JP3443723B2 - Optical recording media using metal complex methine dye - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium using a novel metal complex methine dye having excellent properties as a light absorbing substance and an optical recording method using the same. Things. [0002] Dyes and pigments known as pigments are:
It is widely used in various applications such as a fiber dye, a resin or paint colorant, an image forming agent in photographs, printing, copying machines, and printers, and a light absorbing agent for color filters. Common problems of these dyes include optimization of absorption wavelength and waveform, improvement of molar extinction coefficient, improvement of storage stability including light resistance and heat resistance, and the like. In order to form a full color or three primary colors, three kinds of dyes of yellow, magenta and cyan are required, and a cyan dye having particularly good absorption characteristics and storage stability is desired. Meanwhile, in recent years,
With a rapid increase in the amount of information, large-capacity optical recording media have been spotlighted. 2. Description of the Related Art A long-wavelength absorbing dye that absorbs light in a red to near-infrared region is used for an organic optical recording medium that can easily and at high density record information with an inexpensive semiconductor laser. Conventionally, among various dyes, cyanine dyes having excellent absorption and reflection properties have been used for this purpose.However, due to low storage stability such as light resistance, there is a drawback that information is lost with time and writing cannot be performed. Was. In order to solve such a problem, for example, U.S. Pat.
050,938, JP-A-60-118748, 6
JP-A-3-199248 and JP-A-2-300288 disclose light stabilizers or light stabilization methods, but have not yet achieved sufficient storage stability. Also, JP-A-64-44786, JP-A-2-76884, and 5-
No. 17701 describes a metal chelate dye excellent in storage stability, but cannot be used for applications such as optical recording media because the absorption wavelength is too long. Accordingly, an object of the present invention is to provide a dye having an absorption suitable for a semiconductor laser used in an optical recording apparatus, a high molar extinction coefficient, and excellent light resistance. An object of the present invention is to provide an optical recording medium which is excellent in optical recording characteristics and storage stability by using a recording medium, and an optical recording method using the same. [0004] The above object of the present invention is achieved by the following constitutions. (1) A compound represented by the following general formula (2) or (4) having at least two coordination sites on a substrate:
An optical recording medium comprising: a recording layer containing a metal complex methine dye in which a methine dye to be used is a ligand and a metal ion is chelate-bonded at the coordination site. [0007] [0008] [0009] Wherein X is a group represented by the following general formulas (6) to (13) capable of forming at least a bidentate chelate:
Y represents a group of atoms forming an aromatic hydrocarbon ring or a heterocyclic ring. R ₁ , R ₂ and R ₃ each represent a hydrogen atom, a halogen atom or a monovalent substituent. p represents 0, 1 or 2. [0014] [0014] [Wherein, X represents a group represented by the following general formulas (6) to (13) capable of forming a chelate of at least bidentate:
Y represents a group of atoms forming an aromatic hydrocarbon ring or a heterocyclic ring, and R ₄ and R ₅ each represent a hydrogen atom, a halogen atom or a monovalent substituent. q represents 0, 1, or 2. Hereinafter, the present invention will be described in detail. The metal complex methine dye of the present invention will be described. The metal complex methine dye of the present invention includes the above
As to a methine dye having at least two coordination sites as a ligand, a coordinating seat with metal ions chelated metal complex methine dyes, methine dyes having at least two coordination sites with a metal ion It is a feature of the present invention to use a metal complex methine dye having a chelate bond with methine. [0024] Among them, preferred methine dyes include, for example, methine dyes represented by the above general formulas (2) and (4 ) . In the general formulas (2) and (4), as a group of atoms forming an aromatic hydrocarbon ring or a heterocyclic ring represented by Y, even if the ring further has a substituent. It may have a condensed ring. Specific examples of Y include, for example, benzene ring, naphthalene ring, 3H-pyrrole ring, oxazole ring, imidazole ring, thiazole ring, and 3H-
Pyrrolidine ring, oxazolidine ring, imidazolidine ring,
Thiazolidine ring, 3H-indole ring, benzoxazole ring, benzimidazole ring, benzothiazole ring,
Quinoline ring, pyridine ring, 5-pyrazolone ring, pyrazolopyrrole ring, pyrazolopyrazole ring, pyrazoloimidazole ring, pyrazolotriazole ring, pyrazolotetrazole ring, barbituric acid ring, thiobarbituric acid ring, rhodanine ring, Hydantoin ring, thiohydantoin ring, oxazolone ring, isoxazolone ring, indandione ring,
Examples include a pyrazolidinedione ring, an oxazolidinedione ring, a hydroxypyridone ring, and a pyrazolopyridone ring. These rings may be further carbocyclic (eg benzene)
Or a condensed ring with a heterocyclic ring (for example, a pyridine ring). As a substituent on the ring, an alkyl group, an aryl group, a heterocyclic group, an acyl group, an amino group, a nitro group, a cyano group,
Examples thereof include an acylamino group, an alkoxy group, a hydroxy group, an alkoxycarbonyl group, and a halogen atom, and these groups may be further substituted. In the general formulas (2) and (4), R ₁ ,
In the hydrogen atom, halogen atom or monovalent substituent represented by R ₂ , R ₃ , R ₄ or R ₅ , examples of the halogen atom include a fluorine atom and a chlorine atom. For example, an alkyl group, an alkoxy group, a cyano group,
Examples include an alkoxycarbonyl group, an aryl group, a heterocyclic group, a carbamoyl group, a hydroxy group, an acyl group, and an acylamino group. In the general formulas (2) and (4), the group or group of atoms represented by X which can form a chelate at least bidentate represents a group which forms a dye via a conjugated system. Preferably, a group or a group of atoms represented by the following general formula (3) is used. Embedded image [In the formula, Z ¹ represents a group of atoms forming a nitrogen-containing heterocyclic ring substituted with a group containing at least one chelatable nitrogen atom. As the group or group of atoms represented by the general formula (3), groups represented by the following general formulas (6) to (13) are particularly preferable. Embedded image [Wherein R ₁₁ , R ₁₂ and R ₁₃ represent a hydrogen atom, a halogen atom (eg, a fluorine atom, a chlorine atom, a bromine atom, etc.) or a monovalent substituent (eg, an alkyl group, an aryl group, Ring group, acyl group, amino group, nitro group, cyano group, acylamino group, alkoxy group, hydroxy group,
R ₁₄ represents a hydrogen atom or a monovalent substituent (eg, an alkyl group, an aryl group, a heterocyclic group, an acyl group, an amino group, a nitro group, a cyano group, an acylamino group, an alkoxy group, a hydroxy group) Group, alkoxycarbonyl group, etc.). Q represents a group of atoms forming a nitrogen-containing heterocyclic ring, and includes a pyrrole ring, a pyrrolidine ring, a pyrazole ring, an imidazole ring, an oxazole ring, a thiazole ring, a triazole ring, a thiadiazole ring, a pyridine ring, a quinoline ring, a pyridazine ring, and a pyrimidine ring. , A pyrazine ring, a triazine ring, an indole ring, a benzthiazole ring, a benzimidazole ring and the like. The ring may further have a substituent, and may have a condensed ring. The metal complex methine dye of the present invention is supplied as a metal complex methine dye at the time of production of an optical recording medium, or by adding a methine dye and a metal ion supply compound at the time of preparing a coating solution. can do. The following are specific examples of the present invention and a reference metal complex methine dye, but the present invention is not limited thereto. Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image The metal complex methine dye of the present invention can be made into a polymer by introducing a polymerizable substituent, if necessary, and LB by introducing an oil-soluble group or a hydrophilic group.
It can be processed into various forms such as film formation, dispersion using oil, or microcapsules. Further, the metal complex methine dye of the present invention can be used alone or in combination with another dye. The storage stability can be further improved by adding various storage stability improvers to the metal complex methine dye of the present invention. For example, ultraviolet absorbers such as benzotriazolylphenol derivatives, β-carotene, tocopherol derivatives, hydroquinone derivatives, spiroindane derivatives, phenol derivatives, amine derivatives, thioether derivatives, Ni dithiol derivatives, Ni phenanthroline derivatives, Ni benzylidene aniline derivatives And the like, and a light stabilizer. These may be used alone or as a mixture of two or more. Hereinafter, the present invention will be described in detail with reference to examples, but embodiments of the present invention are not limited thereto. Example 1 << Spectral Absorption Characteristics >> Table 1 shows the spectral absorption characteristics in methanol of the metal complex methine dye of the present invention and a methine dye not forming a metal complex (Comparative Compound A) as a comparison. Embedded image [Table 1] As is clear from the results in Table 1, the metal complex methine dye of the present invention has a high molar extinction coefficient and an absorption suitable for a semiconductor laser. Hereinafter, an optical recording medium using the metal complex methine dye of the present invention will be described. As the substrate constituting the optical recording medium of the present invention, the wavelength range of laser light used for recording / reproducing (600 to
At 800 nm) (substantially 80% or more). As the shape of the substrate,
When used as a normal compact disc,
The thickness is about 1.2 mm and the diameter is about 80 to 120 mm. Examples of the material forming the substrate include transparent resins such as polymethyl methacrylate resin, acrylic resin, polycarbonate resin, epoxy resin, polysulfone resin, and methylpentene polymer, and glass. Note that an oxygen barrier coating may be formed on the outer surface, inner surface, and inner / outer peripheral surface of the substrate as necessary. It is preferable that a groove for tracking is formed on the substrate on which the recording layer is formed. The recording layer using the metal complex methine dye of the present invention has a preferable extinction coefficient k in the wavelength region of laser light as a recording layer of an optical recording medium. And also has a suitable reflectance. Here, if the extinction coefficient k of the recording layer in the wavelength region of the laser beam is too large, the reflectivity is reduced, and the reproduction by the reflected light cannot be performed sufficiently well. If the extinction coefficient k is too small, it becomes difficult to perform recording with normal recording power. The extinction coefficient k is preferably 0.01 to 0.1. on the other hand,
The refractive index n (real part of the complex refractive index) of the recording layer in the wavelength region of the laser beam is preferably 1.8 to 4.0. The recording layer constituting the optical recording medium of the present invention contains other kinds of dye compounds, various resins, surfactants, antistatic agents, dispersants, antioxidants, crosslinking agents, and the like. May be. The recording layer may be formed on one surface of the substrate, or may be formed on both surfaces of the substrate. The thickness of the recording layer is usually 500
３3000 ° is preferred. The method for forming the recording layer on the substrate is not particularly limited, for example, a spin coating method, a dip coating method, a spray coating method, a blade coating method, a roller coating method, a bead coating method, a Meyer coating method, Various methods such as a curtain coating method can be applied. Examples of the solvent used in forming the recording layer include ketone solvents such as cyclohexanone, ester solvents such as butyl acetate, ether solvents such as ethyl cellosolve, alcohol solvents, aromatic solvents such as toluene, and halogenated solvents. Alkyl solvents and the like can be mentioned. A reflective layer may be formed on the recording layer. As the reflective layer, for example, Au, Al-Mg alloy, A
It can be formed by using a metal having high reflectance such as l-Ni alloy, Ag, Pt, and Cu by means such as vapor deposition and sputtering. It is preferable that the thickness of the reflection layer is 500 ° or more. A protective film made of, for example, an ultraviolet-curable resin may be formed on the reflective layer. The thickness of the protective film is about 0.1 to 100 μm, and its hardness is 25.
The pencil hardness at C is preferably H to 8H. An adhesive layer may be provided between the recording layer and the reflective layer to make them adhere to each other. It is desirable that the thickness of the adhesive layer be 10 to 300 °. As a light source for recording and reproducing information on and from the optical recording medium of the present invention, a solid-state laser, a gas laser, a dye laser, and a semiconductor laser can be considered. From the viewpoint, a semiconductor laser is preferable. Since the compound of the present invention has particularly high recording sensitivity, a semiconductor laser having a wavelength of 600 to 800 nm is suitable. Examples of the optical recording medium using the metal complex methine dye of the present invention will be described below. Example 2 << Evaluation as Optical Recording Medium >> Evaluation of absorption maximum, light resistance, optical recording characteristics, etc. in a thin film was performed in the following procedure. (1) Formation of Recording Layer The metal complex methine dyes (D-12) and (D-3) of the present invention
1 g each of 1), (D-45) and comparative compounds (B), (C) were weighed and dissolved in 50 ml of fluorinated alcohol.
The coating solution is applied onto a glass substrate (thickness 1.1 mm, diameter 80 mm) by spin coating,
By drying for 0 minutes, a thickness of 10
A recording layer of about 00 ° was formed. Embedded image (2) Light fastness test Using a xenon fade meter (manufactured by Suga Test Instruments Co., Ltd.), the recording layer of each sample was irradiated with xenon light, and the residual dye ratio after irradiation was measured. Here, as the irradiation conditions, the illuminance on the recording layer surface is 70,000 lux, and the temperature at the time of irradiation is 4
3 ° C. and the irradiation time was 30 hours. The dye residual ratio was determined from the following equation by measuring the light transmittance at the maximum absorption wavelength of the dye before and after irradiation with xenon light. Dye residual ratio = (100−T) / (100−T ₀ ) [where T ₀ is the transmittance before irradiation with xenon light, and T is the transmittance after irradiation with xenon light] The results are shown in Table 2. [Table 2] [0072] As apparent from the results in Table 2, specimen 2 and 3 which is a recording medium using a metal complex methine dye of the present invention has a sample 4 equivalent absorption maximum comparisons using cyanine dye Further, it can be seen that the residual ratio of the dye is higher than that of the comparative example, and that it has excellent light resistance. On the other hand, it can be seen that Sample 5 using a metal complex dye different from that of the present invention has an absorption maximum that is too long and is not suitable as an optical recording medium. (3) Production and evaluation of optical recording medium (3-1) A recording layer was coated on a 5 inch diameter grooved polycarbonate substrate using the metal complex methine dye (D-30) of the present invention. Reflective layer (Au, thickness 1000)
Å) and a protective film (ultraviolet curable resin, thickness 5 μm) were sequentially formed in accordance with a standard method to manufacture an optical recording medium 6 of the present invention. As a comparison, an optical recording medium 7 was similarly manufactured using the comparative compound (B) for the recording layer. When the reflectance was measured, both of the optical recording media 6 and 7 showed 70% or more. Information was recorded on these samples by changing the power with a 780 nm semiconductor laser, and reproduction was performed at 0.8 mW. Using the xenon fade meter used in Example 2, a similar recording / reproducing experiment was performed after light irradiation at 70,000 lux for 30 hours. Table 3 shows the results. (3-2) Example 2 The procedure of Example 3-1 was repeated except that the following dye (D) and metal ion-supplying compound (M) were added to the coating solution instead of the metal complex methine dye. An optical recording medium 8 of the present invention was manufactured in the same manner as in Example 2 (3-1). Table 3 also shows the results of the evaluation of recording and storage properties. Embedded image [Table 3] As is clear from the results shown in Table 3, the optical recording media 6 and 8 of the present invention were able to perform good recording / reproduction satisfying the CD standard, and in particular, to provide stable recording excellent in light resistance. -It became clear that it has reproduction characteristics. On the other hand, in the comparative optical recording medium 7, the reflectivity was reduced by the reproduction light of the laser, the reproduction failure occurred, and the phenomenon that the recording could not be performed even by the light irradiation by the xenon fade meter was observed. As is apparent from the above, the optical recording medium using the metal complex methine dye according to the present invention has an optical recording characteristic,
Has excellent storage stability. According to the present invention, the metal complex methine dye according to the present invention, which has an absorption suitable for a semiconductor laser used in an optical recording apparatus, has a high molar extinction coefficient and is excellent in light resistance, is used. As a result, an optical recording medium excellent in optical recording characteristics and storage stability and an optical recording method using the same can be provided.

Continuation of the front page (56) References JP-A-60-249143 (JP, A) JP-A-2-29385 (JP, A) JP-A-3-246092 (JP, A) JP-A-5-112078 (JP, A) , A) JP-A-61-137775 (JP, A) JP-A-10-226172 (JP, A) JP-A-9-143382 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B41M 5/26 G11B 7/24 516 CAPLUS (STN) REGISTRY (STN)

Claims (1)

(57) [Claim 1] A methine dye represented by the following general formula (2) or (4) having at least two coordination sites is provided on a substrate. An optical recording medium comprising a recording layer containing a metal complex methine dye which is a ligand and is chelated to a metal ion at the coordination site. Embedded image [Wherein, X represents a chelate capable of forming at least bidentate;
A group selected from the groups represented by the general formulas (6) to (13)
And Y is an atom forming an aromatic hydrocarbon ring or a heterocyclic ring
Represents a collection of R ₁ , R ₂ and R ₃ are each a hydrogen atom
Represents a substituent, a halogen atom or a monovalent substituent. p is 0,
Represents 1 or 2. ] [Of 4] [Wherein, X represents a chelate capable of forming at least bidentate;
A group selected from the groups represented by the general formulas (6) to (13)
And Y is an atom forming an aromatic hydrocarbon ring or a heterocyclic ring
Wherein R ₄ and R ₅ are each a hydrogen atom, a halo
Represents a gen atom or a monovalent substituent. q is 0, 1, or
2 is represented. ] [Of A] [Wherein, R ₁₁ , R ₁₂ and R ₁₃ represent a hydrogen atom, a halogen atom or
Represents a monovalent substituent, and R ₁₄ represents a hydrogen atom or a monovalent substituent.
Represents a group. Q represents a group of atoms forming a nitrogen-containing heterocyclic ring.
And further may have a substituent on the ring,
It may have a ring. ]