CN114507073A - Zirconium nitride powder and preparation method thereof - Google Patents

Abstract

The invention provides a high insulation material which can obtain high insulation and high blackness and has high insulation. The volume resistivity of the zirconium nitride powder of the present invention in a state of a green compact compacted with a pressure of 5MPa was 10⁷A particle size distribution D of not less than Ω · cm and obtained by ultrasonic dispersion for 5 minutes in a state diluted with water or an alcohol having 2 to 5 carbon atoms₉₀Is 10 μm or less. In addition, the above-described zirconium nitride powder may be dispersed in an acrylic monomer or an epoxy monomer to prepare a monomer dispersion. Further, the above-described zirconium nitride powder may be dispersed as a black pigment in a dispersion medium and mixed with a resin to prepare a black composition.

Description

Zirconium nitride powder and preparation method thereof

technical field

The present invention relates to a zirconium nitride powder suitable for use as a black pigment having high ultraviolet transmittance and high blackness, and having high insulating properties, and a preparation method thereof.

Background technique

Conventionally, a zirconium nitride powder has been disclosed. The zirconium nitride powder has a specific surface area of 20 m ² /g to 90 m ² /g measured by the BET method, and has a peak of zirconium nitride in an X-ray diffraction pattern, and does not It has a peak of zirconium dioxide and a peak of subvalent zirconium oxide (for example, refer to Patent Document 1 (claim 1, paragraph [0016])). In the transmission spectrum of the dispersion liquid of the zirconium nitride powder with the powder concentration of 50ppm, the light transmittance X at 370nm is at least 18%, the light transmittance Y at 550nm is 12% or less, the light transmittance Y at 550nm and the light at 370nm are at least 18%. The ratio (X/Y) of the transmittance X is 2.5 or more.

The zirconium nitride powder thus constituted has a specific surface area of 20 m ² /g or more, so it has the effect of suppressing sedimentation when used as a resist, and has a sufficient light-shielding property because it is 90 m ² /g or less. Effect. In addition, since it has a peak of zirconium nitride in the X-ray diffraction pattern, and does not have a peak of zirconium dioxide, a peak of subvalent zirconium oxide, and a peak of subvalent zirconium oxynitride, it has dispersion at a powder concentration of 50 ppm In the liquid transmission spectrum, the light transmittance X at 370 nm is at least 18%, the light transmittance Y at 550 nm is 12% or less, and X/Y is 2.5 or more. Since X/Y is 2.5 or more, more ultraviolet rays are transmitted. Therefore, a high-resolution patterned film can be formed when a black patterned film is formed as a black pigment, and the formed patterned film has high light-shielding performance.

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2017-222559.

SUMMARY OF THE INVENTION

The problem to be solved by the invention

In the case of the zirconium nitride powder shown in the above-mentioned Patent Document 1, if the coarse zirconium nitride powder is dispersed in a dispersion medium, and the dispersibility is improved by using a bead mill (medium: zirconia) or the like, although high insulation can be obtained. However, if the zirconium nitride powder is directly kneaded into a high-viscosity resin paste, the coarse zirconium nitride powder remains and the dispersibility is insufficient. Therefore, when the zirconium nitride powder is used as a black pigment, the tinting strength of the black paint is lowered, and there is a disadvantage that the resistance value is lowered due to the residue of the zirconium nitride coarse powder. In addition, when the above-mentioned coarse zirconium nitride powder is forcibly pulverized with a dry pulverizer or the like, the diameter of the powder becomes small, and an oxidation reaction occurs on the surface of the powder. Therefore, although the insulating properties are improved, there is a problem that the blackness of the black paint decreases. .

The first object of the present invention is to provide a zirconium nitride powder having high insulating properties while obtaining high insulating properties 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 a high blackness by pulverizing in a low-temperature wet medium or pulverizing with a jet mill having a small calorific value. The third object of the present invention is to provide a method for producing a zirconium nitride powder capable of improving the insulating properties of a black film by firing in an inert gas atmosphere.

means of solving problems

A first aspect of the present invention is a zirconium nitride powder having a volume resistivity of 10 7 Ω·cm or more in a state of a compact compacted with a pressure of 5 MPa, and having a volume resistivity of 10 ⁷ Ω·cm or more when subjected to water or carbon atoms. The particle size distribution D ₉₀ at the time of ultrasonic dispersion for 5 minutes in the state of dilution with alcohol in the range of 2 to 5 was 10 μm or less.

A second aspect of the present invention is a method for producing a zirconium nitride powder, the production method comprising the steps of: generating a coarse zirconium nitride powder by a thermal agent method or a plasma synthesis method; A step of producing a zirconium nitride precursor powder by performing low-temperature wet-medium pulverization at the following dispersion medium temperature or jet mill pulverization under an air pressure of 0.3 MPa or more, the zirconium nitride precursor powder being mixed with water or carbon atoms in The particle size distribution D ₉₀ at the time of ultrasonic dispersion for 5 minutes in the state of dilution with alcohol in the range of 3 to 5 is 10 μm or less; and by calcining the pulverized zirconium nitride precursor powder in an inert gas atmosphere to prepare zirconium nitride In the step of powdering, the zirconium nitride powder has a volume resistivity of 10 ⁷ Ω·cm or more in a state of a compact compacted with a pressure of 5 MPa.

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 .

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 resin.

A fifth aspect of the present invention is a method for producing a black film comprising the steps of applying the monomer dispersion according to the third aspect on a substrate to form a coating film, and thermally curing the coating film Or the process of UV curing to make a black film.

A sixth aspect of the present invention is a method for producing a black film comprising the steps of applying the black composition according to the fourth aspect to a substrate to form a coating film, and thermally curing or thermally curing the coating film. The process of making a black film by ultraviolet curing.

effect of invention

Since the zirconium nitride powder of the first aspect of the present invention has a volume resistivity of 10 ⁷ Ω·cm or more in a compacted state with a pressure of 5 MPa, when a thick black film having a thickness of about 10 μm to 100 μm is produced The insulation can be improved. In addition, since the particle size distribution _D90 of the zirconium nitride powder in the state of being diluted with water or an alcohol having a carbon number in the range of 2 to 5 by ultrasonic dispersion for 5 minutes is 10 μm or less, it is possible to obtain a coarse powder of zirconium nitride that does not exist. good dispersion or dispersion. Thereby, the black film produced from the dispersion or dispersion liquid using the above-mentioned zirconium nitride powder can obtain high insulating properties and high blackness, and has high insulating properties.

In the method for producing a zirconium nitride powder according to the second aspect of the present invention, if the coarse zirconium nitride powder is pulverized in a low-temperature wet medium at a dispersion medium temperature of 10° C. or lower, the calorific value is small, so that nitriding is not performed. The surface of zirconium is oxidized to maintain high blackness. In addition, when the zirconium nitride coarse powder is pulverized by a jet mill under an air pressure of 0.3 MPa or more, the zirconium nitride coarse powder does not remain, and the insulating properties of the black film can be improved. In addition, the insulating properties of the black film can be improved by firing the pulverized zirconium nitride precursor powder in an inert gas atmosphere.

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 these monomers have high viscosity , the dispersibility of the zirconium nitride powder relative to the above monomers can also be kept good. As a result, the black film obtained by using the monomer dispersion has high insulating properties while obtaining high insulating properties and high blackness.

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 a resin, so that the zirconium nitride powder is uniformly dispersed in the dispersion medium middle. As a result, the black film obtained by using the black composition has high insulating properties while obtaining high insulating properties and high blackness.

In the method for producing 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 UV-cured to produce a black film, so the black color is The film has high insulating properties while obtaining high insulating properties and high blackness.

In the method for producing a black film according to the sixth aspect of the present invention, after applying the above-mentioned black composition on a substrate to form a coating film, the black film is produced by thermally curing or ultraviolet curing the coating film. It has high insulating properties while obtaining high insulating properties and high blackness.

Detailed ways

Next, the form for implementing this invention is demonstrated. The zirconium nitride powder of the present embodiment has a volume resistivity of 10 ⁷ Ω·cm or more, preferably 10 ⁸ Ω·cm or more, in the state of a compact compacted with a pressure of 5 MPa, and has a volume resistivity of 10 7 Ω·cm or more in water or the number of carbon atoms in The particle size distribution D ₉₀ at the time of ultrasonic dispersion for 5 minutes in the state of being diluted with alcohol in the range of 2 to 5 is 10 μm or less, preferably 8 μm or less. Here, the reason why the above-mentioned volume resistivity is limited to 10 ⁷ Ω·cm or more is that if it is less than 10 ⁷ Ω·cm, the insulating properties when a black thick film with a thickness of about 1 μm to 100 μm is produced using zirconium nitride powder will decrease. In addition, the reason why the particle size distribution D ₉₀ is limited to 10 μm or less is that if it exceeds 10 μm, coarse zirconium nitride powder remains, and a good dispersion and black film cannot be obtained.

The said volume resistivity is measured by the four-terminal four-probe method using, for example, a low-resistivity meter Loresta-GP (model number: UV-3101PC) manufactured by Mitsubishi Chemical Corporation. In the four-terminal four-probe method, four needle-shaped electrodes are placed on a straight line at a predetermined interval on the surface of a sample (green compact), and a constant flow of a predetermined amount of needle-shaped electrodes flows between the two outer needle-shaped electrodes. A method of obtaining the volume resistivity by measuring the potential difference generated between the two needle-shaped electrodes on the inner side of the current.

In addition, the zirconium nitride powder is a state of secondary particles in which primary particles are aggregated, and is a particle size distribution on a volume basis measured by a laser diffraction scattering method. Here, the measurement of the volume-based particle size distribution by the laser diffraction scattering method is performed as follows. First, 0.1 g of zirconium nitride powder (secondary particles) was put into 20 g of ion-exchanged water, and 25 kHz ultrasonic waves were irradiated for 5 minutes to disperse the zirconium nitride powder in the ion-exchanged water. Next, an appropriate amount of the obtained dispersion of zirconium nitride powder was dropped into 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 was measured according to the program of the device. . The particle size distribution measured by this laser diffraction scattering method is the particle size distribution of the secondary particles in which the primary particles of the zirconium nitride powder are aggregated. It should be noted that, instead of ion-exchanged water, an alcohol having a carbon number in the range of 2 to 5 may be used. Examples of the alcohol having 2 carbon atoms include ethanol; examples of the alcohol having 3 carbon atoms include 1-propanol, 2-propanol, and the like; and examples of the alcohol having 4 carbon atoms include 1 -Butanol, 2-butanol, etc.; Examples of the alcohol having 5 carbon atoms include 1-pentanol, 2-pentanol, and the like. It should be noted that when the number of carbon atoms is 1 or less, the volatility is high and the measurement value is not stable, and when the carbon number is 6 or more, the affinity is insufficient and the measurement value is not stable.

A method for producing the zirconium nitride powder having such a structure will be described. First, a coarse powder of zirconium nitride is produced by a thermal agent method or a plasma synthesis method. In the present specification, the thermal method (thermit method) refers to a method of reducing zirconia powder by reacting it with N ₂ gas (nitrogen gas) in the presence of metallic magnesium. In this embodiment, as the zirconia powder, zirconia (ZrO ₂ ) powder or silica-coated zirconia (ZrO ₂ ) powder is used. In addition, magnesium nitride (Mg ₃ N ₂ ) powder is added to the metallic magnesium powder. These powders are used as starting materials, and are calcined in a specific atmosphere at a specific temperature and time to produce a zirconium nitride coarse powder having a specific surface area measured by the BET method of 20 m ² /g to 90 m ² /g.

[Zirconium dioxide powder]

As the zirconium dioxide powder, for example, powders of zirconium dioxide such as monoclinic zirconium dioxide, cubic zirconium dioxide, and yttrium-stabilized zirconium dioxide can be used, from the viewpoint of increasing the generation rate of zirconium nitride powder From the standpoint, monoclinic zirconium dioxide powder is preferred. In addition, in order to obtain a zirconium nitride coarse powder having a specific surface area of 20 m ² /g to 90 m ² /g measured by the BET method, the zirconium dioxide powder was calculated as an average primary particle size obtained by performing spherical conversion from the measured value of the specific surface area. Or the average primary particle size of the silica-coated zirconium dioxide powder and the average primary particle size of the magnesium oxide powder are preferably 500 nm or less, and the average primary particle size is preferably 500 nm from the viewpoint of easy handling of the powder. less than 10 nm or more.

[Silica-coated zirconia powder]

The silica-coated zirconia powder is obtained by mixing zirconia powder and a silicate sol-gel solution to prepare a slurry, and drying and pulverizing the slurry. Regarding the mixing ratio of zirconium dioxide and the silicate sol-gel solution, in terms of mass ratio, it is preferable that the amount of zirconium dioxide: the silica content of the silicate sol-gel solution is (90.0~99.5):(10.0~0.5) . If the amount of silica is less than the lower limit, the coverage rate of silica on the surface of the zirconium dioxide will be too low; if the amount of silica exceeds the upper limit, the resulting zirconium nitride powder may be used to form a patterned film. Insufficient light-shielding properties.

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

By using silica-coated zirconium dioxide powder as the starting material, grain growth can be suppressed during calcination, and finer particles with a specific surface area of 20 m ² /g to 90 m ² /g as measured by the BET method can be obtained. Zirconium nitride powder. At this time, 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. When it exceeds 10.0 mass %, when a patterned film is formed using the obtained zirconium nitride powder, the light-shielding property may be insufficient.

[Metal magnesium powder]

If the particle size of the magnesium metal powder is too small, the reaction proceeds rapidly and the risk of handling increases. Therefore, the magnesium metal powder is preferably a granular powder having a particle size of 100 μm to 1000 μm in terms of mesh pass. , particularly preferably a granular powder of 200 μm to 500 μm. However, even if not all of the metallic magnesium falls within the above-mentioned particle size range, 80% by mass or more, particularly 90% by mass or more, may fall within the above-mentioned range.

The amount of the magnesium metal powder to be added to the zirconium dioxide powder affects the reducing power of the zirconium dioxide together with the amounts of ammonia gas and hydrogen gas in the atmospheric gas described later. If the amount of metallic magnesium is too small, the reduction will be insufficient, and it will be difficult to obtain the target zirconium nitride powder; if the amount is too large, the reaction temperature will rise sharply due to the excess metallic magnesium, which may cause grain growth of the powder, and will Not economical. The magnesium metal powder is added to and mixed with the zirconium dioxide powder in a ratio of 2.0 to 6.0 times the mole of the zirconium dioxide depending on the particle size of the metal magnesium powder. If it is less than 2.0 times the mol, the reduction reaction of zirconium dioxide will be insufficient, and if it exceeds 6.0 times the mol, the reaction temperature will be rapidly increased due to the excess metal magnesium, and the grain growth of the powder may be caused, and it will become unsatisfactory. economy.

[Magnesium Nitride Powder]

The magnesium nitride powder coats the surface of the zirconium nitride during sintering, thereby relaxing the reducing force of the metal magnesium to prevent the sintering and grain growth of the zirconium nitride powder. Magnesium nitride powder is added to and mixed with zirconium dioxide in a ratio of 0.3 to 3.0 times the mole of zirconium dioxide, depending on the size of the particle diameter. If it is less than 0.3 times the mole, the sintering of the zirconium nitride powder cannot be prevented, and if it exceeds 3.0 times the mole, the usage amount of the acidic solution required for acid cleaning after baking may increase. Preferably, it is 0.4-fold mol to 2.0-fold mol. The magnesium nitride powder is preferably 1000 nm or less in terms of the average primary particle diameter obtained by converting the measured value of the specific surface area into spheres, and preferably 10 nm or more and 500 nm in terms of the average primary particle diameter in terms of easy handling of the powder. the following. It should be noted that not only magnesium nitride but also magnesium oxide is effective in preventing sintering of zirconium nitride, so it is also possible to use a part of magnesium oxide mixed with magnesium nitride.

[Reduction Reaction Using Metal Magnesium Powder]

The temperature at the time of the reduction reaction with metallic magnesium for producing the coarse zirconium nitride powder is 650°C to 900°C, preferably 700°C to 800°C. 650° C. is the melting temperature of metallic magnesium, and if the temperature is lower than this temperature, the reduction reaction of zirconium dioxide does not sufficiently occur. In addition, even if the temperature is higher than 900° C., the effect does not increase, and the powder is sintered while wasting heat energy, which is not preferable. In addition, the reduction reaction time is preferably 30 minutes to 90 minutes, and more preferably 30 minutes to 60 minutes.

The reaction vessel in which the above-mentioned reduction reaction is performed is preferably a vessel with a lid so that the raw materials and products are not scattered during the reaction. The reason for this is that when the metal magnesium begins to melt, the reduction reaction rapidly proceeds, the temperature rises, and the gas inside the container expands, thereby possibly scattering the substance inside the container to the outside.

[Atmospheric gas at the time of reduction reaction with magnesium metal powder]

The atmosphere gas is nitrogen element, or a mixed gas of nitrogen and hydrogen, or a mixed gas of nitrogen and ammonia. The above-mentioned reduction reaction is carried out in the gas flow of the above-mentioned mixed gas. Nitrogen in the mixed gas has the function of preventing the metal magnesium or the reduction product from contacting with oxygen, thereby preventing them from oxidizing, and simultaneously reacting nitrogen and zirconium to generate zirconium nitride. Hydrogen or ammonia in the mixed gas has the effect of reducing zirconium dioxide together with metal magnesium. The above-mentioned mixed gas preferably contains 0 to 40% by volume of hydrogen, and more preferably contains 10 to 30% by volume of hydrogen. Moreover, it is preferable to contain 0 to 50 volume% of ammonia gas in the said mixed gas, and it is more preferable to contain 0 to 40 volume% of ammonia gas. By using the atmospheric gas having reducing power, a zirconium nitride powder that does not contain subvalent zirconium oxide and subvalent zirconium oxynitride can be finally produced. On the other hand, if the ratio of hydrogen gas or nitrogen gas is higher than this range, the reduction proceeds, but the nitrogen source decreases, so that subvalent zirconium oxide or subvalent zirconium oxynitride is produced, which is not preferable. In addition, it is considered that the ratio of ammonia gas is higher than that of hydrogen gas because the gas nitriding ability of ammonia is higher than that of hydrogen.

On the other hand, the method of generating coarse zirconium nitride powder by plasma synthesis is a method of introducing metal zirconium powder into a plasma nanoparticle preparation device, and obtaining zirconium nitride nanoparticles in an N ₂ gas atmosphere. For zirconium nitride synthesized by this method, zirconium nitride with a specific surface area of 20 m ² /g to 90 m ² /g can be obtained, but there is a risk of high flammability of metal zirconium used as a raw material and an increase in cost. High disadvantage. It should be noted that the nanoparticles produced by the plasma synthesis method are coarsened by rapid surface oxidation, adhesion, aggregation, etc. in the cooling process and the product extraction process, and become coarse powder, so they are produced by the plasma synthesis method. The zirconium nitride is also used as zirconium nitride coarse powder.

Next, the zirconium nitride precursor powder is produced by subjecting the zirconium nitride coarse powder to low-temperature wet-medium pulverization at a dispersion medium temperature of 10° C. or lower or jet mill pulverization at an air pressure of 0.3 MPa or more. The particle size distribution D ₉₀ of the zirconium precursor powder in the state of being diluted with water or an alcohol having a carbon number in the range of 3 to 5 by ultrasonic dispersion for 5 minutes is 10 μm or less. It should be noted that the specific surface area of the zirconium nitride precursor powder measured by the BET method was 22 m ² /g to 120 m ² /g.

The above-mentioned low-temperature wet medium pulverization method refers to dispersing the coarse powder of zirconium nitride in a dispersion medium such as ion-exchanged water or an alcohol having 2 to 5 carbon atoms, and keeping the temperature of the dispersion medium at 10°C or lower, using an average A bead mill pulverization method for media such as zirconia, alumina, glass, and polyurethane resin with a particle size of 50 μm to 500 μm. Here, the reason why the temperature of the dispersion medium is kept at 10° C. or lower is that, when it exceeds 10° C., the pulverization of the zirconium nitride precursor powder proceeds, and the OD value of the black film described later decreases. It should be noted that, in order to keep the temperature of the dispersion medium below 10°C, liquid nitrogen can be used as the dispersion medium, or dry ice beads can be used as the medium. In addition, when the zirconium nitride coarse powder is pulverized by the above-mentioned low-temperature wet medium pulverization method, the calorific value is small, so that the surface oxidation of the zirconium nitride does not proceed, and a high degree of blackness can be maintained.

In addition, pulverization in a jet mill with a gas pressure of 0.3 MPa or more means that inert gas or steam such as high-pressure air, nitrogen, etc. of 0.3 MPa or more injected from a nozzle collides with the powder in the form of an ultra-high-speed jet, and the powder is crushed by the impact of each other. A device that pulverizes the powder to a level of several μm, and the ejected air or steam reaches about the speed of sound. The characteristics of the jet mill include that the temperature of the jetted gas is lowered due to the adiabatic expansion, so that it can be pulverized at a low temperature, and the oxidation of even a reducing substance such as zirconium nitride in the present invention can be suppressed. Here, the reason why the above-mentioned gas pressure is limited to 0.3 MPa or more is that if it is less than 0.3 MPa, the coarse zirconium nitride powder will remain. It should be noted that when the coarse zirconium nitride powder is pulverized by the above-mentioned jet mill pulverization method, the coarse zirconium nitride powder does not remain, and the insulating properties of the black film can be improved.

Further, by calcining the pulverized zirconium nitride precursor powder in an inert gas atmosphere, zirconium nitride having a volume resistivity of 10 ⁷ Ω·cm or more in the state of a compact compacted with a pressure of 5 MPa was prepared powder. As an inert gas, N ₂ gas, helium gas, argon gas, etc. are mentioned. The 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 why the preferable calcination temperature is limited to the range of 250°C to 550°C is that if the temperature is lower than 250°C, the increase in resistance value is insufficient, and if it exceeds 550°C, the powders are fused together. Coarse powder will increase. In addition, the reason why the preferable firing time is limited to the range of 1 hour to 5 hours is that if it is less than 1 hour, the rise of the resistance value will not be sufficient, and even if it exceeds 5 hours, the effect will not change, which is not economical. . It should be noted that the insulating properties of the black film can be improved by firing the zirconium nitride precursor powder in an inert gas atmosphere. The detailed mechanism for improving the insulating properties of the black film by firing in an inert gas atmosphere is not clear, but it is presumed that the coarse powder of zirconium nitride disappears, the uniformity of the powder is improved, the number of contact points decreases, or the black film is formed on the surface caused by a very thin insulating layer.

A monomer dispersion is prepared by dispersing the above-mentioned zirconium nitride powder in an acrylic monomer or an epoxy monomer. The monomer dispersion can be used for dispersing resin compositions containing inorganic powders, resin moldings, and the like. In addition, the above-mentioned monomer dispersion may further contain a metal oxide powder, and may further contain a plasticizer. The plasticizer is not particularly limited, and examples thereof include phosphate-based plasticizers such as tributyl phosphate and 2-ethylhexyl phosphate; Phthalate-based plasticizers, aliphatic monobasic ester-based plasticizers such as butyl oleate and glycerol monooleate, dibutyl adipate, di-2-ethylhexyl sebacate, etc. Aliphatic dibasic acid ester plasticizers, diethylene glycol dibenzoate, triethylene glycol di-2-ethyl butyrate and other glycol ester plasticizers, methyl acetyl ricinoleate, Conventionally well-known plasticizers, such as oxyester-type plasticizers, such as acetyl tributyl citrate. In addition, other monomers may be added to the monomer dispersion. It does not specifically limit as another monomer, For example, (meth)acrylic-type monomers, such as (meth)acrylic acid and (meth)acrylate, styrene, such as styrene, vinyltoluene, and divinylbenzene, are mentioned. The monomers include acetyl-based monomers such as vinyl chloride and vinyl acetate, urethane-based monomers such as urethane acrylate, and conventionally known monomers such as the various polyols mentioned above. In addition, considering the dispersibility of zirconium nitride powder, it is preferable to set the viscosity of a monomer dispersion in the range of 10 Pa.s-1000 mPa.s (10 mPa.s-1000 mPa.s). For the dispersion into the monomer, the grinding method using a grinding medium can be used in the same manner as the dispersion into the solvent. In addition, although it is not an essential component, in order to further improve dispersibility, you may use a polymeric dispersing agent. The molecular weight of the polymer dispersant is effectively several thousands to tens of thousands. In addition, as the functional group adsorbed on the pigment, secondary amines, tertiary amines, carboxylic acids, phosphoric acid, phosphoric acid esters, etc. can be listed, especially tertiary amines, carboxylic acid Acid is effective. In place of the polymer dispersant, adding a small amount of a silane coupling agent is also effective for improving the dispersibility. On the other hand, after performing planetary stirring, a dispersion liquid can also be obtained by passing through three rolls several times. On the other hand, a black composition obtained by dispersing zirconium nitride powder as a black pigment in a dispersion medium and mixing a resin was prepared. As the said dispersion medium, propylene glycol monomethyl ether acetate (PGMEA), methyl ethyl ketone (MEK), butyl acetate (BA), etc. are mentioned. Moreover, as said resin, an acrylic resin, an epoxy resin, etc. are mentioned. For solvent-based dispersion, it is effective to add a polymer dispersant in the same manner as monomer dispersion, and similarly to monomer dispersion, it is effective to have a molecular weight of several thousands to tens of thousands, and as functional groups, tertiary amines and carboxylic acids are effective.

Next, a method for producing a black film using the above-mentioned monomer dispersion will be described. First, after adding a photopolymerization initiator to the monomer dispersion, the monomer dispersion is applied on a substrate to form a coating film. Next, this coating film is thermally cured or UV-cured to prepare a black film. As said board|substrate, glass, a silicone resin, a polycarbonate, a polyester, an aramid, a polyamideimide, a polyimide etc. are mentioned, for example. In addition, appropriate pretreatments such as chemical treatment using a silane coupling agent, plasma treatment, ion plating, sputtering, gas-phase reaction method, and vacuum vapor deposition may be performed in advance on the above-mentioned substrate as necessary. When coating the monomer dispersion on the substrate, a suitable coating method such as spin coating, cast coating, and roll coating can be employed.

In order to thermoset the said coating film, it is preferable to hold|maintain at the temperature of 80 degreeC - 250 degreeC in the atmosphere for 5 minutes - 60 minutes. Here, the reason why the thermosetting temperature of the coating film is limited to the range of 80°C to 250°C is that if the temperature is lower than 80°C, the coating film is not sufficiently cured, and if it exceeds 250°C, the substrate is softened. In addition, the reason why the thermal curing time of the coating film is limited to the range of 5 minutes to 60 minutes is that if it is less than 5 minutes, the coating film is not sufficiently cured, and if it exceeds 60 minutes, it will take longer than necessary to prevent the economy. On the other hand, Irgacure 184 (manufactured by BASF), Irgacure 250 (manufactured by BASF), Irgacure 270 (manufactured by BASF), and Irgacure 369 (manufactured by BASF) were previously added to the monomer dispersion in order to cure the above-mentioned coating film by ultraviolet rays. ), Irgacure 500 (manufactured by BASF), Irgacure 907 (manufactured by BASF), and ADEKA OPTOMER N-1919 (manufactured by ADEKA) are photopolymerization initiators that are cleaved by ultraviolet rays. Then, after applying the monomer dispersion to which the photopolymerization initiator is added on the substrate, prebaking is performed to evaporate the solvent, thereby forming a photoresist film. Next, after exposing the photoresist film to a predetermined pattern shape through a photomask, it is developed using an alkali developing solution to dissolve and remove the unexposed portion of the photoresist film, and then preferably post-baking is performed. Thereby, a predetermined black film is formed.

It is preferable that the film thickness of the black film after hardening exists in the range of 0.1 micrometer - 100 micrometers. It is especially suitable for the production of thick black films with a film thickness of 10 μm to 100 μm. In addition, the OD (Optical Density) value of a black film is an optical density as an index which shows the light-shielding property (decrease of transmittance) of the black film using a zirconium nitride powder. Specifically, the OD value is a logarithmic value representing the degree to which light is absorbed when passing through a black film, and is defined by the following formula (1). In Formula (1), I is the amount of transmitted light, and I ₀ is the amount of incident light.

OD value=-log10(I/I ₀ ) …………(1)

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

A method of producing a black film using the above-mentioned black composition will be described. First, the black composition is coated on a substrate to form a coating film. Next, this coating film is thermally cured or UV-cured to prepare a black film. Since the production method of the black film using this black composition is substantially the same as the production method of the black film using the above-mentioned monomer dispersion, the overlapping description is omitted.

Example

Next, the Example of this invention is demonstrated in detail together with the comparative example.

<Example 1>

First, zirconium nitride coarse powder is produced by the thermal agent method. Specifically, to 7.4 g of monoclinic zirconium dioxide powder having an average primary particle diameter of 50 nm calculated from the specific surface area measured by the BET method, 7.3 g of magnesium metal powder having an average primary particle diameter of 150 μm and 3.0 g of magnesium nitride powder having an average primary particle size of 200 nm was uniformly mixed in a reaction apparatus in which a graphite boat was installed in a glass tube made of quartz. At this time, the amount of metal magnesium added was 5.0 times the mole of zirconium dioxide, and the amount of magnesium nitride added was 0.5 times the mole of zirconium dioxide. The mixture was calcined at a temperature of 700° C. for 60 minutes under a nitrogen atmosphere to obtain a calcined product. The calcined product was dispersed in 1 liter of water, 10% hydrochloric acid was slowly added, the pH was 1 or more, and the temperature was kept at 100° C. or less while washing, and then adjusted to pH 7 to pH 8 with 25% ammonia water, and filtered. This filtered solid content was redispersed in water to 400 g/liter, acid washing was performed again in the same manner as above, and pH was adjusted with ammonia water, followed by filtration. After repeating the acid cleaning and pH adjustment with ammonia water twice in this way, the filtrate was dispersed in ion-exchanged water at a solid content of 500 g/liter, heated and stirred at 60°C to adjust to pH 7, and then filtered with a suction filter. , and further washed with an equal amount of ion-exchanged water, and dried with a hot-air dryer with a set temperature of 120° C. to obtain a coarse powder of zirconium nitride.

Next, 20 g of the above-mentioned coarse zirconium nitride 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 isopropyl alcohol (dispersion medium) at this time is 5°C or lower. Furthermore, after drying the said zirconium nitride precursor powder, it calcined at the temperature of 350 degreeC in _N2 gas atmosphere for 4 hours, and obtained the zirconium nitride powder. This zirconium nitride powder was taken as Example 1.

<Examples 2 to 12 and Comparative Examples 1 to 10>

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

<Comparative Test 1>

For the zirconium nitride powders of Examples 1 to 12 and Comparative Examples 1 to 10, the volume resistivity in the state of the compact compacted with a pressure of 5 MPa and the ultrasonic dispersion for 5 minutes in the state of dilution with water were measured, respectively. The particle size distribution D ₉₀ . These results are shown in Table 1.

<Comparative Test 2>

As shown in Table 1, 40 g of the zirconium nitride powders of Examples 1 to 11 and Comparative Examples 1 to 9 were dispersed in 200 ml of acrylic monomers or epoxy monomers to prepare monomer dispersions. On the other hand, to 40 g of the zirconium nitride powders of Example 12 and Comparative Example 10, as shown in Table 1, an amine-based dispersant was added, and the test was carried out in 200 ml of a propylene glycol monomethyl ether acetate (PGMEA) solvent. After the dispersion treatment to prepare black pigment dispersion liquids, acrylic resins were added and mixed to these black pigment dispersion liquids 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 Corporation) was added to the above-mentioned monomer dispersion or black composition. Next, the above-mentioned monomer dispersion or black composition was spin-coated on a glass substrate so that the film thickness after firing was as shown in Table 1, and then pre-baked to evaporate the solvent to form a photoresist agent film. Further, after exposing the photoresist film to a predetermined pattern shape through a photomask, it is developed using an alkali developing solution to dissolve and remove the unexposed portion of the photoresist film, and then post-baking is performed to obtain a This respectively forms a black film. For these black films, based on the aforementioned formula (1), the OD values of ultraviolet rays (central wavelength: 370 nm) and visible light (central wavelength: 560 nm) were measured using a densitometer (densitometer) of the trade name D200 manufactured by Macbeth, respectively, and also The volume resistivity (Ω·cm) of the black films was measured, respectively. These results are shown in Table 1.

[Table 1]

As can be seen from Table 1, the zirconium nitride powders of Comparative Examples 1 and 10, that is, the zirconium nitride coarse powders were produced by the thermal agent method, but the zirconium nitride was not pulverized, but was carried out at a temperature of 350°C in a nitrogen atmosphere. The volume resistivity of the zirconium nitride powder obtained by holding the calcination for 4 hours in a compacted state with a pressure of 5 MPa was 1×10 ⁵ Ω·cm, respectively, which was lower than an appropriate range (1×10 ⁷ Ω cm or more), and the particle size distribution _D90 when ultrasonically dispersed for 5 minutes in the state of dilution with water was 30 μm, which was larger than an appropriate range (10 μm or less). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 1 in the acrylic monomer was 1.0, which was smaller than an appropriate range (2.0 or more), and the volume resistivity was 1×10 ⁶ Ω·cm , smaller than the appropriate range (1×10 ¹³ or more), and the coating film is uneven. In 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 an appropriate range (2.0 or more), and the volume resistivity was 1.9. 6×10 ¹² Ω·cm is smaller than an appropriate range (1×10 ¹³ or more).

The zirconium nitride powder of Comparative Example 3 was prepared as a coarse zirconium nitride powder by the 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 lower (low temperature wet medium pulverization). ), but the zirconium nitride powder obtained without calcining the zirconium nitride precursor powder has a particle size distribution D ₉₀ of 9 μm when it is ultrasonically dispersed for 5 minutes in a state of dilution with water, which is within an appropriate range (10 μm or less) , but the volume resistivity in the state of the compact compacted with a pressure of 5 MPa is 1×10 ⁶ Ω·cm, which is smaller than an appropriate range (1×10 ⁷ Ω·cm or more). In addition, although the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 3 in the acrylic monomer was 2.1, which was within an appropriate range (2.0 or more), the volume resistivity was 5×10 ¹¹ Ω cm, which is smaller than an appropriate range (1×10 ¹³ or more).

On the other hand, for the zirconium nitride powders of Examples 1 and 12, the zirconium nitride coarse powder was prepared by the thermal agent method, and the zirconium nitride was pulverized by the bead mill method with a dispersion medium temperature of 5°C or lower. The zirconium nitride powder obtained by calcining at a temperature of 350° C. for 4 hours in a nitrogen atmosphere after the (low-temperature wet-medium pulverization), the volume resistivity of the zirconium nitride powder in the state of a compact compacted with a pressure of 5 MPa respectively is 1×10 ⁸ Ω·cm, within the appropriate range (1×10 ⁷ Ω·cm or more), and the particle size distribution D ₉₀ of ultrasonic dispersion for 5 minutes in the state of dilution with water is 7 μm, respectively, within the appropriate range ( 10 μm or less). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 1 in an acrylic monomer was 2.1, and within an appropriate range (2.0 or more), the volume resistivity was 5×10 ¹³ Ω·cm , in an appropriate range (above 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, and the volume resistivity was within an appropriate range (2.0 or more). 5×10 ¹³ Ω·cm is within an appropriate range (1×10 ¹³ or more).

The zirconium nitride powder of Example 9 was prepared as a coarse zirconium nitride powder by a thermal agent method, and the zirconium nitride was pulverized by a bead mill method with a dispersion medium temperature of 5°C (low-temperature wet medium pulverization), and then the zirconium nitride was pulverized in a The zirconium nitride powder obtained by calcining at a temperature of 350° C. for 4 hours in a helium atmosphere has a volume resistivity of 8×10 ⁷ Ω·cm in the state of a compact compacted with a pressure of 5 MPa, In an appropriate range (1×10 ⁷ Ω·cm or more), the particle size distribution D ₉₀ when ultrasonically dispersed for 5 minutes in a state of dilution with water is 7 μm, which is in an appropriate range (10 μm or less). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 9 in the acrylic monomer was 2.2, and the volume resistivity was 3×10 ¹³ Ω·cm within an appropriate range (2.0 or more). , within an appropriate range (above 1×10 ¹³ ).

The zirconium nitride powder of Example 10 was prepared as a coarse powder of zirconium nitride by a thermal agent method, and the zirconium nitride was pulverized by a bead mill method with a dispersion medium temperature of 5°C (low-temperature wet medium pulverization), and then the The zirconium nitride powder obtained by calcining at a temperature of 350° C. for 4 hours in an argon atmosphere has a volume resistivity of 8×10 ⁷ Ω·cm in the state of a compact compacted with a pressure of 5 MPa, In an appropriate range (1×10 ⁷ Ω·cm or more), the particle size distribution D ₉₀ when ultrasonically dispersed for 5 minutes in a state of dilution with water is 9 μm, which is in an appropriate range (10 μm or less). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 10 in an acrylic monomer was 2.2, and within an appropriate range (2.0 or more), the volume resistivity was 3×10 ¹³ Ω·cm , within an appropriate range (above 1×10 ¹³ ).

On the other hand, the zirconium nitride powder of Comparative Example 2, that is, the zirconium nitride coarse powder was produced by the plasma method, but the zirconium nitride was not pulverized, but kept at a temperature of 350° C. for 4 hours in a nitrogen atmosphere The volume resistivity of the zirconium nitride powder obtained by sintering with a pressure of 5 MPa is 3×10 ⁴ Ω·cm, which is an appropriate range (1×10 ⁷ Ω·cm or more) Small, the particle size distribution _D90 when ultrasonically dispersed for 5 minutes in a state of dilution with water is 14 μm, which is larger than an appropriate range (10 μm or less). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 2 in an epoxy monomer was 1.2, which was smaller than an appropriate range (2.0 or more), and the volume resistivity was 2×10 ⁶ Ω·cm , which is smaller than the appropriate range (1×10 ¹³ or more).

The zirconium nitride powder of Comparative Example 4 was prepared as a zirconium nitride coarse powder by a plasma method, and the zirconium nitride coarse powder was pulverized by a bead mill method with a dispersion medium temperature of 5°C or lower (low temperature wet medium pulverization). ), but the zirconium nitride powder obtained without calcining the zirconium nitride precursor powder has a particle size distribution D ₉₀ of 5 μm when it is ultrasonically dispersed for 5 minutes in a state of dilution with water, which is within an appropriate range (10 μm or less) , but the volume resistivity in the state of the compact compacted with a pressure of 5 MPa is 2×10 ⁴ Ω·cm, which is smaller than an appropriate range (1×10 ⁷ Ω·cm or more). In addition, although the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 4 in an epoxy monomer was 2.0, which was within an appropriate range (2.0 or more), the volume resistivity was 2×10 ¹⁰ Ω cm, which is smaller than an appropriate range (1×10 ¹³ or more).

On the other hand, for the zirconium nitride powders of Examples 2 and 4, the zirconium nitride coarse powder was produced by the plasma method, and the zirconium nitride coarse powder was prepared by the bead mill method with the dispersion medium temperature of 5°C or lower. Volume resistance of zirconium nitride powder obtained by calcining at a temperature of 350° C. for 4 hours in a nitrogen atmosphere after pulverization (low-temperature wet medium pulverization) in a compacted state with a pressure of 5 MPa The particle size distribution D ₉₀ of ultrasonic dispersion for 5 minutes in the state of dilution with water is 5 μm, respectively, within the appropriate range (1× ^{10 7 Ω} ·cm or more). range (less than 10 μm). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 2 in an epoxy monomer was 2.2, and the volume resistivity was 2×10 ¹³ Ω·cm within an appropriate range (2.0 or more). , within an appropriate range (above 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, and within an appropriate range (2.0 or more), the volume resistivity was 1×10 ¹³ Ω·cm , within an appropriate range (above 1×10 ¹³ ).

On the other hand, the zirconium nitride powder of Comparative Example 5, that is, the zirconium nitride coarse powder was prepared by the thermal agent method, but the zirconium nitride coarse powder was dispersed in a temperature range higher than a suitable dispersion medium (10° C. or lower). Zirconium nitride powder obtained by pulverizing by the bead mill method at a medium temperature of 12°C (low-temperature wet medium pulverization), and then calcining at a temperature of 350°C for 4 hours in a nitrogen atmosphere, although diluted with water. The particle size distribution D ₉₀ at the time of ultrasonic dispersion for 5 minutes is 10 μm, which is in an appropriate range (10 μm or less), but the volume resistivity in the state of the compacted compact with a pressure of 5 MPa is 7×10 ⁶ Ω·cm, It is smaller than an appropriate range (1×10 ⁷ Ω·cm or more). In addition, although the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 5 in the acrylic monomer was 2.0, which was within an appropriate range (2.0 or more), the volume resistivity was 4×10 ¹² Ω cm, which is smaller than an appropriate range (1×10 ¹³ or more).

On the other hand, the zirconium nitride powder of Example 5 was prepared by the thermal agent method as a zirconium nitride coarse powder, and the zirconium nitride coarse powder was used in a suitable dispersion medium temperature range (below 10°C). The zirconium nitride powder obtained by pulverizing with a bead mill method at a dispersion medium temperature of 10°C (low-temperature wet medium pulverization), and calcining at a temperature of 350°C for 4 hours in a nitrogen atmosphere, was pressed under a pressure of 5 MPa. The volume resistivity in the solid compact state is 8×10 ⁷ Ω·cm, and the particle size distribution is within the appropriate range (1×10 ⁷ Ω·cm or more) after ultrasonic dispersion for 5 minutes in the state of dilution with water D ₉₀ is 10 μm, which is within an appropriate range (10 μm or less). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 5 in the acrylic monomer was 2.0, and the volume resistivity was 3×10 ¹³ Ω·cm within an appropriate range (2.0 or more). , within an appropriate range (above 1×10 ¹³ ).

On the other hand, the zirconium nitride powder of Comparative Example 6 was prepared as a coarse zirconium nitride powder by the thermal agent method, and the zirconium nitride coarse powder was pulverized by a bead mill method with a dispersion medium temperature of 5°C (low temperature). Wet media pulverization), but in a nitrogen atmosphere, the calcination temperature is 200 ℃ lower than the appropriate range (250 ℃ ~ 550 ℃), and the calcination time is kept within the appropriate range (1 hour ~ 5 hours) The zirconium nitride powder obtained by calcination for 4 hours has a particle size distribution D ₉₀ of 8 μm when ultrasonically dispersed for 5 minutes in a state of dilution with water, which is within an appropriate range (10 μm or less), but is compacted with a pressure of 5 MPa. The volume resistivity in the state of the green compact is 1×10 ⁶ Ω·cm, which is smaller than an appropriate range (1×10 ⁷ Ω·cm or more). In addition, although the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 6 in the acrylic monomer was 2.0, which was within an appropriate range (2.0 or more), the volume resistivity was 1×10 ¹² Ω cm, which is smaller than an appropriate range (1×10 ¹³ or more).

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

The zirconium nitride powder of Comparative Example 8 was prepared as a zirconium nitride coarse powder by a thermal agent method, and the zirconium nitride coarse powder was pulverized by a bead mill method with a dispersion medium temperature of 5°C (low temperature wet medium pulverization) However, in a nitrogen atmosphere, the calcination temperature is 600 ℃ higher than the appropriate range (250 ℃ ~ 550 ℃), and the calcination time is kept within the appropriate range (1 hour ~ 5 hours) for 1 hour. The obtained zirconium nitride powder had a volume resistivity of 4×10 ⁶ Ω·cm in the state of a compact compacted with a pressure of 5 MPa, which was smaller than an appropriate range (1×10 ⁷ Ω·cm or more), The particle size distribution D ₉₀ at the time of ultrasonic dispersion for 5 minutes in the state of dilution with water was 14 μm, which was larger than an appropriate range (10 μm or less). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 8 in the acrylic monomer was 1.2, which was smaller than the appropriate range (2.0 or more), and the volume resistivity was 1×10 ⁹ Ω·cm , which is smaller than the appropriate range (1×10 ¹³ or more).

On the other hand, the zirconium nitride powder of Example 6 was prepared as a coarse powder of zirconium nitride by a thermal agent method, and the coarse powder of zirconium nitride was pulverized by a bead mill method with a dispersion medium temperature of 5°C ( After low temperature wet medium pulverization), it is carried out in a nitrogen atmosphere at a calcination temperature of 250 ℃ within the appropriate range (250 ℃ ~ 550 ℃), and the calcination time is kept within the appropriate range (1 hour ~ 5 hours) The zirconium nitride powder obtained by firing for 4 hours has a volume resistivity of 3×10 ⁷ Ω·cm in the state of a compact compacted with a pressure of 5 MPa, which is in an appropriate range (1×10 ⁷ Ω·cm). cm or more), the particle size distribution D ₉₀ at the time of ultrasonic dispersion for 5 minutes in the state of dilution with water is 8 μm, which is within an appropriate range (10 μm or less). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 6 in an acrylic monomer was 2.0, and within an appropriate range (2.0 or more), the volume resistivity was 2×10 ¹³ Ω·cm , within an appropriate range (above 1×10 ¹³ ).

The zirconium nitride powder of Example 7 was prepared as a coarse zirconium nitride powder 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 (low-temperature wet medium pulverization). , in a nitrogen atmosphere, the calcination temperature is 350 ℃ within the appropriate range (250 ℃ ~ 550 ℃), and the calcination time is kept within the appropriate range (1 hour ~ 5 hours) for 1 hour. The obtained zirconium nitride powder has a volume resistivity of 1×10 ⁷ Ω·cm in the state of a compact compacted with a pressure of 5 MPa, which is within an appropriate range (1×10 ⁷ Ω·cm or more), The particle size distribution D ₉₀ at the time of ultrasonic dispersion for 5 minutes in the state of dilution with water is 7 μm, which is within an appropriate range (10 μm or less). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 7 in an acrylic monomer was 2.0, and within an appropriate range (2.0 or more), the volume resistivity was 1×10 ¹³ Ω·cm , within an appropriate range (above 1×10 ¹³ ).

The zirconium nitride powder of Example 8 was prepared as a coarse zirconium nitride powder 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 (low-temperature wet medium pulverization). , in a nitrogen atmosphere, the calcination temperature is 550 ℃ in the appropriate range (250 ℃ ~ 550 ℃), and the calcination time is kept in the appropriate range (1 hour ~ 5 hours) for 1 hour. The obtained zirconium nitride powder has a volume resistivity of 1×10 ⁸ Ω·cm in the state of a compact compacted with a pressure of 5 MPa, which is within an appropriate range (1×10 ⁷ Ω·cm or more), and is in the range of 1×10 8 Ω·cm. The particle size distribution D ₉₀ of 5 minutes of ultrasonic dispersion in the state of dilution with water is 8 μm, which is within an appropriate range (10 μm or less). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 8 in an acrylic monomer was 2.4, and within an appropriate range (2.0 or more), the volume resistivity was 1×10 ¹⁴ Ω·cm , within an appropriate range (above 1×10 ¹³ ).

On the other hand, the zirconium nitride powder of Comparative Example 9, that is, the zirconium nitride coarse powder was produced by the thermal agent method, but the pulverization pressure of the zirconium nitride coarse powder was smaller than an appropriate range (0.3 MPa or more) Zirconium nitride powder obtained by jet mill pulverization at a pulverization pressure of 0.2 MPa, calcined at a temperature of 350° C. for 4 hours in a nitrogen atmosphere, in a compacted state with a pressure of 5 MPa The volume resistivity is 2×10 ⁶ Ω·cm, which is smaller than the appropriate range (1×10 ⁷ Ω·cm or more), and the particle size distribution D ₉₀ when ultrasonically dispersed for 5 minutes in the state of dilution with water is 14 μm, which is an appropriate The range (below 10 μm) is large. In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Comparative Example 9 in an epoxy monomer was 1.3, which was smaller than an appropriate range (2.0 or more), and the volume resistivity was 1×10 ¹¹ Ω·cm , which is smaller than the appropriate range (1×10 ¹³ or more).

On the other hand, the zirconium nitride powder of Example 3 was prepared by the thermal agent method as a zirconium nitride coarse powder, and the zirconium nitride coarse powder was pulverized in a suitable range (0.3MPa or more) with a pulverization pressure. Zirconium nitride powder obtained by jet mill pulverization at a pulverization pressure of 0.5 MPa, calcined at a temperature of 350° C. for 4 hours in a nitrogen atmosphere, in a compacted state with a pressure of 5 MPa The volume resistivity is 2×10 ⁸ Ω·cm, and within an appropriate range (1×10 ⁷ Ω·cm or more), the particle size distribution D ₉₀ when ultrasonically dispersed for 5 minutes in the state of dilution with water is 6 μm. range (below 10 μm). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 3 in an epoxy monomer was 2.2, and within an appropriate range (2.0 or more), the volume resistivity was 2×10 ¹⁴ Ω·cm , within an appropriate range (above 1×10 ¹³ ).

The zirconium nitride powder of Example 11 was prepared as a coarse zirconium nitride powder by a thermal agent method, and the zirconium nitride coarse powder was pulverized under a pulverization pressure of 0.3 MPa within an appropriate range (0.3 MPa or more). The zirconium nitride powder of Example 3 obtained by calcining at a temperature of 350° C. for 4 hours in a nitrogen atmosphere after being pulverized by a jet mill, in the state of a compact compacted with a pressure of 5 MPa The resistivity is 2×10 ⁷ Ω·cm, within the appropriate range (1×10 ⁷ Ω·cm or more), and the particle size distribution D ₉₀ when ultrasonically dispersed for 5 minutes in the state of dilution with water is 10 μm, which is within the appropriate range (10 μm or less). In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 11 in an epoxy monomer was 2.4, and within an appropriate range (2.0 or more), the volume resistivity was 1×10 ¹³ Ω·cm , within an appropriate range (above 1×10 ¹³ ).

Industrial Availability

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

Claims (6)

1. Zirconium nitride powder having a volume resistivity of 10 in the state of a green compact compacted with a pressure of 5MPa⁷A particle size distribution D of not less than Ω · cm and obtained by ultrasonic dispersion for 5 minutes in a state diluted with water or an alcohol having 2 to 5 carbon atoms₉₀Is 10 μm or less.

2. A method of preparing zirconium nitride powder, the method comprising:

a step of forming a zirconium nitride coarse powder by a thermite method or a plasma synthesis method;

a step of producing a zirconium nitride precursor powder having a particle size distribution D obtained by subjecting the zirconium nitride precursor powder to low-temperature wet medium pulverization at a dispersion medium temperature of 10 ℃ or lower or to jet mill pulverization at an air pressure of 0.3MPa or higher, the zirconium nitride precursor powder having a particle size distribution D obtained by ultrasonic dispersion for 5 minutes in a state diluted with water or an alcohol having 2 to 5 carbon atoms₉₀Is less than 10 μm; and

a step of preparing a zirconium nitride powder having a volume resistivity of 10 in a state of a green compact compacted with a pressure of 5MPa by calcining the pulverized zirconium nitride precursor powder in an inert gas atmosphere⁷Omega cm or more.

3. A monomer dispersion obtained by dispersing the zirconium nitride powder according to claim 1 in an acrylic monomer or an epoxy monomer.

4. A black composition obtained by dispersing the zirconium nitride powder according to claim 1 as a black pigment in a dispersion medium and mixing a resin.

5. The manufacturing method of the black film comprises the following steps:

a step of forming a coating film by applying the monomer dispersion according to claim 3 onto a substrate, and

and a step of producing a black film by thermally curing or ultraviolet-curing the coating film.

6. The manufacturing method of the black film comprises the following steps:

a step of forming a coating film by applying the black composition according to claim 4 onto a substrate, and

and a step of producing a black film by thermally curing or ultraviolet-curing the coating film.