WO2002034841A1

WO2002034841A1 - Light resistance improver

Info

Publication number: WO2002034841A1
Application number: PCT/JP2001/009250
Authority: WO
Inventors: Chiaki Kasada; Yasushi Aizawa; Toshio Kawata; Shigeo Yasui
Original assignee: Kabushiki Kaisha Hayashibara Seibutsu Kagaku Kenkyujo
Priority date: 2000-10-27
Filing date: 2001-10-22
Publication date: 2002-05-02
Also published as: JP4743994B2; JP2002201373A

Abstract

The problem of providing an easily handleable light resistance improver which can improve the light resistance of styryl dyes with substantially no damage to the light absorption characteristics of the dyes and its use can be solved by a light resistance improver for styryl dyes which improver contains an azo-type organometallic complex bearing a metal atom and one or more azo compound molecules bonded to the metal atom, a light absorber comprising the improver and a styryl dye; and a photorecording medium containing either the improver or the light absorber.

Description

Specification

Light fastness improver

Technical field

The present invention relates to a light resistance improver for styryl dyes, and more particularly to a light resistance improver containing an azo-based organometallic complex.

Background art

With the advent of the multimedia era, optical recording media such as CD-R (write-once memory using a compact disk) and DVDR- (write-once memory using a digital video disk) have been spotlighted. The optical recording medium is composed of an inorganic optical recording medium that forms the recording layer using an inorganic substance such as tellurium, selenium, rhodium, carbon, and hydrogen sulfide, and an organic recording medium that forms the recording layer using a light absorber mainly composed of an organic dye compound. Optical recording media.

Of these, the organic optical recording medium is usually prepared by dissolving a polymethine dye in an organic solvent such as 2,2,3,3-tetrafluoro-1-propanol (hereinafter abbreviated as “TFP”). Is coated on a polycarbonate substrate, dried to form a recording layer, and then a reflective layer made of a metal such as gold, silver, and copper and a protective layer made of an ultraviolet-curable resin are sequentially adhered to form a recording layer. . The disadvantage of organic optical recording media is that the recording layer is more likely to change due to environmental light such as reading light and natural light than inorganic recording media. However, since the recording layer can be formed by directly applying the light absorbing agent in a solution to the substrate, there is an advantage that the optical recording medium can be manufactured at low cost. In addition, since organic optical recording media are mainly composed of organic substances, they have the advantage of being resistant to corrosion even in environments exposed to moisture and seawater. With the advent of recording media, information recorded on optical recording media in a prescribed format can be read using a commercially available read-only device, and is now becoming the mainstream of inexpensive optical recording media. .

An urgent issue for organic optical recording media is the need for higher densities to meet the multimedia era. At present, research on densification that is being actively promoted in the art mainly focuses on changing the wavelength of laser light used for writing information to the current 775 nm to 795 nm using a GaAs-based semiconductor laser. The aim is to increase the recording capacity per side to 4.7 GB or more by shortening the wavelength to below 70 O nm. For example, in DVD-R, which is expected to replace CD-R as a high-density optical recording medium, it has been proposed to use laser light having a wavelength of about 65 nm as writing light. However, many cyanine dyes developed for CD-R cannot be used to write or read information properly when used in DVD-R. Therefore, in the art, a wide variety of polymethine dyes having sensitivity to visible light having a wavelength shorter than 70 O nm are currently being prototyped, and the optical properties of DVD-R are being tested. Styryl dyes are one type of such polymethine dyes.

A styryl dye that forms an electron conjugated system by a dimethine chain is different from a cyanine dye that forms an electron conjugated system by a polymethine chain such as a trimethine chain or a pentamethine chain in which an odd number of methine groups are connected. It is easy to synthesize those that have appropriate sensitivity to laser light with a wavelength shorter than nm. As a result, it began to attract attention as a light absorber for DVD-R. For example, in Japanese Patent Application Laid-Open Nos. Hei 11-99746, Hei 11-195466 and Hei 11-116995, styryl is used as a light absorbing agent. DVD-R using a dye has been proposed. However, many styryl dyes have low light resistance to reading light, and it is difficult to produce an optical recording medium satisfying the DVD-R standard when used alone. Therefore, in the prior art described above, for example, a transition metal complex, a nitroso compound, an aminium compound, a diimmonium compound, and the like are used in combination in order to improve the light resistance of the styryl dye. However, these complexes and compounds do not exhibit an effective lightfastness-improving ability with respect to styryl dyes, or even if they exhibit an effective lightfastness-improving ability, they are not sufficiently soluble in organic solvents. There was a problem that it was difficult to handle.

Disclosure of the invention

In view of such circumstances, an object of the present invention is to provide an easy-to-handle lightfastness improver that effectively improves lightfastness without substantially impairing the light absorption characteristics of a styryl dye, and an application thereof.

In order to solve such a problem, the present inventors have conducted intensive research and searched. As a result, an azo-based organometallic complex in which one or more azo compounds are bonded to a metal atom (hereinafter referred to as “azo-based organometallic complex”) When used in combination with a styryl dye, not only can the light resistance be improved without substantially impairing the light absorption properties of the styryl dye, but also the compatibility with the styryl dye in an organic solvent and the thin film state can be improved. It was found to be excellent in amorphous properties and easy to handle. An optical recording medium containing such an azo-based organometallic complex and a styryl dye can store various kinds of information by using a laser beam having a wavelength shorter than 700 nm. It has been found that high-density recording can be performed stably for a long period of time.

That is, the present invention solves the above-mentioned problems by providing a styryl dye lightfastness improver containing an azo-based organometallic complex in which one or more azo compounds are bonded to a metal atom. It is. Furthermore, the present invention solves the above-mentioned problems by providing a light absorber comprising such a light resistance improving agent and a styryl dye.

Further, the present invention solves the above-mentioned problems by providing an optical recording medium comprising such a light resistance improving agent or a light absorbing agent. However, it is not known that azo-based organometallic complexes exert such an effect on styryl dyes. The present invention is based on the discovery of a novel use of an azo-based organometallic complex, and a light-stability improving agent for styryl dyes containing an azo-based organometallic complex is the first of this invention. .

BEST MODE FOR CARRYING OUT THE INVENTION

As described above, the azo-based organometallic complex referred to in the present invention is a complex having a metal atom as a central atom, and one or more azo compounds as ligands are bonded to the metal atom. Complex in general. In the present invention, any azo-based organometallic complex which can improve the light resistance of the styryl dye to a practically usable level without substantially impairing the light absorption properties of the styryl dye is considered. It can be used irrespective of the chemical structure and preparation method. When multiple azo compounds are bonded to a metal atom, those azo compounds may be the same or different. You may use it. Examples of such azo-based organometallic complexes include, for example, those represented by the general formula

One represented by 1. All of the group of azo-based organometallic complexes represented by the general formula 1 have remarkable effects on improving the light resistance of styryl dyes, and also have a styryl dye even when used in optical recording media in combination with styryl dyes. It is extremely useful in practicing the present invention because the light absorption properties of the dye and the solubility in organic solvents are not substantially impaired. General formula 1:

+

Z in the general formula 1, or z ₄ represent the same or different aromatic or heterocyclic ring together, these aromatic rings and heterocyclic ring may have one or more substituents. Examples of the aromatic ring include a monocyclic or condensed polycyclic aromatic hydrocarbon residue such as a benzene ring, a naphthylene ring and an indandione ring. Of these, a monocyclic ring containing a benzene ring Formulas are preferred. The heterocycle includes one or more heteroatoms selected from a nitrogen atom, an oxygen atom, a sulfur atom, a selenium atom, and a tellurium atom. For example, an imidazole ring, a quinoline ring, a thiazolyl ring, a thiodiazole ring , A triazole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a benzothiazole ring and the like, among which an isoxazolone skeleton, an oxazolone skeleton, a thionaphthene skeleton, a pyrazolone skeleton, a barbituric acid skeleton, a hydantoin skeleton or a rhodanin skeleton are included. Are preferred.

Such aromatic rings and heterocyclic rings are, for example, methyl group, ethyl group, propyl Group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, tert_pentyl group, 1-methylpentyl group, 2-methylpentyl group, hexyl group Aliphatic hydrocarbon groups such as isohexyl group, 5-methylhexyl group, cycloaliphatic hydrocarbon groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, phenyl group, biphenylyl Group, o-tolyl group, m_tolyl group, p-tolyl group, o-cumenyl group, m-cumenyl group, p-cumenyl group, xylyl group, mesityl group, styryl group, cinnamoyl group, naphthyl group, etc. Aromatic hydrocarbon group, methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, acetoxy group, benzoyloxy group Such as ester group, primary amino group or methylamino group, dimethylamino group, ethylamino group, ethylamino group, propylamino group, dipropylamino group, isopropylamino group, diisopropylamino group, butylamino group, dibutylamino group, anily Substituted or unsubstituted aliphatic, alicyclic, or aromatic groups such as, o-toludino, m-toludino, p-toludino, xylidino, pyridylamino, piperazinyl, piperidino, and pyrrolidino Amino group, methylsulfamoyl group, dimethylsulfamoyl group, ethylsulfamoyl group, getylsulfamoyl group, propylsulfamoyl group, dipropylsulfamoyl group, isopropylsulfamoyl group, diisopropylsulfamoyl , Alkylsulfamoyl groups such as butylsulfamoyl group and dibutylsulfamoyl group, and furthermore, carbamoyl group, carboxy group, cyano group, nitro group, hydroxy group, sulfo group, sulfoamino group, and sulfonamide group. It may have one or more substituents.

Depending on the application, a hydrogen atom in such a substituent may be one or more of Are plural, for example, methyl group, ethyl group, propyl group, isopropyl group

, Butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, tert-pentyl, 1-methylpentyl, 2-methylpentyl, hexyl, isohexyl, 5 —Aliphatic hydrocarbon groups such as methylhexyl group, phenyl group, biphenylyl group, o—tolyl group, m—tolyl group, p—tolyl group, o—cumenyl group, m—cumenyl group, p— Aromatic hydrocarbon groups such as cumenyl group, xylyl group, mesityl group, styryl group, cinnamoyl group, naphthyl group, methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec—butoxy group, tert —Ethyl groups such as butoxy, pentyloxy, phenoxy, benzyloxy, fluoro, chloro, bromo, and odo groups Halogen group, further, Karupokishi group, arsenate Dorokishi group, Shiano group, may be substituted by a nitro group.

The azo-based organometallic complex represented by the general formula 1 is obtained by bonding one or more azo compounds, which are the same or different from each other, to a metal atom M serving as a central atom as a ligand. is there. The metal atom M is usually scandium, yttrium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, orifice, Metal elements of Groups 3 to 12 in the periodic table, such as iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, and mercury, are employed.In the field of optical recording media, Cobalt or nickel is usually used because it is easily available and easy to handle. In addition, A and A ′ in the general formula 1 can form a coordinate bond by donating an electron pair to a metal atom, for example, in a periodic table such as an oxygen atom, a sulfur atom, a selenium atom, and a tellurium atom. Same as each other selected from the elements of Group 16 Or different heteroatoms.

In the general formula 1, L + represents an appropriate counter ion, and is usually, for example, an inorganic cation such as sodium ion, potassium ion, or calcium ion, or an organic cation such as ammonium ion, alkyl ammonium ion, or pyridinium ion. Is selected from

Examples of such azo-based organometallic complexes include, for example, those represented by Chemical Formulas 1 to 7. All of these have remarkable properties to improve the light resistance of styryl dyes to the visible region, more specifically, to ambient light of a wavelength of 350 to 850 nm, and have compatibility with styryl dyes. It is extremely useful in practicing the present invention since it does not substantially impair the solubility of the styryl dye in an organic solvent. In addition, all of the azo-based organometallic complexes represented by Chemical Formulas 1 to 7 are azo-compounds constituting the azo-based organometallic complex represented by General Formula 1 in a conventional manner. and Jiazoniumu salts with Z E or Z ₂ corresponding to the general formula 1, in the molecule, having an active methylene group adjacent to the carbonyl group, for example, iso Okisazoron compound, Okisazoron compound, Chionafuten compound, Vila Zoron compounds, barbituric The desired amount can be obtained by reacting a heterocyclic compound such as an acid compound, a hydantoin compound, and a rhodanine compound.

Formula 2:

CF ₃

Formula 6:

Chemical formula 7:

The lightfastness improving agent referred to in the present invention means a general optical functional material which essentially contains one or more of such azo-based organometallic complexes and whose purpose is to improve the lightfastness of styryl dyes. The styryl dye to which the light resistance improver is applied will be described. The styryl dye referred to in the present invention is a dimethine chain in which a heteroaromatic ring is bonded to one end and an aromatic ring or a heteroaromatic ring is bonded to the other end. In general, an organic dye compound represented by the general formula 2 is used. When the use in combination with an azo-based organometallic complex is an optical recording medium, the compound represented by the general formula 2 is preferable.

General formula 2:

I

In the general formula 2, Z ₅ represents a heteroaromatic ring, and the heteroaromatic ring may have one or more substituents. Y in Z ₅ is, for example, ChissoHara Represents a heteroatom selected from elements of Group 15 or 16 in the Periodic Table such as atoms, oxygen atoms, sulfur atoms, selenium atoms, and tellurium atoms, and represents a counter ion X-- and an onium salt described below. Form. Z ₆ represents an aromatic ring or a heteroaromatic ring, and the aromatic ring and the heteroaromatic ring may have one or more substituents. Examples of the heteroaromatic ring in Z ₅ and Z ₆ include, for example, an imidazole ring, a benzimidazole ring, a quinoxalizimidazole ring, an indolenine ring, an α-naphthoindolenin ring,) 3—naphthindrenine ring, oxazole Ring, benzoxazole ring, naphthoxazole ring, β-naphthoxazole ring, oxazoline ring, quinoline ring, benzoselenazole ring, thiazole ring, benzothiazole ring, α_naphthothiazole ring, / 3- naphthoquinone Tochiazoru ring, thiazol down ring, pyran ring, Chiopiran ring, benzopyran ring, a pyridine ring, pyrrolidine ring, etc., and as the contact Keru aromatic ring Zeta _4, for example, benzene ring, naphthoquinone evening Ren ring, anthracene down And a phenanthrene ring.

The substituent in Zeta ₅ and Z _s, for example, Furuoro group, black port group, bromo group, a halogen group such as Yodo group, a methyl group, Echiru group, propyl group, isopropyl group, 1 one propenyl group, 2 —propenyl, 2 —vinyl, butyl, isobutyl, sec —butyl, tert —butyl, 2 —butenyl, 1,3 —butenyl, pentyl, isopentyl, Aliphatic hydrocarbon groups such as neopentyl, tert-pentyl, 1-methylpentyl, 2-methylpentyl, 2-pentenyl, 2-penten-4-yl, hexyl, and isohexyl , Methoxy, ethoxy, propoxy, isopropoxy, butoxy, tert-butoxy, pentyloxy, phenoxy, benzyloxy, etc. , Main butoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, butoxycarbonyl group, Penchiruo Ester groups such as xycarbonyl, acetoxy, benzoyloxy, etc., methylamino, dimethylamino, ethylamino, getylamino, propylamino, dipropylamino, isopropylamino, diisopropylamino, butylamino Group, amino group such as dibutylamino group, piperidino group, methylsulfonyl group, ethylsulfonyl group

Alkylsulfonyl groups such as propylsulfonyl group, isopropylsulfonyl group, butylsulfonyl group, methylsulfamoyl group, dimethylsulfamoyl group, ethylsulfamoyl group, getylsulfamoyl group, propylsulfamoyl group, dipropylsulfamoyl Groups, an alkylsulfamoyl group such as a butylsulfamoyl group and a dibutylsulfamoyl group, and a hydroxy group, a carboxy group, a sulfo group, a nitro group, a cyano group, and the like. As for a hydrogen atom in such a substituent, one or more of the hydrogen atoms may be, for example, a halogen group such as a fluoro group, a chloro group, a bromo group, a sulfide group, a methoxy group, an ethoxy group, a propoxy group, Ether groups such as isopropoxy, butoxy, tert-butoxy, and phenoxy groups, phenyl, o-tolyl, m-tolyl, p-tolyl, xylyl, mesityl, o-cumenyl, m —It may be replaced by an aromatic hydrocarbon group such as a cumenyl group, p_cumenyl group, biphenylyl group and the like. Incidentally, the substituent in Z ₄ is are bound together substituent What happened adjacent, for example, may form a Mechirenjiokishi group, cyclic ether group comprising a like Echirenjiokishi group.

R in the general formula 2 represents an aliphatic hydrocarbon group. Each aliphatic hydrocarbon group usually has up to 12 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, a isopropyl group, an isopropyl group. Propenyl group, 2-propynyl group, 2-propynyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, 2-butenyl group, 1,3-butenyl group, pen Tyl group, isopentyl group, neopentyl group, tert-pentyl group, 1-methylpentyl group, 2-methylpentyl group, 2-pentenyl group, 2-pentene-4-ynyl group, hexyl group, isohexyl group, heptyl Group, octyl group, decyl group and the like. One or more of the hydrogen atoms in such an aliphatic hydrocarbon group may be, for example, a halogen group such as a fluoro group, a chloro group, a bromo group, an aldehyde group, a methyl group, an ethyl group, a propyl group, or an isopropyl group. Aliphatic hydrocarbon groups such as butyl, isobutyl, sec-butyl, and tert-butyl groups; alicyclic hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups; phenyl Group, o — tolyl group, m _ tolyl group, p — tolyl group, xylyl group, mesityl group, o — cumenyl group, m-cumenyl group, p-cumenyl group, biphenylyl group, etc. Hydrogen, methoxy, trifluoromethoxy, ethoxy, propoxy, isopropoxy, butoxy, tert-butoxy, benzyloxy, phenyl Esters such as ether group such as xy group, methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, benzyloxy group, acetooxy group and benzoyl group, 2-furyl group, 2-phenyl group, 2-pyrrolyl Or a heterocyclic group such as a 2-pyridyl group or a 2-quinolyl group, and may further be substituted with a hydroxy group, a carboxy group, a sulfo group, a cyano group, a nitro group, or the like. Note that when Y in Z ₅ is a first group 5 heteroatoms other than the elements of the periodic table is, R, it does not exist.

R ₂ in the general formula 2 represents a hydrogen atom or an appropriate substituent. Examples of the substituent in R ₂ include an aliphatic hydrocarbon group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group and a tert-butyl group. Methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec—butoxy Examples of the substituent include an ether group such as a tert-butoxy group, a halogen group such as a fluoro group, a chloro group, a bromo group and an odo group, a cyano group, a nitro group, and the like. And one or more of them may be substituted by an octalogen group such as, for example, a fluoro group, a chloro group, a bromo group, and an iodo group. When R ₂ is an aliphatic hydrocarbon group or an ether group, the aliphatic hydrocarbon group and the ether group are bonded to the carbon atom constituting Z ₅ to form a ring such as a cyclohexene ring. May form a structure.

X in the general formula 2 represents an appropriate counter ion. Depending on the application, the counter ion may be appropriately determined in consideration of the solubility of the styryl dye in each organic solvent and the stability in the glassy state, and is usually a fluoride ion, a chloride ion, a bromine ion, or the like. Iodine ion, perchlorate ion, periodate ion, hexafluorophosphate ion, hexafluoroantimonate ion, hexafluorostannate ion, phosphate ion, borofluoride ion, tetrafluoroborate ion Inorganic acid anions, such as thiocyanate ion, benzenesulfonic acid ion, naphthalenesulfonic acid ion, naphthalene disulfonic acid ion, p_toluenesulfonic acid ion, alkylsulfonic acid ion, benzenecarboxylic acid ion, alkylcarboxylic acid Ion, trihaloalkyl carboxylate ion, alkyl sulfate ion, Organic acid anions such as kill sulfate ion and nicotinate ion, and organic metal complexes such as azo, bisphenyldithiol, thiocatechol chelate, thiobisphenolate chelate, bisdiol-α-diketone, etc. Choose from When the styryl dye represented by the general formula 2 has isomers such as cis-trans isomers in structure, any isomers are included in the present invention.

Specific examples of such styryl dyes include, for example, Chemical Formulas 8 to 18 are mentioned. In addition, any of these can be obtained in a desired amount according to a known method.

Formula 8:

Chemical formula 9:

Chemical formula 10

Formula 11:

Chemical formula 13:

Chemical formula 14:

Chemical Formula 15:

2 H ⁿ 5 CIO. Formula 16:

Chemical formula 17:

The light absorber according to the present invention comprises one or more styryl dyes as described above and one or more azo organometallic complexes as a lightfastness improver. The use of organic dye compounds, lightfastness improvers, binders, and general-purpose dispersants, flame retardants, lubricants, antistatic agents, surfactants, thermal interference inhibitors, plasticizers, etc. It is prepared in liquid, solid or semi-solid depending on the conditions. The azo-based organometallic complex is capable of preventing the styryl dye from deteriorating, fading, discoloring, and discoloring due to exposure to ambient light such as artificial light and natural light without substantially impairing the light absorption characteristics of the styryl dye. It contains an azo-based organometallic complex and a styryl dye because it effectively suppresses undesired changes, and has excellent compatibility with styryl dyes in organic solvents and excellent amorphous properties in a thin film state. The light absorber of the present invention is extremely useful as a material constituting a recording layer of an organic optical recording medium such as DVD-R. Although it depends on the application, for example, when used for a high-density optical recording medium such as DVD-R, 0.01 parts by weight or more of the azo-based organometallic complex is used for 1 part by weight of the styryl dye. In an optical recording medium, if the amount of the azo-based organometallic complex is less than 0.01 part by weight, the light resistance of the styryl dye is not improved to the expected level, while 0.5 part by weight is not improved. If the amount exceeds the above range, the electrical characteristics of the optical recording medium are remarkably deteriorated. Therefore, the amount is usually adjusted within the range of 0.05 to 0.5 part by weight, preferably 0.1 to 0.4 part by weight. When the azo-based organometallic complex is used in advance, even if it is previously mixed with the styryl dye, it is separated from the styryl dye and added to the target. It may be adjusted so that

The application of the light absorber according to the present invention to an optical recording medium will be described as an example. When used in an optical recording medium, the light absorber of the present invention does not require any special treatment or operation. Therefore, the optical recording according to the present invention The medium can be manufactured according to a conventionally known optical recording medium. For example, the light absorbing agent according to the present invention may contain one or more other organic dye compounds that substantially absorb visible light, if necessary, in order to adjust the light reflectance and light absorption in the recording layer. Add one or more general-purpose binders, dispersants, flame retardants, lubricants, antistatic agents, surfactants, heat interference inhibitors, plasticizers, etc., dissolve them in an organic solvent, and spray the solution. Uniformly apply to one side of the substrate by immersion method, roller coating method, spin coating method, etc., dry it to form a thin film of a light absorbing agent that becomes the recording layer, and then read the written information as necessary Obtained reflectivity, usually 10% or more, preferably 30% or more, by vacuum evaporation, chemical vapor deposition, sputtering, ion plating, etc., using gold, silver, copper, etc. Platinum, aluminum Metal, such as cobalt, tin, nickel, iron, and chromium, or alloys thereof, or a general-purpose organic reflective layer material to form a reflective layer that is in close contact with the recording layer, and to protect the recording layer from scratches, dust, dirt, etc. For the purpose of protection, an ultraviolet curable resin or thermosetting resin containing a flame retardant, stabilizer, antistatic agent, etc. is applied, and the protective layer that adheres to the reflective layer by being irradiated with light or heated and cured. Form. Thereafter, if necessary, a pair of substrates on which the recording layer, the reflective layer, and the protective layer are formed as described above are attached to each other with the protective layers facing each other with, for example, an adhesive or an adhesive sheet, or A protective plate having the same material and shape as that of the substrate is attached to the protective layer. The method for forming the recording layer should not be limited to the method of applying the light absorbing agent of the present invention in a solution, and the method of sublimation is not limited thereto. For example, a vacuum evaporation method, A thin film of the light absorbing agent may be formed directly on the substrate by a method such as a chemical vapor deposition method or an atomic layer epitaxy method.

As another organic dye compound used in combination with the styryl dye in the present invention, it substantially absorbs visible light and reflects light from an optical recording medium. There is no particular limitation as long as the rate and the light absorption can be adjusted. Such an organic dye compound may have a substituent at both ends of a polymethine chain such as a monomethine chain or a dimethine chain, a trimethine chain, a tetramethine chain, a pentamethine chain, a hexamethine chain, and a heptamethine chain which may have one or more substituents. Imidazoline ring, imidazole ring, imidazole ring, benzimidazole ring, 1-naph-to-imidazole ring, β-naph-to-imidazole ring, indole ring, isoindole ring, indolenine ring, isoindone Renin ring, benzoindolenine ring, pyridinoindolenine ring, oxazoline ring, oxazole ring, isoxazole ring, benzoxazole ring, pyridinoxazole ring, α-naphthoxazole ring, / 3-naphthoxazole ring, selenazoline ring , Serenazo Ring, benzoselenazole ring, naphthoselenazole ring, 3-naphthoselenazole ring, thiazoline ring, thiazole ring, isothiazole ring, benzothiazole ring, α_naphthothiazole ring, / 3-naphthothiazole ring , Tellurazoline ring, tellurazole ring, benzotellurazole ring, α-naphthotellurazole ring,] 3-naphthotellurazole ring, and further, acridine ring, anthracene ring, isoquinoline ring, isopirroyl ring, imidanoxali Ring, indandione ring, indazole ring, indalline ring, oxaziazole ring, kylarbazole ring, xanthene ring, quinazoline ring, quinoxaline ring, quinoline ring, chroman ring, cyclohexanedione ring, Cyclopentane dione ring, cinnoline ring, thiodiazole ring, thione Xazolidone ring, thiophene ring, thionaphthene ring, thiobarbituric acid ring, thiohydantoin ring, tetrazole ring, triazine ring, naphthylene ring, naphthyridine ring, pyrazine ring, pyrazine ring, pyrazole ring, pyrazoline ring, Pyrazolidine ring, pyrazolone ring, pyran ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrylium ring, pyrrolidine ring, pyrrolin ring, pyrrolyl ring, Cyclic nuclei such as enazine ring, phenanthridine ring, phenanthrene ring, phenanthroline ring, phthalazine ring, pteridine ring, furazane ring, furan ring, pyridine ring, benzene ring, benzoxazine ring, benzopyran ring, morpholin ring, and rhodanine ring Dyes, merocyanine dyes, oxonol dyes, azurenium dyes, squarylium dyes, pyrylium dyes, thiopyrylium dyes, phenanthrene dyes, and other polymethine dyes formed by binding of , Azo-based, anthraquinone-based, indigo-based, indanthrene-based, oxazine-based, xanthene-based, dioxazine-based, thiazine-based, thioindigo-based, tetravilaborphyrazine-based, triphenylmethane-based, triphenothiazine-based, Naphthoquinone-based, phthalocyanine-based, benzoquinone-based, benzopyran-based, benzofuranone-based, porphyrin-based, rhodamine-based, and pyrromethene-based dyes are listed, and these may be used in an appropriate combination as needed.

As described above, the light absorbing agent of the present invention containing a styryl dye and an azo-based organometallic complex has extremely high light resistance. There is no need to add a lightfastness improver as an indispensable element. However, the optical recording medium according to the present invention does not exclude an aspect in which another light resistance improving agent is appropriately used in combination, and a general-purpose nitroso compound, a tetracyanoquinodimethane compound, a dimonium compound, a metal, and the like can be used without departing from the object of the invention. A complex or the like can be appropriately used in combination.

As described above, the styryl dye and the azo-based organometallic complex used in the present invention both exhibit solubility that does not hinder practical use in various kinds of organic solvents. Since it has excellent amorphous properties in a state, there is no particular limitation on the organic solvent for applying the light absorbing agent to the substrate. Therefore, the production of the optical recording medium according to the present invention is For example, TFP, which is frequently used in the production of optical recording media, or hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, ethylcyclohexane, isopropylcyclohexane, tert-butylcyclohexane , Octane, cyclooctane, benzene, toluene, xylene and other hydrocarbons, carbon tetrachloride, chloroform, 1,2-dichloroethane, 1,2-dibromoethane, trichloroethylene, tetrachlorethylene, cyclobenzene, Bromobenzene, halides such as α-dichlorobenzene, methanol, ethanol, 2,2,2-trifluoroethanol, 2-methoxyethanol (methylcellulose solvent), 2-ethoxyethanol (ethylsulphate solvent), 2 —Isopropoxy 1 —Ethanor , 1 — propanol, 2 — propanol, 1 — methoxy — 2 _ propanol, 1 — ethoxy — 2 — propanol, 1 — butyl, 1 — methoxy, 2 — butanol, 3 — methoxy, 1 — butyl Evening oil, 4-Methoxy-1 -Busanol, Isobutyl alcohol, Pentyl alcohol, Isopentyl alcohol, Cyclohexanol, Gethylen glycol, Triethylene glycol, Propylene glycol, Dali serine, Diacetone alcohol, Phenol , Alcohols such as benzyl alcohol, cresol, and phenols, getyl ether, diisopropyl ether, tetrahydrofuran, tetrahydropyran, 1,4-dioxane, anisol, 1,2-dimethoxetane, and methylenglycol dimethyle Ter, dicyclohexyl 18-crown-16, ethers such as methyl carbitol, ethyl carbitol, furfural, acetone, 1,3, diacetyl acetone, ketones such as ethyl methyl ketone, cyclohexanone, acetic acid Esters such as ethyl, butyl acetate, ethylene carbonate, propylene carbonate, trimethyl phosphate, formamide, Ν-methylformamide, Ν, Ν-dimethylformamide, Amides such as xamethylphosphoric acid triamide, nitriles such as acetonitril, propionitrile, succinonitryl, benzonitrile, nitro compounds such as nitromethane and nitrobenzene, ethylenediamine, pyridine, pyridine and morpholine Select from general-purpose organic solvents other than TFP, such as amines such as N-methylpyrrolidone and sulfur-containing compounds such as dimethylsulfoxide and sulfolane, and use them in an appropriate combination as necessary.

In particular, the styryl dye and the azo-based organometallic complex used in the present invention have a high solubility in an organic solvent that is easily evaporated, such as, for example, TFP methyl sorb, ethyl sorb, and diacetone alcohol. However, even when applied to a substrate, after drying, crystals of styryl dye or azo-based organometallic complex do not appear, and the thickness and surface of the recording layer do not become uneven. Many of the styryl dyes and azo-based organometallic complexes used in the present invention are non-halogen solvents, for example, cellosolves such as methylacetosolve and ethylacetosolve, alcohols such as diacetone alcohol, and the like. Has good solubility in ketones such as ethyl methyl ketone and cyclohexanone. When the light absorbing agent according to the present invention is dissolved in such cellosolves or alcohols and applied to a plastic substrate such as polycarbonate, there is a practical advantage that the substrate is not easily damaged by the solvent and the environment is not easily polluted.

The substrate may be a general-purpose substrate. Usually, an appropriate material such as an extrusion molding method, an injection molding method, an extrusion injection molding method, a photopolymer method (2P method), a thermosetting integrated molding method, a light curing integrated molding method, or the like is used. Depending on the end use, for example, it is formed into a disk having a diameter of 12 cm and a thickness of 0.1 to 1.2 mm, and is used as a single plate, or is appropriately attached with an adhesive sheet, an adhesive, or the like. Use together. The substrate material is substantially transparent and has a wavelength of 400 to 800 nm. In principle, any material can be used as long as it has a light transmittance of 80% or more, preferably 90% or more. Individual materials include, for example, glass, ceramic, polymethyl methacrylate, polycarbonate, polystyrene (styrene copolymer), polymethylpentene, polyester etherimide, polyether sulfone, and polyarylate. Polycarbonate, polystyrene alloy, polyester carbonate, polyphthalate-to-carbonate, polycarbonate acrylate, amorphous polyolefin, methacrylate copolymer, diaryl carbonate diethylene glycol Plastics such as epoxy resin and epoxy resin are used, and polycarbonate is frequently used. In the case of a plastic substrate, the synchronization signal and the recess indicating the address of the track or sector are usually transferred to the inner circumference of the track during molding. Although the shape of the concave portion is not particularly limited, the concave portion is formed so that the average width is in a range of 0.3 to 0.8 m and the depth is in a range of 70 to 200 nm. It is desirable to do.

The light absorber according to the present invention is prepared in a solution in which the concentration of the styryl dye in the organic solvent is 0.5 to 5% (w / w) while considering the viscosity, and the dried recording layer is prepared. Is uniformly applied to the substrate so that the thickness of the substrate is 10 to 1000 nm, preferably 50 to 500 nm. Prior to the application of the solution, an undercoat layer may be provided for the purpose of protecting the substrate or improving the adhesiveness, if necessary. Examples of the material of the undercoat layer include ionomers, resins, and polyamides. Polymers such as resins, vinyl resins, natural resins, silicones, and liquid rubbers. When a binder is used, cellulose esters such as nitrocellulose, cellulose phosphate, cellulose sulfate, cellulose acetate, cellulose propionate, cellulose butyrate, cellulose palmitate, and cellulose acetate propionate; methyl cellulose; Such as ethyl cellulose, propyl cellulose, and butyl cellulose. Which cellulose ethers, polystyrene, polyvinyl chloride, polyvinyl acetate, vinyl acetal, polyvinyl bityl butyral, polyvinyl formal, polyvinyl alcohol, polyvinyl resin such as polyvinyl pyrrolidone, styrene-butadiene copolymer, styrene-acrylonitrile Copolymers such as copolymers, styrene-butadiene-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, maleic anhydride copolymer, polymethyl methacrylate, polymethyl acrylate, polyacrylate, polymethacrylate Acrylic resins such as polyacrylate, polyacrylamide, polyacrylonitrile, polyesters such as polyethylene terephthalate, polyethylene, chlorinated polyethylene, poly Polymers including Poriorefui emissions such as, alone or in combination propylene, heavy ratio, used 0.0 1 1 0 times the styryl dye.

The method of using the optical recording medium according to the present invention will be described. The high-density optical recording medium such as a DVD-R according to the present invention includes, for example, GaN-based, A1GalnP-based, GaAsP-based, a AlAs, InGaP, InGaAsP, or InGaA1P semiconductor laser, or second-harmonic such as distributed feedback or Bragg reflection Laser light with a wavelength shorter than 70 O nm by an Nd-YAG laser or the like combined with a wave generating element (SHG element), especially from 400 to 450 nm or 63 to 680 Various kinds of information can be written at high density using a laser beam of nm. For reading, use a laser beam of the same wavelength as that used for writing, or a wavelength slightly higher or lower than that. Regarding the laser output at the time of writing and reading, the optical recording medium according to the present invention has a laser at the time of writing information, though it depends on the type and the mixing ratio of the styryl dye and the azo-based organometallic complex used in combination. The output is relatively strong above the energy threshold at which the pit is formed, while reading the written information It is desirable to set the output at that time below the threshold and relatively low

. Generally, writing is performed in a range of more than 4 mW and not exceeding 50 mW, and reading is adjusted in a range of 0.1 to 4 mW. The recorded information is read by detecting a change in the amount of reflected light or the amount of transmitted light between the pit and the portion where the pit is not formed on the recording surface of the optical recording medium by optical pickup.

Thus, in the optical recording medium according to the present invention, an optical pickup using a laser beam having a wavelength shorter than 700 nm, in particular, a laser beam having a wavelength of 400 to 450 nm or 63 to 68 nm. With a track pitch of less than 1.6 m, which is the current CD-R track pitch (typically 0.74 m), and a pitch length of less than 0.834 mZ, (Usually 0.2 A mZ pits), and minute pits can be formed with high density and speed. Therefore, for example, when a disk-shaped substrate with a diameter of 12 cm is used, the recording capacity far exceeds 0.682 GB on one side, which cannot be easily achieved with the current CD-R (usually, An extremely high-density optical recording medium capable of recording moving images for about 2 hours can be realized.

Since the optical recording medium according to the present invention can record character information, image information, audio information, and other digital information at a high density, it records and stores documents, drawings, data, computer programs, and the like. It is extremely useful as a recording medium for consumer and business use. Examples of the types of business and information that can use the optical recording medium according to the present invention include construction, construction in civil engineering, civil engineering drawings, maps, roads, river ledgers, apachiyua cards, architectural drawings, disaster prevention materials, and wiring. Drawings, layout drawings, newspaper / magazine information, local information, construction reports, etc., manufacturing blueprints, ingredient lists, prescriptions, product specifications, product price lists, parts lists, maintenance information, accidents. Collections, complaint handling casebooks, manufacturing process charts, technical materials, drawings, details, company work collections, technical reports, inspection reports, etc., customer information in sales, business partner information, company information, contracts, newspapers and magazines Information, business reports, corporate credit surveys, inventory lists, etc. in finance, company information, stock price records, statistical materials, newspapers, magazine information, contracts, customer lists, various applications, notifications, licenses, licenses, licenses, business Reports, real estate · Property information in transport, building sketches, maps, regional information, etc. Wiring and plumbing diagrams in power and gas, disaster prevention materials, work standards, survey materials, technical reports, medical records, medical records, etc. Medical history • Case files, medical diagrams, etc., textbooks at cram schools / prep schools, problem books, educational materials, statistical materials, etc. Member list of various organizations, such as academic papers, academic conference records, research monthly reports, research data, literature and literature indexes, research data in information, papers, patent gazettes, weather maps, data analysis records, customer files, legal precedents, etc. , Past books, work records, competition records, tournament records, etc., tourism information in tourism, traffic information, etc., media, index of our own publications in publishing, newspapers, magazine information, person files, sports records, telop files, broadcasting Examples include government-related maps such as scripts, roads, river ledgers, fingerprint files, resident certificates, various applications, notifications, licenses, licenses, license materials, statistical materials, and public materials. In particular, the optical recording medium of the present invention, which can be written only once, must not be falsified or erased. For example, in addition to preserving records such as medical records and official documents, museums, libraries, museums, broadcasting stations, etc. It is also very useful as an electronic library.

Some special applications of the optical recording medium according to the present invention include a compact disk, a digital video disk, a laser disk, an MD (information recording system using a magneto-optical disk), a CDV (a laser disk using a compact disk). ), DAT (information recording system using magnetic tape) System), CD-ROM (read-only memory using a compact disk), DVD_RAM (writable read memory using a digital video disk), digital photos, movies, video software, audio software, computers It can be used for editing and proofreading graphics, publications, broadcast programs, commercial messages, game software, etc., as well as for large-sized computers and as an external program recording means for car navigation.

In the above, the application of the light absorbing agent according to the present invention in the field of optical recording media has been mainly described for application to optical recording media using laser light having a wavelength shorter than 70 O nm as writing light. Was. However, in the field of optical recording media, the use of the light absorber according to the present invention is not limited to high-density optical recording media such as DVD-R, but also to current optical recording media such as CD-R. Adjust or correct the light absorption or light reflectance of the optical recording medium by combining it with one or more other organic dye compounds that substantially absorb the laser light of 775 to 795 nm Can also be advantageously used as a material for this. Also, even when applied to an optical recording medium that uses laser light having a wavelength shorter than 70 O nm as writing light, instead of using a styryl dye to directly form a pit on a substrate, it is not necessary to use a stylyl dye. Laser light of a shorter wavelength than 700 nm, for example, by combining it with one or more other organic dye compounds that substantially absorbs the longer wavelength, eg, 775-795 nm laser light. A pit may be formed indirectly by transferring the excitation energy of the compound to these organic dye compounds via the styryl dye, and thereby decomposing the latter organic compound. More specifically, the optical recording medium according to the present invention means any recording medium utilizing the property that the styryl dye substantially absorbs visible light having a wavelength shorter than 700 nm. , Besides the heat-deformable type, for example, organic dyeing A thermal coloring method that uses a chemical reaction between the color former and the developer due to the heat generated by the light absorption of the compound, and a phenomenon in which the periodic uneven pattern provided on the surface of the substrate is flattened by such heat generation Using the so-called “moth-eye method”

". The light absorbing agent of the present invention containing the styryl dyes represented by Chemical Formulas 14 and 16 substantially absorbs visible light having a wavelength of around 400 nm in a thin film state. It is also useful as a material for forming a recording layer of a high-density optical recording medium using a laser beam having a wavelength of 405 nm as incident light.

Further, the light absorbing agent of the present invention which substantially absorbs visible light is used, for example, for a material for polymerizing a polymerizable compound by exposing the polymerizable compound to visible light and a solar cell in addition to the use in an optical recording medium. It is useful as a material for sensitizing, a light absorbing material in an optical filter, a laser active substance in a dye laser, and a material for dyeing various kinds of clothing. Further, the light absorbing agent of the present invention may be used, if necessary, together with one or more other light absorbing agents that absorb light in the ultraviolet, visible, and / or infrared regions, as well as general clothing and other clothing. For example, drapes, laces, casements, prints, venetian blinds, roll screens, shutters, goodwill, blankets, futons, futon lands, futon covers, futon cotton, sheets, cushions, pillows, pillowcases , Cushions, mats, carpets, sleeping bags, tents, car interior materials, built-in bedding products such as window glass and window glass, disposable diapers, eyeglasses, monocles, mouth nets, etc. Shoe insoles, shoe lining, satoshi, furoshiki, umbrellas, umbrellas, stuffed animals and lighting equipment, for example, cathode ray tube displays, liquid crystal displays, electroluminescent displays Television receivers that use sprays, plasma displays, etc.—Classes for information display devices such as personal computers, panels and screens, sunglasses, sunroofs, sun visors, PET bottles , Storage, plastic greenhouses, cold gauze, optical fiber, prepaid cards, microwave ovens, ovens, etc., as well as packaging materials for packing, filling or containing these items, filling materials, containers, etc. Sometimes, not only can we prevent or reduce inconveniences caused by environmental light such as natural light and artificial light on living things and goods, we can also adjust the chromaticity, color, color tone, texture, etc. of goods, There is a benefit in that light reflected or transmitted from an article can be adjusted to a desired color balance.

Hereinafter, embodiments of the present invention will be described based on examples.

Example 1: Light absorber

Take 10 Om 1 of TFP, add 0.8 g of the azo-based organometallic complex represented by the chemical formula 1 and 2 g of the styryl dye represented by the chemical formula 11 to this, and temporarily heat, After dissolving by applying a sound wave, the resulting solution was subjected to membrane filtration according to a conventional method to obtain a light absorber exhibiting an absorption maximum near a wavelength of 600 nm in a thin film state.

This product, which has high resistance to environmental light such as natural light and artificial light, and is easy to handle, is useful as a light absorber constituting the recording layer of an optical recording medium.

Example 2: Light absorber

Take 100 ml of TFP, add 0.4 g of the azo-organometallic complex represented by the chemical formula 2 and 2 g of the styryl dye represented by the chemical formula 13 and heat for a while. After applying and dissolving the solution, the solution was subjected to membrane filtration according to a conventional method to obtain a light absorber having an absorption maximum at a wavelength of about 598 nm in a thin film state.

This product has high resistance to environmental light such as natural light and artificial light, and is easy to handle. Is useful as a light absorber constituting a recording layer of an optical recording medium. Example 3: Light absorber

Take 100 ml of TFP, add 0.6 g of the azo-organometallic complex represented by the chemical formula 7 and 2 g of the styryl dye represented by the chemical formula 18 and heat for a while. After applying and dissolving the solution, the solution was subjected to membrane filtration according to a conventional method to obtain a light absorber having a maximum absorption at a wavelength of about 562 nm in a thin film state.

This product, which has high resistance to environmental light such as natural light and artificial light, and is easy to handle, is useful as a light absorber constituting the recording layer of an optical recording medium. Example 4: Light absorber

Take lOO ml of TFP, add 0.6 g of the azo-based organometallic complex represented by the chemical formula 5 and 2 g of the styryl dye represented by the chemical formula 16 to the mixture, and heat for a while to generate ultrasonic waves. After applying and dissolving, the resultant was subjected to membrane filtration according to a conventional method to obtain a light absorber having a maximum absorption at a wavelength of about 350 nm in a thin film state.

This product, which has high resistance to environmental light such as natural light and artificial light, and is easy to handle, is useful as a light absorber constituting the recording layer of an optical recording medium. Example 5: Light fastness of light absorber

Either the method described in any of Examples 1 to 4 or the light absorber having the composition shown in Table 1 prepared according to these methods was applied to a glass substrate (5 cmX 5 cm). A certain amount was dropped on one side, and the solution was uniformly applied to the substrate by rotating the substrate at 1, OOO rpm for 1 minute. Then, hot and cold air were blown in this order and dried. Note that the formulations shown in Table 1 When the azo organic metal complex was added to the styryl dye, the amount of the azo organic metal complex was -0.3 part by weight per 1 part by weight of the styryl dye.

Next, the transmittance (T _Q ) at a wavelength of 400 nm or 600 nm of the substrate coated with the styryl dye was measured according to the absorption maximum wavelength of the styryl dye, and then the glass substrate was moved to 500 W xenon. The lamp was exposed for 25 minutes. Immediately thereafter, the transmittance (T) at a wavelength of 400 nm or 600 nm was measured again, and these transmittances T and T were measured. Was substituted into Formula 1 to calculate the residual dye ratio (%). At the same time, a system was provided in which the azo-based organometallic complex was omitted for each styryl dye, and these were treated in the same manner as above to serve as controls. Table 1 summarizes the results.

100 one T

Dye residual rate (¾) = X 100

100 One To Table 1:

Styryl dye azo-based organometallic complex Dye residual ratio in thin film state Remarks

Absorption maximum wavelength (nm) ()

Chemical formula 8 Chemical formula 1 540 97.6 Present invention Chemical formula 8 No addition 540 92.2 Reference Chemical formula 1 1 Chemical formula 1 600 8 9.5 Present invention Chemical formula 1 1 Chemical formula 2 600 1 0 0.0 0.0 Present invention chemical formula 1 1 Additive 600 3.2 Control Chemical Formula 1 2 Chemical Formula 1 586 9 0.8 Present Chemical Formula 1 2 Additive 586 1.0 Control Chemical Formula 1 3 Chemical Formula 2 598 9 2.6 Present Chemical Formula 1 3 Chemical Formula 5 598 7 6.7 Chemical formula of the present invention 1 3 Chemical formula 6 598 9 1.2 Chemical formula 13 of the present invention not added 598 54.5 Reference Chemical formula 16 6 Chemical formula 5 350 (54.5) 6) Reference Chemical formula 18 Chemical formula 2 562 (95.8) Chemical formula of the present invention 18 Chemical formula 7 562 (100.0.0) Chemical formula 18 of the present invention No additive 562 (8.1.2) Comparative Note: The numbers in parentheses indicate the residual dye ratio measured at a wavelength of 400 nm <

As can be seen from the results in Table 1, in systems that did not use any azo-based organometallic complex, exposure for only 25 minutes changed about 8 to 99% of the styryl dye, and the initial light absorption characteristics Can not be demonstrated. On the other hand, in the system in which the styryl dye is blended with the azo-based organometallic complex, the ratio at which the styryl dye changes is significantly smaller than the system in which no azo-based organometallic complex is used, and depending on the combination. However, the residual ratio of the dye reached twice or more. These results indicate that azo-based organometallic complexes are extremely effective in improving the light fastness of styryl dyes. Example 6: Optical recording medium

A polycarbonate disk prepared by transferring a light absorbing agent prepared by any of the methods in Examples 1 to 3 onto the inner periphery of a track, by transferring a synchronization signal and a concave portion indicating the address of a track and a sector. The substrate (diameter: 12 cm, thickness: 0.6 mm) was evenly spin-coated on one side and dried to form a 120-nm-thick recording layer. Thereafter, silver is sputtered on the substrate to a thickness of 100 nm to form a reflective layer which is in close contact with the recording layer, and a known UV-curable resin (trade name “Dicure Clear”) is applied to the reflective layer. SD 1700 ”(manufactured by Dainippon Ink & Chemicals, Inc.), spin-coated uniformly, irradiate light to form a protective layer that adheres to the reflective layer, and then adhere to the protective layer to make a polycarbonate disc. Three types of optical recording media were prepared by attaching a protective plate (diameter 12 cm, thickness 0.6 mm). Each of the optical recording media of this example has a recording capacity of more than 4 GB and uses a laser beam having a wavelength of about 65 nm to produce a large amount of document information, image information, audio information, and other digital information. Information can be written at high density. Observation with an electron microscope of the recording surface of the optical recording medium of this example, in which information was written using a semiconductor laser element with an oscillation wavelength of 658 nm, showed that a fine pit less than 1 m / pit was 1 m. It was formed at a high track density with a track pitch less than Each of the light absorbers used in this example is not only easy to handle and excellent in workability, but also applied to a substrate in a state of being dissolved in TFP, and after drying, a styryl dye or an azo-based dye. No crystals of the metal complex were deposited or the film thickness and surface of the recording layer became non-uniform. This indicates that the light absorber according to the present invention is excellent in compatibility with an organic solvent and amorphousness in a thin film state. You. Example 7: Optical recording medium

An optical recording medium was produced in the same manner as in Example 6, except that the light absorber prepared by the method of Example 4 was used and the substrate and the protective plate were changed to those made of acryl resin.

The optical recording medium of this example has a recording capacity of more than 15 GB and uses a laser beam having a wavelength of around 400 nm to enhance a large amount of document information, image information, audio information, and other digital information. Can write to density

INDUSTRIAL APPLICABILITY As described above, the present invention is based on the discovery of a novel use of an azo-based organometallic complex. When applied to styryl dyes, the lightfastness improver of the present invention containing an azo-based organometallic complex can improve lightfastness without substantially impairing the light absorption characteristics of styryl dyes, and can be used for reading light and natural light. It has the benefit of effectively suppressing unwanted changes such as degradation, fading, discoloration and denaturation of styryl dyes due to exposure to ambient light. Therefore, the lightfastness improver of the present invention has a wide variety of uses in various fields, such as optical recording media, photochemical polymerization, solar cells, optical filters, and dyeing, where styryl dyes are used. . Above all, azo-based organometallic complexes have excellent compatibility with styryl dyes in organic solvents and excellent amorphous properties in the thin film state. It has the benefit of improving the yield of the work and the application of the coating to the substrate. Using such a styryl dye as a light absorber, information is written by a single laser beam having a wavelength shorter than 100 nm. The optical recording medium of the present invention writes information with a laser beam having a wavelength of 775 or 795 nm. Compared with current optical recording media such as CD_R, it is possible to stably form fine pits with a smaller track pitch and higher density, so that character information, image information, audio information, and other digital information can be formed. It will be possible to record at an extremely large amount and high density, and as a result, there is a real benefit that the cost per bit required for information recording can be greatly reduced.

It can be said that the present invention having such remarkable effects is a significant invention that greatly contributes to the art.

Claims

The scope of the claims

1. A styryl dye lightfastness improver containing an azo organic metal complex in which one or more azo compounds are bonded to a metal atom.

2. The lightfastness improver according to claim 1, wherein the azo-based organometallic complex is represented by the general formula 1. General formula 1:

In the general formula 1, z 1 to z ₄ represent the same or different aromatic rings or hetero rings, and these aromatic rings and hetero rings may have a substituent. M represents a metal atom, and A and A ′ represent a hetero atom capable of forming a coordination bond by donating an electron pair to the metal atom M. L + represents an appropriate ion.

3. The lightfastness improver according to claim 1 or 2, wherein the metal atom is a metal element belonging to Groups 3 to 12 in the periodic table.

4. The lightfastness improver according to claim 1, wherein the azo organic metal complex is applied in an amount of 0.01 part by weight or more based on 1 part by weight of the styryl dye.

5. The lightfastness improver according to any one of claims 1 to 4, which is effective against environmental light having a wavelength of 350 to 850 nm.

6. The lightfastness improver according to any one of claims 1 to 5, A light absorber comprising a styryl dye.

7. The light absorber according to claim 6, wherein the styryl dye is represented by the general formula 2. General formula 2:

In the general formula 2, ₅ represents a heteroaromatic ring, and the heteroaromatic ring may have a substituent. Zeta ₆ represents an aromatic ring or a heteroaromatic ring, these aromatic heterocyclic rings and aromatic rings may have a substituent. R 1 represents an aliphatic hydrocarbon group, and the aliphatic hydrocarbon group may have a substituent. R ₂ represents a hydrogen atom or an appropriate substituent, and X— represents a counter ion. Υ represents a heteroatom capable of forming an onium salt with the counter ion X. When Υ is a heteroatom other than an element of Group 15 of the periodic table, R, does not exist.

8. The light absorbent according to claim 6, wherein the azo-based organometallic complex is contained in an amount of 0.01 part by weight or more based on 1 part by weight of the styryl dye.

9. The method according to claim 6, 7, or 8, comprising one or more other organic dye compounds that substantially absorb visible light, together with the styryl dye and the azo-based organometallic complex. Light absorber.

10. The light absorber according to any one of claims 6 to 9, which has sensitivity to visible light having a wavelength shorter than 700 nm in a thin film state.

11. An optical recording medium comprising the light resistance improving agent or the light absorbing agent according to any one of claims 1 to 10.

12. The optical recording medium according to claim 11, wherein a laser light having a wavelength shorter than 700 nm is used as the writing light.