JP2001206708A - Manufacturing method of metallic nitride powder at least partially nitrided - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture metallic nitride powder which is at least partially nitrided, formed into spherical fine powder and free from the generation of aggregation, with a small man-hour at a low cost. SOLUTION: A w/o type emulsion prepared by mixing an aqueous solution containing a metal element capable of being nitrided with an inflammable liquid is sprayed and combusted in an atmosphere containing oxygen in the quantity smaller than oxygen demand necessary for completely combusting the inflammable liquid and forming a most stable oxide of the metal element and nitrogen atom is added in the combustion atmosphere at the time of the spray combustion. A reducing atmosphere of oxygen deficiency is formed during the spray combustion and the reducing atmosphere becomes further powerful in the presence of a carbon component generated by the incomplete combustion of the inflammable liquid and nitrogen atom existing around the metal element is reacted with the metal element to progress the nitriding reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a metal nitride powder or a partially nitrided metal nitride powder, and more particularly to a production method using a spray combustion method.

[0002]

2. Description of the Related Art Since metal nitrides have better thermal conductivity than metal oxides, the thermal conductivity of resin molded articles can be improved by mixing them as fillers in resin. Therefore, it is expected to be used as a filler of a package resin used for electronic materials that become hot, such as a CPU of a computer.

When used as a resin filler, the metal nitride must be in powder form. Therefore, it is desirable to manufacture by a manufacturing method that can manufacture a powdery metal nitride. As such a manufacturing method, for example,
JP-A-9-052704 discloses a method of pulverizing a nitride precursor and thermally decomposing or nitriding it. Also JP
JP-A-58-095606 discloses a method of spray pyrolysis of a nitride precursor, and JP-A-2-233509 discloses a method of spraying and nitriding a nitride precursor in an amminia atmosphere. JP-A-7-265689 discloses a method of subjecting a nitride precursor to ultrasonic spray pyrolysis.

Japanese Patent Application Laid-Open No. 63-156007 discloses a method in which molten metal is sprayed to form spherical metal particles, which are then heat-treated and nitrided. Japanese Patent Application Laid-Open No. 7-048609 discloses a method in which molten metal is placed in a nitrogen atmosphere. Japanese Patent Application Laid-Open No. H8-100205 discloses a method of ultrasonically pyrolyzing a molten metal.

Further, Japanese Patent Application Laid-Open No. 61-132504 discloses a method in which a metal is irradiated with nitrogen plasma to be melted and sprayed to be powdered, and Japanese Patent Application Laid-Open No. 1-287202 discloses a method of ion beam sputtering. Japanese Patent Application Laid-Open No. 7-242404 discloses a method of nitriding the surface of a metal powder, and a method of nitriding metal fine particles by glow discharge in a nitrogen atmosphere.
No. 02 discloses a method of partially nitriding a metal powder by high energy pulverization in a nitrogen atmosphere.

On the other hand, Japanese Patent Application Laid-Open No. 7-081905 discloses a W / O
A method for producing oxide fine particles by burning a mold emulsion in an oxidizing atmosphere is disclosed. Japanese Patent Application Laid-Open No. 9-202607 discloses a W / O containing a metal salt in an aqueous phase.
A method for producing oxide fine particles having oxygen defects by burning a type emulsion under oxygen-deficient conditions is disclosed.

[0007]

When a metal nitride powder is used as a filler for a polymer member requiring high thermal conductivity, the smaller the particle size, the more preferable it is, the more desirably the particles do not aggregate, and the shape is spherical. It is preferred that However, the above-described conventional manufacturing method has problems such as difficulty in manufacturing a fine metal nitride powder and an increase in man-hours. For example, in the method of pulverizing a nitride precursor and thermally decomposing or nitriding it, it is a two-step process, and the process becomes complicated. Have difficulty.

The method of producing a nitride precursor by spray pyrolysis is an excellent method capable of synthesizing spherical fine particles.
m or more. Therefore, less than 5 μm or 2 μm
In the case of producing the following fine particles, it is necessary to lower the spraying efficiency or to lower the concentration of the raw material solution in order to reduce the diameter of the sprayed droplet, and there is a problem that the synthesis efficiency is reduced and the cost is increased. .

The method of spraying a molten metal has the same problem as described above, and furthermore, it is necessary to melt the metal as a raw material, so that the cost is further increased.

On the other hand, methods using plasma spraying, ion beam sputtering, or glow discharge are excellent methods, respectively, but require a plasma generator, a vacuum apparatus, and the like, and thus are expensive. Further, in the method using high energy pulverization, energy costs are large and it is difficult to produce spherical fine particles.

The method of burning a W / O emulsion disclosed in the above publication is for producing a metal oxide, and there is no description or suggestion of a metal nitride.

The present invention has been made in view of such circumstances, and an object of the present invention is to produce metal nitride powder which is spherical and does not cause agglomeration with fine particles at low cost with a small number of steps.

[0013]

A feature of the present invention for solving the above-mentioned problems is that an aqueous solution containing a nitridable metal element is mixed with a flammable liquid by mixing an aqueous solution containing a nitridable metal element. The W / O emulsion or suspension formed by the above method is burned in an atmosphere containing an amount of oxygen that is less than the amount of oxygen necessary for the combustible liquid to completely burn and the metal element to form the most stable oxide in the atmosphere. A method for performing spray combustion, wherein at least one of the following two conditions is satisfied. (1) The W / O emulsion or the suspension contains at least one of ions other than nitrate ions containing nitrogen atoms and molecules containing nitrogen atoms. (2) The atmosphere contains at least one of a nitrogen atom-containing ion and a nitrogen atom-containing molecule other than N ₂ .

In the production method of the present invention, the required amount of oxygen is 10
It is desirable to perform spray combustion in an atmosphere containing an oxygen content of about 90%, and the nitrogen atom referred to in the condition (1) is ammonia,
It is desirable to supply from at least one selected from ammonium ion, hydrazine and hydrazinium ion.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION W used in the manufacturing method of the present invention
In the spray combustion of the / O emulsion or suspension, the dispersed particles in the W / O emulsion or suspension in the sprayed mist become atomized particles composed of an aqueous phase or a solid phase covered with an oil film composed of a flammable liquid, Once ignited, combustion of the oil slick is induced. Due to this heat generation, the metal in the water phase or solid phase inside the atomized particles exposed to the high temperature is oxidized to generate metal oxide powder. Since the atomized particles are fine, generation of a temperature distribution between the particles can be suppressed, and a homogeneous metal oxide powder can be obtained.

According to the production method of the present invention, the W / O emulsion or the suspension is completely burned by the flammable liquid and the metal element is smaller than the oxygen amount required for forming the most stable oxide in the atmosphere. Spray burning in an atmosphere containing oxygen. Therefore, during the spray combustion, the reducing atmosphere becomes oxygen-deficient, and the reducing atmosphere is further enhanced by the presence of the carbon component generated by the incomplete combustion of the flammable liquid. Since the combustion atmosphere contains nitrogen atoms, nitrogen atoms or ions containing nitrogen atoms existing around the metal element react with the metal element to at least partially nitride the metal element. As a result, the metal nitride powder that is at least partially nitrided can be manufactured in a fine particle state.

In the spray combustion of a W / O emulsion or suspension, the diameter of one dispersed particle (several nm to several μm) in the emulsion or suspension becomes the size of one reaction field, and one dispersed particle becomes one Particles are synthesized. The diameter of the dispersed particles in the emulsion or suspension can be controlled by the type of the flammable liquid, the type of the dispersant, the mixing ratio, and the like, and the metal element concentration in the aqueous phase can be arbitrarily set within the range of the saturation concentration or less. Therefore, according to the present invention, metal nitride particles having a desired particle size can be synthesized. Furthermore, the dispersed particles in the emulsion or suspension are each present independently, and the at least partially nitrided metal nitride particles synthesized therefrom are also independent. Since the reaction time is extremely short and high heat does not act after the reaction, aggregation does not occur.

The spray combustion atmosphere is oxygen deficient, that is, the amount of oxygen introduced into the reaction vessel is necessary for the complete combustion of the flammable liquid and for the metal element to form the most stable oxide in the atmosphere. It must be less than the amount of oxygen. When the amount of oxygen to be introduced exceeds the required amount of oxygen, only the oxidation reaction proceeds, and it becomes difficult to synthesize a metal nitride powder that is at least partially nitrided. Therefore, the required amount of oxygen is 10
It is desirable to perform spray combustion in an atmosphere containing 90% of oxygen. If the amount of oxygen in the atmosphere is less than 10% of the required amount of oxygen, the W / O emulsion or suspension becomes difficult to burn, and there is a risk of misfiring. If the amount of oxygen in the atmosphere is more than 90% of the required amount of oxygen, the oxidation reaction proceeds easily, and the nitridation reaction hardly occurs. Therefore, considering the balance between oxidation and nitridation and the risk of misfiring,
The amount of oxygen in the atmosphere is particularly preferably in the range of 20 to 80% of the required amount of oxygen.

In order to include at least one of ions other than nitrate ions containing nitrogen atoms and molecules containing nitrogen atoms in the combustion atmosphere at the time of spray combustion, it may be contained in a W / O emulsion or suspension. Alternatively, it can be contained in the atmospheric gas in the spray combustion vessel. W / O
Simultaneously with or separately from the spraying of the emulsion or suspension, an aqueous solution or emulsion containing nitrogen atoms can be sprayed into the spray combustion vessel.

When at least one of ions other than nitrate ions containing nitrogen atoms and molecules containing nitrogen atoms is contained in a W / O emulsion or suspension, or when supplied as another aqueous solution or emulsion, ammonia , Ammonium ion, hydrazine,
An ion or molecule such as a hydrazinium ion, urea, or amine can be included. One of these may be used, or a plurality of them may be used in combination. Further, it may be contained in either the water phase or the oil phase, or may be contained in both. Among them, it is preferable to use at least one selected from ammonia, ammonium ion, hydrazine, and hydrazinium ion. These ions or molecules are easily decomposed because of their low molecular weight, and because they are composed of only nitrogen and hydrogen atoms, the decomposed hydrogen atoms create a reducing atmosphere, thereby promoting the nitriding reaction. In addition, the concentration of these nitrogen sources is not particularly limited, and may be adjusted as needed within the range of the solubility limit concentration or less.

It is conceivable to use nitric acid as a nitrogen source. However, when nitric acid ions are rapidly heated, they are decomposed to release oxygen, and the atmosphere becomes an oxidizing atmosphere, so that a nitriding reaction hardly occurs. Therefore, it is desirable not to use nitric acid.

When nitrogen atoms are contained as ions or molecules in the atmospheric gas in the spray combustion vessel, a gaseous nitrogen source such as ammonia or amine can be used. Among them, ammonia consisting of only a nitrogen atom and a hydrogen atom is particularly desirable for the same reason as described above. The concentration is not particularly limited, and may be adjusted as needed. Although the use of nitrogen gas as a nitrogen source is also conceivable, it is difficult to use nitrogen gas as a nitrogen source for nitridation in the production method of the present invention because nitrogen gas is inactive and hardly causes a nitridation reaction. . When nitrogen gas is used for purposes such as adjusting the oxygen concentration, it may be used.

A comparison between the case where nitrogen atoms are contained in a W / O emulsion or suspension, the case where nitrogen atoms are supplied as another aqueous solution or emulsion, and the case where nitrogen atoms are contained in atmospheric gas in a spray combustion vessel, shows that It is desirable to include it in the / O emulsion or suspension. In a W / O emulsion or suspension, ions or molecules containing nitrogen atoms are mixed with metal ions at the atomic level, so that the distance between the metal ions and the nitrogen atoms is extremely short, and the nitriding reaction is promoted. is there. The nitrogen atoms are preferably contained in the W / O emulsion or the suspension and also in the atmospheric gas in the spray combustion vessel. This further promotes the nitridation reaction.

The metal element used in the present invention is not particularly limited as long as it is a metal that can be nitrided.
Examples include titanium, iron, silicon, boron, gallium, niobium, zirconium, and chromium. One of these may be used, or a plurality of types may be used in combination.

The above metal element is supplied as a compound soluble in water, and is mixed with a flammable liquid as an aqueous solution to form W.
/ O emulsion. Typical examples of the metal compound soluble in water include metal salts such as nitrates, acetates, sulfates, and chlorides. In some cases, metal complexes and organic metal salts may be used. As described above, metal nitrates are not preferable because they easily create an oxidizing atmosphere. Further, when there is no suitable water-soluble metal salt, a suspension containing fine metal salt particles in the aqueous phase of the W / O emulsion can be used.

As the flammable liquid, an organic solvent is typically exemplified, and an organic solvent capable of forming a W / O emulsion with an aqueous metal salt solution such as hexane, octane, kerosene and gasoline can be used. It is also preferable to use a dispersant in combination. The dispersant may be any of a cationic surfactant, an anionic surfactant, and a nonionic surfactant, and the type and amount thereof are adjusted according to the type of the aqueous solution and the organic solvent or the required dispersed particle size. can do. Note that the organic solvent and the dispersant are flammable liquids, and the required oxygen amount needs to be calculated from the total amount of the organic solvent and the dispersant.

The mixing ratio between the aqueous metal salt solution and the flammable liquid when forming a W / O emulsion is not particularly limited. However, if the volume ratio of water exceeds 70% by volume, the dispersion phase of the emulsion and the May be reversed. In order to stably obtain a W / O emulsion, the ratio of water is desirably 70% or less, and particularly desirably 65% or less. On the other hand, if the ratio of the aqueous metal salt solution becomes extremely small, the yield of the metal nitride powder with respect to the amount of the emulsion decreases, so that the water ratio is desirably 20% or more.
% Is particularly desirable.

The diameter of water droplets in the W / O emulsion is not particularly limited, and can be arbitrarily controlled by the type and amount of the dispersant. However, if the diameter of the water droplet is too large, the combustion of the emulsion may become unstable. Therefore, the diameter of the water droplet is preferably 5 μm or less. However, as a means for reducing the water droplet diameter, it is common to reduce the proportion of water in the emulsion. If the proportion of water is too small, the yield of the metal nitride powder relative to the amount of the emulsion will decrease. Therefore, it cannot be said unconditionally, but in consideration of the yield, the water droplet diameter is preferably 50 nm or more, and more preferably 100 nm or more.

In the case of suspension, it is desirable that the particle size of the fine metal salt particles contained in the aqueous phase be 1 μm or less. When the particle size is larger than 1 μm, 5 μm
It is difficult to be contained in water droplets having a diameter of less than m. Since the W / O emulsion referred to in the present invention has a particle diameter reduced to an atomic level, there is no lower limit on the particle diameter of metal salt fine particles and the like.

The combustion temperature during spray combustion in the present invention is:
It is desirable to be 500-1000 degreeC. At a combustion temperature of less than 500 ° C., there is a risk of misfire. At a combustion temperature of more than 1000 ° C., the generated metal nitride particles may aggregate to form coarse particles. Note that the combustion temperature can be controlled by adjusting the type and mixing ratio of the flammable liquid, the amount of spray, the amount of oxygen supplied, and the like.

The at least partially nitrided metal nitride powder produced according to the present invention may be a partially nitrided metal oxide or a fully nitrided metal nitride. Is also good. Further, according to the production method of the present invention, both hollow particles and solid particles can be produced, and the particle shape can be selected according to the application.

[0032]

The present invention will be described more specifically with reference to examples and comparative examples.

Example 1 A mixed aqueous solution in which 16% by weight of titanium tetrachloride was dissolved and 10% by weight of ammonium chloride was dissolved, kerosene, and a dispersant ("Solgen 90" manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were used. Mix and mix using a homogenizer.
Stir at 2,000 rpm for 10 minutes, and
A type emulsion was prepared. The ratio of the water phase to the oil phase was 63/37 (water / oil phase = 63/37) by volume, and the dispersant was added at 3% by weight with respect to kerosene. As a result of observation with an optical microscope, the water droplet diameter in the emulsion was about 1 to 2 μm.

This emulsion was sprayed and burned on a reactor shown in a conceptual view in FIG. This reaction apparatus comprises a cylindrical vessel 1 and a metering pump 2 for supplying an emulsion to the vessel 1. The vessel 1 comprises a reaction chamber 11 and a collection chamber 12
It is composed of An atomizer 13 for spraying is provided at an upper part of the reaction chamber 11, and a burner 14 is provided at a side surface of the reaction chamber 11. Combustion gas is supplied to the atomizer 13 from the gas passage 15 and the atomizing pump 2
And an atomizer 13 sprays a mixed mist of the combustion gas and the emulsion into the reaction chamber 11. The sprayed mist is ignited and burned by the burner 14, and the metal nitride powder that is at least partially nitrided is collected by a bag filter provided in the collection chamber 12. The exhaust gas is discharged from the collection chamber 12 to the outside.

Using the above reactor, a combustion gas comprising oxygen and nitrogen was supplied to the atomizer 13 from the gas passage 15, and the above emulsion was supplied to the atomizer 13 from the metering pump 2 and sprayed into the reaction chamber 11. The ratio of nitrogen gas and oxygen gas in the combustion gas is N ₂ : O by volume ratio.
₂ = 90: 10 and then, as kerosene and dispersing agent is completely burned and titanium of 60% of the amount of oxygen required amount of oxygen required to form the TiO _2, adjust the flow rate of the combustion gas and emulsion did. The temperature measured by a thermocouple installed at the center of the flame in the reaction chamber 11 was about 800 ° C.

After the completion of the combustion, the powder is collected from the bag filter in the collection chamber 12 and placed at 400 to 600 ° C. in an oxidizing atmosphere.
For 4 hours to remove the remaining unburned carbon components. FIG. 2 shows a scanning electron microscope (SEM) photograph of the powder after the heat treatment. Further, the amount of nitrogen contained in the powder after the heat treatment was analyzed by an X-ray photoelectron spectrometer (XPS), and the results are shown in Table 1.

Example 2 An emulsion was prepared in the same manner as in Example 1 except that an aqueous solution in which only titanium tetrachloride was dissolved without containing ammonium chloride was used, and the composition of the combustion gas was changed to N ₂ by volume ratio. : O ₂ : NH ₃ = 80: 10: 1
Spray combustion in the same manner as in Example 1 except that it was set to 0,
The obtained powder was similarly heat-treated. The amount of nitrogen contained in the powder after the heat treatment was analyzed with an X-ray photoelectron spectrometer (XPS), and the results are shown in Table 1.

(Embodiment 3) The same emuljo as in Embodiment 1.
And the composition of the combustion gas is N_Two : O _Two : N
H_Three Same as Example 1 except that = 85: 10: 5
And the resulting powder was similarly heat-treated.
The amount of nitrogen in the powder after heat treatment was determined by X-ray photoelectron spectroscopy.
The results are shown in Table 1.

(Embodiment 4) The same emuljo as in Embodiment 1.
And the composition of the combustion gas is N_Two : O _Two: N
H_Three = Same as Example 1 except that 80:10:10
Spray combustion in the same manner and heat-treat the resulting powder
Was. The content of nitrogen in the powder after heat treatment was determined by X-ray photoelectron spectroscopy.
The results are shown in Table 1.

Example 5 Using the same emulsion as in Example 1, the kerosene and the dispersant were completely burned and the titanium required 30% of the oxygen required for forming TiO _2.
Spray combustion was carried out in the same manner as in Example 1 except that the flow rates of the combustion gas and the emulsion were adjusted so that the oxygen content became as follows. The amount of nitrogen contained in the powder after the heat treatment was analyzed with an X-ray photoelectron spectrometer (XPS), and the results are shown in Table 1.

Example 6 An emulsion was prepared in the same manner as in Example 1 except that aluminum chloride was used instead of titanium tetrachloride, and spray-burned as in Example 1 to obtain a powder. Was similarly heat-treated. X-Ray Photoelectron Spectroscopy (XPS)
And the results are shown in Table 1.

COMPARATIVE EXAMPLE 1 Using the same emulsion as in Example 1, the kerosene and the dispersant were completely burned, and the amount of oxygen required for titanium to form TiO ₂ was 150.
%, And sprayed and burned in the same manner as in Example 1 except that the flow rates of the combustion gas and the emulsion were adjusted so that the amount of oxygen became 0%. X-Ray Photoelectron Spectroscopy (XPS)
And the results are shown in Table 1.

Comparative Example 2 An emulsion was prepared in the same manner as in Example 1 except that an aqueous solution containing only ammonium tetrachloride and containing no ammonium chloride was used. The obtained powder was similarly heat-treated. The amount of nitrogen contained in the powder after the heat treatment was analyzed with an X-ray photoelectron spectrometer (XPS), and the results are shown in Table 1.

(Comparative Example 3) An emulsion was prepared in the same manner as in Example 1 except that an aqueous solution in which only aluminum nitrate was dissolved was used. Heat treatment was performed similarly. The amount of nitrogen contained in the powder after the heat treatment was analyzed with an X-ray photoelectron spectrometer (XPS), and the results are shown in Table 1.

<Evaluation>

[0046]

[Table 1]

As can be seen from FIG. 1, the powder synthesized by the production method of Example 1 was spherical particles having a diameter of submicron to about 2 μm. Each particle was independent, and aggregation was not particularly observed. The powders produced in the other examples were also observed by SEM. As in FIG. 1, the powders were independent spherical particles having a particle diameter of about submicron to about 2 μm, and no agglomeration was observed.

In Table 1, the amount of nitrogen contained in the powder is represented by the molar ratio of nitrogen atoms / oxygen atoms. From Table 1, it is clear that the powder produced by each example was partially nitrided titanium oxide or partially nitrided aluminum oxide. And from the comparison of Example 1 and Example 2,
When nitrogen atoms are contained in the aqueous solution, nitridation is promoted more than when nitrogen atoms are contained in the combustion gas, and nitrogen atoms are contained in both the aqueous solution and the combustion gas as in Example 3. It can be seen that the inclusion further promotes nitriding. It is also clear from the comparison between Example 3 and Example 4 that the larger the amount of nitrogen atoms contained, the more the nitriding is promoted. Further, from the comparison between Example 1 and Example 5, it can be seen that nitriding is promoted even when the amount of introduced oxygen is reduced and oxygen deficiency becomes conspicuous. Also, as in Example 6, it can be seen that aluminum is also partially nitrided similarly to titanium.

On the other hand, nitriding is difficult if the amount of oxygen introduced is too large as in Comparative Example 1, and nitriding is difficult if there is no nitrogen atom even if oxygen is insufficient as in Comparative Example 2. Further, even if nitrogen atoms are contained as nitrate ions as in Comparative Example 3, nitriding is difficult.

That is, from the results of the above examples, it was confirmed that by controlling the synthesis conditions, it is possible to synthesize from an oxide partially nitrided by several percent to a nitride nearly 100%.

[0051]

According to the method for producing at least partially nitrided metal nitride powder of the present invention, since the powder is produced by the spray combustion method, no external heating device such as an electric furnace is required, and the plasma is produced. Since a generator, a vacuum device and the like are not required, the equipment becomes extremely inexpensive. Furthermore, it can be manufactured continuously, and the reaction time is very short.

The obtained at least partially nitrided metal nitride powder is fine particles, and is spherical and does not agglomerate. Therefore, it is suitably used as a filler for filling a polymer member requiring high thermal conductivity. be able to.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a reaction apparatus used in an example of the present invention.

FIG. 2 is a scanning electron micrograph showing the particle structure of the powder obtained by the production method of Example 1.

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[Procedure amendment]

[Submission date] May 9, 2000 (200.5.9)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Toshihiko Tani 41 Toyota Chuo R & D Laboratories Co., Ltd.

Claims (5)

[Claims] 1. A W / O emulsion or suspension formed by mixing an aqueous solution containing a nitridable metal element with a flammable liquid, wherein the flammable liquid completely burns and the metal element is most stable in the atmosphere. Spraying in an atmosphere containing an amount of oxygen smaller than the amount of oxygen required to form a stable oxide, wherein the W / O emulsion or the suspension contains ions other than nitrate ions containing nitrogen atoms. And at least one of a molecule containing a nitrogen atom. 2. A W / O emulsion or suspension formed by mixing an aqueous solution containing a nitridable metal element with a flammable liquid, wherein the flammable liquid completely burns and the metal element is most stable in the atmosphere. a method for spray combustion in an atmosphere containing Do oxide oxygen amount less than the required amount of oxygen required to form a molecule other than N ₂ containing ions and nitrogen atoms in said atmosphere containing a nitrogen atom A method for producing an at least partially nitrided metal nitride powder, characterized by containing at least one of the following. 3. A W / O emulsion or suspension formed by mixing an aqueous solution containing a nitridable metal element with a flammable liquid, wherein the flammable liquid completely burns and the metal element is most stable in the atmosphere. Spraying in an atmosphere containing an amount of oxygen smaller than the amount of oxygen required to form a stable oxide, wherein the W / O emulsion or the suspension contains ions other than nitrate ions containing nitrogen atoms. and at least one of the molecules comprising a nitrogen atom is included, at least partially, characterized in that during the atmosphere contains at least one molecule other than N ₂ containing ions and nitrogen atom containing a nitrogen atom A method for producing a nitrided metal nitride powder. 4. The at least partially nitrided according to claim 1, wherein the nitrogen atom is supplied from at least one selected from ammonia, ammonium ion, hydrazine, and hydrazinium ion. A method for producing a metal nitride powder. 5. The at least partially nitrided metal nitride powder according to claim 1, wherein spray combustion is performed in an atmosphere containing an oxygen content of 10 to 90% of the required oxygen content. Production method.