JP2003127542A - Optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dye usable in an optical recording medium especially fitted to the recording regeneration due to semiconductor laser with a short wavelength. SOLUTION: In the optical recording medium wherein a recording layer possible in the recording and/or regeneration of data due to laser is provided on a substrate, the recording layer contains a carbostyryl compound or a 1,8- naphthyridine compound represented by formula (1) (wherein, X is a nitrogen atom or C-R6 , R1 is an arbitrary substituent and R2 , R3 , R4 , R5 , R6 , R7 and R8 are each independently a hydrogen atom or an arbitrary substituent and two adjacent groups among R2 -R8 may be bonded to form a ring).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a write-once type optical recording medium using an organic dye in a recording layer, and more particularly to a write-once type optical recording medium compatible with a blue laser.

[0002]

2. Description of the Related Art In recent years, semiconductor lasers with a short oscillation wavelength have been developed, and the wavelengths of lasers used in the past 78
There is a demand for a high-density recordable / reproducible optical recording medium using laser light having a wavelength shorter than 0 nm and 830 nm. Conventionally proposed optical recording media include magneto-optical recording media,
There are phase change recording media, chalcogen oxide optical recording media, organic dye-based optical recording media, and the like. Among them, the organic dye-based optical recording media are low in cost and easy to manufacture. Is considered to have an advantage.

At present, as the organic dye-based optical recording medium, a writable compact disc (CD-R) of a type in which a metal layer having a high reflectance is laminated on the organic dye layer is mass-produced and widely known. , A high-density organic dye-based optical recording medium for recording with a red semiconductor laser having a shorter wavelength than the laser used for recording / reproducing of this CD-R (DVD-
R) has also been developed and put into practical use. However, as laser oscillation of shorter wavelength becomes possible, laser of shorter wavelength than that of DVD-R, that is, blue semiconductor laser (wavelength 350 nm to 5 nm, is aimed at further higher density in the future.
The need for optical recording media capable of recording and reproducing at 30 nm) will increase.

[0004]

In general, an optical recording medium used as a CD-R or a DVD-R has a problem that when recorded and reproduced by a blue semiconductor laser having a short wavelength, the reflectance is low and recording and reproduction cannot be performed. Have For such a problem, for example, Japanese Patent Application Laid-Open No. 2001-96918 discloses an optical recording medium having a recording layer containing a carbostyryl compound having an amino group at the 7-position. However, according to the study by the present inventors, Japanese Unexamined Patent Application Publication No.
It was found that when the carbostyryl compound described in Japanese Patent Application Laid-Open No. 001-96918 is used as the recording layer, crystallization occurs during film formation and sufficient reflectance cannot be obtained as the recording layer. As a result of earnest studies to solve this problem, it was found that a good recording layer free from crystallization can be obtained by using a carbostyryl compound having a specific structure as the recording layer. An object of the present invention is to provide an organic dye-based optical recording medium that can be recorded and reproduced by a blue semiconductor laser.

[0005]

As a result of various investigations by the present inventors on organic dyes having high sensitivity to blue semiconductor lasers, a carbostyril derivative or a 1,8-naphthyridine compound represented by a specific structural formula The present invention has been achieved by knowing that it can be used for a recording layer of an optical recording medium corresponding to a blue semiconductor laser.

That is, the gist of the present invention is an optical recording medium in which a recording layer capable of recording and / or reproducing information by a laser is provided on a substrate, and the recording layer has the following general formula [I]. A carbostyril compound or 1,
An optical recording medium is characterized by containing an 8-naphthyridine compound.

[0007]

[Chemical 2]

(In the formula, X represents a nitrogen atom or C—R ₆ , R ₁ represents an optional substituent, R ₂ , R ₃ , R ₄ , R ₅ ,
R ₆ , R ₇ and R ₈ each independently represent a hydrogen atom or any substituent. Further, adjacent _{two of} R _{2 to} R ₈
May combine with each other to form a ring. )

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
It The compound of the general formula [I] used in the present invention is
Has appropriate absorption in the blue light wavelength range of 350 to 530 nm
However, it is a dye suitable for recording with blue laser light. The above
In the general formula (1), R₁Is any substituent,
Among these, the following are exemplified as preferable substituents.
Be done. Methyl, ethyl, propyl, isopropyl
Group, n-butyl group, sec-butyl group, tert-butyl group, n-to
Linear or branched alkyl having 1 to 18 carbon atoms such as butyl group
Group; cyclopropyl group, cyclopentyl group, cyclohexyl
Cyclor having 3 to 18 carbon atoms such as syl group and adamantyl group
Alkyl group; vinyl group, propenyl group, hexenyl group, etc.
A straight-chain or branched alkenyl group having 2 to 18 carbon atoms; cyclo
3 to 18 carbon atoms such as pentenyl group and cyclohexenyl group
Cycloalkenyl group; 2-thienyl group, 2-pyridyl group,
Furyl group, thiazolyl group, benzothiazolyl group, morpho
Rino group, pyrrolidinyl group, tetrahydrothiophenedio
Saturated or unsaturated heterocyclic group such as quiside group; phenyl
6 carbon atoms, such as rulyl group, tolyl group, xylyl group, mesityl group
~ 18 aryl groups; charcoal such as benzyl and phenethyl groups
Aralkyl group having a prime number of 7 to 20; acetyl group, propioni
Group, butyryl group, isobutyryl group, valeryl group, iso
Linear or branched acyl having 2 to 18 carbon atoms such as valeryl group
Groups and the like. R₂~ R₈The substituent represented by
The following is exemplified. Hydrogen atom; methyl group, d
Cyl group, propyl group, isopropyl group, n-butyl group, se
Number of carbon atoms such as c-butyl group, tert-butyl group, n-heptyl group
1-18 linear or branched alkyl groups; cyclopropyl
Group, cyclopentyl group, cyclohexyl group, adamantchi
A cycloalkyl group having 3 to 18 carbon atoms such as a vinyl group; vinyl
Group, propenyl group, hexenyl group and the like having 2 to 18 carbon atoms
Linear or branched alkenyl group; cyclopentenyl group,
Cycloalkenyl having 3 to 18 carbon atoms such as chlorhexenyl group
Group; 2-thienyl group, 2-pyridyl group, furyl group, thiazo
Ryl group, benzothiazolyl group, morpholino group, pyrrolidi
Nyl group, tetrahydrothiophene dioxide group, etc.
A saturated or unsaturated heterocyclic group; a phenyl group, a tolyl group,
Aryl having 6 to 18 carbon atoms such as xylyl group and mesityl group
Group; benzyl group, phenethyl group and the like, having 7 to 20 carbon atoms
Ralalkyl group; acetyl group, propionyl group, butyryl
Group, isobutyryl group, valeryl group, isovaleryl group, etc.
A linear or branched acyl group having 2 to 18 carbon atoms; methoxy
Group, ethoxy group, n-propoxy group, isopropoxy group,
n-butoxy group, sec-butoxy group, tert-butoxy group, etc.
A straight-chain or branched alkoxy group having 1 to 18 carbon atoms;
Penenyloxy group, butenyloxy group, pentenyloxy
A linear or branched alkenyl group having 3 to 18 carbon atoms such as a group
Xy group; methylthio group, ethylthio group, n-propylthio group
Group, n-butylthio group, sec-butylthio group, tert-butyl
Linear or branched alkyl having 1 to 18 carbon atoms such as thio group
Thio group; halogen such as fluorine atom, chlorine atom, bromine atom
Atom; nitro group; cyano group; hydroxy group; formyl
Group; sulfonic acid group; carboxyl group; -OCOR₉Table
Acryloxy group: -NR_TenR₁₁Amino represented by
Group; -NHCOR₁₂An acylamino group represented by: -NH
COOR ₁₃Carbamate group represented by: -NHSO₂R
₁₄A sulfonamide group represented by: -COOR₁₅Represented by
Carboxylate group; -CONR₁₆R₁₇Represented by
Carbamoyl group; -SO₂NR₁₈R₁₉Sulf represented by
Amoyl group; -SO₃R₂₀Sulfonic acid ester represented by
And the like.

The substitution positions are not particularly limited, and a plurality of substitution positions may be used.
When it has a substituent of, it may be the same or different. Also
R₂~ R₈Of two adjacent rings forming a ring
Is the quinoline ring, which is the basic skeleton, and 1,8-naphthyridine.
A saturated or unsaturated hydrocarbon ring or ring fused to a ring
Elementary ring, R₇And R₈Formed with a nitrogen atom by
Groups, nitrogen-containing heterocycles such as pyrrolidinyl groups, and oxygen atoms
A morpholinyl group containing R, or R ₇And R₈, R₇And R₆,
Or R₈And R_FiveThe julolidine ring, etc.
Can be mentioned. Even if these rings have further substituents,
good.

Examples of such a ring include a structure in which a hydrogen atom on the nitrogen atom adjacent to the carbonyl group in the following structure is substituted with an arbitrary substituent.

[0012]

[Chemical 3]

Although not described in the above structural formula, the ring formed by combining two adjacent R _{2 to} R ₈ in each compound may have a substituent. R _{9 to} R ₂₀ are each a hydrogen atom, an optionally substituted linear, branched or cyclic alkyl group, an optionally substituted linear, branched or cyclic alkenyl group, an optionally substituted aryl group, or a substituted Represents an aralkyl group which may be substituted. Also, R ₁
The alkyl group, alkenyl group, aryl group and heterocyclic group contained in the groups represented by R ₂₀ to R ₂₀ may be further substituted. As the substituent in this case, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group and the like having 1 to 1 carbon atoms.
10 alkoxy group; methoxymethoxy group, ethoxymethoxy group, propoxymethoxy group, ethoxyethoxy group, propoxyethoxy group, methoxybutoxy group and other alkoxyalkoxy groups having 2 to 12 carbon atoms; methoxymethoxymethoxy group, methoxymethoxyethoxy group, Methoxyethoxymethoxy group, methoxymethoxyethoxy group,
C3 to C15 alkoxyalkoxyalkoxy group such as ethoxyethoxymethoxy group; allyloxy group; C6 to C12 aryl group such as phenyl group, tolyl group, xylyl group (even if these are further substituted with a substituent. An aryloxy group having 6 to 12 carbon atoms such as phenoxy group, tolyloxy group, xylyloxy group and naphthyloxy group; alkenyloxy group having 2 to 12 carbon atoms such as allyloxy group and vinyloxy group; acetyl group, propionyl group An acyl group such as; a cyano group; a nitro group; a hydroxyl group; a tetrahydrofuryl group; an amino group; an N, N-dimethylamino group, an N, N-diethylamino group, etc., having 1 carbon atom
Alkylamino group of 10; alkylsulfonylamino group having 1 to 6 carbon atoms such as methylsulfonylamino group, ethylsulfonylamino group, n-propylsulfonylamino group; halogen atom such as fluorine atom, chlorine atom, bromine atom; methoxy Carbonyl group, ethoxycarbonyl group, n-
C2-C7 alkoxycarbonyl groups such as propoxycarbonyl group, isopropoxycarbonyl group, n-butoxycarbonyl; methylcarbonyloxy group, ethylcarbonyloxy group, n-propylcarbonyloxy group, isopropylcarbonyloxy group, n-butyl C2-C7 alkylcarbonyloxy group such as carbonyloxy group; methoxycarbonyloxy group, ethoxycarbonyloxy group, n-propoxycarbonyloxy group, isopropoxycarbonyloxy group, n-butoxycarbonyloxy group, etc. 2 carbon atoms ~ 7 alkoxycarbonyloxy groups and the like are mentioned.

Substituents R ₂ , R _{4 of} the carbostyril compound,
R ₅ and R ₆ are preferably hydrogen atom, optionally substituted alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, aralkyl group, alkoxy group, alkylthio group, alkenyloxy group, aryl group. , Saturated or unsaturated heterocyclic group, halogen atom, nitro group, cyano group, formyl group, hydroxy group, carboxyl group, sulfonic acid group, amino group, acylamino group, carbamate group, sulfonamide group, carbamoyl group, carboxylic acid It is an ester group, a sulfamoyl group, a sulfonic acid ester group, or a case where adjacent _{two of} R _{2 to} R ₆ are bonded to each other to form a saturated or unsaturated hydrocarbon ring or heterocycle.

More preferred are hydrogen atom, optionally substituted alkyl group, alkenyl group, aralkyl group, alkoxy group, alkylthio group, aryl group, saturated or unsaturated heterocyclic group, halogen atom, Nitro group,
Cyano group, hydroxy group, carboxyl group, amino group,
Acylamino group, carbamate group, sulfonic acid amide group, carbamoyl group, carboxylic acid ester group,
Alternatively, _two adjacent R _{2 to} R ₆ are bonded to each other to form 5 to 6
This is the case of forming a saturated hydrocarbon ring of a member ring or a saturated heterocycle.

Particularly preferably, a hydrogen atom and a carbon number of 1 to 6 are used.
Alkyl group, C6-18 aryl group, C7
To 18 aralkyl groups, 2 to 18 carbon linear or branched alkenyl groups, 1 to 6 carbon alkoxy groups, 1 to 6 carbon fluoroalkyl groups, 1 to 6 carbon fluoroalkoxy groups, and 8 carbon atoms 1 to 6 fluoroalkylthio groups, halogen atoms, nitro groups, cyano groups, substituted amino groups, acyl groups, carboxylic acid ester groups and the like can be mentioned, with a hydrogen atom and an alkyl group having 1 to 6 carbon atoms being most preferred. Most preferably, R ₄ and R ₆ are hydrogen atoms,
Compounds in which R ₂ and R ₅ are any of the groups described above. R ₃ , R ₇ and R ₈ are preferably any substituents other than hydrogen atom in order to have an absorption spectrum suitable for recording with a blue laser, and more preferably R ₃ has a substituent. Optionally substituted alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkoxy group, alkylthio group, aralkyl group, alkenyloxy group, aryl group, saturated or unsaturated heterocyclic group, halogen atom, nitro group, cyano Group, formyl group,
A group selected from a hydroxy group, a carboxyl group, a sulfonic acid group, an amino group, an acylamino group, a carbamate group, a sulfonamide group, a carbamoyl group, a carboxylic acid ester group, a sulfamoyl group and a sulfonic acid ester group, and R ₇ and R ₈ Are each independently an alkyl group, an alkenyl group, an aralkyl group, or an acyl group which may have a substituent, or R ₇ and R ₈ are not bonded to each other, and R ₇ and R ₆ , and R ₈ and A ring formed by combining at least one of R _{5 s} .

More preferably, R ₇ and R ₈ are linear or branched alkyl groups having 1 to 6 carbon atoms, and _{7 to} 18 carbon atoms.
Is an aralkyl group, a linear or branched alkenyl group having 2 to 18 carbon atoms, an acyl group, or a saturated hydrocarbon ring or saturated heterocycle formed by combining R ₇ and R ₆ or R ₈ and R ₅ . Among them, particularly preferable is a hydrogen atom and a carbon number of 1
6 is a linear or branched alkyl group of 6 or a saturated hydrocarbon ring condensed with adjacent substituents which may have a substituent. The molecular weight of the compound represented by the general formula [I] is preferably 2,000 or less, more preferably 1,
It is 000 or less. Specific examples of the compound represented by the general formula [I] include, but are not limited to, the followings.

[0018]

[Chemical 4]

[0019]

[Chemical 5]

[0020]

[Chemical 6]

[0021]

[Chemical 7]

[0022]

[Chemical 8]

[0023]

[Chemical 9]

[0024]

[Chemical 10]

[0025]

[Chemical 11]

[0026]

[Chemical 12]

[0027]

[Chemical 13]

The dyes of the present invention are extremely useful as dyes for use in the recording layer of an optical recording medium, because they are excellent in thin film forming properties when forming a recording layer from a solution containing the dye. Is. In addition, the dye of the present invention has a recording layer containing the dye, which has absorption of intensity suitable for recording / reproduction by laser light in a shorter wavelength region (350 nm to 530 nm). It is extremely useful as a dye for use in an optical recording medium for reproduction.

The optical recording medium of the present invention basically comprises a substrate and a recording layer containing the above-mentioned compound, and if necessary, an undercoat layer, a metal reflection layer and a protective layer may be formed on the substrate. You may provide a layer etc. As an example of a preferred layer structure, a recording layer is provided on a substrate, and a medium having a high reflectance in which a metal reflecting layer such as gold, silver or aluminum and a protective layer are further provided on the recording layer, or gold on the substrate, A medium having a high reflectance, in which a metal reflective layer such as silver or aluminum is provided and a protective layer is further provided on the metal reflective layer, may be mentioned.

The optical recording medium of the present invention will be described below by taking the medium having this structure as an example. The material of the substrate in the optical recording medium of the present invention may basically be transparent at the wavelengths of recording light and reproducing light. Such materials include, for example, acrylic resin, methacrylic resin, polycarbonate resin, polyolefin resin (particularly amorphous polyolefin), polyester resin, polystyrene resin, epoxy resin, or other resin, or glass. It is possible to use, for example, a glass provided with a resin layer made of a radiation curable resin such as a photocurable resin.

Injection-molded polycarbonate is preferable from the viewpoints of high productivity, cost, resistance to moisture absorption and the like. chemical resistance,
From the viewpoint of moisture absorption resistance, amorphous polyolefin is preferable. A glass substrate is preferable from the viewpoint of high-speed response. A resin substrate or resin layer may be provided in contact with the recording layer, and a guide groove or pit for recording / reproducing light may be provided on the resin substrate or resin layer. If the guide groove is spiral,
The groove pitch is preferably about 0.2 to 1.2 μm. A recording layer containing the compound of the present invention is formed on a substrate, or on the surface of which a subbing layer or the like is provided, if necessary.

As the film forming method of the recording layer, a vacuum vapor deposition method,
Sputtering method, doctor blade method, casting method,
Examples of commonly used thin film forming methods include spin coating and dipping. The spin coating method is preferable in terms of mass productivity and cost. Further, from the viewpoint that a recording layer having a uniform thickness can be obtained, the vacuum vapor deposition method or the like is preferable to the coating method.

In the case of film formation by the spin coating method, the rotation speed is preferably 500 to 15000 rpm, and after spin coating, treatment such as heating or applying to solvent vapor may be performed depending on the case. The coating solvent for forming the recording layer by a coating method such as a doctor blade method, a casting method, a spin coating method, or a dipping method is not particularly limited as long as it does not attack the substrate. For example, a ketone alcohol solvent such as diacetone alcohol and 3-hydroxy-3-methyl-2-butanone; a cellosolve solvent such as methyl cellosolve and ethyl cellosolve; a chain hydrocarbon solvent such as n-hexane and n-octane Cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane,
Cyclic hydrocarbon solvents such as n-butylcyclohexane, tert-butylcyclohexane, cyclooctane; perfluoroalkyl alcohol solvents such as tetrafluoropropanol, octafluoropentanol, hexafluorobutanol; methyl lactate, ethyl lactate, methyl isobutyrate And other hydroxycarboxylic acid ester-based solvents.

In the case of the vacuum vapor deposition method, for example, the compound of the present invention and, if necessary, other recording layer components such as other dyes and various additives are put in a crucible installed in the vacuum container, and the inside of the vacuum container is filled. After evacuating to about 10 ^-2 to 10 ^-5 Pa with an appropriate vacuum pump, the crucible is heated to evaporate the components of the recording layer,
A recording layer is formed by vapor deposition on a substrate placed facing the crucible. The recording layer is a transition metal chelate compound (eg, acetylacetonate chelate, bisphenyldithiol, salicylaldehyde oxime, bisdithio-α-diketone, etc.) as a singlet oxygen quencher for the purpose of improving stability and light resistance of the recording layer. ) Etc.,
In order to improve the recording sensitivity, a recording sensitivity improving agent such as a metal compound may be contained. Here, the metal-based compound means that a metal such as a transition metal is contained in the compound in the form of an atom, an ion, a cluster, etc., for example, an ethylenediamine-based complex, an azomethine-based complex, a phenylhydroxyamine-based complex, a phenanthroline-based complex, Organometallic compounds such as dihydroxyazobenzene-based complexes, dioxime-based complexes, nitrosoaminophenol-based complexes, pyridyltriazine-based complexes, acetylacetonate-based complexes, metallocene-based complexes, and porphyrin-based complexes are mentioned. The metal atom is not particularly limited, but a transition metal is preferable. Furthermore, dyes of other systems can be used in combination, if necessary. The other type of dye may be any dye having a suitable absorption mainly in the laser wavelength range for recording,
There is no particular limitation. In addition, near-infrared lasers with a wavelength selected from 770 to 830 nm such as CD-R and 620 to 69 such as DVD-R.
A dye suitable for recording with a red laser selected from 0 nm can be used together to provide an optical recording medium compatible with recording by laser light in a plurality of wavelength regions. Other types of dyes include metal-containing azo dyes, phthalocyanine dyes, naphthalocyanine dyes, cyanine dyes, azo dyes,
Squarylium dye, metal-containing indoaniline dye,
Triarylmethane dyes, merocyanine dyes, azurenium dyes, naphthoquinone dyes, anthraquinone dyes, indophenol dyes, xanthene dyes,
Examples include oxazine dyes and pyrylium dyes.
Further, if necessary, a binder, a leveling agent, a defoaming agent and the like can be used in combination. Preferred binders include polyvinyl alcohol, polyvinylpyrrolidone, nitrocellulose, cellulose acetate, ketone resins, acrylic resins, polystyrene resins, urethane resins, polyvinyl butyral, polycarbonate, polyolefins and the like.

The film thickness of the recording layer is not particularly limited because the suitable film thickness depends on the recording method etc.
50 to 300 nm. A reflective layer may be formed on the recording layer, and the thickness thereof is preferably 50 to 300 nm. The material of the reflective layer has a sufficiently high reflectance at the wavelength of the reproduction light, for example, Au, Al, Ag, Cu, Ti, Cr, Ni, P
The metals t, Ta, Cr and Pd can be used alone or as an alloy. Among these, Au, Al and Ag have high reflectance and are suitable as materials for the reflective layer. In addition to containing these as main components, the following may be included. For example, M
g, Se, Hf, V, Nb, Ru, W, Mn, Re, Fe, Co, Rh, I
r, Cu, Zn, Cd, Ga, In, Si, Ge, Te, Pb, Po, Sn, Bi
Metals and semi-metals such as Above all
A material containing Ag as a main component is particularly preferable in that the cost is low, a high reflectance is likely to be obtained, and when a print receiving layer to be described later is provided, a white background and a beautiful one are obtained. Here, the main component means one having a content rate of 50% or more. It is also possible to stack a low refractive index thin film and a high refractive index thin film alternately with a material other than metal to form a multilayer film and use it as a reflective layer.

As a method of forming the reflective layer, for example,
The sputtering method, the ion plating method, the chemical vapor deposition method, the vacuum vapor deposition method and the like can be mentioned. Further, a known inorganic or organic intermediate layer or adhesive layer may be provided on the substrate or below the reflective layer in order to improve reflectance, recording characteristics, adhesion, and the like. The material of the protective layer formed on the reflective layer is not particularly limited as long as it protects the reflective layer from external force. As a material of the organic substance, a thermoplastic resin,
A thermosetting resin, an electron beam curable resin, a UV curable resin, etc. can be mentioned. Further, as the inorganic substance, SiO ₂ ,
_{Si 3 N 4, MgF 2,} SnO 2 and the like. A thermoplastic resin, a thermosetting resin, etc. can be formed by dissolving in a suitable solvent, applying a coating solution, and drying. UV
The curable resin can be formed as it is or by dissolving it in an appropriate solvent to prepare a coating liquid, applying the coating liquid, and irradiating with UV light to cure the coating liquid.
As the UV curable resin, for example, an acrylate resin such as urethane acrylate, epoxy acrylate, polyester acrylate can be used. These materials may be used alone or as a mixture, or 1
You may use not only a layer but a multilayer film. As the method of forming the protective layer, a coating method such as a spin coating method or a casting method, a sputtering method, a chemical vapor deposition method, or the like is used as in the recording layer, and the spin coating method is preferable among them.

The thickness of the protective layer is generally in the range of 0.1 to 100 μm, but in the present invention, it is preferably 3 to 30 μm. The above description has been given by taking an example of an optical recording medium having a basic layer structure in which a substrate / recording layer / reflection layer / protective layer are laminated in this order and recording / reproducing is performed by laser light irradiated through the substrate. As long as the characteristics of the present invention are not impaired, any layer may be provided between these layers. Further, a substrate may be further bonded on the protective layer or on the reflective layer without providing the protective layer via an adhesive layer or the like. The substrate may be the substrate itself without any layer, or may have any layer on the bonding surface or the opposite surface. A protective layer and / or a reflective layer are opposed to each other, and at least two substrates having a recording layer are opposed to each other,
It may be an optical recording medium capable of double-sided recording / reproduction. By the way, as one means for increasing the recording density of the optical recording medium, it has been proposed to increase the numerical aperture of the objective lens to minimize the light spot condensed on the information recording surface. Increasing the numerical aperture increases the aberration of the focused light spot due to the influence of the warp of the disc,
There is a problem that a good recording / reproducing signal cannot be stably obtained. In order to reduce the above-mentioned aberration generated by the warp of the medium, for example, the thickness of the transparent substrate through which the recording / reproducing laser beam passes is reduced to about 0.1 mm, or the substrate / reflection layer / recording is performed. Recording / reproduction is preferably performed through a protective layer on an optical recording medium in which layers / protective coating are sequentially laminated. This protective film may be formed by adhering a film or sheet in the form of an adhesive, or may be formed by applying a coating liquid for film formation as in the case of the above-mentioned protective layer. Any layer may be provided between each of the above layers as long as the characteristics of the present invention are not impaired. In any of the media laminated in any of the above order, a print receiver capable of printing (printing) on a surface other than the incident surface of the recording / reproducing light by various printers such as inkjet, thermal transfer, or various writing instruments, if necessary. Layers may be provided. The laser light used for the optical recording medium of the present invention has a shorter wavelength for high density recording, but is preferably 350 to 530 nm. Typical examples of such laser light, the central wavelength 405nm, 410nm,
Laser light of 515 nm can be mentioned.

An example of the laser light in the wavelength range of 350 to 530 nm can be obtained by using a high-power semiconductor laser of 405 nm, 410 nm blue or 515 nm blue-green. A semiconductor laser capable of continuous oscillation with an oscillation wavelength of 740 to 960 nm, or (b) excited by a semiconductor laser and having a fundamental oscillation wavelength of 740 to 960 nm.
It can also be obtained by wavelength-converting any of the solid-state lasers capable of continuous oscillation by a second harmonic generation element (SHG). Any SHG may be used as long as it is a piezo element lacking inversion symmetry.
P, ADP, BNN, KN, LBO, compound semiconductors and the like are preferable. As a concrete example of the second harmonic, in the case of a semiconductor laser having a fundamental oscillation wavelength of 860 nm, its overtone is 430 nm, and in the case of a solid-state laser excited by a semiconductor laser, Cr-doped LiSrAlF ₆ crystal (fundamental oscillation wavelength of 860 nm). 430nm of the harmonic wave from is mentioned. Recording on the optical recording medium of the present invention obtained as described above is performed by irradiating a recording layer provided on both sides or one side of the substrate with a laser beam focused to about 0.4 to 0.6 μm. In the portion irradiated with laser light, thermal deformation of the recording layer such as decomposition, heat generation, and dissolution occurs due to absorption of laser light energy, and optical characteristics change.

The recorded information is reproduced by reading the difference in reflectance between the portion where the change in the optical characteristics is caused and the portion where the change in the optical characteristic is not caused by the laser light.

[0040]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples as long as the gist thereof is not exceeded. [Synthesis Method of Compound] As for the synthesis method of 7-amino-substituted carbostyril, a plurality of synthesis methods have been reported so far.
As a general production method, a method of cyclizing an m-phenylenediamine derivative and a β-ketoester derivative as shown in the following Chemical Formula 10 and then performing an N alkylation reaction can be mentioned (ref. JOC56,3 ( 1991) 980, J.Med.Chem.31,7
(1988) 1347, J. Med. Chem. 41, 4 (1998) 623). These reactions can also be applied to the synthesis of 1,8-naphthyridine.

[0041]

[Chemical 14]

Regarding the method for synthesizing the 7-acylamino compound, it has been reported that, for example, the acetamide compound can be synthesized by stirring 7-aminocarbostyryl in acetic anhydride in the presence of sulfuric acid (J. Chem. Eng. data.1
3,3 (1968) 440). Example 1

[0043]

[Chemical 15]

N, N-di-n represented by the above structural formula
-Propyl-m-phenylenediamine 2.88 g (0.8.
015 mol) and ethyl acetoacetate represented by
21 g (0.017 mol) of the mixed solution was heated with stirring in an oil bath at 160 ° C. for 19 hours. afterwards,
10 ml of ethyl acetate was added to the solid precipitated by heating, the mixture was refluxed for 1 h, and the product was filtered. The filtered product was suspended in 10 ml of ethyl acetate, stirred for 1 h at room temperature, filtered, and the filtered product was dried to obtain 1.77 g of a product represented by the following structural formula.

[0045]

[Chemical 16]

Next, 0.517 g (0.002 mol) of the obtained compound represented by the structural formula was added to 10 ml of N, N-dimethylformamide and 1.12 g of potassium hydroxide.
(0.02 ml), and 1.42 g (0.01 mol) of methyl iodide was added dropwise to this mixed solution with stirring. After completion of dropping, the mixture was stirred at room temperature for 7 hours, neutralized with saturated aqueous ammonium chloride solution, and extracted with ethyl acetate. The ethyl acetate layer was concentrated to dryness to obtain 0.43 g of the product represented by Exemplified Compound (85). The λmax of this compound in chloroform was 369.0 nm, and the molar extinction coefficient was 1.8 × 10 ⁴ .

This compound was dissolved in octafluoropentanol and adjusted to 1.0 wt%. The solution obtained by filtering this is dropped onto an injection molded polycarbonate resin substrate with a diameter of 120 mm and a thickness of 1.2 mm and applied by spin coating,
After coating, it was dried at 100 ° C. for 30 minutes. Λ of this coating film
The max was 379.5 nm. Examples 2 and 3 Hereinafter, the compounds of Exemplified Compounds (48) and (9) were synthesized according to the above-mentioned synthesis method, and the film spectrum was measured.

Comparative Example 1 The compound of the above structural formula obtained as an intermediate of Example 1 was dissolved in octafluoropentanol to give 1.
Adjusted to 0 wt%. The solution obtained by filtering this solution has a diameter of 12
It is dropped on an injection molded polycarbonate resin substrate of 0 mm and 1.2 mm in thickness, and applied by spin coating. After application, 10
It was dried at 0 ° C. for 30 minutes. The obtained coating film was found to have crystallized dye and was cloudy. Comparative Example 2 According to the method of Example 1, a compound represented by the following structural formula was synthesized and applied on a polycarbonate resin substrate in the same manner as in Comparative Example 1. The obtained coating film was found to have crystallized dye and was cloudy.

[0049]

[Chemical 17]

Table 1 shows the maximum absorption wavelength, the molar absorption coefficient, and the maximum absorption wavelength of the coating film in the solutions of the compounds of Examples 1 to 3 and Comparative Examples 1 and 2.

[Table 1]

For example, a silver film is formed on this coating film by a sputtering method or the like to form a reflection layer, and then an ultraviolet curable resin is applied by spin coating or the like and cured by UV irradiation to form a protective layer. It can be formed into an optical recording medium. It is clear from this value of λmax of the coating film that this optical recording medium can be recorded / reproduced by a semiconductor laser having a central wavelength of 410 nm, for example.

[0052]

The solution containing the compound of the present invention is capable of forming a coating film having absorption suitable for recording / reproducing with a short wavelength laser beam, and is also excellent in film forming property.
A recording medium having a recording layer using the compound of the present invention is useful as an optical recording medium for recording / reproducing compatible with a short wavelength laser.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C07D 221/16 C07D 471/04 102 5D029 471/04 102 112Z 5D090 112 112 114Z 114 471/16 471/16 B41M 5 / 26 Y F term (reference) 2H111 EA03 EA22 EA32 EA33 FB41 FB42 4C031 JA01 JA02 JA03 JA07 JA11 JA14 4C034 CH02 4C065 AA04 AA07 BB04 BB09 CC01 CC05 DD02 EE02 EE03 HH01 HH02 HH08 HH09 JJ02 JJ03 JJ04 JJ05 KK01 KK02 KK04 KK08 KK09 LL01 LL02 LL03 LL06 LL07 PP01 PP09 4H056 DD03 DD04 DD29 EA13 FA06 5D029 JA04 JB47 JC03 5D090 AA01 DD02 KK06

Claims (8)

[Claims] 1. An optical recording medium in which a recording layer capable of recording and / or reproducing information with a laser is provided on a substrate, and the recording layer has a carbostyril represented by the following general formula [I]. An optical recording medium containing a compound or a 1,8-naphthyridine compound. [Chemical 1] (In the formula, X represents a nitrogen atom or C—R _6. R ₁ represents an arbitrary substituent. R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each independently. Represents a hydrogen atom or an arbitrary substituent, and two adjacent R _{2 to} R ₈ may combine to form a ring.) 2. In the general formula [I], R ₃ , R ₇ and R ₈ each independently represent an arbitrary substituent, and R ₂ , R 7
₄ , R ₅ and R ₆ each independently represent a hydrogen atom or an optional substituent, provided that two adjacent R _{2 to} R ₈
The optical recording medium according to claim 1, wherein R ₈ and R ₅ and / or R ₇ and R ₆ may combine to form a ring. 3. In the general formula [I], R ₁ is an optionally substituted alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, aralkyl group, aryl group, saturated or unsaturated heterocycle. The optical recording medium according to claim 1, which represents a group selected from a group and an acyl group. 4. In the general formula [I], R ₃ is an optionally substituted alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkoxy group, alkylthio group, aralkyl group, alkenyloxy group, Aryl group, saturated or unsaturated heterocyclic group, halogen atom, nitro group, cyano group, formyl group, hydroxy group, carboxyl group, sulfonic acid group, amino group, acylamino group,
Carbamate group, sulfonamide group, carbamoyl group,
4. The optical recording medium according to claim 1, which represents a group selected from a carboxylic acid ester group, a sulfamoyl group and a sulfonic acid ester group. 5. In the general formula [I], R ₂ , R ₄ , R ₅ and R ₆ are each independently a hydrogen atom, an optionally substituted alkyl group, a cycloalkyl group or an alkenyl group. , Cycloalkenyl group, alkoxy group, alkylthio group, aralkyl group, alkenyloxy group, aryl group, saturated or unsaturated heterocyclic group, halogen atom, nitro group, cyano group, formyl group, hydroxy group, carboxyl group, sulfonic acid Group, amino group, acylamino group,
Carbamate group, sulfonamide group, carbamoyl group,
The optical recording medium according to any one of claims 1 to 4, which represents a group selected from a carboxylic acid ester group, a sulfamoyl group, and a sulfonic acid ester group. 6. In the general formula [I], R ₂ , R ₄ , R ₅ and R ₆ are each independently a hydrogen atom, an optionally substituted alkyl group, an alkenyl group, an aralkyl group or an alkoxy group. Group, alkylthio group, aryl group, saturated or unsaturated heterocyclic group, halogen atom, nitro group, cyano group, hydroxy group, carboxyl group, amino group, acylamino group, carbamate group, sulfonic acid amide group, carbamoyl group, carboxylic group The optical recording medium according to claim 5, which represents a group selected from acid ester groups. 7. R ₇ and R ₈ in the general formula [I] are
Each independently represents an alkyl group which may have a substituent, an alkenyl group, an aralkyl group, or an acyl group, provided that
7. The optical recording medium according to claim 1, wherein R ₇ and R ₆ and / or R ₈ and R ₅ may combine to form a ring. 8. A laser beam wavelength for recording and / or reproducing information is 350 nm to 530 nm.
7. The optical recording medium according to 7.