Zirconium nitride powder and method for producing the same

Abstract

To provide zirconium nitride powder exhibiting excellent shielding property in a visible light region and excellent humidity resistance, when used as a black pigment for forming a black patterning film.SOLUTION: The zirconium nitride powder contains a zinc composition. The powder contains aluminum in a ratio of from 0.3 to 10.0 mass% and zinc in a ratio of from 0.1 to 1.1 mass%, provided that the total amount of the powder is 100 mass% and is of a specific surface area of from 20 to 90 m2 / g measured by the BET method.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to zirconium nitride powder containing an aluminum-based composition and a zinc-based composition that are suitably used as insulating black pigments, and to a method for producing the same. [Background technology]

[0002] This type of black pigment is dispersed in a photosensitive resin to prepare a black photosensitive composition. This composition is then applied to a substrate to form a photoresist film, and the photoresist film is exposed to photolithography to form a patterned film. This composition is used in black matrices for image forming elements such as color filters in liquid crystal displays, image sensors, camera modules, and light-shielding films inside sensors. Furthermore, black photosensitive compositions prepared by dispersing black pigment in a photosensitive resin are used in a wide range of applications as black photosensitive adhesives, coating materials, and molded product forming materials. These include sealing materials, frame materials, and surface coloring films for liquid crystal panels, as well as coverlay films, light-shielding films, color-tuning films, underfill materials, solder resists, black adhesives, and housings for various display devices, automotive equipment, and consumer electronics.

[0003] Conventionally, it was coated with alumina, and its volume resistivity was 1 × 10⁻⁶. 6 A zirconium nitride powder is disclosed having a density of Ω·cm or higher, a coating amount of alumina of 1.5% to 9% by mass relative to 100% by mass of zirconium nitride, and an isoelectric point of 5.7 or higher (see Patent Document 1 (Claim 1, paragraph

[0006] )). Patent Document 1 describes that this zirconium nitride powder can improve compatibility with acrylic resins and the like, and in combination with its gas barrier properties, can also improve moisture resistance.

[0004] On the other hand, a composite particle characterized by being a composite of ZrN and at least one of Al and Ti has been disclosed (see Patent Document 2 (Claim 1, paragraph

[0007] )). Patent Document 2 describes that this composite particle has lower transmittance in the visible light region, that is, higher light-shielding properties in the visible light region. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-158377 [Patent Document 2] WO2019-124100 publication [Overview of the project] [Problems that the invention aims to solve]

[0006] However, both the alumina-coated zirconium nitride powder described in Patent Document 1 and the particles composed of ZrN and Al described in Patent Document 2 still had the problem that, when used as black pigments to form black patterns, their transmittance in the visible light region was not low, meaning that their shielding properties in the visible light region were not sufficiently high.

[0007] The object of the present invention is to provide a zirconium nitride powder that exhibits excellent shielding properties in the visible light region and good moisture resistance when used as a black pigment to form a black patterning film, and a method for producing the same. [Means for solving the problem]

[0008] A first aspect of the present invention is a zirconium nitride powder containing an aluminum-based composition and a zinc-based composition, wherein, when the total amount of the powder is 100% by mass, the powder contains aluminum in a proportion of 0.3% to 10.0% by mass and zinc in a proportion of 0.1% to 1.1% by mass, and has a specific surface area of ​​20 m² as measured by the BET method. 2 / g~90m 2This is a zirconium nitride powder characterized by having a weight of / g.

[0009] A second aspect of the present invention is an invention based on the first aspect, wherein, in the transmission spectrum of a dispersion with a powder concentration of 50 ppm, the light transmittance X at 365 nm is 25% or more, the light transmittance Y at 550 nm is 8% or less, and the light transmittance X at 365 nm (X / Y) relative to the light transmittance Y at 550 nm is 6.0 or more, and the present invention is a zirconium nitride powder.

[0010] A third aspect of the present invention is a mixture of zirconium dioxide powder and a mixture of 0.02 to 0.46 molar amounts of the zirconium dioxide powder. Al source And, 0.03 to 0.25 times the molar amount of the zirconium dioxide powder Zn source The method for producing zirconium nitride powder according to the first or second aspect (hereinafter sometimes referred to as the calcination method) involves mixing 2.0 to 6.0 times the molar amount of metallic magnesium powder and 0.3 to 5.0 times the molar amount of magnesium oxide powder to obtain a mixture, and then calcining the mixture under a nitrogen gas atmosphere at a temperature of 700°C to 1100°C for 60 to 180 minutes to reduce the zirconium dioxide powder.

[0011] A fourth aspect of the present invention is an invention based on the third aspect, and the above Al source However, the powder is one or more of the following: metallic aluminum, aluminum oxide, aluminum hydroxide, aluminum chloride, or aluminate compounds. Zn source This is a method for producing zirconium nitride powder, which is a powder of one or more of the following: metallic zinc, zinc oxide, zinc hydroxide, zinc chloride, or zinc carbonate.

[0012] A fifth aspect of the present invention is the use of a zirconium compound-containing powder and Al source and Zn sourceIn a nitrogen gas atmosphere, a mixed gas atmosphere of nitrogen and hydrogen, a mixed gas atmosphere of nitrogen and argon, or a mixed gas atmosphere of nitrogen and ammonia, by a thermal plasma method, a flame method or an arc plasma method, a nitriding reaction is carried out to produce a zirconium nitride powder containing zinc and aluminum (hereinafter, sometimes referred to as a plasma synthesis method).

[0013] A sixth aspect of the present invention is a black dispersion in which the zirconium nitride powder of the first or second aspect is dispersed in a solvent or a monomer compound.

[0014] A seventh aspect of the present invention is a black paste containing an organic polymer compound in the black dispersion of the sixth aspect.

[0015] An eighth aspect of the present invention is a black photosensitive composition containing the zirconium nitride powder of the first or second aspect as a black pigment.

[0016] A ninth aspect of the present invention is a UV-curable black adhesive obtained by using the black photosensitive composition of the eighth aspect.

[0017] A tenth aspect of the present invention is a black patterning film obtained by using the black photosensitive composition of the eighth aspect.

[0018] An eleventh aspect of the present invention is a black molded body obtained by using the black photosensitive composition of the eighth aspect.

Advantages of the Invention

[0019] In the zirconium nitride powder of the first aspect of the present invention, when the total amount of this powder is 100% by mass, this powder contains aluminum at a ratio of 0.3% by mass to 10.0% by mass and zinc at a ratio of 0.1% by mass to 1.1% by mass, and the specific surface area measured by the BET method is 20 m 2 / g to 90 m 2 / g. Since the BET specific surface area of this zirconium nitride powder is 20 m 2 / g or more, there is an effect of suppressing sedimentation when used as a resist, and also 90 m 2Because the amount is less than / g, it has the effect of providing sufficient visible light shielding. When this zirconium nitride powder contains aluminum in the above proportion, the aluminum-containing powder acts as an auxiliary agent for the thermite reduction reaction, resulting in high crystallinity and uniform fine particle size, thus improving ultraviolet light transmission and moisture resistance. Furthermore, when the zirconium nitride powder contains zinc in the above proportion, the particle size reduction and uniformity effect is enhanced, increasing the ultraviolet light transmission inherent in the zirconium nitride powder, further improving the shielding of visible light, and improving infrared light transmission. In addition, by including aluminum and zinc simultaneously, the effects of uniform fine particle size and improved crystallinity are further enhanced.

[0020] The zirconium nitride powder according to the second aspect of the present invention further exhibits, in the transmission spectrum of a dispersion with a powder concentration of 50 ppm, a light transmittance X at 365 nm of 25% or more, a light transmittance Y at 550 nm of 8% or less, and a light transmittance X at 365 nm (X / Y) of 6.0 or more relative to the light transmittance Y at 550 nm. Therefore, it has the advantage of transmitting ultraviolet light even more effectively, and when used as a black pigment to form a black patterning film, it is possible to form a patterning film with even higher resolution, and the formed patterning film has higher visible light shielding performance.

[0021] In the third aspect of the present invention, a method for producing zirconium nitride powder (calcination method) involves mixing zirconium oxide with an aluminum compound, a zinc compound-containing powder, metallic magnesium powder, and magnesium oxide powder in predetermined proportions, and producing zirconium nitride powder at a temperature of 700°C to 1100°C. As a result, the powder contains an aluminum-based composition and a zinc-based composition. In particular, because the aluminum-containing powder and the zinc compound-containing powder contribute more gently to the thermite reduction reaction than metallic magnesium, the crystallinity of the zirconium nitride powder is not reduced, maintaining high crystallinity and improving the purity and particle size of the zirconium nitride powder.

[0022] Although the detailed mechanism of the thermite reduction reaction is unknown, it is expected that using zinc compound-containing powder as the reaction material will produce the following side reactions during the thermite reduction reaction, and it is presumed that these side reactions will result in good optical properties.

[0023] When the aluminum compound is metallic aluminum and the zinc compound is metallic zinc, these metallic aluminum and metallic zinc reduce zirconium oxide and assist in the nitridation of zirconium under a nitrogen gas atmosphere. This reaction is shown in equations (1) and (2). ZrO2+ 4 / 3Al + 1 / 2N2→ ZrN + 2 / 3Al2O3(1) ZrO2+ 2Zn + 1 / 2N2→ ZrN + 2ZnO (2) If the aluminum compound is aluminum oxide, aluminum hydroxide, aluminum chloride, or an aluminate compound, or if the zinc compound is zinc oxide, zinc hydroxide, zinc chloride, or zinc carbonate, then these aluminum or zinc compounds are first reduced to metallic aluminum or metallic zinc with metallic magnesium, and then the reaction of formula (1) or formula (2) described above takes place. The reactions shown in formulas (1) and (2) above produce a mixture of zirconium nitride, an aluminum-based compound, and a zinc-based compound.

[0024] Metallic aluminum and metallic zinc undergo thermite reactions at high temperatures, similar to metallic magnesium. However, the reaction is longer and slower than that of magnesium, resulting in zirconium nitride, a reactant product, which is less prone to coarse particle formation due to thermal sintering. This results in a small particle size with excellent uniformity, which is thought to contribute particularly to improved transmittance in the ultraviolet and infrared regions.

[0025] In the manufacturing method according to the fourth aspect of the present invention, since the aluminum compound-containing powder is one or more powders of metallic aluminum, aluminum oxide, aluminum hydroxide, aluminum chloride, or aluminate compounds, and the zinc compound-containing powder is one or more powders of metallic zinc, zinc oxide, zinc hydroxide, zinc chloride, or zinc carbonate, both powders are reduced by metallic magnesium during calcination to produce metallic aluminum and metallic zinc, and zirconium nitride powder is obtained according to formulas (1) and (2) above.

[0026] The fifth aspect of the present invention relates to a manufacturing method (plasma synthesis method) which allows for the production of zirconium nitride powder containing zinc and aluminum by nitriding zirconium compound-containing powder, aluminum compound-containing powder, and zinc compound-containing powder in a nitrogen-containing atmosphere using a thermal plasma method, flame method, or arc plasma method. This manufacturing method (plasma synthesis method) has the advantage of producing zirconium nitride powder with fewer impurities and superior uniformity compared to the manufacturing method (calcination method) of the third aspect.

[0027] The black dispersion according to the sixth aspect of the present invention has the characteristic that, by dispersing the zirconium nitride powder according to the first or second aspect in a solvent or monomer compound, the zirconium nitride transmits ultraviolet light, blocks visible light, and transmits infrared light. As a result, this black dispersion is suitably used as a material for forming black patterning films.

[0028] Since the black paste according to the seventh aspect of the present invention contains an organic polymer compound in the black dispersion, and the black photosensitive composition according to the eighth aspect of the present invention contains zirconium nitride powder as a black pigment, and the UV-curable black adhesive according to the ninth aspect of the present invention is obtained using this black photosensitive composition, if a black patterning film is formed using this black paste, black pigment composition, or UV-curable black adhesive, the black patterning film will have a high ultraviolet transmittance, and a high-resolution patterning film can be formed even if the amount of photoinitiator used is reduced. Furthermore, the addition of aluminum and zinc makes the particles finer and more uniform, improving infrared transmittance, so that the alignment when patterning the black matrix that constitutes the color filter can be done with high precision.

[0029] The black patterning film according to the tenth aspect of the present invention has high resolution, high shielding performance for visible light, and high transmission performance in the ultraviolet and infrared regions.

[0030] The black molded body according to the eleventh aspect of the present invention has the advantage of curing with a low amount of UV irradiation and having reduced heat retention because it does not absorb near-infrared rays, thus preventing the internal temperature from becoming high. [Brief explanation of the drawing]

[0031] [Figure 1] These are spectral curves showing the light transmittance of dispersions obtained by diluting the zirconium nitride powder dispersions obtained in Example 1 and Comparative Example 1, respectively, to a powder concentration of 50 ppm. [Figure 2] This is a flow chart for producing zirconium nitride powder by the first manufacturing method (calcination method) of the present invention. [Figure 3] This is a flow chart for producing zirconium nitride powder by the second manufacturing method (plasma synthesis method) of the present invention. [Modes for carrying out the invention]

[0032] Next, embodiments for carrying out the present invention will be described.

[0033] [First method for producing zirconium nitride powder (calcination method)] A distinctive feature of the first method for producing the zirconium nitride powder (hereinafter sometimes referred to as the final product) of the present invention is that, together with metallic magnesium powder, an aluminum compound-containing powder and a zinc compound-containing powder are used, and these aluminum and zinc compounds contribute to the reduction of zirconium oxide.

[0034] [A mixture of aluminum compound-containing powder, zinc compound-containing powder, ZrO2 powder, metallic Mg powder, and MgO powder] In the first manufacturing method, as shown in Figure 2, aluminum compound-containing powder 11 and zinc compound-containing powder 12 are mixed with zirconium oxide (ZrO2) powder 13, metallic magnesium (metallic Mg) powder 14, and magnesium oxide (MgO) powder 15 to obtain a mixture 20.

[0035] This mixture 20 is obtained by mixing zirconium oxide powder 13, aluminum compound-containing powder 11 in an amount of 0.02 to 0.46 moles of zirconium oxide, zinc compound-containing powder 12 in an amount of 0.03 to 0.25 moles of zirconium oxide, metallic magnesium powder 14 in an amount of 2.0 to 6.0 moles of zirconium oxide, and magnesium oxide powder 15 in an amount of 0.3 to 5.0 moles of zirconium oxide.

[0036] [Aluminum compound-containing powder] The aluminum compound-containing powder 11 is a powder of one or more of the following: metallic aluminum, aluminum oxide, aluminum hydroxide, aluminum chloride, or aluminate compounds. Aluminum compounds other than metallic aluminum are used to produce metallic aluminum by reduction with metallic magnesium during calcination. Therefore, if the aluminum compound-containing powder is metallic aluminum, the amount of metallic magnesium used can be kept to a minimum. Aluminum hydroxide can be synthesized by dissolving inorganic aluminum compounds such as aluminum nitrate, aluminum acetate, and aluminum chloride in water, adding alkali, washing the synthesized product to remove impurities, and then using it in a dried state. Alternatively, inorganic aluminum compounds such as aluminum nitrate, aluminum acetate, and aluminum chloride can be synthesized by dissolving them in water, adding alkali, washing the synthesized product to remove impurities, and preparing a slurry. Zirconium oxide, metallic magnesium, and magnesium oxide can then be added to this slurry, mixed, dried, and used in a dried powder state.

[0037] When the aluminum compound-containing powder 11 is metallic aluminum powder, it is preferable that the metallic aluminum powder has an average particle size of 1 μm to 200 μm. If it is below the lower limit, the reaction tends to proceed rapidly, and if it exceeds the upper limit, the reaction does not proceed smoothly. When the aluminum compound-containing powder 11 is a powder other than metallic aluminum powder, these powders are ionic compounds and readily decompose thermally, so there are no restrictions on the average particle size of the powder 11.

[0038] The amount of aluminum compound-containing powder 11 (other than metallic aluminum) added to the zirconium oxide powder 13 affects the amount of metallic aluminum produced. If the amount of aluminum compound-containing powder is too small, there will be insufficient metallic aluminum, making it difficult for the thermite reduction reaction by aluminum to occur. If the amount is too large, ZrAl3, a compound of aluminum and zirconium, will be produced, and the optical properties of the final product will deteriorate. The aluminum compound-containing powder 11 is added to the zirconium oxide powder 13 and mixed in a ratio of 0.02 to 0.46 moles of zirconium oxide. If the amount is less than 0.02 moles, the amount of metallic aluminum produced is likely to be insufficient, and if it exceeds 0.46 moles, the optical properties of the final product will deteriorate. A ratio of 0.025 to 0.2 moles is preferable. Here, the number of moles of the aluminum compound-containing powder is the value converted to the molecular weight per aluminum atom constituting the aluminum compound-containing powder.

[0039] [Zinc compound-containing powder] The zinc compound-containing powder 12 is a powder of one or more of the following: metallic zinc, zinc oxide, zinc hydroxide, zinc chloride, or zinc carbonate. Zinc compounds other than metallic zinc are used to produce metallic zinc by reduction with metallic magnesium during calcination. Therefore, if the zinc compound-containing powder is metallic zinc, the amount of metallic magnesium used can be kept to a minimum. Zinc hydroxide can be synthesized by dissolving an inorganic zinc compound such as zinc nitrate, zinc acetate, or zinc chloride in water, adding alkali, washing the synthesized product to remove impurities, and then using it in a dried state. Alternatively, an inorganic zinc compound such as zinc nitrate, zinc acetate, or zinc chloride can be synthesized by dissolving it in water, adding alkali, washing the synthesized product to remove impurities, and preparing a slurry. Zirconium oxide, metallic magnesium, or magnesium oxide can then be added to this slurry, mixed, dried, and used in a dried powder state.

[0040] When the zinc compound-containing powder 12 is metallic zinc powder, it is preferable that the metallic zinc powder has an average particle size of 1 μm to 200 μm. If it is below the lower limit, the reaction tends to proceed rapidly, and if it exceeds the upper limit, the reaction does not proceed smoothly. When the zinc compound-containing powder 12 is a powder other than metallic zinc powder, these powders are ionic compounds and readily decompose under heat, so there are no restrictions on the average particle size of the powder 12.

[0041] The amount of zinc compound-containing powder 12 (other than metallic zinc) added to the zirconium oxide powder 13 affects the amount of metallic zinc produced. If the amount of zinc compound-containing powder is too small, there will be insufficient metallic zinc, making it difficult to perform the thermite reduction reaction by zinc. If the amount is too large, ZrZn2, a compound of zinc and zirconium, will be produced, and the optical properties of the final product will deteriorate. The zinc compound-containing powder 11 is added to and mixed with the zirconium oxide powder 12 in a ratio of 0.03 to 0.25 moles of zirconium oxide. If the ratio is less than 0.03 moles, the amount of metallic zinc produced is likely to be insufficient, and if it exceeds 0.25 moles, the optical properties of the final product will deteriorate. A ratio of 0.04 to 0.20 moles is preferable. Here, the number of moles of the zinc compound-containing powder is the molecular weight per zinc atom constituting the zinc compound-containing powder.

[0042] [Zirconium oxide powder] As the zirconium oxide powder 13, any zirconium oxide powder such as monoclinic zirconium oxide, cubic zirconium oxide, or yttrium-stabilized zirconium oxide can be used, but monoclinic zirconium oxide powder is preferred from the viewpoint of increasing the production rate of zirconium nitride powder. Zirconium oxide usually contains about 2% by mass of hafnium as an unavoidable impurity, but at a level of 2% by mass, it does not affect the optical properties of the product.

[0043] [Magnesium metal powder] If the particle size of the metallic magnesium powder 14 is too small, the reaction will proceed too rapidly, increasing the risk of complications during operation. Therefore, it is preferable that the particle size of the metallic magnesium powder 14 be granular with a particle size of 100 μm to 1000 μm in the mesh pass of the sieve, and particularly preferably granular with a particle size of 200 μm to 500 μm. However, it is not necessary for all of the metallic magnesium powder 14 to be within the above particle size range; it is sufficient if 80% or more by mass, and particularly 90% or more by mass, is within the above range.

[0044] The amount of metallic magnesium powder 14 added to zirconium oxide powder 13 affects the reducing power to zirconium oxide. If the amount of metallic magnesium is too little, insufficient reduction will occur, making it difficult to obtain the desired zirconium nitride powder. If the amount is too much, the reaction temperature will rise rapidly due to the excess metallic magnesium, which may cause particle growth and is uneconomical. The metallic magnesium powder 14 is added to the zirconium oxide powder 13 and mixed so that the ratio of metallic magnesium to zirconium oxide is 2.0 to 6.0 moles, depending on the particle size. If the amount is less than 2.0 moles, the reducing power of zirconium oxide is likely to be insufficient, and if it exceeds 6.0 moles, the reaction temperature is likely to rise rapidly due to the excess metallic magnesium, which may cause particle growth and is uneconomical. 2.0 to 5.0 moles is preferred.

[0045] [Magnesium oxide powder] Magnesium oxide powder 15 is used to prevent the sintering of zirconium nitride, which is produced by the reduction reaction of zirconium oxide with metallic magnesium. The amount used varies depending on the particle size of the magnesium oxide, but is generally 0.3 to 5.0 moles per mole of zirconium oxide powder. Preferably, it is 0.5 to 4.5 moles. Only an amount of magnesium oxide powder 15 is needed that is sufficient to prevent the sintering of zirconium nitride. Using an excess will increase the amount of acidic solution required during acid washing after the reaction, so it is preferable to use it within the above range.

[0046] [Catering of the mixture] Aluminum compound-containing powder 11, zinc compound-containing powder 12, zirconium oxide powder 13, metallic magnesium powder 14, and magnesium oxide powder 15 are placed in a reaction vessel (not shown), and the mixture 20 is calcined. The temperature during the reduction reaction with metallic magnesium to reduce the zirconium oxide powder 13 to produce zirconium nitride powder, i.e., the calcination temperature, is 700°C to 1100°C, preferably 950°C to 1000°C. Below the lower limit of 700°C, the aluminum compound-containing powder and zinc compound-containing powder cannot be effectively utilized in the thermite reduction reaction, and the reduction reaction of zirconium oxide does not occur sufficiently. Furthermore, even if the temperature is raised above 1100°C, the effect does not increase, and it is undesirable as it wastes thermal energy and causes sintering of the particles. The reduction reaction time, i.e., the calcination time, is 60 minutes to 180 minutes, preferably 60 minutes to 120 minutes, for the same reasons as the reduction reaction temperature. The atmospheric gas during this reduction reaction, i.e., calcination, is a nitrogen gas atmosphere to prevent oxidation of the reduction product. To promote the above reduction reaction, a mixture of nitrogen gas and hydrogen gas, or a mixture of nitrogen gas and ammonia gas, may be used. The above mixture 20 is calcined to obtain a calcined product 21.

[0047] [Processing of fired products] The calcined product 21 obtained by calcining the above mixture is removed from the reaction vessel and finally cooled to room temperature, then washed with an acid solution 22 such as hydrochloric acid aqueous solution to remove magnesium oxide produced by the oxidation of metallic magnesium, magnesium oxide (MgO) that was initially included to prevent sintering of the product, and magnesium nitride (Mg3N2) produced by calcination. In addition, the zinc in the zinc compound-containing powder is partially dissolved and removed by washing with the acid solution according to the following reaction equation (3). Zn + 2HCl → ZnCl2 + H2(3) This acid washing is preferably carried out at a pH of 0.5 or higher and a temperature of 90°C or lower, and more preferably at a pH of 1.0 to 3.0 and a temperature of 90°C or lower. This is because if the acidity is too strong or the temperature is too high, there is a risk that even zirconium may dissolve. After the acid washing, the pH is adjusted to 5 to 6 with ammonia water or the like, the solids are separated by filtration or centrifugation, the solids are dried and then pulverized to obtain the zirconium nitride powder 23 of this embodiment. The zirconium nitride powder 23 may contain impurities that may be present in the process, derived from the raw materials used or the material of the stainless steel reaction vessel. Examples of impurities include magnesium salts such as magnesium chloride and magnesium oxide, ammonium salts such as ammonium chloride, fluorine, chlorine, bromine, metallic zinc, zinc nitride, carbon, adsorbed water, iron, nickel, chromium, tungsten, molybdenum, vanadium, niobium, titanium, cobalt, potassium, copper, and hafnium compounds. Even if these impurities are present in trace amounts in the zirconium nitride powder 23, it does not affect its optical properties, electrical insulation properties, or changes in properties under constant temperature and humidity conditions.

[0048] [Second method for producing zirconium nitride powder (plasma synthesis method)] A second method for producing the zirconium nitride powder (hereinafter sometimes referred to as the final product) of the present invention is a method for producing zirconium nitride powder containing aluminum and zinc by a thermal plasma method. Although this method is common for obtaining metal nitrides, it has not been established as a means for obtaining zirconium nitride powder with high purity. Examples of apparatus for carrying out the above thermal plasma method include thermal plasma devices such as a high-frequency induction thermal plasma nanoparticle synthesis apparatus (JEOL TP40020NPS). This thermal plasma apparatus comprises a gas supply unit for reaction gases such as nitrogen (N2) gas, hydrogen (H2) gas, and ammonia (NH3) gas; a raw material supply unit that supplies zirconium compound-containing powder, aluminum compound-containing powder, and zinc compound-containing powder to a plasma torch; a plasma torch connected to the raw material supply unit that synthesizes and nitrides the raw materials by thermal plasma; an induction coil wound around the outer circumference of the plasma torch; a high-frequency power supply electrically connected to the induction coil and supplying high-frequency power to the induction coil; a chamber connected to the plasma torch through which cooling gases such as N2 gas and Ar gas circulate; and a bag filter connected to the chamber for recovering the zirconium nitride powder containing aluminum and zinc.

[0049] To produce zirconium nitride powder containing aluminum and zinc using the above-described thermal plasma apparatus, as shown in Figure 3, first, zirconium compound-containing powder 16, aluminum compound-containing powder 17, and zinc compound-containing powder 18, which are the raw materials, are supplied to the raw material feeder. Examples of zirconium compound-containing powder 16 include metallic zirconium powder, zirconium oxide powder (ZrO2), and zirconium nitride (ZrN) powder. The aluminum compound-containing powder 17 and zinc compound-containing powder 18 may be the same as or different from the aluminum compound-containing powder 11 and zinc compound-containing powder 18 used in the first manufacturing method. Specifically, aluminum oxide powder and aluminum nitride powder are preferred for the aluminum compound-containing powder 17. Zinc oxide and zinc nitride are preferred for the zinc compound-containing powder 18. When the zirconium compound-containing powder 16 is metallic zirconium powder, the purity of the metallic zirconium powder is preferably 98% or higher, and the average primary particle size is preferably 30 μm or less. Furthermore, if the aluminum compound-containing powder 17 is metallic aluminum powder, the purity of the metallic aluminum powder is preferably 98% or higher, and the average primary particle size is preferably 200 μm or less. In addition, if the zinc compound-containing powder 18 is metallic zinc powder, the purity of the metallic zinc powder is preferably 98% or higher, and the average primary particle size is preferably 150 μm or less. The reason for limiting the purity of the metallic zirconium powder to 98% or higher is that if it is less than 98%, the purity of the target zirconium nitride decreases, and sufficient properties cannot be obtained. Furthermore, the reason for limiting the average primary particle size of the metallic zirconium powder to 30 μm or less is that if it is 30 μm or less, a high-purity zirconium nitride powder can be obtained, whereas if it exceeds 30 μm, the dissolution and gasification of the metallic zirconium powder becomes insufficient, and the metallic zirconium powder is recovered as unnitrided metallic zirconium powder, and zirconium nitride powder that exhibits sufficient properties cannot be obtained. On the other hand, the reason for limiting the purity of the metallic aluminum powder and metallic zinc powder to 98% or higher is that if it is less than 98%, the purity of the target zirconium nitride decreases, and sufficient properties cannot be obtained.Furthermore, the reason for limiting the average primary particle size of the metallic aluminum powder to 200 μm or less and the average primary particle size of the metallic zinc powder to 150 μm or less is that exceeding these upper limits would prevent the acquisition of zirconium nitride powder uniformly containing aluminum and zinc. When the zirconium compound-containing powder 16, aluminum compound-containing powder 17, and zinc compound-containing powder 18 are oxide powders or nitrides, it is preferable to adjust the reaction temperature and reaction time using the boiling point and melting point of each compound as indicators. The average primary particle size of the above metal powder is the particle size measured using a particle size distribution analyzer (LA-950, manufactured by Horiba, Ltd.), and is a volume-based average primary particle size.

[0050] Next, the raw materials are introduced into a plasma torch by a carrier gas such as N2 gas or Ar gas. At this time, the inside of the plasma torch is an atmosphere of N2 gas, a mixed gas atmosphere of N2 and H2, a mixed gas atmosphere of N2 and Ar, or a mixed gas atmosphere of N2 and NH3. These mixed gases are heated by supplying high-frequency power from a high-frequency power supply to an induction coil, generating a thermal plasma of N2 gas, a thermal plasma of a mixed gas of N2 and H2, a thermal plasma of a mixed gas of N2 and Ar, or a thermal plasma (plasma flame) of a mixed gas of N2 and NH3. As a result, the raw materials introduced into the plasma torch are volatilized and gasified by the high-temperature thermal plasma of N2 gas, etc., generated in the plasma torch at several thousand degrees Celsius, i.e., undergo a synthetic nitriding reaction by the thermal plasma method. Next, the gasified raw materials are rapidly cooled in a chamber through which a cooling gas such as N2 gas or Ar gas flows, i.e., they are instantly cooled and condensed by a cooling gas such as N2 gas or Ar gas in a chamber below the plasma torch, thereby obtaining zirconium nitride powder 24 containing aluminum and zinc, as shown in Figure 3. Furthermore, this zirconium nitride powder is recovered by a bag filter. In this way, a nano-sized (average primary particle size: 10 nm to 50 nm) black material consisting of zirconium nitride powder containing aluminum and zinc is obtained. The average primary particle size of the black material is a value measured by spherical conversion from the measured specific surface area using equation (4) described later.

[0051] [Properties of Zirconium Nitride Powder] The zirconium nitride powder obtained by the first and second manufacturing methods contains aluminum in a proportion of 0.3% to 10.0% by mass and zinc in a proportion of 0.1% to 1.1% by mass, when the total amount of powder is 100% by mass. If the proportion of aluminum is below the lower limit, moisture resistance decreases, and the effects of crystallinity improvement and particle uniformity reduction due to the thermite reduction reaction do not occur, resulting in low light transmittance at a wavelength of 365 nm. If the proportion exceeds the upper limit, the aluminum compound becomes a residual impurity, increasing the transmittance in the visible light region (380 nm to 780 nm) and decreasing the light shielding performance in the visible light region. Similarly, if the proportion of zinc is below the lower limit, the effects of crystallinity improvement and particle uniformity reduction due to the thermite reduction reaction do not occur, resulting in low light transmittance at a wavelength of 365 nm. If the proportion exceeds the upper limit, the zinc compound becomes a residual impurity, reducing the light shielding performance in the visible light region (380 nm to 780 nm). The preferred proportion of aluminum is 0.3% to 6.0% by mass, and the preferred proportion of zinc is 0.1% to 1.0% by mass.

[0052] Although unconfirmed, the forms of the aluminum-based and zinc-based compositions in this zirconium nitride powder are presumed to be present at the grain boundaries of the zirconium nitride particles or to partially replace zirconium atoms. Examples of aluminum-based compositions include aluminum nitride, aluminum oxynitride, and aluminum oxide, while examples of zinc-based compositions include zinc nitride, zinc oxynitride, and zinc oxide.

[0053] The presence or absence of the adhesion of the aluminum-based composition and the zinc-based composition on the surface of the powder is confirmed using a scanning transmission electron microscope (STEM) and an energy-dispersive X-ray spectroscopy (EDS). Specifically, the confirmation of the presence or absence is performed by observing the particle appearance under the conditions of an acceleration voltage of 200 kV, setting the magnification to a value at which 1 to 5 particles can be confirmed among magnifications from 10,000 times to 200,000 times using STEM (Titan G2 ChemiSTEM manufactured by Thermo Fisher Scientific). Further, the confirmation of the presence or absence is performed by performing elemental mapping for aluminum element, zinc element, zirconium element, oxygen element, and nitrogen element using EDS (Velox manufactured by Thermo Fisher Scientific) in the same field of view, and discriminating the aluminum-based composition, the zinc-based composition, and zirconium nitride. Briefly, when observing the particle appearance, it is also possible to discriminate the aluminum-based composition, the zinc-based composition, and zirconium nitride from the contrast difference of the aluminum-based composition, the zinc element, and the zirconium element in a high-angle annular dark field (HAADF: High-Angle Annular Dark Field) image.

[0054] The content ratios of aluminum and zinc are measured using an inductively coupled plasma optical emission spectrometer (ICP optical emission spectrometer ICPS-7510 manufactured by Shimadzu Corporation).

[0055] Also, the zirconium nitride powder has a BET specific surface area of 20 m 2 / g to 90 m 2 / g. If the specific surface area of this zirconium nitride powder is less than 20 m 2 / g, there is a problem that the pigment precipitates during long-term storage when used as a black resist. If it exceeds 90 m 2 / g, there is a problem that the visible light shielding performance is insufficient when forming a patterning film as a black pigment. A range of 30 m 2 / g to 85 m 2 / g is preferable. From the above specific surface area, the average particle diameter, assuming a spherical shape, can be calculated using the following formula (4). The average particle diameter of the zirconium nitride powder of this embodiment, calculated from this BET specific surface area, is 10 nm to 50 nm. In formula (4), L is the average particle diameter (μm), and ρ is the density of the powder (g / cm³). 3 ), S is the specific surface area (m²) of the powder. 2 It is / g). L = 6 / (ρ × S) (4)

[0056] In the zirconium nitride powder of this embodiment, it is preferable that the light transmittance X at 365 nm is 25% or more and the light transmittance Y at 550 nm is 8% or less in the transmission spectrum of a dispersion with a powder concentration of 50 ppm. If the light transmittance X is less than 25%, the bottom of the photoresist film is not exposed when forming a patterning film as a black pigment, and undercuts of the patterning film are likely to occur. Also, if the light transmittance Y exceeds 8%, the visible light shielding properties of the patterning film tend to be poor. A more preferable light transmittance X is 26% or more, and an even more preferable light transmittance Y is 6% or less. Considering the contradictory characteristics of light transmittance Y and light transmittance X as described above, it is preferable that the zirconium nitride powder of this embodiment has a light transmittance X at 365 nm (X / Y) of 6.0 or more relative to the light transmittance Y at 550 nm, and more preferably 7.0 or more. That is, an X / Y ratio of 6.0 or more results in high light shielding properties in the visible light region.

[0057] Furthermore, it is essential that the final zirconium nitride powder is well dispersed without particle aggregation. Sufficient dispersion can be achieved, for example, by using a polymer-based dispersant containing functional groups such as phosphoric acid and amines, and performing dispersion treatment for a predetermined time using a grinding medium such as zirconia beads. An indicator of dispersion degree is that no secondary aggregates exceeding 200 nm are detected using a dynamic scattering particle size analyzer (e.g., UPA from Microtrac or SZ-100 from Horiba, Ltd.).

[0058] [Preparation of black dispersion] A black dispersion is prepared by dispersing the final product, zirconium nitride powder, in a solvent or a monomer compound such as an acrylic monomer or epoxy monomer.

[0059] Acrylic monomers are monomers having a (meth)acryloyl group. The (meth)acryloyl group includes both an acryloyl group and a methacryloyl group. Acrylic monomers may be monofunctional acrylic monomers having one (meth)acrylic group in a single molecule, or they may be polyfunctional acrylic monomers having two or more (meth)acrylic groups in a single molecule.

[0060] Examples of monofunctional (meth)acrylic monomers include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, isoamyl acrylate, tetrahydrofurfuryl (meth)acrylate, and isobornyl (meth)acrylate.

[0061] Examples of difunctional (meth)acrylic monomers include 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, ethylene oxide-modified bisphenol A di(meth)acrylate, and neopentyltriethylene glycol di(meth)acrylate.

[0062] Examples of polyfunctional (meth)acrylic monomers include pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and trimethylolpropane tri(meth)acrylate.

[0063] Epoxy monomers are substances that have an epoxy group. Epoxy monomers may be monofunctional epoxy monomers having one epoxy group in a single molecule, or polyfunctional epoxy monomers having two or more epoxy groups in a single molecule. Examples of epoxy monomers include glycidyl ethers and alicyclic epoxys.

[0064] By adding this black dispersion, which is a monomer dispersion, to a polymer such as an acrylic resin, epoxy resin, or silicone resin, a resin composition containing the above-mentioned zirconium nitride powder in a dispersed manner is prepared, and a resin molded article is formed from this resin composition. Furthermore, the black dispersion, which is a monomer dispersion, may further contain metal oxide powder and may further contain a plasticizer. The plasticizer is not particularly limited, but examples of conventionally known plasticizers include phosphate ester plasticizers such as tributyl phosphate and 2-ethylhexyl phosphate, phthalate ester plasticizers such as dimethyl phthalate and dibutyl phthalate, aliphatic-basic ester plasticizers such as butyl oleate and glycerin monooleate, aliphatic dibasic acid ester plasticizers such as dibutyl adipate and di-2-ethylhexyl sebacate; dihydric alcohol ester plasticizers such as diethylene glycol dibenzoate and triethylene glycol di-2-ethyl butyrate; and oxyacid ester plasticizers such as methyl acetylricinoleate and tributyl acetylcitrate.

[0065] Furthermore, other monomers can be added to the black dispersion, which is a monomer dispersion. The other monomers are not particularly limited and can include, for example, (meth)acrylic monomers such as (meth)acrylic acid and (meth)acrylic acid esters, styrene monomers such as styrene, vinyltoluene, and divinylbenzene, vinyl monomers such as vinyl chloride and vinyl acetate, urethane monomers such as urethane acrylate, and the various polyols mentioned above, as well as other conventionally known monomers. The viscosity of the monomer dispersion is preferably set within the range of 10 mPa·s to 1000 mPa·s, taking into consideration the dispersibility of the zirconium nitride powder. Dispersion into the monomer can also be performed using a milling method with grinding media, similar to dispersion into the solvent described below. Although not an essential component, a polymeric dispersant can also be used to further improve dispersibility. A polymeric dispersant with a molecular weight of several thousand to tens of thousands is effective. Furthermore, functional groups of polymeric dispersants that adsorb to pigments include secondary amines, tertiary amines, carboxylic acids, phosphoric acid, and phosphate esters, with tertiary amines and carboxylic acids being particularly effective. Adding a small amount of silane coupling agent instead of polymeric dispersants is also effective in improving dispersibility. Alternatively, it is possible to obtain a black dispersion by passing the mixture through a three-roll roller several times after planetary stirring.

[0066] For black dispersions dispersed in solvents, the addition of polymeric dispersants is effective, similar to black dispersions dispersed with monomer compounds. The polymeric dispersant should have a molecular weight of several thousand to tens of thousands, similar to black dispersions dispersed with monomer compounds, and effective functional groups for the polymeric dispersant include tertiary amines and carboxylic acids. Examples of solvents include isopropanol (IPA), butyl acetate (BA), and methyl ethyl ketone (MEK).

[0067] [Preparation of black paste] The black paste is prepared by adding a polymer compound that acts as a binder, such as acrylic, epoxy, or urethane, to the black dispersion mentioned above, and then adding and mixing various additives as needed. This black paste is used as a photosensitive black film-forming material for light-shielding films and as an adhesive in various electronic devices.

[0068] [Preparation of black photosensitive composition] A black composition is prepared by dispersing the final product, zirconium nitride powder, as a black pigment in a dispersion medium, and then mixing it with a resin. Examples of the dispersion medium include propylene glycol monomethyl ether acetate (PGM-Ac), methyl ethyl ketone (MEK), and butyl acetate (BA). Examples of the resin include photosensitive acrylic resin and epoxy resin. By mixing this black photosensitive composition to a predetermined viscosity, a UV-curable black adhesive can be obtained. This UV-curable black adhesive is used in various electronic devices. Furthermore, by adding a photoinitiator to this black photosensitive composition and curing it with UV light, a black molded body can be obtained. This black molded body is used in liquid crystal displays, optical sensors, lenses, and the like.

[0069] [Method for forming patterned films using zirconium nitride powder as a black pigment] This section describes a method for forming patterned films, such as black matrices, using the above-mentioned zirconium nitride powder as a black pigment. First, the zirconium nitride powder is dispersed in a solvent to prepare a black dispersion. It is preferable to use an amine-based dispersant. Examples of solvents include propylene glycol monomethyl ether acetate (PGM-Ac), diethyl ketone, and butyl acetate. A photosensitive acrylic resin is added to this dispersion in a mass ratio of black pigment:resin = (10:90) to (80:20) to prepare a black photosensitive composition. Next, this black photosensitive composition is applied to a substrate, and the solvent is evaporated to form a photoresist film. Then, the photoresist film is exposed to a predetermined pattern shape via a photomask, and developed using an alkaline developer to dissolve and remove the unexposed areas of the photoresist film. Subsequently, a post-bake is preferably performed to form a predetermined black patterned film.

[0070] Examples of the above-mentioned substrates include glass, silicon, polyethylene terephthalate, polycarbonate, polyester, aromatic polyamide, polyamide-imide, and polyimide. The substrate may also be subjected to appropriate pretreatment, such as chemical treatment with a silane coupling agent, plasma treatment, ion plating, sputtering, gas-phase reaction, or vacuum deposition, if desired. When applying the black photosensitive composition to the substrate, various coating methods such as rotary coating, casting, or roll coating can be used. The coating thickness, as a film thickness after drying, is typically 0.1 μm to 10 μm, preferably 0.2 μm to 7.0 μm, and more preferably 0.5 μm to 6.0 μm. In this embodiment, electromagnetic waves with a wavelength in the range of 250 nm to 365 nm are preferred as the radiation used to form the patterning film. The integrated light intensity of the electromagnetic waves is preferably 10 J / m². 2 ~10,000 J / m 2 That is the case.

[0071] As the alkaline developer, aqueous solutions of sodium carbonate, sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene, and 1,5-diazabicyclo-[4.3.0]-5-nonene are preferred. Appropriate amounts of water-soluble organic solvents such as methanol and ethanol, or surfactants, may also be added to the alkaline developer. After alkaline development, the film is usually washed with water. Developing methods such as shower development, spray development, dip development, and paddle development can be applied, and the development conditions are preferably 5 to 300 seconds at room temperature. The patterned film thus formed is suitably used in high-definition liquid crystals, black matrices for organic EL displays, light-shielding materials for image sensors, light-shielding materials for optical components, light-shielding filters, IR cut filters, etc. This black patterned film can also be used as an element constituting a black film. Specifically, a black film is obtained by providing a support film and the black patterning film on this support film. [Examples]

[0072] Next, examples of the present invention will be described in detail along with comparative examples. In Examples 1 to 14 and Comparative Examples 1 to 6, the final product, zirconium nitride powder, was produced by the first manufacturing method (calcination method), while in Examples 15, 16 and Comparative Example 7, the final product, zirconium nitride powder, was produced by the second manufacturing method (plasma synthesis method).

[0073] <Example 1> BET specific surface area is 30m² 2 100g of monoclinic zirconium dioxide powder with a specific surface area of ​​200m² is added to 100g of aluminum compound-containing powder. 2 2.6 g of aluminum oxide powder (0.064 moles relative to zirconium oxide) was mixed with 5.0 g of zinc oxide powder containing a zinc compound with an average particle size of 100 μm (0.076 moles relative to zirconium oxide), 79 g of metallic magnesium powder (4.0 moles relative to zirconium oxide), and 46 g of magnesium oxide powder (1.4 moles relative to zirconium oxide). The mole numbers in parentheses represent the ratio to 1 mole of zirconium oxide. This mixture was placed in a reaction vessel and calcined at 1000°C for 180 minutes under a nitrogen gas atmosphere. The calcined product was dispersed in 2.5 liters of water, and 10% hydrochloric acid was gradually added to wash the mixture while maintaining the pH above 1 and the temperature below 90°C. After that, the pH was adjusted to 7-8 with 2.5% ammonia water and filtered. The filtered solid was redispersed in 10 liters of water, and the acid washing and pH adjustment with ammonia water were performed again in the same manner as above, and then filtered. After repeating the acid washing and pH adjustment with ammonia water process twice, the filtrate was dispersed in deionized water at a solid content of 5 g / liter, heated and stirred at 60°C, and the pH was adjusted to 7. The filtrate was then filtered using a suction filter, washed again with an equal amount of deionized water, and dried in a hot air dryer set to 120°C to obtain the final powder product. The manufacturing conditions for Example 1 are shown in Tables 1 and 2 below.

[0074] [Table 1]

[0075] [Table 2]

[0076] <Examples 2-14 and Comparative Examples 1-6> In the production of the final product powders for Examples 2-14 and Comparative Examples 1-6, the BET specific surface area of ​​the zirconium oxide (ZrO2) powder was kept the same as or different from that of Example 1, and the types of aluminum compound-containing powder (aluminum (Al) source) and zinc compound-containing powder (zinc source) were kept the same as or different from those of Example 1. Furthermore, the addition ratios of aluminum compound-containing powder (Al source), zinc compound-containing powder (Zn source), metallic magnesium (metallic Mg) powder, and magnesium oxide (MgO) powder to the zirconium oxide (ZrO2) powder were kept the same as or different from those of Example 1. In addition, the atmosphere during firing was standardized to a nitrogen gas atmosphere, and the temperature and time were kept the same as or different from those of Example 1 to obtain the final product powders for Examples 2-14 and Comparative Examples 1-6. These details are shown in Tables 1 and 2 above.

[0077] <Example 15> In a high-frequency induction thermal plasma nanoparticle synthesis apparatus (JEOL Ltd.: TP40020NPS), 50g of metallic zirconium powder (99% purity, average primary particle size 20μm), 5g of metallic aluminum powder (99.9% purity, average primary particle size 20μm), and 3g of metallic zinc powder (99% purity, average primary particle size 50μm) were supplied to the raw material feeder. These raw materials were introduced into a plasma torch and volatilized by the thermal plasma of N2 gas generated by the torch. The volatilized raw materials were then rapidly cooled in a chamber through which a mixed gas of N2 and Ar flowed, and recovered to synthesize zirconium nitride powder containing aluminum and zinc. This zirconium nitride powder was used as the final product.

[0078] <Example 16> Using the same high-frequency induction thermal plasma nanoparticle synthesis apparatus as in Example 15, 50 g of metallic zirconium powder (99% purity, average primary particle size 20 μm), 10 g of metallic aluminum powder (99.9% purity, average primary particle size 10 μm), and 5 g of metallic zinc powder (99% purity, average primary particle size 50 μm) were supplied to the raw material feeder. The final product, zirconium nitride powder, was synthesized in the same manner as in Example 15.

[0079] <Comparative Example 7> Using the same high-frequency induction thermal plasma nanoparticle synthesis apparatus as in Example 15, 50 g of metallic zirconium powder (99% purity, average primary particle size 20 μm) and 10 g of metallic aluminum powder (99.9% purity, average primary particle size 10 μm) were supplied to the raw material feeder. Metallic zinc powder was not supplied. The final product, zirconium nitride powder, was synthesized in the same manner as in Example 15. The contents of Examples 15, 16, and Comparative Example 7 are shown in Table 1 above.

[0080] <Comparative Test> Powder samples of the final products from Examples 1-16 and Comparative Examples 1-7 were used as samples. The presence or absence of aluminum-based and zinc-based compositions was confirmed from these samples, and the respective content ratios of aluminum and zinc were measured. This confirmation and measurement were performed using the method described above. Next, for these samples, (1) the BET specific surface area was measured, (2) the light transmittance X at 365 nm and the light transmittance Y at 550 nm were read from the spectral curves and the X / Y ratio was calculated, and (3) the moisture resistance was measured. The results are shown in Table 3 below.

[0081] (1) BET specific surface area: For all samples, the specific surface area was measured using a single-point BET method with nitrogen adsorption, using a specific surface area measuring device (SA-1100, manufactured by Shibata Chemical Co., Ltd.).

[0082] (2) Spectral curves in dispersions with a powder concentration of 50 ppm: For each sample from Examples 1 to 16 and Comparative Examples 1 to 7, these samples were placed separately in a circulating horizontal bead mill (media: zirconia), an amine-based dispersant was added, and dispersion treatment was performed in a propylene glycol monomethyl ether acetate (PGM-Ac) solvent. The resulting 23 dispersions were diluted 100,000 times to adjust the powder concentration to 50 ppm. The light transmittance of each sample in these diluted dispersions was measured using a Hitachi High-Tech Fielding Co., Ltd. (UH-4150) in the wavelength range of 300 nm to 1200 nm to obtain spectral curves. The light transmittance X at a wavelength of 365 nm near the i-line (365 nm) and the light transmittance Y at 550 nm were read from the spectral curves. Figure 1 shows the two spectral curves for Example 1 and Comparative Example 1.

[0083] The ratio X / Y was calculated from the light transmittances X and Y read from the spectral curves of each sample in Examples 1-16 and Comparative Examples 1-7.

[0084] (3) Moisture resistance: For each sample from Examples 1 to 16 and Comparative Examples 1 to 7, an amine-based dispersant was added to the sample, and dispersion was prepared by dispersing in a propylene glycol monomethyl ether acetate (PGM-Ac) solvent. An acrylic resin was added to this dispersion in a mass ratio of black pigment:resin = 5:5 and mixed to prepare a black composition. This black composition was spin-coated onto a glass substrate and held at a temperature of 250°C for 30 minutes to obtain a dry coating film with a thickness of 1 μm. The moisture resistance of the coating films was evaluated by measuring the volume resistivity of each.

[0085] The volume resistivity of the coating film was measured immediately after its preparation (initial state) and after being held in an atmosphere of 80°C and 80% humidity for 1000 hours (after heating and humidification). The initial and post-heating and humidification volume resistivity (Ω·cm) of the coating film was measured using a resistivity meter (HIRESTA (trademark), model number: MCP-HT450) manufactured by Mitsubishi Chemical Analytec Co., Ltd. The volume resistivity after heating and humidification was 1 × 10⁻⁶. 6 A value of Ω·cm or higher is judged to indicate "good" moisture resistance, and 1 × 10 6A value of less than Ω·cm was judged to indicate 'poor' moisture resistance.

[0086] [Table 3]

[0087] <Rating> As is clear from Table 3, in Comparative Examples 1 and 7, analysis of the final product powder using an inductively coupled plasma emission spectrometer revealed that no zinc was present. Furthermore, STEM observation confirmed that no zinc compounds were present on the surface of these zirconium nitride powders. Examination of the interior of these powders using an electron diffraction spectrometer also revealed no zinc compounds.

[0088] In Comparative Example 1, the effects of crystallinity improvement and particle uniformity reduction due to the thermite reduction reaction containing the zinc compound were not observed. The transmittance Y at 550 nm was high at 8.1%, and the X / Y value was 3.5, which is less than 6.0. In Comparative Example 7, since zinc was not contained, the transmittance X at 365 nm was 29.0%, and the transmittance Y at 550 nm was 5.0%, which was good, but the X / Y value was 5.8, which is less than 6.0. As a result, the light-shielding properties in the visible light region were low in Comparative Examples 1 and 7.

[0089] In Comparative Example 2, the amount of metallic zinc powder, which is a zinc compound-containing powder, added was too small at 0.008 times the molar amount relative to zirconium oxide, resulting in a zinc content of only 0.02% by mass in the final powder product. Consequently, the effects of crystallinity improvement and particle uniformity reduction due to the thermite reduction reaction containing the zinc compound did not manifest in this powder. The transmittance Y at 550 nm was 10.0%, exceeding 8%, and the X / Y value was 4.0, less than 6.0. Therefore, the light-shielding properties in the visible light region were poor.

[0090] In Comparative Example 3, the amount of metallic zinc powder, which is a zinc compound-containing powder, added was too high at 0.303 times the molar ratio of zirconium oxide. Analysis of the zinc content in the final product powder using an inductively coupled plasma emission spectrometer revealed it to be 1.2% by mass, which was also too high. In this powder, the excess metallic zinc remained as an impurity, resulting in a high transmittance Y at 550 nm of 8.2%, and an X / Y value of 4.4, which was less than 6.0.

[0091] In Comparative Example 4, the amount of metallic aluminum powder, which is an aluminum compound-containing powder, added was too small at 0.012 times the molar amount relative to zirconium oxide, resulting in an aluminum content of only 0.2% by mass in the final product powder. Consequently, this powder did not exhibit the effects of improved crystallinity and finer particle uniformity, and the transmittance X at 365 nm was 23.6%, below 25%, resulting in an X / Y value of 4.9, less than 6.0. Therefore, the light-shielding properties in the visible light region were poor. Furthermore, due to the low content of the aluminum oxide-based composition, the moisture resistance was poor.

[0092] In Comparative Example 5, the amount of metallic aluminum powder, which is an aluminum compound-containing powder, added was too high at 0.483 times the molar ratio of zirconium oxide. Analysis of the zinc content in the final product powder using an inductively coupled plasma emission spectrometer revealed it to be 11.0% by mass, which was also too high. In this powder, the excess metallic aluminum remained as an impurity, resulting in a high transmittance Y at 550 nm of 10.0%, and an X / Y value of 4.7, which was less than 6.0.

[0093] In Comparative Example 6, the BET specific surface area of ​​the final zirconium nitride powder was 19 m². 2 Because the value was too small ( / g), when the final product powder was dispersed in a dispersion with a powder concentration of 50 ppm, the powder settled, resulting in a decrease in optical performance.

[0094] In contrast, the final products of Examples 1 to 16 were zirconium nitride powder. Analysis of these final product powders using an inductively coupled plasma atomic emission spectrometer revealed that the aluminum content was in the range of 0.3% to 10.0% by mass, and the zinc content was in the range of 0.1% to 1.1% by mass or less. Further analysis using an electron diffraction spectrometer revealed that aluminum and zinc compounds were either attached to the surface of all final product powders or present as amorphous zinc within the powder. Furthermore, the final products of Examples 1 to 16 were found to satisfy the requirements of the first aspect of the present invention, possessing high visible light shielding performance, being advantageous for patterning due to ultraviolet light transmission, and having good moisture resistance.

[0095] In particular, the BET specific surface area is 20m² 2 / g~90m 2 The final products of Examples 1-4 and 6-16, which are in the range of / g, have a light transmittance X at 365nm of 25% or more, a light transmittance Y at 550nm of 8% or less, and a light transmittance X at 365nm relative to the light transmittance Y at 550nm (X / Y) of 6.0 or more, satisfy the requirements of the second aspect of the present invention and are even more advantageous for patterning because they transmit ultraviolet light due to their higher visible light shielding performance. [Industrial applicability]

[0096] The zirconium nitride powder of the present invention can be used in high-definition liquid crystals, black matrices for organic EL displays, black matrices for microdisplays, light-shielding materials for image sensors, light-shielding materials for optical components, light-shielding filters, IR cut filters, IR sensors, solar cells, liquid crystal frame materials, and the like.

Claims

1. A zirconium nitride powder containing an aluminum-based composition and a zinc-based composition, wherein, when the total amount of the powder is 100% by mass, the powder contains aluminum in a proportion of 0.3% to 10.0% by mass and zinc in a proportion of 0.1% to 1.1% by mass, and has a specific surface area of ​​20 m² as measured by the BET method. 2 / g to 90m 2 Zirconium nitride powder characterized by having a density of / g.

2. The zirconium nitride powder according to claim 1, wherein in the transmission spectrum of a dispersion with a powder concentration of 50 ppm, the light transmittance X at 365 nm is 25% or more, the light transmittance Y at 550 nm is 8% or less, and the light transmittance X at 365 nm (X / Y) relative to the light transmittance Y at 550 nm is 6.0 or more.

3. A method for producing zirconium nitride powder according to claim 1 or 2, comprising mixing zirconium dioxide powder, an Al source in an amount of 0.02 to 0.46 times the molar amount of the zirconium dioxide powder, a Zn source in an amount of 0.03 to 0.25 times the molar amount of the zirconium dioxide powder, a metallic magnesium powder in an amount of 2.0 to 6.0 times the molar amount of the zirconium dioxide powder, and magnesium oxide powder in an amount of 0.3 to 5.0 times the molar amount of the zirconium dioxide powder to obtain a mixture, and then reducing the zirconium dioxide powder by calcining the mixture in a nitrogen gas atmosphere at a temperature of 700°C to 1100°C for 60 to 180 minutes.

4. The method for producing zirconium nitride powder according to claim 3, wherein the Al source is one or more powders of metallic aluminum, aluminum oxide, aluminum hydroxide, aluminum chloride, or aluminate compounds, and the Zn source is one or more powders of metallic zinc, zinc oxide, zinc hydroxide, zinc chloride, or zinc carbonate.

5. A method for producing zirconium nitride powder according to claim 1 or 2, comprising mixing zirconium dioxide powder, an Al source in an amount of 0.02 to 0.46 times the molar amount of the zirconium dioxide powder, a Zn source in an amount of 0.03 to 0.25 times the molar amount of the zirconium dioxide powder, a metallic magnesium powder in an amount of 2.0 to 6.0 times the molar amount of the zirconium dioxide powder, and magnesium oxide powder in an amount of 0.3 to 5.0 times the molar amount of the zirconium dioxide powder to obtain a mixture, and then reducing the zirconium dioxide powder by calcining the mixture in a nitrogen gas atmosphere at a temperature of 700°C to 1100°C for 60 to 180 minutes.

6. A black dispersion in which zirconium nitride powder according to claim 1 or 2 is dispersed in a solvent or monomer compound.

7. A black paste containing an organic polymer compound in the black dispersion according to claim 6.

8. A black photosensitive composition comprising zirconium nitride powder according to claim 1 or 2 as a black pigment.

9. A UV-curable black adhesive obtained using the black photosensitive composition described in claim 8.

10. A black patterning film obtained using the black photosensitive composition described in claim 8.

11. A black molded article obtained using the black photosensitive composition described in claim 8.

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