Method for manufacturing pigment for color filter

Abstract

A method for manufacturing a pigment for a color filter, comprising a kneading step of kneading a mixture containing a crude pigment, an inorganic salt, and an organic solvent at a maximum shear rate exceeding 800 s-1. The crude pigment contains a metal halide phthalocyanine having zinc, iron, aluminum, magnesium, silicon, or vanadium as a central metal. The power consumption for kneading the mixture in the kneading step is greater than 10.0 kWh per 1 kg of the crude pigment.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a pigment for a color filter. Background Art

[0002] Currently, coloring compositions are used in various fields. As specific uses of coloring compositions, the following can be cited: printing inks, coatings, colorants for resins, colorants for fibers, color materials for information recording in information technology (IT) (color filters, toners, inkjets), etc. Pigments used in coloring compositions are mainly roughly classified into pigments and dyes, and organic pigments that are superior in coloring power have attracted attention.

[0003] It is known that organic pigments are effectively used as pigments for color filters. As organic pigments for color filters, phthalocyanine-based pigments have attracted attention and can be used in the green pixel portion of color filters, etc. (for example, refer to Patent Document 1).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Pamphlet of International Publication No. 2018 / 043548 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] An object of the present invention is to provide a method for manufacturing a pigment for a color filter that can improve the brightness of a pixel portion.

[0009] Technical Means for Solving the Problems

[0010] After synthesis, the organic compounds constituting the organic pigment aggregate with each other and exist in the state of an aggregate called a crude product. Therefore, usually, the synthesized organic compound cannot be directly used as a pigment, and a pigmentation step for adjusting the particle size is performed. In the pigmentation step, the aggregate (crude product) of the organic compound to be pigmented is called a crude pigment, and the crude pigment is ground by kneading or the like to obtain a fine organic pigment.

[0011] The pigmentation of the crude pigment for manufacturing an organic pigment is usually performed by kneading a mixture containing the crude pigment, an inorganic salt, and an organic solvent. However, during kneading, crystallization and refinement of the crude pigment occur simultaneously. If the energy input into the kneading of the mixture (the power consumption for kneading) is too large, the crystallization becomes dominant. Therefore, in order to obtain a fine pigment, it is necessary not to input too much energy (for example, the power consumption is set to 8.0 kWh or less per 1 kg of the crude pigment).

[0012] The inventors of the present invention focused on the fact that phthalocyanine-based pigments, although they can improve the brightness of the pixel portion, are pigments that are prone to crystallization. In the production of phthalocyanine-based pigments, as long as crystallization during the kneading can be suppressed, even when kneading with energy greater than normal, the refinement of the crude pigment is advantageous, and the phthalocyanine-based pigment can be further refined. As a result, a concept of obtaining a color filter pigment that can further improve the brightness of the pixel portion was conceived. The inventors of the present invention made diligent studies based on the above concept and, as a result, completed the present invention.

[0013] That is, one aspect of the present invention relates to a method for manufacturing a pigment for a color filter, which includes a kneading step of kneading a mixture containing a crude pigment, an inorganic salt, and an organic solvent at a maximum shear rate exceeding 800 s -1 . The crude pigment contains a metal halide phthalocyanine having zinc, iron, aluminum, magnesium, silicon, or vanadium as a central metal, and the amount of electricity consumed for kneading the mixture in the kneading step is greater than 10.0 kWh per 1 kg of the crude pigment.

[0014] According to the manufacturing method of the above aspect, a pigment for a color filter that can improve the brightness of the pixel portion can be obtained.

[0015] Metal halide phthalocyanine is a compound in which at least a part of the hydrogen atoms on the aromatic ring in metal phthalocyanine is halogenated. Due to the halogenation of the aromatic ring, the phthalocyanine ring is likely to become a distorted structure, and thus has a tendency not to crystallize easily. Therefore, it is speculated that by using a crude pigment containing metal halide phthalocyanine as the crude pigment, even when the energy input during kneading (the amount of electricity consumed for kneading) is increased, crystallization is not likely to occur. On the other hand, although the research results of the inventors of the present invention are clear, when the energy input during kneading (the amount of electricity consumed for kneading) is large, even if the above-mentioned crude pigment containing metal halide phthalocyanine is used, if the maximum shear rate during kneading is 800 s -1 or less, agglomeration of the crude pigment will also occur. Therefore, it is necessary to make the maximum shear rate during kneading greater than 800 s -1 . By making the maximum shear rate during kneading greater than 800 s -1 , a state in which agglomeration of the crude pigment is not likely to occur can be maintained during kneading, and it is speculated that the refinement of the crude pigment is advantageous.

[0016] In one embodiment, the pH of the crude pigment may be less than 5. In this case, the central metal of the crude pigment may be zinc, iron, or magnesium. In addition, in this case, the method for manufacturing a pigment for a color filter may further include a cleaning step of cleaning the kneaded mixture obtained in the kneading step with an aqueous solution having a pH greater than 8 at 25°C.

[0017] In one embodiment, the average number of halogen atoms per molecule of metal halide phthalocyanine in the crude pigment may be 9 or more.

[0018] In one embodiment, in the kneading step, the mixture can be kneaded at a temperature below 110°C.

[0019] In one embodiment, relative to 1 part by mass of the coarse pigment, the amount of the inorganic salt used in the kneading step can be 30 parts by mass or more.

[0020] Effects of the Invention

[0021] According to the present invention, a method for manufacturing a pigment for a color filter capable of improving the brightness of a pixel portion can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic cross-sectional view showing the internal structure of a kneading apparatus used in the manufacturing method of one embodiment.

[0023] Figure 2 is a schematic plan view showing the internal structure of a kneading apparatus used in the manufacturing method of another embodiment.

[0024] Figure 3 is along Figure 2 sectional view taken along line III-III of.

[0025] DESCRIPTION OF SYMBOLS

[0026] 10, 20: Kneading apparatus

[0027] 11, 21: Kneading chamber

[0028] 11a: Inner wall surface

[0029] 12: Blade

[0030] 21a: Bottom surface

[0031] 22: Roller

[0032] 23: Column portion

[0033] 24: Connecting portion

[0034] 25: Compression spring

[0035] C1, C2: Gap

[0036] D: Shortest distance

[0037] L1, L2: Rotation axis

[0038] r: Maximum radius

[0039] W: Wheel width DETAILED DESCRIPTION OF THE INVENTION

[0040] Hereinafter, preferred embodiments of the present invention will be described. It should be noted that the present invention is not limited by any of the following embodiments.

[0041] A method for manufacturing a pigment for a color filter according to an embodiment includes, for example: a first step of preparing a crude pigment; and a second step of pigmenting the crude pigment.

[0042] The crude pigment prepared in the first step contains a metal halide phthalocyanine having zinc, iron, aluminum, magnesium, silicon, or vanadium as a central metal (hereinafter, also simply referred to as "metal halide phthalocyanine"). That is, the crude pigment is a metal halide phthalocyanine crude pigment selected from the group consisting of a zinc halide phthalocyanine crude pigment, an iron halide phthalocyanine crude pigment, an aluminum halide phthalocyanine crude pigment, a magnesium halide phthalocyanine crude pigment, a silicon halide phthalocyanine crude pigment, and a vanadium halide phthalocyanine crude pigment, and the pigment for a color filter manufactured by the manufacturing method of the present embodiment is a metal halide phthalocyanine pigment selected from the group consisting of a zinc halide phthalocyanine pigment, an iron halide phthalocyanine pigment, an aluminum halide phthalocyanine pigment, a magnesium halide phthalocyanine pigment, a silicon halide phthalocyanine pigment, and a vanadium halide phthalocyanine pigment.

[0043] The crude pigment can be obtained, for example, by precipitating the just-synthesized metal halide phthalocyanine (for example, an aggregate of metal halide phthalocyanine). The crude pigment may contain one kind of metal halide phthalocyanine or may contain a plurality of metal halide phthalocyanines having different numbers of halogen atoms.

[0044] The metal halide phthalocyanine has, for example, a structure represented by the following formula (1).

[0045] [Chemical Formula 1]

[0046]

[0047] In formula (1), X 1 ~X 16 each independently represents a hydrogen atom or a halogen atom. M is a central metal and represents Zn (zinc), Fe (iron), Al (aluminum), Mg (magnesium), Si (silicon), or V (vanadium). Z is an axial ligand bonded to the central metal (M) and represents a halogen atom, an oxygen atom, a hydroxyl group, a sulfonic acid group, -OP(=O)R 1 R 2 [R 1 and R 2 each independently represents a hydrogen atom, a hydroxyl group, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, or an aryloxy group which may have a substituent], -OC(=O)R 3 [R 3 represents a hydrogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an aryl group which may have a substituent, or a heterocyclic group which may have a substituent], -OS(=O)2R 4 [R 4A group represented by a hydroxyl group, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heterocyclic group which may have a substituent. m represents the number of Z bonded to M and is an integer from 0 to 2.

[0048] As R 1 ~R 4 Examples of the alkyl group include linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, neopentyl, n-hexyl, n-octyl, stearyl, 2-ethylhexyl, etc. Examples of the substituent of the alkyl group having a substituent include halogen atoms such as chlorine atom, fluorine atom, bromine atom; alkoxy groups such as methoxy group; aryl groups such as phenyl group, tolyl group; nitro group, etc. There may be multiple substituents. Examples of the alkyl group having a substituent include trichloromethyl, trifluoromethyl, 2,2,2-trifluoroethyl, 2,2-dibromoethyl, 2-ethoxyethyl, 2-butoxyethyl, 2-nitropropyl, benzyl, 4-methylbenzyl, 4-tert-butylbenzyl, 4-methoxybenzyl, 4-nitrobenzyl, 2,4-dichlorobenzyl, etc.

[0049] As R 1 ~R 4 Examples of the aryl group include monocyclic aromatic hydrocarbon groups such as phenyl group, p-tolyl group; condensed aromatic hydrocarbon groups such as naphthyl group, anthryl group, etc. Examples of the substituent of the aryl group having a substituent include halogen atoms such as chlorine atom, fluorine atom, bromine atom; alkoxy group; amino group; nitro group, etc. There may be multiple substituents. Examples of the aryl group having a substituent include p-bromophenyl, p-nitrophenyl, p-methoxyphenyl, 2,4-dichlorophenyl, pentafluorophenyl, 2-dimethylaminophenyl, 2-methyl-4-chlorophenyl, 4-methoxy-1-naphthyl, 6-methyl-2-naphthyl, 4,5,8-trichloro-2-naphthyl, anthraquinonyl, etc.

[0050] As R 1 and R 2 Examples of the alkoxy group include linear or branched alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, neopentoxy, 2,3-dimethyl-3-pentyloxy, n-hexoxy, n-octoxy, stearyloxy, 2-ethylhexoxy, etc. Examples of the substituent of the alkoxy group having a substituent include halogen atoms such as chlorine atom, fluorine atom, bromine atom; alkoxy group; aryl groups such as phenyl group, tolyl group; nitro group, etc. There may be multiple substituents. Examples of the alkoxy group having a substituent include trichloromethoxy, trifluoromethoxy, 2,2,2-trifluoroethoxy, 2,2,3,3-tetrafluoropropoxy, 2,2-di-trifluoromethylpropoxy, 2-ethoxyethoxy, 2-butoxyethoxy, 2-nitropropoxy, benzyloxy, etc.

[0051] As R 1 and R 2Examples of the aryloxy group in [the formula] include aryloxy groups containing a monocyclic aromatic hydrocarbon group such as phenoxy group and p-methylphenoxy group; aryloxy groups containing a condensed aromatic hydrocarbon group such as naphthyloxy group and anthryloxy group. Examples of the substituent of the aryloxy group having a substituent include halogen atoms such as chlorine atom, fluorine atom and bromine atom; alkyl group; alkoxy group; amino group; nitro group and the like. There may be a plurality of substituents. Examples of the aryloxy group having a substituent include p-nitrophenoxy group, p-methoxyphenoxy group, 2,4-dichlorophenoxy group, pentafluorophenoxy group, 2-methyl-4-chlorophenoxy group and the like.

[0052] As R 3 Examples of the cycloalkyl group in [the formula] include monocyclic aliphatic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, 2,5-dimethylcyclopentyl group and 4-tert-butylcyclohexyl group; condensed aliphatic hydrocarbon groups such as bornyl group and adamantyl group. Examples of the substituent of the cycloalkyl group having a substituent include halogen atoms such as chlorine atom, fluorine atom and bromine atom; alkyl group; alkoxy group; hydroxyl group; amino group; nitro group and the like. There may be a plurality of substituents. Examples of the cycloalkyl group having a substituent include 2,5-dichlorocyclopentyl group, 4-hydroxycyclohexyl group and the like.

[0053] As R 3 and R 4 Examples of the heterocyclic group in [the formula] include aliphatic heterocyclic groups and aromatic heterocyclic groups such as pyridyl group, pyrazinyl group, piperidyl group, pyranyl group, morpholinyl group and acridinyl group. Examples of the substituent of the heterocyclic group having a substituent include halogen atoms such as chlorine atom, fluorine atom and bromine atom; alkyl group; alkoxy group; hydroxyl group; amino group; nitro group and the like. There may be a plurality of substituents. Examples of the heterocyclic group having a substituent include 3-methylpyridyl group, N-methylpiperidyl group, N-methylpyrrolyl group and the like.

[0054] As X 1 ~X 16 Examples of the halogen atom represented by [X] include fluorine atom, chlorine atom, bromine atom and iodine atom. From the viewpoint of obtaining more excellent brightness, at least one of X 1 ~X 16 is preferably a bromine atom or a chlorine atom, and more preferably a bromine atom. X 1 ~X 16 may all be chlorine atoms or bromine atoms.

[0055] When M is Al, Si, or V, it is easier to obtain more excellent brightness. It is speculated that the reason is as follows: due to the axial ligand (Z) bonded to the central metal (M), it is not easy to generate the stacking of phthalocyanine rings caused by intermolecular interaction, and the crude pigment becomes less crystalline. In addition, when M is Zn, Fe, or Mg, and when a compound that reacts with water to generate an acid is used in the synthesis of metal halide phthalocyanine, it is easier to obtain more excellent brightness. The reason is speculated as follows. That is, in metal halide phthalocyanine with a distorted structure due to halogenation, when M is Zn, Fe, or Mg, compared with the case where M is Cu (copper), Ni (nickel), Co (cobalt), etc., the distance between the central metal (M) of the phthalocyanine ring and the nitrogen atom on the isoindoline unit is longer, and a large pore is formed around the central metal (M). Therefore, when the nitrogen atom on the isoindoline unit is protonated under acidic conditions, when M is Zn, Fe, or Mg, compared with the case where M is Cu (copper), Ni (nickel), Co (cobalt), etc., the counter anion (such as a halide ion like a chloride ion) is more likely to be stabilized in a state close to the central metal. Due to the presence of the counter anion, it is not easy to generate the stacking of phthalocyanine rings caused by intermolecular interaction, and thus the crude pigment becomes less crystalline. Therefore, it is speculated that more excellent brightness can be obtained.

[0056] m varies according to the valence of M. When the valence of M is 2, that is, when M is Zn, Fe, or Mg, m is 0. When the valence of M is 3, that is, when M is Al, m is 1. In the above cases, Z is a halogen atom, a hydroxyl group, a sulfonic acid group, a group represented by -OP(=O)R 1 R 2 represented group, a group represented by -OC(=O)R 3 represented group, a group represented by -OS(=O)2R 4 represented group. When the valence of M is 4, that is, when M is Si or V, m is 1 or 2. When the valence of M is 4 and m is 1, Z is an oxygen atom, and M and Z (oxygen atom) are bonded to each other by a double bond. When the valence of M is 4 and m is 2, Z is a halogen atom, a hydroxyl group, a sulfonic acid group, a group represented by -OP(=O)R 1 R 2 represented group, a group represented by -OC(=O)R 3 represented group, a group represented by -OS(=O)2R 4 represented group, and multiple Zs can be the same as or different from each other. Examples of the halogen atom represented by Z include: fluorine atom, chlorine atom, bromine atom, and iodine atom.

[0057] The average number of halogen atoms in one molecule of a metal halide phthalocyanine (for example, the compound represented by formula (1)) in the crude pigment is 0.1 or more and 16 or less. The average number of halogen atoms may also be less than 9, preferably 9 or more. When the average number of halogen atoms is 9 or more, 5 or more halogen atoms are present at the α-position of the phthalocyanine ring (in the compound represented by formula (1), at least five of X 1 、X 4 、X 5 、X 8 、X 9 、X 12 、X 13 and X 16 become halogen atoms), and at least two halogen atoms are adjacent to each other. Therefore, the phthalocyanine ring tends to form a distorted structure and the crystallinity of the crude pigment becomes lower. Therefore, when the average number of halogen atoms is 9 or more, there is a tendency to significantly obtain the effects of the present invention. From this viewpoint, the average number of halogen atoms may be 10 or more, 11 or more, 12 or more, 13 or more, 14 or more, or 15 or more. Further, when the metal halide phthalocyanine contains a halogen atom in the axial ligand, the number of the halogen atoms means the number of halogen atoms substituting the hydrogen atoms of the aromatic ring.

[0058] The average number of bromine atoms in one molecule of a metal halide phthalocyanine (for example, the compound represented by formula (1)) in the crude pigment may be less than 13, or may be 13 or more.

[0059] When the average number of bromine atoms is less than 13, the average number of chlorine atoms in one molecule of a metal halide phthalocyanine (for example, the compound represented by formula (1)) in the crude pigment may be 5 or less, 3 or less, 2.5 or less, or less than 2. The average number of chlorine atoms may be 0.1 or more, 0.3 or more, 0.6 or more, 0.8 or more, 1 or more, 1.3 or more, or 2 or more.

[0060] When the average number of bromine atoms is less than 13, the average number of chlorine atoms in one molecule of a metal halide phthalocyanine (for example, the compound represented by formula (1)) in the crude pigment may be 5 or less, 3 or less, 2.5 or less, or less than 2. The average number of chlorine atoms may be 0.1 or more, 0.3 or more, 0.6 or more, 0.8 or more, 1 or more, 1.3 or more, or 2 or more.

[0061] When the average number of bromine atoms is less than 13, the average number of halogen atoms in one molecule of the metal halide phthalocyanine (for example, the compound represented by formula (1)) in the crude pigment may be 14 or less, 13 or less, less than 13, or 12 or less. The average number of halogen atoms may be 8 or more, 9 or more, or 10 or more.

[0062] When the average number of bromine atoms is 13 or more, the average number of bromine atoms may be 15 or less. The average number of bromine atoms may also be 14 or more.

[0063] When the average number of bromine atoms is 13 or more, the average number of chlorine atoms in one molecule of the metal halide phthalocyanine (for example, the compound represented by formula (1)) in the crude pigment may be 0.1 or more or 1 or more. The average number of chlorine atoms may be 3 or less or less than 2.

[0064] When the average number of bromine atoms is 13 or more, the average number of halogen atoms in one molecule of the metal halide phthalocyanine (for example, the compound represented by formula (1)) in the crude pigment may be 13 or more, 14 or more, or 15 or more. The average number of halogen atoms may be 15 or less.

[0065] The number of the halogen atoms (for example, the number of bromine atoms and the number of chlorine atoms) is specified, for example, by mass analysis of the crude pigment using a matrix-assisted laser desorption ionization time-of-flight mass spectrometer (such as JMS-S3000 manufactured by JEOL Ltd.). Specifically, the number of each halogen atom can be calculated as a relative value per one metal atom based on the mass ratio of the metal atom (the metal atom that becomes the central metal of the metal halide phthalocyanine) in the crude pigment to each halogen atom.

[0066] The first step includes, for example: a step of synthesizing a metal halide phthalocyanine having zinc, iron, aluminum, magnesium, silicon, or vanadium as a central metal by an existing production method such as the chlorosulfonic acid method, the halogenated phthalonitrile method, or the melting method; and a step of precipitating the synthesized metal halide phthalocyanine to obtain a crude pigment (a crude metal halide phthalocyanine pigment). The step of synthesizing the metal halide phthalocyanine may also be, for example, a step of synthesizing the metal halide phthalocyanine using a compound that reacts with water to generate an acid. Examples of the method of synthesizing the metal halide phthalocyanine using a compound that reacts with water to generate an acid include the chlorosulfonic acid method and the melting method.

[0067] As the chlorosulfonic acid method, the following methods can be cited: Dissolve metal phthalocyanine (e.g., zinc phthalocyanine) in a sulfur oxide-based solvent such as chlorosulfonic acid, and introduce chlorine gas and bromine thereto for halogenation. The reaction at this time is carried out, for example, in the range of a temperature of 20°C to 120°C and a time of 3 hours to 20 hours. In the chlorosulfonic acid method, the sulfur oxide-based solvent such as chlorosulfonic acid is a compound that reacts with water to generate an acid. For example, chlorosulfonic acid reacts with water to generate hydrochloric acid and sulfuric acid.

[0068] As the phthalonitrile halogenation method, for example, the following methods can be cited: Appropriately use phthalic acid or phthalodinitrile in which part or all of the hydrogen atoms of the aromatic ring are substituted by halogen atoms such as bromine and chlorine, and a metal that becomes the central metal or a salt of the metal as starting materials to synthesize the corresponding metal halide phthalocyanine. In the above case, a catalyst such as ammonium molybdate may also be used as needed. The reaction at this time is carried out, for example, in the range of a temperature of 100°C to 300°C and a time of 7 hours to 35 hours.

[0069] As the melting method, the following methods can be cited: In a melt of about 10°C to 170°C containing one or more mixtures of various compounds that become solvents during halogenation, such as aluminum halides (e.g., aluminum chloride, aluminum bromide), titanium halides (e.g., titanium tetrachloride), alkali metal halides or alkaline earth metal halides (hereinafter referred to as “alkali (earth) metal halides”) (e.g., sodium chloride, sodium bromide), and thionyl chloride, halogenate metal phthalocyanine (e.g., zinc phthalocyanine) using a halogenating agent. In the melting method, the compounds such as aluminum halides, titanium halides, alkali (earth) metal halides, and thionyl chloride that become solvents during halogenation are compounds that react with water to generate an acid. For example, aluminum chloride reacts with water to generate hydrochloric acid.

[0070] The preferred aluminum halide is aluminum chloride. The addition amount of aluminum halide in the method using aluminum halide is usually 3 times the molar amount or more, preferably 10 times the molar amount to 20 times the molar amount, relative to metal phthalocyanine (e.g., zinc phthalocyanine).

[0071] Aluminum halide can be used alone, but if an alkali (earth) metal halide is used in combination with aluminum halide, the melting temperature can be further reduced, which is advantageous in terms of operation. The preferred alkali (earth) metal halide is sodium chloride. Regarding the amount of the added alkali (earth) metal halide, within the range of forming a molten salt, the alkali (earth) metal halide is preferably 1 part by mass to 15 parts by mass relative to 10 parts by mass of aluminum halide.

[0072] As the halogenating agent, the following can be cited: chlorine gas, sulfonyl chloride, bromine, etc.

[0073] The halogenation temperature is preferably 10°C to 170°C, more preferably 30°C to 140°C. Furthermore, in order to accelerate the reaction rate, pressure can also be applied. The reaction time can be 5 hours to 100 hours, preferably 30 hours to 45 hours.

[0074] Using two or more melting methods of the compound, the content ratio of the metal halide phthalocyanine having a specific halogen atom composition in the produced metal halide phthalocyanine can be arbitrarily controlled by adjusting the ratio of chloride, bromide, and iodide in the molten salt, or changing the introduction amount of chlorine, bromine, iodine, etc. and the reaction time. Therefore, it is preferred. In addition, according to the melting method, the decomposition of the raw materials during the reaction is less, the yield based on the raw materials is more excellent, and the reaction can be carried out using inexpensive equipment without using strong acids.

[0075] In the present embodiment, by optimizing the raw material charging method, the type and amount of the catalyst used, the reaction temperature, and the reaction time, a metal halide phthalocyanine having a halogen atom composition different from that of the existing metal halide phthalocyanine can be obtained.

[0076] Even in any of the above methods, in the reaction solution obtained after the reaction, the metal halide phthalocyanine is in a state dissolved in the reaction solution. After the reaction, the obtained mixture (reaction solution) is poured into an acidic aqueous solution such as water or hydrochloric acid, or a basic aqueous solution such as sodium hydroxide aqueous solution, so that the produced metal halide phthalocyanine precipitates (separates out). At this time, in the case of using the compound that reacts with water to generate an acid, if an acidic aqueous solution such as water or hydrochloric acid is used, acids such as hydrochloric acid and sulfuric acid are generated, and the acids are included in the precipitate, resulting in the acids remaining in the crude pigment. On the other hand, in the case of using a basic aqueous solution, the generation of acids can be suppressed, so that the inclusion of acids in the precipitate can be suppressed, and the remaining of acids in the crude pigment can be suppressed. If the crude pigment contains acids, it promotes the aggregation of particles caused by the acids during pigmentation, and it is considered to hinder the refinement of pigment particles. However, by reducing the acids included in the crude pigment by the above method, finer pigment particles can be obtained.

[0077] The first step may further include a post-treatment step of post-treating the precipitate after the precipitation step.

[0078] The first step may also further include a step of filtering the precipitate (first post-treatment step), for example. The first post-treatment step may be a step of filtering and washing the precipitate, or a step of filtering, washing, and drying the precipitate. Washing can be carried out using aqueous solvents such as water, sodium bisulfate water, sodium bicarbonate water, and sodium hydroxide water, for example. In the washing, organic solvents such as acetone, toluene, methanol, ethanol, and dimethylformamide may also be used as needed. For example, after washing with an aqueous solvent, washing with an organic solvent can be carried out. The washing can be repeated multiple times (for example, 2 to 5 times). Specifically, it is preferred to carry out the washing until the pH of the filtrate is the same as the pH of the water used in the washing (for example, the difference between the two is 0.2 or less).

[0079] The first step may further include, for example, a step of dry-grinding the precipitate (second post-treatment step). The dry-grinding can be carried out, for example, in a grinder, ball mill, vibration mill, vibration ball mill or other pulverizer. The dry-grinding can be carried out while heating (for example, while heating in such a way that the temperature inside the pulverizer becomes 40°C to 200°C). After the dry-grinding, washing with water can be carried out. By carrying out the washing with water after the dry-grinding (especially after the dry-grinding using a grinder), the amount of acid contained in the crude pigment can be further reduced. The washing can be either water washing (washing with water at a temperature below 40°C) or hot water washing (washing with water at a temperature of 40°C or higher). The washing is preferably carried out in the same manner as the first post-treatment step until the pH of the filtrate is equal to the pH of the water used in the washing (for example, the difference between the two is 0.2 or less). Furthermore, before or during the washing with water, a treatment for improving the wettability of the precipitate (for example, a treatment of bringing the precipitate into contact with a water-soluble organic solvent such as methanol) can be carried out. The dry-grinding and the washing can be repeated multiple times.

[0080] The first step may further include, for example, a step of kneading the precipitate together with water (third post-treatment step). By carrying out the third post-treatment step, the amount of acid contained in the crude pigment can be further reduced. The kneading can be carried out, for example, using a kneader, a mixing mill or the like. The kneading can be carried out while heating. For example, the temperature of the water can be set to 40°C or higher. An inorganic salt can be added to the water. At this time, by allowing at least a part of the inorganic salt to exist in a solid state, the force applied during the kneading can be increased. During the kneading, an organic solvent (for example, the organic solvent that can be used in the second step described later) can be used, but the amount of the organic solvent used is preferably less than the amount of water used, and more preferably no organic solvent is used. After the kneading, washing can be carried out in the same manner as the first post-treatment step. The kneading and the washing can be repeated multiple times.

[0081] The first step may further include, for example, a step of heating the precipitate in water (for example, boiling) (fourth post-treatment step). By carrying out the fourth post-treatment step, the amount of acid contained in the crude pigment can be further reduced. The heating temperature in water can be, for example, 40°C or higher and below the boiling point, and the heating time can be, for example, 1 minute to 300 minutes. An organic solvent (for example, the organic solvent that can be used in the second step described later) can be mixed and present in the water. The mixing amount of the organic solvent is preferably 20 parts by mass or less relative to 100 parts by mass of water. In the fourth post-treatment step, from the viewpoint of further removing the acid, washing can be carried out after heating the precipitate in water, or washing can be carried out after heating the precipitate in water, and further, the heating and washing in water can be repeated one or more times (preferably two or more times). The washing can be carried out in the same manner as the first post-treatment step.

[0082] In the present embodiment, two or more of the first post-treatment step to the fourth post-treatment step can be implemented. When two or more of the first post-treatment step to the fourth post-treatment step are implemented, the order thereof is not particularly limited.

[0083] The crude pigment can be obtained through the first step. As described above, in the present embodiment, the precipitate obtained in the first step can be directly used as the crude pigment, or the product obtained by subjecting the precipitate to the post-treatment step (at least one of the first post-treatment step to the fourth post-treatment step) can be used as the crude pigment.

[0084] The arithmetic standard deviation of the particle size distribution of the crude pigment is, for example, 15 nm or more. The arithmetic standard deviation of the particle size distribution of the crude pigment is, for example, 1500 nm or less. If the arithmetic standard deviation of the particle size distribution of the crude pigment is within such a range, it is easier to obtain finer pigment particles. The arithmetic standard deviation of the particle size distribution of the crude pigment can be measured using a dynamic light scattering particle size distribution measuring device. Specifically, it can be measured by the following method and conditions.

[0085] <Method>

[0086] Using zirconium beads with a size of 0.3 mm to 0.4 mm, disperse 2.48 g of the crude pigment, 1.24 g of BYK-LPN6919 manufactured by BYK-Chemie GmbH, 1.86 g of Unidic ZL-295 manufactured by DIC Corporation, and 10.92 g of propylene glycol monomethyl ether acetate together for 2 hours using a paint shaker manufactured by Toyo Seiki Seisaku-sho, Ltd. to obtain a dispersion. Dilute 0.02 g of the dispersion after removing the zirconium beads using a nylon sieve with 20 g of propylene glycol monomethyl ether acetate to obtain a dispersion for particle size distribution measurement.

[0087] <Conditions>

[0088] · Measuring instrument: Dynamic light scattering particle size distribution measuring device LB-550 (manufactured by Horiba, Ltd.)

[0089] · Measuring temperature: 25 °C

[0090] · Measuring sample: Dispersion for particle size distribution measurement

[0091] · Data analysis conditions: Particle size-based scattered light intensity, refractive index of the dispersion medium 1.402

[0092] The crude pigment may contain an acid inside. The case where the crude pigment contains an acid inside can be confirmed in the following way: Mix 5 g of the crude pigment with 5 g of methanol, and then further mix it with 100 ml of ion-exchanged water. Heat the obtained mixture for 5 minutes to bring it to a boiling state, and then heat it for another 5 minutes while maintaining the boiling state. Let the heated mixture cool to below 30 °C, and then adjust the total amount of the mixture to 100 ml with ion-exchanged water. After that, filter it and measure the pH of the obtained filtrate at 25 °C. In this specification, the pH of the filtrate measured by the above method is defined as the "pH of the crude pigment". When the pH of the crude pigment is less than 5, there is a tendency to significantly obtain the effects of the present invention. Especially when the central metal of the metal halide phthalocyanine constituting the crude pigment is zinc, iron or magnesium, when the crude pigment contains an acid inside, the crystallinity is more likely to become even lower, and there is a tendency to further significantly obtain the effects of the present invention. From the above perspective, the pH of the crude pigment can be 4.5 or less, or 3.5 or less. The pH of the filtrate can be, for example, 2.0 or more.

[0093] The second step includes a kneading step of kneading a mixture containing the crude pigment prepared in the first step, an inorganic salt, and an organic solvent at a maximum shear rate exceeding 800 s -1 . In the kneading step, the mixture is kneaded by using a kneading device to grind and refine the crude pigment. As the kneading device, for example, a kneader, a mix muller, a planetary mixer, a continuous single-shaft kneader, a flusher, etc. can be used. The kneading device can be an open type or a closed type, but if it is a closed type, the volatilization of the organic solvent can be suppressed, and the kneading time can be further extended. In addition, the kneader can be a tangential type or an intermeshing type. If it is a tangential type, kneading can be efficiently performed even when the viscosity of the kneaded material is high.

[0094] Figure 1 is a schematic cross-sectional view showing the internal structure of the kneading device used in the manufacturing method of one embodiment. Figure 1 The shown kneading device 10 is a double-arm kneader, including a kneading chamber 11 and a pair of blades 12 provided in the kneading chamber 11. In the kneading step, the mixture is put into the kneading chamber 11, and then the pair of blades 12 are rotated by a motor. In the kneading device 10, there is a clearance C1 between the inner wall surface 11a of the kneading chamber 11 and the blade 12, and the pair of blades 12 rotate around the rotation axis L1 in opposite directions ( Figure 1 the arrow direction shown), thereby applying a shear stress to the mixture passing through the clearance C1 to refine the crude pigment. Usually, the shapes of the pair of blades 12 are the same as each other.

[0095] Figure 2is a schematic plan view showing the internal structure of a kneading device used in another embodiment. Figure 3 is a sectional view taken along line Figure 2 III-III of Figure 2 and Figure 3 The kneading device 20 shown in and includes a kneading chamber 21 having a circular bottom surface 21a, a pair of muller wheels 22 provided in the kneading chamber 21, a column portion 23, a connecting portion 24, and a compression spring 25. The muller wheels 22 are connected to the column portion 23 through the connecting portion 24. The column portion 23 extends vertically from the center of the bottom surface 21a and can be rotated about the rotation axis L2 by a motor. In the kneading step, after the mixture is placed on the bottom surface 21a of the kneading chamber 21, the pair of muller wheels 22 revolve around the column portion 23 by rotating the column portion 23. In the kneading device 20, there is a clearance C2 between the bottom surface 21a of the kneading chamber 21 and the muller wheels 22. In a state where a load is applied from the vertical direction by the self-weight of the muller wheels 22 and / or the compression spring 25, the muller wheels 22 revolve and at the same time rotate by contacting the mixture passing through the clearance C2, whereby a kneading action, a smearing action, and a spatulating action act on the mixture, thereby making the coarse pigment finer. Usually, the shapes of the pair of muller wheels 22 are the same as each other.

[0096] When the maximum shear rate during kneading exceeds 800 s -1 , from the viewpoint of further suppressing the aggregation of the coarse pigment during kneading and further making the coarse pigment finer, it may also be 1500 s -1 or more or 2500 s -1 or more. From the viewpoint of preventing the breakage of the pigment particles, the maximum shear rate may be 5000 s -1 or less. From these viewpoints, the maximum shear rate may be more than 800 s -1 and 5000 s -1 or less, 1500 s -1 to 5000 s -1 or 2500 s -1 to 5000 s -1 . Here, the "maximum shear rate" refers to the shear rate at the part where the shear rate of the kneaded material in the kneading device is the maximum. When the moving speed of the kneaded material (the distance moved per unit time) is set to v and the width length of the part through which the kneaded material passes at the moving speed v is set to h, the "shear rate" can be expressed as v / h. For example, in the case of using the kneading device 10 shown in Figure 1 , the shear rate in the clearance C1 can be obtained by setting the moving speed of the kneaded material when passing through the clearance C1 to v and the width of the clearance C1 to h. In addition, for example, in the case of usingFigure 2 In the case of the kneading device 20 shown, the shear rate in the gap C2 can be obtained by setting the moving speed of the kneaded material passing through the gap C2 as v and the width of the gap C2 as h. Generally, at the narrowest part of the gap, the moving speed (distance moved per unit time) of the kneaded material is the maximum, and the shear rate is the maximum. Generally, the kneaded material is most affected by the shear caused by kneading at the part where the shear rate is the maximum. Therefore, by making the maximum shear rate greater than 800 s -1 , a state in which agglomeration of coarse pigments is less likely to occur can be maintained.

[0097] The maximum shear rate can be adjusted, for example, according to the shape of the kneading device and the rotational speed of the rotating body (such as the blade 12, the column part 23, etc.). Specifically, for example, Figure 1 In the kneading device 10 shown, the product of the outer circumference (2 × maximum radius r × π) of the rotational orbit of the blade 12 and the rotational speed of the blade 12, which is obtained based on the maximum radius r of the blade 12 (the longest distance among the shortest distances from the rotational axis L1 of the blade 12 to the surface of the blade 12), is the maximum moving speed of the kneaded material. Therefore, by adjusting the shape of the blade 12, the rotational speed of the blade 12, etc. to adjust the maximum moving speed and the gap of the kneaded material, the desired maximum shear rate can be set. Additionally, for example, Figure 2 In the kneading device 20 shown, the product of the outer circumference (2 × [shortest distance D + wheel width W] × π) of the revolution orbit of the roller 22 and the rotational speed of the column part 23, which is obtained based on the sum of the shortest distance D from the rotational axis L2 passing through the center of the column part 23 to the roller 22 and the wheel width W of the roller, is the maximum moving speed of the kneaded material. Therefore, by adjusting the shape of the roller, the length in the horizontal direction of the connecting part 24, the rotational speed of the column part 23, the intensity of the tension applied to the roller, etc. to adjust the maximum moving speed and the gap of the kneaded material, the desired shear rate can be set.

[0098] When using Figure 1 the kneading device 10 shown, the minimum value of the width of the gap C1 can be set, for example, to 0.1 mm to 3.0 mm, 0.1 mm to 1.0 mm, or 0.1 mm to 0.4 mm. The rotational speed of the blade 12 (in the case where the rotational speeds of a pair of blades 12 are different, it is the rotational speed of the blade 12 on the faster side) can be set, for example, to 30 rpm to 300 rpm, 100 rpm to 200 rpm, or 120 rpm to 160 rpm. The rotational speed ratio of the rotational speeds of a pair of blades 12 can be, for example, 2:1 to 1:2 or 1.5:1 to 1:1.5. As the blade, a sigma blade, a kneader blade, a Z blade, a double angle blade, etc. can be used.

[0099] When using Figure 2In the case of the kneading device 20 shown, the minimum value of the width of the gap C2 can be set, for example, to 1 mm to 30 mm, 1 mm to 20 mm, or 1 mm to 5 mm. The wheel width X of the roller 22 can be set, for example, to 10 mm to 100 mm, 20 mm to 50 mm, or 30 mm to 40 mm. In addition, the rotational speed of the column portion 23 (the revolution speed of the roller) can be set, for example, to 10 rpm to 100 rpm, 10 rpm to 60 rpm, or 15 rpm to 45 rpm. The rotational speed of the roller's self-rotation can be set, for example, to 10 rpm to 100 rpm, 10 rpm to 60 rpm, or 15 rpm to 45 rpm. The rotational speed of the roller's self-rotation can be the same as the revolution speed of the roller.

[0100] The maximum moving speed of the kneaded material can be set, for example, to 500 mm / s to 3500 mm / s, 700 mm / s to 3000 mm / s, or 2000 mm / s to 3000 mm / s.

[0101] In the kneading step, the mixture can be kneaded at a temperature below 110°C. By having a kneading temperature less than 110°C, the crystallization of the coarse pigment can be further suppressed. In terms of the above view, the kneading temperature can be 100°C or less, or 90°C or less. The kneading temperature can be, for example, 25°C or higher, 40°C or higher, or 60°C or higher. The kneading temperature can also be 110°C or higher. The kneading temperature can be, for example, 25°C to 150°C, 25°C or higher and less than 110°C, 40°C to 100°C, or 60°C to 90°C. Furthermore, the kneading temperature is the temperature of the mixture (kneaded material) during kneading. In the kneading step, in order to adjust the temperature of the kneaded material to the above range, a temperature adjustment device can be used. For example, the mixture can be heated by flowing a heat medium (such as ethylene glycol) that has been heated by the temperature adjustment device through the jacket of the kneading device.

[0102] In the kneading step, the power consumption for kneading the mixture is more than 10.0 kWh per 1 kg of coarse pigment. Here, "the power consumption for kneading the mixture" has the same meaning as the energy input into the mixture through kneading, and can be obtained by subtracting the power consumption of the kneading device when the kneading device runs empty for the same time as the kneading time without putting the mixture into the kneading device from the total power consumption of the kneading device during the kneading time of the mixture, that is, from the start to the end of kneading. Among them, in the case of consuming power for heating, the power for heating (for example, the power for heating the heat medium using the temperature adjustment device) is not included in the above power.

[0103] From the perspective of further refining the crude pigment to obtain a color filter pigment with a more excellent brightness improvement effect, the power consumption for kneading the mixture can be set to 14.0 kWh or more, or 25.0 kWh or more per 1 kg of the crude pigment. From the perspective of suppressing the aggregation of the crude pigment caused by excessive kneading, the power consumption for kneading the mixture can be set to 100.0 kWh or less, 70.0 kWh or less, or 50.0 kWh or less per 1 kg of the crude pigment. From these perspectives, the power consumption for kneading the mixture can be set to more than 10.0 kWh and 100.0 kWh or less, 14.0 kWh to 70.0 kWh, or 14.0 kWh to 50.0 kWh per 1 kg of the crude pigment. Furthermore, the power consumption for kneading the mixture can be adjusted according to the kneading time, the shape of the kneading device, the rotation speed of the rotating body (such as the blade 12, the column part 23, etc.), the blending ratio of the mixture, the type of the organic solvent in the mixture, etc.

[0104] From the perspective of further refining the crude pigment to obtain a color filter pigment with a more excellent brightness improvement effect, the kneading time can be 5 hours or more, 7 hours or more, or 9 hours or more. From the perspective of suppressing the aggregation of the crude pigment caused by excessive kneading, the kneading time can be 100 hours or less, 50 hours or less, or 30 hours or less. From these perspectives, the kneading time can be 5 hours to 100 hours, 7 hours to 50 hours, or 9 hours to 30 hours.

[0105] It is preferable to use an organic solvent that does not dissolve the crude pigment and the inorganic salt described below. As the organic solvent, it is preferable to use an organic solvent that can suppress crystal growth. As such an organic solvent, a water-soluble organic solvent can be preferably used. As the organic solvent, for example, diethylene glycol, glycerol, 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, ethylenecyanohydrin, etc. can be used. The organic solvent can be used alone or in combination of multiple kinds.

[0106] In terms of promoting the wetting of the surface of pigment particles and more efficiently refining the pigment particles, the amount of the organic solvent (e.g., water-soluble organic solvent) used may be 1 part by mass or more, 30 parts by mass or more, or 50 parts by mass or more with respect to 100 parts by mass of the coarse pigment. In terms of the force applied to the coarse pigment during kneading becoming greater due to the increase in the viscosity of the mixture and further suppressing the aggregation of the coarse pigment during kneading, the amount of the organic solvent (e.g., water-soluble organic solvent) used may be 500 parts by mass or less, 400 parts by mass or less, or 200 parts by mass or less with respect to 100 parts by mass of the coarse pigment. In terms of these viewpoints, the amount of the organic solvent (e.g., water-soluble organic solvent) used may be 1 part by mass to 500 parts by mass, 30 parts by mass to 400 parts by mass, or 50 parts by mass to 200 parts by mass with respect to 100 parts by mass of the coarse pigment. Furthermore, the amount of the organic solvent used can also be said to be the content of the organic solvent in the mixture.

[0107] As the inorganic salt, an inorganic salt having solubility in water and / or methanol can be preferably used, and an inorganic salt having solubility in water (water-soluble inorganic salt) can be more preferably used. Specific examples of the inorganic salt include sodium chloride, potassium chloride, lithium chloride, sodium sulfate, etc. The average particle diameter of the primary particles of the inorganic salt (average primary particle diameter) is, for example, 0.5 μm to 50 μm.

[0108] Such an inorganic salt can be easily obtained by finely pulverizing a common inorganic salt. The average primary particle diameter of the inorganic salt can be measured by the same method as the average primary particle diameter of the pigment described later. Specifically, the inorganic salt can be ultrasonically dispersed in cyclohexane, and then photographed using a microscope, and the average particle diameter of the primary particles (average primary particle diameter) can be calculated based on the average value of 40 primary particles constituting the aggregate on the two-dimensional image.

[0109] In terms of the force applied to the coarse pigment during kneading becoming greater and further suppressing the aggregation of the coarse pigment during kneading, the amount of the inorganic salt (e.g., water-soluble inorganic salt) used may be 30 parts by mass or more, 40 parts by mass or more, or 50 parts by mass or more with respect to 1 part by mass of the coarse pigment. In terms of improving the production efficiency of the pigment, the amount of the inorganic salt (e.g., water-soluble inorganic salt) used may be 100 parts by mass or less, 80 parts by mass or less, or 60 parts by mass or less with respect to 1 part by mass of the coarse pigment. In terms of these viewpoints, the amount of the inorganic salt (e.g., water-soluble inorganic salt) used may be 30 parts by mass to 100 parts by mass, 30 parts by mass to 60 parts by mass, or 40 parts by mass to 60 parts by mass with respect to 1 part by mass of the coarse pigment. Furthermore, the amount of the inorganic salt used can also be said to be the content of the inorganic salt in the mixture.

[0110] In the kneading step, it is preferable not to use water. With respect to 100 parts by mass of the crude pigment, the amount of water used is, for example, 20 parts by mass or less, and may also be 10 parts by mass or less or 5 parts by mass or less.

[0111] After the kneading step, a cleaning step of cleaning the kneaded mixture may be carried out. As the cleaning, depending on the type of inorganic salt, water washing, hot water washing, washing with an organic solvent (for example, an organic solvent with a low surface tension such as methanol), and combinations thereof may be employed. In the case of using a water-soluble inorganic salt and a water-soluble organic solvent, the organic solvent and the inorganic salt can be easily removed by water washing.

[0112] In the case of using a crude pigment containing an encapsulated acid (for example, a crude pigment with a pH of less than 5), the cleaning step may be carried out using an alkaline aqueous solution such as an aqueous potassium hydroxide solution. By using the alkaline aqueous solution, the counter anion is detached from a part of the metal phthalocyanine halide protonated under acidic conditions, and there is a tendency for the heat resistance to increase and an effect of further improving the brightness to be obtained. From the viewpoint of easily obtaining the above effect, as the alkaline aqueous solution, an aqueous solution with a pH greater than 8 at 25 °C can be used. The temperature of the alkaline aqueous solution is, for example, 40 °C to 90 °C.

[0113] The cleaning can be carried out by stirring the mixture in a cleaning liquid (for example, water, an organic solvent, or an alkaline aqueous solution, etc.). The cleaning can be repeated, for example, within the range of 1 to 5 times. With respect to 100 parts by mass of the total amount of the mixture, the amount of the cleaning liquid used for one cleaning is, for example, 200 parts by mass to 1500 parts by mass. If necessary, acid cleaning can also be carried out.

[0114] After the cleaning, operations such as filtration, drying, and pulverization of the cleaned mixture (a solid material mainly composed of a pigment) may also be carried out as needed. As the drying after the above cleaning and filtration, for example, batch-type or continuous drying for dehydrating and / or desolventizing the pigment by heating at 80 °C to 120 °C using a heat source provided in a dryer can be cited. As the dryer, generally, a box-type dryer, a belt dryer, a spray dryer, etc. can be cited. In particular, spray drying using a spray dryer is easy to disperse when making a paste, so it is preferred. In the case of using an organic solvent in the cleaning, vacuum drying is preferably carried out at 0 °C to 60 °C.

[0115] The pulverization after drying is not an operation for increasing the specific surface area or reducing the average particle diameter of the primary particles, but an operation for pulverizing the pigment by spreading it when the pigment becomes in a ramp shape or the like in the case of drying using, for example, a box-type dryer or a belt dryer. For example, pulverization using a mortar, a hammer mill, a disk mill, a needle mill, a jet mill, etc. can be cited.

[0116] According to the manufacturing method, compared with the pigmentation of a crude metal halide phthalocyanine pigment by an existing method, further refinement can be achieved. That is, the pigment obtained by the manufacturing method is a further refined metal halide phthalocyanine pigment, and when used as a pigment for a color filter, the brightness of the pixel portion (especially the green pixel portion) can be further increased. Generally, the smaller the particle diameter (primary particle diameter) of the color filter pigment, the higher the brightness and contrast of the pixel portion. Therefore, when the metal halide phthalocyanine pigment obtained by the manufacturing method is used as a green pigment for a color filter, there is a tendency to obtain excellent contrast as well.

[0117] The average particle diameter (average primary particle diameter) of the primary particles of the pigment obtained by the method is, for example, 30 nm or less. According to the method, for example, a pigment having an average primary particle diameter of 25 nm or less can also be obtained. The average primary particle diameter of the pigment can be 10 nm or more. Here, the average primary particle diameter is the average value of the major axis lengths of the primary particles, and can be obtained by measuring the major axis lengths of the primary particles in the same way as the measurement of the average aspect ratio described later.

[0118] The average aspect ratio of the primary particles of the pigment is, for example, 1.2 or more, 1.3 or more, 1.4 or more, or 1.5 or more. The average aspect ratio of the primary particles of the pigment is, for example, less than 2.0, 1.8 or less, 1.6 or less, or 1.4 or less. With a pigment having such an average aspect ratio, more excellent brightness and contrast can be obtained.

[0119] Preferably, the pigment in which the average aspect ratio of the primary particles is in the range of 1.0 to 3.0 does not contain primary particles having an aspect ratio of 5 or more, more preferably does not contain primary particles having an aspect ratio of 4 or more, and still more preferably does not contain primary particles having an aspect ratio exceeding 3.

[0120] The aspect ratio and average aspect ratio of the primary particles can be measured by the following method. First, particles within the field of view are photographed using a transmission electron microscope (for example, JEM-2010 manufactured by JEOL Ltd.). Then, the longer diameter (major axis) and the shorter diameter (minor axis) of the primary particles present on the two-dimensional image are measured, and the ratio of the major axis to the minor axis is taken as the aspect ratio of the primary particles. In addition, for 40 primary particles, the average values of the major axis and the minor axis are obtained, and the ratio of the major axis to the minor axis is calculated using these values and taken as the average aspect ratio. At this time, with respect to the pigment as the sample, it is ultrasonically dispersed in a solvent (for example, cyclohexane), and then photographed using a microscope. In addition, a scanning electron microscope can also be used instead of the transmission electron microscope.

[0121] Examples

[0122] Hereinafter, the content of the present invention will be described in more detail using experimental examples, but the present invention is not limited to the following experimental examples.

[0123] <Synthesis of Crude Pigment>

[0124] (Synthesis of Crude Pigment A1)

[0125] Into a 300 ml flask, 91 g of sulfonyl chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 109 g of aluminum chloride (manufactured by Kanto Chemical Co., Inc.), 15 g of sodium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.), 30 g of zinc phthalocyanine (manufactured by DIC Corporation), and 230 g of bromine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were charged, and then the temperature was raised to 130 °C and maintained at 130 °C for 40 hours. The reaction mixture (reaction solution) was taken out into water, and after the precipitate was precipitated, the precipitate was filtered, washed with water, and dried to obtain crude pigment A1. Furthermore, the water washing was carried out until the difference between the pH of the filtrate and the pH of the water used for washing became ±0.2.

[0126] For crude pigment A1, mass analysis was performed using JMS-S3000 manufactured by JEOL Ltd., and it was confirmed to be a zinc phthalocyanine halide with an average bromine number of 13.2 and an average chlorine number of 1.8. Furthermore, the delay time during mass analysis was 500 ns, the laser intensity was 44%, and the resolving power value of the peak with m / z = 1820 or more and 1860 or less was 31804.

[0127] (Synthesis of Crude Pigment A2)

[0128] Into a 300 ml flask, 90 g of sulfonyl chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 105 g of aluminum chloride (manufactured by Kanto Chemical Co., Inc.), 14 g of sodium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.), 27 g of zinc phthalocyanine (manufactured by DIC Corporation), and 55 g of bromine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were charged, and then the temperature was raised to 130 °C and maintained at 130 °C for 40 hours. The reaction mixture (reaction solution) was taken out into water, and after the precipitate was precipitated, the precipitate was filtered, washed with water, and dried to obtain crude pigment A2. Furthermore, the water washing was carried out until the pH of the filtrate became the same as the pH of the water used for washing.

[0129] For the crude pigment A2, quality analysis was performed using a JMS-S3000 manufactured by JEOL Ltd., and it was confirmed to be a zinc halide phthalocyanine with an average bromine number of 9.3 and an average chlorine number of 2.9. Furthermore, the delay time during quality analysis was 510 ns, the laser intensity was 40%, and the resolving power value for peaks with m / z = 1820 or more and 1860 or less was 65086.

[0130] (Synthesis of crude pigment A3)

[0131] Into a 300 ml flask, 91 g of sulfuryl chloride (manufactured by FUJIFILM Wako Pure Chemical Corporation), 109 g of aluminum chloride (manufactured by Kanto Chemical Co., Inc.), 15 g of sodium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.), 30 g of chloroaluminum phthalocyanine (manufactured by Tokyo Chemical Industry Co., Ltd.), and 230 g of bromine (manufactured by FUJIFILM Wako Pure Chemical Corporation) were charged, and then the temperature was raised to 130 °C and maintained at 130 °C for 40 hours. The reaction mixture (reaction solution) was taken out into water, and after the precipitate was precipitated, the precipitate was filtered, washed with water, and dried to obtain crude pigment A3. Furthermore, the water washing was carried out until the difference between the pH of the filtrate and the pH of the water used for washing became ±0.2.

[0132] For the crude pigment A3, quality analysis was performed using a JMS-S3000 manufactured by JEOL Ltd., and it was confirmed to be a chloroaluminum halide phthalocyanine (aluminum halide phthalocyanine having a chlorine group in the axial ligand) with an average bromine number of 14.3 and an average chlorine number of 1.4 (excluding the chlorine atoms (chlorine groups) of the axial ligand). Furthermore, the delay time during quality analysis was 275 ns, the laser intensity was 40%, and the resolving power value for peaks with m / z = 1820 or more and 1860 or less was 56320.

[0133] (Synthesis of crude pigment A4)

[0134] Into a 300 ml flask, 91 g of sulfonyl chloride (manufactured by Fujifilm Wako Pure Chemical Corporation), 109 g of aluminum chloride (manufactured by Kanto Chemical Co., Inc.), 15 g of sodium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.), 30 g of copper phthalocyanine (manufactured by Tokyo Chemical Industry Co., Ltd.), and 230 g of bromine (manufactured by Fujifilm Wako Pure Chemical Corporation) were charged. Then, the temperature was raised to 130 °C and maintained at 130 °C for 40 hours. The reaction mixture (reaction solution) was taken out into water, and after the precipitate was precipitated, the precipitate was filtered, washed with water, and dried to obtain crude pigment A4. Furthermore, the water washing was carried out until the difference between the pH of the filtrate and the pH of the water used in the washing became ±0.2.

[0135] For crude pigment A4, mass analysis using JMS-S3000 manufactured by JEOL Ltd. was carried out, and it was confirmed to be a copper phthalocyanine halide with an average bromine number of 13.0 and an average chlorine number of 2.6. Furthermore, the delay time during mass analysis was 275 ns, the laser intensity was 34%, and the resolving power value of the peak with m / z = 1820 or more and 1860 or less was 42805.

[0136] <Measurement of pH of Crude Pigment>

[0137] In a 300 ml beaker, 5 g of the crude pigment (crude pigments A1 to A4) and 5 g of methanol were measured and mixed. Then, 100 ml of ion-exchanged water was further measured, and it was set to a boiling state for 5 minutes using a hot stirrer, and boiling was continued for 5 minutes. Then, it was allowed to cool to 30 °C or lower, and then transferred to a 100 ml graduated cylinder. The total volume was adjusted to 100 ml using ion-exchanged water, and then filtered, and the pH of the filtrate was measured. The pH was measured using a PH71 personal pH meter manufactured by Yokogawa Electric Corporation. The results are shown in Table 1.

[0138] <Experimental Example 1>

[0139] (Pigmentation of Crude Pigment)

[0140] 320 g of crude pigment A1, 3200 g of crushed sodium chloride (manufactured by Naruto Salt Industry Co., Ltd., trade name: Selected Super Grade Salt Eddy Salt Particles, average primary particle diameter after crushing: 120 μm), and 504 g of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged into a double-arm kneader (manufactured by Inoue Seisakusho Co., Ltd., product name: KHD-8, closed type tangential type). For this mixture, kneading was carried out while adjusting the kneading temperature (temperature of the mixture during kneading) to 80 °C (temperature variation range: about 2 °C to 3 °C). At this time, the blades of the double-arm kneader used sigma blades with a shape where the outer circumference of the rotation orbit was 0.35 m and the minimum width of the gap between the blade and the inner wall surface of the kneading chamber (trough) was 0.5 mm. By setting the rotation speed of the blade (the rotation speed of the faster side) to 140 rpm (rotation speed ratio = 1:1.4), the maximum moving speed of the kneaded material (outer circumference of the blade's rotation orbit × rotation speed of the blade) was set to 817 mm / s, and the maximum shear speed (maximum moving speed of the kneaded material × minimum width of the gap) was set to 1633 s -1 . In addition, the power consumption of the double-arm kneader was measured using a Watt Monitor TAP-TST8N manufactured by SANWA SUPPLY Co., and the kneading time was adjusted so that the power consumption for kneading the mixture was 15.0 kWh per 1 kg of crude pigment A1. The kneading time was set to 10 hours. The kneaded mixture was taken out into 16 kg of water at 80 °C, stirred for 1 hour, then filtered, washed with hot water, dried, and pulverized to obtain green pigment G1.

[0141] (Measurement of average primary particle diameter)

[0142] Green pigment G1 was ultrasonically dispersed in cyclohexane, and then photographed using a microscope. The average particle diameter (average primary particle diameter) of the primary particles was calculated based on the average of 40 primary particles constituting the aggregates on the two-dimensional image. The average particle diameter of the primary particles was 28 nm.

[0143] (Evaluation of contrast and brightness)

[0144] Using zirconium beads with a diameter of 0.3 mm to 0.4 mm, 1.65 g of pigment yellow 138 (Chromofine Yellow 6206EC manufactured by Dainichi Seika Co., Ltd.) was dispersed with 3.85 g of DISPERBYK-161 (manufactured by BYK-Chemie GmbH) and 11.00 g of propylene glycol monomethyl ether acetate for 2 hours using a paint shaker manufactured by Toyo Seiki Co., Ltd. to obtain a dispersion.

[0145] Add 4.0 g of the said dispersion, 0.98 g of Unidic ZL-295, and 0.22 g of propylene glycol monomethyl ether acetate, and mix them using a paint shaker to obtain a yellow composition for color adjustment (TY1).

[0146] Using zirconium beads with a diameter of 0.3 mm to 0.4 mm, disperse 2.48 g of the green pigment G1 obtained in Experimental Example 1, 1.24 g of BYK-LPN6919 manufactured by BYK Chemie GmbH, 1.86 g of Unidic ZL-295 manufactured by DIC Corporation, and 10.92 g of propylene glycol monomethyl ether acetate together for 2 hours using a paint shaker manufactured by Toyo Seiki Co., Ltd. to obtain a pigment dispersion for color filter (MG1).

[0147] Add 4.0 g of the said pigment dispersion for color filter (MG1), 0.98 g of Unidic ZL-295 manufactured by DIC Corporation, and 0.22 g of propylene glycol monomethyl ether acetate, and mix them using a paint shaker to obtain an evaluation composition (CG1) for forming a green pixel portion of a color filter.

[0148] Spin-coat the evaluation composition (CG1) onto a soda lime glass substrate, dry it at 90°C for 3 minutes, and then heat it at 230°C for 1 hour. Thus, a glass substrate for contrast evaluation with a colored film on the soda lime glass substrate is produced. Furthermore, adjust the rotation speed during spin-coating so that the thickness of the colored film obtained by heating at 230°C for 1 hour is 1.8 μm.

[0149] Furthermore, spin-coat the coating solution obtained by mixing the produced yellow composition for color adjustment (TY1) and the evaluation composition (CG1) onto a soda lime glass substrate, dry it at 90°C for 3 minutes, and then heat it at 230°C for 1 hour. Thus, a glass substrate for brightness evaluation with a colored film on the soda lime glass substrate is produced. Furthermore, by adjusting the mixing ratio of the yellow composition for color adjustment (TY1) and the evaluation composition (CG1) and the rotation speed during spin-coating, produce a colored film whose chromaticity (x, y) under a C light source of the colored film obtained by heating at 230°C for 1 hour becomes (0.275, 0.570).

[0150] The contrast of the colored film on the glass substrate for contrast evaluation was measured using the contrast tester CT-1 manufactured by Kamban Electric Co., Ltd., and the brightness of the colored film on the glass substrate for brightness evaluation was measured using the U-3900 manufactured by Hitachi High-Technologies Science Corporation. The results are shown in Table 1. Furthermore, the contrast and brightness shown in Table 1 are values based on the contrast and brightness of Experimental Example 7.

[0151] <Experimental Example 2>

[0152] The blade was changed to a sigma blade with a larger diameter so that the minimum value of the width of the gap between the blade and the inner wall surface of the kneading chamber was 0.25 mm, and kneading was performed with the shear rate set to 3267 s -1 , and except for this, green pigment G2 was obtained in the same manner as in Experimental Example 1. Furthermore, the power consumption for kneading the mixture was 28.3 kWh per 1 kg of crude pigment A1. In addition, the average primary particle diameter of green pigment G2 was measured in the same manner as in Experimental Example 1. In addition, except for using green pigment G2 instead of green pigment G1, a glass substrate for contrast evaluation and a glass substrate for brightness evaluation were produced in the same manner as in Experimental Example 1, and the contrast and brightness were measured. The results are shown in Table 1.

[0153] <Experimental Example 3>

[0154] Except for setting the kneading temperature to 130 °C, green pigment G3 was obtained in the same manner as in Experimental Example 1. Furthermore, the power consumption for kneading the mixture was 13.7 kWh per 1 kg of crude pigment A1. In addition, the average primary particle diameter of green pigment G3 was measured in the same manner as in Experimental Example 1. In addition, except for using green pigment G3 instead of green pigment G1, a glass substrate for contrast evaluation and a glass substrate for brightness evaluation were produced in the same manner as in Experimental Example 1, and the contrast and brightness were measured. The results are shown in Table 1.

[0155] <Experimental Example 4>

[0156] Except for setting the usage amount of crude pigment A1 to 80 g so that the usage amount of sodium chloride became 40 times the usage amount of the crude pigment, green pigment G4 was obtained in the same manner as in Experimental Example 1. Furthermore, the power consumption for kneading the mixture was 14.6 kWh per 1 kg of crude pigment A1. In addition, the average primary particle diameter of green pigment G4 was measured in the same manner as in Experimental Example 1. In addition, except for using green pigment G4 instead of green pigment G1, a glass substrate for contrast evaluation and a glass substrate for brightness evaluation were produced in the same manner as in Experimental Example 1, and the contrast and brightness were measured. The results are shown in Table 1.

[0157] <Experimental Example 5>

[0158] A green pigment G5 was obtained in the same manner as in Experimental Example 4, except that the kneaded mixture was taken out into a 5% potassium hydroxide aqueous solution at 80°C (pH at 25°C: 13.8) instead of water at 80°C. In addition, the average primary particle diameter of the green pigment G5 was measured in the same manner as in Experimental Example 1. Further, a glass substrate for contrast evaluation and a glass substrate for brightness evaluation were produced in the same manner as in Experimental Example 1, except that the green pigment G5 was used instead of the green pigment G1, and the contrast and brightness were measured. The results are shown in Table 1.

[0159] <Experimental Example 6>

[0160] 3 kg of crude pigment A1, 30 kg of pulverized sodium chloride, and 4.7 kg of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged into a kneader (manufactured by Shin-Tong Kogyo Co., Ltd., product name: MSG-60E), and the mixture was kneaded at a kneading temperature of 80°C (temperature of the mixture during kneading). At this time, as the roller in the kneader, a roller with a diameter of 1200 mm and a thickness of 360 mm was used, and the position of the roller and the intensity of the tension applied to the roller (the tension applied to the roller was set to 3365 kg) were adjusted so that the outer circumference of the revolution orbit of the roller was 3.75 m and the minimum value of the width of the gap between the roller and the bottom surface of the kneading chamber was 3 mm. In addition, by setting the rotational speed of the column part (revolution speed of the roller) to 40 rpm, the maximum moving speed of the kneaded material (outer circumference of the revolution orbit of the roller × rotational speed of the column part) was set to 2500 mm / s, and the maximum shear speed (maximum moving speed of the kneaded material × minimum value of the width of the gap) was set to 833 s -1 . Furthermore, the rotational speed of the roller's self-rotation was set to 40 rpm. In addition, the power consumption of the kneader was measured using a watt monitor (Watt Monitor) TAP-TST8N manufactured by SANWA SUPPLY Co., and the kneading time was adjusted so that the power consumption for kneading the mixture was 11.5 kWh per 1 kg of crude pigment A1. The kneading time was set to 2.5 hours. The kneaded mixture was taken out into 150 kg of water at 80°C, stirred for 1 hour, then filtered, washed with hot water, dried, and pulverized to obtain a green pigment G6.

[0161] The average primary particle diameter of the green pigment G6 was measured in the same manner as in Experimental Example 1. A glass substrate for contrast evaluation and a glass substrate for brightness evaluation were produced in the same manner as in Experimental Example 1, except that the green pigment G6 was used instead of the green pigment G1, and the contrast and brightness were measured. The results are shown in Table 1.

[0162] <Experimental Example 7>

[0163] The blades were changed to sigma blades with a smaller diameter so that the minimum width of the gap between the blades and the inner wall surface of the kneading chamber was 1 mm for kneading. The rotational speed of the blades was set to 70 rpm, and the maximum moving speed of the kneaded material (outer circumference of the rotational orbit of the blades × rotational speed of the blades) was set to 408 mm / s. The maximum shear speed (maximum moving speed of the kneaded material × minimum width of the gap) was set to 408 s -1 , and the kneading time was set to 8 hours, and the power consumption for kneading the mixture was set to 8.0 kWh per 1 kg of crude pigment A1. Other than that, green pigment G7 was obtained in the same manner as in Experimental Example 1. In addition, the average primary particle diameter of green pigment G7 was measured in the same manner as in Experimental Example 1. In addition, except for using green pigment G7 instead of green pigment G1, a glass substrate for contrast evaluation and a glass substrate for brightness evaluation were produced in the same manner as in Experimental Example 1, and the contrast and brightness were measured. The results are shown in Table 1.

[0164] <Experimental Example 8>

[0165] The kneading time was set to 24 hours, and the power consumption for kneading the mixture was set to 23.9 kWh per 1 kg of crude pigment A1. Other than that, green pigment G8 was obtained in the same manner as in Experimental Example 7. In addition, the average primary particle diameter of green pigment G8 was measured in the same manner as in Experimental Example 1. In addition, except for using green pigment G8 instead of green pigment G1, a glass substrate for contrast evaluation and a glass substrate for brightness evaluation were produced in the same manner as in Experimental Example 1, and the contrast and brightness were measured. The results are shown in Table 1.

[0166] [Table 1]

[0167]

[0168] <Experimental Example 9>

[0169] A green pigment G9 was obtained in the same manner as in Experimental Example 5, except that crude pigment A2 was used instead of crude pigment A1. Furthermore, the power consumption for kneading the mixture was 14.7 kWh per 1 kg of crude pigment A2. In addition, the average primary particle diameter of green pigment G9 was measured in the same manner as in Experimental Example 1. Additionally, Pigment Yellow 185 (Paliotol Yellow D1155 manufactured by BASF) was used instead of Pigment Yellow 138 (Chromofine Yellow 6206EC manufactured by Dainichi Seika), green pigment G9 was used instead of green pigment G1, and the chromaticity (x, y) of the colored film was adjusted to (0.230, 0.670). Except for this, a glass substrate for contrast evaluation and a glass substrate for brightness evaluation were produced in the same manner as in Experimental Example 1, and the contrast and brightness were measured. The results are shown in Table 2. Furthermore, the contrast and brightness shown in Table 2 are values based on the contrast and brightness of Experimental Example 10.

[0170] <Experimental Example 10>

[0171] A green pigment G10 was obtained in the same manner as in Experimental Example 7, except that crude pigment A2 was used instead of crude pigment A1. Furthermore, the power consumption for kneading the mixture was 8.0 kWh per 1 kg of crude pigment A2. In addition, the average primary particle diameter of green pigment G10 was measured in the same manner as in Experimental Example 1. Additionally, a glass substrate for contrast evaluation and a glass substrate for brightness evaluation were produced in the same manner as in Experimental Example 9, except that green pigment G10 was used instead of green pigment G9, and the contrast and brightness were measured. The results are shown in Table 2.

[0172] [Table 2]

[0173]

[0174] <Experimental Example 11>

[0175] A green pigment G11 was obtained in the same manner as in Experimental Example 5, except that crude pigment A3 was used instead of crude pigment A1. Furthermore, the power consumption for kneading the mixture was 14.4 kWh per 1 kg of crude pigment A3. The average primary particle diameter of green pigment G11 was measured in the same manner as in Experimental Example 1. Additionally, a glass substrate for contrast evaluation and a glass substrate for brightness evaluation were produced in the same manner as in Experimental Example 1, except that green pigment G11 was used instead of green pigment G1, and the contrast and brightness were measured. The results are shown in Table 3. Furthermore, the contrast and brightness shown in Table 3 are values based on the contrast and brightness of Experimental Example 12.

[0176] <Experimental Example 12>

[0177] A green pigment G12 was obtained in the same manner as in Experimental Example 7, except that coarse pigment A3 was used instead of coarse pigment A1. Furthermore, the power consumption for kneading the mixture was 8.0 kWh per 1 kg of coarse pigment A3. In addition, the average primary particle diameter of the green pigment G12 was measured in the same manner as in Experimental Example 1. Further, a glass substrate for contrast evaluation and a glass substrate for brightness evaluation were produced in the same manner as in Experimental Example 1, except that the green pigment G12 was used instead of the green pigment G1, and the contrast and brightness were measured. The results are shown in Table 3.

[0178] [Table 3]

[0179]

[0180] <Experimental Example 13>

[0181] A green pigment G13 was obtained in the same manner as in Experimental Example 5, except that coarse pigment A4 was used instead of coarse pigment A1. Furthermore, the power consumption for kneading the mixture was 14.3 kWh per 1 kg of coarse pigment A4. The average primary particle diameter of the green pigment G13 was measured in the same manner as in Experimental Example 1. In addition, a glass substrate for contrast evaluation and a glass substrate for brightness evaluation were produced in the same manner as in Experimental Example 1, except that the green pigment G13 was used instead of the green pigment G1, and the contrast and brightness were measured. The results are shown in Table 4. Furthermore, the contrast and brightness shown in Table 4 are values based on the contrast and brightness of Experimental Example 14.

[0182] <Experimental Example 14>

[0183] A green pigment G14 was obtained in the same manner as in Experimental Example 7, except that coarse pigment A4 was used instead of coarse pigment A1. Furthermore, the power consumption for kneading the mixture was 8.0 kWh per 1 kg of coarse pigment A4. In addition, the average primary particle diameter of the green pigment G14 was measured in the same manner as in Experimental Example 1. Further, a glass substrate for contrast evaluation and a glass substrate for brightness evaluation were produced in the same manner as in Experimental Example 1, except that the green pigment G14 was used instead of the green pigment G1, and the contrast and brightness were measured. The results are shown in Table 4.

[0184] [Table 4]

[0185]

Claims

1. A method for manufacturing a pigment for a color filter, comprising a kneading step of kneading a mixture containing a crude pigment, an inorganic salt, and an organic solvent at a maximum shear rate exceeding 800 s -1 ; The kneading temperature in the kneading step is 60°C to 150°C, The crude pigment contains a metal halide phthalocyanine having zinc, iron, aluminum, magnesium, silicon or vanadium as a central metal, The power consumption for kneading the mixture in the kneading step is more than 10.0 kWh per 1 kg of the crude pigment, Relative to 1 part by mass of the crude pigment, the amount of the inorganic salt used in the kneading step is 30 to 100 parts by mass, The organic solvent includes one or more selected from the group consisting of diethylene glycol, glycerol, 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, methanol and ethylene cyanohydrin.

2. The manufacturing method of the pigment for color filters according to claim 1, wherein, The pH of the crude pigment is less than 5, The central metal of the crude pigment is zinc, iron or magnesium.

3. The manufacturing method of the pigment for color filters according to claim 1 or 2, wherein, The pH of the crude pigment is less than 5, The manufacturing method further includes a cleaning step of cleaning the kneaded mixture obtained in the kneading step with an aqueous solution having a pH greater than 8 at 25°C.

4. The manufacturing method of the pigment for color filters according to claim 1 or 2, wherein, The average number of halogen atoms in one molecule of the metal halide phthalocyanine in the crude pigment is 9 or more.

5. The manufacturing method of the pigment for color filters according to claim 1 or 2, wherein, In the kneading step, the mixture is kneaded at a temperature of 60°C or higher and lower than 110°C.

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