Coloring agent

Abstract

To provide a pigment composition which can exhibit good dispersibility and dispersion stability of a pigment in a polyurethane ink etc., and to provide a colorant and a liquid ink which each contain the pigment composition.SOLUTION: A pigment composition comprises: at least one organic pigment selected from the group consisting of benzimidazolone azo pigments and quinacridone pigments, and at least one polycarboxylic acid compound represented by, for example, the following formula. (In the formula, R1 represents an alkylene group that may be substituted with a hydroxyl or carboxyl group, or a single bond). (In the formula, R2 represents an alkyl group that may be substituted with a hydroxyl or carboxyl group).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a pigment composition, and to a colorant and a liquid ink containing the same. [Background technology]

[0002] Pigments have long been used primarily for the coloring of inks, paints, toners, rubber and plastics, dope coloring of synthetic fibers, pigment printing, and coloring of miscellaneous goods. Among these, the printing application of inks and the like is important. Printing is carried out by making a printing plate, applying printing ink to the surface of the plate, and transferring the image to paper, film, cloth, etc. Printing plates include lithographic, intaglio, relief, and stencil printing, and printing methods such as offset printing, gravure printing, and flexographic printing are used depending on the shape of the plate. Among these, gravure printing and flexographic printing are widely used in printing food packaging films, soft packaging films, etc., and are industrially important printing methods.

[0003] Gravure inks used in gravure printing and flexographic inks used in flexographic printing are composed of binder resins, solvents, auxiliaries, etc., in addition to colorants such as pigments. In particular, polyurethane inks using polyurethane resins as binders occupy an important position in the field of food packaging. This is because polyurethane resins have good adhesion to many substrates, excellent film properties, and excellent resistance to hot water during retort treatment (high retort resistance). On the other hand, polyurethane resins have a low ability to disperse pigments, so there is a demand for pigment compositions that exhibit good dispersibility and dispersion stability in polyurethane inks.

[0004] The polyurethane resin binders and polyurethane inks containing them are known in the following Patent Documents 1 and 2. However, these methods may not provide sufficient pigment dispersibility and dispersion stability. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-221539 A [Patent Document 2] JP 2007-238953 A DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a pigment composition that can exhibit good pigment dispersibility and dispersion stability in polyurethane inks and the like, and a colorant and liquid ink containing the same. [Means for solving the problem]

[0007] The present inventors have focused on acid compounds capable of improving the dispersibility and dispersion stability of pigments in pigment compositions and have found that carboxylic acid compounds are effective. Further investigation has found that monocarboxylic acid compounds have little effect, but polycarboxylic acid compounds having two or more carboxyl groups in the molecule have excellent effects. It is speculated that this is because the polycarboxylic acid compound mediates between the organic pigment and the binder resin such as polyurethane resin, making it easier for the resin component to be adsorbed to the organic pigment, stabilizing the dispersion system.

[0008] Further investigation of this polycarboxylic acid compound revealed that the distance between carboxyl groups of the polycarboxylic acid compound and the position of the substituent are important for the polycarboxylic acid compound to exert a particular effect. As a result, the present inventors found at least one polycarboxylic acid compound represented by the following formulae (I) to (III).

[0009] The considerations regarding each polycarboxylic acid compound are as follows. In the case of polycarboxylic acid having carboxyl groups at both ends of the alkylene group as in formula (I), if the alkylene group is too short, the resin may become sterically crowded when adsorbed onto the organic pigment surface, and sufficient effect may not be obtained.On the other hand, if the alkylene group is too long, the solubility of the polycarboxylic acid compound in the solvent increases, and the amount of the resin adsorbed onto the organic pigment surface decreases, resulting in a smaller effect. In addition, in the case of polycarboxylic acid compounds in which two carboxyl groups are substituted with ethene, such as in formula (II), the stereochemical configuration of the carboxyl groups is important. If it is a cis isomer, both of the two carboxyl groups will be adsorbed to either the organic pigment or the resin component, and will not be able to mediate between the pigment and the resin, so there is little effect in improving dispersibility and dispersion stability. On the other hand, if a trans isomer is used, it is possible to adsorb the resin to the pigment, which is a great effect in improving dispersibility and dispersion stability. In the case of polycarboxylic acid compounds having carboxyl groups on aromatic rings or multiple alkyl groups on aromatic rings substituted with carboxyl groups as in formula (III), the substitution position of the carboxyl groups is important. If two carboxyl groups are substituted at the ortho position, for the same reason as with the cis form of carboxyl-substituted ethene, the compound will be adsorbed to either the pigment or the resin, and sufficient effect will not be obtained. Polycarboxylic acid compounds having carboxyl groups at the meta and para positions can interact with both the organic pigment and the resin, improving dispersibility and dispersion stability.

[0010] Furthermore, the inventors also investigated organic pigments that exhibit good effects in combination with at least one polycarboxylic acid compound represented by formulas (I) to (III), and surprisingly found that, among the organic pigments, benzimidazolone azo pigments and quinacridone pigments exhibit particularly good dispersibility and dispersion stability as polyurethane inks.

[0011] That is, the present invention is Item 1. A pigment composition comprising at least one organic pigment selected from the group consisting of benzimidazolone azo pigments and quinacridone pigments, and at least one polycarboxylic acid compound represented by the following formulas (I) to (III). TIFF0007673782000001.tif856...(I) (R1 in formula (I) represents an alkylene group which may be substituted with a hydroxyl group or a carboxyl group, or a single bond.) TIFF0007673782000002.tif2750...(II) (R2 in formula (II) represents an alkyl group which may be substituted with a hydroxyl group or a carboxyl group.) TIFF0007673782000003.tif3534...(III) (In formula (III), R3 represents a carboxyl group or an alkyl group substituted with a carboxyl group, R4 to R6 each independently represent a hydrogen atom, a hydroxyl group, a carboxyl group, or an alkyl group which may be substituted with a hydroxyl group or a carboxyl group, and at least one of R4 to R6 represents a carboxyl group or an alkyl group substituted with a carboxyl group.) Item 2. A colorant comprising the pigment composition according to item 1. Item 3. A liquid ink containing the colorant according to item 2. Effect of the Invention

[0012] The pigment composition of the present invention is excellent in dispersibility and dispersion stability of the pigment in polyurethane inks, etc. Therefore, the pigment composition of the present invention is suitable for use as a colorant or liquid ink (particularly, polyurethane ink containing polyurethane as a binder resin). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention will be described in detail below.

[0014] [Pigment composition] The pigment composition of the present invention contains at least one organic pigment selected from the group consisting of benzimidazolone azo pigments and quinacridone pigments, and at least one polycarboxylic acid compound represented by the following formulas (I) to (III). TIFF0007673782000004.tif856...(I) (R1 in formula (I) represents an alkylene group which may be substituted with a hydroxyl group or a carboxyl group, or a single bond.) TIFF0007673782000005.tif2750...(II) (R2 in formula (II) represents an alkyl group which may be substituted with a hydroxyl group or a carboxyl group.) TIFF0007673782000006.tif3937...(III) (In formula (III), R3 represents a carboxyl group or an alkyl group substituted with a carboxyl group, R4 to R6 each independently represent a hydrogen atom, a hydroxyl group, a carboxyl group, or an alkyl group which may be substituted with a hydroxyl group or a carboxyl group, and at least one of R4 to R6 represents a carboxyl group or an alkyl group substituted with a carboxyl group.) In this specification, at least one polycarboxylic acid compound represented by the above formulas (I) to (III) may be simply referred to as a "polycarboxylic acid compound." Note that the compound represented by formula (I) does not include the compounds represented by formulas (II) and (III).

[0015] (Organic pigments) The organic pigment in the present invention is at least one selected from the group consisting of benzimidazolone azo pigments and quinacridone pigments. Examples of benzimidazolone azo pigments include CI Pigment Yellow 180 (PY180), CI Pigment Yellow 181 (PY181), CI Pigment Yellow 185 (PY185), CI Pigment Yellow 154 (PY154), CI Pigment Yellow 120 (PY120), CI Pigment Yellow 151 (PY151), CI Pigment Yellow 167 (PY167), CI Pigment Yellow 175 (PY175), CI Pigment Yellow 194 (PY194), CI Pigment Orange 36 (PO36), CI Pigment Yellow 195 (PY195), CI Pigment Yellow 200 (PY200), CI Pigment Yellow 210 (PY210), CI Pigment Yellow 220 (PY220), CI Pigment Yellow 230 (PY230), CI Pigment Yellow 240 (PY240), CI Pigment Yellow 250 (PY250), CI Pigment Yellow 260 (PY260), CI Pigment Yellow 270 (PY270), CI Pigment Yellow 280 (PY280), CI Pigment Yellow 290 (PY290), CI Pigment Yellow 300 (PY300), CI Pigment Yellow 310 (PY310), CI Pigment Yellow 320 (PY320), CI Pigment Yellow 330 (PY330), CI Pigment Yellow 340 (PY340), CI Pigment Yellow 350 (PY350), CI Pig Pigment Orange 62 (PO62), CI Pigment Orange 60 (PO60), CI Pigment Orange 64 (PO64), CI Pigment Orange 72 (PO72), CI Pigment Red 171 (PR171), CI Pigment Red 175 (PR175), CI Pigment Red 176 (PR176), CI Pigment Red 185 (PR185), CI Pigment Red 208 (PR208), CI Pigment Violet 32 ​​(PV32), CI Pigment Brown 25 (PBr25), and CI Pigment Brown 32 (PBr32). In addition, examples of quinacridone pigments include CI Pigment Violet 19 (PV19), CI Pigment Red 122 (PR122), CI Pigment Red 209 (PR209), CI Pigment Red 202 (PR202), CI Pigment Red 206 (PR206), CI Pigment Orange 48 (PO48), CI Pigment Orange 49 (PO49), and CI Pigment Violet 42 (PV42). Among them, benzimidazolone azo pigments are preferably benzimidazolone acetone azo pigments, particularly preferably PY180, and quinacridone pigments are preferably PV19 and PR122. These organic pigments may be used alone or in combination of two or more, or may be a solid solution of two or more.

[0016] The primary particle size of the benzimidazolone azo pigment and the quinacridone pigment is, for example, 0.01 to 5.0 μm, and preferably 0.1 to 2.5 μm. The specific surface area of ​​the benzimidazolone azo pigment and the quinacridone pigment is, for example, 10 to 150 m. 2 / g, preferably 20 to 100m 2 When the primary particle size and the specific surface area are within the above ranges, the coloring power and dispersibility are excellent.

[0017] The organic pigment in the present invention may contain organic pigments (dyes) other than benzimidazolone azo pigments and quinacridone pigments, as well as natural colorants. Examples of such organic pigments (dyes) include insoluble azo, condensed azo, quinophthalone, isoindolinone, isoindoline, azomethine, anthraquinone, xanthene, diketopyrrolopyrrole, perylene, perinone, indigoid, dioxazine, and phthalocyanine. Further, examples of such natural pigments include carotenoid pigments such as annatto pigment, gardenia yellow pigment, dunaliella carotene, carrot carotene, palm oil carotene, potato carotene, tomato pigment, shrimp pigment, krill pigment, orange pigment, crab pigment, corn pigment, Phaffia pigment, Haematococcus algae pigment, marigold pigment, saffron pigment, and chili pepper pigment (paprika pigment), quinone pigments such as madder pigment, cochineal pigment, Lithospermum Root pigment, and lac pigment, red cabbage pigment, red radish pigment, perilla pigment, hibiscus pigment, grape juice pigment, grape skin pigment, purple potato pigment, purple corn pigment, purple yam pigment, elderberry pigment, cranberry pigment, cherry pigment, hibiscus pigment, Examples of pigments include anthocyanin pigments such as blackberry pigment, plum pigment, blueberry pigment, raspberry pigment, and boysenberry pigment; flavonoid pigments such as cacao pigment, kohlrauss pigment, sorghum pigment, rosewood pigment, onion pigment, tamarind pigment, persimmon pigment, carob pigment, licorice pigment, Suo pigment, peanut pigment, pecan nut pigment, safflower red pigment, and safflower yellow pigment; porphyrin pigments such as chlorophyllin, chlorophyll (chlorophyll), chlorella pigment, and spirulina pigment; diketone pigments such as turmeric pigment; betacyanin pigments such as red beet pigment; azaphilone pigments such as red koji pigment (Monascus pigment); and others such as red koji yellow pigment, caramel, gardenia blue pigment, and gardenia red pigment. Examples of pigments include anthocyanin pigments such as red cabbage pigment, perilla pigment, gardenia pigment, grape juice pigment, purple sweet potato pigment, and red radish pigment, flavonoid pigments such as safflower pigment, chlorophyll pigments such as chlorophyll a, carotenoid pigments such as zeaxanthin, and phycocyanin pigments such as phycocyanopyrin.The content of organic pigments (dyes) and natural pigments other than these benzimidazolone azo pigments and quinacridone pigments (the total content when two or more types are included) is, for example, 50% by mass or less, preferably 30% by mass or less, and more preferably 10% by mass or less, based on 100% by mass of the total amount of organic pigments (dyes) and natural pigments. Therefore, the content of the benzimidazolone azo pigments or quinacridone pigments (the total content when both are included) is, for example, 50% by mass or more, preferably 70% by mass or more, and more preferably 90% by mass or more, based on 100% by mass of the total amount of organic pigments (dyes).

[0018] (Polycarboxylic acid compound) The polycarboxylic acid compound is at least one of the polycarboxylic acid compounds represented by the formulas (I) to (III). Examples of the alkyl group in the alkyl group that may be substituted with the carboxyl group of the at least one polycarboxylic acid compound represented by the formulas (I) to (III) include, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. Examples of the compound represented by formula (I) include tartaric acid, succinic acid, citric acid, glutaric acid, adipic acid, oxalic acid, malic acid, aspartic acid, malonic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. Examples of the compound represented by formula (II) include aconitic acid, fumaric acid, and mesaconic acid. Examples of the compound represented by formula (III) include isophthalic acid, terephthalic acid, trimesic acid, benzenetricarboxylic acid, methylisophthalic acid, hydroxyisophthalic acid, methylterephthalic acid, hydroxyterephthalic acid, and phenylene diacetic acid. Among them, the compound represented by formula (I) is preferably tartaric acid, succinic acid, citric acid, or glutaric acid, the compound represented by formula (II) is preferably aconitic acid or fumaric acid, and the compound represented by formula (III) is preferably isophthalic acid or terephthalic acid. When the polycarboxylic acid compound is a compound having optical isomerism, it may be a racemic mixture or any of the optical isomers. The polycarboxylic acid compound may be used alone or in combination of two or more kinds.

[0019] The number of carboxyl groups in the polycarboxylic acid compound may be 2 or more, and is preferably 2 to 5, and more preferably 2 to 4. The number of hydroxyl groups in the polycarboxylic acid compound is, for example, 0 to 10, preferably 0 to 6, and more preferably 0 to 4. When the numbers of carboxyl groups and hydroxyl groups are within the above ranges, the pigment is particularly excellent in dispersibility and dispersion stability.

[0020] The content of the polycarboxylic acid compound is, for example, 0.01 to 20 parts by mass, preferably 0.1 to 15 parts by mass, and more preferably 0.2 to 10 parts by mass, per 100 parts by mass of the organic pigment. The content of the polycarboxylic acid compound is, for example, 0.01 to 20% by mass, preferably 0.1 to 15% by mass, and more preferably 0.2 to 10% by mass, per 100% by mass of the pigment composition. When the content of the polycarboxylic acid compound is within the above range, the pigment is particularly excellent in dispersibility and dispersion stability.

[0021] The pigment composition of the present invention may contain components other than the organic pigment (dye) and the polycarboxylic acid compound (hereinafter, sometimes referred to as "other components"), as long as the effects of the present invention are not impaired. Examples of the other components include pigment derivatives, inorganic pigments, dispersants (surfactants), rosin, etc.

[0022] Examples of the pigment derivatives include sulfonic acid pigment derivatives, amino group-containing pigment derivatives, and phthalimidomethyl group-containing pigment derivatives. Examples of the inorganic pigments include calcium carbonate, magnesium carbonate, precipitated barium sulfate, kaolin, clay, alumina white, and white carbon. Examples of the dispersants (surfactants) include anionic compounds, cationic compounds, nonionic compounds, and polymer compounds.

[0023] When the above other components are contained, the content thereof is, for example, 0.1 to 10% by weight, preferably 0.2 to 5% by weight, and more preferably 0.3 to 3% by weight, relative to 100% by weight of the pigment composition.

[0024] [Method of producing pigment composition] The pigment composition of the present invention can be obtained, for example, by adding a polycarboxylic acid compound to an organic pigment. The method of addition is not particularly limited, and the powdered polycarboxylic acid compound may be added to the organic pigment (dry blend), the powdered polycarboxylic acid compound may be added to a slurry-like organic pigment in which the powdered polycarboxylic acid compound has been dispersed in a solvent beforehand (wet method), or the polycarboxylic acid compound dissolved in a solvent such as water may be added to the organic pigment as described above. The polycarboxylic acid compound may be added to the organic pigment all at once, or may be added in several batches. After adding the polycarboxylic acid compound to the organic pigment, the mixture is thoroughly stirred to disperse the polycarboxylic acid compound in the organic pigment, thereby obtaining a pigment composition. After thorough mixing in the liquid, the slurry pH may be made acidic to cause the polycarboxylic acid to precipitate, or an inorganic salt may be added to cause the polycarboxylic acid to salt out in the form of a Ca salt, Mg salt, Al salt, or the like. The organic pigment may be the above-mentioned benzimidazolone azo pigment and quinacridone pigment that are commercially available as they are. In addition, the polycarboxylic acid compound may also be a commercially available reagent that is commercially available as it is.

[0025] The amount of the polycarboxylic acid compound added is, for example, 0.01 to 20 parts by mass, preferably 0.1 to 15 parts by mass, and more preferably 0.2 to 10 parts by mass, per 100 parts by mass of the organic pigment.

[0026] The pigment composition obtained above may be subjected to general pigmentation treatments such as particle size adjustment, pH adjustment, filtration, alcohol washing, water washing, drying, and pulverization, if necessary. The particle size may be adjusted by heating, stirring, and aging the pigment in water and / or an organic solvent under normal pressure or pressure, or by known methods such as the acid paste method, acid slurry method, dry milling method, solvent method, and solvent milling method. In addition, the pigment particle surface may be treated with a pigment derivative such as a sulfonic acid pigment derivative, an amino group-containing pigment derivative, or a phthalimidomethyl group-containing pigment derivative, a polymer such as a dispersant, a surfactant, rosin, or the like.

[0027] [Colorants and liquid inks] The colorant of the present invention is not particularly limited as long as it contains the above-mentioned pigment composition, and can be suitably used for any colorant application that requires a coloring function. For example, it can be used for various known and commonly used applications such as paints, printing inks, colored molded products, toners, color filters and black matrices of display devices, inks for inkjet recording, etc. The colorant of the present invention contains components suitable for each application in addition to the pigment composition of the present invention.

[0028] The liquid ink of the present invention is one embodiment of a printing ink, but is not particularly limited as long as it contains the pigment composition of the present invention, and can be used for gravure printing or flexographic printing. That is, the liquid ink of the present invention can be used, for example, as gravure ink or flexographic ink. Liquid inks are broadly classified into organic solvent-based liquid inks in which an organic solvent is the main solvent, and water-based liquid inks in which water is the main solvent, but the liquid ink of the present invention can be applied to both organic solvent-based liquid inks and water-based liquid inks. The liquid ink of the present invention contains components suitable for each ink in addition to the pigment composition of the present invention, as described below.

[0029] The liquid ink of the present invention contains, in addition to the pigment composition of the present invention, for example, a binder resin, a solvent, and a dispersant. When the main component of the solvent is an organic solvent, the liquid ink is an organic solvent-based liquid ink, and when the main component of the solvent is a water-miscible organic solvent or an aqueous solvent such as water, the liquid ink is an aqueous liquid ink.

[0030] Liquid ink is obtained by dispersing a mixture of pigment and binder resin in a disperser to obtain a pigment dispersion, then adding resin, solvent, and additives such as leveling agents as necessary to the obtained pigment dispersion, and stirring and mixing. The ink viscosity of liquid ink is preferably in the range of 10 mPa·s or more to prevent pigment sedimentation and to disperse the pigment appropriately, and 1000 mPa·s or less to ensure workability during ink production and printing.

[0031] The binder resin is not particularly limited, and may be any of those used in general liquid inks, such as polyurethane resin, acrylic resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-acrylic copolymer resin, chlorinated polyolefin resin, modified polyolefin resin, cellulose, cellulose derivative, polyamide resin, ethylene-vinyl acetate copolymer resin, vinyl acetate resin, styrene resin, dammar resin, styrene-maleic acid copolymer resin, polyester resin, alkyd resin, polyvinyl chloride resin, rosin resin, rosin-modified maleic acid resin, terpene resin, phenol-modified terpene resin, ketone resin, cyclized rubber, chlorinated rubber, butyral, polyacetal resin, petroleum resin, and modified resins thereof. Among these, the liquid ink of the present invention preferably contains a polyurethane resin as the binder resin.

[0032] Examples of the organic solvent include aromatic hydrocarbon organic solvents such as toluene, xylene, Solvesso #100, and Solvesso #150; aliphatic hydrocarbon organic solvents such as hexane, methylcyclohexane, heptane, octane, and decane; and esters such as methyl acetate, ethyl acetate, isopropyl acetate, normal propyl acetate, butyl acetate, amyl acetate, ethyl formate, and butyl propionate. Examples of the water-miscible organic solvent include alcohols such as methanol, ethanol, propanol, butanol, and isopropyl alcohol; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; and glycol ethers such as ethylene glycol (mono, di)methyl ether, ethylene glycol (mono, di)ethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, monobutyl ether, diethylene glycol (mono, di)methyl ether, diethylene glycol (mono, di)ethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol (mono, di)methyl ether, propylene glycol (mono, di)methyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and dipropylene glycol (mono, di)methyl ether.

[0033] The liquid ink of the present invention uses the pigment composition of the present invention, but may also use organic pigments (dyes), inorganic pigments, and natural colorants that are used in general inks as colorants within the scope of not affecting the effects of the present invention.

[0034] Examples of the organic pigments include phthalocyanine pigments, halogenated phthalocyanine pigments, anthraquinone pigments, anthranthrone pigments, dianthraquinonyl pigments, anthrapyrimidine pigments, perylene pigments, perinone pigments, thioindigo pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, insoluble azo pigments, condensed azo pigments, azomethine pigments, flavanthrone pigments, diketopyrrolopyrrole pigments, isoindoline pigments, indanthrone pigments, carbon black pigments, etc. Examples of the inorganic pigments include white pigments such as titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, lithopone, antimony white, and gypsum.

[0035] Examples of inorganic pigments other than the white pigment include aluminum particles, mica, bronze powder, chrome vermilion, yellow lead, cadmium yellow, cadmium red, ultramarine, Prussian blue, iron oxide red, yellow iron oxide, iron black, and zircon.

[0036] The liquid ink of the present invention may further contain various additives, such as wax, a chelating crosslinking agent, an extender pigment, a leveling agent, an antifoaming agent, a plasticizer, an infrared absorbing agent, an ultraviolet absorbing agent, an aromatic agent, and a flame retardant, if necessary. EXAMPLES

[0037] The present invention will be described in more detail below using examples and comparative examples. In the following examples and comparative examples, "parts" and "%" represent "parts by mass" and "% by mass" unless otherwise specified.

[0038] (Examples 1 to 19, 22 to 27, Comparative Examples 1 to 22) As shown in Table 1 below, an organic pigment and an acid compound were placed in a mill cup-sized mixing grinder LAB MILL (manufactured by Osaka Chemical Co., Ltd.) and mixed for 30 seconds to obtain each pigment composition.

[0039] (Example 20) In a 2L stainless steel cup filled with 1000g of water, 130g (50g of pigment) of CI Pigment Yellow 180 water wet (manufactured by DIC Corporation) was added and stirred for 1 hour. Then, 2.5g of L(+)-tartaric acid (manufactured by Kanto Chemical Co., Ltd.) was added and stirred for 1 hour. This was filtered through a Buchner funnel, and the wet cake was dried at 98°C for 18 hours and pulverized for 30 seconds with a mixer and pulverizer LAB MILL (manufactured by Osaka Chemical Co., Ltd.) to obtain PY180 composition 20.

[0040] Example 21 PY180 composition 21 was obtained by carrying out the same procedure as in Example 20, except that L(+)-tartaric acid (manufactured by Kanto Chemical Co., Ltd.) was replaced with citric acid (manufactured by Kanto Chemical Co., Ltd.).

[0041] The notations in Tables 1 and 2 are as follows. (Organic pigments) PY180 ‥ CI Pigment Yellow 180 (DIC Corporation) PR122 / V19 ‥CI Pigment Red 122 / Violet 19 solid solution (DIC Corporation) PR122 ‥ CI Pigment Red 122 (DIC Corporation) PV19 ‥CI Pigment Violet 19 (DIC Corporation) PY83 ‥ CI Pigment Yellow 83 (DIC Corporation) PR146 ‥ CI Pigment Red 146 (DIC Corporation) PR213 ‥ CI Pigment Red 213 (DIC Corporation) PB15:3 ‥CI Pigment Blue 15:3 (DIC Corporation) PV23 ‥ CI Pigment Violet 23 (DIC Corporation) PR254 ‥ CI Pigment Red 254 (DIC Corporation) (acid compound) Tartaric acid - L(+)-tartaric acid (Kanto Chemical Co., Ltd.) Succinic acid - Succinic acid (Kanto Chemical Co., Ltd.) Citric acid - Citric acid (Kanto Chemical Co., Ltd.) Adipic acid... Adipic acid (manufactured by Kanto Chemical Co., Ltd.) Oxalic anhydride - Oxalic anhydride (Kanto Chemical Co., Ltd.) Oxalic acid dihydrate - Oxalic acid dihydrate (Kanto Chemical Co., Ltd.) Fumaric acid - Fumaric acid (Kanto Chemical Co., Ltd.) Glutaric acid - Glutaric acid (Kanto Chemical Co., Ltd.) Isophthalic acid - Isophthalic acid (Kanto Chemical Co., Ltd.) Terephthalic acid - Terephthalic acid (Kanto Chemical Co., Ltd.) Aconitic acid - trans-aconitic acid (FUJIFILM Wako Pure Chemical Corporation) Benzoic acid - Benzoic acid (Kanto Chemical Co., Ltd.) Phthalic acid - Phthalic acid (manufactured by Kanto Chemical Co., Ltd.) Disodium phthalate - Disodium phthalate (manufactured by Kanto Chemical Co., Ltd.) Sodium benzenesulfonate - Sodium benzenesulfonate (manufactured by Kanto Chemical Co., Ltd.) Glycine - Glycine (Kanto Chemical Co., Ltd.) Aspartic acid - Aspartic acid (Kanto Chemical Co., Ltd.) Hydroxystearic acid - Hydroxystearic acid (Kanto Chemical Co., Ltd.) Maleic acid - Maleic acid (Kanto Chemical Co., Ltd.) Mellitic acid - Mellitic acid (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0042] [Table 1]

[0043] [Preparation of polyurethane ink] For each of the pigment compositions obtained in Examples 1 to 27 and Comparative Examples 1 to 22, 10 g of the pigment composition, 20 g of polyurethane resin Sanprene IB-501 (manufactured by Sanyo Chemical Industries, Ltd.), 13 g of ethyl acetate, 7 g of isopropyl alcohol, and 180 g of 1 / 8 inch steel beads (manufactured by Mochigi Steel Ball Bearing Co., Ltd.) were placed in a 250 mL polyethylene wide-mouth bottle and dispersed for 30 minutes using a paint shaker (manufactured by Toyo Seiki Seisakusho Co., Ltd.). Thereafter, 35 g of polyurethane resin Sanprene IB-501, 9.75 g of ethyl acetate, and 5.25 g of isopropyl alcohol were further added to the wide-mouth bottle and dispersed for 5 minutes using a paint shaker (manufactured by Toyo Seiki Seisakusho Co., Ltd.) to obtain each polyurethane ink. Further, polyurethane inks were obtained in the same manner from the organic pigments (organic pigments not containing acid compounds) used as raw materials in preparing the respective pigment compositions.

[0044] (Initial viscosity measurement of polyurethane ink) The obtained polyurethane ink was allowed to stand in a thermostatic chamber at 20° C. for at least 1 hour, and the viscosity was measured at a rotation speed of 60 rpm using an R85 ​​type viscometer RB85L (manufactured by Toki Sangyo Co., Ltd.).

[0045] (Measurement of viscosity over time of polyurethane ink) The obtained polyurethane ink was stored in a multi-safety dryer MSO-45TPH (manufactured by Futaba Chemical Co., Ltd.) at 50°C for 7 days, and then left to stand in a thermostatic chamber at 20°C for at least 1 hour, and the viscosity was measured at a rotation speed of 60 rpm using an R85 ​​type viscometer RB85L (manufactured by Toki Sangyo Co., Ltd.).

[0046] (Determination of dispersibility) The effect of improving dispersibility by the acid compound was calculated using the following formula. The smaller the calculated value, the better the dispersibility. [Initial viscosity of polyurethane inks with pigment compositions from Examples and Comparative Examples] / [Initial viscosity of polyurethane inks with organic pigments used as raw materials] In addition, when the value of the above formula was 25% or less, it was judged as ◎, when it was 25-50%, it was ◯, when it was 50-100%, it was △, and when it was 100% or more, it was judged as ×. In descending order of dispersibility, it is rated as ◎, ◯, △, and ×.

[0047] (Determination of Dispersion Stability) The effect of improving the dispersion stability by the acid compound was calculated using the following formula. The smaller the calculated value, the better the dispersion stability. [Temporal viscosity of polyurethane inks using pigment compositions from Examples and Comparative Examples] / [Temporal viscosity of polyurethane inks using organic pigments as raw materials] When the value of the above formula was 25% or less, it was judged as ⊚, when it was 25-50%, it was ◯, when it was 50-100%, it was △, and when it was 100% or more, it was judged as ×. The order of dispersion stability is ⊚, ◯, △, and ×.

[0048] The evaluation results of dispersibility and dispersion stability for the above polyurethane ink are shown in Table 2.

[0049] [Table 2]

[0050] As shown in Table 2, it was found that the pigment composition of the present invention using the organic pigment consisting of the benzimidazolone azo pigment or quinacridone pigment of Examples 1 to 27 and at least one polycarboxylic acid compound represented by formulas (I) to (III) had improved dispersibility and dispersion stability compared to the case of only the organic pigment without the polycarboxylic acid compound. On the other hand, it was found that the improvement in dispersibility and dispersion stability as in Examples 1 to 27 was not observed when an acid compound other than at least one polycarboxylic acid compound represented by formulas (I) to (III) of Comparative Examples 1 to 9 was used or when an organic pigment other than the benzimidazolone azo pigment or quinacridone pigment of Comparative Examples 10 to 22 was used. From the above, it can be said that the combination of the organic pigment consisting of the benzimidazolone azo pigment or quinacridone pigment in the pigment composition of the present invention and at least one polycarboxylic acid compound represented by formulas (I) to (III) specifically exhibits the effects of dispersibility and dispersion stability.

Claims

1. A composition comprising a binder resin and a colorant, The binder resin contains a urethane resin, The colorant contains a pigment composition, The pigment composition contains at least one organic pigment selected from the group consisting of benzimidazolone azo pigments and quinacridone pigments, and at least one polycarboxylic acid compound represented by the following formulas (I) to (III): The composition is a coating material, a printing ink, a colored molded product, a toner, a color filter, a black matrix, or an ink for ink-jet recording. 【Chemistry 1】 ... (I) (R in formula (I) １ represents an alkylene group which may be substituted with a hydroxyl group or a carboxyl group, or a single bond. 【Chemistry 2】 ... (II) (R in formula (II) ２ represents an alkyl group which may be substituted with a hydroxyl group or a carboxyl group. 【Chemistry 3】 ... (III) (R in formula (III) ３ is a carboxyl group or an alkyl group substituted with a carboxyl group, R ４ ~R ６ each independently represents a hydrogen atom, a hydroxyl group, a carboxyl group, or an alkyl group which may be substituted with a hydroxyl group or a carboxyl group; R ４ ~R ６ At least one of the groups is a carboxyl group or an alkyl group substituted with a carboxyl group.

2. The composition according to claim 1, wherein the content of the polycarboxylic acid compound is 0.01 to 20 parts by mass per 100 parts by mass of the organic pigment.

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