JP2001219653A - Optical information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cross talk characteristics and jitter characteristics for the purpose of obtaining the better interchangeability between both characteristics. SOLUTION: A cyanin organic coloring matter provided with a fluorinated alkyl is dissolved into an organic solvent in a recording layer, and film is formed by the spin coat method, and the maximum film thickness is 150 nm or less.

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 having an organic dye-based recording layer, and more particularly to a recordable optical information medium having excellent recording characteristics and storage stability.

[0002]

2. Description of the Related Art In recent years, with the development of information technology, an optical recording medium which is a small and large-capacity recording medium has been used. Such optical recording media are CD-ROM, DVD-RO
M or other read-only media, CD-R (compact disc-
Recordable recording media such as recordable), MO, DV
It is classified as a rewritable medium represented by a D-RAM. Among these, as a write-once recording medium on which writing can be performed only once, a recording medium using an organic dye for a recording layer is known. In this write-once type recording medium, recording is performed by irradiating the recording layer with a laser beam when information is recorded, changing the organic dye constituting the recording layer by its thermal energy, and changing its optical characteristics. . As an organic dye used in the recording layer of such a write-once type optical recording medium, a cyanine dye is known (JP-A-58-11279).
0, JP-A-59-24692, JP-A-5-67349
etc).

At present, as a recording medium using a dye material,
CD-R (C) compatible with existing CD formats
D-recordable) has become widespread. A total of 300 million CD recorders have been released worldwide, with over 1 billion CDs annually.
DR discs are being produced. However, among rare CD-R discs, it is rare that a recorded disc cannot be reproduced by an existing CD player or the like. This is a problem caused not only by the disc but also by the recorder. Since the specifications of the optical head of the recorder differ depending on the drive, signals may not be accurately written depending on the disc. For example, since the crosstalk between recorded radial pits is large, the drive may not be able to track the pit row of the disk and may not be able to recognize the disk with a reproducing machine, or the signal length of the recorded EFM signal may be large. Variation,
That is, data may not be read due to an increased error due to a large jitter.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. The object of the present invention is to use a dye material according to the present invention with a dye according to the present invention and a recording medium according to the production method according to the present invention. By manufacturing, it is possible to greatly reduce the possibility that the above-described inconvenience occurs.

[0005]

In order to achieve the above object, the present invention provides an optical information recording medium having a recording layer containing a cyanine-based organic dye on a substrate and capable of recording and reproducing information by light irradiation. It is targeted. The cyanine-based organic dye is an organic compound represented by the following general structural formula (1) or (2), and in the cyanine-based organic dye, at least one of the dye molecules is substituted with fluorine. The cyanine dye is formed on the recording portion with a maximum film thickness of 150 nm or less. In the recording medium produced by using the cyanine dye material according to the present invention, the edges of the pits recorded by the laser beam are accurately controlled in the signal length direction and also in the pit width direction. Therefore, it has excellent recording and reproducing characteristics. General structural formula (1)

[0006]

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(Wherein R and R ′ may be the same or different, at least one of them represents a fluorine-substituted alkyl group and the other represents a fluorine-substituted alkyl group or hydrogen atom, amine, alkyl , Alkoxyl, alkylamine, alkylhydrazone, alkoxyl, alkylsulfate, or an aromatic ring having these functional groups, where n represents the number of polymerizations and is an integer of 0 to 3. Y1 and Y2 may be the same or different. And may represent C (CH ₃ ) ₂ , —C ＝ C—, S or O.
X represents a counter ion, and represents a halogen or a halogen compound. A1 and A2 may be the same or different and each represents an atom group forming a benzene ring or a substituted benzene ring. ) General structural formula (2)

[0008]

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(In the formula, R- represents an alkylsulfonyl group, an alkylcarboxyl group, an alkylhydroxy group or a fluorine substituent of these functional groups, and R represents a fluorine-substituted alkyl group. N represents a polymerization number.) , 0
It is an integer of 3. Y1 and Y2 may be the same as or different from each _{other, C (CH 3) 2,} -C = C-, showing the S or O. A1 and A2 may be the same or different and each represents an atom group forming a benzene ring or a substituted benzene ring. The cyanine dye used in the present invention can be obtained by a known general synthesis method. For example, a precursor is synthesized by reacting 2-methylbenzoindolenine with iodide of a target substituent. A dye is obtained by mixing and reacting two kinds of precursors having different substituents with propene dianyl or ethyl formate in a molar ratio of 1: 1: 1. After exchanging the anion of the synthesized dye relating to the general structural formula (1) from iodine to a desired halide ion, a high-purity target product is obtained by a recrystallization method using methanol or the like.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The organic dye constituting the recording layer of the optical information recording medium of the present invention has a structure other than the cyanine-based organic dye represented by the general structural formula (1) or (2). May be added.
In addition to cyanine dyes, the recording layer is composed of one or a mixture of two or more of squarylium dyes, polymethine dyes such as azurenium dyes, macrocyclic azaanelene dyes such as phthalocyanine dyes, and dithiol dyes. You can also. Further, in the present invention, the organic dye constituting the recording layer of the optical information recording medium contains a deterioration inhibitor. The share of the deterioration inhibitor is preferably 5 to 30% by weight. If the content is less than 5% by weight, the effect of preventing deterioration is not sufficiently exhibited. On the other hand, if the share ratio exceeds 30% by weight, it becomes difficult to control the recording pits by laser light, and as a result, the processing rate is increased. There is a problem with reliability. These additives include dithiol metal complexes, amino compounds, azo compounds and the like.

The recording layer may also contain a resin such as an acrylic resin, a polycarbonate resin, a polyester resin, a fluororesin, a polyvinyl alcohol or the like, if necessary. Performance can be improved.

In order to form the recording film on a substrate, the organic material forming the recording film is dissolved in a polar organic solvent such as alcohol in an amount of 0.1 to 5%, and the film is formed by spin coating. preferable. With a dilute solution of less than 0.1%, it is difficult to control the recording film to a constant film thickness, and pinholes and the like tend to occur. 5%
When the concentration of the solution is higher than the above range, re-precipitation of the dye tends to occur, and the precipitated dye particles become defects.

The thickness of the recording layer is suitably from 30 to 300 nm. It is also possible to use a mixed solvent to assist in dissolving the deterioration inhibitor or the like or to control the volatility of the solvent.

If the dye solution is too concentrated, the optical information recording medium according to the present invention generally has a structure in which a first intermediate layer, a recording layer, a second intermediate layer, and a protective layer are laminated on a substrate. Among them, the first intermediate layer, the second intermediate layer, and the protective layer are the remaining two layers or one if at least one of the three layers is present.
Layers can be removed. Further, it is also possible to adopt a structure in which the two surfaces of the optical information recording medium having the above configuration are bonded via an adhesive layer with the incident surface of the recording / reproducing laser facing outward as in the DVD standard. The present invention also provides a lubricating layer on the incident surface of the recording / reproducing laser for reducing damage due to contact with the head, or printing on the opposite surface for protection and decoration of the lower layer. It does not disturb the gist.

As the substrate, acrylic, polycarbonate, polymethine methacrylate, polymethylpentene,
A transparent resin substrate material such as polyolefin or epoxy can be used, and it is preferable that such a material is injection-molded using a stamper or the like in which a preformat signal is formed in the form of pits. Further, a transparent ceramic plate made of glass or the like having a replica layer of a photocurable resin formed on one surface can be used as the substrate.

As an intermediate layer, a reflection layer for improving the reflectance characteristics, a heat diffusion layer for promoting heat radiation of laser light or heat generated by decomposition of the recording layer, a reaction for the recording layer or for promoting the reaction of the recording layer A second recording layer whose reaction is accelerated by light excitation, a hard layer for separating the recording layer from external stress, and an air groove layer provided by a spacer or the like are provided as necessary. When the intermediate layer is provided as a reflective layer or a heat conductive layer, an alloy containing gold, aluminum, silver, copper, or the like as a main component is preferable. When the intermediate layer is provided as a hard layer, SiO 2 having a high melting point is used.
Hard inorganic materials such as ₂ , SiN, AlN, and Al ₂ O ₃ are preferred. When the intermediate layer is provided as the second recording layer, it is preferable to use an amorphous-crystalline phase change film made of an alloy containing a rare earth metal, a dye layer having an optical property different from that of the cyanine dye, or the like. Can be formed by a dry process such as

The protective layer can be formed by, for example, screen printing an organic material such as an ultraviolet curable resin, a thermosetting resin, a two-part curable resin, and a room temperature curable resin on the intermediate layer.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. (Embodiment 1) In this embodiment, a write-once optical recording medium having a structure in which a recording layer, an intermediate layer, and a protective layer are laminated on a substrate and containing a cyanine dye and a deterioration inhibitor in the recording layer is manufactured.

A transparent substrate on a disk having a preformat pattern formed thereon and having a center hole in the center was prepared by injection molding a polycarbonate resin. FIG. 2 shows an outline of the planar structure of the obtained substrate 1. In the preformat pattern, guide grooves 5 for following a recording / reproducing laser beam, recording tracks 8 defined by the guide grooves 5, prepits 6 for displaying sector addresses and reference clocks are formed. Guide groove 5 is center hole 7
And concentric spirals or concentric circles. Further, the guide groove 5 may be a wobble groove. Guide groove 5
Is a wobble groove, information such as address information and a synchronization signal can be detected from the wobble groove. Also,
The guide groove 5 and the pre-pit 6 can be formed at different depths. In this embodiment, a wobble groove is employed.

A recording layer was formed on the polycarbonate substrate 1 manufactured as described above as follows. 19 parts by weight of the cyanine dye represented by the structural formula (3) and 1 part by weight of the deterioration inhibitor represented by the structural formula (4) were added to 4-hydroxy-
Dissolved in 480 parts by weight of 4-methyl-2-pentanone.
The obtained solution was filtered with a 0.45 μm filter.
The filtrate was applied on a polycarbonate substrate by spin coating to form a dye layer (recording layer groove portion) having a thickness of 110 nm.

After the dye layer was dried in a high temperature environment, an intermediate layer made of an Ag / Au alloy was formed on the dye layer to a thickness of 50 nm using a sputtering apparatus. After forming the intermediate layer, the dye attached to the substrate is washed with alcohol, and finally an ultraviolet curable resin is applied by screen printing to obtain a film having a thickness of 10 μm.
m of protective layers were formed.

In the optical recording medium thus obtained, as shown in FIG. 1, a recording layer 2, an intermediate layer 3 made of an Ag / Au alloy and an ultraviolet curable resin protective layer 4 are sequentially laminated on a polycarbonate substrate 1. It has a structure consisting of Structural formula (3)

[0023]

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Structural formula (4)

[0025]

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(Embodiment 2) In this embodiment, a dye material having a structure different from that of Embodiment 1 is used for the recording layer, but the other materials and methods are the same as those of Embodiment 1 and the structure shown in FIG. An optical disk was manufactured.

On a polycarbonate substrate 1 produced in the same manner as in Example 1, 19 parts by weight of a cyanine dye represented by the structural formula (5) and 1 part by weight of a deterioration inhibitor represented by the structural formula (4) were added to 4-hydroxy- 4-methyl-2-pentanone 480
It dissolved in parts by weight. After the obtained solution was filtered through a 0.45 μm filter, the filtrate was applied on a polycarbonate substrate by spin coating to form a dye layer (recording layer groove portion) having a thickness of 120 nm.

After the dye layer was dried in a high temperature environment, an intermediate layer made of an Ag / Au alloy was formed on the dye layer at a thickness of 60 nm using a sputtering apparatus. After forming the intermediate layer, the dye attached to the substrate is washed with alcohol, and finally, an ultraviolet curable resin is applied by screen printing to obtain a film having a thickness of 10 μm.
A protective layer having a thickness of μm was formed. Thus, an optical disk having the structure shown in FIG. 1 was produced. Structural formula (5)

[0029]

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(Embodiment 3) In this embodiment, a dye material having a structure different from that of Embodiment 1 is used for the recording layer, but the other materials and methods are the same as those of Embodiment 1 and the structure shown in FIG. An optical disk was manufactured.

On a polycarbonate substrate 1 prepared in the same manner as in Example 1, 19 parts by weight of a cyanine dye represented by the structural formula (6) and 1 part by weight of a deterioration inhibitor represented by the structural formula (4) were added to 4-hydroxy- 4-methyl-2-pentanone 480
It dissolved in parts by weight. After the obtained solution was filtered through a 0.45 μm filter, the filtrate was applied on a polycarbonate substrate by spin coating to form a dye layer (recording layer groove portion) having a thickness of 120 nm.

After the dye layer was dried in a high temperature environment, an intermediate layer made of an Ag / Au alloy was formed on the dye layer at a thickness of 60 nm using a sputtering apparatus. After forming the intermediate layer, the dye attached to the substrate is washed with alcohol, and finally, an ultraviolet curable resin is applied by screen printing to obtain a film having a thickness of 10 μm.
A protective layer having a thickness of μm was formed. Thus, an optical disk having the structure shown in FIG. 1 was produced. Structural formula (6)

[0033]

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(Embodiment 4) In this embodiment, a dye material having a structure different from that of Embodiment 1 is used for the recording layer, but the other materials and methods are the same as those of Embodiment 1 and the structure shown in FIG. An optical disk was manufactured.

On a polycarbonate substrate 1 prepared in the same manner as in Example 1, 19 parts by weight of a cyanine dye represented by the structural formula (7) and 1 part by weight of a deterioration inhibitor represented by the structural formula (4) were added to 4-hydroxy- 4-methyl-2-pentanone 480
It dissolved in parts by weight. After the obtained solution was filtered through a 0.45 μm filter, the filtrate was applied on a polycarbonate substrate by spin coating to form a dye layer (recording layer groove portion) having a thickness of 130 nm.

After the dye layer was dried in a high temperature environment, an intermediate layer made of an Ag / Au alloy was formed on the dye layer to a thickness of 60 nm using a sputtering device. After forming the intermediate layer, the dye attached to the substrate is washed with alcohol, and finally, an ultraviolet curable resin is applied by screen printing to obtain a film having a thickness of 10 μm.
A protective layer having a thickness of μm was formed. Thus, an optical disk having the structure shown in FIG. 1 was produced. Structural formula (7)

[0037]

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(Embodiment 5) In this embodiment, a dye material having a structure different from that of Embodiment 1 is used for the recording layer, but the other materials and methods are the same as those of Embodiment 1 and the structure shown in FIG. An optical disk was manufactured.

On a polycarbonate substrate 1 prepared in the same manner as in Example 1, 19 parts by weight of a cyanine dye represented by the structural formula (8) and 1 part by weight of a deterioration inhibitor represented by the structural formula (4) were added to 4-hydroxy- 4-methyl-2-pentanone 480
It dissolved in parts by weight. After the obtained solution was filtered through a 0.45 μm filter, the filtrate was applied on a polycarbonate substrate by spin coating to form a dye layer (recording layer groove portion) having a thickness of 120 nm.

After the dye layer was dried in a high temperature environment, an intermediate layer made of an Ag / Au alloy was formed on the dye layer at a thickness of 60 nm using a sputtering apparatus. After forming the intermediate layer, the dye attached to the substrate is washed with alcohol, and finally, an ultraviolet curable resin is applied by screen printing to obtain a film having a thickness of 10 μm.
A protective layer having a thickness of μm was formed. Thus, an optical disk having the structure shown in FIG. 1 was produced. Structural formula (8)

[0041]

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(Embodiment 6) In this embodiment, a dye material having a structure different from that of Embodiment 1 is used for the recording layer, but the other materials and methods are the same as those of Embodiment 1 and the structure shown in FIG. An optical disk was manufactured.

On a polycarbonate substrate 1 produced in the same manner as in Example 1, 19 parts by weight of a cyanine dye represented by the structural formula (9) and 1 part by weight of a deterioration inhibitor represented by the structural formula (4) were added to 4-hydroxy- 4-methyl-2-pentanone 480
It dissolved in parts by weight. After the obtained solution was filtered through a 0.45 μm filter, the filtrate was applied on a polycarbonate substrate by spin coating to form a dye layer (recording layer groove portion) having a thickness of 120 nm.

After the dye layer was dried in a high-temperature environment, an intermediate layer made of an Ag / Au alloy was formed on the dye layer at a thickness of 60 nm using a sputtering apparatus. After forming the intermediate layer, the dye attached to the substrate is washed with alcohol, and finally, an ultraviolet curable resin is applied by screen printing to obtain a film having a thickness of 10 μm.
A protective layer having a thickness of μm was formed. Thus, an optical disk having the structure shown in FIG. 1 was produced. Structural formula (9)

[0045]

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(Comparative Example 1) 19 parts by weight of a cyanine dye represented by the structural formula (10) and 1 part by weight of a deterioration inhibitor represented by the structural formula (6) were formed on a polycarbonate substrate 1 produced in the same manner as in Example 1. Was dissolved in 480 parts by weight of 4-hydroxy-4-methyl-2-pentanone. The resulting solution was added to 0.
After filtration with a 45 μm filter, the filtrate was applied on a polycarbonate substrate using the spin coating method under the same conditions as in Example 1. Structural formula (10)

[0047]

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The optical recording media obtained in Examples 1 to 6 and Comparative Example 1 were rotated at a linear velocity of 1.2 m / sec.
An EFM signal was recorded at a wavelength of 780 nm, an aperture NA of 0.50, and an output of 14.0 mW using a semiconductor laser.
The signal of each optical recording medium on which the signal is recorded is converted to a wavelength of 783n.
m, the aperture NA = 0.45, and the output value was 0.4 mW. The data was read by a reproducing machine using a semiconductor laser, and the jitter value was measured by a jitter meter. As a result, the reflectance and the degree of modulation of the disk satisfied the specification values of Red Book, which is the CD standard, and the jitter values of the optical recording media of Examples 1 to 4 according to the present invention were all 10% or less. This was lower than 12.5% of the measured jitter value of the recording medium according to Comparative Example 1, and it was revealed that the recording medium had excellent recording and reproduction characteristics.

In the above embodiment, the present invention has been described using a write-once optical recording medium. However, the optical recording medium of the present invention is not limited to this, and any optical recording medium containing an organic dye in the recording layer can be used. It is adaptable to.

[0050]

The recording medium according to the present invention is an optical information recording medium capable of recording and reproducing information by irradiating light, and is represented by the general structural formula (1) or (2), wherein at least One includes a cyanine-based organic dye organic compound having a fluorine-substituted alkyl group. As a result, in the manufactured recording medium, the edge portion of the pit recorded by the laser beam is accurately controlled in the signal length direction and also in the width direction of the pit. Has characteristics.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a magneto-optical recording medium according to an embodiment of the present invention.

FIG. 2 is a plan view of a magneto-optical recording medium according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Dye layer 3 Intermediate layer 4 Protective layer 5 Guide groove 6 Pit 7 Center hole 8 Track 10 Optical recording medium

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H111 EA03 EA12 EA22 EA25 EA37 EA40 FA01 FA11 FA12 FA14 FA18 FA23 FB43 FB63 GA00 GA07 5D029 JA04 JB35 LB03 MA13 5D121 AA01 EE22

Claims (7)

[Claims] 1. An optical information recording medium in which a recording layer containing an organic dye is provided on a substrate and information is recorded / reproduced by light irradiation, wherein the recording layer is a color element represented by the following general structural formula (1): An optical information recording medium characterized in that a cyanine-based organic dye having an alkyl fluoride group is dissolved in an organic solvent, the film is formed by a spin coating method, and the maximum film thickness of a recording portion is 150 nm or less. General structural formula (1) (Wherein R1 and R2 may be the same or different, but at least one represents a fluorine-substituted alkyl group and the other represents a fluorine-substituted alkyl group or a hydrogen atom, amine, alkyl, alkoxyl, alkyl Amine, alkylhydrazone, alkoxyl, alkylsulfate, or an aromatic ring having these functional groups, wherein n represents a polymerization number and is an integer of 0 to 3. Y1 and Y2 may be the same or different; C (CH ₃ ) ₂ , —C ＝ C—, S or O. X represents a counter ion and represents a halogen or a halogen compound, and A1 and A2 may be the same or different and each represents a benzene ring or a substituted group. The group of atoms that form a benzene ring is shown.) 2. The optical information recording medium according to claim 1, wherein the fluorine-substituted alkyl group in the cyanine-based organic dye molecule has a different number of carbon atoms. 3. An optical information recording medium having a recording layer containing an organic dye on a substrate and recording / reproducing information by light irradiation, wherein the recording layer is formed of a dye molecule represented by the following general structural formula (2): An optical information recording medium characterized in that a cyanine-based organic dye having an alkyl fluoride group is dissolved in an organic solvent, the film is formed by a spin coating method, and the maximum film thickness of a recording portion is 150 nm or less. General structural formula (2) (Wherein, R- represents an alkylsulfonyl group, an alkylcarboxyl group, an alkylhydroxy group or a fluorine substituent of these functional groups, and R represents a fluorine-substituted alkyl group. N represents a polymerization number; 3 of .Y1 and Y2 are integers may be the same as or different from each _{other, C (CH 3) 2,} -C = C-, .A1 showing an S or O
And A2 may be the same or different and each represents an atom group forming a benzene ring or a substituted benzene ring. ) 4. The optical information recording medium according to claim 1, wherein the fluorine-substituted alkyl group in the cyanine-based organic dye molecule has one, two or three carbon atoms. . 5. The method according to claim 1, wherein the organic solvent used for spin coating is 4-hydroxy-4.
-An optical information recording medium comprising methyl-2-pentanone. 6. An optical information recording medium according to claim 1, wherein said recording layer contains 5 to 30% by weight of a deterioration inhibitor. 7. The recording medium according to claim 1, wherein an intermediate layer and a protective layer are sequentially formed on the recording layer, and the intermediate layer is made of a metal alloy containing gold, silver, copper, platinum, or aluminum. An optical information recording medium characterized by being constituted.