JP2006124611A - Coloring compound and ink composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coloring compound which can give images prevented from discoloration and color fading with the passage of time, when printed, and can stably maintain the qualities of the images, and further to provide ink having excellent fastness. <P>SOLUTION: This coloring compound represented by the general formula (1) [Z is a group for forming a five-membered or six-membered ring (including heterocyclic groups) not participating in molecular resonance on the movement of the proton in the molecule; R<SP>1</SP>is H or an electron-attracting group; n1 is 1 or 2; R<SP>2</SP>is H or a substituent; n2 is an integer of 1 to 4; Ar is an electron-attracting substituent] and having a structure capable of moving a proton in the molecule, and an ink composition containing the compound. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a dye compound having a singlet oxygen quenching ability resulting from an intramolecular proton transfer mechanism and excellent in fastness, and an ink composition excellent in fastness containing the dye compound.

  Ink-jet printing has features such as low cost of equipment itself, easy running of color, and easy recording of digital signals. Inkjet printers are rapidly spreading as output devices.

  Here, as for the recording ink used in the ink jet printer, a dye ink in which a dye is dissolved in an aqueous medium or a non-aqueous medium, a pigment ink in which a pigment is dispersed in an aqueous medium or an oil medium, or heat melting There are proposals for various types of ink, such as possible solid inks. Among these, the current mainstream ink is a dye ink in which a dye is dissolved in an aqueous medium, and has features such as beautiful coloring and high safety to the human body and the environment. In recent years, inkjet printers that can be easily printed at home and in offices have become widespread, and image quality similar to silver halide photography has been developed. However, since water-based dyes are inferior in light resistance and oxidation resistance, images formed with dye inks are inferior in storage stability compared to silver salt photographs, and in particular, image quality and hue deteriorate over time due to light and the like. There is a problem of doing.

As a solution to the above problem, various solutions for preventing the deterioration of the dye in the ink have been proposed. As the method, there are mainly a method of adding an antioxidant or an ultraviolet absorber to the ink (for example, see Patent Document 1) and a method of overcoating the image surface. However, to date, there have been approaches from the singlet oxygen quenching rate regarding the types and methods of addition of these additives to be contained in the ink, the effects of antioxidants, and the selection method (for example, Patent Document 2). 3), no singlet oxygen quenching rate (k _Q ) possessed by the dye compound itself, and no singlet oxygen quenching mechanism have been approached to prevent deterioration of images over time.

JP-A-10-29369 JP 2000-226544 A JP 2003-94797 A

  Accordingly, an object of the present invention is to provide a dye compound capable of preventing discoloration and fading (hereinafter referred to as “discoloration” in the present invention) of an image formed by printing, and maintaining stable image quality. Is to provide an ink composition excellent in fastness.

  As a result of intensive studies to solve the above-described problems that have occurred in the prior art, the present inventors have used a dye compound having an intramolecular proton transfer mechanism and a high-speed singlet oxygen quenching rate. Thus, the present inventors have found that the discoloration color of the formed image is remarkably improved, and have reached the present invention.

（一般式（１）中、Ｚは、分子内プロトン移動時の分子共鳴に関与しない５員環又は６員環（ヘテロ環を含む）を形成する基を表し、Ｒ¹は、水素原子又は電子吸引性基を表し、ｎ１は１又は２を表し、Ｒ²は水素原子又は置換基を表し、ｎ２は１〜４の何れかの整数を表し、Ａｒは電子吸引性置換基を表す。） The above object is achieved by the present invention described below. That is, the present invention is a dye compound characterized by having a structure capable of intramolecular proton transfer represented by the following general formula (1).

(In the general formula (1), Z represents a group that forms a 5-membered ring or a 6-membered ring (including a heterocycle) that does not participate in molecular resonance during intramolecular proton transfer, and R ¹ represents a hydrogen atom or an electron represents an attractive group, n1 represents 1 or 2, R ² represents a hydrogen atom or a substituent, n2 represents any integer of 1 to 4, Ar represents an electron-withdrawing group.)

  According to another aspect of the present invention, there is provided an ink composition containing the coloring compound.

According to the present invention, a structural unit for achieving an intramolecular proton transfer mechanism in a dye compound, or a singlet oxygen quenching rate (k _Q ), more preferably, an intramolecular electronic state for achieving them is grasped. Therefore, images formed with inks containing these dye compounds can improve image fastness (residual density) after the light exposure test, and in particular, prevent discoloration of images formed by the ink jet printing method. It is possible to efficiently provide a coloring compound that exhibits an excellent effect.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. There are several theories, models, measurement methods, and calculation methods related to the singlet oxygen quenching rate (k _Q ) that have been conducted in the past, which have already been studied and published in the literature. For example, Harry H. et al. Wasserman, Robert W. Several measuring methods are published in Chapter 5 Quenching of Single Oxygen, etc. of SINGLET OXYGEN (1979) by Murray. Further, as an example of a document in which a compound already measured and a value of singlet oxygen quenching rate (k _Q ) are published, Journal of Physical Chemistry Reference Data, Vol. 10, no. 4, pp. 809 to 999 (1981), etc., and the singlet oxygen quenching rate (k _Q ) discussed in these known documents and documents is a so-called antioxidant (antioxidant, singlet oxygen quenching). It is only for the agent), and there is no theory, model, measurement method or calculation method for the singlet oxygen quenching rate (k _Q ) of the dye compound.

The measurement of the singlet oxygen quenching rate constant (k _Q ) of the dye compound is performed in a solution, but there is a certain degree of correlation even in the state of being adsorbed or dispersed on the recording sheet. For example, paper is in a state where a dye is dissolved or dispersed in a cellulose polymer and also contains water, so that there is a correlation between the measured value in the solution and the performance on the recording sheet. Since the lifetime of singlet oxygen in water is (5 ± 2) × 10 ⁵ M ⁻¹ s ⁻¹ , it should be a compound having at least a value of k _Q of 1 × 10 ⁶ M ⁻¹ s ⁻¹ or more. Is said to be preferable. Up to now, regarding the singlet oxygen quenching rate (k _Q ) of the singlet oxygen quencher, page 7 of the 22nd Annual Meeting of the Oxidation Reaction Discussion (Ehime Univ., Mukai, Dr. et al.); Am. Chem. Soc. 93: 5774-5779; 1971 (Young, R. Het. Al), or Chem. Phys. Lett. 262: 125-130; 1996 (M. Mitsui et.al) has been measured using the time-resolved ESR (Electron spin resonance) method.

That is, it is measured by the competitive reaction method described below, but in the present invention, the measurement was basically performed using the same method. In the competitive reaction method, first, an ethanol solvent capable of dissolving a substance to be measured (in the present invention, a colorant) is used, and at 35 ° C., 3- (1,4-epoxyoxyl-4-methyl-1,4-dihydro -1-naphthyl) propionic acid (EP) from Tetrahedron Lett. , 41, 2177-2181 (1985), etc., according to the method described by Inoue et al., Generating singlet oxygen and using 2,5-diphenyl-3,4-benzofuran (DPBF) as a reference material for quenching rate. Used, a substance to be measured and DPBF having a known reaction rate with singlet oxygen are allowed to coexist, and both are subjected to a competitive reaction with singlet oxygen, and the absorbance decay rate at the absorption wavelength of DPBF (λ _max = 411 nm). The singlet oxygen quenching rate (k _Q ) is measured by tracking the concentration dependency of the substance to be measured with respect to the lowering effect with a multiple spectrophotometer equipped with a reaction rate measurement mode.

As another method for measuring the singlet oxygen quenching rate (k _Q ), singlet oxygen and TEMPO (2,2,6,6-tetramethylpiperidinyl-1-oxyl) using an organic solvent such as benzene and toluene. And a time-resolved ESR method for tracking the time-dependent change in the concentration of the substance to be measured in the CIDEP (Chemically Induced Dynamic Electron Polarization) spectrum.

In the present invention, the measuring method is not limited as long as it is a method capable of measuring the singlet oxygen quenching rate of the colorant, and the singlet oxygen generating means, the coloring is determined depending on the solubility of the colorant in the solvent for speed measurement. Depending on the absorption wavelength of the agent, a quenching rate reference substance and singlet oxygen quenching rate measuring means (competitive reaction method using a spectrophotometer, time-resolved ESR method using ESR) can be appropriately selected and used.
As a matter of course, the mixing ratio of the colorant mixture for which the singlet oxygen quenching rate is measured needs to be the same as the mixing ratio of the colorant in the ink.

In the present invention, the point of focus is transferred to the dye compound, various different dye compounds are synthesized, the singlet oxygen quenching rate (k _Q ) and the logarithmic value (logk _Q ) of the dye compound are obtained, and these values are obtained. And the correlation between the fastness of the image obtained by the ink having the coloring compound and the present invention were intensively studied. At this time, the fastness of the image is determined based on the optical density of the image obtained by printing on the recording medium using the ink containing the target dye compound, and the optical density measured after the light exposure test on the image. The density residual rate was calculated from the density and evaluated. The conditions and methods of the light exposure test performed at this time are a 260-hour accelerated light resistance test under a temperature and humidity condition of 24 ° C. and 60% RH using a 70,000 lux white fluorescent lamp. The reflection density was measured with a spectrophotometer Spectrolino (manufactured by Gretag Macbeth).

Here, with respect to colorants (pigments, dyes), no example of measuring the singlet oxygen quenching rate (k _Q ) has been conventionally known for the following reasons. (1) The colorant often absorbs in the vicinity of the absorption wavelength λ _{max of} 411 nm of DPBF, which is a reference material for extinction rate measurement, (2) the colorant is often difficult to dissolve in an ethanol solvent, (3) Dielectric Measurements in water systems with a high rate are not suitable for the ESR method. On the other hand, in the present invention, a colorant that does not absorb near 411 nm can be dissolved in an ethanol solvent by appropriately irradiating ultrasonic waves or the like, and the singlet oxygen quenching rate (k _Q ) of the colorant. And (k _Qmix ) have been successfully measured, and the above-described examination can be performed. With respect to the measuring means singlet oxygen quenching rate (k _Q), if there is means for measuring the addition to singlet oxygen quenching rate (k _Q), according to the type of the colorant to be measured You can choose to use them.

Results of the study, a singlet oxygen quencher speed of the dye compound in the ink (k _Q) and its logarithm (log k _Q), is a correlation between the robustness of an image obtained by an ink having a dye compound Furthermore, when the singlet oxygen quenching rate (k _Q ) of the dye compound is 2.2 × 10 ⁸ M ⁻¹ s ⁻¹ or more, an image having good fastness when used as an ink can be obtained. I found it preferable in terms of being obtained. In addition, in order to achieve a high singlet oxygen quenching rate, intramolecular proton transfer is necessary, and for this purpose, the dye compound needs to have a specific structural unit and further a more preferable electronic state. A mechanism analysis result was obtained and the present invention was completed.

A dye compound having a singlet oxygen quenching rate (k _Q ) of 2.2 × 10 ⁸ M ⁻¹ s ⁻¹ or more has a property of quenching excited singlet oxygen more rapidly. The quenching mechanism includes chemical quenching rate ( _kr ) that quenches the quenching compound and singlet oxygen to form an oxide, and physical quenching that converts singlet oxygen to triplet oxygen without reaction. Although there is a velocity (k _q ), the singlet oxygen quenching rate (k _Q ) usually includes both quenching rates. The singlet oxygen quenching rate (k _Q ) is a measure of the rate at which singlet oxygen is quenched, and this value is a singlet oxygen quencher solution (dye compound) having a concentration of 1 M (mol · dm ⁻³ ). It represents the number of singlet oxygen molecules that quench the quencher molecules in the solution per second. That is, it can be said that the larger this value, the higher the ability to quench the singlet oxygen of the quencher (dye compound).

In the present invention, the value of k _Qmix is preferably 1.0 × 10 ¹² M ⁻¹ s ⁻¹ or less. _If the value of k _Qmix exceeds 1.0 × 10 ¹² M ⁻¹ s ⁻¹ , the colorant activity becomes too strong and it may be difficult to exist stably.

Further, in the present invention, as the dye compound, those that obtain the value of the singlet oxygen quenching rate (k _Q ) by the chemical quenching rate (k _r ) are not preferable in the present invention. The dye compound according to the present invention has a singlet oxygen quenching rate (k _Q ) of 2.2 × 10 ⁸ M ⁻¹ s ⁻¹ or more, and the value of k _Q is a physical quenching rate (k _q It is the most preferable form that is infinitely close to. Specifically, the ratio of the chemical quenching rate (k _r ) in the singlet oxygen quenching rate (k _Q ) (k _rmix / k _Qmix ) is preferably 10% or less. Here, the physical quenching rate (k _q ) and the chemical quenching rate (k _r ) cannot be easily measured at present, but the competitive reaction method used in the present invention or The number of molecules involved in the chemical quenching rate can be estimated by measuring the concentration of a non-measured compound before and after measurement using a time-resolved ESR method using a spectroscopic analysis method such as a UV-Vis spectrum.

（一般式（１）中、Ｚは、分子内プロトン移動時の分子共鳴に関与しない５員環又は６員環（ヘテロ環を含む）を形成する基を表し、Ｒ¹は、水素原子又は電子吸引性基を表し、ｎ１は１又は２を表し、Ｒ²は水素原子又は置換基を表し、ｎ２は１〜４の何れかの整数を表し、Ａｒは電子吸引性置換基を表す。） The dye compound according to the present invention preferably has a singlet oxygen quenching rate (k _Q ) of 2.2 × 10 ⁸ M ⁻¹ s ⁻¹ or more, and is not particularly limited. As a result of studying various dye compounds, the present inventors have been able to suppress deterioration of an image by the above-described mechanism when used in an ink, and it is possible to obtain a highly robust image. As the dye compound, a dye compound having a structure capable of intramolecular proton transfer represented by the following general formula (1) was found.

(In the general formula (1), Z represents a group that forms a 5-membered ring or a 6-membered ring (including a heterocycle) that does not participate in molecular resonance during intramolecular proton transfer, and R ¹ represents a hydrogen atom or an electron represents an attractive group, n1 represents 1 or 2, R ² represents a hydrogen atom or a substituent, n2 represents any integer of 1 to 4, Ar represents an electron-withdrawing group.)

Here, although there are various theories about the fading mechanism of the dye compound, it is generally considered as follows. Light causes a colorant such as a dye to enter a triplet excited state, and excited singlet oxygen is generated by energy exchange between the triplet state colorant and the ground state triplet oxygen. This singlet oxygen has a high activity and a relatively long life, and is considered to cause degradation of an image by reacting with a colorant such as a dye to oxidize or decompose. In contrast, when the dye compound (colorant) according to the present invention having a singlet oxygen quenching rate (k _Q ) of 2.2 × 10 ⁸ M ⁻¹ s ⁻¹ or more is used, this singlet oxygen is converted into a colorant. By quenching itself, the concentration of singlet oxygen in the vicinity of the dye compound can be lowered, and as a result, image discoloration can be prevented.

As shown below, a compound having a structural unit represented by the general formula (1), which is a representative dye compound according to the present invention, undergoes intramolecular proton transfer as described in the general formula (2). This is the basic principle.

In order to achieve intramolecular proton transfer and achieve the singlet oxygen quenching rate (k _Q ) defined in the present invention, it is necessary to take an electronic state as described below. This will be described below. First, in the general formula (1), Z must be a group that forms a 5-membered ring or a 6-membered ring (including a heterocycle) that is not involved in molecular resonance during intramolecular proton transfer. In other words, in order to efficiently transfer protons within a molecule, the molecular resonance distance should be as short as possible and the resonance route should be limited. The molecular resonance extending to the Z portion is a long molecular resonance distance. At the same time, there are a plurality of resonance routes, which leads to a decrease in proton transfer rate, possibly leading to a decrease in singlet oxygen quenching rate, which is not preferable.

On the other hand, the singlet oxygen quenching rate (k _Q ) measured using the competitive reaction method or the time-resolved ESR method is 2.2 × 10 ⁸ M ⁻¹ s ⁻¹ or more as described above. Preferably it is. That is, if this value is on the order of 10 ⁷ M ⁻¹ s ⁻¹ , it reflects the region of the chemical quenching mechanism (so-called chemical reaction rate region), so the physical quenching mechanism described above. This is not preferable because the initial purpose of preferentially expressing the above is not achieved. On the other hand, when it is less than 2.2 × 10 ⁸ M ⁻¹ s ⁻¹ , the possibility that a chemical quenching mechanism coexists increases, which is not preferable. As described above, the ratio of the chemical quenching rate (k _r ) in the more preferable singlet oxygen quenching rate (k _Q ) is 10% or less.

  Furthermore, when the calculation is performed using the semiempirical molecular orbital method, the charge on the hydrogen atom of NH is 0.220 or more, and the charge on the oxygen atom of C═O is −0.373 or more. Having a certain structural unit is suitable for effectively expressing the intramolecular proton transfer mechanism. That is, the charge on the hydrogen atom of NH represents the acidity of the hydrogen atom, and the larger this value, the easier the proton moves. If this value is less than 0.220, it means that the acidity of the hydrogen atom is lowered, and proton transfer is difficult to occur. Further, the charge on the oxygen atom of C═O represents the basicity of the oxygen atom, and can be interpreted as being easy to receive protons. The intramolecular proton transfer reaction is a phenomenon in which the release and capture of protons are performed between NH and C = O. Therefore, these two parameters are balanced and it is preferable to keep this range. .

Furthermore, the dye compound according to the present invention preferably has an energy level (E _HOMO ) of the highest occupied orbit by semiempirical molecular orbital calculation of −8.280 [eV] or less. This value affects the expression of the chemical quenching mechanism, the nitrogen atom charge of NH, and the oxygen atom charge of C = O, and is balanced by the electron-withdrawing substituent-inducing effect of the substituent Ar in the structural unit. ing. That is, when this value is less than −8.280 [eV], the system is more easily oxidized (HOMO is shallower), and each electronic parameter is affected and a suitable state cannot be obtained.

The energy of this HOMO depends on the electrical properties (electron-withdrawing property, electron-donating property, positive / negative of σ value) of the substituents of R ¹ and Ar described in the general formula (1) and the general formula (2). to be influenced. Here, when many substituents having an electron donating property (σ value is negative) are substituted, the energy of HOMO is affected in a shallow direction, so that the desired HOMO energy level in the present invention is used. May deviate from the above, which is not preferable. Therefore, it is preferable that the substituent is a hydrogen atom (σ value is 0) or an electron-withdrawing group (σ value is positive). On the other hand, R ² is not a position that greatly affects the electronic state of the molecule as much as R ¹ or Ar, but is preferably selected in consideration of the electronic balance of the entire molecule. In addition, since the acidity of the hydrogen atom on NH is affected by the same effect as described above, the substituent that R ² has is preferably an electron-withdrawing (σ value is positive).

As described above, it is preferable that R ¹ , R ^2, and Ar in the general formula (1) are appropriately selected in consideration of the electronic balance of the entire molecule and the combination of the types of substituents and the substitution positions. . Typical examples of preferable electron withdrawing groups include carboxylic acid group, sulfonic acid group, trifluoromethyl group, cyano group, nitro group, quaternary amino group, pyridyl group and the like. These substituents can have a function as an aqueous solvent solubilizing group as well as a role as an electron withdrawing group (electronic state adjusting group) like a sulfonic acid group, for example. A substituent may be appropriately selected and used according to the use of the dye compound so that the dye compound has a desired function. In addition, these structural units have a function as a dye alone, but constitute a dye compound in which the structural unit is a dimer or more by a method that does not impair the molecular resonance and electronic state during proton transfer described above. Also good.

  As for the semi-empirical molecular orbital calculation method, the calculation accuracy advances day by day due to technical progress, and there is a non-empirical molecular orbital method such as Gaussian et al. Dr. James J.M. P. Evaluation was performed using the results calculated using the PM3 method (Parametic Method 3), which is a Hamiltonian of the semi-empirical molecular orbital method program MOPAC packaged by Stewart.

  The dye compound according to the present invention has a structural unit represented by the general formula (1) and capable of intramolecular proton transfer in the molecule, and this is characterized by an intramolecular proton transfer mechanism. When the molecule is tautomerized, a Stokes shift is observed, which can be verified. In the present invention, it can be considered that a sufficient intramolecular proton transfer mechanism works when the Stokes shift width has a value of 30.0 nm or more.

  The dye compound according to the present invention constructed from the above viewpoint is not particularly limited as long as it satisfies the requirements specified in the claims, and was synthesized so as to satisfy the specified requirements. Of course it is included in terms of things.

  Of course, these dye compounds can be used alone as a dye compound for ink, but for other purposes as antioxidants, they can also be used, for example, as additives contained in ink. In addition, since the coloring compound according to the present invention is colored, for example, in ink applications, it can be adjusted to contribute to improving the fastness of the ink, and as an antioxidant in a portion that may be colored. Can be used.

  A preferred ink form containing the dye compound according to the present invention described above will be described by taking an ink jet recording ink as an example. The ink composition according to the present invention (hereinafter referred to as “ink”) is basically composed of various dyes (the coloring compound according to the present invention) selected according to the above-mentioned regulations, water, and a water-soluble organic solvent. .

  As the water-soluble organic solvent that can be used in the above, a water-soluble high-boiling low-volatile organic solvent is preferably used. Specific examples of preferable water-soluble high-boiling low-volatile organic solvents include, for example, alkylene glycols containing 2 to 6 carbon atoms such as ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol; glycerin; polyethylene glycol Polyalkylene glycols such as polypropylene glycol; polyhydric alcohol lower monoalkyl ethers such as ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether; And polyhydric alcohol lower dialkyl ethers such as dimethyl (or ethyl) ether. The addition amount of these water-soluble high-boiling low-volatile organic solvents may be determined as appropriate, but it is preferably added in the range of 5 to 35% by mass with respect to the total mass of the ink. The reason is that if the amount is too large, these solvents remaining in the printed matter may absorb moisture in the air and cause bleeding of images during storage.

  Other water-soluble organic solvents include amides such as dimethylformamide and dimethylacetamide; ketones or ketone alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; methyl alcohol, ethyl alcohol, and n-propyl alcohol Alkyl alcohols having 1 to 5 carbon atoms such as n-butyl alcohol; sulfolane, pyrrolidone, N-methyl-2-imidazolidinone, 1,5-pentanediol, 1,2-hexanediol, 1,2-pentane Diol etc. are mentioned. These water-soluble organic solvents can be used alone or in combination, and can be used in combination with the water-soluble high-boiling low-volatile organic solvent.

  Furthermore, polyhydric alcohol lower alkyl ethers as listed below can be included. Preferred examples of the lower alkyl ether of polyhydric alcohol include mono-, di-, and triethylene glycol alkyl ethers having 1 to 6 carbon atoms, mono-, di-, and tripropylene glycol alkyl ethers having 1 to 6 carbon atoms, and more. Preferred are triethylene glycol monobutyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, propylene glycol monobutyl ether, and the most preferred among these is diethylene glycol monobutyl ether. The amount of addition may be determined as appropriate, but is preferably about 5 to 15% by mass, for example.

  Further, the ink according to the present invention can contain acetylene glycol. In this case, commercially available acetylene glycol can be used. For example, Surfynol 82, 104, 440, 465, TG (Orphine STG) (manufacturer: Air Products and Chemicals Inc., sales) Original: Nissin Chemical Industry Co., Ltd.) can be used. Although the addition amount of acetylene glycol as described above may be appropriately determined, for example, it is preferably about 0.3 to 1.8% by mass. It is also a preferred form to use a combination of a polyhydric alcohol lower alkyl ether and acetylene glycol. That is, by using these in combination, the ink adhering to the recording medium penetrates quickly, and it is possible to effectively prevent deterioration in print quality due to color mixing between adjacent dots, which is often a problem in color ink jet recording. Become.

  Furthermore, additives for improving its various properties can be included. Examples of the additive include, for example, adjustment of various physical properties of the ink such as viscosity, surface tension, pH, specific resistance, antiseptic and antifungal, fatty acid salt, alkyl sulfate ester salt, alkylbenzene sulfonic acid Anionic surfactants such as alkyl naphthalene sulfonate; nonionic surfactants such as acetylene glycol, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester; and celluloses Water-soluble natural or synthetic polymer such as polyvinyl pyrrolidone, polyvinyl alcohol, water-soluble resin; diethanolamine, triethanolamine; lithium chloride, ammonium chloride, inorganic salts of sodium chloride, benzotriazole, etc. Kill.

  The amount of the additive as described above is preferably in the range of 1 to 30% by mass, and more preferably in the range of 3 to 20% by mass. The addition amount of the surfactant is preferably in the range of 0.01 to 10% by mass, and more preferably in the range of 0.05 to 3% by mass. Preferred physical properties of the ink are as follows with respect to viscosity, surface tension, and pH (all at 25 ° C.). The viscosity is preferably in the range of 1.5 to 10 cps (mPa · s), more preferably in the range of 1.8 to 5 cps (mPa · s). The surface tension is preferably in the range of 25 to 45 dyn / cm (mN / m). The preferable range of pH is adjusted to be 4 to 10, more preferably 6 to 9.

  Examples of the recording medium used when the ink according to the present invention is used in the ink jet recording method include information transmission sheets such as paper and film, fibers, and leather. The information transmission sheet is preferably a surface-treated sheet, specifically, an ink receiving layer provided on the substrate surface. Those provided with an ink receiving layer are usually called ink jet exclusive paper (film) or ink jet glossy paper (film). Examples of commercially available ones include gloss film HG-101 (manufactured by Canon Inc.). ), Professional photo paper PR-101 (manufactured by Canon Inc.), matte photo paper MP-101 (manufactured by Canon Inc.), and the like. An example of the case of forming the ink receiving layer is, for example, inorganic fine particles capable of adsorbing pigments in ink, such as porous silica, alumina sol, and special ceramics, together with hydrophilic polymers such as polyvinyl alcohol and polyvinyl pyrrolidone. Application to the material surface is mentioned. The ink according to the present invention can be used for plain paper as well as the recording medium having the ink receiving layer.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not limited to these. In the text, “parts” and “%” mean mass basis unless otherwise specified.

<Examples 1-5, Comparative Examples 1 and 2>
First, the structure of the colorant used in Examples and the like, together with the compound identification data of each ¹ H NMR, ¹³ C NMR, high resolution mass spectrometer (FAB), and UV-visible absorption spectrum (maximum absorption wavelength, molar absorption coefficient). It is shown below. As these colorants, those synthesized according to the synthesis flow of “methylation → bromination → acylation → cyclization → ulmann reaction → sulfonation” were used in the same manner as in the case of synthesizing known anthrapyridone dyes.

  In the above synthesis, an acid anhydride or ester is used as a reaction reagent for acylation, and the cyclization reaction is dehydration reaction at high temperature and high pressure (120 to 160 ° C., 2 atm.) In the presence of alkali. As the alkali, an aqueous sodium hydroxide solution was used in the case of an acetylated product, and an aqueous sodium carbonate solution was used in the case of an acetoacylated product. Dyes 1 to 5 and 7 were synthesized from bromoanthrapyridone with industrial products, and Dye 6 was synthesized from acylation.

δ_H（Ｄ₂Ｏ）２．７８（３Ｈ，ｓ），４．００（１Ｈ，ｓ），６．４２（１Ｈ，ｄ），７．０２（１Ｈ，ｄ），７．２４−７．６５（５Ｈ，ｍ），７．７０−７．８０（３Ｈ，ｍ），８．２１−８．４８（３Ｈ，ｍ）；
δ_C（Ｄ₂Ｏ）３５．０，１１７．０，１１９．８，１２０．５，１２４．９，１２５．０，１２５．１，１２５．９，１２７．４，１２７．５，１２９．３，１３０．０，１３０．３，１３１．０，１３２．１，１３３．５，１３４．２，１３４．３，１３５．５，１３６．５，１３８．０，１４４．０，１４０．３，１４４．８，１６１．１，１６２．３，１８７．０；
Ｆｏｕｎｄ：Ｍ⁺，７６１．９６３６ Ｃ₃₀Ｈ₁₇Ｎ₂Ｏ₁₂Ｓ₃Ｎａ₃ ｒｅｑｕｉｒｅｓ ７６１．９６３７；
λ_max（ＥｔＯＨ，ｌｏｇε）５４７．０（４．０７）ｎｍ

δ _H (D ₂ O) 2.78 (3H, s), 4.00 (1H, s), 6.42 (1H, d), 7.02 (1H, d), 7.24-7.65 (5H, m), 7.70-7.80 (3H, m), 8.21-8.48 (3H, m);
δ _C (D ₂ O) 35.0, 117.0, 119.8, 120.5, 124.9, 125.0, 125.1, 125.9, 127.4, 127.5, 129.3 , 130.0, 130.3, 131.0, 132.1, 133.5, 134.2, 134.3, 135.5, 136.5, 138.0, 144.0, 140.3, 144 .8, 161.1, 162.3, 187.0;
Found: M ⁺ , 761.9636 C ₃₀ H ₁₇ N ₂ O ₁₂ S ₃ Na ₃ requests 761.9637;
λ _max (EtOH, log ε) 547.0 (4.07) nm

δ_H（Ｄ₂Ｏ）４．００（１Ｈ，ｓ），６．４２（１Ｈ，ｄ），７．０２（１Ｈ，ｄ），７．２４−７．６５（５Ｈ，ｍ），７．７３−７．８０（２Ｈ，ｄｄ），８．００（１Ｈ，ｓ），８．２１−８．４８（３Ｈ，ｍ）；
δ_C（Ｄ₂Ｏ）１１７．０，１１９．８，１２０．５，１２４．９，１２５．０，１２５．１，１２５．９，１２７．４，１２７．５，１２９．３，１３０．０，１３０．３，１３２．１，１３３．５，１３４．２，１３４．３，１３５．５，１３６．５，１３８．０，１４０．３，１４４．０，１４４．８，１６１．１，１６３．８，１８７．０；
Ｆｏｕｎｄ：Ｍ⁺，７４７．９４７９ Ｃ₂₉Ｈ₁₅Ｎ₂Ｏ₁₂Ｓ₃Ｎａ₃ ｒｅｑｕｉｒｅｓ ７４７．９４８０
λ_max（ＥｔＯＨ，ｌｏｇε）５４４．５（３．７３）ｎｍ

δ _H (D ₂ O) 4.00 (1H, s), 6.42 (1H, d), 7.02 (1H, d), 7.24-7.65 (5H, m), 7.73 -7.80 (2H, dd), 8.00 (1H, s), 8.21-8.48 (3H, m);
δ _C (D ₂ O) 117.0, 119.8, 120.5, 124.9, 125.0, 125.1, 125.9, 127.4, 127.5, 129.3, 130.0 130.3, 132.1, 133.5, 134.2, 134.3, 135.5, 136.5, 138.0, 140.3, 144.0, 144.8, 161.1, 163 .8, 187.0;
_{^{Found: M +, 747.9479 C 29}} H 15 N 2 O 12 S 3 Na 3 requires 747.9480
λ _max (EtOH, log ε) 544.5 (3.73) nm

δ_H（Ｄ₂Ｏ）１．３０（３Ｈ，ｔ），４．０（１Ｈ，ｓ），４．１９（２Ｈ，ｑ），６．４２（１Ｈ，ｄ），７．０２（１Ｈ，ｄ），７．２４−７．６５（５Ｈ，ｍ），７．７０（１Ｈ，ｄ），８．００（１Ｈ，ｓ），８．３５（１Ｈ，ｓ）；
δ_C（Ｄ₂Ｏ）１３．７，５９．２，１１４．１，１１７．０，１２０．５，１２４．９，１２５．０，１２５．１，１２５．９，１２７．４，１２９．３，１３０．０，１３１．０，１３２．１，１３４．２，１３４．３，１３５．５，１３６．５，１４０．３，１４４．８，１６１．１，１６３．８，１６５．０，１８７．０；
Ｆｏｕｎｄ：Ｍ⁺，６１４．００４１ Ｃ₂₅Ｈ₁₆Ｎ₂Ｏ₁₀Ｓ₂Ｎａ₂ ｒｅｑｕｉｒｅｓ ６１４．００４２；
λ_max（ＥｔＯＨ，ｌｏｇε）５４３．０（４．２２）ｎｍ

δ _H (D ₂ O) 1.30 (3H, t), 4.0 (1H, s), 4.19 (2H, q), 6.42 (1H, d), 7.02 (1H, d ), 7.24-7.65 (5H, m), 7.70 (1H, d), 8.00 (1H, s), 8.35 (1H, s);
δ _C (D ₂ O) 13.7, 59.2, 114.1, 117.0, 120.5, 124.9, 125.0, 125.1, 125.9, 127.4, 129.3 , 130.0, 131.0, 132.1, 134.2, 134.3, 135.5, 136.5, 140.3, 144.8, 161.1, 163.8, 165.0, 187 0.0;
_{^{Found: M +, 614.0041 C 25}} H 16 N 2 O 10 S 2 Na 2 requires 614.0042;
λ _max (EtOH, log ε) 543.0 (4.22) nm

δ_H（Ｄ₂Ｏ）２．７８（３Ｈ，ｓ），４．００（１Ｈ，ｓ），６．４２（１Ｈ，ｄ），６．７６（１Ｈ，ｓ），６．９３（１Ｈ，ｓ），７．０９（１Ｈ，ｄ），７．２４−７．５３（４Ｈ，ｍ），７．６１−７．６５（２Ｈ，ｍ）；
δ_C（Ｄ₂Ｏ）３５．０，１０８．８，１１６．０，１１６．１，１１７．０，１１９．３，１２４．９，１２５．１，１２５．９，１２７．４，１２７．５，１２９．３，１３０．０，１３２．１，１３５．５，１３５．７，１３６．２，１３６．５，１４０．３，１４１．３，１５４．１，１６２．３，１８７．０；
Ｆｏｕｎｄ：Ｍ⁺，５２２．０４７３ Ｃ₂₄Ｈ₁₄Ｎ₂Ｏ₅ＳＦ₃Ｎａ ｒｅｑｕｉｒｅｓ ５２２．０４７３；
λ_max（ＥｔＯＨ，ｌｏｇε）５２３．０（４．１１）ｎｍ

δ _H (D ₂ O) 2.78 (3H, s), 4.00 (1H, s), 6.42 (1H, d), 6.76 (1H, s), 6.93 (1H, s ), 7.09 (1H, d), 7.24-7.53 (4H, m), 7.61-7.65 (2H, m);
δ _C (D ₂ O) 35.0, 108.8, 116.0, 116.1, 117.0, 119.3, 124.9, 125.1, 125.9, 127.4, 127.5 , 129.3, 130.0, 132.1, 135.5, 135.7, 136.2, 136.5, 140.3, 141.3, 154.1, 162.3, 187.0;
Found: M ⁺ , 522.0473 C ₂₄ H ₁₄ N ₂ O ₅ SF ₃ Na requests 522.0473;
λ _max (EtOH, log ε) 523.0 (4.11) nm

δ_H（Ｄ₂Ｏ）；２．７８（３Ｈ，ｓ），４．００（１Ｈ，ｓ），６．４２（１Ｈ，ｄ），６．７６（１Ｈ，ｓ），６．９３（２Ｈ，ｄｄ），７．２４−７．６５（５Ｈ，ｍ）；
δ_C（Ｄ₂Ｏ）；３５．０，１０８．８，１１１．６，１１７．０，１１９．３，１２４．９，１２５．１，１２５．９，１２６．６，１２７．４，１２９．３，１３０．０，１３２．１，１３５．５，１３６．５，１４０．３，１４７．６，１５４．１，１６２．３，１８７．０；
Ｆｏｕｎｄ：Ｍ⁺，５９０．０３４７ Ｃ₂₅Ｈ₁₃Ｎ₂Ｏ₅ＳＦ₆Ｎａ ｒｅｑｕｉｒｅｓ ５９０．０３４７；
λ_max（ＥｔＯＨ，ｌｏｇε）５１８．５（４．１６）ｎｍ

δ _H (D ₂ O); 2.78 (3H, s), 4.00 (1H, s), 6.42 (1H, d), 6.76 (1H, s), 6.93 (2H, dd), 7.24-7.65 (5H, m);
δ _C (D ₂ O); 35.0, 108.8, 111.6, 117.0, 119.3, 124.9, 125.1, 125.9, 126.6, 127.4, 129. 3, 130.0, 132.1, 135.5, 136.5, 140.3, 147.6, 154.1, 162.3, 187.0;
Found: M ⁺ , 590.0347 C ₂₅ H ₁₃ N ₂ O ₅ SF ₆ Na requests 590.0347;
λ _max (EtOH, log ε) 518.5 (4.16) nm

δ_H（Ｄ₂Ｏ）２．３５（３Ｈ，ｄｄ），２．７８（３Ｈ，ｓ），４．００（１Ｈ，ｓ），６．４２（１Ｈ，ｄ），６．６２（１Ｈ，ｄ），６．８０（１Ｈ，ｄ），７．２４−７．５３（５Ｈ，ｍ），７．６５（１Ｈ，ｄ）；
δ_C（Ｄ₂Ｏ）２０．６，３５．０，１１７．０，１１９．１，１２３．１，１２４．９，１２５．１，１２５．９，１２７．４，１２７．９，１２８．５，１２９．２，１２９．３，１３０．０，１３２．１，１３２．８，１３３．９，１３５．５，１３６．５，１３８．０，１４０．３，１５８．８，１６２．３，１８７．０，１９６．５；
Ｆｏｕｎｄ：Ｍ⁺，５６４．０５７９ Ｃ₂₆Ｈ₁₆Ｎ₂Ｏ₆ＳＦ₃Ｎａ ｒｅｑｕｉｒｅｓ ５６４．０５７９；
λ_max（ＥｔＯＨ，ｌｏｇε）５４０．５（３．７０）ｎｍ

δ _H (D ₂ O) 2.35 (3H, dd), 2.78 (3H, s), 4.00 (1H, s), 6.42 (1H, d), 6.62 (1H, d ), 6.80 (1H, d), 7.24-7.53 (5H, m), 7.65 (1H, d);
δ _C (D ₂ O) 20.6, 35.0, 117.0, 119.1, 123.1, 124.9, 125.1, 125.9, 127.4, 127.9, 128.5 , 129.2, 129.3, 130.0, 132.1, 132.8, 133.9, 135.5, 136.5, 138.0, 140.3, 158.8, 162.3, 187 0.0, 196.5;
Found: M ⁺ , 564.0579 C ₂₆ H ₁₆ N ₂ O ₆ SF ₃ Na requests 564.0579;
λ _max (EtOH, log ε) 540.5 (3.70) nm

δ_H（Ｄ₂Ｏ）２．７８（３Ｈ，ｓ），３．７３（３Ｈ，ｓ），４．００（１Ｈ，ｓ），６．４２（１Ｈ，ｄ），６．５０−６．６３（２Ｈ，ｄｄ），６．７６（１Ｈ，ｓ），７．１９（１Ｈ，ｓ），７．２４−７．６５（５Ｈ，ｍ）；
δ_C（Ｄ₂Ｏ）３５．０，５６．０，１０８．８，１１２．８，１１７．０，１１８．８，１２０．２，１２４．９，１２５．１，１２５．９，１２７．４，１２９．３，１３０．０，１３２．１，１３３．３，１３３．９，１３５．５，１３６．５，１４０．３，１５２．８，１５４．１，１６２．３，１８７．０；
Ｆｏｕｎｄ：Ｍ⁺，４８４．０７０５ Ｃ₂₄Ｈ₁₇Ｎ₂Ｏ₆ＳＮａ ｒｅｑｕｉｒｅｓ ４８４．０７０５；
λ_max（ＥｔＯＨ，ｌｏｇε）５２８．０（３．８９）ｎｍ

δ _H (D ₂ O) 2.78 (3H, s), 3.73 (3H, s), 4.00 (1H, s), 6.42 (1H, d), 6.50-6.63 (2H, dd), 6.76 (1H, s), 7.19 (1H, s), 7.24-7.65 (5H, m);
δ _C (D ₂ O) 35.0, 56.0, 108.8, 112.8, 117.0, 118.8, 120.2, 124.9, 125.1, 125.9, 127.4 , 129.3, 130.0, 132.1, 133.3, 133.9, 135.5, 136.5, 140.3, 152.8, 154.1, 162.3, 187.0;
Found: M ⁺ , 4844.0705 C ₂₄ H ₁₇ N ₂ O ₆ SNa requests 484.0705;
λ _max (EtOH, log ε) 528.0 (3.89) nm

For dyes 1-7 obtained above were measured singlet oxygen quenching rate (k _Q) by the above-described competition reaction method. Since some substances are difficult to dissolve in ethanol, a solution having a desired concentration was prepared by appropriately irradiating ultrasonic waves and used for measurement. K _Q value of the results obtained dyes 1-7, and shown in Table 1 as a logarithmic value log k _Q value.

As is clear from Table 1, dyes 1 to 5 have a Stokes shift width of 30.0 nm or more, and it can be considered that a sufficient intramolecular proton transfer mechanism works. also were those said to embodiments of the present invention in a k _Q value and its logarithm log k _Q value. On the other hand, dyes 6 and 7, the Stokes shift width indicates a lower value than 30.0 nm, and those which do not say that worked sufficient intramolecular proton transfer mechanism, also, k _Q values and pairs thereof The numerical logk _Q value was not an example of the present invention. Hereinafter, the dyes 1 to 5 are called dyes 1 to 5 of Examples, and the dyes 6 and 7 are called dyes 6 and 7 of Comparative Examples 1 and 2.

(Preparation of inks containing the pigments of Examples 1 to 5)
The inks containing the pigments 1 to 5 of the examples obtained above were prepared by the ink compositions and methods described later to obtain the inks of Examples 1 to 5. And each obtained ink was mounted in the inkjet printer PIXUS990i (made by Canon Inc.), inkjet recording was performed, and the following ink was evaluated. At the time of recording, professional photo paper PR-101 (manufactured by Canon Inc.), which is a dedicated inkjet paper, is used as the recording medium, and an area of 1.0 cm × 1.0 cm is controlled by controlling the print duty, thereby providing an OD ( Printing was performed so as to be in the range of 0.9 to 1.1. Using the printed matter thus obtained as a sample, the fastness of the image was evaluated by the method described later.

(Preparation of ink containing pigments of Comparative Examples 1 and 2)
The inks containing the pigments 6 and 7 of Comparative Examples 1 and 2 obtained above were prepared by the same composition and method as in Examples, and the inks of Comparative Examples 1 and 2 were obtained. Then, using the obtained ink, ink jet recording was performed in the same manner as in the example, and a print sample was obtained. About the obtained sample, it evaluated similarly to the Example.

The inks of Examples 1 to 5 and Comparative Examples 1 and 2 were prepared as follows.
-5 parts of the above dye 1-7-5 parts of diethylene glycol-10 parts of glycerin-Acetylenol EH (manufactured by Kawaken Fine Chemical Co., Ltd.)
1 part: 79 parts of ion-exchanged water The above composition was mixed and further filtered under pressure through a membrane filter having a pore size of 0.2 microns to obtain respective recording inks.

(Evaluation)
In order to confirm the effect of the present invention, a color fading test was performed on a print sample as follows. The color fading test was performed in an accelerated light resistance test in which a print sample was held for 260 hours under a temperature condition of 24 ° C. and 60% RH using a 70,000 lux white fluorescent lamp. The evaluation method is to measure the optical density using a spectrophotometer Spectrolino (manufactured by Gretag Macbeth Co.) for each of the print samples before and after this accelerated test, and calculate the following formula (A) to obtain the concentration of the dye. The survival rate was determined.

Concentration residual ratio (%) = (D / D ₀ ) × 100 (A)
(D in the above formula (A) is the optical density after the light resistance acceleration test (after 260 hours), and D ₀ is the optical density before the light resistance acceleration test.)

Then, Examples 1 to 5, singlet oxygen quenching rate of dye 1-7 Examples and Comparative Examples was used as a colorant in each ink of Comparative Examples 1 and 2 (k _Q), and its log k _Q, Table 1 and FIG. 1 show the relationship of the residual concentration rate as an indicator of fastness. Further, Table 2 shows characteristic values measured for the dyes 1 to 7.

As is apparent from Tables 1 and 2 and FIG. 1, the singlet oxygen quenching rate (k _Q ) of the dye compound and the image fastness (density residual ratio) of the image formed by the ink containing the compound by the light exposure test. ) And a singlet oxygen quenching rate (k _Q ) of 2.2 × 10 ⁸ M ⁻¹ s ⁻¹ or more can provide satisfactory image fastness. Recognize. Further, by using in the ink a dye compound having a structural unit capable of transferring an intramolecular proton represented by the general formula (1) such as the dye 1 to 5 in the molecule, a high fastness image can be obtained. I understand that.

It is a correlation diagram of the fastness of a pigment compound and the singlet oxygen quenching rate (real number).

Claims (8)

A dye compound having a structure capable of transferring an intramolecular proton represented by the following general formula (1):

(In the general formula (1), Z represents a group that forms a 5-membered ring or a 6-membered ring (including a heterocycle) that does not participate in molecular resonance during intramolecular proton transfer, and R ¹ represents a hydrogen atom or an electron represents an attractive group, n1 represents 1 or 2, R ² represents a hydrogen atom or a substituent, n2 represents any integer of 1 to 4, Ar represents an electron-withdrawing group.) The dye compound according to claim 1, wherein the singlet oxygen quenching rate (k _Q ) measured by a competitive reaction method or a time-resolved ESR method is 2.2 × 10 ⁸ M ⁻¹ s ⁻¹ or more. Ratio, the dye compound of claim 2 is 10% or less of the singlet oxygen quenching rate (k _Q) chemical quenching rate during (k _r).   When calculation is performed using the semi-empirical molecular orbital method, the charge on the hydrogen atom of NH in the structure is 0.220 or more, and the charge on the oxygen atom of C═O is −0.373. The dye compound according to any one of claims 1 to 3, which has a structural unit as described above. The dye compound according to any one of claims 1 to 4, wherein an energy level (E _HOMO ) of the highest occupied orbit by the semi-empirical molecular orbital calculation is -8.280 [eV] or less.   The dye compound according to any one of claims 1 to 5, wherein the Stokes shift width has a value of 30.0 nm or more.   6. The dye compound according to claim 4 or 5, wherein the semi-empirical molecular orbital method is the PM3 method of the program system MOPAC. An ink composition comprising the dye compound according to any one of claims 1 to 7.

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