JPH0818461B2 - Optical recording medium - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an optical recording medium, and more particularly to an optical recording medium used in optical disk and optical card technology and having improved recording / reproducing characteristics and storage stability.

[Conventional technology]

In general, an optical disc and an optical card have a small (for example, about 1 μ) optically detectable pit (recess) formed in a thin recording layer on a substrate in a spiral, circular, or linear track shape to provide high-density information. Can be recorded.

To write information on such a disc, a laser beam focused on the surface of the laser-sensitive layer is scanned, and pits are formed only on the surface irradiated with this laser beam, and the pits are formed in a spiral shape, a circular shape, or a straight line. It is necessary to form it in the form of a flat track.

The laser sensitive layer is capable of absorbing laser energy to form optically detectable pits.

For example, in the heat mode recording method, the laser-sensitive layer absorbs thermal energy, and small pits can be formed at the location by evaporation or melting, and in another heat mode recording method, absorption of the irradiated laser energy causes A pit having an optically detectable density difference can be formed at that location.

As an optical recording medium used in this type of optical recording / reproducing apparatus, a recording medium including a substrate, a metal reflective layer, and a recording layer containing a dye is known.

This optical recording medium is formed so that the laser light incident on the recording layer containing the dye reaches the metal reflection layer and is reflected from the metal reflection layer so that the reflected light can be easily detected. The layer is provided to compensate for the amount of reflected light that is insufficient with the recording layer alone.

However, the presence of the metal reflective layer complicates the structure of the optical recording medium and causes a high cost.

On the other hand, if the organic dye thin film is used as the recording layer having a high reflectance, the above problems can be solved.

In particular, when a polymethine dye, an azulene dye, a cyanine dye, a pyrylium dye that has a large light absorption for laser light is used as the organic dye thin film, a light absorbing / reflecting film exhibiting a metallic luster (reflectance of 10 to 50%). Thus, an optical recording medium capable of laser recording and capable of reflective reading can be obtained.

In particular, when a semiconductor laser having an oscillation wavelength of 700 to 800 nm is used as the laser light source, the size and cost of the device can be reduced.

However, the organic dye thin film generally has a problem that it is easily deteriorated by heat and light, and has a drawback that recording / reproducing characteristics and storage stability are deteriorated.

Further, the optical recording medium is recorded with a strong laser power using the same laser as described above and is reproduced with a weaker laser power. Therefore, it is necessary to have a clear threshold value for the laser power. Under the present circumstances, it is difficult to obtain the above-described clear threshold value as compared with the inorganic thin film, and the deterioration tends to occur during reproduction.

[Problems to be solved by the invention]

An object of the present invention is to provide an optical recording medium in which an organic dye thin film is provided as a recording layer on a substrate, in which the stability of the organic dye thin film against heat and light is improved, and long-term storage stability and repeated reproduction characteristics are improved. The purpose is to provide a recording medium.

Another object of the present invention is that the organic dye thin film has high sensitivity and C /
An object of the present invention is to provide an optical recording medium having excellent recording / reproducing characteristics, which has not only an N ratio (carrier / noise ratio) but also a clear threshold value for laser power.

[Means and Actions for Solving Problems]

The present invention provides an optical recording medium in which a recording layer is provided on a substrate, the recording layer comprising at least one diazulenium salt compound represented by the following general formula [I], [II] or [III] and an aminium salt compound. Alternatively, it is characterized by containing one or more diimonium salt compounds.

General formula [I] General formula (II) General formula (III) In the general formulas [I], [II] and [III], R _{1 to} R ₇ and R ′ _{1 to} R ′ ₇ are hydrogen atom, halogen atom (chlorine atom, bromine atom, iodine atom) or monovalent organic Represents a residue. The monovalent organic residue can be selected from a wide range, but particularly alkyl groups (methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, n-amyl, n-hexyl). , N-octyl, 2-
Ethylhexyl, t-octyl, etc.), alkoxy groups (methoxy, ethoxy, propoxy, butoxy, etc.),
A substituted or unsubstituted aryl group (phenyl, tolyl,
Xylyl, ethylphenyl, methoxyphenyl, ethoxyphenyl, chlorophenyl, nitrophenyl, dimethylaminophenyl, α-naphthyl, β-naphthyl, etc., and a substituted or unsubstituted aralkyl group (benzyl,
2-phenylethyl, 2-phenyl-1-methylethyl, bromobenzyl, 2-bromophenylethyl, methylbenzyl, methoxybenzyl, nitrobenzyl), acyl group (acetyl, propionyl, butyryl, valeryl, benzoyl, trioyl, naphthoyl, Phthaloyl, furoyl, etc.), substituted or unsubstituted amino group (amino, dimethylamino, diethylamino, dipropylamino, acetylamino, benzoylamino, etc.), substituted or unsubstituted styryl group (styryl, dimethylaminostyryl, diethylaminostyryl, dipropyl) Aminostyryl, methoxystyryl, ethoxystyryl, methylstyryl, etc.), nitro group, hydroxy group, carboxyl group, cyano group or substituted or unsubstituted arylazo group (phenylazo, α- Fuchiruazo, beta-naphthylazo, dimethylaminophenylazo, chlorophenyl azo, nitrophenylazo, methoxyphenylazo, etc. Toriruazo) can be exemplified.

 Also, R₁And R₂， R₂And R₃， R₃And R_Four， R_FourAnd R_Five， R_FiveAnd R₆， R₆
And R₇And R '₁And R '₂, R ′₂And R '_Three, R ′_ThreeAnd R '
_Four, R ′_FourAnd R '₅, R ′₅And R '₆, R ′₆And R '₇Union
At least one of the combinations is substituted or unsubstituted
A ring may be formed. 5 or 6 membered fused rings,
Is a condensed ring of 7-membered ring, aromatic ring (benzene, naphtha
Len, chlorobenzene, bromobenzene, methylbenze
Amine, ethylbenzene, methoxybenzene, ethoxyben
Zen, etc.), heterocycles (furan ring, benzofuran ring, pyro
Ring, thiophene ring, pyridine ring, quinoline ring, thia
Sol ring, etc.), aliphatic ring (dimethylene, trimethylene)
And tetonamethylene). Z Is anio
Represents a residue.

R _{1 to} R ₇ and R ′ _{1 to} R ′ ₇ may be the same or different.

 A represents a monovalent organic residue. Such A is a component
As specific examples of diazurhenium salt compounds included as
Are those represented by the following general formulas (1) to (11).
be able to. However, Q in the formula Is the following Azureni
Q in the formula showing the um salt nucleus The right side except for shows A
It

 Diazulenium salt nucleus (Q ) General formula (1) Where R₁~ R₇And R '₁~ R '₇Is defined above
It has the same definition as

General formula (2) In the formula, R _{1 to} R ₇ and R ′ _{1 to} R ′ ₇ have the same definition as defined above.

General formula (3) In the formula, R ″ _{1 to} R ″ ₇ have the same definitions as R _{1 to} R ₇ defined above.

 Z Represents an anion residue, for example chloride ion,
Bromide ion, iodide ion, perchlorate ion, glass
Phosphate ion, benzenesulfonate ion, P-toluene
Sulfonate ion, methyl sulfate ion, ethyl sulfate
Salt ion, propyl sulfate ion, tetrafluorophore
Urate ion, tetraphenylborate ion, hexa
Fluorophosphate ion, benzenesulfinate ion
Ion, acetate ion, trifluoroacetate ion, propionate
On-acetate ion, benzoate ion, oxalate ion
Ion, succinate ion, malonate ion, oleic acid
Salt ion, stearate ion, citrate ion,
Monohydrogen diphosphate ion, dihydrogen monophosphate ion,
Chlorochlorostannate ion, chlorosulfonate ion
Ion, fluorosulfonate ion, trifluoromethane
Sulfonate ion, hexafluoroarsenate ion,
Xafluoroantimonate ion, molybdate
On, tungstate ion, titanate ion, di
Represents anions such as ruconate.

R ₈ and R ₉ represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, an alkyl group (methyl, ethyl, propyl, butyl, etc.) or an aryl group (phenyl, tolyl, xylyl, etc.), and n is 0, 1 or Represents 2.

 General formula (4) R in the formula₁~ R₇And R '₁~ R '₇Is also defined above
Has the same definition as, and Q Diazirhenium
The salt nucleus and the diazulene salt nucleus on the right side of the formula (4) are
It may be symmetrical or asymmetrical.

 R₈， R₉And Z Is the same definition as defined above
And n represents 0, 1 or 2.

 General formula (5) General formula (6) Where R₁~ R₇, R ′₁~ R '₇, R ″₁, R ″_Three~ R ″₇,
And Z Has the same definition as defined above
It Also, Q And the above formula (6)
May be symmetric with the diazulenic salt nucleus on the right side of
Or it may be asymmetric.

 General formula (7) Where R₁~ R₇, R ′₁~ R '₇， R₈And Z Is above
It has the same definition as defined. Also, Q Indicated by
Azurenium salt nucleus and diaz on the right-hand side in formula (7) above
May or may not be symmetrical with the ren salt nucleus
Good.

A ₁ is a divalent hydrocarbon group which forms a substituted or unsubstituted 5- or 6-membered ring (for example, —CH ₂ —CH ₂ , —CH ₂ —CH ₂ —CH
_2- , -CH = CH-, etc.) and may be condensed with a 5- or 6-membered benzene ring, naphthalene ring or the like. n and m represent 1, 2 or 3.

 General formula (8) General formula (9) X in general formulas (8) and (9)₁Is pyridine, thiazo
Ru, benzothiazole, naphthothiazole, oxazo
, Benzoxazole, naphthoxazole, imida
Zole, benzimidazole, naphthimidazole, 2
-Quinoline, 4-quinoline, isoquinoline or indole
Group of non-metal atoms necessary to complete a nitrogen-containing heterocycle such as ru
Represents a halogen atom (chlorine atom
Child, bromine atom, iodine atom), alkyl group (methyl, ethyl)
, Propyl, butyl, etc.), aryl groups (phenyl,
Even if it is substituted with (tril, xylyl, etc.)
Good. R_TenIs an alkyl group (methyl, ethyl, propyl,
Butyl, etc.), substituted alkyl groups (2-hydroxyethyl)
2-methoxyethyl, 2-ethoxyethyl, 3-hi
Droxypropyl, 3-methoxypropyl, 3-etoki
Cypropyl, 3-chloropropyl, 3-bromopropyi
, 3-carboxypropyl, etc.), cyclic alkyl groups
(Cyclohexyl, cyclopropyl), allyl, aral
Kill group (benzine, 2-phenylethyl, 3-phenyl
Propyl, 4-phenylbutyl, α-naphthylmethyl,
β-naphthylmethyl), substituted aralkyl groups (methylben
Zil, ethylbenzyl, dimethylbenzyl, trimethyl
Benzyl, chlorobenzyl, bromobenzyl, etc.)
Reel group (phenyl, tolyl, xylyl, α-naphthyl
Or β-naphthyl) or a substituted aryl group (chlorophenyl)
Le, dichlorophenyl, trichlorophenyl, ethyl
Phenyl, methoxyphenyl, dimethoxyphenyl, ami
Nophenyl, nitrophenyl, hydroxyphenyl
Represents). m represents 0, 1 or 2, and R₈， R₉,
R₁₁， A₁And Z Is the same definition as defined above
Having.

 General formula (10) Where R₁₂Is a substituted or unsubstituted aryl group (phenyl
, Tolyl, xylyl, biphenyl, α-naphthyl, β
-Naphthyl, anthralyl, pyrenyl, methoxyphenyl
, Dimethoxyphenyl, trimethoxyphenyl, eth
Xyphenyl, diethoxyphenyl, chlorophenyl,
Dichlorophenyl, trichlorophenyl, bromophenyl
Le, dibromophenyl, tribromophenyl, ethyl group
Phenyl, diethylphenyl, nitrophenyl, aminop
Phenyl, dimethylaminophenyl, diethylaminophen
Nyl, dibenzylaminophenyl, dipropylaminophenyl
Phenyl, morpholinophenyl, piperidinylphenyl,
Piperazinophenyl, diphenylaminophenyl, ace
Tylaminophenyl, benzoylaminophenyl, ace
Phenyl, benzoylphenyl, cyanophenyl
Represents). Z Is the same definition as defined above
Having. Further, m represents 0, 1 or 2.

 General formula (11) Where R₁₃Is furan, thiophene, benzofuran,
Onaphthene, dibenzofuran, carbazole, phenothi
Derived from heterocycles such as azine, phenoxazine and pyridine
Represents a derived monovalent heterocyclic group, Is defined above
Has the same definition as In addition, m is 1 or 2
Represent.

 General formula (12) Where R₁₄Is an alkyl group (methyl, ethyl, propyl
Or butyl) or a substituted or unsubstituted aryl group
(Phenyl, tolyl, xylyl, biphenyl, ethyl
Phenyl, chlorophenyl, methoxyphenyl, ethoxy
Phenyl, nitrophenyl, aminophenyl, dimethyl
Aminophenyl, diethylaminophenyl, acetyl
Minophenyl, α-naphthyl, β-naphthyl, anthra
Lil, birenyl, etc.). R₁₂And Z Is before
It has the same definition as defined above. m is 1 or
Represents 2.

 General formula (13) Where X₂Is an optionally substituted pyran, thiapiran,
Lenapyran, benzopyran, benzothiapyran, benzo
Serenapyran, Naphthopyran, Naphthiapiran or Na
The following shows the atomic groups required to complete Fusselenapyran. l
Is 0 or 1. Y is a sulfur atom, an oxygen atom or se
Represents a len atom. R₁₄And R_FifteenIs a hydrogen atom (meth
, Ethyl, propyl, butyl, etc.), alkoxy groups
(Methoxy, ethoxy, propoxy, butoxy, etc.),
A substituted or unsubstituted aryl group (phenyl, tolyl,
Xylyl, chlorophenyl, biphenyl, methoxyphen
Nil), a substituted or unsubstituted styryl group (styryl)
, P-methylstyryl, o-chlorostyryl, p-meth
Substituted or unsubstituted 4-phenol.
Nyl 1,3-butadienyl group (4-phenyl 1,3-butadiene
Nil, 4- (p-methylphenyl) -1,3-budadieni
Group) or a substituted or unsubstituted heterocyclic group (quinoli
, Pyridyl, carbazolyl, furyl, etc.).
Also, R₈， R₉, m and Z Is the same as defined above
Has the definition of

Specific examples of the diazurhenium salt compound used in the present invention are listed below.

Examples of compounds represented by the general formula (1) Compound No. Examples of compounds represented by the general formula (2) Examples of compounds represented by the general formula (3) Examples of compounds represented by the general formula (4) Examples of compounds represented by the general formula (5) Examples of compounds represented by the general formula (6) Examples of compounds represented by the general formula (7) Examples of compounds represented by the general formulas (8) and (9) Examples of compounds represented by the general formula (10) Examples of compounds represented by the general formula (11) Examples of compounds represented by the general formula (12) Examples of compounds represented by the general formula (13) Such a dye not only has good solubility in an organic solvent, but also exhibits an absorption peak with a large extinction coefficient in the near-infrared region, and good properties can be obtained for optical recording media.
The present inventors have found that the recording and reproducing characteristics and the storage stability are improved when an aminium salt compound or a diimonium salt compound is contained in the recording layer in addition to the above-mentioned diazulenium salt compound.

The aminium salt compound and diimonium salt compound used in the present invention are represented by the following general formula [IV] and general formula [V], respectively.

General formula (IV) General formula [V] In the general formulas [IV] and [V], R ₁₆ is a hydrogen atom or an alkyl group (for example, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, sec-butyl group, iso- Butyl group, t-butyl group, n-amino group,
t-amyl group, n-hexyl group, n-octyl group, t-
Indicates an alkyl group octyl group and C ₉ ~ _12), yet another group, for example substituted alkyl group (e.g.,
2-hydroxyethyl group, 3-hydroxypropyl group,
4-hydroxybutyl group, 2-acetoxyethyl group, carboxymethyl group, 2-carboxyethyl group, 3-carboxypropyl group, 2-sulfoethyl group, 3-sulfopropyl group, 4-sulfobutyl group, 3-sulfatepropyl group , 4-sulfatebutyl group, N- (methylsulfonyl) -carbamylmethyl group, 3- (acetylsulfamyl) propyl group, 4- (acetylsulfamyl) butyl group, etc.), cyclic alkyl group (for example, , Cyclohexyl group), alkenyl group (vinyl group, allyl group, propenyl group, butenyl group, pentenyl group, hexenyl group,
Heptenyl group, octenyl group, dodecynyl group, prenyl group, etc.), aralkyl group (eg, benzyl group, phenethyl group, α-naphthylmethyl group, β-naphthylmethyl group, etc.), substituted aralkyl group (eg carboxybenzyl group, sulfobenzyl group) Group, hydroxybenzyl group, etc.)
Includes.

 A₂IsIs shown. X Indicates an anion.

These aminium salt compounds and diimonium salt compounds can be synthesized according to the synthetic methods disclosed in USP Nos. 3484467 and 3637769.

Next, typical examples of the aminium salt compound represented by the general formula [IV] will be given.

Next, typical examples of the diimonium salt compound represented by the general formula [V] will be given.

The optical recording medium of the present invention may have a structure as shown in FIG. 1, for example. The optical recording medium shown in FIG.
It can be formed by providing the recording layer 2 which is an organic thin film containing at least the diazurhenium salt compound and the aminium salt compound or diimonium salt compound on the substrate 1. The recording layer 2 has the above-mentioned general formulas [I] and [II].
It can be formed by applying a coating solution prepared by dissolving or mixing the compounds represented by [III], [IV] and [V] in an organic solvent.

In forming the recording layer 2, the above general formula [I] is used.
Two or more compounds represented by [II], [III], [IV] and [V] can be used in combination, and further, other dyes such as the above-mentioned general formulas [I], [II], [III] and [IV] can be used. And polymethine compounds other than the compounds of [V], azulene compounds, pyrylium compounds, squalium compounds, croconium compounds, triphenylmethane compounds, xanthene compounds, anthraquinone compounds, cyanine compounds, phthalocyanine compounds, dioxazine compounds, tetrahydrocholine compounds, triphenothiazine compounds. , Phenanthrene-based dyes, metal chelate complex-based dyes, or metals and metal compounds, such as Al, Te, Bi, Sn, In, Se, SnO, Te
It may be mixed and dispersed or laminated with O ₂ , As, Cd and the like.

Further, the compounds of the above general formulas [I] to [V] may be contained in a binder in a dispersed state or a dissolved state, for example, nitrocellulose, cellulose phosphate, cellulose sulfate, cellulose acetate, cellulose propionate, butyric acid. Cellulose, cellulose myristate, cellulose palmitate, cellulose acetate / propionate, acetic acid, cellulose butyrate, and other cellulose esters, methyl cellulose, ethyl cellulose, propyl cellulose, butyl cellulose, and other cellulose ethers, polystyrene, polyvinyl chloride, polyvinyl acetate , Polyvinyl butyral, polyvinyl acetal, polyvinyl alcohol, polyvinylpyrrolidone and other vinyl resins,
Copolymer resins such as styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-butadiene-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, polymethyl methacrylate, polymethyl acrylate, polybutyl acrylate, polyacrylic acid, polymethacrylic acid, Polyacrylamide,
Acrylic resins such as polyacrylonitrile, polyesters such as polyethylene terephthalate, poly (4,
4'-isopropylidenediphenylene-co-1,4-cyclohexylene dimethylene carbonate), poly (ethylenedioxy-3,3'-phenylene thiocarbonate), poly (4,4'-isopropylidenediphenylene carbonate) Co-terephthalate), poly (4,4'-isopropylidenediphenylene carbonate), poly (4,4'-sec)
-Butylidene diphenylene carbonate), poly (4,
4'-isopropylidene diphenylene carbonate-block-oxyethylene) and other polyarylate resins, or polyamides, polyimides, epoxy resins, phenolic resins, polyolefins such as polyethylene, polypropylene and chlorinated polyethylene. be able to.

The recording layer 2 which is an organic thin film may contain a surfactant, an antistatic agent, a stabilizer, a dispersant, a flame retardant, a lubricant, a plasticizer and the like.

The organic solvent that can be used during coating varies depending on whether it is in a dispersed state or in a dissolved state, but generally, alcohols such as methanol, ethanol, isopropanol, diacetone alcohol, and ketones such as acetone, methyl ethyl ketone, and cyclohexanone. Kind, N, N
-Dimethylformamide, amides such as N, N-dimethylacetamide, sulfoxides such as dimethyl sulfoxide, tetrahydrofuran, dioxane, ethers such as ethylene glycol monomethyl ether, esters such as methyl acetate, ethyl acetate and butyl acetate, chloroform, Aliphatic halogenated hydrocarbons such as methylene chloride, dichloroethylene, carbon tetrachloride, trichloroethylene, benzene, toluene, xylene, monochlorobenzene, dichlorobenzene aromatics, or n-hexane, cyclohexane ligroin, etc. Hydrocarbons and the like can be used.

The coating can be performed by a coating method such as a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a Meyer bar coating method, a blade coating method, a roller coating method, and a curtain coating method.

The addition amount of the aminium salt compound represented by the general formula [IV] or the diimonium salt compound represented by the general formula [V] is 1 to 60% by weight, preferably 5 to 40% by weight based on the total solid content of the recording layer 2. % Is appropriate. The dry film thickness of the recording layer 2 is 50Å to 100 μm, preferably 200Å to 1 μm.

As the substrate 1, plastics such as polyester, polycarbonate acrylic resin, polyolefin resin, phenol resin, epoxy resin, polyamide and polyimide, glass or metals can be used.

Further, the present invention can be configured to have an undercoat layer 3 and / or a protective layer 4 as shown in FIGS. 2 to 4.

The undercoat layer is provided for the purpose of improving adhesiveness, barrier against water or gas, improving storage stability of recording layer, improving reflectance, protecting substrate from solvent, forming pregroove and heat dissipation effect. To be

In addition, the protective layer is protected from scratches, dust, dirt, etc.
It is provided for the purpose of improving storage stability and reflectance of the recording layer.

Further, as another constitution of the optical recording medium according to the present invention, the recording layer 2 using two recording mediums of the same constitution shown in FIG. 1 to FIG. It may be a so-called air sandwich structure in which is disposed inside and sealed, or a so-called close contact structure (bonding structure) in which the layers are adhered via the protective layer 4.

The optical recording medium of the present invention includes an argon laser (oscillation wavelength 488 nm), a helium-neon laser (oscillation wavelength 633n).
It is also possible to record by irradiation with a gas laser such as m) or a helium-cadmium laser (oscillation wavelength 442 nm).

Recording can also be performed by irradiation with light having a wavelength half the laser light using an SHG element or the like, but preferably a laser having a wavelength of 650 nm or more, particularly a gallium-aluminum-arsenic semiconductor laser (oscillation wavelength 830 nm) A method of recording by irradiating a laser beam having an oscillation wavelength in a certain infrared region such as near infrared is suitable. Further, the laser beam described above can be used for reading. On this occasion,
Writing and reading can be performed with lasers of the same wavelength, or with lasers of different wavelengths.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1 A polymethylmethacrylate (hereinafter abbreviated as "PMMA") substrate having a diameter of 130 mmφ and a thickness of 1.2 mm was coated with an epoxy-acrylate UV-curable resin by a 2P method (photopolymer method) to a thickness of 50 μm. A pregroove is provided, and a solution prepared by dissolving the diazulenium salt compound No. (17) and the aminium salt compound No. A-9 in 1,2-dichloroethane at a weight ratio of 80:20 is applied thereto by a spinner coating method. After that, it was dried to obtain an 850Å organic thin film layer.

The optical recording medium thus prepared was mounted on a turntable, the turntable was rotated by a motor at 1800 rpm, and a semiconductor laser with an oscillation wavelength of 830 nm was used from the substrate side to a spot size of 1.5 μmφ and recording power on the organic thin film recording layer. Information is written at 6 mW and a recording frequency of 2 MHz, read at a read power of 1.0 mW, and the reproduced waveform is spectrum analyzed (scanning filter, bandwidth 30 kHz) and C
The / N ratio (carrier / noise ratio) was measured.

Next, the portion where the same recording medium was recorded under the above measurement conditions was repeated and the C / N ratio was measured after reading 10 ⁶ times.

Further, the same recording medium produced under the above conditions was 60 ° C.
Reflectivity (R (%): 830 nm measurement) and C / after being left for 2000 hours under the condition of 90% RH for environmental preservation stability test
The N ratio was measured. In addition, 1000 W / m ₂ (300
(About 900 nm) was irradiated for 70 hours with a xenon lamp, and the reflectance (R (%): 830 nm measurement) and C / N ratio after the light stability test were performed were measured. The results are shown in Table-1.

Examples 2 to 8 A recording medium was prepared in the same manner as in Example 1, except that the combination of the diazulenium salt compound (AZ) and the aminium salt compound (A) used in Example 1 was replaced with the combination shown in Table 2 below. The optical recording media of Examples 2 to 8 were used.

The optical recording media of Examples 2 to 8 were measured in the same manner as in Example 1, and the results are shown in Table 4.

Comparative Examples 1 and 2 An optical recording medium was prepared and evaluated in the same manner as in Example 1 except that the aminium salt compounds used in Examples 1 and 6 were excluded from Nos. A-9 and A-5, respectively. The results are shown in Table-4.

Examples 9-12 4 parts by weight of a mixture of a combination of a diazulenium salt compound (AZ) and an aminium salt compound (A) shown in Table 3 below, and 1 part by weight of a nitrocellulose resin (Ohaless Lacquer, manufactured by Daicel Chemical Industries, Ltd.) Was mixed with 95 parts by weight of methyl ethyl ketone by a spinner coating method to apply it to a polycarbonate substrate having a pregroove and having a diameter of 130 mmφ and a thickness of 1.2 mm to obtain an organic thin film recording layer having a dry film thickness of 950 Å.

The optical recording medium thus manufactured was measured in the same manner as in Example 1, and the results are shown in Table 4.

Examples 12 to 15 Wallet-sized 0.4 mm thick polycarbonate (hereinafter abbreviated as "PC") substrates were provided with pregrooves by a hot pressing method, and diazulenium salt compounds and aminium salts shown in Table 5 below were provided thereon. A liquid prepared by mixing the compound in diacetone alcohol was applied by the bar coating method, and then dried to form an 850Å organic thin film recording layer. Further, an optical recording medium having a close contact structure was prepared by a hot roll method and a wallet-sized 0.3 mm thick PC substrate with an ethylene-vinyl acetate dry film interposed therebetween.

The optical recording media of Examples 12 to 15 produced in this manner were treated with X.
It is mounted on the stage that is driven in the -Y direction, and the oscillation wavelength is 83
Information is written in the Y-axis direction with a spot size of 3.0 μmφ, a recording power of 4.0 mW and a recording pulse of 80 μsec on the recording layer from the PC substrate side of 0.4 mm thickness using a semiconductor laser of 0 nm, and the read power is 0.4 mW for reproduction. Contrast ratio Was measured.

Furthermore, the same recording medium produced under the above conditions was used in Example 1.
An environmental storage stability test and a light stability test were performed under the same conditions as above, and then the reflectance and the contrast ratio were measured. The results are shown in Table-6.

Examples 16 to 22 By replacing the aminium salt compound used in Example 1 with a diimonium salt compound and making the combinations shown in Table 7, recording media were prepared in the same manner as in Example 1, and Examples 16 to 22 respectively.
Optical recording medium.

The optical recording media of Examples 16 to 22 were measured in the same manner as in Example 1, and the results are shown in Table-9.

Examples 23 to 26 A recording medium was prepared in the same manner as in Example 1 except that the aminium salt compound (A) used in Example 9 was replaced with the diimonium salt compound (D) and the combinations shown in Table 8 were prepared. The optical recording media of Examples 23 to 26 were used.

The optical recording media of Examples 23 to 26 were measured in the same manner as in Example 1, and the results are shown in Table-9.

Examples 27 to 30 Recording media were prepared in the same manner as in Example 12 by using the combinations shown in Table 10 in place of the diimonium salt compound (I) in place of the aminium salt compound (A) used in Example 12, and The optical recording media of Examples 27 to 30 were used.

The optical recording media of Examples 27 to 30 were measured in the same manner as in Example 12, and the results are shown in Table-11.

Example 31 Using the optical recording medium prepared in Example 19, Example 19
In the evaluation, the recording laser power was changed from 0.5 mW to 7 mW, the C / N ratio was measured, and the threshold value was investigated. The result is shown in FIG.

Comparative Example 3 An optical recording medium was prepared and measured in the same manner as in Example 31, except that the aminium salt compound was omitted. The result is shown in FIG.

With the optical recording medium of Example 31, a clear threshold value was obtained in which recording was not performed at a low laser power of 2 mW or less.
On the other hand, in Comparative Example 3, recording was performed even at a low power of 2 mW or less, and the threshold value was not clear. This indicates that it tends to deteriorate during repeated reproduction.

Further, in Example 31, a higher C / N value was obtained than in Comparative Example 3.

〔The invention's effect〕

As is clear from the above, since the optical recording medium of the present invention contains the specific diazurhenium salt compound and the aminium salt compound or the diimonium salt compound in the recording layer, (a) high sensitivity and C / N ratio can be obtained. And a clear threshold for laser power is obtained.

(B) High stability against heat and light, excellent long-term storage stability, and little deterioration due to reproduction.

Such a remarkable effect can be achieved.

[Brief description of drawings]

1 to 4 are sectional views of optical recording media showing different embodiments of the present invention. FIG. 5 is a diagram showing recording / reproducing characteristics in one example of the present invention and one comparative example. 1 ... Substrate, 2 ... Recording layer, 3 ... Undercoat layer, 4 ... Protective layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 62-140887 (JP, A) JP 62-140888 (JP, A) JP 62-141537 (JP, A) JP 62- 141654 (JP, A) JP 62-142688 (JP, A) JP 63-309497 (JP, A)

Claims (3)

[Claims] 1. An optical recording medium having a recording layer provided on a substrate.
Where the recording layer has the following general formula [I], “II” or
One or more diazulenium salt compounds represented by [III]
Of an aminium salt compound or a diimonium salt compound
Optical recording medium containing one or more kinds
body. General formula [I]General formula [II]General formula [III](However, in the general formulas [I], [II] and [III]
, R₁~ R₇And R₁′ ~ R₇′ Is hydrogen atom, halogen source
Represents a child or a monovalent organic residue, R₁And R₂, R₂And R₃,
R₃And R_Four, R_FourAnd R_Five, R_FiveAnd R₆, R₆And R₇, R₁′ And R₂′, R₂'When
R₃′, R₃′ And R_Four′, R_Four′ And R_Five′, R_Five′ And R₆′ And R₆′
And R₇'At least one of the combinations
May form a substituted or unsubstituted fused ring. A is 1
Represents a valent organic residue, Z Represents an anion residue
You. ) 2. The aminium salt compound is represented by the following general formula [I
V] is a compound represented by Claim (1)
An optical recording medium according to the item.(However, R₁₆Represents a hydrogen atom or an alkyl group, A₂IsIs shown. X Is an anion. ) 3. The diimonium salt compound is represented by the following general formula:
A compound represented by [V].
An optical recording medium according to item (1). General formula [V](However, R in the formula₁₆And X Is the same as above)