yellow pigment

Abstract

To provide a yellow pigment that does not contain hazardous substances and is economically efficient. [Solution] The yellow pigment contains a composite oxide as its main component, with TiO2 and NiO as essential components, and at least one of Li2O and ZrO2.

Description

[Technical Field]

[0001] This invention relates to a yellow pigment that does not contain hazardous substances. [Background technology]

[0002] Conventionally, yellow pigments containing antimony trioxide, titanium dioxide, and nickel oxide are known. However, in the case of yellow pigments containing antimony trioxide, the toxic antimony sublimes during the calcination process in their manufacture. Therefore, it is preferable to manufacture yellow pigments without using antimony trioxide, which is a highly toxic substance.

[0003] Patent Document 1 describes an invention of a yellow pigment manufactured without using antimony trioxide. Specifically, the yellow pigment described in Patent Document 1 contains oxides of Ti, W, Ni, and La as the main components of the raw material oxides, and is configured such that the content of the main components is 90% by mass or more of the total pigment. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2007-217545 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the yellow pigment described in Patent Document 1 is not suitable for industrial use as a relatively inexpensive and mass-produced pigment because it uses lanthanum (La), a rare earth element, and tungsten (W), an expensive raw material.

[0006] This invention has been made in view of the above-mentioned problems, and aims to provide a yellow pigment that does not contain hazardous substances and is economically efficient. [Means for solving the problem]

[0007] The yellow pigment in the present invention is characterized by containing, as a main component, a composite oxide having TiO2 and NiO as essential components and containing at least one of Li2O and ZrO2.

[0008] The above yellow pigment may contain a composite oxide represented by the compositional formula aTiO2·bLi2O·cNiO (mol%), and a, b, and c in the compositional formula are configured to satisfy the relationships 50≦a≦95, 1≦b≦24, 4≦c≦49, a + b + c = 100, and c > b.

[0009] The above yellow pigment may contain a composite oxide represented by the compositional formula aTiO2·bZrO2·cNiO (mol%), and a, b, and c in the compositional formula are configured to satisfy the relationships 30≦a≦95, 1≦b≦60, 4≦c≦49, and a + b + c = 100.

[0010] The above yellow pigment may contain a composite oxide represented by the compositional formula aTiO2·bLi2O·cZrO2·dNiO (mol%), and a, b, c, and d in the compositional formula are configured to satisfy the relationships 50≦a≦93, 1≦b≦20, 1≦c≦30, 5≦d≦30, and a + b + c + d = 100.

[0011] The above yellow pigment, in the CIELAB color system, may be configured such that L * is 79.3 to 88.3, a * is -11.7 to -1.1, and b * is 36.5 to 74.9.

Advantages of the Invention

[0012] The yellow pigment of the present invention contains TiO2 and NiO as essential components and contains, as a main component, a composite oxide containing at least one of Li2O and ZrO2. It does not contain highly toxic substances and does not contain rare earths or expensive raw materials, so it has high safety and excellent economic efficiency.

Brief Description of the Drawings

[0013] [Figure 1] (a) shows the data distribution according to the composition (TiO2, Li2O, NiO) of the yellow pigment in the examples and comparative examples, and (b) shows the blending range (mol%) in which the desired color development is obtained. [Figure 2] Figure 1(b) is a data graph in which the data for formulations that underwent chemical resistance testing are marked with triangles and displayed overlaid on top of each other. [Figure 3] (a) shows the data distribution according to the composition (TiO2, ZrO2, NiO) of the yellow pigment in the examples and comparative examples, and (b) is a figure in which the data for formulations in which chemical resistance tests were performed within the formulation range (mol%) in which the desired color development was obtained are marked with triangles and displayed overlaid. [Modes for carrying out the invention]

[0014] The yellow pigment of the present invention contains a composite oxide as its main component, with TiO2 (titanium dioxide) and NiO (nickel oxide) as essential components, and at least one of Li2O (lithium oxide) and ZrO2 (zirconium oxide). Specifically, the yellow pigment of the present invention contains a composite oxide containing TiO2, NiO, and Li2O as its main component, or contains a composite oxide containing TiO2, NiO, and ZrO2 as its main component, or contains a composite oxide containing TiO2, NiO, Li2O, and ZrO2 as its main component. Note that "main component" means the component with the largest mass ratio.

[0015] The yellow pigment in one embodiment contains a composite oxide represented by the compositional formula aTiO2·bLi2O·cNiO (mol%), wherein a, b, and c in the compositional formula satisfy the following relationships: 50≦a≦95, 1≦b≦24, 4≦c≦49, a+b+c=100, and c>b.

[0016] In another embodiment of the present invention, the yellow pigment contains a composite oxide represented by the compositional formula aTiO2·bZrO2·cNiO (mol%), wherein a, b, and c in the compositional formula satisfy the relationships 30≦a≦95, 1≦b≦60, 4≦c≦49, and a+b+c=100.

[0017] In yet another embodiment of the present invention, the yellow pigment contains a composite oxide represented by the compositional formula aTiO2·bLi2O·cZrO2·dNiO (mol%), wherein a, b, c, and d in the compositional formula satisfy the following relationships: 50≦a≦93, 1≦b≦20, 1≦c≦30, 5≦d≦30, and a+b+c+d=100.

[0018] The yellow pigment mentioned above is L in the CIELAB color system. * 79.3~88.3, ​​a * ga -11.7 to -1.1, b * The values ​​ranged from 36.5 to 74.9, indicating that sufficient color development was achieved as a yellow pigment.

[0019] (Manufacturing method) The method for producing the yellow pigment of the present invention will now be described. First, the raw materials to be used in the production of the yellow pigment of the present invention are prepared. The starting raw materials are "titanium," "nickel," and "lithium and / or zirconium," and these raw materials may all be oxides, hydroxides, carbonates, or compounds that become oxides upon heating. For example, as a titanium source, anatase-type titanium oxide, rutile-type titanium oxide, etc. are preferred; as a nickel source, nickel oxide, nickel carbonate, nickel hydroxide, etc. are preferred; as a lithium source, lithium oxide, lithium carbonate, etc. are preferred; and as a zirconium source, zirconium oxide, zirconium carbonate, zirconium hydroxide, etc. are preferred.

[0020] After mixing the compounds of each element in the desired ratio, the mixture is mixed using either a dry or wet method. For dry mixing, high-speed fluid mixers such as the Henschel mixer from Henschel GmbH or the Super Mixer from Kawata GmbH can be used as mixers. For wet mixing, rotary ball mills, vibratory mills, planetary mills, etc., can be used as mixers. In the case of wet mixing, the slurry obtained by mixing is dried and then crushed using a micropulverizer or hammer mill.

[0021] Next, the batch obtained by mixing the ingredients is fired in a firing furnace or electric furnace. Rutile-type crystals are formed and grow during firing, yielding a composite oxide yellow pigment. As the firing furnace, batch or continuous type furnaces such as shuttle kilns, tunnel kilns, roller house kilns, and pusher kilns can be used. The firing temperature is preferably between 900°C and 1100°C, and the firing time is preferably between 3 hours and 6 hours. There are no particular restrictions on the firing atmosphere; for example, an air atmosphere is acceptable.

[0022] The calcined material obtained by firing is ground using either a dry or wet method to adjust it to the target particle size. For dry grinding, jet mills, ball mills, hammer mills, dynamic mills, fine mills, and micropulverizers can be used as grinders. For wet grinding, ball mills, vibratory mills, planetary mills, and media-stirring mills can be used as grinders. In the case of wet grinding, the slurry obtained is dried in a drying oven, and then crushed using a micropulverizer or hammer mill to obtain a composite oxide yellow pigment with the target particle size. [Examples]

[0023] Examples relating to the yellow pigment of the present invention are shown below. However, the present invention is not limited to the following examples.

[0024] (Yellow pigment with chemical formula aTiO2·bLi2O·cNiO) The yellow pigments of Examples 1 to 13 and Comparative Examples 1 to 3 shown in Table 1 were prepared according to the procedure described below. These yellow pigments mainly contain a composite oxide represented by the compositional formula aTiO2·bLi2O·cNiO (mol%). However, a, b, and c satisfy the relationship a+b+c=100. Some of the yellow pigments in the Comparative Examples did not produce a yellow color, but in this specification, these pigments are also referred to as "yellow pigments" for consistency.

[0025] The yellow pigments for each example and comparative example were prepared by the following method. First, TiO2, Li2O, and NiO were weighed to a total mass of 100 g in the desired composition shown in Table 1. Next, the weighed raw materials were mixed using a Henschel mixer to form a uniform batch, and then 30 g of the batch was weighed into a crucible and fired in an electric furnace at 1050°C for 6 hours.

[0026] Next, 25g of the obtained calcined material, 100g of 3mm diameter glass beads, and 50g of distilled water were weighed into a 140mL glass container, and after covering it, the mixture was ground with paint conditioner for 30 minutes to obtain a slurry. After that, the obtained slurry was removed from the container and dried at 120°C for 4 hours. The dried material was then crushed using a mortar and pestle to prepare a yellow pigment of the desired composition.

[0027] The prepared yellow pigments were visually inspected to determine if the desired color was achieved. In Table 1, "○" indicates that the desired color was achieved, and "×" indicates that the desired color was not achieved. For yellow pigments that achieved the desired color, the hue was also checked.

[0028] [Table 1]

[0029] For the prepared yellow pigment, paint tests (color tone), chemical resistance tests, and heat resistance tests were conducted. The paint tests were carried out according to the following procedure. First, 10 parts by mass of each yellow pigment was dispersed in 100 parts by mass of an acrylic resin using a paint conditioner, and the resulting paint was spread on black and white color development paper using an applicator with a thickness of 200 μm. Then, after drying, the coating film was measured for color using a spectrophotometer (KONICA MINOLTA SPECTROPHOTOMETER CM-3600A, standard light source C, 2° field of view). Table 1 also shows the color measurement results of the yellow pigments of each example and each comparative example according to the CIELAB color system.

[0030] For the yellow pigments of Examples 1 to 13 shown in Table 1, the desired color development was obtained. On the other hand, for the yellow pigments of Comparative Examples 1 to 3, the desired color development was not obtained. Here, from the results of the paint tests, the hue range having excellent color characteristics was defined as L * : 79.3 to 88.3, a * : -11.7 to -1.1, b * : 36.5 to 74.9.

[0031] Figure 1(a) shows the data distribution according to the composition (TiO2, Li2O, NiO) of the yellow pigment prepared by the method described above, and Figure 1(b) shows the blending range (mol%) in which the desired color development is obtained. The yellow pigments in region S1 of Figure 1(b) obtained the desired color development. Region S2 is a region that satisfies b > c, and the color development is green instead of yellow. Also, the yellow pigments in region S3 where a < 50 did not have color development.

[0032] The yellow pigments of Examples 1 to 13 in which the desired color development was obtained are included in region S1, and for a, b, and c in the composition formula aTiO2·bLi2O·cNiO (mol%), the relationships 50 ≦ a ≦ 95, 1 ≦ b ≦ 24, 4 ≦ c ≦ 49, a + b + c = 100, and c > b are satisfied. The yellow pigments of Comparative Examples 1 to 3 that did not satisfy the above requirements did not obtain sufficient color development.

[0033] The chemical resistance test was conducted using the following procedure. First, the prepared yellow pigment was immersed in a 5% by mass HCl aqueous solution or a 20% by mass NaOH aqueous solution for 3 days. Here, the concentration of the yellow pigment in the aqueous solution was adjusted to 10% by mass. Next, the aqueous solution containing the yellow pigment was filtered to separate the yellow pigment from the eluent. The yellow pigment was washed until the filtrate reached a pH of approximately 7, and then dried. After that, the dried yellow pigment was crushed and spread on black and white colored paper using the method described in the paint test above. The color was then compared to the yellow pigment before immersion using a spectrophotometer (KONICA MINOLTA SPECTROPHOTOMETER CM-3600A, standard light source C 2° field of view). The chemical resistance was then determined by the color difference.

[0034] Figure 2 is a diagram in which the data for several formulations that underwent chemical resistance testing is superimposed on the data graph of Figure 1(b), with the data for each formulation marked with a triangle.

[0035] As an example, Table 2 shows the color measurement results for the yellow pigment of Example 8 using the CIELAB color system. In Table 2, the L values ​​are based on the value before immersion in HCl aqueous solution or NaOH aqueous solution. * a * , b * Each of the changes ΔL * Δa * Δb * And, chromatic difference ΔE * This indicates that.

[0036] [Table 2]

[0037] As shown in Table 2, the yellow pigment of Example 8 has a color difference ΔE after immersion in an aqueous HCl solution. * The value is 0.4, and the color difference ΔE after immersion in NaOH aqueous solution. * Because its value is small at 0.2, it has chemical resistance.

[0038] Similar tests were conducted on the yellow pigments in region S1, excluding the yellow pigment used in Example 8, and it was confirmed that they possessed chemical resistance.

[0039] The heat resistance test was conducted using the following procedure. First, 0.5 phr of the yellow pigment from Example 8 was added to 400 g of polypropylene resin and dispersed with paint conditioner. Next, the resin with the dispersed yellow pigment was put into an injection molding machine and injection molded at 280°C. After that, plates molded at the normal molding temperature of 210°C and plates molded at 280°C were color-compared using a spectrophotometer (KONICA MINOLTA SPECTROPHOTOMETER CM-3600A, standard light source C 2° field of view), and the heat resistance was determined by the color difference. In addition, a color comparison was also performed between plates molded at 280°C as described above without any stagnation, and plates molded after stagnation at 280°C for 10 minutes.

[0040] As an example, Table 3 shows the color measurement results using the CIELAB color system for the yellow pigment of Example 8 when molded at 280°C, and Table 4 shows the color measurement results using the CIELAB color system when molded after being left at 280°C for 10 minutes. In Table 3, the L values ​​are based on the product molded at 210°C, and in Table 4, the L values ​​are based on the product molded at 280°C. * a * , b * Each of the changes ΔL * Δa * Δb * And, chromatic difference ΔE * This indicates that.

[0041] [Table 3]

[0042] [Table 4]

[0043] As shown in Table 3, the yellow pigment of Example 8 has a color difference ΔE when molded at 280°C, compared to when molded at 210°C. * The value is small at 0.6, and as shown in Table 4, the color difference ΔE when molded after being left at 280°C for 10 minutes. * Because its value is small at 0.9, it has heat resistance.

[0044] As described above, a yellow pigment containing a composite oxide represented by the compositional formula aTiO2·bLi2O·cNiO as its main component, where a, b, and c in the above compositional formula satisfy the relationships 50≦a≦95, 1≦b≦24, 4≦c≦49, a+b+c=100, and c>b, does not contain hazardous substances, rare earth elements, or expensive raw materials, making it highly safe and economical. Furthermore, it has chemical resistance and heat resistance, allowing it to be used in a variety of applications.

[0045] (Yellow pigment with chemical formula aTiO2·bZrO2·cNiO) The yellow pigments of Examples 14-26 and Comparative Examples 4-6 shown in Table 5 were prepared according to the procedure described below. These yellow pigments mainly contain a composite oxide represented by the compositional formula aTiO2·bZrO2·cNiO (mol%). However, a, b, and c satisfy the relationship a+b+c=100.

[0046] [Table 5]

[0047] The yellow pigments for each example and comparative example were prepared using the same procedure as for the yellow pigments in Examples 1 to 13 described above, after weighing TiO2, ZrO2, and NiO to a total mass of 100 g, according to the desired composition shown in Table 5. Furthermore, the prepared yellow pigments underwent paint tests (color tone), chemical resistance tests, and heat resistance tests, similar to those for the yellow pigments in Examples 1 to 13.

[0048] Figure 3(a) shows the data distribution according to the composition (TiO2, ZrO2, NiO) of the yellow pigment prepared by the method described above, and Figure 3(b) shows the data of several formulations that underwent chemical resistance testing within the formulation range (mol%) in which the desired color was obtained, with the data marked by triangles and superimposed. The yellow pigment in region S4 of Figure 3(b) obtained the desired color.

[0049] The yellow pigments of Examples 14-26 that produced the desired color were located in region S4 and satisfy the following relationships for a, b, and c in the composition formula aTiO2·bZrO2·cNiO (mol%): 30≦a≦95, 1≦b≦60, 4≦c≦49, and a+b+c=100. The yellow pigments of Comparative Examples 4-6 that did not satisfy the above requirements did not produce sufficient color.

[0050] Chemical resistance tests were conducted on the yellow pigments of Examples 14 to 26. As an example, the color measurement results for the yellow pigment of Example 18 using the CIELAB color system are shown in Table 6.

[0051] [Table 6]

[0052] As shown in Table 6, the yellow pigment of Example 18 has a color difference ΔE after immersion in an HCl aqueous solution. * The value is 0.6, and the color difference ΔE after immersion in NaOH aqueous solution. * Because its value is small at 0.8, it has chemical resistance.

[0053] Similar tests were conducted on yellow pigments in region S4, excluding the yellow pigment used in Example 18, to confirm their chemical resistance.

[0054] Tables 7 and 8 show the colorimetric results using the CIELAB color system when the yellow pigment of Example 18 was subjected to a heat resistance test.

[0055] [Table 7]

[0056] [Table 8]

[0057] As shown in Table 7, the yellow pigment of Example 18 has a color difference ΔE when molded at 280°C, compared to when molded at 210°C. * The value is small at 0.6, and as shown in Table 8, the color difference ΔE when molded after being left at 280°C for 10 minutes. * Because its value is small at 0.3, it has heat resistance.

[0058] As described above, the yellow pigment containing a composite oxide represented by the compositional formula aTiO2·bZrO2·cNiO as its main component, and satisfying the relationships 30≦a≦95, 1≦b≦60, 4≦c≦49, and a+b+c=100 for a, b, and c in the above compositional formula, does not contain hazardous substances, rare earth elements, or expensive raw materials, making it highly safe and economical. Furthermore, it has chemical resistance and heat resistance, so it can be used in a variety of applications.

[0059] (Yellow pigment with chemical formula aTiO2·bLi2O·cZrO2·dNiO) The yellow pigments of Examples 27-36 and Comparative Examples 7-9 shown in Table 9 were prepared using the procedure described below. These yellow pigments mainly contain a composite oxide represented by the compositional formula aTiO2·bLi2O·cZrO2·dNiO (mol%). However, a, b, c, and d satisfy the relationship a+b+c+d=100.

[0060] [Table 9]

[0061] The yellow pigments for each example and comparative example were prepared using the same procedure as for the yellow pigments in Examples 1 to 26 described above, after weighing TiO2, Li2O, ZrO2, and NiO to a total mass of 100 g, according to the desired composition shown in Table 9. Furthermore, the prepared yellow pigments underwent paint tests (color tone), chemical resistance tests, and heat resistance tests, similar to those for the yellow pigments in Examples 1 to 26.

[0062] As shown in Table 9, the yellow pigments of Examples 27-36 achieved the desired color, while the yellow pigments of Comparative Examples 7-9 did not. The yellow pigments of Examples 27-36, which achieved the desired color, satisfy the following relationships for a, b, c, and d in the composition formula aTiO2·bLi2O·cZrO2·dNiO (mol%): 50≦a≦93, 1≦b≦20, 1≦c≦30, 5≦d≦30, and a+b+c+d=100. The yellow pigments of Comparative Examples 7-9, which did not satisfy the above requirements, did not achieve sufficient color.

[0063] Chemical resistance tests were conducted on several yellow pigments from Examples 27 to 36. As an example, the colorimetric results for the yellow pigment of Example 32, using the CIELAB color system, are shown in Table 10.

[0064] [Table 10]

[0065] As shown in Table 10, the yellow pigment of Example 32 has a color difference ΔE after immersion in an HCl aqueous solution. * The value is 0.4, and the color difference ΔE after immersion in NaOH aqueous solution. * Because its value is small at 0.6, it has chemical resistance.

[0066] Similar tests were conducted on yellow pigments other than the yellow pigment used in Example 32 that produced the desired color, and it was confirmed that they possessed chemical resistance.

[0067] Tables 11 and 12 show the colorimetric results using the CIELAB color system when the yellow pigment of Example 32 was subjected to a heat resistance test.

[0068] [Table 11]

[0069] [Table 12]

[0070] As shown in Table 11, the yellow pigment of Example 32 has a color difference ΔE when molded at 280°C, compared to when molded at 210°C. * The value is small at 0.7, and as shown in Table 12, the color difference ΔE when molded after being left at 280°C for 10 minutes. * Because its value is small at 0.3, it has heat resistance.

[0071] As described above, a yellow pigment containing a composite oxide represented by the compositional formula aTiO2·bLi2O·cZrO2·dNiO as its main component, where a, b, c, and d in the above compositional formula satisfy the relationships 50≦a≦93, 1≦b≦20, 1≦c≦30, 5≦d≦30, and a+b+c+d=100, does not contain hazardous substances, rare earth elements, or expensive raw materials, making it highly safe and economical. Furthermore, it possesses chemical resistance and heat resistance, allowing it to be used in a variety of applications.

[0072] Furthermore, yellow pigments containing a composite oxide represented by the compositional formula aTiO2·bLi2O·cZrO2·dNiO as the main component have better color development and superior heat resistance than yellow pigments containing a composite oxide represented by the compositional formula aTiO2·bLi2O·cNiO(mol%) as the main component, and yellow pigments containing a composite oxide represented by the compositional formula aTiO2·bZrO2·cNiO(mol%) as the main component.

[0073] (Yellow pigment made from titanium-nickel composite oxide) As a sample for Comparative Example 10, a conventional titanium-nickel composite oxide yellow pigment (CIPigment Yellow 53) was prepared and its properties were evaluated in the same manner. The yellow pigment of Comparative Example 10 mainly contains a composite oxide represented by the compositional formula aTiO2·bSb2O3·cNiO (mol%) (where a+b+c=100). The colorimetric results of Comparative Example 10 using the CIELAB color system are shown in Table 13, the colorimetric results of the chemical resistance test using the CIELAB color system are shown in Table 14, and the colorimetric results of the heat resistance test using the CIELAB color system are shown in Tables 15 and 16.

[0074] [Table 13]

[0075] [Table 14]

[0076] [Table 15]

[0077] [Table 16]

[0078] As shown in Table 13, the yellow pigment of Comparative Example 10 achieves the desired color, but it contains antimony trioxide, which is a hazardous substance. Also, as shown in Table 14, the color difference ΔE of the yellow pigment of Comparative Example 10 after immersion in an HCl aqueous solution * 2.2, Color difference ΔE after immersion in NaOH aqueous solution * The color difference ΔE is large at 3.2, indicating that it does not have chemical resistance. However, as shown in Table 15, the color difference ΔE when molded at 280°C is compared to when molded at 210°C. * The value is 0.9, and as shown in Table 16, the color difference ΔE when molded after being left at 280°C for 10 minutes. * Because its value is small at 0.5, it has heat resistance.

[0079] (A yellow pigment made from a composite oxide with the chemical formula aTiO2·bWO3·cNiO·dLa2O3) As a sample for Comparative Example 11, a conventional yellow pigment containing a composite oxide represented by the compositional formula aTiO2·bWO3·cNiO·dLa2O3 (mol%) (where a+b+c+d=100) as the main component was prepared and the same property evaluation was performed. The yellow pigment of Comparative Example 11 uses lanthanum (La), a rare earth element, and tungsten (W), an expensive raw material. The color measurement results of Comparative Example 11 using the CIELAB color system are shown in Table 17, the color measurement results using the CIELAB color system when chemical resistance tests were conducted are shown in Table 18, and the color measurement results using the CIELAB color system when heat resistance tests were conducted are shown in Tables 19 and 20.

[0080] [Table 17]

[0081] [Table 18]

[0082] [Table 19]

[0083] [Table 20]

[0084] As shown in Table 17, the yellow pigment of Comparative Example 11 achieved the desired color. Furthermore, as shown in Table 18, the yellow pigment of Comparative Example 11 showed a color difference ΔE after immersion in an HCl aqueous solution. * The value is 0.6, and the color difference ΔE after immersion in NaOH aqueous solution. * The color difference ΔE is 0.9, indicating chemical resistance. However, as shown in Table 19, the color difference ΔE when molded at 280°C is compared to the color difference when molded at 210°C. *As shown in 3.5 and Table 20, the color difference ΔE when molded after being held at 280°C for 10 minutes is compared to when molded without holding at 280°C. * Because its value is large at 2.2, it does not have heat resistance.

[0085] The yellow pigment of the present invention can be used in a variety of applications as a coloring material for plastics, paints, printing inks, glass, and the like. As mentioned above, the yellow pigment of the present invention has chemical resistance and heat resistance, so it can be used in situations where chemical resistance, heat resistance, weather resistance, etc., are required.

[0086] The present invention is not limited to the embodiments described above, and various applications and modifications can be made within the scope of the present invention. For example, the yellow pigment of the present invention may contain minor components or additives in amounts that do not affect its properties.

Claims

1. TiO ２ It has NiO as an essential component, and Li ２ O and ZrO ２ A yellow pigment characterized by containing a complex oxide as its main component, which includes at least one of the following.

2. Composition formula aTiO ２ ・bLi ２ It contains a complex oxide represented as O・cNiO (mol%), The yellow pigment according to claim 1, characterized in that a, b, and c in the composition formula satisfy the following relationships: 50 ≤ a ≤ 95, 1 ≤ b ≤ 24, 4 ≤ c ≤ 49, a + b + c = 100, and c > b.

3. Composition formula aTiO ２ ・bZrO ２ • Contains a composite oxide represented as cNiO (mol%), The yellow pigment according to claim 1, characterized in that a, b, and c in the composition formula satisfy the following relationships: 30 ≤ a ≤ 95, 1 ≤ b ≤ 60, 4 ≤ c ≤ 49, and a + b + c = 100.

4. Composition formula aTiO ２ ·bLi ２ O·cZrO ２ ·dNiO (mol%) and contains a composite oxide represented by The yellow pigment according to claim 1, characterized in that a, b, c, and d in the composition formula satisfy the following relationships: 50 ≤ a ≤ 93, 1 ≤ b ≤ 20, 1 ≤ c ≤ 30, 5 ≤ d ≤ 30, and a + b + c + d = 100.

5. In the CIELAB color system, L ＊ 79.3-88.3, ​​a ＊ ga -11.7 to -1.1, b ＊ The yellow pigment according to any one of claims 1 to 4, characterized in that the ratio is 36.5 to 74.9.

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