JPH0780355B2 - Optical information recording medium - Google Patents

Description

The present invention relates to an optical information recording medium having a recording layer containing a novel dye. In particular, it relates to an optical information recording medium for recording and reproducing by using a laser beam.

[Conventional technology]

Conventionally, there is known an information recording medium for recording and reproducing information by irradiating a rotating disc-shaped information recording medium with a laser beam. As a recording layer of such a recording medium, one using a low melting point metal or a low melting point metal and a dielectric has been proposed. However, these have drawbacks such as poor storage stability, low resolution, low recording density, and high manufacturing cost. In recent years, it has been proposed and practiced to use a dye thin film capable of changing physical properties with light having a relatively long wavelength in a recording layer, but in general, a dye having an absorption band at a long wavelength has stability against heat and light. There are problems such as low,
The present situation is that a recording layer having a recording characteristic that is stable and satisfactory over a long period of time has not necessarily been developed.

[Object of the Invention]

Therefore, an object of the present invention is to provide an optical information recording medium having a dye recording layer excellent in stability that can maintain sufficient recording characteristics for a long period of time.

[Structure of Invention]

As a result of intensive studies, the present inventor has found that the dye represented by the following general formula (I) is useful in producing a stable recording material, and completed the present invention. That is, the present invention is an optical information recording medium characterized in that a dye represented by the following general formula (I) is carried on a substrate.

General formula (I) [In the formula, R ¹ represents a substituted or unsubstituted heterocyclic group,
R ² , R ⁵ and R ^{6, which} may be the same or different, each represents a hydrogen atom or a group capable of substituting it, R ³ and R ⁴
May be the same or different from each other, represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkyl group, R ⁷ and R ⁸ may be the same or different from each other, It represents a substituted or unsubstituted aryl group, an acyl group, a sulfonyl group, or an atomic group necessary for R ⁷ and R ⁸ to be linked to each other to form a 5- or 6-membered ring. R ³ and R ⁵ , R ⁴ and R ⁶ , R ⁵ and R ⁷ , R ⁶ and R ⁸ , R ⁷ and
R ⁸ may combine with each other to form a ring. Z represents an atomic group necessary for forming a benzene ring, a 5-membered or a 6-membered heterocycle. The substituted or unsubstituted heterocycle represented by R ¹ is a monocycle or a condensed heterocycle, preferably a heteroaromatic ring. Preferred heteroatoms constituting the heterocycle represented by R ¹ are B, N, O, S, P, Se and Te. The heterocycle represented by R ¹ is preferably a 5-membered or 6-membered ring, preferably CO on the carbon atom present at the position adjacent to the heteroatom.
It can be bonded to an NH-group.

Among the heterocyclic groups represented by R ¹ , particularly preferred are 1,
3-thiazole ring, 1,3,4-triazole ring, benzothiazole ring, tetrazole ring, benzimidazole ring, benzoxazole ring, 1,3,4-thiadiazole ring, 1,3,4
-Oxadiazole ring, imidazole ring, indole ring, benzoselenazole ring, pyridine ring, pyrimidine ring, 1,3,5-triazine ring and quinoline ring.

The substituent on the heterocyclic group represented by R ¹ includes a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted arylthio group, and a mercapto group. , Hydroxyl group, substituted or unsubstituted amino group (substituent is alkyl group, aryl group, acyl group, alkylsulfonyl group, arylsulfonyl group), sulfonic acid group, carboxyl group, alkyl or arylsulfonyl group, substituted or unsubstituted The ureido group, a substituted or unsubstituted carbamoyl group, a sulfamoyl group halogen atom (more preferably F, Cl), a nitro group, or a cyano group are preferable.

The compound represented by the general formula (I) includes R ¹ , R ² , R ³ , R ⁴ ,
A dimer may be formed via any group of R ⁵ , R ⁶ , R ^{7 and} R ⁸ .

The alkyl groups represented by R ⁷ or R ⁸ may be the same as or different from each other, and are alkyl groups having 1 to 18 carbon atoms (for example, methyl group, ethyl group, propyl group, i-butyl group, n-octyl group, n -Dodecyl group, n-octadecyl group, etc.)
Substituents (eg, cyano group, hydroxyl group, methoxy group, alkoxy group such as ethoxy group, aryloxy group such as phenoxy group, acetamido group, amide group such as methanesulfonamide group, chlorine atom, halogen atom such as fluorine atom) Etc.) may be included.

The aryl groups represented by R ⁷ or R ⁸ may be the same as or different from each other, and may be a substituted or unsubstituted phenyl group (eg, a substituent such as a hydroxyl group, a cyano group, a halogen atom (eg, chlorine atom, fluorine atom, etc.), carbon C 2-18 acyl group (eg acetyl group, propionyl group, stearoyl group etc.), C 1-18 sulfonyl group (eg methanesulfonyl group, ethanesulfonyl group, octanesulfonyl group etc.), C 1-18 A carbamoyl group (eg, an unsubstituted carbamoyl group, a methylcarbamoyl group, an octylcarbamoyl group), a sulfamoyl group having 1 to 18 carbon atoms (eg, an unsubstituted sulfamoyl group, a methylsulfamoyl group, a butylsulfamoyl group), An alkoxycarbonyl group having 2 to 18 carbon atoms (eg, methoxycarbonyl group, trichloro group) Ethoxycarbonyl group, decyloxycarbonyl group, etc.), C1-C18 alkoxy group (eg, methoxy group, butoxy group, pentadecyloxy group, etc.), amino group (eg, dimethylamino group, diethylamino group, dihexylamino group, etc.) Etc.) or a substituted or unsubstituted naphthyl group (the substituent is preferably the same as in the case of a phenyl group).

Preferred among the substituents represented by R ³ and R ⁴ are a hydrogen atom, a chlorine atom and a fluorine atom; a substituted or unsubstituted alkoxy group having 1 to 18 carbon atoms (for example, a methoxy group,
Ethoxy group, octoxy group, etc.), substituted or unsubstituted alkyl group (eg, methyl group, isopropyl group, 2-
Methoxyethyl group, benzyl group, etc.), and preferably R ³ and R ⁴ represent an alkyl group having 1 to 5 carbon atoms.

The ring formed by connecting R ³ and R ⁵ , and R ⁴ and R ⁶ is preferably a 5-membered or 6-membered ring, particularly an aromatic ring such as a benzene ring or a pyridine ring, an imidazole ring, a thiazole ring. And heteroaromatic rings such as pyrimidine rings are preferred.

The ring formed by connecting R ⁵ and R ⁷ and R ⁶ and R ⁸ is preferably a 5-membered or 6-membered ring.

The ring formed by connecting R ⁷ and R ⁸ is preferably a 5-membered or 6-membered ring, particularly preferably a pyrrolidine ring, a piperidine ring or a morpholine ring.

The group capable of substituting the hydrogen atom represented by R ² , R ⁵ and R ⁶ is
Halogen atom (eg, fluorine atom, chlorine atom, bromine atom, etc.), hydroxyl group, cyano group or substituted or unsubstituted alkyl group having 1 to 18 carbon atoms bonded to a benzene ring directly or through a divalent linking group (eg, (Methyl group, ethyl group, butyl group, 2-ethylhexyl group, stearyl group, etc.), or a substituted or unsubstituted phenyl group or naphthyl group having 6 to 24 carbon atoms (eg, phenyl group, naphthyl group, 3-sulfamoyl) It represents a phenyl group, 5-methanesulfonamido-1-naphthyl group or the like, and the divalent linking group is, for example, —O—, —NHCO—, —NHSO ₂ —, —NHCOO.
-, - NHCONH -, - COO -, - CO -, - SO 2 -, - NR-
(R is a hydrogen atom or a substituted or unsubstituted carbon number 1 to
Represents 18 alkyl groups. ) Etc.

Particularly preferred among the groups represented by R ² are an alkyl or aryl sulfonamide group, an acylamino group,
It is an alkyl or aryl substituted ureido group, an alkoxy or aryloxycarbonylamino group, a fluorine atom or a chlorine atom, and the preferred substitution position is the 5-position.

The ring completed by Z is a benzene ring, a 5-membered or 6-membered heterocyclic ring, and preferable heteroatoms include nitrogen, oxygen, sulfur and selenium. Particularly preferred are benzene ring and pyridine ring, and benzene ring is most preferred. Preferred heterocycles other than the pyridine ring include pyrimidine, triazole, imidazole, thiazole, selenazole, oxazole and the like.

Specific examples of the compound represented by the general formula (I) used in the present invention are shown below, but the scope of the present invention is not limited thereto.

The compound represented by the general formula (I) of the present invention is a method of condensing a dialkylaniline and 4-nitrosonaphthol in concentrated sulfuric acid, a coexistence of an α-naphthol and a p-phenylenediamine with a base and an oxidizing agent. A method of condensing below,
A method of oxidatively condensing 4-amino-1-naphthols and dialkylanilines in a sodium hypochlorite solution, p-
It can be synthesized by a method of condensing nitrosodialkylanilines and α-naphthols, for example, JP-A-50-100116, JP-A-60-32851 or Journal of Organic Chemistry (Journa).
l of Organic Chemistry) Volume 48, pp. 177-183 (19
It can be synthesized according to the method described by Fujita in 1983).

The synthesis method will be described below with reference to synthesis examples.

Synthesis Example 1 <Synthesis of Compound 31> 2- (1) obtained by heating 1-hydroxy-2-naphthalenecarboxylic acid phenyl ester and 2-amino-5-methyl-1,3,4-thiadiazole under reduced pressure. -Hydroxy-
2-naphthalene carbonamido) -5-methyl-1,3,4
-Thiadiazole 4.3 g ethanol 40 ml ethyl acetate 80
ml, an aqueous solution prepared from 11 g of sodium carbonate and 110 ml of water, and 4-diethylamino-2,6-dimethylaniline
Add 3.5 g of ammonium persulfate to 70 g with stirring.
A solution prepared by dissolving in ml of water was added dropwise over 30 minutes.

Then, after stirring for 2 hours, the ethyl acetate layer was taken out and washed with water, and ethyl acetate was distilled off. The residue was dissolved in chloroform and then cooled to obtain a compound 31 crystal.

Yield 1.2 g, melting point 181-182 ° C. The compounds shown in Table 1 were obtained in the same manner as in the above Synthesis Example except that the structures of α-naphthols and p-phenylenediamines were changed.

The indoaniline dye used in the optical recording medium of the present invention may be used alone or in combination of two or more kinds, or may be used in combination with a dye other than the indoaniline dye of the present invention. It is also effective to use various antioxidants and singlet oxygen quencher in combination for improving reading durability. Also, various resins may be used in combination.

Alternatively, durability can be increased by adding a transition metal ion to form a chelate for use. This is particularly effective when Z in the general formula (I) represents an atomic group necessary for forming a nitrogen-containing heterocycle such as a pyridine ring.

Various quenchers can be used as the quencher used in the optical recording medium of the present invention. As such a quencher, a transition metal complex that reduces regeneration deterioration and has good compatibility with a dye is preferable. In this case, preferable center metals are Ni, Co, Cu, Pd, Pt and the like.

Examples of the novel quencher include those represented by the following general formula (II) or (III).

(In the formula, [Cat ₁ ] and [Cat ₂ ] represent cations necessary for neutralizing the complex, M ₁ and M ₂ represent nickel, copper, cobalt, palladium or platinum. N is 1 Or 2.) In the compound represented by the general formula [II] or [III], the inorganic cation among the cations represented by [Cat ₁ ] or [Cat ₂ ] is an alkali metal (for example, Li , Na, K, etc.), alkaline earth metals (Mg, Ca, Ba)
Etc.) or NH ₄ ⁺ .

The organic cation may be a quaternary ammonium ion or a quaternary phosphonium ion.

Among the above cations [Cat ₁ ] and [Cat ₂ ], the following general formulas (IV-a), (IV-b) and (IV-
c), (IV-d) or (IV-e).

In the formula, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ ,
R ¹⁹ , R ²⁰ , R ²¹ and R ²² each represent a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group having 6 to 14 carbon atoms, and Z ¹ and Z ² are each Represents a group of non-metal atoms that form a 5-membered or 6-membered ring by combining with a nitrogen or phosphorus atom in each formula.

Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, n-butyl group, iso-amyl group, n-dodecyl group and n-octadecyl group. Examples of the aryl group having 6 to 14 carbon atoms include phenyl group, tolyl group, α
-A naphthyl group and the like can be mentioned.

These alkyl groups or aryl groups include cyano groups, hydroxyl groups, alkyl groups having 1 to 20 carbon atoms (eg, methyl group, ethyl group, n-butyl group, n-octyl group, etc.),
An aryl group having 6 to 14 carbon atoms (eg, phenyl group, tolyl group, α-naphthyl group, etc.), 2 to 4 carbon atoms
20 acyloxy groups (eg acetoxy group, benzoyloxy group or p-methoxybenzoyloxy group), alkoxy groups having 1 to 6 carbon atoms (eg methoxy group, ethoxy group, propoxy group, butoxy group), aryloxy groups (eg , A phenoxy group, a triloxy group, etc.), an aralkyl group (eg, a benzyl group, a phenethyl group or an anisyl group), an alkoxycarbonyl group (eg, a methoxycarbonyl group, an ethoxycarbonyl group, an n-butoxycarbonyl group, etc.),
Aryloxycarbonyl group (eg, phenoxycarbonyl group, triloxycarbonyl group, etc.), acyl group (eg, acetyl group, benzoyl group, etc.), acylamino group (eg, acetylamino group, benzoylamino group, etc.), carbamoyl group (For example, N-ethylcarbamoyl group, N-phenylcarbamoyl group, etc.),
Alkylsulfonylamino group (eg, methylsulfonylamino group, phenylsulfonylamino group, etc.), sulfamoyl group (eg, N-ethylsulfamoyl group, N-phenylsulfamoyl group, etc.), sulfonyl group (eg, mesyl) Groups, tosyl groups, etc.) and the like.

Z ¹ and Z ² represent a group of non-metal atoms necessary for forming a 5-membered ring or a 6-membered ring as described above. Examples of the 5-membered ring or 6-membered ring include a pyridine ring, an imidazole ring, a pyrrole ring, a 2-pyrroline ring, a pyrrolidine ring, a piperidine ring, a pyrazole ring, a pyrazoline ring, and an imidazoline ring. Examples of the cation represented by the general formula (IV-b) include a dodecylpyridinium group, a hexadecylpyridinium group, and a dodecylimidazolium group. General formula (IV-c)
Examples of the cation represented by: N-ethyl-N-hexadecylpiperidinium group, N-ethyl-N
Examples thereof include a dodecylpyrazolidinium group.

The above general formulas (IV-a), (IV-b), (IV-c),
Among the cations represented by (IV-d) and (IV-e), those particularly preferably used in the present invention are (IV-a), in terms of availability of production raw materials and production cost. (IV-
b), (IV-d) and (IV-e).

The types of the cations [Cat ₁ ] and [Cat ₂ ] affect the solubility of the compound represented by the general formula [II] or [III] in an organic solvent.

Generally, when the substituent bonded to the quaternary heteroatom is an alkyl group, the longer the chain length, the higher the solubility,
Especially in the case of tetraalkyl-substituted ammonium or phosphonium, this tendency is remarkable, and in the case of an ammonium cation, a cation having a total carbon number of 17 or more, and in the case of a phosphonium cation, a cation having a total carbon number of 4 or more has high solubility. give.

In the compound represented by the general formula [II] or [III], M ₁ or M ₂ is preferably in the order of nickel, cobalt, copper, palladium and platinum.

The metal complex of the general formula [II] or [III] has a three-dimensional structure having a plane four-coordinate. In the compound of the general formula [III], it is not uniquely determined whether the thioketone group is symmetrical or asymmetrical with respect to the central metal, but in the present invention, the compound of the general formula [II
I].

The compound represented by the general formula [II] or [III] can be synthesized as follows.

The compound of the general formula [II] (n = 2) is prepared by reacting disodium-1,3-dithiol-2-thione-4,5-dithiolate, which is obtained by reacting carbon disulfide with sodium, into a zinc complex. React with benzoyl chloride to give a bisbenzoyl thio form. It is obtained by decomposing this with an alkali and then reacting it with a metal salt.

The compound of the general formula [II] (n = 1) can be obtained by oxidizing the complex (n = 2) obtained above with a suitable oxidizing agent.

The compound of the general formula [III] (n = 2) is prepared by first reacting carbon disulfide with sodium to obtain disodium-1,
3-dithiol-2-thione-4,5-dithiolate
Heat to 130 ° C to disodium-1,2-dithiol-3-
Isomerized to thione-4,5-dithiolate. This is made into a zinc complex, and this is reacted with benzoyl chloride to give a bisbenzoylthio body. After decomposing this with alkali,
Obtained by reacting a metal salt.

Further, the general formula [III] (n = 1) is obtained by using the complex (n
= 2) is oxidized with a suitable oxidizing agent.

The 1,3-dithiol-2-thione-4,5-dithiolate anion, which is an intermediate for obtaining the compound of the general formula [II] or [III], can be obtained by electrochemical reaction in addition to the reduction method with Na as described above. It can also be obtained by effective reduction.

Preferred examples of the compound represented by the general formula [II] are shown below.

A synthesis example of the compound represented by the general formula (II) is shown below.

Synthesis Example 8 <Synthesis of Exemplified Compound (II-4)> (1-1) Synthesis of bis (tetraethylammonium) -bis (1,3-dithiol-2-thione-4,5-dithiolato) zinc complex.

All reaction operations were performed under an argon atmosphere. After cutting 23 g of sodium into small pieces and dispersing in 180 ml of carbon disulfide,
200 ml of dimethylformamide was slowly added dropwise to this while stirring. At this time, be careful not to generate intense heat.
After completion of the dropwise addition of dimethylformamide, the mixture was carefully heated and refluxed for 24 hours. After the reaction was completed, unreacted sodium was filtered off. Then, 50 ml of ethanol was added to the filtrate, and the mixture was stirred at room temperature for 2 hours. Carbon disulfide is distilled off from this solution at room temperature under reduced pressure. Then, 300 ml of water was slowly added dropwise, and the resulting solution was filtered.

Then, 20 g of zinc chloride was dissolved in 500 ml of methanol in advance, and 500 ml of concentrated ammonium water was added to the solution to prepare a solution, which was added to the above reaction solution (room temperature) and stirred for 5 minutes, then 53 g of tetraethylammonium bromide
When an aqueous solution in which 250 ml of water is dissolved is added, a red precipitate immediately begins to precipitate. This was filtered and air dried to obtain a zinc complex.

Synthesis of (1-2) 4,5-bis (benzoylthio) -1,3-dithiol-2-thione.

22 g of the zinc complex obtained in (1-1) is dissolved in 500 ml of acetone and filtered. While stirring the filtrate, add benzoyl chloride 15 to it.
Add 0 ml. Immediately a yellow precipitate forms. After filtration, washing with water, and air drying, 16 g of the title compound was obtained.

(1-3) Synthesis of Exemplified Compound (II-4) 9.2 g of the bis (benzoylthio) compound obtained in (1-2) is dissolved in 50 ml of methanol. Of sodium methoxide
Add 6.3 g of 28% methanol solution and stir for 10 minutes. To this solution 2.4 g of nickel chloride (hexahydrate) 50
Add the solution dissolved in ml and stir for 30 minutes at room temperature. When a solution prepared by dissolving 8.5 g of tetrabutylphosphonium bromide in 100 ml of methanol is added to this solution, a black precipitate is immediately deposited. The mixture was stirred for additional 20 minutes, filtered, washed with acetone, air-dried, and recrystallized from acetone-isopropyl alcohol to obtain the title compound. Yield 3.8g Synthesis Example 9 <
Synthesis of Exemplified Compound (II-2)> 1 g of the nickel complex obtained in (1-3) was dissolved in 60 ml of acetone, 30 ml of acetic acid was added thereto, the mixture was stirred for 3 hours, and the solvent was distilled off to deposit black crystals. did. Acetone-
Recrystallization from methanol gave the desired exemplary compound (II-
2) was obtained. Yield 0.4g, mp185 ℃ λ _max : 1125nm, ε
_max : 2.51 × 10 ⁴ (in CH ₂ Cl ₂ ) Known quenchers are described in JP-A-59-178295. The following compounds may be mentioned.

(I) Bisdithio-α-diketone system R ^{1 to} R ⁴ represent an alkyl group or an aryl group, and M is 2
Represents a valent transition metal atom.

(Ii) Bisphenyldithiol type R ⁵ and R ⁶ represent an alkyl group or a halogen atom, and M represents a divalent transition metal element.

(Iii) Acetylacetonate chelate system (iv) Dithiocarbamic acid chelate system (v) Bisphenylthiol system (vi) Thiocatechol chelate system (vii) Salicylaldehyde oxime system (viii) Thiobisphenolate chelate system (ix) Phosphonite Acid chelate type (x) Benzoate type (xi) Hindered amine type (xii) Transition metal salt In addition to these, aminium type or diimonium type compounds represented by the following formulas can be mentioned, and specific examples include IRG-002 manufactured by Nippon Kayaku Co., Ltd., IRG-003, IRG-022, IRG-033 are mentioned.

(In the formula, R represents an alkyl group or an aryl group.) In the present invention, a combination of the cation of the dye and the anion of the quencher can also be used.

The quencher is generally 0.05 to 12 per mol of the dye.
Moles, preferably 0.1 to 1.2 moles are used.

The quencher is preferably contained in the dye thin film recording layer, but may be contained in a layer different from the recording layer. If necessary, the optical recording medium of the present invention can be provided with an undercoat layer on the substrate, a protective layer on the recording layer, and a reflective layer on the substrate or on the recording layer.

Any known substrate can be used as the substrate. Typical examples thereof include glass or plastic, and as the plastic, acrylic, polycarbonate, polysulfone, polyimide, amorphous polyolefin, epoxy resin, polyester, or the like is used. Various shapes such as a disk shape, a card shape, a sheet shape, and a roll film shape are possible.

A guide groove may be formed on the glass or plastic substrate to facilitate tracking during recording. A glass binder or a plastic substrate may be provided with a plastic binder or an undercoat layer such as an inorganic oxide or an inorganic sulfide. An undercoat layer having a lower thermal conductivity than that of the substrate is preferable. It is also possible to form a so-called air sandwich structure in which two recording media face each other with the recording layers inside.

The recording layer in the present invention can be formed, for example, by the general formula (I)
A dye and a quencher represented by an organic solvent (for example, methanol, ethanol, isopropyl alcohol,
Fluorinated alcohols such as 2,2,3,3-tetrafluoropropanol, dichloromethane, dichloroethane, acetone, etc.), dissolved in a suitable binder (e.g. PVA, PVP, polyvinyl butyral, polycarbonate, nitrocellulose, if necessary) Polyvinyl formal, methyl vinyl ether, chlorinated paraffin, maleic anhydride copolymer, styrene-butadiene copolymer, xylene-based resin) is added, and this solution is applied (for example, spin-coated). It can be carried out by co-evaporating the quencher or by vacuum-depositing the dye represented by the general formula (I) and then applying the quencher. When a binder is used, the weight of the binder is preferably 0.01 to 2 times the weight of the dye. The dye of the general formula (I) can also be used as a thin film by the so-called Langmuir-Projet method.

The recording layer in the present invention is one layer or two or more layers.

An antioxidant or an anti-fading agent may be present in the recording layer or a layer adjacent thereto in order to prevent deterioration of the dye.

The thickness of the recording layer is usually 0.01 μm to 2 μm, preferably 0.1 μm.
It is in the range of 02 to 0.8 μm. In the case of reflection reading, it is particularly preferably an odd multiple of 1/4 of the laser wavelength used for reading.

When a reflective layer such as a semiconductor laser or a He-Ne laser is provided, a reflective layer is provided on the substrate and then a recording layer is provided on the reflective layer by the method as described above, or
Alternatively, there is a method of providing a recording layer on the substrate and then providing a reflective layer on the recording layer.

The reflective layer can be formed by the following method in addition to the vapor deposition method, the sputtering method, the ion plating method, and the like.

For example, a metal salt or a metal complex salt is dissolved in a water-soluble resin (PVP, PVA, etc.), and a solution containing a reducing agent is applied to the substrate and dried by heating at 50 ° C to 150 ° C, preferably 60 ° C to 100 ° C. It is formed by

The weight ratio of metal salt or metal complex salt to resin is 0.1.
-10 is preferably 0.5-1.5. At this time, the thickness of the recording layer is suitably in the range of 0.01 to 0.1 μm for the metal particle reflection layer and 0.01 to 1 μm for the light absorption layer.

As the metal salt or metal complex salt, silver nitrate, silver cyanide potassium, potassium gold cyanide, silver ammine complex, silver cyan complex, gold salt or gold cyan complex can be used. As a reducing agent, formalin, poxalic acid, pivalate, a reducing agent,
Hypophosphite, sodium borohydride, dimethylamine borane and the like can be used. The reducing agent can be used in an amount of 0.2 to 10 mol, preferably 0.5 to 4 mol, per 1 mol of the metal salt or metal complex salt.

In the optical recording medium of the present invention, information recording is performed by irradiating a recording layer with a spot-like high energy beam such as a laser (for example, a semiconductor laser, a He-Ne laser) through the substrate or from the side opposite to the substrate. , The light absorbed in the recording layer is converted into heat, and pits (holes) are formed in the recording layer
Is formed.

Information is read by irradiating a laser beam with a low output which is equal to or lower than a threshold energy for recording and detecting a change in reflected light amount or transmitted light amount in a pit portion and a portion where no pit is formed.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 Dyes, quenchers and, in some cases, binders shown in Table 2 were dissolved in a mixed solvent of methanol-methylethylketone-dichloroethane in an appropriate ratio and surface-hardened with grooves (1.6 μ pitch, depth 750Å). ) A polycarbonate substrate was coated with a spinner to a thickness of 0.1 μm and dried. The weight ratio of dye to quencher is 3:
1. When using a binder, the weight of the binder was 1/5 of the dye.

The evaluation conditions were as follows.

(Recording and reproducing) Laser: Semiconductor laser (GaAlAs) Laser wavelength: 780nm Laser beam diameter: 1.6μm Linear velocity: 5m / s Recording power: 8mW Recording frequency: 2.5MHz Recording duty: 50% Reproducing power: 0.4mW ( Evaluation of reproduction deterioration) Reproduction power: 1.0mW Number of reproduction times: 10 ⁵ times (Evaluation of deterioration during storage) Storage temperature and humidity: 60 ℃ 90% RH Storage time: 30 days Comparative dyes represented by A and B in Table 2 have the following structural formulas.

[Effects of the Invention] From the results of Table 2, the optical information recording medium of the present invention has sufficient recording characteristics with high C / N, and has high stability for long-term storage or long-term reading. Is clear.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-181381 (JP, A) JP-A-62-231795 (JP, A) JP-A-63-3062 (JP, A)

Claims (2)

[Claims] 1. An optical information recording medium for recording, reproducing and erasing with a laser beam, characterized in that a substrate carries a dye represented by the following general formula (I). recoding media. General formula (I) [In the formula, R ¹ represents a substituted or unsubstituted heterocyclic group,
R ² , R ⁵ and R ^{6, which} may be the same or different, each represents a hydrogen atom or a group capable of substituting it, R ³ and R ⁴
May be the same or different from each other, represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkyl group, R ⁷ and R ⁸ may be the same or different from each other, It represents a substituted or unsubstituted aryl group, an acyl group, a sulfonyl group, or an atomic group necessary for R ⁷ and R ⁸ to be linked to each other to form a 5- or 6-membered ring. R ³ and R ⁵ , R ⁴ and R ⁶ , R ⁵ and R ⁷ , R ⁶ and R ⁸ , R ⁷ and
R ⁸ may combine with each other to form a ring. Z represents an atomic group necessary for forming a benzene ring, a 5-membered or a 6-membered heterocycle. ] 2. The optical information recording medium according to claim 1, wherein the dye represented by the general formula (I) and a singlet oxygen quencher are supported on the substrate.