KR101110369B1 - Manufacturing method of tantalum nitride encapsulated with silica and tantalum nitride manufactured by the method - Google Patents

Abstract

The present invention, tantalum nitride (Ta ₃ N ₅₎ comprising the steps of preparing a powder, the tantalum nitride in the solvent (Ta ₃ N ₅₎ was added to disperse the powder, the tantalum nitride (Ta ₃ N ₅₎ the powder is thoroughly Adding a surfactant to the prepared solution to modify the surface of the tantalum nitride (Ta ₃ N ₅ ) powder particles to a hydrophobic surface, and adding a basic solution to the solution in which the tantalum nitride (Ta ₃ N ₅ ) powder is dispersed. And adding tetraethyl orthosilicate to the solution to which the basic solution was added and stirring and centrifuging the stirred solution by adding tetraethyl orthosilicate to silica coated tantalum nitride (Ta ₃ N ₅ ). It relates to a method for producing tantalum nitride encapsulated with silica comprising obtaining a powder and to tantalum nitride produced thereby. According to the present invention, it is possible to obtain tantalum nitride (Ta ₃ N ₅ ) encapsulated with silica, which is coated with silica, thermally stabilized, and oxidation can be prevented even at a high temperature of 500 ° C. or higher.

Tantalum nitride, silica, surfactants, anti-oxidation

Description

Manufacture method of tantalum nitride encapsulated with silica and tantalum nitride manufactured by the method

The present invention relates to tantalum nitride and a method for manufacturing the same, and more particularly to the production of encapsulated tantalum nitride encapsulated with silica, which can be thermally stabilized by silica and prevent oxidation even at a high temperature of 500 ° C. or higher. A method and tantalum nitride produced thereby.

Tantalum nitride (Ta ₃ N ₅ ) is a material that emits red. Tantalum nitride (Ta ₃ N ₅ ) is known to be obtainable by nitriding tantalum oxide (Ta ₂ O ₅ ) with ammonia.

However, tantalum nitride (Ta ₃ N ₅ ) is not thermally stable and is oxidized at a temperature of 500 ° C. or higher, thereby not exhibiting red color. Therefore, a method for thermally stabilizing tantalum nitride (Ta ₃ N ₅ ) and preventing oxidation is needed.

The technical problem to be achieved by the present invention is to provide a method for producing tantalum nitride encapsulated with silica which can be coated with silica and thermally stabilized and prevented oxidation even at a high temperature of 500 ° C. or higher. In providing.

The present invention, tantalum nitride (Ta ₃ N ₅₎ comprising the steps of preparing a powder, the tantalum nitride in the solvent (Ta ₃ N ₅₎ was added to disperse the powder, the tantalum nitride (Ta ₃ N ₅₎ the powder is thoroughly Adding a surfactant to the prepared solution to modify the surface of the tantalum nitride (Ta ₃ N ₅ ) powder particles to a hydrophobic surface, and adding a basic solution to the solution in which the tantalum nitride (Ta ₃ N ₅ ) powder is dispersed. And adding tetraethyl orthosilicate to the solution to which the basic solution was added and stirring and centrifuging the stirred solution by adding tetraethyl orthosilicate to silica coated tantalum nitride (Ta ₃ N ₅ ). It provides a method for producing tantalum nitride encapsulated with silica comprising obtaining a powder.

The surfactant may be 3-aminopropyltriethoxy-silane, and the solvent may be alcohol, water or a mixed solution of alcohol and water.

The surfactant may be poly (oxyethylene) nonylphenyl ether and the solvent may be cyclohexane.

The basic solution may be ammonium hydroxide (NH ₄ OH).

In addition, the present invention, tantalum nitride (Ta ₃ N ₅₎ comprising the steps of preparing a powder, the tantalum nitride (Ta ₃ N ₅₎ by adding the powder to a solution containing cetyl trimethyl ammonium bromide and the tantalum nitride (Ta ₃ N ₅ ) The surface of the powder particles are modified to a hydrophobic surface, and the L-ascorbate solution is added to the solution in which the tantalum nitride (Ta ₃ N ₅ ) powder is dispersed and cetyltrimethyl ammonium bromide is activated. The step of elevating to, the step of adding a basic solution to the solution in which the tantalum nitride (Ta ₃ N ₅ ) powder is dispersed and stirring, and the solution to which the basic solution is added is cooled, and added by adding tetraethyl orthosilicate And it provides a method for producing a tantalum nitride encapsulated with silica comprising the step of obtaining a silica-coated tantalum nitride (Ta ₃ N ₅ ) powder by centrifugation.

The basic solution may be sodium hydroxide solution.

The preparing of the tantalum nitride (Ta ₃ N ₅ ) powder may be performed by adding tantalum chloride (TaCl ₅ ) to a hydrochloric acid (HCl) solution to promote separation of chlorine (Cl) ions of tantalum chloride (TaCl ₅ ). with aqueous ammonia (NH ₄ OH) was added to hydroxide, tantalum (Ta (OH) _5); and by washing the produced hydroxide, tantalum (Ta (OH) ₅₎ as a washing liquid and centrifugation hydroxide, tantalum (Ta (OH for preparing ₅ ) obtaining a powder and nitriding heat treatment of the tantalum hydroxide (Ta (OH) ₅ ) powder in a furnace to synthesize tantalum nitride (Ta ₃ N ₅ ).

The nitriding heat treatment uses ammonia (NH ₃ ) gas as the reaction gas, it is preferably carried out for 1 to 12 hours at a temperature of 800 ~ 1200 ℃.

The method further comprises the step of micronizing the synthesized tantalum nitride (Ta ₃ N ₅ ) powder by performing a grinding process, wherein the particle size of the tantalum nitride (Ta ₃ N ₅ ) powder is used as a thickness of the silica to be coated, a red light-emitting pigment. In consideration of luminescence efficiency and luminescence properties in this case, it may be pulverized and finely divided to have a range of 20 nm to 2 μm.

In addition, the present invention is prepared by the method for producing tantalum nitride, the thickness of the coated silica is characterized in that 10 ~ 500nm range in consideration of powder particle size and thermal stability of tantalum nitride (Ta ₃ N ₅ ). To provide tantalum nitride encapsulated with silica.

According to the present invention, it is possible to obtain tantalum nitride (Ta ₃ N ₅ ) encapsulated with silica, which is coated with silica, thermally stabilized, and oxidation can be prevented even at a high temperature of 500 ° C. or higher.

Silica coated on tantalum nitride (Ta ₃ N ₅ ) powder has the advantage that it is transparent and almost does not reduce the luminous efficiency and luminescence properties that express red color, and thermally stabilizes tantalum nitride (Ta ₃ N ₅ ) In addition, there is an advantage in that red can be expressed by preventing oxidation even at a high temperature of 500 ° C. or higher.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the following embodiments are provided to those skilled in the art to fully understand the present invention, and may be modified in various forms, and the scope of the present invention is limited to the embodiments described below. It doesn't happen. Like numbers refer to like elements in the figures.

Tantalum hydroxide (Ta (OH) ₅ ) is synthesized using tantalum chloride (TaCl ₅ ). Adding ammonia water (NH ₄ OH) with stirring by the addition of chlorine (Cl) in order to facilitate the separation of ionic chloride in the hydrochloric acid (HCl) solution of tantalum (TaCl ₅₎ of the chloride of tantalum (TaCl ₅₎ in the manner described reaction formula 1 below Tantalum hydroxide (Ta (OH) ₅ ) can be prepared.

TaCl ₅ (S) + 5NH ₄ OH (aq) → Ta (OH) ₅ (S) + 5NH ₄ Cl (S)

When ammonia water is added, precipitation of tantalum hydroxide (Ta (OH) ₅ ) occurs. The precipitated tantalum hydroxide (Ta (OH) ₅ ) may be centrifuged to obtain tantalum hydroxide (Ta (OH) ₅ ) powder.

Tantalum hydroxide (Ta (OH) ₅ ) powder may be nitrided in an electric furnace to synthesize tantalum nitride (Ta ₃ N ₅ ) as in Scheme 2 below.

3Ta (OH) ₅ (S) + NH ₄ Cl (S) + 5NH ₃ (g) → Ta ₃ N ₅ (S) + NH ₄ Cl (g) + 15H ₂ O (g)

The nitriding heat treatment is preferably performed for 1 to 12 hours at a temperature of 800 ~ 1200 ℃. As the reaction gas of the nitriding heat treatment, ammonia (NH ₃ ) gas is preferably used, and nitrogen (N ₂ ) gas may be used together with the reaction gas as an atmosphere gas inside the electric furnace. Meanwhile, the powder obtained by centrifugation is present in a state in which tantalum hydroxide (Ta (OH) ₅ ) and ammonium chloride (NH ₄ Cl) are mixed, and a process of removing ammonium chloride (NH ₄ Cl) may be performed separately, but Ammonium (NH ₄ Cl) is burned and removed in the form of a gas when it is 300 to 400 ° C. in the nitriding heat treatment process, so that the nitriding heat treatment process may be performed as it is while ammonium chloride (NH ₄ Cl) is mixed. In the nitriding heat treatment process, ammonium chloride (NH ₄ Cl) is exhausted in the form of gas, and tantalum hydroxide (Ta (OH) ₅ ) is nitrided to become tantalum nitride (Ta ₃ N ₅ ).

However, the synthesized tantalum nitride (Ta ₃ N ₅ ) is not thermally stable and is oxidized at a temperature of 500 ° C. or higher and does not express red color. Therefore, there is a need for an antioxidant film for oxidation prevention. Thermally stable and transparent silica (SiO ₂ ) can be coated on the tantalum nitride (Ta ₃ N ₅ ) particles to solve the thermal instability.

As a method of coating nano powder with silica (SiO ₂ ), there is a stober method using tetraethyl orthosilicate (TEOS) in a basic atmosphere, but most nano powder surfaces have trioctylphosphine (TOP). , Oleic acid (oleic acid) and so on is well dispersed in an organic solvent. Therefore, the present invention uses a microemulsion method using tetraethyl orthosilicate (TEOS), not a silica coating using the Stober method.

Tantalum nitride (Ta ₃ N ₅ ) powder synthesized before silica coating is preferably micronized by performing a grinding process. By micronizing the tantalum nitride (Ta ₃ N ₅ ) powder by using the grinding process, it is possible to separate the aggregated tantalum nitride (Ta ₃ N ₅ ) powder particles can be coated with a uniform thickness during silica coating. The grinding process may use a variety of grinding methods, such as a ball mill (plane mill), planetary mill (planetary mill). The particle size of the tantalum nitride (Ta ₃ N ₅ ) powder finely divided by the grinding process takes into account the thickness of the coated silica, the luminous efficiency and emission characteristics when used as a red light emitting pigment, and the requirements for the pigment particle size. The thickness is preferably in the range of 20 nm to 2 μm.

Tantalum nitride (Ta ₃ N ₅ ) powder was added to the solvent to disperse, and a solution containing sufficient dispersion of tantalum nitride (Ta ₃ N ₅ ) powder was added with a basic solution such as surfactant and ammonium hydroxide (NH ₄ OH). Add and stir. The solvent may be an alcohol such as ethanol, water, a mixed solution thereof, or a cyclohexane solution. In the silica coating, a small amount of the basic solution may have an uneven shape and may be uneven in size, so it is desirable to adjust the amount appropriately.

Tantalum nitride with a surfactant such as Igepal Co-520 (poly (oxyethylene) nonylphenyl ether) before coating silica (SiO ₂ ) with tetraethyl orthosilicate (TEOS) (Ta ₃ N ₅₎ by doing the surface modification of hydrophobic powder (hydrophobe) tantalum nitride (Ta ₃ N ₅₎ can be silica (silica) coating of the nanopowder. The surface-modified surface of the surfactant using not only poly (oxyethylene) nonylphenyl ether but 3-aminopropyltriethoxy-silane (APTES) or cetyltrimethyl ammonium bromide (CTAB) A method of coating silica can be used. Poly (oxyethylene) nonylphenyl ether, 3-Aminopropyltriethoxy-silane (APTES) or Cetyltrimethyl Ammonium Bromide (CTAB) is a tantalum nitride (Ta ₃ N ₅ ) powder surface It is modified to give a hydrophobe (hydrophobe), and by modifying the tantalum nitride (Ta ₃ N ₅ ) powder surface to a hydrophobic surface to enable a silica (silica) coating can be made. The surfactant is used to control the thickness of the coated silica by controlling the amount of tetraethyl orthosilicate (TEOS) and surfactant during surface modification.

After adding a basic solution and stirring for a predetermined time (for example, 5 minutes-2 hours), tetraethyl orthosilicate (TEOS) is added. After adding tetraethyl orthosilicate (TEOS), it is stirred for a predetermined time (for example, 1 to 30 hours). At this time, too fast agitation can make the shape and thickness of the coated silica very uneven, and too slow agitation can also make the thickness of the coated silica uneven, so it is desirable to adjust it properly. The speed is preferably about 50 to 1000 rpm.

Centrifugation yields a silica coated tantalum nitride (Ta ₃ N ₅ ) powder. At this time, the coating of silica (Silica) (120 in Fig. 1) thickness of the tantalum nitride (Ta ₃ N _5), powder particle size, and the tantalum nitride (Ta ₃ N ₅₎ long, 10 ~ 500㎚ consideration of the thermal stability of the It is desirable to have the same or smaller thickness as compared to the radius (r of FIG. 1) size of the powder particles (110 of FIG. 1). Tantalum nitride (Ta ₃ N _5), the powder particles (110) radial size is large, tantalum nitride (Ta ₃ N _5), the thermal stability is excellent, but the tantalum nitride (Ta ₃ N ₅₎ of the powder particle-to-particle agglomeration, if more of the May occur or the red light emission efficiency may be lowered.

Meanwhile, the tantalum nitride (Ta ₃ N ₅ ) powder is added to a solution containing cetyltrimethyl ammonium bromide to modify the surface of the tantalum nitride (Ta ₃ N ₅ ) powder particles to a hydrophobic surface, and the tantalum nitride (Ta ₃₎ N ₅ ) After the L-ascorbate solution was added to the solution in which the powder was dispersed and raised to a temperature at which cetyltrimethyl ammonium bromide was activated, the tantalum nitride (Ta ₃ N ₅ ) powder was dispersed in the solution. After adding and stirring a basic solution, the solution to which the basic solution is added may be cooled, stirred by adding tetraethyl orthosilicate, and centrifuged to obtain a silica-coated tantalum nitride (Ta ₃ N ₅ ) powder. .

The invention is described in more detail with reference to the following examples, which do not limit the invention.

Tantalum hydroxide (Ta (OH) ₅ ) was prepared using tantalum chloride (TaCl ₅ ). Tantalum chloride (TaCl ₅ ) was used as a product of Sigma-Aldrich company with a purity of 99.8%.

At this time, a solvent based on hydrochloric acid was prepared to promote separation of chlorine (Cl) ions of tantalum chloride (TaCl ₅ ). To prepare a solvent, 5M hydrochloric acid / methanol solvent was prepared using hydrochloric acid (HCl) (large purified gold, 35%, Korea) and methanol (Carlo Erba, 99.9%, Italy).

4 g of tantalum chloride (TaCl ₅ ) was added to 60 mL of prepared 5M hydrochloric acid / methanol, followed by stirring for 1 hour. To prepare tantalum hydroxide (Ta (OH) ₅ ) in the stirring solvent, ammonia water (NH ₄ OH) (great gold, 25%, South Korea) was added. Ammonia water was added and stirred for 1 hour and 30 minutes for complete reaction, and when ammonia water was added, precipitation of tantalum hydroxide (Ta (OH) ₅ ) occurred as in Scheme 1 above.

Precipitated tantalum hydroxide (Ta (OH) ₅ ) was washed three times with anhydrous ethanol (JT Baker, 94.9%). The washed solution was centrifuged at 10,000 rpm to obtain tantalum hydroxide (Ta (OH) ₅ ) powder, which was dried in a drier (80 ° C) for 12 hours.

3 g of dried tantalum hydroxide (Ta (OH) ₅ ) powder was placed in an alumina boat (Al ₂ O ₃ 99.8%, total length: 12 cm) and subjected to nitriding heat treatment at 1000 ° C. for 5 hours in an electric furnace. Ammonia gas (NH ₃ , 99.8%) was used as the reaction gas, nitrogen gas (N ₂ , 99.999%) was used as the atmosphere gas inside the electric furnace, and ammonia (NH ₃ ) gas and nitrogen (N ₂ ) gas were used. Each was charged at 0.5 ml / min.

The length of the hot zone (temperature deviation: ± 1 ° C) of the electric furnace was about 10 cm. It heated up at the speed | rate of 5 degrees C / min to nitriding heat processing temperature (1000 degreeC).

Tantalum hydroxide (Ta (OH) ₅ ) was nitrided in an electric furnace to synthesize tantalum nitride (Ta ₃ N ₅ ) as shown in Scheme 2 above.

However, the synthesized tantalum nitride (Ta ₃ N ₅ ) is not thermally stable and is oxidized at a temperature of 500 ° C. or higher and does not express red color. Therefore, there is a need for an antioxidant film for oxidation prevention. Thermally stable and transparent silica (Silica, SiO ₂ ) was coated on the tantalum nitride (Ta ₃ N ₅ ) particles to solve the thermal instability.

Tantalum nitride (Ta ₃ N ₅ ) powder synthesized before silica coating was milled for 2 hours and 6 hours with a planetary mill for pulverization and grinding. Figure 2 is a graph showing the grain size (grain size) of tantalum nitride (Ta ₃ N ₅ ) powder with milling time using a planetary mill. As shown in FIG. 2, as the milling time increases, the particle size of the tantalum nitride (Ta ₃ N ₅ ) powder gradually decreases.

3A is a scanning electron microscope (SEM) photograph when milling for 2 hours using a planetary mill, and FIG. 3B is a scanning electron microscope (SEM) when milling for 6 hours using a planetary mill. ) Photo. As shown in FIG. 3A, the average particle size of the tantalum nitride (Ta ₃ N ₅ ) powder after milling for 2 hours is 50 to 150 nm, and as shown in FIG. 3B, tantalum nitride (Ta) after milling for 6 hours is shown in FIG. 3B. ₃ N ₅ ) It can be seen that the average particle size of the powder is 30 ~ 120nm.

Silica coating was performed using surfactant (Surfactant) and tetraethyl ortho silicate (TEOS). The silica coating acts as an antioxidant that prevents high temperature oxidation of tantalum nitride (Ta ₃ N ₅ ) powder, allowing for continuous redness. Tantalum nitride (Ta ₃ N ₅ ) powder particles are encapsulated by silica as shown in FIG. 1, so that the thermal stability is excellent and oxidation is prevented.

The surfactants include cetyltrimethyl ammonium bromide (CTAB), 3-aminopropyltriethoxy-silane (APTES) and poly (oxyethylene) nonylphenyl ether; H (CH ₂ ) 9Ph (OC ₂ H ₄ ) ₅ ) was used.

Hereinafter, an example in which silica is coated on tantalum nitride (Ta ₃ N ₅ ) powder will be described in more detail with reference to the following examples.

≪ Example 1 >

A method of coating using 3-aminopropyltriethoxy-silane (APTES) as a surfactant will be described.

Disintegrated and pulverized tantalum nitride (Ta ₃ N ₅ ) powder by milling was put into a solvent 50mg and stirred for 10 minutes. The solvent is a solution of 5 ml of ethanol and 5 ml of water.

₁₅ μl of 3-aminopropyltriethoxy-silane (APTES) was added to a solution in which the tantalum nitride (Ta ₃ N ₅ ) was sufficiently dispersed, followed by stirring for 10 minutes. The 3-aminopropyltriethoxy-silane (APTES) was used as the product of Sigma-Aldrich.

3-aminopropyltriethoxy-silane (APTES) was added thereto, and 40 µl of ammonium hydroxide (NH ₄ OH) was added to the stirred solution.

After adding ammonium hydroxide (NH ₄ OH) and stirring for 30 minutes, 30 µl of tetraethyl orthosilicate (TEOS) was added thereto. Tetraethyl orthosilicate (TEOS) was added and stirred for 16 hours. The stirring rate after adding tetraethyl orthosilicate (TEOS) was about 200 rpm.

Tetraethyl orthosilicate (TEOS) was added and stirred for 16 hours, followed by centrifugation at 10,000 rpm for 10 minutes to obtain a silica-coated tantalum nitride (Ta ₃ N ₅ ) powder. Tantalum nitride (Ta ₃ N ₅ ) powder particles are encapsulated by silica, so that the thermal stability is excellent and oxidation is prevented.

Silica-coated tantalum nitride (Ta ₃ N ₅ ) was dispersed in ethanol and confirmed by coating with a Transmission Electron Microscope (TEM). 4 is a transmission electron microscope (TEM) photograph of silica coated tantalum nitride (Ta ₃ N ₅ ) powder. Figure 4 (a) is a transmission electron microscope (TEM) picture when milling for 2 hours using a planetary mill, Figure 4 (b) is a transmission when milling for 6 hours using a planetary mill An electron microscope (TEM) photograph.

Figure 5a is a graph showing the weight (weight) change with temperature of the silica-coated tantalum nitride (Ta ₃ N ₅ ) powder using 3-aminopropyltriethoxy-silane (APTES), Figure 5b A graph showing heat flow change with temperature of silica-coated tantalum nitride (Ta ₃ N ₅ ) powder using aminopropyltriethoxy-silane (APTES). As shown in Figure 5a, even if the silica-coated tantalum nitride (Ta ₃ N ₅ ) powder increases from 0 ℃ to 950 ℃, the weight is reduced only by about 31.26%, and as shown in FIG. It was found that the heat flow was slowly falling slowly and the heat flow temperature was 659.53 ° C.

<Example 2>

A method of coating poly (oxyethylene) nonylphenyl ether as a surfactant will be described.

Disintegrated and pulverized tantalum nitride (Ta ₃ N ₅ ) powder is prepared by milling.

0.22 g of poly (oxyethylene) nonylphenyl ether was added to 4.5 ml of cyclohexane and stirred. Poly (oxyethylene) nonylphenyl ether was used as Igepal Co-520 from Sigma-Aldrich. 160 μl of a 1 mol (mol) tantalum nitride (Ta ₃ N ₅ ) solution dispersed in cyclohexane was prepared and added to the solution into which Igepal Co-520 was added and stirred.

The solution of tantalum nitride (Ta ₃ N ₅ ) was added and 40 μl of ammonium hydroxide (NH ₄ OH) was added to the stirred solution.

After adding ammonium hydroxide (NH ₄ OH) and stirring for 10 minutes, 30 µl of tetraethyl orthosilicate (TEOS) was added thereto. Tetraethyl orthosilicate (TEOS) was added and stirred for 16 hours. The stirring rate after adding tetraethyl orthosilicate (TEOS) was about 200 rpm.

Tetraethyl orthosilicate (TEOS) was added thereto, stirred for 16 hours, dispersed in methanol, and then centrifuged at 10,000 rpm for 10 minutes to obtain a silica-coated tantalum nitride (Ta ₃ N ₅ ) powder.

The obtained tantalum nitride (Ta ₃ N ₅ ) powder is dispersed in ethanol (Ethanol) and dried to obtain a powder. Tantalum nitride (Ta ₃ N ₅ ) powder particles are encapsulated by silica, so that the thermal stability is excellent and oxidation is prevented.

FIG. 6A is a graph showing weight change with temperature of silica coated tantalum nitride (Ta ₃ N ₅ ) powder using poly (oxyethylene) nonylphenyl ether, and FIG. 6B is poly (oxyethylene) It is a graph showing the change in heat flow (heat flow) according to the temperature of the silica-coated tantalum nitride (Ta ₃ N ₅ ) powder using nonylphenyl ether. As shown in FIG. 6A, the silica-coated tantalum nitride (Ta ₃ N ₅ ) powder is reduced by only about 26.62% even if it is increased from 0 ° C. to 950 ° C., and also heats at 500 ° C. or higher as shown in FIG. It can be seen that the flow falls slowly and stably, and the heat flow temperature was 650.50 ° C.

<Example 3>

A method of coating using cetyltrimethyl ammonium bromide (CTAB) as a surfactant will be described.

Disintegrated and pulverized tantalum nitride (Ta ₃ N ₅ ) powder is prepared by milling.

CTAB solution was made with 45 ml of water and 164 mg of cetyltrimethyl ammonium bromide (CTAB). 1.25 mg of milled tantalum nitride (Ta ₃ N ₅ ) powder was added. Cetyltrimethyl ammonium bromide (CTAB) was manufactured by Sigma-Aldrich.

10 ml of water and 0.198 g of L-ascorbate were prepared and 2.5 ml of L-ascorbate was prepared. L-ascorbate solution was added and stirred for 30 minutes. The stirring speed after adding L-ascorbate was about 200 rpm.

The beaker containing the tantalum nitride (Ta ₃ N ₅ ) solution was adjusted to 55 ° C., the temperature at which cetyltrimethyl ammonium bromide (CTAB) was activated.

1 ml of a sodium hydroxide solution was added to the solution in which the tantalum nitride (Ta ₃ N ₅ ) powder was dispersed, stirred for 10 minutes, and cooled to room temperature. The stirring speed after adding sodium hydroxide was about 200 rpm. Tetraethyl orthosilicate was added and stirred in the same manner as in Example 1 and Example 2.

The solution containing tantalum nitride (Ta ₃ N ₅ ) was centrifuged at 10,000 rpm for 10 minutes to obtain silica coated tantalum nitride (Ta ₃ N ₅ ) powder. Tantalum nitride (Ta ₃ N ₅ ) powder particles are encapsulated by silica, so that the thermal stability is excellent and oxidation is prevented.

FIG. 7A is a graph showing weight change with temperature of silica coated tantalum nitride (Ta ₃ N ₅ ) powder using cetyltrimethyl ammonium bromide (CTAB), and FIG. 7B is cetyltrimethyl ammonium bromide (CTAB) Is a graph showing a change in heat flow (heat flow) according to the temperature of silica coated tantalum nitride (Ta ₃ N ₅ ) powder. As shown in FIG. 7a, even when the silica-coated tantalum nitride (Ta ₃ N ₅ ) powder is increased from 0 ° C. to 450 ° C., the weight decreases only by about 8.24% and increases by 3.31% from 450 ° C. to 620 ° C. It can be seen that there is little change in weight stably even at a temperature of 620 ℃ or more, and also as shown in Figure 7b it can be seen that the heat flow is slowly falling stable even at 500 ℃ or more, the heat flow temperature was 660.70 ℃.

As mentioned above, although preferred embodiment of this invention was described in detail, this invention is not limited to the said embodiment, A various deformation | transformation by a person of ordinary skill in the art within the scope of the technical idea of this invention is carried out. This is possible.

1 is a view showing a silica coated on the tantalum nitride (Ta ₃ N ₅ ) powder.

2 is a graph showing the particle size of tantalum nitride (Ta ₃ N ₅ ) powder with milling time using a planetary mill.

3A is a scanning electron micrograph when milling for 2 hours using a planetary mill, Figure 3b is a scanning electron micrograph when milling for 6 hours using a planetary mill.

4 is a transmission electron micrograph of a silica coated tantalum nitride (Ta ₃ N ₅ ) powder.

Figure 5a is a graph showing the weight (weight) change with temperature of the silica-coated tantalum nitride (Ta ₃ N ₅ ) powder using 3-aminopropyltriethoxy-silane (APTES), Figure 5b A graph showing heat flow change with temperature of silica-coated tantalum nitride (Ta ₃ N ₅ ) powder using aminopropyltriethoxy-silane (APTES).

FIG. 6a is a graph showing weight change with temperature of a tantalum nitride (Ta ₃ N ₅ ) powder coated with silica using poly (oxyethylene) nonylphenyl ether, and FIG. 6b is poly (oxyethylene) nonyl A graph showing heat flow change with temperature of silica coated tantalum nitride (Ta ₃ N ₅ ) powder using phenyl ether.

Figure 7a is a graph showing the weight (weight) change with temperature of silica coated tantalum nitride (Ta ₃ N ₅ ) powder using cetyltrimethyl ammonium bromide (CTAB), Figure 7b is cetyltrimethyl ammonium bromide (CTAB) Is a graph showing a change in heat flow (heat flow) according to the temperature of silica coated tantalum nitride (Ta ₃ N ₅ ) powder.

Claims (12)

Preparing a tantalum nitride (Ta ₃ N ₅ ) powder; The tantalum nitride (Ta ₃ N ₅₎ was added to disperse the powder, the tantalum nitride (Ta ₃ N ₅₎ the powder is sufficiently a surfactant added to the dispersion solution of the tantalum nitride (Ta ₃ N ₅₎ powder in a solvent Modifying the surface of to a hydrophobic surface; Adding a basic solution to a solution in which the tantalum nitride (Ta ₃ N ₅ ) powder is dispersed; Adding tetraethyl orthosilicate to the solution to which the basic solution is added and stirring; And A method for producing tantalum nitride encapsulated with silica comprising tetraethyl orthosilicate added and centrifuging a stirred solution to obtain silica coated tantalum nitride (Ta ₃ N ₅ ) powder. The method of claim 1, wherein the surfactant is 3-aminopropyltriethoxy-silane. 3. The method of claim 2, wherein the solvent is alcohol, water or a mixed solution of alcohol and water. The method of claim 1, wherein the surfactant is poly (oxyethylene) nonylphenyl ether. The method of claim 4, wherein the solvent is cyclohexane. The method of claim 1, wherein the basic solution is ammonium hydroxide (NH ₄ OH). Preparing a tantalum nitride (Ta ₃ N ₅ ) powder; Modifying the surface of the tantalum nitride (Ta ₃ N ₅ ) powder particles with a hydrophobic surface by adding tantalum nitride (Ta ₃ N ₅ ) powder to a solution containing cetyltrimethyl ammonium bromide; Adding an L-ascorbate solution to a solution in which the tantalum nitride (Ta ₃ N ₅ ) powder is dispersed and raising the temperature to activate cetyltrimethyl ammonium bromide; Adding and stirring a basic solution to a solution in which the tantalum nitride (Ta ₃ N ₅ ) powder is dispersed; And Cooling the solution to which the basic solution was added, adding tetraethyl orthosilicate, stirring and centrifuging to obtain a silica-coated tantalum nitride (Ta ₃ N ₅ ) powder of the tantalum nitride encapsulated with silica Manufacturing method. 8. The method of claim 7, wherein the basic solution is a sodium hydroxide solution. The method of claim 1 or 7, wherein the preparing of tantalum nitride (Ta ₃ N ₅ ) powder, By the addition of aqueous ammonia (NH ₄ OH) with stirring by the addition of chlorine (Cl) in order to facilitate the separation of ionic chloride in the hydrochloric acid (HCl) solution of tantalum (TaCl ₅₎ of the chloride of tantalum (TaCl ₅₎ hydroxide, tantalum (Ta (OH ₅ ) preparing); Washing the prepared tantalum hydroxide (Ta (OH) ₅ ) with a washing solution and centrifuging to obtain tantalum hydroxide (Ta (OH) ₅ ) powder; And Method of producing tantalum nitride encapsulated with silica comprising the step of nitriding the tantalum hydroxide (Ta (OH) ₅ ) powder in a furnace to synthesize tantalum nitride (Ta ₃ N ₅ ). The method of claim 9, wherein the nitriding heat treatment uses ammonia (NH ₃ ) gas as a reaction gas, and a method of producing tantalum nitride encapsulated with silica, which is performed for 1 to 12 hours at a temperature of 800 to 1200 ° C. . The method of claim 9, further comprising the step of micronizing the synthesized tantalum nitride (Ta ₃ N ₅ ) powder by performing a grinding process, wherein the particle size of the tantalum nitride (Ta ₃ N ₅ ) powder is the thickness of the coated silica And pulverizing and micronizing so as to have a range of 20 nm to 2 μm in consideration of luminescence efficiency and luminescence properties when used as a red luminescent pigment. Silica prepared by the method according to claim 1 or 7, wherein the thickness of the coated silica ranges from 10 to 500 nm in consideration of powder particle size and thermal stability of tantalum nitride (Ta ₃ N ₅ ). Tantalum nitride encapsulated with.

Images