JPH1142854A - Optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide satisfactory recording sensitivity and excellent light resistance with low recording power and small waveform distortion even with high output of long bit by forming a recording layer by a vapor deposition method, and using as a constituting material for one or more types of phthalocyanine dye having sublimability of compound represented by a specific formula. SOLUTION: In the optical recording medium comprising a recording layer 2 for transmitting and absorbing laser beam, reflecting layer 3 and protective layer 4 sequentially formed on a base 1, the layer 2 is formed by a vapor deposition method, and as a constituting material, it is selected from compound represented by a formula 1, and at least one or more types of phthalocyanine dye having sublimability is used, where substituents X1 to X16 independently contain, for example, hydrogen atom, halogen atom, substituted or unsubstituted alkyl group, alkoxy group, alkylthio group, aryl group, aryloxy group and arylthio group and one or more of the X1 to X16 each has one or more trifluoromethyl group at its end, and M denotes metal derivative such as two hydrogen atoms.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical recording medium on which information can be recorded / reproduced by a laser beam.
The present invention relates to an optical recording medium in which a recording layer contains at least an organic dye.

[0002]

2. Description of the Related Art In recent years, there are various types of optical recording media for recording and reproducing information by using a laser beam, in which a recording layer is formed on a substrate and a reflective layer and a protective layer are formed thereon. One is that the recording layer is formed by containing an organic dye. This is because when the recording layer is irradiated with laser light from the substrate side, the laser light is partially absorbed by the recording layer,
When the irradiated portion is locally heated and physical or chemical changes such as melting, evaporation, sublimation, or decomposition occur, pits are formed and information is recorded.

[0003] The pit information thus formed has optical characteristics that are different from those of the other portions, and is reproduced by irradiating a laser beam having a lower power than during recording.

The material used for the recording layer is an organic compound such as a dye, which is generally formed on a substrate by dissolving it in a solvent and then wet-coating such as spin coating. For this reason, the organic compound such as a dye used here has a substituent introduced in its molecular structure to improve the solubility in a solvent.

[0005]

However, in the above-mentioned conventional dye material for a wet method, when a material having low solvent resistance such as a polycarbonate resin is used for the substrate, the solvent for dissolving the dye becomes soluble in the substrate material. Despite the use of alcohol-based or cellosolve-based
When the recording layer is formed, a very small amount of the top surface of the substrate is dissolved, so that a small amount of the substrate resin material is mixed in the recovered coating solution, and separation and purification costs are incurred in the reuse of the dye material, or And the characteristics are deteriorated.

Further, when a phthalocyanine dye is used as a dye material, the solubility of the phthalocyanine dye in a solvent is improved to improve the solubility, thereby deteriorating the excellent light resistance inherent in the phthalocyanine dye. .

On the other hand, when a recording layer is formed by a dry method such as a vapor deposition method, the sublimation property of the dye material is used, and if the material itself does not have a certain degree of heat resistance, the material is decomposed during the process and formed. Can not film. Therefore, it is necessary to select a material with high heat resistance,
The obtained optical recording medium had a problem that the recording sensitivity was low and the characteristics were insufficient.

[0008]

The present invention has been made to solve the above-mentioned problems, and has at least one trifluoromethyl group at a terminal of a substituent introduced into a phthalocyanine ring or a central metal as a dye material for forming a recording layer. By using a phthalocyanine dye having the above-described properties and sublimability and forming a film by a dry method such as evaporation, a recording layer can be formed without dissolving a substrate material such as a polycarbonate resin, and recording by laser light. It is possible to provide an optical recording medium in which power can be reduced, high output is ensured even in a long pit such as 11T, signal waveform is not distorted, recording sensitivity is good, and light resistance is excellent.

[0009]

The optical recording medium according to the first aspect of the present invention is an optical recording medium in which a recording layer that transmits and absorbs a laser beam, a reflective layer, and a protective layer are sequentially formed on a substrate. An optical recording medium in which a recording layer is formed by a vapor deposition method, and as a constituent material thereof, at least one kind of a phthalocyanine dye having a sublimation property, which is a compound represented by the following formula (1), is used.

In the formula (1), the substituents X _{1 to} X ₁₆ are
For example, hydrogen atom, halogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted aryl group, substituted or unsubstituted aryloxy group, substituted Alternatively, it may have an unsubstituted arylthio group, nitro group, amino group and the like independently, but is not limited thereto.

However, at least one of X _{1 to} X ₁₆ has at least one trifluoromethyl group at the terminal of its substituent. M is two hydrogen atoms, a divalent metal atom, a trivalent or tetravalent metal derivative. Here, since the trifluoromethyl group only needs to be at the end of the dye molecule, for example, when M has a trivalent or tetravalent metal derivative, a trifluoromethyl group is present at the end of the substituent to be introduced into the metal. You may.

The halogen atom is fluorine, chlorine, bromine or iodine. The substituted or unsubstituted alkyl group may be straight-chain or branched, saturated or unsaturated, for example, methyl, ethyl, n-propyl group, is
Examples include an o-propyl group, an n-butyl group, a tert-butyl group, and the like. Similarly, the substituted or unsubstituted alkoxy group may be linear or branched, saturated or unsaturated, and includes a methoxy group, an ethoxy group, a methoxymethyl group, and a propoxy group.

Similarly, the substituted or unsubstituted alkylthio group may be linear or branched, saturated or unsaturated, and includes a methylthio group, an ethylthio group and a tert-butylthio group. Examples of the substituted or unsubstituted aryl group include a phenyl group, a naphthyl group, and a pyrrole group. Representative examples of the substituted or unsubstituted aryloxy group include a phenoxy group.

In the metal represented by M, divalent metals include Cu, Co, Zn, Ni, Co, Fe, Pd,
Pt, Sn, Mg and the like. As the trivalent metal, A
l, Ga, In and the like.
i, Ge, Sn, Ti, V, etc., and in the case of a trivalent or tetravalent metal, the metal has a substituent. For example, halogen, oxygen, alkyl, alkoxy, acyl, phenyl And derivatives such as phenoxy groups are well known.

When the laser beam is partially transmitted and absorbed by the recording layer and the irradiated portion is locally heated, first, the phthalocyanine dye introduced into the molecular terminal before breaking the stable phthalocyanine skeleton. A fluoromethyl group leaves the molecular structure of the dye. In other words, a trifluoromethyl group is a substituent having a large electron-withdrawing property and being sterically bulky. Therefore, if it is located at the end of the molecular structure, the association between molecules will be reduced, and the light intensity during recording will be reduced. Intramolecular vibration is amplified by absorption.

As a result, the trifluoromethyl group is easily desorbed, so that recording can be performed with low power, and high-output and high-sensitivity recording / reproducing characteristics can be obtained. The trifluoromethyl group is not limited to the terminal of a so-called fluorine-substituted alkoxy group, and may be directly bonded to a benzene ring or the like.

[0017] It has also been clarified that low-power recording is insufficient when one of the fluorine atoms of the trifluoromethyl group is replaced by a hydrogen atom.

Also, since the intermolecular interaction becomes small,
The sublimability is also improved, making it suitable for vapor deposition. Furthermore, the introduction of this trifluoromethyl group does not impair the original light resistance of the phthalocyanine dye.

Therefore, by using a phthalocyanine dye containing at least one trifluoromethyl group at the terminal of the substituent introduced into the phthalocyanine ring or the central metal, optical recording with good recording sensitivity and excellent light resistance can be obtained. A medium is obtained.

In the optical recording medium according to a second aspect of the present invention, the phthalocyanine dye constituting the recording layer has an evaporation or sublimation onset temperature in the range of 100 to 350 ° C. 5 difference from decomposition temperature
The temperature is in the range of 0 to 400 ° C.

When the phthalocyanine-based dye constituting the phthalocyanine-based dye has an evaporation or sublimation onset temperature lower than 100 ° C., its reliability cannot be ensured because it is affected by an environmental change during transport or storage of the optical recording medium. On the other hand, if the temperature exceeds 350 ° C., the decomposition temperature becomes relatively high, so that the recording power by a laser beam is increased and the recording sensitivity is significantly reduced. Therefore, the evaporation or sublimation start temperature of the phthalocyanine dye used in the recording layer of the optical recording medium is 100 to 350 ° C.
Is suitable.

If the difference between the temperature at which the phthalocyanine dye starts evaporation or sublimation and the decomposition temperature is smaller than 50 ° C., the temperature of the evaporation source is set to 20 to 30 degrees below the starting temperature when forming the recording layer by vapor deposition. Decomposition of the dye gradually starts in the evaporation source due to the setting of about ° C. higher or the temperature variation of the evaporation source, so that a uniform recording layer cannot be formed.

On the other hand, if the temperature is higher than 400 ° C., this means that the decomposition temperature of the dye is relatively high, so that the recording power is increased and the recording sensitivity is remarkably reduced. Therefore, the difference between the evaporation or sublimation initiation temperature and the decomposition temperature of the phthalocyanine dye used in the recording layer of the optical recording medium is preferably in the range of 50 to 400C.

In the optical recording medium according to the third aspect, the central metal of the phthalocyanine dye constituting the recording layer is a divalent metal and is made of Co, Cu, Zn, Ni, or Pd.

When the center of the phthalocyanine dye is non-metallic, the waveform distortion of a long pit such as 11T is slightly caused, and the signal quality is slightly lowered. On the other hand, in the case of divalent metals, 1
High output at 1T, especially Co, Cu, Zn, Ni, P
As for d, the recording power is low and good. Therefore, the central metal is a divalent metal, preferably Co, Cu, Zn, N
An optical recording medium in which a recording layer is formed using a phthalocyanine dye to which i and Pd are coordinated has a low recording power,
High output can be obtained with long pits such as T, and good signal quality with almost no waveform distortion can be obtained.

According to a fourth aspect of the present invention, there is provided an optical recording medium, wherein a spiral groove is provided on a substrate, and a ratio of a groove width to a track pitch (hereinafter, referred to as TP) and a laser wavelength λ are determined. , The groove depth when the refractive index n of the substrate is within the following ranges.

Groove width / TP: 0.25 to 0.45 Groove depth: 20 to 80% of (λ / 4n) When the recording layer is formed by the vapor deposition method, the dye evaporated or sublimated from the evaporation source is coated on the entire surface of the substrate. Is uniformly formed along the groove of the substrate. Therefore, the step of the recording layer between the groove of the substrate and the groove is determined by the groove depth, so that the tracking error signal can be adjusted by the groove depth of the substrate.

Here, when the groove width / TP of the substrate is smaller than 0.25, the ratio of the groove width to the spot diameter of the laser beam becomes small, and the amount of light reflected from between the grooves becomes dominant, and the tracking error signal is reduced. It will be smaller. On the other hand, when it is larger than 0.45, the difference in the amount of reflected light between the groove and the groove becomes small, and the characteristics as an optical recording medium such as the radial contrast become small. Therefore,
The groove width / TP of a substrate used for an optical recording medium having a recording layer formed by vapor deposition is suitably in the range of 0.25 to 0.45.

When the groove depth is smaller than 20% of (λ / 4n), the tracking error signal becomes smaller,
On the other hand, if it is larger than 80%, the reflectance becomes low, and the characteristics as an optical recording medium deteriorate. Therefore, the groove depth is suitably in the range of 20 to 80% of (λ / 4n).

An optical recording medium according to an embodiment of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is an enlarged sectional view of an optical recording medium according to an embodiment of the present invention. As shown in FIG. 1, the recording layer 2 includes a substrate 1, a recording layer 2, a reflective layer 3, and a protective layer 4.
A recording auxiliary layer or the like may be provided.

First, it is desirable that the substrate 1 used in the present invention has a transmittance of recording laser light of 85% or more and a small optical anisotropy. The material is, for example, a thermoplastic resin such as a glass acrylic resin, a polycarbonate resin, a polyolefin resin, a polyester resin, a polystyrene resin, a polymethyl methacrylate resin, a thermosetting resin such as an epoxy resin, an allyl resin, an ultraviolet curable resin, or the like. Is mentioned. Of these, the most common thermoplastic resin is a polycarbonate resin which can be molded by an injection (compression) molding machine and has high mass productivity and particularly excellent impact resistance.

The substrate thus formed is not particularly limited in thickness, and may be a plate or a film. The shape may be circular or card-like, and the size is not particularly limited. Further, another layer, for example, a solvent-resistant layer such as SiO ₂ or an enhancement layer may be provided on the substrate.

Further, on the surface of the substrate on the recording layer side, means for guiding the traveling path of the laser beam are provided. this is,
For example, address pits formed of pits formed at predetermined intervals may be used, but spiral or concentric guide grooves are desirable. A laser beam travels along the groove to enable recording and reproduction.

Next, the recording layer 2 formed on the guide groove side of the substrate is made of a trifluoromethyl group at the terminal of the substituent molecular structure introduced into the phthalocyanine ring, as shown in Chemical Formula 1. And one or more phthalocyanine dyes having sublimability are used. The dye may be any dye that has a certain level of light absorption at the wavelength of the laser light used.Therefore, the substituent introduced into the phthalocyanine ring is not particularly limited except for the trifluoromethyl group. It is necessary to finely adjust the transmission and absorption characteristics in accordance with the wavelength.

This trifluoromethyl group may be bonded directly or indirectly to the benzene ring of the phthalocyanine ring, for example, via an alkyl group, an alkenyl group, an aryl group, oxygen, sulfur or the like. Is also good.

The dye is not limited to a single dye, but may be a mixture of a plurality of dyes. In order to improve recording characteristics and the like, macrocyclic azaannulene dyes (phthalocyanine dyes, naphthalocyanine dyes, porphyrin dyes, etc.) ), Polymethine dyes (cyanine dyes, merocyanine dyes, styryl dyes, squarylium dyes, etc.), azo dyes, dithiol metal complexes, anthraquinone dyes and other organic dyes, nitrocellulose, ethylcellulose,
Resins such as acrylic resins, polystyrene resins, and urethane resins, and additives such as dispersants, leveling agents, and defoaming agents can be used in combination as long as the effects of the present invention are not impaired.

The production method may be selected or used in combination with a dry method or a wet method depending on the organic compound. In the case of the phthalocyanine dye having a trifluoromethyl group at the molecular end, the characteristics of the molecule are utilized. In order to form it by a dry method, a dry method is suitable.
Further, in consideration of the influence on the substrate material, it is desirable to select a compound that can be prepared by a dry method, and particularly when the compound is prepared by a vapor deposition method, the productivity is excellent.

The reflective layer 3 is made of gold, silver, copper,
Metals such as platinum and aluminum and alloys containing these as main components, metal oxides such as MgO, ZnO and SnO, Si
Nitrides such as N ₄ , AlN, and TiO are exemplified. Above all, gold having high absolute reflectance and excellent storage stability is optimal, but any gold may be used as long as the reflectance required for recording and reproducing with the laser beam used can be secured. This reflective layer is formed by a vacuum evaporation method, a sputtering method, or the like.

The protective layer 4 is formed of a resin having excellent impact resistance and low curing shrinkage like the above-mentioned substrate.
This is formed, for example, by applying an ultraviolet curable resin by a spin coating method and then irradiating the applied ultraviolet light to cure the resin. In addition, an epoxy resin, an acrylic resin, a silicone-based hard coat resin, or the like may be used.

[0040]

An embodiment of the present invention will be described. Here, a list of the materials used as the recording layer is described based on (Chemical Formula 1).

[0041]

[Table 1]

Shown in FIG. (Example 1) In Example 1, a phthalocyanine dye shown in (Table 1) was used for the recording layer. In addition, this compound
It includes isomers substituted at the α-position, and the synthesis method is shown below.

First, 3- [2- (trifluoromethyl)
[Phenoxy] phthalonitrile is synthesized. In a reaction flask equipped with a cooling tube, 3-nitrophthalonitrile 8.7 was added.
g, 2- (trifluoromethyl) phenol 9.4 g,
13.8 g of anhydrous potassium carbonate, dimethyl sulfoxide 3
50 ml was charged and heated to 50 ° C. while stirring under a nitrogen stream. After stirring at 50 ° C. for 3 hours, heating was stopped, the reaction solution was cooled, and then poured into 500 ml of water. The precipitated crystals were collected by filtration and dried to obtain 13.5 g of the desired compound.

Next, 3.5 g of the above phthalonitrile derivative, 1-pentanol 1 were placed in a reaction flask equipped with a cooling tube.
8 ml, 1,8-diazabicyclo [5.4.0] -7-
After 2.7 g of undecene (hereinafter abbreviated as DBU) and 0.4 g of cuprous chloride were charged and stirred at 110 ° C. for 5 hours under a nitrogen stream, heating was stopped, and the reaction solution was poured into 200 ml of methanol.
Further, 40 ml of water was added, and the precipitated crystals were collected by filtration and dried to obtain 1.8 g of a crude product.

The crude product was purified by column chromatography (silica gel / toluene: ethyl acetate = 40: 1) to obtain the desired compound α, α, α, α-tetrakis [2- (trifluoromethyl) phenoxy] copper 1.6 g of phthalocyanine was obtained.

On a recording layer side of a transparent substrate having an outer diameter of 120 mm, an inner diameter of 15 mm, and a thickness of 1.2 mm, which is injection-molded with a polycarbonate resin, a width of 0.6 μm, a depth of 70 nm and a TP
A 1.6 μm spiral guide groove is provided. On this substrate, the phthalocyanine-based dye was deposited to a thickness of 2
A recording layer of 00 nm was provided. At this time, the evaporation start temperature is 190 ° C., and the difference between the evaporation start temperature and the decomposition temperature is 22
It was 0 ° C.

On top of this, a 100 nm thick reflective film made of a sputtered gold film and a 7 μm thick protective layer made of an ultraviolet curable resin (Die Cure Clear SD-17 manufactured by Dainippon Ink Co., Ltd.) are provided. A recording medium was manufactured. Groove width/
TP is 0.38, laser wavelength λ is 788 nm,
If the refractive index n of the substrate is 1.55, the groove depth is (λ / 4
n) is 55%.

Example 2 In Example 2, a phthalocyanine dye shown in Table 1 was used for the recording layer. This compound contains an α-substituted isomer, and its synthesis method is described below.

First, 3- (2,2,3,3,3-pentafluoropropoxy) phthalonitrile is synthesized. In a reaction flask, 8.7 g of 3-nitrophthalonitrile, 2,
2,3,3,3-pentafluoropropanol 9.0
g, anhydrous potassium carbonate (13.8 g) and dimethyl sulfoxide (350 ml) were charged, and the mixture was stirred for 50 minutes under a nitrogen stream.
The temperature was raised to ° C. After stirring at 50 ° C. for 4 hours, heating was stopped, the reaction solution was cooled, and then poured into 500 ml of water. The precipitated crystals were collected by filtration and dried to obtain 13.2 g of the target compound.

Next, 13.1 g of the above phthalonitrile derivative, 90 ml of 1-pentanol, DB
U10.8 g and cuprous chloride 1.5 g were charged and heated to 110 ° C. while stirring under a nitrogen stream. After stirring at the same temperature for 5 hours, the heating was stopped, the reaction solution was poured into 400 ml of methanol, and the precipitated crystals were collected by filtration and dried to obtain 10.1 g of a crude product. This crude product was dissolved in 800 ml of dioxane, heated to 60 ° C. with stirring, 1 g of activated clay was added, stirred for 30 minutes, filtered to remove the activated clay layer, and the filtrate was concentrated with an evaporator and dried. Solid content of methanol 400m
After the dispersion, the crystals were filtered and the crystals were dried to obtain α, α, α, α-tetrakis (2,2,3,3,3
-Pentafluoropropoxy) copper phthalocyanine.
3 g were obtained.

Using the dye thus obtained, Example 1
In the same manner as in the above, an optical recording medium was formed on the substrate to a thickness of 180 nm by vapor deposition. The evaporation start temperature of this dye was 210 ° C., and the difference between the evaporation start temperature and the decomposition temperature was 220 ° C.

Example 3 In Example 3, phthalocyanine dyes shown in Table 1 were used for the recording layer. This compound contains an α-substituted isomer, and its synthesis method is described below.

A reaction flask was charged with 5.5 g of a phthalonitrile derivative obtained in the same manner as in the dye synthesis operation of Example 2, 36 ml of 1-pentanol, and 3.6 g of DBU, and heated to 115 ° C. while stirring under a nitrogen stream. After stirring at the same temperature for 5 hours, heating was stopped and the reaction solution was 300 ml of methanol.
The precipitated crystals were collected by filtration and dried to obtain 2.7 g of a crude product. 140 ml of this crude product in tetrahydrofuran
Then, 2.7 g of activated clay was added with stirring, and the mixture was stirred for 15 minutes. After filtration, the filtrate was concentrated with an evaporator and dried. After dispersing the solid content in 260 ml of methanol, filtration and drying of the crystal were carried out to obtain α, α, α, α
-2.0 g of tetrakis (2,2,3,3,3-pentafluoropropoxy) phthalocyanine was obtained.

Using the dye thus obtained, Example 1
In the same manner as in the above, an optical recording medium was formed on the substrate to a thickness of 190 nm by vapor deposition. The evaporation start temperature of this dye was 240 ° C., and the difference between the evaporation start temperature and the decomposition temperature was 220 ° C.

Example 4 In Example 4, a phthalocyanine dye shown in Table 1 was used for the recording layer. This compound contains an α-substituted isomer, and its synthesis method is described below.

First, 3- (2,2,2-trifluoroethoxy) phthalonitrile is synthesized.

In a reaction flask, 8.7 g of 3-nitrophthalonitrile, 8,2,2-trifluoroethanol.
2 g, anhydrous potassium carbonate (13.8 g) and dimethylformamide (350 ml) were charged, and the mixture was stirred for 5 minutes under a nitrogen stream.
The temperature was raised to 0 ° C. After stirring at 50 ° C. for 5 hours, the heating was stopped, the reaction solution was cooled, and then poured into 500 ml of water. The precipitated crystals were collected by filtration and dried to obtain 12.9 g of the target compound.

Next, 12.9 g of the above phthalonitrile derivative, 90 ml of 1-pentanol, DB
U10.8 g and nickel chloride 2.0 g were charged and heated to 110 ° C. while stirring under a nitrogen stream. After stirring at the same temperature for 5 hours, the heating was stopped and the reaction solution was methanol 400 ml.
The precipitated crystals were collected by filtration and dried to obtain 9.6 g of a crude product. 800 ml of this crude product in tetrahydrofuran
Then, add 4 g of activated clay while stirring, and after stirring for 5 minutes,
After filtering to remove the activated clay layer, the filtrate was concentrated with an evaporator and dried. After the solid content was dispersed in 400 ml of methanol, the crystals were filtered and the crystals were dried to obtain 1.3 g of α, α, α, α-tetrakis (2,2,2-trifluoroethoxy) nickel phthalocyanine as a target compound. .

Example 1 was prepared using the thus obtained dye.
In the same manner as described above, an optical recording medium was formed on a substrate to have a thickness of 200 nm by vapor deposition. The evaporation start temperature of this dye was 170 ° C., and the difference between the evaporation start temperature and the decomposition temperature was 260 ° C.

Example 5 In Example 5, a phthalocyanine dye shown in Table 1 was used for the recording layer. This compound contains an α-substituted isomer, and its synthesis method is described below.

First, 3- [2,2-bis (trifluoromethyl) propoxy] phthalonitrile is synthesized. In a reaction flask, 8.7 g of 3-nitrophthalonitrile, 2,
2-bis (trifluoromethyl) propanol 11.8
g, anhydrous potassium carbonate (13.8 g) and dimethyl sulfoxide (350 ml) were charged, and the mixture was stirred under a nitrogen stream while stirring.
The temperature was raised to ° C. After stirring at 60 ° C. for 5 hours, heating was stopped, the reaction solution was cooled, and then poured into 500 ml of water. The precipitated crystals were collected by filtration and dried to obtain 12.8 g of the target compound.

Next, 4.8 g of the above phthalonitrile derivative, 27 ml of 1-pentanol, DBU were placed in a reaction flask.
After 4.6 g of cobalt chloride and 0.65 g of cobalt chloride were charged and stirred at 110 ° C. for 5 hours in a nitrogen stream, the heating was stopped, the reaction solution was poured into 150 ml of methanol, and 30 ml of water was further added, and the precipitated crystals were collected by filtration and dried. 2.5 g of crude product were obtained. The crude product is purified by column chromatography (silica gel / toluene: tetrahydrofuran = 80: 1) to obtain the target compound α, α, α, α-tetrakis [2,2-bis (trifluoromethyl) propoxy] cobalt phthalocyanine. Was obtained in an amount of 0.34 g.

Using the dye thus obtained, Example 1
In the same manner as in the above, an optical recording medium was manufactured by forming a film having a thickness of 280 nm on the substrate by vapor deposition. The evaporation start temperature of this dye was 250 ° C., and the difference between the evaporation start temperature and the decomposition temperature was 170 ° C.

Example 6 In Example 6, a phthalocyanine dye shown in Table 1 was used for the recording layer. This compound contains an α-substituted isomer, and its synthesis method is described below.

A phthalonitrile derivative 6.4 obtained in the same manner as in the synthesis procedure used in Example 5 was placed in a reaction flask.
g, 46 ml of 1-pentanol, 6.1 g of DBU, and 0.91 g of zinc chloride were stirred at 110 ° C. for 6 hours under a nitrogen stream, then heating was stopped, the reaction solution was poured into 160 ml of methanol, and 40 ml of water was added to precipitate crystals. Was collected by filtration and dried to obtain 5 g of a crude product. 3.1 g of this crude product was subjected to column chromatography (silica gel / toluene: ethyl acetate = 3).
0: 1) to purify the target compound α, α,
1.8 g of α, α-tetrakis [2,2-bis (trifluoromethyl) propoxy] zinc phthalocyanine was obtained.

Example 1 was prepared using the dye thus obtained.
In the same manner as in the above, an optical recording medium was formed on the substrate to a thickness of 190 nm by vapor deposition. The evaporation start temperature of this dye was 220 ° C, and the difference between the evaporation start temperature and the decomposition temperature was 250 ° C.

Example 7 In Example 7, a phthalocyanine dye shown in Table 1 was used as a recording layer. The synthesis method is described below.

First, 3,4,5,6-tetrakis (2,
(2,2-trifluoroethoxy) phthalonitrile is synthesized. Add tetrafluorophthalonitrile 1 to the reaction flask.
0 g, 2,2,2-trifluoroethanol 50 g, anhydrous potassium carbonate 55 g, dimethylformamide 30 ml
After stirring at 50 ° C. for 3 hours, the heating was stopped, the reaction solution was cooled, and then poured into 500 ml of water. The precipitated crystals were collected by filtration and dried to obtain 25.2 g of the desired compound.

Next, 25 g of the above phthalonitrile derivative, 2,2,2-trifluoroethanol 1 were placed in a reaction flask.
The temperature was raised to 55 ° C. while stirring under a nitrogen stream, and 1.6 g of cuprous chloride was further charged, followed by further raising the temperature and stirring at 80 ° C. for 6 hours. afterwards,
The heating was stopped, the system was cooled, and 50 ml of water was added dropwise to collect crystals, which were collected by filtration and dried to obtain 16.3 g of a crude product. 12.5 g of this crude product was purified by column chromatography (silica gel / toluene: ethyl acetate = 2: 1) and dried to obtain hexadeca (2,2,2-trifluoroethoxy) copper phthalocyanine, which was the target compound, in an amount of 11 g. 0.6 g was obtained.

Using the dye thus obtained, Example 1
In the same manner as in the above, an optical recording medium was formed on the substrate to a thickness of 180 nm by vapor deposition. The evaporation start temperature of this dye was 170 ° C, and the difference between the evaporation start temperature and the decomposition temperature was 220 ° C.

Example 8 In Example 8, the phthalocyanine dye shown in Table 1 was used for the recording layer. The synthesis method is described below.

In a reaction flask, 2.5 g of a phthalonitrile derivative obtained in the same manner as in the synthesis operation of Example 7, 2, 2, 2
-10 ml of trifluoroethanol and 2 g of DBU were charged and the temperature was raised to 55 ° C while stirring under a nitrogen stream, 0.29 g of palladium chloride was charged, and the temperature was further raised and stirred at 80 ° C for 9 hours. After that, stop heating and cool, water 10ml
Was added dropwise, and the precipitated crystals were collected by filtration and dried to obtain 1.4 g of a crude product. The crude product was purified by column chromatography (silica gel / toluene: ethyl acetate = 2: 1) and dried to obtain hexadeca (2,2,2-trifluoroethoxy) palladium phthalocyanine as a target compound in a concentration of 0.1%.
41 g were obtained.

Using the thus obtained dye, Example 1
In the same manner as in the above, an optical recording medium was formed on the substrate to a thickness of 330 nm by vapor deposition. The evaporation start temperature of this dye was 140 ° C., and the difference between the evaporation start temperature and the decomposition temperature was 290 ° C.

Example 9 In Example 9, the dye used in Example 2 was similarly formed on a substrate having a groove shape of 0.4 μm in width, 50 nm in depth, and 1.6 μm in TP.
An optical recording medium was manufactured. The groove width / TP is 0.25,
Laser wavelength λ is 788 nm, refractive index n of the substrate is 1.5
Assuming that 5, the groove depth is 39% of (λ / 4n).

For comparison with Examples 1 to 9, the optical recording media of Comparative Examples 1 to 4 were manufactured.

Comparative Example 1 In Comparative Example 1, a phthalocyanine dye having a branched alkoxy group introduced therein (not containing a trifluoromethyl group) shown in Table 1 was used as a recording layer. This compound contains an α-substituted isomer, and its synthesis method is described below.

First, 3- (2-pentyloxy) phthalonitrile is synthesized. A reaction flask was charged with 8.7 g of 3-nitrophthalonitrile, 12 g of 2-pentanol, 26 g of anhydrous potassium carbonate, and 100 ml of dimethyl sulfoxide, and heated to 70 ° C. while stirring under a nitrogen stream.
After stirring at 70 ° C. for 16 hours, the heating was stopped, the reaction solution was cooled, and then poured into 500 ml of water. The precipitated crystals were collected by filtration and dried to obtain 4.4 g of the target compound.

Next, 4.3 g of the above phthalonitrile derivative, 30 ml of 1-pentanol, DBU were placed in a reaction flask.
4.6 g was charged and stirred at 85 ° C. under a nitrogen stream, and 0.57 g of cuprous chloride was charged. After stirring at 95 ° C. for 9 hours, heating was stopped, the reaction solution was poured into 200 ml of methanol, and 20 ml of water was further added. The precipitated crystals were collected by filtration and dried to obtain 1.5 g of a crude product. This crude product is subjected to column chromatography (silica gel / toluene: ethyl acetate =
30: 1) to purify the target compound α, α,
0.84 g of α, α-tetrakis (2-pentyloxy) copper phthalocyanine was obtained.

Using the dye thus obtained, Example 1
In the same manner, a film having a thickness of 150 nm was formed on the substrate by vapor deposition to produce an optical recording medium. The evaporation start temperature of this dye was 180 ° C, and the difference between the evaporation start temperature and the decomposition temperature was 210 ° C.

Comparative Example 2 In Comparative Example 2, a phthalocyanine dye shown in Table 1 in which one fluorine in a trifluoromethyl group was replaced by hydrogen was used as a recording layer. This compound contains an α-substituted isomer, and its synthesis method is described below.

First, 3- (2,2,3,3,4,4,4
5,5-octafluoropentyloxy) phthalonitrile is synthesized. In a reaction flask, 5.2 g of 3-nitrophthalonitrile, 8.4 g of 2,2,3,3,4,4,5,5-octafluoropentanol, and 8.8 g of anhydrous potassium carbonate.
3 g and dimethyl sulfoxide (21 ml) were charged, and the mixture was stirred at 50 ° C. for 5 hours under a nitrogen stream. After stopping the heating, the reaction solution was cooled and poured into water (300 ml).
Drying yielded 8.2 g of the target compound.

Next, 3.6 g of the above phthalonitrile derivative, 20 ml of 1-pentanol, DBU were placed in a reaction flask.
After charging 2.3 g and cuprous chloride 0.28 g, stirring at 100 ° C. for 5 hours while stirring under a nitrogen stream, heating was stopped, the reaction solution was poured into 100 ml of methanol, and 30 ml of water was added dropwise to precipitate crystals. The crystals were collected by filtration and dried to obtain 2.8 g of a crude product. The crude product was purified by column chromatography (silica gel / toluene: ethyl acetate = 40: 1) to obtain α, α, α, α-tetrakis (2,
1.4 g of 2,3,3,4,4,5,5-octafluoropentyloxy) copper phthalocyanine was obtained.

Using the dye thus obtained, Example 1
In the same manner, a film having a thickness of 160 nm was formed on the substrate by vapor deposition to produce an optical recording medium. The evaporation start temperature of this dye was 200 ° C, and the difference between the evaporation start temperature and the decomposition temperature was 270 ° C.

Comparative Example 3 In Comparative Example 3, a phthalocyanine dye shown in Table 1 in which the benzene ring of the phenoxy group was substituted with fluorine was used as the recording layer. This compound contains an α-substituted isomer, and its synthesis method is described below.

First, 3- (pentafluorophenoxy)
Synthesize phthalonitrile. A reaction flask was charged with 3.4 g of 3-nitrophthalonitrile, 4.4 g of pentafluorophenol, 2.8 g of anhydrous potassium carbonate, and 10 ml of dimethyl sulfoxide, and the mixture was stirred at 50 ° C. for 5 hours under a nitrogen stream, and then stopped by heating. After cooling the liquid, 200 ml of water
And the precipitated crystals were collected by filtration and dried to obtain 5.8 g of the target compound.

Next, 5 g of the above phthalonitrile derivative, 30 ml of 1-pentanol, DBU 3.4 were placed in a reaction flask.
g) and 0.5 g of cuprous chloride, and the mixture was stirred at 100 ° C. for 8 hours while stirring under a nitrogen stream. Then, the heating was stopped, the reaction solution was poured into 300 ml of methanol, and the precipitated crystals were collected by filtration and dried. 2 g of crude product were obtained. This crude product was purified by column chromatography (silica gel / tetrahydrofuran) to obtain 1.7 g of the target compound α, α, α, α-tetrakis (pentafluorophenoxy) copper phthalocyanine.

Example 1 was prepared using the thus obtained dye.
In the same manner, an optical recording medium was formed with a thickness of 190 nm by vapor deposition on the substrate. The evaporation start temperature of this dye was 170 ° C, and the difference between the evaporation start temperature and the decomposition temperature was 280 ° C.

Comparative Example 4 In Comparative Example 4, the dye used in Example 1 was similarly formed on a substrate having a groove shape of 0.4 μm in width, 110 nm in depth, and 1.6 μm in TP. A recording medium was manufactured. When the groove width / TP is 0.25, the laser wavelength λ is 788 nm, and the refractive index n of the substrate is 1.55, the groove depth is 86% of (λ / 4n).

Comparative Example 5 In Comparative Example 5, on the substrate of Comparative Example 4, a coating solution prepared by dissolving a solubilized phthalocyanine dye (TX-104A) manufactured by Nippon Shokubai Co., Ltd. in ethyl cellosolve at 3 wt% was used. This was formed on the substrate of Comparative Example 4 to a thickness of 150 nm by a spin coating method, and an optical recording medium was manufactured in the same manner.

Incidentally, the evaporation start temperature is 1 × 10 ⁻⁵ torr.
The dye was heated at the following degree of vacuum, and the temperature of the evaporation source when the value of the quartz oscillation film thickness meter became 0.1 nm / sec was determined. Further, the decomposition temperature was defined as an exothermic temperature of differential scanning calorimetry in a nitrogen gas atmosphere.

The optical recording medium produced as described above was measured for a wavelength of 788 nm using a CD-R tester manufactured by Pulstec.
m at a linear velocity of 1.4 m / sec.
The 1T output was measured. Also, the signal waveform distortion at 11T was observed, and those with large waveform distortion were evaluated as (x), those with small distortion (△), and those with almost no distortion (○). Further, as a light fastness test, a xenon long life fade meter manufactured by Suga Test Instruments Co., Ltd.
If there is almost no characteristic deterioration after 0 hour irradiation (○),
Those with large deterioration were evaluated as (x). The result

[0092]

[Table 2]

Shown in FIG. From Table 2, as is clear from the comparison between Comparative Examples 1 to 3 and 5 having no trifluoromethyl group and Examples 1 to 9, the recording power was reduced by having the trifluoromethyl group, The output of 11T is high, the waveform distortion is improved, and stable characteristics can be obtained. In this embodiment, the phthalocyanine-based dye having a divalent metal center has a higher output and a greater effect of improving waveform distortion than the non-metallic one (Example 3). , Cu, Zn, and Ni have a good balance of properties. Also, as the number of trifluoromethyl groups increases (Examples 1 to 8), the recording power tends to decrease, and the output gradually increases. It became clear that it was effective for improvement of the quality.

The groove depth of the substrate is (λ)
/ 4n) exceeds 80% (Comparative Example 4), the reflectivity decreased, tracking could not be achieved, and recording could not be performed.

Further, in light resistance, all of the examples were superior to those using the solubilized phthalocyanine (Comparative Example 5), and high reliability was obtained.

[0096]

As described above, the optical recording medium of the present invention is an optical recording medium in which a recording layer that transmits and absorbs laser light, a reflective layer, and a protective layer are sequentially formed on a substrate. Is formed by a vapor deposition method, and as a constituent material, a phthalocyanine dye having at least one trifluoromethyl group at the terminal of the molecular structure and having a sublimation property is used, so that the recording power is low and the length is 11T or the like. Even with pits, an optical recording medium having high output, small waveform distortion, good recording sensitivity, and excellent light resistance can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the configuration of an optical recording medium according to an embodiment of the present invention;

[Description of Signs] 1 Substrate 2 Recording layer 3 Reflective layer 4 Protective layer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomiji Hosaka 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Toshiaki Kunieda 1006 Kadoma Kadoma Kadoma City, Osaka Matsushita Electric Industrial Co. 72) Inventor Katsuyuki Takahashi 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Inventor Toshiro Narizuka 1-1, Kamitobagamichocho-cho, Minami-ku, Kyoto-shi, Kyoto, Japan Inside Yamada Chemical Industry Co., Ltd. (72) Inventor Kodan Tomita 1-1-1, Kamitobakamicho-cho, Minami-ku, Kyoto, Kyoto Prefecture Yamada Chemical Industry Co., Ltd. (72) Inventor Kyoto-shi, Kyoto Minami-ku, Kamitobakamichoshi-cho, address 1 Yoshiharu Numa 1 Yamada Chemical Industry Co., Ltd. in

Claims (4)

[Claims] 1. An optical recording medium comprising a recording layer that transmits and absorbs a laser beam, a reflective layer, and a protective layer sequentially formed on a substrate, wherein the recording layer is formed by a vapor deposition method. As a material constituting: An optical recording medium comprising at least one phthalocyanine dye selected from the compounds shown in (1) and having sublimability. In the chemical formula 1, the substituents X _{1 to} X ₁₆ are, for example, a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted An aryl group of
It may have a substituted or unsubstituted aryloxy group, a substituted or unsubstituted arylthio group, a nitro group, an amino group, etc., independently of each other. In at least one or more of X _{1 to} X ₁₆ , Has at least one trifluoromethyl group at the terminal. M represents two hydrogen atoms, a divalent metal atom, a trivalent or tetravalent metal derivative, and has a trifluoromethyl group at a terminal of a substituent introduced into a trivalent or tetravalent metal. You may. ] 2. The optical recording according to claim 1, wherein the phthalocyanine dye has an evaporation or sublimation onset temperature of 100 to 350 ° C., and a difference between the evaporation or sublimation onset temperature and the decomposition temperature is 50 to 400 ° C. Medium. 3. The optical recording medium according to claim 1, wherein the central metal contained in the phthalocyanine dye is a divalent metal and is Co, Cu, Zn, Ni, or Pd. 4. A spiral groove is provided on a substrate, and the groove shape is defined as a ratio between a groove width and a track pitch (hereinafter, referred to as TP), a laser wavelength λ, and a refractive index n of the substrate. The groove depths at the time are respectively in the following ranges.
Or the optical recording medium according to 3. Groove width / TP: 0.25 to 0.45 Groove depth: 20 to 80% of (λ / 4n)