JP6077433B2 - Composite oxide black pigment and method for producing the same - Google Patents

Description

  The present invention substantially does not contain chromium, cobalt, and nickel, which are easily subject to environmental restrictions at home and abroad, and has a composite oxide having durability comparable to conventional chromium-based highly durable black pigments It is related with a black pigment and its manufacturing method.

  As highly durable black pigments, complex oxide pigments such as Cu—Cr—Mn black pigments that are superior in terms of economy, durability, frit resistance, and blackness are used. Since complex oxide pigments are particularly excellent in weather resistance and the like, they are widely used as colorants for paints, building materials, resins and the like in fields requiring durability.

Since complex oxide pigments are composites of oxides of different metals, they are more stable and more durable than single metal oxides such as titanium oxide and zinc oxide. it is conceivable that. In order to further stabilize the complex oxide pigment, chromium may be dissolved. When chromium is dissolved, the durability tends to be improved as compared with the case where other metal elements are dissolved. As a related prior art, for example, a black pigment made of a calcined pigment containing Fe ₂ O ₃ as an essential component and containing Cr ₂ O ₃ , Mn ₂ O ₃ or NiO is known (Patent Document 1).

  However, the Cu—Cr—Mn-based black pigment and the black pigment described in Patent Document 1 or the like often have legal restrictions because they contain chromium (Cr) in the constituent components. Furthermore, with increasing interest in environmental issues in recent years, pigments containing chromium are more likely to be restricted in use. This is because attention has been paid to the toxicity and carcinogenicity of hexavalent chromium, and chromium-containing products tend not to be used in consideration of health.

  On the other hand, non-chromium composite oxide pigments that do not contain chromium have been proposed. For example, Ni-Fe-based complex oxide pigments (Patent Document 2) and Fe-Co-Al-based complex oxide pigments (Patent Document 3) have been proposed.

JP 2001-311049 A JP 2007-112694 A Japanese Patent No. 5170360

  The Ni—Fe based complex oxide pigment described in Patent Document 2 contains nickel as a constituent element and has acid resistance. However, since the actual hue is close to brown, it is difficult to apply to applications where black is required. Moreover, although it is a Fe-Co-Al-based complex oxide pigment and a non-chromium-based complex oxide pigment described in Patent Document 3, there is a problem in that it contains cobalt as a constituent element, and the conventional chromium-based complex oxide pigment. Compared to complex oxide pigments, it is disadvantageous in terms of cost.

  The present invention has been made in view of such problems of the prior art, and the subject is high blackness and excellent durability such as acid resistance, heat resistance, and weather resistance. In addition, the present invention provides a complex oxide black pigment that has good coloring power, is inexpensive, and that is sufficiently considered for the environment, and a method for producing the same. Another object of the present invention is to provide a coloring preparation containing the composite oxide black pigment.

That is, according to the present invention, the following composite oxide black pigment is provided.
[1] A composite oxide of main component metals including copper, manganese, and aluminum, and the content ratio of each metal with respect to the total of copper, manganese, and aluminum is 32 to 45 mol% copper and 25 to 70 mol% manganese. , and an aluminum 2-40 mol%, chromium, cobalt, and containing no composite oxide black pigment nickel.
[2] The composite oxide black pigment according to [1], which is a single compound having a spinel structure and having no heterogeneous phase.

Moreover, according to this invention, the manufacturing method of the complex oxide black pigment shown below is provided.
[ 3 ] The method for producing a composite oxide black pigment according to [1] or [2] , wherein a mixed salt aqueous solution and an alkaline aqueous solution of a metal salt containing copper, manganese, and aluminum are mixed and coprecipitated. And a step of precipitating the pigment precursor, and a step of washing the precipitated pigment precursor with water and drying, followed by firing at 500 to 1000 ° C.
[ 4 ] The method for producing a composite oxide black pigment according to [ 3 ], wherein in the step of depositing the pigment precursor, the mixed salt aqueous solution and the alkaline aqueous solution are mixed in the presence of an oxidizing agent.

Moreover, according to this invention, the formulation for coloring shown below is provided.
[ 5 ] A coloring preparation containing the composite oxide black pigment according to [1] or [2] .

  According to the present invention, the degree of blackness is high, the acid resistance, the heat resistance, the weather resistance, and the like are excellent, the coloring power is good, the cost is low, and the environment is sufficient. Provided are complex oxide black pigments that have been considered, and methods for producing the same. Moreover, according to this invention, the formulation for coloring containing said complex oxide black pigment is provided.

<Composite oxide black pigment>
The composite oxide black pigment of the present invention (hereinafter also simply referred to as “black pigment”) is a composite oxide of main component metals including copper, manganese, and aluminum. And the content rate of each metal with respect to the sum total of a metal element is copper 25-45 mol%, manganese 25-70 mol%, and aluminum 2-40 mol%, and does not contain chromium, cobalt, and nickel substantially. Is. Although the metal element which comprises the complex oxide black pigment of this invention contains copper, manganese, and aluminum, chromium, cobalt, and nickel are not contained substantially. Hereinafter, preferred embodiments will be described as examples, and the details of the composite oxide black pigment of the present invention will be described.

  Countermeasures for environmental problems are not limited to Japan, but tend to be globalized. Under these circumstances, the Joint Industry Guide for Material Composition Declaration for Electronic Products (JIG) prepared by industry associations in Japan, the United States, and Europe contains a list of restricted compounds. Yes. “Level A” of this chemical substance list includes cadmium and hexavalent chromium, and “Level B” includes nickel and the like. In addition, the Industrial Safety and Health Act was amended (enforced on January 1, 2013), and cobalt was added to the Specialized Law Class II substance.

  The complex oxide black pigment of the present invention does not contain chromium, cobalt, and nickel, which are subject to use restrictions in the above-mentioned joint industry guidelines and occupational safety and health law, and is sufficiently considered for the environment. In addition, even if these metal elements are not contained, by setting the content ratios of copper, manganese, and aluminum, which are main component metals, in appropriate ranges, the blackness is high and the coloring power is good. It has excellent durability (acid resistance, heat resistance, and weather resistance) equivalent to or better than conventional chromium-based high durability black pigments containing chromium.

  In the composite oxide black pigment of the present invention, the content ratio of copper (Cu) to the total of metal elements is 25 to 45 mol%, preferably 32 to 35 mol%. Crystallinity falls that the content rate of copper with respect to the sum total of a metal element is less than 25 mol%. On the other hand, if the copper content exceeds 45 mol%, the excess copper becomes difficult to dissolve.

  Furthermore, the composite oxide black pigment of the present invention has a manganese (Mn) content ratio of 25 to 70 mol%, preferably 40 to 55 mol%, based on the total amount of metal elements. Sufficient blackness can be obtained by making the content rate of manganese with respect to the sum total of a metal element into said numerical range. However, if the manganese content is less than 25 mol%, the blackness becomes insufficient. On the other hand, when the content ratio of manganese exceeds 70 mol%, the blackness is improved but the acid resistance is lowered.

  In the composite oxide black pigment of the present invention, the content ratio of aluminum (Al) to the total of metal elements is 2 to 40 mol%, preferably 10 to 25 mol%. When the content ratio of aluminum with respect to the total of the metal elements is less than 2 mol%, durability such as acid resistance is lowered. On the other hand, when the aluminum content exceeds 40 mol%, the coloring power is lowered, resulting in a tight pigment.

  As described above, the composite oxide black pigment of the present invention in which the content of the main component metal is within the above range is a conventional chromium-based pigment such as a copper (Cu) -chromium (Cr) -manganese (Mn) -based black pigment. Compared with a highly durable black pigment, it has durability such as acid resistance, heat resistance, weather resistance and the like that is comparable to that of a highly durable black pigment. Furthermore, the blackness and coloring power of the composite oxide black pigment of the present invention are superior to conventional chromium-based high durability black pigments.

As a method for expressing the color tone, there is a CIE L ^* a ^* b ^* color system (color space) which is expressed by the International Commission on Illumination (CIE) and expresses a visible color as a color space. In this CIE L ^* a ^* b ^* color system, a color is expressed by three coordinates, lightness is “L ^* ”, red (magenta) to green is “a ^* ” (positive is magenta, negative is green) , Yellow to blue correspond to “b ^* ” (positive is yellow, negative is blue), respectively. Further, it is preferable that the color tone of black (black) is closer to 0 for both the a ^* value and the b ^* value.

By using the composite oxide black pigment of the present invention, for example, an article having at least a colored portion having a lightness L ^* value of 13 or less, preferably 6 or less, more preferably 3 or less can be produced. The lightness L ^* value is an index indicating the tendency of blackness. When the lightness L ^* value exceeds 13, the blackness tends to be insufficient.

Moreover, if the composite oxide black pigment of the present invention is used, for example, an article having at least a colored portion having an a ^* value of 1 to 3 and a b ^* value of −5 to 0 can be produced. When the a ^* value is less than 1 regardless of the b ^* value, redness tends to increase. On the other hand, if the a ^* value is more than 3 regardless of the b ^* value, the greenness tends to become strong. In any case, it may be difficult to obtain the target black color. Further, when the b ^* value is less than −5 regardless of the a ^* value, the bluish color tends to be strong. On the other hand, if the b ^* value is more than 0 regardless of the a ^* value, the yellowness tends to become strong. In any case, it may be difficult to obtain the target black color.

Further, the achromaticity C ^* calculated from the following formula (1), which is an index of blackness as in the lightness L ^* value, is preferably 0 to 5, and more preferably 0 to 4. .
If the achromatic chromaticity C ^* is more than 5, the blackness tends to be insufficient.
Achromaticity C ^* = (a ^{* 2} + b ^{* 2} ) ^1/2 (1)

<Method for producing composite oxide black pigment>
Next, the manufacturing method of the complex oxide black pigment of this invention is demonstrated. The method for producing a composite oxide black pigment of the present invention comprises a step (1) of mixing a mixed salt aqueous solution of metal salts containing copper, manganese, and aluminum and an alkaline aqueous solution to precipitate a pigment precursor as a coprecipitate. This is a so-called wet synthesis method including a step (2) in which the precipitated pigment precursor is washed with water and dried and then calcined at 500 to 1000 ° C.

  In step (1), a mixed salt aqueous solution is prepared using a metal salt containing a main component metal. Examples of the metal salt include salts used for the production of conventional composite oxide pigments such as sulfate, nitrate, chloride, or acetate of each metal. More specific examples of the metal salt include aluminum chloride hexahydrate and manganese sulfate monohydrate. Moreover, metal salts other than the above can also be used. In step (1), an alkaline agent is used. As the alkaline agent, for example, soda ash (anhydrous sodium carbonate), caustic soda (sodium hydroxide), or the like can be used. Moreover, alkali agents other than the above can also be used. In addition, an alkaline agent can be used in the state of the aqueous alkali solution obtained by dissolving the predetermined amount in water. A mixed salt aqueous solution and an alkaline aqueous solution are simultaneously dropped into a predetermined precipitation tank prepared in advance to deposit (precipitate) a metal salt carbonate and / or hydroxide as a pigment precursor which is a coprecipitate. .

  The concentration of the metal salt in the mixed salt aqueous solution is suitably about 5 to 50% by mass. The mixed salt aqueous solution may be dropped into a precipitation tank prepared in advance together with an alkaline aqueous solution used as a precipitant, for example. The reaction concentration in terms of metal salt is not required to have a particularly bad influence on the precipitate (coprecipitate). In consideration of workability and subsequent steps, the reaction concentration in terms of metal salt is preferably 0.05 to 0.2 mol / L. When the reaction concentration in terms of metal salt is less than 0.05 mol / L, the resulting dried product tends to be very hard and the yield tends to decrease. On the other hand, if the reaction concentration in terms of metal salt is more than 0.2 mol / L, the synthesized product may be non-uniform.

  The pH of the solution (reaction solution) when the pigment precursor that is a coprecipitate is precipitated is preferably 10-13. By setting the pH of the reaction solution in the above range, a pigment precursor in which each component is more uniformly mixed is formed. When the pH of the reaction solution is outside the above range, the uniformity of the obtained pigment precursor may be lowered, and it tends to be difficult to obtain a compound having a stable spinel composition. In addition, obstacles such as an increase in the heat treatment temperature during firing tend to occur, and irregular particles such as coarse particles may be generated.

  It is preferable that the temperature (synthesis temperature) of the reaction liquid when depositing the pigment precursor which is a coprecipitate is 20 to 30 ° C. If the synthesis temperature is too low, the generated particles may be small and the baking may be hard. On the other hand, when the synthesis temperature is too high, the generated particles tend to be large, leading to a decrease in the color density. Next, the obtained pigment precursor slurry is heated to 50 ° C. or higher, preferably 60 ° C. or higher for aging. At this time, oxidation of manganese is promoted, and a stable spinel composition is easily obtained.

  In the step (1) of depositing the pigment precursor, it is preferable to mix the mixed salt aqueous solution and the alkaline aqueous solution in the presence of an oxidizing agent. When the mixed salt aqueous solution and the alkaline aqueous solution are mixed in the presence of the oxidizing agent, the oxidation is promoted and the properties of the obtained pigment precursor can be changed. Specifically, since a finer particulate pigment precursor is generated, a composite oxide black pigment with improved blackness and coloring power can be obtained. Specific examples of the oxidizing agent include known oxidizing agents such as sodium hypochlorite, hydrogen peroxide, and potassium permanganate.

  The use of this oxidizing agent is useful in the method for producing the composite oxide black pigment of the present invention, which is a wet synthesis method. In a so-called dry synthesis method in which a mixture of a predetermined metal oxide or metal carbonate is baked, uniformity is not guaranteed even if an oxidizing agent is mixed. For this reason, the wet synthesis method is more suitable for forming a highly stable spinel crystal using an oxidizing agent. However, even in the case of a dry synthesis method, a composite oxide black pigment having excellent durability such as acid resistance, heat resistance, and weather resistance and good coloring power can be produced at a low cost as in the case of the wet synthesis method. It is possible. For this reason, the composite oxide black pigment of the present invention can be produced by either a wet synthesis method or a dry synthesis method.

  In step (2), the precipitated pigment precursor is washed with water and dried. By washing with water, the water-soluble alkali metal salt by-produced during the synthesis can be removed. In addition, it is preferable to wash with water until the electrical conductivity of a filtrate will be 500 microseconds / cm or less, and it is further more preferable to wash with water until it will be 300 microseconds / cm or less. Washing with water until the electrical conductivity of the filtrate falls below the above range makes it difficult to adversely affect the subsequent firing step. On the other hand, if water washing is insufficient, coarse particles may be generated.

  In the step (2), the washed and dried pigment precursor is fired at 500 to 1000 ° C. The pigment precursor can be crystallized by firing. When the firing temperature is lower than the above temperature range, color development is difficult. On the other hand, if the firing temperature is higher than the above temperature range, sintering occurs. After firing, it is preferable to wash with water in order to remove the alkali metal salt by-produced by firing. In addition, it is preferable to wash with water until the electrical conductivity of a filtrate will be 300 microseconds / cm or less. Then, it is preferable to dry at about 120 ° C. for about 12 hours. Thereby, the complex oxide black pigment of the present invention can be obtained. When the composite oxide black pigment thus obtained is analyzed by, for example, powder X-ray diffraction, it can be confirmed that it is a single compound having a spinel structure and having no heterogeneous phase.

<Coloring preparation>
Next, the coloring preparation of the present invention will be described. The coloring preparation of the present invention contains the aforementioned complex oxide black pigment. Specific examples of coloring preparations include coating liquid coloring preparations such as pigment dispersions containing a high concentration of complex oxide black pigment used for coloring coating liquids such as paints; resin molded articles, etc. A resin coloring preparation such as a masterbatch containing a complex oxide black pigment at a high concentration, which is used for coloring the constituent resin material, can be mentioned.

  The pigment dispersion used as a coating liquid coloring preparation usually contains the above-described composite oxide black pigment, a dispersion medium in which the composite oxide black pigment is dispersed, and various resins. A conventionally well-known organic solvent etc. can be used as a dispersion medium. The content ratio of the composite oxide black pigment in the pigment dispersion is usually 0.1 to 40 parts by mass, preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the resin.

  A masterbatch used as a resin coloring preparation usually contains the aforementioned composite oxide black pigment and a compound resin in which the composite oxide black pigment is dispersed. As the compound resin, conventionally known resins such as polyamide resin and polyolefin resin can be used. The content ratio of the composite oxide black pigment in the master batch is usually 0.05 to 100 parts by mass, preferably 0.4 to 40 parts by mass with respect to 100 parts by mass of the compound resin.

  Various additives, dispersion aids, and the like may be further contained in the coloring preparations such as the pigment dispersion and the master batch as necessary. Examples of the additive include an antioxidant, an ultraviolet ray inhibitor, an antistatic agent, an antibacterial agent, a stabilizer, a crosslinking agent, a plasticizer, a lubricant, a release agent, a flame retardant, and an inorganic filler. . Examples of the dispersion aid include metal soaps such as lithium stearate, magnesium stearate, zinc stearate, calcium stearate, magnesium palmitate, calcium oleate, and cobalt oleate; general polymerization type, decomposition type, modification, etc. And polyethylene wax.

  Moreover, you may make the preparation for coloring further contain various organic pigments and inorganic pigments other than the complex oxide black pigment of this invention as needed. Examples of organic pigments include phthalocyanine pigments, azo pigments, azomethine pigments, isoindolinone pigments, quinacridone pigments, anthraquinone pigments, dioxazine pigments, and perinone / perylene pigments. In addition, as inorganic pigments, other than complex oxide pigments other than black, carbon black, ultramarine blue, red rose, etc., titanium oxide pigments such as titanium oxide white pigments, titanium oxide yellow pigments, titanium oxide black pigments, etc. Can be mentioned.

  The masterbatch used as a resin coloring preparation, for example, contains a compound oxide black pigment in a compound resin and, if necessary, further contains other pigments, various additives, and dispersion aids. The master batch mixture obtained in this manner can be produced by mixing using a mixer such as a Henschel mixer. The master batch obtained as described above may be further kneaded using a kneader or a heated two-roll mill, and then cooled and pulverized using a pulverizer to obtain a coarse powder master batch. Furthermore, the master batch obtained as described above may be extruded using an extruder and formed into a bead shape or a column shape.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited at all by the following Example, unless the summary is exceeded. In the following text, “parts” and “%” are based on mass unless otherwise specified.

<Composite oxide black pigment>
[Example 1]
A mixed salt aqueous solution was prepared by dissolving 195 parts of copper sulfate pentahydrate, 131.9 parts of manganese sulfate monohydrate, and 188.5 parts of aluminum chloride hexahydrate in 1000 parts of water. Further, 250 parts of caustic soda was dissolved in 1300 parts of water to prepare an aqueous alkaline solution. The obtained mixed salt aqueous solution and alkaline aqueous solution were simultaneously dropped into 1300 parts of water to precipitate a pigment precursor. In addition, while controlling precipitation pH to 12, care was taken so that temperature might not become 30 degreeC or more, and the coolant was used as needed. After the precipitation of the pigment precursor was completed, it was heated to 70 ° C. and aged for 1 hour to obtain a pigment precursor slurry. The obtained pigment precursor slurry was decanted, and the precipitate was washed with water until the electric conductivity of the filtrate reached 300 μS / cm or less, and then dried at 120 ° C. for about 12 hours to obtain a pigment precursor. The obtained pigment precursor was heat treated (calcined) at 700 ° C. for 1 hour, then decanted and washed with water until the filtrate had an electric conductivity of 300 μS / cm or less. Subsequently, it dried at 120 degreeC for 10 hours, and obtained about 160 parts of black pigments. When the obtained pigment was analyzed by powder X-ray diffraction, it was found to be a single compound having a spinel structure and having no heterogeneous phase. The obtained pigment was slightly hard, but there was no problem in dispersibility. Moreover, while durability, such as acid resistance, was favorable, it was superior to the pigment of the reference example 2 mentioned later about blackness and coloring power.

[Example 2]
A mixed salt aqueous solution was prepared by dissolving 195 parts of copper sulfate pentahydrate, 250.7 parts of manganese sulfate monohydrate, and 18.8 parts of aluminum chloride hexahydrate in 1000 parts of water. Further, 228 parts of caustic soda was dissolved in 1300 parts of water to prepare an alkaline aqueous solution. 180 parts of a black pigment were obtained in the same manner as in Example 1 except that the mixed salt aqueous solution and the alkaline aqueous solution thus obtained were used. When the obtained pigment was analyzed by powder X-ray diffraction, it was found to be a single compound having a spinel structure and having no heterogeneous phase. The obtained pigment had excellent durability such as acid resistance, and was superior to the pigment of Reference Example 2 described later in terms of blackness and coloring power. Moreover, about blackness and coloring power, it was equivalent to the pigment of the reference example 1 mentioned later.

[Example 3]
A mixed salt aqueous solution was prepared by dissolving 195 parts of copper sulfate pentahydrate, 210 parts of manganese sulfate monohydrate, and 68.2 parts of aluminum chloride hexahydrate in 1000 parts of water. Moreover, 230 parts of caustic soda was dissolved in 1300 parts of water to prepare an aqueous alkaline solution. 175 parts of a black pigment was obtained in the same manner as in Example 1 except that the mixed salt aqueous solution and the alkaline aqueous solution thus obtained were used. When the obtained pigment was analyzed by powder X-ray diffraction, it was found to be a single compound having a spinel structure and having no heterogeneous phase. The obtained pigment had excellent durability such as acid resistance, and was superior to the pigment of Reference Example 2 described later in terms of blackness and coloring power. Moreover, about blackness and coloring power, it was equivalent to the pigment of the reference example 1 mentioned later.

[Example 4]
When the pigment precursor was precipitated, 173 parts of a black pigment was obtained in the same manner as in Example 3 except that 100 parts of 30% aqueous hydrogen peroxide was further added. When the obtained pigment was analyzed by powder X-ray diffraction, it was found to be a single compound having a spinel structure and having no heterogeneous phase. The obtained pigment had excellent durability such as acid resistance, and was superior to the pigment of Reference Example 2 described later in terms of blackness and coloring power. Moreover, about blackness and coloring power, it was equivalent to the pigment of the reference example 1 mentioned later.

[Example 5]
62.7 parts of basic copper carbonate monohydrate, 83.8 parts of manganese dioxide, and 26.1 parts of aluminum oxide were sufficiently pulverized and mixed using a dry attritor, and then calcined at 1000 ° C. for 4 hours. As a result, 98 parts of a black pigment were obtained. When the obtained pigment was analyzed by powder X-ray diffraction, it was found that although it had a spinel structure, a heterogeneous phase was partially present. The obtained pigment was slightly dark. It was somewhat hard and took some time to grind. Also, the blackness and coloring power were slightly lower than those of the pigments of other examples.

[Comparative Example 1]
A mixed salt aqueous solution was prepared by dissolving 149.7 parts of copper sulfate pentahydrate, 380.0 parts of manganese sulfate monohydrate, and 36.2 parts of aluminum chloride hexahydrate in 1000 parts of water. Further, 336 parts of caustic soda was dissolved in 1300 parts of water to prepare an alkaline aqueous solution. 230 parts of a black pigment were obtained in the same manner as in Example 1 except that the mixed salt aqueous solution and the alkaline aqueous solution thus obtained were used. When the obtained pigment was analyzed by powder X-ray diffraction, it was found that although it had a spinel structure, a heterogeneous phase was partially present. In addition, about the blackness and coloring power of the obtained pigment, it was superior to the pigment of the reference example 2 mentioned later, and was equivalent to the pigment of the reference example 1. However, the durability such as acid resistance was inferior to that of the pigment of Reference Example 1.

[Comparative Example 2]
A mixed salt aqueous solution was prepared by dissolving 374.2 parts of copper sulfate pentahydrate, 101.0 parts of manganese sulfate monohydrate, and 217.3 parts of aluminum chloride hexahydrate in 1000 parts of water. Moreover, 300 parts of caustic soda was dissolved in 1300 parts of water to prepare an aqueous alkaline solution. 211 parts of a black pigment were obtained in the same manner as in Example 1 except that the mixed salt aqueous solution and the alkaline aqueous solution thus obtained were used. When the obtained pigment was analyzed by powder X-ray diffraction, it was found that although it had a spinel structure, a heterogeneous phase was partially present. In addition, about the blackness and coloring power of the obtained pigment, it was superior to the pigment of the reference example 2 mentioned later, and was equivalent to the pigment of the reference example 1. However, the durability such as acid resistance was inferior to that of the pigment of Reference Example 1.

[Comparative Example 3]
A mixed salt aqueous solution was prepared by dissolving 149.7 parts of copper sulfate pentahydrate, 101.3 parts of manganese sulfate monohydrate and 434.7 parts of aluminum chloride hexahydrate in 1000 parts of water. Further, 336 parts of caustic soda was dissolved in 1300 parts of water to prepare an alkaline aqueous solution. 182 parts of a black pigment were obtained in the same manner as in Example 1 except that the mixed salt aqueous solution and the alkaline aqueous solution thus obtained were used. When the obtained pigment was analyzed by powder X-ray diffraction, it was found that although it had a spinel structure, a heterogeneous phase was partially present. In addition, although the blackness and coloring power of the obtained pigment were superior to the pigment of Reference Example 2 described later, they were inferior to those of Reference Example 1. The durability such as acid resistance was the same as that of the pigment of Reference Example 2.

[Reference Examples 1 and 2]
A commercially available Cu—Fe—Mn black pigment was used as Reference Example 1. This Cu—Fe—Mn black pigment is a non-Cr pigment, but is slightly inferior in durability. A commercially available Cu—Cr—Mn black pigment was used as Reference Example 2.

  Table 1 shows the compositions of the pigments of Examples, Comparative Examples, and Reference Examples.

<Evaluation>
[L ^* value, a ^* value, b ^* value and C ^* value]
A pigment and a resin were blended so as to be an acrylic lacquer resin 30PHR (containing 30 parts of pigment with respect to 100 parts of resin), and dispersed for 1 hour with a paint conditioner to prepare a paint. The prepared paint was developed on art paper with a black belt with a 6 mil applicator to prepare a sample for evaluation (dry film thickness: 20 μm). Using a Karacom colorimeter (manufactured by Dainichi Seika Kogyo Co., Ltd.), the L ^* value, a ^* value, and b ^* value in the CIE LAB (L ^* a ^* b ^* ) color system of the prepared evaluation sample While measuring, achromaticity C ^* was calculated according to the following formula (1). The results are shown in Table 2. The lightness L ^* value is a value that is a measure of brightness. Also, the closer the value of the achromaticity C ^* is to 0 (zero), the blacker it looks. And the smaller the value of both C ^* and L ^* , the higher the blackness and the more black it looks.
Achromaticity C ^* = (a ^{* 2} + b ^{* 2} ) ^1/2 (1)

[Hue and tinting strength]
An acrylic lacquer resin and a black pigment were mixed to prepare a primary color paint of 30 PHR (containing 30 parts of pigment with respect to 100 parts of resin). Further, an acrylic lacquer resin and a pigment (titanium oxide: black pigment (mass ratio) = 9: 1) were mixed to prepare a light-color paint of 30 PHR (containing 30 parts of pigment with respect to 100 parts of resin). The prepared primary color paint and light color paint were respectively developed on white art paper using a 6 mil applicator to produce a primary color sample and a light color sample (dry film thickness: 20 μm). The produced primary color sample was visually observed and the hue was evaluated. The results are shown in Table 2. Moreover, the spectral reflectance of the light color sample was measured using a Karakom colorimeter (manufactured by Dainichi Seika Kogyo Co., Ltd.), and the relative value of the spectral reflectance calculated with the spectral reflectance of Reference Example 1 as “100%” was calculated. It was set as “coloring power (%)”. The results are shown in Table 2.

[Acid resistance]
1 g of pigment was put into 20 mL of 5% sulfuric acid aqueous solution and left at room temperature for 2 days to observe whether the supernatant liquid was colored or not, and the acid resistance of the pigment was evaluated according to the following criteria. The results are shown in Table 2.
A: The supernatant liquid is not colored.
○: The supernatant liquid was slightly colored.
Δ: The supernatant liquid was slightly colored.
X: There is a clear difference.

[Heat-resistant]
The pigment was left in an oven set at 700 ° C. for 5 hours. After cooling, the hue of the pigment powder was visually observed, and the heat resistance of the pigment was evaluated according to the following criteria. The results are shown in Table 2.
A: No difference is observed before and after heating.
A: A slight difference is observed before and after heating (becomes whitish after heating).
Δ: A difference is clearly recognized before and after heating.

[Weatherability]
A pigment and a fluororesin were blended and dispersed for 1 hour using a paint conditioner to prepare a paint (coating liquid) that was a fluororesin 30PHR (containing 30 parts of pigment with respect to 100 parts of resin) dispersion. . Subsequently, the SWOM acceleration test was conducted for 2,000 hours to evaluate the weather resistance of the pigment. Specifically, first, the prepared paint was spread on an aluminum plate to prepare a coated plate (dry film thickness: 20 to 30 μm). Next, using a sunshine weatherometer, the produced coated plate was irradiated with carbon arc light for 2,000 hours. The color difference and gloss of the coated plate before and after irradiation were visually observed, and the weather resistance of the pigment was evaluated according to the following criteria. The results are shown in Table 2.
A: There is no difference in color difference and gloss.
○: There is almost no difference in color difference and gloss.
(Triangle | delta): A color difference and gloss fall can be confirmed (it becomes a mat).

<Application example>
[Application Example 1: Coating liquid]
6 parts of the pigment of Example 1, 3.5 parts of a commercially available melamine resin (solid content: 60%), and 2 parts of thinner were mixed and dispersed using a paint shaker for 120 minutes to obtain a dispersed slurry. To the obtained dispersion slurry, an acrylic polyol resin (solid content: 55%) was added so as to be 40 parts of pigment with respect to 100 parts of resin solid content to prepare a coating solution. Using the 6 mil applicator, the prepared coating solution was applied to art paper, a polyethylene sheet, and a glass plate, respectively, to prepare samples for evaluation. Hue was evaluated about each produced sample for evaluation. As a result, it was confirmed that any sample for evaluation had an achromatic chromaticity C ^* of 5 or less, and was excellent in coloring power and weather resistance.

[Application Example 2: Resin molded product]
100 parts of high density polyethylene (density: 0.949 g / cm ³ , MFR: 0.10 g / 10 min.), 0.4 part of pigment of Example 2, and polyethylene wax (trade name “Sunwax 151P”, Sanyo Chemical Industries) 0.1 part) was kneaded at 180 ° C. for 4 minutes using a two roll to obtain a colored resin. The obtained colored resin was hot-pressed to produce a press sheet having a thickness of 2 mm. The press sheet was prepared under conditions of preheating at 230 ° C. for 2 minutes (20 kg / cm ² ), pressing for 2 minutes (200 kg / cm ² ), and cooling at 20 ° C. for 5 minutes. Moreover, a test piece of 20 mm × 120 mm was produced from the produced press sheet. About the produced test piece, the fading evaluation using a chlorine water and the blister generation | occurrence | production test were done. Test conditions are shown below. As a result, it was found that the test piece hardly fades and has excellent color fastness and durability against blistering.
・ Chlorine water concentration: 2000 ± 100ppm
・ Chlorine water temperature: 60 ± 1 ℃
・ PH: 6.5 ± 0.5
・ Test time: 336 hours

  The composite oxide black pigment of the present invention includes paints, building materials, roads, inks, and glass; copying machine toners; ink jet inks; liquid crystals (LCDs), field emission displays (FEDs, SEDs), organic and inorganic ELs. (Electroluminescence) It can be suitably used for neutral gray and black matrix for flat panel displays such as displays.

Claims (5)

It is a complex oxide of main component metals including copper, manganese, and aluminum,
Copper, manganese, and the content of each metal to the total of aluminum, copper 32-45 mol%, manganese 25 to 70 mol%, and an aluminum 2-40 mol%,
Chromium, cobalt, and containing no composite oxide black pigment nickel. The composite oxide black pigment according to claim 1, which is a single compound having a spinel structure and having no heterogeneous phase. A method for producing the complex oxide black pigment according to claim 1 or 2 ,
A step of precipitating a pigment precursor that is a coprecipitate by mixing a mixed salt aqueous solution and an alkaline aqueous solution of a metal salt containing copper, manganese, and aluminum;
A step of calcining the precipitated pigment precursor at 500 to 1000 ° C. after washing and drying;
The manufacturing method of the complex oxide black pigment which has this. In the step of precipitating the pigment precursor,
The method for producing a complex oxide black pigment according to claim 3 , wherein the mixed salt aqueous solution and the alkaline aqueous solution are mixed in the presence of an oxidizing agent. The coloring preparation containing the complex oxide black pigment of Claim 1 or 2 .