JPH08905B2 - Phthalocyanine near infrared absorber and optical recording medium using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a phthalocyanine near-infrared absorber having a maximum absorption wavelength (λ _max ) at 650 to 750 nm and an optical disk (WORM, CD-WORM, phase change) containing the same in a recording layer. Rewriting disc) and an optical recording medium such as an optical card.

[0002]

2. Description of the Related Art A technique for utilizing a phthalocyanine dye, particularly an alkoxy-substituted phthalocyanine, in a recording layer of an optical recording medium such as an optical disk or an optical card is disclosed in JP-A-61-154.
888 publication (EP 186404), 61-197.
No. 280, No. 61-246091, No. 62-
39,286 No. (USP 4,769,307), the 63-37991 and JP are disclosed in, for example, the 63-39 3 88 JP.

[0003]

However, the compounds disclosed in the above publications have sufficient sensitivity, reflection characteristics and recording characteristics when an optical recording medium is manufactured. It was hard to say.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found a near infrared absorbent represented by the following formulas (I) to (IV).

That is, the present invention is of the formula (I)

[0006]

[Chemical 5] Or formula (II)

[0007]

[Chemical 6] Or formula (III)

[0008]

[Chemical 7] Or formula (IV)

[0009]

Embedded image [In Formulas (I), (II), (III) and (IV), Y
¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ , Y ⁶ , Y ⁷ , Y ⁸ , Y ⁹ , Y ¹⁰ ,
Y ¹¹ , Y ¹² , Y ¹³ , Y ¹⁴ , Y ¹⁵ and Y ¹⁶ each independently represent an alkoxy group or an alkylthio group, and group A: R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ ,
R ⁹ , R ¹⁰ , R ¹¹ and R ¹² group B: R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R
²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ group C: R ²⁵ , R ²⁶ , R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , R ³¹ , R ^31
32 , R ³³ , R ³⁴ , R ³⁵ and R ³⁶ group D: R ³⁷ , R ³⁸ , R ³⁹ , R ⁴⁰ , R ⁴¹ , R ⁴² , R ⁴³ , R
⁴⁴ , R ⁴⁵ , R ⁴⁶ , R ⁴⁷ and R ^{48 In} each group of the above groups A to D, the substituents R ³ , R ^{6 of the} group A ,
At least one of R ⁹ and R ¹² , a substituent of group B R ¹⁵ ,
At least one of R ¹⁸ , R ¹⁹ , and R ²² , a substituent of group C
At least one of R ²⁷ , R ²⁸ , R ³³ and R ^34, of group D
At least one of the substituents R ³⁹ , R ⁴² , R ⁴⁵ and R ⁴⁶ is
Represents a halogen atom, the other substituents are each independently
Represents a hydrogen atom, a halogen atom, a nitro group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group
You. However, in each group of A to D, the halogen atom is replaced
The maximum number possible is 8. Met has 2 hydrogen atoms, 2
A valent metal atom represents a trivalent or tetravalent metal derivative. ]
The near-infrared absorber which is a phthalocyanine and its tautomer represented by is excellent in producing an optical recording medium (large molar absorption coefficient, solvent solubility, large refractive index when formed into a thin film, optical recording Found to have sensitivity, reflectance, recording characteristics and durability when used as a medium,
The present invention has been completed.

Particularly, the alkoxy group or alkylthio group represented by Y ^{1 to} Y ¹⁶ is a secondary or tertiary hydrocarbon having a sum of the number of carbon atoms, oxygen atoms and sulfur atoms of 5 to 12. It is preferable.

The central metal represented by Met is Pd,
Cu, Ru, Pt, Ni, Co, Rh, Zn, VO, T
iO, Si (Y) ₂ , Sn (Y) ₂ , Ge (Y) ₂ (Y is a halogen atom, an alkoxy group, an aryloxy group, an acyloxy group, a hydroxy group, an alkyl group, an aryl group,
An alkylthio group, an arylthio group, a trialkylsilyloxy group, a trialkyltinoxy group or a trialkylgermaniumoxy group) is particularly preferable.

Formulas (I), (II), (III) and (IV)
Among them, the halogen atom represented by R ^{1 to} R ⁴⁸ is fluorine, chlorine, bromine or iodine, and particularly preferably bromine. As the substituted or unsubstituted alkyl group, a linear or branched alkyl group, aralkyl group, alkenyl group, alkoxyalkyl group, alkoxyalkoxyalkyl group, alkoxyalkoxyalkoxyalkyl group, alkoxycarbonylalkyl group, alkoxycarbonyloxyalkyl group, Linear or branched selected from the group of alkoxyalkoxycarbonyloxyalkyl groups, hydroxyalkyl groups, hydroxyalkoxyalkyl groups, hydroxyalkoxyalkoxyalkyl groups, acyloxyalkyl groups, acyloxyalkoxyalkyl groups, acyloxyalkoxyalkoxyalkyl groups and halogenated alkyl groups. Examples of the alkyl group of have 1 carbon atoms
~ 20 hydrocarbon groups, considering the processability by coating on polycarbonate substrate, 2P substrate, acrylic substrate, epoxy substrate, etc., methyl group, ethyl group, n-propyl group,
n-butyl group, n-hexyl group, 4-ethylpentyl group, 2-ethylhexyl group, 3,5,5-trimethylhexyl group, n-octyl group, 2-methyl-1-iso-propylbutyl group, 3- Methyl-
Examples thereof include 1-iso-butylbutyl group.

The alkoxyalkyl group includes methoxymethyl group, ethoxymethyl group, propoxymethyl group, butoxymethyl group, methoxyethyl group, ethoxyethyl group, propoxyethyl group, butoxyethyl group, n-hexyloxyethyl group, 4- Ethyl pentoxyethyl group, 1,3-
Dimethylbutoxyethyl group, 2-ethylhexyloxyethyl group, n-octyloxyethyl group, 3,3,5-trimethylhexyloxyethyl group, 2-methyl-1-iso-propyloxyethyl group, 3-methyl-1- Examples thereof include alkoxyalkyl groups having a total carbon number of 2 to 20, such as iso-propylbutyloxyethyl group, 2-ethoxy-1-methylethyl group and 3-methoxybutyl group.

Examples of alkoxyalkoxyalkyl groups include methoxyethoxyethyl group, ethoxyethoxyethyl group, propoxyethoxyethyl group, butoxyethoxyethyl group, hexyloxyethoxyethyl group, 1,2-dimethylpropoxyethoxyethyl group, 3-methyl- 1-iso-butylbutoxyethoxyethyl group, 2-methoxy-1-methylethoxyethyl group, 2-butoxy-1-methylethoxyethyl group, 2- (2'-ethoxy-1'-methylethoxy) -1-methyl Examples thereof include an ethyl group.

Alkoxyalkoxyalkoxyalkyl groups include methoxyethoxyethoxyethyl group, ethoxyethoxyethoxyethyl group, butoxyethoxyethoxyethyl group, 2 '-(2 "-ethoxy-1" -methylethoxy).
-1'-methylethoxyethyl group and the like.

Examples of the alkoxycarbonylalkyl group include methoxycarbonylmethyl group, ethoxycarbonylmethyl group, butoxycarbonylmethyl group, methoxycarbonylethyl group, ethoxycarbonylethyl group, butoxycarbonylethyl group and the like.

Examples of the alkoxycarbonyloxyalkyl group include methoxycarbonyloxyethyl group, ethoxycarbonyloxyethyl group, butoxycarbonyloxyethyl group and the like.

Examples of the alkoxyalkoxycarbonyloxyalkyl group include a methoxyethoxycarbonyloxyethyl group, an ethoxyethoxycarbonyloxyethyl group and a butoxyethoxycarbonyloxyethyl group.

Examples of the hydroxyalkyl group are 2-hydroxyethyl group, 4-hydroxybutyl group, 2-hydroxy-3-methoxypropyl group, 2-hydroxy-3-chloropropyl group, 2-hydroxy-3-ethoxy group. Examples thereof include a propyl group, a 3-butoxy-2-hydroxypropyl group, a 2-hydroxy-3-phenoxypropyl group, a 2-hydroxypropyl group and a 2-hydroxybutyl group.

Examples of the hydroxyalkoxyalkyl group include hydroxyethoxyethyl group and 2- (2'-hydroxy group.
-1'-methylethoxy) -1-methylethyl group and the like, and examples of the hydroxyalkoxyalkoxyalkyl group include a hydroxyethoxyethoxyethyl group and [2'-
(2 ″ -hydroxy-1 ″ -methylethoxy) -1′-methylethoxy] ethoxyethyl group and the like.

Examples of the acyloxyalkyl group are acetoxyethyl group, propionyloxyethyl group, butyryloxyethyl group, valeryloxyethyl group, 1-ethylpentylcarbonyloxyethyl group and 2,4,4-trimethylpentylcarbonyl group. Oxyethyl group and the like,
Examples of the acyloxyalkoxyalkyl group include acetoxyethoxyethyl group, propionyloxyethoxyethyl group, valeryloxyethoxyethyl group, 1-ethylpentylcarbonyloxyethoxyethyl group, 2,4,4-trimethylpentylcarbonyloxyethoxyethyl group. And the like, and examples of the acyloxyalkoxyalkoxyalkyl group include an acetoxyethoxyethoxyethyl group, a propionyloxyethoxyethoxyethyl group,
Examples thereof include a valeryloxyethoxyethoxyethyl group and a 1-ethylpentylcarbonyloxyethoxyethoxyethyl group.

Examples of the halogenated alkyl group include a chloromethyl group, a chloroethyl group, a 2,2,2-trifluoroethyl group, a trifluoromethyl group, a bromomethyl group and an ethyl iodide group.

Examples of the substituted or unsubstituted aryl group include substituted or unsubstituted phenyl group derivatives such as phenyl group, naphthyl group and tolyl group, naphthyl group derivatives, thiophene, oxazole, thiazole, thiadiazole,
Substituted or unsubstituted heterocycles such as furan, pyrrole, quinoline, pyridine are included.

Examples of the alkoxy group represented by Y ^{1 to} Y ¹⁶ include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and the like. Particularly, an alkoxy group having 4 to 11 carbon atoms and substituted with a hydrocarbon is preferable. preferable. For example, tert-butoxy group, 1,3-dimethylbutoxy group, 2-methyl-1-iso-
Propylpropoxy group, 2,2-dimethyl-1-iso-propylpropoxy group, 2,2-dimethyl-1-iso-propylbutoxy group, 1-tert-butyl-2,2-dimethylpropoxy group, 3-methyl- 1-iso-propylbutoxy group, 1-iso-butyl-3-methylbutoxy group, 2-ethylhexyloxy group and the like can be mentioned.

Examples of the alkylthio group represented by Y ^{1 to} Y ¹⁶ include a methylthio group, an ethylthio group and the like, and a hydrocarbon-substituted alkylthio group having 4 to 11 carbon atoms is particularly preferable. For example, tert-butylthio group, 1,3-dimethylbutylthio group, 2-methyl-1-iso-propylpropylthio group, 2,2-dimethyl-1-iso-propylpropylthio group, 2,2-dimethyl- 1-iso-propylbutylthio group, 1-ter
t-butyl-2,2-dimethylpropylthio group, 3-methyl-1-is
Examples thereof include an o-propylbutylthio group, a 1-iso-butyl-3-methylbutylthio group and a 2-ethylhexylthio group.

Further, examples of the divalent metal represented by Met include Cu ^(II) , Zn ^(II) , Fe ^(II) , Co ^(II) and Ni.
^(II) , Ru ^(II) , Rh ^(II) , Pd ^(II) , Pt ^(II) , Mn
^(II) , Mg ^(II) , Be ^(II) , Ca ^(II) , Ba ^(II) , Cd
Examples of mono-substituted trivalent metals such as ^(II) , Hg ^(II) and Sn ^(II) are Al-Cl, Al-Br, Al-F and Al-.
I, Ga-Cl, Ga-F, Ga-I, Ga-Br, I
n-Cl, In-Br, In-I, In-F, T1-C
l, Tl-Br, Tl- I, Tl-F, Al-C 6 H 5,
_{Al-C 6 H 4 CH 3} , In-C 6 H 5, In-C 6 H 4 C
_{H 3, In-C 10 H} 7, etc. Mn (OH) and the like.

An example of a disubstituted tetravalent metal is CrCl.
₂ , SiCl ₂ , SiBr ₂ , SiF ₂ , SiI ₂ , ZrC
l ₂ , GeCl ₂ , GeBr ₂ , GeI ₂ , GeF ₂ , Sn
_{Cl 2, SnBr 2, SnI 2} , SnF 2, TiCl 2, T
iBr ₂ , TiF ₂ , Si (OH) ₂ , Ge (OH) ₂ , Z
r (OH) ₂ , Mn (OH) ₂ , Sn (OH) ₂ , Ti
_{R 2, CrR 2, SiR 2} , SnR 2, GeR 2 [R is an alkyl group, a phenyl group, a naphthyl group and a derivative _{thereof], Si (OR ') 2} , Sn (OR') 2, Ge (OR ' )
₂ , Ti (OR ') ₂ , Cr (OR') ₂ [R 'is an alkyl group, a phenyl group, a naphthyl group, a trialkylsilyl group,
Represents a derivative of a trialkyltin group, a trialkylgermanium group, a dialkylalkoxysilyl group, or an acyl group], Si (SR ") ₂ , Sn (SR") ₂ , Ge (S
R ") ₂ [R" represents an alkyl group, a phenyl group, a naphthyl group or a derivative thereof] and the like.

Examples of oxymetals include VO, Mn
O, TiO, etc. are mentioned.

The phthalocyanine compounds represented by the formulas ((I) to (IV) are synthesized by the following formula (V) or (VI)

[0030]

[Chemical 9] [The benzene ring in formulas (V) and (VI) may have a substituent as described in the above formulas (I) to (IV). ] 1 to 4 kinds of the compounds represented by the following are mixed, for example, 1,8-diazabicyclo [5.4.0] -7-undecene (DBU)
A phthalocyanine derivative is obtained by reacting in butanol under heating in the presence of phthalocyanine, and the obtained phthalocyanine derivative is further treated with an appropriate solvent (eg, acetic acid, carbon tetrachloride).
The phthalocyanine compound represented by the formulas (I) to (IV) of the present invention or a tautomer thereof can be obtained by halogenating or nitrating in the solution.

In the method for producing an optical recording medium using the near infrared absorbing agent of the present invention, 1 to 3 compounds containing the near infrared absorbing agent of the present invention are coated on a transparent substrate in one layer or two layers. Alternatively, there is a method of vapor deposition, and as a coating method, the binder resin is 20% by weight or less, preferably 0%, and the near infrared absorbing agent of the present invention is 0.05% by weight to 20% by weight, preferably 0.1%.
There is a method in which it is dissolved in a solvent so as to be 5% by weight to 20% by weight and then applied by a spin coater. Moreover, as a vapor deposition method, there is a method of depositing a near-infrared absorber on a substrate at 10 ⁻⁵ to 10 ⁻⁷ torr and 100 to 300 ° C.

The substrate may be any optically transparent resin. Examples thereof include acrylic resin, polyethylene resin, vinyl chloride resin, vinylidene chloride resin, polycarbonate resin, ethylene resin, polyolefin copolymer resin, vinyl chloride copolymer resin, vinylidene chloride copolymer resin, and styrene copolymer resin.

The substrate may be surface-treated with a thermosetting resin or an ultraviolet curable resin.

In the case of producing an optical recording medium (optical disk, optical card, etc.), a polyacrylate substrate or a polycarbonate substrate is used as the substrate and it is applied by a spin coating method in terms of cost and handling by the user. preferable.

Due to the solvent resistance of the substrate, the solvent used for spin coating is a halogenated hydrocarbon (eg, dichloromethane, chloroform, carbon tetrachloride, tetrachloroethylene, dichlorodifluoroethane, etc.), ethers (eg, tetrahydrofuran, diethyl ether, diether, etc.). Propyl ether, dibutyl ether, etc.), alcohols (eg, methanol, ethanol, propanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), hydrocarbons (hexane, cyclohexane, etc.)
Octane, benzene, toluene, xylene, etc.) are preferably used.

In order to process it as a recording medium, it is covered with a substrate as described above, or two substrates provided with recording layers are laminated with air gaps facing each other, or a reflective layer (aluminum) is provided on the recording layer. Alternatively, there is a method in which gold) is provided and a protective layer of a thermosetting (photocurable) resin is laminated.

[0037]

EXAMPLES The present invention will be specifically described below with reference to examples, but the embodiments of the present invention are not limited thereto. All parts in the examples are parts by weight.

Example 1 The following formula (A)

[0039]

[Chemical 10] (Melting point: 118 to 124 ° C., decomposition start temperature: 329 ° C.,
1 part of phthalocyanine represented by λ _max : 715 nm and extinction coefficient (ε _max ) at maximum absorption wavelength: 1.5 × 10 ⁵ g ^-1 cm ^-1 ) was dissolved in 200 parts of dibutyl ether and applied on a polycarbonate optical disk substrate. . Gold was vapor-deposited on this, and then photo-cured by overcoating with a photo-curable polyacrylic resin. The optical disc manufactured in this manner had a C / N ratio of 60 dB at a linear velocity of 1.4 m / sec and a laser power of 7 mW, and had good sensitivity. Also, fade meter 63 ℃ / 10
After irradiation for 0 hours, no deterioration of the recording layer was observed.

Example 2 The following formula (B)

[0041]

[Chemical 11] (Melting point: 240 to 250 ° C, decomposition start temperature: 290 ° C,
_{λ max: 721nm, ε m ax} : 1.4 × 10 5 g -1 c
5 parts of phthalocyanine represented by m ^-1 ) is added to n-octane 25
It was dissolved in 0 part and was applied on a polycarbonate substrate for CD-WO by a spin coater so as to have a dry film thickness of 150 nm. A 30 nm gold layer was deposited thereon by sputter deposition, and a UV-curable resin was coated and UV-cured to form a protective layer, and a CD-WO medium was produced.

The CD-WO medium produced in this manner had a reflectance of 70%, a linear velocity of 1.3 m / sec, and a length of 6.5 m.
A C / N ratio of 60 dB was recorded by using a laser beam of W and 790 nm. Further, this recording medium did not change even in the light resistance test at 63 ° C. for 200 hours in a carbon arc lamp.

Example 3 The following formula (C)

[0044]

[Chemical 12] (Melting point: 100 to 110 ° C, decomposition start temperature: 280 ° C,
_{λ max: 705nm, ε m ax} : 1.2 × 10 5 g -1 c
5 parts of phthalocyanine represented by m ^-1 ) is added to n-octane 15
It was dissolved in 0 part and applied to a polycarbonate substrate for CD-WO by a spin coater. The film thickness was 120 nm. 50 nm of gold was vapor-deposited thereon, and then a protective layer was formed using a UV-curable resin.

The thus-produced CD-WO medium was recorded by a 780 nm laser having a linear velocity of 1.3 m / sec and 7 mW, and a recording with a C / N ratio of 55 dB was obtained.

A light resistance test was conducted on this medium with a xenon lamp at 50 ° C., and it was confirmed that there was no change even after 200 hours.

Example 4 The following formula (D)

[0048]

[Chemical 13] (Melting point: 148 to 155 ° C, decomposition start temperature: 260 ° C,
_{λ max: 695nm, ε m ax} : 1.2 × 10 5 g -1 c
5 parts of phthalocyanine represented by m ⁻¹ ) is dissolved in 300 parts of a 3: 1 mixture of dibutyl ether and diisopropyl ether, and is applied to a PMMA CD-WO substrate with a thickness of 120 nm by a spin coater, and then gold is sputtered with a thickness of 20 nm. Then, finally, a protective layer was formed with a UV curable resin to prepare a recording medium.

The obtained medium has a linear velocity of 1.4 m / sec,
When recording with a 8 mW, 780 nm laser, C /
A record with an N ratio of 60 dB was obtained.

[0050]

[0051]

[0052]

Example 5 The following formula (F)

[0054]

[Chemical 15] (Λ _max : 754 nm, ε _max : 1.5 × 10 ⁵ g ^-1 cm
^-1 ) was dissolved in 250 parts of ethylcyclohexane and spin-coated on a CD-WO substrate. A gold layer is formed on it by a sputtering method,
Subsequently, a protective layer was formed with a UV curable resin to prepare a recording medium.

The reflectance of the obtained medium was 67%, which was 8
C / N ratio of 5 with a 30 nm, 6 mW semiconductor laser
A record of 5 dB was made.

Example 6 The following formula (G)

[0057]

Embedded image (Λ _max : 756 nm, ε _max : 1.6 × 10 ⁵ g ^-1 cm
An optical card was produced in the same manner as in Example 5 by using the phthalocyanine represented by ^-1 ). The optical card obtained had a reflectance of 50%, and when recorded with a semiconductor laser of 830 nm, a signal with a C / N ratio of 57 dB was obtained.

Example 7 The following formula (H)

[0059]

[Chemical 17] (Λ _max : 700 nm, ε _max : 1.5 × 10 ⁵ g ^-1 cm
^-1 ) was used to prepare a CD-WO medium in the same manner as in Example 1. 775nm, 8mW
When recorded with the semiconductor laser of No. 5, a signal with a C / N ratio of 55 dB was obtained.

Comparative Test The performances of the optical recording medium obtained above and the known optical recording medium using alkoxyphthalocyanine were compared.
The medium produced in Examples 2 and 4 was used as the medium of the present invention, the following four types of known alkoxyphthalocyanines were used as Comparative Examples, and the medium produced in the same manner as in Example 2 was used.

Comparative Example 1: Alkoxy phthalocyanine represented by the following structural formula

[0062]

[Chemical 18] Comparative Example 2: JP-A-62-39286, Exemplified Compound
XIX

[0063]

[Chemical 19] Comparative Example 3: JP 61-197280 and JP-exemplified compound (10) Deca _{- (OC 5 H 11) -H} 2 Pc Comparative Example 4: JP-B 59-1311 Patent Publication (JP-50-
No. 85630), Example 23 Dodecachlor-tetraphenoxy copper phthalocyanine.

However, in Table 1, 1) symmetry is at a recording power of 5 to 90 mW,
A fluctuation rate of 5% or less is ◯, a fluctuation rate of 5% or more is X, 2) The pulse width correction is a 4T signal (231 × 4 = 924n).
sec), the required correction width is 0 to -100n
The time of sec is ○, the time of −100 to −200 nsec is Δ, and the time of −200 nsec or more is x. 3) The distortion of recording is measured by measuring the distortion of the recording waveform with an oscilloscope and observing the recording pits with a microscope. As a result of observing the strains of No. 3, those with no strain were marked with ◯, and those with distortion were marked with x.

[0065]

[Table 1]

[0066]

INDUSTRIAL APPLICABILITY As described above, the near-infrared ray absorbing agent of the present invention can be used as a dye for CD-WO by adding halogenated alkoxyphthalocyanine to 770, which is necessary as a dye for CD-WO.
By increasing the absorption ability and the refractive index of light of up to 800 nm and promoting the decomposability of phthalocyanine by the introduction of halogen atoms in the recording characteristics of the medium, it becomes possible to record with a low power semiconductor laser. Further, by controlling the decomposition of the dye by introducing halogen, the symmetry property of recording is improved, the signal amplitude is increased and the signal distortion is reduced, and the laser pulse correction during recording can be reduced.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C09B 47/22 G02B 5/22 G02F 1/137 G11B 7/24 B 7215-5D (72) Inventor Shin Aihara 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (56) Reference JP-A-3-62878 (JP, A) JP-A-4-226388 (JP, A) JP-A-1- 31692 (JP, A)

Claims (6)

[Claims] 1. Formula (I): Or formula (II) Or formula (III): Or formula (IV) [In Formulas (I), (II), (III) and (IV), Y
¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ , Y ⁶ , Y ⁷ , Y ⁸ , Y ⁹ , Y ¹⁰ ,
Y ¹¹ , Y ¹² , Y ¹³ , Y ¹⁴ , Y ¹⁵ and Y ¹⁶ each independently represent an alkoxy group or an alkylthio group, and group A: R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ ,
R ⁹ , R ¹⁰ , R ¹¹ and R ¹² group B: R ¹³ , R ¹⁴ , R ¹⁵ ,
^{R 16, R 17, R 18} , R 19, R 20, R 21, R 22, R 23 and R ²⁴ group ^{C: R 25, R 26,} R 27, R 28, R 29, R 30, R 31, R
³² , R ³³ , R ³⁴ , R ³⁵ and R ³⁶ group D: R ³⁷ , R ³⁸ , R ³⁹ , R ⁴⁰ , R ⁴¹ , R ⁴² , R ⁴³ , R
⁴⁴ , R ⁴⁵ , R ⁴⁶ , R ⁴⁷ and R ^{48 In} each group of the above groups A to D, the substituents R ³ , R ^{6 of the} group A ,
At least one of R ⁹ and R ¹² , a substituent of group B R ¹⁵ ,
At least one of R ¹⁸ , R ¹⁹ , and R ²² , a substituent of group C
At least one of R ²⁷ , R ²⁸ , R ³³ and R ^34, of group D
At least one of the substituents R ³⁹ , R ⁴² , R ⁴⁵ and R ⁴⁶ is
Represents a halogen atom, the other substituents are each independently
Represents a hydrogen atom, a halogen atom, a nitro group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group
You. However, in each of groups A to D, a halogen atom is substituted.
The maximum number is eight. Met represents two hydrogen atoms, a divalent metal atom, a trivalent or tetravalent metal derivative. ] The near-infrared absorber which is phthalocyanine and its tautomer shown by these. 2. Formulas (I), (II), (III) and (IV)
In, the alkoxy group or alkylthio group represented by Y ^{1 to} Y ¹⁶ is a secondary or tertiary hydrocarbon, and the sum of the number of carbon atoms, oxygen atoms and sulfur atoms is 5 to 1
2. The near-infrared absorbing agent according to claim 1, which is 2. 3. The central metal represented by Met is Pd,
Cu, Ru, Pt, Ni, Co, Rh, Zn, VO, T
iO, Si (Y) ₂ , Sn (Y) ₂ , Ge (Y) ₂ (Y is a halogen atom, an alkoxy group, an aryloxy group, an acyloxy group, a hydroxy group, an alkyl group, an aryl group,
It represents an alkylthio group, an arylthio group, a trialkylsilyloxy group, a trialkyltinoxy group or a trialkylgermaniumoxy group), and the near-infrared absorber according to claim 2. 4. In each group of groups A to D, 1 to 1 of the substituents
The near infrared absorbing agent according to claim 3, wherein four are bromine atoms. 5. An optical recording medium containing the near-infrared absorber according to claim 1. 6. The optical recording medium according to claim 5, wherein a recording layer containing a near-infrared absorbing agent is formed on a substrate, a reflective layer made of gold or aluminum is formed on the recording layer, and a protective layer is further formed thereon. .