Manufacturing method of inorganic powder using chemical vapor phase synthetic method, and manufacturing device thereof

Abstract

To provide: a manufacturing method of inorganic powder using a chemical vapor phase synthetic method, which is capable of increasing a manufacturing yield by suppressing a side reaction, and of increasing stability of continuous steps by preventing a reaction vessel from being closed; and a manufacturing device thereof.SOLUTION: A manufacturing method of inorganic powder using a chemical vapor phase synthetic method according to one embodiment of the present invention comprises the steps of: feeding a precursor; feeding a side reaction prevention gas for preventing a side reaction of the precursor to the precursor; feeding a reaction gas to the precursor; and forming inorganic powder by chemically reacting the precursor with the reaction gas.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The technical concept of the present invention relates to a method and an apparatus for producing an inorganic powder using a chemical vapor synthesis method, which can increase the production yield by suppressing side reactions and can increase the stability of a continuous process by preventing clogging of a reactor. [Background technology]

[0002] Inorganic powders such as metal powders or ceramic powders are used in various technical fields. For example, nickel powder, which is one of the metal powders, is used in the electrode layers of multi-layer ceramic capacitors (MLCCs). Multi-layer ceramic capacitors are chip-shaped capacitors that temporarily charge electricity and remove noise in electronic circuits, and are components that store current and stably supply electricity as needed to ensure that electronic devices operate correctly. The most important technology for such multi-layer ceramic capacitors is to laminate nickel electrode layers as thinly and as many times as possible.

[0003] Chemical vapor synthesis is one of the methods for producing metal powders or ceramic powders. Chemical vapor synthesis produces a solid phase material through a chemical reaction between a vaporized precursor and a reaction gas. When a chloride is used as the precursor, the chloride contains water due to its strong hygroscopicity, and the water reacts with the chloride to form an oxide in an undesired position, which may clog the reactor, thereby reducing the production yield of the inorganic powder and the stability of the continuous process. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application No. 2013-548154 Summary of the Invention [Problem to be solved by the invention]

[0005] The technical problem to be solved by the technical idea of ​​the present invention is to provide a method and an apparatus for producing an inorganic powder using a chemical vapor synthesis method, which can increase the production yield by suppressing side reactions and can increase the stability of a continuous process by preventing clogging of a reactor.

[0006] However, these problems are merely examples, and the technical idea of ​​the present invention is not limited thereto. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided a method and an apparatus for producing an inorganic powder using chemical vapor synthesis.

[0008] According to an embodiment of the present invention, the method for producing an inorganic powder using a chemical vapor synthesis method may include the steps of: supplying a precursor; supplying a side reaction prevention gas to the precursor to prevent a side reaction of the precursor; supplying a reaction gas to the precursor; and chemically reacting the precursor with the reaction gas to form an inorganic powder.

[0009] According to an embodiment of the present invention, the side reaction prevention gas can suppress the formation of metal oxides due to a chemical reaction between the precursor and water or oxygen.

[0010] According to an embodiment of the present invention, the water may be provided in a state in which it is chemically or physically adsorbed on the precursor, or in a state in which it forms a hydrate.

[0011] According to an embodiment of the present invention, the side reaction prevention gas may be the same as a part of the product formed by a chemical reaction between the precursor and water or oxygen.

[0012] According to an embodiment of the present invention, the side reaction prevention gas may suppress the formation of some of the products formed by the chemical reaction between the precursor and water or oxygen, thereby suppressing the chemical reaction between the precursor and the water or oxygen.

[0013] According to an embodiment of the present invention, the side reaction prevention gas can suppress or delay the formation of the inorganic powder due to a chemical reaction between the precursor and the reaction gas.

[0014] According to an embodiment of the present invention, the side reaction prevention gas may be the same as a part of the product formed by a chemical reaction between the precursor and the reaction gas.

[0015] According to an embodiment of the present invention, the side reaction prevention gas may suppress the formation of some of the products formed by the chemical reaction between the precursor and the reactant gas, thereby suppressing the chemical reaction between the precursor and the reactant gas.

[0016] According to an embodiment of the present invention, the precursor may contain one or more of the elements constituting the side reaction prevention gas.

[0017] According to an embodiment of the present invention, the non-metallic element of the precursor and the non-metallic element of the side reaction prevention gas may be the same material.

[0018] According to one embodiment of the present invention, the precursor may include one or more of a metal chloride, a metal acetate, a metal bromide, a metal carbonate, a metal carbonyl, a metal fluoride, a metal hydroxide, a metal iodide, a metal nitrate, a metal oxide, a metal phosphate, a metal silicate, a metal sulfate, and a metal sulfide.

[0019] According to one embodiment of the present invention, the metal constituting the precursor may include one or more of nickel, copper, silver, iron, aluminum, silicon, boron, cobalt, platinum, gold, tin, magnesium, tungsten, niobium, molybdenum, zinc, yttrium, zirconium, ruthenium, iridium, tantalum, and titanium.

[0020] According to one embodiment of the present invention, the side reaction prevention gas may include one or more of hydrogen chloride gas (HCl), acetic acid gas (C2H4O2), hydrogen bromide gas (BrH), carbon dioxide gas (H2CO3), hydrogen fluoride gas (HF), water vapor (H2O), hydrogen iodide gas (HI), nitric acid gas (HNO3), phosphoric acid gas (H3PO4), silicon hydride gas (SiH4), sulfuric acid gas (H2SO4), chlorine gas (Cl2), and hydrogen sulfide gas (H2S).

[0021] According to one embodiment of the present invention, the reaction gas may include a reducing gas including any one or more of hydrogen gas, carbon monoxide gas, magnesium vapor gas, sodium vapor gas, and calcium vapor gas; an oxidizing gas including any one or more of oxygen gas, water vapor gas, and ozone gas; a nitriding gas including any one or more of ammonia gas and nitrogen gas; or a carbonizing gas including any one or more of methane gas and acetylene gas.

[0022] According to an embodiment of the present invention, the inorganic powder may include a metal powder.

[0023] According to an embodiment of the present invention, the inorganic powder may include ceramic powder.

[0024] According to an embodiment of the present invention, the method for producing an inorganic powder using chemical vapor synthesis may include the steps of: supplying a precursor; supplying a side reaction prevention gas to the precursor to prevent a side reaction of the precursor; supplying a reaction gas to the precursor; and forming a metal powder by chemically reacting the precursor with the reaction gas.

[0025] According to one embodiment of the present invention, the precursor is nickel chloride, the side reaction prevention gas is hydrogen chloride gas, the reaction gas is hydrogen gas, the metal powder is nickel powder, and the hydrogen chloride gas can suppress the formation of nickel oxide formed by a chemical reaction between the precursor and water.

[0026] According to an embodiment of the present invention, the relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the water may satisfy the range of the following formula:

[0027] P H2O / P HCl 2 <= 10 6

[0028] According to an embodiment of the present invention, the relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the hydrogen gas may satisfy the following range:

[0029] 10 -18 ≦P H2 / P HCl 2

[0030] According to one embodiment of the present invention, the precursor is copper chloride, the side reaction prevention gas is hydrogen chloride gas, the reaction gas is hydrogen gas, the metal powder is copper powder, and the hydrogen chloride gas can suppress the formation of copper oxide formed by a chemical reaction between the precursor and water.

[0031] According to an embodiment of the present invention, the relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the water may satisfy the range of the following formula:

[0032] P H2O / P HCl 2 <= 10 15

[0033] According to an embodiment of the present invention, the relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the hydrogen gas may satisfy the following range:

[0034] 10 -30 ≦P H2 / P HCl 2

[0035] According to an embodiment of the present invention, the method for producing an inorganic powder using chemical vapor synthesis may include the steps of: supplying a precursor; supplying a side reaction prevention gas to the precursor to prevent a side reaction of the precursor; supplying a reaction gas to the precursor; and forming a ceramic powder by chemically reacting the precursor with the reaction gas.

[0036] According to an embodiment of the present invention, the apparatus for manufacturing an inorganic powder may include a reaction chamber providing a reaction space in which a precursor and a reactive gas react to form an inorganic powder, a precursor supplying unit for supplying the precursor to the reaction chamber, a side reaction preventing gas supplying unit for supplying a side reaction preventing gas to the precursor to prevent a side reaction of the precursor, and a reactive gas supplying unit for supplying the reactive gas to the precursor.

[0037] According to an embodiment of the present invention, the method may further include a heating unit for providing heat so that the precursor and the reaction gas react with each other to form the inorganic powder.

[0038] According to an embodiment of the present invention, the side reaction preventing gas supply unit may include a first side reaction preventing gas supply unit disposed inside the precursor supply unit and configured to provide the side reaction preventing gas to the inside of the precursor supply unit.

[0039] According to an embodiment of the present invention, the side reaction preventing gas supply unit may include a second side reaction preventing gas supply unit disposed outside the precursor supply unit and configured to provide the side reaction preventing gas to the outside of the precursor supply unit.

[0040] According to an embodiment of the present invention, the side reaction prevention gas supply unit may be integrated with the precursor supply unit.

[0041] According to one embodiment of the present invention, the side reaction prevention gas and the precursor may be supplied simultaneously or at different times.

[0042] According to an embodiment of the present invention, the plasma processing apparatus may further include an internal precursor storage unit disposed inside the precursor supply unit and configured to store the precursor.

[0043] According to an embodiment of the present invention, the precursor supplying unit may include a nozzle unit that supplies the precursor in a vaporized state.

[0044] According to one embodiment of the present invention, the reaction chamber may include a vaporization region where the precursor is vaporized, a reaction region where the precursor reacts with a reaction gas to form an inorganic powder, and a collection region where the inorganic powder is collected.

[0045] According to one embodiment of the present invention, the reaction chamber may be one or more of a vertical reaction chamber having a hollow shape extending vertically, a horizontal reaction chamber having a hollow shape extending horizontally, and an oblique reaction chamber having a hollow shape extending obliquely. Effect of the Invention

[0046] According to the technical concept of the present invention, the method and apparatus for producing inorganic powder using chemical vapor synthesis can suppress the formation of metal oxides due to a chemical reaction between the precursor and water before the precursor reacts with a reactive gas by supplying the side reaction prevention gas, suppress the formation of inorganic powder composed of metal oxides formed at undesired positions due to a chemical reaction between the precursor and water, or suppress the formation of inorganic powder composed of metals formed at undesired positions due to a chemical reaction between the precursor and a reactive gas. Therefore, it is possible to prevent clogging of the reactor due to the formation of inorganic powders formed at undesired positions, and to ensure the supply of a fixed amount of precursor by preventing the consumption of the precursor, thereby increasing the production yield of inorganic powders and the stability of continuous processes.

[0047] The above-mentioned effects of the present invention have been described as examples, and the scope of the present invention is not limited to these effects. [Brief description of the drawings]

[0048] [Figure 1] FIG. 2 is a schematic diagram illustrating an example of an inorganic powder manufacturing apparatus for carrying out the inorganic powder manufacturing method using the chemical vapor synthesis method according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram illustrating an example of an inorganic powder manufacturing apparatus for carrying out the inorganic powder manufacturing method using the chemical vapor synthesis method according to one embodiment of the present invention. [Diagram 3] 1 is a flowchart showing a method for producing an inorganic powder using a chemical vapor synthesis method according to an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram showing blockage of a precursor supply section due to a side reaction in the method for producing an inorganic powder by chemical vapor synthesis according to one embodiment of the present invention. [Diagram 5] 4 is a graph showing a change in Gibbs free energy with respect to temperature for a chemical reaction of nickel chloride occurring in the method for producing an inorganic powder using the chemical vapor synthesis method according to an embodiment of the present invention. [Figure 6] 4 is a graph showing a calculation result of a phase content for nickel chloride according to the addition of a side reaction prevention gas in the method for producing an inorganic powder using the chemical vapor synthesis method according to an embodiment of the present invention. [Figure 7] 4 is a graph showing in detail the change in Gibbs free energy with respect to temperature for a chemical reaction of nickel chloride occurring in the method for producing an inorganic powder using the chemical vapor synthesis method according to an embodiment of the present invention. [Figure 8] 4 is a graph showing in detail the change in Gibbs free energy with respect to temperature for a chemical reaction of nickel chloride occurring in the method for producing an inorganic powder using the chemical vapor synthesis method according to an embodiment of the present invention. [Figure 9] 4 is a graph showing in detail the change in Gibbs free energy with respect to temperature for a chemical reaction of nickel chloride occurring in the method for producing an inorganic powder using the chemical vapor synthesis method according to an embodiment of the present invention. [Figure 10]4 is a graph showing a change in Gibbs free energy with respect to temperature for a chemical reaction of copper chloride occurring in the method for producing an inorganic powder using the chemical vapor synthesis method according to an embodiment of the present invention. [Figure 11] 4 is a graph showing a change in Gibbs free energy with respect to temperature for a chemical reaction of aluminum chloride occurring in the method for producing an inorganic powder using the chemical vapor synthesis method according to an embodiment of the present invention. [Figure 12] 4 is a photograph showing the state of a reaction chamber according to whether or not a side reaction is prevented in the method for producing an inorganic powder using the chemical vapor synthesis method according to an embodiment of the present invention; [Figure 13] 1 is a photograph of an inorganic powder formed by the method for producing an inorganic powder using a chemical vapor synthesis method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments of the present invention are provided to more completely explain the technical idea of ​​the present invention to those skilled in the art, and the following embodiments may be modified into various other forms, and the scope of the technical idea of ​​the present invention is not limited to the following embodiments. Rather, these embodiments are provided to make the present disclosure more complete and complete, and to fully convey the technical idea of ​​the present invention to those skilled in the art. In the entire specification, the same reference numerals refer to the same elements. Furthermore, various elements and regions in the drawings are illustrated diagrammatically. Therefore, the technical idea of ​​the present invention is not limited by the relative sizes and spacings shown in the accompanying drawings.

[0050] In the present specification, the term "precursor" refers to a precursor for producing an inorganic powder, and refers to a substance in the form of a compound containing a metal element for producing an inorganic powder. The precursor can form a metal powder or a ceramic powder as the final synthetic product, which is an inorganic powder.

[0051] In this specification, the term "side reaction" refers to a reaction in which an oxide such as nickel oxide or aluminum oxide is formed, as well as a reaction in which inorganic powder such as nickel, nickel oxide, or aluminum oxide is formed to adhere to the inside and outside of the precursor supply portion.

[0052] For example, in the case of synthesizing a metal powder such as nickel powder as a final synthesis product, the side reaction may refer to a reaction in which nickel oxide is formed and attached to the precursor supply part before the precursor comes into contact with the reaction gas, or may refer to a reaction in which nickel is formed and attached to the precursor supply part after the precursor comes into contact with the reaction gas.

[0053] In addition, the side reaction may refer to a reaction in which aluminum oxide is formed and adheres to the precursor supply part before and after the precursor comes into contact with the reaction gas when a ceramic powder such as aluminum oxide powder is synthesized as a final synthesis product.

[0054] That is, if such substances adhere to the precursor supply section, they may cause blockage of the precursor supply section, and therefore it is necessary to suppress the formation of such substances.

[0055] In this specification, the term "side reaction prevention gas" refers to a gas that can prevent the above-mentioned side reactions, for example, a gas such as hydrogen chloride that causes a reverse reaction and thereby suppresses or removes the formation of oxides or inorganic powders.

[0056] The method for producing an inorganic powder using chemical vapor synthesis according to the technical concept of the present invention is a method for producing an inorganic powder using chemical vapor synthesis of a precursor and a reactive gas, and by supplying a side reaction prevention gas to the precursor, it is possible to suppress or delay the formation of an oxide formed by a chemical reaction between the precursor and water chemically or physically adsorbed on the precursor or in a hydrated state, and also to suppress or delay the formation of a part of the inorganic powder formed at an undesired position by the chemical reaction between the precursor and the reactive gas.

[0057] 1 and 2 are schematic diagrams illustrating an example of an inorganic powder manufacturing apparatus for carrying out the inorganic powder manufacturing method using the chemical vapor synthesis method according to one embodiment of the present invention.

[0058] 1 and 2, an inorganic powder manufacturing apparatus 100, 100a may include a reaction chamber 110, a precursor supply unit 120, a reaction gas supply unit 130, a first side reaction preventing gas supply unit 140, a second side reaction preventing gas supply unit 150, and a heating unit 160.

[0059] The inorganic powder manufacturing apparatus 100a of FIG. 2 may further include an internal precursor storage unit 123 that is installed inside the precursor supply unit 120 and stores the precursor.

[0060] The reaction chamber 110 may provide a reaction space in which a precursor reacts with a reaction gas to form an inorganic powder. In the drawings, a vertical reaction chamber having a hollow shape extending vertically is shown, but this is merely an example and the technical idea of ​​the present invention is not limited thereto. For example, the reaction chamber 110 may be a horizontal reaction chamber having a hollow shape extending horizontally or an oblique reaction chamber having a hollow shape extending obliquely.

[0061] The reaction chamber 110 may be comprised of a vaporization region 112 in which the precursor is vaporized, a reaction region 114 in which the precursor reacts with a reaction gas to form an inorganic powder, and a collection region 116 in which the formed inorganic powder is collected.

[0062] When the reaction chamber 110 is a vertical reaction chamber, the vaporization region 112, the reaction region 114, and the collection region 116 may be arranged in this order from the top where the gas starts to flow to the bottom.

[0063] When the reaction chamber 110 is a horizontal or inclined reaction chamber, the vaporization region 112, the reaction region 114, and the collection region 116 may be arranged in sequence from one side where the gas starts to flow to the other side where the gas flows.

[0064] The precursor supply unit 120 may be disposed on one side of the reaction chamber 110, for example, in the vaporization region 112, for example, on the upper side. The precursor supply unit 120 may supply the vaporized precursor formed by vaporizing the precursor by heating to the reaction region 114 of the reaction chamber 110, and may include the vaporized precursor or various flow paths through which the vaporized precursor can flow.

[0065] The precursor supply section 120 may include a precursor injection section 122 , a precursor storage section 124 , and a nozzle section 126 .

[0066] The precursor injector 122 may be disposed above the precursor supply unit 120 and may be configured as a separate tube or as a partial region of the precursor supply unit 120. The precursor injector 122 may use a flow of a carrier gas to supply the precursor in a solid phase state, which is a raw material, to the precursor storage unit 124 together with the carrier gas. The carrier gas may include, for example, an inert gas such as argon or nitrogen.

[0067] 2, an internal precursor storage unit 123 is installed inside the precursor supply unit 120. The precursor in a solid state is stored in the internal precursor storage unit 123 in advance, and the precursor is vaporized by heating. After the vaporized precursor is discharged from the internal precursor storage unit 123, the precursor is transported inside the reaction chamber 110 by a carrier gas input into the precursor supply unit 120.

[0068] In addition, in order to make the flow rate of the precursor supplied to the reaction region 114 uniform, when the precursor is partially discharged from the precursor supply unit 120, a quenching gas for cooling may be further supplied. The quenching gas may be supplied through the precursor supply unit 120 or through a separate flow path additionally installed.

[0069] The precursor vaporized externally or internally may be contained in the precursor containing portion 124. The precursor containing portion 124 may be disposed in correspondence with the vaporization region 112.

[0070] The nozzle unit 126 is disposed below the precursor storage unit 124, and can function as a flow path for introducing the vaporized precursor into the reaction region 114. In other words, the precursor supply unit 120 can include the nozzle unit 126 for supplying the precursor in a vaporized state. As long as the nozzle unit 126 has a configuration for supplying the precursor to the reaction region 114, there are no particular limitations on the shape or path.

[0071] A reactant gas supply 130 may be disposed in the reaction chamber 110 to supply into the reaction chamber 110 a reactant gas that reacts with the vaporized precursor or the vaporized precursor.

[0072] The reaction gas may be, for example, a reducing gas, an oxidizing gas, a nitriding gas, or a carbonizing gas. The reaction gas may, for example, include a reducing gas including one or more of hydrogen gas, carbon monoxide gas, magnesium vapor gas, sodium vapor gas, and calcium vapor gas, an oxidizing gas including one or more of oxygen gas, water vapor gas, and ozone gas, a nitriding gas including one or more of ammonia gas and nitrogen gas, or a carbonizing gas including one or more of methane gas and acetylene gas.

[0073] In the drawings, the reaction gas supply section 130 is shown as being disposed above the reaction chamber 110, but this is by way of example only, and the shape and path are not particularly limited as long as it has a configuration for directly supplying reaction gas to the reaction region 114.

[0074] The side reaction preventing gas supply unit may include one or more of a first side reaction preventing gas supply unit 140 and a second side reaction preventing gas supply unit 150.

[0075] The first side reaction preventing gas supply unit 140 may supply a side reaction preventing gas. The first side reaction preventing gas supply unit 140 is disposed inside the precursor supply unit 120 and may supply the side reaction preventing gas to the inside of the precursor supply unit 120.

[0076] The first side reaction preventing gas supply unit 140 supplies the side reaction preventing gas to the inside of the precursor supply unit 120, and the side reaction preventing gas chemically reacts with the metal oxide formed by the chemical reaction between the precursor and water to remove the metal oxide or suppress the formation of the metal oxide. This prevents the precursor receiving unit 124 or the nozzle unit 126 from being clogged due to the formation of the metal oxide inside the precursor receiving unit 124 or the nozzle unit 126, and prevents the precursor from being consumed, ensuring the constant supply of the precursor, thereby increasing the production yield of the inorganic powder and the stability of the continuous process.

[0077] The second side reaction preventing gas supply unit 150 may supply a side reaction preventing gas. The second side reaction preventing gas supply unit 150 may be disposed outside the precursor supply unit 120 and may supply the side reaction preventing gas to the outside of the precursor supply unit 120.

[0078] The second side reaction prevention gas supply unit 150 supplies the side reaction prevention gas to the outside of the precursor supply unit 120, so that the side reaction prevention gas can chemically react with the metal oxide formed by the chemical reaction of the precursor with water to remove the metal oxide or suppress the formation of the metal oxide. In addition, the side reaction prevention gas can delay the chemical reaction of the precursor with the reaction gas, so that a part of the inorganic powder can be removed or the formation of the inorganic powder can be suppressed inside and outside the precursor supply unit 120, for example, inside and outside the precursor receiving unit 124 or the nozzle unit 126. This can prevent the precursor supply unit 120 from being clogged due to the formation of the metal oxide and the inorganic powder inside and outside the precursor supply unit 120, and can ensure the constant supply of the precursor by preventing the exhaustion of the precursor, thereby increasing the production yield of the inorganic powder and the stability of the continuous process.

[0079] The first side reaction preventing gas supply unit 140 is optional and may be omitted. For example, the first side reaction preventing gas supply unit 140 may be integrated with the precursor supply unit 120. The side reaction preventing gas and the precursor may be simultaneously supplied through the precursor injector 122 of the precursor supply unit 120. In addition, the case where the side reaction preventing gas and the precursor are supplied at different times through the precursor injector 122 of the precursor supply unit 120 is also included in the technical spirit of the present invention.

[0080] In addition, even if the first side reaction preventing gas supply unit 140 and the precursor supply unit 120 have separate configurations, the side reaction preventing gas may be supplied simultaneously with the precursor. In addition, the case where the side reaction preventing gas and the precursor are supplied at different times is also included in the technical spirit of the present invention.

[0081] The second side reaction preventing gas supply unit 150 is optional and may be omitted. Alternatively, only one of the first side reaction preventing gas supply unit 140 and the second side reaction preventing gas supply unit 150 may be selected and disposed.

[0082] The side reaction prevention gas may include, for example, hydrogen chloride (HCl) gas. However, this is merely an example, and the side reaction prevention gas may include any type of gas capable of preventing a side reaction, and is within the scope of the present invention. The side reaction and the side reaction prevention gas will be described in detail below.

[0083] The heating unit 160 may provide heat so that the precursor and the reaction gas react chemically to form an inorganic powder. The heating unit 160 may be disposed on the outer periphery of the reaction chamber 110 to heat the reaction chamber 110. The heating unit 160 may be, for example, a resistance heater that is heated electrically.

[0084] The heating unit 160 is divided into a plurality of heaters, and the temperature of each heater may be controlled independently. For example, three heaters may be arranged in the downward direction, such as a first heater 162, a second heater 164, and a third heater 166. The first heater 162, the second heater 164, and the third heater 166 may be controlled to different temperatures, so that various temperature distributions may be realized according to the position of the reaction chamber 110.

[0085] FIG. 3 is a flow chart showing a method for producing an inorganic powder using chemical vapor synthesis according to one embodiment of the present invention.

[0086] Referring to FIG. 3, the method for producing an inorganic powder (S100) includes a step of supplying a precursor (S110), a step of supplying a side reaction prevention gas to the precursor to prevent a side reaction of the precursor (S120), a step of supplying a reaction gas to the precursor (S130), and a step of chemically reacting the precursor with the reaction gas to form an inorganic powder (S140).

[0087] The side reaction prevention gas can suppress the formation of metal oxides formed by chemical reactions between the precursor and water or oxygen.

[0088] The side reaction prevention gas may be identical to a portion of the product formed by the chemical reaction of the precursor with water, and may inhibit the chemical reaction of the precursor with water according to Le Chatelier's principle.

[0089] The water or oxygen can chemically react with the precursor to form a metal oxide.

[0090] The water may be provided in a state of being chemically or physically adsorbed to the precursor, or in a state of forming a hydrate. Alternatively, the water may be provided in a form remaining in the reaction chamber, provided by leakage, or provided as being included in the carrier gas and the reaction gas. In general, water is most often contained as water of crystallization (chemical bond). In addition, since a reactor cannot be completely sealed 100%, the inflow of moisture and oxygen may occur even due to minute leaking.

[0091] The side reaction prevention gas can also suppress or delay the formation of some of the inorganic powders formed by the chemical reaction between the precursor and the reactant gas. The side reaction prevention gas can be identical to some of the products formed by the chemical reaction between the precursor and the reactant gas, and can suppress the chemical reaction between the precursor and the reactant gas according to Le Chatelier's principle.

[0092] The precursor may include one or more of the elements constituting the side reaction prevention gas. For example, the nonmetallic element of the precursor and the nonmetallic element of the side reaction prevention gas may be the same substance. For example, the nonmetallic element of the precursor and the nonmetallic element of the side reaction prevention gas may both be chlorine (Cl). For example, the precursor may be nickel chloride (NiCl2), the side reaction prevention gas may be hydrogen chloride (HCl), and the precursor and the side reaction prevention gas may both be chlorides. Or, for example, the precursor may be copper chloride (CuCl), the side reaction prevention gas may be hydrogen chloride (HCl), and the precursor and the side reaction prevention gas may both be chlorides. Or, for example, the precursor may be aluminum chloride (AlCl3), the side reaction prevention gas may be hydrogen chloride (HCl), and the precursor and the side reaction prevention gas may both be chlorides.

[0093] The precursors may include, but are not limited to, any one or more of, for example, a metal chloride, a metal acetate, a metal bromide, a metal carbonate, a metal carbonyl, a metal fluoride, a metal hydroxide, a metal iodide, a metal nitrate, a metal oxide, a metal phosphate, a metal silicate, a metal sulfate, and a metal sulfide.

[0094] The metal constituting the precursor may include, for example, one or more of nickel, copper, silver, iron, aluminum, silicon, boron, cobalt, platinum, gold, tin, magnesium, tungsten, niobium, molybdenum, zinc, yttrium, zirconium, ruthenium, iridium, tantalum, and titanium. However, this is merely an example and the technical idea of ​​the present invention is not limited thereto.

[0095] For example, the precursor may be a chloride. The precursor may include, for example, one or more of nickel chloride, copper chloride, silver chloride, iron chloride, aluminum chloride, cobalt chloride, platinum chloride, gold chloride, tin chloride, magnesium chloride, tungsten chloride, niobium chloride, molybdenum chloride, zinc chloride, yttrium chloride, zirconium chloride, ruthenium chloride, iridium chloride, tantalum chloride, and titanium chloride. However, this is merely an example, and the technical idea of ​​the present invention is not limited thereto.

[0096] The side reaction prevention gas may include, for example, one or more of hydrogen chloride gas (HCl), acetic acid gas (C2H4O2), hydrogen bromide gas (BrH), carbon dioxide gas (H2CO3), hydrogen fluoride gas (HF), water vapor (H2O), hydrogen iodide gas (HI), nitric acid gas (HNO3), phosphoric acid gas (H3PO4), silicon hydride gas (SiH4), hydrogen gas (H2), sulfuric acid gas (H2SO4), chlorine gas (Cl2), and hydrogen sulfide gas (H2S). However, this is merely an example, and the technical idea of ​​the present invention is not limited thereto.

[0097] The reaction gas may be a reducing gas, an oxidizing gas, a nitriding gas, or a carbonizing gas. The reaction gas may include a reducing gas including one or more of hydrogen gas, carbon monoxide gas, magnesium vapor gas, sodium vapor gas, and calcium vapor gas, an oxidizing gas including one or more of oxygen gas, water vapor gas, and ozone gas, a nitriding gas including one or more of ammonia gas and nitrogen gas, or a carbonizing gas including one or more of methane gas and acetylene gas. However, this is merely an example, and the technical idea of ​​the present invention is not limited thereto.

[0098] In the following, an example of a method for producing an inorganic powder carried out using the inorganic powder production apparatus 100 will be described.

[0099] A precursor for forming a desired inorganic powder is injected together with a carrier gas into the precursor supply unit 120 through the precursor injection unit 122. When the precursor is previously stored in the internal precursor storage unit 123 within the precursor supply unit 120, the precursor injection unit 122 may inject only the carrier gas for gas flow.

[0100] In the precursor supply unit 120 disposed in the vaporization region 112 of the reaction chamber 110, the precursor is vaporized to form a vaporized precursor. Such vaporization may be performed by a first heater 162 of the heating unit 160. The vaporized precursor is supplied to the reaction region 114 of the reaction chamber 110 through a nozzle unit 126. In addition, in the vaporization region 112, a reaction gas, a carrier gas, etc. may be preheated.

[0101] In the reaction region 114 of the reaction chamber 110, the vaporized precursor reacts with a reaction gas supplied through a reaction gas supply unit 130 to form an inorganic powder.

[0102] The formed inorganic powder is collected in the collection area 116 of the reaction chamber 110. The collected inorganic powder may be further subjected to a series of processes such as classification and powder washing. The collection device and collection method may be performed in various ways and are within the technical scope of the present invention.

[0103] The temperatures of the different regions of the reaction chamber 110 can be selected in various ways depending on the precursors introduced. The vaporization region 112 can have a temperature range in which the precursors can be vaporized, and may be, for example, in the range of 20°C to 1400°C. The reaction region 114 can have a temperature range in which the precursors react with the reaction gas, and may be, for example, in the range of 200°C to 1400°C. The collection region 116 can have a temperature range in which the formed inorganic powder precipitates in a solid phase, and may be, for example, in the range of 20°C to 1000°C.

[0104] The inorganic powder produced by this method may include, for example, nickel, copper, silver, iron, aluminum, silicon, boron, cobalt, platinum, gold, tin, magnesium, tungsten, niobium, molybdenum, zinc, yttrium, zirconium, ruthenium, iridium, tantalum, titanium, and alloys containing these. However, this is merely an example, and the technical idea of ​​the present invention is not limited thereto.

[0105] Alternatively, the inorganic powder may be any one of oxides, nitrides, and carbides of, for example, nickel, copper, silver, iron, aluminum, silicon, boron, cobalt, platinum, gold, tin, magnesium, tungsten, niobium, molybdenum, zinc, yttrium, zirconium, ruthenium, iridium, tantalum, and titanium. However, this is merely an example, and the technical idea of ​​the present invention is not limited thereto.

[0106] The inorganic powder may include a metal powder, a ceramic powder, or both. For example, the inorganic powder may include one or more of nickel powder, copper powder, nickel-copper alloy powder, aluminum oxide powder, iron-aluminum oxide powder, and aluminum nitride powder. However, this is merely an example, and the technical idea of ​​the present invention is not limited thereto.

[0107] A method for producing an inorganic powder using a chemical vapor synthesis method according to an embodiment of the present invention may include the steps of: supplying a precursor; supplying a side reaction prevention gas to the precursor to prevent a side reaction of the precursor; supplying a reaction gas to the precursor; and forming a metal powder by chemically reacting the precursor with the reaction gas.

[0108] The precursor is nickel chloride, the side reaction prevention gas is hydrogen chloride gas, the reaction gas is hydrogen gas, the metal powder is nickel powder, and the hydrogen chloride gas can suppress the formation of metal oxides formed by a chemical reaction between the precursor and water.

[0109] For example, in the case where the precursor is nickel chloride and the inorganic powder to be synthesized is nickel powder, a method for producing an inorganic powder using a chemical vapor synthesis method according to one embodiment of the present invention may include the steps of: supplying nickel chloride; supplying hydrogen chloride gas to the nickel chloride to prevent a side reaction of the nickel chloride; supplying a reaction gas to the nickel chloride; and chemically reacting the nickel chloride with the reaction gas to form nickel powder.

[0110] For example, after solid-phase nickel chloride is vaporized, the vaporized nickel chloride may be supplied to the reaction chamber 110 by a carrier gas, and the nickel chloride may be reduced using a reducing gas such as hydrogen to nucleate and grow nickel particles, thereby forming the nickel powder.

[0111] The hydrogen chloride gas can suppress or delay the formation of nickel oxides due to a chemical reaction between the nickel chloride and water, and can suppress or delay the formation of the nickel powder due to a chemical reaction between the nickel chloride and the reaction gas.

[0112] Thus, in order to prevent the side reaction of the nickel chloride, the relationship between the partial pressures of the hydrogen chloride gas and the water, and the relationship between the partial pressures of the hydrogen chloride gas and the hydrogen gas must be taken into consideration.

[0113] In order to suppress or delay the formation of nickel oxide due to a chemical reaction between the nickel chloride and the water, the relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the water may satisfy the following range.

[0114] Nickel chloride in the gas phase: P H2O / P HCl 2 <= 10 3

[0115] Solid nickel chloride:P H2O / P HCl 2 <= 106

[0116] P H2O / P HCl 2 is the upper limit of 10 for gas-phase nickel chloride. 3 or the upper limit of 10 for solid nickel chloride. 6 If the partial pressure of water exceeds 1000 ppm, that is, if the partial pressure of water is higher, the effect of preventing the side reaction may be small.

[0117] P H2O / P HCl 2 Although there is no lower limit, if the amount of hydrogen chloride gas is excessively large, it may slow down the reaction of forming inorganic powder in the reaction zone, so it is preferable to control the amount of hydrogen chloride gas. H2O / P HCl 2 The lower limit is 10 for gas-phase nickel chloride. -15 In the case of solid nickel chloride, it is 10 -5 may be also possible.

[0118] In order to suppress or delay the formation of the nickel powder in the nozzle portion due to a chemical reaction between the nickel chloride and the hydrogen, the relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the hydrogen gas can satisfy the following range.

[0119] 10 -18 ≦P H2 / P HCl 2 <= 10 3

[0120] On the other hand, in the reaction region, the nickel powder should be formed by a chemical reaction between the nickel chloride and the hydrogen, and the relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the hydrogen gas should satisfy the range of the following formula.

[0121] 10 -8 ≦P H2 / P HCl 2

[0122] Here, P H2 / P HCl 2 The upper limit of is not limited, but may be, for example, 10 1000000 may be also possible.

[0123] For example, when the precursor is copper chloride and the inorganic powder to be synthesized is copper powder, a method for producing an inorganic powder using chemical vapor synthesis according to an embodiment of the present invention may include the steps of: supplying copper chloride; supplying hydrogen chloride gas to the copper chloride to prevent a side reaction of the copper chloride; supplying a reaction gas to the copper chloride; and chemically reacting the copper chloride with the reaction gas to form copper powder.

[0124] For example, after solid-phase copper chloride is vaporized, the vaporized copper chloride may be supplied to the reaction chamber 110 by a carrier gas, and the copper chloride may be reduced with a reducing gas such as hydrogen to nucleate and grow copper particles, thereby forming the copper powder.

[0125] The hydrogen chloride gas can suppress or delay the formation of copper oxide due to the chemical reaction between the copper chloride and water, and can suppress or delay the formation of the copper powder due to the chemical reaction between the copper chloride and the reaction gas.

[0126] In this way, in order to prevent the side reaction of the copper chloride, the relationship between the partial pressures of the hydrogen chloride gas and the water, and the relationship between the partial pressures of the hydrogen chloride gas and the hydrogen gas must be taken into consideration.

[0127] In order to suppress or delay the formation of the copper oxide due to a chemical reaction between the copper chloride and the water, the relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the water may satisfy the following range.

[0128] Copper chloride in the gas phase: P H2O / P HCl 2 <= 101

[0129] Solid copper chloride: P H2O / P HCl 2 <= 10 15

[0130] P H2O / P HCl 2 is the upper limit of 10 for gas-phase copper chloride. 1 or the upper limit of 10 for solid copper chloride. 15 If the partial pressure of water exceeds 1000 ppm, that is, if the partial pressure of water is higher, the effect of preventing the side reaction may be small.

[0131] P H2O / P HCl 2 Although there is no lower limit, if the amount of hydrogen chloride gas is excessively large, it may slow down the reaction of forming inorganic powder in the reaction zone, so it is preferable to control the amount of hydrogen chloride gas. H2O / P HCl 2 The lower limit of is 10 for gas-phase copper chloride. -25 In the case of solid copper chloride, -1 may be also possible.

[0132] In order to suppress or delay the formation of the copper powder in the nozzle portion due to a chemical reaction between the copper chloride and the hydrogen, the relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the hydrogen gas can satisfy the following range.

[0133] 10 -30 ≦P H2 / P HCl 2 <= 10 1

[0134] On the other hand, in the reaction region, the copper powder should be formed by a chemical reaction between the copper chloride and the hydrogen, and the relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the hydrogen gas should satisfy the range of the following formula.

[0135] 10 -20 ≦P H2 / P HCl 2

[0136] Here, P H2 / P HCl 2 The upper limit of is not limited, but may be, for example, 10 1000000 may be also possible.

[0137] A method for manufacturing an inorganic powder using a chemical vapor synthesis method according to an embodiment of the present invention may include the steps of: supplying a precursor; supplying a side reaction prevention gas to the precursor to prevent a side reaction of the precursor; supplying a reaction gas to the precursor; and chemically reacting the precursor with the reaction gas to form a ceramic powder.

[0138] For example, when the precursor is aluminum chloride and the inorganic powder to be synthesized is aluminum oxide powder, a method for producing an inorganic powder using chemical vapor synthesis according to one embodiment of the present invention may include the steps of: supplying aluminum chloride; supplying hydrogen chloride gas to the aluminum chloride to prevent a side reaction of the aluminum chloride; supplying a reactive gas to the aluminum chloride; and chemically reacting the aluminum chloride with the reactive gas to form an aluminum oxide powder.

[0139] For example, after solid-phase aluminum chloride is vaporized, the vaporized aluminum chloride may be supplied to the reaction chamber 110 by a carrier gas, and the aluminum chloride may nucleate and grow aluminum oxide particles by an oxidation reaction using an oxidizing gas such as water to form the aluminum oxide powder.

[0140] In addition, the hydrogen chloride gas can suppress or delay the formation of the aluminum oxide due to a chemical reaction between the aluminum chloride and water as the reactive gas.

[0141] In this way, in order to prevent the side reaction of the aluminum chloride, the relationship between the partial pressures of the hydrogen chloride gas and the water must be taken into consideration.

[0142] In order to suppress or delay the formation of the aluminum oxide due to a chemical reaction between the aluminum chloride and the water, the relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the water may satisfy the following range.

[0143] Aluminum chloride in gas phase: P H2O 3 / P HCl 6 <= 10 -1

[0144] Solid aluminum chloride: P H2O 3 / P HCl 6 <= 10 -5

[0145] P H2O 3 / P HCl 6 is the upper limit of 10 for gaseous aluminum chloride. -1 or the upper limit of 10 for solid aluminum chloride. -5 If the partial pressure of water exceeds 1000 ppm, that is, if the partial pressure of water is higher, the effect of preventing the side reaction may be small.

[0146] P H2O 3 / P HCl 6 Although there is no lower limit, if the amount of hydrogen chloride gas is excessively large, it may slow down the reaction of forming inorganic powder in the reaction zone, so it is preferable to control the amount of hydrogen chloride gas. H2O 3 / P HCl 6 The lower limit is 10 for gaseous aluminum chloride. -30 In the case of solid aluminum chloride, it is 10 -25 may be also possible.

[0147] On the other hand, in the reaction zone, the aluminum oxide powder should be formed by a chemical reaction between the aluminum chloride and the water, and the relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the water should satisfy the range of the following formula:

[0148] 10 -25 ≦P H2O 3 / P HCl 6

[0149] Here, P H2O 3 / P HCl 6 The upper limit of is not limited, but may be, for example, 10 1000000 may be also possible.

[0150] For example, in the case where the precursor is aluminum chloride and the inorganic powder to be synthesized is aluminum nitride powder, a method for producing an inorganic powder using chemical vapor synthesis according to one embodiment of the present invention may include the steps of: supplying aluminum chloride; supplying hydrogen chloride gas to the aluminum chloride to prevent a side reaction of the aluminum chloride; supplying a reactive gas to the aluminum chloride; and chemically reacting the aluminum chloride with the reactive gas to form aluminum nitride powder.

[0151] For example, after solid-phase aluminum chloride is vaporized, the vaporized aluminum chloride is supplied to the reaction chamber 110 by a carrier gas, and the aluminum chloride nucleates and grows aluminum nitride particles by a nitridation reaction using a nitriding gas such as ammonia, thereby forming the aluminum nitride powder.

[0152] FIG. 4 is a schematic diagram showing blockage of a precursor supply section due to a side reaction in the method for producing an inorganic powder using chemical vapor synthesis according to one embodiment of the present invention.

[0153] Referring to FIG. 4, an oxide 128 such as nickel oxide or aluminum oxide may be formed inside the precursor supply unit 120 by the above-mentioned chemical reaction, and the oxide 128 may be solidified and deposited inside the nozzle unit 126. This deposition may be performed in the precursor storage unit 124 or the nozzle unit 126 of the precursor supply unit 120. Since the oxide 128 consumes the chloride of the precursor, the chloride may not be supplied to the reaction region 114 (see FIG. 1) at a constant rate. The oxide 128 may be solidified and deposited outside the precursor supply unit 120. If the oxide 128 is deposited inside and outside the precursor supply unit 120, the gas pressure may change due to unwanted consumption of the chloride of the precursor, which may change the conditions of the manufacturing process, and the precursor supply unit 120, for example, the nozzle unit 126, may be clogged with the oxide 128 inside, outside, or inside and outside.

[0154] Furthermore, when inorganic powder 129 such as nickel or aluminum oxide is formed inside and outside the precursor supply portion 120 by the chemical reaction, the inorganic powder 129 may be solidified on the outside of the precursor supply portion 120, which may cause the gas pressure to change due to unwanted consumption of the chloride of the precursor, and may even cause the precursor supply portion 120, for example the nozzle portion 126, to be clogged by the inorganic powder 129.

[0155] On the other hand, in the method for producing inorganic powder using chemical vapor synthesis according to the technical idea of ​​the present invention, by further providing a side reaction prevention gas such as hydrogen chloride gas, it is possible to prevent the formation of oxides and inorganic powder inside and outside the precursor supply unit 120, thereby ensuring the constant supply of the precursor to the reaction region and preventing the occurrence of a pressure difference in the precursor supply unit 120, and preventing clogging of, for example, the nozzle unit 126 of the precursor supply unit 120.

[0156] The side reaction prevention gas may be supplied to the inside of the precursor supply unit 120 through the precursor injector 122. Alternatively, the side reaction prevention gas may be supplied through a side reaction prevention gas supply unit. For example, the side reaction prevention gas may be supplied to the inside of the precursor supply unit 120 in the reaction chamber 110 through a first side reaction prevention gas supply unit 140 and may be supplied to the inside of the nozzle unit 126. For example, the side reaction prevention gas may be supplied to the outside of the precursor supply unit 120 in the reaction chamber 110 through a second side reaction prevention gas supply unit 150 and may be supplied to the outside of the nozzle unit 126.

[0157] The side reaction prevention gas may be injected continuously at a uniform injection amount, continuously at a non-uniform injection amount, discontinuously at a uniform injection amount, or discontinuously at a non-uniform injection amount.

[0158] Hereinafter, in the method for producing an inorganic powder using chemical vapor synthesis according to one embodiment of the present invention, the role of the side reaction and the side reaction prevention gas will be described based on thermodynamic theory.

[0159] In the following description, an example will be described in which the precursor is nickel chloride, the reactive gas is hydrogen gas, the inorganic powder is nickel powder, and the side reaction prevention gas is hydrogen chloride.

[0160] FIG. 5 is a graph showing the change in Gibbs free energy with respect to temperature for the chemical reaction of nickel chloride occurring in the method for producing an inorganic powder using the chemical vapor synthesis method according to one embodiment of the present invention.

[0161] Referring to FIG. 5, nickel chloride can react as shown in the following chemical formula:

[0162] [ka]

[0163] [ka]

[0164] [ka]

[0165] When the precursor is nickel chloride, nickel powder can be formed according to Chemical Formula 1.

[0166] According to the Gibbs free energy, below about 1400° C., the reaction of nickel chloride with hydrogen gas to form nickel becomes dominant, and hydrogen gas must be provided for this reaction to occur.

[0167] Therefore, in an environment where the hydrogen gas is not provided, such as inside the precursor supply unit 120, the reaction in which nickel chloride reacts with water to form nickel oxide is dominant. As shown in Chemical Formula 2, before the nickel chloride is vaporized, solid phase NiCl2(s) can react with water (H2O) to form nickel oxide (NiO). As shown in Chemical Formula 3, after the nickel chloride is vaporized, gas phase NiCl2(g) can react with water (H2O) to form nickel oxide (NiO).

[0168] The precursor is in a solid phase at room temperature and may contain water that is chemically or physically adsorbed or in the form of a hydrate. In particular, metal chlorides such as nickel chloride are difficult to completely dry, contain even a trace amount of water (H2O), and have very strong hygroscopicity, so they easily adsorb water (H2O) or form hydrates. The water is difficult to remove by normal drying.

[0169] In addition, since water (H2O) is highly reactive with NiCl2(s) and NiCl2(g), nickel chloride reacts with water to form nickel oxide, consuming the raw material nickel chloride and forming unwanted nickel oxide (NiO). That is, the water can react with solid-phase nickel chloride as shown in Chemical Formula 2. Alternatively, the water can react with gas-phase nickel chloride as shown in Chemical Formula 3. As a result, an oxide, for example, nickel oxide (NiO), can be formed.

[0170] The nickel oxide may clog the precursor supply unit in the production apparatus or consume nickel in the nickel precursor, so it is preferable to remove the nickel oxide or suppress the formation of the nickel oxide.

[0171] When nickel oxide is formed, hydrogen chloride (HCl) is also produced as another product. If it is desired to suppress the formation of nickel oxide, it is possible to suppress the forward reaction by supplying hydrogen chloride (HCl) or to cause the reverse reaction.

[0172] Specifically, when hydrogen chloride is additionally supplied into the precursor supply unit 120, a forward reaction in which nickel chloride reacts with water is suppressed, or a reverse reaction in which nickel oxide reacts with the supplied hydrogen chloride occurs, thereby suppressing the formation of the nickel oxide or removing the nickel oxide.

[0173] In addition, nickel formed on the inside or outside adjacent to the precursor supply unit 120 may be deposited on the precursor supply unit 120, for example, on the nozzle unit 126, and thus the nozzle unit 126 may be blocked by the nickel. The reactants NiCl2(g) and hydrogen (H2) can only react uniformly if they are mixed after being sufficiently preheated to a high reaction temperature. However, due to the high diffusivity of hydrogen (H2), it may diffuse in the opposite direction to the gas flow (i.e., toward the nozzle unit), and thus a reaction may occur in an undesired area, and nickel may adhere to the nozzle unit 126, causing the nozzle unit 126 to be blocked.

[0174] Therefore, by additionally supplying hydrogen chloride to the inside and outside of the precursor supply unit 120 through one or more of the first side reaction preventing gas supply unit 140 and the second side reaction preventing gas supply unit 150, the forward reaction in which nickel chloride reacts with hydrogen to form nickel can be suppressed or a reverse reaction can occur. As a result, the formation of nickel can be suppressed in undesired regions of the precursor supply unit 120, for example, the outside adjacent to the nozzle unit 126, and the formation of nickel can be performed at a position somewhat separated from the precursor supply unit 120, for example, the nozzle unit 126.

[0175] As described above, the formation of nickel oxide or nickel can make it difficult to meter the NiCl2 precursor and can cause pressure in the reaction chamber, making continuous operation difficult. In order to solve these problems, the present invention increases the partial pressure of hydrogen chloride (HCl) in a localized area to suppress undesired reactions.

[0176] In the case of Formula 1, P H2 / P HCl 2 Only when the ratio of P is small can undesired reactions be suppressed. In the case of Formula 2 and Formula 3, H2O / P HCl 2 Only when the ratio of P is small can unwanted reactions be suppressed.H2 is the partial pressure of hydrogen gas, P H2O is the partial pressure of water, P HCl is the partial pressure of hydrogen chloride gas.

[0177] FIG. 6 is a graph showing the calculation results of the phase content for nickel chloride according to the addition of a side reaction prevention gas in the method for producing an inorganic powder using the chemical vapor synthesis method according to one embodiment of the present invention.

[0178] Referring to Fig. 6, when only NiCl2 and H2O are present, NiO begins to form at about 300°C, and all NiCl2 is converted to NiO at about 750°C. When HCl is provided as a side reaction prevention gas, the NiO formation start temperature increases and the amount of NiO formed decreases. When the molar ratio of NiCl2 to HCl exceeds 8, NiO is not formed. The required content of the side reaction prevention gas can be calculated based on the partial pressures of water and hydrogen chloride gas.

[0179] 7 to 9 are graphs showing in detail the change in Gibbs free energy with respect to temperature for the chemical reaction of nickel chloride occurring in the method for producing an inorganic powder using the chemical vapor synthesis method according to one embodiment of the present invention.

[0180] Referring to FIG. 7, the change in Gibbs free energy with temperature for the chemical reaction of solid phase NiCl2(s) and H2O(g) of Chemical Formula 2 is shown. The solid phase NiCl2 is P H2O / P HCl 2 When P is 1, it reacts with water at temperatures above about 700°C. It is necessary to maintain an appropriate gas partial pressure to suppress the chemical reaction, taking into account the internal temperature of the reaction chamber. For example, at a temperature of 900°C, P H2O / P HCl 2 The chemical reaction can be suppressed by providing hydrogen chloride (HCl) in an amount sufficient to form an atmosphere with a .DELTA. of 0.1 or less.

[0181] Referring to FIG. 8, the change in Gibbs free energy with temperature for the chemical reaction of gaseous NiCl2(g) and H2O(g) in Chemical Formula 3 is shown. The gaseous NiCl2 is P H2O / P HCl 2 When is 1, it reacts with H2O at temperatures below 1400°C. However, at temperatures below 600°C, the saturated vapor pressure of NiCl2 is low, so the reaction must be suppressed above the temperature at which a sufficient amount of NiCl2 gas is formed, and therefore an appropriate gas partial pressure must be maintained. For example, at 600°C, the saturated vapor pressure of NiCl2 is only about 13 Pa, so P H2O / P HCl 2 The chemical reaction can be largely suppressed by providing hydrogen chloride (HCl) in an amount sufficient to form an atmosphere with a pH of 0.001 or less.

[0182] Referring to FIG. 9, the change in Gibbs free energy with temperature for the chemical reaction of NiCl2(g) and H2(g) in the gas phase of Chemical Formula 1 is shown. The formation of nickel powder in undesired areas, such as the nozzle portion 126, is due to the diffusion of hydrogen (H2). Whether the chemical reaction is a forward or reverse reaction in such areas is determined by the P H2 / P HCl 2 However, the diffuse P H2 Since it is difficult to accurately predict the value of H2 / P HCl 2 It is difficult to calculate exactly. However, P H2 / P HCl 2 The smaller the value, the more the adhesion of nickel can be suppressed.

[0183] In the following description, an example will be described in which the precursor is copper chloride, the reactive gas is hydrogen gas, the inorganic powder is copper powder, and the side reaction prevention gas is hydrogen chloride.

[0184] FIG. 10 is a graph showing the change in Gibbs free energy with respect to temperature for the chemical reaction of copper chloride occurring in the method for producing an inorganic powder using the chemical vapor synthesis method according to one embodiment of the present invention.

[0185] Referring to FIG. 10, copper chloride can react as shown in the following chemical formula:

[0186] [ka]

[0187] [ka]

[0188] [ka]

[0189] When the precursor is copper chloride, copper powder can be formed according to Chemical Formula 4.

[0190] According to the Gibbs free energy, below about 1400° C., the reaction of copper chloride with hydrogen gas to form copper becomes dominant, and hydrogen gas must be provided for this reaction to occur.

[0191] Therefore, in an environment where the hydrogen gas is not provided, such as inside the precursor supply unit 120, the reaction in which copper chloride reacts with water to form copper oxide is dominant. As shown in Chemical Formula 5, before the copper chloride is vaporized, solid-phase CuCl(s) may react with water (H2O) to form copper oxide (Cu2O). As shown in Chemical Formula 6, after the copper chloride is vaporized, gas-phase CuCl(g) may react with water (H2O) to form copper oxide (Cu2O).

[0192] The copper oxide may clog the precursor supply unit in the production apparatus or consume copper in the copper precursor, so it is preferable to remove the copper oxide or suppress the formation of the copper oxide.

[0193] When copper oxide is formed, hydrogen chloride (HCl) is also produced as another product. If it is desired to suppress the formation of copper oxide, it is possible to suppress the forward reaction by supplying hydrogen chloride (HCl) or to cause the reverse reaction.

[0194] As described above, when hydrogen chloride is additionally supplied into the precursor supply unit 120, the forward reaction of copper chloride reacting with water is inhibited, or the reverse reaction of copper oxide reacting with the supplied hydrogen chloride occurs, thereby inhibiting the formation of the copper oxide or removing the copper oxide.

[0195] In addition, by supplying additional hydrogen chloride, the forward reaction of copper chloride reacting with hydrogen to form copper can be suppressed or a reverse reaction can occur, thereby suppressing the formation of copper in undesired regions, such as the outer side adjacent to the precursor supply unit 120, for example, the nozzle unit 126, and allowing the copper to be formed at a position somewhat separated from the precursor supply unit 120, for example, the nozzle unit 126.

[0196] In the case of the above formula 4, P H2 / P HCl 2 Only when the ratio of P is small can undesired reactions be suppressed. In the case of Formula 5 and Formula 6, H2O / P HCl 2 Only when the ratio of P is small can unwanted reactions be suppressed. H2 is the partial pressure of hydrogen gas, P H2O is the partial pressure of water, P HCl is the partial pressure of hydrogen chloride gas.

[0197] In the following description, an example will be described in which the precursor is aluminum chloride, the reactive gas is water, the inorganic powder is aluminum oxide powder, and the side reaction prevention gas is hydrogen chloride.

[0198] FIG. 11 is a graph showing the change in Gibbs free energy with respect to temperature for the chemical reaction of aluminum chloride occurring in the method for producing inorganic powder using the chemical vapor synthesis method according to one embodiment of the present invention.

[0199] Referring to FIG. 11, aluminum chloride can react as shown in the following chemical formula:

[0200] [ka]

[0201] [ka]

[0202] When the precursor is aluminum chloride, aluminum oxide powder can be formed according to Chemical Formula 7.

[0203] According to the Gibbs free energy, below about 1400° C., the reaction of aluminum chloride with water to form aluminum oxide becomes dominant, and water must be provided for this reaction to occur.

[0204] As shown in the formula 8, before aluminum chloride is vaporized, solid phase AlCl3(s) can react with water (H2O) to form aluminum oxide (Al2O3). As shown in the formula 7, after aluminum chloride is vaporized, gas phase AlCl3(g) can react with water (H2O) to form aluminum oxide (Al2O3).

[0205] The aluminum oxide is the desired inorganic powder, but if it is formed in an undesired location, it may clog the precursor supply section in the manufacturing apparatus, and therefore it is necessary to remove the aluminum oxide or suppress the formation of the aluminum oxide.

[0206] When aluminum oxide is formed, hydrogen chloride (HCl) is also produced as another product. If it is desired to suppress the formation of aluminum oxide, the hydrogen chloride (HCl) can be supplied to suppress the forward reaction or the reverse reaction can be generated.

[0207] As described above, when hydrogen chloride is additionally supplied to the interior of the precursor supply unit 120, the forward reaction in which aluminum chloride reacts with water to form aluminum oxide can be suppressed or a reverse reaction can occur. This can suppress the formation of the aluminum oxide in undesired regions of the precursor supply unit 120, such as the outer side adjacent to the nozzle unit 126, and can allow the aluminum oxide to be formed at a position somewhat separated from the precursor supply unit 120, such as the nozzle unit 126.

[0208] In the case of the formula 7 and the formula 8, P H2O / P HCl 2 Only when the ratio of P is small can unwanted reactions be suppressed. H2O is the partial pressure of water, P HCl is the partial pressure of hydrogen chloride gas.

[0209] In addition, similarly to the aluminum oxide, the technical concept of the present invention can be applied to aluminum nitrides such as those represented by the following Formulas 9 and 10.

[0210] [ka]

[0211] [ka]

[0212] In the above description, a case where chemical vapor synthesis (CVS) is used to produce an inorganic powder has been described, but this is merely an example and the technical idea of ​​the present invention is not limited thereto.

[0213] The inorganic powder thus formed can be applied to various fine ceramic fields. For example, nickel powder produced using the manufacturing method and manufacturing apparatus according to the technical concept of the present invention can be applied to the electrode layer of a multilayer ceramic capacitor (MLCC).

[0214] Experimental Example

[0215] In the following, preferred experimental examples are presented to aid in understanding the present invention. However, the following experimental examples are merely intended to aid in understanding the present invention, and the present invention is not limited to the following experimental examples.

[0216] For the production of the inorganic powder, the inorganic powder production apparatus shown in FIG. 1 was used.

[0217] As a precursor, nickel chloride (NiCl2) solid raw material was used. The moisture content of the nickel chloride was 0.21 wt% as measured using a halogen moisture meter (Mettler Toledo, HC103).

[0218] In the embodiment, hydrogen chloride (HCl) was introduced at 0.6 LPM (liter per minute) as a side reaction prevention gas, and P H2 / P HCl 2 The nickel powder was formed in an atmosphere where the .DELTA..times ...

[0219] In the comparative example, nickel powder was formed without adding hydrogen chloride (HCl) as a side reaction prevention gas.

[0220] FIG. 12 is a photograph showing the state of the reaction chamber depending on whether or not side reactions are prevented in the method for producing an inorganic powder using chemical vapor synthesis according to one embodiment of the present invention.

[0221] Referring to FIG. 12, the precursor injector 122 providing nickel chloride and the precursor supply 120 housing the precursor injector 122 are shown after the nickel powder has been formed.

[0222] In the comparative example, when the reaction was performed without adding hydrogen chloride (HCl), nickel oxide was formed on the inner wall of the precursor injection unit 122. Nickel oxide was also formed on the inner wall of the lower side of the precursor supply unit 120. A nickel film was also formed with a length of about 4 cm from the bottom. It was analyzed that the nickel film was formed by nickel element formed after the chemical reaction being precipitated on the inner or outer side of the lower side of the precursor supply unit 120, or by fine nickel powder formed in the gas phase after the chemical reaction being collided with and heat-treated on the inner or outer side of the lower side of the precursor supply unit 120.

[0223] On the other hand, in the Example, nickel oxide was not formed on the inner wall of the precursor injection part 122. In addition, green nickel oxide was not formed on the inner wall of the lower side of the precursor supply part 120. In addition, a nickel film was formed with a length of about 2 cm from the bottom, that is, a shorter length than that of the Comparative Example. By increasing the input amount of hydrogen chloride (HCl), H2 / P HCl 2 It is analyzed that the formation of the nickel film can be further suppressed by further reducing the temperature.

[0224] FIG. 13 is a photograph of an inorganic powder formed by the method for producing an inorganic powder using chemical vapor synthesis according to one embodiment of the present invention.

[0225] Referring to FIG. 13, the nickel powders of the comparative example formed without using hydrogen chloride (HCl) and the example formed using hydrogen chloride (HCl) had almost similar properties such as particle size, distribution, and shape.

[0226] It will be apparent to those having ordinary skill in the art to which the technical idea of ​​the present invention pertains that the technical idea of ​​the present invention described above is not limited to the above-mentioned embodiments and the accompanying drawings, and various substitutions, modifications and alterations are possible within the scope not departing from the technical idea of ​​the present invention. [Explanation of symbols]

[0227] 100, 100a Inorganic powder manufacturing equipment 110 Reaction Chamber 112 Vaporization Region 114 Reaction Area 116 Collection area 120 Precursor supply section 122 Precursor injection section 123 Internal Precursor Storage 124 Precursor Containment Unit 126 Nozzle section 128 Oxide 129 Inorganic powder 130 Reactive gas supply section 140 First side reaction prevention gas supply section 150 Second side reaction prevention gas supply section 160 Heating section 162 First heater 164 Second Heater 166 Third Heater

Claims

1. Providing a precursor; supplying a side reaction prevention gas to the precursor to prevent a side reaction of the precursor; supplying a reactive gas to the precursor; and forming an inorganic powder by chemical vapor synthesis using the precursor and the reactive gas.

2. The side reaction prevention gas is The method for producing an inorganic powder using a chemical vapor synthesis method according to claim 1 , wherein formation of a metal oxide due to a chemical reaction between the precursor and water or oxygen is suppressed.

3. The method for producing an inorganic powder using chemical vapor synthesis according to claim 2 , wherein the water is provided in a state in which it is chemically or physically adsorbed on the precursor, or in a state in which it forms a hydrate.

4. The side reaction prevention gas is The method for producing an inorganic powder using a chemical vapor synthesis method according to claim 1 , wherein the precursor is the same as a part of the product formed by a chemical reaction of the precursor with water or oxygen.

5. 2. The method for producing an inorganic powder using chemical vapor synthesis according to claim 1, wherein the side reaction prevention gas suppresses the formation of a part of products formed by the chemical reaction between the precursor and water or oxygen, thereby suppressing the chemical reaction between the precursor and water or oxygen.

6. The side reaction prevention gas is The method for producing an inorganic powder using chemical vapor synthesis according to claim 1 , wherein the formation of the inorganic powder by a chemical reaction between the precursor and the reactant gas is suppressed or delayed.

7. The side reaction prevention gas is The method for producing an inorganic powder using a chemical vapor synthesis method according to claim 1 , wherein the precursor is the same as a part of the product formed by a chemical reaction between the precursor and the reaction gas.

8. 2. The method for producing an inorganic powder using chemical vapor synthesis according to claim 1, wherein the side reaction prevention gas suppresses the formation of a part of products formed by the chemical reaction between the precursor and the reactive gas, thereby suppressing the chemical reaction between the precursor and the reactive gas.

9. The precursor is 2. The method for producing an inorganic powder using a chemical vapor synthesis method according to claim 1, wherein the side reaction preventing gas contains one or more of the elements constituting the side reaction preventing gas.

10. 2. The method for producing an inorganic powder using chemical vapor synthesis according to claim 1, wherein the nonmetallic element of the precursor and the nonmetallic element of the side reaction prevention gas are the same substance.

11. The precursor is Metal chloride, metal acetate, metal bromide, metal carbonate, metal carbonyl, metal fluoride, metal hydroxide, metal iodide, metal nitrate, metal oxide, metal phosphate, metal silicate, metal sulfate, and metal sulfide.

2. The method for producing an inorganic powder using a chemical vapor synthesis method according to claim 1, further comprising the step of:

12. The metal constituting the precursor is Nickel, copper, silver, iron, aluminum, silicon, boron, cobalt, platinum, gold, tin, magnesium, tungsten, niobium, molybdenum, zinc, yttrium, zirconium, ruthenium, iridium, tantalum, and titanium. The method for producing an inorganic powder using the chemical vapor synthesis method according to claim 11, comprising any one or more of the following:

13. The side reaction prevention gas is Hydrogen chloride gas (HCl), acetic acid gas (C ２ H ４ O ２ ), hydrogen bromide gas (BrH), carbon dioxide gas (H ２ CO ３ ), hydrogen fluoride gas (HF), water vapor (H ２ O), hydrogen iodide gas (HI), nitric acid gas (HNO ３ ), phosphoric acid gas (H ３ P.O. ４ ), silicon hydride gas (SiH ４ ), sulfuric acid gas (H ２ SO ４ ), chlorine gas (Cl ２ ), and hydrogen sulfide gas (H ２ The method for producing an inorganic powder using a chemical vapor synthesis method according to claim 1, further comprising the steps of:

14. The reaction gas is a reducing gas comprising one or more of hydrogen gas, carbon monoxide gas, magnesium vapor gas, sodium vapor gas, and calcium vapor gas; An oxidizing gas includes one or more of oxygen gas, water vapor gas, and ozone gas; a nitriding gas containing one or more of ammonia gas and nitrogen gas; or 2. The method for producing an inorganic powder using a chemical vapor synthesis method according to claim 1, comprising the step of: providing a carbonizing gas containing one or more of methane gas and acetylene gas.

15. providing a precursor; supplying a side reaction prevention gas to the precursor to prevent a side reaction of the precursor; supplying a reactive gas to the precursor; and forming a metal powder by chemical vapor synthesis using the precursor and the reactant gas.

16. the precursor is nickel chloride; The side reaction preventing gas is hydrogen chloride gas, the reactant gas is hydrogen gas; the metal powder is nickel powder, The method for producing an inorganic powder using chemical vapor synthesis according to claim 15, wherein the hydrogen chloride gas suppresses the formation of nickel oxide formed by a chemical reaction between the precursor and water.

17. The relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the water satisfies the range of the following formula, P Ｈ２Ｏ / P ＨＣｌ ２ ≦10 ６ The method for producing an inorganic powder using a chemical vapor synthesis method according to claim 16, wherein a relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the hydrogen gas satisfies the following range. 10 －１８ ≦P Ｈ２ / P ＨＣｌ ２

18. the precursor is copper chloride; The side reaction preventing gas is hydrogen chloride gas, the reactant gas is hydrogen gas; The metal powder is copper powder, The method for producing an inorganic powder using a chemical vapor synthesis method according to claim 15, wherein the hydrogen chloride gas suppresses the formation of copper oxide formed by a chemical reaction between the precursor and water.

19. The relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the water satisfies the range of the following formula, P Ｈ２Ｏ / P ＨＣｌ ２ ≦10 １５ The method for producing an inorganic powder using a chemical vapor synthesis method according to claim 18, wherein a relationship between the partial pressure of the hydrogen chloride gas and the partial pressure of the hydrogen gas satisfies the following range. 10 －３０ ≦P Ｈ２ / P ＨＣｌ ２

20. providing a precursor; supplying a side reaction prevention gas to the precursor to prevent a side reaction of the precursor; supplying a reactive gas to the precursor; and chemically reacting the precursor with the reactant gas to form a ceramic powder.

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