Naphthol-based azo pigment, coloring composition, and method for producing naphthol-based azo pigment

Abstract

An object of the present invention is to provide a naphthol-based azo pigment which is excellent in dispersibility and dispersion stability as well as in coloring power and weather resistance, and a method for producing the same. [Solution] The naphthol-based azo pigment has an average primary particle diameter of 90 nm or more and 1000 nm or less and an average primary particle aspect ratio of 1 or more and 3.3 or less, and is represented by the following general formula. JPEG0007658484000019.jpg4758 [In the formula, R1 is H, an alkyl group, a halogen group, a nitro group, a carboxy group, etc., and R2 and R3 are independently H, an alkoxy group, an alkyl group, a halogen group, a nitro group, etc. One of X1 and X2 is a carboxy group or a carbamoyl group, at least one of Y1 to Y3 is an alkoxy group or a halogen group, and the rest are H.]

Description

[Technical field]

[0001] The present invention relates to a naphthol-based azo pigment. [Background technology]

[0002] Architectural signs, outdoor signs, paints, etc. are used outdoors for long periods of time, so the pigments used for coloring them must have excellent resistance to heat, light, water, etc. (hereinafter collectively referred to as weather resistance). Among pigments, pigments with hues from red to magenta include quinacridone pigments, which are red pigments with excellent weather resistance, and Patent Document 1 discloses a printing ink using a quinacridone pigment. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-050818 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, quinacridone pigments have the drawbacks of being expensive and having poor coloring power and dispersion stability, while quinacridone pigments have good heat resistance and color clarity, whereas naphthol azo pigments, which are classified as insoluble azo pigments, have high coloring power and a good balance between production cost and fastness, but have the problem of insufficient weather resistance.

[0005] An object of the present invention is to provide a naphthol-based azo pigment which is excellent in dispersibility and dispersion stability, and has high coloring power and weather resistance. [Means for solving the problem]

[0006] <1> The present invention relates to a naphthol-based azo pigment, which is a compound represented by the following general formula (1) having an average primary particle diameter of 90 nm or more and 1,000 nm or less and an average primary particle aspect ratio of 1 or more and 3.3 or less, and which satisfies the following condition 1 or condition 2. General formula (1) [ka]

[0007] [In general formula (1), R1 is a hydrogen atom, an alkyl group, a halogen group, a nitro group, a carboxy group, a sulfo group, a phosphate group, a sulfamoyl group, a carbamoyl group, an alkylsulfamoyl group, or an alkylcarbamoyl group. R2 and R3 each independently represent a hydrogen atom, an alkoxy group, an alkyl group, a halogen group, a nitro group, a carboxy group, a sulfo group, a phosphate group, a sulfamoyl group, a carbamoyl group, an alkylsulfamoyl group, or an alkylcarbamoyl group. Condition 1: Either one of X1 and X2 is a carboxy group or a carbamoyl group, at least one of Y1, Y2, and Y3 is an alkoxy group or a halogen group, and the remainder of X1, X2, Y1, Y2, and Y3 are hydrogen atoms. Condition 2: Either X1 or X2 is an alkoxy group or a halogen group, at least one of Y1, Y2, and Y3 is a carboxy group or a carbamoyl group, and the remaining of X1, X2, Y1, Y2, and Y3 are hydrogen atoms. <2> R1 is a hydrogen atom or an alkyl group, and R2 and R3 are hydrogen atoms. <1> Naphthol-based azo pigment. <3> <1> or <2> A coloring composition comprising the naphthol azo pigment of the above formula (1) and a dispersion medium. <4> <1> or <2> A paint comprising the naphthol azo pigment of the above formula (1), a resin, and a solvent. <5> <1> or <2> The ink comprises a naphthol-based azo pigment, a resin, and a solvent. <6> <1> or <2> and a polymerizable compound. <7> <1> A method for producing a naphthol azo pigment comprising the steps of: A method for producing a naphthol-based azo pigment, comprising: carrying out a coupling reaction between a solution containing a coupler component represented by the following general formula (2) and a solution containing a diazonium salt represented by the following general formula (4) obtained by diazotizing an aromatic amine represented by the following general formula (3) in the presence of a water-soluble organic solvent, to obtain a compound represented by the general formula (1). [ka]

[0008] [In general formula (2), general formula (3) and general formula (4), R1 is a hydrogen atom, an alkyl group, a halogen group, a nitro group, a carboxy group, a sulfo group, a phosphate group, a sulfamoyl group, a carbamoyl group, an alkylsulfamoyl group, or an alkylcarbamoyl group. R2 and R3 each independently represent a hydrogen atom, an alkoxy group, an alkyl group, a halogen group, a nitro group, a carboxy group, a sulfo group, a phosphate group, a sulfamoyl group, a carbamoyl group, an alkylsulfamoyl group, or an alkylcarbamoyl group. [Z n- ] 1 / n is an anion of any valence n (n is an integer from 1 to 3). X1, X2, Y1, Y2, and Y3 satisfy either condition 1 or condition 2 below. Condition 1: Either one of X1 and X2 is a carboxy group or a carbamoyl group, at least one of Y1, Y2, and Y3 is an alkoxy group or a halogen group, and the remainder of X1, X2, Y1, Y2, and Y3 are hydrogen atoms. Condition 2: Either X1 or X2 is an alkoxy group or a halogen group, at least one of Y1, Y2, and Y3 is a carboxy group or a carbamoyl group, and the remaining of X1, X2, Y1, Y2, and Y3 are hydrogen atoms. Effect of the Invention

[0009] According to the present invention, it is possible to provide a naphthol-based azo pigment having excellent dispersibility and dispersion stability, and high coloring power and weather resistance. The present invention also provides a coloring composition, a paint, an ink, an active energy ray-curable ink, and the like. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic cross-sectional side view of an apparatus for producing an evaluation sheet of an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiments of the present invention will be described in more detail. However, the present invention is not limited to the following embodiments, and may be modified in various ways without departing from the spirit and scope of the present invention, and various embodiments are included. As used herein, the aspect ratio is the major axis of a particle divided by the minor axis.

[0012] <1> Naphthol azo pigments The naphthol azo pigment according to an embodiment of the present invention is a compound represented by the following general formula (1) having an average primary particle diameter of 90 nm or more and 1000 nm or less and an average primary particle aspect ratio of 1 or more and 3.3 or less. The compound represented by the general formula (1) satisfies the following condition 1 or condition 2. General formula (1) [ka]

[0013] [In general formula (1), R1 is a hydrogen atom, an alkyl group, a halogen group, a nitro group, a carboxy group, a sulfo group, a phosphate group, a sulfamoyl group, a carbamoyl group, an alkylsulfamoyl group, or an alkylcarbamoyl group. R2 and R3 each independently represent a hydrogen atom, an alkoxy group, an alkyl group, a halogen group, a nitro group, a carboxy group, a sulfo group, a phosphate group, a sulfamoyl group, a carbamoyl group, an alkylsulfamoyl group, or an alkylcarbamoyl group. Condition 1: Either one of X1 and X2 is a carboxy group or a carbamoyl group, at least one of Y1, Y2, and Y3 is an alkoxy group or a halogen group, and the remainder of X1, X2, Y1, Y2, and Y3 are hydrogen atoms. Condition 2: Either one of X1 and X2 is an alkoxy group or a halogen group, at least one of Y1, Y2, and Y3 is a carboxy group or a carbamoyl group, and the remaining of X1, X2, Y1, Y2, and Y3 are hydrogen atoms.

[0014] In the naphthol azo pigment of the present specification, by satisfying condition 1 or condition 2, the substituent of X1 or X2 of the molecule of general formula (1) forms an intermolecular hydrogen bond with the substituents of Y1 to Y3 of the adjacent molecule, thereby enhancing chemical stability. It is presumed that this allows the molecular structure to be maintained even when used for a long period of time in harsh outdoor environments, thereby providing weather resistance. Furthermore, by setting the aspect ratio of the naphthol-based azo pigment particles to 1 or more and 3.3 or less, the particle shape becomes close to a sphere, and the distance between the particles can be made uniform (a suitable distance between the particles can be obtained). This makes it possible to suppress the aggregation of the particles, so that the viscosity is less likely to increase when preparing the coloring composition. Furthermore, it is possible to suppress the increase in viscosity caused by the aggregation of the particles during long-term storage of the coloring composition. In addition, the average primary particle diameter of the particles is 90 nm or more and 1000 nm or less, and thus it is possible to achieve both dispersibility and weather resistance in addition to coloring power.

[0015] In the general formula (1), the "alkyl group" may have 1 to 8 carbon atoms and may have any of a straight-chain structure, a branched structure, and a ring structure. In one embodiment, the alkyl group preferably has a straight-chain structure. The number of carbon atoms in the alkyl group is preferably 1 to 4, more preferably 1 or 2, and further preferably 1.

[0016] The above-mentioned "halogen group" includes a fluorine atom, a chlorine atom, or a bromine atom. In one embodiment, a chlorine atom or a fluorine atom is preferred, and a chlorine atom is more preferred.

[0017] The "alkyl" in the "alkylsulfamoyl group" is the same as the alkyl group described above. The same also applies to the "alkyl" in the "alkylcarbamoyl group". Although there are no particular limitations, in one embodiment, the alkyl groups in the alkylsulfamoyl group and the alkylcarbamoyl group are each independently preferably an alkyl group having 1 to 4 carbon atoms.

[0018] The "alkoxy group" may have 1 to 8 carbon atoms and may have any of a straight chain structure, a branched structure, and a ring structure. In one embodiment, the alkoxy group preferably has a straight chain structure. The number of carbon atoms in the alkoxy group is preferably 1 to 4, more preferably 1 or 2, and even more preferably 1.

[0019] The naphthol azo pigment of the present invention has an average aspect ratio of primary particles of 1 or more and 3.30 or less. The aspect ratio is preferably 1 or more and 3.11 or less, and more preferably 1 or more and 3 or less. It is presumed that if the aspect ratio is 1 or more and 3.3 or less, the pigment particle shape is close to a sphere and the distance between each particle can be made uniform, so that aggregation between particles can be suppressed. This is because the aspect ratio being in the above range can suppress the increase in viscosity during dispersion of the pigment and the increase in viscosity caused by aggregation between particles during long-term storage. It is not necessary for the aspect ratio of all particles to be in the above range, and it is sufficient that the average value of the ratio of the major axis to the minor axis is within the above range. The measurement of primary particles is the same as described below.

[0020] The naphthol azo pigment of the present invention is characterized in that the average value of the major axis of the primary particles of the pigment (hereinafter sometimes referred to as the "average primary particle diameter") is 90 nm or more and 1000 nm or less. The average primary particle diameter of the naphthol azo pigment is preferably 700 nm or less, more preferably 503 nm or less, and even more preferably 352 nm or less. The average primary particle diameter can be determined by calculating the average of the longer diameters of about 50 primary particles of pigment particles extracted from multiple photographs taken at a magnification of 10,000 times with a transmission electron microscope. When the average primary particle diameter of the compound (A) is within the above range, it is possible to achieve both dispersibility and weather resistance in addition to coloring power. Details of the method for measuring the major axis and minor axis of the primary particles and the method for calculating the average value are shown in the Examples.

[0021] In one embodiment, the naphthol azo pigment is represented by the general formula (1), where R1 is a hydrogen atom or an alkyl group, and R2 and R3 are preferably hydrogen atoms. In addition, the naphthol azo pigment of the present invention can be used in combination with two or more compounds represented by the general formula (1) having different substituents.

[0022] In still another embodiment, the naphthol azo pigment may further contain other components within a range that allows the problem to be solved. The other components may be, for example, a resin and / or a surfactant used for the purpose of surface modification of the pigment during production of the naphthol azo pigment.

[0023] In one embodiment, the content of the resin is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the pigment. The content of the surfactant is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, and even more preferably 1 to 3 parts by mass, relative to 100 parts by mass of the pigment.

[0024] <2> Pigment manufacturing method The naphthol-based azo pigment of the compound represented by the general formula (1) of the above embodiment can be synthesized by a coupling reaction between a base component and a coupler component in the presence of a water-soluble organic solvent. Specifically, an aromatic amine represented by the following general formula (3) is diazotized as a base component to synthesize a solution (1) containing a diazonium salt represented by the following general formula (4). Separately, a solution (2) containing a coupler component represented by the general formula (2) is prepared. Then, these solutions (1) and (2) are mixed to perform a coupling reaction between the diazonium salt and the coupler component. At least one of the solutions (1) containing the diazonium salt and the solution (2) containing the coupler component contains a water-soluble organic solvent. In one embodiment, it is preferable that at least the solution containing the coupler component contains a water-soluble organic solvent. This results in pigment particles having an average primary particle size of 90 nm to 1000 nm and an average aspect ratio of the primary particles of 1 to 3.3.

[0025] [ka]

[0026] In the above general formulas (2), (3), and (4), R1 to R3, X1, X2, and Y1 to Y3 are as already explained. [Z n- ] 1 / n is an anion of any valence n (n is an integer from 1 to 3). Any anion can be used as long as the diazonium salt is stable and soluble in water, but chloride ion, bromide ion, nitrate ion, nitrite ion, acetate ion, sulfate ion, and phosphate ion are preferred.

[0027] The solution containing the coupler component contains the coupler component, a base, and water, and may further contain a water-soluble organic solvent as required. The solution containing the coupler component is prepared, for example, by dissolving the coupler component in a heated basic aqueous solution. As another example, the solution is prepared by mixing water, a water-soluble organic solvent, a coupler component, and a base at room temperature (about 10°C to 30°C) and dissolving the coupler component and the base. The dissolution temperature can be adjusted according to the type and amount of the water-soluble organic solvent to be added, the amount of water, and the type and amount of the base. For example, when the solution contains a water-soluble organic solvent, the temperature is preferably about 15 to 50°C. When the solution does not contain a water-soluble organic solvent, the temperature is preferably 50 to 95°C.

[0028] The base is, for example, a compound that dissolves in water and dissolves the coupler component. In addition, a base that does not form an insoluble salt when neutralized with an acid in an acid aqueous solution or a solution containing a diazonium salt, which will be described later, is preferable. Such a base has advantages in terms of cost, dissolving power of the coupler component, waste liquid treatment, etc. The base is preferably, for example, sodium hydroxide or potassium hydroxide.

[0029] The solution containing the diazonium salt contains a diazonium salt and water. The solution containing the diazonium salt may contain a reaction mixture of a base component used in the preparation of the diazonium salt, an acid component, and aqueous sodium nitrite. The diazonium salt can be obtained by diazotizing the base component of the above general formula (3). A known method can be used for the diazotization method. For example, hydrochloric acid or sulfuric acid is added to a solution of the base component slurried in ice water to dissolve it, and sodium nitrite is further added to perform diazotization. Sulfamic acid may be added to eliminate excess sodium nitrite used for diazotization. A water-soluble organic solvent may be added to the solution containing the diazonium salt.

[0030] The water-soluble organic solvent that can be used during the coupling reaction is not particularly limited. The water-soluble organic solvent may be any organic solvent that can be mixed with water. The water-soluble organic solvent may be used to obtain a solution containing a coupler component and / or a solution containing a diazonium salt. Examples of the water-soluble organic solvent include aprotic polar solvents such as acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, and N-methyl-2-pyrrolidone; ketones such as acetone and methyl ethyl ketone; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; dihydric alcohols such as ethylene glycol, diethylene glycol, and polyethylene glycol; and monohydric alcohols such as methanol, ethanol, and isopropanol.

[0031] The water-soluble organic solvent may be one of the above solvents used alone or two or more of them may be used in combination. Although not particularly limited, the water-soluble organic solvent is preferably one or more selected from the group consisting of aprotic polar solvents, ketones, monohydric alcohols, and cyclic ethers. The boiling point of the water-soluble organic solvent is preferably 100°C or less. Such water-soluble organic solvents having a boiling point of 100°C or less are advantageous in terms of solvent recovery from waste liquid. For example, one or more selected from the group consisting of acetonitrile, acetone, methyl ethyl ketone, methanol, and isopropanol are preferred.

[0032] The amount of the water-soluble organic solvent to be added can be adjusted depending on the type of the water-soluble organic solvent. In one embodiment, when the water-soluble organic solvent is added to either the solution containing the coupler component or the solution containing the diazonium salt, the amount of the water-soluble organic solvent to be added is preferably 3% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, based on the total 100% by mass of the water and the water-soluble organic solvent contained in the slurry after coupling. Also, it is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less.

[0033] Examples of the coupling method include reverse coupling, forward coupling, acid precipitation forward coupling, etc. Among them, reverse coupling, which will be described later, is preferred from the viewpoints of particle size control and reaction yield.

[0034] A known method can be used for the reverse coupling method. For example, a method of adding a solution containing a coupler component to a solution containing a diazonium salt can be used. The temperature during coupling is preferably 0 to 50°C. From the viewpoint of suppressing the alteration and decomposition of the diazonium salt and the reaction rate, 10 to 30°C is particularly preferred.

[0035] A buffer solution may be added to the solution containing the diazonium salt in advance. The type of buffer solution is not particularly limited, and any buffer solution may be used as long as it has buffering ability. For example, an aqueous solution of acetic acid and sodium acetate is preferred. When a buffer solution is added, it is desirable to adjust the pH of the solution containing the diazonium salt to a range of 3.0 to 6.5. From the viewpoint of improving the reaction rate and dispersibility, the slurry after coupling may be heated as necessary. The heating temperature is preferably 50°C to 100°C.

[0036] The naphthol azo pigment slurry obtained by the coupling reaction can be filtered using a known suction filter, filter press, ultrafilter, etc. to remove water, solvent, water-soluble salts, etc. In this way, a pigment press cake is obtained. The pigment press cake can be washed with a solvent such as water or an organic solvent, if necessary. The pigment press cake can be used as it is for the production of a coloring composition. A powder pigment can be produced by drying and pulverizing according to a known method.

[0037] In one embodiment, a well-known technique for producing a naphthol azo pigment can be applied when producing the pigment. For example, when producing the pigment, components well known to those skilled in the art may be used in addition to the raw materials for the pigment, if necessary. For example, well-known components such as a resin and / or a surfactant can be used to be present in the pigment.

[0038] When components such as resin and / or surfactant are used during the production of the pigment, these remain on the surface of the pigment even after production. Therefore, it is preferable that the resin and surfactant are hydrophilic or soluble in base. The use of such resin and surfactant can improve dispersibility by alleviating pigment aggregation, and can impart affinity of the pigment to the dispersion resin and solvent selected according to various applications. In addition, when the above components are used, it is also possible to obtain effects such as improving reactivity by promoting dissolution of the coupler component and suppressing crystal growth of the pigment.

[0039] The resin may be, for example, a resin having an acid group such as a styrene-(meth)acrylic acid copolymer, a (meth)acrylic acid-(meth)acrylic acid alkyl ester copolymer, a styrene-(meth)acrylic acid-(meth)acrylic acid alkyl ester copolymer, a styrene-α-methylstyrene-(meth)acrylic acid copolymer, a styrene-α-methylstyrene-(meth)acrylic acid-(meth)acrylic acid alkyl ester copolymer, a polyacrylic acid, a polymethacrylic acid, a vinylnaphthalene-(meth)acrylic acid copolymer, a styrene-(anhydride)maleic acid copolymer, a maleic acid-maleic anhydride copolymer, a vinylnaphthalene-(anhydride)maleic acid copolymer, an α-olefin-(anhydride)maleic acid copolymer, an α-olefin-maleic acid alkyl ester copolymer, a polyester-modified acrylic acid polymer, an acrylic copolymer, or a salt thereof. The resin may be used alone or in combination of two or more.

[0040] When the above resin is used, a compound capable of forming a salt with the above resin can be further used, for example, a basic compound such as an inorganic base or an organic base. Examples of inorganic bases include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, etc.; alkali metal salts of silicic acid such as sodium orthosilicate, sodium metasilicate, sodium sesquisilicate, etc.; alkali metal salts of phosphoric acid such as trisodium phosphate, etc.; alkali metal salts of carbonate such as disodium carbonate, sodium hydrogen carbonate, dipotassium carbonate, etc.; alkali metal salts of boric acid such as sodium borate, and ammonia.

[0041] Examples of the organic base include alkylamines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, and triethylamine; alkanolamines such as aminoethanol, methylaminoethanol, dimethylaminoethanol, ethylaminoethanol, butylaminoethanol, diethylaminoethanol, dibutylaminoethanol, diethanolamine, and triethanolamine; and amines having a nonionic group such as methoxypoly(oxyethylene / oxypropylene)-2-propylamine. The basic compounds may be used alone or in combination of two or more.

[0042] In yet another embodiment, a surfactant can be used in the preparation of the pigment, such as, for example, anionic, nonionic, or amphoteric surfactants.

[0043] Examples of the anionic surfactant include fatty acid salts, alkyl sulfate salts, alkylaryl sulfonates, alkylnaphthalenesulfonates, alkyl sulfates, dialkylsulfonates, dialkylsulfosuccinates, alkyl diaryl ether disulfonates, alkyl phosphates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkylaryl ether sulfates, naphthalenesulfonate-formaldehyde condensates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phosphate salts, glycerol borate fatty acid esters, and polyoxyethylene glycerol fatty acid esters.

[0044] Examples of amphoteric surfactants include betaine, sulfobetaine, alkylbetaine, and alkylamine oxide.

[0045] Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyethylene oxypropylene block copolymers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, polyoxyethylene fatty acid esters, and polyoxyethylene alkylamines.

[0046] In one embodiment, the surfactant is preferably an amphoteric surfactant or an anionic surfactant. Although not particularly limited, when the surfactant is added to a solution containing a coupler component, an anionic or amphoteric surfactant is preferred. When the surfactant is added to a slurry obtained after the coupling reaction, a nonionic surfactant may be used. The surfactants may be used alone or in combination of two or more.

[0047] <3> coloring composition One embodiment of the present invention is a coloring composition comprising the naphthol azo pigment and a dispersion medium. The dispersion medium comprises at least one selected from the group consisting of a resin and a polymerizable compound. The dispersion medium may further comprise a solvent.

[0048] The dispersion medium is selected according to the application of the coloring composition. In one embodiment, the coloring composition includes a pigment and a resin, and may further include a solvent as necessary. In another embodiment, the coloring composition includes a pigment and a polymerizable compound, and may further include at least one of a resin and a solvent as necessary. The coloring compositions of the above embodiments may each include various additives as necessary. Examples of applications of the coloring composition include pigment dispersions, resin colored materials, paints, and printing inks. In addition, examples of applications include printed materials, coated materials, and resin molded materials colored by pigment dispersions, resin colored materials, paints, and inks. Hereinafter, more specific embodiments of the coloring composition will be described.

[0049] <Pigment dispersion> In one embodiment, the coloring composition may be in the form of a pigment dispersion containing the pigment of the above embodiment as a main component and further containing a dispersion medium for dispersing the pigment. The dispersion medium contains at least a resin, and may further contain a solvent depending on the application. In other words, the coloring composition may be referred to as a pigment dispersion. The pigment dispersion can be suitably used as an intermediate for paints, inks, etc. The pigment dispersion used as the intermediate may contain a pigment, a resin, and a solvent. The resin contained in the pigment dispersion may contain a resin-type pigment dispersant.

[0050] The pigment dispersion of the present embodiment is superior in dispersibility and low initial viscosity compared to conventional pigment dispersions containing quinacridone pigments. The pigment dispersion of the present embodiment is also superior in viscosity stability.

[0051] When the pigment dispersion contains a solvent, the solvent can be selected from water, a water-soluble solvent, and a non-water-soluble solvent. When the solvent contains at least water, an aqueous pigment dispersion is obtained. The water-soluble solvent and the non-water-soluble solvent are not particularly limited. For example, they may be the same as the water-soluble solvent and the non-water-soluble solvent that constitute the paint described later.

[0052] Examples of dispersing machines used for preparing the aqueous pigment dispersion include horizontal sand mills, vertical sand mills, annular bead mills, attritors, microfluidizers, high-speed mixers, homomixers, homogenizers, high-pressure homogenizers, ball mills, paint shakers, roll mills, stone mills, ultrasonic dispersers, high-pressure dispersers, opposed collision dispersers, and oblique collision dispersers.

[0053] Furthermore, prior to dispersion, pre-dispersion using a mill mixer such as a kneader or a three-roll mill, or solid dispersion using a two-roll mill, etc. may be performed. After dispersion using various dispersers, post-treatment such as storing the mixture in a heated state at 30 to 80°C for several hours to about one week, and post-treatment using an ultrasonic disperser or a collision-type beadless disperser improve the dispersion stability of the pigment dispersion.

[0054] <Paint> In one embodiment, the naphthol azo pigment can be used as a paint. The paint can include the naphthol azo pigment, a resin, and a solvent. The paint preferably uses the pigment dispersion already described, and may further contain other resins (such as binder resins).

[0055] The other resins include thermosetting resins and thermoplastic resins. The thermosetting resins are preferably resins having a glass transition temperature of 10° C. or higher. The thermosetting resins include self-curable resins and resins that are cured by the combined use of a curing agent. Examples of the thermosetting resin include acrylic resin, polyester resin, polyurethane resin, and melamine resin. The thermosetting resin preferably has a functional group capable of reacting with a curing agent. Examples of the functional group include a carboxyl group and a hydroxyl group. Examples of the curing agent include an isocyanate curing agent, an epoxy curing agent, an aziridine curing agent, and an amine curing agent. The thermoplastic resin is preferably a resin having a glass transition temperature of 30° C. or higher. Examples of the thermoplastic resin include nitrocellulose resin, acrylic resin, polyester resin, etc. Thermosetting resin and thermoplastic resin may be used in combination.

[0056] The solvent may be water, a water-insoluble solvent, or a water-soluble solvent. When the solvent contains at least water, it can form a water-based paint. Examples of the non-water-soluble solvent include toluene, xylene, butyl acetate, methyl acetate, methyl isobutyl ketone, and aliphatic hydrocarbons. The water-soluble solvent may be, for example, a monohydric alcohol, a dihydric alcohol, etc. Examples of the water-soluble solvent include monohydric alcohols such as ethanol, n-propanol, isopropanol, and isobutanol, dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol, and polyhydric alcohols having a valence of 3 or more such as glycerin. The water-soluble solvent may be a water-dilutable monoether derived from a polyhydric alcohol, for example, methoxypropanol or methoxybutanol. Other examples include water-dilutable glycol ethers such as butyl glycol or butyl diglycol.

[0057] In one embodiment, the paint can further contain a lustrous material. Examples of the lustrous material include metal flakes, mica, and coated glass flakes. Examples of the metal flakes include aluminum flakes and gold powder. Examples of the mica include normal mica and coated mica. Examples of the coated glass flakes include glass flakes coated with a metal oxide such as titanium oxide. The content of the lustrous material is preferably 0.1 to 10 mass% in 100 mass% of the paint. The lustrous material is preferably particles having an average thickness of 0.5 to 10 μm and an average particle size of 5 to 50 μm.

[0058] The paint may further contain other components. The other components may be, for example, color pigments, additives, etc. The method for producing the paint and the method for applying and drying the paint are not particularly limited, and methods well known in the art may be applied. Examples of applications of the paint include paint for metals and paint for plastics.

[0059] In one embodiment, the paint can be suitably applied to substrates such as metals, resins, wood, concrete, and stone. Examples of metals include iron, aluminum, stainless steel, silver, copper, and gold, as well as alloys containing these. Examples of the shape of the substrate include a plate, rod, cylinder, or sphere having a flat or curved surface. Examples of the resin substrate include molded bodies formed by known methods. Examples of the type of resin include polyolefin resin, polyacrylic resin, polycarbonate resin, polystyrene resin, acrylonitrile-styrene copolymer resin, polyvinyl chloride resin, acetate resin, ABS resin, polyester resin, and polyamide resin.

[0060] <Ink> In one embodiment, the naphthol-based azo pigment can be suitably used in ink applications. The ink contains the pigment of the above embodiment and a dispersion medium, and the dispersion medium can be appropriately selected depending on the type of printing ink. Depending on the presence or absence of a solvent and the type of dispersion medium, the ink can be roughly classified into solvent-based printing ink, water-based printing ink, and active energy ray curable printing ink. Depending on the printing format, the ink can be classified into, for example, offset printing ink, flexographic printing ink, gravure printing ink, color filter ink, inkjet printing ink, etc. The pigment of this embodiment has excellent dispersibility, coloring power, clarity, and transparency, and can therefore be suitably used in various printing ink applications. Representative printing inks are exemplified below.

[0061] <Inkjet printing ink> In one embodiment, the naphthol-based azo pigment can be used in inkjet printing inks (hereinafter referred to as IJ inks). In one embodiment, the IJ ink contains a pigment and a resin. In another embodiment, the IJ ink preferably contains a pigment, a resin, and further contains a solvent. The IJ ink is preferably prepared using a pigment dispersion containing a pigment, a resin, and, if necessary, a solvent. In another embodiment, the IJ ink may be composed of a composition in which the resin in the IJ ink of the embodiment described above is changed to a polymerizable compound, or a composition in which a resin and a polymerizable compound are used in combination. For example, an IJ ink can be prepared by mixing a pigment dispersion with an IJ ink resin, where the resin in the pigment dispersion and the resin used to prepare the IJ ink can be the same or different.

[0062] IJ inks can be broadly classified into (solvent-based) IJ inks, water-based IJ inks, and active energy ray curable IJ inks, depending on the presence or absence of a solvent and the type of solvent, and the type of resin or polymerizable compound that serves as the dispersion medium. Furthermore, active energy ray curable IJ inks can be broadly classified into photocurable IJ inks and electron beam curable IJ inks, depending on the curing means of the polymerizable compound. Although not particularly limited, the coloring composition of the above embodiment can be suitably used as an aqueous IJ ink. Below, an aqueous IJ ink will be described as an example of an IJ ink.

[0063] With the total mass of the water-based IJ ink taken as 100 mass %, the pigment content is preferably from 0.5 to 30 mass %, and more preferably from 1 to 15 mass %.

[0064] The resin used in water-based IJ inks is important for ensuring that the ink adheres well to the substrate. Examples of the resin include acrylic resin, olefin-maleic acid resin, styrene-acrylic resin, polyester resin, polyamide resin, polyurethane resin, etc. The form of the resin may be, for example, a water-soluble resin, emulsion particles, etc. Among them, the form of emulsion particles is preferable. The emulsion particles may be, for example, particles of a single composition, core-shell type particles, etc., and can be arbitrarily selected for use. When emulsion particles are used, it is easy to reduce the viscosity of the water-based IJ ink, and recorded matter with excellent water resistance can be easily obtained.

[0065] The resin content is preferably 2 to 30% by mass, and more preferably 3 to 20% by mass, relative to 100% by mass of the nonvolatile content in the water-based IJ ink. When the IJ ink contains a resin within the above range, the ejection stability and fixation properties tend to be improved.

[0066] From the viewpoint of forming a water-based IJ ink, the solvent contains at least water. The solvent may further contain either a water-insoluble solvent or a water-soluble solvent. In one embodiment, the solvent preferably contains water and a water-soluble solvent. Examples of the water-soluble solvent include glycol ethers, diols, etc. These solvents penetrate into the substrate very quickly, even into substrates with low liquid absorption.

[0067] Examples of low-absorbency substrates include coated paper, art paper, polyvinyl chloride, plastic film, and leather. When a solvent with excellent permeability to substrates is used as described above, drying during printing is fast and accurate printing can be easily achieved. Furthermore, when a water-soluble solvent with a high boiling point is used, the solvent also acts as a wetting agent.

[0068] Water-soluble solvents are important for preventing water-based IJ ink from drying and solidifying in the nozzles of the printer head and for ensuring ink ejection stability. Examples of the water-soluble solvent include ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, polyethylene glycol, glycerin, tetraethylene glycol, dipropylene glycol, ketone alcohol, diethylene glycol monobutyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, 1,2-hexanediol, N-methyl-2-pyrrolidone, substituted pyrrolidone, 2,4,6-hexanetriol, tetrafurfuryl alcohol, and 4-methoxy-4-methylpentanone.

[0069] In one embodiment, the total content of water and the water-soluble solvent is preferably 30 to 70 mass% in 100 mass% of the IJ ink. Here, the content of the water-soluble solvent may be preferably 10 to 90 mass%, more preferably 20 to 80 mass%, and even more preferably 30 to 70 mass%, based on the total mass of the water and the water-soluble solvent.

[0070] IJ inks can further contain additives, such as drying accelerators, penetrants, preservatives, chelating agents, pH adjusters, defoamers, wetting agents, and surfactants.

[0071] In this specification, the active energy ray-curable IJ ink contains, in addition to the naphthol-based azo pigment, a polymerizable compound, a photopolymerization initiator, etc. The content of the pigment is preferably 0.5 to 30 mass%, and more preferably 1 to 15 mass%, relative to the total mass of the active energy ray-curable IJ ink being 100 mass%.

[0072] The polymerizable compound used in the active energy ray curable IJ ink is important for obtaining the fixation of the ink to the printed material (substrate). The polymerizable compound is not particularly limited as long as it is a compound that undergoes a polymerization reaction and hardens by the application of some kind of energy, and any type of monomer, oligomer, or polymer can be used, but radical polymerizable monomers are preferred. The polymerizable monomer can be used alone or in combination with a plurality of monomers for the purpose of adjusting the reaction rate, the physical properties of the cured film, the physical properties of the ink, and the like. The polymerizable monomer may be a monofunctional monomer or a polyfunctional monomer having two or more functionalities, and a combination of a monofunctional monomer and a polyfunctional monomer is preferred. Examples of the polymerizable compound include (meth)acrylate compounds, vinyl ether compounds, compounds having a (meth)acrylate group and a vinyl ether group, allyl compounds, N-vinyl compounds, unsaturated carboxylic acids, etc. Among these, one or more selected from (meth)acrylate compounds, compounds having a (meth)acrylate group and a vinyl ether group, and N-vinyl compounds are preferred.

[0073] In one embodiment, the content of the polymerizable compound is preferably from 30 to 99 mass %, more preferably from 50 to 95 mass %, and even more preferably from 60 to 90 mass %, based on the total mass of the active energy ray-curable IJ ink.

[0074] The active energy ray-curable IJ ink may contain a photopolymerization initiator. In one embodiment, the photopolymerization initiator may be a molecular cleavage type or hydrogen abstraction type photopolymerization initiator that generates radicals. In one embodiment, the photopolymerization initiator may be used alone or in combination of two or more types. Also, a photopolymerization initiator that generates radicals and a photopolymerization initiator that generates cations may be used in combination. Examples of the photopolymerization initiator include alkylphenone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, oxime ester-based photopolymerization initiators, benzophenone-based photopolymerization initiators, etc. Among these, from the viewpoint of curability and storage stability, at least one selected from the group consisting of bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one is preferred.

[0075] The content of the photopolymerization initiator is preferably 2 to 30% by mass, more preferably 5 to 20% by mass, and even more preferably 10 to 20% by mass, based on the total mass of the polymerizable compound. When the content of the photopolymerization initiator is 2% by mass or more, good curability can be easily obtained. On the other hand, when the content is 20% by mass or less, the curing speed can be efficiently increased, no undissolved components of the photopolymerization initiator are generated even at low temperatures, and good inkjet ejection properties can be easily obtained.

[0076] The active energy ray-curable IJ ink may contain additives such as polymerization inhibitors, organic solvents, surface conditioners, and pigment dispersants, as necessary.

[0077] In one embodiment, the IJ ink is particularly suitable for use as a red or orange ink. The IJ ink may be combined with an ink of a color other than red or orange to form an ink set. For example, examples of colors that can be combined with the IJ ink include cyan, yellow, black, white, magenta, green, blue, violet, pink, gold, silver, and bronze.

[0078] The ink set may be, for example, a five-color ink set that adds cyan, yellow, magenta, and black to the red or orange inks using the IJ inks of the above embodiment. In other embodiments, it may be suitably used as an ink set of six or more colors that further includes special colors such as green and violet. The pigment concentration, viscosity, dynamic viscoelasticity, surface tension, application order, evaporation rate of volatile matter, and the like of each ink are design items and can be appropriately adjusted according to the desired characteristics.

[0079] The inkjet ink of the above embodiment can be applied to various conventionally known substrates, such as highly water-absorbent substrates, such as plain paper, fabric, and knitted fabric, low water-absorbent substrates, such as art paper, coated paper, polyvinyl chloride, wood, concrete, polyethylene film, polypropylene film, polyethylene terephthalate film, natural leather, and artificial leather, and non-water-absorbent substrates, such as metals (aluminum, stainless steel, etc.).

[0080] <Colored resin composition> In one embodiment, the naphthol-based azo pigment can be suitably used in the application of a colored resin composition. The colored resin composition can be used to prepare a resin molded body. The colored resin composition includes the naphthol-based azo pigment of the above embodiment and a dispersion medium (resin). The colored resin composition may further include components well known to those skilled in the art, such as a lubricant and a reinforcing material.

[0081] Examples of the resin include polyethylene resin, polypropylene resin, polystyrene resin, acrylonitrile-styrene (AS) resin, acrylonitrile-butadiene-styrene (ABS) resin, and polyvinyl chloride (PVC) resin.

[0082] In one embodiment, the resin of the colored resin composition is preferably a polyethylene resin, a polystyrene resin, an ABS resin, or a polyvinyl chloride resin, and more preferably a polyvinyl chloride resin. The naphthol-based azo pigment of this embodiment is particularly suitable for polyvinyl chloride resin among the above resins. Therefore, in one embodiment, the colored resin composition preferably contains a naphthol-based azo pigment and a resin containing a polyvinyl chloride resin. In such a colored resin composition, the naphthol-based azo pigment of the above embodiment is uniformly and finely dispersed in the resin containing the polyvinyl chloride resin. Therefore, the naphthol-based azo pigment composition of the above embodiment can provide a high-quality colored resin composition. The colored resin composition of the present invention can be molded into a sheet or film and used for interior materials, cover members, etc. EXAMPLES

[0083] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples. In addition, "parts" means "parts by mass" and "%" means "% by mass".

[0084] The abbreviations and product names used in the following examples are as follows. <Coupler> Naphthol AS-RL: 3-hydroxy-4'-methoxy-2-naphthanilide (Sigma-Aldrich) Naphthol AS-E: 4'-chloro-3-hydroxy-2-naphthanilide (Sigma-Aldrich) Naphthol AS-m-OMe: 3-hydroxy-3'-methoxy-2-naphthanilide (Synsonics) Naphthol AS-p-COOH: 4-[[(3-hydroxy-2-naphthyl)carbonyl]amino]benzoic acid Naphthol AS-p-CONH2: N-(4-carbamoylphenyl)-3-hydroxy-2-naphthamide Naphthol AS-OL: 3-hydroxy-2'-methoxy-2-naphthanilide (Sigma-Aldrich)

[0085] <Bass> M-60: 3-amino-4-methylbenzamide (Tokyo Chemical Industry Co., Ltd.) M-70: 4-aminobenzamide (Tokyo Chemical Industry Co., Ltd.) 4-Aminobenzoic acid (Tokyo Chemical Industry Co., Ltd.) 4-Chloroaniline (Tokyo Chemical Industry Co., Ltd.) 4-Methoxyaniline (Tokyo Chemical Industry Co., Ltd.)

[0086] <Naphthol-based azo pigments> [ka] JPEG0007658484000006.jpg48149JPEG0007658484000007.jpg48138 JPEG0007658484000008.jpg49145JPEG0007658484000009.jpg3698

[0087] [Preparation of Coupler] (Production Example 1) Production of Naphthol AS-p-COOH In a 4L 4-neck flask equipped with an internal thermometer, a gas removal tube, and a stirrer, 494.0 parts of 3-hydroxy-2-naphthoic acid and 2470 parts of xylene were introduced, and 6 parts of N,N'-dimethylformamide were added. 328 parts of thionyl chloride were added thereto over 1 hour at 47-50°C, and then the mixture was stirred for 3 hours until gas evolution ceased, to obtain a xylene solution of 3-hydroxy-2-naphthoyl chloride. Separately, 1800 parts of N-methylpyrrolidone were introduced into a 10L four-neck flask equipped with a dropping funnel, a reflux condenser, an internal thermometer and a stirrer, and 291.5 parts of sodium carbonate were added. Then, 342.9 parts of 4-aminobenzoic acid were added at 25°C. While stirring this at 25°C to 28°C, the obtained xylene solution of 3-hydroxy-2-naphthoyl chloride was added over 6.5 hours. After stirring for another 30 minutes, the product was suction filtered, and the filter cake was washed with 215 parts of xylene 10 times. Furthermore, 2500 parts of water were introduced into a 6L four-neck flask equipped with a distillation bridge equipped with a stirrer, an internal thermometer and a 1L one-neck flask as a receiver, and then the filter cake was introduced. Then, 200 parts of sodium carbonate were added, and the mixture was heated to 100°C to distill off xylene and water. The product was filtered under suction at 100° C., and the filter cake was washed with three portions of water, totaling 2100 parts, until neutral. The filter cake was dried at 80° C. for 24 hours to obtain 662 parts of Naphthol AS-p-COOH.

[0088] (Production Example 2) Production of Naphthol AS-p-CONH2 Naphthol AS-p-CONH2 was obtained in the same manner as in Production Example 1, except that 342.9 parts of 4-aminobenzoic acid in Production Example 1 was replaced with 340.4 parts of 4-aminobenzamide.

[0089] <1> Pigment manufacturing Example 1: Production of Pigment 1 As a base component, 18.02 parts of M-60 was added to 267 parts of water and stirred to prepare a suspension. 55.6 parts of 30% hydrochloric acid was added thereto and stirred for 15 minutes. Then, 57.2 parts of ice was added and stirred until the temperature reached -5°C to 5°C, and 21.4 parts of 40% aqueous sodium nitrite solution was added over 20 minutes. Diazotization was carried out by stirring at 5°C or less for 90 minutes. Sulfamic acid was added to the reaction mixture obtained by the above diazotization to eliminate excess nitrous acid. Sulfamic acid was added until no free nitrous acid was detected using potassium iodide paper. 24.9 parts of sodium acetate and 2.75 parts of 80% acetic acid were added to the mixture to obtain a solution containing a diazonium salt. On the other hand, a mixture of 190 parts of methanol as a water-soluble organic solvent and 30.9 parts of 30.5% aqueous sodium hydroxide solution was adjusted to 15 to 25°C. 35.92 parts of naphthol AS-RL as a coupler component was added and dissolved therein to prepare a coupler solution. This solution was added to the solution containing the diazonium salt over 20 minutes to carry out a coupling reaction. The slurry obtained by the coupling reaction was stirred at 25°C for 30 minutes. The slurry was then heated to 70°C and stirred for 60 minutes. The slurry was filtered and washed with water at 60°C to obtain a press cake of a naphthol-based azo pigment. The press cake was dried at 80°C for 24 hours and then pulverized to obtain 53.9 parts of Pigment 1 represented by chemical formula (5).

[0090] (Examples 2 to 8) Production of Pigments 2 to 8 Pigments 2 to 8 were obtained in the same manner as in Example 1, except that the base component was changed to M-60 with the corresponding base type and base mass part in Table 1, and the coupler component was changed to Naphthol AS-RL with the corresponding coupler type and coupler mass part in Table 1.

[0091] Example 9: Preparation of Pigment 9 Pigment 9 was obtained in the same manner as in Example 1, except that M-60 was used as the base component in the corresponding base type and base mass parts in Table 1, naphthol AS-RL was used as the coupler component in the corresponding coupler type and coupler mass parts in Table 1, and the solvent used to dissolve the coupler solution was changed from 190 parts of methanol to 190 parts of acetonitrile.

[0092] Example 10: Preparation of Pigment 10 Pigment 10 was obtained in the same manner as in Example 1, except that M-60 was used as the base component in the corresponding base type and base mass part in Table 1, naphthol AS-RL was used as the coupler component in the corresponding coupler type and coupler mass part in Table 1, and the solvent used to dissolve the coupler solution was changed from 190 parts of methanol to a mixed solvent of 90 parts of isopropanol and 100 parts of water.

[0093] Example 11: Preparation of Pigment 11 Pigment 11 was obtained in the same manner as in Example 1, except that the amount of water used to suspend the base component was reduced by 40 parts, and 40 parts of methanol was added after the addition of sodium acetate after diazotization.

[0094] Example 12: Preparation of Pigment 12 Naphthol-based azo pigment 12 was obtained in the same manner as in Example 2, except that the amount of water used to suspend the base component was reduced by 20 parts and 20 parts of methyl ethyl ketone was added instead, and the solvent used for the coupler solution was changed from 190 parts of methanol to a mixed solvent of 20 parts of methyl ethyl ketone and 170 parts of water.

[0095] Example 13: Preparation of Pigment 13 Pigment 13 was obtained in the same manner as in Example 1, except that the water used to suspend the base component was reduced by 70 parts, 40 parts of acetone was added after the addition of sodium acetate after diazotization, the solvent used to dissolve the coupler was changed from 190 parts of methanol to 190 parts of acetone, and the slurry heating temperature after coupling was changed from 70°C to 45°C.

[0096] Example 14: Preparation of Pigment 14 The press cake prepared in the same manner as in Example 2 was reslurried in a mixed solution of 100 parts of water and 100 parts of methyl ethyl ketone, and stirred for 1 hour at 35° C. The slurry was filtered, washed with water at 60° C., and dried at 80° C. for 24 hours, and then pulverized to obtain pigment 14 represented by chemical formula (6).

[0097] Comparative Examples 1 and 2: Production of Pigments 101 and 102 Pigments 101 to 102 were obtained in the same manner as in Example 1, except that M-60 was used as the base component in the corresponding base type and base mass part in Table 1, naphthol AS-RL was used as the coupler component in the corresponding coupler type and coupler mass part in Table 1, and the solvent used in the coupler solution was changed from 190 parts of methanol to 280 parts of water.

[0098] Comparative Example 3: Preparation of Pigment 103 A press cake prepared in the same manner as in Comparative Example 2 was reslurried in a mixed solution of 100 parts of water and 100 parts of methyl ethyl ketone, and stirred for 1 hour at 35° C. The slurry was filtered, washed with water at 60° C., and dried at 80° C. for 24 hours, and then pulverized to obtain Pigment 103 represented by chemical formula (6).

[0099] (Comparative Example 4) Pigment 104 Pigment 104 represented by chemical formula (15) was obtained in the same manner as in Example 1, except that the base component was changed from M-60 to the corresponding base type and base mass part in Table 1, and the coupler component was changed from Naphthol AS-RL to the corresponding coupler type and coupler mass part in Table 1.

[0100] (Comparative Example 5) Pigment 105 CI Pigment Red 150 (TOSHIKI RED 150T, Tokyo Color Materials Co., Ltd., average primary particle diameter 140 nm, average aspect ratio 2.3), which is a naphthol-based azo pigment represented by chemical formula (16), was used as pigment 105.

[0101] (Comparative Example 6) Pigment 106 CI Pigment Red 122 (TONER MAGENT E, Heubach, average primary particle size 80 nm, average aspect ratio 3.25), which is a quinacridone pigment represented by chemical formula (17), was used as pigment 106.

[0102] <2> Particle size and major / minor diameter ratio measurement The average primary particle size and aspect ratio of the colored compositions of the Examples and Comparative Examples were determined by observation with a transmission electron microscope (TEM) as follows. For 50 primary particles of the coloring composition randomly selected from multiple photographs taken at a magnification of 10,000 times using a transmission electron microscope, a rectangle with the smallest area circumscribing the image of the particle was drawn, and the length of the long side of the rectangle was taken as the long diameter, and the length of the short side of the rectangle was taken as the short diameter. The average value of the long diameters was taken as the average primary particle diameter, and the average value of the ratio of the long diameter to the short diameter was taken as the aspect ratio.

[0103] In Examples 1 to 14 and Comparative Examples 1 to 4, the structures of the produced pigments, the raw materials used in the production of the pigments, the average primary particle diameters, and the aspect ratios are shown in Table 1. [Table 1]

[0104] <3> coloring composition The following relates to specific examples of coloring compositions containing the naphthol azo pigments prepared above. Pigment Dispersion (A1) Preparation of pigment dispersion (Example A-1) Preparation of pigment dispersion a-1 The following raw materials and 70 parts of zirconia beads having a diameter of 1.25 mm were charged into a 70 ml glass bottle and dispersed for 60 minutes using a paint shaker manufactured by Red Devil Co., Ltd., to obtain a dispersion with a non-volatile content of 19.3%. Naphthol azo pigment 1:3.15 parts Pigment dispersant (Allnex polyester modified acrylic acid polymer, ADDITOL XW6528): 5.25 parts Wetting agent (Allnex, ADDITOL VXW6374): 0.95 parts Defoamer (Allnex, ADDITOL VXW6211): 0.63 parts Ion-exchanged water: 21.52 parts Next, the zirconia beads were removed from the above dispersion to obtain pigment dispersion a-1.

[0105] (Examples A-2 to A-14, Comparative Examples A-1 to A-6) Preparation of pigment dispersions a-2 to a-14, a-101 to a-106) Except for changing the pigment 1 in Example A-1 as shown in Table 2, the same procedure as in Example A-1 was carried out to obtain pigment dispersions a-2 to a-14 and a-101 to a-106.

[0106] (A2) Evaluation of pigment dispersions <Initial viscosity and viscosity stability> The initial viscosity of the resulting pigment dispersion was measured at 25°C using an E-type viscometer (ELD-type viscometer manufactured by Toki Sangyo Co., Ltd.). In the same manner, the viscosity was measured after accelerated aging at 60°C for one week. The viscosity increase rate relative to the initial viscosity was calculated based on the obtained measured value, and used as an index of viscosity stability, which was evaluated according to the following evaluation criteria. The results are shown in Table 2. The lower the initial viscosity, the better the dispersibility. Furthermore, the smaller the viscosity increase rate, the better the dispersion stability. A rating of "4" or "3" on the following evaluation criteria is at a practical level.

[0107] (Initial viscosity evaluation criteria) 4: The initial viscosity is less than 5.0 mPa·s. Very good 3: The initial viscosity is 5.0 mPa·s or more and less than 7.5 mPa·s. Good 2: The initial viscosity is 7.5 mPa s or more and less than 10.0 mPa s. 1: The initial viscosity is 10.0 mPa·s or more. Very poor

[0108] (Evaluation criteria for viscosity stability) 4: Viscosity increase rate is less than 20%. Very good 3: The viscosity increase rate is 20% or more and less than 30%. Good 2: Viscosity increase rate is 30% or more and less than 40%. 1: Viscosity increase rate is 40% or more. Very poor

[0109] [Table 2]

[0110] water-based paint (B1) Preparation of water-based paints and coating films (Example B-1) Preparation of water-based paint b-1 and preparation of coating film The following raw materials were mixed using a mixer to obtain water-based paint b-1 with a non-volatile content of 49.5%. Pigment dispersion a-1: 1.4 parts Acrylic resin (DIC, Burnock WD-304): 13.6 parts Melamine resin (Allnex, Cymel 325): 3.4 parts

[0111] The obtained water-based paint b-1 was applied to a commercially available polyethylene terephthalate (PET) film having a thickness of 100 μm using a 7 mil applicator. After the application, the PET film was dried at room temperature for 18 hours. Then, it was dried at 60°C for 5 minutes and at 140°C for 20 minutes to obtain a coating film.

[0112] (Examples B-2 to B-14, Comparative Examples B-1 to B-6) Preparation of water-based paints b-2 to b-14, b-101 to b-106 and preparation of coating films) Except for changing the pigment dispersion 1 in Example B-1 as shown in Table 3, the same procedure as in Example B-1 was carried out to obtain water-based paints b-2 to b-14, b-101 to b-106, and their coating films.

[0113] (B2) Evaluation of Paint Film <Coloring power> The coated films (painted objects) were visually observed and rated according to the following criteria. The results are shown in Table 3. A rating of "3" or "2" on the following criteria is considered to be at a practical level. (Evaluation criteria for coloring strength) 3: The coloring power is much higher than the standard paint. 2: Higher coloring power than the standard coating 1: Tinting strength is equal to or inferior to the standard coating

[0114] <Weather resistance> The film coated with the paint was subjected to an accelerated weathering test using an ultra-accelerated weathering tester (Iwasaki Electric Co., Ltd., Eye Super Xenon Tester SUV-W151) at 90 mW / cm 2 The test was carried out for 96 hours (four cycles of 12 hours day and night), and the color difference (ΔE*) before and after the weather resistance test was evaluated using a Konica Minolta CM-700d color difference meter. The results are shown in Table 3. A rating of "3" or "2" on the following scale is considered to be at a practical level. (Weather resistance evaluation criteria) 3: Color change before and after the test (ΔE*) is less than 2.5, good 2: The color change before and after the test (ΔE*) is between 2.5 and 4, suitable for practical use 1: Color change before and after the test (ΔE*) is 4 or more, defective

[0115] [Table 3]

[0116] <c>Solvent paint (C1) Preparation of solvent paint (Example C-1) Preparation of solvent paint c-1 Naphthol azo pigment 1:9 parts, Acrylic resin (DIC Corporation, Acrydic 47-712): 7.7 parts Dispersion medium (a mixed solvent of toluene, xylene, butyl acetate, and T-SOL150FLUID manufactured by ENEOS in a mass ratio of 3:3:2:2): 40.7 parts The above materials and 230 parts of steel beads were placed in a glass container that could be sealed, sealed, and dispersed for 60 minutes using a paint shaker manufactured by Red Devil Co., Ltd. Furthermore, 75.4 parts of Acrydic 47-712 and 17.2 parts of melamine resin (manufactured by DIC Corporation, Amidia L-117-60) were added and dispersed for another 10 minutes. The steel beads were then removed to obtain solvent paint c-1.

[0117] (Examples C-2 to C-14, Comparative Examples C-1 to C-6) Preparation of solvent paints c-2 to c-14, c-101 to c-106 Except for changing the naphthol-based azo pigment 1 of Example C-1 as shown in Table 4, the same procedure as in Example C-1 was carried out to obtain solvent-based paints c-2 to c-14 and c-101 to c-106.

[0118] (C2) Evaluation of solvent-based paints <Initial viscosity and viscosity over time> The obtained solvent-based paint was placed in a sealable glass bottle, sealed, and immersed in a thermostatic bath at 25°C for 1 hour to keep the temperature constant, and the viscosity at 25°C and 6 rpm (referred to as "initial viscosity") was measured using a B-type viscometer (a BII-type viscometer manufactured by Toki Sangyo Co., Ltd.). The viscosity was also measured again in the same manner after storage at 40°C for 1 week (referred to as "viscosity over time"). The results are shown in Table 4. A rating of "4" or "3" on the following evaluation criteria is at a practical level.

[0119] (Evaluation criteria for initial viscosity and viscosity over time) 4: Viscosity is less than 4000 mPa·s, extremely good. 3: Viscosity is 4000 mPa·s or more and less than 10000 mPa·s, good. 2: Viscosity is 10,000 mPa·s or more and less than 13,000 mPa·s, defective. 1: Viscosity is 13,000 mPa·s or more, or the material has gelled; extremely poor quality.

[0120] (C3) Preparation of top coat clear paint Acrylic resin (DIC Corporation, Acrydic 44-179): 120 parts Melamine resin (DIC, Amidea L117-60): 30 parts Dilution solvent (a mixed solvent of toluene, xylene, ENEOS T-SOL150FLUID, ethyl 3-ethoxypropionate, and ethyl acetate in a mass ratio of 3:2:2:1:2): 50 parts The above materials were mixed and stirred with a high speed mixer to obtain a top coat clear paint.

[0121] (C4) Preparation of painted boards Preparation of painted plate c'-1 One part of the solvent-based paint c-1 prepared in Example C-1 was sprayed with a spray gun to paint a steel plate that had been subjected to primer treatment. In order to adjust the viscosity to be easily sprayed, a dilution solvent (a mixed solvent consisting of toluene: xylene: T-SOL150FLUID manufactured by ENEOS Corporation: ethyl 3-ethoxypropionate: ethyl acetate in a mass ratio of 3:2:2:1:2) was appropriately mixed with the solvent-based paint at a ratio of approximately 10 to 20 mass%. The painting was done in nine coats, followed by six coats of topcoat clear paint sprayed on. After drying at 25°C for 1 hour, it was dried at 140°C for 30 minutes to obtain a coated plate c'-1.

[0122] Preparation of painted panels c'-2 to c'-14, c'-101 to c'-106 Coated plates c'-2 to c'-14 and c'-101 to c'-106 were obtained in the same manner as for the preparation of coated plate c'-1, except that the solvent paint c-1 was changed as shown in Table 4.

[0123] (C5) Evaluation of painted panels <Coloring power> The coated panels were visually observed and rated according to the following criteria. The results are shown in Table 4. A rating of "3" or "2" on the following criteria is considered to be at a practical level. (Evaluation criteria for coloring strength) 3: Extremely stronger coloring than the standard painted board 2: Higher coloring power than the standard painted board 1: Tinting strength is equal to or inferior to the standard painted board

[0124] <Weather resistance> For the weather resistance test, the above-mentioned painted panels were subjected to an accelerated weather resistance test using an ultra-accelerated weather resistance tester (Iwasaki Electric Co., Ltd., Eye Super Xenon Tester SUV-W151) at 90 mW / cm 2 The test was carried out for 96 hours (four cycles of 12 hours day and night), and the color difference (ΔE*) before and after the weather resistance test was evaluated using a Konica Minolta CM-700d color difference meter. The results are shown in Table 4. A rating of "3" or "2" on the following scale is considered to be at a practical level. (Weather resistance evaluation criteria) 3: Color change before and after the test (ΔE*) is less than 2.5, good 2: The color change before and after the test (ΔE*) is between 2.5 and 4, suitable for practical use 1: Color change before and after the test (ΔE*) is 4 or more, defective

[0125] [Table 4]

[0126] <d>Water-based inkjet ink (D1) Preparation of Water-Based Inkjet Ink (Water-Based IJ Ink) (Example D-1) Preparation of Water-Based IJ Ink d-1 200 parts of zirconia beads having a diameter of 1.25 mm and the following raw materials were charged into a 200 ml glass bottle and dispersed for 6 hours using a Red Devil paint shaker. Naphthol azo pigment 1: 19.0 parts Styrene-acrylic acid copolymer (BASF Japan, Joncryl 61J): 16.4 parts Surfactant (Kao Corporation, Emulgen 420): 5.0 parts Ion-exchanged water: 59.6 parts Next, the zirconia beads were removed from the above dispersion to obtain a pigment dispersion.

[0127] Next, the above pigment dispersion and the following raw materials were mixed and stirred for 30 minutes using a high-speed mixer to obtain a mixture. Obtained pigment dispersion: 12.5 parts Styrene-acrylic acid copolymer (BASF Japan, Joncryl 60): 3.3 parts Surfactant (Kao Corporation, Emulgen 420): 2.0 parts Ion-exchanged water: 64.9 parts Next, diethylene glycol monobutyl ether was added to the above mixture to adjust the viscosity at 25°C to 2.5 mPa·s (25°C) and the surface tension to 40 mN / m, and then the mixture was filtered using a 1.0 μm membrane filter and further filtered using a 0.45 μm membrane filter to obtain water-based IJ ink d-1.

[0128] (Examples D-2 to D-14, Comparative Examples D-1 to D-6) Preparation of Water-Based IJ Inks d-2 to d-14, d-101 to d-106 Except for changing the naphthol-based azo pigment 1 in Example D-1 as shown in Table 5, the same procedure as in Example D-1 was carried out to obtain water-based IJ inks d-2 to d-14 and d-101 to d-106.

[0129] (D2) Evaluation of water-based inkjet ink <Viscosity stability> The initial viscosity of each water-based IJ ink was measured at 25°C using an E-type viscometer (ELD-type viscometer manufactured by Toki Sangyo Co., Ltd.). In the same manner, the viscosity was measured after accelerated aging at 70°C for 2 weeks. Using each measured value, the viscosity increase rate relative to the initial viscosity was calculated and used as an index of viscosity stability, which was evaluated according to the following criteria. The results are shown in Table 5. The smaller the viscosity increase rate, the better the viscosity stability is considered to be, and a rating of "3" on the following evaluation criteria is at a practical level. (Evaluation criteria for viscosity stability) 3: Viscosity increase rate is less than 15% 2: Viscosity increase rate is 15% or more but less than 30% 1: Viscosity increase rate is 30% or more

[0130] <Coloring power> The prepared water-based IJ ink was filled into the cartridge of a Seiko Epson printer PX-105 (piezo type inkjet printer), and a solid print was made on A4 size plain paper. The print was visually observed and evaluated according to the following criteria. The results are shown in Table 5. A rating of "3" or "2" on the following criteria is a practical level. (Evaluation criteria for coloring strength) 3: The coloring strength is significantly higher than the standard print. 2: Higher coloring power than the reference print 1: Tinting strength is equal to or worse than the reference print

[0131] <Light resistance> Using the IJ ink coated products prepared as described above and standard blue dyed fabrics (blue scale) of grades 2 to 8 specified in JIS L 0841:2004, a lightfastness test was performed using a Suga Test Instruments xenon weather meter SX75 under conditions of irradiance 60 W, black panel temperature 63°C, and 50% RH based on the third exposure method of the "Test method for color fastness to xenon arc lamp light" specified in JIS L 0843:2006. Next, the degree of fading when the blue scale of each grade faded was visually judged to determine the lightfastness of the IJ ink coated products. The results are shown in Table 5. If the evaluation criteria below are "3" or "2", it is at a practical level. (Evaluation criteria for light resistance) 3: Blue scale level 7 or above 2: Blue scale level 5 to 6 1: Blue scale level 4 or below

[0132] In addition, when the substrate was changed from A4 plain paper to coated paper, polypropylene film (OPP film), aluminum foil, and artificial leather (polyurethane sheet), the same results were obtained when the tinting power was evaluated. When the substrate was not paper, the substrate was attached to A4 plain paper. In addition, when a tank filled with the prepared water-based IJ ink was installed as magenta ink in a Canon MAXIFYMB5430 (thermal inkjet printer) and the coloring power was evaluated, similar results were obtained.

[0133] [Table 5]

[0134] <e>Active energy ray curable inkjet ink (Active energy ray curable IJ ink) (E1) Preparation of active energy ray curable inkjet ink (Example E-1) Preparation of active energy ray curable IJ ink e-1 The following materials were mixed and stirred in a high-speed mixer until homogenous, and the resulting mill base was dispersed in a horizontal mill for 1 hour to obtain a pigment dispersion. Naphthol azo pigment 1:5 parts Pigment dispersant (Lubrizol, Solsperse 32000): 1 part Polymerizable compound (dipropylene glycol diacrylate, Miramer M222, manufactured by BASF Japan): 19 parts Next, to 25 parts of the obtained pigment dispersion, the following materials were successively added with stirring, and stirring was continued until the photopolymerization initiator was dissolved to obtain a mixture. Polymerizable compound (Osaka Organic Industry Co., Ltd., lauryl acrylate): 30 parts Polymerizable compound (dipropylene glycol diacrylate, Miramer M222, manufactured by BASF Japan): 5.2 parts Polymerizable compound (2-(2-vinyloxyethoxy)ethyl acrylate, VEEA-AI, manufactured by Nippon Shokubai Co., Ltd.): 30 parts Photopolymerization initiator (4-benzoyl-4'-methyl-diphenyl sulfide, KAYACURE BMS, manufactured by Nippon Kayaku Co., Ltd.): 3.0 parts Photopolymerization initiator (BASF Japan 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, Irgacure TPO): 3.0 parts Polymerization accelerator (Ethyl 4-(dimethylamino)-benzoate, SB-PI-704, manufactured by Sort): 3.0 parts DEDG (Diethylene glycol diethyl ether, manufactured by Nippon Nyukazai Co., Ltd.): 0.5 parts Polymerization inhibitor (Seiko Chemical Co., Ltd., phenothiazine): 0.1 parts Surface conditioner (BYK Chemie polyether modified polydimethylsiloxane, BYK-UV3510): 0.2 parts Next, the resulting mixture was filtered through a membrane filter having a pore size of 1 μm to remove coarse particles, thereby obtaining active energy ray-curable IJ ink e-1.

[0135] (Examples E-2 to E-14, Comparative Examples E-1 to E-6) Preparation of Water-Based IJ Inks e-2 to e-14, e-101 to e-106) Except for changing the naphthol-based azo pigment 1 in Example E-1 as shown in Table 6, the same procedure as in Example E-1 was carried out to obtain water-based IJ inks e-2 to e-14 and e-101 to e-106.

[0136] (E2) Evaluation of active energy ray curable inkjet ink <Viscosity stability> The ink was filled into a sealable storage bottle to 90% capacity and left at 60°C for two weeks. The rate of change in viscosity before and after leaving it was evaluated based on the following evaluation criteria to evaluate storage stability. The evaluation results are shown in Table 6. A rating of "4" or "3" on the following criteria is considered to be at a practical level. 4: The rate of change is less than 10% compared to the initial value. 3: The rate of change is 10% or more but less than 15% compared to the initial value. 2: The rate of change is 15% or more but less than 25% of the initial value. 1: The rate of change is 25% or more compared to the initial value.

[0137] (E3) Preparation of active energy ray curable inkjet prints The prepared ink was printed under the following printing conditions. Using an inkjet ejection device (Trytec OnePassJET) equipped with a Kyocera head (resolution 600dpi x 600dpi), 100% solid images were printed on a Lintec substrate PET K2411 under printing conditions of 14pl ink droplet volume. The film thickness of each ink was approximately 8μm. The conveyor speed was 50 m / min, and a 160 W / cm metal halide lamp (365 nm) manufactured by Harrison Toshiba Lighting was used as the radiation source. The ink was cured in the atmosphere to obtain an inkjet print.

[0138] <Coloring power> The IJ ink prints produced above were visually observed and rated according to the following criteria. The results are shown in Table 6. A rating of "3" or "2" on the following criteria is at a practical level. (Evaluation criteria for coloring strength) 3: The coloring strength is significantly higher than the standard print. 2: Higher coloring power than the reference print 1: Tinting strength is equal to or worse than the reference print

[0139] <Light resistance> Using the IJ ink printed matter prepared as described above and standard blue dyed fabrics (blue scale) of grades 2 to 8 specified in JIS L 0841:2004, a lightfastness test was performed using a Suga Test Instruments xenon weather meter SX75 under conditions of irradiance 60 W, black panel temperature 63°C, and 50% RH based on the third exposure method of the "Test method for color fastness to xenon arc lamp light" specified in JIS L 0843:2006. Next, the degree of fading when the blue scale of each grade faded was visually judged to determine the lightfastness of the IJ ink coated matter. The results are shown in Table 6. If the grade is "3" or "2" in the following evaluation criteria, it is at a practical level. (Evaluation criteria for light resistance) 3: Blue scale level 7 or above 2: Blue scale level 5 to 6 1: Blue scale level 4 or below

[0140] [Table 6]

[0141] <f>colored resin composition (F1) Preparation of colored resin composition and evaluation sheet (Example F-1) Preparation of colored resin composition f-1 The following raw materials were mixed and stirred in a super mixer while being heated to 100° C., and then cooled to 30° C. to prepare a colored resin composition f-1. Pigment: Naphthol-based azo pigment 1:4 parts Chlorinated polyvinyl chloride resin (Kaneka Corporation, H-516A): 75.0 parts Vinyl chloride-ethylene copolymer (TE-650, manufactured by Taiyo Vinyl Corporation): 25.0 parts Impact resistance improver (Kaneka Corporation, Kane Ace FM-50): 6.0 parts -Processability improver (Kaneka Corporation, Kane Ace PA-40): 5.0 parts Heat stabilizer (dimethyltin compound, AT-1500, manufactured by Nitto Kasei Co., Ltd.): 3.5 parts Lubricant (Kao stearic acid, Lunac S-70V): 0.5 parts Lubricant (Honeywell's oxidized polyethylene wax, AC-629A): 3.0 parts Antioxidant (BASF Japan hindered phenol antioxidant, Irganox1010): 0.2 parts The obtained colored resin composition was charged from a hopper 100 of a manufacturing apparatus 10 shown in FIG. 1 and melt-kneaded in an extruder 200 set at a temperature of 180° C. Then, the colored resin composition was extruded as a molten sheet from a calendar head. The sheet was flattened by passing through rollers 301, 302, and 303 while in contact with them. Then, it passed through a feed roller 401 and a cooling roller 400 to be cooled. Then, after passing between two guide rollers, it was cut to a predetermined length using a cutter 501 to obtain a sheet-like evaluation sheet 1 having a thickness of 2.0 mm.

[0142] (Examples F-2 to F-14, Comparative Examples F-1 to F-6) Preparation of colored resin compositions f-2 to f-14, f-101 to f-106) Except for changing the naphthol-based azo pigment 1 of Example F-1 as shown in Table 7, the same procedure as in Example F-1 was carried out to obtain colored resin compositions f-2 to f-14 and f-101 to f-106. Each of the obtained colored resin compositions was extruded in the same manner to obtain evaluation sheets.

[0143] <Dispersibility> The obtained evaluation sheet was cut into 1 mm squares (approximately 0.001 g), sandwiched between two glass slides and pressed at 90°C to create a test piece. This was observed in its entirety under an optical microscope at 450x magnification, and evaluated according to the following criteria based on the size and number of coarse particles. A rating of "4" or "3" on the following criteria is at a practical level. The results are shown in Table 7. 4: No coarse particles of 10 μm or more are present, and there are 0 to 9 coarse particles of 2 μm or more. 3: No coarse particles of 10 μm or more are present, and there are 10 to 29 coarse particles of 2 μm or more. 2: There are no coarse particles of 10 μm or more, and there are 30 or more coarse particles of 2 μm or more 1: Coarse particles of 10 μm or more are present

[0144] <Coloring power> The evaluation sheets prepared as described above were visually observed and evaluated according to the following criteria. The results are shown in Table 7. In the following evaluation criteria, a rating of "3" or "2" is a practical level. (Evaluation criteria for coloring strength) 3: Extremely high coloring power compared to standard colored resin compositions 2: Higher coloring power than the standard colored resin composition 1: Tinting strength is equal to or inferior to the standard colored resin composition

[0145] <Weather resistance> For the weather resistance test, the evaluation sheet was subjected to an accelerated weather resistance test using an ultra-accelerated weather resistance tester (Iwasaki Electric Co., Ltd., Eye Super Xenon Tester SUV-W151) at 90 mW / cm 2 The test was carried out for 96 hours (four cycles of 12 hours day and night), and the color difference (ΔE*) before and after the weather resistance test was evaluated using a Konica Minolta CM-700d color difference meter. The results are shown in Table 7. A rating of "3" or "2" on the following scale is considered to be at a practical level. (Weather resistance evaluation criteria) 3: Color change before and after the test (ΔE*) is less than 2.5, good 2: The color change before and after the test (ΔE*) is between 2.5 and 4, suitable for practical use 1: Color change before and after the test (ΔE*) is 4 or more, defective

[0146] [Table 7]

[0147] From the results in Tables 2 to 7, it can be seen that the use of the naphthol azo pigment of the present invention allows the production of coatings, inks and colored resin compositions that are excellent in dispersibility, dispersion stability, coloring power, light resistance and weather resistance. On the other hand, the paint and ink using a pigment with a particle size smaller than the specified range in Comparative Example 1 did not have excellent initial viscosity or viscosity stability, and also lacked light resistance and weather resistance. The paint and ink using a pigment with an aspect ratio outside the specified range in Comparative Example 2 lacked viscosity stability. In Comparative Example 3, a pigment with a particle size larger than the specified range was used, so the paint, ink, and colored resin composition lacked coloring power. In Comparative Examples 4 and 5, since a naphthol pigment having a low light resistance was used, a coating material, an ink, and a colored resin composition having excellent light resistance and weather resistance could not be obtained. In Comparative Example 6, since a quinacridone pigment was used, a coating material, an ink, and a colored resin composition having excellent coloring power, viscosity stability, and dispersibility could not be obtained.< / f> < / e> < / d> < / c>

Claims

1. A method for producing a naphthol-based azo pigment, comprising: a compound having an average primary particle diameter of 90 nm or more and 1,000 nm or less and an average aspect ratio of the primary particles of 1 or more and 3.3 or less, and represented by the following general formula (1), which satisfies the following condition 1 or condition 2, A method for producing a naphthol-based azo pigment, comprising: carrying out a coupling reaction between a solution containing a water-soluble organic solvent and a coupler component represented by the following general formula (2) and a solution containing a diazonium salt represented by the following general formula (4) obtained by diazotizing an aromatic amine represented by the following general formula (3), to obtain a compound represented by the general formula (1). The water-soluble organic solvent is any one of acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, acetone, methyl ethyl ketone, tetrahydrofuran, 1,4-dioxane, ethylene glycol, diethylene glycol, polyethylene glycol, methanol, ethanol, and isopropanol. General formula (1) 【Chemistry 1】 In general formula (1), R1 represents a hydrogen atom, an alkyl group, a halogen group, a nitro group, a carboxy group, a sulfo group, a phosphate group, a sulfamoyl group, a carbamoyl group, an alkylsulfamoyl group, or an alkylcarbamoyl group. R2 and R3 are each independently a hydrogen atom, an alkoxy group, an alkyl group, a halogen group, a nitro group, a carboxy group, a sulfo group, a phosphate group, a sulfamoyl group, a carbamoyl group, an alkylsulfamoyl group, or an alkylcarbamoyl group. 【Chemistry 2】 [In general formula (2), general formula (3) and general formula (4), R1 is a hydrogen atom, an alkyl group, a halogen group, a nitro group, a carboxy group, a sulfo group, a phosphate group, a sulfamoyl group, a carbamoyl group, an alkylsulfamoyl group, or an alkylcarbamoyl group. R2 and R3 each independently represent a hydrogen atom, an alkoxy group, an alkyl group, a halogen group, a nitro group, a carboxy group, a sulfo group, a phosphate group, a sulfamoyl group, a carbamoyl group, an alkylsulfamoyl group, or an alkylcarbamoyl group. [Z n− ] 1 / n is an anion of any valence n (n is an integer from 1 to 3). X1, X2, Y1, Y2, and Y3 satisfy either the following condition 1 or condition 2. Condition 1: Either one of X1 and X2 is a carboxy group or a carbamoyl group, at least one of Y1, Y2, and Y3 is an alkoxy group or a halogen group, and the remainder of X1, X2, Y1, Y2, and Y3 are hydrogen atoms. Condition 2: Either X1 or X2 is an alkoxy group or a halogen group, at least one of Y1, Y2, and Y3 is a carboxy group or a carbamoyl group, and the remaining of X1, X2, Y1, Y2, and Y3 are hydrogen atoms.

2. 2. The method for producing a naphthol azo pigment according to claim 1, wherein R1 is a hydrogen atom or an alkyl group, and R2 and R3 are hydrogen atoms.

3. A method for producing a coloring composition, comprising mixing the naphthol-based azo pigment obtained according to claim 1 or 2 with a dispersion medium.

4. A method for producing a paint, comprising mixing the naphthol-based azo pigment obtained according to claim 1 or 2 with a resin and a solvent.

5. A method for producing an ink, comprising mixing the naphthol-based azo pigment obtained in claim 1 or 2 with a resin and a solvent.

6. A method for producing an active energy ray-curable ink, comprising mixing the naphthol azo pigment obtained according to claim 1 or 2 with a polymerizable compound.

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