JPH10273603A - Phthalocyanine derivative and optical recording medium using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a novel derivative that has a specific acetylenic bond, storing against light such as sunlight, has high solubility in solvents, can readily form a recording layer by coating and give an optical recording medium of high recording sensitivity. SOLUTION: This compound is represented by formula I [M is two hydrogen atoms, a divalent metallic atom or a trivalent or tetravalent metal derivative; R<1> -R<4> are each a (substituted) alkyl, an aryl, cycloalkyl], typically tetra(3,3- dimethyl-1-butynyl)phthalocyanine. The objective compound is prepared, for example, by reducing nitrophthalonitrile of formula II, diazotizing, allowing to react with an acetylene compound and heating the resultant compound of formula III together with a metal compound in a solvent such as quinoline at 150-250 deg.C for 1-5 hours.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel phthalocyanine derivative and an optical recording medium using the same.

[0002]

2. Description of the Related Art An optical recording medium using a laser, particularly a semiconductor laser, is capable of recording, storing and reproducing information at a high density. An example of such an optical recording medium is an optical disk. In general, an optical disc performs high-density information recording by irradiating a thin recording layer provided on a circular base with a laser beam converged to about 1 μm.

[0003] Among optical disks, a writable compact disk (CD W) has recently attracted particular attention.
write Once). The user can record music and information only once using a recording device, and the recorded music and information can be reproduced using an existing CD player or CD ROM drive. It is possible.

This disc usually has a structure in which a recording layer mainly composed of a dye, a metal reflective film and a protective film are sequentially laminated on a plastic substrate having a guide groove. Recording of information is performed by irradiating a laser beam (usually 780 nm in wavelength) to cause a thermal change such as decomposition, evaporation, or melting in a recording layer, a reflective layer, or a substrate at the irradiated location. The reproduction of the information thus performed is performed by reading the difference in the reflectance between the portion where the change has occurred by the laser beam and the portion where the change has not occurred.

Therefore, as a recording medium, the recording sensitivity to the laser beam used for recording is high, and the reflectance for the laser beam used for reproduction is low in the recording section.
It is important that it is high in the unrecorded part. In order to perform reproduction with a compact disc player, it is necessary that the reflectance of the unrecorded portion with respect to the laser beam (normally 780 nm) used for reproduction is 65% or more and the reflectance of the recorded portion is 45% or less.

As a dye used in the recording layer of such a CD write once, a cyanine dye has been conventionally proposed. However, a dye using a cyanine dye has a disadvantage that it is weak to sunlight and other light. I was As an optical recording medium using another dye, a medium using a squarylium dye, a naphthoquinone dye, a phthalocyanine dye, a naphthalocyanine dye, or the like has been proposed.

Of the above dyes, phthalocyanine dyes and naphthalocyanine dyes are generally preferred because of their excellent weather resistance, but those having no substituent on the benzene ring or naphthalene ring have extremely high solubility in solvents. Due to the low temperature, there is a problem that a recording layer cannot be formed by coating. On the other hand, Japanese Patent Application No. 6-08174
No. 2 proposes to introduce a tetrahydrofurfuryloxy group or the like into a benzene ring in a phthalocyanine dye. However, these phthalocyanine derivatives have a problem that the recording sensitivity is not so high when used as a dye for a recording layer of CD Write Once.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object the purpose of being resistant to light such as sunlight, having high solubility in a solvent, and easily forming a recording layer by coating. An object of the present invention is to provide a novel phthalocyanine derivative. Another object of the present invention is to provide an optical recording medium having high recording sensitivity using the phthalocyanine derivative.

[0009]

The phthalocyanine derivative according to the present invention is characterized by having an acetylene bond represented by the general formula [I].

[0010]

Embedded image

Wherein M represents two hydrogen atoms, a divalent metal atom or a derivative of a trivalent or tetravalent metal;
¹ , R ² , R ³ and R ⁴ each independently represent an optionally substituted alkyl group, aryl group or cycloalkyl group, and rings A, B, C and D each independently represent Further, it may have a substituent. )

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail. In the above general formula [I] representing the phthalocyanine derivative according to the present invention, R ^{1 to} R ⁴ represent a methyl group,
Ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, sec-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-decyl group , N-dodecyl group, n-octadecyl group and the like, a linear or branched alkyl group having 1 to 20 carbon atoms, preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms An aryl group having 6 to 12 carbon atoms such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group; And 10 cycloalkyl groups. Substituents bonded to R ^{1 to} R ⁴ include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, tert-butoxy, sec-butoxy, n-pentyloxy, n- -Hexyloxy group, n-heptyloxy group, n
-1 carbon atom such as octyloxy group, n-decyloxy group, etc.
10 to 10 alkoxy groups; 2 carbon atoms such as methoxymethoxy, ethoxymethoxy, propoxymethoxy, methoxyethoxy, ethoxyethoxy, propoxyethoxy, methoxypropoxy, ethoxypropoxy, methoxybutoxy, ethoxybutoxy, etc. ~ 12 alkoxyalkoxy groups; methoxymethoxymethoxy groups,
A C3-15 alkoxyalkoxyalkoxy group such as a methoxymethoxyethoxy group, a methoxyethoxymethoxy group, a methoxyethoxyethoxy group, an ethoxymethoxymethoxy group, an ethoxymethoxyethoxy group, an ethoxyethoxymethoxy group, an ethoxyethoxyethoxy group; an allyloxy group; C6-C12 aryl groups such as phenyl, tolyl, xylyl and naphthyl; C6-C12 aryloxy such as phenoxy, tolyloxy, xylyloxy and naphthyloxy; cyano; nitro Groups; hydroxy groups; tetrahydrofuryl groups;
Methylsulfonylamino group, ethylsulfonylamino group, n-propylsulfonylamino group, isopropylsulfonylamino group, n-butylsulfonylamino group, t
tert-butylsulfonylamino group, sec-butylsulfonylamino group, n-pentylsulfonylamino group,
an alkylsulfonylamino group having 1 to 6 carbon atoms such as an n-hexylsulfonylamino group; a halogen atom such as a fluorine atom, a chlorine atom and a bromine atom; a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group and an isopropoxycarbonyl group , N-butoxycarbonyl group,
C2-C7 alkoxycarbonyl groups such as tert-butoxycarbonyl group, sec-butoxycarbonyl group, n-pentyloxycarbonyl group, n-hexyloxycarbonyl group; methylcarbonyloxy group, ethylcarbonyloxy group, n-propyl Carbonyloxy group,
Isopropylcarbonyloxy group, n-butylcarbonyloxy group, tert-butylcarbonyloxy group, s
an alkylcarbonyloxy group having 2 to 7 carbon atoms such as an ec-butylcarbonyloxy group, an n-pentylcarbonyloxy group, an n-hexylcarbonyloxy group; a methoxycarbonyloxy group, an ethoxycarbonyloxy group, an n-
Propoxycarbonyloxy group, isopropoxycarbonyloxy group, n-butoxycarbonyloxy group, te
Examples thereof include an alkoxycarbonyloxy group having 2 to 7 carbon atoms such as an rt-butoxycarbonyloxy group, a sec-butoxycarbonyloxy group, an n-pentyloxycarbonyloxy group, and an n-hexyloxycarbonyloxy group.

As the divalent metal atom represented by M,
Cu, Ni, Co, Zn, Fe, Mn, Mg, Pd, R
u, Pt, Rh, Ca, Ba, Cd, Hg, Pb, S
n, Ti, Be, Cr and the like. Trivalent metal atom
Derivatives of AlF, AlCl, AlBr, Al
I, GaF, GaCl, GaBr, GaI, InF, I
nCl, InBr, InI, TlF, TlCl, TlB
two valences of trivalent metal atoms such as r and TlI remain
Are included. As a derivative of a tetravalent metal atom
The SiF_Two, SiCl_Two, SiBr_Two, SiI_Two,
GeF_Two, GeCl_Two, GeBr_Two, GeI_Two, SnF
_Two, SnCl_Two, SnBr_Two, SnI_Two, TiF_Two, T
iCl_Two, TiBr_Two, TiI_Two, ZrCl_Two, HfC
l_Two, Si (OH)_Two, Ge (OH)_Two, Sn (OH)
_Two, Zr (OH)_Two, Hf (OH) _Two, SiR_Two, Ge
R_Two, SnR_Two, TiR_Two(Even if R has a substituent,
Represents a good alkyl or aryl group. ), Si (O
R ')_Two, Ge (OR ')_Two, Sn (OR ')_Two, Ti
(OR ')_Two(R ′ is an optionally substituted alkyl
Group, aryl group, acyl group, trialkylsilyloxy
Represents a cy group or the like. ), Two sources of tetravalent metal atoms
Those whose child price remains are mentioned. VO, T
Metal oxides such as iO and PbO are also included. Especially preferred
Metal atoms or derivatives of metal atoms are Pd, Cu, Ni,
Pb, SnCl_Two, Si (OR ')_Two, AlCl, V
O and TiO.

The substituents on the rings A, B, C and D include an alkyl group, an alkoxy group, an alkylthio group, an arylthio group, an aryloxy group, an aralkyl group, an aryl group,
A halogen atom, a cyano group, a nitro group, an ester group, a carbamoyl group, an acyl group, an acylamino group, a sulfamoyl group, a sulfinic acid group, an amino group, a hydroxyl group, a phenylazo group, a pyridinoazo group, and a vinyl group. The group may further have a substituent.
Among these substituents, preferred are a hydroxyl group, a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 25 carbon atoms which may have a substituent, and an alkoxy group having 1 to 25 carbon atoms. Group, an alkylthio group having 1 to 25 carbon atoms, an arylthio group having 6 to 30 carbon atoms, 1 carbon atom
-25-alkylsulfamoyl group, C6-C30 phenylsulfamoyl group, C1-C25 alkylsulfinic acid group, C6-C30 phenylsulfinic acid group, C6-C30 pyridinoazo Group, having 2 to 2 carbon atoms
6, an ester group having 6 carbon atoms, an alkylcarbamoyl group having 2 to 26 carbon atoms, a phenylcarbamoyl group having 6 to 30 carbon atoms, an acyl group having 2 to 26 carbon atoms, or an acylamino group having 1 to 25 carbon atoms. Also, -NR ⁵ R ⁶ (R ⁵
And R ⁶ each independently represent a hydrogen atom or an optionally substituted alkyl group having 1 to 25 carbon atoms or a phenyl group, and R ⁵ and R ⁶ are bonded to each other to form a 5-membered ring or A 6-membered ring may be formed. ^{), - CR 7 = C (} C
N) R ⁸ (R ⁷ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ⁸ represents a cyano group or an alkoxycarbonyl group having 2 to 7 carbon atoms). More preferred are an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, and a halogen atom.

Each of the phthalocyanine derivatives of the present invention has an absorption in the near infrared region around 600 to 800 nm,
It has good light fastness and heat resistance, and is very useful as a light absorbing material for an optical recording medium as described later. Among them, phthalocyanine derivatives represented by the following general formula [II] are particularly preferred.

[0016]

Embedded image

(In the formula, M represents a derivative of two hydrogen atoms, a divalent metal atom or a trivalent or tetravalent metal.) The phthalocyanine derivative according to the present invention is produced, for example, as follows. be able to.

[0018]

Embedded image

Nitrophthalonitrile (I) is reduced to aminophthalonitrile (II), which is diazotized to iodophthalonitrile (III). When an acetylene compound is reacted therewith, phthalonitrile (IV) to which the acetylene compound is bonded is obtained. The synthesis of iodophthalonitrile (III) is described in C.I. C. Leznoff
et al; Can. J. Chem. , 73,435
(1995) and S.M. W. Marcuccio; Can.
J. Chem. , 63, 3057 (1985). This phthalonitrile (IV) is mixed with a metal compound in a quinoline or chloronaphthalene solvent for 150 minutes.
Heat to ~ 250 ° C for about 1-5 hours or 1,8-
N-pentanol, n with a basic catalyst such as diazabicyclo [5.4.0] -7-undecene or lithium
70- in high boiling alcohols such as hexanol
When heated to 120 ° C. for about 1 to 20 hours, the phthalocyanine derivative (V) according to the present invention is obtained.

The metal compounds used in the process of converting phthalonitrile (IV) to phthalocyanine derivative (V) include I
Group B, IIA, IIB, IIIA, IVA, IVB, V
Group B, VIB group, various kinds of VIII group can be used, but from the viewpoint of ease of synthesis and performance of the obtained compound, copper, magnesium, zinc, titanium, aluminum,
Oxides such as indium, tin, lead, vanadium, chromium, iron, cobalt, nickel, ruthenium, palladium,
Preferred are halides, acetates and the like, magnesium,
Zinc and copper halides are particularly preferred.

The optical recording medium according to the present invention basically comprises a substrate and a recording layer containing the above-mentioned phthalocyanine derivative. Further, if necessary, an undercoat layer and a recording layer may be further formed on the substrate. A reflective layer and / or a protective layer can be provided thereon. The substrate may be either transparent or opaque to the laser light used. As the material of the substrate, glass, plastic, paper, plate-like or foil-like metal, etc., which are generally used as a support for this type of recording medium can be used, but plastics are preferable in various respects. . As plastics, for example, acrylic resin, methacrylic resin, vinyl acetate resin,
Examples thereof include vinyl chloride resin, nitrocellulose, polyethylene resin, polypropylene resin, polycarbonate resin, polyimide resin, and polysulfone resin.

The thickness of the recording layer containing the phthalocyanine derivative represented by the general formula (I), which is the information recording layer in the optical recording medium of the present invention, is 100 to 5 μm, preferably 500 to 3 μm. The recording layer is preferably formed by coating. That is, the phthalocyanine derivative is
A coating solution dissolved or dispersed in a solvent or a mixture of a solvent and a binder may be applied to a substrate by a conventional coating method such as spin coating or spray coating. As the binder, a polyimide resin, a polyamide resin, a polystyrene resin, an acrylic resin, a polyester resin, a polycarbonate resin, a cellulose resin, or the like can be used.

The ratio of the phthalocyanine derivative to these resins is preferably at least 10% by weight. As the solvent, dimethylformamide, methyl ethyl ketone,
Various substances such as methyl cellosolve, ethyl alcohol, tetrahydrofuran, dichloromethane, and chlorobenzene can be used. When using a polycarbonate resin substrate or a methacrylic resin substrate manufactured by injection molding as the substrate, as the solvent,
Preferred are ethyl cellosolve, ethyl alcohol, octafluoropentanol, hexafluorobutanol, ethylcyclohexane, n-butylcyclohexane, t-butylcyclohexane and the like. The recording layer of the optical recording medium of the present invention may be provided on both sides of the substrate, or may be provided only on one side.

The recording on the optical recording medium is performed by irradiating a recording layer provided on both sides or one side of the substrate with a laser beam, preferably a semiconductor laser beam, converged to about 1 μm. Thermal deformation of the recording layer such as decomposition, evaporation, and melting occurs due to absorption of laser energy in the portion irradiated with the laser beam. Reproduction of recorded information is performed by reading the difference in reflectance between a portion where thermal deformation has occurred and a portion where thermal deformation has not occurred using a laser beam.

As the light source, various lasers such as a He-Ne laser, an argon laser and a semiconductor laser can be used, but a semiconductor laser is particularly preferable in terms of price and size. As the semiconductor laser, one having a center wavelength of 830 nm or 780 nm is usually used, but a laser having a wavelength shorter than 780 nm can also be used. The phthalocyanine derivative of the general formula (I) according to the present invention may be used for coloring various materials such as plastic and paper, dyeing various fibers, coloring optical filters, and the like.
It can also be used for applications other than optical recording media.

[0026]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. “%” Is “% by weight” unless otherwise specified. Example 1 Synthesis of 3-aminophthalonitrile; 150 m of ethanol
To each l., 5.19 g (30 mmol) of 3-nitrophthalonitrile and a palladium catalyst (10% Pd /
C) About 0.55 g was added and the mixture was heated at 22 ° C. under atmospheric pressure for 72 hours
Reduced. The product was purified by silica gel column chromatography to give white 3-aminophthalonitrile 3.0.
g (70% yield). Its melting point is about 200 ° C
Met.

Synthesis of 3-iodophthalonitrile; 60 m
To 1 l of concentrated hydrochloric acid, 3.0 g (21 mmol) of 3-aminophthalonitrile was added, and the mixture was stirred at 0 ° C. for 10 minutes. To this, 2.2 g (31.5 mmol) of sodium nitrite solution was added dropwise so that the solution temperature did not rise to 0 ° C or higher. Continue 0
After stirring at 1.5 ° C. for 1.5 hours, the mixture was quickly filtered by suction. 30 ml of an aqueous solution containing 3.8 g (31.5 mmol) of potassium iodide was added dropwise to the filtrate, and the mixture was stirred and cooled to room temperature. A black precipitate was obtained by filtration, washed with cold water, and dissolved in benzene. The benzene solution was washed successively with cold water, a 5% aqueous solution of sodium hydrogen carbonate, cold water, a saturated aqueous solution of sodium thiosulfate and cold water, and then dried over magnesium sulfate. The solution was concentrated and purified by silica gel column chromatography. Then, crystallization was performed to obtain 2.7 g (yield: 50.5%) of white crystals of 3-iodophthalonitrile having a melting point of 169 ° C.

3- (3,3-dimethyl-1-butynyl)
Synthesis of phthalonitrile; 1.8 g (7.1 mmol) of 3-iodophthalonitrile, 0.64 g (7.9 mmol) of t in 50 ml of freshly distilled diethylamine
-Butyl acetylene, 0.14 g (0.071 mmol) of cuprous iodide and 0.1 g (0.16 mmol)
(Triphenylphosphine) palladium dichloride was added, and the mixture was stirred at room temperature for 72 hours under a nitrogen stream. During this time,
While checking the progress of the reaction about every 12 hours by thin-layer chromatography, t-butylacetylene, cuprous iodide and (triphenylphosphine) palladium dichloride were added little by little as needed. Filter and wash the filter cake with benzene. The filtrate and the washing solution were combined, concentrated, and purified by silica gel column chromatography. Then, it was crystallized to obtain 1.12 g of white crystals of 3- (3,3-dimethyl-1-butynyl) phthalonitrile having a melting point of 61 ° C (yield: 75.
9%).

Synthesis of tetra (3,3-dimethyl-1-butynyl) phthalocyanine; 3 mg of lithium was added to 0.5 ml of anhydrous pentanol and dissolved by heating.
To this was added 19.6 mg (0.1 mmol) of 3- (3,3-dimethyl-1-butynyl) phthalonitrile, and the mixture was refluxed for 2 hours. After cooling, a solution of methanol and one drop of concentrated hydrochloric acid was added thereto, and the resulting blue precipitate was collected by filtration. After drying, this was dissolved in a chloroform solvent, purified by a silica gel column, and then recrystallized to obtain 9.5 mg (yield: 48%) of the following tetra (3,3-dimethyl-1-butynyl) phthalocyanine. The λmax thereof in a chloroform solution was 714 nm, and the molecular extinction coefficient was 15.9 × 10 ⁴ . FIG. 1 shows the absorption spectrum of the chloroform solution.

[0030]

Embedded image

Example 2 To 40 ml of α-chloronaphthalene were added 0.78 g of vanadium trichloride, 0.2 g of ammonium molybdate and 4.6 g of 3- (3,3-dimethyl-1-butynyl) phthalonitrile, and the mixture was added with 180 g of Stirred at ~ 200 ° C for 4 hours. After allowing to cool, 30 ml of n-hexane was added thereto, followed by filtration to obtain 3.2 g of blue filter cake. This was dissolved in 30 ml of chloroform and subjected to silica gel column chromatography (filler: Wakogel C-200 (manufactured by Wako Pure Chemical Industries, Ltd.),
(Developing solvent; chloroform-methanol mixed system), followed by crystallization to obtain 2.7 g of a blue substance. It is considered that this is not a pure product but contains isomers, and a typical structure thereof is considered as follows. The λmax of this product in a chloroform solution was 718 nm,
The molecular extinction coefficient was 19.2 × 10 ⁴ . FIG. 2 shows the absorption spectrum in this chloroform solution.

[0032]

Embedded image

Example 3 A reaction and purification were carried out in the same manner as in Example 2 except that anhydrous cuprous chloride was used instead of vanadium trichloride to obtain a phthalocyanine having the following structure. Its λmax in a chloroform solution was 690 nm, and the molecular extinction coefficient was 18.5 × 10 ⁴ .

[0034]

Embedded image

Examples 4 to 15 According to the method of Example 2, phthalocyanine derivatives having the following structures were synthesized. Table 1 shows λmax and molecular extinction coefficient of each phthalocyanine derivative in a chloroform solution.
Shown in

[0036]

[Table 1]

[0037]

[Table 2]

Examples 16 to 19 According to the method of Example 2, phthalocyanine derivatives having the following structures were synthesized. Table 2 shows λmax and the molecular extinction coefficient of each phthalocyanine derivative in a chloroform solution.

[0039]

[Table 3]

Example 20 A 1.5% solution of the phthalocyanine derivative obtained in Example 2 in hexafluorobutanol was prepared, and the solution was spin-coated (at 500 rpm) to obtain a solution having a diameter of 12%.
It was applied on a polycarbonate substrate having a thickness of 0 mm and a thickness of 1.2 mm. An optical recording medium was manufactured by depositing gold on the dye thin film to form a reflective layer, and further providing a protective layer of an ultraviolet curable resin thereon. The reflectance at 775 nm of the unrecorded portion of the obtained optical recording medium was 70%.

While rotating the optical recording medium at a linear velocity of 1.2 m / s, a semiconductor laser beam having a center wavelength of 775 nm was irradiated at an output of 9.4 mW to record an EFM signal.
Next, when the recorded portion was reproduced by a CD player having a semiconductor laser having a center wavelength of 780 nm, a good reproduced signal was obtained. In addition, light resistance (xenon fade meter acceleration test; 60 hours) and storage stability (70 ° C., 8 hours)
(5% RH; 100 hours) As a result of the test, the sensitivity and the reproduction signal were not deteriorated as compared with the initial stage, and the optical recording medium was extremely excellent.

Example 21 2.5% t of the phthalocyanine derivative obtained in Example 7
-Butylcyclohexane solution was prepared, and using this, an optical recording medium was manufactured under the same conditions as in Example 20. The reflectance of the unrecorded portion of the obtained optical recording medium at 775 nm was 68%. This optical recording medium was converted to a linear velocity of 1.2 m /
While rotating at s, a semiconductor laser beam having a center wavelength of 775 nm was irradiated at an output of 7.8 mW, and an EFM signal was recorded. Next, when the recorded portion was reproduced by a CD player having a semiconductor laser having a center wavelength of 780 nm, a good reproduced signal was obtained. In addition, light resistance (xenon fade meter acceleration test; 60 hours) and storage stability (70 hours)
(° C., 85% RH; 100 hours) As a result of the test, the sensitivity and the reproduction signal were not deteriorated as compared with the initial stage, and the optical recording medium was extremely excellent.

[0043]

The novel phthalocyanine derivative of the present invention has strong absorption in the visible to near-infrared region around 600 to 800 nm, has good light resistance and heat resistance, and changes in the absorption wavelength due to heating. And it is easy to apply to a plastic substrate. Further, the optical recording medium of the present invention using this phthalocyanine derivative has excellent light resistance and heat resistance, and also has good recording sensitivity and recording / reproducing characteristics.

[Brief description of the drawings]

FIG. 1 is an absorption spectrum of a phthalocyanine derivative synthesized in Example 1 in a chloroform solution.

FIG. 2 is an absorption spectrum of a phthalocyanine derivative synthesized in Example 2 in a chloroform solution.

Claims (3)

[Claims] 1. A phthalocyanine derivative represented by the following general formula [I]. Embedded image (Wherein, M represents a hydrogen atom, a divalent metal atom or a derivative of a trivalent or tetravalent metal, and R ¹ , R ² , R
³ and R ⁴ each independently represent an optionally substituted alkyl group, aryl group or cycloalkyl group, and rings A, B, C and D each independently have a further substituent May be. ) 2. A phthalocyanine derivative represented by the following general formula [II]. Embedded image (In the formula, M represents a hydrogen atom, a divalent metal atom, or a derivative of a trivalent or tetravalent metal.) 3. An optical recording medium having a recording layer containing the phthalocyanine derivative according to claim 1 on a substrate.