KR20220056680A - Zirconium nitride powder and production method therefor - Google Patents

Abstract

The present invention relates to zirconium nitride powder having high insulation property and high blackness. The zirconium nitride powder according to the present invention has a volumetric resistance of 10^7 Ω.cm or more in the state of compressed powder hardened under a pressure of 5 MPa and shows a particle size distribution D_90 of 10 micrometers or less when the same is diluted with a C2-C5 alcohol and dispersed with ultrasonication for 5 minutes. In addition, a monomer dispersion is obtained by dispersing the zirconium nitride powder in an acryl monomer or epoxy monomer. Further, the zirconium nitride powder as a black pigment is dispersed in a dispersion medium and mixed with a resin to prepare a black colored composition.

Description

Zirconium nitride powder and its manufacturing method

The present invention relates to a zirconium nitride powder preferably used as a black pigment having high ultraviolet transmittance and high blackness, and having high insulating properties, and a method for producing the same.

Conventionally, the specific surface area measured by the BET method is 20 m / g to 90 m / g, and in the X-ray diffraction profile, it has a peak of zirconium nitride, while having a peak of zirconium dioxide and a peak of lower-order zirconium oxide. A zirconium nitride powder is disclosed (see, for example, Patent Document 1 (Claim 1, Paragraph [0016]). This zirconium nitride powder has a light transmittance X of at least 18% at 370 nm in the dispersion liquid transmission spectrum with a powder concentration of 50 ppm, and a light transmittance Y at 550 nm of 12% or less, with respect to the light transmittance X at 370 nm. The light transmittance Y (X/Y) of 550 nm is 2.5 or more.

Since the specific surface area of the zirconium nitride powder constituted in this way is 20 m 2 /g or more, there is an effect of suppressing sedimentation when it is used as a resist, and since it is 90 m 2 /g or less, there is an effect of having sufficient light-shielding properties. In addition, in the X-ray diffraction profile, while having a peak of zirconium nitride, it does not have a peak of zirconium dioxide, a peak of a lower-order zirconium oxide, and a peak of a lower-order zirconium oxynitride, so in the dispersion liquid transmission spectrum with a powder concentration of 50 ppm, 370 The light transmittance X at nm is at least 18%, the light transmittance Y at 550 nm has the characteristics of 12% or less, and X/Y has the characteristics of 2.5 or more. When X/Y is 2.5 or more, there exists a feature which transmits an ultraviolet-ray further. As a result, when forming a black patterning film as a black pigment, a high-resolution patterning film can be formed, and the formed patterning film has high light-shielding performance.

Japanese Laid-Open Patent Publication No. 2017-222559

In the zirconium nitride powder shown in Patent Literature 1, high insulation is obtained by dispersing a coarse zirconium nitride powder in a dispersion medium and increasing the dispersibility using a bead mill (media: zirconia) or the like, but this zirconium nitride When the powder is directly kneaded into a high-viscosity resin paste, coarse zirconium nitride powder remains and the dispersibility is insufficient. For this reason, when zirconium nitride powder was used as a black pigment, while the coloring power of a black coating material fell, there existed a problem that a resistance value became low by residual zirconium nitride coarse powder. In addition, when the coarse zirconium nitride powder is forcibly pulverized with a dry pulverizer or the like, the powder diameter becomes small and an oxidation reaction on the surface of the powder occurs, so that the insulating property is improved, but there is a problem in that the blackness of the black paint is lowered.

The 1st objective of this invention is providing the zirconium nitride powder which has high insulation while being able to obtain high insulation and high blackness, and its manufacturing method. A second object of the present invention is to provide a method for producing a zirconium nitride powder capable of maintaining high blackness by grinding with a low-temperature wet media or by grinding in a jet mill with a small calorific value. It is a 3rd object of this invention to provide the manufacturing method of the zirconium nitride powder which can improve the insulation of a black film by baking in an inert gas atmosphere.

A first aspect of the present invention provides a volume resistivity of 10 ⁷ Ω·cm or more in the state of a green compact hardened at a pressure of 5 MPa, and diluted with water or alcohol having 2 to 5 carbon atoms for 5 minutes It is a zirconium nitride powder whose particle size distribution D90 at the time of ultrasonic dispersion is ₁₀ micrometers or less.

A second aspect of the present invention is a step of producing a coarse zirconium nitride powder by the thermite method or plasma synthesis method, and performing low-temperature wet media grinding of the coarse zirconium nitride powder at a dispersion medium temperature of 10° C. or less, or 0.3 MPa or more A step of producing a zirconium nitride precursor powder having a particle size distribution D ₉₀ of 10 μm or less when ultrasonically dispersed for 5 minutes in a state of being diluted with water or alcohol having 3 to 5 carbon atoms by performing jet mill pulverization with gas pressure; By calcining this pulverized zirconium nitride precursor powder in an inert gas atmosphere, a zirconium nitride powder having a volume resistivity of 10 ⁷ Ω·cm or more in the state of a green compact hardened at a pressure of 5 MPa is produced. manufacturing method.

A third aspect of the present invention is a monomer dispersion in which the zirconium nitride powder according to the first aspect is dispersed in an acrylic monomer or an epoxy monomer.

A fourth aspect of the present invention is a black composition in which the zirconium nitride powder described in the first aspect is dispersed as a black pigment in a dispersion medium and further mixed with a resin.

A fifth aspect of the present invention is a method for producing a black film, comprising a step of forming a coating film by applying the monomer dispersion according to the third aspect to a substrate, and a step of thermosetting or UV curing the coating film to produce a black film. .

A sixth aspect of the present invention is a method for producing a black film, comprising a step of applying the black composition according to the fourth aspect to a substrate to form a coating film, and a step of thermosetting or UV curing the coating film to produce a black film.

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 the state of a green compact hardened at a pressure of 5 MPa, when a black thick film having a thickness of about 10 μm to 100 μm is produced Insulation can be improved. In addition, the zirconium nitride powder has a particle size distribution D ₉₀ of 10 µm or less when ultrasonically dispersed for 5 minutes in a state of being diluted with water or alcohol having 2 to 5 carbon atoms, so there is no coarse zirconium nitride powder, which is good A dispersion or a dispersion liquid can be obtained. As a result, the black film manufactured with the dispersion or dispersion liquid using the said zirconium nitride powder has high insulation while being able to obtain high insulation and high blackness.

In the method for producing zirconium nitride powder of the second aspect of the present invention, when the coarse zirconium nitride powder is subjected to low-temperature wet media grinding at a dispersion medium temperature of 10 ° C. or less, the calorific value is small, so the surface oxidation of zirconium nitride does not proceed, High blackness can be maintained. Moreover, when the coarse zirconium nitride powder is jet milled with a gas pressure of 0.3 MPa or more, the coarse zirconium nitride powder does not remain, and the insulation of the black film can be improved. In addition, by calcining the pulverized zirconium nitride precursor powder in an inert gas atmosphere, the insulation of the black film can be improved.

In the monomer dispersion of the third aspect of the present invention, since the zirconium nitride powder of the first aspect of the present invention is dispersed in an acrylic monomer or an epoxy monomer, even if the viscosity of these monomers is relatively high, the zirconium nitride powder of the monomer is Acidity can be maintained favorably. As a result, the black film|membrane using a monomer dispersion has high insulation while being able to obtain high insulation and high blackness.

In the black composition of the fourth aspect of the present invention, the zirconium nitride powder of the first aspect of the present invention is dispersed as a black pigment in a dispersion medium and a resin is further mixed, so that the zirconium nitride powder is uniformly dispersed in the dispersion medium. As a result, while being able to obtain high insulation and high blackness, the black film using a black composition has high insulation.

In the method for producing a black film of the fifth aspect of the present invention, after forming a coating film by applying the monomer dispersion to a substrate, this coating film is thermally cured or UV cured to prepare a black film, so the black film has high insulation and high black While being able to obtain a degree, it has high insulation.

In the method for producing a black film of the sixth aspect of the present invention, after the black composition is applied to a substrate to form a coating film, and then the coating film is thermally cured or UV cured to prepare a black film, the black film has high insulating properties and high blackness can be obtained and has high insulation properties.

Next, the form for implementing this invention is demonstrated. The zirconium nitride powder of this embodiment has a volume resistivity of 10 ⁷ Ω·cm or more, preferably 10 ⁸ Ω·cm or more, in the state of a green compact hardened at a pressure of 5 MPa, and has water or carbon number of 2 to 5 The particle size distribution D ₉₀ when ultrasonically dispersed for 5 minutes in a state of being diluted with alcohol within the range is 10 µm or less, preferably 8 µm or less. Here, when the volume resistivity is limited to 10 ⁷ Ω·cm or more, when the volume resistivity is less than 10 ⁷ Ω·cm, a black thick film having a thickness of about 1 μm to 100 μm is produced using zirconium nitride powder. Because. Moreover, the reason that the said particle size distribution D90 is limited to ₁₀ micrometers or less is because when it exceeds 10 micrometers, a coarse zirconium nitride powder remains and a favorable dispersion and a black film cannot be obtained.

The said volume resistivity is measured by the four-point probe method using the low resistivity meter Loresta GP (model: UV-3101PC) by Mitsubishi Chemical Corporation, for example. In this four-point probe method, four needle electrodes are placed in a straight line with a predetermined interval on the surface of the sample (green body), a constant current is passed between the two outer needle electrodes, and a constant current is passed between the two inner needle electrodes. It is a method to obtain the volume resistivity by measuring the potential difference occurring in

In addition, a zirconium nitride powder is a state of the secondary particle|grains which primary particles aggregated, and is a volume-based particle size distribution measured by the 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 particle) is thrown into 20 g of ion-exchange water, 25 kHz ultrasonic wave is irradiated for 5 minutes, and a zirconium nitride powder is disperse|distributed to ion-exchange water. Next, the dispersion liquid of the obtained zirconium nitride powder is dripped at the observation cell of the laser diffraction scattering type particle size distribution analyzer (Horiba Corporation brand name: LA-300), an appropriate amount is dripped, The particle size distribution is measured according to the procedure of this apparatus. The particle size distribution measured by this laser diffraction scattering method is the particle size distribution of the secondary particle|grains which the primary particle of zirconium nitride powder aggregated. Moreover, you may use the alcohol in the range of C2-C5 instead of ion-exchange water. Examples of the C2 alcohol include ethanol, examples of the C3 alcohol include 1-propanol and 2-propanol, and examples of the C4 alcohol include 1-butanol and 2-butanol; Examples of the alcohol having 5 carbon atoms include 1-pentanol and 2-pentanol. In addition, if the carbon number is 1 or less, there is a problem that the measured value is not stable due to high volatility, and if the carbon number is 6 or more, there is a problem that the measured value is not stable due to insufficient affinity.

The manufacturing method of the zirconium nitride powder comprised in this way is demonstrated. First, a coarse zirconium nitride powder is produced by a thermite method or a plasma synthesis method. In the present specification, the thermite method refers to a method for reducing zirconium oxide powder by reacting it with N ₂ gas (nitrogen gas) in the presence of magnesium metal. In this embodiment, as the zirconium oxide powder, a zirconium dioxide (ZrO ₂ ) powder or a silica-coated zirconium dioxide (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 calcined under a specific atmosphere at a specific temperature and time to produce a coarse zirconium nitride powder having a specific surface area of 20 m 2 /g to 90 m 2 /g measured by the BET method.

[Zirconium Dioxide Powder]

As zirconium dioxide powder, all of the powders of zirconium dioxide, such as monoclinic zirconium dioxide, cubic zirconium dioxide, and yttrium stabilized zirconium dioxide, can be used, For example, From a viewpoint of the production rate of zirconium nitride powder becoming high, monoclinic zirconium dioxide Powders are preferred. In addition, each average primary particle diameter of zirconium dioxide powder or silica-coated zirconium dioxide powder and the average primary particle diameter of magnesium oxide powder are zirconium nitride whose specific surface area is 20 m 2 /g to 90 m 2 /g measured by the BET method. In order to obtain a coarse powder, the average primary particle diameter in terms of spherical conversion from the measured value of the specific surface area is preferably 500 nm or less, and from the viewpoint of easy handling of the powder, the average primary particle diameter is preferably 500 nm or less and 10 nm or more.

[Silica-coated zirconium dioxide powder]

The silica-coated zirconium dioxide powder is obtained by mixing zirconium dioxide powder and a silicate sol gel liquid to prepare a slurry, drying the slurry and pulverizing it. The mixing ratio of zirconium dioxide and silicate sol gel liquid is preferably zirconium dioxide: silica content of silicate sol gel liquid (90.0 to 99.5): (10.0 to 0.5) in mass ratio. When the silica content is less than the lower limit, the silica coverage on the surface of zirconium dioxide is too low, and when the silica content exceeds the upper limit, there is a problem of insufficient light-shielding property when a patterning film is formed using the obtained zirconium nitride powder.

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

By using the silica-coated zirconium dioxide powder as the starting material, it becomes possible to suppress grain growth during firing, and a finer specific surface area measured by the BET method of 20 m 2 /g to 90 m 2 /g Zirconium nitride powder can be obtained. At this time, zirconium nitride powder is 10.0 mass % or less of silicon oxide and/or silicon nitride, Preferably it contains in the ratio of 9.0 mass % or less. When it exceeds 10.0 mass % and a patterning film is formed using the obtained zirconium nitride powder, there exists a problem that light-shielding property is insufficient.

[Metal Magnesium Powder]

When the particle size of the metallic magnesium powder is too small, the reaction proceeds rapidly and the operational risk increases. Therefore, it is preferable that the particle size is 100 µm to 1000 µm granular in the mesh pass of the sieve, especially 200 µm to 500 µm It is preferable that it is granular. However, even if none of metallic magnesium is within the said particle diameter range, 80 mass % or more, especially 90 mass % or more should just be in the said range.

A large amount of the metal magnesium powder added to the zirconium dioxide powder affects the reducing power of zirconium dioxide together with the amounts of ammonia gas and hydrogen gas in atmospheric gas which will be described later. When the amount of metallic magnesium is too small, the target zirconium nitride powder cannot be easily obtained due to insufficient reduction. It becomes uneconomical with existence. The metallic magnesium powder is mixed by adding the metallic magnesium powder to the zirconium dioxide powder so that the metallic magnesium is in a ratio of 2.0 to 6.0 moles of zirconium dioxide, depending on the size of the particle size. If it is less than 2.0 times mole, the reduction reaction of zirconium dioxide is insufficient, and if it exceeds 6.0 times mole, the reaction temperature rises rapidly due to excess metallic magnesium, which may cause grain growth of the powder and is uneconomical. do.

[Magnesium Nitride Powder]

Magnesium nitride powder coats the surface of zirconium nitride during firing to relieve the reducing power of metallic magnesium and prevents sintering and grain growth of the zirconium nitride powder. Magnesium nitride powder is added and mixed with zirconium dioxide so that magnesium nitride may become a ratio of 0.3 times mole - 3.0 times mole of zirconium dioxide according to the size of the particle size. If it is less than 0.3 times mole, sintering of the zirconium nitride powder cannot be prevented, and if it exceeds 3.0 times mole, there is a problem in that the amount of the acidic solution used at the time of acid washing after baking increases. Preferably it is 0.4 times mole - 2.0 times mole. The magnesium nitride powder preferably has an average primary particle diameter of 1000 nm or less in terms of spherical conversion from the measured value of the specific surface area, and is preferably 10 nm or more and 500 nm or less in average primary particle diameter from the viewpoint of easy handling of the powder. In addition, not only magnesium nitride but also magnesium oxide is effective in preventing sintering of zirconium nitride, and therefore magnesium oxide may be mixed with some magnesium oxide and used.

[Reduction reaction by metallic magnesium powder]

The temperature at the time of the reduction reaction by the metallic magnesium for producing|generating the zirconium nitride coarse powder is 650 degreeC - 900 degreeC, Preferably it is 700 degreeC - 800 degreeC. 650°C is the melting temperature of metallic magnesium, and when the temperature is lower than that, 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, heat energy is wasted, and sintering of the powder proceeds, which is undesirable. Moreover, 30 minutes - 90 minutes are preferable, and, as for the reduction reaction time, 30 minutes - 60 minutes are more preferable.

It is preferable that the reaction container at the time of performing the said reduction reaction has a cover so that a raw material and a product may not scatter at the time of reaction. This is because, when the melting of metallic magnesium is started, the reduction reaction proceeds rapidly, and the temperature rises with it, and the gas inside the container expands, and as a result, there is a possibility that the inside of the container is scattered to the outside. .

[Atmospheric gas during reduction reaction with metallic magnesium powder]

Atmospheric gas is a single nitrogen gas, a mixed gas of nitrogen gas and hydrogen gas, or a mixed gas of nitrogen gas and ammonia gas. The reduction reaction is carried out in an airflow of the mixed gas. Nitrogen gas in the mixed gas prevents contact of magnesium metal, a reduction product, and oxygen, prevents oxidation thereof, and reacts nitrogen with zirconium to form zirconium nitride. Hydrogen gas or ammonia gas in the mixed gas has a role of reducing zirconium dioxide together with metallic magnesium. It is preferable to contain 0 volume% - 40 volume% in the said mixed gas, and, as for hydrogen gas, it is more preferable to contain 10 volume% - 30 volume%. Moreover, it is preferable to contain 0 volume% - 50 volume% in the said mixed gas, and, as for ammonia gas, it is more preferable to contain 0 volume% - 40 volume%. By using the atmospheric gas with this reducing power, finally, the zirconium nitride powder which does not contain a low-order zirconium oxide and a low-order oxynitride can be manufactured. On the other hand, when the ratio of hydrogen gas or the ratio of ammonia gas is higher than this range, although reduction advances, since a nitrogen source decreases, a low-order zirconium oxide or a low-order oxynitride is produced|generated, and it is unpreferable. The reason that the ratio of ammonia gas is higher than that of hydrogen gas is considered to be because ammonia has a higher nitridation capability than hydrogen.

On the other hand, the production method of the zirconium nitride coarse powder by the plasma synthesis method is a method of introducing a metal zirconium powder into a plasma nanoparticle manufacturing apparatus, and obtaining zirconium nitride nanoparticles in an N ₂ gas atmosphere. The zirconium nitride synthesized by this method can be obtained with a specific surface area measured by the BET method of 20 m / g to 90 m / g, but the flammability of the metal zirconium as a raw material is high, dangerous, and the cost is high. There are disadvantages. In addition, the nanoparticles produced by the plasma synthesis method are coarsened by rapid surface oxidation, adhesion, aggregation, etc. in the cooling process and product taking out process, and become coarse powder. What was produced was also made into coarse zirconium nitride powder.

Next, this coarse zirconium nitride powder is subjected to low-temperature wet media grinding at a dispersion medium temperature of 10 ° C. or less or jet mill grinding at a gas pressure of 0.3 MPa or more, diluted with water or alcohol having 3 to 5 carbon atoms. A zirconium nitride precursor powder having a particle size distribution D ₉₀ of 10 μm or less when ultrasonically dispersed in the state of being dispersed for 5 minutes is prepared. In addition, the specific surface area measured by the BET method of this zirconium nitride precursor powder is 22 m<2>/g - 120 m<2>/g.

In the low-temperature wet media grinding method, coarse zirconium nitride powder is dispersed in a dispersion medium such as ion-exchanged water or alcohol having 2 to 5 carbon atoms, and zirconia having an average particle size of 50 µm to 500 µm while the temperature of the dispersion medium is maintained at 10°C or less. , refers to a bead mill grinding method using media such as alumina, glass, or urethane resin. Here, the reason why the temperature of the dispersion medium is maintained at 10°C or lower is that, when the temperature exceeds 10°C, pulverization of the zirconium nitride precursor powder advances and the OD value of the black film described later decreases. In addition, in order to maintain the dispersion medium temperature at 10° C. or less, liquid nitrogen may be used as the dispersion medium, or dry ice beads may be used as the medium. Further, when the coarse zirconium nitride powder is pulverized by the above-mentioned low-temperature wet media pulverization method, since the amount of heat generated is small, the surface oxidation of zirconium nitride does not proceed, and high blackness can be maintained.

In addition, in jet mill pulverization with a gas pressure of 0.3 MPa or more, high-pressure air of 0.3 MPa or more, an inert gas such as nitrogen, or steam injected from a nozzle are collided with the powder as an ultra-high speed jet, It refers to a device that pulverizes to fine powder, and the air or steam sprayed reaches before and after the speed of sound. As a characteristic of the jet mill, since the temperature is lowered by the adiabatic expansion of the injected gas, it is possible to grind at a low temperature, and it is possible to suppress oxidation even with a reducing substance such as zirconium nitride in the present invention. Here, the reason that the said gas pressure is limited to 0.3 MPa or more is because the zirconium nitride coarse powder remains when it is less than 0.3 MPa. In addition, when the coarse zirconium nitride powder is pulverized by the jet mill grinding method, the coarse zirconium nitride powder does not remain and the insulation of the black film can be improved.

Further, by calcining the pulverized zirconium nitride precursor powder in an inert gas atmosphere, a zirconium nitride powder having a volume resistivity of 10 ⁷ Ω·cm or more in the state of a green compact hardened at a pressure of 5 MPa is produced. Examples of the inert gas include N ₂ gas, helium gas, and argon gas. It is preferable that the said calcination temperature exists in the range of 250 degreeC - 550 degreeC, and it is preferable that calcination time exists in the range of 1 hour - 5 hours. Here, the reason why the preferable firing temperature is limited to within the range of 250°C to 550°C is that the increase in resistance value is insufficient when it is less than 250°C, and when it exceeds 550°C, fusion of the powders proceeds and the coarse powder increases. . Moreover, the reason why the preferable firing time is limited to within the range of 1 hour to 5 hours is that if less than 1 hour, the increase in resistance value is insufficient, and even if it exceeds 5 hours, the effect does not change and it is uneconomical. In addition, the insulation of the black film can be improved by firing the zirconium nitride precursor powder in an inert gas atmosphere. Although the detailed mechanism by which the insulation of the black film is improved by firing in an inert gas atmosphere is not clear, the coarse powder of zirconium nitride is lost, the uniformity of the powder is improved, the contact points are reduced, and the surface of the black film is ultra-thin insulation It is presumed to originate from the formation of a layer.

The zirconium nitride powder is dispersed in an acrylic monomer or an epoxy monomer to prepare a monomer dispersion. This monomer dispersion is useful for uses, such as a resin composition containing an inorganic powder disperse|distributed, and a resin molded object. In addition, the monomer dispersion may further contain a metal oxide powder and further contain a plasticizer. Although it does not specifically limit as a plasticizer, For example, Phosphate ester plasticizers, such as tributyl phosphate and 2-ethylhexyl phosphate, phthalate ester plasticizers, such as dimethyl phthalate and dibutyl phthalate, butyl oleate, glycerol monooleate ester aliphatic-basic ester plasticizers, such as aliphatic dibasic acid ester plasticizers, such as dibutyl adipate and di-2-ethylhexyl sebacate; dihydric alcohol ester plasticizers such as diethylene glycol dibenzoate and triethylene glycol di-2-ethyl butyrate; A conventionally well-known plasticizer, such as an oxy acid ester type plasticizer, such as methyl acetyl ricinoleate and tributyl acetyl citrate, is mentioned. In addition, other monomers can be further added to the monomer dispersion. There is no limitation in particular as another monomer, For example, (meth)acrylic-type monomers, such as (meth)acrylic acid and (meth)acrylic acid ester, styrene-type monomers, such as styrene, vinyltoluene, divinylbenzene, vinyl chloride, acetic acid A conventionally well-known monomer, such as vinyl-type monomers, such as vinyl, urethane-type monomers, such as urethane acrylate, and the said various polyols, is mentioned. In addition, the viscosity of the monomer dispersion is preferably set within the range of 10 Pa·s to 1000 mPa·s in consideration of the dispersibility of the zirconium nitride powder. The dispersion with respect to a monomer can also use the mill method using a grinding|pulverization media similarly to dispersion|distribution with respect to a solvent. Moreover, although it is not an essential component, in order to improve dispersibility more, a polymer dispersing agent can also be used. Polymer dispersants having a molecular weight of several thousand to tens of thousands are effective, and examples of the functional group adsorbed to the pigment include secondary amines, tertiary amines, carboxylic acids, phosphoric acid, phosphoric acid esters, and the like. Acids are available. Instead of the polymer dispersing agent, adding a small amount of a silane coupling agent is also effective for improving the dispersibility. On the other hand, after performing planetary stirring, it is also possible to pass three rolls several times to obtain a dispersion liquid. On the other hand, a black composition in which zirconium nitride powder is dispersed as a black pigment in a dispersion medium and further mixed with a resin is prepared. Examples of the dispersion medium include propylene glycol monomethyl ether acetate (PGMEA), methyl ethyl ketone (MEK), and butyl acetate (BA). Moreover, as said resin, an acrylic resin, an epoxy resin, etc. are mentioned. Also for solvent-based dispersion, the addition of a polymer dispersant is effective as in monomer dispersion, and similarly to monomer dispersion, those having a molecular weight of several thousand to tens of thousands are effective, and tertiary amines and carboxylic acids are effective as functional groups.

Next, a method for producing a black film using the monomer dispersion will be described. First, a photoinitiator is added to the monomer dispersion, and then this monomer dispersion is applied to a substrate to form a coating film. Next, this coating film is heat-cured or UV-cured to prepare a black film. Examples of the substrate include glass, silicone, polycarbonate, polyester, aromatic polyamide, polyamideimide, and polyimide. Further, the substrate may be subjected to appropriate pretreatment such as chemical treatment with a silane coupling agent or the like, plasma treatment, ion plating, sputtering, vapor phase reaction method, vacuum deposition, or the like, if desired. When apply|coating a monomer dispersion to a board|substrate, appropriate application|coating methods, such as rotation application|coating, cast application|coating, roll application|coating, are employable.

In order to thermoset the said coating film, it is preferable to hold|maintain for 5 minutes - 60 minutes at the temperature of 80 degreeC - 250 degreeC in air|atmosphere. Here, the reason why the thermal curing temperature of the coating film is limited within the range of 80°C to 250°C is that the coating film does not sufficiently harden when it is less than 80°C, and the substrate becomes softened when it exceeds 250°C. In addition, the reason that the thermal curing time of the coating film is limited to within the range of 5 minutes to 60 minutes is that the coating film does not fully cure when it is less than 5 minutes, and it takes more time than necessary when it exceeds 60 minutes, which is uneconomical. On the other hand, in order to UV-curing the coating film, Irgacure 184 (manufactured by BASF), Irgacure 250 (manufactured by BASF), Irgacure 270 (manufactured by BASF), Irgacure 369 (manufactured by BASF) in advance in the monomer dispersion A photoinitiator cleaved by ultraviolet rays such as Irgacure 500 (manufactured by BASF Corporation), Irgacure 907 (manufactured by BASF Corporation), and Adeka Optomer N-1919 (manufactured by ADEKA Corporation) is added. And after apply|coating this monomer dispersion to which this photoinitiator was added on a board|substrate, prebaking is performed, the solvent is evaporated, and a photoresist film is formed. Next, the photoresist film is exposed in a predetermined pattern shape through a photomask, developed using an alkali developer, and the unexposed portion of the photoresist film is dissolved and removed, and then preferably post-baking is performed. A predetermined black film is formed.

It is preferable that the film thickness of the black film|membrane after hardening exists in the range of 0.1 micrometer - 100 micrometers. In particular, it is suitable for production of a thick black film having a film thickness of 10 µm to 100 µm. In addition, the OD value (Optical Density value) of a black film|membrane is an optical density as an index|index which shows the light-shielding property (attenuation of transmittance) of the black film|membrane using zirconium nitride powder. Specifically, the OD value is a logarithmic expression of the degree to which light is absorbed when passing through the 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 = -log ₁₀ (I/I ₀ ) … … … … (One)

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

A method for producing a black film using the black composition will be described. First, a black composition is applied to a substrate to form a coating film. Next, this coating film is heat-cured or UV-cured to prepare a black film. Since the manufacturing method of the black film using this black composition is substantially the same as the manufacturing method of the black film using the said monomer dispersion, repeated description is abbreviate|omitted.

Example

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

<Example 1>

First, a coarse zirconium nitride powder was prepared by the Thermite method. Specifically, to 7.4 g of monoclinic zirconium dioxide powder having an average primary particle size 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 size of 150 μm and an average primary particle size of 200 nm 3.0 g of phosphorus magnesium nitride powder was added, and it mixed uniformly by the reactor which built-in the boat of graphite in the glass tube made from quartz. At this time, the addition amount of metallic magnesium was 5.0 times mole of zirconium dioxide, and the addition amount of magnesium nitride was 0.5 times mole of zirconium dioxide. This mixture was calcined for 60 minutes at a temperature of 700°C in an atmosphere of nitrogen gas to obtain a calcined product. This calcined product is dispersed in 1 liter of water, 10% hydrochloric acid is gradually added, the pH is 1 or more, and the temperature is 100° C. or less, followed by washing, and then adjusting the pH to 7 to pH 8 with 25% aqueous ammonia; filtered. The filtered solid content was redispersed in water at 400 g/liter, and again, after acid washing and pH adjustment in ammonia water in the same manner as above, filtration was performed. After repeating the acid washing-pH adjustment with ammonia water twice in this way, the filtrate was dispersed in ion-exchanged water at 500 g/liter in terms of solid content, heated and stirred at 60° C. and adjusted to pH 7, and then aspirated. The coarse zirconium nitride powder was obtained by filtering with a filtration apparatus, further washing|cleaning with an equivalent amount of ion-exchange water, and drying with the hot-air dryer of set temperature:120 degreeC.

Next, 20 g of the coarse zirconium nitride powder was dispersed in 5 liters of isopropanol, and low-temperature wet media pulverization (media: alumina) was performed for 60 minutes to obtain a zirconium nitride precursor powder. The temperature of isopropanol (dispersion medium) at this time was 5 degrees C or less. In addition, after drying the said zirconium nitride precursor powder, it was hold|maintained and baked at the temperature of 350 degreeC in N2 gas atmosphere for ₄ hours, and the zirconium nitride powder was obtained. This zirconium nitride powder was used as Example 1.

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

The zirconium nitride powders of Examples 2-12 and Comparative Examples 1-10 each produced|generated, respectively grind|pulverized and calcined each zirconium nitride coarse powder by the method shown in Table 1. In addition, a zirconium nitride powder was manufactured 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 production method of the zirconium nitride coarse powder in Table 1, "TM" is the Thermite method, and "PZ" is the plasma method. Moreover, in the column of the grinding|pulverization method of zirconium nitride coarse powder of Table 1, "BM" is a bead mill method, and "JM" is a jet mill method. In addition, in the column of sintering time/gas of zirconium nitride precursor powder of Table ₁ , "N2" 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 a green compact hardened at a pressure of 5 MPa, and the particle size distribution D ₉₀ when diluting with water and ultrasonically dispersing for 5 minutes were measured respectively. These results are shown in Table 1.

<Comparative Test 2>

About 40 g of the zirconium nitride powders of Examples 1-11 and Comparative Examples 1-9, as shown in Table 1, it was made to disperse|distribute to 200 milliliters of acryl monomer or an epoxy monomer, and the monomer dispersion was prepared. On the other hand, to 40 g of zirconium nitride powder of Example 12 and Comparative Example 10, as shown in Table 1, an amine-based dispersant was added and dispersion treatment was performed in 200 ml of a propylene glycol monomethyl ether acetate (PGMEA) solvent. After preparing a black pigment dispersion, an acrylic resin was added to these black pigment dispersions in a mass ratio of black pigment:resin=3:7, and mixed to prepare a black composition. Then, 4 g of Irgacure 500 (photoinitiator: manufactured by BASF) was added to the monomer dispersion or the black composition. Next, after spin-coating the said monomer dispersion or black composition so that the film thickness after baking might become the thickness shown in Table 1 on a glass substrate, it prebaked and evaporated the solvent, and formed the photoresist film. Further, the photoresist film is exposed in a predetermined pattern shape through a photomask, then developed using an alkali developer to dissolve and remove the unexposed portions of the photoresist film, and then post-baking, so that the black film is each was formed. For these black films, the OD values of ultraviolet light (center wavelength 370 nm) and visible light (center wavelength 560 nm) were respectively measured using a densitometer of the product name D200 manufactured by Macbeth Corporation based on the above-mentioned formula (1). While measuring, the volume resistivity (Ω·cm) of the black film was also measured, respectively. These results are shown in Table 1.

As is clear from Table 1, the zirconium nitride powders of Comparative Examples 1 and 10, ie, the coarse zirconium nitride powder, were produced by the Thermite method, but the zirconium nitride was not pulverized and maintained at a temperature of 350° C. in a nitrogen gas atmosphere for 4 hours. ^In the case of ^zirconium nitride powder subjected to firing, The particle size distribution D ₉₀ when ultrasonically dispersed for 5 minutes in the same state was 30 µm, which was larger than the 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 is 1.0, which is smaller than the appropriate range (2.0 or more), and the volume resistivity is 1 × 10 ⁶ Ω·cm in the appropriate range (1 × 10 ¹³ or more), and the coating film did not become uniform. 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 the appropriate range (2.0 or more), and the volume resistivity was 6 × 10 ¹² Ω·cm was smaller than the appropriate range (1 × 10 ¹³ or more).

The zirconium nitride powder of Comparative Example 3, that is, the coarse zirconium nitride powder was prepared by the Thermite method, and this coarse zirconium nitride powder was pulverized by the bead mill method with a dispersion medium temperature of 5 ° C. or less (low temperature wet media grinding), but the zirconium nitride precursor powder was In the case of unfired zirconium nitride powder, the particle size distribution D ₉₀ when ultrasonically dispersed for 5 minutes in a state of dilution with water was 9 μm, which was within an appropriate range (10 μm or less), but in the state of a green compact hardened at a pressure of 5 MPa. The volume resistivity was 1 × 10 ⁶ Ω·cm, which was smaller than the appropriate range (1 × 10 ⁷ Ω·cm or more). In addition, 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, within an appropriate range (2.0 or more), but the volume resistivity was 5 × 10 ¹¹ Ω·cm in an appropriate range (1 × 10 ¹³ or more) was smaller.

On the other hand, the zirconium nitride powders of Examples 1 and 12, that is, the coarse zirconium nitride powder, were prepared by the Thermite method, and the zirconium nitride was pulverized by the bead mill method with a dispersion medium temperature of 5 ° C. or less (low-temperature wet media pulverization), In the case of zirconium nitride powder, which was calcined in a nitrogen gas atmosphere at a temperature of 350 ° C. for 4 hours, the volume resistivity in the state of a green compact hardened at a pressure of 5 MPa is 1 × 10 ⁸ Ω·cm, respectively, in an appropriate range (1 × 10 ⁷ Ω·cm or more), and the particle size distribution D ₉₀ when it was ultrasonically dispersed for 5 minutes in a diluted state with water was 7 μm, respectively, and was 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 1 in the acrylic monomer is 2.1, within an appropriate range (2.0 or more), and the volume resistivity is 5 × 10 ¹³ Ω·cm in an appropriate range (1 × 10 ¹³ or higher). 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, within an appropriate range (2.0 or more), and the volume resistivity was 5 × 10 ¹³ Ω·cm was within an appropriate range (1 × 10 ¹³ or more).

The zirconium nitride powder of Example 9, that is, the coarse zirconium nitride powder was prepared by the Thermite method, and the zirconium nitride was pulverized by the bead mill method with a dispersion medium temperature of 5 ° C. (low temperature wet media grinding), In the case of zirconium nitride powder that has been calcined at a temperature of 4 hours, the volume resistivity in the state of a green compact hardened at a pressure of 5 MPa is 8 × 10 ⁷ Ω·cm, within an appropriate range (1 × 10 ⁷ Ω·cm or more). and the particle size distribution D ₉₀ when ultrasonically dispersed for 5 minutes in a state of being diluted with water was 7 μm, which was 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 9 in the acrylic monomer is 2.2, within an appropriate range (2.0 or more), and the volume resistivity is 3 × 10 ¹³ Ω·cm in an appropriate range (1 × 10 ¹³ and above) was mine.

The zirconium nitride powder of Example 10, that is, the coarse zirconium nitride powder was prepared by the Thermite method, and the zirconium nitride was pulverized by the bead mill method with a dispersion medium temperature of 5 ° C. (low temperature wet media grinding), In the case of zirconium nitride powder that has been calcined at a temperature of 4 hours, the volume resistivity in the state of a green compact hardened at a pressure of 5 MPa is 8 × 10 ⁷ Ω·cm, within an appropriate range (1 × 10 ⁷ Ω·cm or more). and the particle size distribution D ₉₀ when ultrasonically dispersed for 5 minutes in a state of being diluted with water was 9 μm, which was 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 10 in an acrylic monomer is 2.2, within an appropriate range (2.0 or more), and the volume resistivity is 3 × 10 ¹³ Ω·cm in an appropriate range (1 × 10 ¹³ and above) was mine.

On the other hand, although the zirconium nitride powder of Comparative Example 2, that is, the coarse zirconium nitride powder was produced by the plasma method, the zirconium nitride powder was calcined without pulverizing the zirconium nitride and held at a temperature of 350 ° C. in a nitrogen gas atmosphere for 4 hours. , When the volume resistivity in the state of the green compact hardened at a pressure of 5 MPa is 3 × 10 ⁴ Ω·cm, which is smaller than the appropriate range (1 × 10 ⁷ Ω·cm or more), and ultrasonically dispersed for 5 minutes in a state of being diluted with water The particle size distribution D ₉₀ of 14 μm was larger than the 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 the epoxy monomer is 1.2, which is less than the appropriate range (2.0 or more), and the volume resistivity is 2 × 10 ⁶ Ω·cm in the appropriate range (1 × 10 ¹³ or more) was smaller.

The zirconium nitride powder of Comparative Example 4, that is, the coarse zirconium nitride powder was produced by the plasma method, and this coarse zirconium nitride powder was pulverized by the bead mill method with a dispersion medium temperature of 5°C or less (low-temperature wet media pulverization), but the zirconium nitride precursor powder was fired In the case of the untreated zirconium nitride powder, the particle size distribution D ₉₀ when it was ultrasonically dispersed for 5 minutes in a state of dilution with water was within an appropriate range (10 μm or less) of 5 μm, but the volume in the state of a green compact hardened by a pressure of 5 MPa The resistivity was 2 × 10 ⁴ Ω·cm, which was smaller than the 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 the epoxy monomer was 2.0 within an appropriate range (2.0 or more), the volume resistivity was 2 × 10 ¹⁰ Ω·cm in an appropriate range (1 × 10 ¹³ or more) was smaller.

On the other hand, the zirconium nitride powders of Examples 2 and 4, that is, the coarse zirconium nitride powder, were prepared by plasma method, and this coarse zirconium nitride powder was pulverized by the bead mill method with a dispersion medium temperature of 5° C. or less (low-temperature wet media pulverization). , in the case of zirconium nitride powder that was calcined in a nitrogen gas atmosphere at a temperature of 350 ° C. for 4 hours, the volume resistivity in the state of a green compact hardened at a pressure of 5 MPa is 1 × 10 ⁷ Ω·cm, respectively, in an appropriate range (1 ×10 ⁷ Ω·cm or more), and the particle size distribution D ₉₀ when ultrasonically dispersed for 5 minutes in a diluted state with water was within an appropriate range (10 μm or less) of 5 μm, respectively. In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 2 in the epoxy monomer is 2.2, within an appropriate range (2.0 or more), and the volume resistivity is 2 × 10 ¹³ Ω·cm in an appropriate range (1 × 10 ¹³ and above) was mine. In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 4 in an acrylic monomer is 2.3, within an appropriate range (2.0 or more), and the volume resistivity is 1 × 10 ¹³ Ω·cm in an appropriate range (1 × 10 ¹³ and above) was mine.

On the other hand, although the zirconium nitride powder of Comparative Example 5, that is, the coarse zirconium nitride powder was prepared by the Thermite method, this coarse zirconium nitride powder was pulverized by a bead mill method with a dispersion medium temperature of 12°C higher than the appropriate dispersion medium temperature range (10°C or less) ( In the case of zirconium nitride powder that was calcined for 4 hours at 350 ° C. in a nitrogen gas atmosphere after pulverization with low-temperature wet media), the particle size distribution D ₉₀ when diluting with water and ultrasonically dispersing for 5 minutes was 10 μm. Although it was within the range (10 µm or less), the volume resistivity in the state of the green compact hardened at a pressure of 5 MPa was 7 × 10 ⁶ Ω·cm, which was smaller than the 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 an acrylic monomer was 2.0 within an appropriate range (2.0 or more), the volume resistivity was 4 × 10 ¹² Ω·cm in an appropriate range (1 × 10 ¹³ or more) was smaller.

On the other hand, the zirconium nitride powder of Example 5, that is, the coarse zirconium nitride powder was prepared by the Thermite method, and this coarse zirconium nitride powder was pulverized by the bead mill method with a dispersion medium temperature of 10°C within an appropriate dispersion medium temperature range (10°C or less) ( In the case of zirconium nitride powder that was calcined in a nitrogen gas atmosphere at a temperature of 350 ° C. for 4 hours after pulverization with low-temperature wet media), the volume resistivity in the state of a green compact hardened at a pressure of 5 MPa was 8 × 10 ⁷ Ω· It was within an appropriate range (1 × 10 ⁷ Ω·cm or more) in cm, and the particle size distribution D ₉₀ when it was ultrasonically dispersed for 5 minutes in a diluted state with water was within an appropriate range (10 μm or less) of 10 μm. In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 5 in the acrylic monomer is 2.0, within an appropriate range (2.0 or more), and the volume resistivity is 3 × 10 ¹³ Ω·cm in an appropriate range (1 × 10 ¹³ and above) was mine.

On the other hand, the zirconium nitride powder of Comparative Example 6, that is, the coarse zirconium nitride powder was prepared by the Thermite method, and this coarse zirconium nitride powder was pulverized by the bead mill method at a dispersion medium temperature of 5°C (low-temperature wet media pulverization), but in a nitrogen gas atmosphere. , In the zirconium nitride powder that has been calcined, the calcination temperature is maintained at a temperature of 200 °C lower than the appropriate range (250 °C to 550 °C) and the calcination time is within the appropriate range (1 hour to 5 hours) for 4 hours, in a state of being diluted with water The particle size distribution D ₉₀ when ultrasonically dispersed for 5 minutes was within an appropriate range (10 μm or less) of 8 μm, but the volume resistivity in the state of a green compact hardened at a pressure of 5 MPa was 1 × 10 ⁶ Ω·cm. It was smaller than the 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 an acrylic monomer was 2.0 within an appropriate range (2.0 or more), the volume resistivity was 1 × 10 ¹² Ω·cm in an appropriate range (1 × 10 ¹³ or more) was smaller.

The zirconium nitride powder of Comparative Example 7, that is, the coarse zirconium nitride powder was prepared by the Thermite method, and this coarse zirconium nitride powder was pulverized by the bead mill method at a dispersion medium temperature of 5°C (low-temperature wet media pulverization), but calcined in a nitrogen gas atmosphere In the case of zirconium nitride powder calcined in which the temperature is maintained at a temperature of 350 °C within an appropriate range (250 °C to 550 °C) and the calcination temperature is shorter than the appropriate range (1 hour to 5 hours) for 0.5 hours, in a state of being diluted with water 5 Although the particle size distribution D ₉₀ when ultrasonically dispersed for minutes was within an appropriate range (10 μm or less) of 7 μm, the volume resistivity in the state of a green compact hardened at a pressure of 5 MPa was 3 × 10 ⁶ Ω·cm in an appropriate range ( 1 × 10 ⁷ Ω·cm or more). In addition, 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, within an appropriate range (2.0 or more), but the volume resistivity was 2 × 10 ¹² Ω·cm in an appropriate range (1 × 10 ¹³ or more) was smaller.

The zirconium nitride powder of Comparative Example 8, that is, the coarse zirconium nitride powder was prepared by the Thermite method, and this coarse zirconium nitride powder was pulverized by the bead mill method at a dispersion medium temperature of 5°C (low-temperature wet media pulverization), but calcined in a nitrogen gas atmosphere In the zirconium nitride powder, which was calcined at a temperature of 600 °C higher than the appropriate range (250 °C to 550 °C) and the calcination time is maintained within the appropriate range (1 hour to 5 hours) for 1 hour, The volume resistivity in the green state is 4 × 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 it is ultrasonically dispersed for 5 minutes in a diluted state with water is 14 It was larger than the appropriate range (10 μm or less) in 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 is 1.2, which is smaller than the appropriate range (2.0 or more), and the volume resistivity is 1 × 10 ⁹ Ω·cm in an appropriate range (1 × 10 ¹³ or more) was smaller.

On the other hand, the zirconium nitride powder of Example 6, that is, the coarse zirconium nitride powder was prepared by the Thermite method, and this coarse zirconium nitride powder was pulverized by the bead mill method at a dispersion medium temperature of 5°C (low-temperature wet media pulverization), followed by nitrogen In a gas atmosphere, the zirconium nitride powder subjected to calcination held at a temperature of 250 ° C. within an appropriate range (250 ° C. to 550 ° C.) and a calcination time within an appropriate range (1 hour to 5 hours) for 4 hours, 5 MPa ^The particle size distribution when the volume resistivity in the state of the green compact ^hardened by the pressure of D ₉₀ was in an appropriate range (10 micrometers or less) at 8 micrometers. In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 6 in an acrylic monomer is 2.0 within an appropriate range (2.0 or more), and the volume resistivity is 2 × 10 ¹³ Ω·cm in an appropriate range (1 × 10 ¹³ and above) was mine.

The zirconium nitride powder of Example 7, that is, the coarse zirconium nitride powder was prepared by the Thermite method, and the coarse zirconium nitride powder was pulverized by the bead mill method at a dispersion medium temperature of 5 ° C. (low temperature wet media grinding), and then in a nitrogen gas atmosphere, In the zirconium nitride powder, which has been calcined at a temperature of 350 °C within an appropriate range (250 °C to 550 °C) and a calcination time is maintained within an appropriate range (1 hour to 5 hours) for 1 hour, The volume resistivity of the green compact is 1 × 10 ⁷ Ω·cm, which is within an appropriate range (1 × 10 ⁷ Ω·cm or more), and the particle size distribution D ₉₀ when it is ultrasonically dispersed for 5 minutes after dilution with water is 7 It was in an appropriate range (10 micrometers or less) in micrometer. In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 7 in the acrylic monomer is 2.0, within an appropriate range (2.0 or more), and the volume resistivity is 1 × 10 ¹³ Ω·cm in an appropriate range (1 × 10 ¹³ and above) was mine.

The zirconium nitride powder of Example 8, that is, the coarse zirconium nitride powder was prepared by the Thermite method, and the coarse zirconium nitride powder was pulverized by the bead mill method at a dispersion medium temperature of 5 ° C. (low temperature wet media grinding), and then in a nitrogen gas atmosphere, In the zirconium nitride powder, which has been calcined at a temperature of 550 °C within an appropriate range (250 ° C. to 550 ° C.) and calcination time is maintained within an appropriate range (1 hour to 5 hours) for 1 hour, The volume resistivity in the green state is 1 × 10 ⁸ Ω·cm, which is within an appropriate range (1 × 10 ⁷ Ω·cm or more), and the particle size distribution D ₉₀ when it is ultrasonically dispersed for 5 minutes in a state of being diluted with water is 8 It was in an appropriate range (10 micrometers or less) in micrometer. In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 8 in the acrylic monomer is 2.4, within an appropriate range (2.0 or more), and the volume resistivity is 1 × 10 ¹⁴ Ω·cm in an appropriate range (1 × 10 ¹³ and above) was mine.

On the other hand, although the zirconium nitride powder of Comparative Example 9, that is, the coarse zirconium nitride powder was produced by the Thermite method, this coarse zirconium nitride powder was jetted at a grinding pressure of 0.2 MPa, which is smaller than the grinding pressure within an appropriate range (0.3 MPa or more). For zirconium nitride powder that was calcined after mill-pulverization at a temperature of 350° C. in a nitrogen gas atmosphere for 4 hours, the volume resistivity in the state of a green compact hardened at a pressure of 5 MPa is 2 × 10 ⁶ Ω·cm, which is suitable It was smaller than the range (1×10 ⁷ Ω·cm or more), and the particle size distribution D ₉₀ when it was ultrasonically dispersed for 5 minutes in a state of being diluted with water was 14 μm, which was larger than the 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 9 in the epoxy monomer is 1.3, which is smaller than the appropriate range (2.0 or more), and the volume resistivity is 1 × 10 ¹¹ Ω·cm in the appropriate range (1 × 10 ¹³ or more) was smaller.

On the other hand, the zirconium nitride powder of Example 3, that is, the coarse zirconium nitride powder was prepared by the Thermite method, and this coarse zirconium nitride powder was subjected to a jet mill at a grinding pressure of 0.5 MPa within an appropriate range (0.3 MPa or more). For zirconium nitride powder that was pulverized and then calcined in a nitrogen gas atmosphere at a temperature of 350° C. for 4 hours, the volume resistivity in the state of a green compact hardened at a pressure of 5 MPa is 2 × 10 ⁸ Ω·cm in an appropriate range (1×10 ⁷ Ω·cm or more), and the particle size distribution D ₉₀ when ultrasonically dispersed for 5 minutes in a state of being diluted with water was 6 μm, and was 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 3 in the epoxy monomer is 2.2, within an appropriate range (2.0 or more), and the volume resistivity is 2 × 10 ¹⁴ Ω·cm in an appropriate range (1 × 10 ¹³ and above) was mine.

The zirconium nitride powder of Example 11, that is, the coarse zirconium nitride powder was prepared by the Thermite method, and the coarse zirconium nitride powder was jet milled at a grinding pressure of 0.3 MPa in an appropriate range (0.3 MPa or more). , in the zirconium nitride powder of Example 3, which was calcined in a nitrogen gas atmosphere at a temperature of 350 ° C. for 4 hours, the volume resistivity in the state of a green compact hardened at a pressure of 5 MPa was 2 × 10 ⁷ Ω·cm It was within the range (1×10 ⁷ Ω·cm or more), and the particle size distribution D ₉₀ when it was ultrasonically dispersed for 5 minutes in a state of being diluted with water was within an appropriate range (10 μm or less) of 10 μm. In addition, the OD value of the black film prepared by dispersing the zirconium nitride powder of Example 11 in the epoxy monomer is 2.4, within an appropriate range (2.0 or more), and the volume resistivity is 1 × 10 ¹³ Ω·cm in an appropriate range (1 × 10 ¹³ and above) was mine.

The zirconium nitride powder of this invention can be used as a black pigment for obtaining the black film which has high insulation, high blackness, and high insulation.

Claims (6)

Particle size distribution D when the volume resistivity in the state of the green compact hardened at a pressure of 5 MPa is 10 ⁷ Ω·cm or more, and ultrasonically dispersed for 5 minutes in a state of being diluted with water or alcohol within the range of 2 to 5 carbon atoms Zirconium nitride powder having ₉₀ of 10 µm or less. A step of producing a coarse zirconium nitride powder by thermite method or plasma synthesis method;
This coarse zirconium nitride powder is subjected to low-temperature wet media 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, in a state of being diluted with water or alcohol having 2 to 5 carbon atoms. A step of producing a zirconium nitride precursor powder having a particle size distribution D ₉₀ of 10 μm or less when ultrasonically dispersed for minutes;
By calcining the pulverized zirconium nitride precursor powder in an inert gas atmosphere, the zirconium nitride powder having a volume resistivity of 10 ⁷ Ω·cm or more in the state of a green compact hardened at a pressure of 5 MPa is produced. manufacturing method. A monomer dispersion in which the zirconium nitride powder according to claim 1 is dispersed in an acrylic monomer or an epoxy monomer. A black composition in which the zirconium nitride powder according to claim 1 is dispersed as a black pigment in a dispersion medium and further mixed with a resin. A step of forming a coating film by applying the monomer dispersion according to claim 3 to a substrate;
A method for producing a black film, comprising the step of producing a black film by thermally curing or UV curing the coating film. A step of applying the black composition according to claim 4 to a substrate to form a coating film;
A method for producing a black film, comprising the step of producing a black film by thermally curing or UV curing the coating film.