Method for producing zinc phthalocyanine halide pigment

Abstract

A method for producing a zinc phthalocyanine halogenide pigment comprises a step of pigmenting a zinc phthalocyanine halogenide crude pigment, wherein the zinc phthalocyanine halogenide crude pigment is a substance obtained by precipitating zinc phthalocyanine halogenide synthesized using a compound that reacts with water to generate an acid, and the step comprises a pretreatment step of dry-grinding the zinc phthalocyanine halogenide crude pigment with a grinder and then washing the dry-grinded zinc phthalocyanine halogenide crude pigment with water.

Description

Technical Field

[0001] The present invention relates to a method for preparing a zinc phthalocyanine halide pigment. Background Art

[0002] Currently, coloring compositions are used in various fields. Specific uses of coloring compositions include printing inks, coatings, colorants for resins, colorants for fibers, and colorants for IT information recording (color filters, toners, inkjet). Coloring materials used in coloring compositions are mainly divided into two categories: pigments and dyes. Organic pigments, which have an advantage in coloring power, have attracted much attention.

[0003] After synthesis, the organic compound constituting the organic pigment aggregates with each other and exists in a state of aggregate called crude. Therefore, the synthesized organic compound cannot be used directly as a pigment, and a pigmentation process is performed to adjust the particle size. The aggregate (crude) of the organic compound pigmented in the pigmentation process is called a crude pigment, and the crude pigment is ground by kneading, etc., so that a fine organic pigment can be obtained.

[0004] As organic pigments, zinc phthalocyanine halide pigments used in green pixel portions of color filters and the like have attracted attention (see, for example, Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2018 / 043548 Pamphlet Summary of the invention

[0008] Problems to be solved by the invention

[0009] An object of the present invention is to provide a novel method for producing a zinc phthalocyanine halide pigment capable of further miniaturizing pigment particles.

[0010] Methods for solving problems

[0011] As the synthetic method of zinc phthalocyanine halide, for example, chlorosulfonic acid method, melting method etc. are known. In these methods, the compound that produces acid with water reaction is used to synthesize zinc phthalocyanine halide. By making the synthesized zinc phthalocyanine halide precipitate in water or acidic solution, a crude pigment (zinc phthalocyanine halide crude pigment) as an agglomerate of zinc phthalocyanine halide is obtained. In such a method, usually on the crude pigment, there is attached an acid from the compound that produces acid with water reaction etc., therefore before the crude pigment is pigmented, a washing for removing the acid attached to the crude pigment is carried out. However, the research results of the inventors etc. show that, even if the crude pigment is washed until the pH of the filtrate becomes the pH equivalent to the water used in the washing, there will be acid residue inside the crude pigment. The present invention is made based on such research results.

[0012] That is, one aspect of the present invention relates to a method for producing a zinc phthalocyanine halogenide pigment, which comprises a step of pigmenting a zinc phthalocyanine halogenide crude pigment. The zinc phthalocyanine halogenide crude pigment used in the method is a substance obtained by precipitating zinc phthalocyanine halogenide synthesized using a compound that generates an acid by reaction with water, and the above-mentioned step comprises a pretreatment step of dry-grinding the above-mentioned zinc phthalocyanine halogenide crude pigment with a grinder and then washing the dry-grinded zinc phthalocyanine halogenide crude pigment with water.

[0013] According to the production method of the above aspect, the acid contained in the crude zinc phthalocyanine halide pigment can be removed, thereby obtaining a fine zinc phthalocyanine halide pigment.

[0014] In one embodiment, the crude zinc phthalocyanine halide pigment may be dry-pulverized while being heated in the pretreatment step.

[0015] In one embodiment, in the pretreatment step, a zinc phthalocyanine halide prepigment having a pH of 5.0 or higher can be obtained.

[0016] Effects of the Invention

[0017] According to the present invention, a new method for producing a zinc phthalocyanine halide pigment capable of further miniaturizing pigment particles can be provided. DETAILED DESCRIPTION

[0018] Preferred embodiments of the present invention are described below, but the present invention is not limited to the following embodiments.

[0019] A method for producing a zinc phthalocyanine halogenide pigment in one embodiment includes a first step of preparing a zinc phthalocyanine halogenide crude pigment and a second step of pigmenting the zinc phthalocyanine halogenide, wherein the second step includes a pretreatment step of dry-grinding the zinc phthalocyanine halogenide crude pigment with a grinder and then washing the dry-grinded zinc phthalocyanine halogenide crude pigment with water. Here, the zinc phthalocyanine halogenide crude pigment is a substance obtained by precipitating zinc phthalocyanine halogenide synthesized using a compound that reacts with water to generate an acid, and the zinc phthalocyanine halogenide is a compound having a structure represented by the following formula (1).

[0020] [Chemistry 1]

[0021]

[0022] [In formula (1), X 1 ~X 16 Each independently represents a hydrogen atom or a halogen atom.]

[0023] In the first step, a zinc phthalocyanine halide crude pigment is prepared. The zinc phthalocyanine halide crude pigment contains one type of zinc phthalocyanine halide or a plurality of types of zinc phthalocyanine halide having different numbers of halogen atoms.

[0024] Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms. The zinc phthalocyanine halogenide preferably has at least one of a bromine atom and a chlorine atom as a halogen atom, and preferably has a bromine atom. The zinc phthalocyanine halogenide may also have only one or both of a chlorine atom and a bromine atom as a halogen atom. That is, X in the above formula (1) 1 ~X 16 It may be a chlorine atom or a bromine atom.

[0025] In one embodiment, the average number of bromine atoms in one molecule of the compound represented by formula (1) in the crude zinc phthalocyanine halogenide pigment is less than 13. The average number of bromine atoms may be 12 or less or 11 or less. The average number of bromine atoms may be 0.1 or more, 6 or more, or 8 or more. The above upper and lower limits may be combined arbitrarily. For example, the average number of bromine atoms may be 0.1 or more and less than 13, 8 to 12, or 8 to 11. In the following similar description, the upper and lower limits recorded separately may also be combined arbitrarily.

[0026] When the average number of bromine atoms is less than 13, the average number of halogen atoms in one molecule of the compound represented by formula (1) in the crude zinc phthalocyanine halogenide pigment may be 14 or less, 13 or less, less than 13, or 12 or less. The average number of halogen atoms may be 0.1 or more, 8 or more, or 10 or more.

[0027] When the average number of bromine atoms is less than 13, the average number of chlorine atoms in one molecule of the compound represented by formula (1) in the crude zinc phthalocyanine halide 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.

[0028] In another embodiment, the average number of bromine atoms in one molecule of the compound represented by formula (1) in the crude zinc phthalocyanine halide pigment is 13 or more, 14 or more, or 15 or less.

[0029] When the average number of bromine atoms is 13 or more, the average number of halogen atoms in one molecule of the compound represented by formula (1) in the crude zinc phthalocyanine halogenide pigment may be 13 or more, 14 or more, or 15 or more. The average number of halogen atoms may be 16 or less, or 15 or less.

[0030] When the average number of bromine atoms is 13 or more, the average number of chlorine atoms in one molecule of the compound represented by formula (1) in the crude zinc phthalocyanine halide 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.

[0031] The number of halogen atoms (e.g., the number of bromine atoms and the number of chlorine atoms) can be determined, for example, by mass analysis of a crude zinc phthalocyanine halogenide pigment using a matrix-assisted laser desorption ionization time-of-flight mass spectrometer (JMS-S3000 manufactured by JEOL Ltd., etc.). Specifically, the number of each halogen atom can be calculated as a relative value per one zinc atom from the mass ratio of zinc atoms to each halogen atom in the crude zinc phthalocyanine halogenide pigment.

[0032] The first step includes, for example, a step of synthesizing zinc phthalocyanine halide using a compound that generates an acid by reaction with water, and a step of precipitating the synthesized zinc phthalocyanine halide to obtain a zinc phthalocyanine halide crude pigment.

[0033] Examples of a method for synthesizing zinc phthalocyanine halide using a compound that generates an acid by reaction with water include a chlorosulfonic acid method and a melting method.

[0034] As the chlorosulfonic acid method, there is a method in which zinc phthalocyanine is dissolved in a sulfur oxide solvent such as chlorosulfonic acid, and chlorine gas or bromine is added therein for halogenation. The reaction is carried out at a temperature of 20 to 120° C. and for 3 to 20 hours. In the chlorosulfonic acid method, the sulfur oxide 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.

[0035] As a melting method, there can be mentioned a method of halogenating zinc phthalocyanine with a halogenating agent in a melt of about 10 to 170° C. composed of aluminum halides such as aluminum chloride and aluminum bromide, titanium halides such as titanium tetrachloride, alkali metal halides or alkaline earth metal halides such as sodium chloride and sodium bromide (hereinafter referred to as "alkaline (earth) metal halides"), thionyl chloride, etc., or a mixture of one or more compounds that serve as solvents during halogenation. In the melting method, the compounds that serve as solvents during halogenation such as the aluminum halides, titanium halides, alkaline (earth) metal halides, thionyl chloride, etc. are compounds that react with water to generate an acid. For example, aluminum chloride reacts with water to generate hydrochloric acid.

[0036] A preferred aluminum halide is aluminum chloride. In the above method using an aluminum halide, the amount of the aluminum halide added is usually 3 times or more, preferably 10 to 20 times the mole of zinc phthalocyanine.

[0037] Aluminum halide can be used alone. If an alkaline (earth) metal halide is used together with an aluminum halide, the melting temperature can be further reduced, which is advantageous in operation. The preferred alkaline (earth) metal halide is sodium chloride. As for the amount of the alkaline (earth) metal halide added, the amount of the alkaline (earth) metal halide is preferably 1 to 15 parts by mass relative to 10 parts by mass of the aluminum halide within the range of generating a molten salt.

[0038] Examples of the halogenating agent include chlorine gas, sulfuryl chloride, and bromine.

[0039] The halogenation temperature is preferably 10 to 170° C., more preferably 30 to 140° C. In order to increase the reaction rate, pressure may be applied. The reaction time may be 5 to 100 hours, preferably 30 to 45 hours.

[0040] The melting method using two or more of the above compounds can arbitrarily control the ratio of the halogenated zinc phthalocyanine composed of specific halogen atoms in the generated halogenated zinc phthalocyanine by adjusting the ratio of chloride, bromide and iodide in the molten salt, or changing the introduction amount and reaction time of chlorine, bromine, iodine, etc., so it is preferred. In addition, according to the melting method, the decomposition of the raw materials in the reaction is less, the yield from the raw materials is better, and no strong acid is used, and the reaction can be carried out using cheap equipment.

[0041] In this embodiment, by optimizing the method of adding raw materials, the type and amount of catalyst used, the reaction temperature and the reaction time, it is possible to obtain a zinc phthalocyanine halide having a halogen atom composition different from that of the existing zinc phthalocyanine halide.

[0042] In any of the above methods, after the reaction is completed, the obtained mixture is put into an acidic aqueous solution such as water or hydrochloric acid to precipitate (separate) the generated zinc phthalocyanine halide. At this time, the compound that reacts with water to generate an acid generates an acid. Examples of the acid include hydrochloric acid and sulfuric acid.

[0043] As the zinc phthalocyanine halide crude pigment, the above-mentioned precipitate can be used directly, and it is preferred to use a product obtained by filtering the above-mentioned precipitate, washing with water, sodium bisulfate water, sodium bicarbonate water or sodium hydroxide water, washing with an organic solvent such as acetone, toluene, methanol, ethanol, dimethylformamide, etc. as needed, and drying.

[0044] It is also possible to use the above-mentioned precipitate or the precipitate after the above-mentioned post-treatment as required by dry grinding in a pulverizer such as a ball mill, a vibration mill, a vibrating ball mill, etc. as a crude zinc phthalocyanine halogenide pigment. The arithmetic standard deviation of the particle size distribution of the crude zinc phthalocyanine halogenide pigment is, for example, more than 15nm. The arithmetic standard deviation of the particle size distribution of the crude zinc phthalocyanine halogenide pigment is, for example, less than 1500nm. If the arithmetic standard deviation of the particle size distribution of the crude zinc phthalocyanine halogenide pigment is within such a range, it is easy to obtain the acid removal effect in the pretreatment process described later. The arithmetic standard deviation of the particle size distribution of the crude zinc phthalocyanine halogenide 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.

[0045] <Method>

[0046] 2.48 g of the crude zinc phthalocyanine halogenide pigment, 1.24 g of BYK-LPN6919 manufactured by BYK Chemical Co., Ltd., 1.86 g of Unidic ZL-295 manufactured by DIC Corporation, and 10.92 g of propylene glycol monomethyl ether acetate were dispersed together with 0.3 to 0.4 mm zirconium beads using a paint shaker manufactured by Toyo Seiki Co., Ltd. for 2 hours to obtain a dispersion. 0.02 g of the dispersion after removing the zirconium beads using a nylon sieve was diluted with 20 g of propylene glycol monomethyl ether acetate to obtain a dispersion for particle size distribution measurement.

[0047] <Conditions>

[0048] ·Measurement equipment: Dynamic light scattering particle size distribution measuring device LB-550 (manufactured by Horiba, Ltd.)

[0049] ·Measurement temperature: 25℃

[0050] ·Measurement sample: Dispersion for particle size distribution measurement

[0051] Data analysis conditions: particle size-based scattered light intensity, dispersion medium refractive index 1.402

[0052] The zinc phthalocyanine halogenide crude pigment obtained in the first step (the zinc phthalocyanine halogenide crude pigment used in the second step) contains an acid (hydrochloric acid, sulfuric acid, etc.), and its pH is, for example, below 4.0, or below 3.8. The pH of the zinc phthalocyanine halogenide crude pigment is, for example, above 1.5, or above 3.5. Here, the pH of the zinc phthalocyanine halogenide crude pigment can be confirmed by the following method: 5g of the zinc phthalocyanine halogenide crude pigment is mixed with 5g of methanol, and then further mixed with 100ml of ion exchange water, and the obtained mixture is heated for 5 minutes to form a boiling state, and further heated for 5 minutes to maintain the boiling state, and the heated mixture is allowed to stand and cool to below 30°C, and then the total amount of the mixture is adjusted to 100ml with ion exchange water, and then filtered, and the pH of the obtained filtrate is measured at 25°C.

[0053] The reason why the zinc phthalocyanine halide obtained in the first step contains acid (hydrochloric acid, sulfuric acid, etc.) in the crude pigment is inferred as follows. That is, it is believed that in the zinc phthalocyanine halide, the distance between the zinc as the central metal and the nitrogen atom on the isoindoline unit is far, and the central metal (zinc) has a large hole around it, so after the nitrogen of the phthalocyanine ring is protonated under acidic conditions, the counter anion (such as chloride ion) is easy to approach the central metal (zinc), and the counter anion and the central metal (zinc) are easily combined to form a stable structure. Therefore, it is inferred that, for example, even after the zinc phthalocyanine halide is precipitated, the precipitate is washed until the pH of the filtrate becomes the same pH as the water used in the washing, the acid (acid from the compound that reacts with water to produce acid, etc.) contained in the precipitate is also difficult to be removed, and the acid will remain in the crude pigment.

[0054] The second step includes, for example, a pretreatment step of further dry-grinding the zinc phthalocyanine halogenated crude pigment with a grinder, washing the dry-grinded crude pigment with water, and a step of kneading and grinding the zinc phthalocyanine halogenated crude pigment after the pretreatment step (hereinafter also referred to as "zinc phthalocyanine halogenated pre-pigment") to make it fine (a fine-grinding step). The kneading in the fine-grinding step can be performed using, for example, a kneader, a mixer, or the like.

[0055] From the viewpoint of being able to more effectively remove the acid by washing, the dry pulverization treatment in the pretreatment step can be performed at a rotational speed of 20 m / min or more, for example. From the viewpoint of preventing the acid exposed on the surface of the crude pigment due to pulverization from being included again due to the reagglomeration of the crude pigment and avoiding the mixing of impurities due to the wear of the grinding mechanism components and grinding beads, the rotational speed of the mill can be 100 m / min or less.

[0056] Examples of the grinding beads used in the dry pulverization process include glass beads, zirconium oxide beads, aluminum oxide beads, magnetic beads, steel beads, stainless steel beads, brass beads, carbon beads, and resin beads. The beads are preferably beads that are difficult to react with acid, and for example, glass beads and stainless steel beads are preferred. The average particle size of the beads may be 0.5 mm or more, 30 mm or less, and 0.5 to 30 mm.

[0057] The dry pulverization treatment can be carried out while heating the zinc phthalocyanine halogenide crude pigment. From the viewpoint of making it easier to remove the acid contained in the zinc phthalocyanine halogenide crude pigment, the heating can be carried out, for example, in a manner in which the temperature inside the mill is 40°C or more, preferably in a manner in which the temperature inside the mill is 50°C or more. The temperature inside the mill during the dry pulverization treatment can be 200°C or less. From the viewpoint of making it easier to remove the acid contained in the zinc phthalocyanine halogenide crude pigment, the temperature inside the mill during the dry pulverization treatment is preferably 120°C or less, more preferably 100°C or less.

[0058] The treatment time of the dry pulverization treatment can be appropriately adjusted according to the amount of the crude zinc phthalocyanine halide pigment and the like, and can be, for example, 15 to 600 minutes.

[0059] The washing in the pretreatment step may be any of water washing (washing with water below 40°C) and hot water washing (washing with water above 40°C). From the viewpoint that the acid contained in the zinc phthalocyanine halide crude pigment is more easily removed, the water temperature is preferably above 40°C. The washing may be repeated multiple times (e.g., 2 to 5 times). Specifically, the washing is preferably performed until the pH of the filtrate becomes equal to the pH of the water used for washing (e.g., the difference between the two is 0.2 or less).

[0060] The water used for washing is not particularly limited as long as it can dissolve the acid contained in the crude zinc phthalocyanine halide pigment, and may be deionized water, ion exchange water, ultrapure water, etc. The pH of the water at 25° C. may be, for example, 5.5 to 8.5.

[0061] From the viewpoint of making it easier to remove the acid contained in the zinc phthalocyanine halide crude pigment, it is preferred to improve the wettability of the zinc phthalocyanine halide crude pigment to water when or before washing with water (when or before contacting the zinc phthalocyanine halide crude pigment after dry pulverization with water). As a method for improving the wettability of the zinc phthalocyanine halide crude pigment to water, for example, a method of contacting the zinc phthalocyanine halide crude pigment with a water-soluble organic solvent such as methanol can be cited. Relative to 100 parts by mass of zinc phthalocyanine halide crude pigment, the amount of the water-soluble organic solvent used can be, for example, more than 1 part by mass, and can be less than 300 parts by mass.

[0062] From the viewpoint of making it easier to remove the acid contained in the zinc phthalocyanine halogenide crude pigment, washing may include a step of stirring the zinc phthalocyanine halogenide crude pigment (preferably the zinc phthalocyanine halogenide crude pigment with improved wettability after dry pulverization) in water. The stirring time is preferably 10 minutes to 5 hours. In this case, after stirring, filtering may be performed, and then normal washing may be performed until the pH of the filtrate becomes equal to the pH of the water used in washing (for example, the difference between the two is 0.2 or less).

[0063] After washing, filtering, drying, pulverization and the like can be performed as required.

[0064] In the pretreatment step, the dry pulverization treatment and washing may be repeated a plurality of times from the viewpoint of further removing the acid contained in the crude zinc phthalocyanine halide pigment.

[0065] In the above-mentioned pretreatment step, a zinc phthalocyanine pre-pigment is obtained in which at least a part of the acid contained in the zinc phthalocyanine halogenide crude pigment is removed. Regarding the pH of the zinc phthalocyanine pre-pigment (after mixing 5g of the zinc phthalocyanine pre-pigment with 5g of methanol, further mixing with 100ml of ion exchange water, heating the obtained mixture for 5 minutes to form a boiling state, further heating for 5 minutes to maintain the boiling state, standing and cooling the heated mixture to below 30°C, adjusting the total amount of the mixture to 100ml with ion exchange water, and then filtering to obtain the pH of the filtrate at 25°C), from the viewpoint of easily obtaining finer pigment particles, it is preferably 4.0 or more, more preferably 5.0 or more, more preferably 6.0 or more, and particularly preferably 6.5 or more. The pH of the zinc phthalocyanine pre-pigment is, for example, below 8.5, and can also be below 7.0.

[0066] The micronizing step may be a step of kneading the zinc phthalocyanine halogenide preformed pigment with an organic solvent, or a step of kneading with an inorganic salt and an organic solvent. Preferably, no water is used in the micronizing step. The amount of water used is, for example, 20 parts by mass or less, 10 parts by mass or less, or 5 parts by mass or less relative to 100 parts by mass of the organic solvent.

[0067] The organic solvent can use a substance that does not dissolve the halogenated zinc phthalocyanine pre-made pigment and the inorganic salt. As the organic solvent, it is preferred to use an organic solvent that can inhibit crystal growth. As such an organic solvent, a water-soluble organic solvent can be appropriately used. As an organic solvent, for example, diethylene glycol, glycerol, ethylene glycol, propylene glycol, 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, etc. can be used. The amount of the organic solvent (e.g., a water-soluble organic solvent) used is not particularly limited, and is preferably 1 to 500 parts by mass relative to 100 parts by mass of the halogenated zinc phthalocyanine pre-made pigment.

[0068] In the micronizing step, the zinc phthalocyanine halogenide pre-pigment may be kneaded while being heated. From the viewpoint of easily obtaining finer pigment particles, the heating temperature is preferably 40° C. or higher, more preferably 60° C. or higher, further preferably 80° C. or higher, and particularly preferably 90° C. or higher. The heating temperature may be, for example, 150° C. or lower.

[0069] The kneading time in the refinement step may be, for example, 1 to 60 hours.

[0070] When an inorganic salt and an organic solvent are used in the micronization step, a mixture containing a zinc phthalocyanine halide pigment, an inorganic salt and an organic solvent is obtained. The organic solvent and the inorganic salt can be removed from the mixture, and the solid material mainly containing the zinc phthalocyanine halide pigment can be washed, filtered, dried, pulverized, etc. as needed.

[0071] As washing, any of water washing and hot water washing can be adopted. Washing can be repeated within the range of 1 to 5 times. When a water-soluble inorganic salt and a water-soluble organic solvent are used, the organic solvent and the inorganic salt can be easily removed by water washing. If necessary, acid washing, alkali washing, and organic solvent washing can also be performed.

[0072] As the drying after the above-mentioned washing and filtration, for example, batch or continuous drying can be cited, in which the pigment is dehydrated and / or desolvated by heating at 80 to 120° C. using a heating source provided in a dryer. Examples of dryers generally include box dryers, belt dryers, spray dryers, etc. In particular, spray drying using a spray dryer is preferred because it is easy to disperse when making a paste.

[0073] The pulverization after drying is not an operation for increasing specific surface area or reducing the average particle size of primary particles, but is carried out for decomposing the pigment and powdering it when the pigment forms a block (lamb shape) etc., such as when using a box-type dryer or a belt dryer for drying. For example, the pulverization using a mortar, a hammer mill, a disc mill, a pin mill, a jet mill etc. can be cited.

[0074] According to the above-mentioned manufacturing method, a fine zinc phthalocyanine halogenide pigment can be obtained. The inventors of the present invention speculate that the reasons for obtaining such an effect are as follows. First, when an acid is present during pigmentation, the acid promotes particle aggregation, thereby hindering the miniaturization of pigment particles. On the other hand, in the above-mentioned manufacturing method, the acid contained in the crude pigment in the pretreatment process is removed, so the influence of the above-mentioned acid can be alleviated. Therefore, using the above-mentioned method, a fine zinc phthalocyanine halogenide pigment can be obtained.

[0075] The zinc phthalocyanine halogenide pigment obtained in the above-mentioned manufacturing method is suitable for use as a green pigment for color filters. Generally, there is a tendency that the smaller the particles of the pigment used in the pixel portion of the color filter, the higher the contrast and brightness. Therefore, when the zinc phthalocyanine halogenide pigment obtained by the above-mentioned manufacturing method is used as a green pigment for color filters, there is a tendency to obtain excellent contrast, and in addition, there is a tendency to obtain excellent brightness.

[0076] The average particle diameter (average primary particle diameter) of the primary particles of the zinc halogenide phthalocyanine pigment obtained by the aforesaid method is for example below 30nm. According to the aforesaid method, for example, the zinc halogenide phthalocyanine pigment with the average primary particle diameter below 25nm can also be obtained. The average primary particle diameter of the zinc halogenide phthalocyanine pigment can be more than 10nm. Here, the average primary particle diameter is the mean value of the major diameter of primary particles, can be operated in the same manner as the mensuration of the average aspect ratio described later, by measuring the major diameter of primary particles to obtain.

[0077] The average aspect ratio of the primary particles of the zinc phthalocyanine halogenide 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 zinc phthalocyanine halogenide pigment is, for example, less than 2.0, less than 1.8, less than 1.6, or less than 1.4. Using a zinc phthalocyanine halogenide pigment having such an average aspect ratio, a more excellent contrast can be obtained.

[0078] The zinc phthalocyanine halide pigment having an average primary particle aspect ratio within the range of 1.0 to 3.0 preferably contains no primary particles having an aspect ratio of 5 or more, more preferably contains no primary particles having an aspect ratio of 4 or more, and further preferably contains no primary particles having an aspect ratio exceeding 3.

[0079] The aspect ratio of primary particles and average aspect ratio can be measured by the following method. First, utilize transmission electron microscope (for example JEM-2010 of JEOL Ltd. system) to take pictures of particles in visual field. Then, measure the longer diameter (major diameter) and the shorter diameter (minor diameter) of the primary particles present in the two-dimensional image, and use the ratio of major diameter to minor diameter as the aspect ratio of primary particles. In addition, for 40 primary particles, obtain the mean value of major diameter and minor diameter, use these values ​​to calculate the ratio of major diameter to minor diameter, and use it as average aspect ratio. At this time, make the zinc phthalocyanine pigment as sample be dispersed with a microscope after ultrasonic wave in solvent (for example cyclohexane). In addition, scanning electron microscope can also be used to replace transmission electron microscope.

[0080] Example

[0081] The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples.

[0082] <Synthesis of crude pigment>

[0083] (Synthesis of Crude Pigment A1)

[0084] 91 g of sulfonyl chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 109 g of aluminum chloride (manufactured by Kanto Chemical Co., Ltd.), 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 placed in a 300 ml flask. The temperature was raised to 130° C. and maintained at 130° C. for 40 hours. The reaction mixture was extracted into water, filtered, washed with water, and dried to obtain a crude zinc phthalocyanine halogenide pigment (crude pigment A1). The washing was performed until the difference between the pH of the filtrate and the pH of the water used for washing became ±0.2.

[0085] The crude pigment A1 was mass analyzed using JMS-S3000 manufactured by JEOL Ltd., and it was confirmed to be a zinc phthalocyanine halide having an average chlorine number of 1.8 and an average bromine number of 13.2. The delay time (Delay Time) during mass analysis was 500 ns, the laser intensity (Laser Intensity) was 44%, and the resolution value (Resolving Power Value) of the peak at m / z=1820 or more and 1860 or less was 31804.

[0086] (Synthesis of Crude Pigment A2)

[0087] 90 g of sulfuryl chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 105 g of aluminum chloride (manufactured by Kanto Chemical Co., Ltd.), 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 placed in a 300 ml flask. The temperature was raised to 130° C. and maintained at 130° C. for 40 hours. The reaction mixture was extracted into water, filtered, washed with water, and dried to obtain a crude zinc phthalocyanine halogenide pigment (crude pigment A2). The washing was performed until the pH of the filtrate became the same as the pH of the water used for washing.

[0088] The crude pigment A2 was mass analyzed using JMS-S3000 manufactured by JEOL Ltd., and was confirmed to be a zinc phthalocyanine halide having an average chlorine number of 2.9 and an average bromine number of 9.3. The delay time (Delay Time) during mass analysis was 510 ns, the laser intensity (Laser Intensity) was 40%, and the resolution value (Resolving Power Value) of the peak at m / z=1820 or more and 1860 or less was 65086.

[0089] (pH Determination of Crude Pigment A1 and Crude Pigment A2)

[0090] After measuring and mixing 5g of crude pigment (crude pigment A1 or crude pigment A2) and 5g of methanol in a 300ml beaker, further measure 100ml of ion exchange water, use a heating stirrer to form a boiling state for 5 minutes, and continue boiling for another 5 minutes. Next, after standing and cooling to below 30°C, move to a 100ml measuring cylinder, adjust the total amount to 100ml with ion exchange water, and filter. Determine the pH and specific conductivity of the filtrate. The pH of crude pigment A1 at 25°C is 3.7, and the specific conductivity is 163μS / cm (micro Siemens per centimeter). The pH of crude pigment A2 at 25°C is 3.4, and the specific conductivity is 193μS / cm. It is thus confirmed that crude pigment A1 and crude pigment A2 contain acid, and even if water washing is performed until the pH of the filtrate becomes the same pH as the water used in washing, the acid cannot be removed. The pH was measured using a PH71 personal pH meter manufactured by Yokogawa Electric Corporation, and the specific conductivity was measured using SevenEasy S30 manufactured by Mettler-Toledo.

[0091] <Example 1>

[0092] (Pretreatment process)

[0093] 595 parts by mass of crude pigment A1 were loaded into a 5L dry mill equipped with 13500 parts by mass of 3 / 8 inch steel balls, and dry-pulverized for 2 hours at a rotation speed of 45m / min and 70°C. Next, the dry-pulverized crude pigment was washed. Specifically, 100g of the dry-pulverized crude pigment and 100g of methanol were measured and mixed in a 5L beaker, and 2L of water was added. After stirring for 1 hour, the mixture was filtered and washed with water until the pH of the filtrate was ±0.2 compared to the pH of the water used in the washing. By the above operation, a zinc phthalocyanine prefabricated pigment (prefabricated pigment B1) was obtained.

[0094] (pH determination of preformed pigment B1)

[0095] After measuring and mixing 5g of pre-pigment B1 and 5g of methanol in a 300ml beaker, further measure 100ml of ion exchange water, use a heating stirrer to form a boiling state for 5 minutes, and continue to boil for 5 minutes. Next, after standing and cooling to below 30°C, move to a 100ml measuring cylinder, adjust the total amount to 100ml with ion exchange water, and filter. The pH and specific conductivity of the filtrate were measured. As a result, the pH at 25°C was 6.2 and the specific conductivity was 97μS / cm. It was thus confirmed that at least a portion of the acid contained in the pre-pigment B1 was removed.

[0096] (Micro-refining process)

[0097] 40 g of pre-pigment B1, 400 g of crushed sodium chloride and 63 g of diethylene glycol were placed in a double-arm kneader and kneaded at 80° C. for 8 hours. The kneaded mixture was extracted into 2 kg of 80° C. water and stirred for 1 hour. Thereafter, it was filtered, washed with hot water, dried and crushed to obtain green pigment G1.

[0098] (Determination of average primary particle size)

[0099] Green pigment G1 was ultrasonically dispersed in cyclohexane, and then photographed using a microscope. The average particle size of the primary particles was calculated from the average value of 40 primary particles constituting the agglomerates on the two-dimensional image. The average particle size of the primary particles was 26 nm.

[0100] (pH measurement of green pigment G1)

[0101] After measuring and mixing 5g of green pigment G1 and 5g of methanol in a 300ml beaker, further measure 100ml of ion exchange water, use a heating stirrer to form a boiling state for 5 minutes, and continue to boil for 5 minutes. Next, after standing and cooling to below 30°C, move to a 100ml measuring cylinder, adjust the total amount to 100ml with ion exchange water, and filter. The pH and specific conductivity of the filtrate were measured. As a result, the pH at 25°C was 6.3 and the specific conductivity was 62μS / cm.

[0102] (Contrast and brightness evaluation)

[0103] 1.65 g of Pigment Yellow 138 (Chromofine Yellow 6206EC manufactured by Dainichi Seika Co., Ltd.), 3.85 g of DISPERBYK-161 (manufactured by BYK Chemicals Co., Ltd.), and 11.00 g of propylene glycol monomethyl ether acetate were dispersed together with 0.3 to 0.4 mm zirconium beads for 2 hours using a paint shaker manufactured by Toyo Seiki Co., Ltd. to obtain a dispersion.

[0104] 4.0 g of the above dispersion, 0.98 g of Unidic ZL-295, and 0.22 g of propylene glycol monomethyl ether acetate were added and mixed with a paint shaker to obtain a yellow composition for tinting (TY1).

[0105] 2.48 g of the green pigment G1 obtained in Example 1, 1.24 g of BYK-LPN6919 manufactured by BYK Chemical Co., Ltd., 1.86 g of Unidic ZL-295 manufactured by DIC Corporation, and 10.92 g of propylene glycol monomethyl ether acetate were dispersed together with zirconium beads of 0.3 to 0.4 mm in a paint shaker manufactured by Toyo Seiki Co., Ltd. for 2 hours to obtain a pigment dispersion for color filter (MG1).

[0106] 4.0 g of the color filter pigment dispersion (MG1), 0.98 g of Unidic ZL-295 manufactured by DIC Corporation, and 0.22 g of propylene glycol monomethyl ether acetate were added and mixed with a paint shaker to obtain an evaluation composition (CG1) for forming a green pixel portion for a color filter.

[0107] The evaluation composition (CG1) was spin-coated on an alkali glass substrate, dried at 90°C for 3 minutes, and then heated at 230°C for 1 hour. In this way, a glass substrate for contrast evaluation having a colored film on an alkali glass substrate was prepared. The thickness of the colored film obtained by heating at 230°C for 1 hour was set to 1.8 μm by adjusting the rotation speed during spin coating.

[0108] Furthermore, the coating liquid obtained by mixing the yellow composition for toning (TY1) and the composition for evaluation (CG1) prepared above was spin-coated on an alkali glass substrate, dried at 90°C for 3 minutes, and then heated at 230°C for 1 hour. Thus, a glass substrate for brightness evaluation having a colored film on an alkali glass substrate was prepared. By adjusting the mixing ratio of the yellow composition for toning (TY1) and the composition for evaluation (CG1) and the rotation speed during spin coating, a colored film having a chromaticity (x, y) of (0.275, 0.570) under light source C of the colored film obtained by heating at 230°C for 1 hour was prepared.

[0109] The contrast of the colored film in the glass substrate for contrast evaluation was measured using a contrast tester CT-1 manufactured by Tsubosaka Electric Co., Ltd., and the brightness of the colored film in the glass substrate for brightness evaluation was measured using a U-3900 manufactured by Hitachi High-Technologies Corporation. The results are shown in Table 1. The contrast and brightness shown in Table 1 are based on the contrast and brightness of Comparative Example 1.

[0110] <Examples 2 to 4>

[0111] Pre-pigments B2 to B4 were obtained in the same manner as in Example 1 except that the heating temperature during the dry pulverization treatment in the pre-treatment step was changed as shown in Table 1. In addition, the pH and specific conductivity of the pre-pigments B2 to B4 were measured in the same manner as in Example 1. The results are shown in Table 1. Here, "room temperature" is 25±5°C.

[0112] Green pigments G2 to G4 were obtained by the same operation as in Example 1 except that preformed pigments B2 to B4 were used instead of preformed pigment B1, respectively. In addition, the average primary particle size, pH and specific conductivity of green pigments G2 to G4 were measured in the same manner as in Example 1. In addition, glass substrates for contrast evaluation and glass substrates for brightness evaluation were prepared in the same manner as in Example 1 except that green pigments G2 to G4 were used instead of green pigment G1, respectively, and the contrast and brightness were measured. The results are shown in Table 1.

[0113] <Examples 5 and 6>

[0114] As shown in Table 1, the heating temperature and / or mixing time during mixing in the micronization process were changed. Otherwise, the same operation as in Example 1 was performed to obtain green pigments G5 and G6, respectively. In addition, the average primary particle size, pH and specific conductivity of green pigments G5 and G6 were measured in the same manner as in Example 1. In addition, green pigment G5 or G6 was used instead of green pigment G1. Otherwise, the same operation as in Example 1 was performed to make a glass substrate for contrast evaluation and a glass substrate for brightness evaluation, and to measure contrast and brightness. The results are shown in Table 1.

[0115] <Comparative Example 1>

[0116] Use coarse pigment A1 to replace pre-made pigment B1, otherwise, operate in the same manner as in Example 1, carry out a micronization process, and obtain green pigment G7. That is, in Comparative Example 1, the pretreatment process in Example 1 is not carried out. In addition, operate in the same manner as in Example 1, measure the average primary particle size, pH and specific conductivity of green pigment G7. In addition, use green pigment G7 to replace green pigment G1, otherwise, operate in the same manner as in Example 1, make a glass substrate for contrast evaluation and a glass substrate for brightness evaluation, and measure contrast and brightness. The results are shown in Table 1.

[0117] <Comparative Example 2>

[0118] Prepigment B8 was obtained in the same manner as in Example 1 except that washing after dry pulverization was not performed in the pretreatment step. In addition, pH and specific conductivity of prepigment B8 were measured in the same manner as in Example 1. The results are shown in Table 1.

[0119] Use prefabricated pigment B8 to replace prefabricated pigment B1, otherwise, operate in the same manner as in Example 1 to obtain green pigment G8. In addition, operate in the same manner as in Example 1 to measure the average primary particle size, pH and specific conductivity of green pigment G8. In addition, use green pigment G8 to replace green pigment G1, otherwise, operate in the same manner as in Example 1 to make a glass substrate for contrast evaluation and a glass substrate for brightness evaluation, and measure contrast and brightness. The results are shown in Table 1.

[0120] <Example 7>

[0121] The crude pigment A2 was used instead of the crude pigment A1, and the crude pigment was pretreated in the same manner as in Example 1 to obtain a pre-pigment B9. In addition, the pH and specific conductivity of the pre-pigment B9 were measured in the same manner as in Example 1. The results are shown in Table 2.

[0122] Use prefabricated pigment B9 to replace prefabricated pigment B1, in addition, operate in the same manner as Example 1 to obtain green pigment G9. In addition, operate in the same manner as Example 1, measure the average primary particle size, pH and specific conductivity of green pigment G9. In addition, use Pigment Yellow 185 (BASF Paliotol Yellow D1155) to replace Pigment Yellow 138 (Chromofine Yellow 6206EC made by Dainichi Seika Co., Ltd.), use green pigment G9 to replace green pigment G1, and the chromaticity (x, y) of the colored film is adjusted to (0.230, 0.670), in addition, operate in the same manner as Example 1, make contrast evaluation glass substrate and brightness evaluation glass substrate, measure contrast and brightness. The results are shown in Table 2.

[0123] <Comparative Example 3>

[0124] Use coarse pigment A2 to replace pre-made pigment B9, otherwise, operate in the same manner as in Example 7, carry out a micronization process, and obtain green pigment G10. That is, in Comparative Example 3, the pretreatment process in Example 7 is not carried out. In addition, operate in the same manner as in Example 7, measure the average primary particle size, pH and specific conductivity of green pigment G10. In addition, use green pigment G10 to replace green pigment G9, otherwise, operate in the same manner as in Example 7, make a glass substrate for contrast evaluation and a glass substrate for brightness evaluation, and measure contrast and brightness. The results are shown in Table 2.

[0125] [Table 1]

[0126]

[0127] [Table 2]

[0128]

Claims

1. A method for producing a zinc phthalocyanine halide pigment, comprising the steps of pigmenting a crude zinc phthalocyanine halide pigment, The zinc phthalocyanine halide crude pigment is obtained by precipitating zinc phthalocyanine halide synthesized using a compound that reacts with water to generate an acid. The compound that reacts with water to generate an acid is selected from the group consisting of chlorosulfonic acid, aluminum halide, titanium halide, alkali (earth) metal halide, thionyl chloride and sulfonyl chloride, The process comprises: The zinc phthalocyanine halogenide crude pigment is dry-pulverized by a mill and then washed with water to obtain a zinc phthalocyanine halogenide pre-pigment; and the zinc phthalocyanine halogenide pre-pigment is mixed with an inorganic salt and an organic solvent to obtain a fine powder. 2 . The production method according to claim 1 , wherein in the pretreatment step, the crude zinc phthalocyanine halide pigment is dry-pulverized using an attritor in the absence of a water-soluble inorganic salt. 3 . The production method according to claim 1 , wherein in the pretreatment step, the crude zinc phthalocyanine halide pigment is dry-pulverized while being heated. 4 . The production method according to claim 1 , wherein in the pretreatment step, a zinc phthalocyanine halide prepigment having a pH of 5.0 or higher is obtained.

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