JP2002184038A - Optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an effective method with which uniform characteristics are obtained over the entire face and which is a new format post-script type DVD system provided with a semiconductor laser generating oscillation in a shorter wavelength regions, as compared to a conventional system, eliminating an unrecorded region in the area with newly added data like an Lpp(land prepit) method, being a superior method, free of data errors due to the fine control of cut width during manufacturing of a stamper or due to leakage of Lpp signals to the data area as compared to the land prepit method for a DVD-R. SOLUTION: The medium has a recording layer formed on a substrate and has a reflection layer, as necessary. The medium is obtained, by using a substrate which is molded by the stamper having 1,000 to 2,500 Å groove depth, 0.64 to 0.8 μm track pitch, and 0.18 to 0.4 μ halfwidth of the groove width, where the groove depth becomes deeper forward the outer periphery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording medium, and more particularly, to an information recording medium by irradiating a light beam.
It relates to an information recording medium that causes optical changes such as the transmittance and reflectivity of the recording material, records and reproduces information, and is recordable, and is used for data write-once optical discs and write-once compact discs. CD-I,
Applied to CD-V, DVD-R.

[0002]

2. Description of the Related Art Conventionally, data write-once discs using a cyanine dye as a recording material (JP-A-57-82093, JP-A-58-56892, and JP-A-58-112790) are known. Gazette, JP-A-58-1
14989, JP-A-59-85791, JP-A-60-83236, JP-A-60-89842
And phthalocyanine dyes as recording materials (see JP-A-6-25886).
1-1150243, JP-A-61-177287, JP-A-61-154888, and JP-A-61-1.
No. 246091, JP-A-62-39286,
JP-A-63-37791, JP-A-63-3988
No. 8) is proposed.

As a write-once compact disc, a disc using a cyanine dye / metal reflective layer as a recording material (JP-A-1-159842, JP-A-2-42)
652, JP-A-2-13656, JP-A-2
And phthalocyanine (azaannulene) dyes as recording materials (see Japanese Unexamined Patent Publication No.
-176585, JP-A-3-215466, JP-A-4-113886, JP-A-4-226
390, JP-A-5-1272, JP-A-5-127
171052, JP-A-5-116456,
JP-A-7-268227, JP-A-7-31489
No. 7) and those using an azo metal chelate dye as a recording material (JP-A-4-46186, JP-A-4-141489, JP-A-4-361088, JP-A-5-279580) JP-A-7-516
No. 73, Japanese Patent Application Laid-Open No. 7-16069, Japanese Patent Application Laid-Open
-372272, JP-A-7-71867,
JP-A-8-231866, JP-A-8-29581
No. 1 publication) has been proposed.

Further, as for the DVD-R, a DVD using a cyanine dye / metal reflective layer as a recording material (Pioneer R & D Vol.6 No. 6).
2: Development of DVD-Recordable, DVD-R
Basic research on dye disks), ISOM / ODS ('9
6: High Density of recordi
ngon Dye material Disc ap
(proach for 4.7 GB), using a polymethine dye as a recording material (JP-A-10-83577).
JP, JP-A-10-119434, JP-A-10-119434
JP-A-1499583, JP-A-10-188339, JP-A-10-278426, etc.), and those using a polymethine dye + a light stabilizer as a recording material (JP-A-10-109475, JP-A-10-109475) -1094
No. 76, JP-A-10-134413, JP-A-10-166439, etc.), and those using an azo metal chelate dye / metal reflective layer as a recording material (Japanese Patent Publication No. 5-67438, JP-A-7-67438) -161069, JP-A-8-156408, JP-A-8-231
866, JP-A-8-332772, JP-A-9-58123, JP-A-9-175031, JP-A-9-193545, JP-A-9-274
732, JP-A-9-277703, JP-A-10-6644, JP-A-10-6650,
JP-A-10-6651 and JP-A-10-36693
JP, JP-A-10-44606, JP-A-10-44606
JP-A-58828, JP-A-10-86519, JP-A-10-149584, JP-A-10-1572
No. 93, JP-A-10-157300, JP-A-10-157301, JP-A-10-157302
JP, JP-A-10-181199, JP-A-10-181199
JP-A-181201, JP-A-10-181203, JP-A-10-181206, JP-A-10-1
No. 88340, JP-A-10-188341,
JP-A-10-188358, JP-A-10-208
No. 303, JP-A-10-214423, JP-A-10-228671, JP-A-10-36693
And Japanese Patent Application Laid-Open No. H11-12483, and those using a tetraazaporphyrin (porphyrazine) dye / metal reflective layer as a recording material (Japanese Patent Application Laid-Open No. 9-26756).
No. 2, JP-A-9-309268, JP-A-9-309268
JP-A-10-856, etc.) and those using other dye / metal reflective layers as recording materials (JP-A-10-86517, JP-A-10-93788, JP-A-10-2).
No. 26172, Japanese Unexamined Patent Publication No. 10-244758,
JP-A-10-287819, JP-A-10-297
103, JP-A-10-309871, JP-A-10-309872, etc.), cyanine dye +
Using an azo metal chelate dye / metal reflective layer as a recording material (Japanese Patent Publication No. 7-51682,
No. 34499), and those using formazan (metal chelate) dye + other dyes as recording materials (Japanese Patent No. 2791944, Japanese Patent Application Laid-Open No. 8-29507).
9, JP-A-9-095520, JP-A-9-95520
JP-A-193546, JP-A-10-337958, etc.), and those using dipyrromethene (metal chelate) dye + other dyes as recording materials (JP-A-10-16)
2430, JP-A-10-166732, JP-A-10-226172, JP-A-11-0428
No. 58, JP-A-11-042858, JP-A-11-092682, JP-A-11-165465
JP, JP-A-11-208111, JP-A-11-208111
-227332, JP-A-11-227333, JP-A-11-255774, JP-A-11-2
No. 56057).

At present, as a next-generation large-capacity optical disk, D
VD-R is under development. The elemental technologies for improving the recording capacity include recording material development for miniaturizing recording pits,
It is necessary to develop technology such as adoption of image compression technology represented by PEG2 and shortening of the wavelength of a semiconductor laser for reading recorded pits. Until now, semiconductor lasers in the red wavelength range have been used for bar code readers and measuring instruments.
Although only the 1GaInP laser diode has been commercialized, the red laser is being used in the optical storage market in earnest as the density of optical disks increases. DV
In the case of D drive, 635 nm band and 650 n
It is standardized by two wavelengths of the m-band laser diode. On the other hand, a DVD-ROM drive for reproduction only has a wavelength of 6
Commercialized up to 50 nm. Under these circumstances, the most preferable DVD-R media has a wavelength of 630-68.
It is a medium that can record and reproduce at 0 nm. The groove depth of a general DVD-R medium is preferably from 1000 to 2500 from the relationship between the optical constant of the dye and the recording / reproducing wavelength. However, when forming a substrate with a deeper groove than when an inorganic recording layer is provided, it is necessary to develop a molding method that takes into account uniform transferability over the entire surface, and in some cases, it is not possible to shorten the molding time There is concern that productivity will be poor.

[0006] The format of DVD-R media is standardized as a format called a land pre-pit in which a part of a land portion is cut. With this method, when the reproduction wavelength is 635 nm, if the land pre-pit signal (Lppb) is less than 0.16, the pre-pit information such as the pre-pit address cannot be reproduced properly. The data itself behaves like noise in the data area, and many data errors occur. Therefore, Lpp is obtained by finely adjusting the cut width suitable for the recording material with a stamper (Lppb =) 0.16 to 0.32.
The land cut width must be controlled so as to fall within the range. Japanese Patent Application Laid-Open No. H11-134718 relates to a mini-disc having a recording layer of a perpendicular magnetization film. (Detection of address information of guide groove by differential signal from detector) In order to provide an optical disk substrate on which an optical disk with a low error rate can be manufactured, a spiral-shaped convex portion composed of meandering wobble grooves having address information is provided. When manufacturing a stamper for an optical disc substrate, the height of the convex portion at the innermost peripheral portion is about 65 nm, and 70
It is described that the height of the convex portion on the inner peripheral side is made smaller than the height of the convex portion on the outer peripheral side so as to approach the nm.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a write-once type DV using a semiconductor laser having uniform characteristics over the entire surface and having an oscillation wavelength shorter than that of the conventional system.
This is a new format system of the D system, and provides an effective system for eliminating an unrecorded area in a data rewriting portion similar to the Lpp system. Further, as compared with the DVD-R land pre-pit method, the present invention provides an excellent method in which a fine cut width control at the time of manufacturing a stamper and a data error due to leakage of an Lpp signal to a data portion do not occur.

[0008]

As a result of studies by the present inventors, if the groove depth of the stamper is made deeper (narrower) toward the outer periphery, the molding process is not indispensable and uniform groove characteristics can be obtained over the entire surface. Can be It has a wobble with a frequency of 4T to 96T,
The refractive index n of the recording layer single layer with respect to light in the wavelength range of recording / reproducing wavelength ± 5 nm as the recording layer is 1.5 ≦ n ≦ 3.0,
By creating an optical recording medium having an organic dye film having an extinction coefficient k of 0.02 ≦ k ≦ 0.2, the unrecorded area at the head of the rewritten data portion can be reduced, and a DVD having a low error rate can be obtained.
A write-once disc is obtained. That is, the present invention was achieved by adjusting the depth and width of the stamper groove, providing a substrate having uniform characteristics over the entire surface without impairing the molding process, and combining a high-frequency wobble format with an organic dye.

An object of the present invention is to provide (1) an optical recording medium comprising a recording layer provided on a substrate and a reflection layer provided as necessary, wherein the groove depth is 1000 ° to 2500 °; The pitch is 0.64 μm to 0.8 μm, the groove width is 0.18 μm to 0.4 μm at half width,
Use a stamper whose groove depth becomes deeper as going to the outer circumference,
Optical recording medium characterized by using a molded substrate ",
(2) “The optical recording medium according to the above (1), wherein a substrate formed by using a stamper whose groove depth is deeper and the groove width is wider toward the outer periphery is used,
(3) "It has a wobble of a frequency of 4T to 96T, and the refractive index n of the recording layer single layer with respect to light in the wavelength range of recording / reproducing wavelength ± 5 nm as the recording layer is 1.5 ≦ n ≦ 3.0; The optical recording medium according to the above (1) or (2), comprising an organic dye film having an extinction coefficient k of 0.02 ≦ k ≦ 0.2 ”, (4)“ Wobble ” The ratio (Wo / PP) between the amplitude Wo and the push-pull amplitude PP is 0.1 ≦ Wo
/PP≦0.4, the optical recording medium according to any one of the above items (1) to (3), ”and (5) that the organic dye of the recording layer is a metal. Chelating dyes,
The optical recording medium according to any one of the above items (1) to (4), comprising at least one of a polymethine dye, a squarylium dye, and an azaannulene dye ”, ( 6) “Any one of the above items (1) to (5), wherein the metal chelate dye in the recording layer is any one of an azo metal chelate dye, a formazan metal chelate dye, and a dipyrromethene metal chelate dye. And (7) that the metal of the metal chelate dye of the recording layer is nickel, copper, cobalt, manganese,
(8) The optical recording medium according to (5) or (6), wherein the polymethine dye in the recording layer is a trimethine cyanine dye,
The azaannulene-based dye is a tetraazaporphyrin dye, wherein the optical recording medium according to the above item (7), (9) the decomposition temperature of the recording layer is 360 ° C. or less. (10) The optical recording medium according to any one of the above items (1) to (8) ", (10)" when the reflective layer is required, the reflective layer is made of gold, silver, aluminum, The optical recording medium according to any one of the above items (1) to (9), wherein the recording wavelength is 720 to 600 nm.
(1) to (10), wherein
Optical recording medium according to any one of the paragraphs ", (12)" 720
using an optical pickup with a recording wavelength of
Optical recording method characterized by performing recording and / or reproduction on the optical recording medium according to any one of the above items (1) to (10) "
Is achieved by

Therefore, the effect is described in the above (1).
Is a basic configuration of the present invention, and a substrate of uniform quality over the entire surface can be obtained with high productivity, and (2) is to further improve (1) and not to add to the molding process. ) Is D
This is a new format that replaces the VD-R format and is another basic configuration of the present invention. (4) is the limitation of the optimum range of the standardized wobble amplitude of (3),
(5) is a constitution of an organic material that can be used in the present invention, (6) is a limitation of a chelating dye material, (7) is a limitation of a chelating metal to be used (material optimization), (8)
Is the limitation on the structure of the non-chelating dye, (9) is the limitation on the thermophysical properties of the recording material, (10) is the limitation on the optimum material when a reflective layer is used, and (11) is the recording wavelength of the present invention. (12) is a recording method using the recording medium of (1) to (10).

[0011] The optical recording medium of the present invention comprises a recording layer provided on a substrate, a reflection layer provided if necessary, and a groove depth of 10 mm.
The track pitch is 0.64 μm.
The invention is based on an optical recording medium, characterized in that a stamper whose groove depth is deeper (and the groove width is wider) as it goes to the outer periphery is used and a molded substrate is used. It is. The (stamper) substrate as described above further has a high frequency wobble of 4T to 96T, and the refractive index n of the recording layer single layer with respect to light in the wavelength range of recording / reproducing wavelength ± 5 nm is 1.5 ≦. The structure is characterized by having an organic dye film in which n ≦ 3.0 and the extinction coefficient k is 0.02 ≦ k ≦ 0.2. The T defined here is the recording pit length (unit: μm) when recording at the basic clock frequency, and T ≒ 0.13 μm for (47 GB) media. Most of optical recording media having a dye as a recording layer have a groove depth of 1000 to 2500 °.
There is an optimum groove depth. In order to form such grooves with good transferability, the molding conditions are controlled with high precision.
Unless the molding time is further increased, a uniform groove shape cannot be obtained over the entire surface in most cases. Therefore, the present invention has been made in consideration of productivity while maintaining uniformity of the entire surface of a dye-based medium called a so-called DVD.

That is, in order to accurately reproduce a stamper having a uniform groove shape over the entire surface as described above, a load is imposed on the molding process. What is necessary is just to make the outer peripheral part of the stamper deep in advance. Further, when the groove is narrow, it is easy to form the groove, but the recording characteristics are poor. Therefore, in some cases, it is desirable to make the groove deeper and wider toward the outer periphery. It is a ratio of deepening (widening) the groove, but a method of deepening (widening) from the inner circumference to the outside according to a certain coefficient may be used, or if the transferability can be secured up to the middle circumference, gradually from the middle circumference The present invention can be achieved by preparing a stamper whose outer periphery is deeper (wider) than the inner periphery in a method similar to these even if the stamper is deeper (wider). The ratio of deepening the groove is about 10% to 70% on the outer circumference, preferably about 30% to 60% compared to the inner circumference, and the degree of widening is 5% to 50%, preferably 10% on the outer circumference. % To 30%. If the ratio of deepening (widening) is small, the effect of the present invention will not be obtained, and if too deep (widening), the uniformity over the entire surface will be poor.

[0013] The above stamper is particularly useful for the following new DVDs.
Formats can also be used. Usually, a wobble frequency band corresponding to 150T to 400T is used. In this frequency band, when adding data regardless of frequency modulation or phase modulation, the wobble frequency is too low, so there is a considerable gap between the previous data and the added data, and high-density recording is performed. Not suitable for On the other hand, D
The VD-R is provided with Lpp, and the Lpp signal controls the data write position. However, L
In the pp method, Lpp cannot be read well if the amplitude of Lpp is too small, and conversely if Lpp is too large, Lpp
Lpp is in the range of 0.16 ≦ Lppb ≦ 0.32, preferably 0.18 ≦ Lppb ≦ 0, when the reproduction wavelength is 635 nm, since the signal itself leaks into the write data and a data error frequently occurs. .26, and the cut width of the land must be finely controlled when the stamper is manufactured.

On the other hand, if a high-frequency wobble is used, Lpp is not necessary, and the wobble is modulated and synchronized, so that Lpp
This does not lead to a situation in which data errors frequently occur as in the system. In the present invention, the ratio of the push-pull signal (PP) Wo / PP = NWO to the wobble amplitude (Wo) after passing through a suitable filter to the wobble amplitude (Wo) after passing through a suitable filter is equal to 0. 1 ≦ NWO ≦
If the value is in the range of 0.4, synchronization with the wobble, which is the object of the present invention, is possible, and the more preferable NWO value is in the range of 0.15 ≦ NWO ≦ 0.30. If the value of NWO is 0.1 or less, the signal strength is insufficient for synchronization, and if it exceeds 0.4, the data error tends to increase. However, as compared with the Lpp method, the influence of the occurrence of the data error is smaller than the data error of the medium having a large Lpp, and the data error accompanying the increase in the wobble amplitude is moderate. Further, when creating a stamper, the Lpp cut width of the Lpp method is Lppb = 0.1
Although an advanced cut width control technique is required to make the range of 6 to 0.32, in the high-frequency wobble system of the present invention, the high-frequency generation source and the magnitude of the wobble swing amount (the wobble swing amount is controlled). The objective is achieved only by managing the amount of swing that can be created with high reproducibility arbitrarily in a circuit that performs the process, so that the yield of the stamper and the yield of the media can be dramatically improved.

In the groove shape of the substrate having the above format, the recording layer is formed mainly by a solvent coating method using an organic dye. In this case, the optimum groove depth is 10.
00 ° to 2500 °, more preferably 1500 °
{2000}. If the groove depth is less than 1000 °, a sufficient push-pull signal cannot be obtained, and tracking control cannot be performed. If the groove depth is more than 2500 °, transferability during substrate molding is undesirably increased. In addition, the recording density is 4 GB
In order to secure a capacity of up to 5 GB, the track pitch needs to be about 0.64 μm to 0.8 μm. Although the groove width varies depending on the recording material, it can be applied to almost all organic materials with a half width of 0.18 μm to 0.40 μm.

Next, regarding the configuration of the recording medium, optical characteristics are raised as items necessary for forming the recording layer. The condition required for the optical characteristics is a recording / reproducing wavelength of 63.
It is necessary to have a large absorption band on the short wavelength side with respect to 0 nm to 690 nm and the recording / reproducing wavelength to be near the long wavelength end of the absorption band. This is the recording / reproducing wavelength of 63.
It means that it has a large refractive index and an extinction coefficient at 0 nm to 690 nm. Specifically, the refractive index n of the recording layer single layer with respect to light in the wavelength region near the recording / reproducing wavelength and near the long wavelength is 1.5 or more and 3.0 or less, and the extinction coefficient k is 0.1 or less.
It is preferably in the range from 02 to 0.2. When n is less than 1.5, it is difficult to obtain a sufficient optical change, so that the recording modulation degree becomes low, which is not preferable. When n exceeds 3.0, the wavelength dependency becomes too high. Therefore, an error occurs even in the recording / reproducing wavelength region, which is not preferable. If k is less than 0.02, the recording sensitivity deteriorates, which is not preferable.
If the ratio exceeds 50, it is difficult to obtain a reflectance of 50% or more, which is not preferable. The conditions required for the board shape are
The track pitch on the substrate is 0.7 μm to 0.8 μm, and the groove width is half width, 0.18 μm to 0.40 μm.

Next, specific examples of the dye material usable in the present invention include an azo (metal chelate) dye, a formazan (metal chelate) dye, and dipyrromethene (metal chelate).
Dyes, polymethine dyes, squarylium dyes, azaannulene dyes and the like can be applied, and specifically, metal chelate dyes, trimethine cyanine dyes, squarylium dyes, and tetraazaporphyrin dyes are particularly preferable. Here, an azo (metal chelate) dye, which has an azo bond in between and the azo compound forming units on both sides are substituted and unsubstituted aromatic rings,
Pyridine residue, pyrimidine residue, pyrazine residue, piperazine residue, pyridazine residue, triazine residue, imidazole residue, thiazole residue, triazole residue, pyrazole residue, isothiazole residue, benzothiazole residue, etc. An azo compound is formed by the combination of the above, and a metal chelate compound of the azo compound is particularly preferable. The formazan (metal chelate) dye is represented by the following general formula.

[0018]

Embedded image

In the formula, Z is a residue which forms a polyheterocycle together with the carbon atom and the nitrogen atom to which it is bonded, and specifically includes a pyridazine ring, a pyrimidine ring, a pyrazine ring and a triazine ring. It is. Further, the heterocyclic ring may have a substituent such as an alkyl group, an alkoxy group, an alkylthio group, a substituted amino group, an allyl group, an allyloxy group, an anilino group, and a keto group. A represents an alkyl group, an aralkyl group, an allyl group, or a cyclohexyl group, and may have a substituent such as an alkyl group, an alkoxy group, a halogen atom, a keto group, a carboxyl group or an ester thereof, a nitrile group, or a nitro group. . B represents an allyl group, which may have an alkyl group, an alkoxy group, a halogen group, a carboxyl group, or a substituent thereof such as an ester, a nitrile group, and a nitro group. In the case of a metal chelate, the metal is a divalent metal atom. Next, as for dipyrromethene (metal chelate) dye, the general formula of the dipyrromethene compound is shown below.

[0020]

Embedded image

In the formula, R _{1 to} R ₉ each independently represent a hydrogen atom, a halogen atom, an unsubstituted alkyl group, an alkoxy group,
Alkenyl group, acyl group, alkoxycarbonyl group, aralkyl group, aryl group, represents a heteroaryl group,
In the case of a metal chelate, the metal is a divalent metal atom. In the case of a chelate compound together with an azo compound, a formazan compound and a dipyrromethene compound, the metal includes a transition metal, for example, Ni, Co, Cu, Mn, VO, Zn,
Fe, Cr, Al and the like are listed, and Ni, Co, Cu, Mn, and VO are particularly preferable in terms of production and disk characteristics.

As the polymethine dye, 530 nm to 6
A dye having an absorption band at 00 nm is applicable to the present invention, but a trimethine cyanine dye is particularly preferable, and both ends of the trimethine chain are preferably unsubstituted indolenine and benzindolenine. _{, ClO 4, BF 4, PF} 6, SbF addition to or in various metal chelate anion typified by nickel dithiolate complex such as _6.

Examples of the squarylium dye include squarylium formed by a combination of unsubstituted indolenine, benzindolenine, pyrazole, carbazole, quinoxaline, isoindole, aromatic ring, and substituted amino group residue at both ends of a squalene ring. Dyes are preferred and can be used in the present invention.

Examples of the azaannulene dye include phthalocyanine, naphthalocyanine, tetrapyrazinoporphyrazine, tetrapyridinoporphyrazine, tetraazaporphyrin and the like, each having a specific substituent. Of these, tetraazaporphyrin is particularly preferred. Azaporphyrin is preferred, followed by tetrapyridinoporphyrazine, tetrapyrazinoporphyrazine, and phthalocyanine.

The thermal decomposition characteristics of the above-mentioned dyes are as follows.
In both cases where the dyes are used alone or in combination, the decomposition starting temperature of the recording material is preferably 360 ° C. or lower. Particularly, 100 to 350 ° C. is preferable. Decomposition temperature is 3
If the temperature is higher than 60 ° C., pit formation during recording is not performed well, and the jitter characteristics are poor. If the temperature is lower than 100 ° C., the storage stability of the disc will deteriorate.

(Construction of Recording Body) The recording body of the present invention has a structure of FIG. 2 which is a usual write-once optical disc (a so-called air sandwich in which two sheets of FIG. 2 are laminated, or a close lamination structure). The structure of the CD-R medium shown in FIG. 3 may be used.

(Required Properties of Each Layer and Examples of Constituent Materials) The basic structure of the recording medium of the present invention is a structure in which a first substrate and a second substrate are bonded together with an adhesive via a recording layer. The recording layer may be a single layer of an organic dye layer, or may be a laminate of an organic dye layer and a metal reflective layer to increase the reflectance. The recording layer and the substrate may be layered with an undercoat layer or a protective layer interposed therebetween, or may be formed by laminating them for improving the function. The most commonly used structure is a first substrate / organic dye layer / metal reflective layer / protective layer / adhesive layer / second substrate structure.

<< Substrate >> The substrate to be used must be transparent to the laser used only when recording and reproduction are performed from the substrate side. When recording and reproduction are performed from the recording layer side, the substrate need not be transparent. Absent. As a substrate material,
For example, polyester, acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, plastics such as polyimide,
Alternatively, glass, ceramic, metal, or the like can be used. A guide groove for tracking, a guide pit, and a preformat such as an address signal may be formed on the surface of the substrate.

<< Recording Layer >> The recording layer causes some optical change by irradiation with a laser beam, and records information by the change. The recording layer contains the dye of the present invention. When forming the recording layer, the dye of the present invention may be used alone or in combination of two or more. Further, the dye of the present invention may be used by mixing or laminating with other organic dyes, metals and metal compounds for the purpose of improving optical characteristics, recording sensitivity, signal characteristics and the like. Examples of organic dyes include polymethine dyes, naphthalocyanine-based, phthalocyanine-based, squarylium-based,
Croconium, pyrylium, naphthoquinone, anthraquinone (indanthrene), xanthene, triphenylmethane, azulene, tetrahydrocholine, phenanthrene, triphenothiazine dyes and metal complex compounds. Examples of metals and metal compounds include In, Te, Bi, Se, Sb, Ge,
Examples thereof include Sn, Al, Be, TeO ₂ , SnO, As, and Cd, which can be used in the form of dispersion mixing or lamination. Further, various materials such as an ionomer resin, a polyamide resin, a vinyl resin, a natural polymer, silicone, a liquid rubber or a silane coupling agent may be dispersed and mixed in the dye, For the purpose of improvement, a stabilizer (eg, a transition metal complex), a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant, a plasticizer, and the like can be used together.

The recording layer can be formed by ordinary means such as vapor deposition, sputtering, CVD or solvent coating. When the coating method is used, the dye or the like can be dissolved in an organic solvent, and the coating can be performed by a conventional coating method such as spraying, roller coating, dipping, and spin coating.
Examples of the organic solvent used include alcohols such as methanol, ethanol, and isopropanol; ketones such as acetone, methyl ethyl ketone and cyclohexanone; amides such as N, N-dimethylformamide and N, N-dimethylacetamide; and dimethyl sulfoxide. Sulfoxides, ethers such as tetrahydrofuran, dioxane, diethyl ether, ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, and aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethane, carbon tetrachloride, and trichloroethane Benzene, xylene, monochlorobenzene, dichlorobenzene, etc., aromatics, methoxyethanol, ethoxyethanol, etc., cellosolves, hexane, pen Down, cyclohexane, and hydrocarbons such as methylcyclohexane. The thickness of the recording layer is 100 to 10 μm, preferably 200 to 2 μm.
2,000 is appropriate.

<< Undercoat layer >> The undercoat layer improves the adhesiveness,
It is used for the purpose of barrier for water or gas, improvement of storage stability of recording layer, improvement of reflectance, protection of substrate from solvent, formation of guide groove, guide pit, preformat, etc. For the purpose of polymer materials, such as ionomer resins, polyamide resins, vinyl resins,
Various polymer compounds such as natural resins, natural polymers, silicones, liquid rubbers, and silane coupling agents can be used, and for the purpose, inorganic compounds other than the above-mentioned polymer materials, for example, SiO 2 , MgF, Si
O ₂ , TiO, ZnO, TiN, SiN and the like, and further, a metal or a metalloid such as Zn, Cu, Ni, Cr,
Ge, Se, Au, Ag, Al, or the like can be used. Also, for the purpose of metal, for example, Al, Au,
Ag or the like, an organic thin film having a metallic luster, for example, a methine dye, a xanthene dye, and the like,
For the purpose (1), an ultraviolet curable resin, a thermosetting resin, a thermoplastic resin, or the like can be used. The thickness of the undercoat layer is 0.01 to 30 μm, preferably 0.05 to 10 μm.
m is appropriate.

<< Metal Reflective Layer >> The metal reflective layer is made of a metal, a semi-metal, or the like which can provide a high reflectance by itself and is hardly corroded. Examples of materials include Au, Ag, Cr, Ni, Al, and F.
Although e, Sn and the like are mentioned, Au, Ag, and Al are most preferable in terms of reflectance and productivity, and these metals and metalloids may be used alone or as two kinds of alloys.
Examples of the film forming method include vapor deposition and sputtering, and the film thickness is 50 to 5000 °, preferably 100
３3000Å.

<< Protective Layer, Hard Coat Layer on Substrate Surface >> The protective layer and the hard coat layer on the substrate surface protect the recording layer (reflection / absorption layer) from scratches, dust, dirt, etc., and preserve the storage of the recording layer (reflection / absorption layer). It is used for the purpose of improving the properties and the reflectance. For these purposes, the materials shown in the undercoat layer can be used. Further, as the inorganic material, SiO, SiO ₂ or the like can be used, and as the organic material, polymethyl acrylate, polycarbonate, epoxy resin, polystyrene, polyester resin,
Thermal softening properties of vinyl resin, cellulose, aliphatic hydrocarbon resin, natural rubber, styrene butadiene resin, chloroprene rubber, wax, alkyd resin, drying oil, rosin,
Hot-melt resins can also be used. The most preferable example of the above materials is an ultraviolet curable resin having excellent productivity. The thickness of the protective layer or the hard coat layer on the substrate surface is 0.
The thickness is suitably from 01 to 30 μm, preferably from 0.05 to 10 μm. In the present invention, the undercoat layer, the protective layer, and the substrate-side hard coat layer, like the recording layer, a stabilizer, a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant,
A plasticizer and the like can be contained.

<< Protective Substrate >> When the protective substrate is irradiated with laser light from the protective substrate side, it must be transparent to the laser light used.
Transparency does not matter. The usable substrate material is exactly the same as the substrate material. Use a plastic such as polyester, acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, polyimide, or glass, ceramic, or metal. Can be.

<< Adhesive, Adhesive Layer >> Any material capable of adhering the two recording media may be used. In view of productivity, an ultraviolet-curable or hot-melt adhesive is preferable.

[0036]

Embodiment 1 The groove depth changes linearly at an inner circumferential groove depth of 1680 ° and an outer circumferential groove depth of 1850 °, a half value width of 0.22 μm, a track pitch of 0.74 μm, and a wobble frequency of 32T, A stamper having a band having a guide groove with a wobble runout width of 35 nm was used to mold an injection-molded polycarbonate substrate having a thickness of 0.6 mm with an injection molding cycle time of 5 seconds. A liquid in which the following compound example (I) was dissolved in 2,2,3,3-tetrafluoro-1-propanol was spin-coated on the substrate to form an organic dye layer having a thickness of 900 °, and then gold 1100 ° by sputtering. After a reflective layer having a thickness of 7 μm was formed on the reflective layer with an acrylic photopolymer, an injection molded polycarbonate flat plate having a thickness of 0.6 mm was adhered with the acrylic photopolymer to form a recording medium.

[0037]

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Example 2 The procedure of Example 1 was repeated except that the compound (I) was replaced with a dye obtained by mixing the compounds (II) and (III) at a weight ratio of 50:50. Then, a recording medium was formed.

[0039]

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[0040]

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<< Embodiment 3 >> The groove depth changes from 1700 ° to 1880 ° from the innermost circumference to a radius of 35mm, linearly from 35mm to the outermost circumference, and changes from 1700 ° to 1880 ° from the innermost circumference to a radius of 35mm. Value width 0.24 μm, 35
The groove half width is 0.24μ linearly from mm to the outermost circumference.
m to 0.26 μm, and the track pitch is 0.1 μm.
A stamper having a band having a guide groove of 74 μm, a wobble frequency of 16 T, and a wobble runout width of 30 nm was molded into an injection-molded polycarbonate substrate having a thickness of 0.6 mm with an injection molding cycle time of 6 seconds. A liquid in which the following compound example (IV) is dissolved in a mixed solvent of ethylcyclohexane and 2-methoxyethanol is spin-coated on the substrate to form an organic dye layer having a thickness of 1000 、, and then a reflective layer of gold 1100 に よ り is formed by sputtering. After a protective layer having a thickness of 7 μm was formed thereon using an acrylic photopolymer, an injection-molded polycarbonate flat substrate having a thickness of 0.6 mm was adhered with the acrylic photopolymer to obtain a recording medium.

[0042]

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Comparative Example 1 A recording medium was obtained in the same manner as in Example 1, except that the substrate groove depth was 1680 ° over the entire surface, the width and the track pitch were exactly the same.

<< Embodiment 4 >> Change in groove depth similar to Embodiment 1,
Groove half width 0.21 μm, track pitch 0.74 μm,
On a 0.6 mm thick injection molded polycarbonate substrate obtained by molding a stamper having a guide groove with a wobble runout width of 40 nm corresponding to a wobble frequency of 16 T in 5 seconds, 2,2,3, A solution dissolved in 3, -tetrafluoro-1-propanol is spinner-coated,
After forming an organic dye layer having a thickness of 900 °, a reflection layer of gold 1100 ° is provided by a sputtering method, and a protective layer of 7 μm is further provided thereon with an acrylic photopolymer.
A 0.6 mm thick injection molded polycarbonate flat substrate was bonded with an acrylic photopolymer to form a recording medium.

[0045]

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Example 5 The same as Example 4 except that a dye obtained by mixing the compounds (VI) and (VIII) in a weight ratio of 40:60 was used instead of the compound (V) in Example 4. Then, a recording medium was formed.

[0047]

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[0048]

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Example 6 Example 4 was repeated except that the compound (IV) was used in place of the compound (V) and the solvent was a mixed solvent of ethylcyclohexane and 2-methoxyethanol.
A recording medium was formed in exactly the same manner as in Example 4.

[0050]

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Comparative Example 2 In Example 5, the substrate groove depth was 1680 °, the uniformity, width, and track pitch were completely the same. The wobble amount was 5 nm, and the wobble frequency was 1
A recording medium was formed in exactly the same manner as in Example 5, except that a condition substrate in which an Lpp cut width equivalent to 90T was shaken by 12 levels was used.

<Recording Conditions> The optical recording media obtained in Examples 1 to 3 and Comparative Example 1 were subjected to an oscillation wavelength of 635 nm and a beam diameter of 0.9 μm.
m, a push-pull signal output through a 30 KHz filter is applied to the innermost circumference, 30 mm, 4 mm.
Detection was performed at 0 mm, 50 mm, and the outermost position.

The optical recording medium obtained in Examples 4 to 6 and Comparative Example 2 was subjected to EFM while tracking using a semiconductor laser beam having an oscillation wavelength of 657 nm and a beam diameter of 0.85 μm.
Bottom Ji signal (linear velocity 3.5 m / sec.)
The recording was performed with a strategy and recording power that minimized tert.
% And adjust the equalizer gain to play back.
The PI Error at that time was measured. The Lppb values of the disks of Comparative Example 2 were 0.1
2, 0.22, and 0.36 are selected.
At that time, the Lpp block error rate was also measured with a recording pickup. <Evaluation results>

[0054]

[Table 1] <Evaluation results>

[0055]

[Table 2] The above embodiment is an example in which the groove depth (width) is changed to a high frequency Wo.
Although only the bble medium is shown, it goes without saying that the medium whose depth and width are changed by the Lpp method in DVD-R is uniform over the entire surface and has high productivity.

[0056]

As is apparent from the detailed and specific description, according to the present invention, a DVD medium having good productivity can be obtained, and it is simpler than the land pre-pit format used in DVD-R. The data portion can be efficiently added with a high-frequency wobble format that can be manufactured at a high speed.
This is an extremely excellent effect that a recording medium in almost the same format as C-RW can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a general write-once optical recording medium according to the present invention.

FIG. 2 is a diagram showing a configuration of a medium for CD-R according to the present invention.

FIG. 3 is a diagram showing a medium configuration for a DVD-R according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Recording layer 3 Undercoat layer 4 Protective layer 5 Hard coat layer 6 Metal reflective layer 7 Protective substrate 8 Adhesive layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B41M 5/26 G11B 7/26 511 G11B 7/26 511 B41M 5/26 Y F term (Reference) 2H111 EA03 EA12 EA22 FA01 FA11 FA23 FA31 FB42 FB43 FB45 FB48 5D029 JA04 JC05 JC11 MA13 WA02 WB11 WB15 WB17 WB19 5D121 AA02 CA03

Claims (11)

[Claims] 1. An optical recording medium comprising a recording layer provided on a substrate and a reflection layer as required, wherein the groove depth is 1000 ° to 2500 ° and the track pitch is 0.1 mm.
The groove width is 64 μm to 0.8 μm, and the groove width is 0.18 in half width.
An optical recording medium characterized by using a stamper having a diameter of from 0.4 μm to 0.4 μm, and using a stamper whose groove depth becomes deeper toward the outer periphery. 2. The optical recording medium according to claim 1, wherein a stamper whose groove depth is increased and the groove width is increased toward the outer periphery is used. 3. A wobble having a frequency of 4T to 96T,
The refractive index n of the recording layer single layer with respect to light in the wavelength range of recording / reproducing wavelength ± 5 nm as the recording layer is 1.5 ≦ n ≦ 3.0,
The optical recording medium according to claim 1, further comprising an organic dye film having an extinction coefficient k of 0.02 ≦ k ≦ 0.2. 4. The wobble amplitude Wo and the push-pull amplitude P
P (Wo / PP) is 0.1 ≦ Wo / PP ≦ 0.
The optical recording medium according to any one of claims 1 to 3, wherein the optical recording medium is in the range of (4). 5. The organic dye in the recording layer is a metal chelate dye,
The optical recording medium according to any one of claims 1 to 4, comprising at least one of a polymethine dye, a squarylium dye, and an azaannulene dye. 6. The optical recording according to claim 1, wherein the metal chelate dye of the recording layer is any one of an azo metal chelate dye, a formazan metal chelate dye, and a dipyrromethene metal chelate dye. Medium. 7. The optical recording medium according to claim 5, wherein the metal chelate dye of the recording layer is nickel, copper, cobalt, manganese, or vanadium oxide. 8. The optical recording medium according to claim 5, wherein the polymethine dye in the recording layer is a trimethine cyanine dye, and the azaannulene dye is a tetraazaporphyrin dye. 9. The optical recording medium according to claim 1, wherein a decomposition start temperature of the recording layer is 360 ° C. or less. 10. When the reflective layer is required, the reflective layer is made of gold,
10. The optical recording medium according to claim 1, wherein the optical recording medium is silver, aluminum, or an alloy with another metal containing these as a main component. 11. The optical recording medium according to claim 1, wherein a recording wavelength is from 720 nm to 600 nm.