Pigment composition, method for producing same, ink, toner, coating material and resin molded product

Abstract

The present invention addresses the problem of providing a pigment composition which can be easily sieved, from which foreign objects can be easily removed and which, when used in an ink, can suppress an increase in viscosity of the ink.　Specifically, provided are: a pigment composition which contains C. I. Pigment Yellow 180 and a surfactant, and in which the content of the surfactant is 1.5-7.0 mass% relative to 100 mass% of the pigment composition; and an ink, a toner, a coating material and a resin molded product that are obtained using the pigment composition.　In addition, the present invention is also a method for producing a pigment composition, the method including at least: a mixing step for mixing C. I. Pigment Yellow 180, a surfactant and water to obtain a slurry of a pigment composition; and a heating step for heating the slurry. The content of the surfactant is 1.5-7.5 parts by mass relative to 100 parts by mass of the C. I. Pigment Yellow 180.

Description

Pigment composition, its method of manufacture, ink, toner, paint and resin molded product

[0001] The present invention relates to a pigment composition, a method for producing the same, and to an ink, a toner, a paint, and a resin molded product.

[0002] While many yellow pigments have safety concerns, C.I. Pigment Yellow 180 is highly safe and has strong weather resistance and other durability, and is therefore used in many applications such as inks, paints, plastics, toners, and inkjet inks. Because C.I. Pigment Yellow 180 is used in a variety of applications, efforts have been made to improve its physical properties (Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2002-201379

[0004] In Patent Document 1, the physical properties of C.I. Pigment Yellow 180 are improved by adjusting the pH during the coupling reaction or by using a surface treatment agent, but there is still room for improvement. For example, while polyoxyalkylene alkyl ether treatment is performed to improve the pigment's wettability, the presence of polyoxyalkylene alkyl ether causes a problem of a slower sieving speed of the yellow pigment composition and a reduced work efficiency in the dispersion process. Therefore, an object of the present invention is to provide a pigment composition that is easy to sieve, easy to remove foreign matter from, and can suppress an increase in the viscosity of ink when used in ink.

[0005] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by using C.I. Pigment Yellow 180 and a predetermined amount of a surfactant, and have thus completed the present invention. An example of the configuration of the present invention that solves the above-mentioned problems is as follows.

[0006] Item 1. A pigment composition comprising C.I. Pigment Yellow 180 and a surfactant, wherein the content of the surfactant in 100% by mass of the pigment composition is 1.5 to 7.0% by mass.

[0007] Item 2. The pigment composition according to Item 1, wherein the surfactant is a nonionic surfactant.

[0008] Item 3. The pigment composition according to Item 1 or 2, wherein the ratio (h1 / h2) of the absolute intensity (h1) of X-ray diffraction at a Bragg angle 2θ = 17.5° ± 0.2° to the absolute intensity (h2) of X-ray diffraction at the same Bragg angle 2θ = 18.2° ± 0.2° in a powder X-ray diffraction pattern using CuKα characteristic X-rays of the pigment composition is 2.00 to 10.00.

[0009] Item 4. The specific surface area of ​​the pigment composition is 40 m ２ / g or more.

[0010] Item 5. The sieving speed of the pigment composition is 3.10 mg / (cm ２ 5. The pigment composition according to any one of items 1 to 4, wherein the viscosity is 1 / 2 s or more.

[0011] Item 6. An ink containing the pigment composition according to any one of items 1 to 5.

[0012] Item 7. A toner comprising the pigment composition according to any one of items 1 to 5.

[0013] Item 8. A paint comprising the pigment composition according to any one of items 1 to 5.

[0014] Item 9. A resin molded product comprising the pigment composition according to any one of items 1 to 5.

[0015] Item 10. A method for producing a pigment composition, comprising at least a mixing step of mixing C.I. Pigment Yellow 180, a surfactant, and water to obtain a slurry of the pigment composition, and a heating step of heating the slurry, wherein the amount of the surfactant added per 100 parts by mass of the C.I. Pigment Yellow 180 is 1.5 to 7.5 parts by mass.

[0016] According to the present invention, it is possible to provide a pigment composition that is easy to sieve and from which foreign matter can be easily removed. Furthermore, the pigment composition according to the present invention has good wettability with respect to a pigment solvent, and therefore, when used in an ink, it is possible to suppress an increase in the viscosity of the ink.

[0017] (C.I. Pigment Yellow 180) The pigment composition according to the present invention contains C.I. Pigment Yellow 180. C.I. Pigment Yellow 180 is a compound represented by the following formula (1). Note that C.I. Pigment Yellow 180 is an azo-hydrazo tautomer, and therefore may contain both an azo form (—N═N—) and a hydrazo form (>N—NH—).

[0018]

[0019] C.I. Pigment Yellow 180 may be synthesized or commercially available. The content of C.I. Pigment Yellow 180 in 100% by mass of the pigment composition is preferably 93.0 to 98.5% by mass, preferably 93.5 to 98.0% by mass, and preferably 94.0 to 97.0% by mass, because an excessively small content of C.I. Pigment Yellow 180 reduces coloring strength, while an excessively large content leaves no room for adding a treatment agent for the purpose of improving physical properties.

[0020] (Surfactant) The pigment composition according to the present invention contains a surfactant. Examples of the surfactant include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. However, from the viewpoint of work efficiency during dispersion, nonionic surfactants are preferred. As the nonionic surfactant, polyoxyalkylene alkyl ethers are preferred. As the polyoxyalkylene alkyl ethers, polyoxyethylene polyoxypropylene lauryl ether, polyoxyethylene polyoxypropylene tridecyl ether, polyoxyethylene polyoxypropylene branched decyl ether, polyoxyethylene lauryl ether, polyoxyethylene isodecyl ether, polyoxyethylene polyoxypropylene oleyl cetyl ether, etc. are preferred.

[0021] From the viewpoint of improving adsorption to the pigment and wetting of the pigment, the HLB value of the surfactant is preferably 1 to 19, preferably 2 to 18, preferably 5 to 15, and preferably 8 to 12. In this specification, "HLB (Hydrophile-Lipophile Balance)" is a value proposed by Griffin that indicates the balance between hydrophilic groups and lipophilic groups in a surfactant molecule. This HLB value can be determined experimentally by comparing the emulsifying power of various surfactants, but can typically be calculated from the following formula 1. Formula 1: HLB value = 20 × weight % of hydrophilic portion of surfactant / molecular weight of surfactant

[0022] The cloud point of the surfactant is preferably 35°C or higher, preferably 35 to 100°C, and preferably 60 to 80°C, from the viewpoint of avoiding phase separation of the surfactant and treating C.I. Pigment Yellow 180. In this specification, the "cloud point" refers to the temperature at which the transparency of an aqueous surfactant solution decreases and the solution begins to become cloudy and white when heated. The cloud point is measured under conditions selected from a 1% by mass aqueous solution of the surfactant, a 1% by mass aqueous solution (containing 5% by mass potassium sulfate), a 10% by mass aqueous solution (containing 25% by mass diethylene glycol monobutyl ether), and the like, depending on the solubility of the surfactant in water.

[0023] The surfactant may be used alone or in combination of two or more. Commercially available surfactants can be used. The content of the surfactant in the pigment composition (100% by mass) is 1.5 to 7.0% by mass, preferably 2.0 to 6.5% by mass, and preferably 3.0 to 6.0% by mass. If the content of the surfactant in the pigment composition (100% by mass) is less than 1.5% by mass, the pigment's wettability with respect to the solvent cannot be sufficiently ensured, and therefore, when the pigment composition is used in an ink, the increase in the ink viscosity cannot be sufficiently suppressed. Furthermore, if the content of the surfactant in the pigment composition (100% by mass) exceeds 7.0% by mass, the surfactant attracts water molecules in the environment, resulting in a large amount of water molecules adsorbing onto the surface of the pigment powder. As a result, when the pigment composition is sieved, the powder particles of the pigment composition tend to clump together, clogging the sieve, slowing the sieving speed and reducing work efficiency.

[0024] (Other Components) The pigment composition may contain other components other than C.I. Pigment Yellow 180 and surfactants, as needed, as long as the effects of the present invention are not impaired. Examples of other components include pigment derivatives, inorganic pigments, dispersants, rosin, and polycarboxylic acid compounds. 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 polycarboxylic acid compound 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, sebacic acid, aconitic acid, fumaric acid, mesaconic acid, isophthalic acid, terephthalic acid, trimesic acid, benzenetricarboxylic acid, methylisophthalic acid, hydroxyisophthalic acid, methylterephthalic acid, hydroxyterephthalic acid, and phenylene diacetic acid.

[0025] (Pigment Composition) The hue of the pigment composition is preferably yellow (yellow pigment composition).

[0026] In the pigment composition, the ratio (h1 / h2) of the absolute intensity (h1) of the X-ray diffraction at a Bragg angle 2θ = 17.5° ± 0.2° in a powder X-ray diffraction pattern using CuKα characteristic X-rays to the absolute intensity (h2) of the X-ray diffraction at 2θ = 18.2° ± 0.2° is preferably 2.00 to 10.00, preferably 2.50 to 4.00, and preferably 2.50 to 3.75, since higher crystallinity leads to stronger solvent resistance and improved dispersion stability in the ink, enabling the ink viscosity to be maintained low. The ratio (h1 / h2) of the absolute intensity (h1) of the X-ray diffraction at a Bragg angle 2θ = 17.5° ± 0.2° in a powder X-ray diffraction pattern using CuKα characteristic X-rays to the absolute intensity (h2) of the X-ray diffraction at the same Bragg angle 2θ = 18.2° ± 0.2° was measured using an Empyrean multipurpose X-ray diffractometer (manufactured by Malvern Panalytical Co., Ltd.) First, the pigment composition was filled into a measurement cell, and the pigment powder was pressed with fingers from the side opposite the measurement surface onto a smooth glass plate (a 500 mL bell glass plate, manufactured by Shibata Scientific Co., Ltd.) to smooth the measurement surface, and then the cell was set in the X-ray diffractometer. A powder X-ray diffraction pattern was obtained by scanning at a scan step size of 0.0262 and a time per step of 4.59. The maximum intensity of the peaks present at a Bragg angle 2θ = 17.5° ± 0.2° in the obtained powder X-ray diffraction pattern was defined as the absolute intensity of X-ray diffraction (h1), and the minimum intensity of the valleys present at a Bragg angle 2θ = 18.2° ± 0.2° was defined as the absolute intensity of X-ray diffraction (h2), and the absolute intensity ratio (h1 / h2) was calculated.

[0027] The specific surface area of ​​the pigment composition is preferably 40 m from the viewpoint of the coloring power and dispersibility of the pigment composition. ２ / g or more, preferably 40 to 80m ２ / g, preferably 40 to 60 m ２ The specific surface area was measured by measuring the gas (nitrogen) adsorption amount by the single-point method using 200 mg of the pigment composition and a fully automatic specific surface area measuring device, Macsorb HM model-1208 (manufactured by Mountec Co., Ltd.).

[0028] When producing a pigment composition or charging the pigment composition into a disperser, the pigment is passed through a sieve to prevent foreign matter from being filtered out. If the sieve becomes clogged, there is a concern that workability will be reduced. However, the pigment composition according to the present invention is excellent in workability, for example, in sieving speed. From the viewpoint of work efficiency, the sieving speed of the pigment composition is preferably 3.10 mg / (cm ２ ·sec) or more, preferably 3.10 to 4.10 mg / (cm ２ ·sec), preferably 3.10 to 4.00 mg / (cm ２ The sieving speed was measured as follows. First, 10.0 g of the pigment composition was placed on a sieve (manufactured by Fujiwara Seisakusho Co., Ltd., mesh size 355 μm, wire diameter 224 μm, diameter 10 cm), and the sieve was vibrated laterally for 20 seconds at an amplitude of 5 cm and a vibration frequency of 3 Hz (3 reciprocations per second), and the weight of the pigment composition that passed through the sieve was measured. Next, the sieving speed was determined by dividing the weight that passed by the sieving time and the area of ​​the sieve.

[0029] (Method for Producing Pigment Composition) The pigment composition according to the present invention can be produced, for example, by a method for producing a pigment composition that includes at least a mixing step of mixing C.I. Pigment Yellow 180, a surfactant, and water to obtain a slurry of the pigment composition, and a heating step of heating the slurry, in which the amount of the surfactant added is 1.5 to 7.5 parts by mass per 100 parts by mass of the C.I. Pigment Yellow 180.

[0030] The amount of the surfactant added relative to 100 parts by mass of CI Pigment Yellow 180 is 1.5 to 7.5 parts by mass, preferably 2.0 to 7.0 parts by mass, and more preferably 3.5 to 6.5 parts by mass.

[0031] The mixing temperature in the mixing step is preferably 15 to 90° C., preferably 20 to 80° C., and preferably 20 to 40° C., from the viewpoint of uniformly treating the pigment particle surfaces with the surfactant. The mixing time in the mixing step is preferably 0.1 to 180 minutes, preferably 0.2 to 120 minutes, and preferably 30 to 90 minutes, from the viewpoint of uniformly treating the pigment particle surfaces with the surfactant.

[0032] The amount of water used may be an amount sufficient to obtain a slurry. The amount of water used is preferably 10 to 1,000 parts by mass, preferably 10 to 100 parts by mass, and preferably 10 to 50 parts by mass per part by mass of C.I. Pigment Yellow 180. Furthermore, the amount of water used is preferably 50 to 10,000 parts by mass, preferably 100 to 5,000 parts by mass, preferably 150 to 2,000 parts by mass, and preferably 300 to 1,500 parts by mass per part by mass of the surfactant.

[0033] The pH of the pigment composition slurry is preferably 9.5 to 11.5 from the viewpoint of elongating the pigment particles and enhancing crystallinity. In this specification, pH refers to the value measured for a pigment composition slurry at 25°C using a pH meter (product name: Personal pH / ORP Meter PH72, manufactured by Yokogawa Electric Corporation). The pH of the pigment composition slurry can be adjusted by using a basic compound. Examples of basic compounds include alkali metal hydroxides and alkaline earth metal hydroxides. Examples of alkali metal hydroxides include sodium hydroxide and potassium hydroxide. Examples of alkaline earth metal hydroxides include calcium hydroxide. The basic compound may be used in an amount that allows the slurry to have the desired pH.

[0034] The mixing step can be carried out using a stirrer, mixer, shaker, rotator, homogenizer, or the like.

[0035] The heating temperature in the heating step is preferably 40 to 160°C, preferably 80 to 160°C, and preferably 120 to 150°C, from the viewpoints of uniformly treating the pigment particle surfaces with the surfactant and enhancing the crystallinity of the pigment. The heating time in the heating step is preferably 0.5 to 24 hours, preferably 1 to 12 hours, and preferably 3 to 12 hours, from the viewpoints of uniformly treating the pigment particle surfaces with the surfactant and enhancing the crystallinity of the pigment. The heating step can be carried out using an autoclave, a mantle heater, a hot plate, a block bath, a water bath, an oil bath, a bead bath, an immersion heater, an electromagnetic heater, a microwave heater, steam blowing, or the like.

[0036] After the heating step, a filtration step of performing filtration, a water washing step of performing water washing, a drying step of performing drying, and a pulverization step of performing pulverization may be performed as necessary.

[0037] (Ink) The ink according to the present invention is characterized by containing the pigment composition described above. Examples of the ink include ink for lithographic printing, gravure ink, flexographic ink, metal ink, screen ink, UV ink, resist ink for producing color filters, and inkjet ink.

[0038] (Toner) The toner according to the present invention is characterized by containing the pigment composition described above. The toner is preferably a toner for developing electrostatic images. Examples of toner for developing electrostatic images include one-component magnetic toners (color toners for magnetic one-component development) that contain a magnetic material in the toner, two-component magnetic toners (color toners for magnetic two-component development) that are charged by mixed friction with a magnetic carrier, one-component non-magnetic color toners (color toners for non-magnetic one-component development) that do not contain a magnetic material, and two-component non-magnetic color toners (color toners for non-magnetic two-component development) that contain a carrier.

[0039] (Paint) The paint according to the present invention is characterized by containing the above-mentioned pigment composition. Examples of the paint include architectural paint, automotive paint, automotive repair paint, marine paint, general industrial paint, and woodwork paint.

[0040] (Resin Molded Product) The resin molded product according to the present invention is characterized by comprising the pigment composition described above. Examples of the resin molded product include thermoplastic resin molded products and thermosetting resin molded products, and specific examples thereof include polyester resins, polyamide resins, styrene resins (PS resins, AS resins, ABS resins, etc.), acrylic resins, polyolefin resins (polyethylene resins, polyester resins, etc.), polyalkylene terephthalate resins (polyethylene terephthalate resins, polybutylene terephthalate resins, etc.), polyvinyl chloride resins, methylpentene resins, polycarbonate resins, polyurethane resins, polyacetal resins, fluororesins (PTFE resins, etc.), polyethersulfone resins, polyphenylene sulfide resins, and polyetheretherketone resins.

[0041] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples in any way.

[0042] (Production Example 1) Preparation of Crude Wet Cake of C.I. Pigment Yellow 180 After dispersing 225 parts by mass of 1,2-bis(2-aminophenoxy)-ethane in 3,300 parts by mass of water, 538.5 parts by mass of 35% by mass hydrochloric acid was added, and while adding ice to maintain the temperature at 5°C or below, 337 parts by mass of a 40% by mass aqueous solution of sodium nitrite was added dropwise to prepare a diazo component. Next, 455 parts by mass of 5-acetoacetylamino-benzimidazolone was dispersed in 3,400 parts by mass of water, and 595 parts by mass of a 25% by mass aqueous solution of sodium hydroxide was added and dissolved to obtain a coupler component. The liquid volumes of the diazo component and coupler component were adjusted to 6,500 parts by mass and 4,500 parts by mass, respectively, by adding water and ice. Next, 30.6 parts by mass of 90% by mass acetic acid was added to 6,500 parts by mass of water, and the temperature of this acetic acid solution was adjusted to 20°C. Then, a portion of the coupler component was added dropwise to the acetic acid solution until the pH reached 6.0. Thereafter, the dropwise addition of the diazo component to the acetic acid solution was initiated at a constant rate. The dropwise addition of the remaining coupler component was initiated simultaneously with the dropwise addition of the diazo component so as to prevent the presence of excess diazonium salt in the acetic acid solution, and the coupling was carried out while maintaining the pH of the acetic acid solution at 6.0 by adjusting the dropwise addition rate of the coupler component. During coupling, ice or a 5% by mass sodium hydroxide solution was added as needed to maintain the temperature of the reaction solution at 20°C and the pH at 6.0. The dropwise addition of the coupler component and diazo component was then completed in about 3 hours, and the mixture was then heated to 90°C and maintained for 1 hour. The mixture was then filtered and washed with water to obtain a wet cake of C.I. Pigment Yellow 180 crude. The solids content of the C.I. Pigment Yellow 180 crude wet cake was 34.1% by mass.

[0043] (Example 1) Preparation of Yellow Pigment Composition 1 A 2L beaker was charged with 103 parts by mass of C.I. Pigment Yellow 180 crude wet cake (solids content 34.1% by mass), 660 parts by mass of water, and 0.70 parts by mass of a nonionic surfactant (polyoxyethylene lauryl ether, HLB value: 10.8, cloud point: 69 ° C. (measured as a 10% by mass aqueous solution (containing 25% by mass of diethylene glycol monobutyl ether))) and stirred with an anchor-type stirring blade A-80 (manufactured by AS ONE Corporation) at 25 ° C. for 1 hour. After stirring, a 5% by mass aqueous sodium hydroxide solution was added to obtain a slurry of a yellow pigment composition in which the pH was adjusted to 10.5. In the resulting slurry of the yellow pigment composition, the amount of water was 21 parts by mass per part by mass of C.I. Pigment Yellow 180, and 1,040 parts by mass per part by mass of the nonionic surfactant. Next, the pigment slurry was transferred to a 1 L autoclave (manufactured by Taiatsu Glass Kogyo Co., Ltd.), heated to 140°C over 3 hours, and maintained at 140°C for 7 hours. After cooling to room temperature, the autoclave was filtered and washed with water, and the resulting wet cake of yellow pigment composition was dried at 100°C for 12 hours in a constant temperature air blower dryer WFO-520 (manufactured by Tokyo Rikakikai Co., Ltd.). Next, the entire amount of the resulting dried lamp was charged into a large mill cup (200 mL capacity) of a portable laboratory mill LAB MILL (manufactured by Osaka Chemical Co., Ltd.), and milled for 30 seconds, to obtain Yellow Pigment Composition 1.

[0044] (Example 2) Production of Yellow Pigment Composition 2 Yellow pigment composition 2 was obtained by the same procedure as in Example 1, except that the amount of nonionic surfactant added in Example 1 was changed to 1.40 parts by mass. In the slurry of the yellow pigment composition, the amount of water was 21 parts by mass per part by mass of C.I. Pigment Yellow 180, and 520 parts by mass per part by mass of the nonionic surfactant.

[0045] (Example 3) Production of Yellow Pigment Composition 3 Yellow pigment composition 3 was obtained by the same procedure as in Example 1, except that the amount of nonionic surfactant added in Example 1 was changed to 2.10 parts by mass. In the slurry of the yellow pigment composition, the amount of water was 21 parts by mass per part by mass of C.I. Pigment Yellow 180, and 345 parts by mass per part by mass of the nonionic surfactant.

[0046] (Example 4) Production of Yellow Pigment Composition 4 Yellow pigment composition 4 was obtained by the same procedure as in Example 1, except that the amount of nonionic surfactant added in Example 1 was changed to 1.23 parts by mass. In the slurry of the yellow pigment composition, the amount of water was 21 parts by mass per part by mass of C.I. Pigment Yellow 180, and 594 parts by mass per part by mass of the nonionic surfactant.

[0047] (Comparative Example 1) Preparation of Yellow Pigment Composition A Yellow pigment composition A was obtained by the same procedure as in Example 1, except that the amount of nonionic surfactant added in Example 1 was zero. In the slurry of the yellow pigment composition, the amount of water was 21 parts by mass per part by mass of C.I. Pigment Yellow 180.

[0048] (Comparative Example 2) Preparation of Yellow Pigment Composition B The same procedure as in Example 1 was carried out, except that the amount of nonionic surfactant added in Example 1 was changed to 2.80 parts by mass, to obtain Yellow Pigment Composition B. In the slurry of the yellow pigment composition, the amount of water was 21 parts by mass per part by mass of C.I. Pigment Yellow 180, and 260 parts by mass per part by mass of the nonionic surfactant.

[0049] <Evaluation of Pigment Composition> The absolute intensity ratio (h1 / h2) in X-ray diffraction, specific surface area, sieving speed, and ink viscosity of the produced pigment composition were measured. The results are shown in Table 1. The ink viscosity was measured as follows. First, 6.0 g of the yellow pigment composition, 24.0 g of polyamide (PA) gravure varnish (manufactured by DIC Corporation), 4.2 g of toluene (manufactured by Kanto Chemical Co., Ltd.), 0.9 g of ethyl acetate (manufactured by Kanto Chemical Co., Ltd.), 0.9 g of isopropanol (manufactured by Kanto Chemical Co., Ltd.), and 120 g of 1 / 8-inch steel beads (manufactured by Mochigi Steel Ball Bearing Co., Ltd.) were placed in a 100 mL polyethylene wide-mouth bottle and dispersed for 30 minutes using a paint shaker (manufactured by Toyo Seiki Seisaku-sho, Ltd.). Next, 12.0 g of polyamide gravure varnish (manufactured by DIC Corporation) and 12.0 g of nitrocellulose (NC) varnish (manufactured by DIC Corporation) were added, and the mixture was dispersed for 5 minutes to obtain a PA / NC ink. The prepared PA / NC ink was transferred to a glass bottle (tableware bottle M-70, manufactured by Kakuyo Glass Co., Ltd.) and allowed to stand at 50°C for 7 days in a multi-safety dryer MSO-45TPH (manufactured by Futaba Chemical Co., Ltd.). Subsequently, the PA / NC ink was allowed to stand in a thermostatic chamber at 20°C for at least 1 hour, and then the ink viscosity was measured using an R85 ​​type viscometer RB85L (manufactured by Toki Sangyo Co., Ltd.) at a rotation speed of 60 rpm.

[0050]

[0051] From the examples and comparative examples, it was confirmed that the pigment composition according to the present invention has a good sieving speed. Furthermore, it was confirmed that the pigment has good wettability with respect to solvents, and therefore, when used in ink, it is possible to suppress an increase in the viscosity of the ink.

[0052] The pigment composition of the present invention can be used in inks, toners, paints, and resin molded products.

Claims

1. A pigment composition comprising C.I. Pigment Yellow 180 and a surfactant, wherein the content of the surfactant in 100% by mass of the pigment composition is 1.5 to 7.0% by mass.

2. The pigment composition according to claim 1, wherein the surfactant is a nonionic surfactant.

3. The pigment composition according to claim 1 or 2, wherein the ratio (h1 / h2) of the absolute intensity (h1) of the X-ray diffraction at a Bragg angle 2θ = 17.5° ± 0.2° to the absolute intensity (h2) of the X-ray diffraction at the same 2θ = 18.2° ± 0.2° in the powder X-ray diffraction pattern of the pigment composition by CuKα characteristic X-rays is 2.00 to 10.

00.

4. The specific surface area of the pigment composition is 40 m ２ / g or more, and the pigment composition according to any one of claims 1 to 3.

5. The sieving rate of the pigment composition is 3.10 mg / (cm ２ · second) or more, and the pigment composition according to any one of claims 1 to 4.

6. An ink comprising the pigment composition according to any one of claims 1 to 5.

7. A toner comprising the pigment composition according to any one of claims 1 to 5.

8. A paint comprising the pigment composition according to any one of claims 1 to 5.

9. A resin molded article comprising the pigment composition according to any one of claims 1 to 5.

10. A method for producing a pigment composition, comprising at least a mixing step of obtaining a slurry of the pigment composition by mixing C.I. Pigment Yellow 180, a surfactant, and water, and a heating step of heating the slurry, wherein the addition amount of the surfactant with respect to 100 parts by mass of C.I. Pigment Yellow 180 is 1.5 to 7.5 parts by mass.

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