JP2002222546A - Optical information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical information recording medium generating less noise and free from deterioration in tone quality. SOLUTION: The optical information recording medium wherein a recording layer consisting of a dystuff material is deposited directly or via an another layer on a substrate having a guide groove on the surface thereof, a reflection layer is deposited directly or via an another layer on the surface side of the recording layer and a protective layer and a print layer consisting of UV curing resin successively deposited on the reflection layer is characterized in that the print layer has >=1.1 g/cm3 specific gravity, >=20 μm thickness, RCb(radial contrast) value expressed by the following formula of <=0.1 and has a guide groove having wobble groove of <=36 nm Wobble amplitude. RCb=2(ll-lg)/(ll+ lg) [wherein ll denotes the Land level in an unrecorded signal and lg denotes the Groove level in the unrecorded signal].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording medium, and more particularly, to an optical information recording medium having little noise and no sound quality deterioration.

[0002]

2. Description of the Related Art In recent years, in addition to optical information recording media such as read-only CDs (compact disks), recordable C
D (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 recorded signal satisfies the conventional CD standard, and can be reproduced by a commercially available CD player. Has features. As one method of realizing such a medium, for example, in the case of CD-R, it has been proposed to provide a light absorption layer by spin coating a dye on a substrate and provide a metal reflection layer behind the light absorption layer. (JP-A-2-42652).

[0003]

In such an optical information recording medium, digital recording of music information is performed. However, at that time, digitally recorded,
Despite playback, noise enters from the recording and playback system,
The fact that this is related to sound quality deterioration has been confirmed by sensory evaluations of some music experts. In particular, a CD-R after recording is a CD-D having a conventional press pit.
There is a disadvantage that the sound quality is easily deteriorated as compared with A.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical information recording medium which eliminates the above-mentioned drawbacks of the prior art and has little noise and no sound quality deterioration.

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted intensive studies focusing on the characteristics of the printed layer. As a result, the specific gravity, thickness, RCb value, wobble a
It has been found that the above problem can be solved by specifying mplitude, and the present invention has been completed based on this finding.

That is, according to the present invention, first, a recording layer made of a dye material is formed directly or via another layer on a substrate having a guide groove on the surface, and a recording layer is formed on the surface side of the recording layer. ,
In an optical information recording medium in which a reflective layer is formed directly or via another layer, and a protective layer made of an ultraviolet curable resin and a printed layer are sequentially formed on the reflective layer, the specific gravity of the printed layer is 1. An optical information recording medium is provided, wherein the optical information recording medium is 1 g / cm ³ or more, the thickness is 20 μm or more, and the RCb value represented by the following formula (1) is 0.1 or less. RCb = 2 (Il-Ig) / (Il + Ig) (1) [In the equation (1), Il indicates a Land level in the unrecorded SIGNAL, and Ig indicates a Groove level in the unrecorded SIGNAL. ]

According to the present invention, secondly, a guide groove is formed on the surface.
From the dye material directly or through another layer on the substrate having
Formed on the surface side of the recording layer, directly or by another
Having a reflective layer through a layer of UV curing on the reflective layer
Information in which a protective layer and a printing layer made of a conductive resin are sequentially formed
In the recording medium, the specific gravity of the printing layer is 1.1 g / cm. ^Three
As described above, the thickness is 20 μm or more, and wobble amplitu
de has a wobble groove of 36 nm or less.
An optical recording information medium is provided.

The first and second inventions are directed to an optical information recording medium having a printed layer formed on the surface of a 120 mm disk-shaped optical information recording medium and having a weight of 0.2 to 4 g, and a depth of the guide groove. Is 1800 ° or less and the width is 0.6 μm or less, the optical material is a phthalocyanine-based compound represented by the following general formula (2), and music information is recorded. Optical information recording media.

Embedded image [In the formula (2), M is a divalent metal atom, a substituted trivalent metal atom,
Represents a disubstituted tetravalent metal atom or an oxymetal, and A ¹ and A ² ;
A ³ and A ⁴ , A ⁵ and A ⁶ and A ⁷ and A ⁸ each independently represent an alkyl group, an alkoxy group, a phenyl group, an alkylthio group, a phenylthio group, a halogen, a nitro group, a cyano group or a hydrogen atom. ]

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a printing layer provided on a protective layer, changing the amplitude decay time and the frequency decay time in the direction perpendicular to the disk is effective for reducing noise. FIG. 1 shows a state of vibration damping when vibration is externally applied to the optical information recording medium. The horizontal axis represents the elapsed time, and the vertical axis represents the vibration amplitude of the disk. The amplitude decay time and the frequency decay time (t) can be changed depending on the printing layer conditions.
Also, suppressing a signal from the guide groove of the CD-R is effective for noise reduction. The guide groove is not provided on a CD-DA having a press pit, but is additionally recorded on a CD-R.
It is an indispensable configuration.

In the present invention, the specific gravity of the printing layer is set to 1.1.
The above problem was solved by forming a layer made of an ultraviolet curable resin having a thickness of at least g / cm ³ and having a thickness of at least 20 μm, and further optimizing the intensity of a signal reflected from the guide groove.
When the specific gravity is less than 1.1 g / cm ³ and the thickness is less than 20 μm, it is difficult to obtain the effect of changing and reducing the vibration damping time and the frequency damping time in the direction perpendicular to the disk.

The specific gravity can be increased by mixing coloring particles such as titanium oxide, magnesium oxide, and silicon oxide with a recording liquid (ink).
Also, the thickness of the printing layer can be adjusted by screen mesh squeegee pressure during screen printing,
Further, it can be adjusted by laminating a large number of printing layers.

In order to obtain the above-mentioned conditions for the printing layer, a diameter of 1
For a 20 mm disc-shaped optical information recording medium (disk size),
It is preferable that the weight of the printing layer is in the range of 0.2 to 4 g. If the weight is less than 0.2 g, it is difficult to obtain the effect of changing or reducing the vibration decay time and the frequency decay time in the vertical direction of the disk. Absent. The signal characteristics of the guide groove are RCb and / or wobble amp.
Determined by adjusting litude. The RCb value is
0.1 or less, preferably 0.05 to 0.1. If this value exceeds 0.1, the reflection effect of the guide groove becomes large, and if it is less than 0.05, it becomes difficult to obtain the signal intensity required for the additional recording operation, which is not preferable. This value is 0 when there is no guide groove.

RCb is represented by the following equation (1). RCb = 2 (Il-Ig) / (Il + Ig) (1) [In the equation (1), Il indicates a Land level in the unrecorded SIGNAL, and Ig indicates a Groove level in the unrecorded SIGNAL. This RCb is preferably in the range of 0.05 to 0.08. Also, the wobble amplitude is 3
It is 6 nm or less, preferably 20 to 36 nm. This value corresponds to the amount of meandering displacement of the guide groove, and becomes zero when there is no meandering of the guide groove. If this value exceeds 36 nm, the influence of the meandering of the guide groove becomes large, and
If it is less than nm, it is difficult to obtain the signal intensity required for the additional recording operation, which is not preferable. In order to obtain this RCb, it is preferable that the depth of the guide groove of the substrate is 1800 A or less and the width is 0.6 μm or less. 180 depth
If the angle exceeds 0 °, or if the width exceeds 0.6 μm, the step of the guide groove becomes large, and RCb easily exceeds 0.1, which is not preferable. In general, the deeper the groove,
The larger the groove width, the larger the RCb. The preferred groove depth is in the range of 1000-1600 °.

In the present invention, the dye material is preferably a phthalocyanine compound represented by the following general formula (2). The phthalocyanine-based compound represented by the general formula (2) can easily obtain a desired RCb value due to the coatable film, and has excellent durability, so that a change in signal can be reduced.

Embedded image [In the above general formula (2), M is a divalent metal atom,
Represents a substituted trivalent metal atom, a disubstituted tetravalent metal atom or an oxymetal; A ¹ and A ² , A ³ and A ⁴ , A ⁵ and A ^6, and A ⁷ and A
⁸ are each independently an alkyl group, an alkoxy group, a phenyl group, an alkylthio group, a phenylthio group, a halogen,
It represents a nitro group, a CN group or a hydrogen atom. ]

The central metal M of this phthalocyanine compound
As a divalent metal, Cu ²⁺, Zn²⁺, F
e²⁺, Co²⁺, Ni²⁺, Ru²⁺, Rh²⁺, Pd²⁺, Pt
²⁺, Mn ²⁺, Mg²⁺, Ti²⁺, Be²⁺, Ca²⁺, B
a²⁺, Cd²⁺, Hg²⁺, Pb²⁺, Sn ²⁺Etc.
You.

Al-Cl, A
l-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-C₆H_Five, Al-C₆H_Four(C
H_Three), In-C₆H_Five, In-C₆H_Four(CH_Three), In-
C_TenH ₇, Mn (OH), Mn (OC₆H_Five), Mn [O
Si (CH_Three)_Three], FeCl, RuCl and the like.
You.

As the disubstituted tetravalent metal, CrCl ₂ , S
iCl ₂ , SiBr ₂ , SiF ₂ , SiI ₂ , ZrCl ₂ ,
GeCl ₂ , GeBr ₂ , GeI ₂ , GeF ₂ , SnC
l ₂ , SnBr ₂ , SnI ₂ , SnF ₂ , TiCl ₂ , Ti
Br ₂ , Ti, F ₂ , Si (OH) ₂ , Ge (OH) ₂ , Zr
(OH) ₂ , Mn (OH) ₂ , Sn (OH) ₂ , TiR ₂ , CrR
₂ , SiR ₂ , SnR ₂ , GeR ₂ (R represents an alkyl group, a phenyl group, a naphthyl group and derivatives thereof), Si (O
R ′) ₂ , Sn (OR ′) ₂ , Ge (OR ′) ₂ , Ti (OR ′) ₂ ,
Cr (OR ′) ₂ (R ′ represents an alkyl group, a phenyl group, a naphthyl group, a trialkylsilyl group, a dialkylalkoxysilyl group and a derivative thereof), Sn (SR ⁻ ) ₂ , Ge
(SR ⁻ ) ₂ (R ⁻ represents an alkyl group, a phenyl group, a naphthyl group and derivatives thereof) and the like.

As the oxymetal, VO, MnO, Ti
O, among others, Zn, Ni, Cu, Pd, V
One metal atom or metal oxide selected from O and TiO is preferred.

These compounds having M are easy to produce and have good light absorption properties.
Examples of the substituents A ^{1 to} A ⁸ include a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an alkoxy group, an alkylthio group, an aryl group having 6 to 20 carbon atoms, an aryloxy group, an arylthio group, and a halogen atom. , A nitro group, a cyano group and a hydrogen atom are preferred.

Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, an n-butyl group, an iso group.
-Butyl group, tert-butyl group, sec-butyl group,
n-pentyl group, iso-pentyl group, neo-pentyl group, 1-methylbutyl group, 2-methylbutyl group, n-
Hexyl group, 2-ethylbutyl group, 3-methylpentyl group, 2,3-dimethylbutyl group, n-heptyl group, n-
Octyl group, 2-ethylhexyl group, n-nonyl group,
2,5,5-trimethylhexyl group, n-decyl group, 4
-Ethyloctyl group, 4-ethyl-4,5 dimethylhexyl group, n-undecyl group, n-dodecyl group, 1,3,
5,7-tetramethyloctyl group, 4-butyloctyl group, 6,6-diethyloctyl group, n-tridecyl group,
Examples thereof include a 6-methyl-4-butyloctyl group, an n-tetradecyl group, an n-pentadecyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, and a 2-chlorobutyl group.

The alkoxy group having 1 to 10 carbon atoms includes
Methoxy, ethoxy, propyloxy, iso-
Propyloxy group, n-butyloxy group, iso-butyloxy group, tert-butyloxy group, sec-butyloxy group, n-pentyloxy group, neo-pentyloxy group, iso-pentyloxy group, tert-pentyloxy group, 1- Examples include a methylbutyloxy group, a 2-methylbutyloxy group, an n-hexyloxy group, a cyclohexyloxy group, an adamantyloxy group, a norbornyloxy group, and a 2-chlorobutyloxy group.

The alkylthio group having 1 to 10 carbon atoms includes a methylthio group, an ethylthio group, an n-propylthio group, an iso-propylthio group, an n-butylthio group, an is-thio group.
o-butylthio group, tert-butylthio group, sec-
Butylthio group, n-pentylthio group, iso-pentylthio group, neo-pentylthio group, 1,2-dimethylpropylthio group, n-hexylthio group, 1-ethyl-2-
Methylpropylthio group, 2-ethylbutylthio group, cyclohexylthio group, 2-methyl-1-iso-propylthio group, n-heptylthio group, 2-methylhexylthio group, 1-ethylpentylthio group, n-octylthio group ,
2-ethylhexylthio group, 3-methyl-1-iso-
Propylbutylthio, n-nonylthio, 3-methyl-1-iso-butylbutylthio, 3,5,5-trimethylhexylthio, 2-chlorobutylthio, 4-
a tert-butylcyclohexylthio group;

The aryl group having 6 to 20 carbon atoms includes phenyl, 2-methylphenyl, 2,4-dimethylphenyl, 2,4,6-trimethylphenyl, 2-i
so-propylphenyl group, 4-bromophenyl group,
Examples thereof include a 2,6-dichlorophenyl group and a naphthyl group. Specific examples of the aryloxy group having 6 to 20 carbon atoms include a phenoxy group, a 2-methylphenoxy group, and a 2,4-
A dimethylphenoxy group, a 2,4,6-trimethylphenoxy group, a 2-iso-propylphenoxy group, a 4-bromophenoxy group, a 2,6-dichlorophenoxy group, a naphthyloxy group, and the like; Specific examples of the arylthio group include a phenylthio group, a 2-methylphenylthio group, a 2,4-dimethylphenylthio group, a 2,4,6-trimethylphenylthio group, a 2-is
Examples include an o-propylphenylthio group, a 4-bromophenylthio group, a 2,6-dichlorophenylthio group, a naphthylthio group, and the like. Further, specific examples of the halogen atom include F, Cl, Br and I atoms.

Among these substituents, particularly preferred are a linear or branched alkyl group having 4 to 10 carbon atoms, an alkoxy group, an alkylthio group and a C 6 to C 15 group.
Are aryloxy and arylthio groups. Compounds having these groups have excellent solubility and are easy to apply and form. On the other hand, if the number of carbon atoms is larger than these, the absorbance per unit film of the light absorbing layer decreases, and it becomes difficult to obtain appropriate optical characteristics (complex refractive index), which is not preferable.

In addition, other groups are added to A ^{1 to} A ⁸ for the purpose of improving the recording sensitivity, adjusting the absorption wavelength of the light absorbing layer, and improving the solubility in a coating solvent, and the like. Examples of such a group include a sulfonic acid group, a sulfonic acid amine, a carboxyl group, an amide group, and an imide group.

Further, as the most preferred structure of A ^{1 to} A ⁸ , one of A ¹ and A ² , A ³ and A ⁴ , A ⁵ and A ^6, and A ⁷ and A ⁸ , Independently -O
—C (R ₁ ) (R ₃ ) —R ₂ , the other being a hydrogen atom (R ₁ , R ₂
Represents an alkyl group, a fluorine-substituted alkyl group or a hydrogen atom, and R ₂ represents an alkyl group, a substituted phenyl group or an unsubstituted phenyl group. ). Specific examples of R ₁ and R ₃ include methyl, ethyl, propyl, isopropyl, n-propyl, butyl, n-butyl, sec-butyl, tert-
_{Butyl, -CF 3, -C 2 F 5} , -CF (CF 3) 2, can be exemplified hydrogen atom. In particular, it is preferable that both the substituents R ₁ and R ₃ are —CF ₃ . The —CF ₃ group lowers the thermal decomposition temperature and improves the recording sensitivity and jitter characteristics.

R ₂ is a phenyl group, a naphthyl group,
2-methylphenyl group, 2,4-dimethylphenyl group,
Examples include a 2,4,6-trimethylphenyl group, a 2-isopropylphenyl group, a 2.5-dimethylphenyl group, a 2,6-dimethylphenyl group, and a 2-ethylphenyl group. The carbon number of the alkyl group provided to the phenyl group is 1 to
4 is preferred. If the number of carbon atoms exceeds 4, the absorbance per unit film thickness of the light absorbing layer tends to decrease, and it becomes difficult to obtain a favorable complex refractive index.

The phthalocyanine compound represented by the general formula (2) can be easily produced by a cyclization reaction of the corresponding phthalonitrile mixture. That is, phthalonitrile is converted to, for example, 1,8-diazabicyclo [5,
It can be produced by heating and reacting a metal derivative with an alcohol in the presence of [4,0] -7-undecene. The recording layer comprising the phthalocyanine-based compound,
This compound can be easily obtained by dissolving this compound in a solvent and coating it on a substrate as a coating solution. Furthermore, the central metal M
Is Fe ²⁺ , Co ²⁺ , Zn ²⁺ , Cd ²⁺ , Mn ²⁺ , it is preferable to add an amino compound. When M is any of these metals, the amino compound is easily coordinated with M, and the coordination improves the solubility in a solvent and the coating film forming property. Examples of the amino compound include, but are not limited to, the following compounds. Among them, compounds containing an N atom in a heterocyclic ring are preferable because they have a high effect of preventing the association of the phthalocyanine compound and have excellent durability (heat resistance and light resistance).

From the viewpoint of maintaining the thermal stability of the light absorbing layer, the amino compound preferably has a melting point of 150 ° C. or higher. When the melting point is lower than 150 ° C., the characteristics (particularly, optical characteristics) of the light absorbing layer under a high temperature and high humidity environment
Is likely to change. Among them, particularly preferred are imidazole, benzimidazole and thiazole derivatives.

Examples of the amino compound include n-butylamine, n-hexylamine, tert-butylamine, pyrrole, pyrrolidine, pyridine, piperidine, purine,
Imidazole, benzimidazole, 5,6-dimethylbenzimidazole, 2,5,6-trimethylbenzimidazole, naphthymidazole, 2-methylnaphthoimidazole, quinoline, isoquinoline, quinoxaline,
Benzquinoline, phenanthridine, indoline, carbazole, norharman, thiazole, benzthiazole, benzoxazole, benztriazole, 7-azaindole, tetrahydroquinoline, triphenylimidazole, phthalimide, benzoisoquinoline-5
10-dione, triazine, perimidine, 5-chlorotriazole, ethylenediamine, azobenzene, trimethylamine, N, N-dimethylformamide, 1 (2
H) phthalazinone, phthalhydrazide, 1,3-diiminoisoindoline, oxazole, polyimidazole,
Polybenzimidazole, polythiazole and the like can be mentioned.

As the dye material, in addition to the phthalocyanine compound (2), an arbitrary dye conventionally known as a recording material for an information recording medium can be mixed and used. Such dyes include, for example, cyanine dyes, phthalocyanine dyes, pyrylium / thiopyrylium dyes, azulenium dyes, squarylium dyes, metal complex salt dyes such as Ni and Cr, naphthoquinone / anthraquinone dyes, India Examples thereof include phenol dyes, indoaniline dyes, triphenylmethane dyes, triallylmethane dyes, aminium / diimmonium dyes, and nitroso compounds. Further, other third components, for example, a binder, a stabilizer and the like can be contained as needed.

The thickness of the light absorbing layer is 100 to 500.
0 ° is preferable, and particularly preferably 500 to 3000 °.
If the thickness of the light absorbing layer is less than 500 °, the recording sensitivity is lowered, and if it exceeds 3000 °, the reflectance is undesirably reduced.

The substrate used in the present invention can be arbitrarily selected from various materials used as conventional substrates for information recording media. As a substrate material, acrylic resin such as polymethyl methacrylate, polyvinyl chloride, vinyl chloride resin such as vinyl chloride copolymer, epoxy resin, polycarbonate resin, amorphous polyolefin, polyester, glass such as soda lime glass and ceramics. Can be mentioned. In particular, polymethyl methacrylate, polycarbonate resin, epoxy resin, amorphous polyolefin, polyester, glass, and the like are preferable in terms of dimensional stability, transparency, planarity, and the like.

On the substrate surface on the side where the light absorbing layer is provided,
An undercoat layer may be provided for the purpose of improving flatness, improving adhesive strength, and preventing deterioration of the light absorbing layer. Examples of the material for the undercoat layer include polymethyl methacrylate, acrylic acid / methacrylic acid copolymer, styrene / maleic anhydride copolymer, polyvinyl alcohol, N-methylolacrylamide, styrene / sulfonic acid copolymer, and 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. And organic substances such as silane coupling agents, and inorganic substances such as inorganic oxides (SiO ₂ and Al ₂ O ₃ ) and inorganic fluorides (MgF ₂ ). The thickness of the undercoat layer is generally 0.005 to 20 μm.
m, preferably in the range of 0.01 to 10 μm.

Further, a pre-group layer may be provided on the substrate (or undercoat layer) for the purpose of forming irregularities representing information such as tracking grooves or address signals. As a 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 reflection layer is provided on the light absorption layer for the purpose of improving the S / N ratio, the reflectance, and the sensitivity during recording. The light-reflective substance that is the material of the reflection layer is a substance having a high reflectance with respect to 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, Au, Al and Ag are preferred. These substances may be used alone, in combination of two or more or as an alloy. The thickness of the reflective layer is generally 100 to
In the range of 3000 °.

On the light absorbing layer (or reflecting layer),
A protective layer is used to physically and chemically protect the light absorbing layer.
Provided. This protective layer is provided with the light absorbing layer of the substrate
The other side is provided for the purpose of enhancing the scratch resistance and moisture resistance.
You may. Examples of materials used for the protective layer include S
i, O, SiO_Two, MgF_Two, SnO _TwoInorganic substances such as heat
Lists plastic resins, thermosetting resins, and ultraviolet curing resins
be able to.

The thickness of the protective layer is generally 50
It is in the range of 0 ° to 50 μm. The printing layer can be formed by screen printing using an ultraviolet curable resin. Urethane acrylate, epoxy acrylate, or the like can be used as a main component of the ultraviolet curable resin. By mixing inorganic or organic coloring pigments or fillers with these, a desired printed layer is formed.

[0039]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. Example 1 A 1.2 m / s reproduction linear velocity guide groove uneven pattern having a depth of about 1500 °, a width of about 0.45 m, and a track pitch of 1.6 μm on the surface of a polycarbonate disk having a diameter of 120 mm and a thickness of 1.2 mm. Is prepared, a phthalocyanine-based compound is used as an organic dye material, M is VO,
R ₁ and R ₂ are CF ₃ , R ₂ is phenyl, M is Zn,
A pigment material in which A ¹ , A ³ , A ⁵ , and A ⁷ are 2-methyl-thiophenyl was mixed at 2/1, and tetrahydrofuran and 2-methyl-thiophenyl were mixed.
The recording layer was provided by dissolving in a mixed solvent of methoxyethanol and methylcyclohexane and spin coating as a coating solution. The thickness of the light absorbing layer was about 1500A. Next, Ag was applied to a thickness of about 1400 ° on the recording layer by sputtering using Ar as a sputtering gas to form a reflective layer. Further, a protective layer made of an ultraviolet curable resin (SD1700, Dainippon Ink) is further provided thereon for about 5 minutes.
μm in thickness, and an ultraviolet curable ink (RC
D-29, Jujo Kako) about 0,10,2
Four types of optical information recording media (1), (2), which are formed by screen printing to a thickness of 0 or 40 μm and have different print layer thicknesses.
(3) and (4) were obtained. The specific gravity of this printed layer is 1.85
g / cm ³ . This medium is used as a signal evaluation device (DU)
U, Pulstec Co.), wavelength 790 nm, N
A: When the signal was evaluated under the condition of 0.5, RCb was 0.05 and wobble amplitude was 30 n.
m. An audio writer (CDW9
At 00E), a music signal was recorded, and the noise of the reproduced sound was examined. The presence / absence of noise is a result of sensory evaluation in which a person listens to and evaluates music, and the playback player uses STUD.
D730 manufactured by ER was used. When the relationship between the print layer thickness and the noise was examined, the print layer thickness was 20 μm (1), 40 μm.
m (2) of the optical information recording medium of the present invention is 0 μm (3);
The noise was smaller than that of 10 μm (4).

Example 2 The dye material used in Example 1 was replaced by the following general formula (3)
In the same manner as in Example 1 except that the film was formed by coating with 2,2,3,3, tetrafluoropropanol instead of the cyanine dye material consisting of a 1/2 mixture of Types of optical information recording media for reference (5), (6),
(7) and (8) were obtained.

[0041]

Embedded image

Embedded image This medium had RCb of 0.14 and wobble amplitude.
Was 30 nm. When noise was evaluated for these in the same manner as in Example 1, the noise was 0 μm (5), 10 μm
(6), 20 μm (7), and 40 μm (8) all had more noise than in Example 1.

[0042]

According to the present invention, there is provided an optical information recording medium with little noise and no deterioration in sound quality, which greatly contributes to the field of designing and manufacturing this recording medium.

[Brief description of the drawings]

FIG. 1 is a diagram showing vibration damping when vibration is externally applied to an optical information recording medium.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 7/24 561 G11B 7/24 561M 561Q B41M 5/26 C09B 47/067 // C09B 47/067 B41M 5 / 26 Y

Claims (6)

[Claims] 1. A recording layer made of a dye material is formed directly or via another layer on a substrate having a guide groove on the surface, and reflection is made on the surface side of the recording layer directly or via another layer. Forming a layer, on the reflective layer, an optical information recording medium in which a protective layer and a print layer made of an ultraviolet curable resin are sequentially formed,
The specific gravity of the printing layer is 1.1 g / cm ³ or more and the thickness is 20 μm.
m, and an RCb (radial contrast) value represented by the following formula (1): 0.1 or less. RCb = 2 (Il-Ig) / (Il + Ig) (1) [In the formula (1), Il is an unrecorded SIGNAL (signal)
Indicates Land level, Ig is unrecorded SIGNAL
Indicates a Groove level. ] 2. A recording layer made of a dye material is formed directly or via another layer on a substrate having a guide groove on the surface, and is reflected on the surface side of the recording layer directly or via another layer. In the optical information recording medium having a layer, a protective layer made of an ultraviolet curable resin and a printing layer formed in this order on the reflection layer, the specific gravity of the printing layer is 1.1 g / cm ³ or more, and the thickness is 20 μm.
An optical information recording medium characterized by having a wobble groove having a wobble amplitude (wobble amplitude) of 36 nm or less. 3. The optical information recording medium according to claim 1, wherein the weight of the printing layer formed on the surface of the 120 mm disc-shaped optical information recording medium is 0.2 to 4 g. 4. The optical information recording medium according to claim 1, wherein said guide groove has a depth of 1800 ° or less and a width of 0.6 μm or less. 5. The optical information recording medium according to claim 1, wherein the coloring material is a phthalocyanine compound represented by the following general formula (2). Embedded image [In the formula (2), M is a divalent metal atom, a substituted trivalent metal atom,
Represents a disubstituted tetravalent metal atom or an oxymetal, and A ¹ and A ² ;
A ³ and A ⁴ , A ⁵ and A ⁶ and A ⁷ and A ⁸ each independently represent an alkyl group, an alkoxy group, a phenyl group, an alkylthio group, a phenylthio group, a halogen, a nitro group, a cyano group or a hydrogen atom. ] 6. The music information is recorded on a computer.
6. The optical information recording medium according to any one of items 1 to 5,