JP2003168241A - Optical recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phthalocyanine based optical recording medium having excellent recording properties in the condition of high speed recording and high durability, even though a phthalocyanine based optical recording medium is used in a optical recording medium such as a CD-R, by relating the maximum absorption wavelength peak and a sub peak on the shorter wavelength area side thereof in the light absorption spectrum of a recording layer in a specified relation. <P>SOLUTION: The optical information recording medium wherein a dyestuff recording layer is formed on a substrate and a metal reflection layer is formed thereon is characterized in that the recording layer contains a phthalocyanine compound and the ratio (P2/P1) of the sub peak (P2) on the wavelength area side shorter than the maximum absorption wavelength peak (P1) to the peak P1 in the light absorption spectrum of the recording layer is ≤40%. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium, and more particularly to an optical recording medium whose recording layer used for CD-R, DVD-R, etc. contains a phthalocyanine compound.

[0002]

2. Description of the Related Art In recent years, in addition to an optical recording medium such as a read-only CD (compact disc), a recordable CD
(CD-R, CD-RW) has been put to practical use. CD-
Unlike conventional CDs, R and CD-RW allow a user to record information, and the signal after recording is a conventional CD.
In order to satisfy the standard (1), it is possible to play back on a commercially available CD player.

As one of the methods for realizing such a medium, for example, in CD-R, Japanese Patent Laid-Open No. 2-42652 is used.
Japanese Patent Laid-Open Publication No. 2003-242242 discloses that a substrate is spin-coated with a dye to provide a light absorbing layer, and a metal reflecting layer is provided behind the light absorbing layer. As a material for such a light absorption layer, a cyanine dye-based material has been mainly used.
This type of dye has excellent optical characteristics in that it has a large absorption coefficient, but it has a drawback that it has poor light resistance.

Therefore, it has been proposed in JP-A-3-62878 to use a phthalocyanine dye material having excellent light resistance.

Further, Japanese Patent Laid-Open No. 10-45761 discloses
Is A¹~ A⁸To -OC (R¹) (R ³) -R²Have a group
Phthalocyanine compound that can be used for CD-R
A phthalocyanine compound is disclosed in JP-A-10-181204.
In the publication, A¹~ A⁸To -OC (R¹) (R³) -R²Basis
Phthalocyanine compounds with different thermal decomposition characteristics
By mixing with another phthalocyanine compound,
Patent No. 3 that creates a CD-R with excellent signal and playback characteristics
No. 024998 has A¹~ A⁸Has an amino group in
The core metal M is a substituted trivalent metal atom, a disubstituted tetravalent metal atom (S
i, Sn, Ge, etc.) specific phthalocyanine compound
JP-A-5-177948, Toyo Ink Manufacturing Co., Ltd.
Ltd., the central metal M is a disubstituted tetravalent metal atom (Si,
A specific phthalocyanine compound which is Sn) as a recording material
The used CD-R is disclosed.

[0006]

On the other hand, as the recording drive, a model having a higher recording speed than the conventional CD speed (about 1.2 m / s) recording has been commercialized, and due to its high processing speed, it can be used by general users. It has become popular. Already 16 times speed (about 19.2m / s)
High-speed recording drives are commercially available, and a CD-R medium capable of recording under such high-speed recording conditions is required.

In order to form the recording pits under such a high speed condition, in addition to the high decomposition speed of the dye material, it is necessary that the recording pits do not interfere with each other due to heat. That is, when recording pits are formed under high speed conditions,
Due to the influence of the front, rear, left and right recording pits, it is difficult to form pits of an appropriate size, and there is a problem that signal jitter increases. As a media configuration that suppresses the influence of the recording pits in the front, rear, left, and right, it is preferable to reduce the film thickness of the dye layer that is the recording layer to allow heat to escape to the reflective layer.

However, the CD-R media using the conventional phthalocyanine dye is excellent in durability,
There is a problem that the light absorption coefficient is smaller than that of the cyanine dye, and that when the dye film thickness is reduced, it is difficult to obtain the modulation degree which is the signal contrast. Also, regarding the thermal decomposition characteristics, there was a problem that the decomposition temperature was higher than that of cyanine dyes, and it was difficult to obtain high sensitivity.

An object of the present invention is to solve these problems and to use a phthalocyanine type optical recording medium, and to provide a maximum absorption wavelength peak of a light absorption spectrum of a recording layer and a sub peak in a wavelength range shorter than that. Is to provide a highly durable phthalocyanine-based optical recording medium having excellent recording characteristics under high-speed recording conditions.

[0010]

The above object of the present invention can be achieved by the following means. According to the invention of claim 1, in an optical information recording medium in which a dye recording layer is formed on a substrate and then a metal reflective layer is formed on the recording layer, the recording layer contains a phthalocyanine compound, and the recording layer Ratio (P2 and P) of the maximum absorption wavelength peak (P1) of the optical absorption spectrum of P and the sub peak (P2) in the wavelength range shorter than P1
The peak intensity ratio of 1: P2 / P1) is 0.4 or less.

Secondly, in the optical information recording medium according to the first aspect, the maximum absorption wavelength of the optical absorption spectrum of the recording layer is 710 nm to 750 nm.

Thirdly, the optical recording medium according to any one of claims 1 and 2 is characterized in that the dye recording layer contains two or more kinds of phthalocyanine compounds.

Fourthly, in the optical information recording medium according to any one of claims 1 to 3, the recording layer contains a phthalocyanine compound represented by the general formula (I) under the following conditions. .

[0014]

[Chemical 2]

In the formula, M is any one of a divalent metal atom, a monovalent trivalent metal atom, a divalent tetravalent metal atom or an oxymetal, and A ¹ and A ² , A ³ and A ⁴ , A ⁵ and A ⁶ or A ⁷ and A ⁸ are independent of each other,
Is a group represented by the formula —O—C (R ¹ ) (R ³ ) —R ² , the other is a hydrogen atom, and in the formula, R ¹ and R ³ are alkyl groups,
It is any one selected from a fluorine-substituted alkyl group or a hydrogen atom, R ² is a substituted phenyl group or an unsubstituted phenyl group, or in the formula, M is
Represents a di-substituted tetravalent metal atom selected from Si, Sn and Ge, and ^one of A ¹ and A ² , A ⁴ and A ⁵ , A ⁶ and A ⁷ or A ⁸ and A ⁹ is independently a formula. Is a group represented by —O—R ⁴ , the other is a hydrogen atom,
R ⁴ is a linear or branched alkyl group or a fluorine-substituted linear or branched alkyl group.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, under high-speed recording conditions, it is necessary to set the recording layer thinner than before in order to prevent thermal interference of recording pits. However, since it is difficult to obtain the degree of modulation in the conventional phthalocyanine dye, it is necessary to set the recording layer thickness to be large. A block diagram of the CD-R is shown in FIG. Reference numeral 1 is a substrate, 2 is a dye recording layer, 3 is a reflective layer, and 4 is a protective layer, and recording / reproduction is performed by light from the substrate surface side.

In the CD-R, the reflectance is obtained by the multiple interference effect on both interfaces of the dye recording layer. Generally, the thicker the recording layer, the larger the optical change in the pit portion, so that the degree of modulation can be easily obtained. .

In the optical recording medium of the present invention, the recording layer contains a phthalocyanine compound, and the ratio of the maximum absorption wavelength peak (P1) of the optical absorption spectrum of the recording layer to the subpeak (P2) in the wavelength range shorter than P1. Is 0.4 (40% in percent) (P2 / P1) or less, excellent recording characteristics can be obtained in high-speed recording.

FIG. 2 shows an optical absorption spectrum of the phthalocyanine dye film. In the present invention, as a result of examination focusing on the light absorption spectrum and the recording characteristics under high-speed conditions, as shown in FIG. 2, by setting the P2 / P1 ratio to 40% or less, excellent recording in high-speed recording is possible. It has been found that the characteristics can be obtained.

This is because the P1 / P2 ratio is related to the associativity of the dye molecules. The smaller the P1 / P2 ratio, the more un-associated the state is like in a solution. Probably due to meeting.

Since the phthalocyanine dye molecule generally has a planar structure, it is easy to associate with the molecule. The higher the degree of association, the more difficult it is to thermally decompose, and the harder it is to obtain the optical characteristics required for CD-R, that is, the characteristics of high refractive index and low absorptivity, so that the degree of modulation cannot be obtained.

Further, in order to match the recording performance with a CD-R recording / reproducing laser, the maximum absorption wavelength of the optical absorption spectrum of the recording layer is preferably 710 nm-750 nm. The laser light wavelength for CD is ≈780 nm.

Further, it is preferable to mix two or more kinds of dye compounds used as the dye component. this is,
Mixing a plurality of dye components has the effect of reducing association, and a single component has the P1 / P ratio of the present invention.
This is because it is difficult to satisfy the two ratios and to achieve a good balance between thermal characteristics and optical characteristics. As described above, by using two or more kinds of phthalocyanine dye molecules, it is possible to obtain a highly durable optical recording medium having a good balance of thermal characteristics and optical characteristics while suppressing association.

In particular, it is preferable to contain the phthalocyanine dye represented by claim 4. The inventors of the present invention have proposed a structure represented by claim 4 as a phthalocyanine dye excellent in durability and thermal decomposition characteristics in JP-A-10-45761 and JP-A-10-181204. The phthalocyanine dye represented by claim 4 has P
By mixing components such that the 1 / P2 ratio is 40% or less, excellent recording characteristics can be obtained at high speed recording.

As the dye to be mixed, the phthalocyanine dye shown in claim 5 is preferable. The phthalocyanine dye of claim 5 is a di-substituted ion having Si, Sn and Ge as the central metals, and the group bonded to the metal is likely to have a structure protruding above and below the molecular plane and is difficult to associate.

The phthalocyanine compound according to claim 4 is as follows. In the general formula (1), M and A ^{1 to} A
⁸ represents the following, respectively. M: divalent metal atom, monosubstituted trivalent metal atom, disubstituted tetravalent metal atom or oxymetal, A ¹ and A ² , A ³ and A ⁴ , A ⁵ and A ⁶ and A ⁷
And A ⁸ : either one of them independently
^{O-C (R 1) (} R 3) -R 2, the other is hydrogen atom, R ^1, R
³ : Alkyl group, fluorine-substituted alkyl group or hydrogen atom, R ² : alkyl group, substituted phenyl group or unsubstituted phenyl group.

Specific examples of the central metal M include the following, but Zn, Ni, Cu, Pd, V
One metal atom or metal oxide selected from O 2 and Ti 2 O 3 is preferable. These M are easy to synthesize a dye and have a maximum absorption wavelength of 710 nm− in the light absorption spectrum of the recording layer.
At 750 nm. Table 1 shows specific examples of the dye structure.

[0028]

[Table 1]

Bivalent metals Cu ² +, Zn ² +, Fe ² +, Co ² +, Ni ² +, Ru ² +, R
h ² +, Pd ² +, Pt ² +, Mn ² +, Mg ² +, Ti ² +, Be
² +, Ca ² +, Ba ² +, Cd ² +, Hg ² +, Pb ² +, Sn ² +
Such.

Mono- substituted trivalent metal Al-Cl, Al-Br, Al-F, Al-I, Ga-
Cl, Ga-F, Ga-I, Ga-Br, In-Cl,
In-Br, In-I, In-F, Tl-Cl, Tl-
Br, Tl-I, Tl- F, Al-C 6 H 5, Al-C
_{6 H 4 (CH 3),} In-C 6 H 5, In-C 6 H
_{4 (CH 3), In-} C 10 H 7, Mn (OH), Mn
(OC ₆ H ₅ ), Mn [OSi (CH ₃ ) ₃ ], FeC
1, RuCl, etc.

[0031]2-substituted tetravalent metal CrCl₂, SiCl₂, SiBr₂, SiF₂, Si
I₂, ZrCl₂, GeCl₂, GeBr₂, Ge
I₂, GeF₂, SnCl₂, SnBr₂, SnI ₂,
SnF₂, TiCl₂, TiBr₂, TiF₂, Si
(OH)₂, Ge (OH)₂, Zr (OH)₂, Mn
(OH)₂, Sn (OH)₂, TiR₂, CrR ₂, S
iR₂, SnR₂, GeR₂[R is an alkyl group, phenyl
Group, naphthyl group and derivatives thereof], Si (O
R ')₂, Sn (OR ')₂, Ge (OR ')₂, Ti
(OR ')₂, Cr (OR ')₂[R 'is an alkyl group,
Phenyl group, naphthyl group, trialkylsilyl group, dia
Represents a alkylalkylsilyl group and its derivatives],
Sn (SR ~)₂, Ge (SR ~)₂[R is alkyl
Group, phenyl group, naphthyl group and derivatives thereof]
And so on.

Oxy-substituted VO, MnO, TiO and the like.

Specific examples of R1 and R3 include a methyl group,
Ethyl group, propyl group, isopropyl group, n-propyl group, butyl group, n-butyl group, sec-butyl group, te
rt- butyl _{group, -CF 3, -C 2 F 5} , -CF (CF
₃ ) ₂ , hydrogen atoms and the like. In particular, it is preferred substituents R1, R3 are both -CF _3. The --CF ₃ group lowers the thermal decomposition temperature and improves the recording sensitivity.

Specific examples of R2 include phenyl group, naphthyl group, 2-methylphenyl group, 2.4-dimethylphenyl group, 2.4.6-trimethylphenyl group, 2-isopropylphenyl group and 2.5-. Dimethylphenyl group,
Examples thereof include a 2.6-dimethylphenyl group and a 2-ethylphenyl group. The alkyl group attached to the phenyl group preferably has 1 to 4 carbon atoms. This is because when the carbon number is larger than this, the absorbance per unit film thickness of the light absorption layer is likely to decrease, and it becomes difficult to obtain a good complex refractive index.

The phthalocyanine compound represented by the general formula (I) can be easily synthesized by a cyclization reaction of a corresponding phthalonitrile mixture. That is, the phthalonitrile of the following (2) can be easily synthesized by heating and reacting the metal derivative with an alcohol in the presence of, for example, 1,8-diazabicyclo [5,4,0] -7-undecene.

[0036]

[Chemical 3]

The phthalocyanine compound according to claim 5 is as follows. In the general formula (1), M and A ¹ ~
A ⁸ represents the following, respectively. M is Si, Sn,
One di-substituted tetravalent metal atom selected from Ge, A ¹
And A ² , A ³ and A ⁴ , A ⁵ and A ^6, and A ⁷ and A ⁸ , each of which is independently -OR ⁴ ;
The other is a hydrogen atom, and R ⁴ is a linear or branched alkyl group or a fluorine-substituted linear or branched alkyl group. The central metal M is S which is a disubstituted tetravalent metal atom.
Examples thereof include i, Sn and Ge, with Si being preferred. Si
The dye is easy to synthesize in the body, and the maximum absorption wavelength of the light absorption spectrum of the recording layer is 710 nm to 750 nm. Table 2 shows specific examples of the dye structure.

[0038]

[Table 2]

Specific examples of the substituents of the central metal M include the following, -O-R ⁵ , -OCR ⁶ , -O.
-PR ⁷ R ^8, a group selected from -O-SiR ⁹ R ¹⁰ are preferred. With these M substituents, dye synthesis is easy and a good P1 / P2 ratio is obtained. Substituents of the central metal M, a substituted or unsubstituted alkyl group, an aryl group, an alkoxy group, an aryloxy ^{group, -O-P-R 7 R} 8
^{Group, O-P-OR 12 R} 13 ^{groups, -O-Si-R 9 R} 10 R 11
Group, -O-COR ⁶ group, -O-COCOOR ¹⁴ group, -O
-COCOR ¹⁵ group, -O-CONR ¹⁶ R ¹⁷ group, R ^{5 to} R
¹⁷ is independently a hydrogen atom, substituted or unsubstituted 1
Valent aliphatic hydrocarbon group or substituted or unsubstituted 1
A valent aromatic hydrocarbon group, and specific examples of R ⁴ include
Methyl group, ethyl group, propyl group, isopropyl group, n
- propyl group, butyl group, n- butyl group, sec- butyl group, tert- butyl ^{group, -CF 3, -C 2 F 5} , -
Examples thereof include CF (CF ³ ) ² and a hydrogen atom, but a fluorine-substituted linear or branched alkyl group is particularly preferable. These compounds can be easily synthesized by the cyclization reaction of the corresponding phthalonitrile mixture as described above.

Light comprising the phthalocyanine compound of the present invention
The absorption layer is prepared by dissolving the compound in a solvent and applying it as a coating liquid on the substrate.
It can be easily obtained by coating The central metal M
Fe ²+, Co²+, Zn²+, Cd²+, Mn²With +
In some cases it is preferred to add an amino compound.
When M is one of these metals, the amino compound is
It is easy to coordinate and prevents coordination by coordination,
This is because the solubility in water and the coating film-forming property are improved. amino
Examples of the compound include the following compounds.
However, the present invention is not limited to these. Among these
Therefore, the effect of preventing the association of the phthalocyanine compound is high,
And it is also excellent in durability (heat resistance, light resistance)
Compounds containing N atom in the heterocycle are preferred. Moreover, the light
From the standpoint of maintaining the thermal stability of the absorption layer,
The material preferably has a melting point of 150 ° C or higher.
Yes. If the melting point is less than 150 ℃, in a high temperature and high humidity environment
Because the characteristics of the light absorption layer (especially the optical characteristics) change easily.
is there. Among them, particularly preferable are imidazole and benz.
They are imidazole and thiazole derivatives.

Specific examples of the compounds include n-butylamine, n-hexylamine, tert-butylamine, pyrrole, pyrrolidine, pyridine, piperidine, purine, imidazole, benzimidazole, 5,6-dimethylbenzimidazole, 2 , 5,6-Trimethylbenzimidazole, naphthoimidazole, 2-methylnaphthoimidazole, quinoline, isoquinoline, quinoxaline, benzquinoline, phenanthridine, indoline, carbazole, norharman, thiazole, benzthiazole, benzoxazole, benztriazole, 7- Azaindole, tetrahydroquinoline, triphenylimidazole, phthalimide, benzisoquinoline-5,10-dione, triazine, perimidine, 5
-Chlorotriazole, ethylenediamine, azobenzene, trimethylamine, N, N-dimethylformamide, 1 (2H) phthalazinone, phthalhydrazide, 1,
3-diiminoisoindoline, oxazole, polyimidazole, polybenzimidazole, polythiazole and the like.

As the light-absorbing material, in addition to the phthalocyanine compound, other dyes conventionally known as recording materials for information recording media can be mixed and used. Examples of such dyes include cyanine dyes, pyrylium-based / thiopyrylium-based dyes, azurenium-based dyes, squarylium-based dyes, metal complex salt-based dyes such as Ni and Cr, naphthoquinone-based / anthraquinone-based dyes, indophenol-based dyes, Indoaniline dye,
Triphenylmethane dye, triallylmethane dye,
Examples thereof include aminium-based / diimmonium-based dyes and nitroso compounds. Furthermore, if necessary, other third
Ingredients such as binders, stabilizers and the like can be included.

The thickness of the light absorption layer is 100 to 500.
0Å is preferable, and 500 to 3000Å is particularly desirable.
This is because when the thickness of the light absorption layer is smaller than this range, the modulation degree and recording sensitivity are lowered, and when it is thicker, the reflectance is lowered.

The substrate used in the present invention can be arbitrarily selected from various materials used as substrates for conventional information recording media. Examples of substrate materials include
Examples thereof include acrylic resins such as polymethylmethacrylate, vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymer, epoxy resins, polycarbonate resins, amorphous polyolefins, polyesters, glasses such as soda lime glass, and ceramics. In particular, from the viewpoint of dimensional stability, transparency and flatness, polymethyl methacrylate, polycarbonate resin, epoxy resin, amorphous polyolefin, polyester, glass and the like can be mentioned.

On the surface of the substrate on which the light absorption layer is provided,
An undercoat layer may be provided for the purpose of improving flatness, improving adhesive strength, and preventing alteration of the light absorption layer. Examples of the material for the undercoat layer include polymethylmethacrylate, acrylic acid / methacrylic acid copolymer, styrene / maleic anhydride copolymer, polyvinyl alcohol, N-methylolacrylamide, styrene / sulfonic acid copolymer, styrene / Vinyltoluene copolymer, chlorosulfonated polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, vinyl acetate / vinyl chloride copolymer, ethylene / vinyl acetate copolymer, polyethylene, polypropylene, polycarbonate, etc. Polymeric substances: Organic substances such as silane coupling agents: and inorganic substances such as inorganic oxides (SiO ₂ , Al ₂ O ₃ etc.) and inorganic fluorides (MgF ₂ ). The thickness of the undercoat layer is generally 0.005 to 20 μm.
m is in the range, preferably 0.01 to 10 μm.

In addition, a pregroup layer may be provided on the substrate (or undercoat layer) for the purpose of forming a groove for tracking or unevenness representing information such as an address signal. As the material for the pregroup layer, a mixture of at least one monomer (or oligomer) of acrylic acid monoester, diester, triester, and tetraester and a photopolymerization initiator can be used.

Further, a reflective layer may be provided on the light absorbing layer for the purpose of improving the S / N ratio, reflectance and sensitivity during recording. The light-reflecting substance that is the material of the reflecting layer is a substance having a high reflectance for laser light, and examples thereof include Mg, Se, Y, Ti, Zr, Hf, V,
Nb, Ta, Cr, Mo, W, Mn, Re, Fe, C
o, Ni, Ru, Rh, Pd, Ir, Pt, Cu, A
g, Au, Zn, Cd, Al, Ca, In, Si, G
Metals and semimetals such as e, Te, Pb, Po, Sn and Si can be mentioned. Among these, preferable ones are Au, Al and Ag. These substances may be used alone or in combination of two or more or as an alloy. The layer thickness of the reflective layer is generally 100 to
It is in the range of 3000Å.

On the light absorption layer (or reflection layer),
A protective layer may be provided for the purpose of physically and chemically protecting the light absorbing layer and the like. This protective layer may be provided on the side of the substrate where the light absorption layer is not provided for the purpose of enhancing scratch resistance and moisture resistance. Examples of the material used for the protective layer include inorganic substances such as Si, O, SiO ₂ , MgF ₂ , and SnO ₂ , thermoplastic resin, thermosetting resin, and UV curable resin. The layer thickness of the protective layer is generally in the range of 500 Å (50 nm) to 50 μm.

Next, a method for manufacturing the optical recording medium of the present invention will be described. The method for producing an optical recording medium of the present invention is directed to a light absorbing layer containing the phthalocyanine compound (I) as a main component, directly or through another layer on a substrate having grooves and / or pits formed on the surface. Is provided by a coating film forming means, a light reflecting layer is provided thereon by a vacuum film forming means directly or through another layer, and a protective layer is further provided thereon. That is, the manufacturing method of the present invention comprises the following steps.

(B) Means for coating and forming a light absorbing layer containing the phthalocyanine compound (I) as a main component on a substrate having grooves and / or pits formed on the surface, directly or through another layer (B) providing the light reflecting layer on the light absorbing layer directly or via another layer by a vacuum film forming means, and (c) providing a protective layer on the light absorbing layer.

Step of Forming Light Absorption Layer In the method of the present invention, first, a groove and / or
Alternatively, a light absorption layer containing the phthalocyanine compound (I) as a main component is provided by a coating film forming means on the substrate in which the pits are formed, either directly or through another layer. That is, the light absorbing layer is formed by dissolving the phthalocyanine compound (I) in a solvent and coating it on the substrate as a liquid coating solution. As a solvent for adjusting this coating solution, a known organic solvent (for example, alcohol,
Cellosolve, carbon halide, ketone, ether, etc.) can be used. As the coating method, the spin coating method is preferable because the layer thickness can be controlled by adjusting the concentration and viscosity of the light absorbing layer and the drying temperature of the solvent.

An undercoat layer is provided on the surface of the substrate on the side where the light absorbing layer is provided for the purpose of improving the flatness of the substrate surface, improving the adhesive strength, and preventing the deterioration of the light absorbing layer. . The undercoat layer in this case is prepared by, for example, dissolving or dispersing the above-mentioned undercoat layer substance in a suitable solvent to prepare a coating solution, and then spin-coating, dip-coating the coating solution.
It can be formed by coating the substrate surface by a coating method such as extrusion coating.

Light-Reflecting Layer Forming Step In the method of the present invention, a light-reflecting layer is then provided on the light-absorbing layer directly or via another layer by a vacuum film forming means. That is, the above-mentioned light-reflecting substance, for example, by vapor deposition, sputtering or ion plating,
A light reflecting layer is formed on the light absorbing layer.

Protective Layer Forming Step In the method of the present invention, a protective layer is provided on the light reflecting layer. That is, it is formed by vacuum film formation or application film formation of the protective layer material made of the above-mentioned inorganic substance or various resins. In particular, it is preferable to use a UV curable resin, which is formed by spin coating the resin and then irradiating it with ultraviolet rays to cure it.

[Examples] The present invention is described below by referring to Examples, but the present invention is not limited thereto. Example 1 A polycarbonate substrate having a wobble groove with a track pitch of 1.6 μm, a half value width of 0.68 μm and a groove depth of about 1500 Å (150 nm) was formed on a disk surface having a diameter of 120 mm and a thickness of 1.2 mm. It was created by injection molding. Phthalocyanine dyes represented by A and H in Tables 1 and 2 were mixed on this substrate at a molar ratio of 1: 1. The light absorption layer was provided by spin coating with a mixed solvent of tetrahydrofuran, 2-methoxyethanol and ethylcyclohexane as a coating solution. The thickness of this light absorption layer is about 150.
It was 0Å. The P2 / P1 ratio was 39%, and the maximum absorption wavelength was 730 nm. Next, silver (Ag) is formed on the light absorption layer by a sputtering method to a thickness of about 1000Å to form a reflection layer, and a protective layer made of an ultraviolet curable resin is formed on the upper surface of the reflection layer to a thickness of about 5 μm. The optical recording medium No. 1 of the present invention was prepared.

This medium is used as an optical disk recording / reproducing apparatus DDU.
Recording was performed under the conditions of NA: 0.5, wavelength: 790 nm, and linear velocity: 19.2 m / s with -1000 (Pulstec Co., Ltd.), and the signal characteristics were measured. The recording signal is a CD signal (EF
M) and the recording strategy was (n + 0.5) T.
Table 3 shows the measurement results of the signal strength (Itop, I11 / Itop) measured by a playback signal evaluator (CD-CATS manufactured by AUDIO DEVELOPMENT). Good results that satisfy

[0057]

[Table 3]

Example 2 As the phthalocyanine dye in Example 1, Tables 1 and 2 were used.
Optical recording medium No. 2 of the present invention was prepared in the same manner except that the phthalocyanine dye represented by Medium C was used. P2 / P
The 1 ratio was 33%, and the maximum absorption wavelength was 731 nm.
When the signal strength of this medium is measured, it is as shown in Table 3,
Similar to Example 1, good results were obtained.

Example 3 The phthalocyanine dyes used in Example 1 are shown in Tables 1 and 2.
The phthalocyanine dyes represented by A and I are in a molar ratio of 1: 1.
Optical recording medium No. 3 of the present invention in the same manner except that it was mixed in
It was created. The P2 / P1 ratio was 38%, and the maximum absorption wavelength was 731 nm. When the signal intensity of this medium was measured, it was as shown in Table 3, and as in Example 1, good results were obtained.

Example 4 The phthalocyanine dyes used in Example 1 are shown in Tables 1 and 2.
The phthalocyanine dyes represented by Medium B and I have a molar ratio of 1: 1.
Optical recording medium No. 4 of the present invention in the same manner except that it was mixed in
It was created. The PS / P1 ratio was 37%, and the maximum absorption wavelength was 737 nm. When the signal intensity of this medium was measured, it was as shown in Table 3, and as in Example 1, good results were obtained.

Comparative Example 1 The phthalocyanine dyes used in Example 1 are shown in Tables 1 and 2
Comparative optical recording medium No. 5 was prepared in the same manner except that the phthalocyanine dye represented by Medium B was used. P2 / P
The 1 ratio was 60%, and the maximum absorption wavelength was 732 nm.
When the signal strength of this medium is measured, it is as shown in Table 3,
The results satisfying the CD standard were not obtained for both Itop and I11 / Itop.

COMPARATIVE EXAMPLE 2 As phthalocyanine dyes in Example 1, as shown in Tables 1 and 2
Comparative optical recording medium No. 5 was prepared in the same manner except that the phthalocyanine dye represented by Medium A was used. P2 / P
The 1 ratio was 50%, and the maximum absorption wavelength was 721 nm.
When the signal strength of this medium is measured, it is as shown in Table 3,
The results satisfying the CD standard were not obtained for both Itop and I11 / Itop.

[0063]

According to the optical information recording medium of claim 1, the recording layer contains a phthalocyanine compound, and the maximum absorption wavelength peak (P1) of the optical absorption spectrum of the recording layer and a sub-peak (P2) in a wavelength range shorter than P1. ) Ratio is 40% (P2 / P
Since it was 1) or less, good signal characteristics were obtained under high-speed recording conditions.

In the optical information recording medium of claim 2, the maximum absorption wavelength of the optical absorption spectrum of the recording layer is 710 nm-750 nm.
Therefore, good signal characteristics were obtained under the high-speed recording condition with the laser light for CD.

In the optical information recording medium according to claim 3, the recording layer contains two or more kinds of phthalocyanine compounds, and therefore 40%.
The following (P2 / P1) ratio can be easily obtained, and the range of selection of recording materials having thermal decomposition characteristics and optical characteristics suitable for high-speed recording conditions can be widened.

In the optical information recording medium of claim 4, since the recording layer contains a phthalocyanine compound having a specific structure having a benzyloxy group, it is excellent in durability and thermal decomposition characteristics and has good signal characteristics under high speed recording conditions. was gotten.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram of a CD-R of the present invention.

FIG. 2 is an explanatory diagram of a light absorption spectrum of a dye film used in the present invention.

[Explanation of symbols]

1 substrate 2 Dye recording layer 3 reflective layer 4 protective layer

Claims (4)

[Claims] 1. An optical information recording medium in which a dye recording layer is formed on a substrate and then a metal reflection layer is formed on the recording layer, wherein the recording layer contains a phthalocyanine compound, and the optical absorption spectrum of the recording layer is An optical recording medium, characterized in that the ratio (P2 / P1) between the maximum absorption wavelength peak (P1) and the sub-peak (P2) in a wavelength range shorter than P1 is 0.4 or less. 2. The optical information recording medium according to claim 1, wherein the maximum absorption wavelength of the optical absorption spectrum of the recording layer is in the range of 710 nm to 750 nm. 3. The dye recording layer according to claim 1, wherein the dye recording layer contains two or more kinds of phthalocyanine compounds.
The optical recording medium according to any one of 1. 4. The optical information recording medium according to claim 1, wherein the recording layer contains a phthalocyanine compound represented by the general formula (I) under the following conditions. [Chemical 1] (In the formula, M is a divalent metal atom, a mono-substituted trivalent metal atom,
Any one of a disubstituted tetravalent metal atom or an oxymetal, A ¹ and A ² , A ³ and A ⁴ , A ⁵ and A ⁶ or A ⁷ and A ⁸
Independently of each other, one of them is represented by the formula —O—C (R
¹ ) is a group represented by (R ³ ) -R ² and the other is a hydrogen atom, and in the above formula, R ¹ and R ³ are selected from an alkyl group, a fluorine-substituted alkyl group or a hydrogen atom. R ² is a substituted phenyl group or an unsubstituted phenyl group, or in the formula, M is a disubstituted tetravalent metal atom selected from Si, Sn, and Ge. , A ¹ and A ² , A ³ and A ⁴ , A ⁵ and A ⁶ or A ⁷ and A ⁸
When any one of the above is independently a group represented by the formula —O—R ⁴ , the other is a hydrogen atom, and in the above formula, R ⁴ is a linear or branched alkyl group or a fluorine-substituted group. It is a linear or branched alkyl group. )