JPH04202260A - Metal chelate compound and optical recording medium using the compound - Google Patents

Abstract

PURPOSE:To obtain a recording film excellent in storage stability and light resistance by the spinner method by using a specific metal chelate compd. as a recording layer of an optical recording medium. CONSTITUTION:A metal chelate compd. of formula 1 (wherein M is a metal atom selected from the group consisting of Ni, Co, Zn, and Cu; R<1> is 1-12C alkyl; R<2>, R<3>, R<4>, R<5>, and R<6> are each independently H, alkyl, alkoxy, or halogen; X is a sulfur or oxygen atom; Z<-> is an anion; and n is 2 or 3) is used as a recording layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel metal chelate compound and an optical recording medium using the compound.

[Prior Art] Optical recording using lasers has been particularly developed in recent years because it enables high-density information recording storage and reproduction.

An example of an optical recording medium is an optical disc.

In general, optical discs record high-density information by irradiating a thin recording layer provided on a circular base with a laser beam focused to about 1 μm.

The recording is performed by thermal deformation such as decomposition, evaporation, melting, etc. occurring in the recording layer at that location due to absorption of the irradiated laser light energy. Further, recorded information is reproduced by reading the difference in reflectance between a portion where deformation has occurred and a portion where no deformation has occurred by laser light.

Therefore, as an optical recording medium, it is necessary to efficiently absorb the energy of laser light, and the recording layer must
For example, laser absorbing dyes are used.

Various configurations of this type of optical recording medium are known.

For example, JP-A-55-97033 discloses a device in which a single layer of phthalocyanine dye is provided on a substrate. However, phthalocyanine dyes have low sensitivity;
Further, it has problems such as a high decomposition point and difficulty in vapor deposition, and also has an extremely low solubility in organic solvents, making it impossible to use it for coating by coating.

Also, JP-A-58-112790, JP-A-58-11
No. 4989, No. 59-85791 and No. 60-83
No. 236 discloses a recording layer in which a cyanine dye is provided. However, although such dyes have the advantage of being highly soluble and can be coated by coating, they have the problem of poor light resistance.

For this reason, Japanese Patent Laid-Open No. 59-55795 discusses adding a quencher to this cyanine dye to improve light resistance, but this is still at an insufficient level.

[Problems to be Solved by the Invention] The present invention solves the above problems and provides a metal chelate compound suitable for film formation by a spinner method with excellent storage stability and light resistance, and an optical recording medium using the compound. The purpose is to provide the following.

[Means for Solving the Problems] The present invention has the following formula (I) (wherein M represents a metal atom selected from nickel, cobalt, zinc or copper, and R1 represents an alkyl group having 1 to 12 carbon atoms. In the formula, R2, R3, R4, R5 and R6 each independently represent a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, X represents a sulfur atom or an oxygen atom, 2- represents an anion, and n represents an anion. , 2 or 3) and an optical recording medium using the compound.

Hereinafter, the present invention will be explained in detail.

The metal chelate compound represented by formula (I) is 60
It has absorption in the wavelength band of 0 to 800 nm, and has a molecular extinction coefficient of 104 to 106 cm-'.

- In formula (I), R2, R3, R4, R5 and R6 are hydrogen atoms; linear or branched alkyl groups such as methyl, ethyl, propyl, butyl and octyl groups; meth-oxy linear or branched alkoxy groups such as ethoxy group, propoxy group, butoxy group, octyloxy group; halogen atoms such as fluorine atom, chlorine atom, bromine atom, and iodine atom; -1Br
-1C1-1CIO, -1SCN-1CI04~, PF
6-1SbF, -1BF4-1 (1>5o3-1CH3
coo-1StF6-1TiF6-1B-(Q)4
Tonoyin! ring (can be mentioned)

The general synthesis of the metal chelate compound represented by the formula (Il) of the present invention is, for example,
and R3 are the same as defined above. ) and the compound shown by
Oxidative condensation is carried out with a compound represented by the following formula (II (in which R4 is the same as defined above)), and the compound represented by the following formula (IV) (wherein R1, R2, R3 and R4 are the same as defined above) ) was obtained, and the compound represented by the following formula (V) (
In the formula, R6, R6. and X are the same as defined above. ) is reacted in the presence of an alkali, and further converted into the following formula (VI) (where R1, R2-R3-R4-R5-R6
Same as above definition. ) is obtained. Then, it can be produced by reacting the above-mentioned formula (VI) with a metal salt represented by the following formula [■] M''(Z-)2 ... [■].

The metal chelate compound of the present invention is suitably used as a dye in an optical recording medium, and an optical recording medium basically consists of a substrate and a recording layer containing a metal chelate compound, and if necessary, a layer is formed on the substrate. A pull layer is also provided on the recording layer, such as a metal reflective layer, a protective layer, etc.

The substrate used in the present invention is preferably one that is transparent to the laser beam used, and examples of the substrate material include supports for general recording materials such as glass and plastic, but plastic is preferable from various points of view. suitable. Examples of the plastic include acrylic resin, methacrylic resin, vinyl acetate resin, vinyl chloride resin, nitrocellulose, polyethylene resin, polycarbonate resin, polyamide resin, epoxy resin, polysulfone resin, and the like.

Among the two, injection molded polycarbonate resin substrates are particularly preferred from the viewpoint of high productivity, cost, and moisture absorption resistance.

The recording layer containing a metal chelate compound in the optical recording medium of the present invention has a thickness of 1008 to 5 μm, preferably 700 to 3 μm. The film forming method is vacuum evaporation method,
Sputtering method, doctor blade method, casting method,
The film can be formed by a commonly used thin film forming method such as a spinner method or a dipping method, but the spinner method is preferable from the viewpoint of mass productivity and cost.

Moreover, a binder can also be used if necessary. As the binder, known binders such as polyvinyl alcohol, polyvinylpyrrolidone, ketone resin, nitrocellulose, cellulose acetate, polyvinyl butyral, and polycarbonate can be used. In the case of film formation by the spinner method, the rotational speed is preferably 500 to 5000 rpm, and after the spin code, treatment such as heating or exposure to solvent vapor may be performed as the case requires.

In addition, to improve the stability and light resistance of the recording material, transition metal chelate compounds (e.g., acetylacetonate chelate, bisphenyldithiol, salicylaldehyde oxime, bisdithio-α) are used as heavyt oxygen quenchers.
- May contain diketones, etc. Furthermore, other dyes can be used in combination as necessary. Other dyes may be other types of compounds of the same type, or other types of dyes such as triarylmethane dyes, azo dyes, cyanine dyes, squarylium dyes, metal complexes of monoazo compounds, and Ni-indoaniline dyes. It can also be a dye.

Coating solvents used when forming a recording layer by a coating method such as a doctor blade method, a casting method, a spinner method, or a dipping method, especially the spinal method, include tetrafluoropropanol, octafluoropentanol, tetrachloroethane,
Pulmoform, dibromoethane, diacetone alcohol, ethynyl cellosolve, xylene, 3-hydroxy-3
-Methyl-2-butanone, chlorobenzene, cyclohexanone, methyl lactate and the like having a boiling point of 120 to 160'C are preferably used.

Among these, 1. For injection molded polycarbonate resin substrates that are excellent in high productivity, cost, and moisture absorption resistance, especially as a solvent that can be suitably used without destroying the substrate,
Diacetone alcohol, 3-hydroxy-3-methyl-
Ketone alcohol solvents such as 2-butanone; Cellsolve solvents such as methyl cellosolve and ethyl cellosolve; perfluoroalkyl alcohol solvents such as tetrafluoropropanol and octafluoropentanol; hydroxyl solvents such as methyl lactate and methyl imbutyrate Examples include ester solvents.

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

Recording on the recording medium obtained as described above is carried out by irradiating the recording layer provided on both sides or one side of the substrate with laser light, preferably semiconductor laser light, focused to about IAtm. The area irradiated with the laser light is
Thermal deformation of the recording layer, such as decomposition, evaporation, and melting, occurs due to absorption of laser energy.

The recorded information is reproduced by using a laser beam to read the difference in reflectance between a portion where thermal deformation has occurred and a portion where no thermal deformation has occurred.

Laser beams used for the optical recording medium of the present invention include N2, He--Cd, Ar, He--Ne, ruby semiconductor, and dye lasers.

[Examples] Hereinafter, the present invention will be specifically explained with reference to Examples, but these Examples do not limit the present invention.

Example 1 (a) Example of compound production: 1.8 g of the compound represented by the following formula and 2.14 g of the compound represented by the following structural formula were added to 60 ml of water and 1 ml of methanol.
614.48 g of LFe(CN), 1 methanol were added to this solution at a temperature of 25-30 °C.
00ml, 100ml of water and 20ml of 25% ammonia water
A mixed solution of ml was added dropwise. After stirring at room temperature for 3 hours, the precipitate was filtered to obtain a compound represented by the following formula.

Next, 2.0 g of the obtained compound was mixed with 400 ml of ethanol, and while heating and refluxing, a mixture of 1.42 g of 2-amino-thiophenol represented by the following structural formula, 0.75 g of potassium hydroxide, and 80 ml of ethanol was added. dripped. The reaction was carried out under reflux for 3 hours, and after cooling to room temperature, the mixture was discharged into 1.2e water, filtered, and washed with water to obtain a compound represented by the following structural formula.

Next, 1.84g of the above obtained was added to 1.84g of tetrahydrofuran.
5. A 40% aqueous solution of a nickel salt represented by the following structural formula (%) at room temperature. After adding Og and stirring at room temperature day and night, a metal chelate compound (No. 1) represented by dissipation of precipitated crystals was obtained.

The λmax (in chloroform) of this product was 680 nm, and the molecular extinction coefficient (ε) was 6.2×104.

(b) Optical recording medium production example 0.3 g of the metal chelate compound obtained in the above production example (a)
was dissolved in 7.5 g of octafluoropentanol, and 0.
The solution was filtered through a 22 μm filter to obtain a solution. 5 ml of this solution was dropped onto an injection molded polycarbonate resin substrate (5 inches in diameter) with grooves (groups) 700 mm deep and 0.7 □m wide, and coated using a spinner at a rotation speed of 500 rpm. After coating, it was dried at 60°C for 10 minutes. The maximum absorption wavelength of the coating film was 658 nm.

FIG. 1 shows the absorption spectrum of the coating film. The shape of the spectrum broadened.

(C) Optical recording method When the above recording medium was rotated at 1.2 m/s and irradiated with a He-Ne laser beam with a center wavelength of 633 nm and a recording power of 7.0 mW, pits with extremely clear outlines were formed. It was done.

The obtained optical disc had light resistance (xenon fade meter acceleration test l-; 60 hours) and storage stability (700 hours).
C185%RH; As a result of a 500 hour test, no deterioration in sensitivity or reproduced signal was observed compared to the initial stage, and it was found to be an extremely excellent optical recording medium.

Example 2 (a) Compound Production Example The same procedure as Example 1 was carried out except that 1.87 g of the compound represented by the following structural formula was used in Example 1, and the visible part of the metal main compound represented by the following structural formula was prepared in the same manner as in Example 1. The absorption spectrum (in chloroform) is λ
The maximum wavelength was 682 nm.

(b) Optical recording medium production example Metal chelate compound obtained in the above production example (a) 0.15
g was dissolved in 7.5 g of tetrafluoropropanol, and 0
．． The solution was filtered through a 22 μm filter to obtain a solution. 5 ml of this solution was placed on an injection-molded polycarbonate resin substrate (diameter 5 mm) with grooves (groups) 700 mm deep and 0.7 m wide.
inch) and applied using a spinner at a rotation speed of 500 rpm. After coating, it was dried at 60°C for 10 minutes. The maximum absorption wavelength of the coating film was 689 nm, and the shape of the spectrum was wide.

(C-n optical recording method When the above recording medium was rotated at 1.2 m/s and irradiated with a He-Ne laser beam with a center wavelength of 633 nm and a recording power of 8.0 mW, pits with extremely clear outlines were formed. It was done.

The obtained optical disc has good light resistance (xenon fade meter accelerated test; 60 hours) and storage stability (70°C
As a result of a test (185% RH; 500 hours), no deterioration in sensitivity or reproduced signal was observed compared to the initial stage, and it was found to be an extremely excellent optical recording medium.

Example 3 (a) Compound production example In Example 1, except that 1.90 g of the compound represented by the following structural formula was used instead of 1.84 g of the compound represented by the following structural formula.
A metal chelate compound (NO, 3) represented by the following structural formula was obtained in the same manner as in Example 1.

The visible absorption spectrum (in chloroform) of this compound was λmax 683 nm.

(b) Optical recording medium production example Metal chelate compound obtained in the above production example (a) 0.15
g to 3-hydroxy-3-methyl-2-butanone 7.5
g and filtered through a 0.22 μm filter to obtain a solution. Transfer 5 ml of this solution to a depth of 700 A and a width of 0.7
A droplet was placed on an injection-molded polycarbonate resin substrate (5 inches in diameter) with a group of μm, and 50 μm was added using a spinner method.
Coating was performed at a rotation speed of 0 rpm. After application, 10 at 60'C
Dry for a minute. The maximum absorption wavelength of the coating film is 689 nm,
The shape of the spectrum was broad.

(e) Optical recording method While rotating the recording medium at 1.2 m/s, a semiconductor laser beam with a center wavelength of 670 nm is used to record at a recording power of 5.0.
When irradiated with mW, pits with clear outlines were formed.

The obtained optical disc has excellent light resistance (xenon fade meter accelerated test: 60 hours) and storage stability (70°C
As a result of a test (185% RH; 500 hours), no deterioration in sensitivity or reproduced signal was observed compared to the initial stage, and it was found to be an extremely excellent optical recording medium.

Example 4 The same procedure as in Example 1 was carried out except that 1.95 g of the compound represented by the following structural formula was used instead of 1.84 g of the compound represented by the following structural formula, and the compound represented by the following structural formula was The visible absorption spectrum (in chloroform) of this compound is expressed by λmax
It was 680 nm.

(b) Optical recording manufacturing example 0.15 g of the metal chelate compound obtained in the above manufacturing example (a)
was dissolved in 7.5 g of octafluoropentanol, and 0.
The solution was filtered through a 22 μm filter to obtain a solution. 5 ml of this solution was placed on an injection molded polycarbonate resin substrate (5 ml in diameter) with grooves (groups) 700 m deep and 0.7 m wide.
inch) and applied using a spinner at a rotation speed of 500 rpm. After coating, it was dried at 60°C for 10 minutes. The maximum absorption wavelength of the coating film was 685 nm.

(c) Optical recording method While rotating the recording medium at 1.2 m/s, a semiconductor laser beam with a center wavelength of 670 nm was used to record at a recording power of 5.
When irradiated with 0 mW, pits with extremely clear outlines were formed.

The obtained optical disc has good light resistance (xenon fade meter accelerated test; 60 hours) and storage stability (70°C
As a result of a test (185% RH; 500 hours), no deterioration in sensitivity or reproduced signal was observed compared to the initial stage, and it was found to be an extremely excellent optical recording medium.

The following describes the specific metal chelate compounds preferably used in the optical recording medium of the invention.
Shown in the table.

[Effects of the Invention] The metal chelate compound of the present invention has excellent storage stability and light resistance, and is suitable for film formation by a spinner method.
Optical recording media using this compound are extremely useful industrially.

[Brief explanation of the drawing]

FIG. 1 is a drawing showing the visible region absorption spectrum of the metal chelate compound of the present invention (obtained in Example 1) in a solution, where the vertical axis represents absorbance and the horizontal axis represents wavelength (nm).

Claims (2)

[Claims] (1) General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I] (In the formula, M represents a metal atom selected from nickel, cobalt, zinc or copper, and R^1 is carbon Represents an alkyl group of numbers 1 to 12, and R^2, R^3, R^4, R^5 and R^6 each independently represent a hydrogen atom, an alkyl group,
It represents an alkoxy group or a halogen atom, X represents a sulfur atom or an oxygen atom, and Z- represents an anion. n is 2 or 3. ) metal chelate compound. (2) Writing information on the board using a laser and/or
Alternatively, an optical recording medium provided with a readable recording layer, wherein the recording layer contains the metal chelate compound according to claim 1.