Zirconium nitride powder and preparation method thereof

Abstract

The object of the present invention is to obtain high insulation and high blackness while having high insulation. The volume resistivity of the zirconium nitride powder of the present invention in the state of a green compact compacted at a pressure of 5 MPa is 10 7 Ω·cm or more, and the particle size distribution D when ultrasonically dispersed for 5 minutes in a state diluted with water or an alcohol with a carbon number in the range of 2 to 5 90 The zirconium nitride powder may be dispersed in an acrylic monomer or an epoxy monomer to prepare a monomer dispersion. In addition, the zirconium nitride powder may be dispersed in a dispersion medium as a black pigment and mixed with a resin to prepare a black composition.

Description

Technical Field

[0001] The present invention relates to zirconium nitride powder which is suitable for use as a black pigment having high ultraviolet transmittance and high blackness and high insulation properties, and a method for preparing the same. Background Art

[0002] In the past, a zirconium nitride powder was disclosed, wherein the specific surface area of ​​the zirconium nitride powder measured by the BET method was 20 m 2 / g~90m 2 / g, has a peak of zirconium nitride in an X-ray diffraction pattern, and does not have a peak of zirconium dioxide and a peak of sub-zirconium oxide (for example, see Patent Document 1 (Claim 1, paragraph

[0016] )). In a transmission spectrum of a dispersion liquid having a powder concentration of 50 ppm, the zirconium nitride powder has a light transmittance X at 370 nm of at least 18%, a light transmittance Y at 550 nm of 12% or less, and a ratio (X / Y) of the light transmittance Y at 550 nm to the light transmittance X at 370 nm of 2.5 or more.

[0003] The zirconium nitride powder thus formed has a specific surface area of ​​20 m 2 / g or more, so it has the effect of suppressing sedimentation when made into a resist, and because it is 90m 2 / g or less, so it has a sufficient light-shielding effect. In addition, since it has a peak of zirconium nitride in the X-ray diffraction diagram, but does not have a peak of zirconium dioxide, a peak of low-valent zirconium oxide, and a peak of low-valent zirconium oxynitride, it has the characteristics that the light transmittance X at 370nm is at least 18% and the light transmittance Y at 550nm is less than 12% in the transmission spectrum of the dispersion liquid with a powder concentration of 50ppm, and it also has the characteristic that X / Y is greater than 2.5. Since X / Y is greater than 2.5, it has the characteristic of transmitting more ultraviolet rays. Therefore, when a black patterned film is formed as a black pigment, a high-resolution patterned film can be formed, and the formed patterned film has high light-shielding performance.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent document 1: Japanese Patent Application Publication No. 2017-222559. Summary of the invention

[0007] Problems to be solved by the invention

[0008] As for the zirconium nitride powder shown in the above-mentioned patent document 1, if the zirconium nitride coarse powder is dispersed in a dispersion medium and the dispersibility is improved by using a bead mill (medium: zirconium oxide), etc., high insulation can be obtained, but if the zirconium nitride powder is directly kneaded into a high-viscosity resin paste, the zirconium nitride coarse powder remains and the dispersibility is insufficient. Therefore, when the zirconium nitride powder is used as a black pigment, the coloring power of the black paint is reduced, and there is an unfavorable situation that the resistance value is reduced due to the residue of the zirconium nitride coarse powder. In addition, if the above-mentioned zirconium nitride coarse powder is forcibly pulverized by a dry pulverizer, etc., the powder diameter becomes smaller and an oxidation reaction is caused on the powder surface. Therefore, although the insulation is improved, there is a problem that the blackness of the black paint is reduced.

[0009] The first object of the present invention is to provide a zirconium nitride powder having high insulation and high blackness, and a method for producing the same. The second object of the present invention is to provide a method for producing a zirconium nitride powder capable of maintaining high blackness by low-temperature wet medium pulverization or by pulverization using a jet mill with low heat generation. The third object of the present invention is to provide a method for producing a zirconium nitride powder capable of improving the insulation of a black film by calcining in an inert gas atmosphere.

[0010] Means of solving problems

[0011] A first aspect of the present invention is a zirconium nitride powder having a bulk resistivity of 10 7 Ω·cm or more, and the particle size distribution D when ultrasonically dispersed for 5 minutes in a state diluted with water or an alcohol with a carbon number in the range of 2 to 5 90 Less than 10 μm.

[0012] A second aspect of the present invention is a method for preparing zirconium nitride powder, the method comprising: a step of generating a coarse zirconium nitride powder by a thermal agent method or a plasma synthesis method; a step of preparing a zirconium nitride precursor powder by subjecting the coarse zirconium nitride powder to low-temperature wet medium pulverization at a dispersion medium temperature of 10° C. or less or jet mill pulverization at a gas pressure of 0.3 MPa or more, wherein the particle size distribution D of the zirconium nitride precursor powder when ultrasonically dispersed for 5 minutes in a state diluted with water or an alcohol having a carbon number in the range of 3 to 5 is 90 10μm or less; and by calcining the crushed zirconium nitride precursor powder in an inert gas atmosphere to prepare a zirconium nitride powder, wherein the zirconium nitride powder has a bulk resistivity of 10 in a state where the compact is compacted with a pressure of 5MPa. 7 Ω·cm or more.

[0013] A third aspect of the present invention is a monomer dispersion obtained by dispersing the zirconium nitride powder according to the first aspect in an acrylic monomer or an epoxy monomer.

[0014] A fourth aspect of the present invention is a black composition obtained by dispersing the zirconium nitride powder according to the first aspect as a black pigment in a dispersion medium and mixing the mixture with a resin.

[0015] A fifth aspect of the present invention is a method for producing a black film, comprising: applying the monomer dispersion according to the third aspect on a substrate to form a coating film; and thermally curing or ultraviolet curing the coating film to produce a black film.

[0016] A sixth aspect of the present invention is a method for producing a black film, comprising: applying the black composition according to the fourth aspect on a substrate to form a coating film; and thermally curing or ultraviolet curing the coating film to produce a black film.

[0017] Effects of the Invention

[0018] The zirconium nitride powder of the first aspect of the present invention has a bulk resistivity of 10 7 Ω·cm or more, so the insulation of the black thick film with a thickness of about 10μm~100μm can be improved. In addition, the particle size distribution D of the zirconium nitride powder when it is diluted with water or alcohol with a carbon number in the range of 2 to 5 and dispersed by ultrasonic for 5 minutes is 90 The particle size is 10 μm or less, so a good dispersion or dispersion liquid without coarse zirconium nitride powder can be obtained. Thus, a black film made from the dispersion or dispersion liquid using the zirconium nitride powder can have high insulation and high blackness while having high insulation.

[0019] In the method for preparing zirconium nitride powder according to the second aspect of the present invention, if the zirconium nitride coarse powder is subjected to low-temperature wet medium pulverization at a dispersion medium temperature below 10°C, the heat generation is small, so the surface oxidation of the zirconium nitride does not proceed, and a high degree of blackness can be maintained. In addition, if the zirconium nitride coarse powder is jet milled at a gas pressure of 0.3 MPa or more, the zirconium nitride coarse powder does not remain, and the insulation of the black film can be improved. In addition, by calcining the above-mentioned pulverized zirconium nitride precursor powder in an inert gas atmosphere, the insulation of the black film can be improved.

[0020] Since the monomer dispersion of the third aspect of the present invention is obtained by dispersing the zirconium nitride powder of the first aspect of the present invention in an acrylic monomer or an epoxy monomer, even if the viscosity of these monomers is high, the dispersibility of the zirconium nitride powder in the above monomers can be kept good. Therefore, the black film obtained using the monomer dispersion can obtain high insulation and high blackness while having high insulation.

[0021] Since the black composition of the fourth aspect of the present invention is obtained by dispersing the zirconium nitride powder of the first aspect of the present invention as a black pigment in a dispersion medium and mixing with a resin, the zirconium nitride powder is uniformly dispersed in the dispersion medium. Therefore, the black film obtained using the black composition can obtain high insulation and high blackness while having high insulation.

[0022] In the method for preparing a black film according to the fifth aspect of the present invention, after the above-mentioned monomer dispersion is applied on a substrate to form a coating film, the coating film is thermally cured or ultraviolet-cured to prepare a black film. Therefore, the black film can obtain high insulation and high blackness while having high insulation properties.

[0023] In the method for preparing a black film according to the sixth aspect of the present invention, after the above-mentioned black composition is applied on a substrate to form a coating film, the coating film is thermally cured or ultraviolet-cured to prepare a black film. Therefore, the black film can obtain high insulation and high blackness while having high insulation properties. DETAILED DESCRIPTION

[0024] Next, the embodiment of the present invention is described. The volume resistivity of the zirconium nitride powder of the present embodiment in the state of a green compact compacted at a pressure of 5 MPa is 10 7 Ω·cm or more, preferably 10 8 Ω·cm or more, and the particle size distribution D when ultrasonically dispersed for 5 minutes in a state diluted with water or an alcohol with a carbon number in the range of 2 to 5 90 Here, the volume resistivity is limited to 10 7 The reason for the above Ω·cm is that if it is less than 10 7 Ω·cm, the insulation of a black thick film with a thickness of about 1μm to 100μm made of zirconium nitride powder will be reduced. 90 The reason for limiting the size to 10 μm or less is that if the size exceeds 10 μm, coarse zirconium nitride powder will remain, and a good dispersion and a black film cannot be obtained.

[0025] The above-mentioned volume resistivity is measured by a four-terminal four-probe method using, for example, a low resistivity meter Loresta-GP (model: UV-3101PC) manufactured by Mitsubishi Chemical Corporation. The four-terminal four-probe method is a method of placing four needle-shaped electrodes on the surface of a sample (green compact) in a straight line at a predetermined interval, passing a certain current between the two outer needle-shaped electrodes, and measuring the potential difference generated between the two inner needle-shaped electrodes to obtain the volume resistivity.

[0026] In addition, the zirconium nitride powder is in a state of secondary particles formed by agglomeration of primary particles, and is a volume-based particle size distribution measured by a laser diffraction scattering method. Here, the volume-based particle size distribution based on the laser diffraction scattering method is measured as follows. First, 0.1 g of zirconium nitride powder (secondary particles) is put into 20 g of ion exchange water, and irradiated with 25 kHz ultrasonic waves for 5 minutes to disperse the zirconium nitride powder in the ion exchange water. Then, the obtained zirconium nitride powder dispersion is added dropwise to the observation cell of a laser diffraction scattering particle size distribution measuring device (trade name: LA-300 manufactured by Horiba, Ltd.), and the particle size distribution is measured according to the program of the device. The particle size distribution measured by the laser diffraction scattering method is the particle size distribution of secondary particles formed by agglomeration of primary particles of zirconium nitride powder. It should be noted that, instead of ion exchange water, alcohols having a carbon number in the range of 2 to 5 can also be used. As alcohols having 2 carbon atoms, ethanol can be cited; as alcohols having 3 carbon atoms, 1-propanol, 2-propanol, etc. can be cited; as alcohols having 4 carbon atoms, 1-butanol, 2-butanol, etc. can be cited; as alcohols having 5 carbon atoms, 1-pentanol, 2-pentanol, etc. can be cited. It should be noted that if the number of carbon atoms is 1 or less, there is a disadvantage that the volatility is high and the measured value is unstable; if the number of carbon atoms is 6 or more, there is a disadvantage that the affinity is insufficient and the measured value is unstable.

[0027] The method for preparing the zirconium nitride powder thus constituted is described below. First, a coarse zirconium nitride powder is produced by a thermit method or a plasma synthesis method. In this specification, the thermit method refers to a method of reacting zirconium oxide powder with N in the presence of metal magnesium. 2 In this embodiment, zirconium dioxide (ZrO 2 ) powder or zirconium dioxide coated with silicon dioxide (ZrO 2 ) powder. In addition, magnesium nitride (Mg 3 N 2 These powders were used as starting materials and calcined under a specific atmosphere at a specific temperature and time to generate a material with a specific surface area of ​​20 m2 as measured by the BET method. 2 / g~90m 2 / g of zirconium nitride coarse powder.

[0028] [Zirconium dioxide powder]

[0029] As zirconium dioxide powder, for example, monoclinic zirconium dioxide, cubic zirconium dioxide, yttrium-stabilized zirconium dioxide and other zirconium dioxide powders can be used. From the viewpoint of increasing the yield of zirconium nitride powder, monoclinic zirconium dioxide powder is preferred. In addition, in order to obtain a specific surface area of ​​20 m2 measured by the BET method, 2 / g~90m 2 / g of zirconium nitride coarse powder, the average primary particle size of the zirconium dioxide powder or the zirconium dioxide powder coated with silicon dioxide and the average primary particle size of the magnesium oxide powder are preferably 500nm or less in terms of the average primary particle size obtained by spherical conversion from the measured value of the specific surface area, and from the perspective of easy handling of the powder, the average primary particle size is preferably 500nm or less and 10nm or more.

[0030] [Silicon dioxide coated zirconium dioxide powder]

[0031] The zirconium dioxide powder coated with silicon dioxide is prepared by mixing zirconium dioxide powder and silicate sol-gel solution to prepare slurry, and the slurry is dried and crushed to obtain. Regarding the mixing ratio of zirconium dioxide and silicate sol-gel solution, in terms of mass ratio, the amount of silicon dioxide in zirconium dioxide: silicate sol-gel solution is preferably (90.0~99.5): (10.0~0.5). If the amount of silicon dioxide is lower than the lower limit, the silicon dioxide coverage on the surface of zirconium dioxide is too low; if the amount of silicon dioxide exceeds the upper limit, when the obtained zirconium nitride powder is used to form a patterned film, there is a disadvantage of insufficient light shielding.

[0032] In order to uniformly mix zirconium dioxide into the sol-gel solution, it is preferred to add zirconium dioxide powder to a dispersion such as water or alcohol and mix, and then add the mixed solution to a silicate sol-gel solution. The silicate sol-gel solution is preferably a liquid obtained by dissolving a silicate such as methyl silicate or ethyl silicate in a solvent such as water or alcohol. The mixing ratio of zirconium dioxide and the sol-gel solution can be determined in such a way that the solid content concentration of the obtained slurry is 10% to 50% by mass in terms of solid content. The obtained slurry is dried in the air or in a vacuum atmosphere at a temperature of 60°C to 350°C for 1 minute to 360 minutes to obtain zirconium dioxide powder coated with silicon dioxide.

[0033] By using zirconium dioxide powder coated with silicon dioxide as the starting material, grain growth can be suppressed during calcination, and a specific surface area of ​​20 m2 as measured by the BET method can be obtained. 2 / g~90m 2 / g of finer zirconium nitride powder. In this case, the zirconium nitride powder contains silicon oxide and / or silicon nitride in a ratio of 10.0 mass % or less, preferably 9.0 mass % or less. If it exceeds 10.0 mass %, when the obtained zirconium nitride powder is used to form a patterned film, there is a disadvantage of insufficient light shielding.

[0034] [Magnesium metal powder]

[0035] If the particle size of the metal magnesium powder is too small, the reaction proceeds rapidly, thereby increasing the risk of operation. Therefore, the metal magnesium powder is preferably a granular powder with a particle size of 100 μm to 1000 μm in terms of mesh pass, and particularly preferably a granular powder of 200 μm to 500 μm. However, even if the metal magnesium is not entirely within the above particle size range, it may be within the above range as long as 80% by mass or more, particularly 90% by mass or more, is within the above range.

[0036] The amount of magnesium powder added relative to zirconium dioxide powder affects the reducing power of zirconium dioxide together with the amount of ammonia and hydrogen in the atmosphere gas described later. If the amount of magnesium powder is too little, the reduction is insufficient, making it difficult to obtain the target zirconium nitride powder; if it is too much, the reaction temperature rises sharply due to the excess magnesium powder, which may cause the grain growth of the powder and become uneconomical. Magnesium powder is added to zirconium dioxide powder and mixed in a ratio of 2.0 times to 6.0 times the mole of zirconium dioxide according to the size of its particle size. If it is less than 2.0 times the mole, the reduction reaction of zirconium dioxide is insufficient, and if it exceeds 6.0 times the mole, the reaction temperature rises sharply due to the excess magnesium powder, which may cause the grain growth of the powder and become uneconomical.

[0037] [Magnesium nitride powder]

[0038] The magnesium nitride powder covers the surface of zirconium nitride during calcination, thereby easing the reducing power of metal magnesium to prevent sintering and grain growth of the zirconium nitride powder. The magnesium nitride powder is added to zirconium dioxide and mixed in a manner such that magnesium nitride is 0.3 times to 3.0 times the mole of zirconium dioxide according to the size of its particle size. If it is less than 0.3 times the mole, the sintering of the zirconium nitride powder cannot be prevented; if it exceeds 3.0 times the mole, there is an unfavorable situation that the amount of acid solution required for acid cleaning after calcination increases. It is preferably 0.4 times to 2.0 times the mole. Regarding magnesium nitride powder, the average primary particle size obtained by spherical conversion from the measured value of the specific surface area is preferably 1000nm or less; from the perspective of the easy handling of the powder, the average primary particle size is preferably 10nm or more and 500nm or less. It should be noted that not only magnesium nitride, but also magnesium oxide is effective in preventing the sintering of zirconium nitride, so a part of magnesium oxide can also be mixed in magnesium nitride for use.

[0039] [Using the reduction reaction of magnesium metal powder]

[0040] The temperature of the reduction reaction of magnesium metal used to generate the coarse zirconium nitride powder is 650°C to 900°C, preferably 700°C to 800°C. 650°C is the melting temperature of magnesium metal. If the temperature is lower than this temperature, the reduction reaction of zirconium dioxide will not fully occur. In addition, even if the temperature is higher than 900°C, the effect will not increase, and the powder will be sintered while causing waste of heat energy, which is not preferred. In addition, the reduction reaction time is preferably 30 minutes to 90 minutes, and more preferably 30 minutes to 60 minutes.

[0041] The reaction vessel for the reduction reaction is preferably a container with a lid so that the raw materials and products do not scatter during the reaction. The reason is that if the metal magnesium begins to melt, the reduction reaction will proceed rapidly, the temperature will rise, and the gas inside the container will expand, thereby causing the substances inside the container to scatter to the outside.

[0042] [Atmosphere gas when utilizing reduction reaction of metal magnesium powder]

[0043] The atmosphere gas is a nitrogen gas single substance, or a mixed gas of nitrogen and hydrogen, or a mixed gas of nitrogen and ammonia. The above reduction reaction is carried out in the gas flow of the above mixed gas. The nitrogen in the mixed gas has the effect of preventing the metal magnesium or the reduction product from contacting with oxygen, thereby preventing them from being oxidized, and reacting nitrogen with zirconium to generate zirconium nitride. The hydrogen or ammonia in the mixed gas has the effect of reducing zirconium dioxide together with the metal magnesium. It is preferred that 0% to 40% by volume of hydrogen is contained in the above mixed gas, and it is further preferred that 10% to 30% by volume of hydrogen is contained. In addition, it is preferred that 0% to 50% by volume of ammonia is contained in the above mixed gas, and it is further preferred that 0% to 40% by volume of ammonia is contained. By using the atmosphere gas with reducing power, a zirconium nitride powder that does not contain low-priced zirconium oxide and low-priced zirconium oxynitride can be prepared in the end. On the other hand, if the proportion of hydrogen or the proportion of nitrogen is higher than this range, although reduction is performed, the nitrogen source becomes less, so low-priced zirconium oxide or low-priced zirconium oxynitride is generated, which is not preferred. In addition, it is considered that the ratio of ammonia gas is higher than that of hydrogen gas because ammonia has a higher gas nitriding ability than hydrogen.

[0044] On the other hand, the method of producing zirconium nitride coarse powder by plasma synthesis is to introduce metal zirconium powder into a plasma nanoparticle preparation device, 2 A method for obtaining zirconium nitride nanoparticles in a gas atmosphere. With respect to zirconium nitride synthesized by this method, 20 m 2 / g~90m 2 / g of zirconium nitride having a specific surface area measured by the BET method, but there are the disadvantages of high combustibility of metal zirconium as a raw material and increased cost. It should be noted that since the nanoparticles generated by the plasma synthesis method are coarsened due to rapid surface oxidation, adhesion, agglomeration, etc. during the cooling process and product removal process, thus becoming a coarse powder, the zirconium nitride generated by the plasma synthesis method is also used as a coarse zirconium nitride powder.

[0045] Next, the zirconium nitride coarse powder is subjected to low-temperature wet medium pulverization at a dispersion medium temperature of 10° C. or less or to jet mill pulverization at a gas pressure of 0.3 MPa or more to prepare a zirconium nitride precursor powder, wherein the zirconium nitride precursor powder is ultrasonically dispersed for 5 minutes in a state diluted with water or an alcohol having a carbon number in the range of 3 to 5 and has a particle size distribution D 90 The specific surface area of ​​the zirconium nitride precursor powder measured by the BET method was 22 m 2 / g~120m 2 / g.

[0046] The above-mentioned low-temperature wet media pulverization method refers to a method of dispersing zirconium nitride coarse powder in a dispersion medium such as ion exchange water or alcohol having a carbon number of 2 to 5, and using a bead mill pulverization method using a medium such as zirconium oxide, aluminum oxide, glass, polyurethane resin, etc. with an average particle size of 50μm to 500μm while maintaining the dispersion medium temperature below 10°C. Here, the reason for maintaining the dispersion medium temperature below 10°C is that if it exceeds 10°C, the zirconium nitride precursor powder will be pulverized, and the OD value of the black film described later will decrease. It should be noted that in order to maintain the dispersion medium temperature below 10°C, liquid nitrogen can be used as a dispersion medium, or dry ice beads can be used as a medium. In addition, if the zirconium nitride coarse powder is pulverized by the above-mentioned low-temperature wet media pulverization method, the heat generation is small, so the surface oxidation of zirconium nitride will not be carried out, and a high blackness can be maintained.

[0047] In addition, the jet mill pulverization with an air pressure of 0.3 MPa or more refers to a device that collides the high-pressure air, nitrogen or other inert gas or steam ejected from the nozzle with a super-high-speed jet with the powder, and pulverizes the powder into fine powders of several μm level by the impact of each other, and the ejected air or steam reaches about the speed of sound. As the characteristics of the jet mill, it can be listed that: the temperature is reduced due to the adiabatic expansion of the ejected gas, so it can be pulverized at low temperature; thus, even the reducing material such as zirconium nitride in the present invention can be inhibited from oxidation. Here, the reason for limiting the above-mentioned air pressure to 0.3 MPa or more is that if it is lower than 0.3 MPa, the coarse zirconium nitride powder will remain. It should be noted that if the coarse zirconium nitride powder is pulverized by the above-mentioned jet mill pulverization method, the coarse zirconium nitride powder will not remain, and the insulation of the black film can be improved.

[0048] Furthermore, by calcining the pulverized zirconium nitride precursor powder in an inert gas atmosphere, a compact having a volume resistivity of 10 7 Zirconium nitride powder with a relative humidity of Ω·cm or more. Examples of inert gases include N 2 Gas, helium, argon, etc. The above-mentioned calcination temperature is preferably in the range of 250°C to 550°C, and the calcination time is preferably in the range of 1 hour to 5 hours. Here, the reason for limiting the preferred calcination temperature to the range of 250°C to 550°C is that if it is lower than 250°C, the resistance value will not rise sufficiently, and if it exceeds 550°C, the powders will fuse with each other, and the coarse powder will increase. In addition, the reason for limiting the preferred calcination time to the range of 1 hour to 5 hours is that if it is lower than 1 hour, the resistance value will not rise sufficiently, and even if it exceeds 5 hours, the effect will not change, which is not economical. It should be noted that the insulation of the black film can be improved by calcining the zirconium nitride precursor powder in an inert gas atmosphere. The detailed mechanism of improving the insulation of the black film by calcining in an inert gas atmosphere is unclear, but it is speculated that the coarse powder of zirconium nitride disappears, thereby improving the uniformity of the powder, reducing the contact points, or forming an extremely thin insulating layer on the surface of the black film.

[0049] The above-mentioned zirconium nitride powder is dispersed in an acrylic monomer or an epoxy monomer to prepare a monomer dispersion. The monomer dispersion can be used for dispersing resin compositions containing inorganic powders, resin molded bodies and other purposes. In addition, the above-mentioned monomer dispersion may also contain metal oxide powders and may also contain a plasticizer. As the plasticizer, there is no particular limitation, for example, phosphate ester plasticizers such as tributyl phosphate and 2-ethylhexyl phosphate, phthalate plasticizers such as dimethyl phthalate and dibutyl phthalate, aliphatic monobasic acid ester plasticizers such as butyl oleate and glycerol monooleate, aliphatic dibasic acid ester plasticizers such as dibutyl adipate and di-2-ethylhexyl sebacate, diol ester plasticizers such as diethylene glycol dibenzoate and triethylene glycol di-2-ethylbutyrate, oxygen-containing acid ester plasticizers such as acetyl ricinoleic acid methyl ester and acetyl tributyl citrate, and other plasticizers known in the past. In addition, other monomers may also be added to the monomer dispersion. As other monomers, there are no particular limitations, and examples thereof include (meth)acrylic acid, (meth)acrylic acid esters and other (meth)acrylic acid monomers, styrene monomers such as styrene, vinyl toluene, divinyl benzene, acetyl monomers such as vinyl chloride, vinyl acetate, urethane monomers such as urethane acrylate, and the above-mentioned various polyols and other conventionally known monomers. It should be noted that, considering the dispersibility of the zirconium nitride powder, the viscosity of the monomer dispersion is preferably set within the range of 10Pa·s~1000mPa·s (10mPa·s~1000mPa·s). Dispersion into the monomer can also be performed by grinding using a pulverizing medium in the same manner as dispersion into the solvent. In addition, although it is not an essential component, a polymer dispersant can also be used to further improve the dispersibility. The polymer dispersant is effective when the molecular weight is several thousand to tens of thousands. In addition, as the functional group adsorbed on the pigment, secondary amines, tertiary amines, carboxylic acids, phosphoric acid, phosphate esters, etc. can be listed, and tertiary amines and carboxylic acids are particularly effective. Instead of the polymer dispersant, adding a small amount of silane coupling agent is also effective in improving dispersibility. On the other hand, after implementing planetary stirring, the dispersion can be obtained by passing through three rollers several times. On the other hand, a black composition is prepared by dispersing zirconium nitride powder as a black pigment in a dispersion medium and mixing a resin. As the above-mentioned dispersion medium, propylene glycol monomethyl ether acetate (PGMEA), methyl ethyl ketone (MEK), butyl acetate (BA) and the like can be listed. In addition, as the above-mentioned resin, acrylic resins, epoxy resins and the like can be listed. For solvent-based dispersion, it is effective to add a polymer dispersant in the same way as monomer dispersion, and as with monomer dispersion, a molecular weight of several thousand to tens of thousands is effective, and as functional groups, tertiary amines and carboxylic acids are effective.

[0050] Next, the method for making a black film using the above-mentioned monomer dispersion is described. First, after adding a photopolymerization initiator to the monomer dispersion, the monomer dispersion is applied to a substrate to form a coating. Then, the coating is thermally cured or ultraviolet-cured to make a black film. As the above-mentioned substrate, for example, glass, silicone resin, polycarbonate, polyester, aromatic polyamide, polyamide-imide, polyimide, etc. can be listed. In addition, for the above-mentioned substrate, chemical treatment, plasma treatment, ion plating, sputtering, gas phase reaction method, vacuum evaporation and other suitable pre-treatments using silane coupling agents, etc., can also be implemented in advance as needed. When the monomer dispersion is applied to the substrate, suitable coating methods such as spin coating, cast coating, and roller coating can be adopted.

[0051] In order to thermally cure the above-mentioned coating film, it is preferably maintained at a temperature of 80°C to 250°C in the atmosphere for 5 minutes to 60 minutes. Here, the reason for limiting the thermal curing temperature of the coating film to the range of 80°C to 250°C is that if it is lower than 80°C, the coating film is not fully cured, and if it exceeds 250°C, the substrate softens. In addition, the reason for limiting the thermal curing time of the coating film to the range of 5 minutes to 60 minutes is that if it is lower than 5 minutes, the coating film is not fully cured, and if it exceeds 60 minutes, it takes more time than necessary, which is not economical. On the other hand, in order to cure the above-mentioned coating film with ultraviolet rays, a photopolymerization initiator that is decomposed by ultraviolet rays, such as Irgacure 184 (manufactured by BASF), Irgacure 250 (manufactured by BASF), Irgacure 270 (manufactured by BASF), Irgacure 369 (manufactured by BASF), Irgacure 500 (manufactured by BASF), Irgacure 907 (manufactured by BASF), ADEKA OPTOMER N-1919 (manufactured by ADEKA) is added to the monomer dispersion in advance. Then, after the monomer dispersion to which the photopolymerization initiator is added is coated on the substrate, pre-baking is performed to evaporate the solvent, thereby forming a photoresist film. Next, after the photoresist film is exposed to a predetermined pattern shape through a photomask, it is developed using an alkaline developer, and the unexposed portion of the photoresist film is dissolved and removed, and then preferably post-baking is performed to form a predetermined black film.

[0052] The thickness of the cured black film is preferably in the range of 0.1 μm to 100 μm. It is particularly suitable for producing a black film with a thickness of 10 μm to 100 μm. In addition, the OD (optical density) value of the black film is an optical density that is an indicator of the light-shielding property (attenuation of transmittance) of the black film using zirconium nitride powder. Specifically, the OD value is a value that logarithmically represents the degree of absorption of light when passing through the black film, and is defined by the following formula (1). In formula (1), I is the amount of transmitted light, I0 is the amount of incident light.

[0053] OD value = -log10(I / I 0 ) …………(1)

[0054] In addition, in order to ensure high light shielding properties, the OD value of the black film is preferably 2.0 or more, and in order to ensure high insulation properties, the volume resistivity of the black film is preferably 1×10 13 Ω·cm or more.

[0055] A method for producing a black film using the black composition is described. First, the black composition is applied on a substrate to form a coating film. Then, the coating film is thermally cured or ultraviolet-cured to produce a black film. Since the method for producing a black film using the black composition is substantially the same as the method for producing a black film using the monomer dispersion, repeated descriptions are omitted. Example

[0056] Next, examples of the present invention will be described in detail together with comparative examples.

[0057] <Example 1>

[0058] First, a coarse zirconium nitride powder is prepared by a thermal agent method. Specifically, 7.3 g of a metal magnesium powder having an average primary particle size of 150 μm and 3.0 g of a magnesium nitride powder having an average primary particle size of 200 nm are added to 7.4 g of a monoclinic zirconium dioxide powder having an average primary particle size of 50 nm calculated by the specific surface area determined by the BET method, and the mixture is uniformly mixed using a reaction device equipped with a graphite boat in a quartz glass tube. At this time, the amount of metal magnesium added is 5.0 times the mole of zirconium dioxide, and the amount of magnesium nitride added is 0.5 times the mole of zirconium dioxide. The mixture is calcined at a temperature of 700° C. for 60 minutes under a nitrogen atmosphere to obtain a calcined product. The calcined product is dispersed in 1 liter of water, 10% hydrochloric acid is slowly added, and the pH is kept at 1 or above and the temperature is kept below 100° C. while washing, and then adjusted to pH 7 to pH 8 with 25% ammonia water, and filtered. The filtered solid content was redispersed in water at 400 g / L, and acid washing was performed again in the same manner as above, pH was adjusted with aqueous ammonia, and then filtered. After repeating the acid washing-pH adjustment with aqueous ammonia twice, the filtrate was dispersed in ion exchange water at 500 g / L in terms of solid content, heated and stirred at 60°C and adjusted to pH 7, filtered with a suction filter, and then washed with an equal amount of ion exchange water, and dried with a hot air dryer set at 120°C, thereby obtaining a coarse zirconium nitride powder.

[0059] Next, 20 g of the above zirconium nitride coarse powder was dispersed in 5 liters of isopropanol and subjected to low-temperature wet medium pulverization (medium: alumina) for 60 minutes to obtain a zirconium nitride precursor powder. The temperature of the isopropanol (dispersion medium) was 5°C or less. The above zirconium nitride precursor powder was then dried and pulverized in N 2 The zirconium nitride powder was obtained by calcining the mixture at 350° C. for 4 hours in a gas atmosphere. The zirconium nitride powder was used as Example 1.

[0060] <Examples 2 to 12 and Comparative Examples 1 to 10>

[0061] Regarding the zirconium nitride powders of Examples 2 to 12 and Comparative Examples 1 to 10, coarse zirconium nitride powders were generated by the methods shown in Table 1, respectively, and then pulverized and further calcined respectively. It should be noted that the zirconium nitride powder was prepared in the same manner as in Example 1 except for the generation method, pulverization method and calcination method shown in Table 1. It should be noted that in the column of the generation method of the coarse zirconium nitride powder in Table 1, "TM" is a thermal agent method and "PZ" is a plasma method. In addition, in the column of the pulverization method of the coarse zirconium nitride powder in Table 1, "BM" is a bead mill method and "JM" is a jet mill method. In addition, in the column of the calcination time / gas of the zirconium nitride precursor powder in Table 1, "N 2 " is nitrogen, "He" is helium, and "Ar" is argon.

[0062] <Comparative Test 1>

[0063] The zirconium nitride powders of Examples 1 to 12 and Comparative Examples 1 to 10 were measured for their volume resistivity in a compacted state with a pressure of 5 MPa and their particle size distribution D in a state diluted with water and dispersed by ultrasonic for 5 minutes. 90 These results are shown in Table 1.

[0064] <Comparative Test 2>

[0065] 40 g of zirconium nitride powder of Examples 1 to 11 and Comparative Examples 1 to 9 was dispersed in 200 ml of acrylic monomer or epoxy monomer as shown in Table 1 to prepare a monomer dispersion. On the other hand, 40 g of zirconium nitride powder of Example 12 and Comparative Example 10 was dispersed in 200 ml of propylene glycol monomethyl ether acetate (PGMEA) solvent to prepare a black pigment dispersion as shown in Table 1, and then an acrylic resin was added and mixed in the black pigment dispersion at a mass ratio of black pigment: resin = 3:7 to prepare a black composition. Then, 4 g of Irgacure 500 (photopolymerization initiator: manufactured by BASF) was added to the monomer dispersion or black composition. Next, the monomer dispersion or black composition was spin-coated on a glass substrate so that the film thickness after baking was the thickness shown in Table 1, and then pre-baked to evaporate the solvent to form a photoresist film. After the photoresist film is exposed to a predetermined pattern shape through a photomask, it is developed using an alkaline developer, and the unexposed portion of the photoresist film is dissolved and removed, and then post-baked to form black films. For these black films, based on the above formula (1), the OD values ​​of ultraviolet light (central wavelength of 370nm) and visible light (central wavelength of 560nm) are measured using a densitometer (densitometer) with the trade name D200 manufactured by Macbeth, and the volume resistivity (Ω·cm) of the black films is also measured. These results are shown in Table 1.

[0066] [Table 1]

[0067]

[0068] As shown in Table 1, the zirconium nitride powders of Comparative Examples 1 and 10, i.e., the zirconium nitride coarse powders were prepared by the thermal agent method but the zirconium nitride was not crushed and was calcined at 350°C for 4 hours in a nitrogen atmosphere, and the bulk resistivities of the powders in the green compacted state at a pressure of 5 MPa were 1×10 5 Ω·cm, than the appropriate range (1×10 7 Ω·cm or more), the particle size distribution D when ultrasonically dispersed for 5 minutes in a diluted state with water 90 The OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 1 in an acrylic monomer was 1.0, which was smaller than the appropriate range (2.0 or more), and the volume resistivity was 1×10 6 Ω·cm, than the appropriate range (1×10 13In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 10 in propylene glycol monomethyl ether acetate (PGMEA) was 1.9, which was smaller than the appropriate range (2.0 or more), and the volume resistivity was 6×10 12 Ω·cm, than the appropriate range (1×10 13 above) small.

[0069] The zirconium nitride powder of Comparative Example 3, i.e., the zirconium nitride coarse powder was prepared by a thermal agent method and the coarse zirconium nitride powder was pulverized by a bead mill method with a dispersion medium temperature of 5°C or less (low-temperature wet medium pulverization), but the zirconium nitride precursor powder was not calcined. The particle size distribution D of the zirconium nitride powder obtained by ultrasonic dispersion for 5 minutes in a state diluted with water was 90 The thickness of the compact is 9 μm, which is within the appropriate range (less than 10 μm). However, the bulk resistivity of the compact compacted at a pressure of 5 MPa is 1×10 6 Ω·cm, than the appropriate range (1×10 7 In addition, although the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 3 in an acrylic monomer was 2.1, which was within the appropriate range (2.0 or more), the volume resistivity was 5×10 11 Ω·cm, than the appropriate range (1×10 13 above) small.

[0070] In contrast, the zirconium nitride powders of Examples 1 and 12, i.e., the zirconium nitride coarse powders were prepared by the thermal agent method, and the zirconium nitride was pulverized by a bead mill method with a dispersion medium temperature of 5°C or less (low-temperature wet medium pulverization), and then calcined at 350°C for 4 hours in a nitrogen atmosphere, and the bulk resistivities of the zirconium nitride powders in the state of the compacts compacted at a pressure of 5 MPa were 1×10 8 Ω·cm, in an appropriate range (1×10 7 Ω·cm or more), the particle size distribution D when ultrasonically dispersed for 5 minutes in a diluted water state 90 The OD value of the black film prepared by dispersing the zirconium nitride powder of Example 1 in an acrylic monomer was 2.1, which is within the appropriate range (2.0 or more), and the volume resistivity was 5×10 13 Ω·cm, in an appropriate range (1×10 13 In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 12 in propylene glycol monomethyl ether acetate (PGMEA) was 2.1, which was within the appropriate range (2.0 or more), and the volume resistivity was 5×10 13 Ω·cm, in an appropriate range (1×1013 above).

[0071] The zirconium nitride powder of Example 9, i.e., a zirconium nitride coarse powder prepared by a thermal agent method, pulverized by a bead mill method at a dispersion medium temperature of 5°C (low-temperature wet medium pulverization), and then calcined at 350°C for 4 hours in a helium atmosphere, has a bulk resistivity of 8×10 7 Ω·cm, in an appropriate range (1×10 7 Ω·cm or more), the particle size distribution D when ultrasonically dispersed for 5 minutes in a diluted water state 90 The thickness of the black film prepared by dispersing the zirconium nitride powder of Example 9 in an acrylic monomer was 7 μm, which was within the appropriate range (less than 10 μm). The OD value of the black film was 2.2, which was within the appropriate range (more than 2.0), and the volume resistivity was 3×10 13 Ω·cm, in an appropriate range (1×10 13 above).

[0072] The zirconium nitride powder of Example 10, i.e., a zirconium nitride coarse powder prepared by a thermal agent method, pulverized by a bead mill method at a dispersion medium temperature of 5°C (low-temperature wet medium pulverization), and then calcined at 350°C for 4 hours in an argon atmosphere, has a bulk resistivity of 8×10 7 Ω·cm, in an appropriate range (1×10 7 Ω·cm or more), the particle size distribution D when ultrasonically dispersed for 5 minutes in a diluted water state 90 The thickness of the black film prepared by dispersing the zirconium nitride powder of Example 10 in an acrylic monomer was 9 μm, which was within the appropriate range (less than 10 μm). The OD value of the black film was 2.2, which was within the appropriate range (more than 2.0), and the volume resistivity was 3×10 13 Ω·cm, in an appropriate range (1×10 13 above).

[0073] On the other hand, the zirconium nitride powder of Comparative Example 2, which was prepared by plasma method but calcined at 350°C for 4 hours in a nitrogen atmosphere without pulverizing the zirconium nitride, had a bulk resistivity of 3×10 4 Ω·cm, than the appropriate range (1×10 7 Ω·cm or more), the particle size distribution D when ultrasonically dispersed for 5 minutes in a diluted state with water 90The thickness of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 2 in the epoxy monomer was 14 μm, which was larger than the appropriate range (less than 10 μm). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 2 in the epoxy monomer was 1.2, which was smaller than the appropriate range (more than 2.0), and the volume resistivity was 2×10 6 Ω·cm, than the appropriate range (1×10 13 above) small.

[0074] The zirconium nitride powder of Comparative Example 4, i.e., the zirconium nitride coarse powder was prepared by a plasma method and the coarse zirconium nitride powder was pulverized by a bead mill method with a dispersion medium temperature of 5°C or less (low-temperature wet medium pulverization), but the zirconium nitride precursor powder was not calcined. The particle size distribution D of the zirconium nitride powder obtained by ultrasonic dispersion for 5 minutes in a state diluted with water was 90 The thickness of the compact is 5 μm, which is within the appropriate range (less than 10 μm). However, the bulk resistivity of the compact compacted at a pressure of 5 MPa is 2×10 4 Ω·cm, than the appropriate range (1×10 7 In addition, although the OD value of the black film prepared by dispersing the zirconium nitride powder in the epoxy monomer of Comparative Example 4 was 2.0, which was within the appropriate range (2.0 or more), the volume resistivity was 2×10 10 Ω·cm, than the appropriate range (1×10 13 above) small.

[0075] In contrast, the zirconium nitride powders of Examples 2 and 4, i.e., the zirconium nitride coarse powders were prepared by plasma method, pulverized by bead mill method with dispersion medium temperature below 5°C (low temperature wet medium pulverization), and then calcined at 350°C for 4 hours in nitrogen atmosphere, had a bulk resistivity of 1×10 7 Ω·cm, in an appropriate range (1×10 7 Ω·cm or more), the particle size distribution D when ultrasonically dispersed for 5 minutes in a diluted water state 90 The OD value of the black film prepared by dispersing the zirconium nitride powder of Example 2 in the epoxy monomer was 2.2, which is within the appropriate range (above 2.0), and the volume resistivity was 2×10 13 Ω·cm, in an appropriate range (1×10 13 In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 4 in an acrylic monomer was 2.3, which was within the appropriate range (2.0 or more), and the volume resistivity was 1×10 13 Ω·cm, in an appropriate range (1×10 13above).

[0076] On the other hand, the zirconium nitride powder of Comparative Example 5, i.e., the zirconium nitride coarse powder was produced by the thermal agent method, but the coarse zirconium nitride powder was pulverized by a bead mill method at a dispersion medium temperature of 12°C higher than the appropriate dispersion medium temperature range (10°C or less) (low-temperature wet medium pulverization), and then calcined at 350°C for 4 hours in a nitrogen atmosphere, although the particle size distribution D of the zirconium nitride powder obtained by ultrasonic dispersion for 5 minutes in a state diluted with water was 0.1%. 90 The thickness of the compact is 10 μm, which is within the appropriate range (less than 10 μm). However, the bulk resistivity of the compact compacted at a pressure of 5 MPa is 7×10 6 Ω·cm, than the appropriate range (1×10 7 In addition, although the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 5 in an acrylic monomer was 2.0, which was within the appropriate range (2.0 or more), the volume resistivity was 4×10 12 Ω·cm, than the appropriate range (1×10 13 above) small.

[0077] In contrast, the zirconium nitride powder of Example 5, which is a zirconium nitride coarse powder prepared by a thermal agent method, pulverized by a bead mill method at a dispersion medium temperature of 10°C within an appropriate dispersion medium temperature range (below 10°C) (low-temperature wet medium pulverization), and then calcined at 350°C for 4 hours in a nitrogen atmosphere, has a bulk resistivity of 8×10 7 Ω·cm, in an appropriate range (1×10 7 Ω·cm or more), the particle size distribution D when ultrasonically dispersed for 5 minutes in a diluted water state 90 The thickness of the black film prepared by dispersing the zirconium nitride powder of Example 5 in an acrylic monomer was 10 μm, which was within the appropriate range (less than 10 μm). The OD value of the black film was 2.0, which was within the appropriate range (more than 2.0), and the volume resistivity was 3×10 13 Ω·cm, in an appropriate range (1×10 13 above).

[0078] On the other hand, the zirconium nitride powder of Comparative Example 6, that is, the zirconium nitride coarse powder was prepared by the thermal agent method and the zirconium nitride coarse powder was pulverized by the bead mill method with a dispersion medium temperature of 5°C (low-temperature wet medium pulverization), but the zirconium nitride powder was calcined in a nitrogen atmosphere at a calcination temperature of 200°C lower than the appropriate range (250°C to 550°C) and kept for a calcination time within the appropriate range (1 hour to 5 hours) for 4 hours, although the particle size distribution D when ultrasonically dispersed for 5 minutes in a state diluted with water was 0.1717 W / cm2. 90 The thickness of the compact is 8 μm, which is within the appropriate range (less than 10 μm). However, the bulk resistivity of the compact compacted at a pressure of 5 MPa is 1×10 6 Ω·cm, than the appropriate range (1×10 7 In addition, although the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 6 in an acrylic monomer was 2.0, which was within the appropriate range (2.0 or more), the volume resistivity was 1×10 12 Ω·cm, than the appropriate range (1×10 13 above) small.

[0079] The zirconium nitride powder of Comparative Example 7, i.e., the zirconium nitride coarse powder was prepared by the thermal agent method and the coarse zirconium nitride powder was pulverized by the bead mill method with a dispersion medium temperature of 5°C (low-temperature wet medium pulverization), but the zirconium nitride powder was calcined in a nitrogen atmosphere at a temperature of 350°C within an appropriate range (250°C to 550°C) and kept at a calcination temperature of 0.5 hours shorter than the appropriate range (1 hour to 5 hours). The particle size distribution D of the zirconium nitride powder when ultrasonically dispersed for 5 minutes in a state diluted with water was 0.5 hours. 90 The thickness of the compact is 7 μm, which is within the appropriate range (less than 10 μm). However, the bulk resistivity of the compact compacted at a pressure of 5 MPa is 3×10 6 Ω·cm, than the appropriate range (1×10 7 In addition, although the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 7 in an acrylic monomer was 2.0, which was within the appropriate range (2.0 or more), the volume resistivity was 2×10 12 Ω·cm, than the appropriate range (1×10 13 above) small.

[0080] The zirconium nitride powder of Comparative Example 8, i.e., the zirconium nitride coarse powder was prepared by the thermal agent method and the coarse zirconium nitride powder was pulverized by the bead mill method with a dispersion medium temperature of 5°C (low-temperature wet medium pulverization), but the zirconium nitride powder was calcined in a nitrogen atmosphere at a calcination temperature of 600°C, which is higher than the appropriate range (250°C to 550°C), and the calcination time was maintained within the appropriate range (1 hour to 5 hours) for 1 hour. The bulk resistivity of the zirconium nitride powder in the state of the compact compacted with a pressure of 5 MPa was 4×10 6 Ω·cm, than the appropriate range (1×10 7 Ω·cm or more), the particle size distribution D when ultrasonically dispersed for 5 minutes in a diluted state with water 90 The thickness of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 8 in an acrylic monomer was 14 μm, which was larger than the appropriate range (less than 10 μm). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 8 in an acrylic monomer was 1.2, which was smaller than the appropriate range (more than 2.0), and the volume resistivity was 1×10 9 Ω·cm, than the appropriate range (1×10 13 above) small.

[0081] In contrast, the zirconium nitride powder of Example 6, i.e., a zirconium nitride coarse powder is prepared by a thermal agent method, and the zirconium nitride coarse powder is pulverized by a bead mill method with a dispersion medium temperature of 5°C (low-temperature wet medium pulverization), and then calcined in a nitrogen atmosphere at a calcination temperature of 250°C within an appropriate range (250°C to 550°C) and a calcination time of 4 hours within an appropriate range (1 hour to 5 hours), has a bulk resistivity of 3×10 7 Ω·cm, in an appropriate range (1×10 7 Ω·cm or more), the particle size distribution D when ultrasonically dispersed for 5 minutes in a diluted water state 90 The thickness of the black film prepared by dispersing the zirconium nitride powder of Example 6 in an acrylic monomer was 8 μm, which was within the appropriate range (less than 10 μm). In addition, the OD value of the black film was 2.0, which was within the appropriate range (more than 2.0), and the volume resistivity was 2×10 13 Ω·cm, in an appropriate range (1×10 13 above).

[0082] The zirconium nitride powder of Example 7, i.e., a zirconium nitride coarse powder is prepared by a thermal agent method, and the zirconium nitride coarse powder is pulverized by a bead mill method with a dispersion medium temperature of 5°C (low-temperature wet medium pulverization), and then calcined in a nitrogen atmosphere at a calcination temperature of 350°C within an appropriate range (250°C to 550°C) and a calcination time of 1 hour within an appropriate range (1 hour to 5 hours). The volume resistivity of the zirconium nitride powder obtained in the state of the green compact compacted with a pressure of 5 MPa is 1×10 7 Ω·cm, in an appropriate range (1×10 7 Ω·cm or more), the particle size distribution D when ultrasonically dispersed for 5 minutes in a diluted water state 90 The thickness of the black film prepared by dispersing the zirconium nitride powder of Example 7 in an acrylic monomer was 7 μm, which was within the appropriate range (less than 10 μm). The OD value of the black film was 2.0, which was within the appropriate range (more than 2.0), and the volume resistivity was 1×10 13 Ω·cm, in an appropriate range (1×10 13 above).

[0083] The zirconium nitride powder of Example 8, i.e., a zirconium nitride coarse powder is prepared by a thermal agent method, and the zirconium nitride coarse powder is pulverized by a bead mill method with a dispersion medium temperature of 5°C (low-temperature wet medium pulverization), and then calcined in a nitrogen atmosphere at a calcination temperature of 550°C within an appropriate range (250°C to 550°C) and a calcination time of 1 hour within an appropriate range (1 hour to 5 hours). The volume resistivity of the zirconium nitride powder obtained in the state of the green compact compacted with a pressure of 5 MPa is 1×10 8 Ω·cm, in an appropriate range (1×10 7 Ω·cm or more), the particle size distribution D when ultrasonically dispersed for 5 minutes in a diluted water state 90 The thickness of the black film prepared by dispersing the zirconium nitride powder of Example 8 in an acrylic monomer was 8 μm, which was within the appropriate range (less than 10 μm). In addition, the OD value of the black film was 2.4, which was within the appropriate range (more than 2.0), and the volume resistivity was 1×10 14 Ω·cm, in an appropriate range (1×10 13 above).

[0084] On the other hand, the zirconium nitride powder of Comparative Example 9, i.e., the zirconium nitride coarse powder was produced by the thermal agent method, but the coarse zirconium nitride powder was pulverized by a jet mill at a pulverizing pressure of 0.2 MPa, which is smaller than the appropriate range (0.3 MPa or more), and then calcined at 350°C for 4 hours in a nitrogen atmosphere. The bulk resistivity of the zirconium nitride powder in the state of the green compact compacted at a pressure of 5 MPa was 2×106 Ω·cm, than the appropriate range (1×10 7 Ω·cm or more), the particle size distribution D when ultrasonically dispersed for 5 minutes in a diluted state with water 90 The thickness of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 9 in the epoxy monomer was 14 μm, which was larger than the appropriate range (less than 10 μm). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 9 in the epoxy monomer was 1.3, which was smaller than the appropriate range (more than 2.0), and the volume resistivity was 1×10 11 Ω·cm, than the appropriate range (1×10 13 above) small.

[0085] In contrast, the zirconium nitride powder of Example 3, which is a zirconium nitride coarse powder prepared by a thermal agent method, pulverized by a jet mill at a pulverizing pressure of 0.5 MPa within an appropriate range (0.3 MPa or more), and then calcined at 350°C for 4 hours in a nitrogen atmosphere, has a bulk resistivity of 2×10 8 Ω·cm, in an appropriate range (1×10 7 Ω·cm or more), the particle size distribution D when ultrasonically dispersed for 5 minutes in a diluted water state 90 The thickness of the black film prepared by dispersing the zirconium nitride powder of Example 3 in the epoxy monomer was 6 μm, which was within the appropriate range (less than 10 μm). In addition, the OD value of the black film was 2.2, which was within the appropriate range (more than 2.0), and the volume resistivity was 2×10 14 Ω·cm, in an appropriate range (1×10 13 above).

[0086] The zirconium nitride powder of Example 11, i.e., the zirconium nitride coarse powder was prepared by a thermal agent method, and the coarse zirconium nitride powder was pulverized by a jet mill at a pulverizing pressure of 0.3 MPa within an appropriate range (0.3 MPa or more), and then calcined at 350°C for 4 hours in a nitrogen atmosphere. The volume resistivity of the zirconium nitride powder of Example 3 obtained in the state of the green compact compacted at a pressure of 5 MPa was 2×10 7 Ω·cm, in an appropriate range (1×10 7 Ω·cm or more), the particle size distribution D when ultrasonically dispersed for 5 minutes in a diluted water state 90 The thickness of the black film prepared by dispersing the zirconium nitride powder of Example 11 in the epoxy monomer was 10 μm, which was within the appropriate range (less than 10 μm). The OD value of the black film was 2.4, which was within the appropriate range (more than 2.0), and the volume resistivity was 1×10 13 Ω·cm, in an appropriate range (1×10 13above).

[0087] Industrial Applicability

[0088] The zirconium nitride powder of the present invention can be used as a black pigment for obtaining a black film having high insulation, high blackness, and high insulation.

Claims

1. Zirconium nitride powder, which is in the state of secondary particles formed by agglomeration of primary particles, and does not contain low-order zirconium oxide and low-order zirconium oxynitride, The volume resistivity of the zirconium nitride powder in a compacted state compacted at a pressure of 5 MPa is 10 7 Ω·cm or more, and the particle size distribution D of the secondary particles when ultrasonically dispersed for 5 minutes in a state diluted with water or an alcohol having a carbon number in the range of 2 to 5 90 Less than 10 μm.

2. A method for preparing zirconium nitride powder, wherein the method include: The specific surface area is 20m2 by thermal agent method or plasma synthesis method. 2 / g~90m 2 / g of zirconium nitride coarse powder; The process of preparing a zirconium nitride precursor powder by subjecting the zirconium nitride coarse powder to low-temperature wet medium pulverization at a dispersion medium temperature of 10° C. or less or jet mill pulverization at a gas pressure of 0.3 MPa or more, wherein the zirconium nitride precursor powder has a particle size distribution D when ultrasonically dispersed for 5 minutes in a state diluted with water or an alcohol having a carbon number in the range of 2 to 5. 90 Less than 10μm; and The process of preparing zirconium nitride powder by calcining the crushed zirconium nitride precursor powder in an inert gas atmosphere at a calcination temperature of 250° C. to 550° C. and a calcination time of 1 hour to 5 hours, wherein the zirconium nitride powder has a bulk resistivity of 10 7 Ω·cm or more.

3. A monomer dispersion, wherein the zirconium nitride powder according to claim 1 is dispersed in an acrylic monomer or an epoxy monomer.

4. A black composition, wherein the zirconium nitride powder according to claim 1 is dispersed as a black pigment in a dispersion medium and mixed with a resin.

5. A method for producing a black film, wherein the method include: A step of applying the monomer dispersion according to claim 3 on a substrate to form a coating film, and A step of thermally curing or ultraviolet curing the coating film to form a black film.

6. A method for producing a black film, wherein the method include: A step of applying the black composition according to claim 4 on a substrate to form a coating film, and A step of thermally curing or ultraviolet curing the coating film to form a black film.

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