JP2001126309A - Optical information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical information recording medium in which crosstalk hardly occurs and errors are reduced. SOLUTION: In the DVD-R type optical information recording medium having a dye recording layer capable of recording information by laser beams on a transparent disk substrate having a recessed groove formed in a spiral shape from the inner peripheral side to the outer peripheral side of the surface and a reflecting layer thereon, the side wall of the groove is inclined so that an angle which is formed by the extension of the line connecting a point on the side wall of the groove at the position of 10% of the depth of the groove from the bottom surface of the recessed groove to a point in the side wall of the groove at the position of 50% of the depth of the groove and a horizontal surface parallel to the bottom surface of the recessed groove falls within the range of 55-85 deg., and moreover the thickness of the dye recording layer within the recessed groove falls within the range of 55-95 nm. The dye recording layer is preferably formed of a cyanine dye or an oxonol dye.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a DVD-R type optical information recording medium capable of recording and reading information by a laser beam.

[0002]

2. Description of the Related Art A write-once optical information recording medium (so-called CD-R type optical disk) which can record information only once by a laser beam has been put to practical use. A CD-R type optical disc (hereinafter sometimes simply referred to as CD-R) generally has a recording layer made of a dye and a reflective layer made of a metal provided in this order on a disc-shaped substrate, and further has a protective layer made of a resin. It has a structure provided so as to cover the reflective layer by coating.

The CD-R type optical disk cannot sufficiently cope with the recent demand for a large recording capacity. Therefore, an optical information recording medium having a larger recording capacity is required. For example, as an optical disc capable of performing recording and reproduction using a laser beam having a shorter wavelength than a CD-R,
Write-once DVD (Digital Video Disc: DVD
-R) has been proposed (for example, "Nikkei New Media" separate volume "DVD", published in 1995). This document includes a DVD-R type optical disk (hereinafter simply referred to as DVD-R type).
In some cases, the guide groove (pre-groove) for tracking the emitted laser light is a CD-R.
On a transparent disc-shaped substrate formed to be less than half as narrow as compared to, a recording layer made of an organic dye, and usually two laminated bodies provided with a reflective layer and a protective layer on the recording layer, A DVD-R having a structure in which each recording layer is bonded inside with an adhesive inside is described. The above document discloses a DVD-R having a configuration in which a recording layer, a reflective layer, and a protective layer are sequentially provided on only one substrate instead of a disc-shaped protective plate in one of the two laminated bodies. There is also disclosure of.

[0004] Writing (recording) and reading (reproduction) of information on a DVD-R is performed by using a visible laser beam (normally 600 to
The irradiation is performed by irradiating laser light having a wavelength of 700 nm. That is, when the optical disk is irradiated with the laser light having the above wavelength, the irradiated portion of the dye recording layer absorbs the light and locally rises in temperature, and changes physically or chemically (for example, generation of pits or the like), Information is recorded by changing the optical characteristics. On the other hand, reading of information is also usually performed by irradiating the optical disk with laser light having the same wavelength as the recording laser light, and a portion where the optical characteristics of the dye recording layer has changed (recorded portion due to generation of pits or the like). This is carried out by detecting a difference in reflectance between the part and the part that does not change (unrecorded part).

On the surface of the substrate of a DVD-R type optical disk on which the recording layer is provided, generally, grooves (tracking guides, pregrooves) are spirally formed at a predetermined track pitch from the inner peripheral side to the outer peripheral side. Are formed. In the case of a DVD-R, the track pitch is usually 0.
The pitch is provided in the range of 6 to 1.0 μm. However, when the track pitch becomes narrow as described above, there is a problem that crosstalk easily occurs between adjacent grooves. In particular, when the inclination angle of the side wall of the concave groove is relatively gentle, the pits generated during recording may protrude from the bottom surface of the groove and reach the land of the concave groove. It is easy to generate pits that spread in the direction, signal leakage occurs during reproduction, and the jitter value increases with the occurrence of crosstalk, causing an error.

[0006] To solve the above problem, Japanese Patent Laid-Open No. 9-1
JP-A-98714 discloses that a groove of a concave groove (side wall of a groove) of a substrate is steeply inclined so as to have an angle of 70 to 85 ° and a groove width is 300 to 370 nm. Crosstalk is suppressed, and
There has been proposed an optical information recording medium (optical disc) capable of recording and reproducing signals well even with laser light having a short wavelength in the range of 00 nm. In this optical disc, it is described that the thickness of the recording layer is preferably about 100 to 250 nm at the groove. In Example 1, a metal-containing azo dye was used as the dye, and the groove thickness was 210 n.
An example of an optical disk provided with a recording layer formed to be relatively thick as m is described.

[0007]

According to the study by the present inventor, the optical information recording medium described in the above-mentioned Japanese Patent Application Laid-Open No. 9-198714 has a problem in that the side walls of the concave grooves are steeply inclined. Since the dye recording layer was formed relatively thick, crosstalk could not be sufficiently suppressed, and as a result, it was found that an error was likely to occur. Accordingly, an object of the present invention is to provide an optical information recording medium in which crosstalk hardly occurs and errors are reduced.

[0008]

According to the research of the present inventors,
By making the angle of the side wall of the concave groove steep, and reducing the thickness of the dye recording layer in the concave groove within a range where performance such as sensitivity and modulation is hardly reduced, a narrow track is obtained. In spite of the pitch, it has been found that an optical information recording medium in which crosstalk hardly occurs and an error is suppressed can be manufactured. In particular, the research of the present inventors has revealed that a thin dye recording layer can be formed by using a specific dye as a recording material without substantially affecting the recording / reproducing characteristics. It is not clear why the crosstalk is suppressed in this manner, but by using a thin dye recording layer, laser light can be applied to a narrower region, and the temperature of only that region can be increased. As a result, it is considered that small pits can be generated, and pits with little lateral spread are generated. In addition, the steep angle of the side wall of the groove makes the dye melt in that part difficult to spread out of the groove even when the temperature rises due to laser light irradiation, and also avoids affecting adjacent grooves. It is thought to be done.

The present invention provides a dye recording layer capable of recording information by a laser beam on a transparent disk-shaped substrate having a concave groove formed in a spiral form from the inner peripheral side to the outer peripheral side of the surface, and a dye recording layer thereon. In a DVD-R type optical information recording medium having a reflective layer at a depth of 10% of the groove depth from the bottom surface of the concave groove.
And the angle formed by the extension of the straight line connecting the point on the side wall of the groove at the position of the groove and the point on the side wall of the groove at the position of 50% of the depth of the groove, and the horizontal surface on the bottom surface of the concave groove ( Hereinafter, the angle may be simply referred to as the inclination angle of the side wall).
The optical information recording medium is characterized in that the side wall of the groove is inclined so as to fall within the range, and the thickness of the dye recording layer in the concave groove is in the range of 55 to 95 nm.

The present invention also provides a dye recording layer capable of recording information by laser light on a transparent disk-shaped substrate having a concave groove formed spirally from the inner peripheral side to the outer peripheral side of the surface. And two laminated bodies each having a reflective layer thereon, or on a transparent disc-shaped substrate having a concave groove formed in a spiral shape from the inner peripheral side to the outer peripheral side of the surface, by laser light information. A laminate having a recordable dye recording layer and a reflective layer thereon and a disc-shaped protective plate having substantially the same shape as the disc-shaped substrate are interposed via an adhesive layer such that the dye recording layer side is inside. In the DVD-R type optical information recording medium which is bonded by sticking, a point on the side wall of the groove at a position of 10% of the depth of the groove from the bottom of the concave groove and a position of 50% of the depth of the groove. The extension of the straight line connecting the points on the And the side wall of the groove is inclined so that the angle formed by the horizontal surface and the bottom surface of the concave groove is in the range of 55 to 85 °, and the thickness of the dye recording layer in the concave groove. Is in the range of 55 to 95 nm.

The DVD-R type optical information recording medium of the present invention preferably has the following aspects. (1) The track pitch of the concave groove is 0.5 to 1.0 μm
m (more preferably 0.6 to 0.9 μm, particularly preferably 0.7 to 0.8 μm). (2) An optical information recording medium in which the inclination angle of the side wall of the concave groove is in the range of 60 to 80 °. (3) The width (half width) of the concave groove is 100 to 600 nm
(More preferably, 200 to 500 nm, particularly preferably, 250 to 400 nm). (4) The depth of the concave groove is 50 to 250 nm (more preferably 80 to 220 nm, particularly preferably 100 to 250 nm).
Optical information recording medium in the range of 200 nm).

(5) The thickness of the dye recording layer in the concave groove is 6
An optical information recording medium in the range of 0 to 95 nm (more preferably, 65 to 93 nm). (6) An optical information recording medium in which the dye recording layer contains a cyanine dye or an oxonol dye. (7) An optical information recording medium in which the dye recording layer is made of an oxonol dye composed of an anionic dye component and a cationic component, and the cationic component is a compound represented by the following general formula (II-A) :

[0013]

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[In the formula, R ²⁴ and R ²⁵ each independently represent a substituent, and R ²⁶ and R ²⁷ each independently represent an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an aryl group or a heterocyclic group. ring group (an aryl group or a heterocyclic group, still further may be combined ring condensed) represents, R ²⁴ and R ^25, R
²⁴ and R ²⁶ , or R ²⁵ and R ²⁷ may be mutually connected to form a ring, and r 1 and s 1 are each independently
Represents an integer of 0 to 4, and when r1 and s1 are 2 or more, a plurality of R ²⁴ and R ²⁵ may be the same or different from each other]. (8) The anionic dye component has the following general formula (I-2-
Optical information recording medium which is a compound represented by A):

[0015]

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[Wherein R ¹ , R ² , R ³ and R ⁴ each independently represent an alkyl group which may have a substituent;
L ¹¹ , L ¹² , and L ¹³ each independently represent a methine group which may have a substituent (provided that L ¹¹ , L ¹² , and L ¹³ each represent a methine group)
^{When 13} has a substituent, two or more of these may combine to form a ring), n3 represents an integer of 0 to 3, and R ¹ and R ² , Or R ³ and R ⁴
May be linked to each other to form a ring]. (9) An optical information recording medium in which the reflective layer is a layer made of silver or a silver alloy. (10) An optical information recording medium in which a resin protective layer is further provided on the reflective layer.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION In the optical information recording medium of the present invention, a concave groove (pregroove) spirally provided on the surface of a transparent disk-shaped substrate has an angle in the range of 55 to 85 °. Thus, the dye recording layer in the concave groove has a thickness in the range of 55 to 95 nm. The concave groove extends from the inner peripheral side to the outer peripheral side of the surface of the substrate from 0.5 to 1.0 μm (more preferably from 0.6 to 0.9 μm, particularly preferably from 0.7 to 0.9 μm).
It is preferably formed in a spiral shape with a track pitch in the range of 0.8 μm). FIG. 1 is an enlarged schematic sectional view of a concave groove provided on a disk-shaped substrate of the optical information recording medium of the present invention. 1 is a disk-shaped substrate, 2 is a concave groove, 3 is a bottom surface of the concave groove, and 4 (inner peripheral side) and 5 (outer peripheral side) are side walls of the concave groove, respectively. The inclination angle of the side wall of the concave groove according to the present invention is, as shown in FIG. 1, a position h _{10 at} 10% of the groove depth h from the bottom surface of the concave groove.
An extension of the line connecting the point Q on the side walls of the trench 4 (or 5) in the side wall 4 (or 5) 50% position h ₅₀ of point P and the groove depth h of the groove in a concave groove Is formed by an angle θ formed between the bottom surface 3 and the horizontal surface. The side wall 4 (or 5) of the concave groove according to the present invention has an angle θ of 55 to 8
It is inclined to have a range of 5 ° (preferably 60 to 80 °). If the inclination angle of the side wall of the groove exceeds 85 °, the releasability at the time of molding tends to deteriorate. The inclination angle of the side wall of the groove is such that the inner peripheral side 4 and the outer peripheral side 5 are usually formed at the same angle.
The outer peripheral side wall may be formed smoothly within 20 ° (preferably within 10 °) as compared with the inner peripheral side wall.

The depth of the concave groove according to the present invention is 50 to 25.
0 nm (more preferably, 80 to 220 nm, particularly preferably 100 to 200 nm), and the width (half width) of the concave groove is 100 to 450.
nm (more preferably 150 to 400 nm, particularly preferably 200 to 350 nm).

As described above, the dye recording layer of the optical disk of the present invention is selected from dye compounds that can sufficiently maintain performances such as sensitivity and modulation even when formed with a relatively small thickness in the range of 55 to 95 nm as described above. It is preferable to use it.
Examples of such a dye compound include a cyanine dye and an oxonol dye. It is preferred to use oxonol dyes. First, the oxonol dye will be described in detail.

The oxonol dye used in the present invention comprises an anionic dye component and a cationic component, and is preferably a compound represented by the following formula (I-1) or (I-2).

[0021]

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In the formula, A ¹ , A ² , B ¹ and B ² each independently represent a substituent. Y ¹ and Z ¹ each independently represent an atomic group necessary for forming a carbocyclic or heterocyclic ring. E and G each independently represent an atomic group necessary for completing a conjugated double bond chain. X ¹ is ＯO, ＮＲNR ⁰ ,
Or = C (CN) ₂ . X ² represents —O, —NR ⁰ , or —C (CN) ₂ . However, R ⁰ represents a substituent (R
^The substituent represented by ⁰ has the same meaning as the examples of the substituents represented by A ¹ , A ² , B ¹ , and B ² above). L ¹ , L ² , L ³ ,
L ⁴ and L ⁵ each independently represent a methine group which may be substituted. X ^{k +} represents a cation. n1 and n2 are
Each independently represents 0, 1 or 2. x and y each independently represent 0 or 1. K represents an integer of 1 to 10.

Examples of the substituent represented by A ¹ , A ² , B ¹ and B ² include the following. A substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 18 (preferably 1 to 8) carbon atoms;
An alkenyl group having 2 to 18 (preferably 2 to 8) carbon atoms; an alkynyl group having 2 to 18 (preferably 2 to 8) carbon atoms;
A substituted or unsubstituted aryl group having 7 to 18 (preferably 6 to 10 carbon atoms); a substituted or unsubstituted aralkyl group having 7 to 18 (preferably 7 to 12 carbon atoms); To 18 (preferably 2 to 8 carbon atoms) substituted or unsubstituted acyl group;
A substituted or unsubstituted alkyl or arylsulfonyl group having 1 to 18 (preferably 1 to 8 carbon atoms); an alkylsulfinyl group having 1 to 18 (preferably 1 to 8 carbon atoms); An alkoxycarbonyl group having 18 (preferably 2 to 8 carbon atoms); 7 to 18 (preferably 7 to 1 carbon atoms)
2) an aryloxycarbonyl group;

A substituted or unsubstituted alkoxy group having 1 to 18 carbon atoms (preferably 1 to 8 carbon atoms); 6 to 18 carbon atoms (preferably 6 to 10 carbon atoms)
A substituted or unsubstituted aryloxy group; an alkylthio group having 1 to 18 (preferably 1 to 8) carbon atoms; a C6 to 18 (preferably 6) carbon atom
To 10) arylthio groups; 2 to 18 carbon atoms
(Preferably 2 to 8 carbon atoms) substituted or unsubstituted acyloxy group; 1 to 18 (preferably 1 to 8 carbon atoms) substituted or unsubstituted sulfonyloxy group; 18 (preferably 2 carbon atoms)
To 8) substituted or unsubstituted carbamoyloxy group; unsubstituted amino group, or substituted amino group having 1 to 18 carbon atoms (preferably 1 to 8 carbon atoms); 1 to 18 carbon atoms (preferably Is a substituted or unsubstituted carbamoyl group having 1 to 8 carbon atoms; an unsubstituted sulfamoyl group, or a 1 to 18 carbon atom (preferably,
A substituted sulfamoyl group having 1 to 8 carbon atoms; a halogen atom; a hydroxyl group; a nitro group; a cyano group; These substituents may be further substituted with the above substituents.

Y¹[-C (= L¹)-(E) x
−C (= X¹)-] (Hereinafter referred to as W1 for convenience);
Z¹[-C (= L^Five)-(G) y-C (-
X^2-)-] (Hereinafter referred to as W2 for convenience)
Since each is in a conjugate state, Y¹And charcoal formed by W1
An elementary or heterocyclic ring, and Z¹And charcoal formed by W2
Each elementary or heterocyclic ring is considered as one of the resonance structures.
It is. The carbocycle or heterocycle is a 4- to 7-membered ring member
Numbers are preferred, and more preferably a 5- or 6-membered ring
It is. These rings also have other 4- to 7-membered ring members.
And may form a fused ring. These also have substituents
You may have. As the substituent, the aforementioned A ¹, A^Two,
B¹, And B^TwoExamples of the substituent represented by
You.

The carbocycle formed by Y ¹ and W1 and the carbocycle formed by Z ¹ and W2 include, for example,
The following can be mentioned. In the example, Ra
And Rb each independently represent a hydrogen atom or a substituent.

[0027]

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Examples of the heterocycle formed by Y ¹ and W1 and the heterocycle formed by Z ¹ and W2 include the following. In the examples, Ra, Rb and Rc each independently represent a hydrogen atom or a substituent.

[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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The substituents represented by Ra, Rb and Rc in the above examples have the same meanings as those described above as the substituents represented by A ¹ , A ² , B ¹ and B ² . Ra, Rb and Rc may be linked to each other to form a carbocyclic or heterocyclic ring.

In the general formula (I-1) or (I-2), x and y are preferably both 0.
Preferably, ¹ is ＯO and X ² is -O.
k is preferably an integer of 1 to 4, and more preferably k is 2.

The anionic dye component of the oxonol dye (hereinafter, simply referred to as anion portion) used in the present invention is preferably a compound represented by the following formula (I-2-A). Hereinafter, the anion portion will be described in detail.

[0037]

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In the general formula (I-2-A), R ¹ ,
R ² , R ³ and R ⁴ each independently represent an alkyl group which may have a substituent. L ¹¹ , L ¹² and L ¹³ are
Each independently represents a methine group which may have a substituent. However, when L ¹¹ , L ¹² , and L ¹³ have a substituent, two or more of them may combine to form a ring. n3 represents an integer of 0 to 3. R ¹ and R ² , or R ³ and R ⁴ may be connected to each other to form a ring.

Preferred examples of the alkyl group represented by R ¹ , R ² , R ³ and R ⁴ include a linear, branched or cyclic carbon atom which may have a substituent. 1 atom
To 20 (more preferably 1 to 8 carbon atoms) alkyl groups (eg, methyl, ethyl, propyl, butyl, isobutyl, tert-butyl, isoamyl, cyclopropyl, cyclopentyl, cyclohexyl).

Examples of the above substituents include the following. An alkyl group having 1 to 20 carbon atoms (eg, methyl,
Ethyl, propyl, carboxymethyl, ethoxycarbonylmethyl); an aralkyl group having 7 to 20 carbon atoms (eg, benzyl, phenethyl); an alkoxy group having 1 to 8 carbon atoms (eg, methoxy, ethoxy); To 20 aryl groups (eg, phenyl, naphthyl);
An aryloxy group having 6 to 20 carbon atoms (eg, phenoxy, naphthoxy); a heterocyclic group (eg, pyridyl, pyrimidyl, pyridazyl, benzimidazolyl, benzothiazolyl, benzoxazolyl, 2-pyrrolidinone-1-)
Yl, 2-piperidone-1-yl, 2,4-dioxyimidazolidin-3-yl, 2,4-dioxyoxazolidin-3-yl, succinimide, phthalimide, maleimide); a halogen atom (eg, fluorine, chlorine) , Bromine, iodine); carboxyl group; alkoxycarbonyl group having 2 to 10 carbon atoms (eg, methoxycarbonyl, ethoxycarbonyl); cyano group; acyl group having 2 to 10 carbon atoms (eg, acetyl, pivaloyl); Carbamoyl having 1 to 10 atoms (eg, carbamoyl, methylcarbamoyl, morpholinocarbamoyl); amino group; substituted amino group having 1 to 20 carbon atoms (eg, dimethylamino,
Diethylamino, bis (methylsulfonylethyl) amino, N-ethyl-N'-sulfoethylamino); sulfo group; hydroxyl group; nitro group;
A ureido group having 1 to 10 carbon atoms (eg, ureido, methylureide); an alkylsulfonyl group having 1 to 10 carbon atoms (eg, methanesulfonyl, ethanesulfonyl);
An alkylsulfinyl group having 1 to 10 carbon atoms (eg,
Methanesulfinyl); and a sulfamoyl group having 0 to 10 carbon atoms (eg, sulfamoyl, methanesulfamoyl). The carboxyl group and the sulfo group may be in a salt state.

Preferred examples of the above substituents include:
Alkyl group (especially methyl), alkoxy group (especially methoxy), aryl group (especially phenyl), alkoxycarbonyl group (especially ethoxycarbonyl), substituted amino group (especially dimethylamino), hydroxyl group, halogen atom ( Particularly, a fluorine atom) and a sulfonamide group (particularly, methanesulfonamide) can be exemplified.

It is preferable that R ¹ and R ² and / or R ³ and R ⁴ are connected to each other to form a carbocyclic or heterocyclic ring. R ¹ and R ² or R ³
And R ⁴ are connected to each other to form a carbon ring having 3 to 10 carbon atoms (more preferably, 4 to 6 carbon atoms) or a carbon ring having 2 to 9 carbon atoms (more preferably, 3 to 5 carbon atoms). The case where a heterocyclic ring is formed is preferred. Examples of carbocycles include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 2-methylcyclohexyl,
Cycloheptyl and cyclooctyl can be mentioned. Examples of heterocycles include piperidyl, chromanil,
And morpholyl.

L ¹¹ , L ¹² and L ¹³ are each independently
It represents a substituted or unsubstituted methine group, and examples of the substituent include the substituents of the alkyl group represented by R ¹ , R ² , R ³ , and R ⁴ . L ¹¹ , L ¹² and L ¹³
Are each independently an unsubstituted methine group or an alkyl group having 1 to 5 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, It is preferably an alkoxy group, a saturated or unsaturated heterocyclic group, or a methine group substituted with a halogen atom. When L ¹¹ , L ¹² , and L ¹³ have a substituent, it is also preferable that two or more of them combine to form a ring. Examples of the ring formed include a cyclohexene ring. n3 is preferably 1, 2 or 3. Particularly preferably, n3 is
2 or 3.

Preferred specific examples of the anion portion of the oxonol dye represented by formula (I-2-A) are described below.

[0045]

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[0046]

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[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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Next, the cationic component (hereinafter, simply referred to as “cation part”) will be described in detail. Examples of the cation represented by X ^{k +} include a hydrogen ion or a metal ion such as a sodium ion, a potassium ion, a lithium ion, a calcium ion, an iron ion, and a copper ion, a metal complex ion, an ammonium ion, a pyridinium ion, and an oxonium ion. , A sulfonium ion, a phosphonium ion, a selenonium ion, and an iodonium ion. X ^{k +} is preferably not a cyanine dye. Preferably, it is a quaternary ammonium ion.

The quaternary ammonium is generally a tertiary amine (eg, trimethylamine, triethylamine, tributylamine, triethanolamine, N-methylpyrrolidine, N-methylpiperidine, N, N-dimethylpiperazine, triethylenediamine, N, N ', N'
-Tetramethylethylenediamine, etc.) or a nitrogen-containing heterocycle (pyridine ring, picoline ring, 2,2'-bipyridyl ring, 4,4'-bipyridyl ring, 1,10-phenanthroline ring, quinoline ring, oxazole ring, thiazole ring, N-methylimidazole ring, pyrazine ring, tetrazole ring, etc.) can be obtained by alkylation (Menstockkin reaction), alkenylation, alkynylation or arylation.

The quaternary ammonium ion is preferably a quaternary ammonium ion comprising a nitrogen-containing heterocyclic ring, and particularly preferably a quaternary pyridinium ion.

The quaternary ammonium ion is preferably represented by the following general formula (II). These compounds are
Usually, 2,2'-bipyridyl or 4,4'-bipyridyl is reacted with a halide having a desired substituent in a Menshkin reaction (see, for example, JP-A-61-148162) or JP-A-51-16675. And an arylation reaction according to the method described in JP-A-1-96171.

[0057]

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In the formula, R ²⁰ and R ²¹ each independently represent a substituent, and R ²² and R ²³ each independently represent an alkyl group,
Represents an alkenyl group, an alkynyl group, an aralkyl group, an aryl group or a heterocyclic group (the aryl group or the heterocyclic group may be further condensed with another ring), and R ²⁰ and R ²¹ , R ²⁰
And R ²² , or R ²¹ and R ²³ may be linked to each other to form a ring, r and s each independently represent an integer of 0 to 4, and when r and s are 2 or more, Represents a plurality of R ²⁰
And R ²¹ may be the same or different from each other.

The alkyl group represented by R ²² and R ²³ is preferably a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, more preferably 1 to 8 carbon atoms.
Is a substituted or unsubstituted alkyl group. They are,
It may be linear, branched, or cyclic. Examples of these include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, neopentyl, n-hexyl, cyclopropyl, cyclohexyl, adamantyl and the like.

Examples of the substituent of the alkyl group include the following. A substituted or unsubstituted alkenyl group having 2 to 18 carbon atoms (preferably 2 to 8 carbon atoms) (eg, vinyl); substituted or unsubstituted alkenyl group having 2 to 18 carbon atoms (preferably 2 to 8 carbon atoms) A substituted alkynyl group (eg, ethynyl); a substituted or unsubstituted aryl group having 6 to 10 carbon atoms (eg, phenyl, naphthyl);
Halogen atom (eg, F, Cl, Br, etc.); 1 carbon atom
To 18 (preferably 1 to 8 carbon atoms) substituted or unsubstituted alkoxy group (eg, methoxy, ethoxy); 6 to 10 carbon atom substituted or unsubstituted aryloxy group (eg, phenoxy, p- Methoxyphenoxy); a substituted or unsubstituted alkylthio group having 1 to 18 carbon atoms (preferably 1 to 8 carbon atoms) (eg, methylthio, ethylthio);
0 substituted or unsubstituted arylthio group (eg, phenylthio); a substituted or unsubstituted acyl group having 2 to 18 (preferably 2 to 8) carbon atoms (eg, acetyl, propionyl);

A substituted or unsubstituted alkylsulfonyl or arylsulfonyl group having 1 to 18 carbon atoms (preferably 1 to 8 carbon atoms) (eg, methanesulfonyl, p-toluenesulfonyl);
8 (preferably 2 to 8 carbon atoms) substituted or unsubstituted acyloxy group (eg acetoxy, propionyloxy); 2 to 18 (preferably 2 to 8 carbon atoms) substituted or unsubstituted Alkoxycarbonyl group (eg, methoxycarbonyl, ethoxycarbonyl); substituted or unsubstituted aryloxycarbonyl group having 7 to 11 carbon atoms (eg, naphthoxycarbonyl); unsubstituted amino group, or 1 to 1 carbon atom
8 (preferably 1 to 8 carbon atoms) substituted amino group (eg, methylamino, dimethylamino, diethylamino, anilino, methoxyphenylamino, chlorophenylamino, pyridylamino, methoxycarbonylamino, n-butoxycarbonylamino, phenoxycarbonylamino , Methylcarbamoylamino, ethylthiocarbamoylamino, phenylcarbamoylamino, acetylamino, ethylcarbonylamino, ethylthiocarbamoylamino, cyclohexylcarbonylamino, benzoylamino, chloroacetylamino, methylsulfonylamino);

A substituted or unsubstituted carbamoyl group having 1 to 18 carbon atoms (preferably 1 to 8 carbon atoms) (eg, unsubstituted carbamoyl, methylcarbamoyl, ethylcarbamoyl, n-butylcarbamoyl, tert-butylcarbamoyl) Dimethylcarbamoyl, morpholinocarbamoyl, pyrrolidinocarbamoyl); unsubstituted sulfamoyl groups or substituted sulfamoyl groups having 1 to 18 (preferably 1 to 8) carbon atoms (eg, methylsulfamoyl, phenylsulfa Moyl); cyano group; nitro group; carboxyl group; hydroxyl group; heterocyclic group (eg, oxazole ring, benzoxazole ring, thiazole ring, benzothiazole ring, imidazole ring, benzimidazole ring, indolenine ring,
Pyridine ring, piperidine ring, pyrrolidine ring, morpholine ring, sulfolane ring, furan ring, thiophene ring, pyrazole ring, pyrrole ring, chroman ring, coumarin ring).

The alkenyl group represented by R ²² and R ²³ is preferably a substituted or unsubstituted alkenyl group having 2 to 18 carbon atoms, more preferably a substituted or unsubstituted alkenyl group having 2 to 8 carbon atoms. And vinyl, allyl, 1-propenyl, 1,3-butadienyl and the like. As the substituent for the alkenyl group, those mentioned above as the substituent for the alkyl group are preferable.

The alkynyl group represented by R ²² and R ²³ is preferably a substituted or unsubstituted alkynyl group having 2 to 18 carbon atoms, more preferably a substituted or unsubstituted alkynyl group having 2 to 8 carbon atoms. And ethynyl, 2-propynyl and the like. As the substituent for the alkynyl group, those described above as the substituent for the alkyl group are preferable.

The aralkyl group represented by R ²² and R ²³ is preferably a substituted or unsubstituted aralkyl group having 7 to 18 carbon atoms, for example, benzyl, methylbenzyl and the like.

The aryl group represented by R ²² and R ²³ is preferably a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, such as phenyl and naphthyl. As the substituent of the aryl group, those described above as the substituent of the alkyl group are preferable. In addition to these, an alkyl group (eg, methyl, ethyl, etc.) is also preferable.

The heterocyclic group represented by R ²² and R ²³ is a 5- or 6-membered saturated or unsaturated heterocyclic ring composed of a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, Examples of these include an oxazole ring, a benzoxazole ring, a thiazole ring, a benzothiazole ring,
Examples include an imidazole ring, benzimidazole ring, indolenine ring, pyridine ring, piperidine ring, pyrrolidine ring, morpholine ring, sulfolane ring, furan ring, thiophene ring, pyrazole ring, pyrrole ring, chroman ring, and coumarin ring. The heterocyclic group may be substituted, and in this case, the substituent is preferably those exemplified as the substituent for the alkyl group.

The substituents represented by R ²⁰ and R ²¹ have the same meanings as those described above for the alkyl group.
In addition to these, an alkyl group (eg, methyl, ethyl, etc.) can also be mentioned. The substituent represented by R ²⁰ and R ²¹ is preferably a hydrogen atom or an alkyl group. Particularly preferred is a hydrogen atom.

As the quaternary ammonium ion, those represented by the following general formula (II-A) or (II-B) are particularly preferred. Most preferably, it is represented by the general formula (II-A).

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In the formula, R ²⁴ and R ²⁵ have the same meanings as the substituents represented by R ²⁰ and R ²¹ in formula (II), respectively, and the preferred ranges thereof are also the same. R ²⁶ and R ²⁷ each represent the general formula (II)
Has the same meaning as the substituent represented by R ²² and R ²³ in
The preferred ranges are also the same for each. r1 and s1 each independently represent an integer of 0 to 4, and when r1 and s1 are 2 or more, a plurality of R ²⁴
And R ²⁵ may be the same or different from each other.

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In the formula, R ²⁸ and R ²⁹ have the same meanings as the substituents represented by R ²⁰ and R ²¹ in formula (II), respectively, and the preferred ranges thereof are also the same. R ⁶⁸ and R ⁶⁹ are also preferably linked to each other to form a carbocyclic or heterocyclic ring, and particularly preferably form a condensed aromatic ring with the pyridine ring to which R ²⁸ and R ²⁹ are respectively bonded. If you are. r2
And s2 each independently represent an integer of 0 to 4, and when r2 and s2 are 2 or more, a plurality of R ²⁸ and R ²⁹ may be the same or different from each other.

Preferred specific examples of the cation part of the oxonol compound represented by the general formula (II) are described below.

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[0076]

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[0081]

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[0082]

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[0083]

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[0086]

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Preferred specific examples of oxonol dyes used in the present invention are shown in Table 1 below. In Table 1, a specific example (dye number) is composed of a chemical formula in which an anion portion (indicated by "A-") and a cation portion (indicated by "B-") are combined. For example, the dye of dye number 1 is composed of a combination of an anion part (A-1) / cation part (B-21) and is given by the following chemical formula.

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[0092]

[Table 1] Table 1 (Part 1) ───────────────────────────────── Dye Dye No. Anion part Cation part No. Anion part Cation part １ 1 A-1 B-21 2 A-1 B -77 3 A-1 B-124 4 A-2 B-21 5 A-2 B-786 A-3 B-227 A-4 B-228 A-7 B-789 A-7 B- 117 10 A-2 B-124 11 A-8 B-85 12 A-11 B-21 13 A-11 B-77 14 A-11 B-113 15 A-12 B-1 16 A-12 B-149 17 A-12 B-169 18 A-18 B-15 19 A-18 B-103 20 A-20 B-78 21 A-21 B-78 22 A-24 -78 23 A-30 B-21 24 A-30 B-78 25 A-30 B-87 26 A-31 B-21 27 A-31 B-41 28 A-31 B-78 29 A-31 B- 113 30 A-31 B-117 ──────────────────────────────────

[0093]

[Table 2] Table 1 (Part 2) ────────────────────────────────── Dye Dye No. Anion part Cation Part number Anion part Cation part ３１ 31 A-31 B-119 32 A -32 B-117 33 A-32 B-134 34 A-32 B-85 35 A-33 B-23 36 A-33 B-33 37 A-33 B-55 38 A-33 B-78 39 A- 33 B-85 40 A-33 B-117 41 A-33 B-124 42 A-33 B-169 43 A-34 B-21 44 A-34 B-55 45 A-34 B-78 46 A-34 B-85 47 A-34 B-89 48 A-34 B-113 49 A-34 B-117 50 A- 34 B-169 51 A-35 B-21 52 A-38 B-33 53 A-38 B-50 54 A-38 B-78 55 A-38 B-94 56 A-38 B-98 57 A-38 B-117 58 A-38 B-133 59 A-39 B-21 60 A-39 B-53 ────────────────────────── ─────────

[0094]

[Table 3] Table 1 (Part 3) ────────────────────────────────── Dye Dye No. Anion part Cation Part number Anion part Cation part ６１ 61 A-42 B-24 62 A -42 B-33 63 A-42 B-55 64 A-42 B-84 65 A-42 B-110 66 A-42 B-117 67 A-43 B-78 68 A-43 B-94 69 A- 43 B-115 70 A-43 B-117 71 A-44 B-78 72 A-49 B-18 73 A-49 B-82 74 A-49 B-114 75 A-51 B-78 76 A-53 B-33 77 A-53 B-78 78 A-53 B-117 79 A-54 B-17 80 A-54 B-79 81 A-57 B-27 82 A-57 B-77 83 A-61 B-78 84 A-61 B-117 85 A-62 B-26 86 A-62 B-76 87 A-64 B -77 88 A-65 B-77 89 A-65 B-94 90 A-66 B-24 91 A-66 B-78 92 A-74 B-78 93 A-79 B-21 94 A-79 B- 78 95 A-80 B-78 96 A-82 B-78 97 A-2 B-24 ──────────────────────────── ───────

The oxonol dye can be synthesized, for example, according to the synthesis method described in JP-A-10-297103, or according to the synthesis method.

Next, the cyanine dye will be described in detail. The cyanine dye used in the present invention is preferably a compound represented by the following general formula (III).

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Embedded image [DYE ⁺ ] _n X ^n- (III)

The cyanine dye cation represented by DYE represents a monovalent cation having no anionic substituent. X ^n- represents an n-valent anion;
Represents an integer of 2 or more. That is, X ^n- represents a divalent or higher polyvalent organic anion. X ⁿ⁻ is preferably a divalent to tetravalent organic anion, more preferably a divalent or trivalent organic anion, and particularly preferably a divalent organic anion.

The polyvalent organic anion represented by X ^n- includes:
Includes the following: Carboxylate ion (eg, succinate ion, maleate ion, fumarate ion, terephthalate ion); aromatic disulfonic acid ion (eg,
Benzene-1,3-disulfonic acid ion, 3,3′-biphenyldisulfonic acid ion, naphthalene-1,5-disulfonic acid ion, naphthalene-1,6-disulfonic acid ion, naphthalene-2,6-disulfonic acid ion, 1
-Methylnaphthalene-2,6-disulfonic acid ion, naphthalene-2,7-disulfonic acid ion, naphthalene-
2,8-disulfonic acid ion, 2-naphthol-6,8
-Disulfonic acid ion, 1,8-dihydroxynaphthalene-3,6-disulfonic acid ion, 1,5-dihydroxynaphthalene-2,6-disulfonic acid ion); aromatic trisulfonic acid ion (eg, naphthalene-1,3) , 5-
Trisulfonic acid ion, naphthalene-1,3,6-trisulfonic acid ion, naphthalene-1,3,7-trisulfonic acid ion, 1-naphthol-3,6,8-trisulfonic acid ion, 2-naphthol- 3,6,8-trisulfonate ion); aromatic tetrasulfonate ion (eg,
Naphthalene-1,3,5,7-tetrasulfonic acid ion); aliphatic polysulfonic acid ion (eg, butane-1,
4-disulfonate ion, cyclohexane-1,4-disulfonate ion); polysulfate monoester (eg, propylene glycol-1,2-disulfate, polyvinyl alcohol polysulfate ion).

The polyvalent organic anion represented by X ^n- is preferably an aromatic disulfonic acid ion or an aromatic trisulfonic acid ion. Particularly preferred are aromatic disulfonic acid ions, and among them, naphthalene-1,5-disulfonic acid ion, naphthalene-1,
6-disulfonic acid ion, naphthalene-2,6-disulfonic acid ion, 1-methylnaphthalene-2,6-disulfonic acid ion, naphthalene-2,7-disulfonic acid ion, or naphthalene-2,8-disulfonic acid ion Preferably, there is. Most preferred are naphthalene-
1,5-disulfonic acid ion.

The cyanine dye cation represented by DYE is preferably a compound represented by the following formula (IV).

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In the general formula (IV), Z¹¹And Z¹²Is
Indolenine nucleus or ben optionally substituted
Lists the atoms required to complete the zoindrenine nucleus.
You. R ³¹And R³²Are each independently an alkyl group or an ant
Represents a hydroxyl group. R³³ , R³⁴ , R³⁵ And R³⁶ Is German
On the other hand, it represents an alkyl group. L³¹ , L³² , L³³ , L³⁴
And L³⁵ Each independently represents a substituted or unsubstituted methine group
Represent. Also L³¹ ~ L³⁵When having a substituent on the above,
They may be connected to each other to form a ring. j is 0, 1 or 2
And m represents 0 or 1. And n is 2 or more
Represents an integer.

The substituent (or atom) of the indolenine nucleus or benzoindolenine nucleus is preferably a halogen atom (especially chlorine atom) or an aryl group (especially phenyl).

The alkyl group represented by R ³¹ and R ³² may have a substituent, and preferably has 1 carbon atom.
To 18 (more preferably 1 to 8, especially 1 to 6) alkyl groups which may have a linear, cyclic or branched substituent. The aryl group represented by R ³¹ and R ³² may have a substituent, and is preferably an aryl group having 6 to 18 carbon atoms which may have a substituent.

Preferred examples of the substituent of the alkyl group or the aryl group represented by R ³¹ and R ³² include the following. A substituted or unsubstituted aryl group having 6 to 18 carbon atoms (for example, phenyl, chlorophenyl, anisyl, toluyl, 2,4-di-t-amylphenyl, 1-naphthyl), an alkenyl group (for example, vinyl, 2- Methylvinyl), an alkynyl group (eg, ethynyl, 2-methylethynyl, 2-phenylethynyl),
A halogen atom (eg, F, Cl, Br, I), a cyano group, a hydroxyl group, a carboxyl group, an acyl group (eg, acetyl, benzoyl, salicyloyl, pivaloyl), an alkoxy group (eg, methoxy, butoxy, cyclohexyloxy), Aryloxy group (for example, phenoxy, 1-naphthoxy), alkylthio group (for example, methylthio, butylthio, benzylthio, 3-methoxypropylthio), arylthio group (for example, phenylthio, 4-chlorophenylthio), alkylsulfonyl group (for example, Methanesulfonyl, butanesulfonyl), arylsulfonyl group (for example, benzenesulfonyl, paratoluenesulfonyl), and having 1 to 10 carbon atoms
A carbamoyl group, an amide group having 1 to 10 carbon atoms, an acyloxy group having 2 to 10 carbon atoms, and 2-1 carbon atom
A heteroaromatic ring such as pyridyl, thienyl, furyl, thiazolyl, imidazolyl, pyrazolyl, a pyrrolidine ring, a piperidine ring, a morpholine ring, a pyran ring, a thiopyran ring;
An aliphatic heterocycle such as a dioxane ring and a dithiolane ring).

Each of R ³¹ and R ³² is an unsubstituted linear alkyl group having 1 to 8 carbon atoms (preferably having 1 to 6 carbon atoms, particularly 1 to 4 carbon atoms), or an alkoxy group. 1-8 carbon atoms substituted with a group (especially methoxy) or an alkylthio group (especially methylthio)
(Preferably, having 1 to 6 carbon atoms, particularly 1 to 6 carbon atoms
It is preferably a linear alkyl group of 4).

The alkyl group represented by R ³³ , R ³⁴ , R ³⁵ and R ³⁶ preferably has a linear, branched or cyclic substituent having 1 to 18 carbon atoms. Good alkyl group. ^R33 and ^R34 and ^R35 and ^R36
May be connected to each other to form a ring. Preferred examples of the substituent include those described as examples of preferred substituents of the alkyl group or the aryl group represented by R ³¹ and R ³² . R ³³ , R ³⁴ , R ³⁵
And the alkyl group represented by R ³⁶ is preferably a straight-chain unsubstituted alkyl group having 1 to 6 carbon atoms (particularly, methyl or ethyl).

The methine groups represented by L ^{31 to} L ³⁵ are
It may have a substituent. Examples of preferred substituents include alkyl groups having 1 to 18 carbon atoms, aralkyl groups,
And preferred examples of the substituent of the alkyl group or the aryl group represented by R ³¹ and R ³² . Of these, alkyl groups (eg,
Preferred are methyl), an aryl group (eg, phenyl), a halogen atom (eg, Cl, Br), and an aralkyl group (eg, benzyl). Particularly preferred is a methyl group. In the above formula, when j is 2 and m is 0, or j, m
Is preferably independently 0 or 1. L above
³¹ substituents on ~L ³⁵ may combine with each other to form a ring. The number of ring members is preferably a 5- or 6-membered ring, and particularly preferably a cyclohexene ring.

Preferred specific examples of the cyanine dye represented by the general formula (III) are described below.

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[0112]

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[0113]

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[0114]

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[0115]

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[0116]

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[0117]

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The cyanine dye represented by the general formula (III) may be used alone or in combination of two or more. The cyanine dye described in JP-A-11-4
No. 8,615, and can be synthesized with reference to the publication.

The method for manufacturing the DVD-R type optical information recording medium of the present invention will be described below. The DVD-R of the present invention has a predetermined track pitch and an inclination angle of the side wall of the groove of 55.
Basically, a conventional DVD-R manufacturing method is used except that a substrate having a pre-groove in which the side wall of the groove is inclined so as to have an angle of up to 85 ° is used and the dye recording layer is formed to a specific thickness. Can be manufactured. That is, DVD-
R is a substrate characterized by the present invention, on the substrate, a recording layer of a specific thickness, and a reflective layer, and if necessary, two laminates in which a protective layer is formed in order, making each recording layer inside These are manufactured by bonding them with an adhesive or the like, or alternatively, bonding the laminate and a disk-shaped protective substrate having substantially the same dimensions as the substrate of the laminate with an adhesive or the like in the same manner. Can be. Details will be described below.

The substrate (including the protective substrate) can be arbitrarily selected from various materials used as a substrate of a conventional optical information recording medium. Examples of the substrate material include glass; polycarbonate; acrylic resins such as polymethyl methacrylate; vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymer; epoxy resins; amorphous polyolefin and polyester; May be used in combination. 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. The substrate has a diameter of 120 ± 3 mm and a thickness of 0.6 ± 0.1 mm, or a diameter of 80 ± 3 mm
And a thickness of 0.6 ± 0.1 mm is generally used.

An undercoat layer may be provided on the surface of the substrate on which the dye recording layer is provided, for the purpose of improving flatness, improving adhesive strength, preventing deterioration of the recording layer, and the like. As a material of the undercoat layer, for example, polymethyl methacrylate,
Acrylic acid / methacrylic acid copolymer, styrene / maleic anhydride copolymer, polyvinyl alcohol, N-methylol acrylamide, styrene / vinyl toluene copolymer, chlorosulfonated polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, Polyester, polyimide, vinyl acetate / vinyl chloride copolymer,
Examples include polymer substances such as an ethylene / vinyl acetate copolymer, polyethylene, polypropylene, and polycarbonate; and surface modifiers such as a silane coupling agent. The undercoat layer is prepared by dissolving or dispersing the above substance in an appropriate solvent to prepare a coating solution, and then applying the coating solution to the substrate surface using a coating method such as spin coating, dip coating, or extrusion coating. Can be formed. The thickness of the undercoat layer is generally 0.005 to 2
It is in the range of 0 μm, preferably in the range of 0.01 to 10 μm.

On the substrate (or the undercoat layer), a concave groove (pregroove) having a side wall having the above-mentioned inclination angle is formed. The concave groove according to the present invention can be formed by using a resin molding stamper (die) that has been processed so as to have a side wall with a predetermined inclination angle when the substrate is subjected to injection molding or extrusion molding. it can. For example, such a stamper is processed by adjusting irradiation conditions (optical adjustment, irradiation power) of a processing laser beam so as to form a sidewall having a desired inclination angle in a manufacturing process of the stamper. Obtainable.

The formation of the concave groove may be performed by providing a pre-groove layer. As a material for the pregroove 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. For the formation of the pre-groove layer, for example, first, a mixed solution composed of the above-mentioned acrylate ester and the polymerization initiator was applied on a precisely formed master (stamper), and further, a substrate was placed on this coating solution layer. Thereafter, the coating layer is cured by irradiating ultraviolet rays through the substrate or the matrix to fix the substrate and the coating layer. Next, it can be obtained by peeling the substrate from the matrix. Also in the case where the pre-groove layer is provided, the concave groove according to the present invention can be formed by using a stamper (die) previously processed to have a sidewall having a predetermined inclination angle as described above. it can. The thickness of the pre-groove layer is generally in the range from 0.05 to 100 μm, preferably in the range from 0.1 to 50 μm.

The recording layer made of the above-mentioned dye is provided on the substrate having the concave groove according to the present invention.
The dye recording layer is formed, for example, by dissolving a dye in a solvent to prepare a coating solution, applying the coating solution to the surface of the substrate on which the pre-groove is formed to form a coating film, and then drying. Can be performed. In preparing the coating solution, a discoloration inhibitor may be added, and if desired, a binder may be added.

Examples of the solvent for the coating solution for forming the dye recording layer include esters such as butyl acetate and cellosolve acetate; ketones such as methyl ethyl ketone, cyclohexanone and methyl isobutyl ketone;
Chlorinated hydrocarbons such as dichloroethane and chloroform; amides such as dimethylformamide; hydrocarbons such as cyclohexane; ethers such as tetrahydrofuran, ethyl ether and dioxane; ethanol, n-propanol, isopropanol, n-butanol and diacetone alcohol. Alcohols such as 2,2,3,3-tetrafluoropropanol; and glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and 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 compound to be 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.

Representative examples of the anti-fading agent include nitroso compounds, metal complexes, diammonium salts and aminium salts. These examples are described, for example, in JP-A-2-300288 and JP-A-3-224793.
Or each of the publications such as JP-A No. 4-146189. When an anti-fading agent is used, its amount is usually in the range of 0.1 to 50% by weight, preferably in the range of 0.5 to 45% by weight, more preferably in the amount of the dye. Ranges from 3 to 40% by weight, in particular from 5 to 25% by weight.

Examples of the binder include natural organic high-molecular substances such as gelatin, cellulose derivatives, dextran, rosin and rubber; and hydrocarbon resins such as polyurethane, polyethylene, polypropylene, polystyrene and polyisobutylene; polyvinyl chloride. Vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl chloride / polyvinyl acetate copolymer; acrylic resins such as polymethyl acrylate and polymethyl methacrylate; polyvinyl alcohol, chlorinated polyethylene, epoxy resin, butyral resin, rubber derivatives And synthetic organic polymers such as precondensates 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 0.1 to 100 parts by weight of the dye.
It is 2 to 20 parts by weight, preferably 0.5 to 10 parts by weight, more preferably 1 to 5 parts by weight. The concentration of the dye in the coating solution thus prepared is generally in the range of 0.01 to 10% by weight, preferably in the range of 0.1 to 5% by weight.

Examples of the coating method include a spray method, a spin coating method, a dip method, a roll coating method, a blade coating method, a doctor roll method, and a screen printing method. The dye recording layer is preferably formed using a spin coating method. The dye recording layer may be a single layer or a multilayer. The thickness in the concave groove of the dye recording layer of the optical disk of the present invention is 55 to 95 nm (preferably 60 to 9 nm).
5 nm, more preferably 65-93 nm). Further, the thickness of the dye recording layer in the land portion is 30 to 65.
nm (preferably 35 to 60 nm, more preferably
38 to 55 nm).

On the recording layer, a reflective layer is provided for the purpose of improving the reflectivity particularly at the time of reproducing information. The light-reflective substance that is the material of the reflection layer is a substance having a high reflectance to laser light, and examples thereof include Mg, Se, Y,
Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W,
Mn, Re, Fe, Co, Ni, Ru, Rh, Pd, I
r, Pt, Cu, Ag, Au, Zn, Cd, Al, G
a, In, Si, Ge, Te, Pb, Po, Sn, Bi
Metal and semimetal or stainless steel. Of these, preferred are Cr, N
i, Pt, Cu, Ag, Au, Al and stainless steel. These substances may be used alone, or in combination of two or more kinds, or as an alloy. Preferably, Au, Ag, and an alloy containing these metals are used. Particularly preferred are Ag and an alloy containing Ag. The reflective layer is, for example, the above-mentioned reflective substance is deposited,
It can be formed on the recording layer by sputtering or ion plating. The thickness of the reflective layer is generally in the range of 10 to 800 nm, preferably in the range of 20 to 500 nm, more preferably 50 to 300 nm.
nm range.

On the reflective layer, a recording layer and a reflective layer are provided.
A protective layer is provided for the purpose of protecting physically and chemically.
Is preferred. This protective layer is provided by the underlying recording layer.
The other side is also designed to increase scratch and moisture resistance.
You may be beaten. Examples of materials used for the protective layer
For example, SiO, SiO_Two, MgF_Two, SnO_Two, Si _Three
N_FourSuch as inorganic substances, thermoplastic resin, thermosetting resin, U
Organic substances such as V-curable resins can be mentioned. protection
The layer is preferably formed of a resin.

The protective layer can be formed, for example, by laminating a film obtained by extrusion of a plastic on the reflective layer and / or the substrate via an adhesive layer. Alternatively, a protective layer may be provided by a method such as vacuum deposition, sputtering, or coating. In the case of a thermoplastic resin or a thermosetting resin, these are dissolved in an appropriate solvent to prepare a coating solution, and then the coating solution is applied.
The protective layer can be formed by drying.
In the case of a UV-curable resin, a coating solution is prepared as it is or dissolved in an appropriate solvent, and then the coating solution is applied and cured by irradiation with UV light to form a protective layer. Various additives such as an antistatic agent, an antioxidant, and a UV absorber may be added to these coating solutions according to the purpose. The thickness of the protective layer is generally in the range from 0.1 to 100 μm.

Through the above steps, a laminate having a recording layer, a reflective layer, and, if desired, a protective layer provided on a substrate can be manufactured. By laminating the obtained two laminates with an adhesive or the like such that each recording layer is on the inside, a DVD-R type optical information recording medium having two recording layers can be manufactured. . Further, the obtained laminate and a disc-shaped protective substrate having substantially the same dimensions as the substrate of the laminate are bonded with an adhesive or the like so that the recording layer is on the inside, so that the recording layer is provided only on one side. A DVD-R type optical information recording medium can be manufactured. For bonding,
The UV curable resin used for forming the protective layer may be used, or a synthetic adhesive may be used. Alternatively, a double-sided tape may be used. The adhesive layer is usually provided with a thickness in the range of 0.1 to 100 μm (preferably, 5 to 80 μm). In addition, the DVD-R of any aspect
The total thickness of the optical information recording medium of the type is also as follows.
It is preferable that the thickness be adjusted to 2 ± 0.2 mm.

It is convenient for management to display information recorded on the optical information recording medium using titles and patterns.
For that purpose, it is necessary that the surface of the medium (the surface opposite to the side irradiated with the recording / reproducing laser beam) is a surface suitable for such display. In recent years, a printing method using an inkjet printer has been generally used. When printing is performed on the surface of an optical information recording medium using an ink jet printer, the surface of the medium needs to be hydrophilic because the ink is water-based. However, the surface of an optical information recording medium is usually hydrophobic. Therefore, it is necessary to improve the surface of the optical information recording medium to a hydrophilic surface so that the aqueous ink can be easily fixed. An optical information recording medium having such a hydrophilic printing surface (hydrophilic surface layer) is described in, for example, JP-A-7-169700.
Various publications, such as JP-A-10-162438, have been proposed. The optical information recording medium of the present invention can also be provided with a hydrophilic surface layer. When a hydrophilic resin surface layer is provided, the surface layer is made of an ultraviolet curable resin (binder).
It is advantageous to form a layer in which particles made of a hydrophilic organic polymer such as protein particles are dispersed.

Since the lower layer (such as a protective layer) of the hydrophilic surface layer is usually transparent, the surface layer shows a luster due to the metal of the reflective layer. When printing is applied to the hydrophilic surface layer,
There are problems such as that the print screen becomes unclear due to the metallic luster, and that the printing hue cannot be printed with the original hue of the ink. To solve such a problem, it is effective to shield the metallic luster. As a method of shielding metallic luster, for example, a method in which a hydrophilic surface layer contains various kinds of inorganic or organic pigments having a white color, or a method in which a binder such as an ultraviolet curable resin is provided on the lower surface of the hydrophilic surface layer. A method of separately providing a light shielding layer in which a pigment is dispersed is known, and these methods can also be used for the optical information recording medium of the present invention.

The above-mentioned hydrophilic surface layer may contain a fungicide in order to prevent the occurrence of fungi. There is no particular limitation on the fungicide, for example, JP-A-3-73429,
Alternatively, those described in JP-A-10-162438 can be used. Examples of typical fungicides include benzimidazole compounds. When a fungicide is used, the amount used is generally in the range of 0.2 to 2.0 milligrams per gram of layer.

The information recording / reproducing method using the DVD-R of the present invention is carried out, for example, as follows. DVD-R
To a predetermined constant speed (1.2 to 1.2 for CD format)
A laser beam for recording, such as a semiconductor laser beam, is condensed from the substrate side through an optical system and irradiated, while being rotated at a constant angular velocity of 1.4 m / sec or a predetermined constant angular velocity. DVD-
In R, laser light is emitted while rotating at a high speed of usually twice or more. Irradiation of the laser light causes the irradiated portion of the recording layer to absorb the light and locally raise the temperature, and physical or chemical changes occur to change the optical characteristics, thereby recording information. The recording light is a laser light in a visible region, usually 600 nm to 700 nm (preferably 6 nm to 700 nm).
20-680 nm, more preferably 630-660 n
A semiconductor laser beam having an oscillation wavelength in the range of m) is used. The recording light is preferably collected through an optical system having an NA of 0.55 to 0.7. The minimum recording pit length is usually 0.05 to 0.7 μm (preferably,
0.1-0.6 μm, more preferably 0.2-0.4
μm). Reproduction of information recorded as described above involves irradiating a semiconductor laser beam having the same wavelength as at the time of recording from the substrate side while rotating the DVD-R at a predetermined constant linear speed, and detecting the reflected light. Can be performed.

[0137]

EXAMPLES Examples and comparative examples of the present invention will be described below. Example 1 Manufacture of a Disc-Shaped Substrate A polycarbonate (resin trade name: Panlite AD5503) was manufactured using an injection molding machine incorporating a stamper manufactured to have a predetermined track pitch and a predetermined groove shape (pregroove). , A disc-shaped resin substrate (diameter 120 mm, thickness 0.6 mm) manufactured by Teijin Limited. The track pitch of the concave groove of the obtained resin substrate is 0.74 μm.
m, the depth of the groove was 140 nm, the width of the groove was 300 nm, and the inclination angle of the side wall of the groove was 65 ° (see FIG. 1).
The dimensions and angles of these shapes were measured using AFM.

[0138]

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1.0 g of the oxonol dye (dye No. 31) represented by the above formula was dissolved in 100 mL of 2,2,3,3-tetrafluoro-1-propanol to prepare a coating solution for forming a recording layer. This coating solution is applied on the surface of the disc-shaped polycarbonate substrate obtained above, on which the pre-groove is provided, by a spin coating method, dried, and dried to obtain a dye recording layer (thickness in the groove: 90 nm, land area). (Thickness: 50 nm).

Next, Ag was sputtered on the recording layer using a DC magnetron sputtering apparatus (atmosphere in the chamber: argon gas, pressure: 0.5 Pa) to form a reflective layer of Ag having a thickness of about 100 nm. . Further, on the reflective layer, a UV curable resin (trade name: SD318, manufactured by Dainippon Ink and Chemicals, Inc.) was used at a rotation speed of 300 rpm to 4 rpm.
The coating was performed by a spin coating method while changing to 000 rpm. After the application, the coating was irradiated with ultraviolet light from a high-pressure mercury lamp to cure the coating, thereby forming a protective layer having a thickness of 8 μm. The hardness of the protective layer surface was 2H. In this way, two laminates in which the dye recording layer, the reflective layer, and the protective layer were sequentially provided on the substrate were obtained.

On the surface of the protective layer of the two laminates obtained above, an ultraviolet-curable acrylate adhesive (trade name: NX5)
522 (manufactured by CIBA) was applied so as to have a thickness of about 40 μm after bonding, and then irradiated with ultraviolet rays to bond the two laminates together. By the above steps, the DV according to the present invention
A DR type optical disk (DVD-R) was manufactured.

Example 2 A DVD-R according to the present invention was manufactured in the same manner as in Example 1, except that the disk-shaped substrate was changed to a disk-like substrate in which the inclination angle θ of the side wall of the concave groove was 60 °.

Example 3 A DVD-R according to the present invention was manufactured in the same manner as in Example 1, except that the disk-shaped substrate was changed to a disk-like substrate in which the inclination angle θ of the side wall of the concave groove was 60 °.

[Embodiment 4] In Embodiment 1, the side wall of the concave groove was changed to a disk-shaped substrate having an inclination angle θ of 50 °, and the thickness of the dye recording layer was changed to 70 in the groove.
A DVD-R for comparison was manufactured in the same manner except that the thickness of the land portion was changed to 40 nm.

Comparative Example 1 A DVD for comparison was prepared in the same manner as in Example 1, except that the thickness of the dye recording layer was changed to 130 nm in the groove and to 80 nm in the land. R was manufactured.

[Comparative Example 2] A DVD-R for comparison was manufactured in the same manner as in Example 1, except that the inclination angle θ of the side wall of the concave groove was changed to 50 °.

[Evaluation as Optical Information Recording Medium] A laser beam having a wavelength of 635 nm using an OMT2000 (manufactured by Pulstec) was applied to the obtained optical disks of Examples and Comparative Examples using a pickup having an NA of 0.60 and a constant line. 4.5m speed
/ S, recording power of 3-16 mW for 8-16 modulated signal
The recording was performed at the optimum recording power while varying the recording power. Then D
Wavelength 650 using DU1000 (Pulstec)
nm laser light using a NA 0.60 pickup,
The recording signal was reproduced with a constant linear velocity of 4.5 m / sec and a laser power of 0.5 mW, and the track cross was measured. The track cross indicates that the larger the value, the less the occurrence of crosstalk. Table 2 shows the evaluation results.

[0148]

[Table 4] 膜厚 Thickness (nm) of dye recording layer on sidewall of groove Track inclination Angle (θ) Groove part Land part Cross ───────────────────────────── Example 1 65 ° 90 50 0.20 Example 2 60 ° 90 50 0.22 Example 3 75 ° 90 50 0.25 Example 4 65 ° 70 40 0.21 Comparative Example 1 65 ° 130 80 0.11 Comparative Example 2 50 ° 90 50 0.12 ──────

From the results shown in Table 2, in the case of the DVD-R according to the present invention (Example 1) in which the side wall of the concave groove is formed at a large inclination angle and the thickness of the dye recording layer is made thin, the track cross is not large. It can be seen that the crosstalk becomes large and crosstalk hardly occurs. On the other hand, as in the DVD-R of Comparative Example 1, the side wall of the concave groove has a relatively steep inclination angle as defined in the present invention, but the thickness of the dye recording layer in the groove is relatively small. In the case of being formed thick,
As can be seen from VD-R, even when the thickness of the dye recording layer is thin, the track cross becomes small when a substrate having a gentle inclination angle of the side wall of the concave groove is used, and crosstalk is likely to occur. .

[0150]

According to the present invention, a cross-talk is reduced by using a substrate on which a pre-groove having a steep angle of inclination is formed on the side wall of the concave groove and forming the dye recording layer in the groove thin. It is possible to manufacture a DVD-R type optical information recording medium which is unlikely to occur and therefore has high reliability with little error.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a concave groove provided on a disc-shaped substrate of a DVD-R type optical information recording medium of the present invention.

[Explanation of symbols]

 Reference Signs List 1 disc-shaped substrate 2 concave groove (pre-groove) 3 bottom surface of concave groove 4 side wall of concave groove (inner side) 5 side wall of concave groove (outer side)

Claims (7)

[Claims] 1. A transparent disk-shaped substrate having a concave groove formed in a spiral shape from the inner peripheral side to the outer peripheral side of the surface,
In a DVD-R type optical information recording medium having a dye recording layer on which information can be recorded by a laser beam and a reflective layer thereon, a groove at a position 10% of the groove depth from the bottom surface of the concave groove is formed. An angle formed by an extension of a straight line connecting a point on the side wall and a point on the side wall of the groove at a position 50% of the depth of the groove and a horizontal surface on the bottom surface of the concave groove is 55 to 85 °. An optical information recording medium characterized in that the side wall of the groove is inclined so as to fall within the range, and the thickness of the dye recording layer in the concave groove is in the range of 55 to 95 nm. 2. A dye recording layer capable of recording information by a laser beam on a transparent disk-shaped substrate having concave grooves formed spirally from the inner peripheral side to the outer peripheral side of the surface, and a dye recording layer on the transparent recording medium. It is possible to record information by laser light on each of the two laminates having a reflective layer, or on a transparent disk-shaped substrate having a concave groove formed in a spiral shape from the inner peripheral side to the outer peripheral side of the surface A laminate having a dye recording layer and a reflective layer thereon and a disc-shaped protective plate having substantially the same shape as the disc-shaped substrate are bonded together via an adhesive layer such that the dye recording layer side is inside. In the DVD-R type optical information recording medium, a point on the side wall of the groove at a position of 10% of the depth of the groove from the bottom surface of the concave groove and on a side wall of the groove at a position of 50% of the depth of the groove Extension of the straight line connecting the points The side wall of the groove is inclined so that the angle formed between the bottom surface and the horizontal plane is in the range of 55 to 85 °, and the thickness of the dye recording layer in the concave groove is in the range of 55 to 95 nm. An optical information recording medium characterized by the above-mentioned. 3. The optical information recording medium according to claim 1, wherein the dye recording layer contains a cyanine dye or an oxonol dye. 4. A dye recording layer comprising an oxonol dye comprising an anionic dye component and a cationic component, wherein the cationic component is a compound represented by the following formula (II-A). Optical information recording medium according to 1 or 2: [Wherein, R ²⁴ and R ²⁵ each independently represent a substituent,
R ²⁶ and R ²⁷ each independently represent an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an aryl group, or a heterocyclic group (the aryl group or the heterocyclic group may be further condensed with another ring) R ²⁴ and R ²⁵ , R ²⁴ and R ²⁶ , or R ²⁵ and R ²⁷ may be linked to each other to form a ring, and r 1 and s 1 each independently represent an integer of 0 to 4. And when r1 and s1 are 2 or more, a plurality of R ²⁴ and R ²⁵ may be the same or different from each other.] 5. The optical information recording medium according to claim 4, wherein the anionic dye component is a compound represented by the following general formula (I-2-A): [Wherein, R ¹ , R ² , R ³ , and R ⁴ each independently represent an alkyl group which may have a substituent, and L ¹¹ , L ¹² ,
And L ¹³ each independently represent a methine group which may have a substituent (however, when L ¹¹ , L ¹² and L ¹³ have a substituent, two or more of these may be present) May combine to form a ring), n3 represents an integer of 0 to 3, and R ¹ and R ² , or R ³ and R ⁴ are respectively connected to each other to form a ring May be]. 6. The optical information recording medium according to claim 1, wherein the reflection layer is a layer made of silver or a silver alloy. 7. The optical information recording medium according to claim 1, wherein a resin protective layer is further provided on the reflective layer.