JP2008056830A - Water-soluble azo compound or salt thereof, ink composition and colored material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a yellow dye having a hue with high brightness suitable for ink-jet recording, various high fastnesses of a record and excellent preservation stability of an ink composition during preparation of the ink composition and to provide the ink composition comprising the yellow dye. <P>SOLUTION: The ink composition comprises a water-soluble azo compound represented by formula (1) (wherein, m and n represent each independently an integer of 1-3; and x represents an integer of 1-11) or a salt thereof as a free acid. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a water-soluble azo compound or a salt thereof, an ink composition containing the same, and a colored product colored with the ink composition.

  Among various color recording methods, a recording method using an ink jet printer, which is one of the representative methods, has developed various ink ejection methods, all of which generate ink droplets, Recording is performed by attaching to a recording material (paper, film, fabric, etc.). Since this method is not in direct contact with the recording head and the recording material, there is no sound generation and it is quiet, and due to the features of miniaturization, high speed, and easy colorization, it has been rapidly spreading in recent years. Large growth is expected in the future. Conventionally, inks such as fountain pens and felt pens and inks for ink jet recording have been used inks in which a water-soluble dye is dissolved in an aqueous medium. In order to prevent clogging, a water-soluble organic solvent is generally added. These inks provide a recording image with sufficient density, do not cause clogging of the pen tip and nozzles, have good drying properties on the recording material, have little bleeding, and have excellent storage stability. Is required. The formed recorded image is required to have fastness such as water resistance, moisture resistance, light resistance, and gas resistance.

  By the way, in order to record an image or character information on a color display of a computer with an ink jet printer in color, generally, four colors of ink of yellow (Y), magenta (M), cyan (C), and black (K) are used. Subtractive color mixing is used, whereby the recorded image is expressed in color. In order to reproduce the additive color mixture image by red (R), green (G), and blue (B) on a CRT (CRT) display etc. as faithfully as possible with the subtractive color mixture image, each dye used in the ink, especially Y, It is desired that each of M and C has a hue close to a standard and is clear. In addition, the ink is stable for long-term storage, has a high density of the printed image as described above, and has excellent fastness such as water resistance, moisture resistance, light resistance and gas resistance. Desired. Here, the gas resistance means that an oxidizing gas such as nitric oxide gas or ozone gas having an oxidizing action existing in the air reacts with the dye (dye) of the recorded image on the recording paper or in the recording paper and is printed. This is the resistance to the phenomenon of discoloration of an image. In particular, ozone gas is regarded as a main causative substance that promotes the fading phenomenon of ink jet recorded images. Since this discoloration phenomenon is characteristic of ink jet images, improvement of ozone gas resistance is an important technical problem in this field.

In order to obtain photographic image quality, an ink receiving layer may be provided on the surface of an ink jet dedicated paper which is one of recording papers. This ink-receiving layer is often made of a porous white inorganic material in order to expedite ink drying and to reduce bleeding at high image quality. In particular, on such recording paper, discoloration due to ozone gas occurs. It is noticeable. Further, as shown in Non-Patent Document 1, NOx gas and SOx gas other than ozone gas as oxidizing gas are said to have a great influence on the fading phenomenon of printed matter, and particularly NO ₂ gas is in the atmosphere. The effect is not negligible because there is a relatively large amount. With the recent spread of digital cameras and color printers, there are increasing opportunities to print images obtained with digital cameras etc. as photographic image quality at home, and when storing the obtained prints, these oxidizing gases in the air In many cases, the discoloration of the image due to the ozone gas resistance is regarded as a problem.

Examples of yellow pigments for inkjet having excellent water solubility and sharpness include C.I. I. (Color index) Direct yellow 132 is mentioned, and its use examples are disclosed in Patent Documents 1 to 3.
Further, Patent Document 4 discloses an azo yellow dye for ink jet recording.

Japan Hardcopy 2004 Proceedings p. 73-80 JP-A-11-70729 JP2000-154344, Examples A1-5 JP-A-2003-34763, page 24, Table 1-1, Example 4 WO98 / 12264 publication pamphlet

C. I. Direct Yellow 132 does not have sufficient performance in all of various fastnesses such as hue, sharpness, and light resistance, and storage stability, and further improvement has been achieved with respect to these fastnesses and the like. There was a need for the development of yellow pigments.
The present invention is a water-soluble yellow having high water solubility, hue and sharpness suitable for ink jet recording, and excellent fastness such as water resistance, moisture resistance, light resistance and gas resistance of recorded matter. It is an object to provide a dye (compound) and an ink composition containing the same and having good storage stability.

As a result of intensive investigations, the present inventors have found that a water-soluble disazo compound represented by a specific formula and an ink composition containing the same solve the above-described problems, and thus the present invention. Was completed.
That is, the present invention is (1)
A water-soluble azo compound represented by the following formula (1) or a salt thereof,

(In formula (1), m and n each independently represent 1 to 3, and x represents an integer of 1 to 11, respectively.)
(2)
The water-soluble azo compound or a salt thereof according to (1), wherein x in formula (1) is 5 to 11;
(3)
An ink composition comprising the water-soluble azo compound or salt thereof according to (1) or (2);
(4)
The ink composition according to (3), which contains a water-soluble organic solvent;
(5)
The ink composition according to (3) or (4), which is for inkjet recording,
(6)
In an ink jet recording method in which ink droplets are ejected according to a recording signal and recording is performed on a recording material, the ink composition according to any one of (3) to (5) is used as ink. Inkjet recording method,
(7)
The inkjet recording method according to claim 6, wherein the recording material is an information transmission sheet,
(8)
The inkjet recording method according to (7), wherein the information transmission sheet is a sheet having an ink receiving layer containing a porous white inorganic substance,
(9)
A colored body colored with the water-soluble azo compound according to (1) or (2) or the ink composition according to any one of (3) to (5);
(10)
The colored product according to (9), wherein coloring is performed by an inkjet printer,
(11)
An inkjet printer loaded with a container containing the ink composition according to any one of (3) to (5);
About.

  The water-soluble azo compound represented by the above formula (1) or a salt thereof of the present invention is extremely excellent in solubility in water as compared with conventional products. Further, it has a feature of good filterability, for example, for a membrane filter in the process of producing an ink composition, and gives a very clear and highly light yellow hue on an ink jet recording paper. Further, the ink composition of the present invention containing this compound does not cause crystal precipitation, changes in physical properties, changes in hue, etc. after long-term storage, and has extremely good storage stability compared to conventional products. A printed matter using the ink composition of the present invention as an ink for ink-jet recording has an ideal hue as a yellow hue without selecting a recording material (for example, paper, film, etc.). It is also possible to reproduce it faithfully. Furthermore, even if it is recorded on a recording material coated with a porous white inorganic material such as paper for exclusive use for photographic image quality and film, it has various fastness properties, that is, water resistance, moisture resistance, gas resistance, and particularly light resistance. It is good and has excellent long-term storage stability of photographic-tone recorded images. Thus, the water-soluble azo compound of the formula (1) is extremely useful as a yellow pigment for ink, particularly for ink for inkjet recording.

The present invention will be described in detail. In the present specification, unless otherwise specified, acidic functional groups such as sulfo group and carboxy group are represented in the form of free acid.
In the following description, unless otherwise specified, for convenience, the “water-soluble azo compound of the present invention or a salt thereof” or “the compound of the present invention” is referred to as “the dye of the present invention”, or in some cases, simply “ It is expressed as “dye”.
The coloring matter of the present invention is represented by the following formula (1).

In formula (1), m and n each independently represent an integer of 1 to 3.
x represents an integer of 1 to 11, and 5 to 11 is particularly preferable.

  The compound of the above formula (1) exists also as a free acid or a salt thereof. Examples of the salt of the compound of the above formula (1) include salts with inorganic or organic cations. Specific examples of the inorganic cation salt include alkali metal salts such as lithium, sodium, potassium and the like. Examples of organic cations include, but are not limited to, salts of compounds represented by the following formula (2).

(In Formula (2), X < ₁ > -X < ₄ > is a hydrogen atom, a (C1-C4) alkyl group, a hydroxy (C1-C4) alkyl group, or a hydroxy (C1-C4) alkoxy (C1-C4) alkyl group each independently. Represents.)

Here, examples of the alkyl group in X _{1 to} X ₄ include methyl, ethyl and the like, and examples of the hydroxyalkyl group include hydroxymethyl, hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 4-hydroxy Examples of the hydroxyalkoxyalkyl group include hydroxyethoxymethyl, 2-hydroxyethoxyethyl, 3- (hydroxyethoxy) propyl, and 3- (hydroxyethoxy). Examples include butyl and 2- (hydroxyethoxy) butyl.

  Preferable examples of the salt include sodium, potassium, lithium, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine salt, and ammonium salt. Of these, lithium, sodium, and ammonium salts are particularly preferred.

As will be apparent to those skilled in the art, the salt of the compound of the above formula (1) can be easily obtained by the following method.
For example, salt is added to an aqueous solution in which 800 parts of acetone in Example 1 described later before adding acetone, a wet cake containing a compound of the formula (1) or a dried product of the compound of the formula (1), and the like are dissolved. By salting out and filtering, the sodium salt of the compound of formula (1) can be obtained as a wet cake.
Further, after dissolving the obtained sodium salt wet cake in water, an acid such as hydrochloric acid is added to adjust the pH appropriately, and the precipitated solid is filtered to obtain the free acid of the compound of the above formula (1). Alternatively, a mixture of a free acid and a sodium salt in which a part of the compound of the formula (1) is a sodium salt can be obtained.
Further, while stirring the wet cake of the free acid of the compound of the formula (1) with water, for example, potassium hydroxide, lithium hydroxide, ammonia water or a hydroxide of the formula (2) is added to make it alkaline. For example, a corresponding potassium salt, lithium salt, ammonium salt, or quaternary ammonium salt can be obtained. By limiting the number of moles of the above-mentioned salt to the number of moles of free acid, it is possible to prepare, for example, a mixed salt of lithium and sodium, and further a mixed salt of lithium, sodium, and ammonium. is there. The salt of the compound of the above formula (1) may change the physical properties such as solubility or the ink performance when used as an ink depending on the type of the salt. For this reason, it is also preferable to select the type of salt according to the target ink performance.
Among these salts, lithium, sodium, and ammonium salts are particularly preferable as described above.

The pigment | dye shown by the said Formula (1) of this invention can be manufactured as follows, for example. In addition, m, n, and x used appropriately in the following formulas (B) to (H) represent the same meaning as in the above formula (1).
The aniline is converted to the methyl-ω-sulfonic acid derivative (A) using sodium bisulfite and formalin. Subsequently, the aminonaphthalene represented by the following formula (B) is diazotized by a conventional method, and coupled with the methyl-ω-sulfonic acid derivative of the formula (A) obtained above at 0 to 15 ° C. and pH 2 to 4 A compound of the following formula (C) is obtained by carrying out the reaction and subsequently carrying out a hydrolysis reaction at 80 to 95 ° C. and pH 10.5 to 11.5.

  Moreover, the compound of the following formula (E) is obtained by the same method as described above except that the compound of the following formula (D) is used instead of the compound of the above formula (B).

  Next, the obtained compound of the above formula (C) and cyanuric halide such as cyanuric chloride are condensed at a temperature of 10 to 15 ° C. and weakly acidic (usually pH 5 to 6), whereby a compound of the following formula (F) Is obtained. Subsequently, a compound of the following formula (G) is obtained by condensing the compound of the above formula (E) and the compound of the formula (F) at a temperature of 20 to 25 ° C. and weakly acidic (usually pH 5 to 6). .

  Further, by substituting the chlorine atom in the obtained formula (G) with a compound of the following formula (H), preferably under conditions of 75 to 80 ° C. and pH 7 to 9, in the formula (1) of the present invention, The dyes shown can be obtained.

Examples of the compounds of the above formulas (B) and (D) include 2-aminonaphthalene-6-sulfonic acid, 2-aminonaphthalene-6,8-disulfonic acid, 2-aminonaphthalene-5,7-disulfonic acid, 2 Specific examples include -aminonaphthalene-4,8-disulfonic acid, 2-aminonaphthalene-4,6,8-trisulfonic acid, 2-aminonaphthalene-3,6,8-trisulfonic acid, and the like. In the present invention, a combination of these is particularly preferable as the compound of the above formula (1).
Specific examples of the compound of the above formula (H) include glycine, β-alanine, 10-aminodecanoic acid, 6-aminohexanoic acid, 12-aminododecanoic acid and the like. Particularly preferred as the compound 1).

  Next, specific examples of the dye of the present invention are shown in Table 1 below. In Table 1, acidic functional groups such as sulfo groups and carboxy groups are represented in the form of free acids.

The dye of the above formula (1) of the present invention can be isolated as a solid free acid by adding a mineral acid such as hydrochloric acid after the coupling reaction, and the resulting free acid solid is water or, for example, aqueous hydrochloric acid. Inorganic salts contained as impurities, such as sodium chloride and sodium sulfate, can be removed by washing with acidic water such as.
By treating the free acid of the dye of the present invention obtained as described above with a desired inorganic or organic base in an aqueous medium, a solution of the corresponding dye salt can be obtained. The aqueous medium usually means a mixed solution of a water-soluble organic solvent and water. However, although it is not usually classified as an organic solvent, a substance that becomes an aqueous solution by mixing with water, such as urea, can be used as the medium for the base treatment. Therefore, it includes the aqueous solution of such a substance, and is described as an aqueous medium in this specification.
Examples of the inorganic base include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, or alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate, and ammonium hydroxide. Examples of the organic base include, but are not limited to, salts of organic amines represented by the above formula (2), for example, salts of alkanolamines such as diethanolamine and triethanolamine.

The coloring matter of the present invention is suitable for dyeing natural and synthetic fiber materials or blended products, and further for producing inks for writing and ink jet recording.
The reaction liquid containing the pigment of the above formula (1) of the present invention (for example, the reaction liquid before adding 800 parts of acetone in Example 1 described later) is directly used for the production of the ink composition of the present invention. You can also. However, the compound can be isolated from the reaction solution, dried by a method such as spray drying, and then processed into an ink composition. The ink composition of the present invention usually contains 0.1 to 20% by mass, more preferably 1 to 10% by mass, and further preferably 2 to 8% by mass of the dye of the above formula (1) in an aqueous solution.

  In the ink composition of the present invention, the pigment of the formula (1) is dissolved in water and / or an aqueous medium such as a water-soluble organic solvent (an organic solvent miscible with water), and an ink regulator is added as necessary. It is a thing. When this ink composition is used as an ink for an ink jet printer, it is preferable to use an ink composition containing a small amount of an inorganic substance such as a metal cation chloride or sulfate contained as an impurity. In this case, for example, the total content of sodium chloride and sodium sulfate is about 1% by mass or less in the pigment. In order to produce a pigment containing a small amount of inorganic substances, for example, a method using a known reverse osmosis membrane or a dried product or wet cake of a compound of the present invention or a salt thereof in a mixed solvent of alcohol such as methanol and water and filtration. Desalting treatment may be performed by a method such as drying.

  The ink composition of the present invention is prepared using water as a medium, and may contain a water-soluble organic solvent as necessary within a range that does not impair the effects of the present invention. Water-soluble organic solvents are used as dye solubilizers, drying inhibitors (wetting agents), viscosity modifiers, penetration enhancers, surface tension modifiers, antifoaming agents, and the like. Other ink preparation agents include, for example, antiseptic / antifungal agents, pH adjusting agents, chelating reagents, rust preventing agents, UV absorbers, viscosity adjusting agents, dye dissolving agents, antifading agents, emulsion stabilizers, surface tension adjusting agents. And known additives such as antifoaming agents, dispersants, and dispersion stabilizers. The content of the water-soluble organic solvent is 0 to 60% by mass, preferably 10 to 50% by mass, and the ink preparation agent is 0 to 20% by mass, preferably 0 to 15% by mass, based on the entire ink. % Is good. The remainder other than the above is water.

  Examples of water-soluble organic solvents that can be used in the present invention include C1-C4 alkanols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, and tert-butanol; N, N-dimethyl Amides such as formamide or N, N-dimethylacetamide; 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethylimidazolidin-2-one or 1,3-dimethylhexahydropyrimido-2-one Heterocyclic ketones such as: ketones such as acetone, methyl ethyl ketone, 2-methyl-2-hydroxypentan-4-one or keto alcohols; cyclic ethers such as tetrahydrofuran, dioxane; ethylene glycol, 1,2- or 1,3- Propylene glycol, 1,2- or 1, -Monomers and oligomers having (C2-C6) alkylene units such as butylene glycol, 1,6-hexylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, or thiodiglycol Or polyalkylene glycol or thioglycol; polyol (triol) such as glycerin, hexane-1,2,6-triol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether ( Butyl carbitol), triethylene glycol monomethyl ether Polyvalent (C1 -C4) monoalkyl ethers of alcohols, such as triethylene glycol monoethyl ether; gamma-butyrolactone or dimethyl sulfoxide and the like.

  Preferred as the above water-soluble organic solvent are isopropanol, glycerin, mono, di or triethylene glycol, dipropylene glycol, 2-pyrrolidone, N-methyl-2-pyrrolidone and butyl carbitol, more preferably isopropanol, Glycerin, diethylene glycol, 2-pyrrolidone, N-methyl-2-pyrrolidone and butyl carbitol. These water-soluble organic solvents are used alone or in combination.

Examples of antiseptic / antifungal agents include organic sulfur, organic nitrogen sulfur, organic halogen, haloallylsulfone, iodopropargyl, N-haloalkylthio, benzothiazole, nitrile, pyridine, 8- Oxyquinoline, isothiazoline, dithiol, pyridine oxide, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiadiazine, anilide, adamantane, dithiocarbamate, brominated indanone And compounds such as benzyl bromacetate and inorganic salts.
Examples of the organic halogen compound include sodium pentachlorophenol, examples of the pyridine oxide compound include sodium 2-pyridinethiol-1-oxide, and examples of the inorganic salt compound include sodium acetate. Examples of the isothiazoline-based compound include 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, and 5 -Chloro-2-methyl-4-isothiazolin-3-one magnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, 2-methyl-4-isothiazolin-3-one calcium chloride, etc. Can be mentioned.
Other antiseptic / antifungal agents include sodium sorbate sodium benzoate and the like. Other specific examples of antiseptic / antifungal agents include, for example, trade names Proxel GXL (S) and Proxel XL-2 (S) manufactured by Avecia.

  As the pH adjuster, any substance can be used as long as it can control the pH of the ink within the range of 6.0 to 11.0 for the purpose of improving the storage stability of the ink. For example, alkanolamines such as diethanolamine and triethanolamine, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, ammonium hydroxide, or alkali metals such as lithium carbonate, sodium carbonate, and potassium carbonate. And carbonates.

  Examples of the chelating reagent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uracil diacetate and the like.

  Examples of the rust preventive include acidic sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

  Examples of the ultraviolet absorber include a compound that emits fluorescence by absorbing ultraviolet rays represented by benzophenone compounds, benzotriazole compounds, cinnamic acid compounds, triazine compounds, stilbene compounds, or benzoxazole compounds, so-called fluorescence. Brighteners can also be used.

  Examples of the viscosity modifier include water-soluble polymer compounds in addition to water-soluble organic solvents, such as polyvinyl alcohol, cellulose derivatives, polyamines, and polyimines.

  Examples of the dye solubilizer include urea, ε-caprolactam, ethylene carbonate, and the like. It is preferred to use urea.

  The anti-fading agent is used for the purpose of improving image storage stability. As the antifading agent, various organic and metal complex antifading agents can be used. Organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, heterocycles, etc. Complex, zinc complex and the like.

  Examples of the surface tension adjusting agent include a surfactant, and examples thereof include an anionic surfactant, an amphoteric surfactant, a cationic surfactant, and a nonionic surfactant.

  Anionic surfactants include alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and their salts, N-acyl methyl taurates, alkyl sulfates polyoxyalkyl ether sulfates Salt, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester, lauryl alcohol sulfate ester, alkylphenol type phosphate ester, alkyl type phosphate ester, alkyl allyl sulfonate, diethyl sulfosuccinate , Diethylhexylsyl sulfosuccinate, dioctyl sulfosuccinate and the like.

  Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.

  Amphoteric surfactants include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine, and other imidazoline derivatives. There is.

  Nonionic surfactants include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene Ethers such as alkyl ethers; polyoxyethylene oleic acid, polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monoole Esters such as ate and polyoxyethylene stearate; 2,4,7,9-tetramethyl-5-decyne-4,7- Acetylene glycol (alcohol) type such as all, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl-1-hexyn-3-ol (for example, trade name Surfy manufactured by Nisshin Chemical Co., Ltd.) Nord 104, 82, 465, Orphine STG, etc.).

  As the antifoaming agent, a highly oxidized oil-based, glycerin fatty acid ester-based, fluorine-based, or silicone-based compound is used as necessary.

  These ink preparation agents are used alone or in combination. The surface tension of the ink of the present invention is usually 25 to 70 mN / m, more preferably 25 to 60 mN / m. The viscosity of the ink of the present invention is preferably 30 mPa · s or less. Furthermore, it is more preferable to adjust to 20 mPa · s or less.

  In order to produce the ink composition of the present invention, there is no particular limitation on the order of dissolving each agent such as an additive. In preparing the ink, the water to be used is preferably one having few impurities such as ion exchange water or distilled water. Furthermore, if necessary, fine filtration may be performed using a membrane filter to remove impurities. When used as ink for an inkjet printer, it is preferable to perform fine filtration. The pore diameter of the filter for performing microfiltration is usually 1 to 0.1 microns, preferably 0.8 to 0.2 microns.

  The ink composition containing the coloring matter of the present invention is suitable for use in printing, copying, marking, writing, drawing, stamping, or recording (printing), particularly in inkjet recording. In this case, a high-quality yellow print having good resistance to water, light, ozone and friction is obtained, and the light resistance is particularly excellent.

  In some inkjet printers, two types of ink, high density ink and low density ink, are loaded in one printer for the purpose of supplying a high-definition image. In that case, a high-concentration ink composition and a low-concentration ink composition may be prepared using the coloring matter of the present invention and used as an ink set. Moreover, you may use this pigment | dye only for either one. Moreover, you may use together the pigment | dye of this invention, and a well-known yellow pigment | dye. In addition, the colorant of the present invention can be used for toning of other colors, for example, black ink, or for the purpose of preparing a red ink or a green ink by mixing with a magenta colorant or a cyan colorant.

  The colored body of the present invention is a substance colored with the pigment of the present invention. There are no particular restrictions on the material of the colored body, for example, information transmission sheets such as paper and film, fibers and fabrics (cellulose, nylon, wool, etc.), leather, base materials for color filters, etc. Anything is acceptable and not limited to these. Examples of the coloring method include a dip dyeing method, a textile printing method, a printing method such as screen printing, a method using an ink jet printer, and the like, and a method using an ink jet printer is preferable.

The information transmission sheet is preferably a surface-treated sheet, specifically, a sheet such as paper, synthetic paper, or film provided with an ink receiving layer. For example, the ink receiving layer may be formed by impregnating or coating the base material with a cationic polymer, or inorganic fine particles capable of absorbing pigments in ink such as porous silica, alumina sol, and special ceramics, such as polyvinyl alcohol and polyvinyl pyrrolidone. It is provided by a method of coating on the surface of the substrate together with the hydrophilic polymer.
Those provided with such an ink receiving layer are usually called ink jet exclusive paper, ink jet exclusive film, glossy paper, or glossy film.
Among these, the porous silica, alumina sol, special ceramics, etc. mentioned above are coated on the substrate surface because they are easily affected by gases having an oxidizing action in the air, that is, ozone gas and nitrogen oxide gas. This is a special inkjet paper.
An example of a typical commercially available paper for inkjet use is a trade name: Pictorico (manufactured by Asahi Glass Co., Ltd.), a trade name: professional photo paper, super photo paper, and mat photo paper (all of which are Canon Inc.) Product name: Photographic paper Crispia (high gloss), Photographic paper (glossy), Photomat paper (all manufactured by Seiko Epson Corporation), Product name: Advanced photo paper (glossy), Premium glossy film, Photo paper (All made by Hewlett-Packard Japan), product name: Photolike QP (made by Konica Corporation), product name: high-grade coated paper, photo glossy paper (all made by Sony Corporation), etc. .
Since the ink composition of the present invention is excellent in the resistance to the above-mentioned gas, even in recording on such a recording material, an excellent recorded image with small color fading can be obtained. It can also be used for plain paper.

In order to record on a recording material by the ink jet recording method of the present invention, for example, a container filled with the ink composition described above is set at a predetermined position of an ink jet printer and recorded on the recording material by a normal method. Good. The ink jet recording method of the present invention can use magenta ink, cyan ink, and, if necessary, green ink, blue (or violet) ink, red ink, black ink, and the like together with the ink composition of the present invention. In this case, the inks of the respective colors are injected into the respective containers, and these containers are used in a predetermined position of the ink jet printer.
Some inkjet printers use, for example, a piezo method using mechanical vibration, a bubble jet (registered trademark) method using bubbles generated by heating, or the like. The ink jet recording method of the present invention can be used by any method.

The ink composition of the present invention has a clear yellow color, has a particularly high degree of definition of an image recorded on dedicated inkjet paper or glossy paper, and has a hue suitable for the inkjet recording method. Further, the fastness of the recorded image is very high.
The ink composition of the present invention does not precipitate or separate during storage. Further, when the ink composition of the present invention is used for ink jet recording, the ejector (ink head) is not blocked. The ink compositions of the present invention do not undergo changes in physical properties, even under relatively long time interval recirculation with continuous ink jet printers, or even intermittent use with on-demand ink jet printers.

Hereinafter, the present invention will be described more specifically with reference to examples. In the text, “parts” and “%” are based on mass unless otherwise specified.
In addition, (lambda) max (maximum absorption wavelength) of each compound synthesize | combined showed the measured value in pH7-8 aqueous solution. Moreover, although all the pigment | dyes of this invention obtained in the Example are sodium salts, the chemical structural formula was shown as a free acid for convenience. However, as described above, a free acid or an alkali metal salt other than a sodium salt can be easily obtained by using an appropriate method, and the present invention is not limited to this example.

Example 1
20.3 parts of 2-aminonaphthalene-6,8-disulfonic acid was dissolved in 200 parts of water while adjusting the pH to 6 with sodium hydroxide, and 7.2 parts of sodium nitrite was added. This solution was dropped into 300 parts of 5% hydrochloric acid at 0 to 10 ° C. over 30 minutes, followed by stirring at 10 ° C. or lower for 1 hour to carry out a diazotization reaction. Next, 9.3 parts of aniline is dissolved in 130 parts of water while adjusting the pH to 5 with sodium hydroxide, and methylated by a conventional method using 10.4 parts of sodium bisulfite and 8.6 parts of 35% formalin. After preparing the -ω-sulfonic acid derivative, it was put into the previously formed diazonium salt and stirred at 0 to 15 ° C and pH 2 to 4 for 5 hours. The reaction solution was adjusted to pH 11 with sodium hydroxide, stirred at 80 to 95 ° C. for 5 hours while maintaining the same pH, and further salted out with 100 parts of sodium chloride to obtain 100 parts of an azo compound having an amino group. Obtained as a wet cake. Next, add 0.10 parts of LION Co., Ltd., trade name: Leocol TD90 (surfactant) to 250 parts of ice water and vigorously stir it. Add 8.0 parts of cyanuric chloride and add 30 parts at 0-5 ° C. Stir for minutes. Subsequently, this suspension was added dropwise over 30 minutes into a solution obtained from 100 parts of an azo compound having an amino group and 400 parts of water previously obtained from a wet cake. After stirring at -25 ° C for 2 hours, 11.4 parts of glycine was added, and the mixture was stirred at pH 7-9, 75-80 ° C for 3 hours. The obtained reaction solution was cooled to 20 to 25 ° C., 800 parts of acetone was added to the reaction solution, stirred at 20 to 25 ° C. for 1 hour, and filtered to obtain 95.0 parts of a wet cake. This wet cake was dried with a hot air dryer at 80 ° C. to obtain 50.0 parts of a water-soluble azo compound (λmax 394 nm) of the present invention represented by the following formula (3). The compound obtained is a sodium salt.

Example 2
A water-soluble azo compound (λmax 388 nm) represented by the following formula (8) of the present invention in the same manner as in Example 1 except that 11.4 parts of glycine of Example 1 was changed to 19.7 parts of 6-aminohexanoic acid. 55.0 parts were obtained. The compound obtained is a sodium salt.

Examples 3 and 4
(A) Preparation of ink Each azo compound of the present invention obtained in Examples 1 and 2 above was mixed at the composition ratio shown in Table 2 to obtain an ink composition of the present invention, each of 0.45 μm. Contaminants were removed by filtering with a membrane filter. The water was ion-exchanged water, adjusted with a sodium hydroxide aqueous solution so that the pH of the ink composition was about 9, and then added so that the total amount was 100 parts. Tests using the azo compounds obtained in Example 1 and Example 2 are referred to as Example 3 and Example 4, respectively.

Table 2 (Composition ratio of ink composition)
Azo compound obtained in Example 1 or 2 3.5 parts Glycerin 5.0 parts Urea 5.0 parts N-methyl-2-pyrrolidone 4.0 parts Isopropyl alcohol 3.0 parts Butyl carbitol 2.0 parts Name Surfynol 104PG50 (Note) 0.1 part Sodium hydroxide + water 77.4 parts Total 100.0 parts (Note) Acetylene glycol nonionic surfactant, manufactured by Nisshin Chemical Co., Ltd.

Comparative Example 1
As Comparative Example 1, C.I. which is widely used as a yellow dye for ink-jets instead of the azo compounds obtained in Examples 1 and 2 as a dye component. I. A comparative ink composition was prepared using direct yellow 132 at the same composition ratio as in Table 2.

Comparative Example 2
As Comparative Example 2, an ink composition for comparison with the same composition ratio as in Table 2 using the compound described in Example 2 of Patent Document 4 instead of each azo compound obtained in Examples 1 and 2 as a dye component A product was prepared. The structural formula of the compound used is shown in the following formula (5). In addition, evaluation was performed using the sodium salt of following formula (5).

(B) Inkjet printing Glossy paper 1 (trade name: Professional Photo Paper PR-101, manufactured by Canon Inc.) having an ink receiving layer containing a porous white inorganic substance using an inkjet printer (trade name: PIXUS ip4100 manufactured by Canon Inc.) And glossy paper 2 (trade name: Super Photo Paper SP-101, manufactured by Canon Inc.) were subjected to inkjet recording. During ink jet recording, an image pattern was prepared so that gradations with several levels of reflection density were obtained, and a yellow printed matter was obtained.
The moisture resistance test is performed using a printed matter having an unprinted portion and a printed portion, and the reflection resistance D value of the printed matter before the test is closest to 1 in the light resistance test, the nitric oxide gas test, and the ozone gas resistance test. The reflection density of the part was measured. The reflection density was measured using a colorimetry system (SpectroEye, manufactured by GretagMacbeth).
Various test methods for recorded images and evaluation methods for test results are described below.

(C) Moisture resistance test The test pieces printed on glossy paper 1 and glossy paper 2 are left at 50 ° C and 90% RH for 7 days using a thermo-hygrostat (manufactured by Applied Giken Sangyo Co., Ltd.). The bleeding of the print portion pigment (dye) into the unprinted portion was visually determined. The results are shown in Table 3 and Table 4. The evaluation criteria are as follows.
There is almost no bleeding of unprinted part of the dye.
Some blurring of unprinted part of the pigment is seen.
There is considerable bleeding on the unprinted area of the pigment .... ×

(D) Xenon light resistance test A test piece printed on glossy paper 1 and glossy paper 2 is placed in a holder together with a 2 mm thick glass plate through an air layer, and a xenon weatherometer Ci4000 (manufactured by ATLAS) is used. Irradiated at 0.36 W / square meter illumination for 200 hours. After the test, the reflection density was measured using a color measurement system. After the measurement, the dye residual ratio was calculated by (reflected density after test / reflected density before test) × 100 (%) and evaluated in three stages.
Dye remaining rate is 80% or more ...
Dye remaining ratio is 75% or more and less than 80% ・ ・ ・ △
Dye remaining rate is less than 75% ...
The results are shown in Table 3 and Table 4.

(E) Nitrogen oxide gas resistance test A petri dish containing 15 ml of a saturated sodium nitrite aqueous solution and 10 ml of a 5% sulfuric acid aqueous solution is set in the chamber of a nitrogen oxide dyeing fastness tester GF-5 (manufactured by Suga Test Instruments Co., Ltd.). Then, nitrogen oxide gas was generated, and test pieces printed on glossy paper 1 and glossy paper 2 were set in the same chamber and exposed for 30 minutes. After the exposure, the glossy paper was allowed to stand at room temperature for 1 week to release excessively absorbed nitrogen oxide gas, and then the reflection density was measured using the above colorimetric system. After the measurement, the dye residual ratio was calculated by (reflected density after test / reflected density before test) × 100 (%) and evaluated in three stages.
Dye remaining rate is 80% or more ...
Dye residual ratio is 70% or more and less than 80% ・ ・ ・ △
Dye remaining rate is less than 70% ...
The results are shown in Table 3 and Table 4.

(F) Ozone gas resistance test A test piece printed on glossy paper 1 and glossy paper 2 was used in an environment of ozone concentration 10 ppm, humidity 60% RH, temperature 24 ° C. using an ozone weather meter (manufactured by Suga Test Instruments). After the test that was allowed to stand for a period of time, the reflection density was measured using the colorimetric system. After the measurement, the dye residual ratio was calculated by (reflected density after test / reflected density before test) × 100 (%) and evaluated in three stages.
Dye remaining rate is 80% or more ...
Dye residual ratio is 70% or more and less than 80%.
Dye remaining rate is less than 70% ...
The results are shown in Table 3 and Table 4.

(G) Solubility test Each azo compound obtained in Examples 1 and 2 was tested for solubility in water. Water was ion-exchanged water, and the test was conducted at a pH of about 8 and at room temperature (about 25 ° C.). The solubility was evaluated according to the following evaluation criteria.
It has water solubility of 100g / L or more ...
Water solubility of 50g / L or more and less than 100g / L ... △
Has water solubility of less than 50 g / L
The results are shown in Table 3. This test was performed only on glossy paper 1.

(H) Ink Storage Stability Test Each ink composition obtained in Examples 3 and 4 was stored in a sealed container and checked for storage stability at room temperature (18 to 28 ° C.) for 1 month. The evaluation was performed visually and evaluated according to the following evaluation criteria.
No precipitation or gelation after 1 month storage ...
Precipitation occurs after 1 month storage or ink gels. ×
The results are shown in Table 3. This test was performed only on glossy paper 1.

Table 3 Various test results using glossy paper 1

(C) (D) (E) (F) (G) (H)
Example 3 ○ △ ○ ○ ○ ○
Example 4 ○ ○ ○ ○ ○ ○
Comparative Example 1 △ × ○ △ △ ○
Comparative Example 2 ○ △ ○ ○ △ ×


Table 4 Results of various tests using glossy paper 2

(C) (D) (E) (F)
Example 3 ○ ○ ○ ○
Example 4 ○ ○ ○ ○
Comparative Example 1 △ △ ○ ○
Comparative Example 2 ○ ○ △ ○

As is clear from the results of Table 3 in which the test was performed using glossy paper 1, the C.I. of Comparative Example 1 in the light resistance test (D) was obtained. I. The dye residual ratio of direct yellow 132 is less than 75%, and the degree of fading is clearly large in contrast to Example 4 being 80% or more and Example 3 being 75% or more and less than 80%. It is apparent that each of the examples is excellent in light resistance. Further, from a comparison between Example 3 and Example 4, the compound of Example 4 in which x is 5 is more excellent in light resistance than the compound of Example 3 in which x is 1 in the above formula (1). It has been found. On the other hand, Comparative Example 2 is equivalent to Example 3 in terms of light resistance, but in the storage stability test (H) of the ink, a phenomenon that the ink gels when stored at room temperature for 1 month was observed. On the other hand, each example did not precipitate or gel under the same conditions, and was found to be extremely excellent in storage stability as compared with Comparative Example 2.
In the solubility test (G), the solubility in water is 50 g / L or more and less than 100 g / L for each of the comparative examples, whereas each example is 100 g / L or more for each of the comparative examples. Higher water solubility.
In the moisture resistance test (C), it was found that the comparative example 1 showed a slight blur, whereas the recorded images of each example showed almost no blur and had excellent moisture resistance.
In the ozone gas resistance test (F), the pigment residual rate of Comparative Example 1 is 75% or more and less than 80%, whereas each Example is similarly 80% or more, which is more ozone resistant than Comparative Example 1. It turned out to be excellent.

As is apparent from the results of Table 4 in which the test was performed using glossy paper 2, in Comparative Example 2, the residual dye ratio was 75% or more and less than 80% in the nitrogen oxide gas resistance test (E). Each example was 80% or more, and was found to be more resistant to nitric oxide gas than Comparative Example 2.
Similarly to the test using glossy paper 1, when glossy paper 2 is used, Comparative Example 1 shows slight bleeding in the moisture resistance test (C), and the residual dye ratio in the light resistance test (D). 75% or more and less than 80%, and it was recognized that there was a problem. On the other hand, in each of the examples, almost no bleeding was observed in the moisture resistance test (C), and in the light resistance test (D), the dye residual ratio was 80% or more. It became clear that it was superior to Comparative Example 1.
From the above results, the water-soluble azo compound of the present invention is suitable for preparing an ink composition for inkjet recording, and has various fastness properties, in particular, moisture resistance, light resistance, ozone gas resistance and nitrogen oxide gas resistance. In addition, it is highly soluble in water, stable even when stored for a long time without causing precipitation or gelation. From these characteristics, it is clear that the azo compound of the present invention is a very useful compound as various dyes for recording ink, particularly as a yellow dye for inkjet ink.
Further, in the above formula (1), it has been clarified that the longer x is 5 or more, the more excellent fastness is in light resistance.

Claims (11)

Water-soluble azo compound represented by the following formula (1) or a salt thereof

(In formula (1), m and n each independently represent 1 to 3, and x represents an integer of 1 to 11, respectively.) The water-soluble azo compound or a salt thereof according to claim 1, wherein x in the formula (1) is 5 to 11. An ink composition comprising the water-soluble azo compound or a salt thereof according to claim 1 or 2. The ink composition according to claim 3, comprising a water-soluble organic solvent. The ink composition according to claim 3 or 4, which is for inkjet recording. 6. An ink jet recording method for recording on a recording material by ejecting ink droplets according to a recording signal, wherein the ink composition according to any one of claims 3 to 5 is used as an ink. Method The inkjet recording method according to claim 6, wherein the recording material is an information transmission sheet. 8. The ink jet recording method according to claim 7, wherein the information transmission sheet is a sheet having an ink receiving layer containing a porous white inorganic substance. A colored body colored with the water-soluble azo compound according to claim 1 or 2 or the ink composition according to any one of claims 3 to 5. The colored body according to claim 9, wherein coloring is performed by an ink jet printer. An inkjet printer loaded with a container containing the ink composition according to any one of claims 3 to 5.