WO2004113453A1

WO2004113453A1 - Crystalline nonsolvated polymethine compound

Info

Publication number: WO2004113453A1
Application number: PCT/JP2004/008795
Authority: WO
Inventors: Keiki Chichiishi; Sayuri Wada; Shigeo Fujita
Original assignee: Yamamoto Chemicals, Inc.
Priority date: 2003-06-18
Filing date: 2004-06-16
Publication date: 2004-12-29
Also published as: JPWO2004113453A1

Abstract

A novel polymethine compound which exhibits excellent stability in a solution, a high gram absorption coefficient, and excellent storage stability and is easily handleable and highly sensitive to general-purpose semiconductor lasers, that is, the crystalline nonsolvated polymethine compound represented by the formula (I): (I) and a process for the production of the crystalline nonsolvated polymethine compound of the formula (I), characterized by reacting a polymethine ether of the general formula (II) with hydrochloric acid: (II) wherein R is alkyl, alkoxyalkyl, or optionally substituted aryl.

Description

Crystalline unsolvated polymethine compound

Technical field

The present invention relates to a novel crystalline unsolvate of a polymethine compound, a method for producing the same,

The present invention relates to a near-infrared absorbing agent using the crystalline non-solvated polymethine compound. book

Background art

In recent years, polymethine compounds have been widely used as optical recording media, materials for near-infrared absorption filters, photothermal conversion agents for plate making materials using laser light, and the like. Particularly recently, in the field of plate making materials using laser light, general-purpose semiconductor lasers, for example, have a high sensitivity in the laser region of 780 nm to 800 nm, and are suitable for general-purpose solvents, for example, alcohol solvents such as methanol and ethanol. There is an increasing demand for compounds having good solubility. It is also important that they are stable and easy to handle, and that they do not contain impurities that can adversely affect various applications. However, a polymethine compound satisfying such a demand has not been known.

Since the disclosure of Zh. Or. Khim. (1978), 14 (10), various investigations have been made on compounds having structural formulas similar to those of the polymethine compound of the present invention. As a method for synthesizing a compound, for example, the following formula (III):

(In the formula, 1 ^ represents an alkyl group which may have a substituent, and Z represents an acidic residue.) Indolenium-based compound represented by the general formula (CV)

(In the formula, 1 ^ represents an alkyl group which may have a substituent.)

And a diformyl compound represented by the formula (V) or a dianyl compound represented by the formula (VI):

Is known in the presence of a fatty acid salt in the presence of a dehydrating organic acid (WO 01/007524, JP-A-10-195319, pages 8 to 1). 0, J. Org. Chem. 1955, 60, 2394, Patent Publication No. 3044504, Example 1, DE3721850, JP-A-62-36469, etc.).

Of these, the most common method is to react the indrenium-based compound of the formula (III) with the dianyl-based compound of the formula (VI) to synthesize a polymethine-based compound. The type of the acidic residue Z— is restricted from the viewpoint of the reaction yield of the system compound, the operability of isolation and purification, and the like. A powerful production method is generally used for the production of polymethine compounds in which is a residue of perchloric acid, a residue of tetrafluoroboronic acid, or a residue of p-toluenesulfonic acid. Other than halogen ions, special Is not known about what is C 1.

Next, regarding the method for reacting the indolin compound of the formula (IV) with the diformyl compound of the formula (V), the synthesis example in which the counter ion of the polymethine compound is C 1-is described in Example 3 of DE3721850. It is disclosed in 1. However, there is no description of physical properties other than the maximum absorption wavelength (e.g. max) in this document, and the compound obtained by such a synthesis method has a different structure from the polymethine compound of the present invention as described later.

Regarding the method of reacting the indolin compound of the formula (IV) with the dianyl compound of the formula (VI), the compound having a different basic structural formula from the polymethine compound of the present invention has a force Z— having a C 1— A production example is disclosed in Example 3 of Japanese Patent Application Laid-Open No. Sho 62-36469.

Therefore, the present inventors, according to the method disclosed in Example 1 of the above DE3721850 and Example 3 of JP-A-6-36469, a compound having the same structure as the polymethine compound of the present invention. Tried synthesis. However, the obtained compound is a solvate and a very low-purity product from the results of TG-DTA analysis, and cannot be purified by recrystallization with an alcoholic solvent such as methanol or ethanol. Various purification methods were examined for this compound, but it easily formed into a solvate in the presence of water, Z or alcohol, and the same compound as the present compound could not be obtained.

In the present invention, “solvate” is a generic term including hydrates.

Recently, the compound of the same formula as the polymethine compound of the present invention has been described in the reagent catalog of the Japanese version of the Anoredricht catalog (2003-2004). And a low-purity compound.

Incidentally, the chemical structural formula itself of the polymethine compound of the present invention is shown in the table on page 2 of JP-A-62-150187. ) —2. However, there is no description of the examples in this document, and neither the synthesis method nor the physical properties are shown.

As described above, known compounds having the same structural formula as the compound of the present invention are caused by the production method thereof. It is a low-purity solvate, which greatly restricts its use. For example, when a solvate of a compound having the same structural formula as the compound of the present invention is used as a light-to-heat conversion agent for CTP (Computer To Plate) plate making, the solution stability is poor and the purity is not stable. However, the light-to-heat conversion efficiency fluctuates greatly, which is a serious problem in practical use.

In the case of polymethine compounds, there is no report that there is a significant difference in stability and sensitivity in solution depending on the presence or absence of solvation, although the basic structural formula of the compound is the same. Disclosure of the invention

An object of the present invention is to provide a novel polymethine compound having good stability in a solution, high gram extinction coefficient, excellent storage stability, easy handling, and high sensitivity to a general-purpose semiconductor laser. That is.

As a result of various studies to solve the above-mentioned problems, the present inventors have found that a novel crystalline unsolvate of a polymethine compound having a specific structure has good solubility stability in a solvent and a gram extinction coefficient. The present invention was found to be high, stable, easy to remove, and usable as a near-infrared absorbing agent that can be easily processed for various uses.

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

The crystalline unsolvated polymethine compound of the present application has a melting point (decomposition temperature) of 220 ° C. or higher, and the TG-DTA (thermogravimetric-differential thermal analysis) measurement diagram shows that TG weight loss at 50 ° C or less is 3% or less, and it is not substantially solvated. Furthermore diffraction angle in the powder X-ray diffraction method according Cu- kappa _alpha rays (0 20 ±. 2 °) 11. 8. , 13.0 °, 18.7 °, 19.4 °, 21.2 ° The crystalline non-solvent represented by the following formula (I) characterized by an X-ray powder diffraction pattern showing characteristic peaks: It is a Japanese polymethine compound.

The second invention of the present application is the following formula (II):

(In the formula, R represents an alkyl group, an alkoxyalkyl group, or an aryl group which may have a substituent.)

A method for producing a crystalline non-solvated polymethine compound represented by the above formula (I), which comprises reacting a polymethine ether compound represented by the formula with hydrochloric acid. The third invention of the present application is a near-infrared absorbing agent containing a crystalline unsolvated polymethine compound of the formula (I). BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a powder X-ray diffraction diagram of a polymethine compound of Example 1.

FIG. 2 is an IR absorption spectrum of the polymethine compound of Example 1. FIG. 3 is a TG-DTA (thermogravimetry-differential thermal analysis) diagram of the polymethine compound of Example 1.

FIG. 4 is an X-ray powder diffraction diagram of a solid material of Comparative Example 1.

FIG. 5 is a graph showing TG-DTA (thermogravimetry-differential thermal analysis) measurement of the solid material of Comparative Example 1. Detailed description of the invention

Next, the present invention will be described in detail.

The crystalline non-solvate of the polymethine compound represented by the formula (I) of the present invention has a melting point (decomposition temperature) of 220 ° C or more, and preferably 225 ° C to 235 ° C. For solvates and / or low-purity products, the melting point is below 220 ° C. In the case of the compound of the present invention, the melting point (decomposition temperature) can be observed very clearly because the compound gradually foams and decomposes when it begins to be dissolved, but the solvate and / or low-purity product has a clear melting point and The decomposition temperature may not be indicated.

The TG-DTA (thermogravimetry-differential thermal analysis) measurement diagram of the crystalline unsolvated polymethine compound represented by the formula (I) of the present invention shows that the TG loss value at 150 ° C or less is 3%. Or less, preferably 2% or less. For hydrates and Z or low purity products, the TG weight loss below 150 ° C is more than 3%.

The known compound represented by the formula (I) is a compound solvated with water or an organic solvent, has a limited use, and has low industrial value.

On the other hand, the crystalline unsolvate of the polymethine compound represented by the formula (I) of the present invention is a completely novel compound that is not solvated with water or an organic solvent. The crystalline unsolvate of the polymethine compound represented by the formula (I) of the present invention has a diffraction angle (2S ± 0.2 °) of 11.8 in a powder X-ray diffraction method using Cu-ray. , 13.0 °, 18.7 °, 19.4 ° and 21.2 °. The solvate and / or low-purity product shows a completely different powder X-ray diffraction pattern. It has been found that the crystalline non-solvate of the polymethine compound of the present invention can be produced for the first time by passing (as a starting material) a polymethine ether compound represented by the formula (II).

The crystalline non-solvate of the polymethine compound represented by the formula (I) of the present invention has not only the above-mentioned excellent characteristics, but also, surprisingly, a similar polymethine-based compound known so far. Compared with the compound, the solubility in methanol and ethanol is very high, and the absorbance in the 780 to 830 nm region is large.

In other words, when processing near-infrared absorbers such as various markings, filters, films, etc., they are more stable and can be used with high-concentration liquids of alcoholic solvents that are easy to handle, so they are excellent in handling and processability. . In addition, in many recording material fields that use laser light, we are matching semiconductor lasers that have a general light-emitting area in the range of 780 to 830, and we have developed laser thermal transfer recording materials and lasers that use laser light. It is extremely useful in the field of recording materials such as thermal recording materials and in the field of plate making materials.

[Method for producing crystalline unsolvated polymethine compound]

The crystalline unsolvate of the polymethine compound represented by the formula (I) of the present invention can be produced by the following method.

—Manufactured by reacting a polymethine ether compound of the general formula (Π) (for example, R = CH ₃ ) with hydrochloric acid in an organic solvent.

(In the formula, R represents an alkyl group, an alkoxyalkyl group, or an aryl group which may have a substituent.) As R is an alkyl group, a linear or branched alkyl group having 1 to 8 carbon atoms is preferable, and a linear or branched alkyl group having 1 to 4 carbon atoms is particularly preferable. Examples include methynole, ethyl, n-propyl, isopropyl, n-butynole, isobutynole, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl Group, isohexyl group, sec-hexyl group, 2-ethylbutyl group, n-heptyl group, isoheptyl group, sec-heptyl group, n-octyl group, and 2-ethylhexyl group.

As R is an alkoxyalkyl group, those having 2 to 8 carbon atoms are preferred, and those having 2 to 4 carbon atoms are particularly preferred. Examples include a methoxymethyl group, a 2-methoxyl group, a 3-methoxypropyl group, a 2-ethoxymethyl group, a 2-ethoxyl group, a 2-propoxyl group and a 2-butoxyl group.

Examples of the group in which R is an aryl group which may have a substituent include a phenyl group which may have a substituent and a naphthyl group which may have a substituent. A phenyl group which may be substituted is preferred. Examples of the substituent include an alkyl group, an amino group, a nitro group, an alkoxy group, a hydroxyl group, a halogen atom, and the like, and an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms is preferable.

Examples of the group in which R is a phenyl group having an alkyl group include 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 2,3-dimethylphenyl group, 2,4-dimethylphenyl group, 3,4-dimethylphenyl group, 2,5-dimethylphenyl group, 2,6-dimethylphenyl group, 2-erphenyl group, 3-ethylphenyl group, 4-ethylphenyl group, 2,3-ethylphenyl A 2,4-dimethylthiophenyl group, a 3,4-dimethylthiophenylene group, a 2,5-dimethylthiophenylene group, and a 2,6-getylphenyl group.

Examples of the group in which R is a phenyl group having an alkoxy group include a 2-methoxyphenyl group, a 3-methoxyphenyl group, a 4-methoxyphenyl group, a 2,3-dimethoxyphenyl group, and a 2,3-methoxyphenyl group. 4-dimethoxyphenyl group, 3, 4-dimethoxyphenyl And 2,5-dimethoxyphenyl group and 2,6-dimethoxyphenyl group.

Examples of the organic solvent include alcohols such as methanol, ethanol, n-propanol, iso-propanol, and n-butanol; ketones such as acetone, methyl ethyl ketone, methyl propyl ketone and methyl butyl ketone; tetrahydrofuran and dioxane. Ethers such as methyl acetate, ethyl acetate and butyl acetate; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as dichloromethane, trichloromethane, dichloroethane and trichloroethane; dimethylformaldehyde; Aprotic polar solvents such as dimethylacetamide and dimethylsulfoxide; alcohols such as methanol, ethanol, n-propanol, iso-propanol and n-butanol; acetone; Chiruechiruketon, methyl propyl ketone and methyl butyl ketone, methyl acetate, acetic Echiru, esters such as ethyl acetate and butyl acetate are particularly preferred.

The compound represented by the formula (II) and the hydrochloric acid are usually used in an amount of about 0.5 to 3 mol, preferably about 1 to 1.5 mol, of the former per 1 mol.

The organic solvent is generally used in an amount of about 1 to 30 L, preferably about 3 to 20 L, per 1 mol of the compound represented by the specific example (II).

The above reaction proceeds suitably at a temperature of usually 100 ° C. or lower, preferably 10 ° C. to 70 ° C., and is generally completed in about several minutes to 5 hours.

After the reaction, the target substance can be easily isolated by filtration and washing. Further, it can be easily purified by conventional purification means, for example, recrystallization. Examples of the solvent for crystal isolation and / or purification include organic solvents used in the above reaction, and general-purpose organic solvents such as alcohols such as methanol, ethanol, n-propanol, iso-propanol and n-butanol, and acetone. Ketones such as methylethyl ketone, methylpropyl ketone and methylbutyl ketone; ethers such as tetrahydrofuran and dioxane; esters such as methyl acetate, ethyl acetate and butyl acetate Benzene, toluene, xylene, etc., aromatic hydrocarbons, dichloromethane, trichloromethane, dichloroethane, trichloroethane, etc., halogenated hydrocarbons, dimethylformaldehyde, dimethylacetamide, dimethylsulfoxide, etc., aprotic polarities Solvents can be used, but ketone solvents such as acetone, methyl ethyl ketone, methyl propyl ketone, and methyl butyl ketone, ester solvents such as methyl acetate, ethyl acetate, and butyl acetate, or a mixed solvent thereof are preferred. . When a solvent such as methanol, ethanol, or toluene is used, solvation may occur depending on isolation conditions.

The polymethine ether compound (Π) is, for example, a polymethine compound represented by the following formula (VII) and an alkali metal alkoxide salt or alkali metal represented by the following formula (VIII): It can be produced by reacting aryloxide salt in an organic solvent.

(In the formula, Z— represents an acidic residue.)

MOR (VIII)

(In the formula, M represents an alkali metal, and R represents the same as described above.)

In the formula, Z- represents an acidic residue, F one examples, CI-, B r-, I-, B r 0 4 -, C l 0 4 -, BF 4 one, PF ₆ one, SbF ₆ —, CF ₃ C〇 ₂ —, CH ₃ C〇 ₂ —, CF ₃ S〇 ₃ —, CH ₃ S〇 ₃ , benzene carbonate, benzenesulfonate, ρ—toluenesulfonate (hereinafter abbreviated as T s O) , naphthalene carbonate, naphthalene Nji carbonate, naphthalene sulfonate, naphthalene sulfonate or the like elevation Gerare, in particular, CI-, B r-, I-, C 1_Rei ₄ one, BF ₄ -, PF ₆ one, SbF ₆ —, C 8795

11

F ₃ C_〇 _{_{_{2 -, CF 3 S0 3 -}}} , CH 3 S0 3 -, benzene carbonate, benzene Honeto, T s O-are preferable, especially, C 1_Rei _{_{4 -, BF 4 -, T}} s O- Is preferred.

In the above reaction, M includes, for example, alkali metal such as sodium and magnesium.

Examples of the organic solvent include alcohols such as methanol, ethanol, n-propanol, iso-propanol and n-butanol, ethers such as tetrahydrofuran and dioxane, esters such as methyl acetate, ethyl acetate and butyl acetate, and benzene. , Toluene, xylene, etc., aromatic hydrocarbons, dichloromethane, trichloride methane, dichloroethane, trichloroethane, etc., halogenated hydrocarbons, dimethylformaldehyde, dimethylacetamide, dimethylsulfoxide, etc., non-protonic polar solvents Is mentioned.

The ratio of the compound represented by the general formula (VII) to the compound represented by the general formula (VHI) is usually 1 mol of the former; About 30 mol, preferably about 2 to 10 mol is used.

The organic solvent is used in an amount of usually about 2 to 30 L, preferably about 5 to 20 L per 1 mol of the compound represented by the general formula (VID).

The above reaction proceeds normally at about 0 to 100 ° C, preferably at 10 to 70 ° C, and is generally completed in about several minutes to 10 hours.

After the reaction, the target substance can be easily isolated by filtration and washing. Further, it can be easily purified by conventional purification means, for example, recrystallization, column separation and the like.

The compound represented by the general formula (VII) can be synthesized by, for example, a method described in JP-A-2000-226528.

[Near infrared absorber]

The near-infrared absorbing agent of the present invention is a crystalline non-solvate of a polymethine compound of the formula (I) JP2004 / 008795

12

In addition, a binder resin or the like may be contained.

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

Examples of near-infrared absorbing agents that can be used in combination include pigments such as carbon black and aniline black, and “near-infrared absorbing dyes” (P45-51) of Chemical Industry (May, 1986). And “Developments and Market Trends of Functional Dyes in the 1990s” CMC (1991), Polymethine Dyes (Cyanine Dyes), Phthalocyanine Dyes, and Dithiol Metal Complex Dyes described in Chapter 2.3. , Naphthoquinone, anthraquinone dyes, triphenylmethane (similar) dyes, amidium, diimmodium dyes, etc., azo dyes, indoor dilin metal complex dyes, intermolecular CT dyes, etc. Pigments and dye-based pigments.

The binder resin is not particularly limited, but may be, for example, a homopolymer or a copolymer of acrylic acid monomers such as acrylic acid, methacrylic acid, acrylates, and methacrylates, methylcellulose, ethynolecellulose, and cellulose. Cellulose-based polymers such as acetate, polystyrene, vinyl chloride-vinyl acetate copolymer, polyvinylpyrrolidone, polyvinylbutyral, vinyl-based polymers such as polyvinyl alcohol and copolymers of vinyl compounds, polyesters and polyamides Examples include 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.

When the near-infrared absorber of the present invention is used for optical recording materials such as optical power, for example, a liquid in which the near-infrared absorber and an organic solvent are dissolved is coated on a substrate such as glass or plastic resin by a spin coating method or the like. It can be manufactured by coating by various methods conventionally studied. The resin that can be used for the substrate is not particularly limited. For example, acrylic resin, polyethylene resin, vinyl chloride resin, vinylidene chloride resin, polycarbonate And the like. The solvent used for spin coating is not particularly limited, and examples thereof include hydrocarbons, halogenated hydrocarbons, ethers, ketones, alcohols, and cellosolves, and particularly, methanol, ethanol, Alcohol-based solvents such as propanol and so on-type solvents such as methinolace-type sonolebu and ethyl-type sonolebu are preferred.

When the near-infrared absorbing agent of the present invention is used for a near-infrared absorbing filter, a heat-shielding material, or an agricultural film, the near-infrared absorbing agent is mixed with a plastic resin and optionally an organic solvent, and the injection molding method or casting method It can be manufactured by forming into a plate shape or a film shape by a method which has been variously studied. The resin that can be used is not particularly limited, and examples thereof include acryl resin, polyethylene resin, vinyl chloride resin, vinylidene chloride resin, and polycarbonate resin. The solvent to be used is not particularly limited. Examples thereof include hydrocarbons, halogenated hydrocarbons, ethers, ketones, alcohols, and cellosolves. Particularly, alcohol solvents such as methanol, ethanol, and propanol are used. Solvents such as methyl soup and ethyl sonolev 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, the near-infrared absorbing agent may be used in combination with a coloring component or a coloring component. A layer containing a coloring component, a coloring component, or the like may be separately provided. The coloring or coloring components are those that form images by physical or chemical changes due to the heat of sublimable dyes and pigments, electron-donating dye precursors, electron-accepting compounds, and polymerizable polymers. Those which have been variously studied can be used. For example, the coloring component of the laser thermal transfer recording material is not particularly limited, but the pigment type is titanium dioxide, carbon black, zinc oxide, prussian blue, thicadmium sulfate, iron oxide, and lead, zinc, and barium. Inorganic pigments such as chromate of calcium, azo-based, thioindigo-based, anthraquinone-based, anthranthrone-based, trifendioxane-based, phthalocyanine-based, quinatalidone-based And other organic pigments. 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 the property of developing a color by donating electrons or accepting a proton such as an acid, and has a partial skeleton such as ratatone, ratatam, sanoleton, spiropyran, ester, or amide. And a compound which has a partial skeleton ring-opened or cleaved upon contact with an electron-accepting compound. For example, triphenyl methane compounds, fluoran compounds, phenothiazine compounds, indolyl phthalide compounds, leuco auramine compounds, rhodamine lactam compounds, triphenyl methane compounds, triazene compounds, spiropyran compounds, and flupyran compounds. Or the like. Examples of the electron-accepting compound include phenolic compounds, organic acids or metal salts thereof, and oxybenzoic acid esters. Example

Further, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples.

[Example 1] Synthesis of crystalline unsolvated polymethine compound

15.03 g of the polymethine ether compound represented by the formula (II) (R = CH ₃ ) was added to acetone 150 ml, and concentrated hydrochloric acid was added thereto with stirring at 25 to 30 ° C. 20 g was added dropwise. After stirring at the same temperature for 1 hour, the temperature was raised to the reflux temperature, and 5 O ml of ethyl acetate was added dropwise. After stirring at the same temperature for 1 hour, the mixture was cooled to 15 to 20 ° C. The precipitated crystal was separated by filtration, washed with ethyl ethyl drone, and dried to obtain 14.38 g of the compound of the formula (I).

The solubility of this compound in methanol and ethanol was 25% or more, respectively. The elemental analysis value, melting point (decomposition temperature), maximum absorption wavelength (Lmax), and gram extinction coefficient (Eg) of this compound were as follows. Elemental analysis _{_{_{(C 31 H 34 C 1 2}}} N 2): MW = 505. 5

C H N

Calculated value (%) 73.65 6.78 5.54

Actual value (%) 73.01 6.81 5.48

Melting point (° C): 228-232 ° C (decomposition)

Xmax: 808 nm (Diaceton alcohol solution)

ε g: 5.55 X 10. m 1 / gcm

FIG. 1 shows a powder X-ray diffraction pattern of the obtained compound.

FIG. 2 shows the IR spectrum of the obtained compound.

FIG. 3 shows a TG-DTA (thermogravimetry-differential thermal analysis) diagram of the obtained compound.

The stability of the obtained compound in a 20% ethanol solution (between 1013 and room temperature) was good, and no decomposition was observed.

[Example 2] Production of near-infrared absorbing agent

10 g of Delpet 8 ON (acrylic resin manufactured by Asahi Kasei Kogyo Co., Ltd.) and 0.2 g of the compound of formula (I) of the present invention were used as the binder in toluene methyl ethyl ketone Z methanol (1/1/1). 0.1) Prepare a solution dissolved in 90 g of the mixed solvent, apply it to a polyethylene terephthalate (PET) film with an average thickness of 5 μm using a wire bar so that the film thickness after drying is about 5 m. A sample was used.

Laser light from a single-mode semiconductor laser (wavelength: 830 nm) was condensed by a lens and arranged so as to have a beam diameter of l O ^ um 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. Observation of the irradiated sample using an optical microscope confirmed that a through hole with a diameter of about 10 m was formed when the laser power reaching the surface was 5 OmW.

[Comparative Example 1] Synthesis of polymethine compound (Reference: DE3721850 Example 1) 8.67 g of indoline compound represented by formula (IV) (R = CH ₃ ), represented by formula (V) A mixture of 4.92 g of the diformyl.-based compound (n = 1) and 15 g of acetic anhydride was heated to 50 ° C., and then stirred at the same temperature for 10 hours. After cooling to room temperature, a 1000 ml solution of 10 g of sodium chloride was added and stirred. The precipitated solid was separated by filtration, 100 g of 5% saline was added, and the mixture was stirred (dispersed), filtered and dried. 18.21 g was obtained as a solid.

200 ml of acetone was added to the obtained solid, and the mixture was heated to reflux temperature and stirred at the same temperature for 20 minutes. After cooling to room temperature, the precipitated crystal was separated by filtration and dried to obtain 8.95 g. The obtained compound had the following absorption maximum wavelength (λ max) and gram extinction coefficient (ε g).

Melting point (;. C): 199 ~ 201 ° C (decomposition)

Max: 808 nm (diacetone alcohol solution)

E g: 4.6 1 X 1 0 5 m 1 / g · cm

FIG. 4 shows a powder X-ray diffraction pattern of the obtained compound.

FIG. 5 shows a TG-DTA (thermogravimetry-differential thermal analysis) measurement diagram of the obtained compound. The stability of the obtained compound in a 20% ethanol solution was not good, and about 5% of decomposition was observed in 10 days at room temperature.

[Comparative Example 2]

In the same manner as in Example 2 except that 0.2 g of the compound of the formula (I) of the present invention was used instead of 0.2 g of the compound of Comparative Example 1, the resin film thickness after drying was about 5 // m. Average thickness Thickness of 5 μιη was applied to polyethylene terephthalate (PET) finolem to obtain a sample with a beam diameter of 10 Aim on the surface of the sample.

Laser light from a single-mode semiconductor laser (wavelength 83011 m) was condensed by a lens and placed. The semiconductor laser was adjusted so that the power of the laser reaching the surface could be varied in the range of 50 to 20 OmW, and a single pulse was applied to the sample with a pulse width of 20 μs. When the irradiated sample is observed with an optical microscope, it reaches the surface. No penetrating hole was formed even when the laser power was 10 OmW.

[Comparative Example 3]

Synthesis of polymethine compound (Reference: Japanese Patent Application Laid-Open No. Sho 62-34669, Example ₃ ) 8.67 g of indoline compound (R = CH ₃ ) represented by formula (IV), represented by formula (VI) Jianiru compounds (n = 1) 8.64 g _n acetic force Centrum 5.00 g and a mixture of acetic anhydride 3 0 m 1 9 5~; After heating to L 00 ° C, and stirred for 1 5 minutes at the same temperature. After cooling to room temperature, 15 Oml of water was added. The solid formed was filtered off, washed with water and dried.

The obtained solid was recrystallized with 80 ml of methanol to obtain 5.02 g of a red-brown powder. The absorption maximum wavelength (max) of the obtained compound was 542 nm (diacetone alcohol solution), which was not the intended compound of the present invention.

The methanol filtrate was concentrated by an evaporator, 15 Oml of acetone was added to 12.4 g of the obtained concentrate, and the mixture was heated to reflux temperature and stirred at the same temperature for 20 minutes. After cooling to room temperature, the precipitated crystal was separated by filtration and dried to obtain 4.02 g.

max: 808 nm (diacetone alcoholic solution)

ε g: 4.2 1 X 10 ⁵ ml / g-cm

Since the obtained compound was of low purity, for purification, ethanol was used as a recrystallization solvent as an alcoholic solvent other than methanol; acetone and methylethyl ketone as ketone solvents; ethyl ether and disopropyle as ether solvents. Ter; acetate ester solvent, methyl acetate, ethyl acetate; aromatic hydrocarbon solvent, toluene; halogenated aliphatic hydrocarbon solvent, dicloroethane and mixed solvents thereof, but no improvement in purity I didn't get it.

[Comparative Example 4] Polymethine compound sold

The maximum absorption wavelength of a compound having the same chemical structural formula as the crystalline unsolvate of the polymethine compound of the present invention, which is sold in the reagent strength tag of Aldrich's Comprehensive Strength Tag Japan (2003-2004) (: ma _X ), gram extinction coefficient g) and moisture It was.

Xmax: 808 nm (Diaceton alcohol solution)

£ g: 4.68 X 10 ⁵ m1 / g-cm

Moisture: 8.8% (measured with Karl Fischer moisture meter)

The stability of the obtained compound in a 20% ethanol solution was not good.

About 5% degradation was observed in 0 days. Industrial applicability

The crystalline non-solvated polymethine compound of the present invention has a high gram extinction coefficient and a high stability in a solution, is easy to handle, and has high sensitivity to a general-purpose semiconductor laser. In addition, since it has high solubility in alcoholic solvents, it is extremely useful in the field of recording materials and plate making materials using laser light.

Claims

The scope of the claims

1. A crystalline unsolvated polymethine compound represented by the following formula (I).

2. The crystalline unsolvated polymethine compound according to claim 1, having a melting point (decomposition temperature) of 220 ° C or more.

3. The crystalline unsolvated polymethine compound according to claim 1 or 2, wherein a TG weight loss value at 150 ° C or less is 3% or less in a TG-DTA (thermogravimetry-differential thermal analysis) measurement diagram.

4. The crystalline unsolvated polymethine compound according to any one of claims 1 to 3, which is not substantially solvated.

5. Diffraction angle in powder X-ray diffraction using Cu-Kcx ray (20 ± 0.2 °) 1 1.

The crystalline unsolvated polymethine compound according to any one of claims 1 to 4, characterized by a powder X-ray diffraction pattern showing characteristic peaks at 8 °, 13.0 °, 18.7 °, 19.4 °, and 21.2 °.

6. The method for producing a crystalline non-solvated polymethine compound according to any one of claims 1 to 5, wherein a polymethine ether compound represented by the following formula (II) is reacted with hydrochloric acid.

7. A near-infrared absorbing agent comprising the non-solvable polymethine compound according to any one of claims 1 to 5.