KR20200087675A - Azo pigment composition and manufacturing method thereof - Google Patents

Abstract

The present invention relates to an azo pigment composition and a manufacturing method thereof, capable of improving luminance, contrast, and printing density (color development). According to the present invention, the method of manufacturing the azo pigment composition includes: adding a heterogeneous base represented by Formula (3) and a heterogeneous coupler represented by Formula (4) upon manufacture of an azo pigment which is a reaction product of a base represented by Formula (1) and a coupler represented by Formula (2).

Description

AZO PIGMENT COMPOSITION AND MANUFACTURING METHOD THEREOF}

The present invention relates to an azo pigment composition and a method for producing the same.

Azo pigments are widely used as colorants such as paints, offset inks, gravure inks, color toners, inkjet inks for recording, and colorants in color filters. In order to improve various characteristics such as brightness and contrast of the coating film formed in such applications, micronized azo pigments are sometimes used. However, in general, it is known that a colored composition containing a micronized pigment tends to deteriorate its dispersion stability. Therefore, while securing dispersion stability of pigments and the like, measures for improving these various properties have been proposed (Patent Documents 1 to 6).

In Patent Document 1, the production of a red pigment dispersion for a color filter containing an organic pigment, a pigment dispersion aid A which is a sulfonate of a compound having the same skeleton as the organic pigment, a pigment dispersion aid B of a specific structure, a pigment dispersant and an organic solvent In, it is described that mixing the dispersing aid A and the organic pigment to perform the micronization treatment, followed by mixing the pigment dispersing aid B, the pigment dispersing agent and the organic solvent to perform the dispersing treatment. It is said that by using these two types of pigment dispersing aids, the fine dispersibility of the pigment and subsequent dispersion stability are improved, and excellent color characteristics, high transmittance, and contrast can be realized.

In the patent document 2, the coloring composition for color filters comprising the colorant (A) containing the red azo pigment (a1) having a maximum refractive index of 1.8 or less in the wavelength region of 600 to 700 nm and resin (B). This is described. When such a pigment (a1) is included, it is said to be excellent in stability since it is a high contrast ratio and there is no need to refine the pigment excessively.

In Patent Document 3, a pigment dispersion aid having a specific structure, an acrylic block copolymer having a tertiary amino group and/or a quaternary ammonium group, and an organic solvent in a particulate product obtained by micronizing a pigment containing CI pigment red 221 After adding and dispersing to obtain a pigment dispersion, a method of making a red pigment dispersion resist composition for a color filter is described. By this method, the dispersion stability of the fine particles of the pigment containing CI Pigment Red 221 can be improved even when compared with the prior art, and the color is excellent in dispersion stability, coloring power, contrast, brightness, heat resistance and solvent resistance. It is said that a red pigment dispersion resist composition for a filter can be provided.

Patent Document 4 discloses that naphthol red excellent in dispersibility, color development, and transparency can be obtained by surface-treating naphthol red having a specific structure with a hydrophilic naphthol derivative or hydrophilic phenol derivative having a specific structure.

In Patent Document 5, in the production of a monoazo-based red pigment composition containing a monoazo pigment having a specific structure and an azonaphthoic acid component having a specific structure, the monoazo pigment having a specific structure is composed of a diazonium salt component and a coupler component. It is described that the azonaphthoic acid component is synthesized by a coupling reaction, and is obtained by adding hydroxynaphthoic acid to the coupler component in advance before the coupling reaction. The monoazo-based red pigment composition thus obtained and the color toner using the composition maintain the reflective properties of the yellowish-colored areas of the monoazo-based red pigments, and also have good reflective properties in the blue-colored areas. It has been described that the color reproduction range is wide, has sufficient brightness and saturation, and is excellent in transparency, light resistance, and dispersibility.

Patent Document 6 discloses an inkjet ink containing a specific polymer-bonded pigment dispersed in an aqueous ink vehicle. And, with such a configuration, it is said that an inkjet ink capable of generating a printed image having good glossiness and durability without increasing ink viscosity can be provided.

Patent Document 1: Japanese Patent Publication No. 2011-162722 Patent Document 2: Japanese Patent Publication No. 2012-198453 Patent Document 3: Japanese Patent Publication No. 2016-61979 Patent Document 4: Japanese Patent Publication No. 2016-108451 Patent Document 5: Japanese Patent Publication No. 2000-248191 Patent Document 6: Japanese Patent No. 4532387

For example, in the field of a display device in which a color filter is used, or in the field of a recording inkjet ink, there is a strong market demand for high image quality, and there is room for further improvement even if the inventions described in Patent Documents 1 to 6 are employed, for example. Accordingly, it is an object of the present invention to provide an azo pigment composition capable of improving luminance and contrast over conventional ones in the field of a display device in which a color filter is used, and a manufacturing method thereof. In addition, in the field of inkjet inks for recording, it is to provide an azo pigment composition capable of improving the printing density (colorability) than the conventional one, and a method for producing the same.

In order to solve the above-mentioned problems, the present inventor has made extensive studies. As a result, when a specific azo pigment is produced, when a coupling reaction is performed by adding a base and a coupler different from its base and a coupler, for example, in the field of a display device in which a color filter is used, the pigment composition obtained includes The present invention has been completed by discovering that it is possible to improve the brightness and contrast of the coating film and, for example, in the field of inkjet ink for recording, the printing density (colorability) of a printed matter containing the obtained pigment composition than conventional ones. Ordered.

In the first aspect of the present invention, in the preparation of the azo pigment which is the reaction product of the base represented by the following formula (1) and the coupler represented by the following formula (2), the heterogeneous base and formula (3) It relates to a method for producing an azo pigment composition, to which a heterogeneous coupler represented by 4) is added.

(In formula (1), R ¹ represents R ³ -NH-C(=O)-, R ² represents a halogen atom or R ⁴ O-. R ³ represents a hydrogen atom or a phenyl group (-C ₆ H ₅ )) R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms.)

(In formula (2), R ⁵ represents a hydrogen atom or -CONH-R ^6. R ⁶ represents the following formula (2-1).)

(In formula (2-1), R ⁷ represents R ⁹ -NH-C(=O)-, R ⁸ represents a halogen atom or R ¹⁰ O-. R ⁹ is a hydrogen atom or a phenyl group (-C ₆ H ₅ R ¹⁰ represents an alkyl group having 1 to 4 carbon atoms, and * represents a number of bonds.)

(In formula (4), R ¹¹ represents -SO ₃ H or -COOH.)

In the embodiment of the present invention, with respect to 100 parts by weight of the base represented by formula (1), 0.5 to 4 parts by weight of the base represented by formula (3), 100 parts by weight of the coupler represented by formula (2), You may add 2-10 weight part of couplers represented by Formula (4).

In the embodiment of the present invention, a micronization treatment may be performed so that the average primary particle size of the azo pigment is 25 to 70 nm. Further, in this case, the refinement treatment may be performed in the presence of a pigment derivative.

The second aspect of the present invention is an azo pigment composition comprising an azo pigment which is a reaction product of a base represented by the following formula (1) and a coupler represented by the following formula (2), represented by formulas (1) and (3) An azo pigment comprising a base and a reaction product of a coupler represented by formulas (2) and (4), wherein the content (based on solids) of the reaction products of formulas (1) and (2) is 80 to 95% by weight It relates to a composition.

(In formula (1), R ¹ represents R ³ -NH-C(=O)-, R ² represents a halogen atom or R ⁴ O-. R ³ represents a hydrogen atom or a phenyl group (-C ₆ H ₅ )) R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms.)

(In formula (2), R ⁵ represents a hydrogen atom or -CONH-R ^6. R ⁶ represents the following formula (2-1).)

(In formula (2-1), R ⁷ represents R ⁹ -NH-C(=O)-, R ⁸ represents a halogen atom or R ¹⁰ O-. R ⁹ is a hydrogen atom or a phenyl group (-C ₆ H ₅ R ¹⁰ represents an alkyl group having 1 to 4 carbon atoms, and * represents a number of bonds.)

(In formula (4), R ¹¹ represents -SO ₃ H or -COOH.)

In the present invention, the weight ratio ((1)/(3)) of the component derived from formula (1) and the component derived from formula (3) is 90.6/9.4 to 98.9/1.1, and the component derived from formula (2) The weight ratio ((2)/(4)) of the component derived from Formula (4) may be 82.4/17.6-96.5/3.5.

According to the present invention, for example, in the field of a display device in which a color filter is used, the brightness and contrast of a coating film containing the obtained pigment composition, and, for example, in the field of inkjet ink for recording, the printing density of an inkjet printing material It is possible to provide an azo pigment composition capable of improving (coloring property) more than before, and a method for producing the same.

Hereinafter, embodiments of the present invention will be described.

In the embodiment of the method for producing an azo pigment composition according to the present invention, in the production of an azo pigment which is a reaction product of a base represented by the following formula (1) and a coupler represented by the following formula (2), the formula (3) The heterogeneous base and heterogeneous coupler represented by formula (4) are added. In addition, in the following, the base represented by Formula (1) may be referred to as the main base and the coupler represented by Formula (2) as the main coupler. Moreover, the azo pigment obtained from a main base and a main coupler may be called a main azo pigment.

(In formula (1), R ¹ represents R ³ -NH-C(=O)-, R ² represents a halogen atom or R ⁴ O-. R ³ represents a hydrogen atom or a phenyl group (-C ₆ H ₅ )) R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms.)

(In formula (2), R ⁵ represents a hydrogen atom or -CONH-R ^6. R ⁶ represents the following formula (2-1).)

(In formula (2-1), R ⁷ represents R ⁹ -NH-C(=O)-, R ⁸ represents a halogen atom or R ¹⁰ O-. R ⁹ is a hydrogen atom or a phenyl group (-C ₆ H ₅ R ¹⁰ represents an alkyl group having 1 to 4 carbon atoms, and * represents a number of bonds.)

(In formula (4), R ¹¹ represents -SO ₃ H or -COOH.)

The reason why it is possible to improve the luminance and contrast of the color filter or the printing density (coloring property) of inkjet printing by adding a base and a coupler different from the main base and the main coupler constituting a specific azo pigment is as described above. Crystallization and crystal growth of the desired azo pigment (main azo pigment) is caused by the presence of a reaction product other than the main azo pigment (hereinafter sometimes referred to as a sub-product) produced by the presence of a heterogeneous base and a coupler. It is presumed to be due to being suppressed. It is presumed that the crystallization or crystal growth is suppressed as described above, and aggregation of the main azo pigment is also suppressed, and the brightness or contrast of the color filter or the printing density (colorability) of the inkjet print can be improved.

As a main base, what is represented by said Formula (1) can be used. In Formula (1), the bonding position of R ¹ and R ² is not particularly limited. R ¹ is preferably NH ₂ -C(=O)- or C ₆ H ₅ -NH-C(=O)-. R ² is preferably a halogen atom or R ⁴ O-. The halogen atom may be any of chlorine atom and bromine atom. R ⁴ is preferably an alkyl group having 1 to ⁴ carbon atoms, and is preferably a methyl group, ethyl group, propyl group or butyl group. The propyl group and the butyl group may be linear or branched. Examples of such a base include 3-amino-4-methoxybenzanilide, 2-chloro-5-methoxyaniline, 3-chloro-6-methoxyaniline, and the like.

As a main coupler, what is represented by said Formula (2) can be used. In Formula (2), R ⁵ is preferably a hydrogen atom or -CONH-R ⁶ . R ⁶ is preferably a functional group represented by the formula (2-1), and the bonding position of R ⁷ and R ^{8 in} the formula (2-1) is not particularly limited. R ⁷ is preferably NH ₂ -C(=O)- or C ₆ H ₅ -NH-C(=O)-. R ⁸ is preferably a halogen atom or R ¹⁰ O-. The halogen atom may be any of chlorine atom and bromine atom. R ¹⁰ is preferably an alkyl group having 1 to 4 carbon atoms, and is preferably a methyl group, ethyl group, propyl group or butyl group. The propyl group and the butyl group may be linear or branched. Examples of such a coupler include N-(5-chloro-2-methoxyphenyl)-3-hydroxy-2-naphthalenecarboxyamide, β-naphthol, and the like.

It is preferable that the heterogeneous base with respect to the main base described above is represented by formula (3). In Formula (3), the bonding position of the sulfonic acid group is not particularly limited. Examples of such heterogeneous bases include p-aminobenzoic acid (sulfanilic acid), o-aminobenzoic acid (anthranilic acid), and m-aminobenzoic acid. You may use one kind of bases of two kinds, or two or more kinds of bases.

It is preferable that the heterogeneous coupler to the above-described main coupler is represented by formula (4). In Formula (4), the bonding position of R ¹¹ is not particularly limited. R ¹¹ is preferably -SO ₃ H or -COOH, but -COOH is preferred. Examples of the heterogeneous coupler include β-naphthol, BON acid, Schaferic acid, and F acid.

It is preferable that the heterogeneous base and coupler exist when the coupling reaction is performed using the main base and the main coupler. For example, (1) a diazotization solution diazotized with a solution containing a main base and a heterogeneous base and a coupler solution comprising a main coupler and a heterogeneous coupler, and subjected to a coupling reaction, (2) a diazotization solution of the main base When a coupling reaction is performed by mixing a coupler solution containing a main coupler, a method of, for example, adopting a coupling reaction by adding a diazo solution of a heterogeneous base and a coupler solution of a heterogeneous coupler separately from the main base and the main coupler, etc. can do. The diazotization and coupling reaction of the base can be carried out by employing known conditions.

The mixing ratio of the main base and the heterogeneous base, while obtaining the main azo pigment as the main colorant, secures the properties of the main azo pigment, effectively suppresses crystallization and crystal growth of the desired azo pigment by products derived from the heterogeneous base and coupler From the viewpoint of, it is preferable to add the dissimilar base to 0.5 to 4 parts by weight with respect to 100 parts by weight of the main base.

For the same reason, the mixing ratio of the main coupler and the heterogeneous coupler is preferably added so that the heterogeneous base is 2 to 20 parts by weight relative to 100 parts by weight of the main base.

After the coupling reaction, drying is performed by filtration and washing with water to obtain a dried product of the azo pigment composition. It is also possible to use this dried product as an azo pigment composition as it is. It is also possible to use a pulverized product obtained by pulverizing the dried product as an azo pigment composition. It is also possible to use a fine product obtained by micronizing a dried product or a pulverized product as an azo pigment composition.

The pulverized product can be obtained by pulverizing with a disperser such as a roll mill or bead mill. In addition, the fine cargo can be obtained, for example, by a salt milling method or the like. The micronization by the salt milling method, especially the solvent salt milling method, mechanically kneads a mixture obtained by mixing, for example, a dry matter or a pulverized product of a pigment composition, a water-soluble inorganic salt, and a water-soluble solvent using a kneader or the like, and water-soluble inorganic It is performed by grinding a pigment composition with a salt. Conventionally known conditions can be employed for such salt milling. After performing salt milling and washing with water, a water-soluble inorganic salt and a water-soluble solvent are removed, and a refined pigment composition is obtained. Water washing is preferably performed until the water-soluble inorganic salt and the water-soluble solvent are completely removed. Depending on the application, it may be dried to remove water.

When performing the micronization treatment, the micronization treatment may be performed in the presence of a surface treatment agent such as a pigment derivative or resin from the viewpoint of more effectively suppressing crystallization and crystal growth of the azo pigment. For example, in the case of the solvent salt milling method described above, it is good to have a surface treatment agent present when the pigment composition is ground with a kneader. The total amount of the surface treatment agent may be added at the start of kneading, or may be added separately after the start of kneading.

The pigment derivative is a compound having an organic pigment as a basic skeleton and an acidic group or an aromatic group introduced into the side chain as a substituent. Specifically, the organic pigment to be the parent skeleton is a quinacidone-based pigment, a phthalocyanine-based pigment, an azo-based pigment, a quinophthalone-based pigment, an isoindoline-based pigment, an isoindolinone-based pigment, a quinoline pigment, a diketopyro And pyrrole pigments, benzoimidazolone pigments, and dioxazine-based pigments. In addition, the parent skeleton also includes light yellow aromatic polycyclic compounds such as naphthalene-based, anthraquinone-based, triazine-based, and quinoline-based, which are not generally referred to as pigments. As such a pigment derivative, for example, Japanese Patent Laid-Open No. Hei 11-49974, Japanese Patent Laid-Open No. 11-189732, Japanese Patent Laid-Open No. Hei 10-245501, Japanese Patent Laid-Open No. 2006-265528, Japanese Patent Publication No. 8-295810, Japanese Patent Publication No. 11-199796, Japanese Patent Publication No. 2005-234478, Japanese Patent Publication 2003-240938, Japanese Patent Publication No. 2001-356210, Japanese Patent It is possible to use those described in Japanese Patent Application Publication No. 2007-186681, Japanese Patent Publication No. 2003-167112, Japanese Patent Publication No. 2013-199470, and the like.

The amount of the pigment derivative (non-volatile or solid) is preferably 1 to 20 parts by weight based on 100 parts by weight of the pigment composition.

As a resin as a surface treatment agent, vinyl ester resin, acrylic resin, etc. are mentioned, for example. The amount of the resin added as a surface treatment agent is preferably 3 to 30 parts by weight based on 100 parts by weight of the pigment composition.

It is preferable that the average primary particle diameter of the azo pigment in the refined pigment composition is 25 to 70 nm. The average primary particle size is, for example, 50 randomized pigment particles selected from 50,000 times and 100,000 times images by a transmission electron microscope (trade name: JEM-1011, manufactured by Nippon Denshi Co., Ltd.), in the image. The maximum particle size of each micronized pigment particle can be measured on the basis of the indicated measurement length, and can be obtained as the arithmetic mean.

In the case of inkjet ink, the average particle diameter of the secondary particles of the pigment is preferably 300 nm or less, from the viewpoint of improving dispersibility and from the viewpoint of ejectability from the ink ejection nozzle provided in the inkjet recording type printer. It is preferably 150 nm or less. The average particle diameter of the secondary particles of the pigment contained in the pigment composition used for the inkjet ink refers to a measurement value obtained when the colored composition for the inkjet ink or the particles contained in the inkjet ink is measured with a laser zeta potentiometer.

The pigment derivative may be added and mixed after the micronization treatment in addition to being present when the micronization treatment is performed.

Embodiment of the azo pigment composition which concerns on this invention contains the azo pigment which is the reaction product of the base represented by said formula (1), and the coupler represented by said formula (2). In addition, the reaction products of the base represented by the formulas (1) and (3) and the coupler represented by the formulas (2) and (4) are further included, and the reactions of the formulas (1) and (2) are also included. It is preferable that the content of the product (based on solid content) is 80 to 95% by weight. Such azo pigment composition is obtained, for example, by the production method described above.

In addition to the main azo pigment, which is a reaction product produced by a coupling reaction between a main base diazoide and a main coupler, a hetero base and a coupler are involved in the azo pigment composition obtained by the production method as described above, and are involved in the coupling reaction. And side products produced by the like. As described above, it is thought that crystallization and crystal growth of the main azo pigment are suppressed by side products produced by the heterogeneous base and coupler involvement. In addition to exerting the function of the main azo pigment itself, the function of the secondary product is effectively acted to improve the luminance or contrast of the color filter, or the printing density (colorability) of the inkjet method, from the viewpoint of the main azo pigment. The preferred range of content (based on solid content) is as described above. In other words, the content of the side product (based on solid content) is preferably 20 to 5% by weight.

When a micronization process is performed using a pigment derivative and when a pigment derivative is added after the micronization treatment, the azo pigment composition contains a pigment derivative. In this case, the main azo pigment content (based on solid content) is preferably 64 to 94% by weight.

Regarding the composition of the main azo pigment and the sub-product contained in the azo pigment composition, from the viewpoint of exerting the function of the sub-product, further improving the luminance and contrast of the color filter or the printing density (colorability) of the inkjet printing material, The weight ratio ((1)/(3)) of the component derived from Formula (1) and the component derived from Formula (3) is 90.6/9.4 to 98.9/1.1, and the component derived from Formula (2) and Formula (4) It is preferable that the weight ratio ((2)/(4)) of the component derived from) is 82.4/17.6-96.5/3.5.

The composition of the main azo pigment and the secondary product can be grasped from the composition ratio of the starting material, but it is also possible to measure by gas chromatography mass spectrometry (GC/MS) using the obtained azo pigment composition.

If a main azo pigment contained in the manufacturing method which concerns on this invention and an azo pigment composition is illustrated with a color index number, it is C. I. pigment red 269, etc.

The above-mentioned azo pigment composition can be used as a coloring agent, such as a paint, an offset ink, a gravure ink, a color toner, a recording inkjet ink, and a color filter colorant. Since luminance and contrast can be improved more than before, it is particularly suitable as a colorant such as a color filter for an image display device. In addition, recently, in an image display device using a color filter, various light sources such as cold cathode tubes, light emitting diodes, and organic EL elements have been employed as backlights of light sources. Thus, good luminance is obtained in various color gamuts. Moreover, since the printing density (coloring property) can be improved more than before, it is also suitable as a colorant such as inkjet ink for recording.

Hereinafter, first, as an example of using the above-mentioned azo pigment composition as a colorant for color filter use, an outline of the color composition for forming a coating film for color filter use will be described.

The coloring composition for coating film formation includes the above-mentioned azo pigment composition, a dispersing agent, a dispersing auxiliary agent, a solvent, a coating film forming component, and other additives. Among these, a dispersing aid, a solvent, and other additives can be added as needed depending on the components of the azo pigment composition.

As a dispersing agent, resin type dispersing agent, surfactant type dispersing agent, etc. are mentioned, for example. As a specific example of the resin-type pigment dispersant, for example, polyurethane, polyester, unsaturated polyamide, phosphoric acid ester, polycarboxylic acid and its amine salt, ammonium salt, alkylamine salt, polycarboxylic acid ester, hydroxyl group-containing polycarboxyl Water-soluble resins such as acid esters, polysiloxanes, modified polyacrylates, water-soluble resins such as (meth)acrylic acid-(meth)acrylic acid ester copolymers, (meth)acrylic acid-styrene copolymers, styrene-maleic acid copolymers, and water-soluble polymer compounds Can be heard. Examples of the surfactant-type pigment dispersant include a naphthalene sulfonate formalin condensate salt, an aromatic sulfonate formalin condensate, anionic activators such as polyoxyethylene alkyl phosphate esters, nonionic activators such as polyoxyethylene alkyl ethers, alkylamine salts, and quaternary ammonium salts. And cationic active agents. The dispersing agent may be contained in one kind or two or more kinds. The content of the dispersant (solid content or active ingredient) is preferably 10 to 40 parts by weight with respect to 100 parts by weight of the azo pigment composition from the viewpoint of dispersion stability.

Examples of the dispersing aid include the above-described pigment derivatives and dispersing resins. The pigment derivative may be unnecessary when included in the azo pigment composition, but may be further added from the viewpoint of further improving the dispersion stability of the particles in the coloring composition. The content of the pigment derivative (solid content or active ingredient) is preferably 2 to 15 parts by weight with respect to 100 parts by weight of the azo pigment composition from the viewpoint of dispersion stability. When azo pigment composition contains a pigment derivative, it is based on the total amount. As for the dispersing resin, it is particularly suitable to be used when the coating film-forming component contains a photopolymerizable component. As such a dispersion resin, the alkali-soluble resin mentioned later is mentioned. The dispersing resin may be an alkali-soluble resin used as the coating film forming component and a resin species of the same type, or may be a different resin species. The content of the dispersion resin is preferably 10 to 50 parts by weight based on 100 parts by weight of the total pigment composition and pigment derivative.

As a solvent, various organic solvents, such as aromatic type, ketone type, ester type, glycol ether type, alcohol type, and aliphatic type, are mentioned, for example. These can be appropriately selected depending on the kind of coating film forming component and the like. The addition amount of the solvent can be added so that the solid content concentration including the azo pigment composition or the like is 10 to 30% by weight from the viewpoint of handling properties.

Examples of the coating film forming component include polymers such as thermoplastic urethane resins, (meth)acrylic resins, polyamide resins, polyimide resins, styrene-maleic acid resins, polyester resins, silicone resins, and cardo resins. And polymerizable components such as photopolymerizable components. As the polymer, an alkali-soluble resin that exhibits solubility in a solution in an alkali region is preferable. As content in the coloring composition of a polymer, 10-40 weight% is preferable in the total solid content of a coloring composition. When using the above-mentioned dispersion resin, it is a total amount. The photopolymerizable component includes a photopolymerizable compound and a photopolymerization initiator. As such a photopolymerizable compound and a photopolymerization initiator, for example, those described in JP 2009-179789 A can be used. The content of the photopolymerizable compound in the coloring composition is preferably 5 to 70% by weight relative to the total non-volatile components in the coloring composition, and the content of the photopolymerization initiator in the coloring composition is 0.1 to the total nonvolatile component of the coloring composition. 10 mass% is preferred.

Other additives include other pigments, dyes, sensitizers (sensitizers), chain transfer agents, fluorine-based organic compounds, thermal polymerization initiators, thermal polymerization components, fillers, surfactants, adhesion promoters, antioxidants, flocculation inhibitors, surface modifiers (leveling And the like). Other pigments or dyes are pigments or dyes used in combination with the main azo pigment described above for color matching.

The coloring composition for forming a coating film can be obtained by adding and dispersing the above-described components in a known disperser such as a bead mill, a sand mill, or a disper. In addition, as a method for adding each component, all components may be mixed and dispersed, or several components of each component may be mixed and dispersed, and then the remaining components may be added at once or in multiple portions to be dispersed. For example, it can be obtained by preparing a pigment dispersion containing an azo pigment composition, a dispersing agent, a solvent and, if necessary, a dispersing aid, and adding and dispersing a coating film forming component and, if necessary, an additive.

Next, as an example of using the above-described azo pigment composition as a colorant for use in inkjet ink for recording, the outline of the color composition for inkjet ink and inkjet ink will be described.

The coloring composition for inkjet ink contains the above-mentioned azo pigment composition, a dispersing agent, a dispersing aid, a solvent, and other additives. Among these, a dispersing aid, a solvent, and other additives can be added as needed depending on the components of the azo pigment composition.

As a dispersing agent, the thing similar to the case of the coloring composition for coating film formation mentioned above can be used, for example. Further, for example, a resin-type dispersant containing a copolymer comprising a cyclohexyl methacrylate unit and an acrylic acid unit described in International Publication No. 2012/118078 can be used. The content of the dispersant (solid content or active ingredient) is preferably 10 to 40 parts by weight with respect to 100 parts by weight of the azo pigment composition from the viewpoint of dispersion stability.

As a dispersing aid, the pigment derivative mentioned above is mentioned, for example. As in the case of the above-mentioned coloring composition for coating film formation, when a pigment derivative is contained in an azo pigment composition, it can be added as needed. The content of the pigment derivative (solid content or active ingredient) is preferably 2 to 14 parts by weight with respect to 100 parts by weight of the azo pigment composition from the viewpoint of dispersion stability. When azo pigment composition contains a pigment derivative, it is based on the total amount.

Either an organic solvent or an aqueous solvent may be used as the solvent.

As an organic solvent, as an organic solvent other than an aqueous solvent, alcohols, ketones, esters, glycol ethers, glycol acetates, saturated hydrocarbons, unsaturated hydrocarbons, cyclic saturated hydrocarbons, and cyclic unsaturateds commonly used in inkjet ink Organic solvents such as hydrocarbons and aromatic hydrocarbons can be widely used.

Examples of the aqueous solvent include water and/or water-soluble organic solvents. As water, pure or ultrapure water such as ion-exchanged water, ultrafiltration water, reverse osmosis water, distilled water, or the like can be used. The water-soluble organic solvent is not particularly limited as long as it is generally used for inkjet ink. Specifically, those having a smaller vapor pressure than water, for example, polyhydric alcohols such as diethylene glycol, polyhydric alcohol ethers such as triethylene glycol monobutyl ether, ketones, esters, lower alkoxy alcohols, amines, amides, heterocyclic reflux , Sulfoxides, sulfones, and the like. Further, for the purpose of preventing the occurrence of mold or bacteria, sterilized by ultraviolet treatment, hydrogen peroxide treatment, or the like may be used. Here, water-soluble means that it is miscible with water or exhibits solubility in water of 3.3 g/100 mL or more at 20°C.

The content of the solvent is not particularly limited, but is preferably 200 to 600 parts by weight relative to 100 parts by weight of the pigment composition (solid content).

Other additives include other pigments or dyes, surface tension modifiers or penetrants (surfactants), wet drying inhibitors, preservatives, fungicides, pH adjusters, rust inhibitors, moisturizers and the like. These may be used alone or in combination of two or more kinds as appropriate, if necessary.

The pH adjusting agent is not particularly limited as long as it can be controlled to a desired pH, and a known one can be used. Organic amines such as methylamine and ethylamine; Lower alkanolamines such as monoethanolamine, diethanolamine, and triethanolamine; And inorganic bases such as ammonium hydroxide, sodium hydroxide, and potassium hydroxide.

Moreover, it is preferable that the coloring composition for inkjet ink has a viscosity measured by the method mentioned later of about 2-50 mPa*s. Thereby, the viscosity of the inkjet ink containing the coloring composition for the inkjet ink can also be kept low, and the ejection of the inkjet ink from a more stable nozzle becomes possible, so that better ejection performance can be obtained.

Moreover, it is preferable that the coloring composition for inkjet ink has a pH of about 7-10 especially when using an aqueous solvent. Thereby, the storage stability of the coloring composition for inkjet ink becomes more favorable.

The manufacturing method of the coloring composition for inkjet ink is not specifically limited, For example, the above-mentioned azo pigment composition, a dispersing agent, other arbitrary components are added, and the method of dispersing with a disper/high-speed disperser etc. is mentioned. Moreover, you may disperse|distribute with a bead mill, a roll mill, etc. as needed. And finally, in order to remove particles of a certain size or more that may be included in the obtained coloring composition for inkjet ink, filter filtration or centrifugation is performed. Moreover, when performing filter filtration, you may select suitably the pore size (mesh size) of a filter so that the particle diameter of the particle|grains contained in the coloring composition for inkjet ink may be set to a predetermined particle diameter as needed. However, the filter filtration may be performed in the step of preparing the coloring composition for inkjet ink, but may be carried out in the step of preparing the inkjet ink, or may be performed in each step in the preparation of the coloring composition for inkjet ink and inkjet ink.

Examples of the inkjet ink include those obtained by adding conventionally known solvents, surfactants, and other additives as necessary to the coloring composition for inkjet ink described above as a component included in the inkjet ink. Although the content of each component contained in the inkjet ink is not particularly limited, the content of the pigment composition (solid content) is preferably approximately 2 to 10% by weight, the content of the dispersant is preferably approximately 1 to 10% by weight, and the content of the solvent Silver is preferably about 70 to 97% by weight.

The manufacturing method of an inkjet ink is not specifically limited, For example, it is obtained by adding a solvent, surfactant, and other additives to the coloring composition for inkjet ink as needed, mixing, and stirring. The method of mixing and stirring is not particularly limited, and a general mixer may be used, or a bead mill may be used to further improve the dispersibility of the pigment. If necessary, filter filtration or the like may be performed to remove particles having a size larger than a certain size that may be contained in the ink.

Since the inkjet ink described above contains a predetermined azo pigment composition, when used as a recording ink, it has excellent printing density (colorability). The printing density (chromogenicity) can be, for example, a measure of the optical density (OD) described later as an index. The optical density OD can be judged to have excellent printing density in the case of 1.1 to 1.3.

Example

Hereinafter, embodiments of the present invention will be described in more detail based on examples.

(Production Example 1) Preparation of pigment derivative (I)

20 parts by weight of CI Pigment Yellow 138 (manufactured by BASF, Paliotol Gelb K0961HD) and 300 parts by weight of 98% sulfuric acid were placed in a 500 ml separable flask and reacted at 120° C. for 5 hours to sulfonate the phthalimidequinophthalone compound. Got. The reaction mixture was poured into 3000 parts of water while stirring, the sulfonate of the phthalimidequinophthalone compound was precipitated, stirred for 30 minutes, and then filtered and washed with water three times. The obtained wet cake was washed with 300 parts by weight of 1% dilute sulfuric acid, filtered and washed with water. It was dried in a hot air dryer to obtain a pigment derivative (I) represented by the following formula (5) by 54 parts by weight. The resulting pigment derivative (I), manufactured by Hewlett-Packard liquid chromatography mass spectrometry, "LC / MS" (Electro Spray Ionization) the result of the analysis by mass, m / z 733 [MH] ^- said detecting. When elemental analysis and mass spectrometry of the pigment derivative (I) were performed, p=0.8.

(Example 1)

50 g (0.21 mol) of 3-amino-4-methoxybenzanilide and 1.2 g (0.0069 mol) of sulfanic acid as heterogeneous base were dispersed in 1000 g of water, ice was added, and the temperature was set at 0 to 5°C. , 35% hydrochloric acid aqueous solution 55 g (0.53 mol) was added and stirred for 30 minutes. Then, 50 g (0.22 mol) of a 30% aqueous sodium nitrite solution was added and stirred for 60 minutes, followed by adding 1.2 g (0.012 mol) of sulfamic acid to eliminate excess nitrite. Furthermore, 40 g (0.29 mol) of soda acetate and 58 g (0.87 mol) of 90% acetic acid were added to obtain a diazonium salt solution. Apart from this, 64 g (0.1954 moles) of N-(5-chloro-2-methoxyphenyl)-3-hydroxy-2-naphthalenecarboxyamide and 4.4 g (0.0235 moles) of BON acid as heterogeneous couplers are water 1000. g and 25 g (0.63 mol) of caustic soda were dissolved at a temperature of 80°C or lower to obtain a coupler solution. This solution was added to the diazonium salt solution at a temperature condition of 10° C. or lower to perform a coupling reaction, and heat treated at 90° C. The reaction mixture was filtered, washed with water, and dried at 100°C. Thereafter, the dried product was pulverized to obtain a pulverized product. The content of Pigment Red 269, the reaction product of a diazoide of 3-amino-4-methoxybenzanilide and N-(5-chloro-2-methoxyphenyl)-3-hydroxy-2-naphthalenecarboxamide Was 89.1% by weight. The weight ratio ((1)/(3)) of the components originating from the main base 1 and the heterogeneous base 3 is 97.1/2.9, and the weight ratio of components originating from the main coupler 2 and the heterogeneous coupler 4 (( 2)/(4)) was 91.7/8.3.

The obtained pulverized product was subjected to a refinement treatment as follows to obtain a refined azo pigment composition. That is, 300 g of pulverized material, 45 g of surface treatment agent (Lipox (registered trademark) SPC2000, Showa Denko Co., vinyl ester resin), 3000 g of sodium sulfate as a grinding agent, and ethylene glycol (Nihon Sho Co., Ltd.) as a caking additive. 800 g of Cubai) was put into a twin-screw kneader (manufactured by Moriyama, 5 L kneader Σ type, hereinafter referred to as kneader), the temperature was controlled so that the temperature of the kneaded product in the kneader was 40°C, and kneaded for 9 hours. When the kneading is finished, the kneaded product is taken out, transferred to a temperature-controllable tank in which 16 L of deionized water is stored in advance, stirred for 30 minutes at 180 rpm with a stirring device, and the pH adjusted to 2.3-2.5 with 35% hydrochloric acid. The mixture was further stirred for 1 hour to disperse the kneaded product. The dispersion was transferred to a Nutsche and filtered, and the residue was washed with deionized water until the electrical conductivity of the washing wastewater was 3 μS/cm or less. The residue containing water after washing was taken out and taken on a drying shelf (material SUS304), transferred to a dryer and dried at 95°C for 20 hours. The dried product was pulverized with a pulverizer (Kyoritsu Riko Co., Ltd., a small grinder, sample mill SK-M2) to obtain a fine powder-like azo pigment composition. The average primary particle diameter of the particles in the micronized azo pigment composition was 50 nm.

(Example 2)

A micronized powder-like azo pigment composition was obtained in the same manner as in Example 1 except that the amount of sulfanilic acid was 0.7 g (0.0040 mol) and the amount of BON acid was 2.5 g (0.013 mol). The content of Pigment Red 269 was 93.6% by weight. The weight ratio ((1)/(3)) of the components originating from the main base (1) and the heterogeneous base (3) is 98.3/1.7, and the weight ratio of components originating from the main coupler (2) and the heterogeneous coupler (4) (( 2)/(4)) was 95.2/4.8. The average primary particle diameter of the particles in the refined azo pigment composition was 55 nm.

(Example 3)

A micronized powder-like azo pigment composition was obtained in the same manner as in Example 1 except that instead of 4.4 g (0.0235 mol) of BON acid, 5.8 g (0.0235 mol) of sodium sheparate was used. The content of Pigment Red 269 was 88.1% by weight. The weight ratio ((1)/(3)) of the components originating from the main base 1 and the heterogeneous base 3 is 97.1/2.9, and the weight ratio of components originating from the main coupler 2 and the heterogeneous coupler 4 (( 2)/(4)) was 90.6/9.4. The average primary particle diameter of the particles in the micronized azo pigment composition was 65 nm.

(Example 4)

A micronized powder-like azo pigment composition was obtained in the same manner as in Example 1, except that 5.3 g (0.0235 mol) of F acid was used instead of 4.4 g (0.0235 mol) of BON acid. The content of Pigment Red 269 was 88.5% by weight. The weight ratio ((1)/(3)) of the components originating from the main base 1 and the heterogeneous base 3 is 97.1/2.9, and the weight ratio of components originating from the main coupler 2 and the heterogeneous coupler 4 (( 2)/(4)) was 91.1/8.9. The average primary particle diameter of the particles in the micronized azo pigment composition was 60 nm.

(Comparative Example 1)

A dry product was obtained in the same manner as in Example 1, except that sulfanilic acid and BON acid were not added, and then refined to obtain a powdery azo pigment composition. The average primary particle size of the particles in the obtained azo pigment composition was 90 nm.

(Comparative Example 2)

A dry product was obtained in the same manner as in Example 1 except that no BON acid was added, and then refined to obtain a powder-like azo pigment composition. The average primary particle diameter of the particles in the obtained azo pigment composition was 100 nm.

(Comparative Example 3)

A dry product was obtained in the same manner as in Example 1 except that sulfanyl acid was not added, and then refined to obtain a powdery azo pigment composition. The average primary particle diameter of the particles in the obtained azo pigment composition was 120 nm.

(Comparative Example 4)

The dried product was obtained in the same manner as in Example 1, except that 0.95 g (0.0069 mol) of p-aminobenzoic acid was used instead of 1.2 g (0.0069 mol) of sulfanilic acid, followed by micronization to obtain a powdery azo pigment composition. Got. The content of Pigment Red 269 was 87.8% by weight. The weight ratio ((1)/(3)) of the components originating from the main base 1 and the heterogeneous base 3 is 97.3/2.7, and the weight ratio of components originating from the main coupler 2 and the heterogeneous coupler 4 (( 2)/(4)) was 91.7/8.3. The average primary particle size of the particles in the obtained azo pigment composition was 80 nm.

(Comparative Example 5)

A dry product was obtained in the same manner as in Example 1, except that 3.4 g (0.0235 mol) of β-naphthol was used instead of 4.4 g (0.0235 mol) of BON acid, followed by micronization to obtain a powdery azo pigment composition. . The content of Pigment Red 269 was 89.8% by weight. The weight ratio ((1)/(3)) of the components originating from the main base 1 and the heterogeneous base 3 is 97.1/2.9, and the weight ratio of components originating from the main coupler 2 and the heterogeneous coupler 4 (( 2)/(4)) was 92.4/7.6. The average primary particle size of the particles in the obtained azo pigment composition was 110 nm.

(Test Example 1)

<Preparation of pigment dispersions A1 to 9>

The azo pigment composition obtained in Examples 1 to 4 and Comparative Examples 1, 2 and 5: 22.5 wt%, the pigment derivative (I) obtained in Production Example 1: 2.5 wt% (11.1 wt% with respect to the azo pigment composition) (hereinafter, The azo pigment composition and the pigment derivative (I) may also be referred to as a colorant component), a polymer-based dispersant (Bicke-Japan Inc., Disperbyk LPN-21715): the solid content is 28% by weight relative to the colorant component, a polymer-based dispersant (Bicke Japan, manufactured by Disperbyk 111): 2% by weight of the solid content relative to the colorant component, dispersion resin (Soken Chemical Co., Ltd., Poret (trademark) ZAH110, 35.0% solid content, alkali solubility): the solid content of the colorant component 20% by weight, propylene glycol monomethyl ether (PM) as a solvent: 10% by weight, propylene glycol monomethyl ether acetate (PMA) as a solvent: The remainder was charged into a 550 ml stirrer (single mixer) for stirring for 10 minutes. Done. Next, 480 g of zirconia beads (Toray ceram grinding balls manufactured by Toray Corporation) having an average particle diameter of 0.8 mm were added, and stirred for 30 minutes in a constant temperature bath at 40°C to perform dispersion treatment. Thereafter, PMA was added so that the azo pigment composition became 20% by weight, stirring was performed for 10 minutes, and zirconia beads were removed by filtration. Next, zirconia beads (Toray ceram grinding balls manufactured by Toray Corporation) having an average particle diameter of 0.1 mm were added as a weight, and 4 times the total injection amount was added, followed by stirring for 50 minutes in a 40° C. constant temperature bath for dispersion treatment. Thereafter, PMA was added so that the azo pigment composition became 15% by weight, stirring was performed for 10 minutes, and zirconia beads were removed by filtration using a filter (PALL HDCII Membrane Filter, manufactured by PALL) to remove pigment dispersions A1 to 6 , 9 got.

When the azo pigment compositions obtained in Comparative Examples 3 and 4 were subjected to the same dispersing treatment, gelation to obtain desired pigment dispersions A7 and 8 was not obtained. Therefore, the following evaluation was not performed.

<Evaluation>

<<Formation of coating film>>

Coating composition (Soken Chemical Co., Ltd. manufactured by Soken Chemical Co., Ltd.) so that the pigment dispersions A1 to 6 and 9 had an azo pigment composition of 12% by weight, and the total amount of the dispersion resin and the polymer-based dispersant was 100% by weight relative to the azo pigment composition (Registered trademark) ZAH110, an acrylic polymer, 35.0% solid content, alkali-soluble) and PMA were added to prepare colored compositions A1 to 6 and 9. The obtained coloring compositions A1 to 6 and 9 were respectively coated on a glass plate having a thickness of 1 mm and a width of 100 mm using a spin coater (manufactured by Mikasa Co., Ltd., spin coater MS-150A). At this time, for each of the coloring compositions A1 to 6 and 9, three coated plates were prepared so that three coating films with different chromaticity x were formed. That is, the number of revolutions of the spin coater was changed to change the thickness so that the chromaticity x in one of the three sheets was necessarily less than 0.6850, and the chromaticity x in the other sheet was necessarily greater than 0.6850. The obtained coated plate was pre-dried at 90°C for 2.5 minutes, and then dried at 30°C for 30 minutes (postbake).

<<Measurement of chromaticity y, luminance Y, contrast>>

About each coating film after Prebake and Postbake, the tristimulus value by the xyY coloration method was calculated|required using the colorimeter (made by Hitachi Corporation, U3310). The contrast ratio (CR ratio) was determined using a color luminance meter (Topcon Techno House Co., Ltd., BM-5AS). The approximate straight line (calibration line) was obtained from the measured values of the three coated plates prepared as described above for each coating film, and the values of chromaticity y (Ry) and luminance Y (RY) when chromaticity x (Rx) was 0.6850 were determined. It was adopted as a result of the coating film. On the basis of the coating film A1 obtained using the coloring composition A1, the difference in RY of each coating film A2 to 6 and 9 ΔRY(RY(A2 to 6, 9)-RY(A1)), CR ratio (A2 to 6, 9) /A1). Table 1 shows the results.

(Test Example 2)

<Preparation of pigment dispersion B>

In order to evaluate luminance and contrast in addition to the colors (Rx, Ry), a pigment dispersion B containing a yellow pigment for color matching was prepared as follows. First, except for using the yellow pigment instead of the azo pigment composition obtained in Example 1 using CI Pigment Yellow 139 (manufactured by BASF, Irgaphor Yellow S2150CF) as a yellow pigment for color matching, and pigment dispersion A and In the same manner, a yellow pigment dispersion (Y) for color matching was obtained. Next, the pigment dispersions B (CI pigment yellow) in which the pigment dispersions A1 to 6, 9 (R) and the yellow pigment dispersion for color matching (Y) are mixed in a mixing ratio (R/Y, based on weight) in Table 2. A total of 15% by weight of 139 and a colorant component, and 22.50% of solid content) were prepared.

<Evaluation>

The obtained pigment dispersions B1 to 6 and 9 were used, and in the same manner as in Test Example 1, coloring compositions B1 to 6 and 9 and coating films B1 to 6 and 9 were prepared, and chromaticity y (Ry) and luminance for each coating film. Y (RY) and contrast (CR) were measured and evaluated. Table 2 shows the results.

From Tables 1 and 2, when azo pigments, which are reaction products of a specific base and a coupler, are produced, by adding a specific base and a coupler different from the base and a coupler, than the azo pigments and azo pigment compositions obtained by conventional manufacturing methods, It can be seen that an azo pigment composition capable of forming a coating film having excellent contrast and brightness can be provided.

(Production Example 2) Preparation of polymer type dispersant

After nitrogen substitution was performed in a 1000 ml separable flask equipped with a stirring device, a cooler, a thermometer, and a dropping lot, 200 parts by weight of butyl acetate was placed in the separable flask, and the mixture was heated to 100°C while stirring. Subsequently, 200 parts by weight of butyl acetate, 252 parts by weight of cyclohexyl methacrylate (CHMA), 4 parts by weight of styrene (St), 56 parts by weight of butyl acrylate (BA), 88 parts by weight of acrylic acid (AA) and azo 14 parts by weight of bisisobutyronitrile was added and dropped into the separable flask at 100°C over 4 hours. After completion of the dropwise addition, the reaction was maintained for 1 hour to complete the reaction. The end point of the reaction was determined by measuring unreacted monomers in the reaction solution by gas chromatography. Thereafter, butyl acetate was removed by distillation under reduced pressure to obtain a copolymer. The obtained copolymer contained a monomer in a weight ratio of CHMA/BA/AA/St=63/14/22/1, an acid value of 160 mg-KOH/g, and a weight average molecular weight of 5300. This copolymer was used as a dispersant.

(evaluation)

<Measurement of average particle diameter>

The average particle diameter of the particles contained in the inkjet ink obtained in Example 5 was measured using a laser zeta potentiometer (ELS-8000, manufactured by Otsuka Electronics Co., Ltd.).

<Measurement of viscosity>

The viscosity of the inkjet ink obtained in Example 5 was measured at 25°C using a Toki Sangyo Co., Ltd. TV-22 viscometer.

<pH measurement>

The pH of the inkjet ink obtained in Example 5 was measured at 25°C using a pH meter F-54 manufactured by Horiba Corporation.

<Evaluation of factor concentration>

Using the inkjet ink obtained in Example 5, solid printing was performed on a plain paper (manufactured by Seiko Epson Co., Ltd., double-sided good-quality plain paper) with an inkjet printer, and the printing density (optical density: OD) was measured to obtain an index of color development. As for the optical density (OD), GRODAG (registered trademark) RD-19 manufactured by Gretec Macbeth Corporation was used to measure OD with respect to 5 points, and the average value of these was employed.

(Example 5)

15 parts by weight of the refined azo pigment composition prepared in Example 1, 4.50 parts by weight of the dispersant obtained in Preparation Example 2 (solid content), 0.45 parts by weight of a 30% sodium hydroxide aqueous solution as a pH adjuster, 1.35 parts by weight of triethanolamine as a pH adjuster, and antiseptic 0.2 parts by weight of biokiller LS (manufactured by K-I Hwasung Co., Ltd.) as a mold agent, and 0.05 parts by weight of BYK024 (manufactured by BIC Chemie Japan) as an antifoaming agent were added, and ion-exchanged water was added so that the pigment content was 20% by weight, and high speed The dispersion was stirred for 1 hour to obtain a pigment dispersion slurry. The pigment dispersion slurry was introduced into a cylindrical container filled with zirconia beads having a diameter of 0.65 mm, and subjected to dispersion treatment at 2000 rpm for 1.5 hours with a stirrer to obtain a pigment dispersion. The obtained pigment dispersion was filtered with a filter having a pore diameter of 5 µm (manufactured by F-Tech Co., Ltd.) to obtain a coloring composition for inkjet ink. To the obtained coloring composition for inkjet ink, ion-exchanged water was added to a pigment concentration of 15% by weight to prepare an aqueous inkjet ink. The above-mentioned evaluation was performed using the obtained inkjet ink. As a result, the average particle size was 159 nm, viscosity: 8.2 mPa·s, pH: 9.9, and OD: 1.17, which was a good result as an inkjet ink.

Claims (6)

When preparing the azo pigment which is the reaction product of the base represented by the following formula (1) and the coupler represented by the following formula (2), the heterogeneous base represented by formula (3) and the heterogeneous base represented by formula (4) A method for producing an azo pigment composition by adding a coupler.

(In formula (1), R ¹ represents R ³ -NH-C(=O)-, R ² represents a halogen atom or R ⁴ O-. R ³ represents a hydrogen atom or a phenyl group (-C ₆ H ₅ )) R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms.)

(In formula (2), R ⁵ represents a hydrogen atom or -CONH-R ^6. R ⁶ represents the following formula (2-1).)

(In formula (2-1), R ⁷ represents R ⁹ -NH-C(=O)-, R ⁸ represents a halogen atom or R ¹⁰ O-. R ⁹ is a hydrogen atom or a phenyl group (-C ₆ H ₅ R ¹⁰ represents an alkyl group having 1 to 4 carbon atoms, and * represents a combined number (手).)

(In formula (4), R ¹¹ represents -SO ₃ H or -COOH.) According to claim 1, with respect to 100 parts by weight of the base represented by the formula (1), 0.5 to 4 parts by weight of the base represented by the formula (3), 100 parts by weight of the coupler represented by the formula (2), The manufacturing method of an azo pigment composition which adds 2-10 weight part of couplers represented by (4). The method for producing an azo pigment composition according to claim 1 or 2, wherein the azo pigment is refined to have an average primary particle size of 25 to 70 nm. The method for producing an azo pigment composition according to claim 3, wherein the micronization treatment is performed in the presence of a pigment derivative. An azo pigment composition comprising an azo pigment that is a reaction product of a base represented by the following formula (1) and a coupler represented by the following formula (2),
Contains the reaction products of the base represented by formulas (1) and (3) and the coupler represented by formulas (2) and (4), and the content of the reaction products of formulas (1) and (2) (based on solid content) ) 80-95% by weight of the azo pigment composition.

(In formula (1), R ¹ represents R ³ -NH-C(=O)-, R ² represents a halogen atom or R ⁴ O-. R ³ represents a hydrogen atom or a phenyl group (-C ₆ H ₅ )) R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms.)

(In formula (2), R ⁵ represents a hydrogen atom or -CONH-R ^6. R ⁶ represents the following formula (2-1).)

(In formula (2-1), R ⁷ represents R ⁹ -NH-C(=O)-, R ⁸ represents a halogen atom or R ¹⁰ O-. R ⁹ is a hydrogen atom or a phenyl group (-C ₆ H ₅ R ¹⁰ represents an alkyl group having 1 to 4 carbon atoms, and * represents a number of bonds.)

(In formula (4), R ¹¹ represents -SO ₃ H or -COOH.) The weight ratio ((1)/(3)) of the component derived from Formula (1) and the component derived from Formula (3) according to claim 5 is 90.6/9.4 to 98.9/1.1, derived from Formula (2). The azo pigment composition in which the weight ratio ((2)/(4)) of the component to be derived and the component derived from the formula (4) is 82.4/17.6-96.5/3.5.