereto, followed by stirring at 50 to 60 ° C. The crystals were collected by filtration, washed with methanol, and dried under vacuum to obtain 19.4 g (yield: 41.2%) of red crystals.

(Analysis) Structural analysis: ¹ H-NMR measurement (chemical shift ppm; multiplicity; number of protons) (2.26-2.27; s; 3), (2.75-2.7)
6; s; 6) (7.08-7.09; d; 2), (7.38-7.4)
2; t; 2) (7.45-7.59; d + m; 6), (7.75-
7.78; t; 1) (8.08-8.11; d; 2), (8.54-8.5)
8; d; 2) (13.43-13.44; s; 2) Optical property: UV spectrum measurement with chloroform solvent λ _max ; 526 nm, ε; 1.20 × 105 melting point; 215 to 216 ° C., decomposition Point: 218 to 219 ° C

[Production Example 2] (Synthesis of p-toluenesulfonic acid salt of compound No. 4)
In a reaction flask purged with nitrogen, 4.0 g of 1-isoamyl-2-methylindole, 1.6 g of 1,1,3,3-tetramethoxypropane, 2.1 g of p-toluenesulfonic acid monohydrate, diethylene glycol dimethyl ether 1
2.2 g was charged and stirred at 70 ° C. for 7 hours. The solid phase in the system was collected by filtration, washed with diethylene glycol dimethyl ether, water, diethylene glycol dimethyl ether and hexane in that order, and dried in vacuo to obtain blue silver crystals.
1 g (18.0% yield) was obtained.

(Analysis) Structural analysis: ¹ H-NMR measurement (chemical shift ppm; multiplicity; number of protons) (0.98-1.01; d; 12), (1.60-1.
66; q; 4) (1.70-1.80; m; 2), (2.26-2.2)
7; s; 3) (2.83-2.84; s; 6), (4.32-4.3)
7; t; 4) (7.07-7.10; d; 2), (7.44-7.5)
7; d + m; 6) (7.74-7.77; d; 2), (7.84-7.9)
2; t; 1) (8.17-8.20; d; 2), (8.62-8.6)
6; d; 2) Optical properties: UV spectrum measurement with chloroform solvent λ _max ; 560.5 nm, ε; 1.50 × 105 Decomposition point: 181-182 ° C.

[Production Example 3] (Synthesis of p-toluenesulfonic acid salt of Compound No. 10) 4.8 g of 5-fluoro-2-methylindole, 1,1,3,3-tetra 2.6 g of methoxypropane, 3.3 g of p-toluenesulfonic acid monohydrate, diethylene glycol dimethyl ether 1
6.2 g was charged and stirred at 70 ° C. for 7 hours. 50 ml of chloroform and 100 ml of water were added to the system, and the mixture was stirred for 30 minutes, and a solid was collected by filtration. After heating and dissolving the solid collected by filtration in 30 g of dimethylformamide, methanol was added thereto, and the precipitated crystals were washed with methanol and dried under vacuum to obtain 4.8 g (yield: 59.3%) of purple crystals.

(Analysis) Structural analysis: ¹ H-NMR measurement (chemical shift ppm; multiplicity; number of protons) (2.23 to 2.30; s; 3), (2.70 to 2.8)
3; s; 6) (7.06-7.11; d; 2), (7.20-7.2)
7; t; 2) (7.45-7.48; d; 2), (7.51-7.5)
5; m; 2) (7.58-7.66; t; 1), (7.90-7.9)
3; d; 2) (8.51-8.57; d; 2), (13.50-1)
3.52; s; 2) Optical properties: UV spectrum measurement with chloroform solvent λ _max ; 519 nm, ε; 1.33 × 105 melting point; 180-181 ° C, decomposition point: 183-184 ° C

[Production Example 4] (Synthesis of p-toluenesulfonic acid salt of compound No. 16) In a reaction flask purged with nitrogen, 16.2 g of 2-phenylindole and 1,1,3,3-tetramethoxypropane 6. 6 g, p-toluenesulfonic acid monohydrate 8.4
g, diethylene glycol dimethyl ether 47.6 g
And stirred at 70 ° C. for 4 hours. The solid phase in the system is collected by filtration, and this is diethylene glycol dimethyl ether,
After washing in order of water, diethylene glycol dimethyl ether, and hexane, vacuum drying was performed to obtain 21.5 g of green crystals.
(90.3% yield).

(Analysis) Structural analysis: ¹ H-NMR measurement (chemical shift ppm; multiplicity; number of protons) (2.26-2.27; s; 3), (7.08-7.1)
1; d; 2) (7.50-7.9; m; 19), (7.98-8.0)
5; s; 2) (8.35-8.45; d; 2), (13.83-1)
3.87; s; 2) optical properties: UV spectrum measured in chloroform solvent _{λ max; 588nm, ε; 0.9} × 105 mp; 230-231 ° C., decomposition point; two hundred thirty-six to two hundred and thirty-seven ° C.

[Production Example 5] (Synthesis of p-toluenesulfonic acid salt of compound No. 17) 17.4 g of 1-methyl-2-phenylindole, 1,1,3,3-tetrafluoroethylene were placed in a reaction flask purged with nitrogen. 6.6 g of methoxypropane, 8.4 g of p-toluenesulfonic acid monohydrate, and 49.8 g of ethanol were charged, and 70 ° C.
For 4 hours. After removing the solvent, 60 g of dimethylformamide was added to the system and dissolved by heating.
g, cooled, and the precipitated crystals were washed with ethyl acetate and dried under vacuum to obtain 11.5 g of dark green crystals (46.0% yield).
Obtained.

(Analysis) Structural analysis: ¹ H-NMR measurement (chemical shift ppm; multiplicity; number of protons) (2.27-2.28; s; 3), (3.75-3.7)
6; s; 6) (7.08-7.11; d; 2), (7.44-7.4)
7; d; 2) (7.50-7.9; d + s + s + d; 21) Optical properties: UV spectrum measurement with chloroform solvent λ _max ; 594.5 nm, ε; 1.31 × 105 Melting point: 220-221 ° C. 223 DEG-224 DEG C.

[Production Example 6] (Synthesis of bromide salt of Compound No. 4) A chloroform solution of the salt obtained by the same operation as in Production Example 2 was prepared by adding 1.1.
A double molar aqueous solution of potassium sodium bromide was added, and the mixture was stirred at room temperature for 3 hours to perform salt exchange. The solid phase was collected by filtration, washed with water and methanol, and dried under vacuum to obtain green crystals.

(Analysis) Optical properties: UV spectrum measurement with chloroform solvent λ _max : 560.5 nm, ε; 1.65 × 105 Decomposition point: 213 to 214 ° C.

[Production Example 7] (Synthesis of bromine salt of Compound No. 17) A chloroform solution of the salt obtained by the same operation as in Production Example 5 above was used to prepare 1.
A 1 molar aqueous solution of potassium sodium bromide was added, and the mixture was stirred at room temperature for 3 hours to perform salt exchange. The solid phase is filtered, water,
After washing with methanol, vacuum drying was performed to obtain green crystals.

(Analysis) Optical properties: UV spectrum measurement in chloroform solvent λ _max ; 595 nm, ε; 1.40 × 105 Decomposition point: 232 to 233 ° C.

[Production Example 8] (Synthesis of perchlorate of compound No. 17) Salt exchange was carried out using sodium perchlorate in the same manner as in Example 7 above.
Blue-green crystals were obtained.

[0048] (Analysis) optical properties: UV spectrum measured in chloroform solvent _{λ max; 594.0nm, ε; 1.17} × 105 mp; 249~250 ℃, decomposition point; two hundred and fifty-nine to two hundred and sixty ° C.

Example (production and evaluation of recording medium) A titanium chelate compound (trade name: T-50, manufactured by Nippon Soda Co., Ltd.) was applied and hydrolyzed to provide a base layer (0.01 μm) having a diameter of 12 cm. A 2,2,3,3-tetrafluoropropanol solution (concentration: 2%) of the indole compound shown below and the cyanine compound of the comparative example shown below, respectively, was applied on the polycarbonate disk substrate by spin coating. Then, a recording layer having a thickness of 100 nm (within an error of 5%) was formed to obtain an optical recording medium. The UV spectrum absorption of these optical recording media was measured, and the following evaluation (appropriate wavelength region and light resistance) as the optical recording media was performed.

[0050]

Embedded image

(Evaluation Example 1) <Evaluation of appropriate wavelength region> In order to eliminate the influence of film thickness variation and ε, evaluation was performed in an appropriate wavelength region by measuring relative absorbance with λ _{max of} each recording medium corrected to intensity 1. The optical recording medium has low sensitivity when the relative absorbance value is smaller than 0.10, so that the recording and reading characteristics deteriorate,
If it exceeds 0, the light resistance to reading light of the recording layer and the light resistance to natural light deteriorate, so that the storage stability of the recording deteriorates. Therefore, it is appropriate that the optical recording medium has a relative absorbance value in the range of preferably 0.10 to 0.50, more preferably 0.15 to 0.45. The appropriate region in Table 1 has a relative absorbance of 0.15 to 0.15.
It is a wavelength region giving a range of 0.45. The results are shown in Table 1 together with the DVD-R standard.

[0052]

[Table 1]

From the above evaluation, the optical recording material of the present invention was
It was confirmed that it can be used as an optical recording medium in a wide wavelength region, particularly in a short wavelength region. As a DVD-R,
It was confirmed that it can be used similarly to the cyanine compound.

(Evaluation Example 2) <Evaluation of light fastness> The optical recording medium obtained above was exposed to light of 55000 lux for 40 hours using a xenon light fastness tester (Tablesun, manufactured by Suga Test Instruments Co., Ltd.). Irradiation was performed, and the ratio A / A ′ (%) of the absorbance A ′ immediately after coating and film formation at λ _max of the thin film to the absorbance A after irradiation was evaluated as the residual dye ratio. Table 2 shows the results.

[0055]

[Table 2]

From the above evaluations, it was confirmed that the optical recording material of the present invention gave excellent light resistance to the optical recording medium as compared with the cyanine compound.

[0057]

According to the present invention, it is possible to provide an optical recording material comprising a compound suitable for an optical recording material such as a DVD-R.

Claims (4)

[Claims] 1. An optical recording material comprising an indole compound represented by the following general formula (I). Embedded image 2. In the general formula (I), R ₂ and R
The optical recording material according to claim 1, wherein ₂ 'is a group selected from an alkyl group having 1 to 8 carbon atoms and an aryl-containing group having 6 to 30 carbon atoms. 3. The optical recording material according to claim 1, wherein ring A and ring A ′ in the general formula (I) are benzene rings. 4. An optical recording medium comprising a substrate and a thin film formed of the optical recording material according to claim 1 formed thereon.