JPH0776308B2 - Indophenol compound and optical recording medium containing the compound - Google Patents

Description

TECHNICAL FIELD The present invention relates to an indophenol compound and an optical recording medium using the compound.

[Conventional technology]

Optical recording using a laser has been particularly developed in recent years because it enables high-density information recording storage and reproduction.

An optical disc can be given as an example of the optical recording.

In general, an optical disc is one in which a thin recording layer provided on a circular substrate is irradiated with laser light focused to about 1 μm to perform high density information recording. The recording is performed by the absorption of the irradiated laser light energy, which causes thermal deformation such as decomposition, evaporation, and dissolution in the recording layer at that location. The recorded information is reproduced by reading the difference in reflectance between the portion where the laser light is deformed and the portion where the laser light is not deformed.

Therefore, as the optical recording medium, since it is necessary to efficiently absorb the energy of the laser light, the absorption of the laser light of a specific wavelength used for recording is large,
In order to accurately reproduce the information, it is necessary that the reflectance with respect to the laser light of the specific wavelength used for the reproduction is high.

Various types of optical recording media are known as this type of optical recording medium.

For example, JP-A-55-97033 discloses a substrate in which a single layer of a phthalocyanine dye is provided.
However, phthalocyanine dyes have the problems of low sensitivity, high decomposition point and difficulty in vapor deposition, and also have very low solubility in organic solvents and thus cannot be used for coating by coating. ing.

Further, JP-A-58-83344 and JP-A-58-224793 disclose that a recording layer is provided with a phenalene dye and a naphthoquinone dye, respectively. However, while such a dye has an advantage of being easily evaporated, it has a problem of low reflectance. If the reflectance is low, the contrast relating to the reflectance between the portion recorded by the laser beam and the unrecorded portion becomes low, and it becomes difficult to reproduce the recorded information. In addition, organic dyes generally have a problem of poor storage stability.

[Problems to be solved by the invention]

INDUSTRIAL APPLICABILITY The present invention uses an indophenol compound which is easy to deposit, has a high solubility in an organic solvent, can be coated by coating, has a high reflectance, has a good contrast, and has excellent storage stability. It is intended to provide an optical recording medium.

[Means for solving problems]

The present invention provides an indophenol-based compound represented by the following general formula [I] suitable for use as a dye of an optical recording medium for recording / reproducing by causing a state change by a laser beam and a substrate thereof. The gist of the invention is a supported optical recording medium.

General formula [I] (In the formula, Represents a residue of a substituted or unsubstituted aromatic amine, R ¹ , R ² and R ³ represent a hydrogen atom, a halogen atom,
Nitro group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aminocarbonyl group, substituted or unsubstituted carbonylamino group, substituted or unsubstituted aminosulfonyl group, substituted or unsubstituted Represents a sulfonylamino group or a substituted or unsubstituted thiocarbonylamino group. ) In the general formula [I], as a substituent of the alkyl group, alkoxy group, aminocarbonyl group, carbonylamino group, aminosulfonyl group, sulfonylamino group or thiocarbonylamino group represented by R ¹ , R ² and R ³ , For example, thiocyanato group, nitro group, halogen atom, cyano group, alkyl group, alkylsulfonyl group, hydroxyalkylsulfonyl group, alkoxysulfonyl group, alkoxyalkoxysulfonyl group, allylsulfonyl group, alkoxycarbonyl group, alkoxyalkoxycarbonyl group, alkoxy An aryl group such as a phenyl group and a naphthyl group which may be substituted with an alkoxyalkoxycarbonyl group, an alkoxy group, an alkoxyalkoxy group, an alkoxyalkoxyalkoxy group and the like; an alkyl group; an aralkyl group such as a benzyl group; Trahydrofurfuryl group; cycloalkyl group such as cyclohexyl group; amino group such as phenylamino group, alkylamino group, dialkylamino group; nitrothiazolyl group, nitrobenzothiazolyl group, alkylthiothiazoazilyl group, dicyanoalkyldiazolyl And a 5-membered or 6-membered substituted or unsubstituted heterocyclic residue containing a nitrogen atom, an oxygen atom or a sulfur atom, such as a group or a bromobenzothiazole group.

The residue of the substituted or unsubstituted aromatic amine represented by K is, for example, tetrahydroquinoline or the following general formula [II] (In the formula, X and Y represent a hydrogen atom, an alkyl group, an acylamino group, an alkoxy group or a halogen atom, and R ⁴
And R ⁵ represents a hydrogen atom; a C ₁ -C ₂₀ substituted or unsubstituted alkyl group, aryl group or cyclohexyl group. ) And the like. In the formula, as the substituent of the alkyl group, aryl group or cyclohexyl group represented by -R ⁴ and -R ⁵ , for example, an alkoxy group, an alkoxyalkoxy group, an alkoxyalkoxyalkoxy group,
Examples thereof include an allyloxy group, an aryl group, an aryloxy group, a cyano group, a hydroxy group, and a tetrahydrofuryl group.

The indophenol compound represented by the general formula [I] has absorption in the wavelength band of 600 to 800 nm and has a molecular absorption coefficient of 10 ⁴ to 10 ⁵ cm ^-1 .

The general synthesis of the indophenol compound represented by the general formula [I] of the present invention can be carried out by, for example, PW Vittum and GHB
It can be performed according to the description in rown, J. Am. Soc. Chem., 68 2235 (1946).

The optical recording medium of the present invention basically comprises a substrate and a recording layer containing an indophenol compound, but if necessary, an undercoat layer may be formed on the substrate and a recording layer may be formed on the recording layer. A protective layer can be provided.

The substrate in the present invention may be transparent or opaque to the laser light used. Examples of the material for the substrate material include glass, plastic, paper, and a support for general recording material such as plate-shaped or foil-shaped metal.
Plastic is preferable from various points. Examples of the plastic include acrylic resin, methacrylic resin, vinyl acetate resin, vinyl chloride resin, nitrocellulose, polyethylene resin, polypropylene resin, polycarbonate resin, polyimide resin, epoxy resin and polysulfone resin.

When an indophenol compound is used as an information recording layer in the optical recording medium of the present invention, the film thickness is 100Å to 5
μm, preferably 1000Å to 3 μm. As the film forming method, a generally used thin film forming method such as a vacuum vapor deposition method, a sputtering method, a doctor blade method, a cast method, a spinner method, and a dipping method can be used. Further, a binder can be used if necessary. Known binders such as PVA, PVP, nitrocellulose, cellulose acetate, polyvinyl butyral, and polycarbonate are used, and the amount of the idphenol compound with respect to the resin is preferably 0.01 or more by weight. In the case of film formation by the spinner method, the rotation speed is preferably 500 to 5000 rpm, and after spin coating, treatment such as heating or applying to solvent vapor may be performed depending on the case. Also,
In order to improve the stability and light resistance of the recording material, a transition metal chelate compound (for example, acetylacetonate chelate, bisphenyldithiol, salicylaldehyde oxime, bisdithio-α-diketone, etc.) is contained as a singlet oxygen quencher. May be. Furthermore, other dyes can be used in combination, if necessary. Other dyes may be other types of indophenol dyes, or may be other types of dyes such as triarylmethane dyes, azo dyes, dianine dyes, squarylium dyes.

Doctor blade method, cast method, spinner method, dipping method, especially as a coating solvent when forming the recording layer by a coating method such as spinner method, tetrachloroethane, bromoform, dibromoethane, ethyl cellosolve, xylene, chlorobenzene, cyclohexanone Boiling point of 120
Those having a temperature of up to 160 ° C are preferably used.

The recording layer of the optical recording medium of the present invention may be provided on both sides of the substrate, or may be provided on only one side.

Recording on the recording medium obtained as described above is performed by exposing the recording layer provided on both sides or one side of the substrate to a laser beam focused to about 1 μm, preferably a semiconductor laser beam. In the portion irradiated with laser light, thermal deformation of the recording layer such as decomposition, evaporation, and melting occurs due to absorption of laser energy.

Reproduction of the recorded information is performed by reading the difference in reflectance between a portion where thermal deformation has occurred and a portion where thermal deformation has not occurred, using laser light.

Laser light used for the optical recording medium of the present invention is _{N 2, He-Cd, Ar} , He-Ne, ruby, semiconductor, but such a dye laser and the like, in particular, light weight, ease of handling, compactness A semiconductor laser is preferable from the viewpoint of properties and the like.

EXAMPLES The present invention will be specifically described below with reference to examples, but the examples do not limit the present invention.

Example 1 (a) Production Example Structural formula below 0.42 g of the compound represented by was added to 20 ml of DMF, and the mixture was stirred.
Add a solution of 0.1 g of potassium cyanide dissolved in 2.5 ml of water,
The reaction was carried out at room temperature for 2 hours. Next, 0.28 g of DDQ (dicyanodichlorobenzoquinone) was added, and the mixture was reacted at room temperature for 2 hours. After completion of the reaction, 5 ml of water was added, and the formed crystals were washed with water, dried, and 0.35 g (78%) of the indophenol compound represented by the following structural formula was obtained.

The visible absorption spectrum (in acetone) of this compound is λ
It was max710 nm (Fig. 1), and the mass spectrum was as follows. (Measurement condition: 70 eV, 150 ° C.) m / e 363,365 (M ⁺ + H ₂ ) 348,350 (M ⁺ + H ₂ —CH ₃ ) (base peak) (b) Example of recording medium 2 × 10 ^-5 Torr
Under vacuum, heated to about 80 to 150 ° C., and vacuum-deposited on a methacrylic resin (hereinafter referred to as PMMA) substrate having a plate thickness of 1.2 mm. The vapor deposition film thickness was 2015Å as a result of the vacuum vapor deposition film thickness measurement by a crystal vibration type film thickness meter. The maximum absorption wavelength measured by the spectrophotometer was 730 nm, and the shape of the spectrum was wide.

When the coating film was irradiated with a semiconductor laser beam having a central wavelength of 780 nm at an output of 6 mW and a beam diameter of 1 μm, a very clear pit having a width of about 1 μm and a pit length of about 2 μm was formed. The C / N ratio and storage stability (60 ℃, 80% RH) were good.

Example 2 (a) Production Example The following structural formula 0.45 g of the compound represented by 10 ml of DMF was added and stirred, and a solution of 0.1 g of potassium cyanide dissolved in 2.5 ml of water was added and reacted at room temperature for 2 hours. After the reaction, DDQ (0.28 g) was added, and the mixture was further reacted at room temperature for 2 hours. After the reaction,
After washing with water and drying, 0.4 g (83%) of an indophenol compound represented by the following structural formula was obtained.

The visible absorption spectrum (in acetone) of this compound is λma
x615 nm (Fig. 2), and the mass spectrum was as follows. (Measurement conditions: 70 eV, 250 ° C) m / e 384 (M ⁺ -H ₂ ) 369 (M ⁺ -H ₂ -CH ₃ ) (base peak) (b) Recording medium example Idphenol compound of the above structural formula 1 g Was dissolved in 50 g of dibromoethane and passed through a 0.22 μ filter to obtain a solution. 2 ml of this solution was dropped onto a PMMA resin substrate (5 inches) having a depth of 700 L and a width of 0.7 μ and a groove (groove) made of an ultraviolet curable resin, and applied by a spinner method at a rotation speed of 1200 rpm. After coating, it was dried at 60 ° C. for 10 minutes. When it was applied to a glass plate under the same conditions and the film thickness was measured by α-step, it was 700Å. The maximum absorption wavelength of the coating film is 620
nm, and the shape of the spectrum was wide.

When a thin film thus obtained was written with a He-Ne laser as a light source at a beam diameter of 2.4 μm and a wavelength of 632.8 nm, uniform and clear pits were obtained. The carrier level / noise level (C / N) ratio and storage stability were also good.

Example 3 (a) Manufacturing Example In Example 2, the following structural formula was used. Instead of 0.45 g of the compound represented by The same procedure as in Example 2 was carried out except that 0.48 g of the compound represented by the formula (1) was used to obtain 0.4 g of the indophenol compound represented by the following structural formula.

Absorption spectrum of this compound in the visible region (in chloroform)
Is λmax 650 nm (Fig. 3), and the mass spectrum is as follows. (Measurement condition: 70 eV, 250 ° C.) m / e 402 (H ⁺ + H ₂ ) (base peak) 387 (M ⁺ + H ₂ —CH ₃ ) (b) Recording medium example An indophenol compound represented by the above structural formula was used. According to the method described in Example 2, the PMMA resin substrate with grooves was coated by the spinner method.

The coating film thickness was 800Å when measured by the Tarisstep method. The coating film had a maximum absorption wavelength of 650 nm and had a broad spectrum shape.

When a He-Ne laser was used as a light source on the thin film thus obtained and writing was performed with a beam diameter of 2.4 μm and a wavelength of 632.8 nm, pits (holes) with a uniform and clear shape were formed.
was gotten. The C / N ratio and storage stability were also good.

Example 4 (a) Manufacturing Example In Example 3, the following structural formula was used. Instead of 0.45 g of the compound represented by The same procedure as in Example 3 was carried out except that 0.50 g of the compound represented by the above formula was used to obtain 0.45 g of the indophenol compound represented by the following structural formula.

Absorption spectrum of this compound in the visible region (in chloroform)
Was λmax 660 nm (Fig. 4).

(B) Example of Recording Medium According to the method described in Example 2, PMMA with grooves was prepared by using the indophenol compound represented by the above structural formula.
A resin substrate was applied by the spinner method.

The coating film thickness was 750Å as measured by the Tarisstep method. The maximum absorption wavelength of the coating film was 660 nm, and the shape of the spectrum was broad.

When a He-Ne laser was used as a light source on the thin film thus obtained and writing was performed with a beam diameter of 2.4 μm and a wavelength of 632.8 nm, pits (holes) with a uniform and clear shape were formed.
was gotten. The C / N ratio and storability were also good.

Example 5 The compounds shown in Table 1 below were used for vapor deposition instead of the indophenol compound used in Example 1 to obtain a thin film substrate having the maximum absorption wavelength shown in Table 1 below. The thin film thus obtained was used as a light source for He-Ne.
When writing was carried out using a laser or a semiconductor laser, uniform and clear pits were obtained. C /
The N ratio was also good and the storage stability was good.

Example 6 The compounds shown in Table 2 below were used in place of the indophenol compound used in Example 2 to obtain a thin film substrate having the maximum absorption wavelength shown in Table 2 below. The thin film thus obtained was used as a light source for He-Ne.
When writing was carried out using a laser or a semiconductor laser, uniform and clear pits were obtained.
The C / N ratio was also good, and the storage stability was also good.

[Advantages of the Invention] The indophenol compound of the present invention is easy to deposit, has high solubility in an organic solvent, and can be coated by coating, and has high reflectance and good contrast. Since the storage stability is excellent, the optical recording medium using the compound is extremely useful.

[Brief description of drawings]

FIGS. 1 to 4 show absorption spectra in the visible region of four examples of the indophenol compound of the present invention, where the vertical axis represents absorbance and the horizontal axis represents wavelength (nm).

Claims (4)

[Claims] 1. A general formula [I] (In the formula, And K represents a residue of a substituted or unsubstituted aromatic amine, R ¹ , R ² and R ³ represent a hydrogen atom, a halogen atom, a nitro group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted An alkoxy group, a substituted or unsubstituted aminocarbonyl group, a substituted or unsubstituted carbonylamino group, a substituted or unsubstituted aminosulfonyl group, a substituted or unsubstituted sulfonylamino group, or a substituted or unsubstituted thiocarbonylamino group Represent. ) An indophenol compound represented by. 2. In the general formula [I], K is a general formula [II]. (In the formula, X and Y represent a hydrogen atom, an alkyl group, an acylamino group, an alkoxy group or a halogen atom, and R ⁴
And R ⁵ represents a hydrogen atom, a C ₁ -C ₂₀ substituted or unsubstituted alkyl group, an aryl group or a cyclohexyl group. ) The indophenol compound according to claim 1, wherein 3. An optical recording medium for recording / reproducing by causing a state change by a laser beam, the substrate having the general formula [I] (In the formula, And -K represents a residue of a substituted or unsubstituted aromatic amine, -R ¹ , R ² and R ³ represent a hydrogen atom, a halogen atom, a nitro group, a substituted or unsubstituted alkyl group, a substituted or non-substituted A substituted alkoxy group, a substituted or unsubstituted aminocarbonyl group, a substituted or unsubstituted carbonylamino group, a substituted or unsubstituted aminosulfonyl group,
An optical recording medium comprising a recording layer containing an indophenol compound represented by a substituted or unsubstituted sulfonylamino group or a substituted or unsubstituted thiocarbonylamino group. 4. In the general formula [I], K is a general formula [II]. (In the formula, X and Y represent a hydrogen atom, an alkyl group, an acylamino group, an alkoxy group or a halogen atom, and R ⁴
And R ⁵ represents a hydrogen atom; a C ₁ -C ₂₀ substituted or unsubstituted alkyl group, aryl group or cyclohexyl group. 4. An optical recording medium according to claim 3, which is an indophenol compound represented by the formula (4).