Method for manufacturing zinc halide phthalocyanine pigment

Abstract

A method for manufacturing a zinc halide phthalocyanine pigment, which has a step of pigmenting a crude zinc halide phthalocyanine pigment. The crude zinc halide phthalocyanine pigment is obtained by precipitating zinc halide phthalocyanine, and the zinc halide phthalocyanine is synthesized using a compound that reacts with water to produce an acid. The above step includes a pretreatment step of heating the crude zinc halide phthalocyanine pigment in water to obtain a zinc halide phthalocyanine pre-pigment with a pH of 5.0 or higher.

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, and specific uses of coloring compositions include printing inks, coatings, colorants for resins, colorants for fibers, and color materials for IT information recording (color filters, toners, inkjet). Coloring materials used in coloring compositions are mainly divided into pigments and dyes, and 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 an aggregate state called a crude product. Therefore, the synthesized organic compound cannot be used directly as a pigment, and a pigmentation process for adjusting the particle size is required. The aggregate (crude product) 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 synthesis method of zinc phthalocyanine halide, for example, chlorosulfonic acid method, melting method etc. are known. In these methods, a compound that reacts with water and produces acid 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 can be obtained. In such a method, usually, the acid from the compound that reacts with water and produces acid etc. can be attached to the crude pigment, so before the crude pigment is pigmented, 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, acid will remain 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 halide pigment, which comprises a step of pigmenting a zinc phthalocyanine halide crude pigment. The zinc phthalocyanine halide crude pigment used in the method is obtained by precipitating zinc phthalocyanine halide, which is synthesized using a compound that generates an acid by reacting with water, and the above step includes a pretreatment step of heating the zinc phthalocyanine halide crude pigment in water to obtain a zinc phthalocyanine halide pre-pigment having a pH of 5.0 or more.

[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] The temperature at which the zinc phthalocyanine halide crude pigment is heated in the pretreatment step may be 40° C. or higher.

[0015] The time for heating the zinc phthalocyanine halide crude pigment in the pretreatment step may be 1 minute or longer.

[0016] In the pretreatment step, after the zinc phthalocyanine halogenide crude pigment is heated in water, the heated zinc phthalocyanine halogenide crude pigment may be washed with water. In addition, the washed zinc phthalocyanine halogenide crude pigment may be heated in water and then washed with water for two or more times.

[0017] Effects of the Invention

[0018] 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

[0019] Preferred embodiments of the present invention are described below, but the present invention is not limited to the following embodiments.

[0020] A method for producing a zinc phthalocyanine halogenide pigment according to one embodiment includes a first step of preparing a zinc phthalocyanine halogenide crude pigment and a second step of pigmenting the zinc phthalocyanine halogenide crude pigment, wherein the second step includes a pretreatment step of heating the zinc phthalocyanine halogenide crude pigment in water to set the pH of the zinc phthalocyanine halogenide crude pigment to 5.0 or higher. Here, the zinc phthalocyanine halogenide crude pigment is obtained by precipitating zinc phthalocyanine halogenide, the zinc phthalocyanine halogenide is 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).

[0021] [Chemistry 1]

[0022]

[0023] [In formula (1), X 1 ~X 16 Each independently represents a hydrogen atom or a halogen atom.]

[0024] In the first step, a zinc phthalocyanine halide crude pigment is prepared. The zinc phthalocyanine halide crude pigment contains one or more zinc phthalocyanine halides having different numbers of halogen atoms.

[0025] 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.

[0026] In one embodiment, the average number of bromine atoms in the compound represented by the molecular 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. It should be noted that in the same description below, the upper and lower limits recorded separately may be combined arbitrarily.

[0027] When the average number of bromine atoms is less than 13, the average number of halogen atoms in 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.

[0028] 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 the formula (1) in the crude zinc phthalocyanine halogenide 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.

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

[0030] When the average number of bromine atoms is 13 or more, the average number of halogen atoms in 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.

[0031] 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.

[0032] 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.

[0033] The first step includes, for example, a step of synthesizing zinc phthalocyanine halide using a compound that generates an acid by reacting with water, and a step of precipitating the synthesized zinc phthalocyanine halide to obtain a zinc phthalocyanine halide crude pigment.

[0034] Examples of a method for synthesizing zinc phthalocyanine halide using a compound that generates an acid by reacting with water include a chlorosulfonic acid method and a melting method.

[0035] As the chlorosulfonic acid method, there can be mentioned a method in which zinc phthalocyanine is dissolved in a sulfur oxide solvent such as chlorosulfonic acid, and chlorine gas or bromine is added thereto for halogenation. The reaction in this case is carried out, for example, 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.

[0036] As a melting method, there can be mentioned a method of halogenating zinc phthalocyanine with a halogenating agent in a melt at about 10 to 170° C. composed of one or a mixture of two or more compounds that serve as solvents when halogenated, such as aluminum chloride, aluminum bromide, etc., titanium halides such as titanium tetrachloride, alkali metal halides or alkaline earth metal halides (hereinafter referred to as "alkaline (earth) metal halides"), such as sodium chloride, sodium bromide, etc. In the melting method, the compounds that serve as solvents when halogenated, such as the aluminum halide, titanium halide, alkaline (earth) metal halide, thionyl chloride, etc., are compounds that react with water to generate an acid. For example, aluminum chloride reacts with water to generate hydrochloric acid.

[0037] 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.

[0038] 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 alkaline (earth) metal halide to be added, within the range of generating a molten salt, the alkaline (earth) metal halide is preferably 1 to 15 parts by mass relative to 10 parts by mass of aluminum halide.

[0039] Examples of the halogenating agent include chlorine gas, sulfuryl chloride, and bromine.

[0040] 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.

[0041] The melting method using two or more of the above compounds can arbitrarily control the content 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 of chlorine, bromine, iodine and the reaction time, so it is preferred. In addition, according to the melting method, the decomposition of the raw materials in the reaction is less, the yield based on the raw materials is more excellent, and no strong acid is used, and the reaction can be carried out using an inexpensive device.

[0042] In this embodiment, by optimizing the method of feeding raw materials, the type and amount of catalyst used, the reaction temperature and the reaction time, it is possible to obtain zinc phthalocyanine halide having a halogen atom composition different from that of the existing zinc phthalocyanine halide.

[0043] 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 will generate an acid. Examples of the acid include hydrochloric acid and sulfuric acid.

[0044] As the zinc phthalocyanine halide crude pigment, the above-mentioned precipitate can be used directly, and it is preferred to use the above-mentioned precipitate filtered, and washed with water, sodium bisulfate water, sodium bicarbonate water or sodium hydroxide water, and washed with an organic solvent such as acetone, toluene, methanol, ethanol, dimethylformamide, etc. as needed, and then dried as the obtained product.

[0045] 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 grinder, ball mill, vibration mill, vibration ball mill or other pulverizer as a material as a zinc phthalocyanine halide crude pigment. The arithmetic standard deviation of the particle size distribution of the zinc phthalocyanine halide crude pigment is, for example, more than 15nm. The arithmetic standard deviation of the particle size distribution of the zinc phthalocyanine halide crude pigment is, for example, less than 1500nm. If the arithmetic standard deviation of the particle size distribution of the zinc phthalocyanine halide crude 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 zinc phthalocyanine halide crude pigment can be measured using a dynamic light scattering particle size distribution measuring device, and specifically, it can be measured by the following method and conditions.

[0046] <Method>

[0047] Using zirconium beads of 0.3 to 0.4 mm, 2.48 g of a crude zinc phthalocyanine halogenide pigment, 1.24 g of BYK-LPN6919 manufactured by BYK Chemical, 1.86 g of Unidic ZL-295 manufactured by DIC Corporation, and 10.92 g of propylene glycol monomethyl ether acetate were dispersed together for 2 hours using a pigment shaker manufactured by Toyo Seiki Co., Ltd. to obtain a dispersion. 0.02 g of the dispersion after removing the zirconium beads with a nylon sieve was diluted with 20 g of propylene glycol monomethyl ether acetate to obtain a dispersion for particle size distribution measurement.

[0048] <Conditions>

[0049] ·Measurement equipment: Dynamic light scattering particle size distribution measuring device LB-550 (manufactured by Horiba, Ltd.)

[0050] ·Measurement temperature: 25℃

[0051] ·Measurement sample: Dispersion for particle size distribution measurement

[0052] Data analysis conditions: particle size-based scattered light intensity, dispersion medium refractive index 1.402

[0053] 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: 5 g of the zinc phthalocyanine halogenide crude pigment is mixed with 5 g of methanol, and then further mixed with 100 ml of ion exchange water, and the obtained mixture is heated for 5 minutes to a boiling state, and further heated for 5 minutes to maintain the boiling state, and the heated mixture is placed to cool to below 30°C, and the total amount of the mixture is adjusted to 100 ml with ion exchange water, and then filtered, and the pH of the obtained filtrate is measured at 25°C.

[0054] The reason for the inclusion of acid (hydrochloric acid, sulfuric acid, etc.) in the zinc phthalocyanine crude pigment obtained in the first step is inferred as follows. That is, it is believed that: in zinc phthalocyanine, the distance between the zinc as the central metal and the nitrogen atom on the isoindoline unit is far, and there is a large hole around the central metal (zinc), 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 even if, for example, after precipitating zinc phthalocyanine, the precipitate is washed until the pH of the filtrate is equal to the water used in the washing, the acid (acid from the compound that reacts with water to produce acid, etc.) included in the precipitate is also difficult to be removed, and the acid will remain in the crude pigment.

[0055] The second step includes, for example, a pretreatment step of heating the zinc phthalocyanine halogenide crude pigment in water to set the pH of the crude pigment to 5.0 or higher; and a step of kneading and grinding the zinc phthalocyanine halogenide crude pigment (hereinafter also referred to as "zinc phthalocyanine halogenide pre-pigment") after the pretreatment step to perform micronization (micronization step). The kneading in the micronization step can be performed using, for example, a kneader, a sand mixer, etc.

[0056] In the pretreatment step, the zinc phthalocyanine halide crude pigment and water may be mixed and then heated, or the zinc phthalocyanine halide crude pigment may be added to heated water to heat the crude pigment.

[0057] The water used in the pretreatment step is not particularly limited as long as it can dissolve the acid contained in the crude zinc phthalocyanine halogenide 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.

[0058] The amount of water used may be, for example, 100 parts by mass or more, or 10000 parts by mass or less relative to 100 parts by mass of the zinc phthalocyanine halogenide crude pigment. If the amount of water used is greater than the above lower limit, the acid contained in the zinc phthalocyanine halogenide crude pigment tends to be more easily removed.

[0059] Water may contain an organic solvent (for example, an organic solvent that can be used in the micronization step described below). The amount of the organic solvent contained is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, relative to 100 parts by mass of water.

[0060] From the viewpoint that the acid contained in the zinc phthalocyanine halogenide crude pigment is more easily removed, the temperature (heating temperature) at which the zinc phthalocyanine halogenide crude pigment is heated is preferably 40° C. or more, more preferably 60° C. or more, and further preferably 70° C. or more. The heating temperature may be the boiling point of water. That is, in the pretreatment step, the zinc phthalocyanine halogenide crude pigment may be boiled in water. The heating temperature may be, for example, below the boiling point of water, and may be 100° C. or less.

[0061] The time (heating time) for heating the zinc phthalocyanine halogenide crude pigment can be appropriately adjusted according to the amount of the zinc phthalocyanine halogenide crude pigment, for example, it can be more than 1 minute, more than 5 minutes or more than 10 minutes, it can be less than 300 minutes, less than 200 minutes or less than 100 minutes, and it can be 1 to 300 minutes. It should be noted that the heating time can also be referred to as the time for keeping the zinc phthalocyanine halogenide crude pigment at the above-mentioned heating temperature (for example, 40 to 100° C.). Therefore, when the zinc phthalocyanine halogenide crude pigment is mixed with water and heated, the time (heating time) spent on heating is not included in the above-mentioned heating time. The heating time can be, for example, 1 minute to 2 hours.

[0062] From the viewpoint of easier removal of the acid contained in the zinc phthalocyanine halogenide crude pigment, it is preferred to improve the wettability of the zinc phthalocyanine halogenide crude pigment to water before or during the heat treatment in water (when or before the zinc phthalocyanine halogenide crude pigment is contacted with water). As a method for improving the wettability of the zinc phthalocyanine halogenide crude pigment to water, for example, a method of contacting the zinc phthalocyanine halogenide crude pigment with a water-soluble organic solvent such as methanol can be cited. Relative to 100 parts by mass of the zinc phthalocyanine halogenide 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.

[0063] From the viewpoint of fully removing the water containing the acid, it is preferred to wash the crude zinc phthalocyanine halogenide pigment after the heat treatment in water. The washing can be carried out by any of water washing (washing with water below 40°C) and hot water washing (washing with water above 40°C). The washing can be repeated several times (for example, 2 to 5 times). Specifically, it is preferred to wash until the pH of the filtrate is the same as the pH of the water used for washing (for example, the difference between the two is 0.2 or less). After washing, filtering, drying, pulverization and the like can also be performed as needed.

[0064] From the viewpoint of further removing the acid contained in the halogenated zinc phthalocyanine crude pigment, in the pretreatment process, for the washed crude pigment, the operation of heating in water and then washing with water can be repeated multiple times (preferably more than 2 times). The heating conditions and washing conditions at this time are the same as the above heating conditions and washing conditions. Therefore, the pretreatment process can also be referred to as a process in which the pH of the halogenated zinc phthalocyanine crude pigment is set to 5.0 or more by repeating a series of operations of heating the halogenated phthalocyanine crude pigment in water (preferably at a heating temperature of 40 to 100° C. and a heating time of 1 to 300 minutes) and washing the heated crude pigment with water.

[0065] In the above-mentioned pretreatment step, at least a part of the acid contained in the zinc phthalocyanine halogenide crude pigment is removed. Thus, a zinc phthalocyanine halogenide preformed pigment having a pH of 5.0 or more is obtained. Here, the pH of the zinc phthalocyanine halogenide preformed pigment is: 5g of the zinc phthalocyanine halogenide preformed 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 a boiling state, and further heated for 5 minutes to maintain the boiling state, and the heated mixture is placed to cool to below 30°C, and then the total amount of the mixture is adjusted to 100ml with ion exchange water, and then filtered to obtain the pH of the filtrate at 25°C.

[0066] In the pretreatment step, the pH of the zinc phthalocyanine halide prepigment is preferably set to 6.0 or higher, more preferably 6.5 or higher, from the viewpoint of easily obtaining finer pigment particles. The pH of the zinc phthalocyanine halide prepigment may be set to 8.5 or lower, or 7.0 or lower, for example.

[0067] 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.

[0068] The organic solvent can use a substance that does not dissolve the zinc phthalocyanine halogenide preformed 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 zinc phthalocyanine halogenide preformed pigment.

[0069] 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.

[0070] The kneading time in the refinement step may be, for example, 1 to 60 hours.

[0071] 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 can be obtained. However, the organic solvent and the inorganic salt can be removed from the mixture, and the solid matter mainly containing the zinc phthalocyanine halide pigment can be washed, filtered, dried, pulverized, etc. as needed.

[0072] 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.

[0073] As the drying after the above-mentioned washing and filtration, for example, intermittent or continuous drying can be mentioned, 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.

[0074] The pulverization after drying is not an operation for increasing the specific surface area or reducing the average particle size of the primary particles, but is performed to disperse and powderize the pigment when the pigment forms a ramp shape, etc., when drying using, for example, a box dryer or a belt dryer. For example, pulverization using a mortar, a hammer mill, a disk mill, a pin mill, a jet mill, etc. can be cited.

[0075] According to the above-mentioned manufacturing method, a fine zinc phthalocyanine halogenide pigment can be obtained. The inventors of the present invention speculate as follows on the reasons for obtaining such an effect. 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 is removed in the pretreatment process, thereby alleviating the above-mentioned influence caused by the acid. Therefore, using the above-mentioned method, a fine zinc phthalocyanine halogenide pigment can be obtained.

[0076] The zinc phthalocyanine halides obtained by the above-mentioned manufacturing method are suitable for use as green pigments 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 halides obtained by the above-mentioned manufacturing method are used as green pigments for color filters, there is a tendency to obtain excellent contrast, and in addition, there is a tendency to obtain excellent brightness.

[0077] The average particle size (average primary particle size) of the primary particles of the zinc phthalocyanine halogenide pigment obtained by the above method is, for example, less than 30 nm. According to the above method, for example, a zinc phthalocyanine halogenide pigment having an average primary particle size of less than 25 nm can also be obtained. The average primary particle size of the zinc phthalocyanine halogenide pigment can be more than 10 nm. Here, the average primary particle size is the average value of the major diameter of the primary particles, which can be obtained by measuring the major diameter of the primary particles in the same manner as the determination of the average aspect ratio described later.

[0078] 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, 1.8 or less, 1.6 or less, or 1.4 or less. A zinc phthalocyanine halogenide pigment having such an average aspect ratio can provide a more excellent contrast.

[0079] The zinc phthalocyanine halide pigment having an average aspect ratio of primary particles in 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.

[0080] The aspect ratio and average aspect ratio of primary particles can be measured by the following method. First, the particles in the visual field are photographed using a transmission electron microscope (e.g., JEM-2010 manufactured by JEOL Ltd.). Then, the longer diameter (major diameter) and the shorter diameter (minor diameter) of the primary particles present in the two-dimensional image are measured, and the ratio of the major diameter to the minor diameter is set as the aspect ratio of the primary particles. In addition, for 40 primary particles, the average value of the major diameter and the minor diameter is obtained, and the ratio of the major diameter to the minor diameter is calculated using their values, which is used as the average aspect ratio. At this time, the zinc phthalocyanine halogenide pigment as a sample is dispersed in a solvent (e.g., cyclohexane) and then photographed with a microscope. In addition, a scanning electron microscope can also be used instead of a transmission electron microscope.

[0081] Example

[0082] 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.

[0083] <Synthesis of crude pigment>

[0084] (Synthesis of Crude Pigment A1)

[0085] 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 with water, filtered, washed with water, and dried to obtain a crude zinc phthalocyanine halogenide pigment (crude pigment A1). It should be noted that the washing was performed until the difference between the pH of the filtrate and the pH of the water used for washing was ±0.2.

[0086] 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. It should be noted that the delay time (Delay Time) during mass analysis was 500 ns, the laser intensity (Laser Intensity) was 44%, and the resolving power value (Resolving Power Value) of the peak between m / z=1820 and 1860 was 31804.

[0087] (Synthesis of Crude Pigment A2)

[0088] 90 g of sulfonyl 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. After the reaction mixture was extracted with water, it was filtered, washed with water, and dried to obtain a crude zinc phthalocyanine halogenide pigment (crude pigment A2). It should be noted that the washing was performed until the pH of the filtrate was the same as the pH of the water used for washing.

[0089] The crude pigment A2 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 2.9 and an average bromine number of 9.3. It should be noted that the delay time (Delay Time) during mass analysis was 510ns, the laser intensity (Laser Intensity) was 40%, and the resolving power value (Resolving Power Value) of the peak between m / z=1820 and 1860 was 65086.

[0090] (pH Determination of Crude Pigment A1 and Crude Pigment A2)

[0091] In a 300ml beaker, 5g of crude pigment (crude pigment A1 or crude pigment A2) and 5g of methanol were measured and mixed, and then 100ml of ion exchange water was further measured, and a hot stirrer was used to form a boiling state for 5 minutes, and the boiling was further continued for 5 minutes. Next, after cooling to below 30°C, it was moved to a 100ml measuring cylinder, and the total amount was adjusted to 100ml with ion exchange water and filtered. The pH and conductivity of the filtrate were measured. The pH of crude pigment A1 at 25°C was 3.7, and the conductivity was 163μS / cm (micro Siemens per centimeter). The pH of crude pigment A2 at 25°C was 3.4, and the conductivity was 193μS / cm. It was thus confirmed that the crude pigment A1 and crude pigment A2 contained acid, and even if the filtrate was washed with water until the pH of the filtrate was the same as the water used for washing, the acid could not be removed. The pH was measured using a PH71 small portable pH meter manufactured by Yokogawa Electric Corporation, and the conductivity was measured using Seven Easy S30 manufactured by Mettler-Toledo Corporation.

[0092] <Example 1>

[0093] (Pretreatment process)

[0094] 50 g of crude pigment A1, 50 g of methanol and 1 L of ion exchange water were weighed in a 3 L beaker, and the temperature was raised to 90° C. over 20 minutes using a hot stirrer, and further heated at 90° C. for 10 minutes. Thereafter, the mixture was filtered and washed with water. The washing was performed until the pH of the filtrate was the same as that of the water used for washing.

[0095] Next, the washed crude pigment (water-containing crude pigment 1) is transferred to a 3L beaker, and after measuring 1L of ion exchange water, the temperature is raised to 90°C in 20 minutes using a hot stirrer, and further heated at 90°C for 10 minutes. Thereafter, filter and wash with water to obtain water-containing crude pigment 2. The water washing is performed until the pH of the filtrate is the same as the pH of the water used for washing. For the obtained water-containing crude pigment 2, the above series of operations (heating and washing in water) are further repeated once. That is, the water-containing crude pigment 2 is transferred to a 3L beaker, and after measuring 1L of ion exchange water, the temperature is raised to 90°C in 20 minutes using a hot stirrer, and further heated at 90°C for 10 minutes, and then filtered and washed with water. The water washing is performed until the pH of the filtrate is the same as the pH of the water used for washing. Thus, water-containing crude pigment 3 is obtained. The obtained water-containing crude pigment 3 is dried and crushed to obtain a zinc phthalocyanine preformed pigment (preformed pigment B1).

[0096] (pH determination of pre-pigment B1)

[0097] After measuring and mixing 5g of pre-pigment B1 and 5g of methanol in a 300ml beaker, 100ml of ion exchange water was further measured, and a hot stirrer was used to form a boiling state for 5 minutes, and the boiling was further continued for 5 minutes. Next, after cooling to below 30°C, it was transferred to a 100ml measuring cylinder, and the total amount was adjusted to 100ml with ion exchange water and filtered. The pH and conductivity of the filtrate were measured. As a result, the pH at 25°C was 6.0 and the conductivity was 51μS / cm. It was thus confirmed that at least a portion of the acid contained in the pre-pigment B1 had been removed.

[0098] (Micro-refining process)

[0099] 40 g of pre-pigment B1, 400 g of pulverized 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 in 2 kg of 80° C. water and stirred for 1 hour. Thereafter, it was filtered, washed with hot water, dried and pulverized to obtain green pigment G1.

[0100] (Measurement of average primary particle size)

[0101] The green pigment G1 was ultrasonically dispersed in cyclohexane and then photographed under a microscope, and the average particle size of the primary particles was calculated from the average value of 40 primary particles constituting the aggregate on the two-dimensional image. The average particle size of the primary particles was 29 nm.

[0102] (pH measurement of green pigment G1)

[0103] 5g of green pigment G1 and 5g of methanol were measured and mixed in a 300ml beaker, and then 100ml of ion exchange water was further measured, and a hot stirrer was used to form a boiling state for 5 minutes, and the boiling was further continued for 5 minutes. Next, after cooling to below 30°C, it was transferred to a 100ml measuring cylinder, and the total amount was adjusted to 100ml with ion exchange water and filtered. The pH and conductivity of the filtrate were measured. As a result, the pH at 25°C was 6.1 and the conductivity was 46μS / cm.

[0104] (Evaluation of contrast and brightness)

[0105] 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 in a pigment shaker manufactured by Toyo Seiki Co., Ltd. for 2 hours to obtain a dispersion.

[0106] 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 using a pigment shaker to obtain a yellow composition for coloring (TY1).

[0107] 2.48 g of the green pigment G1 obtained in Example 1, 1.24 g of BYK-LPN6919 manufactured by BYK-Chemie, 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 in a pigment shaker manufactured by Toyo Seiki Co., Ltd. for 2 hours to obtain a pigment dispersion for color filter (MG1).

[0108] 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 using a pigment shaker to obtain an evaluation composition (CG1) for forming a green pixel portion for a color filter.

[0109] The evaluation composition (CG1) was spin-coated on a soda-lime 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 the soda-lime glass substrate was prepared. It should be noted that the rotation speed was adjusted during spin coating so that the thickness of the colored film obtained by heating at 230°C for 1 hour was 1.8 μm.

[0110] 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 a soda-lime 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 the soda-lime glass substrate was prepared. It should be noted that 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 was prepared when the colored film was heated at 230°C for 1 hour.

[0111] The contrast of the colored film on 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 on 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. It should be noted that the contrast and brightness shown in Table 1 are based on the contrast and brightness of Comparative Example 1.

[0112] <Example 2>

[0113] In the pretreatment step, the above series of operations (heating and washing in water) were repeated 9 times for the aqueous crude pigment 1, and the pre-pigment B2 was obtained in the same manner as in Example 1. In addition, the pH and conductivity of the pre-pigment B2 were measured in the same manner as in Example 1. The results are shown in Table 1.

[0114] Use prefabricated pigment B2 to replace prefabricated pigment B1, otherwise, operate in the same manner as in Example 1 to obtain green pigment G2. In addition, operate in the same manner as in Example 1 to measure the average primary particle size, pH and conductivity of green pigment G2. In addition, use green pigment G2 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.

[0115] <Examples 3 and 4>

[0116] Pre-pigments B3 and B4 were obtained in the same manner as in Example 1 except that the heating time or heating temperature in water in the pre-treatment step was changed as shown in Table 1. In addition, the pH and conductivity of the pre-pigments B3 and B4 were measured in the same manner as in Example 1. The results are shown in Table 1.

[0117] Use prefabricated pigment B3 or B4 to replace prefabricated pigment B1, otherwise, operate in the same manner as in Example 1 to obtain green pigments G3 and G4. In addition, operate in the same manner as in Example 1 to measure the average primary particle size, pH and conductivity of green pigments G3 and G4. In addition, use green pigment G3 or G4 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.

[0118] <Examples 5 and 6>

[0119] As shown in Table 1, the heating temperature and / or mixing time during mixing in the micronization process were changed. In addition, 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 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. In addition, the same operation as in Example 1 was performed to prepare 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.

[0120] <Comparative Example 1>

[0121] Use crude pigment A1 to replace pre-made pigment B1, otherwise, operate in the same manner as in Example 1, perform a micronization process, and obtain green pigment G7. That is, the pretreatment process in Example 1 is not performed in Comparative Example 1. In addition, operate in the same manner as in Example 1, and measure the average primary particle size, pH, and 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.

[0122] <Comparative Example 2>

[0123] After obtaining a water-containing crude pigment 1 in the same manner as in Example 1, the obtained water-containing crude pigment 1 was dried and pulverized to obtain a zinc phthalocyanine halide pre-pigment (pre-pigment B8). That is, in Comparative Example 2, the water-containing crude pigment 1 was not further heated and washed in water. In addition, the pH and conductivity of the pre-pigment B8 were measured in the same manner as in Example 1. The results are shown in Table 1.

[0124] 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 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.

[0125] <Example 7>

[0126] 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 conductivity of the pre-pigment B9 were measured in the same manner as in Example 1. The results are shown in Table 2.

[0127] Prefabricated pigment B9 is used to replace prefabricated pigment B1, except that, the same operation as Example 1 is performed to obtain green pigment G9. In addition, the same operation as Example 1 is performed to measure the average primary particle size, pH and conductivity of green pigment G9. In addition, Pigment Yellow 185 (Paliotol Yellow D1155 manufactured by BASF) is used to replace Pigment Yellow 138 (Chromofine Yellow 6206EC manufactured by Dainichi Seika Co., Ltd.), green pigment G9 is used to replace green pigment G1, and the chromaticity (x, y) of the colored film is adjusted to (0.230, 0.670), in addition, the same operation as Example 1 is performed 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 2.

[0128] <Comparative Example 3>

[0129] Use coarse pigment A2 to replace pre-made pigment B9, otherwise, operate in the same manner as in Example 7, perform a micronization process, and obtain green pigment G10. That is, the pre-treatment process in Example 7 is not performed in Comparative Example 3. In addition, operate in the same manner as in Example 7, measure the average primary particle size, pH and 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.

[0130] [Table 1]

[0131]

[0132] [Table 2]

[0133]

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, and the zinc phthalocyanine halide is synthesized using a compound that reacts with water to generate an acid. The compound that reacts with water to generate an acid is a compound selected from the group consisting of aluminum halides, titanium halides, alkali metal halides, alkaline earth metal halides, thionyl chloride, sulfuryl chloride, and chlorosulfonic acid, The process includes a pretreatment step of heating the zinc phthalocyanine halogenated crude pigment in water at 90° C. to 100° C. to obtain a zinc phthalocyanine halogenated prepigment having a pH of 5.0 to 7.

0. 2 . The production method according to claim 1 , wherein the time for heating the crude zinc phthalocyanine halide pigment in the pretreatment step is 1 minute to 200 minutes. 3 . The production method according to claim 1 , wherein in the pretreatment step, the crude zinc phthalocyanine halogenide pigment is heated in water and then the heated crude zinc phthalocyanine halogenide pigment is washed with water.

4. The production method according to claim 3, wherein in the pretreatment step, the washed crude zinc phthalocyanine halide pigment is heated in water and then washed with water, which is repeated two or more times.

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