Process for the production of epsilon copper phthalocyanine pigment compositions

Abstract

Provided: A simple method for manufacturing ε-type copper phthalocyanine, which has excellent color characteristics such as contrast and brightness and is useful as a color filter for use in liquid crystals, etc. A method for manufacturing an ε-type copper phthalocyanine pigment composition includes the following steps: treating phthalimide methyl copper phthalocyanine with a nonionic surfactant to obtain treated phthalimide methyl copper phthalocyanine; and milling a mixture containing α-type copper phthalocyanine, ε-type copper phthalocyanine, and the treated phthalimide methyl copper phthalocyanine with a solvent salt to obtain a pigment composition.

Description

Technical Field

[0001] This invention relates to a method for manufacturing ε-type copper phthalocyanine pigment compositions. Background Technology

[0002] Epsilon-type copper phthalocyanine pigments are bright, strong tinting strength, and exhibit excellent lightfastness and heat resistance, resulting in a reddish-blue hue. These properties make them widely used in coatings, plastics, and other fields, and they are also useful as blue pigments for liquid crystal color filters.

[0003] A common method for manufacturing ε-type copper phthalocyanine is known to be a method of solvent salt milling of α-type copper phthalocyanine together with a phthalocyanine derivative (Patent Document 1). Furthermore, phthalocyanine derivatives used in solvent salt milling include phthalimide methyl phthalocyanine (Patent Documents 1 and 2).

[0004] As a method for manufacturing phthalimide methyl phthalocyanine, a method for reacting phthalocyanine with sulfuric acid to form phthalimide methyl phthalocyanine is known (Patent Document 3). In this method, xylenesulfonic acid, an acidic surfactant, is added after the reaction is complete.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 4097053

[0008] Patent Document 2: Japanese Patent Application Publication No. 2002-121420

[0009] Patent Document 3: US Patent No. 2855403 Summary of the Invention

[0010] The problem the invention aims to solve

[0011] In the method proposed in Patent Document 3, phthalimide methyl copper phthalocyanine, which is generated by reacting in concentrated sulfuric acid, can be obtained in a strongly aggregated powder state. Phthalimide methyl copper phthalocyanine is almost insoluble in water-soluble organic solvents such as diethylene glycol used in solvent salt grinding. Therefore, according to the solvent salt grinding proposed in Patent Document 1, etc., uniform mixing with α-type copper phthalocyanine also requires a long time.

[0012] Furthermore, α-type copper phthalocyanine, which is also produced in sulfuric acid similarly to phthalimide methyl copper phthalocyanine, exhibits strong aggregation. Therefore, if the strongly aggregated α-type copper phthalocyanine is subjected to solvent salt milling, a non-uniform crystal transformation from α-type to ε-type easily occurs. As a result, the obtained pigment particles tend to become non-uniform, leading to problems such as reduced performance as a coloring material or the incorporation of large amounts of β-type copper phthalocyanine. In particular, when used as a colorant in liquid crystal color filters, color characteristics such as brightness and contrast tend to become insufficient.

[0013] The present invention was made in view of the problems of the prior art, and its objective is to provide a simple method for manufacturing ε-type copper phthalocyanine, which has excellent color characteristics such as contrast and brightness and is useful as a color filter for use in liquid crystals and the like.

[0014] Solution for solving the problem

[0015] That is, according to the present invention, a method for manufacturing the ε-type copper phthalocyanine pigment composition shown below is provided.

[0016] [1] A method for manufacturing an ε-type copper phthalocyanine pigment composition, comprising the following steps:

[0017] The process involves treating phthalimide methyl copper phthalocyanine with a nonionic surfactant to obtain the treated phthalimide methyl copper phthalocyanine; and,

[0018] The process of grinding a mixture containing α-type copper phthalocyanine, ε-type copper phthalocyanine and the aforementioned treated phthalimide methyl copper phthalocyanine with a solvent salt to obtain a pigment composition.

[0019] [2] The method for manufacturing the ε-type copper phthalocyanine pigment composition according to [1] above, wherein the aforementioned mixture is a precipitate that is precipitated by injecting a sulfuric acid solution containing the aforementioned treated phthalimide methyl copper phthalocyanine and β-type copper phthalocyanine into water.

[0020] [3] According to the manufacturing method of the ε-type copper phthalocyanine pigment composition described in [1] or [2] above, an emulsion containing the aforementioned nonionic surfactant, water-insoluble organic solvent and water is contacted with the aforementioned phthalimide methyl copper phthalocyanine to obtain the aforementioned treated phthalimide methyl copper phthalocyanine.

[0021] [4] The method for manufacturing the ε-type copper phthalocyanine pigment composition according to the above [3], wherein the aforementioned water-insoluble organic solvent is at least one selected from the group consisting of toluene, xylene, ethyl acetate and butyl acetate.

[0022] [5] The method for manufacturing the ε-type copper phthalocyanine pigment composition according to any one of [1] to [4] above, wherein the mixture is subjected to solvent salt milling in the presence of at least one of diethylene glycol and propylene glycol to obtain the pigment composition.

[0023] [6] The method for manufacturing the ε-type copper phthalocyanine pigment composition according to any one of [1] to [5] above further includes a step of further grinding the pigment composition with solvent salt.

[0024] The effects of the invention

[0025] According to the present invention, a simple method for manufacturing ε-type copper phthalocyanine, which has excellent color characteristics such as contrast and brightness and is useful as a color filter for use in liquid crystals and the like, can be provided. Detailed Implementation

[0026] <Method for manufacturing ε-type copper phthalocyanine pigment composition>

[0027] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments. One embodiment of the method for manufacturing the ε-type copper phthalocyanine pigment composition of the present invention (hereinafter also referred to as the "manufacturing method") includes the following steps: treating phthalimide methyl copper phthalocyanine with a nonionic surfactant to obtain treated phthalimide methyl copper phthalocyanine (step (1)); and grinding a mixture containing α-type copper phthalocyanine, ε-type copper phthalocyanine and treated phthalimide methyl copper phthalocyanine with a solvent salt to obtain a pigment composition (step (2)). Hereinafter, the manufacturing method of this embodiment will be described in detail.

[0028] (Process (1))

[0029] In step (1), phthalimide methyl copper phthalocyanine (hereinafter also referred to as "PIM copper phthalocyanine") is treated with a nonionic surfactant to obtain treated PIM copper phthalocyanine. By treating PIM copper phthalocyanine with a nonionic surfactant, unlike the case where it is treated with a surfactant other than a nonionic surfactant, the strong aggregation of PIM copper phthalocyanine can be mitigated. As a result, the processing efficiency of solvent salt grinding in the subsequent step (step (2)) can be improved, and ε-type copper phthalocyanine pigment compositions with excellent color characteristics such as contrast and brightness can be easily manufactured.

[0030] PIM-modified copper phthalocyanine can be manufactured using known methods that utilize copper phthalocyanine as a raw material. For example, as disclosed in U.S. Patent No. 2,855,403, PIM-modified copper phthalocyanine can be obtained by reacting copper phthalocyanine with hydroxymethyl phthalimide in sulfuric acid. It should be noted that phthalimide and oligooxymethylene can also be used instead of hydroxymethyl phthalimide.

[0031] Commercially available products can be used as nonionic surfactants. Specific examples of nonionic surfactants include glycerol fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, sucrose fatty acid esters, fatty acid alkanolamides, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, and polyoxyethylene polystyrene phenyl ethers. Among these, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, and polyoxyethylene polystyrene phenyl ethers are preferred, and polyoxyethylene polystyrene phenyl ethers are particularly preferred.

[0032] In the manufacturing process of PIM copper phthalocyanine, it is preferable to treat the PIM copper phthalocyanine with a nonionic surfactant. The manufacturing process of PIM copper phthalocyanine includes, for example, a reaction step in concentrated sulfuric acid, a precipitation step in water, a filtration / washing step, and a drying step. Preferably, the PIM copper phthalocyanine is treated with a nonionic surfactant after the filtration / washing step and before the drying step.

[0033] Specific methods for treating PIM copper phthalocyanine with nonionic surfactants include, for example, the following methods in the manufacturing process of PIM copper phthalocyanine: (i) adding a nonionic surfactant to the system; (ii) adding an aqueous solution of a nonionic surfactant to the system; (iii) adding an emulsion obtained by mixing a nonionic surfactant, a water-insoluble solvent, and water to the system; etc. Preferably, the emulsion is added to a slurry prepared by dissolving PIM copper phthalocyanine in water, thereby contacting the PIM copper phthalocyanine with the emulsion (contacting the nonionic surfactant). The PIM copper phthalocyanine in the slurry forms strong aggregates. By contacting the PIM copper phthalocyanine with an emulsion prepared using a water-insoluble solvent with high affinity and good wetting properties for PIM copper phthalocyanine, the nonionic surfactant can be used to treat the PIM copper phthalocyanine more uniformly.

[0034] As a water-insoluble organic solvent, at least one selected from the group consisting of toluene, xylene, ethyl acetate and butyl acetate is preferred, with xylene being particularly preferred.

[0035] The treatment of PIM-modified copper phthalocyanine based on nonionic surfactants is preferably carried out under heating conditions. By contacting and treating the PIM-modified copper phthalocyanine with the nonionic surfactant under heating conditions, the uniformity of the treatment can be further improved. The treatment temperature is preferably set to 60–100°C, and more preferably 80–90°C.

[0036] (Process (2))

[0037] In step (2), a mixture containing α-type copper phthalocyanine, ε-type copper phthalocyanine, and pre-treated PIM-modified copper phthalocyanine is subjected to solvent salt milling to obtain a pigment composition. The pre-treated PIM-modified copper phthalocyanine is the PIM-modified copper phthalocyanine treated with a nonionic surfactant in step (1) above, thus mitigating its strong aggregation. Therefore, by performing solvent salt milling on the mixture containing this pre-treated PIM-modified copper phthalocyanine, the crystal transformation from α-type to ε-type is promoted, and ε-type copper phthalocyanine pigment compositions with excellent color characteristics such as contrast and brightness can be manufactured more efficiently.

[0038] Solvent-salt grinding is typically performed as follows: In the presence of a water-soluble organic solvent and an inorganic salt, a mixture containing α-type copper phthalocyanine, ε-type copper phthalocyanine, and pre-treated PIM-modified copper phthalocyanine is kneaded and ground using a mixing machine. Suitable mixing machines include kneaders, planetary mixers, Mirakuru KCK (trade name, manufactured by Asada Steel Co., Ltd.), and Trinamix (trade name, manufactured by Inoue Manufacturing Co., Ltd.).

[0039] α-type copper phthalocyanine can be manufactured using a known method that uses crude copper phthalocyanine containing β-type copper phthalocyanine. Specific examples of methods for manufacturing α-type copper phthalocyanine include: (i) an acid dissolution method in which a sulfuric acid solution containing crude copper phthalocyanine is dissolved in sulfuric acid and precipitated; (ii) a dry grinding method in which crude copper phthalocyanine is dry-milled using a ball mill or similar device; (iii) a solvent salt grinding method in which crude copper phthalocyanine is mixed with an inorganic salt and a water-soluble organic solvent in a kneader or similar mixer; etc. Of these, (i) the acid dissolution method is preferred for obtaining higher purity and finer α-type copper phthalocyanine.

[0040] The concentration of sulfuric acid used in the acid dissolution method is preferably 70–100% by mass. If the concentration of sulfuric acid is below 70% by mass, the crude copper phthalocyanine becomes easily and completely dissolved, and β-type copper phthalocyanine sometimes becomes easily mixed into the resulting precipitate. Furthermore, the particle size of the resulting α-type copper phthalocyanine tends to be larger, so subsequent milling with solvent salts sometimes results in insufficient micronization. On the other hand, if the concentration of sulfuric acid is too high, some of the generated α-type copper phthalocyanine sometimes becomes easily sulfonated. Therefore, considering the purity and particle size of the obtained α-type copper phthalocyanine, the concentration of sulfuric acid used in the acid dissolution method is further preferably 95–98% by mass.

[0041] Epsilon-type copper phthalocyanine can be manufactured using known methods or commercially available products. Known methods for manufacturing ε-type copper phthalocyanine include: the solvent method disclosed in Japanese Patent Publication No. 57-35210; the method of dry grinding followed by solvent treatment disclosed in Japanese Patent No. 3030880; and the method of micronizing ε-type copper phthalocyanine obtained in copper phthalocyanine synthesis by grinding with a solvent salt disclosed in Japanese Patent Publication No. 64-7108; etc.

[0042] From the viewpoints of safety and workability, high-boiling-point solvents are preferred as water-soluble organic solvents. Specific examples of water-soluble organic solvents include diethylene glycol, glycerol, propylene glycol, liquid polyethylene glycol, liquid polypropylene glycol, 2-methoxyethanol, 2-butoxyethanol, 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, and dipropylene glycol monoethyl ether. Among these, it is preferable to perform solvent salt milling on the mixture in the presence of at least one of the water-soluble organic solvents, diethylene glycol and propylene glycol.

[0043] Water-soluble inorganic salts are preferred as inorganic salts. Specific examples of inorganic salts include sodium chloride, potassium chloride, sodium sulfate, and magnesium sulfate.

[0044] Solvent salt milling is preferably performed at 50–150°C, and more preferably at 70–140°C. If solvent salt milling is performed at temperatures below 50°C, the crystal transformation from α-type to ε-type may sometimes become slightly insufficient. On the other hand, if solvent salt milling is performed at temperatures above 150°C, the performance as a coloring material based on crystal growth may sometimes become slightly degraded.

[0045] In order to achieve a higher degree of balance between the crystal transformation from α-type to ε-type and the suppression of crystal growth, and to obtain a further finer ε-type copper phthalocyanine pigment composition, it is preferable to perform solvent salt milling at 120–140°C followed by solvent salt milling at 50–80°C.

[0046] The amount of ε-type copper phthalocyanine is preferably set to 5 to 50 parts by mass relative to 100 parts by mass of α-type copper phthalocyanine, and more preferably to 10 to 30 parts by mass. If the amount of ε-type copper phthalocyanine is less than 5 parts by mass relative to 100 parts by mass of α-type copper phthalocyanine, the crystal transformation from α-type to ε-type sometimes requires slightly more time, and sometimes it becomes easier to form β-type crystals. On the other hand, if the amount of ε-type copper phthalocyanine exceeds 50 parts by mass relative to 100 parts by mass of α-type copper phthalocyanine, the productivity decreases slightly, and it sometimes becomes disadvantageous in industrial applications.

[0047] The amount of water-soluble organic solvent is preferably set to 50-500 parts by mass relative to a total of 100 parts by mass of α-type copper phthalocyanine and ε-type copper phthalocyanine. The water-soluble organic solvent can be added in its entirety at the initial stage of solvent salt milling, or it can be added in stages according to the progress of micronization.

[0048] The amount of inorganic salt is preferably set to 200-2000 parts by mass relative to a total of 100 parts by mass of α-type copper phthalocyanine and ε-type copper phthalocyanine, and can be adjusted appropriately according to the desired degree of refinement of the ε-type copper phthalocyanine pigment composition. The more inorganic salt added, the finer the ε-type copper phthalocyanine pigment composition will be.

[0049] The amount of treated PIM-modified copper phthalocyanine is preferably set to 1 to 20 parts by mass relative to 100 parts by mass of α-type copper phthalocyanine. The treated PIM-modified copper phthalocyanine can be added at the initial stage of solvent salt milling or pre-added during the manufacture of α-type copper phthalocyanine. From the viewpoint of more uniformly treating the PIM-modified copper phthalocyanine, when manufacturing α-type copper phthalocyanine according to the aforementioned acid dissolution method, it is preferable to dissolve the treated PIM-modified copper phthalocyanine together with the crude copper phthalocyanine used as a raw material in sulfuric acid.

[0050] The time required for solvent salt milling varies depending on temperature and the amount of material input, but is preferably set to 2–20 hours, adjusted to account for crystal transformation and micronization. The mixture obtained from solvent salt milling is then dissolved in water, filtered, washed, dried, and pulverized to obtain a powdered pigment composition suitable for use as a coloring material. Filtration and washing are preferably repeated until all water-soluble organic solvents and inorganic salts contained in the mixture are completely removed. The drying temperature can be set to, for example, 70–120°C, and a box dryer, belt dryer, or spray dryer can be used. When pulverizing the dried block into powder, a mortar and pestle mill, hammer mill, disc mill, pin mill, or jet mill can be used.

[0051] (Process (3))

[0052] The pigment composition obtained by the above-mentioned solvent salt milling can be used as the target ε-type copper phthalocyanine pigment composition. In addition, in order to obtain a finer ε-type copper phthalocyanine pigment composition with further superior color characteristics such as contrast and brightness, it is preferable to perform solvent salt milling again on the pigment composition obtained by the above-mentioned solvent salt milling. That is, the manufacturing method of this embodiment preferably also includes a step (step (3)) of performing solvent salt milling again on the pigment composition obtained in step (2) above. In this step (3), it is preferable to perform solvent salt milling at 50 to 80°C, and more preferably at 50 to 70°C.

[0053] (other)

[0054] The obtained ε-type copper phthalocyanine pigment composition can be treated with various phthalocyanine derivatives or other pigment derivatives according to its intended use. Examples of phthalocyanine derivatives include sulfonic acid derivatives of metal-free or metallic phthalocyanines, N-(dialkylamino)methyl derivatives of metal-free or metallic phthalocyanines, and N-(dialkylaminoalkyl)sulfonic acid amide derivatives of metal-free or metallic phthalocyanines. The pigment derivatives can be added during the manufacturing process of the ε-type copper phthalocyanine pigment composition or added to the obtained ε-type copper phthalocyanine pigment composition. Preferably, the pigment derivatives are added when the wet filter cake gel obtained after grinding the solvent salt is dissolved in water. When adding the pigment derivatives, the pH can be adjusted by adding acids or bases as needed.

[0055] In the process of manufacturing ε-type copper phthalocyanine pigment compositions, treatment with a pigment dispersant is acceptable. Commercially available pigment dispersants can be used. Commercially available pigment dispersants include, under the following trade names: DISPERBYK-130, DISPERBYK-161, DISPERBYK-162, DISPERBYK-163, DISPERBYK-170, DISPERBYK-171, DISPERBYK-174, DISPERBYK-180, DISPERBYK-182, DISPERBYK-183, DISPERBYK-184, DISPERBYK-185, DISPERBYK-2000, DISPERBYK-2001, DISPERBYK-2022, DISPERBYK-2050, DISPERBYK-2055, DISPERBYK-2059 ...2050, DISPERBYK-2059, DISPERBYK-2050, DISPERBYK-2050, DISPERBYK-2059, DISPERB ISPERBYK-2070, DISPERBYK-2151, DISPERBYK-2064 (above, manufactured by BYK Co., Ltd.); EFKA46, EFKA47, EFKA452, EFKALP4008, EFKA4009, EFKALP4010, EFKALP4050, EFKALP4055, EFKA400, E Solsperse 3000, Solsperse 9000, Solsperse 13240, Solsperse 13650, Solsperse 13940, Solsperse 17000, Solsperse 18000, Solsperse 20000, Solsperse 21000, Solsperse 20000, Solsperse 24000, Solsperse26000, Solsperse 27000, Solsperse 28000, Solsperse 32000, Solsperse 36000, Solsperse37000, Solsperse 38000, Solsperse 41000, Solsperse 42000, Solsperse43000, Solsperse 46000, Solsperse 54000, Solsperse 71000 (and above, manufactured by Lubrizol);Ajisper PB711, Ajisper PB821, Ajisper PB822, Ajisper PB814, Ajisper PN411, Ajisper PA111 (all manufactured by Ajinomoto Co., Inc.); etc.

[0056] In the process of manufacturing ε-type copper phthalocyanine pigment compositions, various resins can be used for treatment. Examples of resins include acrylic resins; urethane resins; alkyd resins; natural rosins such as wood rosin, resin rosin, and tall oil rosin; modified rosins such as polymerized rosin, disproportionated rosin, hydrogenated rosin, oxidized rosin, and maleic rosin; rosin derivatives such as rosin amines, lime rosin, epoxy alkyl addition rosin, rosin-modified alkyd resins, and rosin-modified phenols; etc.

[0057] As for the treatment method using pigment dispersants and resins, water-soluble pigment dispersants or those that can be uniformly dispersed in water can be treated in the same way as the aforementioned pigment derivatives. Furthermore, pigment dispersants that are soluble in organic solvents can be added during the grinding of the solvent salt.

[0058] Example

[0059] The present invention will now be described in detail based on embodiments, but the present invention is not limited to these embodiments. It should be noted that, unless otherwise specified, "parts" and "%" in the embodiments and comparative examples refer to quality standards.

[0060] <Manufacturing of PIM copper phthalocyanine>

[0061] (Manufacturing Example 1)

[0062] 70 parts of crude copper phthalocyanine, 52 parts of phthalimide, and 20 parts of oligooxymethylene (prepared by conventional methods) were added to 400 parts of 98% sulfuric acid. After stirring and dissolving, the mixture was reacted at 80°C for 3 hours to obtain a reaction solution. The reaction solution was then injected into 8000 parts of ice water. The resulting precipitate was filtered and washed with water to obtain a wet filter cake. The wet filter cake was dissolved in 1000 parts of water and stirred to obtain a homogeneous slurry.

[0063] An emulsion was prepared by mixing 10 parts xylene, 1 part polyoxyethylene polystyrene phenyl ether, and 50 parts water using a disperser. The prepared emulsion was added to the slurry and stirred at 90°C for 1 hour. After naturally cooling to 60°C, the mixture was filtered, dried, and pulverized to obtain 100 parts of PIM-modified copper phthalocyanine. The obtained PIM-modified copper phthalocyanine was a pretreated PIM-modified copper phthalocyanine with a nonionic surfactant.

[0064] (Comparative Manufacturing Example 1)

[0065] 70 parts of crude copper phthalocyanine, 52 parts of phthalimide, and 20 parts of oligooxymethylene, prepared according to conventional methods, were added to 400 parts of 98% sulfuric acid. After stirring and dissolving, the mixture was reacted at 80°C for 3 hours to obtain a reaction solution. The reaction solution was then injected into 8000 parts of ice water. The resulting precipitate was filtered, washed with water, dried, and pulverized to obtain 105 parts of PIM-modified copper phthalocyanine. The obtained PIM-modified copper phthalocyanine was untreated PIM-modified copper phthalocyanine without the use of nonionic surfactants.

[0066] <Preparation of E-type copper phthalocyanine pigment compositions>

[0067] (Example 1)

[0068] 58 parts of crude copper phthalocyanine (including β-type copper phthalocyanine) manufactured according to conventional methods and 3 parts of PIM-modified copper phthalocyanine obtained in Manufacturing Example 1 were added to 400 parts of 98% sulfuric acid. The mixture was stirred at 80°C for 3 hours to obtain a sulfuric acid solution. After injecting the obtained sulfuric acid solution into 8000 parts of ice water, the resulting precipitate was filtered, washed with water, dried, and pulverized to obtain 58 parts of a co-precipitate of α-type copper phthalocyanine and PIM-modified copper phthalocyanine.

[0069] Eighteen parts of the obtained co-precipitate, five parts of ε-type copper phthalocyanine, eighty parts of pulverized salt obtained by pulverizing, and 18 parts of propylene glycol were added to a kneader and kneaded at 140°C for 16 hours. The kneader was cooled, and the mixture was further kneaded at 70°C for 6 hours to obtain a compound. It should be noted that 0.5 parts of propylene glycol were added in several appropriate batches to achieve the appropriate viscosity during the kneading process. After the resulting compound was dissolved in water, 98% sulfuric acid with a sulfuric acid concentration of 2% was added, and the mixture was stirred at 90°C for 1 hour to obtain a slurry. The obtained slurry was filtered, washed with water, dried, and pulverized to obtain 22 parts of the ε-type copper phthalocyanine pigment composition.

[0070] (Example 2)

[0071] Nine parts of the ε-type copper phthalocyanine pigment composition obtained in Example 1, 90 parts of pulverized salt obtained by pulverizing, and 21 parts of diethylene glycol were added to a kneader and kneaded at 60°C for 18 hours. It should be noted that diethylene glycol was added in several appropriate portions, in a manner that achieved a suitable viscosity during kneading. After the resulting mixture was dissolved in water, 98% sulfuric acid with a sulfuric acid concentration of 2% was added, and the mixture was stirred at 90°C for 1 hour to obtain a slurry. The obtained slurry was filtered, washed with water, dried, and pulverized to obtain 10 parts of the ε-type copper phthalocyanine pigment composition.

[0072] (Comparative Example 1)

[0073] Using untreated PIM-modified copper phthalocyanine obtained in Comparative Manufacturing Example 1 instead of the treated PIM-modified copper phthalocyanine, 22 parts of the ε-type copper phthalocyanine pigment composition were obtained in the same manner as in Example 1 above.

[0074] (Comparative Example 2)

[0075] The ε-type copper phthalocyanine pigment composition obtained in Comparative Example 1 was used instead of the ε-type copper phthalocyanine pigment composition obtained in Example 1. Otherwise, 10 parts of the ε-type copper phthalocyanine pigment composition were obtained in the same manner as in Example 2.

[0076] <Evaluation>

[0077] (Preparation of colorants for CF)

[0078] Nine parts of a pre-made ε-type copper phthalocyanine pigment composition, seven parts of pigment dispersant (trade name "DISPERBYK2000", manufactured by BYK Corporation), seven parts of binder resin (trade name "SPC-2000", manufactured by Showa Denko Corporation, an acrylic resin with acidic groups), 30 parts of propylene glycol-1-monomethyl ether-2-acetate, and six parts of n-butanol were added to a sealed container. Zirconia beads of 0.5 mm were added, and the mixture was dispersed for 5 hours using a disperser (trade name "Disperser DAS200", manufactured by LAU Corporation) to obtain a dispersion. Eight parts of the obtained dispersion, one part of binder resin (trade name "SPC-2000", manufactured by Showa Denko Corporation, an acrylic resin with acidic groups), and three parts of propylene glycol-1-monomethyl ether-2-acetate were mixed using a disperser to obtain a colorant for CF (carbon fiber).

[0079] (Preparation of the glass substrate for measurement)

[0080] Using a spin coater, CF colorant was applied to a glass plate. After pre-baking at 90°C for 2 minutes, it was then formally baked at 230°C for 30 minutes to obtain the glass substrate for measurement.

[0081] (Contrast measurement)

[0082] The contrast ratio of the test glass substrate at y = 0.14 was measured using a contrast ratio tester (trade name "CT-1BS", manufactured by Tsubosaka Electric Co., Ltd.). The results are shown in Table 1. It should be noted that the "contrast ratio" values ​​shown in Table 1 are relative values ​​based on the contrast ratio of Example 1 (100).

[0083] (Measurement of brightness)

[0084] The luminance Y of the glass substrate at y = 0.14 was measured using a spectrophotometer (trade name "U-3310", manufactured by Hitachi, Ltd.). The results are shown in Table 1.

[0085] Table 1

[0086] Contrast Brightness Y Example 1 100 16.7 Comparative Example 1 76 16.5 Example 2 171 16.8 Comparative Example 2 124 16.6

[0087] Industrial availability

[0088] The method for manufacturing the ε-type copper phthalocyanine composition according to the present invention can easily produce useful colorants for color filters used in liquid crystals and the like. ε Type copper phthalocyanine.

Claims

1. A method for manufacturing an ε-type copper phthalocyanine pigment composition, comprising the following steps: A process involving contacting an emulsion containing a nonionic surfactant, a water-insoluble organic solvent, and water with phthalimide methyl copper phthalocyanine to obtain treated phthalimide methyl copper phthalocyanine; and The process of solvent-salt grinding a mixture containing α-type copper phthalocyanine, ε-type copper phthalocyanine and the treated phthalimide methyl copper phthalocyanine to obtain a pigment composition.

2. The method for manufacturing the ε-type copper phthalocyanine pigment composition according to claim 1, wherein, The mixture is a precipitate formed by injecting a sulfuric acid solution containing the treated phthalimide methyl copper phthalocyanine and β-copper phthalocyanine into water.

3. The method for manufacturing the ε-type copper phthalocyanine pigment composition according to claim 1, wherein, The water-insoluble organic solvent is at least one selected from the group consisting of toluene, xylene, ethyl acetate, and butyl acetate.

4. The method for manufacturing the ε-type copper phthalocyanine pigment composition according to any one of claims 1 to 3, wherein, The mixture is subjected to solvent salt milling in the presence of at least one of diethylene glycol and propylene glycol to obtain the pigment composition.

5. The method for manufacturing the ε-type copper phthalocyanine pigment composition according to any one of claims 1 to 3, further comprising a step of further solvent salt milling of the pigment composition.