JP3064373B2 - Metal chelate compound and optical recording medium using the compound - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a metal chelate compound and an optical recording medium using the compound.

[Related Art] In recent years, optical recording using a laser has been particularly developed in order to enable high-density information storage and reproduction.

An example of the optical recording is an optical disk.

Generally, an optical disk irradiates a thin recording layer provided on a circular base with a laser beam focused to about 1 μm,
It performs high-density information recording. The recording is performed by generating thermal deformation such as decomposition, evaporation, and dissolution in the recording layer at that location by absorbing the irradiated laser light energy. Reproduction of recorded information is performed by reading the difference in reflectance between a portion where deformation has occurred and a portion where no deformation has occurred due to laser light.

Therefore, it is necessary to efficiently absorb the energy of laser light as an optical recording medium, so that it has a large absorption for laser light of a specific wavelength used for recording, and is used for reproduction in order to accurately reproduce information. It is necessary to have a high reflectance for a laser beam having a specific wavelength.

Various types of optical recording media are known.

For example, Japanese Unexamined Patent Publication (Kokai) No. 55-97033 discloses a structure in which a single layer of a phthalocyanine dye is provided on a substrate. However, phthalocyanine dyes have low sensitivity,
In addition, it has a problem that it has a high decomposition point and is difficult to vapor-deposit, and further has a problem that its solubility in an organic solvent is extremely low, so that it cannot be used for coating by coating.

JP-A-58-83344 discloses a recording layer provided with a phenalene-based dye, and JP-A-58-224798 discloses a recording layer provided with a naphthoquinone-based dye. However, such dyes have the advantage of being low in reflectivity, while having the advantage of being easily deposited. If the reflectance is low, the contrast related to the reflectance between the portion recorded by the laser beam and the unrecorded portion will be low, and it will be difficult to reproduce the recorded information.

Further, organic dyes generally have a problem of poor storage stability.

[Problems to be Solved by the Invention] The present invention has a high solubility in an organic solvent, is capable of being coated by coating, has excellent light resistance, and is used for optical recording for performing recording and reproduction by causing a state change by a laser beam. It is an object of the present invention to provide a metal chelate compound suitable as a dye of a medium and an optical recording medium using the compound.

[Means for Solving the Problems] That is, the present invention provides a compound represented by the general formula [I]: (Where M is a group VIII, Ib, IIb, IIIa, IVa
A metal atom of Group Va, Group Va, Group VIa or Group VIIa, or an oxide or halide thereof, and Ring A may have a substituent. R ¹ and R ² are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
Represents a substituted or unsubstituted aryl group, a substituted or unsubstituted alkenyl group or a substituted or unsubstituted cycloalkyl group, and Q represents an anion. n is 2 or 3. ), And an optical recording medium using the compound.

 Hereinafter, the present invention will be described in detail.

In the general formula [I], M is a Group VIII atom such as iron, cobalt, nickel, ruthenium and rhodium, a Group Ib atom of copper, silver and gold, a Group IIb atom of zinc, cadmium and mercury, scandium and yttrium. Group IIIa atom of titanium, zirconium, hafnium, group IVa atom of vanadium, neodymium, tantalum, chromium, molybdenum, tungsten group VIa atom of tungsten, manganese, technetium, rhenium group VIIa atom, Or halides such as oxides or fluorides, chlorides, bromides and iodides thereof.

Ring A may have one or more substituents selected from an alkyl group, an alkoxy group, a halogen atom, a nitro group, a cyano group, an alkylsulfonyl group, an alkoxycarbonyl group and the like.

Examples of the substituent for the alkyl group, aryl group, alkenyl group or cycloalkyl group represented by R ¹ and R ² include, for example, an alkoxy group, an alkoxyalkoxy group, an alkoxyalkoxyalkoxy group, an allyloxy group, an aryl group, an aryloxy group, Examples include a cyano group, a hydroxy group, a tetrahydrofuryl group, and an alkylsulfonylamino group.

Among the metal chelate compounds represented by the general formula [I],
Preferred are those represented by the general formula (II) (Wherein, M represents a nickel, copper, cobalt, zinc, iron, palladium or platinum atom, and R ³ and R ⁴ each independently represent an alkyl group having 1 to 8 carbon atoms, an alkoxyalkyl group, an alkoxyalkoxyalkyl group) , Alkoxyalkoxyalkoxyalkyl group, allyloxyalkyl group, arylalkyl group, aryloxyalkyl group,
Q represents a cyanoalkyl group, a hydroxyalkyl group, a tetrahydrofurylalkyl group, an alkylsulfonylaminoalkyl group, an acyloxyalkyl group, or an alkenyl group, and Q represents an anion. n is 2 or 3. )
And particularly preferred are the metal chelate compounds represented by the general formula [II], wherein R ³ and R ⁴ are alkyl groups having 1 to 6 carbon atoms.

In the general formulas [I] and [II], examples of the anion represented by Q include I ⁻ , Br ⁻ , Cl ⁻ , F ⁻ , ClO ₄ ⁻ , P
_{^{F 6 -, SbF 6 -,}} BF 4 -, SCN -, _{^{CH 3 COO -, TiF 6 -}} , ^{_{1 / 2SiF 6 2-, 1 /}} 2ZrF 6 2- , and the like.

^{Preferably, I -, Br -, Cl} -, ClO 4 -, PF 6 -, SbF 6 -, BF
₄ ^- is a anion.

The metal chelate compound represented by the general formula (I) is
It has absorption in the wavelength band of 600 to 800 nm, has a high molecular absorption coefficient of 10 ⁵ cm ⁻¹ or more, and has excellent suitability as an optical recording medium.

The general synthesis of the metal chelate compound represented by the general formula [I] is, for example, as follows: And an 8-hydroxyquinoline represented by the following general formula [III] (Wherein, A, R ¹ and R ² are the same as defined above) by oxidative condensation with a compound represented by the following general formula [IV] (Wherein A, R ¹ and R ² are the same as defined above), and then the following general formula [V] MQ... [V] (wherein M and Q are as defined above) The same can be obtained by reacting with a metal salt represented by the following formula:

The optical recording medium of the present invention is basically composed of a substrate and a recording layer containing a metal chelate compound. However, if necessary, an undercoat layer is provided on the substrate and a protective layer is provided on the recording layer. Layers can be provided.

The substrate in the present invention is preferably a substrate transparent to the laser beam to be used, for example, a support of a general recording material such as glass and plastic, but plastic is suitable 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 a metal chelate compound is contained as a recording layer in the optical recording medium of the present invention, the thickness of the recording layer is from 100 ° to 5 μm.
m, preferably 1000 ° to 3 μm. As a film forming method, a vacuum deposition method, a sputtering method, a doctor blade method,
Examples of the method generally include a thin film forming method such as a casting method, a spinner method, and a dipping method. Further, a binder can be used if necessary. Known binders such as polyvinyl alcohol, polyvinyl pyrrolidone, nitrocellulose, cellulose acetate, polyvinyl butyral, and polycarbonate are used as the binder, and the amount of the binder relative to the metal chelate compound is preferably 50% by weight or less.

In order to improve the stability and light resistance of the recording medium, a transition metal chelate compound (eg, acetylacetonate chelate, bisphenyldithiol, salicylaldehyde oxime, bisdithio-α) is used as a singlet oxygen quencher.
-Diketone). Further, other dyes can be used in combination as needed. As the other dye, another kind of the same type of compound may be used, or another type of dye such as a triarylmethane dye, an azo dye, a dianine dye, or a squarylium dye may be used.

As a coating solvent for forming a recording layer by a coating method such as a doctor blade method, a casting method, a spinner method, and an immersion method, particularly a spinner method, tetrachloroethane, bromoform, dibromoethane, ethyl cellosolve, xylene, chlorobenzene, and cyclohexanone Etc. Boiling point 120
Those having a temperature of -160 ° C are preferably used.

Among these, for an injection molded polycarbonate resin substrate excellent in high productivity, cost and moisture absorption resistance, diacetone alcohol, 3-hydroxy-3-methyl is particularly preferable as a solvent that can be suitably used without damaging the substrate. -2
Ketone alcohol solvents such as butanone; cellosolve solvents such as methyl cellosolve and ethyl cellosolve; tetrafluoropropanol; (perfluoroalkyl alcohol solvents such as octafluoropentanol; hydroxy ester solvents such as methyl lactate and methyl isobutyrate) liquid;
Is mentioned. In the case of film formation by a spinner method, the number of revolutions is preferably 500 to 5000 rpm, and after spin coating, depending on the case, treatment such as heating or exposure to solvent vapor may be performed.

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 only on one side.

The recording on the optical recording medium obtained as described above,
This is performed by irradiating a laser beam, preferably a semiconductor laser beam, focused to about 1 μm onto the recording layers provided on both sides or one side of the substrate. Thermal deformation of the recording layer, such as decomposition, evaporation, and melting, occurs due to absorption of laser energy in the portion irradiated with the laser light.

Reproduction of 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 a laser beam.

The laser light used for the optical recording medium of the present invention includes N ₂ , He-Cd, Ar, He-Ne, ruby, semiconductor, dye laser, etc., but, in particular, light weight, ease of handling, and compactness. For this reason, a semiconductor laser is preferable.

[Examples] Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the examples unless it exceeds the gist.

Example 1 (a) Compound production example The following structural formula 0.5 g of 8-aminoquinoline represented by the following structural formula 1.90 g of the aniline derivative represented by sodium hydroxide
The mixture was added to 50 ml of water containing 0.42 g and subjected to ultrasonic treatment. 8.3 ml of water containing 2.271 g of potassium ferricyanide K ₂ Fe (CN) ₆ was added dropwise to this solution at room temperature, followed by stirring at the same temperature for 10 minutes. Then, 167 ml of boiling water containing 0.224 g of zinc powder, 0.47 g of zinc chloride and 13 g of potassium hydroxide were slowly added. After stirring for 10 minutes, heat it, As a result, 1.22 g of a ring-closing type indoaniline derivative of purple powder represented by was obtained.

When this compound was dissolved in acetone, it showed a red-purple fluorescent color.

After dissolving 1.09 g of the above compound in 75 ml of tetrahydrofuran, 1.05 g of nickel chloride NiCl ₂ was added at room temperature, and the mixture was added. The solution was added to 150 ml of water containing 75 g of NaBF ₄ to obtain a precipitate. After washing with water, the following structural formula 0.84 g of a metal chelate compound (ring-closing type indometallic indoaniline compound) represented by

The absorption spectrum of the visible part of the obtained metal chelate compound was λmax 650 nm (in chloroform).

(B) Optical recording medium production example-1 The metal chelate compound obtained in the compound production example (a) 0.1.
1 g was dissolved in 10 g of tetrachloroethane and passed through a 0.22 μm filter to obtain a solution. 1 ml of this solution was dropped on a polymethyl methacrylate (PMMA) resin substrate (52 mm in diameter), and applied at a rotation speed of 800 rpm by a spinner method. After the application, it was dried at 60 ° C. for 10 minutes. The maximum absorption wavelength of the coating film was 670 nm, and the spectrum was broad.

(C) Optical Recording Example-1 When this coating film was irradiated with He-Ne laser light having a center wavelength of 633 nm at an output of 6 mW, pits with extremely clear contours were formed.

The test for promoting light resistance of the obtained optical recording medium using a xenon lamp was extremely good.

(D) Optical recording medium production example-2 The metal chelate compound obtained in the compound production example (a) 0.1.
Dissolve in 2g tetrafluoropropanol 10g, 0.22μm
And a solution was obtained. 5 ml of this solution was dropped onto a polycarbonate resin substrate (injection molded product) having a groove (group) with a diameter of 5 inches and a plate thickness of 1.2 mm and a pitch of 1.6 μm, and applied at a rotation speed of 800 rpm by a spinner method.
After the application, it was dried at 60 ° C. for 10 minutes. The maximum absorption wavelength of the coating film was 670 nm, and the spectrum was broad.

(E) Optical recording example-2 While rotating the polycarbonate resin substrate on which the above recording layer was formed at a linear velocity of 4 m / s, irradiation with a He-Ne laser beam having a center wavelength of 633 nm at a pulse width of 500 nsec, a high C / N ratio was obtained.

The test for promoting light resistance of the obtained optical recording medium using a xenon lamp was extremely good.

Reference Example The following structural formula used in compound production example (a) of Example 1 The aniline derivative represented by was synthesized as follows.

6.81 g of zinc chloride was dissolved in 150 ml of water. This has the following structural formula Was added at room temperature to give a pink solution. Aluminum sulfate
Al ₂ to _{(SO 4) 3 · 16H 2} O77g dissolved in water 150 ml, was added to the solution.

The sodium thiosulfate _{Na 2 S 2 O 3 · 5H} 2 O52g sulfate was dissolved in water 100 ml, was turned light line color when added to further the solution at room temperature. Finally, 100 ml of a concentrated solution of 5.04 g of K ₂ Cr ₂ O ₇ was added,
After stirring at room temperature for 4 hours, a gray precipitate gradually formed. After passing through the precipitate, the precipitate was washed with water and then with benzene and ether. Furthermore, after dissolving in excess sodium carbonate aqueous solution at room temperature, it is neutralized with acetic acid and reprecipitated. 5.86 g (yield 42%) of fine gray crystals represented by

Example 2 (a) Compound Production Example In Example 1, the following structural formula In place of 1.09 g of the compound represented by the following structural formula In the same manner as in Example 1 except that 1.00 g of the compound represented by the following formula was used, a metal chelate compound represented by the following structural formula was obtained.

The visible spectrum absorption spectrum (in chloroform) of the obtained metal chelate compound was λmax 620 nm.

(B) Optical recording medium production example The metal chelate compound obtained in the compound production example (a) was applied to a grooved PMMA resin substrate by a spinner method according to the method described in Example 1. The maximum absorption wavelength of the coating film was 640 nm, and the spectrum was broad.

(C) Optical recording example The PMMA resin substrate on which the recording layer was formed was irradiated with a He-Ne laser beam having a center wavelength of 633 nm at a pulse width of 500 nsec while rotating at a linear velocity of 4 m / s. A ratio was obtained. The light resistance promotion test of the obtained optical recording medium with a xenon lamp was also good.

Obtained in Example 3 (a) Compound Production Example Example 1, except for using NaPF ₆ 75 g instead of NaBF ₄ 75 g, a similar manner to Example 1, a metal chelate compound represented by the following structural formula Was.

The absorption spectrum (in chloroform) of the visible part of the obtained metal chelate compound was λmax 651 nm.

(B) Optical recording medium production example The metal chelate compound obtained in the compound production example (a) was dropped onto a 5-inch diameter grooved polycarbonate resin substrate (injection molded product) according to the method described in Example 1. Then, it was applied at a rotation speed of 600 rpm by a spinner method. After the application, it was dried at 80 ° C. for 10 minutes. The maximum absorption wavelength of the coating film is
It was 671 nm, and the shape of the spectrum was broad.

Next, a gold film having a thickness of 2000 mm was formed on the recording layer by a sputtering method to form a reflector. Further, an ultraviolet curable resin was spin-coated on the reflective layer, and then cured by irradiating ultraviolet rays to form a protective layer having a thickness of 10 μm to obtain an optical recording medium.

(C) Optical recording agent While rotating the polycarbonate resin substrate on which the above recording layer was formed at a linear velocity of 1.4 m / s, an EFM modulation signal was recorded using a semiconductor laser beam having a wavelength of 785 nm, and then reproduced, and the reproduced waveform was reproduced. When the reflectance and 11T modulation were measured from
74% and 72% respectively.

Here, the 11T modulation degree is a value obtained by dividing the signal amplitude of the longest recording pit by the reflectance and expressing the value as a percentage.

The test for accelerating light resistance of the obtained optical recording medium with a xenon lamp was extremely good.

Example 4 A recording layer was formed using the compounds shown in Table 1 in place of the metal chelate compound used in Example 1, and an optical recording medium having the maximum absorption wavelength shown in Table 1 was obtained. . He-Ne is used as a light source on the thin film thus obtained.
When writing was performed using a laser, pits having a uniform and clear shape were obtained. Good C / N ratio,
The light fastness promotion test with a xenon lamp was also good.

In addition to the compounds used in the above examples, specific examples of metal chelate compounds suitably used in the optical recording medium of the present invention include the compounds shown in Tables 2 and 3.

[Effects of the Invention] The metal chelate compound of the present invention has high solubility in organic solvents, can be coated by coating, and has excellent light resistance. This is extremely useful.

Continuation of the front page (58) Fields investigated (Int.Cl. ⁷ , DB name) C07D 513/04 B41M 5/26 C09B 53/00 C09K 3/00 G11B 7/24 CAPPLUS (STN) REGISTRY (STN)

Claims (4)

(57) [Claims] 1. A compound of the formula [I] (Where M is a group VIII, Ib, IIb, IIIa, IVa
A metal atom of Group Va, Group Va, Group VIa or Group VIIa, or an oxide or halide thereof, and Ring A may have a substituent. R ¹ and R ² are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
Represents a substituted or unsubstituted aryl group, a substituted or unsubstituted alkenyl group or a substituted or unsubstituted cycloalkyl group, and Q represents an anion. n is 2 or 3. A) a metal chelate compound represented by the formula: 2. The general formula [II] (Wherein, M represents a nickel, copper, cobalt, zinc, iron, palladium or platinum atom, and R ³ and R ⁴ each independently represent an alkyl group having 1 to 8 carbon atoms, an alkoxyalkyl group, an alkoxyalkoxyalkyl group) , Alkoxyalkoxyalkoxyalkyl group, allyloxyalkyl group, arylalkyl group, aryloxyalkyl group,
Q represents a cyanoalkyl group, a hydroxyalkyl group, a tetrahydrofurylalkyl group, an alkylsulfonylaminoalkyl group, an acyloxyalkyl group, or an alkenyl group, and Q represents an anion. n is 2 or 3. )
The metal chelate compound according to claim 1, which is represented by the following formula: 3. The metal chelate compound according to claim 2, wherein R ³ and R ⁴ in the metal chelate compound represented by the general formula [II] represent an alkyl group having 1 to 6 carbon atoms. 4. A recording medium in which a recording layer containing a dye is carried on a substrate, and recording is performed by irradiating a focused laser beam which gives a thermal change to the dye to cause a partial change in the recording layer. And then performing reproduction by selecting the changed portion, wherein the dye is a metal chelate compound according to any one of claims 1 to 3. Optical recording medium.