JPH07246776A - Optical recording material and write-once compact disk using the same - Google Patents

Abstract

(57) [Abstract] [Purpose] To solve the drawbacks of a conventional CD or CD-ROM having an additional write function and an edit function,
Provided is a write-once compact disc and an optical recording material based on Orange Book capable of reproducing a wavelength of m. [Structure] In the phthalocyanine skeleton, n fluorine-substituted alkoxy groups and m straight-chain or branched unsubstituted alkoxy groups (n + m = 4, n and m represent integers of 1 to 3) and nitro An optical recording material characterized by substituting groups and a write-once compact disc using the same.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium on / from which information can be written / read by a laser beam. More specifically, it relates to a write-once compact disc (CD-R) and a recording film material thereof.

[0002]

2. Description of the Related Art Conventionally, a recording medium having a single film structure in which an organic dye is used as a recording film has been proposed, and a write-once optical disc for a filing system having an editing function has been put into practical use. This write-once optical disc has a reflectance of 20 to 30%.
In addition, since the laser wavelength for recording and reproducing is 830 nm, there is no compatibility with the already popular CD or CD-ROM. After that, by using a cyanine dye having a specific optical constant as a recording film and further providing a reflecting film on the recording film, the reflectance can be improved to 65% or more, and a CD format or CD-ROM format signal can be recorded. Alternatively, an optical disk and a method that can be reproduced by a CD-ROM reproducing device have been proposed (Japanese Patent Laid-Open Nos. 2-42652 and 2-14728).
No. 6), which has already been put to practical use.

However, since cyanine dyes generally have poor photostability, there is a possibility that the reliability of recording may be deteriorated under a use condition where they are directly exposed to sunlight. In R, C for playback only
The same reliability as D or CD-ROM has not been realized. . Therefore, phthalocyanine dyes having excellent chemical and physical stability have been attracting attention, and studies have been conducted to apply them to CD-R recording film materials. The application of phthalocyanine dyes to optical recording media has been carried out since the time of study of write-once optical discs for filing systems, but it has not been possible to impart solubility to organic solvents, control optical characteristics, and improve recording sensitivity. It was a very difficult problem.

Among the studies on phthalocyanine dyes up to now, phthalocyanine dyes in which an optionally substituted alkoxy group is introduced are disclosed in JP-A-61-154888, and fluorine-substituted alkoxy groups are disclosed in JP-A-64-14087. Phthalocyanine dyes having introduced are proposed as optical recording materials. These phthalocyanine dyes impart solubility to organic solvents by introducing an alkoxy group and a fluorine-substituted alkoxy group, but suitable solvent species include halogenated hydrocarbons, aromatics, and fluorine-substituted ones. Since it is alcohol or the like, a substrate having high solvent resistance or an expensive special solvent must be used to form a recording film. Further, this proposal is intended for an optical recording medium having a substrate / recording film configuration, and optical characteristics and thermal characteristics adapted to a CD-R composed of a substrate / recording film / reflection film stack cannot be realized.

Further, in JP-A-3-62878 and JP-A-5-1272, a CD containing an unsubstituted branched alkoxy group and a nitro group in four benzene rings of phthalocyanine is disclosed.
A recording film material for −R has been proposed. With this phthalocyanine dye, for the purpose of improving the optical characteristics such as the refractive index and the thermal characteristics in order to obtain a recording film suitable for the structure of CD-R,
By introducing a nitro group at the ortho position with respect to the introduction position of the alkoxy group, the signal characteristics are clearly improved as compared with the conventional phthalocyanine dye. However,
These compounds have not reached sufficient characteristics as signal quality, as shown in the comparative example of JP-A-5-86301.

Further, when an unsubstituted branched alkoxy group is introduced into the phthalocyanine ring, the absorption wavelength becomes considerably longer due to the effect of the electron donating property of the alkoxy group, and the absorption near 785 nm, which is the object of CD-R, is large. Therefore, in order to realize the optimum optical characteristics in the vicinity of 785 nm, it becomes necessary to use expensive special metals such as palladium, which is effective for shortening the absorption wavelength, as the central metal. Further, these compounds have not reached sufficient characteristics as signal quality, and as a practical problem, there is a tendency that the 3T signal, which is the shortest pit, is long and the 11T signal, which is the longest pit, is short. , The issue remains as the cause of the error occurrence. In addition, a sufficient margin is not obtained even for the suitability for the tracking method based on the phase difference method used in some of the reproducing devices. As described above, even a phthalocyanine dye having excellent durability has reached a level at which it can be used as a recording film material for CD-R, but it is hard to say that it satisfies all practical suitability.

[0007]

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention
Phthalocyanine dye capable of wavelength control suitable for CD-R as a recording film for D-R, which is suitable for CD-R, conforms to the Orange Book standard, and is compatible with pit length, tracking suitability by phase difference method, etc. And a phthalocyanine dye-based recording film material for CD-R, which is excellent in durability and satisfies the above practical applicability.

[0008]

Means for Solving the Problems As a result of intensive studies, the present inventors have reached the following invention. That is, the present invention introduces one alkoxy group and one nitro group into each of the four benzene rings of the phthalocyanine skeleton represented by the formula [1], and the alkoxy group is substituted with n fluorine-substituted alkoxy groups and unsubstituted. The optical recording material is characterized by having m alkoxy groups (n + m = 4, n and m represent an integer of 1 to 3). Expression [1]

[Chemical 2] [In the formula, M represents a hydrogen atom or a metal atom which may be substituted with oxygen, a hydroxyl group or a halogen atom. Furthermore, the present invention provides 1 or 4, 5 or 8, 9 of the four benzene rings of the phthalocyanine skeleton represented by the formula [1].
The optical recording material according to claim 1, wherein an alkoxy group is introduced into one of the substitution positions of 12, 13 or 16 and a nitro group is introduced into the other. Furthermore, the present invention provides a transparent substrate /
A write-once compact disc comprising a laminated body of recording film / reflection film / protective film, wherein the recording film contains the optical recording material according to claim 1 or 2.

The phthalocyanine compound applied to the optical recording material of the present invention and a write-once compact disc using the optical recording material is characterized in that a fluorine-substituted alkoxy group and a nitro group are preferably positioned in the para-position. Introduced, the said alkoxy group is composed of a mixture of a fluorine-substituted alkoxy group and an unsubstituted straight chain or branched alkoxy group. By introducing a fluorine-substituted alkoxy group, the solubility of the phthalocyanine compound in an organic solvent is improved. Further, the interface energy between the recording film and the substrate becomes large, and it becomes easy to form well-balanced pits at the time of recording. It is possible to reduce the sensitivity or improve the distortion of the formed pits. Further, when fluorine is substituted on the alkoxy group, the electron donating property is significantly weakened by the effect of fluorine as compared with the unsubstituted alkoxy group. Therefore, an unsubstituted alkoxy group and this fluorine-substituted alkoxy group are attached to the phthalocyanine ring. By mixing and introducing, the absorption wavelength can be controlled by the mixing ratio. Therefore, there is an advantage that it is very easy to optimize the optical characteristics near 785 nm. as a result,
The balance between the transmittance and the absorbance near 785 nm is improved, and it is possible to simultaneously satisfy the contradictory characteristics of the reflectance affected by the transmittance and the sensitivity in the heat mode recording due to light-to-heat conversion that affects the absorbance. become.

As an effect of the nitro group, the thermal decomposition temperature is lowered at the time of recording, that is, the introduction of a nitro group serving as an oxygen source at the time of decomposition of the recording film, and a large amount of heat is generated at the time of decomposition, so that the recording sensitivity is significantly improved. To do. Furthermore, by introducing this nitro group at the para position to the alkoxy group, the stacking property of the phthalocyanine ring due to steric hindrance is impaired, the sensitivity is improved by the decrease in the thermal decomposition temperature and the solubility by the alkoxy group substituted with fluorine is decreased. Both of the imparting effects are improved.

Typical examples of the fluorine-substituted alkoxy group introduced into the phthalocyanine dye of the present invention include 1,
1,1-trifluoromethoxy group, 1,1,2,2-tetrafluoropropoxy group, 1,1,1,3,3,3-
Hexafluoro-2-propoxy group, 2,2,2, -trifluoroethoxy group, 2,2,3,3,3-pentafluoropropoxy group, 2,2,3,3,4,4, -hexafluoro Butoxy group, 1H, 1H, 5H-octafluoropentyloxy group, 1H, 1H, 7H-dodecafluoroheptyloxy group, 1H, 1H, 9H-hexadecafluorononyloxy group, 2- (perfluorohexyl) ethoxy group, etc. However, the present invention is not limited to these.

Representative examples of the unsubstituted straight-chain and branched alkoxy groups introduced into the phthalocyanine dye of the present invention include methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group, tert-butoxy group, 2 , 4-dimethyl-3-pentoxy group, 2-methyl-1-hexyloxy group, 4-methyl-cyclohexyloxy group, 2-methyl-1-iso-propylpropoxy group, 1,3-dimethylbutoxy group, 2,2 Examples thereof include, but are not limited to, a dimethyl-1-iso-propylpropoxy group and the like.

In the phthalocyanine dye of the present invention, a fluorine-substituted alkoxy group and an unsubstituted linear or branched alkoxy group and a nitro group are introduced, but other substituents may be introduced. . As the substituent which may be introduced, an alkyl group which may have a substituent,
Examples thereof include an aryl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, a halogen atom, an amino group, a nitro group, a cyano group and the like. It is not limited to.

Typical examples of the central metal represented by M in the phthalocyanine dye of the present invention include protons in the case of no metal, Cu, Zn, Fe, Co, Ni, Ru,
Rh, Pd, Pt, Mn, Mg, Be, Ca, Ba, C
d, Hg, Al-Cl, Al-OH, Ca, In-C
l, In-OH, Ti = O, V = O, Cr, Zr, S
n, Si (OH) 2, Ge (OH) 2, etc. Also, 3
In the case of a valent or tetravalent metal, a substituent can be introduced also in the axial direction of the phthalocyanine ring, but when a bulky substituent is introduced in the axial direction, the packing of molecules during the film formation on the recording film. Is inhibited and the optical density is remarkably reduced.
The optimum film thickness as a D-R recording film tends to increase. Therefore, the volume change of pit formation at the time of recording becomes large, and the influence on adjacent tracks may appear and the signal quality may deteriorate. Furthermore, when an electron-withdrawing group such as a nitro group is introduced, the substituent introduced in the axial direction is likely to be eliminated, and durability may be reduced.
Therefore, in the phthalocyanine dye of the present invention, the substituents that can be introduced in the axial direction are limited to relatively small substituents such as oxygen, hydroxyl group and halogen.

The phthalocyanine dye of the present invention can be produced, for example, by the following method. That is, a mixture of phthalonitriles represented by the following general formula [2] and phthalonitriles represented by the following general formula [3] and the formula [1]
A phthalocyanine compound having both a fluorine-substituted alkoxy group and an unsubstituted linear or branched alkoxy group can be produced by a conventional method using various metal salts of the metal represented by M as a starting material. Further, in place of the phthalonitriles of the general formulas [2] and [3], an indoline compound obtained by reacting these phthalonitriles with ammonia is also used. Similarly, a fluorine-substituted alkoxy group and an unsubstituted straight chain or Phthalocyanine compounds having both branched alkoxy groups can be prepared.

General formula [2] [In the formula, R represents a fluorine-substituted alkyl group. ]

[Chemical 3] General formula [3]

[Chemical 4] [In the formula, X represents an unsubstituted linear or branched alkyl group. ]

Next, the phthalocyanine dye of the present invention can be produced by nitrating the obtained phthalocyanine compound having both a fluorine-substituted alkoxy group and an unsubstituted linear or branched alkoxy group. it can.

Phthalocyanine compounds (a) to (k) shown below are typical examples of the phthalocyanine dye of the present invention.
However, the present invention is not limited to these.

[0019]

[Table 1]

The recording film layer using the phthalocyanine dye of the present invention contains an oxygen quencher and an ultraviolet absorber for the purpose of further improving the stability of the recording film such as light resistance and environment resistance and the stability of repeated reproduction. You may add additives, such as.

The recording film layer may be formed by a dry process such as vacuum deposition or sputtering, but a wet process such as spin coating, dipping, spraying, roll coating, or the like. It is also possible by the LB (Langmuir-Blodgett) method. The recording film material of the present invention is soluble in general-purpose organic solvents such as alcohol-based, ketone-based, cellosolve-based, halogen-based, hydrocarbon-based, and fluorocarbon-based materials, and therefore spin-coated from the viewpoint of productivity and recording film uniformity. The method of forming a film by the method is preferable. As described above, when the film is formed by the so-called coating method, a polymer binder may be added if necessary. Examples of the polymer binder include acrylic resin, polycarbonate resin, polyester resin, polyamide resin, vinyl chloride resin, vinyl acetate resin, nitrocellulose, and phenol resin, but are not limited thereto. The mixing ratio of the polymer binder is not particularly limited, but is preferably 30 wt% or less with respect to the dye.

The optimum film thickness of the recording film layer of the present invention is not particularly limited because it varies depending on the type and combination of recording film materials, and is preferably 500 to 3000 A, more preferably 700 to 3000 A.
2500A is the optimum film thickness range.

The reflective film material of the present invention includes gold, silver,
Metals such as copper, platinum, aluminum, cobalt, tin, and alloys containing these as main components, MgO, ZnO, SnO
Examples thereof include metal oxides such as SiN4, nitrides such as SiN4, AlN, and TiN. Gold is most preferable because of its high absolute reflectance and excellent stability. In addition, an organic highly reflective film can be used depending on the case. As a method for forming such a reflective film, a dry process such as a vacuum deposition method or a sputtering method is most preferable, but the method is not limited to these. The optimum thickness of the reflective film of the present invention is not particularly limited, but is preferably in the range of 400 to 1300A.

Further, the disk is protected from above the reflective film in order to prevent chemical deterioration (eg, oxidation, water absorption, etc.) and physical deterioration (eg, scratches, scratches, etc.) of the disk, particularly the recording film layer and the reflective film layer. To provide a protective layer. As a material for the protective layer, a method in which an ultraviolet curable resin is used and applied by spin coating and cured by ultraviolet irradiation is preferable, but the material is not limited to this. Regarding the optimum thickness of the protective layer, when it is thin, the protective effect is lowered, and when it is thick, it causes deterioration of mechanical properties such as warpage of the disk due to shrinkage during curing of the resin. It is preferable to form a film in the micron range.

The disk substrate used in the present invention preferably has a light transmittance of 85% or more for writing and reading a signal and a small optical anisotropy. For example, glass, acrylic resin, polycarbonate resin, polyester resin, polyamide resin, vinyl chloride resin, vinyl acetate resin, polystyrene resin, polyolefin resin (poly-4-
Substrates made of a thermoplastic resin such as methylpentene) or a polyether sulfone resin, or a thermosetting resin such as an epoxy resin or an allyl resin can be given. Among these, those made of a thermoplastic resin are preferable from the standpoint of ease of molding and provision of wobble signals for ATIP and guide grooves, etc. Further, acrylic resin and polycarbonate are preferable in view of optical characteristics, mechanical characteristics and cost. Those made of resin are particularly preferable.

The ATIP wobble signal and the guide groove are preferably provided by using a stamper or the like when molding a thermoplastic resin (injection molding, compression molding), but a so-called 2P method using a photopolymer resin is preferable. Can also be performed by the method according to. The shape of the guide groove of the optical disc of the present invention is not particularly limited and may be trapezoidal or U-shaped. The optimum value of the guide groove depends on the type and combination of recording film materials, but the average groove width (1/2 of the groove depth).
It is preferable that the width) is 0.4 to 0.6 micron and the groove depth is 700 to 2000A.

Since the disk form of the present invention needs to function as a CD or a CD-ROM after recording,
Or CD-ROM standard (Red Book) and R
-It is preferable to comply with the CD standard (Orange Book).

[0028]

The present invention will be specifically described with reference to the following examples and comparative examples, but the present invention is not limited to the following examples. First, a method for producing a typical example of the phthalocyanine compound used in the present invention will be described.

Production Example 1: Production of Phthalocyanine Compound (a) 3- (1,1,2,2-tetrafluoropropyl) oxy-o was added to 100 parts of n-amyl alcohol and 30 parts of diazabicycloundecene (DBU). -Phthalonitrile and 3-
10 parts of a mixture of (neopentyl) oxy-o-phthalonitrile in a molar ratio of 1: 1 and 15 parts of cuprous chloride are added,
After heating and stirring at 130 to 135 ° C. for 3 hours, the mixture is cooled to 500
Diluted with 1 part of methanol. The deposited precipitate was separated by filtration, washed with a mixed solution of methanol / water (4/1) and dried to obtain 10 parts of a blue powder. 5 parts of the copper phthalocyanine compound thus obtained was nitrated with 100 parts of acetic anhydride and 5 parts of acetyl nitrate synthesized from acetic anhydride and fuming nitric acid, and poured into 1000 parts of ice water. The deposited precipitate was separated by filtration, washed with water and dried to obtain 4 parts of the phthalocyanine compound (a).

Production Example 2: Production of Phthalocyanine Compound (b) In the same manner as in Production Example 1, 100 parts of n-amyl alcohol, D
In 30 parts of BU, 3- (2,2-bis (trifluoromethyl) propyl) oxy-o-phthalonitrile and 3-
10 parts of a mixture of (2,4-dimethyl-3-pentyl) oxy-o-phthalonitrile in a molar ratio of 1: 3 and 15 parts of cuprous chloride are added, and the mixture is heated and stirred at 130 to 135 ° C. for 3 hours and then cooled. , Diluted with 1000 parts of methanol, the deposited precipitate was filtered off, washed with a mixed solution of methanol / water (3/1),
After drying, 5.5 parts of blue powder was obtained. 5 parts of the copper phthalocyanine compound thus obtained was nitrated with 100 parts of acetic anhydride and 5 parts of acetyl nitrate synthesized from acetic anhydride and fuming nitric acid, and poured into 1000 parts of ice water. The deposited precipitate was filtered off, washed with water and dried to obtain 3 parts of the phthalocyanine compound (b).

Production Example 3: Production of Phthalocyanine Compound (c) In the same manner as in Production Example 1, 100 parts of n-amyl alcohol, D
In 30 parts of BU, 3- (2,2-bis (trifluoromethyl) propyl) oxy-o-phthalonitrile and 3-
10 parts of a mixture of (1,3-dimethylbutyl) oxy-o-phthalonitrile in a molar ratio of 1: 1 and nickel chloride 5
Parts were added, and the mixture was heated with stirring at 130 to 135 ° C. for 5 hours, cooled, and diluted with 2000 parts of methanol. The deposited precipitate was separated by filtration, washed with a mixed solution of methanol / water (4/1) and dried to obtain 8 parts of a green powder. 5 parts of the nickel phthalocyanine compound thus obtained was nitrated in acetic anhydride and poured into 1000 parts of ice water. The deposited precipitate was separated by filtration, washed with water and dried to obtain 7 parts of a phthalocyanine compound (c).

Production Example 4: Production of Phthalocyanine Compound (d) In the same manner as in Production Example 1, 100 parts of n-amyl alcohol, D
In 30 parts of BU, 3- (2,2-bis (trifluoromethyl) propyl) oxy-o-phthalonitrile and 3-
10 parts of a mixture of (2,4-dimethyl-3-pentyl) oxy-o-phthalonitrile in a molar ratio of 1: 3 and 3 parts of zinc chloride were added, and the mixture was heated and stirred at 130 to 135 ° C. for 5 hours,
Cooled and diluted with 1500 parts of methanol. The deposited precipitate was separated by filtration, washed with a mixed solution of methanol / water (4/1) and dried to obtain 8 parts of a green powder. 5 parts of the vanadium phthalocyanine compound thus obtained was added to acetic anhydride,
It was nitrated and poured into 1000 parts of ice water. The deposited precipitate was separated by filtration, washed with water and dried to obtain 4 parts of phthalocyanine compound (d).

EXAMPLE 1 1200 Angstroms deep, 0.50 micron wide,
1.20m thickness with guide grooves with pitch of 1.6 microns
m, an outer diameter of 120 mm, an inner diameter of 15 mm, a phthalocyanine compound [a] was dissolved in ethoxyethanol at a concentration of 50 mg / ml, and 0.2 micron filtering was performed to prepare a coating liquid. Was used to form a film having a recording film thickness of 900 angstrom by a spin coater. Next, gold was formed into a film having a thickness of 800 angstrom on the recording film thus obtained by sputtering. Further, a protective film layer having a film thickness of 5 μm was formed thereon by an ultraviolet curable resin to form an optical disk. Using the optical disk created in this way,
Linear velocity is 1. using a semiconductor laser with a wavelength of 785 nm.
When an EFM-CD format signal was recorded at 4 m / sec, the reflectance was 67%, the recording laser power was 6.0 mW, and the obtained recording control signal was good. All satisfied the standard values.

Example 2 1200 Angstroms deep, 0.50 micron wide,
1.20m thickness with guide grooves with pitch of 1.6 microns
m, an outer diameter of 120 mm, and an inner diameter of 15 mm, a phthalocyanine compound [b] was dissolved in diacetone alcohol at a concentration of 60 mg / ml, and 0.2 μm filtering was performed to prepare a coating liquid. The liquid was used to form a film with a recording film thickness of 750 angstroms using a spin coater. Next, gold was formed into a film having a thickness of 800 angstrom on the recording film thus obtained by sputtering. Further, a protective film layer having a film thickness of 5 μm was formed thereon by an ultraviolet curable resin to form an optical disk. When an EFM-CD format signal was recorded at a linear velocity of 1.4 m / sec using a semiconductor laser having a wavelength of 785 nm using the optical disk thus prepared, the reflectance was 68% and the optimum recording laser power was 6%. Recording was possible at 0.2 mW, the obtained recording control signal was good, and all the items described in the Orange Book satisfied the standard values.

EXAMPLE 3 1200 Angstroms deep, 0.50 micron wide,
1.20m thickness with guide grooves with pitch of 1.6 microns
m, an outer diameter of 120 mm, an inner diameter of 15 mm, a phthalocyanine compound [c] was dissolved in ethoxyethanol at a concentration of 50 mg / ml, and 0.2 micron filtering was performed to prepare a coating liquid. Was used to form a film having a recording film thickness of 900 angstrom by a spin coater. Next, gold was formed into a film having a thickness of 800 angstrom on the recording film thus obtained by sputtering. Further, a protective film layer having a film thickness of 5 μm was formed thereon by an ultraviolet curable resin to form an optical disk. Using the optical disk created in this way,
Linear velocity is 1. using a semiconductor laser with a wavelength of 785 nm.
When an EFM-CD format signal was recorded at 4 m / sec, the reflectance was 70%, the recording laser power was 6.6 mW, and the obtained recording control signal was good. All satisfied the standard values.

Example 4 Depth 1250 Å, Width 0.48 μm,
1.20m thickness with guide grooves with pitch of 1.6 microns
m, an outer diameter of 120 mm, and an inner diameter of 15 mm, a phthalocyanine compound (d) was dissolved in ethoxyethanol at a concentration of 50 mg / ml, and a 0.2 μm filtering was performed to prepare a coating liquid. Was used to form a film having a recording film thickness of 900 angstrom by a spin coater. Next, gold was formed into a film having a thickness of 800 angstrom on the recording film thus obtained by sputtering. Further, a protective film layer having a film thickness of 5 μm was formed thereon by an ultraviolet curable resin to form an optical disk. Using the optical disk created in this way,
Linear velocity is 1. using a semiconductor laser with a wavelength of 785 nm.
When the EFM-CD format signal was recorded at 4 m / sec, the reflectance was 66%, the optimum recording laser power was 6.0 mW, and the recording was possible. All satisfied the standard values.

Comparative Examples 1 to 4 Optical discs were prepared in the same manner as in Example 1 by using the phthalocyanine compounds (1) to (o) shown in Table 2 below.
Example 1 using the optical disc prepared in this way
Recording and reproduction were performed in the same manner as in. Table 3 shows the reflectance and optimum laser power in this recording / reproduction. As can be seen from the table, when the alkoxy group introduced into the phthalocyanine ring is only a fluorine-substituted alkoxy group and when it is an unsubstituted alkoxy group, the balance between the reflectance and the optimum laser power, that is, the sensitivity is balanced. It's getting worse.
In the case of only a fluorine-substituted alkoxy group, the reflectance tends to be high, but the sensitivity tends to be low. Within the range described in the Orange Book which is the standard of CD-R, there is no margin at the upper limit, and high speed recording is possible. It is impossible to achieve the high sensitivity required for. On the contrary, in the case of only an unsubstituted alkoxy group, 785
Since the absorbance in the vicinity of nm is high, the sensitivity is very high, but the reflectance tends to be low.

[0038]

[Table 2]

Table 3 ────────────────────────────────── Comparative Example Phthalocyanine reflectance Optimum laser power compound (% ) (MW) ────────────────────────────────── 1 (l) 56 5.6 2 (m) 52 5.3 3 (n) 72 7.4 4 (o) 68 8.0 ────────────────────────────── ───

[0040]

As described above, the phthalocyanine dye of the present invention has both a fluorine-substituted alkoxy group and an unsubstituted linear or branched alkoxy group, and further has a nitro group introduced. By using the compound as a recording film, it becomes easy to optimize the optical characteristics in the vicinity of 785 nm, which is a target for CD-R. In addition, the sensitivity and reflectance are well-balanced, and evenly balanced pits are formed, and at the same time, the recording sensitivity is increased, so that adverse effects such as thermal deformation on the substrate are eliminated, and there is no pit length mismatch, and a high-quality signal. The characteristics have come to be obtained.

Claims (3)

[Claims] 1. An alkoxy group and a nitro group are introduced into each of the four benzene rings of the phthalocyanine skeleton represented by the formula [1], and the alkoxy group is composed of n fluorine-substituted alkoxy groups and an unsubstituted alkoxy group. M groups (n + m =
4, n and m represent an integer of 1 to 3). Formula [1] [In the formula, M represents a hydrogen atom or a metal atom which may be substituted with oxygen, a hydroxyl group or a halogen atom. ] 2. An alkoxy group at one of the substitution positions of 1 or 4, 5 or 8, 9 or 12, 13 or 16 of the four benzene rings of the phthalocyanine skeleton represented by the formula [1], and at the other. A nitro group is introduced.
The optical recording material described. 3. A write-once compact disc comprising a laminated body of a transparent substrate / recording film / reflection film / protective film, wherein the recording film contains the optical recording material according to claim 1.