JP2001064255A - Polymethine compound, its production and use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new compound which scarcely absorbs light in the visible light region, highly sensitively absorbs the light of a semiconductor laser having a light-emitting region in the near infrared region and is suitable as a near infrared light absorbent, or the like. SOLUTION: A compound of formula I [R1 is a (substituted) alkoxy; R2 is a (substituted) alkyl; R3 and R4 are each a lower alkyl, or R3 and R4 are bound to each other to form a cyclic structure; X is H, a halogen, or the like; Y is a (substituted) alkoxy, or the like; Z is an electric charge-neutralizing ion], for example, 2-(2- 2-chloro-3-[(1,3-dihydro-3,3,7-trimethyl-5-methoxy-1- methoxyethyl-2H-indol-2-ylidene)ethylidene]-1-cyclohexen-1-yl)ethenyl) -3,3,7- trimethyl-5-methoxy-1-methoxyethylindolium=tetrafluoroborate. The compound of formula I is obtained, for example, by a method comprising condensing an indolium compound of formula II [Z1 is an electric charge-neutralizing ion; (n) is 0 or 1] with a diformyl compound of formula III or a dianil compound of formula IV in the presence of a fatty acid salt in a dehydrating organic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polymethine compound, a method for producing the same, and a near-infrared absorbing agent containing the same. The polymethine compound of the present invention has 750 to 900 n
m having an absorption in the near-infrared region and can be used as a near-infrared absorber used for image recording using a laser beam, for example, a plate making application using a laser beam or a laser thermosensitive recording material application. In addition, it can be used as a spectral sensitizing dye for electrophotography and silver halide photography, a dye for optical disks, and the like.

[0002]

2. Description of the Related Art In recent years, with the development of laser technology, a method of recording an image using a laser beam for the purpose of high-speed recording, high-density, and high-quality recording, for example, a system of recording by converting a laser beam into heat. As an example, an image forming method for a laser thermal recording material, a laser thermal transfer recording material, and the like has been studied.
Also, with the rapid development of electronics such as the spread of computers and the improvement of digital image processing technology, the so-called computer-to-plate technology (CTP plate making technology) that directly creates printing originals from digital data.
The development of is under active consideration.

In a system for recording an image by converting laser light into heat (laser thermal recording system), a light absorber suitable for the wavelength of the laser is used, and the absorbed light is converted into heat to form an image. However, the heat energy required for image formation cannot be obtained unless the output of the laser is considerably increased, and the development of a light absorber having a high light-to-heat conversion efficiency is desired. In a laser thermosensitive recording material, a semiconductor laser having a light emitting region in the near infrared region of 750 nm to 900 nm is generally used, but a near infrared absorbing agent suitable for the wavelength of the laser generally absorbs light in the visible region. Therefore, there is a disadvantage that the background is colored, and a near-infrared absorbing agent having a small absorption of light in a visible region is desired.

In the CTP plate making technology, when classified according to the plate making method, a method of irradiating a laser beam, a method of writing with a thermal head, a method of partially applying a voltage with a pin electrode, and a method of forming an ink repellent or ink-coated layer with an ink jet. A method for forming the film is known. Among them, the method using a laser beam is superior to other methods in terms of resolution and plate making speed, and various image forming methods are being studied.

[0005] Recently, in the near infrared region (750 nm to 9 nm).
(00 nm), small-sized, high-output, and inexpensive semiconductor lasers having a light-emitting region have become readily available.
Semiconductor lasers have become useful as exposure light sources when making plates.

[0006] Direct plate making using a laser beam includes a photosensitive type and a heat-sensitive type. As the photosensitive type plate material, there are an electrophotographic system using an organic semiconductor (OPC), a silver salt system using a silver salt, and the like. Are more expensive than the conventional PS plate (presensitized plate). Also, there is a problem of disposal of the developer.

A disadvantage of the heat-sensitive type plate material is that the sensitivity is lower than that of the photosensitive type plate material. However, since the plate material can be handled in a normal room (light room) and the apparatus is small and inexpensive, it is energetic. Is being considered.

[0008] All heat-sensitive plate materials require a light-to-heat conversion layer for converting light into heat. This light-to-heat conversion layer contains a light-to-heat conversion agent, for example, a near-infrared absorbing agent, and it is essential that the light-to-heat conversion agent absorbs the laser light to be used. It is necessary that the absorption capacity and the light-to-heat conversion efficiency be higher.

As the photothermal conversion agent, there are pigment type and dye type substances. As the pigment type substance, carbon black is usually used, and various dye type substances have been proposed. Usually, a polymethine compound is used. Although carbon black has a wide range of choices for lasers to be used, it generally has a lower laser light absorbing ability and must be used in a larger amount than dye-type substances. In addition, advanced dispersion technology is required.

When a dye-type substance is used, it must have a high ability to absorb laser light, be compatible with other components such as an image forming component and a resin binder, and have good solubility in a solvent to be used. Is required.

The polymethine compound has a methine chain connected by a conjugated double bond in the molecule, and has a visible region to a near infrared region (34).
(0 to 1,400 nm) and has a large absorption coefficient at the absorption maximum due to its large absorption coefficient. For example, photosensitive dyes for silver salt photography, photosensitive dyes for electrophotography, dyes for laser recording, dyes for laser oscillation, etc. Used in

The polymethine compound has a high ability to absorb laser light, but requires matching with the laser light used.
Generally known compounds have low light stability,
There is a problem that compatibility with a binder resin or the like is poor.

Many compounds are already known as polymethine compounds, and compounds having a cyclic structure introduced into a part of a methine chain are known as means for improving durability.
For example, Compound A is disclosed in JP-A-63-319191,
In the specific example compound 9 of P3, the compound B is
Known in Organic Chemistry, 60, 2392, Table 1.

[0014]

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[0015]

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However, compound A and compound B both have a maximum absorption wavelength in the range of 785 to 815 nm, and are insensitive to a small, high-power laser having an emission region at 820 to 840 nm, which is currently under consideration for use. It is enough. In addition, both compound A and compound B have low solvent solubility and low compatibility with resins, and thus have a disadvantage that usable binder resins and the like are limited.

[0017]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the absorption of light in the visible region and to reduce the absorption in the near infrared region (750 nm to 900 nm).
nm), especially 820n
An object of the present invention is to provide a polymethine compound having high sensitivity to a laser having a wavelength of m to 840 nm and suitable for a photothermal conversion layer such as a near-infrared absorbing agent, a laser thermal recording material, and a printing plate for direct plate making.

[0018]

As a result of various studies to solve the above-mentioned problems, the present inventors have found that a novel polymethine compound has a small absorption of light in the visible region and a near infrared region.
(750 nm to 900 nm) It has been found that the compound has good sensitivity to a semiconductor laser having an emission region in the range of (750 nm to 900 nm), has high light-to-heat conversion efficiency, and can be used as a near-infrared absorbing agent which can be easily processed into various uses, thereby achieving the present invention. Was completed.

The first invention of the present application is a polymethine compound represented by the following general formula (I).

[0020]

Embedded image (Wherein, R ₁ represents an alkoxy group which may have a substituent, R ₂ represents an alkyl group which may have a substituent,
_3, R ₄ each represent a lower alkyl group, and R ₃ and R ₄ may combine with each other to form a cyclic structure, X is a hydrogen atom, a halogen atom or a substituted amino group, Y
Represents an alkoxy group which may have a substituent or an alkyl group which may have a substituent, and Z represents a charge neutralizing ion. The second invention of the present application is a polymethine compound represented by the following formula, which is a crystalline modification, a crystalline methanol adduct, and an amorphous product.

[0021]

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The third invention of the present application relates to an indolenium compound represented by the general formula (II) and a diformyl compound represented by the following general formula (III) or a dianyl compound represented by the following (IV): A method for producing a polymethine compound of the above general formula (I), wherein the compound is condensed using a dehydrating organic acid in the presence of a fatty acid salt.

[0023]

Embedded image (Wherein, R ₁ represents an alkoxy group which may have a substituent, R ₂ represents an alkyl group which may have a substituent,
₃ and R ₄ each represent a lower alkyl group; R ₃ and R ₄ may be linked to each other to form a cyclic structure; and Y has an alkoxy group or a substituent which may have a substituent. And Z ₁ represents a charge neutralizing ion, and n represents a number of 0 or 1. )

[0024]

Embedded image (In the formula, X represents a hydrogen atom, a halogen atom or a substituted amino group.)

[0025]

Embedded image (In the formula, X represents a hydrogen atom, a halogen atom or a substituted amino group.) The fourth invention of the present application is characterized in that the polymethine compound of the first invention is recrystallized with a ketone or alcohol solvent. This is a method for producing a melting point crystal.

The fifth invention of the present application is a method for producing a low-melting-point crystal, characterized in that a crystalline solvent adduct or an amorphous product of the polymethine compound of the first invention is treated with a specific solvent. A sixth invention of the present application is a near-infrared absorbing agent comprising the polymethine compound of the first invention.

According to a seventh aspect of the present invention, in a printing plate for direct plate making comprising a light-to-heat conversion layer provided on a support, the light-to-heat conversion layer contains the polymethine compound of the first invention. It is a printing plate for direct plate making.

According to an eighth aspect of the present invention, there is provided a printing plate precursor for direct plate making according to the seventh aspect of the present invention, wherein
In this method, a printing plate is prepared by irradiating a semiconductor laser beam having an emission region at 00 nm.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. [Polymethine compound] First, a polymethine compound represented by the following general formula (I) according to the first and second aspects of the present invention and 2- (2- {2-chloro-3-[(1,3-dihydro) −
3,3,7-trimethyl-5-methoxy-1-methoxyethyl-2H-indole-2-ylidene) ethylidene] -1-cyclohexen-1-yl {ethenyl)-
The crystal modification, crystalline methanol adduct and amorphous of 3,3,7-trimethyl-5-methoxy-1-methoxyethylindolium = tetrafluoroborate (specific compound (55)) will be described below.

[0030]

Embedded image (Wherein, R ₁ represents an alkoxy group which may have a substituent, R ₂ represents an alkyl group which may have a substituent,
_3, R ₄ each represent a lower alkyl group, and R ₃ and R ₄ may combine with each other to form a cyclic structure, X is a hydrogen atom, a halogen atom or a substituted amino group, Y
Represents an alkoxy group which may have a substituent or an alkyl group which may have a substituent, and Z represents a charge neutralizing ion. ) R ₁ is preferably an unsubstituted alkoxy group having 1 to 8 carbon atoms, particularly 1 to 4 carbon atoms.
Are preferred.

When R ₁ is a substituted alkoxy group, examples of the substituent include an alkyloxy group, an alkylthio group, a hydroxyl group, and a halogen atom, and an alkyloxy group is preferred. As R ₁ being alkoxy having an alkyloxy group, those having a total of 2 to 8 carbon atoms are preferred, and those having a total of 2 to 4 carbon atoms are particularly preferred.

Examples of R ₁ include methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, iso-butoxy, sec-butoxy,
Examples thereof include an n-pentoxy group, an iso-pentoxy group, an n-octyloxy group, a 2-ethylhexyloxy group, a methoxymethoxy group, a 2-methoxyethoxy group, and a 2-ethoxyethoxy group.

When R ₂ is an alkyl group having no substituent, a linear or branched alkyl group having 1 to 18 carbon atoms is preferable, and a linear or branched alkyl group having 1 to 8 carbon atoms is particularly preferable. preferable. Examples are methyl, ethyl, n
-Propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, sec-hexyl, 2-ethylbutyl, n −
Heptyl group, isoheptyl group, sec-heptyl group, n
-Octyl group, 2-ethylhexyl group, n-decyl group,
Examples thereof include an n-dodecyl group, an n-pentadecyl group, and an n-octadecyl group.

When R ₂ is a substituted alkyl group, an alkoxyalkyl group, a sulfoalkyl group,
Examples thereof include a carboxyalkyl group and the like, and in the case of an alkoxyalkyl group, those having a total carbon number of 2 to 8 are preferable. Examples include 2-methoxyethyl, 3-methoxypropyl, 4-methoxybutyl, 2-ethoxyethyl, 3-ethoxypropyl, 4-ethoxybutyl,
2-n-propoxyethyl group, 2-iso-propoxyethyl group, 3-n-propoxypropyl group, 4-n-propoxybutyl group, 2-methoxy-2-ethoxyethyl group, 2-ethoxy-2-ethoxyethyl Groups.

When R ₂ is a sulfoalkyl group, a linear or branched sulfoalkyl group having 1 to 18 carbon atoms is preferable, and a linear or branched sulfoalkyl group having 1 to 8 carbon atoms is particularly preferable. Further, it is preferable that at least one of these sulfoalkyl groups R ₂ forms a salt with an alkali metal ion or an alkyl ammonium ion. Examples are 2-sulfoethyl, 3-sulfopropyl, 3-sulfobutyl, 4-sulfobutyl, 4-sulfo-3-methylbutyl, 2- (3-sulfopropoxy) ethyl, 2-hydroxy-3- Sulfopropyl group, 3-sulfo-2- (2-ethoxy) ethoxypropoxy group, 5-sulfopentyl group, 6-sulfohexyl group, 8-sulfooctyl group, 6-sulfo-2-ethylhexyl group, and alkali A salt may be formed with a metal ion or an alkyl ammonium ion.

When R ₂ is a carboxyalkyl group, a straight-chain or branched carboxyalkyl group having 2 to 18 carbon atoms is preferable, and a straight-chain or branched carboxyalkyl group having 2 to 9 carbon atoms is particularly preferable. preferable. Further, those in which at least one of R ₂ is these carboxyalkyl group forms an alkali metal ion or an alkylammonium ion salt. For example, 2-
Carboxyethyl group, 3-carboxypropyl group, 3-
Carboxybutyl group, 4-carboxybutyl group, 4-carboxy-3-methylbutyl group, 2- (3-carboxypropoxy) ethyl group, 2-hydroxy-3-carboxypropyl group, 3-carboxy-2- (2-ethoxy ) Ethoxypropoxy group, 5-carboxypentyl group, 6-
Carboxyhexyl group, 8-carboxyoctyl group, 6
-Carboxy-2-ethylhexyl group, and may form a salt with an alkali metal ion or an alkylammonium ion.

Examples of the case where R ₃ and R ₄ are lower alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and sec-butyl group.

Examples of the cyclic structure formed by connecting R ₃ and R ₄ to each other include a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring and a cycloheptane ring. And a cyclohexane ring are preferred.

X is preferably a hydrogen atom, a halogen atom such as F, Cl, Br or I, or a substituted amino group such as an ethylamino group, a phenylamino group, a diphenylamino group or a morpholino group. Particularly preferred.

As Y is an unsubstituted alkoxy group, those having 1 to 8 carbon atoms are preferable, and those having 1 to 8 carbon atoms are particularly preferable.
Four are preferred.

When Y is a substituted alkoxy group, examples of the substituent include an alkyloxy group, an alkylthio group, a hydroxyl group and a halogen atom, and an alkyloxy group is particularly preferred. When Y is an alkoxy group having an alkyloxy group as a substituent, the total number of carbon atoms is 2 to 8;
Are preferable, and particularly those having a total carbon number of 2 to 4 are preferable.

Examples of such a case where Y is an alkoxy group include methoxy, ethoxy, n-propoxy and i
so-propoxy group, n-butoxy group, iso-butoxy group, sec-butoxy group, n-pentoxy group, iso
-Pentoxy group, n-octyloxy group, 2-ethylhexyloxy group, 2-methoxyethoxy group, and 2-ethoxyethoxy group.

When Y is an alkyl group having no substituent, a straight-chain or branched alkyl group having 1 to 8 carbon atoms is preferable, and a straight-chain or branched alkyl group having 1 to 4 carbon atoms is particularly preferable. . Examples are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, sec -Hexyl group, 2-ethylbutyl group, n-heptyl group, isoheptyl group, sec-heptyl group, n-
Examples include an octyl group and a 2-ethylhexyl group.

When Y is a substituted alkyl group, examples of the substituent include an alkyloxy group, an alkylthio group, a hydroxyl group, a halogen atom and the like, and an alkyloxy group is particularly preferred. When Y is an alkyl group having an alkyloxy group as a substituent, the total number of carbon atoms is 2 to 4;
Are preferred. For example, 2-methoxyethyl group, 3
-Methoxypropyl group, 4-methoxybutyl group, 2-ethoxyethyl group, 3-ethoxypropyl group, 4-ethoxybutyl group, 2-n-propoxyethyl group, 2-iso
-Propoxyethyl group, 3-n-propoxypropyl group, 4-n-propoxybutyl group, 2-methoxy-2-
An ethoxyethyl group and a 2-ethoxy-2-ethoxyethyl group are exemplified.

Z represents a charge neutralizing ion, for example, F⁻,
Cl⁻, Br⁻, I⁻, BrO₄ ⁻, ClO₄ ⁻, P-
Toluenesulfonate, CH₃SO₃ ⁻ , BF₄ ⁻,
CH ₃CO₂ ⁻, CF₃CO₂ ⁻, PF₆ ⁻, SbF₆
⁻, Na⁺, K⁺, Triethylammonium ion
And, in particular, Cl⁻, Br⁻, I⁻, ClO₄ ⁻, P
-Toluenesulfonate, CH₃SO₃ ⁻, BF₄ ⁻,
CF₃CO₂ ⁻, PF ₆ ⁻, SbF₆ ⁻, Na⁺,
K⁺And triethylammonium ion.

Z₁Represents a charge neutralizing ion, for example,
F⁻, Cl⁻, Br⁻, I⁻, BrO₄ ⁻, Cl
O₄ ⁻, P-toluenesulfonate, CH₃SO
₃ ⁻ , BF₄ ⁻, CH₃CO₂ ⁻, CF₃CO₂ ⁻,
PF₆ ⁻, SbF₆ ⁻In particular, Cl ⁻, Br
⁻, I⁻, ClO₄ ⁻, P-toluenesulfonate, C
H₃SO₃ ⁻, BF₄ ⁻, CF₃CO₂ ⁻, PF₆ ⁻,
SbF₆ ⁻Is preferred. Represented by the general formula (I) of the present invention
Preferred specific examples of the polymethine compound are shown below.
However, the scope of the compound is not limited to these.

[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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[0055]

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[0056]

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[0057]

Embedded image In addition, among the compounds (1) to (65) of the above specific examples, the compound represented by the following general formula (V) can also be represented by the general formula (VI).

[0058]

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[0059]

Embedded image (In the formula, R _{1 to} R ₄ , X and Y are the same as described above, and M represents Na, K or triethylammonium.) For example, the specific compound (51) is

[0060]

Embedded image It can also be expressed as

The polymethine compounds represented by the general formula (I) of the present invention include those in which crystalline modifications, crystalline solvent adducts and amorphous substances are present. For example, Compound (55) has a diffraction angle (2) in powder X-ray diffraction using Cu-Kα ray.
θ ± 0.2 °) 11.6 °, 14.6 °, 15.6 °,
Alpha crystals showing characteristic peaks at 19.6 ° and 22.9 °
(Low melting point compound), β crystal (high melting point compound) showing a very strong peak characteristic at diffraction angle (2θ ± 0.2 °) 8.4 °, diffraction angle (2θ ± 0.2 °) 3 °, 17.4 °, 19.
There are crystalline methanol adducts exhibiting characteristic peaks at 8 °, 21.8 °, and 26.9 ° and amorphous substances exhibiting no characteristic peaks at diffraction angles (2θ ± 0.2 °).

[Polymethine Compound and Method for Producing Crystal Modification] The polymethine compound of the present invention may be, for example, an indolenium compound represented by the general formula (II), a diformyl compound represented by the general formula (III) or ( It is produced by condensing the dianyl compound represented by IV) in the presence of a fatty acid salt in a dehydrating organic acid.

[0063]

Embedded image (In the formula, R _{1 to} R ₄ , Y, Z ₁ and n represent the same as described above.)

[0064]

Embedded image (In the formula, X represents the same as described above.)

[0065]

Embedded image (In the formula, X represents the same as above.) In the above condensation reaction, examples of the fatty acid salt include sodium acetate, potassium acetate, calcium acetate, sodium propionate, potassium propionate and the like.

The fatty acid salt is used in an amount of usually about 0.1 to 5 mol, preferably about 0.5 to 2 mol, per 1 mol of the compound represented by the general formula (II).

Examples of the dehydrating organic acid include acetic anhydride, propionic anhydride, butyric anhydride, and γ-butyrolactone.

The dehydrating organic acid is used in an amount of usually about 10 to 100 mol, preferably about 20 to 50 mol, per 1 mol of the compound represented by the general formula (II).

The compound represented by the general formula (II) and the compound represented by the general formula (II)
The proportion of the compound represented by the formula (I) or (IV) is usually about 0.2 to 1.5 mol, preferably about 0.4 to 0.7 mol, per mol of the former.

The above reaction proceeds suitably at about 10 to 150 ° C., preferably at room temperature to 120 ° C., and generally takes several minutes to 3 hours.
Complete in about an hour.

After the reaction, for example, water, methanol, ethanol, n-propanol, iso-propanol, n-propanol
The desired product can be easily isolated from the reaction mixture by injecting a poor solvent such as butanol, or discharging into a poor solvent such as water or methanol, ethanol, n-propanol, iso-propanol, or n-butanol. . Further, it can be easily purified by conventional purification means, for example, recrystallization, column separation and the like.

The polymethine compound represented by the general formula (I) of the present invention includes a crystalline modification, a crystalline solvent adduct, and an amorphous substance. May be a crystal modification, a crystalline solvent adduct and an amorphous substance, or a mixture of a crystal modification, a crystalline solvent adduct and an amorphous substance.

In the polymethine compound of the present invention, for example, the low-melting point compound is prepared by contacting a crystalline solvent adduct or an amorphous substance with a specific solvent, ie, a ketone, an alcohol, or a mixed solvent thereof with an ester and / or an ether. It can be produced by performing a solvent treatment, such as a treatment.
In order to carry out such a treatment, it is preferable to disperse the polymethine compound in a solvent set at a temperature and temperature, for example, under conditions that do not result in a recrystallization operation, that is, a solid solvent in which the solid polymethine compound is not completely dissolved. As the contact treatment, besides dispersing the polymethine compound in the solvent, it is also possible to simply contact the polymethine compound with the solvent.

The high melting point compound is a thermally stable crystalline form, and may be a low melting point compound, a crystalline solvent adduct, an amorphous substance, or a low melting point compound, a high melting point compound, a crystalline solvent adduct, or an amorphous substance. It can be produced by a recrystallization method using a solvent capable of completely dissolving the mixture, for example, ketone, alcohol, or a mixed solvent of ketone and alcohol. In order to carry out recrystallization, it is preferable that after completely dissolving the polymethine compound in a solvent, crystallization is performed while slowly aging, or a seed crystal is added.

As the ketone used for the contact treatment and the recrystallization, various solvents having a carbonyl group, for example, acetone, methyl ethyl ketone, methyl propyl ketone,
Examples include methyl butyl ketone, methyl isopropyl ketone, methyl amyl ketone, diethyl ketone, ethyl butyl ketone, dipropyl ketone, diisopropyl ketone, diacetone alcohol, cyclohexanone, and the like.
Examples of the alcohol include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, and ter.
Examples thereof include t-butanol, n-amyl alcohol, methyl amyl alcohol, 2-ethylhexanol, n-octanol, cyclohexanol, and 2-ethylcyclohexanol. Examples of the ester used for the contact treatment include methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isoamyl acetate, and n-butyl butyrate. Examples of ethers include diethyl ether and isopropyl ether. , N-butyl ether, diglyme and the like.

The amount of the solvent used in the contact treatment for preparing the low melting point compound depends on the solubility in the polymethine compound, and is in a range of not completely dissolving the polymethine compound in a weight ratio of 2 to 70 times the weight of the polymethine compound, preferably 3 times. Use up to 50 times weight ratio. If the amount used is larger than this, the yield is reduced and efficiency is poor. Although the treatment temperature varies depending on the solvent used, it is generally about -10 to 70C, preferably 0 to 50C. Poor solvents such as esters and / or ethers can be mixed and used as the dispersion treatment solvent.

The amount of the recrystallization solvent used for preparing the high melting point compound also depends on the solubility in the polymethine compound, and is in a range of 3 to 100 times the weight ratio of the polymethine compound, preferably 5 to 100, within a range in which the polymethine compound is completely dissolved. 7
Use 0 times weight ratio. If the amount is too small, it may become a crystalline solvent adduct. If the amount used is larger than this, the yield is reduced and the efficiency is reduced. The recrystallization temperature varies depending on the solvent used, but is generally about 20 ° to 150 ° C, preferably 30 ° to 120 ° C. A mixed solvent of ketone and alcohol can be used as the recrystallization solvent.

Among the compounds represented by the formula (I) of the present invention,
For example

[0079]

Embedded image Are low-melting point compounds (melting points: 195 to 197 ° C. α crystals) and high-melting point compounds (melting points: 20
4-206 ° C β-crystals), crystalline methanol adducts and amorphous. The polymethine compound becomes a low melting point compound or a high melting point compound depending on an isolation method and / or a purification method before purification, or becomes a crystalline solvent adduct or an amorphous substance, a low melting point compound, a high melting point compound, It may be a mixture of a crystalline solvent adduct and an amorphous product.

The low melting point compound and the high melting point compound can be produced by the above-mentioned method. The crystalline methanol adduct is obtained by dissolving a high-melting compound, a low-melting compound, an amorphous substance and / or a mixture thereof in methanol and then concentrating the mixture under reduced pressure. , And then can be produced by filtration. The amorphous substance can be produced by completely dissolving the isolated high melting point compound, low melting point compound, crystalline methanol adduct, amorphous substance or a mixture thereof in acetone, and then concentrating and drying under reduced pressure.

The compound represented by the general formula (II) can be synthesized, for example, by the method described in JP-A-1-131277.

The diformyl compounds represented by the general formula (III) are described, for example, in Journal of Organic Chemistry, 42, 885-88.
8 (1977) and the like. The dianyl compound of the general formula (IV) can be easily synthesized by reacting the diformyl compound of the general formula (III) with aniline hydrochloride.

[Near Infrared Ray Absorber] The near infrared ray absorber of the present invention may contain a binder resin and the like in addition to the polymethine compound of the formula (I).

As the near-infrared absorbing agent, various known near-infrared absorbing agents can be used in combination with the polymethine compound of the general formula (I) without departing from the object of the present invention.

Examples of near-infrared absorbers that can be used in combination include pigments such as carbon black and aniline black, and “Chemical
(May 1986) "" Near-infrared absorbing dye "(P45-
51) and "Development and Market Trend of Functional Dyes in the 1990s", CMC (1990), Chapter 2, 2.3, polymethine dyes (cyanine dyes), phthalocyanine dyes, dithiol metal complex salt dyes, naphthoquinones , Anthraquinone dyes, triphenylmethane (similar) dyes, aminium, diimmonium dyes, etc., and azo dyes,
Pigments such as indoaniline metal complex dyes, intermolecular CT dyes, and dye-based dyes.

The binder resin is not particularly limited. For example, homopolymers or copolymers of acrylic monomers such as acrylic acid, methacrylic acid, acrylates, methacrylates, methyl cellulose, ethyl cellulose, cellulose acetate Cellulosic polymers such as polystyrene, vinyl chloride-vinyl acetate copolymer, polyvinylpyrrolidone, polyvinyl butyral, vinyl polymers such as polyvinyl alcohol and copolymers of vinyl compounds, polyesters, condensation polymers such as polyamides, Examples thereof include a rubber-based thermoplastic polymer such as a butadiene-styrene copolymer, and a polymer obtained by polymerizing and crosslinking a photopolymerizable compound such as an epoxy compound.

When the near-infrared absorbing agent of the present invention is used for an optical recording material such as an optical card, a liquid in which the near-infrared absorbing agent and an organic solvent are dissolved is coated on a substrate such as glass or plastic resin by spin coating or the like. It can be manufactured by coating by a method which has been variously studied. The resin that can be used for the substrate is not particularly limited, and examples thereof include an acrylic resin, a polyethylene resin, a vinyl chloride resin, a vinylidene chloride resin, and a polycarbonate resin. There is no particular limitation on the solvent used for spin coating, but, for example, hydrocarbons, halogenated hydrocarbons, ethers,
Examples thereof include ketones, alcohols, and cellosolves. In particular, alcohol solvents such as methanol, ethanol, and propanol, and cellosolve solvents such as methyl cellosolve and ethyl cellosolve are preferable.

When the near-infrared absorbing agent of the present invention is used for a near-infrared absorbing filter, a heat ray shielding material, and an agricultural film, the near-infrared absorbing agent is mixed with a plastic resin and an organic solvent as the case may be, and the injection molding method or the casting method is used. It can be manufactured by forming into a plate shape or a film shape by various methods which have been conventionally studied. As a resin that can be used,
Although there is no particular limitation, examples thereof include acrylic resin, polyethylene resin, vinyl chloride resin, vinylidene chloride resin, and polycarbonate resin. As the solvent used,
There is no particular limitation, for example, hydrocarbons, halogenated hydrocarbons, ethers, ketones, alcohols, cellosolves, but particularly, methanol, ethanol,
Alcohol solvents such as propanol and cellosolve solvents such as methyl cellosolve and ethyl cellosolve are preferred.

When the near-infrared absorbing agent of the present invention is used for a recording material such as a laser thermal transfer recording material and a laser thermosensitive recording material, a coloring component or a coloring component may be mixed with the near-infrared absorbing agent. A layer containing a coloring component or a coloring component may be provided separately. As a color-forming component or a coloring component, a sublimable dye or an electron-donating dye precursor and an electron-accepting compound, which form an image by a physical or chemical change by heat of a polymerizable polymer, etc. What is being considered can be used. For example, the coloring component of the laser thermal transfer recording material is not particularly limited, but as a pigment type, titanium dioxide, carbon black, zinc oxide, Prussian blue,
Inorganic pigments such as cadmium sulfide, iron oxide and chromates of lead, zinc, barium and calcium, azo, thioindigo, anthraquinone, anthantrone,
Organic pigments such as trifendioxane-based, phthalocyanine-based, and quinacridone-based organic pigments are exemplified. Examples of the dye include an acid dye, a direct dye, a disperse dye, an oil-soluble dye, and a metal-containing oil-soluble dye.

The color forming component of the laser thermosensitive recording material is not particularly limited, but those conventionally used in thermosensitive recording materials can be used. The electron-donating dye precursor has a property of coloring by donating electrons or accepting a proton such as an acid, and has a partial skeleton of lactone, lactam, sultone, spiropyran, ester, amide, or the like. Compounds that have a partial skeleton ring-open or cleaved upon contact with an electron-accepting compound are used. For example, triphenylmethane compounds, fluoran compounds, phenothiazine compounds, indolyl phthalide compounds, leuco auramine compounds, rhodamine lactam compounds, triphenylmethane compounds, triazene compounds, spiropyran compounds, fluorene compounds And the like. Examples of the electron-accepting compound include a phenolic compound, an organic acid or a metal salt thereof, and an oxybenzoate.

[Printing master for direct plate making] The polymethine compound of the present invention can be suitably used as a near-infrared absorbing agent for a printing plate for direct plate making. The printing plate precursor for direct plate making is provided with a light-heat conversion layer on a support. Further, a silicon rubber layer may be laminated on the light-to-heat conversion layer, or a protective layer or the like may be further laminated.

The components constituting the light-to-heat conversion layer include, in addition to the polymethine compound of the present invention, an image forming component, a binder resin and the like. Alternatively, a layer containing an image forming component may be provided by being laminated on the photothermal conversion layer.

As the image forming components, those which form an image by physical or chemical change by heat and which have been conventionally studied variously can be used. For example, Japanese Unexamined Patent Publication
JP-A-108588, which contains a microencapsulated heat-fusible substance and a binder resin, etc., is active on a support having a hydrophilic surface disclosed in JP-A-62-164049. Those containing a blocked isocyanate or the like together with a hydrogen-containing binder;
A microcapsule containing a lipophilic component and a hydrophilic binder polymer disclosed in JP-1849, an acid precursor disclosed in JP-A-8-220755, a compound having a vinyl ether group, And those containing an alkali-soluble resin and the like, JP-A-9-59
No. 93, which contains a polymer compound having a hydroxyl group and an o-naphthoquinonediazide compound, etc .; Japanese Patent Application Laid-Open No. 9-131977; 1462
Examples include those containing a polymerization initiator and an ethylenically unsaturated monomer, oligomer, macromonomer, and the like disclosed in JP-A-64, and are not particularly limited.

In some cases, JP-A-9-80745, JP-A-9-131977, JP-A-9-14
No. 6264, etc.
An image area may be formed by laminating a silicon rubber layer on the (photosensitive layer or heat-sensitive recording layer) and, after exposure, by closely contacting or peeling off the silicon rubber layer.

The binder resin used for the light-to-heat conversion layer is not particularly limited, but may be, for example, a homopolymer or a copolymer of an acrylic acid monomer such as acrylic acid, methacrylic acid, acrylate, methacrylate, or the like. Methylcellulose, ethylcellulose, cellulosic polymers such as cellulose acetate, polystyrene, vinyl chloride-vinyl acetate copolymer, polyvinylpyrrolidone, polyvinylbutyral, copolymers of vinyl compounds and vinyl compounds such as polyvinyl alcohol, polyester, polyamide Such a condensation polymer, a rubber thermoplastic polymer such as a butadiene-styrene copolymer, and a polymer obtained by polymerizing and crosslinking a photopolymerizable compound such as an epoxy compound can be exemplified.

The printing plate precursor for plate making of the present invention must have such flexibility that it can be set in an ordinary printing press and at the same time can withstand the load applied during printing. That is, as the support to be used, for example, paper, plastic
(E.g., polyethylene, polypropylene, polystyrene, etc.) laminated paper, such as aluminum (including aluminum alloys), zinc, metal plates such as copper, such as cellulose diacetate, cellulose triacetate, cellulose butyrate, polyethylene terephthalate, Plastic films such as polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc., are mentioned.Typical examples include coated paper, metal plates such as aluminum, plastic films such as polyethylene terephthalate, rubber, and the like. And aluminum, an aluminum-containing alloy, and a plastic film. The thickness of the support is 25 μm to 3 mm, preferably 100 μm to 500 μm.

Usually, a polymethine compound, an image forming component, a binder resin and the like are dispersed or dissolved in an organic solvent or the like and applied to a support to prepare a printing plate precursor for plate making.

Examples of the solvent to be applied include water, alcohols such as methyl alcohol, isopropyl alcohol, isobutyl alcohol, cyclopentanol, cyclohexanol, and diacetone alcohol; methylcellosolve;
Cellsolves such as ethyl cellosolve, aromatics such as toluene, xylene and chlorobenzene, esters such as ethyl acetate, butyl acetate isoamyl acetate, methyl propionate, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and chloride Examples thereof include chlorinated hydrocarbons such as methylene, chloroform and trichloroethylene, ethers such as tetrahydrofuran and dioxane, and aprotic polar solvents such as N, N-dimethylformamide and N-methylpyrrolidone.

[0099] A primer layer may be provided between the support and the light-to-heat conversion layer for improving the adhesion and the printing properties, or the support itself may be subjected to a surface treatment. Examples of the primer layer to be used include those obtained by exposing and curing various photosensitive polymers as described in JP-A-60-22903 before laminating a light-to-heat conversion layer. The epoxy resin disclosed in JP-A-50760 is thermally cured, the gelatin disclosed in JP-A-63-133151 is hardened, and the epoxy resin disclosed in JP-A-3-200965 is disclosed. Using a urethane resin and a silane coupling agent.
And those using a urethane resin disclosed in JP-A-273248.

As a protective film for protecting the surface of the light-to-heat conversion layer or the silicone rubber layer, a transparent film, for example,
Polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyethylene terephthalate, cellophane, etc. may be laminated or these films may be stretched for use.

The printing plate precursor for direct plate making of the present invention corresponds to a semiconductor laser having a specific light emitting region. That is, in order to prepare a printing plate (printing plate) using this printing original plate, it is 750 to 900 nm, preferably 770 to 850 n.
Using a semiconductor laser light source having a light-emitting region at m, irradiating the original plate with laser light by a conventionally known plate-making method to form an image portion or a non-image portion, thereby recording digital data of a computer or the like as a printing plate. I do.

[0102]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 Polymethine Compound (Synthesis of Specific Example Compound (11)) A compound represented by the general formula (II) (R ₁ = methoxy group, R ₂
= Methoxyethyl group, R ₃ = R ₄ = methyl group, Y = 7-
3.79 g of a methoxy group, Z = ClO ₄ ⁻ , n = 1), 0.86 g of the compound represented by the general formula (III) (X = Cl) and 3.36 g of potassium acetate were added to 50 ml of acetic anhydride.
After stirring at 5 to 50 ° C. for 60 minutes, the mixture was discharged into 300 ml of a 2% KClO ₄ aqueous solution. The precipitated crystal was separated by filtration, washed with water, and recrystallized with isopropanol to give a specific compound (1).
1) 2.95 g was obtained.

The elemental analysis value, melting point, maximum absorption wavelength (λmax) and gram extinction coefficient (εg) of this compound were as follows. Elemental analysis _{(C 40 H 52 Cl 2 N} 2 O 10): MW = 791.8 C H N calc (%) 60.68 6.62 3.54 Found (%) 59.96 6.49 3 .58 Melting point (° C.): 152-153 ° C. λmax: 832 nm (diacetone alcohol solution) εg: 2.80 × 10 ⁵ ml / g · cm The IR spectrum of the obtained compound is shown in FIG.

The VIS-NIR absorption spectrum of the obtained compound is shown in FIG.

Example 2 Polymethine Compound (Synthesis of Specific Example Compound (12)) A compound represented by the general formula (II) (R ₁ = methoxy group, R ₂
= Methoxyethyl group, R ₃ = R ₄ = methyl group, Y = 7-
A methoxy group, Z = I ⁻ , n = 1) 4.05 g, and a compound represented by the general formula (I
1.80 g of the compound represented by the formula (V) (X = Cl) and 3.36 g of potassium acetate are added to 50 ml of acetic anhydride, and
After stirring at 60 ° C. for 60 minutes, the mixture was discharged into 300 ml of a 2% KI aqueous solution. The precipitated crystal was separated by filtration, washed with water, and recrystallized with isopropanol to obtain 2.56 g of the specific compound (12).

The elemental analysis value, melting point, maximum absorption wavelength (λmax) and gram extinction coefficient (εg) of this compound were as follows. Elemental analysis (C ₄₀ H ₅₂ ClIN ₂ O ₆ ): MW = 819.2 Calculated value for CH N (%) 58.65 6.40 3.42 Actual value (%) 58.36 6.43 3.32 Melting point (° C.): 167-168 ° C. λmax: 832 nm (diacetone alcohol solution) εg: 2.65 × 10 ⁵ ml / g · cm FIG. 2 shows the IR spectrum of the obtained compound.

Example 3 Polymethine Compound (Synthesis of Specific Example Compound (13)) In Example 1, the compound represented by the general formula (II) was
(R ₁ = methoxy group, R ₂ = methoxyethyl group, R ₃ =
R ₄ = methyl group, Y = 7-methoxy group, Z = BF ₄ ⁻ ,
n = 1) 3.65 g of a 2% KClO ₄ aqueous solution 300 m
In the same manner as in Example 1 except that 300 ml of a 2% aqueous KBF ₄ solution was used in place of 1
(13) 2.92 g was obtained.

The elemental analysis value, melting point, maximum absorption wavelength (λmax) and gram extinction coefficient (εg) of this compound were as follows. Elemental analysis _{(C 40 H 52 BClF 4 N} 2 O 6): MW = 779.1 C H N calc (%) 61.66 6.73 3.60 Found (%) 61.39 6.75 3 .55 Melting point (° C.): 150-152 ° C. λmax: 832 nm (diacetone alcohol solution) εg: 2.85 × 10 ⁵ ml / g · cm The IR spectrum of the obtained compound is shown in FIG.

Example 4 Polymethine Compound (Synthesis of Specific Example Compound (17)) In Example 1, the compound represented by the general formula (II) was
(R ₁ = methoxy group, R ₂ = R ₃ = R ₄ = methyl group, Y
= 6-methoxy group, Z = p-toluenesulfonate, n
= 1) 4.06 g, 2 ml KClO ₄ aqueous solution 300 ml instead of 2% p-toluenesulfonic acid aqueous solution 300 ml
The same operation as in Example 1 was performed except for using, to obtain 2.72 g of a specific compound (17).

The elemental analysis value, melting point, absorption maximum wavelength (λmax) and gram extinction coefficient (εg) of this compound were as follows. Elemental analysis value (C ₄₃ H ₅₁ ClN ₂ O ₇ S): MW = 775.4 Calculated value for CH N (%) 66.61 6.63 3.61 Actual value (%) 65.96 6.72 3. 54 Melting point (° C.): 169 to 171 ° C. λmax: 831 nm (diacetone alcohol solution) εg: 2.60 × 10 ⁵ ml / g · cm The IR spectrum of the obtained compound is shown in FIG.

Example 5 Polymethine Compound (Synthesis of Specific Example Compound (19)) In Example 2, the compound represented by the general formula (II) was
(R ₁ = methoxy group, R ₂ = methoxyethyl group, R ₃ =
R ₄ = methyl group, Y = 7-methyl group, Z = ClO ₄ ⁻ ,
n = 1) 3.61 g, the same operation as in Example 2 except that 300 ml of a 2% aqueous KClO ₄ solution was used instead of 300 ml of a 2% aqueous KI solution, to thereby give a specific compound (19).
3.05 g were obtained.

The elemental analysis value, melting point, absorption maximum wavelength (λmax) and gram extinction coefficient (εg) of this compound were as follows. Elemental analysis _{(C 40 H 52 Cl 2 N} 2 O 8): MW = 759.8 C H N calc (%) 63.23 6.90 3.69 Found (%) 62.87 6.85 3 0.73 Melting point (° C.): 197 to 198 ° C. λmax: 822 nm (diacetone alcohol solution) εg: 3.12 × 10 ⁵ ml / g · cm The IR spectrum of the obtained compound is shown in FIG.

The VIS-NIR absorption spectrum of the obtained compound is shown in FIG.

Example 6 Polymethine Compound (Synthesis of Specific Example Compound (47)) In Example 1, the compound represented by the general formula (II) was
(R ₁ = methoxy group, R ₂ = methoxyethyl group, R ₃ =
R ₄ = methyl group, Y = 7-methyl group, Z = p-toluenesulfonate, n = 1) 4.34 g, except that 300 ml of 2% aqueous solution of p-toluenesulfonic acid was used instead of 300 ml of 2% aqueous solution of KClO ₄ By performing the same operation as in Example 1, 2.70 g of the compound of the specific example compound (47) was obtained.

The elemental analysis value, melting point, maximum absorption wavelength (λmax) and gram extinction coefficient (εg) of this compound were as follows. Elemental analysis (C ₄₇ H ₅₉ ClN ₂ O ₇ S): MW = 831.5 CH N calculated (%) 67.89 7.15 3.37 found (%) 67.20 7.24 3. 45 Melting point (° C.): 205 to 207 ° C. λmax: 822 nm (diacetone alcohol solution) εg: 2.80 × 10 ⁵ ml / g · cm The IR spectrum of the obtained compound is shown in FIG.

Example 7 Polymethine Compound (Synthesis of Specific Example Compound (51)) A compound represented by the general formula (II) (R ₁ = methoxy group, R ₂
= 3-sulfopropyl group, R ₃ = R ₄ = methyl group, Y =
3.25 g of a 7-methyl group, n = 0), 1.80 g of a compound represented by the general formula (IV) (X = Cl) and 3.36 g of potassium acetate were added to 50 ml of acetic anhydride, and the mixture was heated at 65 to 70 ° C. After stirring for 60 minutes, 200 ml of isopropanol was added, and the mixture was further stirred at the same temperature for 60 minutes. After evaporation to dryness, 100 ml of ethyl acetate was added, and the mixture was stirred at room temperature for 1 hour. The precipitated crystal was separated by filtration, washed with 10 ml of ethyl acetate, and recrystallized with 100 ml of methanol. The obtained crystal was dissolved in a solution of 2 g of sodium acetate, 100 ml of methanol and 100 ml of isopropanol, and the solvent was distilled off under normal pressure. The precipitated crystal was separated by filtration and dried to give a specific compound.
(51) 2.30 g was obtained.

Elemental analysis value and absorption maximum wavelength of this compound
(λmax) and gram extinction coefficient (εg) were as follows. Elemental analysis _{(C 40 H 50 ClN 2 NaO} 8 S 2): MW = 809.4 C H N calc (%) 59.36 6.23 3.46 Found (%) 58.69 6.37 3 .37 melting point (° C.): 260 to 261 ° C. or higher (decomposition) λmax: 824 nm (diacetone alcohol solution) εg: 2.82 × 10 ⁵ ml / g · cm FIG. 7 shows an IR spectrum of the obtained compound.

The VIS-NIR absorption spectrum of the obtained compound is shown in FIG.

Example 8 Polymethine Compound (Synthesis of Specific Compound (55)) In Example 2, the compound represented by the general formula (II) (R ₁
= Methoxy group, R ₂ = methoxyethyl group, R ₃ = R ₄ =
Methyl group, Y = 7-methyl group, Z = BF ₄ ⁻ , n = 1)
3.62 g, 2% instead of 300 ml of 2% KI aqueous solution
The same operation as in Example 2 was carried out except that 300 mL of an aqueous KBF ₄ solution was used to obtain a specific compound (55) .2.
20 g were obtained.

The elemental analysis value, melting point, absorption maximum wavelength (λmax) and gram extinction coefficient (εg) of this compound were as follows. Elemental analysis _{(C 40 H 52 BClF 4 N} 2 O 4): MW = 747.1 C H N calc (%) 64.30 7.02 3.75 Found (%) 64.21 6.91 3 .70 Melting point (° C.): 198 to 199 ° C. λmax: 822 nm (diacetone alcohol solution) εg: 3.20 × 10 ⁵ ml / g · cm The IR spectrum of the obtained compound is shown in FIG.

Example 9 Polymethine Compound (Preparation of Amorphous Compound of Specific Compound (55)) 2.0 g of the specific compound (55) obtained in Example 8 was dissolved in 20 ml of acetone, concentrated and dried. As a result, 1.95 g of an amorphous product of the specific example compound (55) was obtained.

The elemental analysis value, melting point, absorption maximum wavelength (λmax) and gram extinction coefficient (εg) of this compound were as follows. Elemental analysis _{(C 40 H 52 BClF 4 N} 2 O 4): MW = 747.1 C H N calc (%) 64.30 7.02 3.75 Found (%) 64.24 6.99 3 .69 melting point (° C.): unclear λmax: 822 nm (diacetone alcohol solution) εg: 3.18 × 10 ⁵ ml / g · cm FIG. 12 shows a powder X-ray diffraction diagram of the obtained compound.

Example 10 Polymethine Compound (Preparation of β Crystal of Specific Example Compound (55)) 2.0 g of the specific example compound (55) obtained in Example 8 was recrystallized from 30 ml of methanol to give a specific product. 1.42 g of β crystal of the example compound (55) was obtained.

The elemental analysis value, melting point, absorption maximum wavelength (λmax) and gram extinction coefficient (εg) of this compound were as follows. Elemental analysis _{(C 40 H 52 BClF 4 N} 2 O 4): MW = 747.1 C H N calc (%) 64.30 7.02 3.75 Found (%) 64.25 6.96 3 .71 Melting point (° C.): 204-206 ° C. λmax: 822 nm (diacetone alcohol solution) εg: 3.21 × 10 ⁵ ml / g · cm FIG. 13 shows a powder X-ray diffraction diagram of the obtained compound.

Example 11 Polymethine Compound (Preparation of Methanol Solvate of Specific Example Compound (55)) 2.0 g of the specific compound (55) obtained in Example 8 was dissolved in 50 ml of methanol, and the evaporator was used. The residue was concentrated under reduced pressure to a residual concentration of 7 g, cooled, filtered and dried to give a methanol solvate of the specific compound (55) 1.92.
g was obtained.

The melting point and maximum absorption wavelength (λma) of this compound
x) and gram extinction coefficient (εg) were as follows. Melting point (° C.): １８０180 ° C. λmax: 822 nm (diacetone alcohol solution) εg: 2.92 × 10 ⁵ ml / g · cm FIG. 14 shows a powder X-ray diffraction diagram of the obtained compound. Example 12 Polymethine Compound (Preparation of α Crystal of Specific Example Compound (55)) Amorphous Compound of Specific Example Compound (55) Obtained in Example 9
By dispersing 5 g in methanol (20 ml) at room temperature, 1.23 g of α-crystal of specific example compound (55) was obtained.

The elemental analysis value, melting point, absorption maximum wavelength (λmax) and gram extinction coefficient (εg) of this compound were as follows. Elemental analysis _{(C 40 H 52 BClF 4 N} 2 O 4): MW = 747.1 C H N calc (%) 64.30 7.02 3.75 Found (%) 64.21 6.93 3 0.71 Melting point (° C.): 195 to 197 ° C. λmax: 822 nm (diacetone alcohol solution) εg: 3.20 × 10 ⁵ ml / g · cm FIG. 15 shows a powder X-ray diffraction diagram of the obtained compound.

[Maximum absorption wavelength] The maximum absorption wavelength (λ) of the polymethine compound of the present invention in a diacetone alcohol solution.
max) is a known compound, compound A or compound B
It was measured together with. Table 1 shows the results.

[0130]

[Table 1]

[Solubility Test] The solubility of the polymethine compound of the present invention in methyl ethyl ketone was measured together with the known compounds A and B. The solubility was measured according to the following method.

Method for measuring solubility 200 mg of each polymethine compound was placed in a 5 ml screw tube.
And 1 ml of methyl ethyl ketone, and Mix-Rot
The mixture was stirred and dissolved at 25 ° C. overnight at or, and the presence or absence of insolubles was visually checked. If there is no insoluble matter, the solubility is 20% or more,
The case where the insoluble matter remained was determined to be less than 20%.

Instead of 200 mg of polymethine compound,
Each polymethine compound 150mg, 100mg, 50m
g, 30 mg and 10 mg were used, and the solubility was measured in the same manner. Table 2 shows the results.

[0134]

[Table 2] The specific compound (55) in Tables 1 and 2 was measured using the compound synthesized in Example 8.

Example 13 Production of Near-Infrared Absorber Polyethylene terephthalate (PET) having an average thickness of 5 μm
As a binder for the film, Delpet 80N (acrylic resin manufactured by Asahi Kasei Kogyo Co., Ltd.); 10 g, a specific compound (11); 0.2 g of toluene / methyl ethyl ketone (1
/ 1) A solution dissolved in 90 g of the mixed solvent was applied using a wire bar so that the film thickness after drying was about 5 μm, to obtain a sample.

A single mode semiconductor laser (wavelength 830n)
The laser light of m) was condensed by a lens and arranged so as to have a beam diameter of 10 μm on the surface of the sample. The semiconductor laser was adjusted so that the power of the laser reaching the surface could be changed in the range of 50 to 200 mW, and a single pulse was applied to the sample with a pulse width of 20 μs. When the irradiated sample was observed with an optical microscope, it was confirmed that a through hole having a diameter of about 10 μm was formed when the laser power reaching the surface was 50 mW.

Example 14 Production of Near-Infrared Absorber In Example 13, compound (11) as a specific example; 0.2 g
The same operation as in Example 9 was performed, except that 0.2 g of the compound (19) of the specific example was used instead of. When the irradiated sample was observed with an optical microscope, it was confirmed that a through hole having a diameter of about 10 μm was formed when the laser power reaching the surface was 50 mW.

Example 15 Preparation of Printing Plate for Direct Plate Making (Formation of Undercoat Layer) A gelatin undercoat layer was formed as a primer layer on a 175 μm-thick polyethylene terephthalate film so as to have a dry film thickness of 0.2 μm. .

(Formation of Light-to-Heat Conversion Layer) A coating solution prepared with the following components was coated on the above-mentioned gelatin-subbed polyethylene terephthalate to a dry film thickness of 2 μm to form a light-to-heat conversion layer. Compound (11) of specific example 0.1 part by weight Crisbon 3006LV 5.0 parts by weight (polyurethane manufactured by Dainippon Ink and Chemicals, Inc.) Solsperse S27000 (manufactured by ICI) 0.4 part by weight Nitrocellulose (n-propanol 30) 4.2 parts by weight Xylylenediamine 1 mol / adduct of glycidyl methacrylate 4 mols 2.0 parts by weight Ethyl Michler's ketone 0.2 parts by weight Tetrahydrofuran 90 parts by weight

(Formation of Silicon Rubber Layer) A coating liquid prepared with the following components was applied onto the above-mentioned light-to-heat conversion layer so as to have a dry film thickness of 2 μm to form a silicon rubber layer. α, ω-divinylpolydimethylsiloxane (degree of polymerization: about 700) 9.0 parts by weight (CH ₃ ) ₃ Si-O- (SiH (CH ₃ ) -O) ₈ -Si (CH ₃ ) ₃ 0.6 parts by weight Polydimethylsiloxane (degree of polymerization: about 8000) 0.5 parts by weight Olefin-chloroplatinic acid 0.08 parts by weight Inhibitor HC @ CC (CH ₃ ) ₂ -O-Si (CH ₃ ) ₃ 0.07 parts by weight Isopar G (Esso Chemical Co., Ltd.) 55 parts by weight

[0141] The printing original plate obtained as described above
The beam diameter should be 10 so that the power on the plate is 110 mW.
Writing was performed using a semiconductor laser having an oscillation wavelength of 830 nm. Laser recording sensitivity is 200mJ / cm
^2. A printing plate having a sharp edge was formed at a resolution of 8 μm.

Example 16 Preparation of a printing plate precursor for direct plate making In Example 15, 0.1 part by weight of the compound (47) of the specific example was replaced by 0.1 part by weight of the compound (11) of the specific example. A printing original plate was prepared in the same manner as in Example 11 except for using the same.

The printing original plate obtained as described above includes
The beam diameter should be 10 so that the power on the plate is 110 mW.
Writing was performed using a semiconductor laser having an oscillation wavelength of 830 nm. Laser recording sensitivity is 200mJ / cm
^2. A printing plate having a sharp edge was formed at a resolution of 8 μm.

[Example 17] Preparation of a printing plate precursor for direct plate making In Example 15, the compound (55) shown in Table 1 was replaced by 0.1 part by weight instead of the compound (11) of the specific example; A printing original plate was prepared in the same manner as in Example 11 except for using the same.

The printing plate obtained as described above is
The beam diameter should be 10 so that the power on the plate is 110 mW.
Writing was performed using a semiconductor laser having an oscillation wavelength of 830 nm. Laser recording sensitivity is 200mJ / cm
^2. A printing plate having a sharp edge was formed at a resolution of 8 μm.

[Comparative Example 1] In Example 13, compound (11) of specific example;
No. 9191, a polymethine compound having the following structural formula;
The same operation as in Example 13 was performed except that 0.2 g was used. When the irradiated sample was observed with an optical microscope, no through hole was formed even when the laser power reaching the surface was 100 mW.

[0147]

Embedded image

[Comparative Example 2] In Example 13, the compound of the specific example (11);
c The same operation as in Example 13 was performed except that 0.2 g of a polymethine compound having the following structural formula described in Chemistry, 60, 2392, Table 1. was used. When the irradiated sample was observed with an optical microscope, the power of the laser reaching the surface was 5
At 0 mW, no through hole was formed.

[0149]

Embedded image

[0150]

The polymethine compound of the general formula (I) has low absorption in the visible region, and a near-infrared absorbing agent containing this compound has good sensitivity to laser light and high photothermal conversion efficiency. It can be suitably used as a laser thermal transfer recording material, a laser thermal recording material, or the like that provides a high-density, high-quality image. Further, the polymethine compound of the general formula (I) has extremely high solubility in various solvents used for producing a photothermal conversion layer of a printing plate for direct plate making, and has good compatibility with various binder resins and the like, so that a coating liquid It is particularly suitable for the production of a printing plate precursor for direct plate making because it is easy to adjust and a uniform light-to-heat conversion layer can be formed.

[Brief description of the drawings]

FIG. 1 is an IR absorption spectrum of the polymethine compound of Example 1.

FIG. 2 is an IR absorption spectrum of the polymethine compound of Example 2.

FIG. 3 is an IR absorption spectrum of the polymethine compound of Example 3.

FIG. 4 is an IR absorption spectrum of the polymethine compound of Example 4.

FIG. 5 is an IR absorption spectrum of the polymethine compound of Example 5.

FIG. 6 is an IR absorption spectrum of the polymethine compound of Example 6.

FIG. 7 is an IR absorption spectrum of the polymethine compound of Example 7.

FIG. 8 is an IR absorption spectrum of the polymethine compound of Example 8.

FIG. 9 is a VIS-NIR absorption spectrum of the polymethine compound of Example 1 in diacetone alcohol.

FIG. 10 is a VIS-NIR absorption spectrum of the polymethine compound of Example 5 in diacetone alcohol.

FIG. 11 is a VIS-NIR absorption spectrum of the polymethine compound of Example 7 in diacetone alcohol.

FIG. 12 is a powder X-ray diffraction chart of the polymethine compound of Example 9.

FIG. 13 is a powder X-ray diffraction chart of the polymethine compound of Example 10.

FIG. 14 is a powder X-ray diffraction chart of the polymethine compound of Example 11.

FIG. 15 is a powder X-ray diffraction chart of the polymethine compound of Example 12.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09K 3/00 105 C09K 3/00 105 G03C 1/20 G03C 1/20 G03F 7/004 505 G03F 7/004 505 G03G 5/05 104 G03G 5/05 104B (72) Inventor Yoshiki Chichiishi 1-43, Yugecho Minami, Yao-shi, Osaka Inside Yamamoto Kasei Co., Ltd. (72) Inventor Yasuhisa Iwasaki 1-43, Yugecho Minami, Yao-shi, Osaka Address Yamamoto Kasei Co., Ltd.

Claims (15)

[Claims] 1. A polymethine compound represented by the following general formula (I). Embedded image (Wherein, R ₁ represents an alkoxy group which may have a substituent, R ₂ represents an alkyl group which may have a substituent,
_3, R ₄ each represent a lower alkyl group, and R ₃ and R ₄ may combine with each other to form a cyclic structure, X is a hydrogen atom, a halogen atom or a substituted amino group, Y
Represents an alkoxy group which may have a substituent or an alkyl group which may have a substituent, and Z represents a charge neutralizing ion. ) 2. R ₁ is an alkoxy group having 1 to 4 carbon atoms, R ₂ is an alkyl group having 1 to 8 carbon atoms, and a total number of 2 to 8 carbon atoms.
Is an alkoxyalkyl group having 1 to 8 carbon atoms, or a carboxyalkyl group having 2 to 9 carbon atoms, wherein Y is an alkoxy group having 1 to 4 carbon atoms or 1 carbon atom.
The polymethine compound according to claim 1, which is an alkyl group of (1) to (4). 3. The method according to claim 1, wherein Z is Cl ⁻ , Br ⁻ , I ⁻ , ClO ₄ ⁻ ,
BF ₄ ⁻ , CF ₃ CO ₂ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , C
H ₃ SO ₃ ^- or p- toluenesulfonate, N
3. The polymethine compound according to claim 1, which is a ⁺ , K ⁺ or triethylammonium ion. Wherein _R 3, _{R 4} is a methyl group, _{R 3} and cyclopentane ring or _{R 3 where R 4} is formed by connecting together R
The polymethine compound according to any one of claims 1 to 3, wherein ₄ is a cyclohexane ring formed by linking each other. 5. The polymethine compound according to claim 1, wherein X is H, Cl, Br or a diphenylamino group. 6. A diffraction angle (2θ ± 0.2 °) of 11.6 °, 14.6 °, 1 ° in a powder X-ray diffraction method using Cu-Kα ray.
2- (2- {2-chloro-3-[() represented by the following formula characterized by a powder X-ray diffraction pattern showing characteristic peaks at 5.6 °, 19.6 ° and 22.9 °. 1,3-dihydro-3,3,7-trimethyl-5-methoxy-1-methoxyethyl-2H-indole-2-ylidene) ethylidene] -1-cyclohexen-1-yl {ethenyl)-
2. The polymethine compound according to claim 1, which is a low-melting crystalline modification of 3,3,7-trimethyl-5-methoxy-1-methoxyethylindolium = tetrafluoroborate. Embedded image 7. A powder X-ray diffraction pattern showing a very strong peak characteristic at a diffraction angle (2θ ± 0.2 °) of 8.4 ° in powder X-ray diffraction by Cu-Kα ray. 2- (2- {2-chloro-3-[(1,3
-Dihydro-3,3,7-trimethyl-5-methoxy-
1-methoxyethyl-2H-indole-2-ylidene) ethylidene] -1-cyclohexen-1-yl {ethenyl) -3,3,7-trimethyl-5-methoxy-1
The polymethine compound according to claim 1, wherein -methoxyethylindolium is a high melting point crystalline modification of tetrafluoroborate. Embedded image 8. A diffraction angle (2θ ± 0.2 °) of 13.3 °, 17.4 °, 1 ° in a powder X-ray diffraction method using Cu-Kα ray.
2- (2- {2-chloro-3-[() represented by the following formula characterized by a powder X-ray diffraction pattern showing characteristic peaks at 9.8 °, 21.8 °, and 26.9 °. 1,3-dihydro-3,3,7-trimethyl-5-methoxy-1-methoxyethyl-2H-indole-2-ylidene) ethylidene] -1-cyclohexen-1-yl {ethenyl)-
The polymethine compound according to claim 1, which is a crystalline methanol adduct of 3,3,7-trimethyl-5-methoxy-1-methoxyethylindolium = tetrafluoroborate. Embedded image 9. A compound represented by the following formula, which is characterized by an X-ray powder diffractogram showing no characteristic peak at a diffraction angle (2θ ± 0.2 °) in a powder X-ray diffraction method using Cu-Kα ray. -(2- {2-chloro-3-[(1,3-dihydro-
3,3,7-trimethyl-5-methoxy-1-methoxyethyl-2H-indole-2-ylidene) ethylidene] -1-cyclohexen-1-yl {ethenyl)-
The polymethine compound according to claim 1, which is an amorphous product of 3,3,7-trimethyl-5-methoxy-1-methoxyethylindolinium tetrafluoroborate. Embedded image 10. An indolenium compound represented by the following general formula (II) and a diformyl compound represented by the following general formula (III) or a dianyl compound represented by the following (IV) are dehydrated in the presence of a fatty acid salt. The method for producing a polymethine compound according to claim 1, wherein the condensation is carried out using a neutral organic acid. Embedded image (Wherein, R ₁ represents an alkoxy group which may have a substituent, R ₂ represents an alkyl group which may have a substituent,
₃ and R ₄ each represent a lower alkyl group; R ₃ and R ₄ may be linked to each other to form a cyclic structure; and Y has an alkoxy group or a substituent which may have a substituent. And Z ₁ represents a charge neutralizing ion, and n represents a number of 0 or 1. ) (In the formula, X represents a hydrogen atom, a halogen atom or a substituted amino group.) (In the formula, X represents a hydrogen atom, a halogen atom or a substituted amino group.) 11. A process for producing a crystalline low melting point polymethine compound according to claim 1, wherein the crystalline solvent adduct or the amorphous product of the polymethine compound according to claim 1 is treated with a solvent. 12. The method for producing a high melting point crystalline product of the polymethine compound according to claim 1, wherein the polymethine compound according to claim 1 is recrystallized with a ketone or alcohol solvent. 13. A near-infrared absorbing agent comprising the polymethine compound according to claim 1. 14. A printing plate precursor for direct plate making comprising a light-to-heat conversion layer provided on a support, wherein the polymethine compound according to claim 1 is contained in the light-to-heat conversion layer. 15. A method for producing a printing plate by irradiating a printing plate precursor for direct plate making according to claim 14 with a semiconductor laser beam having a light emitting region at 750 to 900 nm as a light source.