Method for producing inorganic composition powder

Abstract

To provide a method for producing inorganic composition powder by which inorganic composition powder having a small average particle diameter can be produced.SOLUTION: The method for producing the inorganic composition powder is provided. A solution or a dispersion of an inorganic substance is atomized, and the atomized solution or dispersion is introduced into a flame to synthesize an inorganic composition powder in a gas phase. The inorganic material may be a salt of at least one element selected from the group consisting of Si, Li, Ca, Al, Ba, K, Mg, Na, B, and P. For example, the concentration of the salt in the solution or the dispersion liquid is 5% by mass or more and 50% by mass or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for producing an inorganic composition powder. [Background technology]

[0002] Patent Document 1 describes a method for producing low-sodium hollow glass microspheres, in which an aqueous solution of a glass precursor is spray-dried, and the spray-dried product is then fed into a gas flame furnace.

[0003] Patent Document 2 describes a glass filler for filling in resin, which is produced by crushing glass. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 5-246726 [Patent Document 2] Patent No. 3979546 Summary of the Invention [Problem to be solved by the invention]

[0005] Patent Document 1 describes that the diameter of the low-sodium hollow glass microspheres is 5 to 40 μm, and Patent Document 2 describes that the volume average diameter of the glass filler for filling in resin is 10 μm.

[0006] It has been difficult to produce an inorganic composition powder having a smaller average particle size with the techniques described in Patent Documents 1 and 2. In one aspect of the present disclosure, it is preferable to provide a method for producing an inorganic composition powder that can produce an inorganic composition powder having a small average particle size. [Means for solving the problem]

[0007] One aspect of the present disclosure is a method for producing an inorganic composition powder, which comprises atomizing a solution or dispersion of an inorganic substance and introducing the atomized solution or dispersion into a flame to perform gas-phase synthesis of an inorganic composition powder, wherein the inorganic substance is a salt or oxide of one or more elements selected from the group consisting of Si, Li, Ca, Al, Ba, K, Mg, Na, B, and P.

[0008] According to the method for producing an inorganic composition powder that is one aspect of the present disclosure, an inorganic composition powder having a small average particle size can be produced. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is an explanatory diagram showing the configuration of an apparatus for producing an inorganic composition powder. DETAILED DESCRIPTION OF THE INVENTION

[0010] Exemplary embodiments of the present disclosure will be described with reference to the drawings. 1. Manufacturing method of inorganic composition powder In the method for producing an inorganic composition powder according to the present disclosure, a solution or dispersion of an inorganic substance is atomized, and the atomized solution or dispersion is introduced into a flame, thereby synthesizing the inorganic composition powder in the gas phase.

[0011] The inorganic substance is a salt or oxide of one or more elements selected from the group consisting of Si, Li, Ca, Al, Ba, K, Mg, Na, B, and P. The anion in the salt may be, for example, NO3 - , CO3 - , SO4 2- , Cl - etc.

[0012] The concentration of the salt or oxide in the solution or dispersion is preferably 5% by mass or more and 50% by mass or less. When the concentration of the salt or oxide in the solution or dispersion is within this range, atomization of the solution or dispersion becomes easy.

[0013] The concentration of the insoluble components in the solution or dispersion is preferably 10% by mass or less. When the concentration of the insoluble components is within this range, sedimentation of the insoluble components can be suppressed. Examples of the insoluble components include Si and B.

[0014] It is preferable that 90 mass % or more of the solvent in the solution or the dispersion medium in the dispersion liquid is water. In this case, the produced inorganic composition powder is less likely to contain soot. The solvent or dispersion medium may contain, for example, alcohol, acetone, etc. The mass ratio of alcohol, acetone, etc. in the solvent or dispersion medium is preferably 10 mass % or less. In this case, the produced inorganic composition powder is less likely to contain soot.

[0015] Examples of methods for atomizing an inorganic solution or dispersion include methods using an ultrasonic atomizer, an atomizer equipped with a two-fluid nozzle, etc. The flame temperature is, for example, 1200 to 2000°C. Examples of methods for generating a flame include methods using a burner. For example, oxygen and methane can be supplied to the burner.

[0016] The inorganic composition powder includes, for example, one or more selected from the group consisting of SiO2, Li2O, CaO, Al2O3, BaO, KO, MgO, Na2O, PO5, and BO3. When the inorganic substance includes a salt or oxide of Si, the inorganic composition powder includes SiO2. When the inorganic substance includes a salt or oxide of Li, the inorganic composition powder includes Li2O. When the inorganic substance includes a salt or oxide of Ca, the inorganic composition powder includes CaO. When the inorganic substance includes a salt or oxide of Al, the inorganic composition powder includes Al2O3. When the inorganic substance includes a salt or oxide of Ba, the inorganic composition powder includes BaO. When the inorganic substance includes a salt or oxide of K, the inorganic composition powder includes KO. When the inorganic substance includes a salt or oxide of Mg, the inorganic composition powder includes MgO. When the inorganic substance includes a salt or oxide of Na, the inorganic composition powder includes Na2O. When the inorganic substance includes a salt or oxide of B, the inorganic composition powder includes BO3.

[0017] The inorganic composition powder is, for example, a glass powder. The average particle size of the inorganic composition powder is, for example, 10 nm or more and 2 μm or less. The average particle size is measured as follows: An SEM image of the inorganic composition powder is taken. Particles in which the entire particle can be seen are randomly selected from the SEM image. For each of the selected particles, the diameter (hereinafter referred to as the major diameter) in the direction in which the diameter is longest (hereinafter referred to as the major diameter direction) is measured. The diameter in the direction perpendicular to the major diameter direction (hereinafter referred to as the minor diameter) is also measured. A caliper is used to measure the major diameter and minor diameter. The average value of the major diameter and minor diameter is calculated for each selected particle, and this is defined as the average diameter of each particle. Finally, the average value of the average diameters calculated for each selected particle is calculated, and this is defined as the average particle size of the inorganic composition powder. The shape of the inorganic composition powder is, for example, spherical.

[0018] The produced inorganic composition powder can be collected, for example, using a filter. For example, when a mixture of the inorganic composition powder and a fluid is passed through a filter, the fluid passes through the filter and the inorganic composition powder is collected on the filter. Examples of the fluid include gas and liquid.

[0019] The produced inorganic composition powder can be used as, for example, a composite material, a filler, etc. The composite material and the filler can be used in, for example, electronic devices, resin films, etc.

[0020] 2. Effects of the manufacturing method for inorganic composition powder (1A) According to the method for producing an inorganic composition powder of the present disclosure, an inorganic composition powder having a small average particle size can be produced.

[0021] (1B) According to the method for producing an inorganic composition powder of the present disclosure, the production process can be simplified compared to the production methods described in Patent Documents 1 and 2. Furthermore, according to the method for producing an inorganic composition powder of the present disclosure, the lead time until the inorganic composition powder is completed can be shortened.

[0022] (1C) According to the method for producing an inorganic composition powder of the present disclosure, compared to the method of crushing glass described in Patent Document 2, contamination of the inorganic composition powder can be suppressed. (1D) In ​​the method for producing an inorganic composition powder according to the present disclosure, the average particle size of the inorganic composition powder can be adjusted by adjusting the concentration of the solution or dispersion of the inorganic substance. For example, the average particle size of the inorganic composition powder can be reduced by lowering the concentration of the solution or dispersion of the inorganic substance.

[0023] 3. Working Example (1) Configuration of manufacturing equipment 1 The configuration of a production apparatus 1 used to produce an inorganic composition powder will be described with reference to Fig. 1. The production apparatus 1 includes a raw material storage section 3, a vapor phase synthesis section 5, and a powder collection section .

[0024] The raw material storage unit 3 includes a tank 11 and an ultrasonic vibrator 13. The tank 11 is a hollow member. A raw material solution 15 can be stored inside the tank 11. The raw material solution 15 is a solution of an inorganic substance. A first opening 11A and a second opening 11B are provided at the top of the tank 11.

[0025] The inside of tank 11 communicates with the outside of tank 11 via first opening 11A. Carrier gas 17 is introduced into tank 11 from first opening 11A. Carrier gas 17 is nitrogen gas or air. The inside of tank 11 communicates with the inside of vapor-phase synthesis unit 5 via second opening 11B.

[0026] The ultrasonic vibrator 13 is installed in the lower part inside the tank 11. When the raw material solution 15 is stored inside the tank 11, the ultrasonic vibrator 13 is immersed in the raw material solution 15. The ultrasonic vibrator 13 is an ultrasonic nebulizer (model NE-U780) manufactured by OMRON Corporation. The ultrasonic vibrator 13 corresponds to an ultrasonic atomization device.

[0027] The gas-phase synthesis unit 5 has a cylindrical shape with its axis extending in the vertical direction. The gas-phase synthesis unit 5 is located above the raw material storage unit 3. The lower end of the gas-phase synthesis unit 5 is connected to the tank 11 at the second opening 11B. A burner 21 is provided below the gas-phase synthesis unit 5. The burner 21 includes an oxygen supply port 23 and a methane supply port 25.

[0028] Burner 21 generates flame 27 inside gas-phase synthesis unit 5 using oxygen supplied from oxygen supply port 23 and methane supplied from methane supply port 25. Gas-phase synthesis unit 5 has an opening 5A at its upper end. The interior of gas-phase synthesis unit 5 communicates with the interior of powder collection unit 7 via opening 5A.

[0029] Powder collecting section 7 has a cylindrical shape. One end of powder collecting section 7 is connected to opening 5A. Powder collecting section 7 has outlet 7A on the side opposite opening 5A. The interior of powder collecting section 7 communicates with the outside of powder collecting section 7 via outlet 7A.

[0030] The powder collecting unit 7 has a bag filter 31 therein. The bag filter 31 is provided midway along the path from the opening 5A to the outlet 7A. The mesh size of the bag filter 31 is smaller than the inorganic composition powder to be produced. The bag filter 31 allows gas to pass through.

[0031] (2) Method for producing inorganic composition powder Using the production apparatus 1, inorganic composition powders S1 to S13 were produced by the following method. (2-1) Commonalities in manufacturing methods The manufacturing methods S1 to S13 had the following in common: A raw material solution 15 was stored inside a tank 11. An ultrasonic vibrator 13 was immersed in the raw material solution 15. Next, a flame 27 was generated inside a gas-phase synthesis unit 5 by a burner 21.

[0032] Next, ultrasonic vibrator 13 was activated. Also, introduction of carrier gas 17 into tank 11 began. Carrier gas 17 was nitrogen gas. At this time, part of raw material solution 15 was atomized by the action of ultrasonic vibrator 13. The atomized raw material solution 15, together with carrier gas 17, flowed in the direction of arrow F1 into gas-phase synthesis section 5, passed through burner 21, and was introduced into flame 27.

[0033] In the flame 27, inorganic composition powder was synthesized in the vapor phase from the raw material solution 15. The inorganic composition powder synthesized in the vapor phase entered the powder collector 7 together with the carrier gas 17 and moved toward the outlet 7A. The inorganic composition powder was collected in the bag filter 31. The carrier gas 17 passed through the bag filter 31, flowed in the direction of the arrow F2, and was discharged from the outlet 7A.

[0034] (2-2) Differences in manufacturing methods The manufacturing methods S1 to S13 differed in the composition of raw material solution 15. The compositions of raw material solutions 15 in S1 to S13 were as shown in Table 1 below. The blending amount of each component in Table 1 is in parts by mass. In all of S1 to S13, raw material solution 15 did not contain any insoluble components. In all of S1 to S13, the solvent contained in raw material solution 15 was all water.

[0035] [Table 1]

[0036] The amount of methane supplied to burner 21 in S1 to S13 was the value shown in the "Flame condition CH4 (L / min)" row in Table 2. The amount of oxygen supplied to burner 21 in S1 to S13 was the value shown in the "Flame condition O2 (L / min)" row in Table 2. The flow rate of carrier gas 17 in S1 to S13 was the value shown in the "Carrier gas N2 (L / min)" row in Table 2.

[0037] [Table 2]

[0038] (3) Evaluation of the produced inorganic composition powder The inorganic composition powders produced in S1 to S13 were each evaluated as follows. (3-1) Analysis of the composition of inorganic composition powder The composition of the inorganic composition powder was analyzed using ICP. The results are shown in the row "Composition of inorganic composition powder" in Table 2. The amount of each component in Table 2 is in mass %.

[0039] (3-2) Measurement of the average particle size of inorganic composition powder The average particle size of the inorganic composition powder was measured by the method described above. The measurement results are shown in Table 2 in the row "Average particle size (μm)".

[0040] (3-3) Determining whether the inorganic composition powder is glass powder XRD measurement was performed on the inorganic composition powder. If the XRD measurement results satisfied both of the following conditions J1 and J2, the inorganic composition powder was determined to be a glass powder. If the XRD measurement results did not satisfy either condition J1 or J2, the inorganic composition powder was determined not to be a glass powder. J1: No large peaks at specific angles characteristic of crystals occur. J2: It must be a halo pattern.

[0041] The results of the judgment are shown in the "Vitrified" row in Table 2. "G" indicates that it is glass powder. "N" indicates that it is not glass powder. For S10, three types of flame 27 conditions were used. Specifically, the amounts of methane and oxygen supplied were changed. When the amounts of methane and oxygen supplied were large and the heat power of the flame 27 was high, the inorganic composition powder became glass powder.

[0042] (4) Other Examples Using the manufacturing apparatus 1 described above in (1), an inorganic composition powder was manufactured in the same manner as in (2), and the inorganic composition powder was evaluated in the same manner as in (3), except that the composition of the raw material solution was as follows: SiO2: 20% by mass H2O: 80% by mass In this case as well, an inorganic composition powder, which was a glass powder, could be produced.

[0043] 4. Other Embodiments Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms.

[0044] (1) In the embodiment, a two-fluid nozzle may be used as a method for atomizing the raw material solution 15. (2) In the embodiment, the raw material solution 15 may be a dispersion of an inorganic substance. In this case, at least a part of the inorganic substance is not dissolved in the raw material solution 15 but is dispersed therein.

[0045] (3) The function of one component in each of the above embodiments may be shared among multiple components, or the functions of multiple components may be performed by one component. Also, part of the configuration of each of the above embodiments may be omitted. Furthermore, at least part of the configuration of each of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0046] (4) In addition to the above-described method for producing an inorganic composition powder, the present disclosure can also be realized in various forms, such as an inorganic composition powder, a product containing the inorganic composition powder as a component, a composite agent, a filler, and the like.

[0047] [Technical idea disclosed in this specification] [Item 1] A method for producing an inorganic composition powder, comprising: atomizing a solution or dispersion of an inorganic substance; introducing the atomized solution or dispersion into a flame to synthesize an inorganic composition powder in a gas phase; The inorganic substance is a salt or oxide of one or more elements selected from the group consisting of Si, Li, Ca, Al, Ba, K, Mg, Na, B, and P. A method for producing an inorganic composition powder. [Item 2] Item 1 is a method for producing an inorganic composition powder according to item 1, the concentration of the salt or the oxide in the solution or the dispersion is 5% by mass or more and 50% by mass or less; A method for producing an inorganic composition powder. [Item 3] Item 1 or 2, a method for producing an inorganic composition powder, The inorganic composition powder includes one or more selected from the group consisting of SiO2, Li2O, CaO, Al2O3, BaO, K2O, MgO, Na2O, P2O5, and B2O3; A method for producing an inorganic composition powder. [Item 4] A method for producing an inorganic composition powder according to any one of items 1 to 3, The inorganic composition powder is a glass powder. A method for producing an inorganic composition powder. [Item 5] A method for producing an inorganic composition powder according to any one of items 1 to 4, The average particle size of the inorganic composition powder is 10 nm or more and 2 μm or less. A method for producing an inorganic composition powder. [Item 6] A method for producing an inorganic composition powder according to any one of items 1 to 5, The concentration of insoluble components in the solution or dispersion is 10% by mass or less. A method for producing an inorganic composition powder. [Item 7] A method for producing an inorganic composition powder according to any one of items 1 to 6, 90% by mass or more of the solvent in the solution or the dispersion medium in the dispersion is water. A method for producing an inorganic composition powder. [Explanation of symbols]

[0048] 1... manufacturing equipment, 3... raw material storage section, 5... vapor phase synthesis section, 5A... opening, 7... powder collection section, 7A... outlet, 11... tank, 11A... first opening, 11B... second opening, 13... ultrasonic vibrator, 15... raw material solution, 17... carrier gas, 21... burner, 23... oxygen supply port, 25... methane supply port, 27... flame, 31... bag filter

Claims

1. A method for producing an inorganic composition powder, comprising: atomizing a solution or dispersion of an inorganic substance; introducing the atomized solution or dispersion into a flame to synthesize an inorganic composition powder in a gas phase; The inorganic substance is a salt or oxide of one or more elements selected from the group consisting of Si, Li, Ca, Al, Ba, K, Mg, Na, B, and P; A method for producing an inorganic composition powder.

2. A method for producing the inorganic composition powder according to claim 1, The concentration of the salt or the oxide in the solution or the dispersion is 5% by mass or more and 50% by mass or less. A method for producing an inorganic composition powder.

3. 3. A method for producing an inorganic composition powder according to claim 1 or 2, The inorganic composition powder is SiO ２ , Li ２ O, CaO, Al ２ O ３ ,BaO,K. ２ O, MgO, Na ２ O, P ２ O ５ , and B ２ O ３ comprising one or more selected from the group consisting of: A method for producing an inorganic composition powder.

4. 3. A method for producing an inorganic composition powder according to claim 1 or 2, The inorganic composition powder is a glass powder. A method for producing an inorganic composition powder.

5. 3. A method for producing an inorganic composition powder according to claim 1 or 2, The inorganic composition powder has an average particle size of 10 nm or more and 2 μm or less. A method for producing an inorganic composition powder.

6. 3. A method for producing an inorganic composition powder according to claim 1 or 2, The concentration of insoluble components in the solution or dispersion is 10% by mass or less. A method for producing an inorganic composition powder.

7. 3. A method for producing an inorganic composition powder according to claim 1 or 2, 90 mass% or more of the solvent in the solution or the dispersion medium in the dispersion is water. A method for producing an inorganic composition powder.

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