JP2003246141A - Optical information recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical information recording medium which can be recorded and reproduced by a laser beam having a much shorter wavelength than that of a CD-R or a DVD-R and which has excellent recording characteristics. <P>SOLUTION: The optical information recording medium comprises a recording layer containing a compound represented by formula (I-A) or (I-B) so that a refractive index (n) of the layer in a wavelength range of 350 to 450 nm is 1.0≤n≤2.3, and a distinction coefficient (k) of 0.03≤k≤0.50 in a wavelength band exists, [wherein A<SP>1</SP>and A<SP>2</SP>are each an alkyl group, an aralkyl group, an aryl group or a heterocyclic group, X<SP>1</SP>and X<SP>2</SP>are each a methine group or an azamethine group, R is a substituent substitutable with a carbon atom, m is an integer of 0 to 2, n is an integer of 0 to 4, when m or n is an integer of 2 or more, a plurality of R may be the same or different, and may be coupled to form a ring, and M is a hydrogen atom or a metallic atom]. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording medium capable of recording / reproducing information using a laser beam. In particular, the present invention relates to a heat mode type optical information recording medium suitable for recording information using a short wavelength laser beam having a wavelength of 440 nm or less. Conventionally, an optical information recording medium (optical disk) capable of recording information only once by laser light is known. This optical disc is a recordable CD (so-called CD).
-R), and its typical structure is that a recording layer made of an organic dye, a light reflecting layer made of metal such as gold, and a protective layer made of resin are laminated in this order on a transparent disk-shaped substrate. Is provided. Information recording on this CD-R is performed by irradiating the CD-R with a near-infrared laser beam (usually a laser beam having a wavelength near 780 nm), and the irradiated portion of the recording layer emits the light. Information is recorded by absorbing and locally raising the temperature, causing a physical or chemical change (eg, pit generation) and changing its optical properties. On the other hand, reading (reproduction) of information is also performed by irradiating laser light having the same wavelength as the recording laser light, and the part where the optical characteristics of the recording layer have changed (recorded part) and the part that has not changed (unrecorded) Information is reproduced by detecting the difference in reflectance from (part). In recent years, an optical information recording medium having a higher recording density has been demanded. In response to such a demand, an optical disc called a recordable digital vasatile disc (so-called DVD-R) has been proposed (for example, “Nikkei New Media”, separate volume “DVD”, published in 1995).
This DVD-R is a transparent disk-shaped substrate in which the guide groove (pre-groove) for tracking the irradiated laser beam is narrower than half of the CD-R (0.74-0.8 μm). On top of the recording layer made of a dye, and usually two light reflecting layers on the recording layer, and further a protective layer if necessary, or a disk-shaped protective substrate having the same shape as the disk The recording layer has a structure in which the recording layer is bonded inside with an adhesive. Information recording / reproduction on a DVD-R is performed with visible laser light (usually 630n).
(laser light with a wavelength in the range of m to 680 nm) is performed, and higher density recording than CD-R is possible. Recently, networks such as the Internet and high-definition TVs are rapidly spreading. HDT
V (High Definition Televis
ion) will soon be broadcast, and there is an increasing demand for a large-capacity recording medium for recording image information at low cost and in a simple manner. Although the DVD-R is secured to a certain extent as a large-capacity recording medium, it cannot be said that the DVD-R has a large enough recording capacity to meet future requirements.
Therefore, development of an optical disc having a higher recording capacity by improving the recording density by using a laser beam having a wavelength shorter than that of the DVD-R is underway. For example, JP-A-4-74690, JP-A-7-30425
No. 6, JP-A-7-304257, JP-A-8-
127174, 11-53758, 1
1-334204, 11-334205, 11-334206, 11-33420
No. 7, JP 2000-43423 A, No. 200
No. 0-108513, 2000-113504, 2000-149320, 2000-
In 158818 and 2000-228028, in an optical information recording medium having a recording layer containing an organic dye, the wavelength is 530 nm from the recording layer side toward the light reflecting layer side.
A recording / reproducing method for recording / reproducing information by irradiating the following laser beam is disclosed. In particular,
An optical disk using a porphyrin compound, an azo dye, a metal azo dye, a quinophthalone dye, a trimethine cyanine dye, a dicyanovinylphenyl skeleton dye, a coumarin compound, a naphthalocyanine compound, etc. as a recording layer dye is blue (wavelength 430 nm). 488 nm) or blue-green (wavelength 515 nm) laser light has been proposed to record and reproduce information. [0005] The inventors have studied,
It has been found that the optical disk described in the above publication requires further improvement since it is still insufficient in terms of practical sensitivity and recording characteristics such as reflectance and modulation. An object of the present invention is to provide a laser beam having a shorter wavelength than that of a CD-R or DVD-R, in particular, a semiconductor laser beam having a wavelength of 440 nm or less, particularly a wavelength around 405 nm, or a wavelength of 410 n.
To provide an optical information recording medium which can be recorded and reproduced by SHG laser light in the vicinity of m and has excellent recording characteristics. By using the compound of the present invention as a recording material for a recording layer, the wavelength is 440 nm.
High sensitivity to the following short wavelength laser light,
Further, it has been found that an optical information recording medium having good recording / reproducing characteristics giving a high reflectance and a high degree of modulation can be produced. The optical information recording medium of the present invention has a recording layer containing a compound represented by the following general formula (IA) or (IB) on a substrate and has a wavelength range of 350 to 450 nm. The refractive index (n) of the recording layer is 1.0 ≦ n ≦ 2.
3. A wavelength band having an extinction coefficient (k) in the range of 0.03 ≦ k ≦ 0.50 exists. ## STR2 ## [In the general formulas (IA) and (IB), A ¹ and A ² represent an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group, and X ¹ and X ² represent a methine group or an azamethine group. , R represents a substituent substitutable on a carbon atom, m represents an integer of 0 to 2, n represents an integer of 0 to 4, and when m or n is an integer of 2 or more, a plurality of R are They may be the same as or different from each other, and may be linked to form a ring, and M represents a hydrogen atom or a metal atom. The optical information recording medium of the present invention preferably has the following mode. (1) In the general formulas (IA) and (IB), X ¹
And X ² is azamethine. (2) In the general formulas (IA) and (IB), M
Is one selected from the group consisting of hydrogen atoms, copper, nickel, iron, cobalt, palladium, magnesium, aluminum, zinc, and silicon. (3) A light reflecting layer made of metal is provided separately from the recording layer. (4) A protective layer is provided separately from the recording layer. (5) The substrate has a track pitch of 0.2-0.
It is a transparent disk-like substrate on which 8 μm pregrooves are formed, and a recording layer is provided on the surface on the side where the pregrooves are formed. The optical information recording medium has a wavelength of 440 n.
Information can be recorded on the optical information recording medium by an information recording method for recording information by irradiating a laser beam of m or less. In the optical information recording medium of the present invention, the recording layer contains a compound represented by the following general formula (IA) or (IB) and has a thickness of 350 to 450 nm. In the wavelength region, there exists a wavelength band in which the recording layer has a refractive index (n) in the range of 1.0 ≦ n ≦ 2.3 and an extinction coefficient (k) in the range of 0.03 ≦ k ≦ 0.50. It is characterized by doing. Embedded image In the general formulas (IA) and (IB), A ¹ and A ² represent an alkyl group, an aralkyl group, an aryl group or a heterocyclic group, and X ¹ and X ² represent a methine group or an azamethine group. R represents a substituent substitutable on a carbon atom, m represents an integer of 0 to 2, n represents an integer of 0 to 4, and when m or n is an integer of 2 or more, a plurality of R may be the same or different from each other, and may be linked to form a ring, and M represents a hydrogen atom or a metal atom. In the general formula (IA) or (IB), the alkyl group represented by A ¹ and A ² is preferably a linear or cyclic alkyl group having 1 to 22 carbon atoms,
Further, a linear or cyclic alkyl group having 3 to 18 carbon atoms is preferable, and an alkyl group having a branched chain having 3 to 12 carbon atoms is particularly preferable. In the general formula (IA) or (IB), the aralkyl group represented by A ¹ or A ² is preferably an aralkyl group having 7 to 15 carbon atoms, and more preferably 7 to 7 carbon atoms. 11 alkyl groups are preferred, and benzyl is particularly preferred. In the general formula (IA) or (IB), the aryl group represented by A ¹ and A ² is preferably an aryl group having 6 to 14 carbon atoms, and more preferably 6 to 6 carbon atoms. Ten alkyl groups are preferred, and phenyl is particularly preferred. In the general formula (IA) or (IB), the hetero group represented by A ¹ and A ² is a carbon atom including a nitrogen atom, an oxygen atom, a sulfur atom, a selenium atom or a phosphorus atom. A 5- or 6-membered heterocyclic group having 1 to 5 carbon atoms is preferable, and a 5- or 6-membered heterocyclic group having 2 to 5 carbon atoms including a nitrogen atom, an oxygen atom, a sulfur atom or a selenium atom is preferable. In particular, a 5- or 6-membered heterocyclic group having 3 to 5 carbon atoms and containing a nitrogen atom, oxygen atom or sulfur atom at the 2-position is preferred. In the general formula (IA) or (IB), X ¹ and X ² each independently represent a methine group or an azamethine group, but it is preferable that either one is an azamethine group, particularly both Is preferably an azamethine group. In the general formula (IA) or (IB), preferred examples of R include alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, and 6 to 6 carbon atoms. 14 aryl groups, aralkyl groups having 7 to 15 carbon atoms, heterocyclic groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, aryloxy groups having 6 to 14 carbon atoms, carbon atoms 1 to 20 alkylsulfenyl groups, 6 to 14 arylsulfenyl groups, 1 to 20 alkylsulfonyl groups, 6 to 14 arylsulfonyl groups, 2 carbon atoms
-21 acyl group, carbamoyl group having 1 to 25 carbon atoms, sulfamoyl group having 0 to 32 carbon atoms, alkoxycarbonyl group having 2 to 21 carbon atoms, 7 to 7 carbon atoms
15 aryloxycarbonyl groups, 2 to 2 carbon atoms
1 acylamino group, a sulfonylamino group having 1 to 20 carbon atoms, an amino group having 0 to 32 carbon atoms, a cyano group,
Although a nitro group, a hydroxy group, a carboxy group, a sulfo group, and a halogen atom can be mentioned, more preferable are an alkyl group having 3 to 16 carbon atoms, an aryl group having 6 to 10 carbon atoms, and the number of carbon atoms. An alkoxy group having 3 to 16 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an alkylsulfenyl group having 3 to 16 carbon atoms, and 6 carbon atoms
To 10 arylsulfenyl groups, 3 to 16 carbon atoms
An alkylsulfonyl group, an arylsulfonyl group having 6 to 10 carbon atoms, a carbamoyl group having 1 to 21 carbon atoms,
A sulfamoyl group having 2 to 20 carbon atoms or an alkoxycarbonyl group having 2 to 17 carbon atoms, particularly preferred are an alkyl group having 3 to 12 carbon atoms, an alkoxy group having 3 to 12 carbon atoms, carbon An alkylsulfenyl group having 3 to 12 atoms, a phenylsulfenyl group, an alkylsulfonyl group having 3 to 12 carbon atoms, a phenylsulfonyl group, a carbamoyl group having 1 to 17 carbon atoms, or a sulfamoyl group having 3 to 16 carbon atoms Or an alkoxycarbonyl group having 2 to 13 carbon atoms, m or n
When R is an integer of 2 or more, a plurality of Rs may be connected to each other to form a ring. In this case, the ring is preferably an aromatic ring or a heteroaromatic ring, and further a benzene ring, a naphthalene ring, A pyridine ring or a pyrazine ring is preferable, and a benzene ring is particularly preferable. In the general formula (IA) or (IB), M is a hydrogen atom, copper, nickel, iron, cobalt, palladium, magnesium, aluminum, zinc,
Alternatively, silicon is preferable, and a hydrogen atom, copper, nickel, or cobalt is preferable, and a hydrogen atom, copper, or nickel is particularly preferable. In the general formula (IA) or (IB), X ¹ or X ² in the case of R, A ¹ , A ² or methine group may have a substituent. Examples thereof include those described below. That is, a linear or cyclic alkyl group having 1 to 20 carbon atoms (for example, methyl, ethyl, isopropyl, cyclohexyl), an aryl group having 6 to 18 carbon atoms (for example, phenyl, chlorophenyl, 2, 4). -Gee-
t-amylphenyl, 1-naphthyl), 7 to 7 carbon atoms
18 aralkyl groups (eg benzyl, anisyl),
An alkenyl group having 2 to 20 carbon atoms (for example, vinyl,
2-methylvinyl), alkynyl groups having 2 to 20 carbon atoms (for example, ethynyl, 2-methylethynyl, 2-phenylethynyl), halogen atoms (for example, F, Cl, B)
r, I), a cyano group, a hydroxyl group, a carboxyl group, an acyl group having 2 to 20 carbon atoms (for example, acetyl, benzoyl, salicyloyl, pivaloyl), an alkoxy group having 1 to 20 carbon atoms (for example, methoxy, butoxy) Cyclohexyloxy), aryloxy groups having 6 to 20 carbon atoms (for example, phenoxy, 1-naphthoxy, toluoyl), alkylthio groups having 1 to 20 carbon atoms (for example, methylthio, butylthio, benzylthio,
3-methoxypropylthio), an arylthio group having 6 to 20 carbon atoms (for example, phenylthio, 4-chlorophenylthio), an alkylsulfonyl group having 1 to 20 carbon atoms (for example, methanesulfonyl, butanesulfonyl),
An arylsulfonyl group having 6 to 20 carbon atoms (for example,
Benzenesulfonyl, paratoluenesulfonyl), a carbamoyl group having 1 to 17 carbon atoms (for example, unsubstituted carbamoyl, methylcarbamoyl, ethylcarbamoyl, n-butylcarbamoyl, dimethylcarbamoyl), a sulfamoyl group having 1 to 16 carbon atoms ( For example, unsubstituted sulfamoyl, ethylsulfamoyl,
Diisopropylsulfamoyl, n-butylsulfamoyl, phenylsulfamoyl), 1 to 17 carbon atoms
An acylamino group (for example, acetamino, benzamino), a sulfonylamino having 1 to 16 carbon atoms (for example, butylsulfonylamino, phenylsulfonylamino), an acyloxy group having 2 to 10 carbon atoms (for example,
Acetoxy, benzoyloxy), 2-10 carbon atoms
An alkoxycarbonyl group (for example, methoxycarbonyl, ethoxycarbonyl), a 5- or 6-membered heterocyclic group (for example, an aromatic heterocyclic ring such as pyridyl, thienyl, furyl, thiazolyl, imidazolyl, pyrazolyl, etc.)
A pyrrolidine ring, a piperidine ring, a morpholine ring, a pyran ring, a thiopyran ring, a dioxane ring, a dithiolane ring and the like. In the general formula (IA) or (IB), as the substituent for X ¹ or X ^{2 in} the case of R and methine group, more preferred is a chain having 1 to 16 carbon atoms or Cyclic alkyl group, aryl group having 6 to 14 carbon atoms, aralkyl group having 7 to 15 carbon atoms, 1 carbon atom
-16 alkoxy group, aryloxy group having 6 to 14 carbon atoms, halogen atom, alkoxycarbonyl group having 2 to 17 carbon atoms, alkylthio group having 1 to 16 carbon atoms, arylthio group having 6 to 14 carbon atoms , An alkylsulfonyl group having 1 to 16 carbon atoms, 6 to 14 carbon atoms
Arylsulfonyl groups, carbamoyl groups having 1 to 13 carbon atoms, sulfamoyl groups having 1 to 12 carbon atoms, acylamino groups having 1 to 13 carbon atoms, or 1 to 12 carbon atoms
Among them, a sulfonylamino group having 1 to 12 carbon atoms in a chain or cyclic alkyl group, 7 to 11 carbon atoms aralkyl group, 6 to 10 carbon atoms aryl group, 1 carbon atom is preferable. -12 alkoxy group, aryloxy group having 6-10 carbon atoms, 1-12 carbon atoms
Alkylthio group, arylthio group having 6 to 10 carbon atoms, chlorine atom, alkoxycarbonyl group having 2 to 13 carbon atoms, carbamoyl group having 1 to 11 carbon atoms, sulfamoyl group having 1 to 10 carbon atoms, carbon atom Number 1-12
An alkylsulfonyl group, an arylsulfonyl group having 6 to 10 carbon atoms, an acylamino group having 1 to 11 carbon atoms, or a sulfonylamino group having 1 to 10 carbon atoms, particularly preferably a chain having 3 to 10 carbon atoms. A branched or cyclic alkyl group, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 3 to 9 carbon atoms, and 3 to 3 carbon atoms
10 alkylsulfonyl groups, phenylsulfonyl groups,
A sulfamoyl group having 3 to 8 carbon atoms and phenyl. Of the compounds represented by the general formula (IA) or (IB), the compounds represented by the following general formula (IC) are particularly preferred. Embedded image The general formula (I-C) in, A ^1, A ² and M is formula (I-A) or A ^1, A ² in (I-B)
And M, and A ¹ , A ² or the benzene ring may have a substituent, and the substituent is represented by the general formula (IA)
And (I-B) in the R, A ^1, A ^2, may be mentioned the same groups as the substituent of X ¹ or X ² when it is methine group. The general formula (IA), (IB), or (I
The compound represented by -C) may be bonded at an arbitrary position to form a multimer, and in this case, each unit may be the same as or different from each other, and polystyrene, polymethacrylate, polyvinyl alcohol Or may be bonded to a polymer chain such as cellulose. The compound represented by the general formula (IA) or (IB) used in the optical information recording medium of the present invention may be used alone or in a different structure. May be used as a mixture of two or more kinds, but it is preferable to use them alone. Since the optical information recording medium of the present invention is preferably recorded with a laser beam having a short wavelength of 440 nm or less, the optical physical properties of the recording layer in the wavelength region of the laser beam determine the recording performance. is important. As described above, the optical information recording medium of the present invention contains the compound represented by the general formula (IA) or (IB) in the recording layer, and the refractive index (n) of the recording layer is 1. There is a wavelength band in which 0.0 ≦ n ≦ 2.3 and the extinction coefficient (k) are in the range of 0.03 ≦ k ≦ 0.50. In particular, the refractive index and extinction coefficient are
More preferably, there are wavelength bands in the range of 1.5 ≦ n ≦ 2.2 and 0.04 ≦ k ≦ 0.30,
More preferably, there are wavelength bands in the ranges of ≦ n ≦ 2.2 and 0.04 ≦ k ≦ 0.20. In the following, the general formula (IA) or (IB)
Preferred specific examples of the compound represented by the formula (Exemplary Compound I-1
To I-25), but the present invention is not limited thereto. Embedded image Embedded image Embedded image Embedded image Embedded image The compounds used in the present invention are described in, for example, J. Org.
Chem. Soc. 2490 (1954), Chem.
Rev. 98, 563-575 (1998), which is described as a method for synthesizing hemiporphyrazine, or can be synthesized according to a method similar to these. The optical information recording medium of the present invention has a recording layer containing a compound represented by the general formula (IA) or (IB) on a substrate. In the optical information recording medium of the present invention,
Various configurations are included. The optical information recording medium of the present invention has a configuration in which a recording layer, a light reflecting layer and a protective layer are arranged in this order on a disc-like substrate on which pregrooves having a constant track pitch are formed, or a light reflecting layer and a recording layer on the substrate. A structure having a layer and a protective layer in this order is preferable. In addition, two laminated bodies in which a recording layer and a light reflection layer are provided on a transparent disk-shaped substrate on which pregrooves having a constant track pitch are formed are bonded so that each recording layer is inside. The configuration is also preferable. The optical information recording medium of the present invention has a higher recording density than CD-R and DVD-R in order to achieve higher recording density.
It is possible to use a substrate on which a pre-groove having a narrower track pitch is formed. In the optical information recording medium of the present invention, the track pitch is preferably in the range of 200 to 800 nm, more preferably in the range of 200 to 500 nm, and still more preferably in the range of 250 to 400 nm. Pregroove depth is 10
Preferably in the range of ~ 180 nm, more preferably 20 ~
It is preferably in the range of 150 nm. As an example of the optical information recording medium of the present invention, a manufacturing method having a recording layer, a light reflecting layer, and a protective layer in this order on a disc-like substrate will be described below. The substrate of the optical information recording medium of the present invention can be arbitrarily selected from various materials used as a substrate of a conventional optical information recording medium. Examples of the substrate material include acrylic resins such as glass, polycarbonate and polymethyl methacrylate, vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymers, epoxy resins, amorphous polyolefins and polyesters. You may use them together. These materials can be used as a film or as a rigid substrate. Among the above materials, polycarbonate is preferable from the viewpoint of moisture resistance, dimensional stability, price, and the like. An undercoat layer may be provided on the surface of the substrate on which the recording layer is provided for the purpose of improving the flatness, improving the adhesive force and preventing the recording layer from being altered. Examples of the material for the undercoat layer include polymethyl methacrylate, acrylic acid / methacrylic acid copolymer, styrene / maleic anhydride copolymer, polyvinyl alcohol, N-methylol acrylamide, styrene / vinyl toluene copolymer, chlorosulfonated. High molecular substances such as polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, vinyl acetate / vinyl chloride copolymer, ethylene / vinyl acetate copolymer, polyethylene, polypropylene, polycarbonate; and silane coupling agents And the like. The undercoat layer is formed by dissolving or dispersing the above substances in an appropriate solvent to prepare a coating solution, and then applying this coating solution to the substrate surface by a coating method such as spin coating, dip coating, or extrusion coating. can do.
The thickness of the undercoat layer is generally in the range of 0.005 to 20 μm, preferably in the range of 0.01 to 10 μm. The recording layer is formed by vapor deposition, sputtering,
Although it can carry out by methods, such as CVD or solvent application, solvent application is preferred. In this case, the dye compound, and optionally a quencher, a binder and the like are dissolved in a solvent to prepare a coating solution, and then the coating solution is applied to the substrate surface to form a coating film and then dried. be able to. Examples of the solvent for the coating solution include esters such as butyl acetate, methyl lactate, ethyl lactate, and cellosolve acetate; ketones such as methyl ethyl ketone, cyclohexanone, and methyl isobutyl ketone; dichloromethane,
Chlorinated hydrocarbons such as 1,2-dichloroethane and chloroform; Amides such as dimethylformamide; Hydrocarbons such as methylcyclohexane; Ethers such as dibutyl ether, diethyl ether, tetrahydrofuran and dioxane; Ethanol, n-propanol, isopropanol, n- Alcohols such as butanol and diacetone alcohol; fluorine-based solvents such as 2,2,3,3-tetrafluoropropanol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether,
Examples include glycol ethers such as propylene glycol monomethyl ether. The above solvents can be used alone or in combination of two or more in consideration of the solubility of the dye used. Various additives such as an antioxidant, a UV absorber, a plasticizer, and a lubricant may be further added to the coating solution depending on the purpose. When a binder is used, examples of the binder include natural organic polymer materials such as gelatin, cellulose derivatives, dextran, rosin and rubber; and hydrocarbons such as polyethylene, polypropylene, polystyrene and polyisobutylene. Resin, polyvinyl chloride, polyvinylidene chloride, vinyl resins such as polyvinyl chloride / polyvinyl acetate copolymer, acrylic resins such as polymethyl acrylate and polymethyl methacrylate, polyvinyl alcohol, chlorinated polyethylene, epoxy resin, Examples thereof include synthetic organic polymers such as butyral resins, rubber derivatives, and initial condensates of thermosetting resins such as phenol / formaldehyde resins. When a binder is used in combination as a material for the recording layer, the amount of the binder used is generally in the range of 0.01 to 50 times (mass ratio) with respect to the dye, and preferably 0.8.
It exists in the range of 1 time amount-5 times amount (mass ratio). The concentration of the dye in the coating solution thus prepared is generally 0.01.
-10% by mass, preferably 0.1-5% by mass. Examples of the coating method include spraying, spin coating, dipping, roll coating, blade coating, doctor roll, and screen printing. The recording layer may be a single layer or a multilayer. The thickness of the recording layer is generally in the range of 10 to 500 nm, preferably in the range of 15 to 300 nm, more preferably 2
It is in the range of 0 to 150 nm. The recording layer can contain various anti-fading agents in order to improve the light resistance of the recording layer.
As the antifading agent, a singlet oxygen quencher is generally used. As the singlet oxygen quencher, those described in publications such as known patent specifications can be used. Specific examples thereof include JP-A-58-175.
693, 59-81194, 60-18387
No. 60-19586, No. 60-19587, No. 60-35054, No. 60-36190, No. 60-
No. 36191, No. 60-44554, No. 60-445
55, 60-44389, 60-44390
No. 60-54892, No. 60-47069, No. 63-209995, JP-A-4-25492, JP-B-1-38680, No. 6-26028, etc., German Patent No. 350399 And the one described in the Chemical Society of Japan, October 1992, page 1141 and the like. Examples of preferred singlet oxygen quenchers include compounds represented by the following general formula (II). Embedded image Wherein R ²¹ represents an alkyl group which may have a substituent, and Q ⁻ represents an anion. In the general formula (II), R ²¹ is generally an optionally substituted alkyl group having 1 to 8 carbon atoms, preferably an unsubstituted alkyl group having 1 to 6 carbon atoms. As the substituent of the alkyl group, a halogen atom (eg, F, Cl),
Alkoxy groups (eg, methoxy, ethoxy), alkylthio groups (eg, methylthio, ethylthio), acyl groups (eg,
Acetyl, propionyl), acyloxy groups (eg, acetoxy, propionyloxy), hydroxy groups, alkoxycarbonyl groups (eg, methoxycarbonyl, ethoxycarbonyl), alkenyl groups (eg, vinyl), aryl groups (eg, phenyl, naphthyl) Can be mentioned.
Among these, a halogen atom, an alkoxy group, an alkylthio group, and an alkoxycarbonyl group are preferable. Preferred examples of the Q ⁻ anion include ClO ₄ ⁻ , AsF ₆ ⁻ , B
F ₄ ⁻ and SbF ₆ ⁻ can be mentioned. Formula (II)
Table 1 shows examples of compounds represented by [Table 1] The amount of the antifading agent such as the singlet oxygen quencher used is usually 0.1 to 50 with respect to the amount of the dye.
The mass range is preferably 0.5 to 45 mass%.
More preferably, it is the range of 3-40 mass%, Most preferably, it is the range of 5-25 mass%. It is preferable to provide a light reflecting layer adjacent to the recording layer for the purpose of improving reflectivity during information reproduction. The light reflecting material that is a material of the light reflecting layer is a material having a high reflectivity with respect to laser light.
g, Se, Y, Ti, Zr, Hf, V, Nb, Ta, C
r, Mo, W, Mn, Re, Fe, Co, Ni, Ru,
Rh, Pd, Ir, Pt, Cu, Ag, Au, Zn, C
d, Al, Ga, In, Si, Ge, Te, Pb, P
Examples include metals such as o, Sn, and Bi, metalloids, and stainless steel. These substances may be used alone or in combination of two or more or as an alloy. Of these, preferred are
Cr, Ni, Pt, Cu, Ag, Au, Al, and stainless steel. Particularly preferably, Au metal, Ag metal,
Al metal or an alloy thereof is most preferable, and Ag metal, Al metal, or an alloy thereof is most preferable.
The light reflecting layer can be formed on the substrate or the recording layer, for example, by vapor deposition, sputtering or ion plating of the light reflecting material. The layer thickness of the light reflecting layer is generally in the range of 10 to 300 nm, and preferably in the range of 50 to 200 nm. A protective layer is preferably provided on the light reflecting layer or the recording layer for the purpose of physically and chemically protecting the recording layer and the like. Note that in the case of adopting the same form as in the case of manufacturing a DVD-R type optical information recording medium, that is, a structure in which two substrates are laminated with the recording layer inside, the protective layer is not necessarily provided. Examples of materials used for the protective layer include Zn—SiO ₂ , ZnS, Si
Examples thereof include inorganic substances such as O, SiO ₂ , MgF ₂ , SnO ₂ , and Si ₃ N ₄ , and organic substances such as thermoplastic resins, thermosetting resins, and UV curable resins. The protective layer can be formed, for example, by laminating a film obtained by extrusion of plastic on the reflective layer via an adhesive. Or you may provide by methods, such as vacuum evaporation, sputtering, and application | coating. In the case of a thermoplastic resin or a thermosetting resin, it can also be formed by dissolving these in a suitable solvent to prepare a coating solution, and then applying and drying the coating solution. In the case of a UV curable resin, it can also be formed by preparing a coating solution as it is or by dissolving it in a suitable solvent, coating the coating solution, and curing it by irradiating with UV light.
In these coating solutions, antistatic agents, antioxidants,
Various additives such as UV absorbers may be added according to the purpose. The thickness of the protective layer is generally in the range of 0.1 μm to 1 mm. Through the above steps, a recording layer, a light reflecting layer, and a protective layer on a substrate, or a laminate in which a light reflecting layer, a recording layer, and a protective layer are provided on a substrate can be manufactured. Information is recorded on the optical information recording medium as follows, for example. First, the optical information recording medium is set at a constant linear velocity (1.2 to 1.4 m / in the case of a CD format).
Seconds) or while rotating at a constant angular velocity, recording light such as semiconductor laser light is irradiated from the substrate side or the protective layer side. By this light irradiation, the recording layer absorbs the light and the temperature rises locally, causing a physical or chemical change (for example, generation of pits) and changing its optical characteristics, thereby recording information. It is thought that it is done. In the present invention, semiconductor laser light having an oscillation wavelength of 440 nm or less is used as recording light. A preferred light source is a blue-violet semiconductor laser light having an oscillation wavelength in the range of 390 to 440 nm, and a more preferred light source is a center oscillation wavelength of 850 nm or 82.
A blue-violet SHG laser beam having a central oscillation wavelength of 425 nm or 410 nm, which is a half wavelength of 0 nm infrared semiconductor laser beam using an optical waveguide device, can be mentioned. In particular, it is preferable to use blue-violet semiconductor laser light in terms of recording density. The information recorded as described above is reproduced by irradiating a semiconductor laser beam from the substrate side or the protective layer side while rotating the optical information recording medium at the same constant linear velocity as above and detecting the reflected light. Can be performed. EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples. Example 1 The exemplified compound (I-1) was dissolved in 2,2,3,3-tetrafluoropropanol to obtain a recording layer forming coating solution (concentration: 1% by mass). A polycarbonate substrate (diameter: 120 mm, with a spiral pregroove (track pitch: 0.4 μm, groove width: 0.2 μm, groove depth: 0.05 μm) formed on the surface of this coating solution by injection molding. thickness:
0.6 mm) on the surface of the pre-groove side by spin coating, and the recording layer (thickness (in the pre-groove):
About 80 nm). Next, silver was sputtered on the recording layer to form a light reflecting layer having a thickness of about 100 nm. Furthermore,
A UV curable resin (SD318, manufactured by Dainippon Ink & Chemicals, Inc.) was applied on the light reflecting layer and cured by irradiating with ultraviolet rays to form a protective layer having a layer thickness of 7 μm. The optical disc (optical information recording medium) of Example 1 according to the present invention was obtained through the above steps. [Example 2] to [Example 8] The same procedure as in Example 1 was conducted except that the exemplified compound (I-1) was replaced with the compound shown in Table 2 (the amount used was unchanged). Optical disks (optical information recording media) of Examples 2 to 8 according to the invention were obtained. [Comparative Example 1] to [Comparative Example 4] The same procedure as in Example 1 except that Compound (I-1) was changed to Comparative Dye Compounds A to D shown below (the amount used was unchanged). Thus, a comparative optical disk (optical information recording medium) was obtained. Embedded image [Evaluation as an optical disk] A 14T-EFM signal was recorded on a produced optical disk at a linear velocity of 3.5 m / sec using a blue-violet semiconductor laser beam having an oscillation wavelength of 405 nm, and the recorded signal was reproduced. The modulation degree, groove reflectance, and sensitivity at the optimum power were measured. Recording and recording property evaluation were performed using DDU1000 manufactured by Pulstec. The evaluation results are shown in Table 2. Further, the refractive index (n) and extinction coefficient (k) of the recording layer of the produced optical disk were measured by a rotational check method (ellipsometry). Table 2 shows the measurement results at 405 nm. [Table 2] From the results of Table 2, the optical disks (Examples 1 to 8) having a recording layer containing a compound represented by the general formula (IA) or (IB), which is a feature of the present invention, Compared to optical discs (Comparative Examples 1 to 4) having a recording layer containing comparative compounds (A) to (D), the blue-violet semiconductor laser light exhibits a high reflectance and gives a high degree of modulation,
Moreover, it can be seen that the sensitivity is high. Therefore, it can be seen that by using the specific porphyrazine compound according to the present invention, an optical disc having high recording characteristics with respect to a short wavelength laser beam can be obtained. By using the dye compound characterized by the present invention, high-sensitivity optical information recording that exhibits high reflectivity and gives a high degree of modulation to laser light having a short wavelength of 440 nm or less. A medium can be obtained. Therefore, CD-
It is possible to provide an optical information recording medium capable of recording information at a higher density than in the case of R or DVD-R and capable of recording a larger amount of information.

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Claims (1)

What is claimed is: 1. On a substrate, the following general formula (IA) or (I
-B), and the refractive index (n) of the recording layer is 1.0 ≦ n ≦ 2.3 and the extinction coefficient (k) in the wavelength region of 350 to 450 nm. ) Is 0.0
An optical information recording medium having a wavelength band in a range of 3 ≦ k ≦ 0.50. [Chemical 1] [In the general formulas (IA) and (IB), A ¹ and A ² represent an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group, and X ¹ and X ² represent a methine group or an azamethine group. , R represents a substituent substitutable on a carbon atom, m represents an integer of 0 to 2, n represents an integer of 0 to 4, and when m or n is an integer of 2 or more, a plurality of R are They may be the same as or different from each other, and may be linked to form a ring, and M represents a hydrogen atom or a metal atom. ]