JP2023160276A - Method for manufacturing sheet made of collection of flat powder by joining gap between flat surfaces of flat powder made of metal, alloy, metal oxide, or inorganic compound with collection of metal or metal oxide nanoparticles - Google Patents

Abstract

To provide a method for manufacturing a sheet made of a collection of soft magnetic flat powder.SOLUTION: In a method, a raw material for a substance that joins flat surfaces of flat powder is liquefied into a low-viscosity, low-density liquid, the flat surfaces of the flat powder are overlapped through the liquid, the flat surfaces is transformed into a nano-sized substance that joins the flat surfaces, the nano-sized substance is changed to the substance that joins flat surfaces, and after this, the flat surfaces are joined together by the collection of the substance, an organometallic compound that precipitates metal or metal oxides through thermal decomposition is dispersed in methanol, the methanol dispersion is interposed between the flat surfaces of the flat powder, the methanol is vaporized, the collection of fine crystals of the organometallic compound is deposited in the gaps between the flat surfaces of the flat powder, compressive stress is applied to the collection of flat powder to thermally decompose the fine crystals of the organometallic compound, the collection of metal or metal oxide nanoparticles is deposited, and the flat surfaces of the flat powder are joined together via the collection of nanoparticles joined together by frictional heat.SELECTED DRAWING: Figure 1

Description

The present invention utilizes a collection of metal or metal oxide nanoparticles bonded by frictional heat to fill gaps between flat surfaces of flat powder made of metal, alloy, metal oxide, or inorganic compound. The present invention relates to a method of manufacturing a sheet made of a collection of flat powders. Powders with a large aspect ratio, which is the ratio of the average value of the major axis to the minor axis to the thickness, are variously described as flat powder, flake powder, scale powder, flaky powder, disc powder, and thin plate powder. In the present invention, it is described as flat powder. On the other hand, flat powder made of soft metal or glass is generally described as flake powder.
In the present invention, metals, alloys, metal oxides, or inorganic A suspension in which flat surfaces of flat powder made of one of the compound materials are superimposed is produced in a container. Next, methanol is vaporized from the suspension in the container, and a collection of fine crystals of the organometallic compound is deposited in the gaps between the flat surfaces of the flat powder and on the surface of the collection of flat powder. Furthermore, a plate material is placed over the entire surface of the collection of flat powder, and the entire surface of the plate material is compressed uniformly to crush the collection of fine crystals of the organometallic compound into a collection of even finer crystals. After this, while applying a compressive load evenly to the entire plate material, the temperature of the container is raised to thermally decompose the organometallic compound, and metal or metal A collection of oxide nanoparticles is precipitated all at once, and the nanoparticles are bonded to a flat surface using frictional heat, and the nanoparticles are bonded to each other using frictional heat. As a result, a sheet in which the flat surfaces of the flat powder are joined to each other is produced in the container through a collection of nanoparticles joined by frictional heat.
In addition, the flat powder is a soft magnetic flat powder of metal or alloy, and the material of the nanoparticles has a fixed relative magnetic permeability, and the magnetic permeability loss due to complex magnetic permeability and the dielectric loss due to complex permittivity. If at least one of the two has a certain size, a sheet in which the flat surfaces of the flat powder are joined together through a collection of nanoparticles has a high reception sensitivity for electromagnetic waves, and can be used as a sheet that absorbs electromagnetic noise. It can be used as a sheet with high magnetic shielding effect. In addition, if the flat powder is metal or alloy flake powder, a sheet made by joining the flat surfaces of the metal or alloy flake powder to each other through a collection of metal nanoparticles with high electrical conductivity and thermal conductivity will be charged. It can be used for prevention sheets, electromagnetic shielding sheets, thermally conductive sheets, sheets whose surfaces are made of metals or alloys with excellent lubricity, wiring for electrical equipment, electrodes, etc. In addition, if the flat surfaces of metal or alloy flakes are bonded with highly transparent nickel or aluminum nanoparticles, a sheet with the luster of the metal or alloy can be created without losing the color of the metal or alloy. is obtained. Furthermore, if the flat powder is an insulating flat powder made of glass, alumina, or hematite, the flat surfaces of the flat powder are bonded to each other through a collection of insulating metal oxide nanoparticles. The sheet can be used as an insulating sheet with high insulation properties. Furthermore, if the flat surfaces of a flat powder made of glass or aluminum are coated with a film made of a metal or metal oxide, and the flat surfaces of an inorganic bright pigment are bonded together using highly transparent nickel or aluminum nanoparticles, A sheet having the glossiness of an inorganic glitter pigment can be obtained without losing the color of the inorganic glitter pigment.
Additionally, the present inventor has filed a patent application No. 2020-139002 for a method for producing a paste consisting of a collection of flat powders in which the flat surfaces of the flat powders overlap each other through a solution of an organic compound with a certain viscosity. are doing. That is, the flat surfaces of the flat powder are overlapped with each other via the organic compound solution, and then the organic compound solution is vaporized to create a collection of flat powder in which the flat surfaces of the flat powder are overlapped. Furthermore, one surface of the collection of flat powder is evenly compressed, and the flat surfaces of the flat powder are joined together by frictional heat to produce a sheet made of the collection of flat powder.
In contrast, the present invention produces a sheet in which the flat surfaces of flat powder are joined together through a collection of metal or metal oxide nanoparticles joined by frictional heat. For this purpose, an organometallic compound from which metals or metal oxides are precipitated by thermal decomposition is dispersed in methanol, which has low both viscosity and density, and the flat surfaces of the flat powder are overlapped via the methanol dispersion. Thereafter, the collection of flat powders is compressed, and the organometallic compound is further thermally decomposed, and the flat surfaces of the flat powders are joined together via the collection of metal or metal oxide nanoparticles joined by frictional heat. In other words, the flat surfaces of the flat powder are not completely flat, so even if a collection of flat powders with their flat surfaces overlapped is compressed evenly, the flat powders will not bond together due to frictional heat over the entire surface of the flat surface. , flat powders are bonded to each other by frictional heat on a part of the flat surface. Therefore, the worse the flatness of the flat surfaces of the flat powder, the weaker the bonding force between the flat surfaces. On the other hand, in the present invention, the entire surface of the flat surfaces of the flat powder is joined by a collection of nanoparticles that are two or more orders of magnitude smaller in area than the flat surfaces. Therefore, even if the flatness of the flat surface of the flat powder is low or even if there are irregularities on the flat surface, the nanoparticles are nearly two orders of magnitude smaller than the irregularities on the flat surface, so the flatness of the flat surface and the unevenness of the surface will be affected. Regardless, the entire surfaces of the flat surfaces are bonded together via the collection of nanoparticles, increasing the bonding force between the flat powders.
Furthermore, in the bonding of flat surfaces in the present invention, the size of the nanoparticles precipitated in the gap between the flat surfaces is small, around 10 nm, and the density of nanoparticle precipitation is high, so compressive stress is applied to the collection of nanoparticles. When added, it becomes difficult for the nanoparticles to move, and the strength at which the nanoparticles are bonded to the flat surface and the strength at which the nanoparticles are bonded to each other increases. Therefore, in the present invention, a collection of fine crystals of an organometallic compound precipitated in the gap between flat surfaces is once crushed to the limit size, and a collection of finer crystals is placed in the gap between the flat surfaces. Overlap with high density. After this, a compressive load is applied to the entire collection of flat powder in which the flat surfaces overlap each other, and the finer crystals of the organometallic compound are thermally decomposed, resulting in nanoparticles of metal or metal oxide with a size of about 10 nm. are precipitated all at once, overlapping with high density in the gaps between the flat surfaces, and when stress is applied to the collection of nanoparticles, the nanoparticles bond to the flat surfaces due to frictional heat, and the nanoparticles also generate frictional heat. Join with. As a result, sheets having various properties consisting of a collection of flat powders with increased bonding strength between the flat powders can be obtained.

Powders with flakes or flat surfaces made of metals, alloys, metal oxides, or inorganic compounds include soft magnetic flat powders made of metals or alloys, and flake powders made of metals or alloys. There are four types of pigments: insulating flat powder made of metal oxide or inorganic compound, and inorganic bright pigment made by coating the surface of flat powder made of glass or aluminum with a film made of metal or metal oxide.
First, the background technology related to soft magnetic flat powder made of metal or alloy will be explained. If the flat surfaces of soft magnetic flat powder can be joined together, a sheet consisting of a collection of flat powder can be formed, and by taking advantage of the complex magnetic permeability of flat powder, the sheet can absorb electromagnetic noise. In addition, by taking advantage of the relative magnetic permeability of flat powder, it can be made into a sheet that shields magnetism.
On the other hand, in recent years, electronic devices such as mobile phones and personal computers that use high frequency signals have become widespread. For example, some mobile phones, wireless LANs, and the like use high frequency signals ranging from several GHz to 10 GHz. Furthermore, in addition to the higher frequencies of signals used by electronic devices, as electronic devices become smaller, thinner, and more sophisticated, malfunctions due to electromagnetic interference within electronic devices and failures due to radiated noise to the outside of the devices are becoming more common. is a problem. For this reason, the International Special Committee on Radio Interference (CISPR) standard CISPR22, published in 2005, regulates electromagnetic noise at a maximum of 6 GHz.

By the way, the absorbed energy P of electromagnetic noise is given by Equation 1. The first term is the absorption of electromagnetic noise based on the properties of soft magnetism, and magnetic loss occurs depending on the size and frequency of the imaginary part μ'' of complex magnetic permeability, and this magnetic loss is replaced by heat.The second term is Due to the absorption of electromagnetic noise based on the properties of the dielectric, dielectric loss occurs depending on the size and frequency of the imaginary part ε'' of the complex permittivity, and this dielectric loss is also converted into heat. The third term is absorption of electromagnetic noise based on conductivity, where a conductive current flows on the surface due to the skin effect of a high-frequency electric field, forming a resistive film, and this resistive film causes resistance loss depending on the magnitude of conductivity σ. This resistance loss is also converted into heat. Therefore, in the frequency band of electromagnetic noise, if a sheet that absorbs electromagnetic noise has a constant imaginary part μ'' of complex permeability, or has a constant imaginary part ε'' of complex permittivity. If you have it, electromagnetic noise in a certain frequency band will be absorbed. In Equation 1, E is the magnitude of the electric field in electromagnetic noise, H is the magnitude of the magnetic field in electromagnetic noise, f is the frequency of the electromagnetic noise, and σ is the conductivity. Note that when a magnetic material receives an alternating magnetic field due to electromagnetic noise, there is a phase delay in the change in magnetic flux density, and the magnetic permeability is expressed as μ'-jμ'', which is the difference between the real part μ' and the imaginary part μ''. Given. Alternatively, when a dielectric receives an alternating electric field due to electromagnetic noise, a phase delay occurs in the change in electric flux density, and the dielectric constant is given by the difference ε'-jε'' between the real part ε' and the imaginary part ε''. It will be done.
(Number 1)
P=πfμ”H ² +πfε”E ² +1/2・σE ²

Conventionally, the ability of a sheet to absorb electromagnetic noise has been determined based on the magnetic permeability of the soft magnetic material forming the sheet. That is, for electromagnetic noise up to around 100 MHz, the magnetic flux convergence effect due to the real part μ' of the complex magnetic permeability of the soft magnetic material blocks the magnetic field and brings about a magnetic shielding effect. In addition, the magnetic loss effect due to the imaginary part μ'' of the complex magnetic permeability absorbs electromagnetic noise and converts it into heat, resulting in the effect of suppressing electromagnetic noise.However, many soft magnetic materials The real part of the complex magnetic permeability decreases, and the larger the value of the real part, the more rapidly it decreases.This phenomenon is due to the Snake's limit, where the real part of the complex magnetic permeability of ferrite decreases as the real part increases beyond 10 MHz. On the other hand, the imaginary part of the complex permeability increases rapidly from the frequency before the frequency where the real part shows the peak value, shows the peak value at a certain frequency, and decreases as the distance from the frequency showing the peak value increases. However, it does not have the necessary size in a frequency band exceeding 500 MHz.

On the other hand, if the imaginary part of the complex permittivity in the properties of a dielectric has a constant magnitude in a frequency band exceeding 500 MHz, electromagnetic noise in the frequency band exceeding 500 MHz will be reduced due to the dielectric loss of the dielectric material based on Equation 1. Absorbed. In other words, it is sufficient that the dipoles of the dielectric (this is referred to as orientation polarization) cannot follow changes in the electric field of 500 MHz or higher, and dielectric dispersion occurs in which the dielectric constant of the dielectric decreases. This phenomenon is a phenomenon in which a phase delay occurs in the change in electric flux density in the alternating electric field of electromagnetic noise explained in the third paragraph. However, in a frequency band of 500 MHz or higher, the value of the imaginary part of the complex permittivity of most solid dielectric materials is small. This will be explained below using the value of the imaginary part of the complex permittivity of a dielectric material in a 2.45 GHz microwave used in a microwave oven.
The imaginary part of the complex permittivity of polymeric materials at 2.45 GHz is 0.2-0.5 for phenolic resin, 0.16-0.23 for urea resin, and 0.08-0.0 for vinyl chloride resin. 25, polyamide resin is 0.12-0.28, cellulose resin is 0.03-0.42, synthetic rubber is 0.027-0.03, and polyethylene resin is 1.2×10 ^-3 . , polypropylene resin is 4×10 ⁻⁴ . The imaginary part of the complex permittivity of any polymeric material is small. On the other hand, the imaginary part of the complex dielectric constant of water, which is a typical polar molecule, is as large as 22.0. For this reason, the magnitude of the imaginary part of the complex dielectric constant of water at 2.45 GHz is used as the principle of heating food in a microwave oven. In other words, when food is irradiated with 2.45 GHz microwaves, the water molecules contained in the food are unable to follow changes in the electric field and absorb the microwaves due to dielectric loss, converting them into heat. On the other hand, the imaginary part of the complex permittivity of ice at 2.45 GHz is as small as 2.8×10 ⁻⁴ . Therefore, ice does not melt when exposed to microwaves. In this way, except for liquids made of polar molecules such as water, alcohol, and acetone, the value of the imaginary part of the complex permittivity of many substances in the frequency band of 500 MHz or higher is small, and they absorb electromagnetic noise in the frequency band of 500 MHz or higher. Can not.

By the way, electromagnetic waves have a skin depth. The depth of the skin is the distance at which the electromagnetic field of electromagnetic waves incident on the sheet made of soft magnetic material is attenuated to 1/e (corresponding to 0.368). The depth of the skin is inversely proportional to the square root of the product of the frequency of the electromagnetic wave, the complex magnetic permeability of the flat powder, and the electrical conductivity of the flat powder. Therefore, the higher the frequency of the electromagnetic waves, the greater the complex magnetic permeability of the flat powder, and the greater the electrical conductivity of the flat powder, the shallower the depth of the skin. Therefore, by utilizing the skin effect, a sheet made of soft magnetic material can be made thinner and lighter. Therefore, if the thickness of the sheet made of soft magnetic material is changed depending on the frequency band of the electromagnetic waves to be absorbed, and the sheet is constructed with the required thickness, the amount of soft magnetic material used is small, resulting in a lightweight sheet. Similarly, regarding magnetic shielding sheets, the thickness of the sheet made of soft magnetic material can be changed depending on the frequency band of the electromagnetic waves to be shielded, and if the sheet is constructed with the required thickness, the amount of soft magnetic material used can be reduced. , resulting in a lightweight sheet.

Patent Document 1 discloses a sheet made of a new material composition as a sheet that absorbs electromagnetic waves. In other words, it is a sheet that absorbs electromagnetic waves using fine particles of magnetic material, and includes a first magnetic layer made of a polymeric material in which fine particles of magnetic material are dispersed, and a polymeric material formed on the first magnetic layer. and a second magnetic layer formed on the nonmagnetic layer and made of a polymeric material in which fine particles of magnetic material are dispersed, and the easy axis direction of magnetization in the first magnetic layer. is different from the easy axis direction of magnetization in the second magnetic layer.
In other words, even if electromagnetic waves are radiated in a direction that cannot be efficiently absorbed by the first magnetic layer, the electromagnetic waves can be efficiently absorbed by the second magnetic layer, which has an easy axis direction that is different from that of the first magnetic layer. This is a sheet that absorbs electromagnetic waves for the purpose of
However, if the magnetic material that absorbs electromagnetic waves is not a fine particle but a flat powder with a certain area, if the flat surfaces, which are in the direction of the axis of easy magnetization, are randomly joined to form a sheet, the method described in Patent Document 1 can be applied. There is no need to form three layers, and an inexpensive sheet can be formed.

Patent Document 2 describes an alloy having even higher magnetic permeability by intentionally removing the composition from the alloy powder of Fe-9.6%Si-5.4%Al, which is an alloy powder having high magnetic permeability. flat powder is disclosed.
In Patent Document 2, a sheet using flat powder of this alloy is prepared by dissolving chlorinated polyethylene in toluene, mixing flat alloy powder with this solution, applying it to polyester resin and drying it, and then An example in which a composite sheet was produced by pressing at 130° C. and a pressure of 15 MPa is described as a sheet with high magnetic permeability.
However, chlorinated polyethylene resin is non-magnetic and does not contribute to electromagnetic wave absorption or magnetic shielding. Therefore, the electromagnetic wave absorption performance and magnetic shielding performance of the composite sheet decrease depending on the volume ratio of the non-magnetic chlorinated polyethylene resin. Further, it is stated that flat alloy powder has high magnetic permeability when the flatness is 15 or more. However, in order to reflect the magnetic permeability characteristics of flat powder, which has a large oblateness, in the composite sheet, the flat planes overlap in the same direction as the sheet surface, so that the collection of flat powder can efficiently absorb electromagnetic waves and provide magnetic shielding. To contribute. However, simply mixing flat powder with a size of several tens of microns or less with a solution of chlorinated polyethylene and applying this mixture does not align the flat surface of the flat powder in the same direction as the sheet surface. .
In this way, even if the soft magnetic material has excellent magnetic permeability characteristics, if the magnetic permeability characteristics of the soft magnetic material are not reflected in the structure of the sheet, the sheet will not reflect the magnetic permeability characteristics.

Next, background technology related to flake powder made of metal or alloy will be explained. If a sheet made of a collection of flakes can be formed by joining the flat surfaces of flakes made of metal or alloy, it can be used for antistatic sheets, electromagnetic shielding sheets, wiring for electrical equipment, electrodes, etc. To form such a conductive sheet, a conductive paste is used to form a conductive film. A conventional conductive paste is composed of a fluid composition in which a conductive filler made of a metal or an alloy is dispersed in a vehicle made of a resin binder and a solvent. In addition, when printing a conductive paste by means such as screen printing, the conductive filler is projected onto the printing material through a liquid substance, and the liquid substance consisting of a resin binder and a solvent plays the role of transporting the conductive filler. The liquid substance is called a vehicle.
This conductive paste is available in two types: a resin-curing type in which the conductive fillers are bonded to each other through curing of the resin and a conductive path is formed by the conductive filler, and a resin-curing type in which the conductive fillers are bonded together through curing of the resin, and the organic component is volatilized by baking and the conductive fillers are sintered together. Then, the sintered conductive filler divides the mold into two firing molds in which a current-conducting path is formed.
A resin-curing conductive paste is a paste-like composition consisting of a conductive filler made of metal powder or alloy powder, and an organic binder in which a thermosetting resin such as an epoxy resin is dissolved. By applying heat, the thermosetting resin hardens and contracts together with the conductive filler, and the conductive fillers are pressed together through the hardened resin and come into contact with each other, providing electrical conductivity. This resin-curing conductive paste is heat-treated at a low temperature of around 200°C, so there is little heat damage, and it is used to form wiring on printed wiring boards and circuit boards made of heat-sensitive synthetic resin. .
On the other hand, a fired conductive paste is a paste-like composition in which a conductive filler made of metal powder or alloy powder and glass frit are dispersed in an organic vehicle, and is heated and fired at a high temperature of about 900°C. Conductivity is provided by volatilizing the organic vehicle, then melting the glass frit, and sintering the metal powders or alloy powders together. At this time, the glass frit bonds the conductive film made of metal powder or alloy powder to the substrate, and the organic vehicle converts the metal powder or alloy powder and the glass frit into a liquid medium that allows printing. Due to the high firing temperature of fired conductive paste, it cannot be used for printed wiring boards and circuit boards made of synthetic resin, but it can achieve low resistance because the metal powder or alloy powder is sintered and integrated. For example, it is used for internal electrodes of multilayer ceramic capacitors.

The conductive paste uses metal powder or alloy powder as a conductive filler, and disperses the metal powder or alloy powder, or the metal powder or alloy powder and glass frit, in a vehicle consisting of a resin binder and an organic solvent. It consists of a dispersion liquid. The conductive film formed from this conductive paste has various problems due to the use of metal powder or alloy powder as a conductive filler and the dispersion of this metal powder or alloy powder.
The first problem is that the resistance value of the conductive film formed by heat-treating the conductive paste is greater than the resistance value of the metal powder or alloy powder. That is, in the resin-curing conductive paste, the insulating thermosetting resin prevents metal powders or alloy powders from coming into direct contact with each other. In addition, in the sintered conductive paste, a glass frit with low conductivity prevents sintering of metal powders or alloy powders. As a result, the electrical resistance of the electrical circuit wiring, electrodes, electromagnetic shielding film, antistatic film, etc. formed by heat treatment of the conductive paste increases, resulting in loss of electrical energy and heat generation, which can lead to malfunctions. .
The second problem lies in the dispersibility of metal powder or alloy powder. In other words, if the dispersibility of a collection of metal powders or alloy powders in a vehicle is poor, the metal powders or alloy powders will be unevenly distributed after heat treatment, and the metal powders or alloy powders will not be able to come into direct contact with each other. As a result, as described above, the electrical resistance of the wiring, electrodes, electromagnetic shielding film, and antistatic film of the electrical circuit formed by heat treatment of the conductive paste increases.
The third problem is that when metal powders or alloy powders are sintered together, the metal powders or alloy powders shrink. In other words, when the metal powder or alloy powder shrinks, structural defects such as delamination (layer separation) between the electrode and the dielectric material and cracks in the electrode layer occur in the internal electrodes of the multilayer ceramic capacitor.
The fourth problem is that metal powders or alloy powders coagulate with each other. Furthermore, the finer the powder, the more likely it is to aggregate. When agglomeration of the powder occurs, the dispersibility of the powder in the vehicle deteriorates, and as a result, the electrical resistance of the conductive film formed by heat treatment of the conductive paste increases.
All of the four problems described above are caused by the use of metal powder or alloy powder as the conductive filler and the dispersion medium that disperses the collection of metal powder or alloy powder, so it is difficult to fundamentally solve them.

Various attempts have been made to solve the problems of conductive films using conductive pastes.
For example, in Patent Document 3, a conductive paste is made of a metal powder filler in which metal powder of a relatively base metal is coated with a relatively noble metal, metal nanoparticles coated with a coating agent, and an organic solvent. A conductive paste that does not contain a resin component as a binder is described. In order to disperse metal nanoparticles in a conductive paste, the metal nanoparticles are coated with an alkylamine that has an affinity for an organic solvent and has a boiling point close to that of the organic solvent. When the applied conductive paste is heat-treated, metal nanoparticles are precipitated, the metal filler is bonded to the metal nanoparticles, and a conductive film containing no resin component is formed.
However, metal nanoparticles are extremely susceptible to agglomeration, and once agglomerated, they become nano-sized particles, so it is difficult to release the aggregation, making them difficult to handle. Furthermore, when producing metal nanoparticles, the produced metal nanoparticles easily aggregate with each other. For this reason, it is not possible to adsorb alkylammines to the generated metal nanoparticles, so metal nanoparticles are precipitated in a liquid containing alkylammines, the metal nanoparticles are covered with alkylamines, and the liquid components except the alkyl ammines are separated. The vaporization produces metal nanoparticles coated with alkyl ammine. Therefore, the manufacturing cost of coating metal nanoparticles with an alkylamine greatly exceeds the cost of manufacturing a conductive paste. Therefore, general-purpose conductive films such as electrical circuit wiring, electrodes, electromagnetic shielding films, and antistatic films become expensive films. Note that Patent Document 3 has a description of using metal nanoparticles coated with an alkylamine as a conductive paste, but there is no description of a manufacturing method of coating the metal nanoparticles with an alkylamine.

Patent Document 4 describes a conductive paste made of silver oxide and fatty acid silver having one or more amino groups. In other words, when a coating film coated with conductive paste is heat-treated, the fatty acid silver salt is decomposed into silver by the heat treatment, and while the fatty acid or its decomposition products produced by the decomposition are volatilized, some of the fatty acids produced by the decomposition and the oxidized The silver reacts with the silver to generate a fatty acid silver salt again, and the cycle in which the fatty acid silver is decomposed into silver and fatty acids is repeated to form a conductive film made of silver.
However, fatty acid silver having one or more amino groups can contain α-amino acids having at least one type of hydroxyl group consisting of 2-aminoisobutyric acid, DL-threonine, DL-serine, DL-norvaline, and 6-aminohexane. It is produced by dissolving it in a solvent consisting of toll, methyl ethyl ketone, isophorone, α-terpineol, etc., adding silver oxide powder to this solution, and reacting for a long time at room temperature. Therefore, the cost of producing fatty acid silver using the above-mentioned special chemicals greatly exceeds the cost of producing conductive paste. Therefore, as in Patent Document 3 described above, general-purpose conductive films such as electrical circuit wiring, electrodes, electromagnetic shielding films, and antistatic films become expensive films.

Next, background technology related to insulating flat powder made of glass, alumina, or hematite will be explained. When describing glass flat powder as one type of a collection of insulating flat powder, it is described as glass flat powder, and when describing glass flat powder as individual flat powder, it is described as glass flat powder. Described as flake powder. This is because flat glass powder is generally called glass flake powder. Note that flat silica powder is excluded from insulating flat powder because it is thin, less than 0.1 μm, and may break when joining flat surfaces with a collection of metal oxide nanoparticles. did. In addition, flat mica and boron nitride powders are excluded from insulating flat powders because the interlayer bonds between the crystals are easily broken by shear stress, and crystal pieces are peeled off from the flat powders when the flat surfaces are joined together. did.
The flat powder made of glass and alumina both have high electrical resistivity of 10 ¹⁴ Ωcm or more. Therefore, if the flat surfaces of flat powder can be joined together with a collection of highly insulating metal oxide nanoparticles, an insulating sheet with extremely high insulation resistance can be formed. Note that among glass flake powder, only soda lime glass has an electrical resistivity of 10 ¹² Ωcm. Further, flat powder of hematite (a substance consisting of the alpha phase of ferric oxide Fe ₂ O ₃ ) has a low electrical resistivity of 10 ⁸ Ωcm. However, if the thickness of the flat powder is submicron and the cross-sectional area of the flat hematite powder is 0.3 μm x 10 μm, the electrical resistance per unit length of the flat powder is 3.3 x 10 ¹⁶ Ω/cm. Become. On the other hand, the electrical resistance of a collection of flat powder whose flat surfaces overlap each other is that the electrical resistance of a very large number of flat powder forms series connections and parallel connections, and the insulating film made of a collection of flat hematite powder has a high level of insulation. Show your gender. The flat powder of hematite is a red pigment called red pigment and is a general-purpose flat powder.
On the other hand, in most insulating flat powders, when excessive compressive stress is applied to the flat surface, the flat powders do not deform plastically and break brittle. Therefore, when joining the flat surfaces, it is necessary to join the flat surfaces in a manner that does not apply excessive stress to the flat surfaces. Furthermore, it is necessary that the substance that joins the flat surfaces together does not reduce the insulation properties of the flat powder.
As explained above, flat powder made of glass, alumina, or hematite is an excellent raw material for forming an insulating sheet. However, there have been no cases of joining flat surfaces of insulating flat powder to each other in a way that does not apply excessive stress to the flat surfaces or reduce the insulating properties of the flat powder. do not.
In addition, the surface of flat glass or aluminum powder is coated with metals such as gold, silver, and nickel, or metal oxides such as titanium oxide and iron oxide, using an electroless plating method. There are pigments. However, to date, only inorganic glitter pigments have been used as pigments. On the other hand, if the flat surfaces of the flat powder of inorganic bright pigment can be joined together with a transparent substance, the colors reflected from the bright pigment will not be lost, and the sheet made of flat powder of the inorganic bright pigment can be bonded together. can be created. Furthermore, if you use multiple types of bright pigments that reflect different colors and create a sheet made of a collection of flat powders of multiple types of bright pigments, the color tones reflected by the sheet will be different from multiple types. A variety of colors can be created by combining glitter pigments. However, there has never been a case in which the flat surfaces of flat powder of an inorganic bright pigment are joined together using a transparent substance in a manner that does not damage the coating of metal oxide such as titanium oxide or iron oxide.

Japanese Patent Application Publication No. 2008-198873 Japanese Patent Application Publication No. 2007-118114 Japanese Patent Application Publication No. 2014-035974 Japanese Patent Application Publication No. 2010-102884

Sanyo Special Steel Technical Report, Vol. 13, No. 1, 53-61

First, a problem that occurs when forming a sheet made of a collection of soft magnetic flat powders whose flat surfaces are joined together will be described.
It is known that when soft magnetic powder is flattened in the plane direction, which is the axis of easy magnetization, the demagnetizing field coefficient becomes smaller, and the larger the flatness, the larger the imaginary part μ'' of the complex magnetic permeability. The material of the soft magnetic powder is metal or alloy except for ferrite, so it is electrically conductive.For this reason, the conductive soft magnetic flat powder has the imaginary value of the complex magnetic permeability in Equation 1 described in the third paragraph. The size of the part μ'' and the size of the conductivity contribute to the absorption of electromagnetic noise. Furthermore, flattening of soft magnetic powder does not rely on long-term batch processing using a ball mill, but because the atomized soft magnetic powder or reduced soft magnetic powder is subjected to attritor processing using a media stirring type mill, it can be processed continuously in a short period of time. A flat powder is obtained and manufactured by inexpensive processing.
On the other hand, flat powder is made by overlapping the flat surfaces of soft magnetic flat powder and joining the overlapping flat surfaces with a substance in which at least one of the imaginary part of the complex magnetic permeability or the imaginary part of the complex permittivity has a constant value. A sheet consisting of a collection of can be formed with a large area using a small amount of flat powder. Furthermore, since the flat surfaces form the sheet surface, all of the flat surfaces participate in the absorption of electromagnetic waves, resulting in a sheet with high reception sensitivity and high performance in absorbing electromagnetic waves. This sheet maximizes the flattening effect of soft magnetic flat powder. Furthermore, if the thickness of the sheet can be freely changed according to the frequency band of the electromagnetic waves to be absorbed, the skin effect can be utilized, and the amount of flat powder used can be reduced, resulting in a lightweight sheet.
On the other hand, the size of the imaginary part of the complex magnetic permeability of soft magnetic flat powder depends on the frequency band of electromagnetic waves. Furthermore, the magnitude of the imaginary part of the complex magnetic permeability of the flat powder and the frequency characteristics of the imaginary part of the complex magnetic permeability of the flat powder vary depending on the material of the soft magnetic powder. Therefore, the imaginary part of the complex permeability of multiple types of soft magnetic flat powder has a constant size in different frequency bands, and the frequency characteristics of the imaginary part of the complex permeability of each flat powder are as follows. If there are multiple types of flat powder that have frequency characteristics of the imaginary part of the complex magnetic permeability that complement each other in different frequency ranges, if the flat surfaces of the multiple types of flat powder can be overlapped and the overlapping flat surfaces can be joined, Absorbs electromagnetic noise in a wide frequency band.
Furthermore, a sheet made of a collection of flat powders made by overlapping the flat surfaces of soft magnetic flat powders and bonding the overlapping flat surfaces with a substance with a certain magnetic permeability becomes a sheet that shields magnetism. In other words, the higher the magnetic permeability of the flat powder in a DC magnetic field and the lower the magnetic resistance, the easier the magnetic lines of force will flow to the sheet, and the greater the magnetic shielding effect. On the other hand, since magnetic resistance is inversely proportional to magnetic permeability, a sheet made by overlapping flat surfaces of soft magnetic flat powder with high relative magnetic permeability and bonding the overlapping flat surfaces together will have a high magnetic shielding effect. Furthermore, a sheet with a wide area can be formed using a small amount of flat powder, and since the flat surface forms the sheet surface, all the flat powder participates in magnetic shielding, increasing the effectiveness of magnetic shielding. Furthermore, by changing the thickness of the sheet depending on the frequency band of the electromagnetic waves to be shielded, the skin effect can be utilized, resulting in a lightweight sheet that uses less flat powder.
In this way, a collection of flat powders in which the flat surfaces of soft magnetic flat powders are joined together has excellent effects as a sheet that absorbs electromagnetic noise and as a shield film that shields magnetism. However, in the case where the flat surfaces of soft magnetic flat powder are joined with a material in which at least one of the imaginary part of the complex magnetic permeability or the imaginary part of the complex permittivity has a constant value, it also has a constant magnetic permeability. There has never been a case of bonding using a substance.
As described in Patent Document 2, a conventional sheet is a sheet made of a composite material in which an organic solvent in a binder is vaporized and flat powders are bonded together through bonding of a solid polymer material. However, since the polymer material has properties different from soft magnetic flat powder, the properties of the polymer material are reflected in the sheet. In this way, when soft magnetic flat powders are bonded together through the bonding of solid dissimilar materials occupying a certain volume, the properties of the dissimilar materials are reflected, and the inherent properties of the soft magnetic flat powders are sacrificed. Become. Further, the flat surface does not form a sheet surface.
On the other hand, if a sheet can be formed from a collection of flat powders made by joining together the flat surfaces of soft magnetic flat powders, the amount of flat powder used to form the sheet will be reduced, and the sheet will contain soft magnetic flat powders and flat powders. The characteristics of the surface are reflected. Furthermore, if the flat surface forms a sheet surface, all the flat powder can participate in the absorption of electromagnetic waves, or all the flat powder can participate in magnetic shielding, and the magnetic properties of the soft magnetic flat powder are most reflected. It becomes a sheet. This results in an ideal sheet that can maximize the performance of soft magnetic flat powder.

Next, a problem that occurs when forming a sheet made of a collection of flakes made of metal flakes whose flat surfaces are joined together will be described.
The four problems in forming a conductive film described in paragraph 10 can be fundamentally solved if a conductive filler is not used when forming a sheet. For this reason, if the flat surfaces of metal flake powder could be joined together with a substance that has metallic properties, the four problems would be fundamentally solved.
Furthermore, flat powder made of insulating metal oxides can be bonded to flat surfaces by a method that does not apply excessive stress to the flat surfaces and a method that does not reduce the insulation properties of the flat surfaces. It is sufficient if they can be joined together using an insulating material.
In addition, if the flat surfaces of the flat powder of inorganic bright pigments could be bonded together with a transparent substance without damaging the coating of metal oxides such as titanium oxide or iron oxide, the colors reflected from the bright pigments would disappear. A sheet consisting of a collection of flat powder of inorganic bright pigment can be created without being damaged.
Therefore, the problem of forming a sheet in which the flat surfaces of soft magnetic flat powder are joined together is to overlap the flat surfaces of the flat powder, and to connect the overlapping flat surfaces to the imaginary part of the complex magnetic permeability or the imaginary part of the complex permittivity. At least one of the parts is made of a material having a certain value or a material having a certain relative magnetic permeability. Furthermore, the problem in forming a sheet in which the flat surfaces of metal flake powder are joined together is to overlap the flat surfaces of the flat powder and to join the overlapping flat surfaces with a substance that has metallic properties. Furthermore, the flat insulating powder may be used as long as the flat surfaces can be joined together using an insulating substance in a manner that does not apply excessive stress to the flat surfaces. Further, the flat powder of the inorganic bright pigment may be used as long as the flat surfaces of the flat powder can be joined with a transparent substance without damaging the metal oxide coating.
On the other hand, even if the flatness of the flat surfaces of flat powder is poor, or even if there are irregularities on the flat surfaces, if the material that joins the flat surfaces is composed of a collection of nano-sized substances, the flat surfaces will remain the same. Regardless, the overlapping flat surfaces are bonded to each other via a collection of nano-sized substances on the entire surface, and the bonding force between the flat powders is increased. Furthermore, if the thickness of the collection of nano-sized substances that join the flat surfaces of the flat powder is thinner than the thickness of the flat powder, the area of the flat powder is more than two orders of magnitude larger than the size of the nano-sized substance. , the properties of a sheet made of a collection of flat powders are dominated by the properties of flat powders. Furthermore, when joining flat surfaces to each other via a collection of nano-sized substances, the contact area where the nano-sized substances come into contact with the flat surfaces is extremely small. Therefore, when the nano-sized substance comes into contact with the flat surface, no excessive load is applied to the flat surface. Moreover, the coating provided on the flat surface is not damaged. As a result, even if the powder is flat and easily breaks due to brittleness, the flat surface will not be damaged. Furthermore, processing such as strain relief annealing to eliminate strain caused by stress becomes unnecessary. Furthermore, the glitter properties of the inorganic glitter pigments are not lost. Therefore, it is necessary to overlap the flat surfaces of the flat powder with a nano-sized raw material interposed therebetween. On the other hand, it is possible to separate flat powder whose flat surfaces directly overlap each other into individual flat powders in a liquid. Furthermore, it is easy to overlap the flat surfaces of the flat powder via a liquid. This is because liquids have energy that allows molecules to move freely, and the shape of the liquid can change freely. Therefore, it is possible to generate a shock wave in a liquid, apply the shock wave via the liquid to the flat powder whose flat surfaces directly overlap each other, and separate the flat powder into individual flat powders in the liquid. In addition, if a moving load is applied to the liquid, the flat powder with a large aspect ratio will move in the liquid with its flat surface facing up, and the flat surfaces of the flat powder separated into individual flat powders will be Superposition via liquid is possible. Furthermore, if the liquid is a low-viscosity, low-density liquid, it becomes easier for shock waves to propagate through the liquid, and it also becomes easier for flat surfaces to move in the liquid, allowing them to be separated into individual flat powders. It is easy to overlap the flat surfaces of the flat powders using a low-viscosity, low-density liquid. For this reason, firstly, the nano-sized material that joins the flat surfaces is turned into a liquid phase as a low-viscosity, low-density liquid, and secondly, the nano-sized material that joins the flat surfaces is liquefied as a low-viscosity, low-density liquid. Separate into powder, and third, overlap the flat surfaces of the flat powder in a low-viscosity, low-density liquid, and interpose the liquefied nano-sized substance in the gap between the flat surfaces of the flat powder. There is a need. Fourth, a nano-sized substance is generated from the nano-sized substance that has been liquefied.Fifth, a collection of nano-sized substances is interposed between the flat surfaces of the flat powder.Sixth, If flat surfaces can be bonded together using a collection of nano-sized substances, a sheet made of a collection of flat powder can be produced.
For this purpose, the following six processes are required. The problem to be solved by the present invention is to find a method that can easily implement the following six processes.
First, the raw material for the nano-sized substance that joins the flat surfaces of flat powder is liquefied into a low-viscosity, low-density liquid. Second, the flat powder is separated into individual flat powders using a low-viscosity, low-density liquid, and each flat powder is coated with a low-viscosity, low-density liquid. Thirdly, the flat surfaces of the flat powder are overlapped via a low-viscosity, low-density liquid. Fourth, the low-viscosity, low-density liquid that exists in the gaps between the flat surfaces of the flat powder is transformed into a nano-sized substance that joins the flat surfaces. Fifth, convert nano-sized materials into materials that connect flat surfaces. Sixth, the flat surfaces are joined together using a nano-sized substance to produce a sheet made of a collection of flat powder.

The flat surfaces of the flat powder made of any one of metals, alloys, metal oxides, or inorganic compounds according to the present invention are bonded to each other via a collection of metal or metal oxide nanoparticles. The method of manufacturing the sheet is
An organometallic compound from which metals or metal oxides are precipitated by thermal decomposition is dispersed in methanol, and the methanol dispersion of the organometallic compound is filled into a container. After this, any one of metals, alloys, metal oxides, or inorganic compounds is dispersed. A collection of flat powder made of the material is weighed as a weight less than the weight of the methanol multiplied by the ratio of the density of methanol to the density of the flat powder used, and the weighed collection of flat powder is placed in the container. The collection of flat powder is stirred in the methanol dispersion of the organometallic compound.Furthermore, a homogenizer device is placed in the container, the homogenizer device is operated in the container, and the organometallic compound is stirred in the methanol dispersion of the organometallic compound. A shock wave is repeatedly applied to the collection of flat powders through the methanol dispersion of the compound, and the flat powder is separated one by one through the methanol dispersion of the organometallic compound, and the separated flat powder is , cover with a methanol dispersion of the organometallic compound, then take out the homogenizer from the container, and then repeatedly apply vibrational acceleration to the container in three directions: front and rear, left and right, and up and down, and finally apply vibration in the vertical direction. By applying acceleration, the methanol dispersion of the organometallic compound is introduced into the gap between the flat surfaces of the flat powder, and the flat surfaces of the flat powder overlap each other through the methanol dispersion of the organometallic compound. forming a powder collection on the bottom of the container in the shape of the bottom;
After that, the temperature of the container is raised to the boiling point of methanol, methanol is vaporized from the methanol dispersion of the organometallic compound, and the collection of fine crystals of the organometallic compound is separated from the gaps between the flat surfaces of the flat powder. Further, a plate material that covers the entire surface of the flat powder collection is placed over the entire surface of the flat powder collection, the entire surface of the plate material is evenly compressed, and the organic material is deposited on the surface of the flat powder collection. Crushing fine crystals of metal compounds into even finer crystals,
Furthermore, a compressive load is applied uniformly to the entire surface of the plate material, the temperature of the container is raised to the thermal decomposition temperature of the organic metal compound, and the fine crystals of the organic metal compound are thermally decomposed. A collection of metal or metal oxide nanoparticles overlaps and precipitates all at once in the gaps between the flat surfaces and on the surface of the collection of flat powder, and the collection of nanoparticles is further compressed to form a collection of nanoparticles. are bonded to the flat surfaces of the flat powder by frictional heat, and the nanoparticles are bonded to each other by frictional heat. As a result, the flat surfaces of the flat powder are bonded to each other through the collection of nanoparticles bonded by frictional heat. A sheet made of a collection of the flat powders joined together is produced in the container. After that, vibration acceleration is applied to the container in three directions: front and back, left and right, and up and down, and a sheet made of the collection of the flat powders is produced. The sheet is peeled off from the bottom of the container, and the sheet is taken out from the container. This is a method for producing a sheet made of a collection of flat powders joined together via a collection of particles.

The method of manufacturing a sheet made of a collection of flat powder according to the present invention is a method of successively carrying out the following eight simple processes. As a result, a sheet made of a collection of flat powders in which the flat surfaces of the flat powders are joined to each other via a collection of nanoparticles joined by frictional heat is manufactured.
The first process is to disperse an organometallic compound from which metals or metal oxides are precipitated by thermal decomposition in methanol, create a methanol dispersion of the organometallic compound, and fill a container with the methanol dispersion of the organometallic compound. It is. In the second process, a collection of flat powders made of metals, alloys, metal oxides, or inorganic compounds is multiplied by the weight of methanol by the ratio of the density of methanol to the density of the flat powder used. This is a process in which a mass of flat powder is weighed as less than the weight of the powder, the weighed mass of flat powder is put into a container, and the mass of flat powder is stirred in a methanol dispersion of an organometallic compound. The third process is a process in which a homogenizer device is placed in a container and the homogenizer device is operated in the container. The fourth process is a process in which vibration acceleration is repeatedly applied to the container in three directions, and finally vibration acceleration is applied in the vertical direction. When these four treatments are performed in succession, a collection of flat powders in which the flat surfaces of the flat powders overlap each other is formed in the shape of the bottom surface on the bottom surface of the container via the methanol dispersion of the organometallic compound.
The fifth process is a process of raising the temperature of the container to the boiling point of methanol. The sixth process is to cover the entire surface of the flat powder collection in the container with a plate material, and to compress the entire surface of the plate material uniformly to form fine crystals of the organometallic compound. This is a process of crushing it into even finer crystals. As a result, a collection of finer organometallic compound crystals overlaps and accumulates at a high density in the gaps where the flat surfaces of the flat powder overlap and on the entire surface of the collection of flat powder.
The seventh treatment is a treatment in which a compressive load is applied uniformly to the surface of the plate material, the temperature of the container is raised to the thermal decomposition temperature of the organometallic compound, and the fine crystals of the organometallic compound are thermally decomposed. The eighth process is a process in which vibration acceleration is applied to the container in three directions: front and back, left and right, and up and down, and a sheet made of a collection of flat powder is peeled off from the bottom of the container. As a result, a sheet consisting of a collection of flat powders in which the flat surfaces of the flat powders are joined to each other via a collection of metal or metal oxide nanoparticles joined by frictional heat is obtained.
All eight processes are simple processes. Furthermore, organometallic compounds are general-purpose industrial chemicals. Therefore, a sheet consisting of a collection of flat powders in which the flat surfaces of the flat powders are joined to each other through a collection of metal or metal oxide nanoparticles can be manufactured at low cost.
The thermal decomposition temperature of the organometallic compound having the highest thermal decomposition temperature is 330° C. in the air atmosphere. On the other hand, among soft metals, tin has an extremely low melting point of 232°C, causing low-temperature brittleness at around -40°C. Similarly, zinc also undergoes low temperature brittleness. On the other hand, flat powders of metals, alloys, metal oxides, or inorganic compounds other than tin and zinc have melting points higher than 330°C, and do not have low-temperature brittleness, allowing use at extremely low temperatures. Therefore, a sheet made of a collection of flat powders in which the flat surfaces of the flat powders are joined can be used even in harsh environments such as high temperatures, extremely low temperatures, vacuum, and high pressure. Therefore, flat powder made of metals, alloys, metal oxides, or inorganic compounds other than tin and zinc can be used as a raw material for producing a sheet made of a collection of flat powders.
Here, the phenomena that occur in each process and the effects of each process will be explained.
In the first treatment, when an organometallic compound that precipitates metals or metal oxides by thermal decomposition is dispersed in methanol, the organometallic compound becomes a molecular state and is dispersed in methanol. On the other hand, when an organometallic compound is dissolved in methanol, the metals that make up the organometallic compound become metal ions and elute into the methanol, and the dissolved organometallic compound cannot be returned to the organometallic compound before dissolution. . Therefore, when methanol is vaporized from a methanol solution of an organometallic compound, the organometallic compound before being dissolved does not precipitate. Therefore, as an organometallic compound that precipitates a metal or a metal oxide by thermal decomposition, an organometallic compound that does not dissolve in methanol but is dispersed in methanol is used.
In the second treatment, a collection of flat powders made of metals, alloys, metal oxides, or inorganic compounds is prepared by multiplying the weight of methanol by the ratio of the density of methanol to the density of the flat powder used. Weigh it as less than the weight, and put the weighed collection of flat powder into a container. Permalloy has the highest density among flat powders made of metals, alloys, metal oxides, or inorganic compounds, and the density of permalloy with a nickel content of 45% is 8.25 g/cm ³ . On the other hand, the density of methanol is 0.792 g/cm ³ . Therefore, the density of permalloy is 10 times higher than that of methanol. Further, the organometallic compound is dispersed in methanol up to about 10% by weight, but the density of the organometallic compound is close to 1 g/cm ³ , and the density of a methanol dispersion of the organometallic compound is close to the density of methanol. Furthermore, the viscosity of a methanol dispersion of an organometallic compound in which the organometallic compound is dispersed to about 10% by weight in methanol is close to the viscosity of methanol. Note that the viscosity of methanol is extremely low at 0.59 mPa·sec. Therefore, when using Permalloy flat powder, the weight of the Permalloy flat powder aggregate is less than 1/10 of the methanol dispersion of the organometallic compound. On the other hand, the density of permalloy is 10 times that of methanol. Therefore, the volume ratio of the methanol dispersion of the organometallic compound becomes larger than the volume ratio calculated theoretically from the weight of the permalloy flat powder collection. Therefore, when a collection of flat Permalloy powder is stirred in a methanol dispersion of an organometallic compound with a large volume ratio, the flat Permalloy powder is well dispersed in a methanol dispersion of an organometallic compound with a low density and low viscosity. , evenly mixed into the methanol dispersion. On the other hand, among the flat powders made of metals, alloys, metal oxides, or inorganic compounds, the flat powder with the lowest density is aluminum flat powder with a density of 2.7 g/cm ³ . Therefore, when flat aluminum powder is used, the weight of the aggregate of flat aluminum powder is less than 1/3 of the weight of the methanol dispersion of the organometallic compound. On the other hand, the density of aluminum is 3.4 times that of methanol. Therefore, the volume ratio of the methanol dispersion of the organometallic compound becomes larger than the volume ratio calculated theoretically from the weight of the aggregate of flat aluminum powder. Therefore, when a collection of flat aluminum powder is stirred in a methanol dispersion of an organometallic compound with a large volume ratio, the flat aluminum powder will be well dispersed in a methanol dispersion of an organometallic compound with a low density and low viscosity. , evenly mixed into the methanol dispersion. In this way, the mass of flat powder is weighed as a weight less than the weight of methanol multiplied by the ratio of the density of methanol to the density of the flat powder used, and the mass of the weighed flat powder is When a collection of flat powders is added to a methanol dispersion and stirred in a methanol dispersion of an organometallic compound, all of the flat powders are The flat powder is well dispersed in the methanol dispersion of the organometallic compound with low viscosity and low density, and evenly mixed with the methanol dispersion, so that all the flat powders are covered with the methanol dispersion of the organometallic compound.
In the third process, a homogenizer device is placed within the container and the homogenizer device is operated within the container. At this time, since the methanol dispersion of the organometallic compound is a low-viscosity and low-density liquid, the shock waves generated by the homogenizer device are consumed at a low rate when exciting the methanol dispersion, and the methanol dispersion is Through this, shock waves are efficiently and repeatedly applied to the collection of flat powder. As a result, shock waves are repeatedly applied to all the flat powders via the methanol dispersion of the organometallic compound. On the other hand, among flat powders, even if the density is relatively high, the thickness of the flat powder is extremely thick, and the size of the flat powder is the largest, that is, the density is 7.8 g / cm ³ , One flat sheet of reduced iron powder with a particle size of 100 μm and a thickness of 15 μm weighs only 1×10 ⁻⁶ g. Therefore, even if the flat powder has complex overlapping flat surfaces, shock waves are repeatedly applied to the extremely lightweight flat powder, and the flat powder with overlapping flat surfaces is separated into individual flat powders. The methanol dispersion of the organometallic compound covers the flat powder.
That is, the flat powder has a flat surface with a large aspect ratio, which is the ratio of the average value of the major axis and the minor axis to the thickness. Furthermore, even if the same type of flat powder is used, there are variations in the size and thickness of the flat surface. When such a collection of flat powder is handled in an atmospheric environment, the flat surfaces overlap each other in a complicated manner. On the other hand, when a sheet consisting of a collection of flat powder is formed using flat powder whose flat surfaces directly overlap each other, the flat powder whose flat surfaces directly overlap each other forms a portion of the sheet with weak mechanical strength. Furthermore, if all of the overlapping flat powders can be separated into individual flat powders, the amount of flat powder used when forming a sheet can be reduced. Therefore, a process is required to reliably separate the flat powder in which the flat surfaces of the flat powder overlap each other. On the other hand, when attempting to separate flat powder whose flat surfaces overlap in the atmosphere, frictional force is generated between the overlapping flat surfaces, making separation difficult. Furthermore, it is difficult to identify whether the flat surfaces overlap each other.
On the other hand, a methanol dispersion of an organometallic compound is a liquid with low viscosity and low density, and as mentioned above, the volume ratio of the methanol dispersion of an organometallic compound is theoretically calculated from the weight of a collection of flat powders. When a collection of flat powders is stirred in a methanol dispersion of an organometallic compound, regardless of the density, thickness, and size of the flat powder, the flat powder is larger than the volume ratio of the organometallic compound. Disperses well in methanol dispersion and mixes evenly with methanol dispersion. When shock waves are repeatedly generated in this mixture using a homogenizer, the shock waves spread throughout the methanol dispersion of the organometallic compound, and the energy of the shock waves is less consumed by the methanol dispersion, making it more efficient for the shock waves to attack flat powder. Shock waves are repeatedly applied to areas where the flat surfaces of the flat powder overlap, and since the flat powder is extremely lightweight, the overlapping flat surfaces easily separate. As a result, the flat powder whose flat surfaces overlap each other is reliably separated into individual flat powders. In addition, when an ultrasonic homogenizer is used as the homogenizer, the generation and disappearance of a huge number of bubbles, which are two orders of magnitude smaller than the flat surface of the flat powder, and the disappearance of the bubbles are caused by the methanol dispersion of the organometallic compound. This phenomenon is repeated (this phenomenon is called cavitation), and when the bubbles burst, a shock wave is generated continuously throughout the methanol dispersion of the organometallic compound, and the flat powder, whose flat surfaces overlap each other, forms one by one in a short time. Separate into flat powder. As a result, all the flat powders are covered with the methanol dispersion of the organometallic compound. After this, the homogenizer device is removed from the container.
In the fourth process, vibration acceleration is repeatedly applied to the container in three directions, and finally vibration acceleration is applied in the vertical direction. That is, in the process using the homogenizer device, all the flat powders are covered with a methanol dispersion of a low-viscosity, low-density organometallic compound and are dispersed in the methanol dispersion. When vibrational acceleration is applied to such a mixture in three directions, the low viscosity, low density methanol dispersion of the organometallic compound is repeatedly moved along with the flat powder in the direction of the vibrational acceleration. At this time, since the flat powder has a flat surface with a large aspect ratio, it moves repeatedly in the direction of vibration acceleration together with the methanol dispersion of the organometallic compound with the flat surface facing upward. In addition, a phenomenon in which flat powders rearrange and overlap with their flat surfaces facing up progresses in a methanol dispersion of an organometallic compound. As a result, a collection of flat powders whose flat surfaces overlap each other via the methanol dispersion of the organometallic compound spreads over the entire bottom surface of the container. Finally, vibration acceleration is applied in the vertical direction, and the vibration to the container is stopped. As a result, a collection of flat powders whose flat surfaces overlap each other via the methanol dispersion of the organometallic compound spreads over the entire bottom of the container, forming the shape of the bottom of the container.
In the fifth treatment, the vessel is heated to the boiling point of methanol. At this time, collections of fine crystals of the organometallic compound smaller than 100 nm are precipitated in the gaps where the flat surfaces of the flat powders overlap each other and overlapping the entire surface of the collection of flat powders. That is, in a methanol dispersion of an organometallic compound, the organometallic compound is dispersed in methanol in a molecular state, so when methanol is vaporized, the organometallic compound before dispersion precipitates as a collection of fine crystals smaller than 100 nm. On the other hand, the dispersion concentration of the organometallic compound in the methanol dispersion of the organometallic compound is low, and the volume ratio of the methanol dispersion of the organometallic compound is larger than the volume ratio calculated theoretically from the weight of the flat powder collection. When excess methanol evaporates, the thickness of the collection of microcrystals precipitated in the gaps between the flat surfaces and on the surface of the collection of flat powder is thin, on the order of submicrons. On the other hand, since the organometallic compound that was dispersed in a molecular state precipitates as fine crystals, the microcrystals are a collection of crystals that form a single molecule of the organometallic compound. Therefore, when stress is applied to the microcrystals, the microcrystals are easily crushed. However, as the microcrystals become finer, it becomes more difficult to apply stress to the microcrystals, and there is a limit to the miniaturization of the microcrystals. In addition, vaporized methanol is collected by a recovery machine and reused.
In the sixth process, a plate covering the entire surface of the flat powder collection in the container is placed over the entire surface of the flat powder collection, and the entire surface of the plate is uniformly compressed. At this time, the collection of fine crystals precipitated in the gaps where the flat surfaces of the flat powder overlap and the entire surface of the collection of flat powder is crushed into finer crystals. Since the relatively larger size of the fine crystals is more likely to be crushed, the relatively large fine crystals are crushed preferentially, and while the compressive load is applied, the fine crystals continue to be crushed. On the other hand, when microcrystals are crushed, new voids are formed in the collection of microcrystals, and the collection of crushed and finer crystals moves into the voids and fills them. As the crushing of these fine crystals progresses, the crushed and finer crystals overlap at a high density in the gaps where the flat surfaces of the flat powder overlap and on the entire surface of the collection of flat powder, making it even finer. A collection of crystals accumulates at a high density and forms an extremely thin layer. When the crushing of crystals reaches a critical size, even if a compressive load is applied to the plate, the fine crystals will not be crushed, the plate will no longer move under the compressive load, and the repulsive force from the plate will increase. At this point, the process of compressing the surface of the plate material is stopped. As a result, the size of the microcrystals has been reduced to around 20 nm, which is close to 1/5 of the size at the time of precipitation, and high precipitation occurs in the gaps between flat surfaces and on the surface of collections of flat powder. The thickness of the fine crystals with a size of around 20 nm that are overlapped in density is around 120-180 nm. Note that the compressive load applied to the plate corresponds to 10 to 100 kg weight depending on the size of the container and the amount of fine crystals. Further, the impact acceleration applied to the container is 0.2-1.0G depending on the size of the container and the amount of fine crystals. As a result, a collection of organometallic compound crystals with a size of about 20 nm overlaps at a high density in the gaps where the flat surfaces of the flat powder overlap and on the entire surface of the collection of flat powder.
In the seventh treatment, a compressive load is applied uniformly to the entire surface of the plate material, the temperature of the container is raised to the thermal decomposition temperature of the organometallic compound, and the fine crystals of the organometallic compound are thermally decomposed. First, the moisture adsorbed on the flat powder and foreign substances consisting of compounds with hydroxyl groups vaporize. Next, thermal decomposition of the microcrystals of the organometallic compound begins, and the organometallic compound is thermally decomposed into organic molecules and metal molecules or metal oxide molecules, and when the organic molecules have completed vaporization, the metal Or the metal oxide molecules gather to form granular nanoparticles made of metal or metal oxide with a size of around 10 nm, and 6 to 8 of the granular nanoparticles overlap and precipitate all at once. The collection of nanoparticles forms a thickness of 60-80 nm. The metal or metal oxide nanoparticles do not contain any impurities and are precipitated as genuine metal or metal oxide nanoparticles. Further, since the metal nanoparticles are precipitated as active metal nanoparticles, adjacent metal nanoparticles are metallically bonded to each other at the contact portion. After this, the metal-bonded metal nanoparticles are bonded again by frictional heat. On the other hand, as the thermal decomposition of the microcrystals progresses, the organic foreign matter adsorbed on the flat powder vaporizes. As a result, the flat surface of the flat powder is cleaned, and a collection of nanoparticles of an intrinsic metal or an intrinsic metal oxide is precipitated on the cleaned flat surface, and the metal or metal is bonded to the flat surface by frictional heat. The bonding force of oxide nanoparticles is increased. Further, the bonding force due to frictional heat between nanoparticles of intrinsic metals or metal oxides is also increased. Note that the granular nanoparticles of metal or metal oxide are small, around 10 nm, and the contact area between the granular nanoparticles and the flat surface is extremely small, so the granular nanoparticles of metal or metal oxide are destroyed by frictional heat. When joined to the flat surface, the flat surface is not plastically deformed, and no stress strain is generated on the flat surface. Therefore, it is not necessary to annealing the sheet made of flat powder to remove strain.
In the eighth process, vibration acceleration is applied to the container in three directions: front and back, left and right, and up and down, and the sheet consisting of a collection of flat powder is peeled off from the bottom of the container. As a result, a sheet consisting of a collection of flat powder is obtained. Note that the surface of the flat powder collection and the layer of nanoparticle collection formed in the gaps between the flat particles are a bonding layer with a very thin thickness of 60-80 nm, which corresponds to a collection of 6-8 nanoparticles. Moreover, the size of nanoparticles having a size of around 10 nm is more than two orders of magnitude smaller than the flat surface of flat powder. Therefore, in a sheet made of a collection of flat powders, the properties of flat powders become predominant.
Here, the method of manufacturing a sheet made of a collection of flat powder according to the present invention brings about the following effects.
First, the substance that joins the flat surfaces of the flat powder is metal or metal oxide nanoparticles, and the raw material for the metal or metal oxide nanoparticles is a methanol dispersion in which an organometallic compound is dispersed in methanol. It turned into a liquid phase. Since this liquid is a low viscosity and low density liquid, by continuously performing the second and third treatments, the methanol dispersion of the organometallic compound is separated into flat powder. It becomes possible to intervene in the gap between flat surfaces. This solves the first problem described in paragraph 16.
Second, the homogenizer device is operated in the container, and the shock waves generated by the homogenizer device are used to excite the methanol dispersion of the organometallic compound because the methanol dispersion of the organometallic compound has a low viscosity and low density. The consumption rate is small, and most of the impact energy is efficiently and repeatedly transmitted to the collection of flat powder. Because the flat powder is extremely lightweight, even complex overlapping flat powders can be reliably separated into individual flat powders. A methanol dispersion of an organometallic compound is brought into contact with the surface of the sample. This solves the second problem described in paragraph 16. Note that the surfaces of the flat powders are all hydrophobic and do not react with the methanol dispersion of the organometallic compound, and the methanol dispersion of the organometallic compound comes into contact with the surface of the flat powder.
Third, vibrations are repeatedly applied to the container in three directions: left and right, front and back, and up and down, and finally, vibration is applied in the up and down direction. At this time, since the methanol dispersion of the organometallic compound has a low viscosity and low density, the methanol dispersion of the organometallic compound moves repeatedly in the three directions of vibration acceleration accompanied by flat powder, and the methanol dispersion of the organometallic compound moves repeatedly in three directions of vibration acceleration. In the liquid, the flat surfaces repeatedly rearrange to overlap. As a result, the flat powder spreads over the entire bottom of the container, and a collection of flat powder in which the flat surfaces overlap each other via the methanol dispersion of the organometallic compound is formed on the bottom of the container in the shape of the bottom. This solves the third problem described in paragraph 16.
Fourth, since the flat powder separated into individual flat powders is superimposed on each other flat surfaces via a methanol dispersion of an organometallic compound, the larger the aspect ratio of the flat powder, the more the flat powder is used. quantity decreases. Therefore, even if the flat powder is expensive, a sheet made of a collection of flat powders with their flat surfaces overlapped can be manufactured at low cost.
Fifth, methanol is vaporized from a collection of flat powders whose flat surfaces overlap each other through a methanol dispersion of an organometallic compound, and the organometallic compound is applied to the gaps between the flat surfaces and the surface of the collection of flat powders. A collection of fine crystals is precipitated. Furthermore, the entire surface of the flat powder collection is compressed evenly. As a result, the fine crystals are crushed to about 1/5 of their size, and the crushed crystals overlap and accumulate at a high precipitation density in the gaps between the flat surfaces and on the surface of the flat powder collection. . The crushed fine crystals having a size of about 20 nm become a raw material for a collection of metal or metal oxide nanoparticles that join the flat surfaces of the flat powder. This solves the fourth problem described in paragraph 16.
Sixth, the entire surface of the collection of flat powder is uniformly compressed and heated to thermally decompose the crushed fine crystals. At this time, a collection of metal or metal oxide nanoparticles overlaps and precipitates all at once at a high density in the gaps between the flat surfaces and on the surface of the collection of flat powder. Furthermore, the entire surface of the collection of flat powder is compressed evenly, and the collection of metal or metal oxide nanoparticles precipitated at high density is bonded to the flat surface by frictional heat, and the nanoparticles are also bonded to each other by frictional heat. do. In other words, as a collection of metal or metal oxide nanoparticles overlaps and precipitates at a high density, it becomes difficult for the compressed nanoparticles to move within the collection of nanoparticles, and the contact area of the nanoparticles that come into contact with the flat surface becomes difficult for the compressed nanoparticles. Frictional heat is instantaneously generated at the contact area between the nanoparticles, and the bonding force caused by the frictional heat causes the nanoparticles to bond to a flat surface, and the bonding force due to the frictional heat causes the nanoparticles to bond to each other. As a result, the fifth and sixth problems described in the 16th paragraph are solved, and all the problems described in the 16th paragraph are solved.
Seventhly, flat powder made of metals, alloys, metal oxides, or inorganic compounds other than tin and zinc can be used as flat powder when producing a sheet made of a collection of flat powders. That is, the thermal decomposition temperature of the organometallic compound with the highest thermal decomposition temperature is 330° C. in the air atmosphere. On the other hand, among soft metals, tin has a low melting point of 232°C, causing low-temperature embrittlement at around -40°C. Zinc also causes low temperature brittleness. On the other hand, flat powder of metals, alloys, metal oxides, or inorganic compounds other than tin and zinc has a melting point higher than 330°C, and does not have low-temperature brittleness, making it possible to use it at extremely low temperatures. . Therefore, a sheet made of a collection of flat powders in which the flat surfaces of the flat powders are joined can be used even in harsh environments such as high temperatures, extremely low temperatures, vacuum, and high pressure.
Eighth, organometallic compounds are metals or metal oxides made of various materials that are precipitated by thermal decomposition. For this reason, the material of the nanoparticles that join the flat surfaces of the flat powder should be the material of metal or metal oxide nanoparticles that is most suitable for exhibiting the properties of the sheet made of a collection of flat powder. can.
Ninth, a sheet made of a collection of flat powder can be manufactured using inexpensive materials and at a low cost. That is, the organometallic compound and the flat powder are general-purpose industrial materials, and the amounts of the organometallic compound and the flat powder used are small. Moreover, all eight processes for manufacturing sheets are extremely simple processes. Therefore, the manufacturing cost of the sheet is low.
As explained above, in the sheet manufactured by this manufacturing method, the flat surfaces of the flat powder separated into individual sheets of flat powder are joined together via a collection of metal or metal oxide nanoparticles. Therefore, it is possible to produce a sheet made of a collection of flat powders that has innovative effects not found in conventional collections of flat powders.

The method of manufacturing a sheet made of a collection of flat powder described in paragraph 18 is a method of manufacturing a sheet made of a collection of soft magnetic flat powder, and the method of manufacturing a sheet made of a collection of soft magnetic flat powder. teeth,
The flat powder described in paragraph 18 is a soft magnetic flat powder made of iron, permalloy, silicon steel, sendust, or electromagnetic stainless steel, and the organometallic compound described in paragraph 18 is thermally decomposed. A soft magnetic flat powder made of any of the above materials is used as the flat powder described in paragraph 18, and the nickel octylate is used as the organometallic compound described in paragraph 18. According to the method for manufacturing a sheet made of a collection of flat powder using the method described in paragraph 18, the flat surfaces of the soft magnetic flat powder are joined via a collection of nickel nanoparticles. A method of manufacturing a sheet made of a collection of soft magnetic flat powder.

First, the properties of soft magnetic flat powder of iron, permalloy, silicon steel, sendust, or electromagnetic stainless steel will be explained.
A soft magnetic flat powder made of iron or permalloy has a large initial relative permeability and a high maximum relative magnetic permeability, and a sheet made of a collection of flat powder in which the flat surfaces of the soft magnetic flat powder are joined by a collection of nanoparticles is Effective as a magnetic shielding sheet. In addition, soft magnetic flat powders made of iron, permalloy, silicon steel, sendust, or electromagnetic stainless steel have a constant value in the imaginary part of their complex magnetic permeability in a specific frequency band. A sheet made of a collection of flat powder whose flat surfaces are joined by a collection of nanoparticles is effective as a sheet that absorbs electromagnetic wave noise or prevents interference of electromagnetic noise in a specific frequency band.
Here, flat iron powder will be explained. Electromagnetic soft iron, which has magnetic properties close to those of pure iron, has an initial relative permeability of 150 and a maximum relative permeability of 1×10 ⁴ in a DC magnetic field. Moreover, the relative magnetic permeability in an alternating current magnetic field of 100 kHz is 100. Furthermore, the saturation magnetic flux density of electromagnetic soft iron is the highest among soft magnetic materials, which is 2.2 Tesla. Therefore, a sheet in which the flat surfaces of flat iron powder are stacked on each other effectively acts as a shielding film that shields magnetism. It is particularly effective as a magnetic shield for equipment that generates strong magnetic fields, such as MRI (abbreviation for Magnetic Resonance Imaging) and power transformers. On the other hand, iron has a Vickers hardness of 110 Hv and is a relatively hard metal. In addition, there are two types of iron powder: reduced iron powder and atomized iron powder.Reduced iron powder has many pores and is easier to flatten than atomized iron powder, but due to its high hardness, the thickness of the flat powder is thick. Therefore, the flat reduced iron powder has a larger oblateness than the atomized iron powder, and the imaginary part of the complex magnetic permeability has a constant size in the frequency band of 100 kHz to 10 MHz. Therefore, the sheet made of flat reduced iron powder acts as a sheet for absorbing electromagnetic noise in the frequency band of 100 kHz to 10 MHz or for preventing electromagnetic noise interference. Note that the skin depth of the 100 kHz electromagnetic wave of the reduced iron powder is 50 μm. Therefore, flat powder made of reduced iron powder exhibits excellent performance as a magnetic shield for equipment that generates strong magnetic fields. It is also effective in a limited frequency band as a sheet for absorbing electromagnetic noise or preventing electromagnetic noise interference. For this reason, flat reduced iron powder powder is used as flat powder made of the metal described in paragraph 18, and a sheet made of a collection of flat powders in which the flat surfaces of reduced iron powder are joined together is formed according to the method described in paragraph 18. Then, it can be used as a sheet for magnetic shielding, and as a sheet for absorbing electromagnetic noise or preventing electromagnetic noise interference.
On the other hand, permalloy is a soft magnetic material made of an alloy with high magnetic permeability. The larger the magnetic permeability and the smaller the magnetic resistance of the flat powder, the greater the magnetic shielding effect can be obtained. Since magnetic resistance is inversely proportional to magnetic permeability, a sheet made of flat permalloy powder with high magnetic permeability has a high magnetic shielding effect. For example, permalloy with 45% nickel has an initial relative permeability of 2.5×10 ³ and a maximum relative permeability of 2.5×10 ⁴ in a DC magnetic field. However, the saturation magnetic flux density is smaller than that of electromagnetic soft iron, which is 0.9 Tesla. On the other hand, permalloy, which is composed of 79% nickel and 4% molybdenum, has an initial relative magnetic permeability of 2×10 ⁴ and a maximum relative magnetic permeability of 2×10 ⁵ , which is extremely large. However, as the nickel content increases, permalloy becomes more expensive, so the nickel content is preferably 50% or less. Therefore, a sheet made by overlapping the flat surfaces of permalloy flat powder becomes an excellent magnetic shielding sheet. For this reason, in areas where external magnetic fields are relatively small, such as leakage magnetic fields from electrical equipment, alternating magnetic fields from current transmission and distribution lines, urban magnetic noise, and environmental magnetic fields, sheets made of flat permalloy powder can be used as magnetic shielding sheets. It is valid as According to Non-Patent Document 1, permalloy flat powder containing 50% nickel has an aspect ratio of 38 and an average particle size of 14 μm. Further, the imaginary part of the complex magnetic permeability rises sharply from around 100 MHz, has a peak value of 8.8 at 3.3 GHz, decreases from around 4 GHz, and has a value of 3.5 at 10 GHz. Therefore, this permalloy flat powder has an imaginary part of complex permeability of 5 or more in the frequency band of 1-8 GHz, and a sheet made by overlapping the flat surfaces of the permalloy flat powder has a value of 5 or more in the frequency band of 1-8 GHz. acts as a sheet to absorb electromagnetic noise or prevent electromagnetic noise interference. In this way, a sheet in which the flat surfaces of Permalloy flat powder are stacked on top of each other exhibits excellent performance as a magnetic shielding sheet in a region where the external magnetic field is relatively small. It is also effective in a limited frequency band as a sheet for absorbing electromagnetic noise or preventing electromagnetic noise interference. Therefore, if permalloy flat powder is used as a flat powder made of the alloy described in paragraph 18, and a sheet made of a collection of flat powders in which the flat surfaces of the flat powder are joined together according to the method described in paragraph 18, It can be used as a sheet for magnetic shielding, and as a sheet for absorbing electromagnetic noise or preventing electromagnetic noise interference.
On the other hand, soft magnetic materials made of alloys include silicon steel, which is made by adding a small amount of silicon to iron, permalloy, which is made by adding nickel to iron, sendust, which is made by adding silicon and aluminum to iron, and permalloy, which is made by adding cobalt to iron. There are two types: Mendur and electromagnetic stainless steel, which is made by adding chromium and silicon to iron. Among these, silicon steel becomes brittle as the amount of silicon added increases, and the amount of silicon added that can be flattened is less than 10%. Note that if the amount of silicon added changes slightly, the magnetic permeability characteristics of silicon steel will change significantly. Furthermore, the manufacturing cost of permalloy increases as the amount of nickel added increases, but if the amount of nickel added is small, the magnetic permeability decreases, so it is desirable to suppress the amount of nickel added to about 50%. Furthermore, sendust has high hardness and is brittle, but by adding a small amount of nickel and reducing the amount of silicon added, flattening becomes possible. Furthermore, since permendur is an alloy with cobalt, its production cost is high, and it is not suitable as a flat powder for use in sheets that absorb electromagnetic noise or prevent electromagnetic noise interference. Furthermore, when aluminum is added to electromagnetic stainless steel, flattening becomes easier. Therefore, four types of alloys except permendur can be used as soft magnetic flat powders. Further, the thickness of the flat powder made of the four types of alloys falls within the range of 1-1.5 μm. On the other hand, since the hardness of the reduced iron powder is higher than the hardness of the four types of alloys, the thickness of the flat powder made of the reduced iron powder is as thick as 10-20 μm.
On the other hand, as explained in paragraph 16, the larger the flatness of the flat powder, the larger the imaginary part of the complex magnetic permeability. Furthermore, as shown in Equation 1 described in the third paragraph, the absorption of electromagnetic noise depends on the magnitude of the imaginary part of the complex magnetic permeability and the magnitude of the electrical conductivity of the flat powder. Therefore, sheets used for absorbing electromagnetic noise or preventing interference with electromagnetic noise include flat silicon steel powder with less than 10% added silicon, and flat permalloy powder with less than 50% nickel added. It is possible to use sendust flat powder to which a trace amount of nickel is added and the amount of silicon added is reduced, and flat electromagnetic stainless steel powder to which aluminum is added. However, the complex magnetic permeability of flat powder made of these four types of alloys changes when the composition of components other than iron changes slightly. Further, since the hardness of the four types of alloys is different, the ellipticity of the flat powder is different for each of the four types of alloys, and the size of the imaginary part of the complex magnetic permeability is different for each of the four types of alloys. Furthermore, the frequency characteristics of the imaginary part of the complex magnetic permeability are significantly different for the four types of alloys, and even for the same type of alloy, they differ depending on the components other than iron. Therefore, when creating a sheet made of flat alloy powder used for absorbing electromagnetic noise or preventing electromagnetic noise interference, it is possible to use different soft magnetic flat powder made of alloy depending on the frequency band of the electromagnetic waves to be absorbed. , the characteristics of the imaginary part of the complex magnetic permeability of soft magnetic flat powder made of alloy can be utilized. For this reason, a soft magnetic flat powder made of an alloy is used as a flat powder made of an alloy described in paragraph 18, and a collection of flat powder is obtained by joining the flat surfaces of the flat powder according to the method described in paragraph 18. When a sheet is formed, it can be used as a sheet that absorbs electromagnetic noise or prevents electromagnetic noise interference.
By the way, since the soft magnetic flat powder has different hardness, the thickness of the flat powder changes depending on the material. For example, the thickness of flattened powder obtained by flattening reduced iron powder, which has high hardness and is difficult to flatten, is as thick as 10-20 μm. On the other hand, the thickness of flat powder made by adding a small amount of nickel to sendust, a ternary alloy consisting of iron, silicon, and aluminum to reduce the amount of silicon added and making flattening easier, is 1-1. It is as thin as 5μm. Further, the weight of the flat powder varies greatly depending on the particle size and density of the flat powder, as well as the thickness of the flat powder. For example, the weight of flat reduced iron powder having a particle size of 100 μm and a thickness of 15 μm is extremely light at 0.927×10 ⁻⁶ g. On the other hand, the weight of Sendust flat powder having a particle size of 40 μm and a thickness of 1 μm is even lighter at 0.86×10 ⁻⁸ g. Note that the density of iron is 7.8 g/cm ³ and the density of sendust is 7.6 g/cm ³ , and the densities of the two are close to each other. Therefore, the reason why the weight of the flat reduced iron powder is two orders of magnitude larger than the weight of the Sendust flat powder is due to the difference in the thickness and particle size of the flat powder. However, the weight of one sheet of soft magnetic flat powder is extremely small even if it is a flat reduced iron powder. Note that the density of the soft magnetic flat powder made of metal or alloy is within the range of 7.7-8.3 g/cm ³ .
On the other hand, in the method for manufacturing a sheet consisting of a collection of flat powders in which the flat surfaces of the flat powders are joined together via a collection of nanoparticles described in paragraph 18, the collection of flat powders is used relative to the weight of methanol. The mass of the weighed flat powder is weighed as less than the weight multiplied by the ratio of the density of methanol to the density of the flat powder, and the mass of the weighed flat powder is mixed with a methanol dispersion of an organic compound with low viscosity and low density, and the mixture is homogenized. The device was put into operation. When the homogenizer is operated in the mixture, the methanol dispersion of the organometallic compound is a low-viscosity, low-density liquid, so the shock waves generated by the homogenizer hardly excite the methanol dispersion, causing methanol dispersion to occur. Shock waves are efficiently and repeatedly applied to the collection of soft magnetic flat powder through the liquid. For this reason, since one sheet of soft magnetic flat powder is extremely lightweight, even if the weight, thickness, size, and density of the soft magnetic flat powder are different, the overlapping soft magnetic The flat powder is easily separated into individual flat powders, and the separated soft magnetic flat powder is covered with a methanol dispersion of an organometallic compound.
After this, vibrational acceleration was repeatedly applied to the container in three directions, and finally vibrational acceleration was applied in the vertical direction. In the process using the homogenizer described above, all the soft magnetic flat powders are covered with a methanol dispersion of an organometallic compound having a low viscosity and low density, and are dispersed in the methanol dispersion. Therefore, when vibration acceleration is applied to the container, the methanol dispersion of the organometallic compound has a low viscosity and low density, and since one sheet of soft magnetic flat powder is extremely lightweight, the weight and thickness of the soft magnetic flat powder are reduced. Even if the size and density of the organometallic compound are different, the methanol dispersion of the organometallic compound moves in the direction of the vibrational acceleration together with the soft magnetic flat powder. At this time, since the soft magnetic flat powder has a flat surface with a large aspect ratio, it repeatedly moves in the direction of vibration acceleration with the flat surface facing up, and the flat powder rearranges and overlaps with the flat surface facing up. The process proceeds in a methanol dispersion of an organometallic compound, and the flat surfaces overlap each other through the methanol dispersion of an organometallic compound. As a result, even if the soft magnetic flat powders have different weights, thicknesses, sizes, and densities, a collection of flat powders with their flat surfaces overlapping each other through the methanol dispersion of the organometallic compound will spread over the entire bottom of the container. . Therefore, there are no restrictions on the material, thickness, size, particle size distribution, and hardness of the soft magnetic flat powder used.
Next, the material of the nano-sized substance that joins the flat surfaces of the soft magnetic flat powder made of iron, permalloy, silicon steel, sendust, or electromagnetic stainless steel will be explained. As explained in paragraph 19, the thickness of the layer of a collection of nano-sized substances that joins the flat surfaces of the flat powder is as thin as 60 to 80 nm. Moreover, nanoparticles having a size of about 10 nm are smaller than the area of the flat surface of the soft magnetic flat powder by more than two orders of magnitude. Therefore, in a sheet in which the flat surfaces of the soft magnetic flat powder are joined together by a collection of nanoparticles, the properties of the soft magnetic flat powder become dominant. However, if the material of the nanoparticles is a ferromagnetic material with soft magnetic properties, it will not inhibit the soft magnetic properties of the sheet made of a collection of flat soft magnetic powders. Nickel exists as such a ferromagnetic material.
Nickel has a maximum relative magnetic permeability of 600. Further, the complex magnetic permeability is 1.592 in the real part and 1.349 in the imaginary part at 2.45 GHz and 50°C. Therefore, among metals or metal oxides, nickel corresponds to a ferromagnetic material in which both the maximum relative magnetic permeability and the complex magnetic permeability have constant values. The maximum relative magnetic permeability is smaller than that of iron, which is 1×10 ⁴ , and its magnetic shielding performance is inferior to that of iron. On the other hand, the electrical resistance of nickel is 69.3 × 10 ^-9 Ω・m, which is lower than the electrical resistance of iron, which is 100 × 10 ^-9 Ω・m, so the reflection loss and absorption loss of electromagnetic waves are greater than that of iron. Effective against shields. Furthermore, since the complex magnetic permeability has a constant value in a high frequency frequency band, it has a magnetic shielding effect and a certain effect of absorbing electromagnetic noise in a high frequency frequency band. Further, the Vickers hardness of nickel is 400-500 HV, which is higher than that of PB permalloy, which has the lowest hardness among soft magnetic materials, at 120-160 HV. However, the nickel nanoparticles are small, around 10 nm, and the contact area formed when they come into contact with the flat surface of the flat permalloy powder is extremely small. Therefore, when a collection of nickel nanoparticles comes into contact with the flat surface of Permalloy, the very slight contact portion of the flat surface of Permalloy is slightly elastically deformed, and no stress strain is generated on the flat surface of Permalloy. At this time, the nickel nanoparticles bond to the permalloy's flat surface due to the frictional heat generated at the very slight contact area between the two. Based on this idea, we decided to join the flat surfaces of soft magnetic flat powder with a collection of nickel nanoparticles.
Here, a method for manufacturing a sheet made of a collection of soft magnetic flat powder that joins the flat surfaces of the soft magnetic flat powder through a collection of nickel nanoparticles is described in accordance with the eight processes described in paragraph 18. I will explain.
In the first treatment, nickel octylate is dispersed in methanol to a maximum of 10% by weight to create a methanol dispersion of nickel octylate, and the methanol dispersion is filled into a container. In the second process, a collection of soft magnetic flat powder made of iron, permalloy, silicon steel, sendust, or electromagnetic stainless steel is mixed with the density of methanol relative to the density of the flat powder used relative to the weight of methanol. The mass of the flat powder is put into a container, and the soft magnetic flat powder is stirred. In the third process, a homogenizer device is placed in a container and the homogenizer device is operated in the container. In the fourth process, vibration acceleration is repeatedly applied to the container in three directions, and finally vibration acceleration is applied in the vertical direction. When these four treatments are performed in succession, a collection of flat powders in which the flat surfaces of the flat powders overlap each other is formed in the shape of the bottom surface on the bottom surface of the container via the methanol dispersion of nickel octylate.
The fifth process is to raise the temperature of the container to the boiling point of methanol. The sixth process is to cover the entire surface of the flat powder collection in the container with a plate material, compress the entire surface of the plate material evenly, and further add fine crystals of nickel octylate. Crush into fine crystals. As a result, a collection of finer nickel octylate crystals overlaps and accumulates at a high density in the gaps where the flat surfaces of the flat powder overlap and on the entire surface of the collection of flat powder.
In the seventh treatment, a compressive load is applied evenly to the surface of the plate material, and the temperature of the container is raised to 290° C., where thermal decomposition of nickel octylate is completed, thereby thermally decomposing the nickel octylate. In the eighth process, vibration acceleration is applied to the container in three directions: front and back, left and right, and up and down, and a sheet made of a collection of flat powder is peeled off from the bottom of the container. As a result, a sheet is obtained which is made up of a collection of flat powders whose flat surfaces are joined together through collections of nickel nanoparticles with a size of around 10 nm joined by frictional heat. Note that the thermal decomposition temperature of nickel octylate in a nitrogen atmosphere is 340° C., which is 50° C. higher than that in the air atmosphere.
Here, the phenomena that occur in the eight processes and the effects brought about by each process will be explained.
In the first treatment, when nickel octylate is dispersed in methanol, the nickel octylate becomes a molecular state and is dispersed in methanol. As a result, the raw material for the nickel nanoparticles is turned into a liquid phase. Note that since nickel octylate does not dissolve in methanol, when methanol is vaporized from nickel octylate, fine crystals of nickel octylate are precipitated.
In the second treatment, a collection of soft magnetic flat powder made of iron, permalloy, silicon steel, sendust, or electromagnetic stainless steel is mixed with the density of methanol relative to the density of the flat powder used relative to the weight of methanol. The mass of soft magnetic flat powder is put into a container, and the mass of soft magnetic flat powder is stirred. On the other hand, since the hardness of soft magnetic flat powder differs depending on the material, the thickness of the flat powder changes depending on the material. The thickness of flat powder obtained by flattening reduced iron powder, which has the highest hardness among soft magnetic flat powders and is difficult to flatten, is as thick as 10-20 μm. The weight of flat reduced iron powder having a particle size of 100 μm and a thickness of 15 μm is 0.927×10 ⁻⁶ g. On the other hand, the thickness of flat powder made by adding a small amount of nickel to sendust, a ternary alloy consisting of iron, silicon, and aluminum to reduce the amount of silicon added and making flattening easier, is 1-1. It is as thin as 5μm. The weight of Sendust flat powder having a particle size of 40 μm and a thickness of 1 μm is 0.86×10 ⁻⁸ g. Note that the density of iron is 7.8 g/cm ³ and the density of sendust is 7.6 g/cm ³ , and the densities of the two are close to each other. The reason why the weight of the reduced iron powder flat powder is two orders of magnitude larger than the weight of the Sendust flat powder is due to the difference in the thickness and particle size of the flat powder. On the other hand, the density of methanol is 0.792 g/cm ³ and the density of nickel octylate is 1.08 g/cm ³ . Therefore, the density of the methanol dispersion of nickel octylate is close to 1/10 of the density of soft magnetic flat powder. Therefore, the weight of the soft magnetic flat powder used is less than 10 times the weight of methanol in which nickel octylate is dispersed. On the other hand, the density of a methanol dispersion of nickel octylate is close to 1/10 of the density of soft magnetic flat powder. Therefore, the theoretical volume calculated from the weight and density occupied by the collection of soft magnetic powders is smaller than the volume of the methanol dispersion of nickel octylate. However, the weight of one sheet of soft magnetic flat powder is extremely small. Furthermore, the methanol dispersion concentration of nickel octylate is as low as about 10% by weight. Therefore, the viscosity of the methanol dispersion of nickel octylate is close to that of methanol. Note that the viscosity of methanol is extremely low at 0.59 mPa·sec. Therefore, a collection of soft magnetic flat powder is weighed to be less than 1/10 of the weight of methanol, and mixed with a methanol dispersion of nickel octylate. When stirred in the methanol dispersion, the soft magnetic flat powder is well dispersed in the methanol dispersion of nickel octylate, which has a low density and low viscosity, because the weight of one soft magnetic flat powder is extremely small. Magnetic flat powder is mixed evenly. As a result, all soft magnetic flat powders are covered with the methanol dispersion of nickel octylate even if the soft magnetic flat powders have different weights, thicknesses, sizes, and densities.
In the third process, a homogenizer device is placed within the container and the homogenizer device is operated within the container. At this time, since the methanol dispersion of nickel octylate is a low-viscosity and low-density liquid, the shock waves generated by the homogenizer are consumed at a low rate when exciting the methanol dispersion, and the methanol dispersion is Shock waves are efficiently and repeatedly applied to the collection of soft magnetic flat powder through the shock wave. As a result, shock waves are repeatedly applied to all soft magnetic flat powders via the methanol dispersion of nickel octylate. On the other hand, even if the flat powder of reduced iron powder has a density of 7.8 g/cm ³ , a large particle size of 100 μm, and an extremely thick thickness of 15 μm, it weighs only 1×10 ⁻⁶ g. Therefore, even if the soft magnetic flat powder has flat surfaces that overlap each other in a complicated manner, shock waves are repeatedly applied to the extremely lightweight soft magnetic flat powder, and the flat powder that has the flat surfaces overlapped each other, one by one. It is separated into flat powder, and the separated flat powder is covered with a methanol dispersion of nickel octylate.
In the fourth process, vibration acceleration is repeatedly applied to the container in three directions, and finally vibration acceleration is applied in the vertical direction. In other words, by processing using a homogenizer, the soft magnetic flat powder that overlaps on the flat surface is separated into individual soft magnetic flat powder, and all the soft magnetic flat powder is made of nickel octylate, which has a low viscosity and low density. Covered with methanol dispersion and evenly dispersed in methanol dispersion. When vibrational acceleration in three directions is repeatedly applied to a collection of such flat soft magnetic powders, the methanol dispersion of nickel octylate, which has a low viscosity and low density, is mixed with the flat powders because the soft magnetic flat powders are extremely lightweight. Move repeatedly in the direction of vibration acceleration. At this time, since the soft magnetic flat powder has a flat surface with a large aspect ratio, it moves repeatedly in the direction of the vibration acceleration together with the methanol dispersion of nickel octylate with the flat surface facing upward. When the soft magnetic flat powder is repeatedly moved in the methanol dispersion of nickel octylate, a phenomenon in which the flat powders are rearranged and overlapped with each other with their flat surfaces facing up progresses in the methanol dispersion of nickel octylate. In this way, the flat surfaces of the soft magnetic flat powder overlap each other via the methanol dispersion of nickel octylate. As a result, a collection of flat powders with overlapping flat surfaces spreads over the entire bottom of the container in the shape of the bottom through the methanol dispersion of nickel octylate. Finally, vibration acceleration is applied in the vertical direction, and the vibration to the container is stopped.
In the fifth treatment, the vessel is heated to the boiling point of methanol. At this time, a collection of fine crystals of nickel octylate smaller than 100 nm is precipitated in the gap where the flat surfaces of the soft magnetic flat powder overlap and on the entire surface of the collection of soft magnetic flat powder. That is, in the methanol dispersion of nickel octylate, nickel octylate is dispersed in methanol in a molecular state, so when methanol is vaporized, the nickel octylate before dispersion precipitates as a collection of fine crystals smaller than 100 nm. Note that the dispersion concentration of nickel octylate in the methanol dispersion of nickel octylate is low, and excess methanol vaporizes. At this time, the thickness of the microcrystals precipitated in the gaps between the flat surfaces and on the surface of the collection of flat powders is thin, and is submicron thick. On the other hand, since nickel octylate, which had been dispersed in a molecular state, precipitated as fine crystals, the fine crystals are a collection of crystals that form a single molecule of nickel octylate. Therefore, when stress is applied to the microcrystals, the microcrystals are easily crushed. However, as the microcrystals become finer, it becomes more difficult to apply stress to the microcrystals, and there is a limit to the miniaturization of the microcrystals. In addition, vaporized methanol is collected by a recovery machine and reused.
In the sixth process, a plate covering the entire surface of the collection of soft magnetic flat powder in the container is placed over the entire surface of the collection of soft magnetic flat powder, and the entire surface of the plate is uniformly compressed. At this time, the gap between the overlapping flat surfaces of the soft magnetic flat powder and the collection of fine crystals of nickel octylate that overlap and precipitate over the entire surface of the collection of soft magnetic flat powder are crushed into even finer crystals. . Since relatively large microcrystals are more likely to be crushed, relatively large microcrystals are crushed preferentially, and while the compressive load is applied, the fine crystals continue to be crushed. On the other hand, when microcrystals are crushed, new voids are formed in the collection of microcrystals, and the collection of crushed and finer crystals moves into the voids and fills them. As the crushing of these microcrystals progresses, the crushed and finer crystals overlap at a higher density in the gaps where the flat surfaces of the soft magnetic flat powder overlap and on the entire surface of the collection of soft magnetic flat powder. A collection of fine crystals accumulates at a high density, and the collection of crystals forms a thin layer. When the crushing of nickel octylate crystals reaches a critical size, even if a compressive load is applied to the plate, the fine crystals will not be crushed, and the plate will no longer move under the compressive load, resulting in a repulsive force from the plate. increases. At this point, the process of compressing the surface of the plate material is stopped. As a result, the size of the microcrystals has been reduced to around 20 nm, which is close to 1/5 of the size at the time of precipitation, and the gaps between the soft magnetic flat surfaces and the surface of the collection of soft magnetic flat powder. In addition, the thickness of fine crystals of nickel octylate having a size of around 20 nm, which are overlapped with each other at a high precipitation density, is 120 to 180 nm. Note that the compressive load applied to the plate corresponds to 10 to 100 kg weight depending on the size of the container and the amount of fine crystals. Further, the impact acceleration applied to the container is 0.2-1.0G depending on the size of the container and the amount of fine crystals. As a result, collections of nickel octylate crystals with a size of about 20 nm overlap with each other at a high density in the gaps where the flat surfaces of the soft magnetic flat powders overlap and on the entire surface of the collection of flat powders.
In the seventh treatment, a compressive load is applied uniformly to the entire surface of the plate material, and the temperature of the container is raised to 290° C., where thermal decomposition of nickel octylate is completed, and the fine crystals of nickel octylate are thermally decomposed. First, the moisture adsorbed on the flat powder and foreign substances consisting of compounds with hydroxyl groups vaporize. Next, thermal decomposition of the fine crystals of nickel octylate begins, and nickel octylate is thermally decomposed into octylic acid and nickel. When the vaporization of the octylic acid molecules is completed, the nickel molecules gather and form a 10 nm Granular nickel nanoparticles having different sizes are formed, and 6 to 8 of the granular nickel nanoparticles overlap and precipitate all at once. Nickel nanoparticles do not contain any impurities and are precipitated as genuine nickel nanoparticles. Further, nickel nanoparticles are precipitated as active nanoparticles. Therefore, adjacent nickel nanoparticles are metallically bonded to each other at the contact portion. After this, the metal-bonded nickel nanoparticles are bonded again by frictional heat. On the other hand, as the thermal decomposition of the fine crystals of nickel octylate progresses, foreign substances consisting of organic substances adsorbed to the soft magnetic flat powder are vaporized. As a result, the flat surface of the soft magnetic flat powder is cleaned, and a collection of genuine nickel nanoparticles is precipitated on the cleaned flat surface, and the bonding force of the nickel nanoparticles is bonded to the flat surface by frictional heat. increases. Furthermore, the bonding force due to frictional heat between the intrinsic nickel nanoparticles increases. Note that the nickel nanoparticles are small, around 10 nm, and the contact area between the granular nanoparticles and the flat surface is extremely small, so when the nickel nanoparticles bond to the flat surface due to frictional heat, No stress strain occurs on the surface. For this reason, it is not necessary to subject the sheet made of a collection of flat soft magnetic powders to stress relief annealing.
In the eighth process, vibration acceleration is applied to the container in three directions: front and back, left and right, and up and down, and a sheet made of a collection of soft magnetic flat powder is peeled off from the bottom of the container. As a result, a sheet consisting of a collection of soft magnetic flat powder is obtained. Note that the layer of nickel nanoparticles formed on the surface of the flat powder collection and in the gaps between the flat particles is a very thin layer of 60-80 nm, which corresponds to a collection of 6-8 nanoparticles. Moreover, the size of the nickel nanoparticles having a size of around 10 nm is more than two orders of magnitude smaller than the flat surface of the flat powder. Therefore, in a sheet made of a collection of soft magnetic flat powders, the properties of the soft magnetic flat powders are dominant.
Here, the soft magnetic flat powder is used as the flat powder described in paragraph 18, nickel octylate is used as the organometallic compound described in paragraph 18, and the flat surfaces of the soft magnetic flat powder are connected to each other according to the method described in paragraph 18. , a sheet consisting of a collection of soft magnetic flat powders bonded via a collection of nickel nanoparticles provides the following effects.
First, a collection of nickel nanoparticles was used as the substance that joins the flat surfaces of the soft magnetic flat powder, and nickel octylate, the raw material for the nickel nanoparticles, was dispersed in methanol and turned into a liquid phase. Since this liquid is a low viscosity and low density liquid, by continuously performing the second and third treatments, the methanol dispersion of nickel octylate is separated into soft magnetic flat sheets. It becomes possible to interpose the powder in the gap between the flat surfaces of the powder.
Second, the homogenizer device is operated in the container, and the shock wave generated by the homogenizer device is not effective when exciting the methanol dispersion of nickel octylate because the methanol dispersion of nickel octylate has a low viscosity and low density. The consumption rate is small, and most of the impact energy is efficiently and repeatedly transmitted to the collection of soft magnetic flat powder. Therefore, even if the soft magnetic flat powder has flat surfaces that overlap each other in a complicated manner, it can be reliably separated into individual flat powders because the soft magnetic flat powder is extremely lightweight, and the material and shape of the flat powder can be Regardless of the particle size distribution, the methanol dispersion of nickel octylate comes into contact with the surface of all flat powders. Note that the surfaces of the soft magnetic flat powder are all hydrophobic and do not react with the methanol dispersion of nickel octylate, and the methanol dispersion of nickel octylate comes into contact with the surface of the soft magnetic flat powder.
Third, vibrations are repeatedly applied to the container in three directions: left and right, front and back, and up and down, and finally, vibration is applied in the up and down direction. At this time, the methanol dispersion of nickel octylate has a low viscosity and density, and the soft magnetic flat powder is extremely lightweight. Move repeatedly. As a result, a phenomenon in which the soft magnetic flat powders rearrange and overlap with their flat surfaces facing upward progresses in the methanol dispersion of nickel octylate. As a result, the soft magnetic flat powder spreads over the entire bottom of the container, and a collection of flat powder whose flat surfaces overlap each other via the methanol dispersion of nickel octylate is formed on the bottom of the container in the shape of the bottom. .
Fourthly, since the flat powders separated into individual soft magnetic flat powders are superimposed on each other flat surfaces via the methanol dispersion of nickel octylate, the larger the aspect ratio of the soft magnetic flat powders, the more The amount of soft magnetic flat powder used is reduced. Therefore, even if the soft magnetic flat powder is expensive, a sheet made of a collection of soft magnetic flat powder in which the flat surfaces are overlapped can be manufactured at low cost.
Fifth, methanol is vaporized from a collection of flat powders whose flat surfaces overlap each other through a methanol dispersion of nickel octylate, and fine particles of nickel octylate are added to the gaps between the flat surfaces and the surface of the collection of flat powders. A collection of crystals is precipitated. Furthermore, the entire surface of the collection of soft magnetic flat powder is compressed evenly. As a result, the fine crystals are crushed to about 1/5 of the size, and the crushed crystals overlap and accumulate at a high density in the gaps between the flat surfaces and on the surface of the flat powder collection. The crushed fine crystals of nickel octylate having a size of approximately 20 nm become a raw material for a collection of nickel nanoparticles having a size of approximately 10 nm that join the flat surfaces of the flat powder.
Sixth, the temperature is raised while the collection of soft magnetic flat powder is uniformly compressed, and the crushed fine crystals of nickel octylate are thermally decomposed. At this time, a collection of nickel nanoparticles overlaps and precipitates all at once at a high density in the gaps between the flat surfaces and on the surface of the collection of flat powder. Furthermore, the collection of soft magnetic flat powder is evenly compressed, and the collection of nickel nanoparticles precipitated at high density is bonded to the flat surface by frictional heat, and the nickel nanoparticles are bonded to each other by frictional heat. In other words, the collection of nickel nanoparticles overlapped with each other at high density and precipitated, making it difficult for the compressed nanoparticles to move within the collection of nanoparticles. Frictional heat is generated at the contact area, and the nickel nanoparticles are bonded to the flat surface by the bonding force due to the frictional heat, and the nickel nanoparticles are bonded to each other by the bonding force due to the frictional heat.
Seventhly, soft magnetic flat powder made of iron, permalloy, silicon steel, sendust, or electromagnetic stainless steel can be used as flat powder when manufacturing a sheet made of a collection of flat powders. That is, the thermal decomposition temperature of nickel octylate is 290° C. in the air atmosphere. On the other hand, the melting point of soft magnetic flat powders of iron, permalloy, silicon steel, sendust, or electromagnetic stainless steel is significantly higher than 290°C, and none of the soft magnetic flat powders have low-temperature brittleness and can be used at extremely low temperatures. becomes possible to use. Therefore, a sheet made of a collection of flat soft magnetic powder particles whose flat surfaces are joined together can be used in harsh environments such as high temperatures, extremely low temperatures, vacuum, and high pressure. The thermal decomposition temperature of nickel octylate in a nitrogen atmosphere is 340° C., which is 50° C. higher than that in an air atmosphere, but is significantly lower than the melting point of soft magnetic flat powder.
Eighth, the flat surfaces of the soft magnetic flat powder were joined together with a collection of nickel nanoparticles. Nickel has a maximum relative magnetic permeability of 600. Further, the complex magnetic permeability is 2.45 GHz, the real part is 1.592, and the imaginary part is 1.349. Therefore, among metals or metal oxides, nickel is a ferromagnetic material with both maximum relative magnetic permeability and complex magnetic permeability having constant values. The performance of magnetic shielding is inferior to that of iron, but the complex magnetic permeability has a constant value in the high frequency band. Therefore, the nickel nanoparticles do not inhibit the magnetic permeability characteristics of the soft magnetic flat powder in the sheet in which the flat surfaces of the soft magnetic flat powder are joined together.
Ninth, nickel octylate is a general purpose industrial chemical. Furthermore, since the flat surfaces of the flat powder are joined together, the amount of flat powder used is small. Furthermore, all eight processes for joining flat surfaces with a collection of nickel nanoparticles are simple processes. Therefore, a sheet made of a collection of soft magnetic flat powder can be manufactured using inexpensive materials and at a low cost.
As explained above, the sheet made of a collection of soft magnetic flat powder produced by this manufacturing method has an image that does not exist in a conventional collection of soft magnetic flat powder because the flat surfaces are joined with a collection of nickel nanoparticles. It is a sheet made of a collection of soft magnetic flat powder that has long-term effects.

The method of manufacturing a sheet made of a collection of soft magnetic flat powder described in paragraph 20 is a method of manufacturing a sheet made of a collection of soft magnetic flat powder of multiple types of alloys, and the soft magnetic properties of the multiple types of alloys are The method for producing a sheet made of a collection of flat powder is as follows:
The soft magnetic flat powder described in paragraph 20 is a soft magnetic flat powder made of multiple types of alloys other than iron described in paragraph 20, and the imaginary part of the complex magnetic permeability of the soft magnetic flat powder made of the multiple types of alloys is The frequency characteristics of the imaginary part of the complex magnetic permeability of each of the soft magnetic flat powders are different from each other, and the frequency characteristics of the imaginary part of the complex magnetic permeability of each of the soft magnetic flat powders are different from each other in different frequency ranges. A soft magnetic flat powder made of the plurality of alloys having frequency characteristics of the imaginary part of the complex magnetic permeability that complement each other is used as the flat powder described in paragraph 18, and nickel octylate described in paragraph 20 is used. , according to the method for producing a sheet consisting of a collection of flat powders described in paragraph 18, as an organometallic compound described in paragraph 18, the flat surfaces of the soft magnetic flat powders of the plurality of types of alloys are made of nickel nano This is a method for manufacturing a sheet made of a collection of flat soft magnetic powders of a plurality of types of alloys, which is a sheet made of a collection of flat powders of the plurality of types of alloys bonded together through a collection of particles.

As described in paragraph 16, when soft magnetic powder is flattened in the plane direction, which is the easy axis direction of magnetization, the demagnetizing field coefficient becomes smaller, and the larger the flatness, the larger the imaginary part μ'' of the complex magnetic permeability. In addition, the frequency characteristics of the imaginary part of the complex magnetic permeability of the flat powder vary greatly depending on the material of the flat soft magnetic powder. Therefore, the frequency characteristics of the imaginary part of the complex magnetic permeability of multiple types of flat soft magnetic powder made of metals or alloys vary greatly. If the characteristics are different from each other and the frequency characteristics of the imaginary part of the complex magnetic permeability of each complex magnetic permeability complement each other in different frequency ranges, then multiple types of soft magnetic materials made of such metals or alloys can be used. If you use flat powder and form a sheet by joining multiple types of flat powder randomly between their flat surfaces, the properties of the imaginary part of the complex magnetic permeability of the multiple types of flat powder will be reflected in the sheet, and the sheet will have a wide frequency range. It absorbs electromagnetic noise in the band.It also serves as a sheet to prevent electromagnetic noise interference caused by electromagnetic waves interfering with each other.
However, among the multiple types of soft magnetic flat powder made of metals or alloys, only reduced iron powder flat powder has a higher hardness than other soft magnetic flat powders, so the thickness of the flat powder is extremely small at 10-20 μm. thick. On the other hand, other soft magnetic flat powders are produced by finely adjusting the composition of the atomized soft magnetic powder or reduced soft magnetic powder, thereby reducing the hardness and making flat processing possible, with a thickness deviation of 1-1. It falls within the range of .5 μm. Therefore, when a collection of flat powders in which reduced iron powder flat powders are mixed together with flat powders made of other materials is processed by the method described in paragraph 20, the flat surfaces of all the flat powders are No overlap through the methanol dispersion of nickel octylate. For this reason, when manufacturing a sheet using soft magnetic flat powder made of multiple types of metals or alloys, the flat reduced iron powder is excluded from the soft magnetic flat powder made of metals or alloys described in paragraph 20. . Therefore, the plurality of types of soft magnetic flat powders become the plurality of types of soft magnetic flat powders made of alloys.
As a result, the multiple types of soft magnetic flat powder described in paragraph 20 are, firstly, flat powders made of multiple types of alloys excluding the flat powder of reduced iron powder, and secondly, they are flat powders made of multiple types of alloys. The frequency characteristics of the imaginary part of the complex permeability of the flat powders are different from each other, and thirdly, the frequency characteristics of the imaginary part of the complex permeability of each flat powder are the imaginary parts of the complex permeability that complement each other in different frequency ranges. This makes it possible to combine multiple types of soft magnetic flat powder with three characteristics, each with a frequency characteristic of Furthermore, if a soft magnetic flat powder made of multiple types of alloys having these three characteristics is used as the soft magnetic flat powder described in paragraph 20, and eight treatments are performed according to the method described in paragraphs 20-21, multiple types of A sheet is produced which is made up of a collection of soft magnetic flat powders made of an alloy of which are randomly joined together on their flat surfaces. This sheet reflects the characteristics of the imaginary part of the complex magnetic permeability of soft magnetic flat powder made of multiple types of alloys with three characteristics, and allows complex permeability in a wider frequency band, which is difficult to achieve with a single type of flat powder. Since the imaginary part of the magnetic property has a certain size, the sheet can absorb electromagnetic noise in a wide frequency band, which was difficult to do in the past, or prevent electromagnetic noise interference.
On the other hand, flat powder is produced by subjecting atomized soft magnetic powder or reduced soft magnetic powder to attritor treatment using a media stirring type mill, as described in paragraph 16. Therefore, if the material of the flat powder is different, the shape, structure, and hardness of the atomized soft magnetic powder or reduced soft magnetic powder will change, so not only the oblateness but also the shape, particle size distribution, and hardness of the flat powder will differ. However, as described above, the thickness deviation is as narrow as 1-1.5 μm, and the thickness is small. Furthermore, the method for producing a sheet made of a collection of flat soft magnetic powder consists of the eight treatments described in paragraphs 20-21. On the other hand, even if soft magnetic flat powder made of multiple types of alloys other than reduced iron powder is a flat powder made of multiple types of alloys with different flatness ratios, shapes, particle size distributions, and hardnesses, the eight treatments can be applied. It is possible. Therefore, for a collection of soft magnetic flat powder made of multiple types of alloys excluding reduced iron powder, a sheet can be produced in which the flat surfaces of the flat powder are randomly joined with a collection of nickel nanoparticles.
This sheet provides the following effects similar to those described in paragraph 21.
First, regarding a collection of soft magnetic flat powders made of multiple types of alloys, 6-8 nickel nanoparticles are piled up and precipitated in the gaps between the flat surfaces of the flat powders, resulting in a very thin thickness of 60-80 nm. A bonding layer consisting of is formed to randomly bond the flat surfaces to each other. Since the size of the nickel nanoparticles is two or more orders of magnitude smaller than the area of the flat powder, a sheet made of multiple types of alloys has the predominant properties of the flat powder of the multiple types of alloys.
Second, since a sheet having the shape of the bottom is formed on the bottom of the container, there are no restrictions on the area and shape of the sheet. In addition, even if soft magnetic flat powder made of multiple types of alloys other than reduced iron powder is a flat powder made of multiple types of alloys with different flatness ratios, shapes, particle size distributions, and hardnesses, it is possible to form a sheet. Since eight treatments are possible, it is possible to produce a sheet in which the flat surfaces of flat powder made of multiple types of alloys, excluding reduced iron powder, are joined together with a collection of nickel nanoparticles. Therefore, the present sheet manufacturing method can form sheets with versatility for soft magnetic flat powders other than flat reduced iron powders.
Thirdly, a sheet in which the flat surfaces of soft magnetic flat powder made of a plurality of types of alloys with high relative magnetic permeability are stacked together has a high magnetic shielding effect. Furthermore, if the thickness of the sheet is brought close to the depth of the surface of the flat powder, a sheet with a wide area can be formed with a small amount of flat powder, and all the flat powder will participate in the magnetic shielding, resulting in the effect of magnetic shielding. increases.
Fourth, soft magnetic flat powders made of multiple types of alloys have different frequency characteristics of the imaginary part of their complex permeability, and the frequency characteristics of the imaginary part of each complex permeability complement each other in different frequency ranges. If the frequency characteristics of the imaginary part of the complex magnetic permeability match, a sheet formed using a collection of soft magnetic flat powder made of multiple types of alloys can absorb electromagnetic noise in a wide frequency band, which was previously difficult. do. In addition, if the thickness of the sheet is brought close to the skin depth of flat powder of multiple types of alloys, a sheet with a wide area can be formed with a small amount of flat powder, and all of the flat powder can absorb electromagnetic noise. Participate in the electromagnetic noise absorption effect.
As explained above, the sheet made of a collection of flat soft magnetic powders of multiple types of alloys manufactured by this manufacturing method is made of a collection of nickel nanoparticles that connect the flat surfaces of flat soft magnetic powders of multiple types of alloys. Because they are randomly joined together, this sheet has the effects of soft magnetic flat powder of multiple types of alloys, which is not possible with conventional collections of soft magnetic flat powder.

The method of manufacturing a sheet made of a collection of flat powder described in paragraph 18 is a method of manufacturing a sheet made of a collection of flake powder of a metal or alloy, and the method of manufacturing a sheet made of a collection of flake powder of a metal or alloy is The manufacturing method is
The flat powder described in paragraph 18 is a metal or alloy flake powder made of any material such as silver, copper, brass, nickel, or aluminum, and the organometallic compound described in paragraph 18 is copper octylate, A metal octylate metal compound such as aluminum octylate or nickel octylate, and a metal or alloy flake powder made of any of the above materials is used as the flat powder described in paragraph 18, and any of the above octylate Using an acid metal compound as the organometallic compound described in paragraph 18, according to the method for producing a sheet consisting of a collection of flat powder described in paragraph 18, flat surfaces of metal or alloy flake powder made of any of the above materials are produced. producing a sheet made of a collection of flake powder of the metal or alloy bonded to each other via a collection of nanoparticles made of copper, aluminum, or nickel; This is a method of manufacturing.

First, a method for producing flake powder made of metal or alloy used in the present invention will be explained.
Flake powder made of silver, copper, brass, or nickel, excluding aluminum, is made by grinding metal or alloy powder made of silver, copper, brass, or nickel using a stamp mill and a number of metal punches. Powder or alloy powder is pounded, rolled into thin flakes, and flattened to produce thin flake powder. Incidentally, flake powder made of brass is sometimes called Western gold powder. When the metal or alloy powder is pounded with a large number of metal punches, undulations are formed on the surface of the metal or alloy flake powder, and the flatness of the flake powder is not high. On the other hand, as for aluminum, since the activity of the fine particles is high, the fine particles produced by the atomization method are flattened in a wet ball mill to produce scaly flake powder. This aluminum flake powder has a surface roughness resulting from flattening using a wet ball mill. Flake powder of these metals or alloys has a high aspect ratio, which is the ratio of the thickness to the long axis. Therefore, by overlapping flat surfaces, a sheet with a fixed area can be formed with a small amount of flake powder. Furthermore, since the surface of the flake powder is smooth, the coefficient of friction on the surface is as small as 0.20-0.25. For this reason, the metal or alloy flake powder has a lubricating surface, as well as electrical conductivity and thermal conductivity based on the material, and the color and gloss inherent to the metal or alloy. Among soft metals, tin has a melting point of 232°C, which is lower than the thermal decomposition temperature of metal octylate compounds, and also causes low-temperature brittleness at around -40°C. Similarly, zinc also undergoes low temperature brittleness. For this reason, flake powder consisting of tin and zinc was excluded from the raw materials used when producing a sheet made of a collection of flake powder.
Next, the material of the nanoparticles that join the flat surfaces of the metal or alloy flake powder will be explained.
If the material of the nanoparticles has excellent electrical and thermal conductivity, a sheet made of a collection of flakes joined by a collection of metal nanoparticles will have electrical and thermal conductivity over a wide area that cannot be obtained with flat powder. It becomes a sheet with excellent properties. In addition, if the nanoparticles are made of a transparent material, a sheet consisting of a collection of flakes joined by a collection of transparent nanoparticles will have the color and gloss characteristic of metals or alloys. Become. On the other hand, the conductivity of metals is superior in order of silver, copper, gold, aluminum, calcium, and magnesium. Furthermore, the thermal conductivity of metals is excellent in the order of silver, copper, gold, aluminum, magnesium, and zinc. Furthermore, it is desirable that the metal octylate compound, which is the raw material for the nanoparticles, be relatively inexpensive. Therefore, when producing a sheet with excellent electrical conductivity and thermal conductivity, it is appropriate to bond the flat surfaces of the flake powder with nanoparticles made of copper or aluminum. On the other hand, when manufacturing a sheet with the unique color and luster of a metal or alloy, it is appropriate to bond the flat surfaces of the flake powder with a collection of transparent nanoparticles. As a collection of nanoparticles made of aluminum or nickel is transparent, a collection of flake powder joined by a collection of nanoparticles made of aluminum or nickel is a sheet with the unique color and gloss of flake powder. become.
Here, transparent nanoparticles will be explained. A transparent substance has the first characteristic that it has a refractive index of 0.4 or more and 2.4 or less in the wavelength range of visible light, and the second characteristic that it is a fine particle whose size is at least one order of magnitude smaller than the wavelength of visible light. It is necessary to have the following characteristics. In other words, when the flat surfaces of flake powder are joined together using a substance with a refractive index of 0.4 or more and 2.4 or less, the refractive index is close to the refractive index of air (1), so the surface reflectance of light and the total light transmission are Depending on the rate, more than 70% of visible light is incident on the flat surface of the flake powder. Note that the surface reflectance and total light transmittance will be explained in paragraph 26. Furthermore, if the size of the particles is at least one order of magnitude smaller than the wavelength of visible light, the visible light will hardly be scattered by the collection of particles, and the visible light will be transmitted with high transparency. As a result, when a collection of nanoparticles with a refractive index of 0.4 or more and 2.4 or less and a size nearly two orders of magnitude smaller than the wavelength of visible light is formed on the surface of flake powder, the collection of nanoparticles becomes visible. Light rays pass through. Furthermore, when flat surfaces are joined together via a collection of nanoparticles, visible light passes through the gap between the flat surfaces. Note that the scattering of light in a collection of fine particles will be explained in paragraph 27.
Nanoparticles made of nickel or aluminum exist as transparent substances that have both of these characteristics. That is, nickel or aluminum has a refractive index of 0.4 or more and 2.4 or less in the visible light wavelength region (380-750 nm).
That is, the refractive index of nickel is 1.61 at 380 nm, increases as the wavelength becomes longer, and is 1.75 at 539 nm, 2.21 at 709 nm, 2.28 at 729 nm, and 2.34 at 750 nm. Therefore, the refraction of air and nickel occurs on the surface of the collection of nickel nanoparticles covering the surface of the collection of flake powder, and on the surface of the bonding layer consisting of the collection of nickel nanoparticles that joins the flat surfaces of the flake powder. Light is reflected due to the difference in rate. At this time, the light transmittance is 89% at 380 nm, 86% at 539 nm, 74% at 709 nm, 72% at 729 nm, and 70% at 750 nm. Therefore, a portion of the red visible light component is reflected by the surface of the nickel nanoparticle collection. Furthermore, the size of nickel nanoparticles is nearly two orders of magnitude smaller than the wavelength of visible light. Therefore, the light that has entered the collection of nickel nanoparticles is transmitted through the collection of nickel nanoparticles with almost no scattering.
On the other hand, the refractive index of aluminum is maximum at 2.80 at 800 nm, decreases rapidly as the wavelength becomes shorter, approaches 2.40 at 750 nm, 1.91 at 708 nm, and approaches the refractive index of air 1 at 560 nm. It becomes 0.620 at 450 nm and 0.45 at 380 nm. Therefore, light is reflected on the surface made of a collection of aluminum nanoparticles due to the difference in refractive index between air and aluminum. At this time, the light transmittance is 69% at 750 nm, 81% at 708 nm, 100% at 560 nm, 89% at 450 nm, and 73% at 380 nm. Therefore, part of the red and purple visible light is reflected on the surface of the aluminum nanoparticle collection. Furthermore, the size of aluminum nanoparticles is nearly two orders of magnitude smaller than the wavelength of visible light. For this reason, the light that has entered the collection of aluminum nanoparticles is transmitted through the collection of aluminum nanoparticles with almost no scattering.
As explained above, in a collection of aluminum nanoparticles, part of the light rays that make up visible light is reflected on the surface of the collection of aluminum nanoparticles, and a color corresponding to this light ray is emitted. A collection of nanoparticles is transparent. Furthermore, the collection of nickel nanoparticles is nearly colorless and transparent. As explained above, the collection of nanoparticles made of aluminum or nickel maintains transparency and joins the flat surfaces of the flake powder. Therefore, the color and luster reflected by the flake powder are not lost.
Next, we will explain the phenomenon that occurs when the flat surfaces of flake powder made of metal or alloy are joined together by a collection of nanoparticles. The Mohs hardness of silver, copper, brass, nickel, or aluminum that makes up the flake powder is 2.7 for silver, 2.9 for aluminum, 3.0 for copper, 3-4 for brass, and 3-4 for nickel. is 3.5. The Young's modulus is 69 GPa for aluminum, 82.7 GPa for silver, 130 GPa for copper, 103 GPa to 110 GPa for brass, and 204 GPa for nickel. Therefore, the metals or alloys constituting the flake powder all have low Mohs hardness. On the other hand, since the nanoparticles are approximately 10 nm in size, the thickness of the flake powder, which is the thinnest among the flake powders, is 20 times the size of the nanoparticles, and the area of the flat powder, which has the narrowest surface area, is This is 1000 times the size of nanoparticles. The contact area where nanoparticles come into contact with the flat surfaces of such flake powder is extremely small. Furthermore, the area where nanoparticles come into contact with each other is also extremely small. On the other hand, as mentioned above, metals or alloys other than nickel have a small Young's modulus and are excellent in ductility and malleability. Therefore, when the flat surfaces of flake powder of metals or alloys other than nickel are joined together with a collection of nanoparticles made of copper or aluminum, the nanoparticles made of copper or aluminum come into contact with the flat surfaces, and A local portion of the contact portion is elastically deformed. At this time, frictional heat is generated locally at the contact portion. On the other hand, since the nanoparticles are also made of copper or aluminum, which has a small Young's modulus, the local contact portions of the nanoparticles undergo elastic deformation. At this time, frictional heat is generated locally at the contact portion. Due to the frictional heat between the two, the flat surfaces of the flake powder made of metal or alloy are joined by a collection of nanoparticles made of copper or aluminum. Further, a local portion of the contact portion between the nanoparticles made of copper or aluminum is elastically deformed, and frictional heat is generated in the local portion of the contact portion. As a result, nanoparticles made of copper or aluminum are bonded together by frictional heat. On the other hand, when nanoparticles made of copper or aluminum come into contact with the flat surface of flake powder made of nickel, a local portion of the contact area of the nanoparticles undergoes elastic deformation. At this time, frictional heat is generated locally at the contact portion. On the other hand, since flat nickel powder has a large Young's modulus, the local contact area on the flat surface does not undergo elastic deformation, but generates frictional heat. Due to the frictional heat between the two, the flat surfaces of the flake powder made of nickel are joined together by a collection of nanoparticles made of copper or aluminum. Further, a local portion of the contact portion between the nanoparticles made of copper or aluminum is elastically deformed, and frictional heat is generated in the local portion of the contact portion. As a result, nanoparticles made of copper or aluminum are bonded together by frictional heat.
On the other hand, when nanoparticles made of nickel come into contact with the flat surface of metal or alloy flake powder, the local portion of the contact portion on the flat surface is preferentially elastically deformed. At this time, frictional heat is generated locally at the contact portion. On the other hand, since nickel nanoparticles have a large Young's modulus, the local contact area of the nanoparticles does not undergo elastic deformation, but generates frictional heat. Therefore, due to the frictional heat between the two, the flat surfaces of the flake powder made of metal or alloy are joined together by a collection of nanoparticles made of nickel. Further, frictional heat is generated locally at the contact area between nanoparticles made of nickel. As a result, the nanoparticles made of nickel are bonded together by frictional heat.
As a result, the flat surfaces of the metal or alloy flake powder are joined together by a collection of nanoparticles made of copper, aluminum, or nickel. Furthermore, nanoparticles are also bonded together by frictional heat.
By the way, the heat resistance temperature of metal or alloy flake powder is determined by the softening point, and the lowest softening point of aluminum is 350°C. Further, since metals or alloys made of silver, copper, brass, nickel, or aluminum do not have low-temperature brittleness, they can be used at extremely low temperatures. Therefore, a sheet made of a collection of flake powder whose flat surfaces are joined together can be used in harsh environments such as high temperatures, extremely low temperatures, ultra-vacuum, and ultra-high pressure where oil lubrication is not applicable. Furthermore, the load resistance is as high as 600 MPa or more. Therefore, when the collection of flake powder is compressed, the flat surface of the flake powder resists the compressive stress.
As mentioned above, the softening point of aluminum is as low as 350°C. On the other hand, when joining the flat surfaces of aluminum flake powder with a collection of copper, aluminum, or nickel nanoparticles, the contact area of the copper, aluminum, or nickel nanoparticles with the flat surfaces is Extremely small. Therefore, even when the flat surfaces of aluminum flake powder are joined together by a collection of aluminum nanoparticles, the contact portion between the aluminum flat surfaces and the aluminum nanoparticles does not soften.
Although the metal or alloy flake powder has a smooth surface, the surface is not flat and has unique undulations. On the other hand, the size of copper, aluminum, or nickel nanoparticles is nearly two orders of magnitude smaller than the irregularities on the flat surface. For this reason, regardless of the flatness of the flat surfaces and the unevenness of the surfaces, the entire surfaces of the flat surfaces are joined through the collection of copper, aluminum, or nickel nanoparticles. In addition, aluminum flake powder is flattened using a wet ball mill to form irregularities on its surface. However, the size of copper, aluminum, or nickel nanoparticles is two or more orders of magnitude smaller than the unevenness of the flat surface. Therefore, irrespective of the irregularities on the surfaces of the flat surfaces of the aluminum flake powder, the entire surfaces of the flat surfaces are joined through the collection of copper, aluminum, or nickel nanoparticles.
Incidentally, the thickness of metal or alloy flake powder varies from 0.2 to 1 μm depending on the material, but within the grade of flake powder product used, the thickness deviation is within 0.1 μm. Furthermore, even if the flake powder is made of the same material, the flattening conditions differ depending on the product, so the particle size will vary depending on the product. On the other hand, the density of metals or alloys varies greatly depending on the material. Aluminum is 2.7g/ ^cm3 , silver is 10.5g/ ^cm3 , copper is 9.0g/ ^cm3 , brass is 8.7g/ ^cm3 , and nickel is 8.9g/ ^cm3 . . However, among flake powders, even if the flake powder has the highest density and relatively large flat powder, that is, the density is 10.5 g/ ^cm3 , the particle size is 100 μm, and the thickness is 0.5 μm. Even if it is a silver flake powder consisting of, the weight of the flake powder is only 4.5×10 ⁻⁸ g.
Next, a metal octylate compound that precipitates metal by thermal decomposition will be explained. Carboxylic acid metal compounds have both the first characteristic that the oxygen ion that constitutes the carboxyl group of the carboxylic acid is covalently bonded to the metal ion, and the second characteristic that the carboxylic acid is composed of a saturated fatty acid, in which the metal ion is the largest ion. The distance between the oxygen ion and metal ion that constitute the carboxyl group is longer than the distance between other ions. When a carboxylic acid metal compound with such molecular structural characteristics is heat-treated in the air, when the temperature exceeds the boiling point of the carboxylic acid, the bond between the oxygen ion and the metal ion that constitutes the carboxyl group is first broken. Separates into carboxylic acid and metal. When a carboxylic acid is composed of saturated fatty acids, it does not have an unsaturated structure in which carbon atoms are in excess of hydrogen atoms, so the carboxylic acid absorbs heat of vaporization depending on the molecular weight and number of carboxylic acids. It vaporizes, and when the vaporization is complete, metal is deposited. In addition, the carboxylic acid metal compound is dispersed in methanol up to nearly 10% by weight and is not dissolved in methanol. Therefore, a carboxylic acid metal compound having both of these two characteristics can be used as the organometallic compound described in 5.
Examples of such metal carboxylate compounds include metal octylate compounds, metal laurate compounds, and metal stearate compounds. Note that the boiling point of octylic acid is 228°C, the boiling point of lauric acid is 296°C, and the boiling point of stearic acid is 361°C. Therefore, thermal decomposition of these carboxylic acid metal compounds is completed in an air atmosphere at 290-430°C. Note that among the metal carboxylate compounds, the metal octylate compound has the lowest thermal decomposition temperature, so the metal compound octylate is the most desirable as the metal carboxylate compound. Further, when the octylate metal compound is thermally decomposed in a nitrogen atmosphere, the progress of the thermal decomposition reaction in the nitrogen atmosphere is delayed, and the thermal decomposition temperature rises to 340°C.
Furthermore, carboxylic acid metal compounds are inexpensive industrial chemicals that are easily synthesized. In other words, when a carboxylic acid, which is the most widely used organic acid, is reacted with a strong alkali, an alkali metal carboxylate compound is produced, and when an alkali metal carboxylate compound is reacted with an inorganic metal compound, a carboxylic acid composed of various metals is produced. A metal compound is synthesized. Therefore, it is the cheapest organometallic compound among organometallic compounds.
Next, flake powder consisting of metal or alloy is used as the flat powder described in paragraph 18, copper octylate, aluminum octylate, or nickel octylate is used as the organometallic compound described in paragraph 18, Each phenomenon that occurs when manufacturing a sheet according to the method for manufacturing a sheet made of a collection of flat powder described in 1, and the effects brought about by each phenomenon will be explained.
First, the substance that joins the flat surfaces of the flake powder is a collection of copper, aluminum, or nickel nanoparticles, and the metal octylate compound, which is the raw material for the nanoparticles, is dispersed in methanol to form a liquid phase. It became. Since this liquid is a low viscosity and low density liquid, by continuously performing the second and third treatments, the methanol dispersion of the metal octylate compound is separated into flake powder. It becomes possible to interpose it in the gap between the flat surfaces of.
Second, a homogenizer device is operated within the container, and shock waves are repeatedly generated by the homogenizer device. On the other hand, since the methanol dispersion of the metal octylate compound has a low viscosity and density, a small proportion of the shock wave is consumed when exciting the methanol dispersion of the metal octylate compound, and most of the impact energy is transferred to the flake powder. be efficiently and repeatedly communicated to a group of people. Moreover, as mentioned above, the weight of one flake powder is extremely light. Therefore, even if the flake powder has flat surfaces that overlap each other in a complicated manner, when a shock wave is applied to the flake powder, it will be reliably separated into individual flakes, and the material, shape, and particle size distribution of the flake powder will be separated. Regardless, the methanol dispersion of the metal octylate compound comes into contact with the surface of all the flake powder. Note that the surfaces of the flake powder are all hydrophobic and do not react with the methanol dispersion of the metal octylate compound, and the methanol dispersion of the metal octylate compound comes into contact with the surface of the flake powder.
Third, vibrations are repeatedly applied to the container in three directions: left and right, front and back, and up and down, and finally, vibration is applied in the up and down direction. At this time, the methanol dispersion of the octylate metal compound has a low viscosity and low density, and one flake powder is extremely lightweight, so the methanol dispersion of the octylate metal compound, together with the flake powder, causes vibration acceleration. Move repeatedly in the direction of. When this phenomenon is repeated in three directions (left and right, front and back, and up and down), the soft magnetic flat powder is rearranged with its flat surface facing up, and the flat surfaces overlap each other. Proceed with As a result, the flake powder spreads over the entire bottom surface of the container, and a collection of flat powders whose flat surfaces overlap each other via the methanol dispersion of the metal octylate compound is formed in the shape of the bottom surface on the bottom surface of the container.
Fourthly, since the flake powder separated into individual flakes is superimposed on the flat surfaces of the flake powder via a methanol dispersion of an octylate metal compound, the larger the aspect ratio of the flake powder, the more The amount of flake powder used is reduced. Therefore, even if the flake powder is expensive, the amount of flake powder used is small, so a sheet made of a collection of flake powder can be manufactured at low cost.
Fifth, methanol is vaporized from the collection of flakes in which the flat surfaces of the flakes are overlapped with each other via a methanol dispersion of a metal octylate compound, and the methanol is vaporized between the flat surfaces of the flakes and the surface of the collection of flakes. Then, a collection of fine crystals of the metal octylate compound is precipitated. Furthermore, the entire surface of the flake powder collection is evenly compressed. As a result, the fine crystals are crushed to about 1/5 of the size, and the crushed crystals overlap and accumulate at a high density in the gaps between the flat surfaces and on the surface of the flake powder collection. These crushed microcrystals of octylate metal compound with a size of around 20 nm are the raw material for a collection of copper, aluminum, or nickel nanoparticles with a size of around 10 nm that join the flat surfaces of the flake powder. become.
Sixth, the entire surface of the flake powder collection is uniformly compressed and heated to thermally decompose the crushed fine crystals of the metal octylate compound. At this time, a collection of nanoparticles of copper, aluminum, or nickel with a size of around 10 nm overlap and precipitate all at once at a high density in the gaps between the flat surfaces of the flake powder and on the surface of the collection of flake powder. . Furthermore, the entire surface of the collection of flakes is compressed evenly, and the collection of copper, aluminum, or nickel nanoparticles precipitated at high density is bonded to the flat surface by frictional heat, and the copper, aluminum, or nickel nanoparticles are bonded to the flat surface by frictional heat. Nickel nanoparticles are bonded together by frictional heat. In other words, because clusters of copper, aluminum, or nickel nanoparticles overlap and precipitate at a high density, it becomes difficult for the compressed nanoparticles to move within the nanoparticle cluster, and the nanoparticles that come into contact with the flat surface Frictional heat is generated at the contact area between the nanoparticles and the nanoparticles, and the bonding force caused by the frictional heat causes the copper, aluminum, or nickel nanoparticles to bond to the flat surface. Aluminum or nickel nanoparticles bond together.
Seventhly, flake powder made of silver, copper, brass, nickel, or aluminum can be used as flat powder when producing a sheet made of a collection of flake powder. That is, the thermal decomposition temperature of the metal octylate compound is 290° C. in the air atmosphere. On the other hand, the softening point of any flat powder of silver, copper, brass, nickel, or aluminum is higher than 290°C, and none of the flake powders has low-temperature brittleness, making it possible to use them at extremely low temperatures. Therefore, a sheet made of a collection of flake powder in which the flat surfaces of the flake powder are joined together can be used even in harsh environments such as high temperatures, extremely low temperatures, vacuum, and high pressure. Note that the thermal decomposition temperature of the metal octylate compound in a nitrogen atmosphere is 340°C, which is 50°C higher than that in the air atmosphere. On the other hand, among flake powders made of metals or alloys, aluminum has the lowest softening point at 350°C. Therefore, even if the metal octylate compound is thermally decomposed in a nitrogen atmosphere, aluminum does not soften.
Eighth, the flat surfaces of the flake powder were joined together with a collection of copper, aluminum, or nickel nanoparticles. Both copper and aluminum are metals with excellent electrical conductivity and thermal conductivity among metals or alloys. Therefore, the copper or aluminum nanoparticles do not inhibit the electrical conductivity and thermal conductivity of the metal or alloy flake powder in the sheet in which the flat surfaces of the flake powder are joined together. Additionally, nickel or aluminum nanoparticles are transparent. For this reason, the nickel or aluminum nanoparticles do not lose the color and gloss inherent to the flake powder made of metal or alloy in the sheet in which the flat surfaces of the flake powder are joined together.
Ninth, metal octylate compounds are general-purpose industrial chemicals. Furthermore, since the flat surfaces of the flake powder are bonded together, the amount of flake powder used is small. Furthermore, all eight processes for joining flat surfaces with a collection of copper, aluminum, or nickel nanoparticles are simple processes. Therefore, a sheet made of a collection of flakes can be manufactured using inexpensive materials and at a low cost.
The sheet made of a collection of flake powder produced by the eight treatments described above provides the following effects.
First, regarding a collection of flake powder made of metal or alloy, 6 to 8 nanoparticles of copper, aluminum, or nickel with a size of around 10 nm are piled up on the flat surfaces of the flake powder. Join surfaces. Since the size of the nanoparticles is two or more orders of magnitude smaller than the particle size of the flake powder, the properties of the sheet are dominated by those of the flake powder. Note that both copper and aluminum are metals that have excellent electrical conductivity and thermal conductivity among metals or alloys. Therefore, the bonding layer formed by the collection of nanoparticles does not inhibit the electrical conductivity and thermal conductivity of the flake powder made of metal or alloy in the sheet made of the collection of flake powder. Further, nickel or aluminum nanoparticles have excellent transparency. Therefore, the bonding layer formed by the collection of nanoparticles does not lose the color and gloss inherent to the metal or alloy flake powder in the sheet made of the collection of flake powder.
Second, since a sheet having the shape of the bottom is formed on the bottom of the container, there are no restrictions on the area and shape of the sheet. In addition, all flake powders made of metals or alloys can be subjected to the eight treatments described above, regardless of differences in flake powder oblateness, shape, and particle size distribution. A sheet can be manufactured by bonding the flat surfaces of flake powder with a collection of copper, aluminum, or nickel nanoparticles. Therefore, the present sheet manufacturing method can form a sheet made of a collection of flakes of metal or alloy with versatility.
As explained above, the sheet made of a collection of flake powder produced by the present production method can be formed into a sheet with a wide area using a small amount of flake powder. This sheet has excellent electrical and thermal conductivity, has the color and gloss unique to flake powder, and is also an antistatic sheet, an electromagnetic shielding sheet, and a sheet with excellent lubricity on the surface. .

Surface reflectance and total light transmittance will be explained. When light is incident on a substrate, surface reflection occurs depending on the difference in refractive index between air and the substrate. Therefore, even with transparent glass, loss occurs due to surface reflection, and the total light transmittance is not 100%. Incidentally, a float glass with a thickness of 2 mm has a total light transmittance of about 90% in the wavelength range of visible light. The surface reflectance R on the surface of light that is perpendicularly incident on the base material is calculated by Equation 2 consisting of the refractive index n of the base material and the refractive index m of air. Further, the total light transmittance T is calculated using Equation 3 consisting of the surface reflectance R. Therefore, if the refractive index of the metal is 0.4, the total light transmittance entering the conductive layer will be 67%, and if the refractive index of the metal is 2.4, the total light transmittance entering the conductive layer will be 67%. is 69%, and more than 70% of visible light is incident on the conductive layer.
(Number 2)
R=(n-m) ² /(n+m) ²
(Number 3)
T=(1-R) ²

Next, light scattering will be explained. The Rayleigh scattering equation shown in Equation 4 can be applied to the scattering of light when a collection of particles is irradiated with visible light. In Equation 4, S is a scattering coefficient meaning the scattering ratio, λ is the wavelength of visible light, D is the particle diameter, m is the refractive index of the particle, and π is the circumference. Therefore, the magnitude of the scattering coefficient S depends on the fourth power of the ratio D/λ of the particle diameter D to the wavelength λ of visible light, and also depends on the square of the particle diameter D and the refractive index m. Since the size D of the nanoparticles is nearly two orders of magnitude smaller than the wavelength λ of visible light, the ratio D/λ is small and the particle diameter D is also sufficiently small. Furthermore, the refractive index m of the metal is 0.4 or more and 2.4 or less. Therefore, the scattering coefficient S is extremely small and the conductive layer exhibits high transparency.
(Number 4)
S=4/3・π ⁵ /λ ⁴・D ⁶ {(m ² -1)/(m ² +1)} ²

The method for producing a sheet made of a collection of flat powder described in paragraph 18 is a method for producing a sheet made of a collection of flat insulating powder made of a metal oxide or an inorganic compound, and the metal oxide or inorganic compound The method for producing a sheet made of a collection of flat insulating powder is as follows:
The flat powder described in the 18th paragraph is an insulating flat powder made of a metal oxide or an inorganic compound made of glass, alumina, or hematite, and the organometallic compound described in the 18th paragraph is the metal oxide. A complex consisting of a carboxylic acid metal compound that precipitates an insulating metal oxide having a hardness lower than that of an insulating flat powder made of a substance or an inorganic compound by thermal decomposition, and a metal oxide made of any of the above materials. or an insulating flat powder made of an inorganic compound is used as the flat powder described in paragraph 18, a complex made of the carboxylic acid metal compound is used as the organometallic compound described in paragraph 18, and the flat powder described in paragraph 18 is used. According to a method for producing a sheet consisting of a collection of metal oxides or inorganic compounds, the flat surfaces of the flat insulating powder made of the metal oxide or inorganic compound have a hardness lower than that of the flat insulating powder made of the metal oxide or inorganic compound. manufacturing a sheet consisting of a collection of flat insulating powders made of a metal oxide or an inorganic compound bonded through a collection of nanoparticles made of an insulating metal oxide with a This is a method of manufacturing a sheet made of a collection of flat insulating powder.

First, the insulating flat powder made of metal oxide or inorganic compound used in the present invention will be explained.
The flat powder made of glass and alumina both have high electrical resistivity of 10 ¹⁴ Ωcm or more. Therefore, if the flat surfaces of these flat powders made of metal oxides or inorganic compounds are joined together with a collection of nanoparticles made of insulating metal oxides, an insulating sheet with extremely high insulation resistance is formed. Note that the main components of glass are silicon dioxide and boron oxide, and silicon and boron are metalloid elements, so silicon dioxide and boron oxide are inorganic compounds. Further, other components include metal oxides such as alumina, lead oxide, sodium oxide, potassium oxide, and calcium oxide. Therefore, the glass component consists of a mixture of metal oxides and inorganic compounds. Among glass flake powders, only soda-lime glass has an electrical resistivity of 10 ¹² Ωcm. Further, flat powder of hematite (a substance consisting of the alpha phase of ferric oxide Fe ₂ O ₃ ) has a low electrical resistivity of 10 ⁸ Ωcm. However, if the thickness of the flat hematite powder is submicron and the cross-sectional area of the flat hematite powder is 0.3 μm x 10 μm, the electrical resistance per unit length of the flat powder is 3.3 x 10 ¹⁶ Ω/ It becomes cm. The electrical resistance of the sheet in which the flat surfaces of the flat hematite powder are joined together by a collection of nanoparticles made of insulating metal oxide forms an insulating sheet with extremely high insulation resistance. In other words, a collection of nanoparticles made of an extremely large number of insulating metal oxides that connect the flat surfaces of flat hematite powder forms an electrical resistance in which a collection of nanoparticles made of insulating metal oxides are connected in series. do. Further, the flat powder in which the flat surfaces of hematite are joined through the collection of nanoparticles has an electrical resistance in which the electrical resistance of the flat powder and the electrical resistance of the collection of nanoparticles are connected in parallel. When a huge number of flat powders connected through a collection of nanoparticles form a sheet, the flat powders electrically form parallel connections and series connections and join together. Therefore, a sheet made of a collection of flat hemite powders joined together via a collection of nanoparticles made of an insulating metal oxide becomes an insulating sheet with extremely high insulation resistance. Similarly, a sheet made by bonding flat glass or alumina powder together via a collection of insulating metal oxide nanoparticles also becomes an insulating sheet with extremely high insulation resistance. The flat powder of hematite is a red pigment called red pigment and is a general-purpose flat powder.
As explained above, flat powder made of glass, alumina, or hematite is an excellent raw material for insulating sheets with extremely high insulation resistance.
Here, the characteristics of insulating flat powder made of glass, alumina, and hematite will be explained.
Glass flake powder with an average thickness of 2 to 5 μm and a particle size of 10 to 4000 μm has been commercialized. Furthermore, fine flake powder with an average thickness of 0.4-1.0 μm has also been commercialized. Mohs hardness is 5-6. Further, the material of the glass is C glass or E glass. Flat powder made of alumina is produced by heating scale-like flat powder of boehmite, which is an alumina hydrate, to 500° C. or higher. Three types of flat powder with an aspect ratio of 20-40 and an average particle size of 2 μm, 5 μm, and 9 μm have been commercialized. It has a specific gravity of 3.98 g/cm ³ and a high Mohs hardness of 9. Flat powder made of hematite has a specific gravity of 5.2 g/ ^cm3 , an average particle size ranging from 10 to 20 μm, and an average particle thickness of 0.1 to 0.4 μm. There is. Mohs hardness is 5.5. Note that even if the E glass flat powder has a particle size of 4000 μm, which is extremely large among flat powders, and a thickness of 2 μm, which is relatively thick, the weight of one sheet is only 1.7×10 ⁻⁶ g.
On the other hand, when an excessive compressive stress is applied to the flat surface of insulating flat powder, the flat powder does not deform plastically and suffers brittle fracture. Therefore, when flat surfaces are joined together using a collection of insulating nanoparticles made of metal oxide, the thinner the flat powder is, the more likely it is to undergo brittle fracture. Therefore, when nanoparticles are composed of metal oxides whose insulating metal oxide has a hardness lower than that of flat powder, when a collection of nanoparticles comes into contact with a flat surface, excessive compression occurs on the flat surface. Avoid applying stress.
Here, the hardness of metal oxides will be explained. The metal oxide particles have the highest hardness in the order of aluminum oxide Al ₂ O ₃ , silicon oxide SiO ₂ , tin oxide SnO ₂ , chromium oxide Cr ₂ O ₃ , magnesium oxide MgO and titanium oxide TiO ₂ . Furthermore, the hardness is higher in the order of manganese oxide MnO ₂ , copper oxide CuO, nickel oxide NiO, and zinc oxide ZnO. Therefore, the nanoparticles that join the flat glass powders may be made of an insulating metal oxide that has a hardness lower than that of tin oxide and a Mohs hardness lower than 5. Further, the nanoparticles that join together the flat alumina powders may be made of an insulating metal oxide that has a hardness lower than aluminum oxide and a Mohs hardness lower than 9. Furthermore, the nanoparticles that join the flat hematite powders may be made of an insulating metal oxide that has a hardness lower than that of chromium oxide and has a Mohs hardness lower than 5.5.
Next, a complex made of a carboxylic acid metal compound that precipitates a metal oxide by thermal decomposition will be explained. When a complex made of a carboxylic acid metal compound is heat-treated in an air atmosphere having a temperature of 180-330° C., a metal oxide is precipitated. On the other hand, among the flat powders made of glass, alumina, or hematite, the flat powder with the lowest softening point is the flat powder of glass, and the softening point of glass, which has the lowest softening point among the flat glass powders, is 355. It is ℃. Therefore, the thermal decomposition temperature of the complex made of carboxylic acid metal compound is lower than the softening point of flat powder made of glass, alumina or hematite. Moreover, a complex made of a carboxylic acid metal compound is dispersed in methanol and is not dissolved in methanol. Therefore, a complex consisting of a carboxylic acid metal compound can be used as the organometallic compound described in .
In other words, a complex consisting of a carboxylic acid metal compound in which the carboxylate anion (R-COO ^- ) of a carboxylic acid serves as a ligand and coordinates close to a metal ion is a complex in which the carboxylate anion (R-COO - ) of a carboxylic acid acts as a ligand and coordinates with the metal ion. Since the anion (R-COO ^- ) approaches and forms a coordinate bond, the distance between them becomes shorter. As a result, the distance between the carboxylate anion (R-COO ⁻ ) that is coordinately bonded to the metal ion and the ion that is covalently bonded on the opposite side of the metal ion is the longest. In carboxylic acid metal compounds with such molecular structural characteristics, when the boiling point of the carboxylic acid is exceeded, the bond between the carboxylate anion (R-COO ^- ) and the covalently bonded ion on the opposite side of the metal ion is first broken. It decomposes into metal oxide, which is a compound of metal ions and oxygen ions, and carboxylic acid. When the temperature is further increased, the carboxylic acid absorbs the heat of vaporization and vaporizes, and the vaporization of the carboxylic acid progresses depending on the molecular weight of the carboxylic acid and the number of carboxylic acids that coordinate, and when the vaporization is completed, the metal oxide is Precipitation completes thermal decomposition.
Examples of carboxylic acid metal compounds having such molecular structure characteristics include acetate metal compounds, caprylic acid metal compounds, benzoate metal compounds, and naphthenate metal compounds, in descending order of thermal decomposition temperature. Complexes made of these carboxylic acid metal compounds are thermally decomposed in the air at temperatures of 180-330° C., depending on the boiling point of the carboxylic acid. That is, the boiling point of acetic acid is 118°C, the boiling point of caprylic acid is 237°C, and the boiling point of benzoic acid is 249°C. On the other hand, naphthenic acid is a mixture of saturated fatty acids with a 5-membered ring, and its general formula is C _n H _2n-1 COOH, and its main component is C ₉ H ₁₇ COOH, which has a boiling point of 268°C and a molecular weight of 170. . Therefore, the thermal decomposition temperature of the naphthenic acid metal compound is as high as 330° C. among the complexes made of the carboxylic acid metal compound. Therefore, a metal acetate compound, a metal caprylate compound, a metal benzoate compound, or a metal naphthenate compound can be used as the organometallic compound described in paragraph 18. Note that since the flat powder made of glass, alumina, or hematite is an inorganic compound made of a metal oxide or a metalloid oxide, it does not oxidize even if the temperature is raised to 330° C. in the air.
On the other hand, some metal acetate compounds dissolve in methanol. There is also a metal acetate compound that precipitates an amorphous metal oxide through thermal decomposition. The composition of the amorphous metal oxide is not constant. Such metal acetate compounds cannot be used as raw materials for metal oxide fine particles. Furthermore, among the metal acetate compounds and metal caprylate compounds, there are metal acetate compounds and metal caprylate compounds that precipitate amorphous metal oxides upon thermal decomposition. Such metal acetate compounds or metal caprylate compounds cannot be used as raw materials for metal oxide fine particles. In addition, in metal acetate compounds, metal caprylate compounds, and metal benzoate compounds, oxygen ions approach metal ions and coordinate to form dinuclear complex salts, but they are unstable substances during thermal decomposition. However, there are metal acetate compounds, metal caprylate compounds, and metal benzoate compounds that are difficult to handle during thermal decomposition. In such carboxylic acid metal compounds, naphthenic acid metal compounds are used as a raw material for insulating metal oxide fine particles. Therefore, depending on the substance precipitated by thermal decomposition, a complex made of a carboxylic acid metal compound is used as a raw material for fine crystals.
Furthermore, complexes made of carboxylic acid metal compounds are inexpensive industrial chemicals that can be easily synthesized. That is, when a carboxylic acid is reacted with a strong alkali, a carboxylic acid alkali metal compound is produced. Thereafter, when the alkali metal carboxylate compound is reacted with an inorganic metal compound, a complex made of the metal carboxylate compounds made of various metals is synthesized. Further, the carboxylic acid used as a raw material is an inexpensive organic acid. Therefore, it is the cheapest organometallic compound among organometallic compounds.
Here, a flat powder made of glass, alumina, or hematite is used as the flat powder described in paragraph 18, and nanoparticles of the metal or metal oxide described in paragraph 18 are used as an insulating powder having a hardness lower than that of the flat powder. The effects brought about by a sheet produced according to the method for producing a sheet made of a collection of flat powder described in paragraph 18 will be explained.
First, the material that joins the flat surfaces of the flat powder is a collection of insulating metal oxide nanoparticles that have a hardness lower than that of the flat powder, and furthermore, the material that joins the flat surfaces of the flat powder is a collection of insulating metal oxide nanoparticles, and the material that joins the flat surfaces of the flat powder is a carboxylic acid metal compound that is the raw material for the nanoparticles. The complex consisting of was dispersed in methanol and made into a liquid phase. Since this liquid is a low viscosity and low density liquid, by continuously performing the second and third treatments, the methanol dispersion of the complex consisting of the metal carboxylic acid compound is separated into individual sheets. It becomes possible to interpose the flat powder in the gap between the flat surfaces of the flat powder.
Second, a homogenizer device is operated within the container, and shock waves are repeatedly generated by the homogenizer device. On the other hand, since the methanol dispersion of a complex made of a metal carboxylic acid compound has a low viscosity and low density, the proportion of shock waves consumed when exciting the methanol dispersion of a complex made of a metal carboxylic acid compound is small, and the impact energy is reduced. Much of this is efficiently and repeatedly transmitted to the collection of flat powder. Furthermore, as described above, the weight of one sheet of flat powder is extremely light. Therefore, even if the flat powder has flat surfaces that overlap each other in a complicated manner, when a shock wave is applied to the flat powder, it is reliably separated into individual flat powder. As a result, the methanol dispersion of the complex made of the carboxylic acid metal compound comes into contact with the surface of all the flat powders, regardless of the material, shape, and particle size distribution of the flat powders. In addition, the flat surfaces of any of the flat powders are hydrophobic and do not react with the methanol dispersion of the complex made of the carboxylic acid metal compound, and the methanol dispersion of the complex made of the carboxylic acid metal compound comes into contact with the flat surfaces.
Third, vibrations are repeatedly applied to the container in three directions: left and right, front and back, and up and down, and finally, vibration is applied in the up and down direction. At this time, the methanol dispersion of the complex made of the carboxylic acid metal compound has a low viscosity and low density, and one sheet of flat powder is extremely light. It moves repeatedly in the direction of vibrational acceleration, accompanied by powder. When this phenomenon is repeated in three directions: left and right, front and back, and up and down, the flat powders rearrange and overlap with their flat surfaces facing up in the methanol dispersion of the complex made of the carboxylic acid metal compound. As a result, the flat powder spreads over the entire bottom of the container, and a collection of flat powder with flat surfaces overlapping each other is formed on the bottom of the container in the shape of the bottom through the methanol dispersion of the complex made of carboxylic acid metal compound. be done.
Fourthly, since the flat powder separated into individual flat powders was superimposed with the flat surfaces of the flat powders interposed in a methanol dispersion of a complex made of carboxylic acid metal compounds, the aspect ratio of the flat powders was improved. The larger the size, the less flat flour will be used. Therefore, even if the flat powder is expensive, since the amount of flat powder used is small, a sheet made of a collection of flat powder can be manufactured at low cost.
Fifth, methanol is vaporized from a collection of flat powders made by overlapping the flat surfaces of the flat powders through a methanol dispersion of a complex made of a metal carboxylic acid compound, and the gaps between the flat surfaces and the flat powders are A collection of fine crystals of a complex made of a carboxylic acid metal compound is deposited on the surface of the collection. Furthermore, the entire surface of the flat powder collection is compressed evenly. As a result, the fine crystals are crushed to about 1/5 of the size, and the crushed crystals overlap and accumulate at a high density in the gaps between the flat surfaces and on the surface of the flat powder collection. These crushed microcrystals of the carboxylic acid metal compound complex with a size of around 20 nm are used as raw materials for the collection of metal oxide nanoparticles with a size of around 10 nm that join the flat surfaces of the flat powder. Become.
Sixth, the entire surface of the collection of flat powder is uniformly compressed and heated to thermally decompose the fine crystals of the complex made of the crushed carboxylic acid metal compound. At this time, a collection of metal oxide nanoparticles having a size of around 10 nm overlaps and precipitates all at once at a high density in the gaps between the flat surfaces of the flat powder and on the surface of the collection of flat powder. Furthermore, the entire surface of the collection of flat powder is compressed evenly, and the collection of metal oxide nanoparticles precipitated at a high density is bonded to the flat surface by frictional heat, and the metal oxide nanoparticles are also rubbed together Join by heat. In other words, the collection of metal oxide nanoparticles overlapped and precipitated at a high density, making it difficult for the compressed nanoparticles to move within the collection of nanoparticles, and the contact area of the nanoparticles contacting the flat surface and the nanoparticles Frictional heat is generated at the contact area between the particles, and the bonding force caused by the frictional heat causes the metal oxide nanoparticles to bond to the flat surface, and the bonding force caused by the frictional heat causes the metal oxide nanoparticles to bond to each other. . Note that nanoparticles are composed of insulating metal oxides that have a hardness lower than that of flat powder, so when nanoparticles come into contact with a flat surface, the contact area of the nanoparticles takes priority and is extremely slightly It deforms elastically and no excessive compressive stress is applied to the flat surface. Therefore, flat powder does not undergo brittle fracture. Further, when the nanoparticles come into contact with each other, the contacting portions of the nanoparticles are elastically deformed very slightly, and no excessive compressive stress is applied to the contacting portions of the nanoparticles. Therefore, the collection of nanoparticles is not destroyed. In addition, when compressing the entire surface of a collection of flat powder, the nanoparticles bond to the flat surface with frictional heat, and after the nanoparticles have joined with each other due to frictional heat, if compressive stress is further applied to the collection of flat powder, Since the nanoparticles have been miniaturized to their limit size, a repulsive force is generated on the plate material to which compressive stress is applied, and at this point, the compressive stress applied to the collection of flat powder is stopped.
Seventhly, flat powder made of glass, alumina, or hematite can be used as flat powder when producing a sheet made of a collection of flat powders. That is, the highest thermal decomposition temperature of a complex made of a metal carboxylic acid compound is 330° C. in the air atmosphere. On the other hand, among the flat powders made of glass, alumina, or hematite, the flat powder with the lowest softening point is the flat powder of glass, and the softening point of glass, which has the lowest softening point among the flat glass powders, is 355. It is ℃. Therefore, the thermal decomposition temperature of the complex made of the carboxylic acid metal compound is lower than the softening point of the flat powder. Therefore, a sheet made of a collection of flat powders in which the flat surfaces of the flat powders are joined together can be used in harsh environments such as high temperatures, extremely low temperatures, vacuum, and high pressure. Note that among flat powders made of glass, alumina, or hematite, the flat powder with the lowest melting point is glass flake powder, and the melting point of glass flake powder is as high as 1200° C. or higher. Furthermore, even if a sheet made of a collection of flat powder is heated above the softening point of the flat powder, the sheet made of a collection of flat powder cannot be returned to its original temperature unless stress that deforms the flat powder is applied to the sheet. For example, a sheet consisting of a collection of flat powder exhibits its original properties. For this reason, sheets of flat powder can be used at very high temperatures. Note that among metal oxide nanoparticles, the metal oxide having the lowest melting point is tin oxide, which has a melting point of 1630°C.
Eighth, the flat surfaces of the flat powder were joined together with a collection of insulating metal oxide nanoparticles. A collection of nanoparticles made of a very large number of insulating metal oxides that connect the flat surfaces of the flat powder forms an electrical resistance in which the collection of nanoparticles made of insulating metal oxides are connected in series. Further, flat powder whose flat surfaces are joined to each other through a collection of nanoparticles has an electrical resistance in which the electrical resistance of the flat powder and the electrical resistance of the collection of nanoparticles are connected in parallel. When a huge number of flat powders connected through a collection of nanoparticles form a sheet, the flat powders electrically form parallel connections and series connections and join together. Therefore, a sheet made of a collection of flat powder becomes an insulating sheet with extremely high insulation resistance.
Ninth, complexes made of carboxylic acid metal compounds are general-purpose industrial chemicals. Furthermore, since the flat surfaces of the flat powder are joined together, the amount of flat powder used is small. Furthermore, all eight processes for joining flat surfaces with a collection of metal oxide nanoparticles are simple processes. Therefore, an insulating sheet made of a collection of flat powder and having high insulation resistance can be manufactured using inexpensive materials and at a low cost.
The sheet made of the above-described collection of powder flakes provides the following effects.
First, regarding a collection of flat powders made of glass, alumina, or hematite, 6 to 8 insulating metal oxide nanoparticles with a hardness lower than that of the flat powder are piled up between the flat surfaces of the flat powder. and join the flat surfaces together. Since the size of the nanoparticles is two or more orders of magnitude smaller than the particle size of the flat powder, the properties of the sheet become predominantly those of flake powder. Further, the bonding layer formed by the collection of nanoparticles forms an insulating layer with high insulation resistance. Therefore, in a sheet made of a collection of insulating flat powder, the metal oxide nanoparticles contribute to further increasing the insulation resistance of the sheet.
Second, since a sheet having the shape of the bottom is formed on the bottom of the container, there are no restrictions on the area and shape of the sheet. In addition, all flat powders made of glass, alumina, or hematite can be subjected to the eight treatments described above, regardless of differences in flatness ratio, shape, and particle size distribution. It is possible to produce a sheet in which the flat surfaces of are joined together by a collection of nanoparticles made of insulating metal oxide. Therefore, the present sheet manufacturing method can form an insulating sheet with high insulation resistance made of a collection of flat powders with versatility for flat powders made of glass, alumina, or hematite.
As explained above, the sheet made of a collection of flat powder produced by the present manufacturing method can be formed with a large area using a small amount of flat powder. This sheet becomes an insulating sheet with high insulation resistance.

The method for producing a sheet made of a collection of flat powder described in paragraph 18 produces a sheet made of a collection of inorganic bright pigments in which the surface of flat powder made of glass or aluminum is coated with a film made of metal or metal oxide. A method for producing a sheet made of a collection of inorganic glitter pigments includes:
The flat powder described in paragraph 18 is an inorganic bright pigment in which the surface of the flat powder made of glass or aluminum is coated with a film made of a metal or metal oxide, and the organometallic compound described in paragraph 18 is an inorganic glitter pigment made of glass or aluminum. It is aluminum octylate precipitated by thermal decomposition, the inorganic bright pigment is used as the flat powder described in paragraph 18, the aluminum octylate is used as the organometallic compound described in paragraph 18, and the aluminum octylate is used as the organometallic compound described in paragraph 18. According to a method for producing a sheet made of a collection of flat powder, a sheet made of a collection of the inorganic glitter pigments in which the flat surfaces of the inorganic glitter pigments are bonded to each other via a collection of nanoparticles made of aluminum is manufactured. This is a method for producing a sheet consisting of a collection of inorganic bright pigments.

First, the inorganic bright pigment used in the present invention, which is obtained by coating the surface of flat powder made of glass or aluminum with a film made of metal or metal oxide, will be explained.
An inorganic bright pigment with excellent brightness, made by coating the surface of flat glass or aluminum powder with metals such as gold, silver, nickel, or metal oxides such as titanium oxide or iron oxide using an electroless plating method. There is. The glitter pigment is made by coating glass flake powder with titanium oxide, which is made of glass flake powder with a plate thickness of 1 μm and an average particle size of 20-80 μm, and can be colored white, yellow, or red depending on the thickness of the titanium oxide coating. Glitter pigments that reflect five colors: , blue, and green have been commercialized. In addition, a glittering pigment that reflects a silver color has been commercialized by coating the surface of glass flake powder with a plate thickness of 1 to 5 μm and an average particle size of 25 to 480 μm with a silver film. Furthermore, a glittering pigment made by coating glass flake powder with iron oxide (hematite made of α-Fe ₂ O ₃ ) is made of glass flake powder with a plate thickness of 1 μm and an average particle size of 30 μm and 80 μm. , bright pigments have been commercialized that reflect five colors, yellow, bronze, copper, and russet, depending on the thickness of the iron oxide coating. In addition, a glittering pigment that reflects gold is produced by coating glass flake powder with a plate thickness of 1 μm and average particle diameters of 30 μm and 80 μm with a gold film. Furthermore, glitter pigments made by coating flat aluminum powder with titanium oxide can be produced in different colors, such as yellow, red, orange, or green, depending on the thickness of the titanium oxide coating, similar to glitter pigments made by coating glass flakes with titanium oxide. Glitter pigments that reflect four colors have been commercialized. The flat powder of such inorganic bright pigments is extremely light in weight.
If the flat surfaces of the flat powder of an inorganic bright pigment can be joined with a transparent substance without damaging the metal or metal oxide coating, the color reflected from the bright pigment will not be lost and the inorganic brightness will be maintained. A sheet consisting of a collection of flat pigment powders can be created. Furthermore, if multiple types of bright pigments that reflect different colors can be used and the flat surfaces of flat powders of multiple types of bright pigments can be joined with a transparent substance, it is possible to combine the flat surfaces of flat powders of multiple types of bright pigments. Depending on the combination, the color tones emitted by the collection of flat powders of the plurality of types of bright pigments can be changed into various tones. Examples of such transparent nanoparticles include nanoparticles made of nickel and aluminum described in paragraph 25. In a collection of aluminum nanoparticles, a part of the light rays that make up visible light is reflected by the surface of the collection of aluminum nanoparticles, emitting a color corresponding to this ray, but the collection of aluminum nanoparticles is transparent. have. Furthermore, in the case of a collection of nickel nanoparticles, a collection of aluminum nanoparticles is nearly colorless and transparent. The collection of nanoparticles made of aluminum or nickel maintains transparency and joins the flat surfaces of the flat powder of the inorganic bright pigment. Therefore, the color reflected by the inorganic bright pigment is not lost.
Next, the material of the nanoparticles that join the flat surfaces of the flat powder of the inorganic bright pigment will be explained.
The film covering the surface of the flat powder made of glass or aluminum is a metal such as gold, silver, or nickel, or a metal oxide such as titanium oxide or iron oxide. Among these coating-forming substances, gold has the lowest hardness, with a Mohs hardness of 2.5, and silver has a Mohs hardness of 2.7. Further, the Mohs hardness of titanium oxide is 5.5-6, and the Mohs hardness of hematite is 5.5. On the other hand, the Mohs hardness of aluminum is 2.9, and the Mohs hardness of nickel is 3.5. On the other hand, the Young's modulus of gold is 78 GPa, silver is 82.7 GPa, aluminum is 69 GPa, nickel is 204 GPa, titanium oxide is 300 GPa, and hematite is 160 GPa. By the way, when a collection of nanoparticles comes into contact with the flat surface of flat powder covered with a film of metal or metal oxide, the nanoparticles are as small as around 10 nm, but flake powder is the thinnest among the flat powders. The thickness of the powder is 100 times the size of the nanoparticle, and the area of the flat powder, which has the narrowest surface area, is 2000 times the size of the nanoparticle. Therefore, the contact area between the nanoparticles and the flat surface of the flat powder is extremely small. Furthermore, the area where nanoparticles come into contact with each other is also extremely small. Gold, silver, and aluminum, on the other hand, are soft metals with excellent ductility and malleability. Therefore, the Young's modulus of soft metals is small. Therefore, when the gold or silver coating and the nanoparticles come into contact, a local portion of the contact portion of the gold or silver coating undergoes elastic deformation. At this time, frictional heat is generated locally at the contact portion. On the other hand, if the nanoparticles are made of aluminum, since aluminum is also a soft metal with a small Young's modulus, the local contact portions of the nanoparticles will be elastically deformed. At this time, frictional heat is generated locally at the contact portion. Frictional heat between the two causes the gold or silver coating to bond to the aluminum nanoparticles. On the other hand, the Mohs hardness of nickel is higher than that of aluminum, and the Young's modulus of nickel is larger than that of aluminum. Therefore, when the nanoparticles are subjected to stress, aluminum nanoparticles are more likely to undergo elastic deformation than nickel nanoparticles. For this reason, when the flat surfaces of the flat powder covered with the nickel film are joined together using a collection of aluminum nanoparticles, the local contact portions of the nanoparticles are preferentially elastically deformed. At this time, frictional heat is generated locally at the contact portion. On the other hand, the local contact portion of the nickel film does not undergo elastic deformation and generates heat. The nickel coating and aluminum nanoparticles bond together due to frictional heat between the two. Furthermore, a coating made of titanium oxide or iron oxide, similar to a coating made of nickel, is used when the flat surfaces of flat powder covered with a coating of titanium oxide or iron oxide are bonded together using a collection of aluminum nanoparticles. , local contact areas in the nanoparticles are preferentially elastically deformed. At this time, frictional heat is generated locally at the contact portion. On the other hand, the local contact portion of the titanium oxide or iron oxide film does not undergo elastic deformation and generates heat. The titanium oxide or iron oxide coating and the aluminum nanoparticles are bonded together by the frictional heat between the two. It should be noted that when the flat surfaces of flat powder covered with titanium oxide or iron oxide coating are joined together using a collection of nickel nanoparticles, the Young's modulus of nickel is larger than that of aluminum, and the iron oxide is larger than the Young's modulus of , the amount of elastic deformation in nickel nanoparticles is smaller than the amount of elastic deformation in aluminum nanoparticles. Therefore, the possibility of damaging the iron oxide film cannot be denied. Therefore, when bonding the flat surfaces of flat glass or aluminum powder through a collection of nanoparticles without damaging the metal or metal oxide film, it is necessary to bond the flat surfaces of glass or aluminum powder to each other without damaging the metal or metal oxide film. It is preferable to bond with a collection of nanoparticles made of aluminum.
Here, the flat powder of the inorganic bright pigment is used as the flat powder described in paragraph 18, the metal or metal oxide nanoparticles described in paragraph 18 are used as nanoparticles made of aluminum, and the flat powder described in paragraph 18 is used as the flat powder described in paragraph 18. The effects brought about by a sheet manufactured according to a method for manufacturing a sheet made of a collection of powder will be explained.
First, a collection of nanoparticles made of aluminum was used as the substance that joins the flat surfaces of flat powder of an inorganic bright pigment, and aluminum octylate, which is the raw material for the nanoparticles, was dispersed in methanol to form a liquid phase. Since this liquid is a low-viscosity and low-density liquid, by continuously performing the second and third treatments, the methanol dispersion of aluminum octylate is separated into individual sheets with inorganic brightness. It becomes possible to interpose the pigment in the gap between the flat surfaces of the flat pigment powder.
Second, a homogenizer device is operated within the container, and shock waves are repeatedly generated by the homogenizer device. On the other hand, since the methanol dispersion of aluminum octylate has a low viscosity and low density, the proportion of shock waves consumed when exciting the methanol dispersion of aluminum octylate is small, and most of the impact energy is transferred to the inorganic bright pigment. It is efficiently and repeatedly transmitted to the collection of flat powder. Moreover, the weight of one sheet of flat powder is extremely light. Therefore, even if the flat powder has flat surfaces that overlap each other in a complicated manner, when a shock wave is applied to the flat powder, it is reliably separated into individual flat powder. As a result, the methanol dispersion of aluminum octylate is present on the surface of all flat powder coatings, regardless of the material of the flat powder of the inorganic bright pigment, the material of the coating, the thickness of the coating, the shape of the flat powder, and the particle size distribution. Contact. In addition, in any of the flat powders, the coating on the flat surface is hydrophobic and does not react with the methanol dispersion of aluminum octylate, and the methanol dispersion of aluminum octylate comes into contact with the coating on the flat surface.
Third, vibrations are repeatedly applied to the container in three directions: left and right, front and back, and up and down, and finally, vibration is applied in the up and down direction. At this time, since the methanol dispersion of aluminum octylate has a low viscosity and low density, and one sheet of flat powder is extremely light, the methanol dispersion of aluminum octylate, together with the flat powder, moves in the direction of vibration acceleration. Move repeatedly. When this phenomenon is repeated in three directions: left and right, front and back, and up and down, the flat powders rearrange and overlap with their flat surfaces facing up in the methanol dispersion of aluminum octylate. As a result, the flat powder of the inorganic bright pigment spreads over the entire bottom of the container, and a collection of flat powder of the inorganic bright pigment whose flat surfaces overlap each other through the methanol dispersion of aluminum octylate spreads over the bottom of the container. , formed as the shape of the bottom surface.
Fourthly, the flat powder separated into individual flat powders was superimposed with the flat surfaces of the flat powders via a methanol dispersion of aluminum octylate, so the larger the aspect ratio of the flat powder, the more flat the powder. The amount of powder used is reduced. Therefore, even if the flat powder is expensive, since the amount of flat powder used is small, a sheet made of a collection of flat powder can be manufactured at low cost.
Fifth, methanol is vaporized from a collection of flat powders made by overlapping the flat surfaces of the flat powders through a methanol dispersion of aluminum octylate, and is applied to the gaps between the flat surfaces and the surface of the collection of flat powders. , a collection of fine crystals of aluminum octylate is precipitated. Furthermore, the entire surface of the flat powder collection is compressed evenly. As a result, the fine crystals are crushed to about 1/5 of the size, and the crushed crystals overlap and accumulate at a high density in the gaps between the flat surfaces and on the surface of the flat powder collection. The crushed aluminum octylate microcrystals having a size of approximately 20 nm become a raw material for a collection of aluminum nanoparticles having a size of approximately 10 nm that join the flat surfaces of the flat powder.
Sixth, the entire surface of the flat powder collection is uniformly compressed and heated to thermally decompose the crushed fine crystals of aluminum octylate. At this time, a collection of aluminum nanoparticles having a size of about 10 nm overlaps and precipitates all at once at a high density in the gaps between the flat surfaces of the flat powder and on the surface of the collection of flat powder. Furthermore, the entire surface of the collection of flat powder is compressed evenly, and the collection of aluminum nanoparticles precipitated at high density is bonded to the flat surface by frictional heat, and the aluminum nanoparticles are also bonded to each other by frictional heat. . In other words, as a collection of aluminum nanoparticles overlapped and precipitated at a high density, it became difficult for the compressed nanoparticles to move in the collection of nanoparticles, and the contact area of the nanoparticles that contacted the flat surface and the nanoparticles Frictional heat is generated at the contact area, and the bonding force due to the frictional heat causes the aluminum nanoparticles to bond to the flat surface, and the bonding force due to the frictional heat causes the aluminum nanoparticles to bond to each other. Note that nanoparticles are composed of aluminum, which has low hardness and a small Young's modulus, so when the nanoparticles come into contact with a flat surface, the contact area of the nanoparticles undergoes extremely slight elastic deformation, causing the coating surface of the flat surface to deform. Excessive compressive stress is not applied to the Therefore, the coating is not damaged. Further, when the nanoparticles come into contact with each other, the contacting portions of the nanoparticles are elastically deformed very slightly, and no excessive compressive stress is applied to the contacting portions of the nanoparticles. Therefore, the collection of nanoparticles is not damaged either. In addition, when compressing the entire surface of a collection of flat powder, the nanoparticles bond to the flat surface with frictional heat, and after the nanoparticles have joined with each other due to frictional heat, if compressive stress is further applied to the collection of flat powder, Since the nanoparticles have been miniaturized to their limit size, a repulsive force is generated on the plate material to which compressive stress is applied, and at this point, the compressive stress applied to the collection of flat powder is stopped.
Seventhly, the flat powder of an inorganic bright pigment can be used as a flat powder when producing a sheet made of a collection of flat powders. That is, the thermal decomposition temperature of aluminum octylate is 290° C. in the air atmosphere. On the other hand, the heat resistance of a film formed on the surface of a flat powder of an inorganic glitter pigment made of a metal such as gold, silver, or nickel, or a metal oxide such as titanium oxide or iron oxide is significantly higher than 290°C. expensive. Therefore, a sheet made of a collection of flat powders in which the flat surfaces of the flat powders are joined together can be used in harsh environments such as high temperatures, extremely low temperatures, vacuum, and high pressure.
Eighth, the flat surfaces of the flat powder of the inorganic bright pigment were joined together with a collection of aluminum nanoparticles that were transparent, had low hardness, and had a small Young's modulus. For this reason, the flat surfaces of the flat powder of the inorganic bright pigment can be bonded together using a collection of aluminum nanoparticles without damaging the coating made of metal or metal oxide. As a result, a sheet made of a collection of flat powder of the inorganic glitter pigment can be created without losing the color reflected from the glitter pigment. Furthermore, by using multiple types of bright pigments that reflect different colors, and by joining the flat surfaces of the flat powder of the multiple types of bright pigments with a collection of aluminum nanoparticles, multiple types of bright pigments can be created. Depending on the combination of glitter pigments, the color tone emitted by the collection of flat powders of the plurality of types of glitter pigments can be changed into various tones.
Ninth, aluminum octylate is a general purpose industrial chemical. Furthermore, since the flat surfaces of the flat powder are joined together, the amount of flat powder used is small. Furthermore, all eight processes for joining flat surfaces with a collection of aluminum nanoparticles are simple processes. Therefore, a sheet consisting of a collection of flat powder of an inorganic bright pigment can be produced using inexpensive materials and at a low cost without losing the color reflected from the bright pigment.
Furthermore, further effects can be obtained when the flat surfaces of the flat powder of the inorganic bright pigment are joined together with a collection of aluminum nanoparticles.
First, the surface of the collection of flat powder of the inorganic bright pigment has irregularities based on the size of the nanoparticles. Since the number of nanoparticles is enormous, the total surface area of the surface irregularities has an enormous surface area, and becomes a surface close to a so-called fractal surface. When a droplet comes into contact with the surface of such a collection of flat powder of inorganic bright pigment, the surface tension of the droplet prevents the liquid from penetrating into the nanoparticle-sized unevenness, and the droplet's liquid surface becomes extremely large. makes point contact with the convex part of the nanoparticle. As a result, the surface of the aggregate of the flat powder of the inorganic bright pigment exhibits super water repellency with a contact angle close to 180 degrees, providing water repellency, oil repellency, and stain resistance.
Second, the surface of the collection of flat powder of the inorganic bright pigment has electrical conductivity and thermal conductivity close to that of aluminum that constitutes the nanoparticles. Therefore, the collection of flat powder of inorganic bright pigment has antistatic function, electromagnetic wave shielding function, and heat dissipation property.
As explained above, since the surface of the collection of flat powder of the inorganic bright pigment is covered with the collection of aluminum nanoparticles, the size and material of the aluminum nanoparticles cannot be obtained with the inorganic bright pigment. Excellent effects are brought to the sheet.

FIG. 2 is an explanatory diagram schematically showing a state in which the flat surfaces of flat iron powder are joined by a collection of nickel nanoparticles.

Example 1
In this example, flat iron powder obtained by flattening reduced iron powder was used as the soft magnetic flat powder. Produce a sheet consisting of a collection. Flat iron powder MG150D manufactured by JFE Steel Corporation was used as the flat iron powder. This flat iron powder has a large average particle size of 100 μm and a very thick thickness of 10-20 μm. This is because, although the particles of reduced iron powder are relatively large, the Vickers hardness of reduced iron powder is as high as 160-200 HV, making it difficult to flatten.
First, 42 g (equivalent to 0.12 mol) of nickel octylate Ni (C ₇ H ₁₅ COO) ₂ (e.g., a product of Fuji Film Wako Pure Chemical Industries, Ltd.) was dispersed in methanol at a weight ratio of 10%. Ta. Thereafter, a methanol dispersion of nickel octylate was filled into a container measuring 20 cm x 20 cm x 1.5 cm (depth), and 40 g of flat iron powder was put into the container. Thereafter, ultrasonic vibrations of 20 kHz were applied to the methanol dispersion of nickel octylate in the container for 2 minutes using an ultrasonic homogenizer (for example, LUH300, a product of Yamato Scientific Co., Ltd.). Furthermore, the ultrasonic homogenizer device was removed from the container, and vibration acceleration of 0.3 G in three directions was repeatedly applied to the container, so that the flat surfaces of the flat iron powder overlapped with each other in the container via the methanol dispersion of nickel octylate. A collection of the flat iron powder was prepared.
Next, the temperature of the container was raised to 65°C, methanol was vaporized from the methanol dispersion of nickel octylate, and nickel octylate crystals were formed on the surface of the collection of flat iron powder and in the gaps between the flat surfaces of the flat iron powder. A collection of these was precipitated. Thereafter, a plate material of 20 cm x 20 cm x 2 mm (thickness) was placed over the surface of the collection of flat iron powder, and further, five weights of 10 kg were placed on the plate material at equal intervals.
Further, the container was placed in a heat treatment apparatus in an air atmosphere, the temperature was raised to 290°C, and the container was left at 290°C for 1 minute. Thereafter, vibration acceleration of 0.4 G in three directions was applied to the container, and the collection of flat iron powder inside the container was peeled off from the container.
Next, the surface and side surfaces of the sample were observed using an electron microscope. As the electron microscope, an extremely low acceleration voltage SEM manufactured by JFE Techno Research Co., Ltd. was used. This device is capable of surface observation using extremely low accelerating voltages starting from 100V, and has the feature of directly observing the surface of a sample without forming a conductive film on the sample.
First, a secondary electron beam between 900 and 1000V of the reflected electron beam was taken out and subjected to image processing. Three flat surfaces of flat powder having a thickness of 10-20 μm were stacked on top of each other to form a 20 cm x 20 cm sheet having a thickness of approximately 45 μm. Furthermore, six nanoparticles each having a size of about 10 nm were stacked on the surface of the collection of flat powders and in the gaps between the flat surfaces of the flat powders. Furthermore, the energy between 900 and 1000 V of the reflected electron beam was extracted and image processed, and the quality of the material was observed based on the shading of the image. Since no density was observed, it was found that both the flat powder and the nanoparticles were formed from a single element. Next, the energy and intensity of characteristic X-rays were image-processed to analyze the elements. It was found that the flat powder was iron atoms and the nanoparticles were nickel atoms. Therefore, the collection of flat iron powders was joined to each other on their flat surfaces via the collection of nickel nanoparticles, and the collection of flat iron powders formed a sheet. Note that the depth of the electromagnetic wave skin of reduced iron powder at 100 kHz is 50 μm. Therefore, a sheet having a thickness of around 45 μm effectively absorbs electromagnetic wave noise around 100 kHz by using a small amount of flat powder made of reduced iron powder. FIG. 1 schematically shows a part of the side surface of a sheet consisting of a collection of flat iron powders joined together on their flat surfaces via collections of nickel nanoparticles. 1 is flat iron powder, and 2 is nickel nanoparticles.
Furthermore, the magnetic shielding performance of the produced sheet was evaluated. For comparison, a cold rolled steel plate with a thickness of 45 μm was used. A shield box having a rectangular parallelepiped shape with sides of 100 mm was created using both a sheet and a cold rolled steel plate. The above-mentioned shield box is placed inside the Helmholtz coil placed in the magnetic shield room, and the external magnetic field generated by the Helmholtz coil and the internal magnetic field at the center position of the shield box are measured, and the performance S of the magnetic shield is calculated using the formula: It was evaluated as 5. The magnetic sensor that measures the magnetic field was installed inside the shield box through a hole made in the shield box. The sample had a magnetic shielding performance S value of 7 dB, which was about 3 dB better than the cold rolled steel sheet. As a result, it was found that the produced sheet had an excellent magnetic shielding effect.
(Number 5)
S=20・log((external magnetic field)/(internal magnetic field))
Next, the sheet's ability to absorb electromagnetic noise was evaluated. On a board on which a microstrip line with a length of 220 mm, a width of 30 mm, and a characteristic impedance adjusted to 50 Ω has been constructed, align the length direction of the sheet with the length direction of the microstrip line, and align the centers of each. A magnetic sheet was placed to absorb noise. Thereafter, S parameters were measured using a network analyzer (product N5230A, manufactured by Agilent Technologies, Inc.) connected to the microstrip line. Note that from the S parameter _S11 due to reflection and the S parameter _S12 due to transmission, the transmission loss in the microstrip line becomes the amount of absorption of electromagnetic waves according to the following equation 6.
The measurement results showed that the absorption amount was 12% at 100 kHz, 24% at 800 kHz, and 13% at 10 MHz. The sheet had an absorption of 12% or more in the 100 kHz to 10 MHz frequency band.
(Number 6)
Reflection amount (dB) = 20・log | S ₁₁ |
Transmission amount (dB) = 20・log | S ₁₂ |
Absorption amount (%) = (1 - | S ₁₁ | ² - | S ₁₂ | ² ) × 100

Example 2
In this example, flat permalloy powder is used as the soft magnetic flat powder, and a sheet is manufactured from a collection of flat permalloy powder in which the flat surfaces of the flat permalloy powder are joined via a collection of nickel nanoparticles. Permalloy flat powder containing 50% nickel (for example, a product developed by Sanyo Special Steel) was used as the flat permalloy powder. This flat powder has an oblateness of 38 and an average particle size of 14 μm. As described above, the average thickness of the flat permalloy powder is extremely thin, and the average particle size is also small. Further, the imaginary part of the complex magnetic permeability rises sharply from around 100 MHz, has a peak value of 8.8 at 3.3 GHz, decreases from around 4 GHz, and has a value of 3.5 at 10 GHz. Therefore, in the frequency band of 1-8 GHz, the imaginary part of the complex magnetic permeability has a value of 5 or more. On the other hand, in a DC magnetic field, the initial relative magnetic permeability is 1×10 ⁴ and the maximum relative magnetic permeability is as large as 1.4×10 ⁵ .
First, 21 g (corresponding to 0.08 mol) of nickel octylate used in Example 1 was dispersed in methanol at a weight ratio of 10%. Thereafter, a methanol dispersion of nickel octylate was filled into a container measuring 12 cm x 12 cm x 2 cm (depth), and 18 g of flat permalloy powder was put into the container. Thereafter, ultrasonic vibration of 20 kHz was applied to the methanol dispersion of nickel octylate in the container for 2 minutes using the ultrasonic homogenizer used in Example 1. Furthermore, the ultrasonic homogenizer device was removed from the container, and vibration acceleration of 0.2 G in three directions was repeatedly applied to the container, so that the flat surfaces of the flat permalloy powder overlapped with each other in the container via the methanol dispersion of nickel octylate. A collection of the flat permalloy powder was prepared.
Next, the temperature of the container was raised to 65°C, methanol was vaporized from the methanol dispersion of nickel octylate, and nickel octylate crystals were formed on the surface of the collection of flat permalloy powder and in the gaps between the flat surfaces of the flat permalloy powder. A collection of these was precipitated. Thereafter, a plate of 12 cm x 12 cm x 3 cm (thickness) was placed over the surface of the collection of flat iron powder, and five weights of 6 kg were placed on the plate at equal intervals.
Further, the container was placed in a heat treatment apparatus in an air atmosphere, the temperature was raised to 290°C, and the container was left at 290°C for 1 minute. Thereafter, vibration acceleration of 0.3 G in three directions was applied to the container, and the collection of flat iron powder inside the container was peeled off from the container.
Next, as in Example 1, the surface and side surfaces of the sheet were observed using an electron microscope. A material with a thickness of 0.4-0.5 μm was laminated in 10 layers through a collection of nanoparticles each having a size of around 10 nm. This material was a permalloy because it was composed of nickel and iron atoms. Furthermore, since the nanoparticles were composed of nickel atoms, they were nickel nanoparticles. Note that the skin depth of permalloy at 1 GHz is 5.0 μm, so a sheet with a thickness of 4-5 μm can effectively suppress electromagnetic noise around 1 GHz by using a small amount of flat permalloy powder. Absorb.
Furthermore, the magnetic shielding performance of the sheet was evaluated in the same manner as in Example 1. For comparison, a 5 μm thick sheet made of permalloy containing 47% nickel was used. Similarly to Example 1, a rectangular parallelepiped-shaped shield box with sides of 100 mm was created using a sheet and a permalloy sheet. The sample had a magnetic shielding performance S value of 40 dB, which was about 5 dB better than the 47Ni permalloy sheet. As a result, the sample provides an excellent magnetic shielding effect.
Next, the ability of the sheet to absorb electromagnetic noise was evaluated in the same manner as in Example 1. The absorption amount was 8% at 1 GHz, 10% at 3 GHz, and 8% at 6.8 GHz. Therefore, the sample had an absorption amount of 8% or more in the frequency band from 1 GHz to 7 GHz. However, the amount of electromagnetic waves absorbed is small. This is due to the fact that the average particle diameter of Permalloy flat powder is small and the flatness is low.

Example 3
In this example, flat sendust powder is used as the soft magnetic flat powder, and a sheet is produced which is made of a collection of flat sendust powder in which the flat surfaces of the flat sendust powder are bonded to each other via a collection of nickel nanoparticles.
Sendust's flat powder is a product of Sanyo Special Steel's high permeability type A, with a relatively large average particle size of 50 μm or less, a thickness of about 1 μm, and an oblateness close to 50. Compared to conventional sendust, this flat powder has a trace amount of nickel added and a reduced amount of silicon, making flattening easier, increasing the particle size of the flat powder, and increasing the complex magnetic permeability. The characteristics have been greatly improved. The imaginary part of the complex magnetic permeability has a value of 60 or more in the 10-70 MHz frequency band, and a value of 30 or more in the 3-100 MHz frequency band. Compared to the permalloy flat powder used in Example 2, the flat powder has a larger particle size and is thicker. Furthermore, the frequency band in which the oblateness is large and the value of the imaginary part of the complex magnetic permeability exceeds 10 times extends from 3 to 100 MHz. Furthermore, the real part of the complex magnetic permeability has a large value of 200 at 1-3 MHz. Therefore, it is effective as a countermeasure against electromagnetic wave noise in a frequency band of 3 MHz or higher. On the other hand, the magnetic permeability in a DC magnetic field is two or more orders of magnitude lower than that of the permalloy used in Example 2, so the magnetic shielding effect is low. Note that the skin depth of the flat sendust powder at 3 MHz is 20 μm.
First, 42 g (corresponding to 0.12 mol) of the nickel octylate used in Example 1 was dispersed in methanol at a weight ratio of 10%. Incidentally, the flat powder of Sendust is thicker and has a larger average particle size than flat perme powder. Thereafter, a methanol dispersion of nickel octylate was filled into a container measuring 20 cm x 20 cm x 1.5 cm (depth), and 40 g of flat sendust powder was put into the container. Thereafter, ultrasonic vibration of 20 kHz was applied to the methanol dispersion of nickel octylate in the container for 2 minutes using the ultrasonic homogenizer used in Example 1. Furthermore, the ultrasonic homogenizer device was removed from the container, and vibration acceleration of 0.3 G in three directions was repeatedly applied to the container, so that the flat surfaces of the flat sendust powder overlapped with each other in the container via the methanol dispersion of nickel octylate. A collection of the flat sendust powder was prepared.
Next, the temperature of the container was raised to 65°C, methanol was vaporized from the methanol dispersion of nickel octylate, and nickel octylate crystals were formed on the surface of the collection of flat sendust powder and in the gaps between the flat surfaces of the flat sendust powder. A collection of these was precipitated. Thereafter, a plate of 20 cm x 20 cm x 2 mm (thickness) was placed over the surface of the collection of flat sendust powder, and five weights of 8 kg were placed on the plate at equal intervals.
Further, the container was placed in a heat treatment apparatus in an air atmosphere, the temperature was raised to 290°C, and the container was left at 290°C for 1 minute. Thereafter, vibrational acceleration of 0.4 G in three directions was applied to the container, and the collection of flat sendust powder in the container was peeled off from the container.
Next, as in Example 1, the surface and side surfaces of the sheet were observed using an electron microscope. A substance with a thickness of 1 μm was laminated in 20 layers with a collection of nanoparticles each having a size of around 10 nm interposed therebetween. This substance is dominated by iron atoms, followed by silicon atoms, followed by aluminum atoms, and a small amount of nickel atoms, so it is closer to super sendust than sendust. Furthermore, since the nanoparticles were composed of nickel atoms, they were nickel nanoparticles. Note that the skin depth of flat sendust powder at 3 MHz is 20 μm, so a sheet with a thickness of 20 μm effectively absorbs electromagnetic wave noise around 3 MHz using a small amount of flat sendust powder.
Furthermore, the ability of the prepared sheet to absorb electromagnetic noise was evaluated in the same manner as in Example 2. At 3 MHz, the absorption amount was 28%, at 10 MHz, the absorption amount was 38%, at 20 MHz, the absorption amount was 42%, at 50 MHz, the absorption amount was 38%, and at 100 MHz, the absorption amount was 28%. Therefore, the produced sheet had an absorption amount of 28% or more in the frequency band of 3-100 MHz. Compared to Example 4, the amount of electromagnetic waves absorbed was significantly increased. This is due to the fact that Sendust's flat powder has a larger particle size and a higher oblateness than Permalloy's flat powder.

Example 4
In this example, flat powders made of three types of alloys whose imaginary parts of complex magnetic permeability have peak values in different frequency bands are used, and the flat surfaces of the three types of flat powders are made up of collections of nickel nanoparticles. A sheet is produced from a collection of the three types of flat powders joined together via a .
The flat powders of the three types of alloys were obtained by adding flat powders of silicon steel containing 3% silicon and flat powders of electromagnetic stainless steel to the flat powders of permalloy used in Example 2.
Flat powder made of silicon steel containing 3% silicon (for example, a product developed by Sanyo Special Steel) has an oblateness of 34 and an average particle size of 9 μm. Further, the imaginary part of the complex magnetic permeability has a size necessary in a high frequency band, in contrast to the flat permalloy powder of Example 2. That is, it increases gradually from around 10 MHz, has a value of 2.3 at 1 GHz, intersects the value of the imaginary part of the complex permeability of permalloy at 4.7 GHz, and shows a peak value of 8.7 at 5.9 GHz. , decreases gently from around 6.3 GHz, has a value of 5.9 even at 10 GHz, and has a value of 3.7 at 12 GHz. Therefore, at 4.7 GHz or higher, the value of the imaginary part of the complex magnetic permeability is larger than that of flat permalloy powder.
Flat powder made of electromagnetic stainless steel (for example, a product developed by Sanyo Special Steel), which is made by adding 7% chromium, 1% silicon, and 1.6% aluminum to iron, has an oblateness of 29 and an average particle size. It is 12 μm. In addition, the imaginary part of the complex magnetic permeability increases rapidly from around 10 MHz, has a value of 3.4 at 1 GHz, intersects the imaginary part of silicon steel with 3% silicon at 4.2 GHz, and reaches a value of 3.4 at 4.8 GHz. It shows a peak value of 7.5, gradually decreases from around 5.5 GHz, has a value of 4.8 even at 10 GHz, and has a value of 3.1 at 12 GHz.
Therefore, we used three types of flat powder consisting of permalloy flat powder, silicon steel flat powder containing 3% silicon, and electromagnetic stainless steel flat powder, and a sheet in which the flat surfaces of the three types of flat powder were randomly overlapped. , the properties of the imaginary part of the complex magnetic permeability of the sheet become the properties that are the sum of the properties of the imaginary part of the complex magnetic permeability of three types of flat powder, and electromagnetic noise in the intermediate frequency band from 2 to 8 GHz The ability to absorb In particular, electromagnetic noise in the frequency band from 3.3 GHz, where the imaginary part of the complex magnetic permeability of permalloy has a peak value, to 4.8 GHz, where the imaginary part of the complex magnetic permeability of silicon steel containing 3% silicon has a peak value. Absorption performance is improved.
First, 32 g (corresponding to 0.09 mol) of nickel octylate used in Example 1 was dispersed in methanol at a weight ratio of 10%. Thereafter, a methanol dispersion of nickel octylate was filled into a 15 cm x 15 cm x 1.5 cm (depth) container. Next, 8 g of permalloy flat powder, 7 g of silicon steel flat powder, and 15 g of electromagnetic stainless steel flat powder were charged into the container. Thereafter, ultrasonic vibration of 20 kHz was applied to the methanol dispersion of nickel octylate in the container for 2 minutes using the ultrasonic homogenizer used in Example 1. Furthermore, the ultrasonic homogenizer device was removed from the container, and vibration acceleration of 0.3 G in three directions was repeatedly applied to the container. A collection of flat powders made of the three types of alloys overlapped with each other through the liquid was created.
Next, the temperature of the container was raised to 65°C, and methanol was vaporized from the methanol dispersion of nickel octylate. A collection of nickel octylate crystals was deposited in the gaps between the two. After this, a plate material of 15 cm x 15 cm x 2 mm (thickness) was placed on the surface of the collection of flat powder made of three types of alloys, and five weights of 6 kg were placed on the board material at equal intervals. .
Further, the container was placed in a heat treatment in an air atmosphere, the temperature was raised to 290°C, and the container was left at 290°C for 1 minute. Thereafter, vibrational acceleration of 0.4 G in three directions was applied to the container, and the collection of flat powders made of the three types of alloys in the container was peeled off from the container.
Next, as in Example 1, the surface and side surfaces of the sheet were observed using an electron microscope. A material with a thickness of 0.4-0.6 μm was laminated in 10 layers through a collection of nanoparticles each having a size of around 10 nm.
Furthermore, the ability of the produced sheet to absorb electromagnetic noise was evaluated in the same manner as in Example 1. The absorption amount was 8% at 1 GHz, 10% at 3.3 GHz, 9% at 4.7 GHz, 10% at 5.9 GHz, and 8% at 10 GHz. As a result, the absorption amount was 8% or more in a wide frequency band of 1-10 GHz. However, the amount of electromagnetic waves absorbed is small. This is due to the fact that, compared to the Sendust flat powder used in Example 3, the average particle diameters of the three types of alloys were smaller and the oblateness was lower.
Note that the example of combining soft magnetic flat powders made of multiple types of alloys is not limited to Example 4. In other words, if flat powders made of multiple types of alloys are combined and the amount of each flat powder used is adjusted so that the imaginary part of complex magnetic permeability has a constant value over a wide frequency band, The collection of flat powders in which the flat planes overlap and combine is such that the characteristic of the imaginary part of the complex magnetic permeability of each flat powder is the imaginary part of the complex magnetic permeability added according to the usage amount of each flat powder. As a result, a sheet that absorbs electromagnetic noise in a wide frequency band can be realized.

Example 5
In this example, flake copper powder is used to produce a sheet consisting of a collection of flake copper powder in which the planes of the flake copper powder are joined via a collection of copper nanoparticles. As the flake copper powder, product number MS-800 manufactured by Fukuda Metal Foil and Powder Industries Co., Ltd. was used. This flake copper powder has a particle size distribution in which flake powder larger than 75 μm accounts for more than 4%, flake powder larger than 45 μm accounts for more than 25%, and flake powder smaller than 45 μm accounts for more than 75%. Since the thickness is around 0.5 μm, the aspect ratio is large. In addition, the apparent density is as low as 0.6-1.0 g/cm ³ . Copper octylate Cu (C ₇ H ₁₅ COO) ₂ (for example, a product of Mitsuwa Pharmaceutical Co., Ltd.) was used as the raw material for the copper nanoparticles.
First, 12 g (corresponding to 0.035 mol) of copper octylate were dispersed in methanol in a weight proportion of 10%. Thereafter, a methanol dispersion of copper octylate was filled into a container measuring 8 cm x 8 cm x 2 cm (depth), and 9 g of flake copper powder was put into the container. Thereafter, ultrasonic vibrations of 20 kHz were applied to the methanol dispersion of copper octylate in the container for 2 minutes using the ultrasonic homogenizer used in Example 1. Furthermore, the ultrasonic homogenizer device was removed from the container, and vibration acceleration of 0.2 G in three directions was repeatedly applied to the container, so that the flat surfaces of the flaky copper powder overlapped with each other in the container via the methanol dispersion of copper octylate. A collection of the flaked copper powder was prepared.
Next, the temperature of the container was raised to 65°C, methanol was vaporized from the methanol dispersion of copper octylate, and copper octylate crystals were formed on the surface of the collection of copper flakes and in the gaps between the flat surfaces of the copper flakes. A collection of these was precipitated. Thereafter, a plate material of 8 cm x 8 cm x 2.5 mm (thickness) was placed over the surface of the collection of copper flakes, and further, five weights of 4 kg were placed on the plate material at equal intervals.
Further, the container was placed in a heat treatment apparatus in an air atmosphere, the temperature was raised to 290°C, and the container was left at 290°C for 1 minute. Thereafter, vibrational acceleration of 0.2 G in three directions was applied to the container, and the collection of flaky copper powder in the container was peeled off from the container.
Next, as in Example 1, the surface and side surfaces of the sheet were observed using an electron microscope. Copper flat powder with a thickness of about 0.5 μm was laminated in six layers with a collection of copper nanoparticles each having a size of about 10 nm interposed therebetween.
Furthermore, the electrical resistance of the sample was measured using a DC resistance meter (for example, DC resistance meter model 356H manufactured by Tsuruga Electric Co., Ltd.). Attach terminals to four locations on the sample, apply direct current to the sample in different directions, measure the voltage twice at the two inner terminals, and measure the difference between these two voltage values at the two outer terminals. The resistance value calculated from the value divided by the current value showed a volume resistivity close to that of copper. Therefore, the fabricated sample becomes a sheet with excellent thermal conductivity and electrical conductivity.

Example 6
In this example, using flake copper powder, a sheet made of a collection of flake copper powder in which the planes of the flake copper powder are joined via a collection of nickel nanoparticles is manufactured. The flake copper powder used in Example 5 was used as the flake copper powder. Nickel octylate Ni (C ₇ H ₁₅ COO) ₂ (for example, a product of Fuji Film Wako Pure Chemical Industries, Ltd.) was used as the raw material for the nickel nanoparticles.
First, 12 g (corresponding to 0.035 mol) of the nickel octylate used in Example 1 was dispersed in methanol at a weight ratio of 10%. Thereafter, a methanol dispersion of nickel octylate was filled into a container measuring 8 cm x 8 cm x 2 cm (depth), and 9 g of flake copper powder was placed in the container. Thereafter, ultrasonic vibration of 20 kHz was applied to the methanol dispersion of nickel octylate in the container for 2 minutes using the ultrasonic homogenizer used in Example 1. Furthermore, the ultrasonic homogenizer device was removed from the container, and vibration acceleration of 0.2 G in three directions was repeatedly applied to the container, so that the flat surfaces of the flaky copper powder overlapped with each other in the container via the methanol dispersion of nickel octylate. A collection of the flaked copper powder was prepared.
Next, the temperature of the container was raised to 65°C, methanol was vaporized from the methanol dispersion of nickel octylate, and nickel octylate crystals were formed on the surface of the collection of flaky copper powder and in the gaps between the flat surfaces of the flaky copper powder. A collection of these was precipitated. Thereafter, a plate material of 8 cm x 8 cm x 3 mm (thickness) was placed over the surface of the collection of flaky copper powder, and further, five weights of 4 kg were placed on the plate material at equal intervals.
Further, the container was placed in a heat treatment apparatus in an air atmosphere, the temperature was raised to 290°C, and the container was left at 290°C for 1 minute. Thereafter, vibrational acceleration of 0.3 G in three directions was applied to the container, and the collection of flaky copper powder in the container was peeled off from the container.
Next, as in Example 1, the surface and side surfaces of the sheet were observed using an electron microscope. Copper flat powder with a thickness of about 0.5 μm was laminated in six layers with a collection of nickel nanoparticles each having a size of about 10 nm interposed therebetween.
Furthermore, the electrical resistance of the sample was measured using the DC resistance meter used in Example 5. The sample exhibited a volume resistivity close to that of copper. Additionally, the sample exhibited sheets with a dark yellow-brown color with copper's inherent reddish tints. Therefore, the fabricated sample has excellent thermal conductivity and electrical conductivity, as well as a dark yellow-brown sheet with a reddish tinge unique to copper.

Example 7
In this example, alumina scale powder is used as a flat powder with excellent insulation and lubrication properties, and a sheet is manufactured from a collection of alumina scale powder joined via a collection of magnesium oxide nanoparticles. Alumina scale powder (product BMF-B of Kawai Lime Industry Co., Ltd.) is a scale-shaped boehmite powder (product BMF-B) with an aspect ratio of around 40, an average particle size of 9 μm, and a density of 3.98 g/ ^cm ) is heat-treated at a temperature of 500°C or higher to obtain alumina flake powder that has a shape similar to boehmite.
First, 22 g (corresponding to 0.07 mol) of magnesium caprylate Mg (CH ₃ (CH ₂ ) ₆ COO) ₂ (imported product) was dispersed in methanol in a weight proportion of 10%. Thereafter, a methanol dispersion of magnesium caprylate was filled into a container measuring 11 cm x 11 cm x 2 cm (depth), and 40 g of alumina scale powder was put into the container.
Thereafter, ultrasonic vibration of 20 kHz was applied to the methanol dispersion of nickel octylate in the container for 2 minutes using the ultrasonic homogenizer used in Example 1. Furthermore, the ultrasonic homogenizer device was removed from the container, and vibration acceleration of 0.3 G in three directions was repeatedly applied to the container, so that the flat surfaces of the alumina scale powder overlapped with each other through the methanol dispersion of magnesium caprylate inside the container. A collection of alumina flakes was prepared.
Next, the temperature of the container was raised to 65°C, methanol was vaporized from the methanol dispersion of magnesium caprylate, and magnesium caprylate was applied to the surface of the collection of alumina scale powder and the gap between the flat surfaces of the alumina scale powder. A collection of crystals was precipitated. Thereafter, a plate of 11 cm x 11 cm x 3 mm (thickness) was placed over the surface of the alumina scale powder, and five weights of 5 kg were placed on the plate at equal intervals.
Further, the container was placed in a heat treatment apparatus in an air atmosphere, the temperature was raised to 290°C, and the container was left at 290°C for 1 minute. Thereafter, vibrational acceleration of 0.3 G in three directions was applied to the container, and the collection of alumina scale particles inside the container was peeled off from the container.
Next, as in Example 1, the surface and side surfaces of the sheet were observed using an electron microscope. Flat alumina powder with a thickness of 0.2-0.3 μm was laminated in 10 layers with a collection of magnesium oxide nanoparticles each having a size of around 10 nm interposed therebetween.
Thereafter, when the surface resistance of the sample was measured at multiple locations using an insulation resistance meter, the needle broke off and the resistance value was greater than 100 MΩ.
Next, the static friction coefficient and the kinetic friction coefficient of the plurality of surfaces of the sample were measured using a measuring device (friction coefficient measuring device consisting of a desk-top precision universal tester Autograph AGS-X manufactured by Shimadzu Corporation). The static friction coefficient was 0.15±0.03, and the dynamic friction coefficient was 0.10±0.02. Both friction coefficients are small.

Example 8
In this example, colored flake powder is used as a flat powder, and the flat surfaces of the flake powder are joined through a collection of aluminum nanoparticles to produce a sheet made of a collection of colored flake powder. As the colored flake powder, glass flake powder coated with titanium oxide (Metashine, a product of Nippon Sheet Glass Co., Ltd.) was used. Equal amounts of two types of glass flake powder colored red (variety E025RR) and blue (variety E025RB) were mixed. The colored flake powder has a thickness of 0.5 μm, an average particle size of 25 μm, and a density of 2.6 g/cm ³ .
First, 23 g (corresponding to 0.05 mol) of aluminum octylate Al(C ₇ H ₁₅ COO) ₃ (imported) was dispersed in methanol in a weight proportion of 10%. Thereafter, a methanol dispersion of aluminum octylate was filled into a container measuring 12 cm x 12 cm x 2 cm (depth), and 65 g of colored flake powder was charged into the container.
Thereafter, ultrasonic vibrations of 20 kHz were applied to the methanol dispersion of aluminum octylate in the container for 2 minutes using the ultrasonic homogenizer used in Example 1. Furthermore, the ultrasonic homogenizer device was removed from the container, and vibration acceleration of 0.2 G in three directions was repeatedly applied to the container, so that the flat surfaces of the colored flake powder in the container overlapped with each other through the methanol dispersion of aluminum octylate. A collection of the colored flake powder was prepared.
Next, the temperature of the container was raised to 65°C, methanol was vaporized from the methanol dispersion of aluminum octylate, and aluminum octylate was applied to the surface of the collection of colored flake powder and the gap between the flat surfaces of the colored flake powder. A collection of crystals was precipitated. Thereafter, a plate of 12 cm x 12 cm x 3 cm (thickness) was placed over the surface of the collection of colored flakes, and five weights of 4 kg were placed on the plate at equal intervals.
Further, the container was placed in a heat treatment apparatus in an air atmosphere, the temperature was raised to 290°C, and the container was left at 290°C for 1 minute. Thereafter, vibrational acceleration of 0.3 G in three directions was applied to the container, and the collection of flaky copper powder in the container was peeled off from the container.
First, the spectral reflectance of the sample was examined using a spectrophotometer (CM-700d, manufactured by Konica Minolta Japan, Inc.). The spectral reflectance was highest near a wavelength of 470 nm, which gives off a blue color, and around a wavelength of 700 nm, which gives off a red color.
Next, the side surface of the sample was observed and analyzed using an electron microscope in the same manner as in Example 1. As a result, on the flat surface of the glass flake powder, glass flake powder with a thickness of 0.5 μm was laminated in 10 layers through a collection of aluminum nanoparticles having a size of about 10 nm.
On the other hand, the base material of the flat powder is transparent and flat glass flake powder, and the flat surfaces of the glass flake powder are bonded to each other through a collection of transparent aluminum nanoparticles, resulting in a strong gloss and transparency. A reddish-purple color with a high brightness was emitted from the coating.
From the above results, the flat surfaces of colored glass flake powder coated with titanium oxide were overlapped and bonded in 10 layers to form a sheet made of glass flake powder. This sheet had excellent coloring properties. Therefore, by using the flake powder colored in various colors described in paragraph 29 or a plurality of types of colored flake powder, colored sheets that emit various colors can be formed.

1 Reduced iron powder 2 Nickel nanoparticles

Claims (6)

Consisting of a collection of flat powder made of metal, alloy, metal oxide, or inorganic compound whose flat surfaces are joined via a collection of nanoparticles made of metal or metal oxide. The method of manufacturing the sheet is
An organometallic compound from which metals or metal oxides are precipitated by thermal decomposition is dispersed in methanol, and the methanol dispersion of the organometallic compound is filled into a container.After this, metals, alloys, metal oxides, or inorganic compounds are dispersed in methanol. Weigh a collection of flat powder made of any of the materials as a weight that is less than the weight of the methanol multiplied by the ratio of the density of methanol to the density of the flat powder used, and weigh the collection of flat powder that has been weighed. and stirring the flat powder in the methanol dispersion of the organometallic compound; further, disposing a homogenizer device in the container, operating the homogenizer device in the container, and stirring the flat powder in the methanol dispersion of the organometallic compound; Shock waves are repeatedly applied to the collection of flat powders through the methanol dispersion of the organometallic compound, the particles are separated into flat powders one by one through the methanol dispersion of the organometallic compound, and the separated flat powders are separated into flat powders one by one. The powder is covered with the methanol dispersion of the organometallic compound. After that, the homogenizer device is taken out from the container. Further, vibration acceleration is repeatedly applied to the container in three directions: front and back, left and right, and up and down. Finally, vibration acceleration is applied in the up and down directions. The methanol dispersion of the organometallic compound was introduced into the gap between the flat surfaces of the flat powder by applying a vibration acceleration of forming the collection of flat powder on the bottom of the container in the shape of the bottom;
After that, the temperature of the container is raised to the boiling point of methanol, methanol is vaporized from the methanol dispersion of the organometallic compound, and the collection of fine crystals of the organometallic compound is separated from the gaps between the flat surfaces of the flat powder. Further, a plate material that covers the entire surface of the flat powder collection is placed over the entire surface of the flat powder collection, the entire surface of the plate material is evenly compressed, and the organic material is deposited on the surface of the flat powder collection. Crushing fine crystals of metal compounds into even finer crystals,
Furthermore, a compressive load is applied uniformly to the entire surface of the plate material, the temperature of the container is raised to the thermal decomposition temperature of the organic metal compound, and the fine crystals of the organic metal compound are thermally decomposed. A collection of nanoparticles made of metal or metal oxide overlaps and precipitates all at once in the gaps between the flat surfaces and on the surface of the collection of flat powder, and further, the collection of nanoparticles is compressed, and the nanoparticles are compressed. The nanoparticles are bonded to the flat surface of the flat powder by frictional heat, and the nanoparticles are bonded to each other by frictional heat. A sheet made of a collection of the flat powders joined together is produced in the container. After this, vibration acceleration is applied to the container in three directions (back and forth, left and right, and up and down) to produce a sheet made of the collection of the flat powders. , the sheet is removed from the bottom of the container, and the flat surfaces of the flat powder made of metal, alloy, metal oxide, or inorganic compound are a collection of nanoparticles made of metal or metal oxide. A method for producing a sheet made of a collection of flat powders joined together via a. The method of manufacturing a sheet made of a collection of flat powders according to claim 1 is a method of manufacturing a sheet made of a collection of soft magnetic flat powders, and the sheet made of a collection of soft magnetic flat powders is manufactured. The method is
The flat powder described in claim 1 is a soft magnetic flat powder made of any material of iron, permalloy, silicon steel, sendust, or electromagnetic stainless steel, and the organometallic compound described in claim 1 is It is nickel octylate that precipitates nickel by thermal decomposition, and a soft magnetic flat powder made of any of the above materials is used as the flat powder according to claim 1, and the nickel octylate is used as the flat powder according to claim 1. According to the method for manufacturing a sheet made of a collection of flat powder used as an organometallic compound and according to claim 1, the flat surfaces of the soft magnetic flat powder made of any of the above materials are made of a collection of nanoparticles made of nickel. A method for manufacturing a sheet made of a collection of soft magnetic flat powders, which comprises manufacturing a sheet made of a collection of flat powders joined together via a . The method of manufacturing a sheet made of a collection of flat soft magnetic powders according to claim 2 is a method of manufacturing a sheet made of a collection of flat soft magnetic powders of a plurality of types of alloys, The method for producing a sheet made of a collection of soft magnetic flat powder is as follows:
The soft magnetic flat powder according to claim 2 is a soft magnetic flat powder made of a plurality of types of alloys other than iron according to claim 2, and a complex of soft magnetic flat powders made of the plurality of types of alloys. The frequency characteristics of the imaginary part of the complex magnetic permeability of each of the soft magnetic flat powders are different from each other, and the frequency characteristics of the imaginary part of the complex magnetic permeability of each of the soft magnetic flat powders are different from each other in a different frequency range. Using a soft magnetic flat powder made of the plurality of types of alloys as the flat powder according to claim 1, having a frequency characteristic of the imaginary part of the complex magnetic permeability in which the imaginary parts of the complex magnetic permeability complement each other, The soft magnetic properties of the plurality of types of alloys are obtained by using the nickel octylate described in claim 2 as the organometallic compound described in claim 1, and according to the method for manufacturing a sheet made of a collection of flat powders described in claim 1. A collection of soft magnetic flat powders of multiple types of alloys to produce a sheet consisting of a collection of flat powders of the multiple types of alloys in which the flat surfaces of the flat powders are joined via a collection of nanoparticles made of nickel. A method of manufacturing a sheet consisting of. The method of manufacturing a sheet made of a collection of flat powders according to claim 1 is a method of manufacturing a sheet made of a collection of flake powders made of a metal or an alloy, and the sheet is made of a collection of flake powders made of a metal or an alloy. The method of manufacturing the sheet is
The flat powder according to claim 1 is a flake powder made of a metal or an alloy made of any one of silver, copper, brass, nickel, or aluminum, and the organometallic compound according to claim 1 is A metal octylate compound such as copper octylate, aluminum octylate, or nickel octylate that precipitates copper, aluminum, or nickel upon decomposition, and flake powder consisting of a metal or alloy made of any of the above materials. is used as the flat powder according to claim 1, and any of the metal octylate compounds is used as the organometallic compound according to claim 1, to produce a sheet made of a collection of flat powders according to claim 1. flakes made of the metal or alloy in which the flat surfaces of the flake powder made of the metal or alloy made of any of the above materials are joined via a collection of nanoparticles made of copper, aluminum, or nickel. A method for manufacturing a sheet consisting of a collection of flakes of metal or alloy powder. The method of manufacturing a sheet made of a collection of flat powders according to claim 1 is a method of manufacturing a sheet made of a collection of flat insulating powders made of a metal oxide or an inorganic compound, The method for producing a sheet made of a collection of insulating flat powder made of a compound is as follows:
The flat powder according to claim 1 is an insulating flat powder made of a metal oxide or an inorganic compound made of glass, alumina, or hematite, and the organometallic compound according to claim 1 is , is a complex made of a carboxylic acid metal compound that precipitates an insulating metal oxide having a hardness lower than that of the insulating flat powder by thermal decomposition, and is a complex made of a metal oxide or an inorganic compound made of any of the above materials. The insulating flat powder is used as the flat powder according to claim 1, the complex consisting of the carboxylic acid metal compound is used as the organometallic compound according to claim 1, According to the method for manufacturing a sheet consisting of a sheet, the flat surfaces of the flat insulating powder made of a metal oxide or an inorganic compound made of any of the above-mentioned materials have a hardness lower than that of the flat insulating powder. Insulating flat powder made of a metal oxide or inorganic compound is manufactured by producing a sheet consisting of a collection of flat insulating powder made of the metal oxide or inorganic compound bonded through a collection of nanoparticles made of the metal oxide or inorganic compound. A method for manufacturing sheets made of flat powder. The method for manufacturing a sheet made of a collection of flat powders according to claim 1 is a sheet made of a collection of inorganic bright pigments in which the surface of flat powders made of glass or aluminum is coated with a film made of a metal or a metal oxide. A method for producing a sheet made of a collection of inorganic glitter pigments includes:
The flat powder according to claim 1 is an inorganic bright pigment in which the surface of the flat powder made of glass or aluminum is coated with a film made of metal or metal oxide, and the organometallic compound according to claim 1 is It is aluminum octylate which precipitates aluminum by thermal decomposition, the inorganic bright pigment is used as a flat powder according to claim 1, the aluminum octylate is used as an organometallic compound according to claim 1, According to the method for manufacturing a sheet made of a collection of flat powder described in Item 1, the flat surfaces of the inorganic bright pigment are joined via a collection of nanoparticles made of aluminum. A method of manufacturing a sheet comprising a collection of inorganic bright pigments.