JP2002301870A - Optical information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical information recording medium, capable of high- density recording and reproducing of information by irradiation with the laser beam of a short wavelength of not higher than 450 nm and especially near the wavelength of 405 nm high in conventionality and capable of recording and reproducing by both of a short wavelength laser beam having the wavelength of not higher than 450 nm and a laser beam having the wavelength of 750-850 nm, which is used in a conventional CD-R while excellent in recording characteristics and conventionality. SOLUTION: In the optical information recording medium having a recording layer capable of recording the information by irradiation with a laser, beam having a wavelength of not higher than 450 nm on a substrate, phthalocyanine derivative is contained in the recording layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording medium, and more particularly, to an optical information recording medium capable of recording and reproducing information by irradiating a laser beam. In particular, the present invention relates to a heat mode optical information recording medium suitable for recording information by irradiating a short wavelength laser beam having a wavelength of 450 nm or less.

[0002]

2. Description of the Related Art Conventionally, an optical information recording medium (optical disk) on which information can be recorded only once by a laser beam has been known. This optical disc is a write-once CD (so-called CD-
R), a typical structure of which is formed by laminating a recording layer made of an organic dye, a light reflecting layer made of a metal such as gold, and a protective layer made of a resin in this order on a transparent disk-shaped substrate. is there. The recording of information on the CD-R is performed by irradiating the CD-R with near-infrared laser light (usually a laser light having a wavelength around 780 nm), and the irradiated portion of the recording layer emits the light. The temperature is locally increased by absorption, and information is recorded by changing the optical characteristics of the portion due to a physical or chemical change (for example, generation of pits). On the other hand, reading (reproduction) of information is also performed by irradiating the CD-R with a laser beam having the same wavelength as the recording laser beam, and changes the optical characteristics of the recording layer (the recording portion). This is performed by detecting a difference in reflectance from a portion that has not been recorded (unrecorded portion).

In recent years, an optical information recording medium having a higher recording density has been demanded. In response to such demands, write-once digital versatile discs (so-called DVD-R)
Has been proposed (for example, "Nikkei New Media" separate volume "DVD", published in 1995). This DVD-R is a transparent disc-shaped guide groove (pre-groove) for tracking a laser beam to be irradiated, which is formed with a narrow groove width of half or less (0.74 to 0.8 μm) of the CD-R. A structure in which two disks each having a recording layer containing an organic dye, a light reflecting layer, and a protective layer laminated in this order on a substrate are usually bonded together with the recording layer facing the inside,
Alternatively, the disk has a structure in which a disk-shaped protective substrate having the same shape as the disk is bonded with the recording layer inside. Recording and reproduction of information on the DVD-R are performed by irradiating a visible laser beam (normally, a laser beam having a wavelength in a range of 630 nm to 680 nm).
Higher density recording than DR is possible.

[0004] Recently, networks such as the Internet and high-definition TVs have rapidly become widespread. Also, HDT
V (High Definition Television) is starting to air soon. Under such circumstances, there is a need for a large-capacity recording medium capable of simply and inexpensively recording image information. At present, DVD-Rs play a sufficient role as large-capacity recording media, but demands for large-capacity and high-density are increasing, and it is also necessary to develop recording media that can meet these requirements. . For this reason, DVD-R
A recording medium having a larger capacity capable of performing high-density recording with light having a shorter wavelength than that of the recording medium is being developed.

For example, JP-A-4-74690, JP-A-7-304256, JP-A-7-304257
JP-A-8-127174 and JP-A-11-53
758, 11-334204, 11-
334205, 11-334206, 11-334207, JP-A-2000-43423
JP 2000-108513, JP 2000-108513
-113504, 2000-149320, 2000-158818, and 2000
In -228028, in an optical information recording medium having a recording layer containing an organic dye, a laser beam having a wavelength of 530 nm or less is irradiated from the recording layer side to the light reflection layer side to record and reproduce information. A playback method is disclosed. In these methods, a porphyrin compound, an azo dye, a metal azo dye, a quinophthalone dye, a trimethine cyanine dye, a dicyanovinylphenyl skeleton dye,
An optical disk provided with a recording layer containing a coumarin compound, a naphthalocyanine compound, or the like has a blue color (wavelength 430 nm,
Recording and reproduction of information are performed by irradiating 488 nm) or blue-green (515 nm) laser light.

Further, from the viewpoint of compatibility with currently used CD-R systems, there has been proposed an optical information recording medium capable of recording and reproducing with laser beams in two different wavelength regions. For example, Japanese Patent Application Laid-Open Nos. 2000-141900, 2000-158816, and 2000-1
Nos. 85471, 2000-289342,
JP-A-2000-309165 discloses that a dye used for a CD-R and a dye used for a DVD-R are mixed and used to produce a near-infrared laser light near 780 nm and a visible laser light near 650 nm. There has been proposed an optical information recording medium capable of recording and reproducing with any of the above laser beams.

[0007]

However, according to the study of the present inventor, according to the study of the present inventor, when information is recorded by irradiating a short-wavelength laser beam having a wavelength of 450 nm or less, the optical disc described in the above-mentioned publication has a practical problem. It was found that the required sensitivity could not be obtained, and that other recording characteristics such as reflectance and modulation were not at a satisfactory level, and that further improvement was required. In particular, in the optical disc described in the above publication, the recording characteristics deteriorated when a laser beam having a wavelength of 450 nm or less was irradiated.

The present invention has been made in view of the above-mentioned problems of the prior art, and a first object of the present invention is to provide a light source having a wavelength of 450 nm.
The present invention provides an optical information recording medium capable of performing high-density recording and reproduction of information by irradiating a laser beam having a short wavelength of not more than m, particularly a laser beam having a wavelength of about 405 nm, which is highly versatile, and having excellent recording characteristics. It is in.

A second object of the present invention is to provide a light source having a wavelength of 450.
It is an object of the present invention to provide an optical information recording medium which can be recorded and reproduced by both a short-wavelength laser beam of nm or less and a laser beam having a wavelength of 750 to 850 nm used in a conventional CD-R, and is excellent in versatility. .

[0010]

In order to achieve the first and second objects, the optical information recording medium of the present invention can record information on a substrate by irradiating a laser beam having a wavelength of 450 nm or less on a substrate. An optical information recording medium having a recording layer, wherein the recording layer contains a phthalocyanine derivative. The phthalocyanine derivative has a main absorption band around 700 nm and a sub absorption band around 340 nm. By using this phthalocyanine derivative as a recording material for the recording layer, it exhibits high sensitivity to short-wavelength lasers having a wavelength of 450 nm or less, and has high reflectance, and has good recording / reproducing characteristics giving a high degree of modulation. Optical information recording medium can be obtained. In addition, this optical information recording medium
At the same time, it exhibits high sensitivity to laser light having a wavelength of 750 to 850 nm, has high reflectivity, and has good recording / reproducing characteristics giving a high degree of modulation.

As the phthalocyanine derivative contained in the recording layer, a phthalocyanine derivative represented by the following general formula (I) is preferable.

[0012]

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[Wherein, R represents a substituent, and n represents 1 to 8]
And when n is an integer of 2 or more, a plurality of Rs may be the same or different from each other, and M represents two hydrogen atoms, a metal, a metal oxide, or a metal having a ligand. Represent. In the above general formula (I), the metal representing M is preferably copper, nickel, iron, cobalt, palladium, magnesium, aluminum, zinc, or silicon.
The substituent R is an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 14 carbon atoms, and a carbon atom having 7 carbon atoms.
An aralkyl group having 1 to 15 carbon atoms, a heterocyclic group having 1 to 10 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, an acyl group having 2 to 21 carbon atoms, a carbon atom An alkylsulfonyl group having 1 to 20 carbon atoms, an arylsulfonyl group having 6 to 14 carbon atoms, an aralkylsulfonyl group having 7 to 15 carbon atoms,
Heterylsulfonyl group having 1 to 10 carbon atoms, carbamoyl group having 1 to 25 carbon atoms, 0 to 3 carbon atoms
2, a sulfamoyl group, an alkoxycarbonyl group having 1 to 20 carbon atoms, an aryloxycarbonyl group having 7 to 15 carbon atoms, an acylamino group having 2 to 21 carbon atoms, a sulfonylamino group having 1 to 20 carbon atoms, or It is preferably a halogen atom. Also, n is 1
It is preferably an integer of from 4 to 4.

It is preferable that the optical information recording medium of the present invention further comprises a light reflecting layer made of metal on the recording layer.
More preferably, a protective layer for protecting the recording layer is further provided on the recording layer. Further, it is preferable that a pre-groove having a track pitch of 0.2 to 0.5 μm is formed on the surface of the substrate on which the recording layer is provided.

As a preferable information recording method, there is a method of recording information by irradiating the optical information recording medium with laser light having a wavelength of 450 nm or less or laser light having a wavelength of 750 to 850 nm. Since an optical information recording medium using a phthalocyanine derivative having a main absorption band near 700 nm and a sub absorption band near 340 nm as a recording material of a recording layer is used, a laser beam having a wavelength of 450 nm or less and a wavelength of 750 to 850 nm are used. Information can be recorded by selectively irradiating any of the laser beams.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the optical information recording medium and the information recording method of the present invention will be described in detail.

The optical information recording medium of the present invention is an optical information recording medium having a recording layer on a substrate on which information can be recorded by irradiating a laser beam, wherein the recording layer contains a phthalocyanine derivative. And

The phthalocyanine derivative used in the optical information recording medium of the present invention is preferably a compound represented by the following general formula (I).

[0019]

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(Wherein, R represents a substituent, and n represents 1 to 8)
And when n is an integer of 2 or more, a plurality of Rs may be the same or different from each other, and M represents two hydrogen atoms, a metal, a metal oxide, or a metal having a ligand. Represent. In the general formula (I), preferred examples of the substituent represented by R include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 14 carbon atoms, and a 7 to 15 carbon atoms.
An aralkyl group, a heterocyclic group having 1 to 10 carbon atoms,
An alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, an acyl group having 2 to 21 carbon atoms, an alkylsulfonyl group having 1 to 20 carbon atoms, an aryl having 6 to 14 carbon atoms Sulfonyl group, aralkylsulfonyl group having 7 to 15 carbon atoms, hetenylsulfonyl group having 1 to 10 carbon atoms, 1 carbon atom
A carbamoyl group having 25 to 25 carbon atoms, a sulfamoyl group having 0 to 32 carbon atoms, an alkoxycarbonyl group having 1 to 20 carbon atoms, an aryloxycarbonyl group having 7 to 15 carbon atoms, an acylamino group having 2 to 21 carbon atoms,
Although a sulfonylamino group having 1 to 20 carbon atoms or a halogen atom can be exemplified, an alkyl group having 3 to 16 carbon atoms and a C6 to 10 carbon atom are preferable.
An aryl group, an alkoxy group having 3 to 16 carbon atoms,
Aryloxy group having 6 to 10 carbon atoms, alkylsulfonyl group having 3 to 16 carbon atoms, arylsulfonyl group having 6 to 10 carbon atoms, aralkylsulfonyl group having 7 to 11 carbon atoms, 2 to 20 carbon atoms And more preferably a sulfamoyl group having 4 carbon atoms.
To 12 alkoxy groups, C 4 to C 12 alkylsulfonyl groups, C 6 to C 10 arylsulfonyl groups, and C 4 to C 16 sulfamoyl groups, and particularly preferred are C 6 to C 16 Or 1
2 is a sulfamoyl group.

In the general formula (I), the substituent R may further have a substituent, and examples of the substituent include those described below.

A chain or cyclic alkyl group having 1 to 20 carbon atoms (for example, methyl, ethyl, isopropyl, cyclohexyl) and an aryl group having 6 to 18 carbon atoms (for example, phenyl, chlorophenyl, 2,4-diphenyl) -T-amylphenyl, 1-naphthyl), an aralkyl group having 7 to 18 carbon atoms (eg, benzyl, anisyl), an alkenyl group having 2 to 20 carbon atoms (eg, vinyl, 2-methylvinyl), a carbon atom Alkynyl groups of 2 to 20 (eg, ethynyl, 2-methylethynyl, 2-phenylethynyl), halogen atoms (eg, F, Cl, Br,
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),
20 alkoxy groups (for example, methoxy, butoxy, cyclohexyloxy), aryloxy groups having 6 to 20 carbon atoms (for example, phenoxy, 1-naphthoxy, toluoyl), and alkylthio groups having 1 to 20 carbon atoms (for example, methylthio Butylthio, benzylthio, 3-methoxypropylthio), an arylthio group having 6 to 20 carbon atoms (eg, phenylthio, 4-chlorophenylthio), an alkylsulfonyl group having 1 to 20 carbon atoms (eg, methanesulfonyl, butanesulfonyl) ), An arylsulfonyl group having 6 to 20 carbon atoms (eg, benzenesulfonyl, paratoluenesulfonyl), a carbamoyl group having 1 to 17 carbon atoms (eg, unsubstituted carbamoyl, methylcarbamoyl, ethylcarbamoyl, n-
Butylcarbamoyl, dimethylcarbamoyl), an amide group having 1 to 16 carbon atoms (eg, acetamido, benzamide), an acyloxy group having 2 to 10 carbon atoms (eg, acetoxy, benzoyloxy), 2 carbon atoms
10 to 10 alkoxycarbonyl groups (eg, methoxycarbonyl, ethoxycarbonyl), 5- or 6-membered heterocyclic groups (eg, aromatic heterocycles such as pyridyl, thienyl, furyl, thiazolyl, imidazolyl, and pyrazolyl), pyrrolidine rings, and piperidine rings , A morpholine ring, a pyran ring, a thiopyran ring, a dioxane ring, a hetero ring such as a dithiolane ring).

In the general formula (I), preferred as the substituent for the substituent R are a chain or cyclic alkyl group having 1 to 16 carbon atoms, an aryl group having 6 to 14 carbon atoms,
Aralkyl group having 7 to 15 carbon atoms, 1 to 1 carbon atom
6, an alkoxy group having 6 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, a halogen atom, an alkoxycarbonyl group having 2 to 17 carbon atoms, a carbamoyl group having 1 to 10 carbon atoms,
Amide groups having 1 to 10 carbon atoms, among which preferred are chain or cyclic alkyl groups having 1 to 10 carbon atoms,
An aralkyl group having 7 to 13 carbon atoms, 6-1 carbon atom
An aryl group of 0, an alkoxy group having 1 to 10 carbon atoms,
An aryloxy group having 6 to 10 carbon atoms, a chlorine atom, an alkoxycarbonyl group having 2 to 11 carbon atoms, a carbamoyl group having 1 to 7 carbon atoms, an amide group having 1 to 8 carbon atoms, and particularly preferable ones are A chain branched or cyclic alkyl group having 3 to 10 carbon atoms, an aralkyl group having 7 to 11 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 3 to 9 carbon atoms, phenyl and It is a chlorine atom.

In the general formula (I), n is preferably 2 to 6, more preferably 3 or 4, and particularly preferably 4.
When n is an integer of 2 or more, a plurality of Rs may be the same or different, but preferably the same. In the general formula (I), M is preferably a metal, and among them, copper, nickel or palladium is preferable,
Further, copper or nickel is preferable, and copper is particularly preferable.

The compound represented by the general formula (I) may be bonded at any position to form a multimer. In this case, each unit may be the same or different from each other. It may be bonded to a polymer chain of polymethacrylate, polyvinyl alcohol, cellulose or the like.

The phthalocyanine derivative represented by the general formula (I) used in the optical information recording medium of the present invention may be used alone or as a mixture of two or more compounds having different structures. However, it is preferable to use it alone. In some cases, the phthalocyanine derivative represented by the general formula (I) inevitably contains substitution position isomers of the substituent R at the time of its synthesis, but these substitution position isomers may be the same without distinction from each other. Can be considered. Further, when an isomer is contained in the substituent of R,
Without distinguishing these, they can be regarded as the same phthalocyanine derivative. Therefore, the case where the structures are different means that, when explained by the general formula (I), either the constituent atomic species or the number of substituents R is different or n is different.

The recording layer of the recording medium of the present invention forms recording marks (pits) by chemically or physically decomposing and changing the quality by absorbing the energy of laser light used for recording. This recording mark is detected as a portion where the reflectance has changed during reproduction. Extinction coefficient (k)
Is an optical property related to the amount of light energy absorbed, and is related not only to the amount of laser light energy absorbed by the recording layer during recording, but also to the reflectance detected during recording and reproduction. The refractive index (n) is related to the optical size of the recording mark (the amount of change in reflection quality). Since the output of the laser beam used for recording is practically several mW to several tens of mW, the extinction coefficient (k) and the refractive index (n) correspond to the basic skeleton of the compound used for the recording layer. There is a preferred range of In the case of the recording medium of the present invention, the refractive index (n) and the extinction coefficient (k) of the recording layer containing the compound represented by the general formula (I) are as follows at the wavelength of the laser beam used for recording. 1.0 <n <1.9, 0.0
It is preferably in the range of 3 <k <0.30, more preferably in the range of 1.5 <n <1.9 and 0.04 <k <0.15. The refractive index (n) and the extinction coefficient (k) can be easily measured by, for example, a rotation analyzer method (ellipsometry).

Preferred specific examples of the phthalocyanine derivative used in the present invention are shown in Table 1 below, but the present invention is not limited to these. In addition, the number of the substitution position of the substituent R of the phthalocyanine derivative is shown below.

[0029]

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[0030]

[Table 1]

The phthalocyanine derivatives used in the present invention include, for example, "Phthalocyanine-Chemistry and Function-" (P.1-62) published by IPC Co., Ltd.
C. C. Leznoff-A. B. P. Lever co-authored, VCH issued 'Phthalocyanines-P
rightsies and Application
The compound can be synthesized by the method described in s' (P. 1 to 54), the cited method, or a method similar thereto.

The optical information recording medium of the present invention is not particularly limited as long as it has a recording layer containing the phthalocyanine derivative on a substrate, and can be applied to optical information recording media having various structures. The optical information recording medium of the present invention may have a configuration in which, for example, a recording layer, a light reflecting layer, and a protective layer are provided in this order on a disk-shaped substrate on which pregrooves having a constant track pitch are formed. Hereinafter, the configuration of the optical information recording medium will be described in detail in accordance with the manufacturing process, taking an optical information recording medium having a recording layer, a light reflecting layer, and a protective layer in this order on a disc-shaped substrate as an example.

The substrate of the optical information recording medium of the present invention can be arbitrarily selected from various materials used as the substrate of the conventional optical information recording medium. As a substrate material,
For example, glass, polycarbonate, acrylic resins such as polymethyl methacrylate, polyvinyl chloride, vinyl chloride resins such as vinyl chloride copolymers, epoxy resins, amorphous polyolefins and polyesters, and the like. Is also good. Note that these materials can be used in the form of a film or a rigid substrate. Among the above materials, polycarbonate is preferred from the viewpoints of moisture resistance, dimensional stability, cost, and the like.

For the optical information recording medium of the present invention, in order to achieve a higher recording density, it is preferable to use a substrate on which a pre-groove having a narrower track pitch is formed than a CD-R or DVD-R. . In the case of the optical information recording medium of the present invention, the track pitch is preferably in the range of 0.2 to 0.8 μm, more preferably in the range of 0.2 to 0.5 μm, and more preferably in the range of 0.27 to 0 μm. Particularly preferably, it is in the range of 0.40 μm. Further, the depth of the pre-groove is preferably in the range of 0.01 to 0.18 μm, and more preferably in the range of 0.02 to 0.15 μm.

An undercoat layer may be provided on the surface of the substrate on which the recording layer is provided, for the purpose of improving flatness, improving adhesive strength, and preventing deterioration of the recording layer. Examples of the material of the undercoat layer include polymethyl methacrylate, acrylic acid / methacrylic acid copolymer, styrene / maleic anhydride copolymer, polyvinyl alcohol, N-methylol acrylamide, styrene / vinyl toluene copolymer, and chlorosulfonation. Polymeric substances such as polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, vinyl acetate / vinyl chloride copolymer, ethylene / vinyl acetate copolymer, polyethylene, polypropylene, polycarbonate, etc .; 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 the 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,
It can be performed by a method such as CVD or solvent application, but solvent application is preferred. When the recording layer is formed by applying a solvent, in addition to the phthalocyanine derivative, if necessary, 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. Is formed, the formed coating film is dried. Examples of the solvent for the coating solution include esters such as butyl acetate, ethyl lactate and cellosolve acetate; ketones such as methyl ethyl ketone, cyclohexanone and methyl isobutyl ketone; chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane and chloroform; dimethylformamide and the like. Amides; hydrocarbons such as methylcyclohexane; ethers such as dibutyl ether, diethyl ether, tetrahydrofuran, dioxane; alcohols such as ethanol, n-propanol, isopropanol, n-butanol, diacetone alcohol; 2,2,3,3-tetra Fluorinated solvents such as fluoropropanol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, etc. And the like can be mentioned recall ethers. The above-mentioned 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 according to the purpose.

When a binder is used, examples of the binder include natural organic high-molecular substances such as gelatin, cellulose derivatives, dextran, rosin and rubber; and hydrocarbon-based substances such as polyethylene, polypropylene, polystyrene and polyisobutylene. Resin, polyvinyl chloride, polyvinylidene chloride, vinyl resin such as polyvinyl chloride / polyvinyl acetate copolymer, acrylic resin such as polymethyl acrylate, polymethyl methacrylate, polyvinyl alcohol, chlorinated polyethylene, epoxy resin, Synthetic organic polymers such as butyral resins, rubber derivatives, and initial condensates of thermosetting resins such as phenol / formaldehyde resins can be given. 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 times to 50 times (mass ratio) with respect to the dye, and preferably 0.1 to 50 times.
It is in the range of 1 to 5 times (mass ratio). The concentration of the dye in the coating solution thus prepared is generally 0.01%.
It is in the range of 10 to 10% by mass, preferably in the range of 0.1 to 5% by mass.

Examples of the coating method include a spray method, a spin coating method, a dipping method, a roll coating method, a blade coating method, a doctor roll method, and a screen printing method. 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 to 500 nm.
It is in the range of 0-100 nm.

The recording layer can contain various anti-fading agents in order to improve the light resistance of the recording layer.
Generally, a singlet oxygen quencher is used as an anti-fading agent. As the singlet oxygen quencher, those described in publications such as publicly known patent specifications can be used. A specific example thereof is disclosed in Japanese Patent Application Laid-Open No. 58-175.
Nos. 693, 59-81194, 60-18387
Nos. 60-19586, 60-19587, 60-35054, 60-36190, 60-
No. 36191, No. 60-44554, No. 60-445
No. 55, No. 60-44389, No. 60-44390
Nos. 60-54892, 60-47069, 63-20995, JP-A-4-25492, JP-B1-38680, and 6-26028, and German Patent 350399. And the publications of the Chemical Society of Japan, October, 1992, p. 1141. Preferred examples of the singlet oxygen quencher include a compound represented by the following general formula (II).

[0040]

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(Wherein, R ²¹ represents an alkyl group which may have a substituent, and Q ⁻ represents an anion.) In the general formula (II), R ²¹ represents a carbon number which may be substituted. An alkyl group having 1 to 8 is generally used, and an unsubstituted alkyl group having 1 to 6 carbon atoms is preferable. Examples of the substituent of the alkyl group include a halogen atom (eg, F, Cl), an alkoxy group (eg, methoxy, ethoxy), an alkylthio group (eg, methylthio, ethylthio), an acyl group (eg, acetyl, propionyl), an acyloxy group (Eg, acetoxy, propionyloxy), hydroxy group, alkoxycarbonyl group (eg, methoxycarbonyl, ethoxycarbonyl), alkenyl group (eg, vinyl), aryl group (eg,
Phenyl, naphthyl). Among these, a halogen atom, an alkoxy group, an alkylthio group,
Alkoxycarbonyl groups are preferred. Preferred examples of the anion of Q ⁻ include ClO ₄ ⁻ , AsF ₆ ⁻ , BF ₄ ⁻ , and SbF ₆ ⁻ .

Table 2 shows examples of the compound represented by the general formula (II).

[0043]

[Table 2]

The amount of the anti-fading agent such as the singlet oxygen quencher is usually 0.1 to 50 to the amount of the dye.
%, Preferably 0.5 to 45% by mass.
, More preferably in the range of 3 to 40% by mass, particularly preferably in the range of 5 to 25% by mass.

It is preferable to provide a light reflection layer adjacent to the recording layer for the purpose of improving the reflectance at the time of reproducing information. The light-reflective substance, which is the material of the light-reflective layer, is a substance having a high reflectance with respect to a laser.
e, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, M
o, W, Mn, Re, Fe, Co, Ni, Ru, Rh,
Pd, Ir, Pt, Cu, Ag, Au, Zn, Cd, A
1, Ga, In, Si, Ge, Te, Pb, Po, S
Metals such as n and Bi and semimetals or stainless steel can be mentioned. These substances may be used alone, or in combination of two or more kinds, or may be used as an alloy. Of these, preferred are Cr,
Ni, Pt, Cu, Ag, Au, Al and stainless steel. Particularly preferred are Au metal, Ag metal, Al metal and alloys thereof, and most preferred is Ag metal.
Metal, Al metal, or an alloy thereof. The light reflecting layer can be formed on the substrate or the recording layer by, for example, vapor deposition, sputtering, or ion plating of the light reflecting substance. The thickness of the light reflecting layer is generally in the range of 10 to 300 nm,
It is preferably in the range of 200 nm.

It is preferable to provide a protective layer 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 a configuration similar to that in the case of manufacturing a DVD-R type optical information recording medium, that is, a configuration in which two substrates are bonded together with the recording layer inside, it is not always necessary to provide a protective layer. Examples of the material used for the protective layer include ZnS—SiO ₂ , ZnS, and Si.
Examples 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 a plastic on the reflective layer via an adhesive. Alternatively, it may be provided by a method such as vacuum deposition, sputtering, or coating. In the case of a thermoplastic resin or a thermosetting resin, they can also be formed by dissolving these in an appropriate solvent to prepare a coating solution, applying the coating solution, and drying. 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 an appropriate solvent, applying the coating solution, and irradiating with UV light to cure.
In these coating solutions, furthermore, an antistatic agent, an antioxidant,
Various additives such as a UV absorber may be added according to the purpose. The thickness of the protective layer is generally in the range from 0.1 μm to 1 mm. Through the above steps, a laminate in which the recording layer, the light reflecting layer and the protective layer are provided on the substrate, or the light reflecting layer, the recording layer and the protective layer are provided on the substrate can be manufactured.

The information recording method of the present invention can be performed, for example, as follows, using the above optical information recording medium. First, the optical information recording medium is set at a constant linear speed (1.2 for a CD format).
~ 1.4m / sec) or rotating at a constant angular speed,
Light for recording such as a semiconductor laser is irradiated from the substrate side or the protective layer side. By this light irradiation, the recording layer absorbs the light and locally raises the temperature, causing a physical or chemical change (for example, generation of pits) to change its optical characteristics, thereby recording information. It is thought to be done.
In the present invention, a semiconductor laser having an oscillation wavelength of around 780 nm or 390 to 450 is used as a recording light source.
Any of semiconductor lasers having an oscillation wavelength in the range of nm may be used.

As the semiconductor laser light source having an oscillation wavelength in the range of 390 to 450 nm, a blue-violet semiconductor laser having an oscillation wavelength in the range of 390 to 415 nm, a blue-green semiconductor laser having a center oscillation wavelength of 515 nm, and a center oscillation wavelength of 8
Center oscillation wavelengths 405 to 4 composed of a 50 nm infrared semiconductor laser and an optical waveguide type wavelength conversion element (SHG)
A 25-nm blue-violet SHG laser can be used. It is particularly preferable to use a blue-violet semiconductor laser from the viewpoint of recording density.

The information recorded as described above is reproduced by irradiating a laser beam from the substrate side while rotating the optical information recording medium at the same constant linear speed as above, and detecting the reflected light. Can be performed.

The optical information recording medium of the present invention is a conventional DVD.
Similarly to -R, two laminates in which a recording layer and a light reflection layer are provided on a transparent disk-shaped substrate on which a pre-groove having a constant track pitch is formed such that each recording layer is on the inside. Can be used. Further, a structure in which this laminated body and a disk-shaped protective substrate having the same shape are bonded together with the recording layer facing inward may be adopted. When the bonding structure is adopted, for example, when the diameter of the transparent substrate is 1
The optical information recording medium having a thickness of 20 ± 3 mm and a thickness of 0.6 ± 0.1 mm is used.
It is adjusted to be 0.2 mm. This bonding may be performed using the UV curable resin used for forming the protective layer, or may be performed using a synthetic adhesive. Also,
It can also be laminated with double-sided tape.

The optical information recording medium of the present invention may have a structure in which a light reflecting layer, a recording layer, and a thin film protective layer are provided in this order on a disk-shaped substrate on which a pre-groove having a constant track pitch is formed. it can. In this optical information recording medium, a thin protective layer is provided on the side opposite to the substrate having a predetermined thickness (1.2 mm for CD-R), and recording is performed by irradiating light from the thin protective layer side. The beam diameter of the laser light to be irradiated can be reduced to a small value, and high-density recording can be performed with light having a short wavelength of 450 nm or less.

The thin film protective layer has a thickness of 0.1 to
It is preferably 300 μm, and a photocurable resin or
It is formed from a film-like resin. The thin film protective layer is medium
It may be provided on the recording layer via an interlayer and an adhesive layer. Middle class
Increases the storage stability of the recording layer, and adheres the recording layer to the thin film protective layer.
It is provided to improve the performance. Used for middle layer
As a material, for example, ZnS-SiO_Two, ZnS, S
iO, SiO_Two, MgF _Two, SnO_Two, Si_ThreeN_FourEtc. inorganic
Substances can be mentioned. This intermediate layer is
It can be formed by vacuum deposition such as deposition, sputtering, etc.
it can. The adhesive layer contains an adhesive or photo-curable resin.
It is preferable to use a cryl adhesive. For example, light hard
Dissolvable resin as it is or after dissolving in an appropriate solvent
After preparing the liquid, apply this coating liquid on the intermediate layer and apply
The resin foil obtained by, for example, plastic extrusion on the membrane
Film is laminated and the laminated resin film is
By irradiating light from above to cure the coating film, the resin
The film can be glued on the interlayer. This
A thin film protective layer is formed.

[0053]

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 Exemplified compound (I-1) was dissolved in methylcyclohexane, and a coating solution for forming a recording layer (concentration: 1% by mass)
I got Spiral pre-groove (track pitch: 0.4 μm, groove width: 0.2)
μm, groove depth: 0.08 μm) polycarbonate substrate (diameter: 120 m) formed by injection molding
m, thickness: 0.6 mm) was applied by spin coating to the surface on the pre-groove side to form a recording layer (thickness (within the pre-groove): about 80 nm). Next, silver was sputtered on the recording layer to form a light reflection layer having a thickness of about 100 nm. Further, a UV curable resin (trade name: SD) is formed on the light reflecting layer.
318, manufactured by Dainippon Ink and Chemicals, Inc.) and cured by irradiating ultraviolet rays to form a protective layer having a thickness of 7 μm. The optical disk according to the present invention was obtained through the above steps.

[Examples 2] to [Example 8] In the same manner as in Example 1 except that the above exemplified compound (I-1) was replaced with the compound shown in Table 3 (the amount used was not changed). An optical disk according to the present invention was manufactured.

[Comparative Examples 1] to [Comparative Example 7] The above exemplified compound (I-1) was replaced with the following comparative dye compounds A to G (the amount used was not changed) (the amount used was not changed). Except for this, an optical disc for comparison was manufactured in the same manner as in Example 1.

[Evaluation 1 as Optical Disc] A 14T-EFM signal was recorded on the produced optical disc at a linear velocity of 3.5 m / sec by using a blue-violet semiconductor laser having an oscillation wavelength of 405 nm, and the recorded signal was reproduced. The modulation, groove reflectivity, and sensitivity at optimal power were measured. For recording and recording characteristics evaluation, "DDU1000" manufactured by Pulstec
This was performed using Table 3 shows the evaluation results.

[0057]

[Table 3]

From the results in Table 3, it can be seen that the optical disk having the recording layer containing the phthalocyanine derivative which is a feature of the present invention (Examples 1 to 8) is the optical disk having the recording layer containing the comparative compounds A to G (Comparative Example 1). 7) compared to wavelength 40
It can be seen that it shows a high reflectivity to a laser beam of 5 nm, a high degree of modulation, and a high sensitivity. Therefore, it can be understood that an optical disc having high recording characteristics with respect to a short-wavelength laser beam having a wavelength of 450 nm or less can be obtained by using the phthalocyanine derivative according to the present invention.

[0059]

Embedded image

[0060]

Embedded image

Example 9 The exemplified compound (I-3) was dissolved in dibutyl ether, and a coating solution for forming a recording layer (concentration: 1)
% By mass). A polycarbonate substrate having a spiral pre-groove (track pitch: 1.0 μm, groove width: 0.4 μm, groove depth: 0.15 μm) formed on the surface of this coating solution by injection molding (diameter:
The recording layer (thickness (within the pre-groove): about 170 nm) was formed on the pre-groove side surface having a thickness of 120 mm and a thickness of 0.6 mm by spin coating. Next, silver was sputtered on the recording layer to form a light reflection layer having a thickness of about 100 nm. Further, a UV curable resin (trade name: SD318, Dainippon Ink and Chemicals, Inc.) is provided on the light reflecting layer.
Is applied and cured by irradiating ultraviolet rays, and the layer thickness is 7 μm.
Was formed. The optical disk according to the present invention was obtained through the above steps.

[Evaluation 2 as Optical Disk] After recording a 14T-EFM signal on an optical disk at a linear velocity of 1.4 m / sec using a semiconductor laser having an oscillation wavelength of 780 nm, the recorded signal was reproduced using the same semiconductor laser. And the reproduced signal waveform was observed. In addition, the same optical disc has a linear velocity of 1.4 m.
After recording a 14T-EFM signal using a semiconductor laser having an oscillation wavelength of 405 nm / sec, the signal recorded using the same semiconductor laser was reproduced, and the reproduced signal waveform was observed. As a result, the same clear reproduced signal waveform could be observed when recording was performed using any of the laser beams having different wavelengths. Further, when a signal recorded using a semiconductor laser having an oscillation wavelength of 780 nm was reproduced using a semiconductor laser having an oscillation wavelength of 405 nm, a clear reproduced signal waveform could be observed.

[0063]

According to the optical information recording medium of the present invention, by using a phthalocyanine derivative as a recording material for a recording layer, a short-wavelength laser beam having a wavelength of 450 nm or less, particularly a laser beam having a wavelength of about 405 nm, which is highly versatile, is irradiated. High-density recording and reproduction of information, and high sensitivity,
This has the effect of having good recording and reproduction characteristics such as high reflectivity and high modulation. That is, the conventional CD-R or DV
It is possible to record information at a higher density than that of DR, and it is possible to record a larger amount of information.

Further, the optical information recording medium of the present invention uses a phthalocyanine derivative as a recording material for a recording layer, and can use a short-wavelength laser beam having a wavelength of 450 nm or less without using a different recording material for each different wavelength. C
This has the effect that recording and reproduction can be performed with both laser beams having wavelengths of 750 to 850 nm used for DR. That is, there is an effect that an optical information recording medium having high versatility can be easily provided.

Continued on the front page (72) Inventor Takeshi Tsunoda 2-1-1, Ogimachi, Odawara-shi, Kanagawa F-photograph within Fuji Photo Film Co., Ltd. (Reference) 2H111 EA03 EA12 EA22 EA25 EA32 EA43 FA01 FB45 5D029 JA04

Claims (5)

[Claims] 1. An optical information recording medium having a recording layer capable of recording information by irradiating a laser beam having a wavelength of 450 nm or less on a substrate, wherein the recording layer contains a phthalocyanine derivative. Information recording medium. 2. The optical information recording medium according to claim 1, wherein the phthalocyanine derivative is represented by the following general formula (I). Embedded image [Wherein, R represents a substituent, n represents an integer of 1 to 8, and when n is an integer of 2 or more, a plurality of Rs may be the same or different from each other, and M is two hydrogens. Atoms, metals,
Represents a metal oxide or a metal having a ligand. ] 3. The optical information recording medium according to claim 2, wherein the metal representing M is copper, nickel, iron, cobalt, palladium, magnesium, aluminum, zinc or silicon. 4. The substituent R is an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aralkyl group having 7 to 15 carbon atoms, and a heterocyclic group having 1 to 10 carbon atoms. An alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, and 2 carbon atoms
An acyl group having 1 to 20 carbon atoms, an alkylsulfonyl group having 1 to 20 carbon atoms, an arylsulfonyl group having 6 to 14 carbon atoms, an aralkylsulfonyl group having 7 to 15 carbon atoms, and a hetenylsulfonyl group having 1 to 10 carbon atoms A carbamoyl group having 1 to 25 carbon atoms, a sulfamoyl group having 0 to 32 carbon atoms, an alkoxycarbonyl group having 1 to 20 carbon atoms, an aryloxycarbonyl group having 7 to 15 carbon atoms, and 2 to 21 carbon atoms. 4. The optical information recording medium according to claim 2, wherein the optical information recording medium is an acylamino group, a sulfonylamino group having 1 to 20 carbon atoms, or a halogen atom. 5. The method according to claim 2, wherein n is an integer of 1 to 4.
An optical information recording medium according to claim 1.