JP2008088282A - 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 clarity suitable for inkjet recording, high various fastness of records and excellent preservation stability of an ink composition when preparing the ink composition and to provide the ink composition comprising the yellow dye. <P>SOLUTION: A water-soluble azo compound is represented by formula (1) (wherein, R<SP>1</SP>and R<SP>2</SP>represent each independently a hydrogen atom, a 1-4C alkyl group or a 1-4C alkoxy group; x represents an integer of 1-3; and y represents an integer of 0-2) as a free acid or a salt thereof. The ink composition comprises the compound or a salt thereof. <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.). This method has been rapidly spreading in recent years because of the features that the recording head and the recording material are not in direct contact, so there is no sound generation and is quiet, and the size, speed and color are easy. 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 these water-based inks, the ink at the pen tip or ink discharge nozzle is used. 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.
Ink-jet nozzle clogging occurs when the water content in the ink evaporates near other nozzles and other solvents and additives, and the dye crystallizes and precipitates when the composition state is low in water and high in solvents and additives. There are many things derived from this. Therefore, it is one of the very important required performances that crystals do not easily precipitate even when the ink is evaporated and dried. For this reason, high solubility in solvents and additives is one of the properties required for pigments.

  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.
For yellow, dyes and inks that have better resistance to oxidizing gas compared to magenta and cyan, which are other basic colors of subtractive color mixing, have been developed and used in the past. Among the above fastnesses, water resistance and moisture resistance are required characteristics that are relatively easy to improve fastness by improving the recording material side. Therefore, among the fastness required for yellow dyes and yellow inks for inkjet, it is often the light resistance of recorded images that is most desired to be further improved.

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 US Pat. No. 6,867,286

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 highly soluble in water, has a hue and sharpness suitable for ink jet recording, and has excellent water fastness such as water resistance, gas resistance, and particularly fastness such as moisture resistance and light resistance. An object is to provide a yellow pigment (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 the formula (1), R ^1, R ² each independently represent a hydrogen atom, an alkyl group or an alkoxy group having 1 to 4 carbon atoms having 1 to 4 carbon atoms, x is from 1 3, y is 0 to 2 Each represents an integer.)
(2)
The water-soluble azo compound or a salt thereof according to (1), wherein R ¹ and R ^{2 in} formula (1) are each independently a methoxy group, a methyl group or a hydrogen atom, x is 1 and y is 1;
(3)
The water-soluble azo compound or a salt thereof according to (1) or (2) represented by the following formula (2):

(4)
(1) An ink composition containing the water-soluble azo compound or salt thereof according to any one of (3),
(5)
The ink composition according to (4), which contains a water-soluble organic solvent;
(6)
The ink composition according to (4) or (5), which is for inkjet recording,
(7)
In an ink jet recording method in which ink droplets are ejected in accordance with a recording signal to perform recording on a recording material, the ink composition according to any one of (4) to (6) is used as ink. Inkjet recording method,
(8)
The inkjet recording method according to (7), wherein the recording material is an information transmission sheet,
(9)
The ink jet recording method according to (8), wherein the information transmission sheet is a sheet having an ink receiving layer containing a porous white inorganic substance,
(10)
A water-soluble azo compound according to any one of (1) to (3) or a colored body colored with the ink composition according to any one of (4) to (6);
(11)
The colored body according to (10), wherein coloring is performed by an ink jet printer,
(12)
(4) An inkjet printer loaded with a container containing the ink composition according to any one of (6) to (6),
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), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, x is an integer from 1 to 3, and y is an integer from 0 to 2. Respectively.
Preferred examples of the alkyl group having 1 to 4 carbon atoms are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, 1-methylpropyl and t-butyl.
Preferable examples of the alkoxy group having 1 to 4 carbon atoms are methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, 1-methylpropoxy and t-butoxy.
More preferred R ¹ and R ² are methoxy, methyl or hydrogen atom, x is 1 and y is preferably 1. A particularly preferred compound of the above formula (1) is a compound represented by the above formula (2).

  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 (3).

(In the formula (3), Z ^{1 to} Z ⁴ are each independently a hydrogen atom, a (C1 to C4) alkyl group, a hydroxy (C1 to C4) alkyl group or a hydroxy (C1 to C4) alkoxy (C1 to C4) alkyl group. Represents.)

Here, examples of the alkyl group in Z ^{1 to} Z 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 a reaction solution before adding 800 parts of acetone in Example 1 described later, or an aqueous solution in which a wet cake containing a compound of the formula (1) or a dried product of the compound of the formula (1) is dissolved to add a salt. The sodium salt of the compound of the above formula (1) can be obtained as a wet cake by analyzing and collecting the precipitated solid by filtration.
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 (3) 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. Note that R ¹ , R ² , x, and y, which are appropriately used in the following formulas (A) to (H), have the same meanings as in the above formula (1).
The aminobenzene derivative (A) is converted to the methyl-ω-sulfonic acid derivative (B) using sodium bisulfite and formalin. Subsequently, the aminobenzenesulfonic acid represented by the following formula (C) is diazotized by a conventional method, and the obtained mixture is coupled with the methyl-ω-sulfonic acid derivative of the formula (B) obtained above at 0 to 15 ° C. and pH 2 to 4. A compound of the following formula (D) is obtained by performing a ring reaction and subsequently performing a hydrolysis reaction at 80 to 95 ° C. and pH 10.5 to 11.5.

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

  Next, by condensing the obtained compound (1 equivalent) of the above formula (D) and cyanuric halide such as cyanuric chloride at a temperature of 10 to 30 ° C. and weakly acidic (usually pH 5 to 6), the following formula ( A compound of G) is obtained. Subsequently, the compound of the following formula (H) is condensed by condensing the compound of the formula (F) (1 equivalent) and the compound of the formula (G) at a temperature of 20 to 30 ° C. and slightly acidic (usually pH 5 to 6). Is obtained.

  Further, by substituting the chlorine atom in the obtained formula (H) with a compound of the following formula (I), 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.

Specific examples of the compound of the above formula (A) or (E) include aniline, 3-methylaniline, 2-methylaniline, 2-methoxyaniline, 3-methoxyaniline, and the like. Specific examples of the compound include 4-aminobenzenesulfonic acid, 3-aminobenzenesulfonic acid, 2-aminobenzenesulfonic acid, and the like.
Specific examples of the compound of the above formula (I) include benzylamine, aminomethylbenzenesulfonic acid, aminomethylbenzenedisulfonic acid, aminoethylbenzenesulfonic acid, and the like. Derivatives using these include those of the above formula (1). Particularly preferred as a compound.

  Next, specific examples of the dye of the present invention are shown in Table 1 below. In Table 1, the sulfo group is represented in the form of the free acid.

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. However, urea is generally classified as a dye solubilizer.
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. It is done.
Examples of the organic base include, but are not limited to, salts of organic amines represented by the above formula (3), such as 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, after isolating the compound from the reaction solution, for example, by drying the reaction solution or the like by a method such as spray drying, the compound can be isolated 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 a metal cation chloride contained as an impurity, such as sodium chloride, sulfate, eg, an inorganic substance such as sodium sulfate. . 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 is stirred in a mixed solvent of alcohol such as methanol and water. The solution may be purified by turbidity, and the solid may be collected by filtration and dried for desalting.

  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. , 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, -Mono, oligo 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, trie Polyvalent (C1 -C4) monoalkyl ethers of alcohols, such as 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 and antifungal agents include sodium sorbate and sodium benzoate. 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, and heterocycles, and metal complexes include There are nickel complexes and zinc complexes.

  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 addition, the ink composition of the present invention is less likely to cause crystal precipitation even when dried in the vicinity of the nozzles of an ink jet printer, and for this reason, clogging of the head is also unlikely to occur. Furthermore, when the ink composition of the present invention is used for ink jet recording, a high-quality yellow print having good resistance to water, light, ozone, nitrogen oxide gas, and friction can be obtained, and particularly, the light resistance is extremely high. It is good.

  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 gas having the above oxidizing action, it provides an excellent recorded image with little discoloration even when recording on such a recording material. 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, crystal precipitation due to drying of the ink composition in the vicinity of the nozzle is very unlikely to occur, and the ejector (ink head) is not blocked. The ink composition of the present invention uses a continuous ink jet printer and has physical properties even when the ink is recirculated at relatively long time intervals or intermittently used by an on-demand ink jet printer. Does not change.

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, and the reaction temperature is also the internal temperature.
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
(1)
17.3 parts of 3-aminobenzenesulfonic 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 added dropwise to 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 to prepare a diazonium salt.
On the other hand, 12.3 parts of 2-methoxyaniline is dissolved in 130 parts of water while adjusting the pH to 5 with sodium hydroxide, and is usually used with 10.4 parts of sodium bisulfite and 8.6 parts of 35% formalin. A methyl-ω-sulfonic acid derivative was obtained by the method.
The obtained methyl-ω-sulfonic acid derivative was put into the previously prepared 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, further salted out by adding 100 parts of sodium chloride, and the precipitated solid was collected by filtration. 100 parts of an azo compound having a group was obtained as a wet cake.
Next, add 0.10 parts of Lion Corporation, trade name: Leocol TD90 (surfactant) to 250 parts of ice water and vigorously stir, and then add 8.0 parts of cyanuric chloride at 0-5 ° C. Stir for 30 minutes to obtain a suspension.
A wet cake of 100 parts of an azo compound having an amino group obtained by the above method was dissolved in 400 parts of water, and the above suspension was added dropwise to this solution over 30 minutes. After completion of the dropwise addition, the mixture was stirred at pH 5-6, 20-25 ° C. for 2 hours, 22.8 parts of 4- (aminomethyl) benzenesulfonic acid was added, and the mixture was stirred at pH 7-9, 75-80 ° C. for 3 hours. After cooling the obtained reaction liquid to 20-25 degreeC, 800 parts of acetone was added to this reaction liquid, and it stirred at 20-25 degreeC for 1 hour. The precipitated solid was collected by filtration to obtain 95.0 parts of a wet cake. The wet cake was dried with a hot air dryer at 80 ° C. to obtain 35.0 parts of the water-soluble azo compound (λmax 394 nm) of the present invention represented by the following formula (4).

(2)
4- (Aminomethyl) benzenesulfonic acid used in Example 1 (1) was synthesized as follows.
70.0 parts of 30% fuming sulfuric acid was added to 63.3 parts of 98% sulfuric acid. The solution was cooled in an ice bath and 17.8 parts of benzylamine was added dropwise. During this time, the drop acceleration was adjusted so that the reaction temperature was 40 ° C. or lower. After completion of the dropwise addition, the mixture was stirred at room temperature for 1 hour, and then the reaction solution was slowly added dropwise to 400 g of ice water. After completion of the dropwise addition, the suspension was filtered, washed with 20 parts of hydrochloric acid, and the resulting wet cake was dried at 80 ° C. to obtain 22.8 parts of 4- (aminomethylbenzene) sulfonic acid. The substitution position of sulfonic acid in the obtained compound was determined by ¹ H-NMR (proton nuclear magnetic resonance spectrum).

Example 2
(A) Preparation of ink The azo compound of the present invention obtained in Example 1 was mixed at the composition ratio shown in Table 2 to obtain the ink composition of the present invention, and each was filtered with a 0.45 μm membrane filter. Contaminants were removed by filtration. 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.

Table 2 (Composition ratio of ink composition)
Azo compound obtained in Example 1 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 Nord 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. widely used as a yellow dye for ink-jets, instead of the azo compound obtained in Example 1 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, a compound of the following formula (4) synthesized by the method described in Example 1 of Patent Document 4 was used in place of the azo compound obtained in Example 1 as a dye component, and the same as in Table 2 A comparative ink composition was prepared at a composition ratio. The structural formula of the compound used is shown below. In addition, evaluation was performed using the sodium salt of following formula (5).

(B) Inkjet printing Inkjet recording was performed on glossy paper (trade name: Professional Photo Paper PR-101, manufactured by Canon Inc.) using an inkjet printer (trade name: PIXUS ip4100 manufactured by Canon Inc.). 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 piece printed on glossy paper is 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 dye) on the unprinted portion was visually determined. The results are shown in Table 3. 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 was placed in a holder together with a 2 mm-thick glass plate through an air layer, and a xenon weatherometer Ci4000 (manufactured by ATLAS) was used. Irradiated for 150 hours at square meter illumination.
After the test, the reflection density is measured using a colorimetry system, and the residual ratio of the pigment is calculated by (reflection density after test / reflection density before test) × 100 (%). The color difference ΔE before and after the test was measured.
The results are shown in Table 4.

(E) Nitric 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). Then, nitrogen oxide gas was generated, and a test piece printed on glossy paper was 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.

(F) Ozone gas resistance test A test piece printed on glossy paper was left in an environment of ozone concentration 10 ppm, humidity 60% RH, temperature 24 ° C. for 8 hours using an ozone weather meter (manufactured by Suga Test Instruments Co., Ltd.) 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.

(G) Solubility test Each compound used in Example 1 and Comparative 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 5.

(H) Ink Storage Stability Test Each ink composition obtained in Example 1, Comparative Example 1 and Comparative Example 2 is stored in a sealed container and stored at room temperature (18 to 28 ° C.) for 1 month. The sex was confirmed. 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 5.

Table 3 Test results

(C) (E) (F)
Example 2 ○ ○ ○
Comparative Example 1 △ ○ △
Comparative Example 2 ○ ○ ○


Table 4 Light resistance test results

Dye remaining rate (%) ΔE
Example 2 93.3 2.9
Comparative Example 1 79.4 14.7
Comparative Example 2 89.6 5.3


Table 5 Solubility test and ink storage stability test

(G) (H)
Example 2 ○ ○
Comparative Example 1
Comparative Example 2 ○ ○

As is clear from the results in Table 3, Comparative Example 1 shows (C) a slight blur in the moisture resistance test, and (F) the residual ratio of the pigment in the ozone resistance test is 70 or more and less than 80%. Similarly, Example 2 showed little bleeding in the former, and more than 80% in the latter, but it was found that there was a problem with these fastnesses.
Further, as is apparent from Table 5, in the solubility test (G), the solubility in water is 50 g / L or more and less than 100 g / L for the compound used in Comparative Example 1, whereas it is used in Example 2. The compound was 100 g / L or more, and water solubility higher than that of Comparative Example 1 was exhibited.

Comparative Example 2 is equivalent to Example 2 in each test shown in Tables 3 and 5 except for (D) xenon light resistance shown in Table 4, and it can be seen that it has high performance.
However, it has been found that there is a difference between each comparative example and Example 2 in terms of light fastness, which is often required to be further improved, among the fastness to yellow coloring matter and yellow ink. That is, as apparent from Table 4, in the (D) xenon light resistance test, the dye residual ratios of Comparative Example 1 and Comparative Example 2 were 79.4 and 89.6, respectively, whereas Example 2 It was 93.3, and the improvement effect of the pigment residual ratio was recognized. Further, in the color difference ΔE, Comparative Examples 1 and 2 are 14.7 and 5.3, respectively, whereas Example 2 is 2.9, and the color difference before and after the test is smaller. Comparative Example 1 and Comparative Example It can be said that it is superior to 2.

  From the above results, the water-soluble azo compound of the present invention is suitable for preparing an ink composition for ink jet recording, and has various fastness properties, particularly 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.

Claims (12)

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

(In the formula (1), R ^1, R ² each independently represent a hydrogen atom, an alkyl group or an alkoxy group having 1 to 4 carbon atoms having 1 to 4 carbon atoms, x is from 1 3, y is 0 to 2 Each represents an integer.) The water-soluble azo compound or a salt thereof according to claim 1, wherein R ¹ and R ^{2 in} formula (1) are each independently a methoxy group, a methyl group or a hydrogen atom, x is 1 and y is 1. The water-soluble azo compound or a salt thereof according to claim 1 or 2 represented by the following formula (2):

An ink composition comprising the water-soluble azo compound or a salt thereof according to any one of claims 1 to 3. The ink composition according to claim 4, comprising a water-soluble organic solvent. The ink composition according to claim 4, which is for ink jet recording. In an ink jet recording method for recording on a recording material by ejecting ink droplets according to a recording signal, the ink composition according to any one of claims 4 to 6 is used as an ink. Method 8. The ink jet recording method according to claim 7, wherein the recording material is an information transmission sheet. 9. The ink jet recording method according to claim 8, wherein the information transmission sheet is a sheet having an ink receiving layer containing a porous white inorganic substance. The colored body colored with the water-soluble azo compound according to any one of claims 1 to 3 or the ink composition according to any one of claims 4 to 6. The colored body according to claim 10, wherein coloring is performed by an ink jet printer. An ink jet printer loaded with a container containing the ink composition according to any one of claims 4 to 6.