Method for producing halogenated metal-free phthalocyanine

Abstract

To provide a simple method for producing a halogenated metal-free phthalocyanine exhibiting color tones of clear blue and green.SOLUTION: A method for producing a halogenated metal-free phthalocyanine has a process of eliminating manganese from a halogenated manganese phthalocyanine by mixing the halogenated manganese phthalocyanine with an acid constituent to obtain a halogenated non-metal phthalocyanine, where the acid constituent is a fuming sulfuric acid or a concentrated sulfuric acid having a concentration of 90 mass% or more when an average substitution number of halogen groups per one molecule of the halogenated manganese phthalocyanine is more than 0 and 4 or less, and the acid constituent is a fuming sulfuric acid when an average substitution number of halogen groups per one molecule of the halogenated manganese phthalocyanine is more than 4.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing halogenated metal-free phthalocyanine. By law Regarding. [Background technology]

[0002] Numerous coloring materials such as dyes and pigments are used in a variety of applications, including new applications such as information display devices such as liquid crystal color displays and information recording materials such as inkjet inks, as well as coloring agents for resins, fibers, paper, writing instruments, paints, coatings, and various printing inks. Coloring materials are required not only to be suitable for the object to be colored, but also to exhibit properties such as color tone, tinting strength, clarity, transparency, hiding power, weather resistance, solvent resistance, chemical resistance, fluidity, and dispersibility depending on the application. Among these, pigments are often used in applications requiring various resistances.

[0003] Commonly used phthalocyanine pigments often contain metals. In some applications, there is a movement to refrain from using compounds that contain specific elements in their structure. For example, copper (Cu) has regulated limits set by the Water Supply Act, Water Pollution Control Act, and Basic Environment Act, and there are concerns that industry groups may impose restrictions on it in the future.

[0004] When using conventional pigments as they are, possible solutions include reducing the amount of pigment used or mixing multiple pigments. In the case of phthalocyanine pigments, alternative solutions include changing the central metal. In recent years, there has been a demand for technologies for reducing the metal content in pigments. For example, a method has been proposed in which crude halogenated copper phthalocyanine is treated with fuming sulfuric acid to produce a halogenated copper phthalocyanine pigment in which the free copper content is reduced to a certain level or less (Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4584547 Summary of the Invention [Problem to be solved by the invention]

[0006] However, a method for easily producing a substantially metal-free halogenated phthalocyanine (halogenated metal-free phthalocyanine) that exhibits blue or green color tones by removing the metal from the halogenated metal phthalocyanine structure has not been known until now.

[0007] The present invention has been made in view of the problems associated with the prior art, and an object of the present invention is to provide a simple method for producing a halogenated metal-free phthalocyanine that exhibits a vivid blue or green color tone. Another object of the present invention is to provide a halogenated metal-free phthalocyanine produced by this production method, and a colorant and a bioplastic that use this halogenated metal-free phthalocyanine. [Means for solving the problem]

[0008] That is, according to the present invention, there is provided the following method for producing a halogenated metal-free phthalocyanine. [1] A method for producing a halogenated metal-free phthalocyanine, comprising the steps of mixing a halogenated manganese phthalocyanine with an acid component and eliminating manganese from the halogenated manganese phthalocyanine to obtain a halogenated metal-free phthalocyanine, wherein the acid component is oleum or 90% by mass or more concentrated sulfuric acid when the halogenated manganese phthalocyanine has an average number of halogen groups per molecule that is greater than 0 and not greater than 4, and the acid component is oleum when the halogenated manganese phthalocyanine has an average number of halogen groups per molecule that is greater than 4. [2] The method for producing a halogenated metal-free phthalocyanine according to [1], wherein the halogenated manganese phthalocyanine and the acid component are mixed at a temperature of 5°C or less. [3] The method for producing a halogenated metal-free phthalocyanine according to [1] or [2] above, further comprising a step of obtaining the halogenated manganese phthalocyanine by the Wyler process. [4] The method for producing a halogenated metal-free phthalocyanine according to any one of [1] to [3] above, wherein the halogen atom in the halogenated manganese phthalocyanine is at least one of a chlorine atom and a bromine atom.

[0009] The present invention also provides the following halogenated metal-free phthalocyanine, colorant, and bioplastic. [5] A halogenated metal-free phthalocyanine obtained by the production method according to any one of [1] to [4] above. [6] A colorant containing the halogenated metal-free phthalocyanine according to [5] above. [7] A bioplastic containing a bioplastic material and the colorant described in [6] above. [Effects of the Invention]

[0010] The present invention provides a simple method for producing a halogenated metal-free phthalocyanine that exhibits a vivid blue or green color tone. The present invention also provides the halogenated metal-free phthalocyanine produced by this production method, as well as a colorant and a bioplastic that use this halogenated metal-free phthalocyanine. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Halogenated Metal-Free Phthalocyanine and Its Method of Production> Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments. One embodiment of the method for producing a halogenated metal-free phthalocyanine of the present invention includes a step of mixing a halogenated manganese phthalocyanine with an acid component and removing manganese from the halogenated manganese phthalocyanine to obtain a halogenated metal-free phthalocyanine (metal removal step). When the average number of halogen groups substituted per molecule of the halogenated manganese phthalocyanine is more than 0 but not more than 4, the acid component is oleum or 90% by mass or more concentrated sulfuric acid. When the average number of halogen groups substituted per molecule of the halogenated manganese phthalocyanine is more than 4, the acid component is oleum. One embodiment of the halogenated metal-free phthalocyanine of the present invention is obtained by the above production method.

[0012] (definition) Halogenated phthalocyanines having an average halogen group substitution number per molecule of more than 0 to 16 or less are also referred to as "polyhalogenophthalocyanines." Similarly, halogenated manganese phthalocyanines and halogenated metal-free phthalocyanines having an average halogen group substitution number per molecule of more than 0 to 16 or less are also referred to as "polyhalogenomanganese phthalocyanines" and "polyhalogenometal-free phthalocyanines," respectively. The numbers in parentheses before "halogeno," "bromo," and "chloro" indicate the average substitution numbers of "halogen groups," "bromine (Br) groups," and "chlorine (Cl) groups," respectively, per molecule. Meanwhile, the numbers preceded by a hyphen before "halogeno," "bromo," and "chloro" indicate the substitution positions, respectively. Furthermore, "metal-free" in this specification means that when the target substance is analyzed by inductively coupled plasma (ICP) atomic emission spectroscopy, it is not substantially detected that the substance contains metals such as manganese.

[0013] (Demetallization process) In the demetallization step, the halogenated manganese phthalocyanine (poly(1-16) halogenomanganese phthalocyanine) is mixed with an acid component, thereby removing manganese (Mn) from the halogenated manganese phthalocyanine to obtain the halogenated metal-free phthalocyanine (poly(1-16) halogeno metal-free phthalocyanine).

[0014] The type and concentration of the acid component required for demetallization differ depending on the average substitution number of halogen groups in the halogenated manganese phthalocyanine. Therefore, the type of acid component to be used must be appropriately selected depending on the average substitution number of halogen groups in the halogenated manganese phthalocyanine. Specifically, when the average substitution number of halogen groups per molecule of the halogenated manganese phthalocyanine is greater than 0 and less than 4, fuming sulfuric acid or 90% by mass or more of concentrated sulfuric acid is used as the acid component. On the other hand, when the average substitution number of halogen groups per molecule of the halogenated manganese phthalocyanine is greater than 4, fuming sulfuric acid is used as the acid component. In this way, by selecting and using an acid component depending on the average substitution number of halogen groups in the halogenated manganese phthalocyanine, manganese can be efficiently desorbed from the halogenated manganese phthalocyanine to obtain a halogenated metal-free phthalocyanine.

[0015] The concentrated sulfuric acid used is 90% by mass or more, preferably 93% by mass or more, and more preferably 95% by mass or more. There is no particular upper limit to the concentration of concentrated sulfuric acid, and 100% by mass concentrated sulfuric acid may be used.

[0016] The oleum used has a sulfur trioxide (SO) concentration of preferably 5% by mass or more, more preferably 10% by mass or more, and particularly preferably 20% by mass or more. Hereinafter, oleum having a sulfur trioxide concentration of X% by mass will also be referred to as "X% by mass oleum" or "X% oleum."

[0017] In the demetallization step, the halogenated manganese phthalocyanine is mixed with an acid component, and the halogenated manganese phthalocyanine is dissolved in the acid component to obtain an acid solution. The halogen atom in the halogenated manganese phthalocyanine is preferably at least one of a chlorine atom (Cl) and a bromine atom (Br). The temperature of the acid solution is preferably 5°C or less, more preferably 3°C or less, and particularly preferably 0°C or less. By maintaining the temperature of the acid solution within the above range, the occurrence of side reactions can be suppressed and the yield of the halogenated metal-free phthalocyanine can be improved. The time for mixing the halogenated manganese phthalocyanine with the acid component is not particularly limited and may be appropriately set within the range of, for example, 0.1 to 5 hours.

[0018] (Manufacturing process of halogenated manganese phthalocyanine) The halogenated manganese phthalocyanine used as a raw material can be produced, for example, by the Wyler process (urea process). That is, the production method of this embodiment preferably further includes a step of obtaining a halogenated manganese phthalocyanine by the Wyler process. A halogenated manganese phthalocyanine can also be produced by the nitrile process, but this is disadvantageous in terms of cost compared to the Wyler process. Furthermore, a halogenated metal-free phthalocyanine can also be obtained by producing a metal-free phthalocyanine by the nitrile process and then halogenating it, but this is disadvantageous in terms of cost.

[0019] The Wyler process (urea process) is a method for producing halogenated manganese phthalocyanine by heating and stirring halogenated phthalic acids, urea, metal salts, and a catalyst, together with optional clarifying aids and stirring aids, at high temperatures in the presence or absence of a high-boiling organic solvent. Any of the reaction solvents conventionally used in the Wyler process can be used as the high-boiling organic solvent. Examples of catalysts that can be used include titanium tetrachloride, tetrabutyl orthotitanate, and tetrapropyl orthotitanate. For industrial use, products such as "Orgatix TA-10" manufactured by Matsumoto Pharmaceutical Industries Co., Ltd. can be used.

[0020] (Precipitation process) It is preferable to dissolve the halogenated manganese phthalocyanine in an acid component, and then, for example, remove the metal and precipitate the resulting component (halogenated metal-free phthalocyanine). Examples of methods for precipitating the halogenated metal-free phthalocyanine include the following methods (1) to (3). (1) A method in which a hydrous acid is added to an acid solution to reduce the acid concentration and precipitate a halogenated metal-free phthalocyanine. (2) A method in which the acid solution absorbs water to reduce the acid concentration and precipitate a halogenated metal-free phthalocyanine. (3) A method in which an acid solution is poured into a large amount of water or ice water that is being vigorously stirred or jetted, and halogenated metal-free phthalocyanine is instantly precipitated.

[0021] The water or ice water used in the above method (3) may contain an organic solvent. Among the above methods (1) to (3), method (3) is preferred. In particular, it is preferred to jet water at high speed using a vacuum suction device such as an aspirator or an ejector, and to use the vacuum effect to draw in an acid solution, bring it into contact with the jetted water, and dilute it, thereby precipitating particulate halogenated metal-free phthalocyanine (pigment particles). It is also preferred to inject the acid solution dropwise into vigorously stirred water in a mixing vessel equipped with a high-speed mixer such as a dissolver or homomixer, or a high-efficiency stirrer, and then diffuse the acid solution into the water to precipitate particulate halogenated metal-free phthalocyanine (pigment particles).

[0022] (Pigmentation treatment process) The precipitated halogenated metal-free phthalocyanine is preferably subjected to a pigmentation treatment (pigmentation). Specifically, it is preferable to remove impurities to increase purity, refine the particles, and adjust the pigment crystals. More specifically, there is a method in which an acid solution is poured into water or ice water containing a hydrophobic organic solvent or a hydrophilic organic solvent to precipitate the halogenated metal-free phthalocyanine, while also refining the particles and adjusting the crystals. Another method involves adding a hydrophobic organic solvent or a hydrophilic organic solvent to treatment water containing the precipitate.

[0023] Following the precipitation step, it is preferable to carry out a known pigmentation treatment such as the so-called solvent finish method, in which crystallization is promoted by heat treatment in an organic solvent such as xylol or in a xylol emulsion. Furthermore, if necessary, at least one of surfactants, rosin, various resins, polymer dispersants, and pigment derivatives may be used in combination.

[0024] The pigment can be micronized in the precipitation step or in a step after the precipitation step. Examples of a method for micronizing the pigment in a step after the precipitation step include known pigment micronization methods such as a so-called dry grinding method and a salt milling method, in which the pigment is micronized by kneading and grinding together with a water-soluble salt and, if necessary, a water-soluble organic solvent in a kneader or other mixer.

[0025] If the pigment particles are too fine, they are preferably kneaded with an organic solvent using a kneader or the like to adjust the size while growing crystals.The average particle size of the primary particles of the pigment is preferably 5 to 130 nm, and more preferably 10 to 110 nm.

[0026] The halogen groups that are substituents constituting the halogenated metal-free phthalocyanine are preferably at least one of chlorine (Cl) atoms and bromine (Br) atoms. When the average number of halogen groups substituted per molecule is low, the color tends to be blue. As the average number of halogen groups substituted increases, the color tends to be greenish blue to green. The more bromine (Br) groups there are, the more yellowish green the color tends to be.

[0027] Although a halogenated metal-free phthalocyanine can also be produced by halogenating a metal-free phthalocyanine pigment, this is disadvantageous in terms of cost and makes it difficult to control the average substitution number of halogen groups, etc. Therefore, the production method of the present embodiment, in which a halogenated metal-free phthalocyanine is obtained by eliminating manganese from a halogenated manganese phthalocyanine, is preferred from the viewpoints of cost and of strictly controlling the structure of the resulting halogenated metal-free phthalocyanine.

[0028] From the viewpoint of more strictly controlling the type and average substitution number of halogen groups, it is preferable to use halogenated phthalic anhydrides, halogenated phthalimides, halogenated phthalodinitriles, or halogenated aminoiminoisoindolenines having the desired type and substitution number of halogen groups as raw materials and subject the halogenated manganese phthalocyanines to a condensation reaction to obtain the halogenated manganese phthalocyanines. Brominated manganese phthalocyanines containing only bromine (Br) atoms as halogen groups can be obtained by, for example, using tribromophthalic anhydride (or tetrabromophthalic anhydride), tribromophthalimide (or tetrabromophthalimide), tribromophthalodinitriles (or tetrabromophthalodinitriles), or tribromoaminoiminoisoindolenines (or tetrabromoaminoiminoisoindolenines) as raw materials and subjecting them to a condensation reaction in the presence of a metal salt.

[0029] The halogenated metal-free phthalocyanine produced by the production method of this embodiment, which is useful as a blue pigment, a green pigment, or the like, is excellent in fastness, such as solvent resistance and heat resistance, and in clarity. Specifically, the halogenated metal-free phthalocyanine of this embodiment is far superior in fastness to dyes, lake pigments, monoazo pigments, and the like. The halogenated metal-free phthalocyanine of this embodiment exhibits clarity equal to or greater than that of copper phthalocyanine and zinc phthalocyanine, and is superior in clarity to phthalocyanines containing metals such as cobalt, nickel, and iron. For these reasons, the halogenated metal-free phthalocyanine of this embodiment is particularly useful, for example, as a colorant for coloring bioplastics or as a pigment for pixels in color filters.

[0030] A blue or green pigment dispersion composition can be prepared using the halogenated metal-free phthalocyanine of this embodiment. The pigment dispersion composition can be obtained, for example, by mixing and grinding the halogenated metal-free phthalocyanine with a metal soap or the like. Alternatively, the pigment dispersion composition can be obtained by kneading and dispersing the halogenated metal-free phthalocyanine together with a dispersant in a resin. Furthermore, a pigment dispersion composition can be obtained by mixing the halogenated metal-free phthalocyanine with various liquid media, polymerizable liquid media such as polymerizable oligomers and polymerizable monomers, plasticizers, oligomers, and resin media such as synthetic resins, and, if necessary, dispersing aids such as polymeric dispersants and low-molecular-weight dispersing aids.

[0031] <Coloring agent> One embodiment of the colorant of the present invention contains the above-mentioned halogenated metal-free phthalocyanine. The colorant of this embodiment can be obtained by mixing the above-mentioned pigment dispersion composition with components such as a dilution medium, a thermoplastic polymer, a reactive polymer, a reactive oligomer, a polymerizable monomer, and a crosslinking agent used as a coating material. Furthermore, a curing catalyst or a polymerization catalyst may be added as needed. Various colored articles can be produced by coloring articles using the colorant of this embodiment or the above-mentioned pigment dispersion composition. Furthermore, colored bioplastics can be produced by mixing a bioplastic material with the above-mentioned colorant. [Example]

[0032] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples. In the examples and comparative examples, "parts" and "%" are by mass unless otherwise specified.

[0033] <Production of halogenated metal-free phthalocyanine> Example 1 [1](16) Synthesis of chloromanganese phthalocyanine A reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer and a heating device were prepared. 144.0 parts of nitrobenzene and 31.2 parts of manganese chloride tetrahydrate were placed in the reaction vessel and heated to 160°C with stirring for 8 hours to dehydrate. After cooling, 114.4 parts of tetrachlorophthalic anhydride and 120.1 parts of urea were added, and the temperature was gradually raised to 120°C. 22.7 parts of tetrabutyl orthotitanate were added, and the temperature was raised to 175°C, after which the reaction was continued with stirring for 4 hours. The temperature immediately before the end of the reaction was 190°C. After removing the reaction medium (nitrobenzene), the mixture was treated sequentially with dilute acid and dilute alkali to remove impurities, yielding 101.8 parts of a yellowish-brown crude pigment (A1). The yield was 91.0%.

[0034] Structural analysis was performed using infrared spectroscopy (IR), X-ray fluorescence spectroscopy (XRF), and matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOFMS), confirming that the resulting crude pigment (A1) was (16) chloromanganese phthalocyanine. The metal (manganese) and halogen contents of the sample were measured by inductively coupled plasma (ICP) atomic emission spectroscopy after decomposing the sample with strong acid using a microwave decomposition device. The other examples below were also analyzed using the same method.

[0035] [2] (16) Demetallization of chloromanganese phthalocyanine A reaction vessel equipped with a stirrer, an air cooling tube, and a thermometer, and a cooling device were prepared. 200 parts of 20% fuming sulfuric acid were placed in the reaction vessel, and 10 parts of crude pigment (A1) were slowly added to the reaction vessel while stirring under ice cooling to avoid heat generation, and the mixture was stirred at 0°C for 1 hour. The reaction product was added dropwise to 2,000 parts of stirred ice water, and the resulting precipitate was filtered and washed with water. The mixture was then pigmented using the xylene emulsion method, yielding 7.7 parts of a vivid green (16) chlorometal-free phthalocyanine (A2).

[0036] Example 2 Synthesis of [1] Bromo(12)chloromanganese phthalocyanine In the same manner as in Example 1[1], except that 22.7 parts of 4-bromophthalic anhydride and 85.8 parts of tetrachlorophthalic anhydride were used instead of tetrachlorophthalic anhydride, 92.3 parts of a greenish-black crude pigment (B1) was obtained in a yield of 87.1%.

[0037] [2] Demetallization of Bromo(12)chloromanganese Phthalocyanine 8.7 parts of vivid green bromo(12)chlorometal-free phthalocyanine (B2) was obtained in the same manner as in Example 1[2] above, except that crude pigment (B1) was used instead of crude pigment (A1).

[0038] Example 3 [1] Synthesis of (2) bromo(8) chloromanganese phthalocyanine In the same manner as in Example 1[1], except that 45.4 parts of 4-bromophthalic anhydride and 57.2 parts of tetrachlorophthalic anhydride were used instead of tetrachlorophthalic anhydride, 77.6 parts of a greenish-black crude pigment (C1) was obtained in a yield of 77.5%.

[0039] [2](2) Demetallization of bromo(8)chloromanganese phthalocyanine 9.1 parts of a vivid bluish-green (2) bromo(8) chloro metal-free phthalocyanine (C2) was obtained in the same manner as in Example 1 [2], except that the crude pigment (C1) was used instead of the crude pigment (A1).

[0040] Example 4 [1] Synthesis of (4) bromo(12) chloromanganese phthalocyanine In the same manner as in Example 1[1], except that 46.4 parts of tetrabromophthalic anhydride and 85.8 parts of tetrachlorophthalic anhydride were used instead of tetrachlorophthalic anhydride, 116.0 parts of a greenish-black crude pigment (D1) was obtained in a yield of 89.5%.

[0041] [2](4) Demetallization of Bromo(12)chloromanganese Phthalocyanine Except for using crude pigment (D1) instead of crude pigment (A1), 7.3 parts of a vivid yellowish-green (4) bromo(12) chloro metal-free phthalocyanine (D2) were obtained in the same manner as in Example 1 [2] above. Crude pigment (D1) contained a small amount of (16) bromomanganese phthalocyanine. However, the (4) bromo(12) chloro metal-free phthalocyanine (D2) obtained after demetallization did not contain (16) bromo metal-free phthalocyanine. It is presumed that the halogen configuration was sterically unconfined, causing decomposition during demetallization.

[0042] Example 5 [1] (12.8) Synthesis of chloromanganese phthalocyanine In the same manner as in Example 1 [1], except that 103.0 parts of (3.2) chlorophthalic anhydride was used instead of tetrachlorophthalic anhydride, 93.2 parts of a gray-brown crude pigment (E1) was obtained. The crude pigment yield was 92.4%.

[0043] [2] (12.8) Demetallization of chloromanganese phthalocyanine Except for using crude pigment (E1) instead of crude pigment (A1), the same procedure as in Example 1 [2] was carried out to obtain 8.6 parts of a vivid bluish-green (12.8) chlorometal-free phthalocyanine (E2).

[0044] Example 6 [1](4) Synthesis of chloromanganese phthalocyanine pigment In the same manner as in Example 1[1], except that 73.0 parts of 4-chlorophthalic anhydride was used instead of tetrachlorophthalic anhydride, 60.4 parts of a greenish-black crude pigment (F1) was obtained in a yield of 85.6%.

[0045] [2] (4) Demetallization of chloromanganese phthalocyanine In the same manner as in Example 1[2] described above, except that crude pigment (F1) was used instead of crude pigment (A1), and 200 parts of 95% sulfuric acid was used instead of 20% fuming sulfuric acid, 7.9 parts of a vivid greenish blue (4) chlorometal-free phthalocyanine (F2) was obtained.

[0046] Example 7 [1] Synthesis of chloromanganese phthalocyanine In the same manner as in Example 1[1], except that 18.3 parts of 4-chlorophthalic anhydride and 44.4 parts of phthalic anhydride were used instead of tetrachlorophthalic anhydride, 48.2 parts of a greenish-black crude pigment (G1) was obtained in a yield of 80.1%.

[0047] [2] Demetallization of chloromanganese phthalocyanine 7.6 parts of a vivid blue chlorometal-free phthalocyanine (G2) was obtained in the same manner as in Example 1[2], except that the crude pigment (G1) was used instead of the crude pigment (A1) and 200 parts of 95% sulfuric acid was used instead of 20% fuming sulfuric acid.

[0048] (Reference example 1) [1] Synthesis of unsubstituted manganese phthalocyanine The procedure of Example 1[1] was repeated except that 59.2 parts of phthalic anhydride was used instead of tetrachlorophthalic anhydride and 0.1 parts of ammonium molybdate was used instead of tetrabutyl orthotitanate, to obtain 47.7 parts of a dull green crude pigment (H1). The yield was 84.0%.

[0049] [2] Demetallization of unsubstituted manganese phthalocyanine 500 parts of 5% sulfuric acid and 10 parts of crude pigment (H1) were placed in a stirring tank. The mixture was heated to 80°C and stirred for 1 hour, then filtered and washed with water. The mixture was then pigmented using a butyl cellosolve emulsion method to obtain 9.3 parts of a vivid blue metal-free phthalocyanine (H2).

[0050] (Comparative Example 1) An attempt was made to remove the metal in the same manner as in Reference Example 1 [2] above, except that crude pigment (A1) was used instead of crude pigment (H1), but the resulting crude pigment remained yellowish-brown (A1).

[0051] (Comparative Example 2) An attempt was made to demetallize the crude pigment (A1) in the same manner as in Example 1[2] above, except that 200 parts of 96% sulfuric acid was used instead of 20% oleum. Analysis revealed that the manganese concentration in the resulting product was the same as that in the crude pigment (A1), and demetalization was not possible.

[0052] (Comparative Example 3) An attempt was made to demetallize the crude pigment (A1) in the same manner as in Example 1[2] above, except that 200 parts of 98% sulfuric acid was used instead of 20% oleum. Analysis revealed that the manganese concentration in the resulting product was about 50% of the manganese concentration in the crude pigment (A1), and complete demetallization was not possible.

[0053] Comparative Example 4 An attempt was made to demetallize the crude pigment (A1) in the same manner as in Example 1[2] above, except that 200 parts of 100% sulfuric acid was used instead of 20% oleum. Analysis revealed that the manganese concentration in the resulting product was about 40% of the manganese concentration in the crude pigment (A1), and complete demetallization was not possible.

[0054] (Comparative Example 5) An attempt was made to demetallize the crude pigment (F1) in the same manner as in Example 6[2] above, except that 200 parts of 85% sulfuric acid was used instead of 95% sulfuric acid. Analysis revealed that the manganese concentration in the resulting product was the same as that in the crude pigment (F1), and demetalization was not possible.

[0055] (Comparative Example 6) An attempt was made to demetallize the crude pigment (G1) in the same manner as in Example 7[2] above, except that 200 parts of 85% sulfuric acid was used instead of 95% sulfuric acid. Analysis revealed that the manganese concentration in the obtained product was approximately 70% of the manganese concentration in the crude pigment (G1), and complete demetallization was not possible. [Industrial Applicability]

[0056] The production method of the present invention is useful as a method for easily producing halogenated metal-free phthalocyanines suitable as coloring materials for coloring bioplastics and pigments for pixels in color filters, for example.

Claims

1. a step of mixing a halogenated manganese phthalocyanine with an acid component and eliminating manganese from the halogenated manganese phthalocyanine to obtain a halogenated metal-free phthalocyanine, when the average number of halogen groups substituted per molecule of the halogenated manganese phthalocyanine is more than 0 and not more than 4, the acid component is oleum or concentrated sulfuric acid of 90 mass % or more; When the average number of halogen groups substituted per molecule of the halogenated manganese phthalocyanine is more than 4, the acid component is fuming sulfuric acid.

2. 2. The method for producing a halogenated metal-free phthalocyanine according to claim 1, wherein the halogenated manganese phthalocyanine and the acid component are mixed at a temperature of 5° C. or less.

3. 2. The method for producing a halogenated metal-free phthalocyanine according to claim 1, further comprising a step of obtaining the halogenated manganese phthalocyanine by the Wyler process.

4. The method for producing a halogenated metal-free phthalocyanine according to any one of claims 1 to 3, wherein the halogen atom in the halogenated manganese phthalocyanine is at least one of a chlorine atom and a bromine atom.