Pigment composition, composition for color filter, and method for producing pigment composition

Abstract

Provided is a pigment composition comprising an isoindoline-based pigment (1) and a quinophthalone sulfonate derivative (2), said pigment composition having, in a powder X-ray diffraction pattern using CuKα radiation as an X-ray source, a diffraction peak at a position where a Bragg angle θ is (27.1°±0.5°) / 2, and having a crystallite diameter of not more than 15.5 nm, as calculated by the Scherrer equation using the Bragg angle θ and the full width at half maximum B of the diffraction peak.

Description

Pigment composition, color filter composition, and method for producing the pigment composition

[0001] This disclosure relates to a pigment composition, a color filter composition, and a method for producing a pigment composition.

[0002] A color filter used in a liquid crystal display device generally comprises a transparent substrate such as glass and a colored pixel area formed thereon. The colored pixel area includes red, green, and blue pixels, and in these pixels, in addition to the main pigment corresponding to each color (red pigment, green pigment, and blue pigment), a secondary pigment (for example, yellow pigment) is used (see, for example, Patent Document 1).

[0003] In addition to the pigments, additives may be used in the color filter composition used to form the above-mentioned pixel portions, for purposes such as controlling the crystal growth of the pigments. Generally, such additives are compounds having a structure similar to the pigment, such as pigment derivatives, taking into consideration their affinity with the pigment (see, for example, Patent Documents 2 and 3).

[0004] Japanese Unexamined Patent Publication No. 2010-224309, U.S. Patent No. 6,849116, International Publication No. 2021 / 117410, Japanese Unexamined Patent Publication No. 2007-71924, Japanese Patent No. 7105024, Japanese Patent No. 6893277, Japanese Unexamined Patent Publication No. 2019-104822, International Publication No. 2015 / 118720, Japanese Unexamined Patent Publication No. 2014-002314

[0005] One aspect of this disclosure aims to provide a pigment composition that can improve the contrast of the green pixel area.

[0006] As a result of the inventors' investigations, it was surprisingly discovered that, in the production of a yellow pigment containing an isoindoline pigment, grinding the isoindoline pigment in the presence of a quinophthalone sulfonic acid derivative yields a fine pigment composition with a small crystallite size. This provides superior effects that cannot be obtained by using other additives (e.g., derivatives of isoindoline pigments) or by simply mixing the isoindoline pigment with a quinophthalone sulfonic acid derivative. This disclosure is based on these findings.

[0007] This disclosure provides at least the following [1] to

[14] .

[0008] [1] A pigment composition comprising an isoindoline pigment (1) and a quinophthalone sulfonic acid derivative (2), wherein, in a powder X-ray diffraction pattern using CuKα rays as the X-ray source, the diffraction peak is located at a position where the Bragg angle θ is (27.1° ± 0.5°) / 2, and the crystallite size calculated by Scherrer's formula using the Bragg angle θ and the full width at half maximum B of the diffraction peak is 15.5 nm or less. [2] The isoindoline pigment (1) is a derivative of the following formulas (1-1) to (1-8) The pigment composition according to [1], comprising at least one compound selected from the group consisting of compounds represented by [1]. [3] The quinophthalone sulfonic acid derivative (2) is one of the following formulas (2-1) to (2-6) A pigment composition according to [1] or [2], comprising at least one compound selected from the group consisting of compounds represented by the following formulas: [In formulas (2-1) to (2-6), each of the multiple X's independently represents a hydrogen atom, a halogen atom, a sulfonic acid group, or a sulfonic acid base. However, at least one of the multiple X's in each formula is a sulfonic acid group or a sulfonic acid base.] [4] A pigment composition according to any one of [1] to [3], wherein the content of the isoindoline pigment (1) is 80 to 99% by mass based on the total mass of the pigment composition, and the content of the quinophthalone sulfonic acid derivative (2) is 1 to 20% by mass based on the total mass of the pigment composition. [5] A pigment composition according to any one of [1] to [4], further comprising a rosin compound (3). [6] The rosin compound (3) is represented by the following formulas (3-1) to (3-2) A pigment composition according to [5], comprising at least one compound selected from the group consisting of compounds represented by [1]. [7] A pigment composition according to [5] or [6], wherein the content of the rosin compound (3) is 0.1 to 15% by mass, based on the total mass of the pigment composition. [8] A pigment composition according to any one of [1] to [7], further comprising at least one selected from the group consisting of castor oil, castor oil sulfonic acid, and castor oil sulfonate. [9] A pigment composition according to [8], wherein the total content of the castor oil, castor oil sulfonic acid, and castor oil sulfonate is 1 to 10% by mass, based on the total mass of the pigment composition.

[10] A color filter composition comprising the pigment composition according to any one of [1] to [9] and a zinc halide phthalocyanine pigment.

[11] A color filter composition according to

[10] , further comprising a polymer dispersant.

[12] A method for producing a pigment composition comprising an isoindoline pigment (1) and a quinophthalone sulfonic acid derivative (2), the method comprising a grinding step of grinding the isoindoline pigment (1) together with the quinophthalone sulfonic acid derivative (2).

[13] The method according to

[12] , wherein in the grinding step, the isoindoline pigment (1) is ground together with the quinophthalone sulfonic acid derivative (2) and a rosin compound (3).

[14] The method according to

[12] or

[13] , wherein in the grinding step, the isoindoline pigment (1) is ground together with the quinophthalone sulfonic acid derivative (2) and at least one selected from the group consisting of castor oil, castor oil sulfonic acid, and castor oil sulfonate.

[0009] According to one aspect of this disclosure, the contrast of the green pixel area can be improved.

[0010] The following describes exemplary embodiments of the present invention. However, the present invention is not limited in any way to the embodiments described below. In this specification, numerical ranges indicated using "~" indicate a range that includes the numerical values ​​before and after "~" as the minimum and maximum values, respectively. Also, unless otherwise explicitly stated, the units of the numerical values ​​before and after "~" are the same. Furthermore, the upper and lower limits described individually can be combined in any way. Also, the description "A and / or B" means at least one of A and B.

[0011] <Pigment Composition> One aspect of this disclosure is a pigment composition (hereinafter referred to as "Pigment Composition (A)") comprising an isoindoline pigment (1) and a quinophthalone sulfonic acid derivative (2).

[0012] The pigment composition (A) is a powdered mixed material and can itself be called a pigment. Individual particles in the pigment composition (A) may be composite particles containing, for example, a compound constituting an isoindoline pigment (1) (hereinafter referred to as "isoindoline compound") and a quinophthalone sulfonic acid derivative (2). That is, the pigment composition (A) may contain composite particles containing an isoindoline compound and a quinophthalone sulfonic acid derivative (2). The composite particles may be, for example, particles having a core containing an isoindoline compound and a shell covering the core and containing a quinophthalone sulfonic acid derivative (2).

[0013] Pigment composition (A) has a diffraction peak in a powder X-ray diffraction pattern using CuKα rays as the X-ray source, at a position where the Bragg angle θ is (27.1° ± 0.5°) / 2. In powder X-ray diffraction measurement, the angle between the X-ray source and the sample surface is θ, and the X-ray source and detector are moved so that the angle between the X-ray source and the detector is 2θ. The relationship between the detector angle 2θ and the intensity of the detected X-rays is recorded as an X-ray diffraction pattern. In the X-ray diffraction pattern, the detector angle 2θ at the position of the diffraction peak (peak top position) is called the diffraction angle, and θ at the diffraction angle 2θ is called the Bragg angle.

[0014] In this embodiment, the crystallite size of the pigment composition (A), calculated by Scherrer's formula using the Bragg angle θ and the full width at half maximum B of the diffraction peak, is 15.5 nm or less. The crystallite size of the pigment composition correlates with the primary particle size of the pigment composition; a smaller crystallite size means a smaller primary particle size and a finer pigment composition.

[0015] Here, Scherrer's equation is an equation that expresses the relationship between the width of the diffraction peak in an X-ray diffraction pattern and the crystallite size, and is specifically expressed by the following equation (1): Crystallite size = Kλ / βcosθ ... (1) In equation (1), K represents Scherrer's constant, λ represents the wavelength of the X-ray used in the measurement (1.5418 Å for CuKα rays), β represents the full width at half maximum of the diffraction peak, and θ represents the Bragg angle.

[0016] The X-ray diffraction pattern and crystallite size can be determined, for example, by measuring them using an X-ray diffractometer SmartLab 9kW (manufactured by Rigaku) ​​under the conditions of 2θ = 1 to 40°, step size: 0.02°, and scan speed: 2.0° / min, and then using the refinement function of the automated data processing using the integrated powder analysis software PDXL2 (manufactured by Rigaku). In this case, a Scherrer constant of 0.9400 is used.

[0017] Pigment composition (A), when used as a yellow pigment in the green pixel area, has the function of improving the contrast of the green pixel area. In other words, pigment composition (A) can improve the contrast of the green pixel area. Furthermore, pigment composition (A) tends to improve the brightness of the green pixel area.

[0018] The reason for the above effects is not entirely clear, but it is thought that the quinophthalone sulfonic acid derivative (2) has high color purity among pigment derivatives, and that the quinophthalone sulfonic acid derivative (2) contributes to suppressing crystal growth and improving dispersibility of the isoindoline pigment (1) during the production of pigment composition (A), resulting in pigment composition (A) being a fine pigment composition with the above-mentioned specific crystallite size. The high color purity of the quinophthalone sulfonic acid derivative (2) is thought to be due to the excellent acid and heat resistance of the quinophthalone skeleton, which makes it difficult to decompose during the synthesis of sulfonic acid derivatives using sulfuric acid.

[0019] From the viewpoint of obtaining the above effects more significantly, the crystallite size is preferably 15.0 nm or less, and more preferably 14.5 nm or less. From a similar viewpoint, the crystallite size is preferably 2.0 nm or more, and more preferably 6.0 nm or more. From these viewpoints, the crystallite size is preferably 2.0 to 15.5 nm, more preferably 2.0 to 15.0 nm, and even more preferably 6.0 to 14.5 nm.

[0020] (Isoindoline Pigments) Isoindoline pigments (1) are composed of isoindoline compounds. An isoindoline compound is a compound having an isoindoline skeleton (a skeleton in which a benzene ring and a pyrrolidine ring are bonded with one side sharing). Known compounds used as isoindoline pigments can be used as isoindoline compounds. Note that pigments such as C.I. Pigment Yellow 109, 110, and 173 are sometimes called isoindolinone pigments to distinguish them from isoindoline pigments, but the above isoindoline compounds may also have an isoindolinone skeleton (a skeleton in which a benzene ring and a pyrrolidinenon ring are bonded with one side sharing), and pigments such as those commonly called isoindolinone pigments are also included in the above isoindoline pigments. As an isoindoline compound, one compound may be used alone, or two or more compounds may be used in combination.

[0021] The isoindoline pigment (1) preferably contains at least one compound selected from the group consisting of compounds represented by the following formulas (1-1) to (1-8), and more preferably contains at least one compound selected from the group consisting of compounds represented by the following formulas (1-1) and (1-6), from the viewpoint of enhancing coloring power, obtaining better contrast, and obtaining better brightness.

[0022]

[0023] The compounds represented by formulas (1-1), (1-3), and (1-6) to (1-8) are known as pigment yellow 185, pigment yellow 139, pigment orange 66, pigment orange 69, etc., and are available commercially. The compound represented by formula (1-2) can be produced by the method described in Production Example 2 of Patent Document 4 (Japanese Patent Publication No. 2007-71924). The compound represented by formula (1-4) can be produced by the method described in Production Example 1-10 of Patent Document 5 (Japanese Patent No. 7105024). The compound represented by formula (1-5) can be produced by the method described in Production Example 2-2 of Patent Document 6 (Japanese Patent No. 6893277).

[0024] In one embodiment, it is preferable that the content (total amount) of the compounds represented by formulas (1-1) to (1-8) in the isoindoline pigment (1) is 90 to 100% by mass, based on the total mass of the isoindoline pigment (1).

[0025] In one embodiment, it is preferable that the content (total amount) of the compounds represented by formulas (1-1) to (1-6) in the isoindoline pigment (1) is 90 to 100% by mass, based on the total mass of the isoindoline pigment (1).

[0026] In one embodiment, it is preferable that the content of the compound represented by formula (1-1) in the isoindoline pigment (1) is 90 to 100% by mass, based on the total mass of the isoindoline pigment (1).

[0027] The content of the isoindoline-based pigment (1) may be 75% by mass or more, 80% by mass or more, or 99% by mass or more, may be 99% by mass or less, 97% by mass or less, or 95% by mass or less, and may be 75 to 99% by mass, based on the total mass of the pigment composition (A). From the viewpoints of enhancing coloring power, obtaining better contrast, and obtaining better luminance, the content of the isoindoline-based pigment (1) is preferably 80 to 99% by mass, more preferably 85 to 97% by mass, and even more preferably 90 to 95% by mass, based on the total mass of the pigment composition (A).

[0028] (Quinophthalone sulfonic acid derivative) The quinophthalone sulfonic acid derivative (2) is a compound obtained by sulfonating a quinophthalone compound. Here, the quinophthalone compound is a compound having a quinophthalone skeleton (a skeleton obtained by the reaction of quinazidine and phthalic anhydride). As the quinophthalone compound, known compounds used as quinophthalone-based yellow pigments are used.

[0029] As the quinophthalone sulfonic acid derivative (2), for example, known quinophthalone sulfonic acid derivatives disclosed in Patent Document 2 (US Patent No. 6849116), Patent Document 3 (International Publication No. 2021 / 117410), etc. can be used. As the quinophthalone sulfonic acid derivative (2), one kind of compound may be used alone, or two or more kinds of compounds may be used in combination.

[0030] From the viewpoints of enhancing coloring power, obtaining better contrast, and obtaining better luminance, it is preferable to use at least one compound selected from the group consisting of the compounds represented by the following formulas (2-1) to (2-6) as the quinophthalone sulfonic acid derivative (2). From the viewpoint of obtaining even better luminance, it is more preferable to use at least one compound selected from the group consisting of the compounds represented by the following formulas (2-1) to (2-2), and even more preferable to use the compound represented by the following formula (2-1).

[0031]

[0032] In the plurality of X in formulas (2-1) to (2-6), each is independently a hydrogen atom, a halogen atom, a sulfonic acid group (—SO ３ H) or a sulfonate group (—SO ３ － ). However, among the plurality of X in each formula, at least one is a sulfonic acid group or a sulfonate group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The sulfonate group is —SO ３ － M ＋ (M ＋ represents a metal ion. Examples of the metal ion include a sodium ion (Na ＋ ), a calcium ion (Ca ２＋ ), an aluminum ion (Al ３＋ ), etc.).) or —SO ３ － NR １ R ２ R ３ R ４＋ (R １ to R ４ each independently represent a hydrocarbon chain such as a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, an alkylene group having 2 to 20 carbon atoms, etc. R １ to R ４ may be bonded to each other to form a ring.).

[0033] From the viewpoint of heat resistance, the total number of sulfonic acid groups and sulfonate groups in each compound represented by formulas (2-1) to (2-6) is preferably 1 or more and 3 or less, more preferably 1 or more and 2 or less, and still more preferably 1. The number of sulfonic acid groups may be within the above range, and the number of sulfonate groups may be within the above range. The number of sulfonic acid groups and sulfonate groups can be specified by mass spectrometry using LDI-MS (laser desorption ionization mass spectrometry), MALDI-MS (matrix-assisted desorption ionization mass spectrometry), LC-MS (liquid chromatography mass spectrometry), etc.

[0034] For convenience, details are omitted, but the compounds represented by formulas (2-1) to (2-6) include not only the compounds represented by formulas (2-1) to (2-6) themselves, but also their tautomers. The compounds represented by formulas (2-1) to (2-6) may be the compounds represented by each formula themselves, or their tautomers may be used.

[0035] The compound represented by formula (2-1) is preferably the compound represented by formula (2-1-1) below, the compound represented by formula (2-2) is preferably the compound represented by formula (2-2-1) below, the compound represented by formula (2-3) is preferably the compound represented by formula (2-3-1) below, the compound represented by formula (2-4) is preferably the compound represented by formula (2-4-1) below, and the compound represented by formula (2-6) is preferably the compound represented by formula (2-6-1) below. In these formulas, X has the same meaning as above, and at least one of the multiple Xs in each formula is a sulfonic acid group or a sulfonic acid base.

[0036] The compounds represented by formulas (2-1) to (2-6) are all known compounds. The compounds represented by formulas (2-1), (2-3) to (2-5) can be synthesized, for example, by the method described in Patent Document 2 (U.S. Patent No. 6,849,116). The compound represented by formula (2-2) can be synthesized by the method described in the examples. The compound represented by formula (2-6) is known as Acid Yellow 3 and is commercially available.

[0037] In one embodiment, it is preferable that the content (total amount) of the compounds represented by formulas (2-1) to (2-6) in the quinophthalone sulfonic acid derivative (2) is 90 to 100% by mass, based on the total mass of the quinophthalone sulfonic acid derivative (2).

[0038] In one embodiment, it is preferable that the content (total amount) of the compounds represented by formulas (2-1) to (2-2) in the quinophthalone sulfonic acid derivative (2) is 90 to 100% by mass, based on the total mass of the quinophthalone sulfonic acid derivative (2).

[0039] In one embodiment, it is preferable that the content of the compound represented by formula (2-1) in the quinophthalone sulfonic acid derivative (2) is 90 to 100% by mass, based on the total mass of the quinophthalone sulfonic acid derivative (2).

[0040] The content of quinophthalone sulfonic acid derivative (2) may be 1% by mass or more, 3% by mass or more, or 5% by mass or more, and may be 20% by mass or less, 15% by mass or less, or 13% by mass or less, based on the total mass of pigment composition (A). From the viewpoint of enhancing coloring power, obtaining better contrast, and obtaining better brightness, the content of quinophthalone sulfonic acid derivative (2) is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, and even more preferably 5 to 13% by mass, based on the total mass of pigment composition (A).

[0041] (Rosin compound (3)) Pigment composition (A) may further contain rosin compound (3) from the viewpoint of obtaining better brightness. Here, "rosin compound" means a compound having an abiethane-based diterpene skeleton, such as an abiethic acid derivative. If optical isomers exist for rosin compound (3), rosin compound (3) may be an enantiomer, a racemic mixture, or a scaremic mixture. Rosin compound (3) may be included in the pigment composition in the form of a salt with an acidic compound such as a quinophthalone sulfonic acid derivative (2), or it may be included as a single compound. Rosin compound (3) may be one compound used alone, or two or more compounds may be used in combination.

[0042] As for the rosin compound (3), from the viewpoint of obtaining even better brightness, it is preferable to use a rosin compound having an amino group, more preferably to use at least one compound selected from the group consisting of compounds represented by the following formulas (3-1) to (3-2), and even more preferably to use the compound represented by the following formula (3-1).

[0043]

[0044] For convenience, details are omitted, but the compounds represented by formulas (3-1) to (3-2) include not only the compounds represented by formulas (3-1) to (3-2) themselves, but also their optical isomers. The compounds represented by formulas (3-1) to (3-2) may be the compounds themselves, or their optical isomers may be used.

[0045] The compounds represented by formulas (3-1) and (3-2) are all known compounds. For example, commercially available products such as "Dehydroabietylamine" and "(+)Dehydroabietylamine" manufactured by Tokyo Chemical Industry Co., Ltd. can be used as the compound represented by formula (3-1). For example, commercially available products such as "Rosin Amine D" manufactured by A2B Chem can be used as the compound represented by formula (3-2).

[0046] The content of rosin compound (3) may be 0.1% by mass or more, 0.5% by mass or more, or 1% by mass or more, and may be 15% by mass or less, 10% by mass or less, or 3% by mass or less, based on the total mass of pigment composition (A). From the viewpoint of obtaining better brightness, the content of rosin compound (3) is preferably 0.1 to 15% by mass, more preferably 0.5 to 10% by mass, and even more preferably 1 to 3% by mass, based on the total mass of pigment composition (A).

[0047] (Castor oil, castor oil sulfonic acid, and castor oil sulfonate) The pigment composition (A) may further contain at least one selected from the group consisting of castor oil, castor oil sulfonic acid, and castor oil sulfonate, from the viewpoint of reducing the viscosity when it is used as a pigment dispersion.

[0048] Castor oil sulfonic acid is a sulfonated product of ricinoleic acid. Castor oil sulfonates include, for example, metal salts (such as sodium castor oil sulfonate and calcium castor oil sulfonate) in which at least some of the hydrogen atoms of the sulfonic acid group and carboxylic acid group in castor oil sulfonic acid (a sulfonated product of ricinoleic acid) are replaced with metal cations such as sodium ions and calcium ions. Castor oil sulfonates may be used as a single compound or in combination of two or more compounds.

[0049] The total content of castor oil, castor oil sulfonic acid, and castor oil sulfonate may be 1% by mass or more, or 5% by mass or more, and 10% by mass or less, or 8% by mass or less, based on the total mass of pigment composition (A). From the viewpoint of further reducing the viscosity when used as a pigment dispersion and further enhancing the coloring power, the total content of castor oil, castor oil sulfonic acid, and castor oil sulfonate is preferably 1 to 10% by mass, more preferably 5 to 8% by mass, based on the total mass of pigment composition (A).

[0050] (Other Components) The pigment composition (A) may further contain components other than those described above (other components), to the extent that they do not impede the effects of the present invention. Examples of other components include yellow pigments other than isoindoline pigment (1) and dye derivatives other than quinophthalone sulfonic acid derivative (2). Examples of yellow pigments other than isoindoline pigment (1) include C.I. Pigment Yellow 1, 3, 12, 13, 14, 15, 16, 17, 20, 24, 31, 53, 83, 86, 93, 94, 117, 125, 128, 129, 137, 138, 147, 148, 150, 153, 154, 166, 194, 214, etc. Other than the quinophthalone sulfonic acid derivative (2), known pigment derivatives include compounds derived from pigment compounds (for example, compounds used in diketopyrrolopyrrole pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, perinone pigments, perylene pigments, thiaidine indigo pigments, triazine pigments, benzimidazolone pigments, indole pigments, isoindoline pigments, naphthol pigments, surene pigments, metal complex pigments, azo, disazo, azo pigments, etc.). The pigment derivative may be a compound having an acidic substituent such as a sulfo group, a carboxyl group, or a phosphate group, or an amine salt thereof, or a compound having a basic substituent such as a sulfonamide group or a terminal tertiary amino group, or a compound having a neutral substituent such as a phenyl group or a phthalimidoalkyl group. For examples of pigment compounds, refer to Patent Document 6 (Japanese Patent No. 6893277).

[0051] The pigment composition (A) may also contain polymers as other components. Examples of polymers include styrene-(meth)acrylic acid copolymer, styrene-butyl (meth)acrylate-(meth)acrylic acid copolymer, lauryl (meth)acrylate-(meth)acrylic acid copolymer, styrene-lauryl (meth)acrylate-(meth)acrylic acid copolymer, benzyl (meth)acrylate-(meth)acrylic acid copolymer, benzyl (meth)acrylate-methyl (meth)acrylate copolymer, benzyl (meth)acrylate-methyl (meth)acrylate copolymer, and benzyl (meth)acrylate-methyl (meth)acrylate-(meth)acrylic acid copolymer. The pigment composition (A) may also contain polymer-coated particles coated with these polymers. For example, composite particles containing an isoindoline compound and a quinophthalone sulfonic acid derivative (2) may be coated with the above polymers.

[0052] The pigment composition (A) described above is suitable for color filters, and in particular, is suitable for use as a yellow pigment for forming the green pixel portion of a color filter. In particular, when combined with zinc halide phthalocyanine pigment, contrast and brightness tend to be further improved. However, the uses of pigment composition (A) are not limited to this. Pigment composition (A) can also be used, for example, as a pigment in inkjet inks, toners, etc.

[0053] <Method for Producing Pigment Composition> Another aspect of this disclosure is a method for producing a pigment composition comprising an isoindoline pigment (1) and a quinophthalone sulfonic acid derivative (2), comprising a grinding step of grinding the isoindoline pigment (1) together with the quinophthalone sulfonic acid derivative (2). The details of the isoindoline pigment (1) and the quinophthalone sulfonic acid derivative (2) are the same as the details of the isoindoline pigment (1) and the quinophthalone sulfonic acid derivative (2) contained in the pigment composition, so their description is omitted. Although the isoindoline pigment (1) used in the grinding step and the isoindoline pigment (1) contained in the pigment composition differ in particle size, etc., their constituent components are the same, so for convenience, in this specification, they are not distinguished and are referred to as "isoindoline pigment (1)".

[0054] According to the above method, a pigment composition is obtained in which, in a powder X-ray diffraction pattern using CuKα rays as the X-ray source, the diffraction peak is located at a position where the Bragg angle θ is (27.1° ± 0.5°) / 2, and the crystallite size determined from the diffraction peak is reduced. The crystallite size of the pigment composition obtained by the above method may be, for example, 15.5 nm or less. In other words, the above method makes it possible to produce the pigment composition (A) described above.

[0055] Various additives that may be included in the pigment composition (A) (rosin compound (3), castor oil, castor oil sulfonic acid, castor oil sulfonate, etc.) may be added by mixing them with the isoindoline pigment (1) and quinophthalone sulfonic acid derivative (2) in the grinding process, or by mixing them with the isoindoline pigment (1) and quinophthalone sulfonic acid derivative (2) after the grinding process. Alternatively, a material in which the above additives are pre-mixed (for example, a mixture of isoindoline pigment (1) and castor oil sulfonate) may be used in the grinding process. Details of the various additives are the same as those of the various additives included in the pigment composition, so they are omitted from this description.

[0056] (Grinding Process) The grinding process can be carried out using batch-type or continuous-type kneaders, etc. Examples of kneaders include kneaders, trimixes, two-roll mills, three-roll mills, ball mills, attritors, sand mills, high-speed fluid mixers, planetary mixers, etc. These may be used individually or in combination of two or more types.

[0057] In the grinding process, organic solvents and inorganic salts may be used to suppress the crystal growth of the pigment and to further refine the pigment composition. That is, in the grinding process, the isoindoline pigment (1) may be ground together with the quinophthalone sulfonic acid derivative (2) and an organic solvent and / or an inorganic salt. Either the organic solvent or the inorganic salt may be used, but the above effects are more easily obtained by using both. The organic solvent and the inorganic salt may each be used individually, or two or more may be used in combination.

[0058] Examples of organic solvents include diethylene glycol, glycerin, ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, liquid polyethylene glycol, liquid polypropylene glycol, 2-(methoxymethoxy)ethanol, 2-butoxyethanol, 2-(isopentyloxy)ethanol, 2-(hexyloxy)ethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, trimethyl phosphate, 4-butyrolactone, propylene carbonate, N-methyl-2-pyrrolidone, methanol, and ethylenecyanohydrin. When using inorganic salts in combination, it is preferable to use an organic solvent that does not dissolve the inorganic salts. Examples of suitable organic solvents include diethylene glycol, glycerin, and propylene glycol.

[0059] The amount of organic solvent used may be 5 parts by mass or more, 50 parts by mass or more, 1,000 parts by mass or less, 200 parts by mass or less, 5 to 1,000 parts by mass or 50 to 200 parts by mass, per 100 parts by mass of the total amount of isoindoline pigment (1) and quinophthalone sulfonic acid derivative (2). From the viewpoint of further reducing the viscosity when it becomes a pigment dispersion and from the viewpoint of further increasing the coloring power, the amount of organic solvent used is preferably 5 to 1,000 parts by mass, more preferably 50 to 200 parts by mass, per 100 parts by mass of the total amount of isoindoline pigment (1) and quinophthalone sulfonic acid derivative (2).

[0060] Examples of inorganic salts include sodium chloride, potassium chloride, lithium chloride, and sodium sulfate. Among these, sodium chloride and sodium sulfate are preferred from the viewpoint of promoting the fineness of pigments.

[0061] The amount of inorganic salt used may be 50 parts by mass or more, 500 parts by mass or more, 5000 parts by mass or less, 2000 parts by mass or less, 50 to 5000 parts by mass or 500 to 2000 parts by mass, based on 100 parts by mass of the total amount of isoindoline pigment (1) and quinophthalone sulfonic acid derivative (2). From the viewpoint of processing efficiency and production efficiency, the amount of inorganic salt used is preferably 50 to 5000 parts by mass, and more preferably 500 to 2000 parts by mass, based on 100 parts by mass of the total amount of isoindoline pigment (1) and quinophthalone sulfonic acid derivative (2).

[0062] The grinding temperature in the grinding process is preferably 20 to 90°C, more preferably 20 to 60°C, from the viewpoint of further refining the pigment particles. The grinding time in the grinding process is preferably 1 to 50 hours, from the viewpoint of further refining the pigment particles and production efficiency.

[0063] As described above, in the grinding step, in addition to the isoindoline pigment (1) and the quinophthalone sulfonic acid derivative (2), and optionally used organic solvents and inorganic salts, various additives such as rosin compounds (3), castor oil, castor oil sulfonic acid, and castor oil sulfonates may be used. That is, in the grinding step, the isoindoline pigment (1) may be ground together with the quinophthalone sulfonic acid derivative (2), optionally used organic solvents and / or inorganic salts, optionally used rosin compounds (3), and optionally used castor oil, castor oil sulfonic acid, and castor oil sulfonates, at least one selected from the group. The above-mentioned additives may be added after the grinding step, but from the viewpoint of further refining the pigment composition, it is preferable that they are mixed with the isoindoline pigment (1) in the grinding step (i.e., the isoindoline pigment (1) is ground together with the various additives).

[0064] From the viewpoint of obtaining a pigment composition with superior brightness improvement effect, the amount of rosin compound (3) used is preferably 0.1 to 18 parts by mass, more preferably 0.5 to 12 parts by mass, and even more preferably 1 to 4 parts by mass, based on 100 parts by mass of the total amount of isoindoline pigment (1) and quinophthalone sulfonic acid derivative (2). While it is preferable that the amount of rosin compound (3) used in the grinding step is within the above range, if rosin compound (3) is added after the grinding step, the amount of rosin compound (3) used may be adjusted so that the amount of rosin compound (3) contained in the pigment composition is within the desired range (for example, within the range exemplified as the content of rosin compound (3) contained in the pigment composition (A) described above).

[0065] From the viewpoint of obtaining a pigment composition that is superior in reducing viscosity when the pigment is dispersed, the total amount of castor oil, castor oil sulfonic acid, and castor oil sulfonate used is preferably 1 to 12 parts by mass, and more preferably 5 to 9 parts by mass, per 100 parts by mass of the total amount of isoindoline pigment (1) and quinophthalone sulfonic acid derivative (2). It is preferable that the total amount of castor oil, castor oil sulfonic acid, and castor oil sulfonate used in the grinding process be within the above range. However, if at least one selected from the group consisting of castor oil, castor oil sulfonic acid, and castor oil sulfonate is added after the grinding process, the amounts of castor oil, castor oil sulfonic acid, and castor oil sulfonate used may be adjusted so that the total amount of castor oil, castor oil sulfonic acid, and castor oil sulfonate contained in the pigment composition is within the desired range (for example, within the range exemplified as the total amount of castor oil, castor oil sulfonic acid, and castor oil sulfonate contained in the pigment composition (A) described above).

[0066] The grinding process may be carried out in multiple stages by changing the conditions (e.g., type of kneader, organic solvent, inorganic salt, grinding temperature, grinding time, etc.). For example, the grinding process may include a first grinding process and a second grinding process. The first grinding process and the second grinding process may differ in one or more conditions, such as the type of kneader, organic solvent, inorganic salt, grinding temperature, grinding time, etc. In one embodiment, a ball mill may be used in the first grinding process and a kneader may be used in the second grinding process. In this case, the organic solvent and inorganic salt may not be used in the first grinding process, but they may be used in the second grinding process. In one embodiment, in the first grinding process, the isoindoline pigment (1) may be ground together with a quinophthalone sulfonic acid derivative (2), and in the second grinding process, the mixture obtained in the first process, which contains the isoindoline pigment (1) and the quinophthalone sulfonic acid derivative (2), may be ground together with a rosin compound (3). In this case as well, the first grinding step may not use organic solvents and inorganic salts, while the second grinding step may use organic solvents and inorganic salts. Alternatively, at least one selected from the group consisting of castor oil, castor oil sulfonic acid, and castor oil sulfonate may be used in the first grinding step and / or the second grinding step. In another embodiment, in the first grinding step, the isoindoline pigment (1) or the quinophthalone sulfonic acid derivative (2) may be ground individually, and in the second grinding step, the isoindoline pigment (1) and the quinophthalone sulfonic acid derivative (2) obtained in the first grinding step may be ground together, or, if necessary, together with a rosin compound (3).

[0067] When using organic solvents and / or inorganic salts, a washing step using a washing solution such as water may be performed after the grinding step as needed. Furthermore, drying and pulverization steps may be performed as needed. These steps may be carried out using general methods and conditions that are typically used after conventional grinding steps for pigment refinement. Note that pulverization after drying is not performed to increase the specific surface area or reduce the average particle size of primary particles, but rather to dissolve and powder the pigment when it becomes lamp-shaped, for example, in the case of drying using a box dryer or band dryer. Examples of pulverization methods include grinding using a mortar and pestle, hammer mill, disc mill, pin mill, jet mill, etc.

[0068] <Pigment Dispersion> Another aspect of this disclosure is a pigment dispersion containing the pigment composition (A) described above and a dispersion medium. The pigment dispersion can be used to prepare a color filter composition as described later.

[0069] The content of pigment composition (A) may be 50 to 95% by mass, 60 to 90% by mass, or 70 to 85% by mass, based on the total mass of solids in the pigment dispersion. The solids in the pigment dispersion refer to the components remaining after the dispersion medium has been removed from the pigment dispersion.

[0070] Examples of dispersion media include aromatic solvents such as toluene, xylene, and methoxybenzene; acetic acid ester solvents such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate; propionate solvents such as ethoxyethyl propionate; alcohol solvents such as methanol and ethanol; ether solvents such as butyl cellosolve, propylene glycol monomethyl ether, diethylene glycol ethyl ether, and diethylene glycol dimethyl ether; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aliphatic hydrocarbon solvents such as hexane; nitrogen compound solvents such as N,N-dimethylformamide, γ-butyrolactam, N-methyl-2-pyrrolidone, aniline, and pyridine; lactone solvents such as γ-butyrolactone; carbamic acid esters such as a 48:52 mixture of methyl carbamate and ethyl carbamate; and water. One compound may be used alone as the dispersion medium, or two or more compounds may be used in combination.

[0071] The pigment dispersion may further contain a polymeric dispersant. The polymeric dispersant is a polymer compound also called a resin-type dispersant, having a weight-average molecular weight of 10,000 or more, and containing a moiety that has affinity for the pigment and a moiety that has affinity for the dispersion medium. Because the pigment dispersion contains a moiety that has affinity for the pigment, it can be adsorbed onto the pigment, and because it contains a moiety that has affinity for the dispersion medium, it can be well miscible with the dispersion medium.

[0072] The polymeric dispersant may be, for example, an acidic polymeric dispersant in which the part of the pigment that has affinity for the pigment is an acidic part (e.g., a carboxyl group), or a basic polymeric dispersant in which the part of the pigment that has affinity for the pigment is a basic part (e.g., a tertiary amino group, a quaternary ammonium base, a nitrogen-containing heterocycle, etc.).

[0073] The polymeric dispersant may be a polymer (homopolymer) of a single monomer, or a copolymer of multiple monomers. Furthermore, the polymeric dispersant may be a random copolymer, a block copolymer, or a graft copolymer. If the polymeric dispersant is a graft copolymer, it may be a comb-shaped graft copolymer or a star-shaped graft copolymer. Examples of polymeric dispersants include acrylic resins, polyester resins, polyurethane resins, polyamide resins, polyethers, phenolic resins, silicone resins, polyurea resins, amino resins, epoxy resins, polyamines such as polyethyleneimine and polyallylamine, and polyimides.

[0074] As the polymer dispersant, polymer dispersants known in this art can be used, for example, DISPERBYK-2001, DISPERBYK-2000, BYK-LPN6919, BYK-LPN21116, BYK-LPN22102, etc., manufactured by BIC Chemie Japan can be used. Alternatively, as the polymer dispersant, resin-type dispersants described in paragraphs 0157 to 0164 of Patent Document 7 (Japanese Patent Application Publication No. 2019-104822) can also be used.

[0075] The amount of polymer dispersant may be 0 to 200 parts by mass or 10 to 100 parts by mass per 100 parts by mass of pigment composition (A).

[0076] The pigment dispersion may further contain leveling agents, coupling agents, cationic surfactants, and the like.

[0077] A pigment dispersion can be prepared by mixing a pigment composition (A), a dispersion medium, and other components (such as polymer dispersants) that are added as needed.

[0078] <Composition for Color Filters> Another aspect of this disclosure is a composition for color filters comprising the pigment composition (A) described above and a green pigment. Since the composition for color filters contains the pigment composition (A), it comprises an isoindoline pigment (1) and a green pigment as pigments, and a quinophthalone sulfonic acid derivative (2) as an additive. Here, "for color filters" means used to form the pixel portion of a color filter.

[0079] The content of pigment composition (A) may be 4 to 50% by mass, 5 to 48% by mass, or 6 to 45% by mass, based on the total mass of solids in the color filter composition. The solids in the color filter composition refer to the components remaining after removing the dispersion medium if the color filter composition contains one, and to the color filter composition itself if the color filter composition does not contain one.

[0080] As the green pigment, it is preferable to use zinc halide phthalocyanine pigment from the viewpoint of further enhancing the contrast and brightness improvement effect of pigment composition (A). Zinc halide phthalocyanine pigment is a green pigment known by names such as Pigment Green 58 and Pigment Green 59, and is composed of a zinc halide phthalocyanine compound represented by the following formula (I).

[0081] X in equation (I) １ ~X １６ Each of these independently represents either a hydrogen atom or a halogen atom. However, X １ ~X １６ At least one of them is a halogen atom. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine.

[0082] As the zinc halide phthalocyanine pigment, it is preferable to use a zinc halide phthalocyanine pigment in which the average number of halogen atoms per molecule is 10 to 14, the average number of bromine atoms is 8 to 12, and the average number of chlorine atoms is 2 to 5. It is more preferable to use a zinc halide phthalocyanine pigment in which the average number of halogen atoms is 11 to 13, of which the average number of bromine atoms is 8 to 11 and the average number of chlorine atoms is 2 to 3. By using such a zinc halide phthalocyanine pigment, it is easier to obtain a color filter with a thinner film thickness, and therefore with higher brightness and a wider color reproduction gamut, compared to using other green pigments such as Pigment Green 7.

[0083] The average particle size of the primary particles of the zinc halide phthalocyanine pigment may be 0.01 to 0.30 μm, or 0.01 to 0.10 μm. The average particle size of the primary particles referred to here is the average value obtained by taking images of particles within the field of view with a transmission electron microscope JEM-2010 (manufactured by JEOL Ltd.), determining the longer diameter (major axis) of each of the 50 zinc halide phthalocyanine primary particles constituting the aggregates on the two-dimensional image, and averaging these values. In this case, the zinc halide phthalocyanine pigment sample is ultrasonically dispersed in a solvent before being photographed with the microscope. Alternatively, a scanning electron microscope may be used instead of a transmission electron microscope.

[0084] Zinc halide phthalocyanine pigments having the above-described number of halogen atoms and average particle size can be manufactured, for example, by referring to Patent Document 8 (International Publication No. 2015 / 118720).

[0085] The mass ratio of zinc halide phthalocyanine pigment to isoindoline pigment (1) in the color filter composition is preferably 95 / 5 to 50 / 50, and more preferably 70 / 30 to 55 / 45.

[0086] The color filter composition may further contain a dispersion medium. Details of the dispersion medium are the same as those of the dispersion medium contained in the pigment dispersion described above, and therefore are omitted from this description.

[0087] From the viewpoint of pigment dispersibility, the color filter composition preferably contains a polymeric dispersant. Details of the polymeric dispersant are the same as those of the polymeric dispersant contained in the pigment dispersion described above, so they are omitted from this description.

[0088] The content of the polymeric dispersant is preferably 1 to 100 parts by mass, and more preferably 1 to 80 parts by mass, per 100 parts by mass of pigment. In one embodiment, it is preferable that the content of the polymeric dispersant is within the above range relative to 100 parts by mass of the total amount of zinc halide phthalocyanine pigment and isoindoline pigment (1).

[0089] The color filter composition may further contain a photosensitive resin. That is, the color filter composition may also be a photosensitive resin composition for color filters. The photosensitive resin may be a thermoplastic resin such as a urethane resin, an acrylic resin, a polyamic acid resin, a polyimide resin, a styrene maleic acid resin, or a styrene maleic anhydride resin. The photosensitive resin may be a bifunctional photopolymerizable monomer such as 1,6-hexanediol diacrylate, ethylene glycol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, bis(acryloxyethoxy)bisphenol A, or 3-methylpentanediol diacrylate, or a polyfunctional photopolymerizable monomer such as trimethylolpropane triacrylate, pentaerythritol triacrylate, tris(2-hydroxyethyl) isocyanate, dipentaerythritol hexaacrylate, or dipentaerythritol pentaacrylate.

[0090] The color filter composition may further contain a photopolymerization initiator. The photopolymerization initiator may be used in combination with the above-mentioned photosensitive resin. Examples of photopolymerization initiators include acetophenone, benzophenone, benzyldimethylketanol, benzoyl peroxide, 2-chlorothioxanthone, 1,3-bis(4'-azidobenzal)-2-propane, 1,3-bis(4'-azidobenzal)-2-propane-2'-sulfonic acid, and 4,4'-diazidostilbene-2,2'-disulfonic acid.

[0091] The viscosity of the color filter composition at 20°C is preferably 20 mPa·s or less, more preferably 10 mPa·s or less, and even more preferably 5 mPa·s or less, from the viewpoint of smoothness of the coating film. The viscosity of the color filter composition at 20°C is preferably 1 mPa·s or more, and more preferably 2 mPa·s or more, from the viewpoint of film-forming properties during coating. The above viscosity is obtained by measuring using an E-type viscometer (for example, RE550L manufactured by Toki Sangyo Co., Ltd.) under the conditions of temperature: 20°C, preheating: 120 seconds, rotation speed: 10 rpm, and measurement time: 60 seconds.

[0092] A color filter composition can be prepared by mixing a pigment composition (A), a green pigment, and other components added as needed (dispersion medium, polymer dispersant, photosensitive resin, photopolymerization initiator, etc.). Alternatively, a color filter composition may be prepared by mixing the above-mentioned pigment dispersion with a green pigment (preferably zinc halide phthalocyanine pigment) and other components added as needed (polymer dispersant, photosensitive resin, photopolymerization initiator, etc.).

[0093] (Color Filter) Another embodiment of the present disclosure is a color filter comprising a green pixel portion containing the above-described pigment composition (A) and a green pigment. The green pigment is preferably a zinc halide phthalocyanine pigment.

[0094] The green pixel portion may be a pixel portion formed using the color filter composition described above. For example, the green pixel portion may contain a cured product of the color filter composition (color filter photosensitive resin composition) containing a photosensitive resin. That is, the green pixel portion may contain a cured product of the photosensitive resin. The green pixel portion may also contain the polymer dispersant.

[0095] The green pixel portion can be formed by conventionally known methods such as photolithography, electrodeposition, transfer, micelle electrolysis, and PVED (Photovoltaic Electrodeposition). In photolithography, for example, a photosensitive resin composition for color filters is applied to a transparent substrate such as glass by spin coating, roll coating, slit coating, or inkjet. After pattern exposure of the resulting coating film with ultraviolet light through a photomask, the unexposed areas are washed with an organic solvent or alkaline water to obtain the green pixel portion.

[0096] The other components of the color filter may be the same as those of conventionally known color filters.

[0097] The contents of this disclosure will be described in more detail below using examples and comparative examples, but this disclosure is not limited to the following examples.

[0098] <Materials Used> ・Pigment 1: Yellow 11406 (trade name, manufactured by Vijay Chemical Industries, isoindoline pigment Pigment Yellow 185 (compound represented by formula (1-1))) ・Pigment 2: Palitol Yellow D1155 (trade name, manufactured by Sun Chemical, a mixture containing 93% by mass of Pigment Yellow 185 (compound represented by formula (1-1)), an isoindoline pigment, and 7% by mass of sodium castor oil sulfonate (Na-COS in Table 2)) ・Pigment 3: Fanchon Yellow 139 (trade name, manufactured by Sun Chemical, isoindoline pigment Pigment Yellow 139 (compound represented by formula (1-6))) - Sulfonic acid derivative 1: A compound represented by formula (2-1-1) (number of sulfonic acid groups: 1) synthesized according to the method described in Example 1 of Patent Document 2 (U.S. Patent No. 6,849,116). - Sulfonic acid derivative 2: A sulfonated product of C.I. Pigment Yellow 185 (labeled "Isoindoline Sulfonic Acid Derivative" in Table 2) synthesized according to the method described in the example of Patent Document 9 (Japanese Patent Application Publication No. 2014-002314). - Rosin compound 1: Dehydroabietylamine (trade name, manufactured by Tokyo Chemical Industry Co., Ltd., compound represented by formula (3-1), purity 55.0% by mass or higher). - Rosin compound 2: (+)-Dehydroabietylamine (trade name, manufactured by Tokyo Chemical Industry Co., Ltd., compound represented by formula (3-1), purity 90% by mass or higher). - Castor oil: Manufactured by Kanto Chemical Co., Ltd. (labeled "CO" in Table 2). • Sodium chloride (NaCl in Table 1) • Diethylene glycol (DEG in Table 1) • Glycerin (Gly in Table 1)

[0099] <Example 1> (Preparation of Pigment Composition) 38 g of Pigment 1, 2 g of Quinophthalone Sulfonic Acid Derivative 1, 400 g of Sodium Chloride, and 69 g of Diethylene Glycol were placed in a 1 L kneader (1100-S-1, manufactured by Yoshida Seisakusho) and kneaded for 6 hours while controlling the temperature of the mixture to 40°C to grind Pigment 1. The mixture after kneading was taken out and stirred in 2 L of water for 1 hour. The mixture was then filtered, washed with water, dried overnight at 90°C, and further ground in a blender (7011 HBC, manufactured by WARING) at low speed for 150 seconds to obtain Pigment Composition 1. The content and crystallite size of each component in Pigment Composition 1 are shown in Table 2.

[0100] (Measurement of Crystallite Size) The powder X-ray diffraction pattern of pigment composition 1 was measured using a SmartLab 9kW X-ray diffractometer (manufactured by Rigaku) ​​with CuKα as the X-ray source. The measurement was performed under the conditions of 2θ = 1 to 40°, step width: 0.02°, and scan speed: 2.0° / min. It was confirmed that the powder X-ray diffraction pattern of pigment composition 1 has a diffraction peak at a position where the diffraction angle 2θ is 27.1° ± 0.5°. Furthermore, the crystallite size was calculated using the refinement function of the automated data processing using the integrated powder analysis software PDXL2 (manufactured by Rigaku). In the refinement function of the automated data processing, the Bragg angle θ and the full width at half maximum B of the above diffraction peak were determined, and the crystallite size was calculated using Scherrer's formula. The crystallite sizes are shown in Table 2.

[0101] <Example 2> Except for adding rosin compound 1 as a material to be charged into a 1L kneader and changing the amount of each component used as shown in Table 1, pigment composition 2 was manufactured in the same manner as in Example 1, and the crystallite size of the obtained pigment composition 2 was measured. The content and crystallite size of each component in pigment composition 2 are shown in Table 2. Note that the amount of rosin compound used shown in Table 1 is the actual amount of rosin compound 1 used, including impurities.

[0102] <Example 3> Except for adding castor oil as a material to be loaded into a 1L kneader and changing the amount of each component used as shown in Table 1, pigment composition 3 was manufactured in the same manner as in Example 1, and the crystallite size of the obtained pigment composition 3 was measured. The content and crystallite size of each component in pigment composition 3 are shown in Table 2.

[0103] <Examples 4-7 and 11-13> Pigment compositions 4-7 and 11-13 were prepared in the same manner as in Example 1 or 2, except that the types and / or amounts of each component were changed as shown in Table 1, and the crystallite size of each obtained pigment composition was measured. The content and crystallite size of each component in each pigment composition are shown in Table 2. Note that the amount of pigment 2 shown in Table 1 is the actual amount of pigment 2 used, including sodium castor oil sulfonate.

[0104] <Example 8> 36.4 g of pigment 2, 3.6 g of pigment 3, 2 g of sulfonic acid derivative 1, 1.2 g of rosin compound 1, 400 g of sodium chloride, and 69 g of diethylene glycol were placed in a 1 L kneader (1100-S-1, manufactured by Yoshida Seisakusho) and kneaded for 6 hours while controlling the temperature of the mixture to 40°C, thereby grinding pigment 2 and pigment 3. The mixture after kneading was taken out into 2 L of water and stirred for 1 hour. Then the mixture was filtered, washed with water, dried overnight at 90°C, and further ground in a blender (7011 HBC, manufactured by WARING) at low speed for 150 seconds to obtain pigment composition 8. The crystallite size of pigment composition 8 was then measured in the same manner as in Example 1. The content and crystallite size of each component in pigment composition 8 are shown in Table 2.

[0105] <Example 9> 47.5 g of pigment 2, 2.5 g of sulfonic acid derivative 1, and 24 steel balls with a diameter of 24 mm were placed in a cylindrical steel pot with a diameter of 100 mm and a height of 100 mm. Using a Nittokagaku pot mill turntable ANZ-52D, the mixture was ground at 25°C for 30 hours to obtain yellow powder (first grinding step). 38.8 g of the obtained yellow powder, 1.2 g of aminorosin 1, 400 g of sodium chloride, and 69 g of diethylene glycol were placed in a 1 L kneader (1100-S-1, manufactured by Yoshida Seisakusho) and kneaded for 6 hours while controlling the temperature of the mixture to 40°C to grind the yellow powder (second grinding step). The mixture after kneading was taken out and stirred in 2 L of water for 1 hour. The mixture was then filtered, washed with water, dried overnight at 90°C, and pulverized to obtain pigment composition 9. The crystallite size of pigment composition 9 was then measured in the same manner as in Example 1. The content and crystallite size of each component in the pigment composition 9 are shown in Table 2.

[0106] <Example 10> 36.8 g of pigment 1, 2 g of sulfonic acid derivative 1, 400 g of sodium chloride, and 69 g of diethylene glycol were placed in a 1 L kneader (1100-S-1, manufactured by Yoshida Seisakusho) and kneaded for 6 hours while controlling the temperature of the mixture to 40°C to grind pigment 1. The mixture after kneading was taken out into 2 L of water and stirred for 1 hour. Then the mixture was filtered, washed with water, dried overnight at 90°C, and further ground in a blender (7011 HBC, manufactured by WARING) at low speed for 150 seconds. 1.2 g of rosin compound 1 was added to the obtained pulverized material and mixed to obtain pigment composition 10. The crystallite size of pigment composition 10 was then measured in the same manner as in Example 1. The content and crystallite size of each component in pigment composition 10 are shown in Table 2.

[0107] <Comparative Example 1> Pigment 1 was ground by placing 38 g of pigment 1, 400 g of sodium chloride, and 69 g of diethylene glycol into a 1 L kneader (1100-S-1, manufactured by Yoshida Seisakusho) and kneading for 6 hours while controlling the temperature of the mixture to 40°C. The mixture was then removed and stirred in 2 L of water for 1 hour. The mixture was then filtered, washed with water, dried overnight at 90°C, and further ground in a blender (7011 HBC, manufactured by WARING) at a low speed for 150 seconds. Pigment composition 14 was obtained by adding 2 g of sulfonic acid derivative 1 to the resulting pulverized material and mixing. The crystallite size of pigment composition 14 was then measured in the same manner as in Example 1. The content and crystallite size of each component in pigment composition 14 are shown in Table 2.

[0108] <Comparative Example 2> Pigment composition 15 was prepared in the same manner as in Example 1, except that sulfonic acid derivative 2 was used instead of sulfonic acid derivative 1, and the crystallite size of the obtained pigment composition 15 was measured. The content and crystallite size of each component in pigment composition 15 are shown in Table 2.

[0109] <Comparative Example 3> 40 g of pigment 1, 400 g of sodium chloride, and 69 g of diethylene glycol were placed in a 1 L kneader (1100-S-1, manufactured by Yoshida Seisakusho) and kneaded for 6 hours while controlling the temperature of the mixture to 40°C to grind pigment 1. The mixture after kneading was taken out and stirred in 2 L of water for 1 hour. Then the mixture was filtered, washed with water, dried overnight at 90°C, and further ground in a blender (7011 HBC, manufactured by WARING) at low speed for 150 seconds to obtain pigment composition 16. The crystallite size of pigment composition 16 was then measured in the same manner as in Example 1. The content and crystallite size of each component in pigment composition 16 are shown in Table 2.

[0110] <Evaluation> The pigment compositions (pigment compositions 1 to 16) produced in the above examples or comparative examples were evaluated for viscosity, contrast, and brightness using the following method.

[0111] (Preparation of evaluation dispersion) 1.32 g of the pigment composition was dispersed with 1.485 g of LPN-21116 (manufactured by BYK) and 11.845 g of propylene glycol monomethyl ether acetate using 0.3-0.4 mm zircon beads in a paint shaker (manufactured by Toyo Seiki Co., Ltd.) for 3 hours to obtain an evaluation dispersion.

[0112] (Viscosity Evaluation) The viscosity of the above-mentioned dispersion was measured using a RE550L (Type E viscometer) manufactured by Toki Sangyo Co., Ltd. under the following conditions: temperature: 20°C, preheating: 120 seconds, rotation speed: 10 rpm, measurement time: 60 seconds. The results are shown in Table 2.

[0113] (Contrast Evaluation) 2.48 g of DIC FASTOGEN GREEN C300 was dispersed for 2 hours in a paint shaker (manufactured by Toyo Seiki Co., Ltd.) using 0.3-0.4 mm zircon beads, along with 4.335 g of LPN-21116 (manufactured by BYK Corporation) and 9.685 g of propylene glycol monomethyl ether acetate, to obtain a green dispersion for color tuning.

[0114] A color filter composition was obtained by mixing 1.5 g of evaluation dispersion, 1.35 g of green dispersion for color tuning, and 0.83 g of Unidic ZL-295.

[0115] The obtained color filter composition was applied (spin-coated) onto a soda glass substrate (Nippon Sheet Glass Co., Ltd., soda glass) using a spin coater MS-B100 (Mikasa Corporation), dried at 100°C for 2 minutes, and then heated at 230°C for 30 minutes. This produced a glass substrate for contrast evaluation having a colored film on the soda glass substrate. By adjusting the spin rotation speed during spin coating, the thickness of the colored film obtained after heating at 230°C for 30 minutes was set to 1.5 μm.

[0116] The contrast of the colored film on the glass substrate used for contrast evaluation was measured using a contrast tester CT-1 (manufactured by Tsubosaka Electric Co., Ltd.), and evaluated based on the measurement results of Comparative Example 1. The results are shown in Table 2. Note that the contrast (Std. ratio) in Table 2 is a relative value with the contrast of Comparative Example 1 set to 100.0%.

[0117] (Brightness Evaluation) By adjusting the mixing ratio of the evaluation dispersion and the green dispersion for color tuning, and the spin rotation speed during spin coating, a glass substrate for brightness evaluation was fabricated in which the chromaticity (x, y) of the colored film obtained by heating at 230°C for 30 minutes was (0.223, 0.677) under a C light source.

[0118] The brightness of the glass substrate used for brightness evaluation was measured using a Hitachi High-Tech Science U-3900 and evaluated based on the measurement results of Comparative Example 1. The results are shown in Table 2. Note that the brightness (Std. ratio) in Table 2 is a relative value with the brightness of Comparative Example 1 set to 100.0%.

[0119] *Pigment 2 contains 7% by mass of sodium castor oil sulfonate.

[0120]

Claims

1. A pigment composition comprising an isoindoline pigment (1) and a quinophthalone sulfonic acid derivative (2), wherein, in a powder X-ray diffraction pattern using CuKα rays as the X-ray source, the diffraction peak is located at a position where the Bragg angle θ is (27.1°±0.5°) / 2, and the crystallite size calculated by Scherrer's formula using the Bragg angle θ and the full width at half maximum B of the diffraction peak is 15.5 nm or less.

2. The isoindoline pigment (1) is a given by the following formulas (1-1) to (1-8) The pigment composition according to claim 1, comprising at least one compound selected from the group consisting of compounds represented by .

3. The quinophthalone sulfonic acid derivative (2) is one of the following formulas (2-1) to (2-6) A pigment composition according to claim 1 or 2, comprising at least one compound selected from the group consisting of compounds represented by formulas (2-1) to (2-6): [Each of the multiple X's in formulas (2-1) to (2-6) independently represents a hydrogen atom, a halogen atom, a sulfonic acid group, or a sulfonic acid base. However, at least one of the multiple X's in each formula is a sulfonic acid group or a sulfonic acid base.] 4. The pigment composition according to any one of claims 1 to 3, wherein the content of the isoindoline pigment (1) is 80 to 99% by mass based on the total mass of the pigment composition, and the content of the quinophthalone sulfonic acid derivative (2) is 1 to 20% by mass based on the total mass of the pigment composition.

5. The pigment composition according to any one of claims 1 to 4, further comprising a rosin compound (3).

6. The rosin compound (3) is the following: (3-1) to (3-2) The pigment composition according to claim 5, comprising at least one compound selected from the group consisting of compounds represented by .

7. The pigment composition according to claim 5 or 6, wherein the content of the rosin compound (3) is 0.1 to 15% by mass, based on the total mass of the pigment composition.

8. The pigment composition according to any one of claims 1 to 7, further comprising at least one selected from the group consisting of castor oil, castor oil sulfonic acid, and castor oil sulfonate.

9. The pigment composition according to claim 8, wherein the total content of castor oil, castor oil sulfonic acid, and castor oil sulfonate is 1 to 10% by mass, based on the total mass of the pigment composition.

10. A color filter composition comprising the pigment composition according to any one of claims 1 to 9 and a zinc halide phthalocyanine pigment.

11. The color filter composition according to claim 10, further comprising a polymer dispersant.

12. A method for producing a pigment composition comprising an isoindoline pigment (1) and a quinophthalone sulfonic acid derivative (2), the method comprising a grinding step of grinding the isoindoline pigment (1) together with the quinophthalone sulfonic acid derivative (2).

13. The manufacturing method according to claim 12, wherein in the grinding step, the isoindoline pigment (1) is ground together with the quinophthalone sulfonic acid derivative (2) and the rosin compound (3).

14. The manufacturing method according to claim 12 or 13, wherein in the grinding step, the isoindoline pigment (1) is ground together with a quinophthalone sulfonic acid derivative (2) and at least one selected from the group consisting of castor oil, castor oil sulfonic acid, and castor oil sulfonate.

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