Method for continuously producing sheet having structure in which entire surface of fabric or nonwoven fabric is covered with coating formed by collection of powder of any one material of metal, alloy, metal oxide, and nitride, the powder having micron-sized particle diameter and being joined by friction welding

Abstract

To continuously produce a sheet, ensure that the produced sheet is nonflammable and has mechanical strength as a sheet, enable the sheet to be cut, and allow the cut sheet to be pressure-bonded to a base material or a component.SOLUTION: A plurality of cylindrical rollers, each having a length equal to the container width and having the same diameter, is arranged in parallel to the container width with spacing from each other. A collection of powder of any one of a metal, an alloy, a metal oxide, and a nitride, and an alcohol having viscosity of 3-11 mPa s at 20°C are filled into the container. All rollers except for the first and last rollers are immersed in the suspension. Thereafter, a fabric or a nonwoven fabric drawn from a textile material is sequentially brought into contact with the plurality of cylindrical rollers and further compressed by being sandwiched in a gap between two work rolls of a multi-stage rolling machine. This enables continuous production of a sheet having a structure in which the entire surface of the fabric or nonwoven fabric is covered with a coating formed by a collection of powder joined by friction welding.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for continuously producing a sheet having a structure in which a woven fabric or nonwoven fabric is entirely covered with a coating formed by an aggregation of micron-sized powder particles made of one type of material selected from metals, alloys, metal oxides, and nitrides, which are joined by friction welding, by continuously performing all of the three steps described below. In the first step, a container is installed with multiple cylindrical rollers positioned along the width of the container, the width of the container being wider than the width of the sheet to be produced and the length of the container being long enough to accommodate the multiple cylindrical rollers. The multiple cylindrical rollers rotate at the same peripheral speed, with a time required for one rotation being longer than 20 seconds, and are spaced apart and parallel to the side of the container that defines the width of the container. Then, a micron-sized powder mass made of one material selected from metal, alloy, metal oxide, and nitride, weighing more than the weight required for continuous sheet production, and alcohol having a viscosity of 3-11 mPa·sec at 20°C are filled into the container together with the powder mass. The alcohol has a viscosity of 3-11 mPa·sec at 20°C, and the viscosity increases with the size of the powder, the less symmetrical the powder's shape, and the harder the powder. The alcohol is then stirred to form a suspension. Although fabrics and nonwoven fabrics have many tiny voids, the alcohol that makes up the suspension has a viscosity of 3-11 mPa·sec at 20°C, so the suspension fills these voids and is adsorbed onto the surface of the fabric and nonwoven fabric. In the second step, a roll of fabric or nonwoven fabric having the width of the sheet to be produced is set in a drawing device, and the fabric or nonwoven fabric is continuously drawn out from the roll of fabric at a speed corresponding to the peripheral speed of the multiple cylindrical rollers described above. Furthermore, the plurality of cylindrical rollers are rotated at the same peripheral speed such that the time required for one rotation is longer than 20 seconds. After this, the drawn fabric or nonwoven fabric is SideThe fabric or nonwoven fabric, with the suspension evenly applied, travels between the work rolls of the multi-stage rolling mill and the nip between the two work rolls of the multi-stage rolling mill. Furthermore, the suspension adheres to the entire surface of the fabric or nonwoven fabric immersed in the suspension, with a thickness corresponding to the viscosity of the suspension. In the third process, a multi-high rolling mill having two work rolls with five characteristics is prepared: first, the two work rolls have the same width, wider than the width of the sheet to be produced; second, the same diameter, smaller than 1 / 10 of the sheet width; third, the gap is set to the thickness of the sheet to be produced; fourth, the work rolls rotate in opposite directions at the same peripheral speed as the multiple cylindrical rollers in the first process; and fifth, the work rolls are heated to a temperature 10°C higher than the boiling point of the alcohol that constitutes the suspension. Next, the leading edge of the fabric or nonwoven fabric that has been processed in the second process is inserted into the nip between the two work rolls. This pulls the leading edge of the fabric or nonwoven fabric into the nip between the two work rolls and causes compressive stress from the two work rolls. During this process, the alcohol first evaporates from the suspension that has been evenly applied to the fabric or nonwoven fabric, and the powder deposits on the fabric or nonwoven fabric in layers, covering the fabric or nonwoven fabric. Next, the powder mass comes into contact with the two work rolls, and the surface layer of the powder mass moves toward the rear of the two work rolls. After this, compressive stress is applied evenly to the powder mass and the fabric or nonwoven fabric. During this process, the powder moves to fill the gaps in the powder mass, and the fabric or nonwoven fabric is compressed and deformed. Furthermore, the powder in contact with the fabric or nonwoven fabric applies shear stress to the fabric or nonwoven fabric, causing it to break at the locations where the shear stress is applied. On the other hand, because the powder is small, on the order of microns, and the fabric or nonwoven fabric is covered with a cluster of powder, a large amount of powder comes into contact with the fabric or nonwoven fabric. This results in a large number of breaks in the fabric or nonwoven fabric, which causes the fabric or nonwoven fabric to split. Furthermore, the compressive stress applied to the powder causes the powder to move and fill the broken areas of the fabric or nonwoven fabric, the voids on the front and back surfaces of the split fabric, and the voids on the front and back surfaces of the split nonwoven fabric. Furthermore, compressive stress is applied evenly to the cluster of powder, so that adjacent powder particles in the cluster are joined by friction welding at all contact points, and overlapping clusters of powder are joined by friction welding at all contact points.As a result, all voids in the friction-welded powder mass are trapped within the friction-welded powder mass, and the powder mass forms a coating with no voids communicating with the outside world. Furthermore, the coating is friction-welded to the divided fabric or nonwoven fabric. This phenomenon occurs continuously for the powder mass and the fabric or nonwoven fabric sandwiched between the two work rolls, and a sheet consisting of the divided fabric or nonwoven fabric with the coating friction-welded to its entirety is discharged from the nip between the two work rolls as a sheet the same thickness as the gap between the two work rolls. The discharged sheet is wound up by a winding device that rotates at the same rotational speed as the two work rolls. As a result, the movement speed of the fabric or nonwoven fabric is the same from the time the fabric or nonwoven fabric is pulled out from the roll to the time the sheet is wound up by the winder, so sheets can be produced continuously. In other words, fabrics and nonwoven fabrics are lightweight, thin, have few size restrictions, and can be easily cut, making them inexpensive industrial products with no shape restrictions. However, fabrics and nonwoven fabrics have too little mechanical strength to be used as sheets. Furthermore, both fabrics and nonwoven fabrics are flammable. On the other hand, in the present invention, fabrics and nonwoven fabrics are used as a means for adsorbing a suspension of powder clusters dispersed in alcohol, and when the alcohol is evaporated, the entire fabric or nonwoven fabric is covered with the powder clusters. Furthermore, the powder clusters and the fabric or nonwoven fabric are compressed to form a sheet in which a coating made of powder clusters bonded by friction welding is bonded to the entire fabric or nonwoven fabric. This provides the sheet with mechanical strength based on the bonding force between the powder particles, imparting the properties of the powder to the sheet. Furthermore, the powder particles bonded by friction welding are a coating formed by overlapping and bonding together micron-sized powder particles, and are thinner than 0.25 mm. This allows the sheet to be cut even if the coating is formed by bonding together high-hardness powder particles. Therefore, there are no restrictions on the size and shape of the sheet to be cut. The thickness of the sheet to be manufactured is determined by the gap between the two work rolls, so the thickness of the sheet to be manufactured can be set in advance. Furthermore, the surface of the sheet has irregularities based on the size of the powder particles and irregularities on the powder surface. Therefore, when the cut sheet is placed on the surface of a substrate or part made of various materials and the entire cut sheet is compressed evenly, the aforementioned irregularities are eliminated. Convex part of The cut sheet is pressed onto the surface of the substrate or part via this process. This gives the substrate or part the properties of powder. Furthermore, the coating formed by the collection of powders joined by friction welding has no voids communicating with the outside world, making it airtight and gas-tight against the fabric or nonwoven fabric. Therefore, the fabric or nonwoven fabric does not self-ignite or catch fire. Furthermore, even if the sheet is heated to the thermal decomposition temperature of the fabric or nonwoven fabric, the flammable substances generated during thermal decomposition of the fabric or nonwoven fabric are not emitted to the outside. Therefore, the sheet is non-flammable. The coating also has heat resistance equivalent to the heat resistance temperature of the powder. Furthermore, the surface of the coating is water-repellent, repelling all liquids. Therefore, the sheet has corrosion resistance equivalent to the corrosion resistance of the powder. As explained above, the manufactured sheet is thinner and lighter than conventional synthetic resin sheets or conventional metal sheets, and has mechanical strength, non-combustibility, heat resistance, and corrosion resistance. Among metal sheets, aluminum sheets are the thinnest, and according to JIS H4000, the thickness is 0.2 mm or more. Furthermore, powders made of metals, alloys, metal oxides, or nitrides are made of an extremely wide variety of materials. On the other hand, sheets have the inherent properties of the powder used. Therefore, sheets have an extremely wide variety of properties based on the inherent properties of the powder. This allows sheets to be used for an extremely wide variety of applications. Furthermore, by pressing cut sheets onto substrates or parts made of various materials, sizes, and shapes, the various properties of the powder can be imparted to the substrates or parts. There are two types of fabrics: woven and knit. Woven fabrics are made by weaving warp and weft threads made of natural or chemical fibers, and there are three types of weaving: plain weave, twill weave, and satin weave. Knit fabrics, on the other hand, are knitted in a loop pattern. Woven fabrics are not stretchable, while knit fabrics are stretchable, but they are less expensive. Both woven and knit fabrics are easily deformed but have low mechanical strength. Both woven and knit fabrics have numerous uneven recesses and voids on their surfaces, and powder is pressed into the numerous uneven recesses and voids, filling the numerous voids. When using a fabric as a frame for supporting a powder cluster, stretchability is not required, so a cheaper plain weave or twill weave fabric is suitable for the frame. In contrast, nonwoven fabrics are unwoven fabrics made by collecting fibers in a fixed or random direction and chemically bonding them with adhesive resins, mechanically entangling them, entangling them with a pressurized water flow, or bonding them with heat-sealed fibers. As a result, they are porous and have numerous voids, providing breathability, filtering, and moisture retention. These voids can then be filled with powder. Furthermore, because nonwoven fabrics can be formed directly into sheets from fibers, there is no need to spin fibers as with woven or knitted fabrics. This allows for lower production costs than woven or knitted fabrics. Therefore, nonwoven fabrics, like plain or twill weave fabrics, are suitable as frames for supporting powder aggregates. Natural fibers, chemical fibers, and glass fibers are used as raw materials for nonwoven fabrics.

[0002] The inventor has previously filed a patent application (Japanese Patent No. 6734691) for a method of forming a synthetic resin molded body that is non-flammable and electrically conductive by covering a molding material with a collection of metal nanoparticles that are metal-bonded together and then molding the molding material into a molded body. In addition, a method for producing fibers, threads, fabrics, or nonwoven fabrics with metallic properties by dispersing clusters of metal nanoparticles produced by thermal decomposition of a metal compound in an organic compound, adding multiple fibers or threads, or multiple pieces of fabric or nonwoven fabric of a specified size, to the resulting suspension, and placing the container containing the suspension in the chamber of a vacuum impregnation device, after which the pressure inside the chamber is reduced to a level lower than the vapor pressure of the organic compound, filling both the internal voids and the recesses of the surface irregularities of the fibers, threads, fabrics, or nonwoven fabric with clusters of metal nanoparticles, and covering the surface of the fibers, threads, fabrics, or nonwoven fabric with clusters of metal nanoparticles has been filed (Patent Application No. 2021-205624). In contrast, the present invention differs from the prior application in that it continuously produces a sheet in which a coating made of an aggregate of micron-sized powder particles made of one of the following materials, metal, alloy, metal oxide, or nitride, is joined by friction welding, and the powder is then bonded to a woven or nonwoven fabric having the width of the sheet to be produced. [Background technology]

[0003] Many sheets made of an aggregate of metal or alloy powder are used as conductive sheets, while many sheets made of an aggregate of metal oxide or nitride powder are used as insulating sheets. First, the use of the conductive sheet and prior patent documents relating to this use will be described. In recent years, sheets made of conductive fibers have been studied as electromagnetic wave shielding materials that block electromagnetic waves generated by electronic devices such as mobile phones, and fabrics made of conductive fibers have been studied as antistatic or antistatic materials that suppress the generation of static electricity. Furthermore, among conductive fibers, the most active area of ​​technological development has been in imparting conductivity to polymeric materials. The technologies for imparting conductivity can be divided into two categories: technologies for dispersing conductive substances and technologies for forming metal coatings. Examples include a technology that uses a polymer composition mixed with conductive substances such as carbon powder or metal powder (see, for example, Patent Document 1), a technology that forms a metal vapor deposition film of tin oxide or the like on a plastic molded product by vacuum deposition or the like (see, for example, Patent Document 2), and a technology that forms a metal coating on the surface of a polymeric fiber material by electroless plating (see, for example, Patent Document 3).

[0004] However, polymer compositions filled with conductive materials such as carbon powder or metal powder are composed of a polymer with dispersed conductive particles and a non-conductive polymer, which can easily separate the conductive and non-conductive portions. Furthermore, to achieve conductivity similar to that of metals, the sheet must have pathways in which the conductive particles are continuously joined. This requires a high conductive particle filling rate, but the higher the conductive particle filling rate, the more the polymer composition loses its properties. In other words, with the technology of dispersing conductive particles in fabric or nonwoven fabric, unless a structure in which a continuous current flows through the conductive particles is formed in the fabric or nonwoven fabric, the fabric or nonwoven fabric cannot achieve conductivity close to that of metal. On the other hand, if the filling rate of the conductive particles is increased to 10% or more in an attempt to increase conductivity, the dispersibility of the conductive particles begins to deteriorate, and a high filling rate of the conductive particles cannot be achieved. As such, with the technology of filling conductive particles into fabric or nonwoven fabric, it is difficult to fill the fabric or nonwoven fabric with conductive particles at a high filling rate, so in principle it is difficult to make the properties of the fabric or nonwoven fabric similar to those of metal.

[0005] On the other hand, techniques for forming metal films using methods such as vacuum deposition have problems such as poor abrasion resistance and weather resistance of the metal film, and deterioration of physical properties due to chemical changes over long-term use. Furthermore, forming metal films requires high production costs, which limits its practical use. Furthermore, techniques for forming metal films using electroless plating require many steps and advanced technology, resulting in high production costs. Furthermore, friction and bending are applied to the fabric or nonwoven fabric during use or processing of the conductive sheet, which can cause the metal film to peel off from the fabric or nonwoven fabric. In other words, the technology of forming a metal coating on the surface of a fabric or nonwoven fabric by vacuum deposition or the like is a method of forming a metal coating by depositing deposited metal foil. Therefore, since the deposited metal foils are not bonded to each other by metallic or covalent bonds, the bonding strength between the metal foils is extremely weak, and the metal foils easily peel off when stress is applied to the metal coating. Thus, the problem of easy peeling of the metal coating is caused by the lamination of deposited metal foils, and therefore, this problem cannot be fundamentally solved.

[0006] Next, in the case of an insulating sheet, since the most common case is where an insulating layer is formed on a conductor, prior patent documents relating to this case will be described. There are various methods for forming an insulating layer on a conductor. For example, Patent Document 4 describes a method for forming an alumina insulating film using the sol-gel method. Specifically, an alumina precursor solution, in which a deflocculating agent is added to a sol containing an aluminum compound, is electrophoretically deposited onto a substrate to form an alumina insulating film. Specifically, first, an organic solvent such as ethanol is added to the aluminum compound, and then a deflocculating agent such as hydrochloric acid is added and stirred to prepare a sol. Next, the sol is placed in a thermostatic chamber and stirred for 1-3 hours at a temperature range of 40-60°C, which does not cause gelation, to prepare an alumina precursor solution. Third, to equilibrate the hydrolysis and condensation reactions occurring in the alumina precursor solution, the alumina precursor solution is maintained in the thermostatic chamber at a temperature range of 40-60°C for at least 12 hours. Fourth, an electrode, for example, a silicon substrate with a platinum film formed on its surface, is prepared as the electrodeposited material, and a counter electrode, for example, a silicon substrate with a platinum film formed on its surface, is prepared. Two silicon substrates with electrodes formed on them are immersed in an alumina precursor solution. A DC voltage is applied between the electrodes of the two substrates until a predetermined charge transfer rate is reached, depositing a positively charged alumina precursor on the electrode of the silicon substrate used as the cathode. Fifth, the silicon substrate with the deposited alumina precursor is placed on a plate and heated and dried in air at 100°C or higher for at least 3 minutes. Sixth, the alumina precursor deposited on the platinum electrode of the dried silicon substrate is heated from room temperature to 700°C at a rate of 1-20°C / s in an oxygen atmosphere and held for at least 1 minute, crystallizing the alumina precursor to form an insulating film. An insulating alumina layer is thus formed on the surface of the platinum electrode. Because the process for forming the insulating layer is complex and diverse, and requires a heat treatment at 700°C, this insulating layer formation method is not a general-purpose method.

[0007] Patent Document 5 describes the formation of both insulating layers in a plasma display device: a solid insulating film covering the display electrodes on the front panel to maintain plasma discharge, and an insulating film covering the address electrodes formed on the rear panel. Specifically, an insulating paste consisting of a thermal polymerization initiator, a thermosetting component, and glass particles is applied to a substrate. The applied film is heated to a semi-curing treatment to achieve a cure rate of 30-95%, and then further heated to form an insulating layer. Specifically, the applied film is heated to 95°C, left for 30 minutes, and then cooled to 25°C to form a semi-cured film. The semi-cured film is then heated at 380°C for 10 minutes to remove the organic components, and then heated at 600°C for 10 minutes to sinter the glass particles and form an insulating layer. In other words, because electrodes are formed on the substrate, the firing shrinkage of the semi-cured film on the convex portions (electrode-forming portions) of the substrate is significantly higher than the firing shrinkage of the semi-cured film on the concave portions (electrode-free portions) of the substrate, resulting in an insulating film with high overall smoothness. For this reason, a semi-cured film is required. Because this insulating film has a relatively large surface area, the complex heat treatment described above is necessary to form an insulating film with excellent smoothness. Furthermore, the chemicals consisting of a thermal polymerization initiator and a thermosetting component are specialized industrial chemicals. Thus, the method for forming the insulating film requires the use of specialized chemicals, complex and diverse heat treatments, and a heat treatment at 600°C. Therefore, this method for forming an insulating layer is not a general-purpose method for forming an insulating layer.

[0008] Patent Document 6 describes a method for forming a low-dielectric-constant interlayer insulating film required for high-density semiconductor devices. Specific substances for a low-dielectric-constant interlayer insulating film with good moisture absorption resistance and heat resistance are listed as trimethylsilane (TMS) among Si-containing alkyl compounds and tetraethylorthosilicate (TEOS) among Si-containing alkoxy compounds. However, the electrical conductivity of TEOS is 3×10 -6 S / m, and the electrical conductivity is 59×10 6 S / m of copper is 5×10 -13 Therefore, when an electronic circuit is operated for a long time, the insulating layer generates heat due to leakage current flowing through the insulating layer, which may cause thermal degradation of electronic components placed on the conductor. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-212453 [Patent Document 2] Special Publication No. 61-132652 [Patent Document 3] Japanese Patent Application Laid-Open No. 2000-96431 [Patent Document 4] Japanese Patent Application Laid-Open No. 2014-175389 [Patent Document 5] International Publication No. WO2014 / 61590 [Patent Document 6] Japanese Patent Application Laid-Open No. 2000-332010 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0010] A coating made of a collection of powder particles bonded together, each of which is made of one of micron-sized metals, alloys, metal oxides, and nitrides, is applied to a fabric or nonwoven fabric. surface The following explains the challenges involved in continuously manufacturing fully bonded sheets. The majority of the powder particles are smaller than 30 μm, with only a small portion exceeding 100 μm. Therefore, the powder is lightweight. If sheets made of fabric or nonwoven fabric could be continuously produced using rolls of fabric or nonwoven fabric, thin, lightweight sheets with large areas could be continuously produced. Furthermore, if the sheets could be cut, there would be no restrictions on the size and shape of the sheets. However, fabric or nonwoven fabric does not have the mechanical strength required for a sheet and is flammable. Furthermore, although fabric or nonwoven fabric can be easily cut, the conditions under which a sheet can be cut are unknown. For this reason, there have been no attempts to produce sheets using fabric or nonwoven fabric to date. In contrast to this, a coating made of a collection of powder particles bonded together, each of which is made of one of the following materials: metal, alloy, metal oxide, or nitride, each of which has a micron size, is applied to a fabric or nonwoven fabric. surface If the method for manufacturing fully bonded sheets can solve the following 13 problems, it will be possible to continuously produce sheets that not only have the properties of powder made from one type of material (metal, alloy, metal oxide, or nitride), but also have mechanical strength, non-combustibility, corrosion resistance, and heat resistance. First, the sheet can be produced continuously. This allows thin, lightweight, large-area sheets to be produced continuously at low cost. For this reason, it is essential to optimize multiple processing methods so that the processes from pulling out the woven or nonwoven fabric from the roll of fabric or nonwoven fabric to winding up the sheet can be carried out continuously. Second, the sheet can be cut, which means there are no restrictions on the size and shape of the sheet. For this reason, it is essential that the thickness of the coating, which is made up of a collection of bonded powder particles, is thin enough to be cut. Third, the cut sheets can be pressed onto substrates or parts made of various materials, thereby imparting various powder properties to the surface of the substrate or part. Fourth, the sheet is non-flammable. While powders made of metals, alloys, metal oxides, or nitrides are non-flammable, fabrics or non-woven fabrics are flammable. If the fabric or non-woven fabric that makes up the sheet were to burn, the sheet would lose its functionality and many of its properties. Therefore, it is essential that the entire flammable fabric or non-woven fabric be covered with a non-flammable powder. Furthermore, it is essential that the non-flammable powder has no voids that connect it to the outside world. This prevents the fabric or non-woven fabric from being exposed to the atmosphere, making the flammable fabric or non-woven fabric non-flammable. Not only does the fabric or non-woven fabric not burn, but flammable substances generated by the thermal decomposition of the fabric or non-woven fabric are trapped within the coating, preventing the spread of fire and suppressing the generation of harmful gases that accompany the fire, resulting in a disaster prevention and non-flammable sheet. Fifth, the cut sheets are also non-flammable. In other words, even if the continuously produced sheet is non-flammable, the cut sheets have a wide range of uses, so it is essential that the cut sheets also be non-flammable. Therefore, even if a fabric or non-woven fabric is visible on the cross section of a cut sheet, it is essential that the fabric or non-woven fabric in the area other than the edge of the cut sheet is broken up into countless pieces by the accumulation of powder, and that the accumulation of powder does not have any voids communicating with the outside world. As a result, even if the cut sheet is exposed to an atmosphere in which fabric or non-woven fabric is flammable, damage to the cut sheet is limited to the fabric or non-woven fabric visible on the cross section, and the area other than the cross section of the cut sheet remains non-flammable. Sixth, the sheet must have sufficient mechanical strength. To achieve this, it is essential that all powder particles be joined by friction welding wherever they come into contact. This allows the coating, made up of the joined powder particles, to have mechanical strength based on the bonding force between the powder particles. The sheet, in which the coating covers the entire woven or nonwoven fabric, has a certain level of mechanical strength. Seventh, if the powder is made of a metal or alloy, the sheet becomes a conductive sheet, while if the powder is made of a metal oxide or nitride, the sheet becomes an insulating sheet. Therefore, it is essential that all adjacent powder particles be bonded at their contact points. As a result, if the powder is made of a metal or alloy, a path for continuous electron movement is formed in the coating. Therefore, the coating has conductivity based on the conductivity of the powder. In contrast, if the powder is made of a metal oxide or nitride, the coating has insulating properties based on the resistivity of the powder. That is, the resistivity of the coating is proportional to the resistivity of the metal oxide or nitride, inversely proportional to the cross-sectional area of ​​the coating, and proportional to the length of the coating. Therefore, a thin coating increases the insulation resistance of the coating. This prevents leakage current from flowing through the insulating sheet, preventing the insulating sheet from generating heat, and therefore preventing thermal degradation over the long term. Eighth, the thickness of the coating formed by the friction-welded powder mass is maintained at a constant value. This allows for the continuous production of a sheet with a predetermined conductivity when the powder is made of a metal or alloy. Furthermore, for powders made of metal oxides or nitrides, it allows for the continuous production of a sheet with a predetermined insulating property. Ninth, the sheet has water-repellent properties that repel all liquids, making the coating a corrosion-resistant sheet based on the corrosion-resistant properties of the powder. Tenth, the sheet has a heat resistance corresponding to the heat resistance temperature of the powder, and the cut sheets also have a heat resistance corresponding to the heat resistance temperature of the powder. Eleventh, there are no restrictions on the powder material used to form the coating, which allows the sheet to have the properties of various powders and be used for a variety of purposes. Twelfth, there are no restrictions on the material or size of the woven or nonwoven fabric used, which allows for the formation of a lightweight, versatile sheet with no size restrictions. Thirteenth, the sheet can be manufactured using an inexpensive manufacturing method, which allows the sheet to be used for a variety of purposes. For this reason, it is essential that all processes in the sheet manufacturing process are simple and that the materials used are inexpensive. Many of the 13 problems described above can be solved by finding a method in which adjacent powder particles are bonded to each other at all contact points, and in which overlapping powder particles are bonded to each other at all contact points, and in which a coating made of the aggregate of bonded powder particles is bonded to a woven or nonwoven fabric. The problem to be solved by the present invention is to find a method for manufacturing a sheet that solves the above 13 problems. [Means for solving the problem]

[0011] A method for continuously producing a sheet having a structure in which a woven fabric or nonwoven fabric is entirely covered with a coating formed by an aggregation of micron-sized powder particles made of one of metals, alloys, metal oxides, and nitrides, which are joined together by friction welding, comprises the steps of: First, a container in which a plurality of cylindrical rollers are provided in the width direction of the container has a width wider than the width of the sheet to be produced and a vertical width long enough to provide the plurality of cylindrical rollers, and the plurality of cylindrical rollers rotate at the same peripheral speed in the container, the time required for one rotation being longer than 20 seconds, and the plurality of cylindrical rollers having the same length and diameter as the width of the container are provided parallel to the width of the container at a distance from each other, and the arrangement positions of the plurality of cylindrical rollers in the container are as follows: a first roller has a topmost roller that is aligned with the fabric to be used in the second step; the first roller is placed at a position corresponding to the height at which it comes into contact with the fabric or nonwoven fabric pulled out from the roll of fabric around which it is wound, and at a position within the container that is 1 cm or more away from one side surface that defines the width of the container; the second roller is placed at a position that is farther away from one side surface that defines the width of the container by the size of the first roller than the position at which the first roller is placed, and at a position within the container that is 1 cm or more away from the bottom of the container; and the last roller is placed at a position within the container that is 1 cm or more away from the other side surface that defines the width of the container; The second roller is placed at the same height as the first roller, and the penultimate roller is placed at a position further away from the other side of the container that defines the width of the container by the size of the last roller than the position where the last roller is placed, and at a position within the container that is 1 cm or more away from the bottom of the same container as the second roller, and the remaining rollers are placed at a position further away from the bottom of the same container as the second roller by 1 cm or more away from the bottom of the same container as the second roller, with a distance of less than twice the diameter of the cylindrical roller between the second roller and the penultimate roller, and each roller is placed at equal intervals, Next, a collection of powder made of one material of metal, alloy, metal oxide or nitride having a size of micron size is filled into the container, the weight of the powder being greater than the weight required for continuous sheet production, and also, an alcohol having a viscosity of 3-11 mPa·sec at 20°C is used, and the smaller the size of the powder, the less symmetrical the shape of the powder, and the higher the hardness of the powder, the higher the viscosity of the alcohol is used, and the alcohol isa first step of filling the container with an amount of alcohol that will form a volume in which all rollers except the first roller and the last roller are immersed, stirring the alcohol to prepare a suspension in which the powder aggregates are dispersed in the alcohol, and immersing all rollers of the plurality of cylindrical rollers except the first roller and the last roller in the suspension; A roll of fabric or nonwoven fabric having the width of the sheet to be manufactured is set in a roll-pulling device, and the fabric or nonwoven fabric is continuously pulled out from the roll of fabric at a speed corresponding to the peripheral speed of the plurality of cylindrical rollers in the first step. In addition, the roller drive unit rotates eight cylindrical rollers continuously at the same peripheral speed, rotating one rotation every 25 seconds.Thereafter, the pulled-out fabric or nonwoven fabric comes into contact with the top of the first roller, and moves together with the first roller with the side of the first roller in contact with the side of the first roller, approximately 1 / 4 of the way up. Thereafter, the direction of movement is changed downward, and the fabric or nonwoven fabric moves, being immersed in the suspension, and then comes into contact with the side of the second roller. Since the rotation direction of the second roller is opposite to that of the first roller, the fabric or nonwoven fabric that has come into contact with the side of the second roller comes into contact with the side of the second roller with the side of the second roller in contact with the side of the second roller. The fabric or nonwoven fabric contacts the side of the second roller and moves together with the second roller, then changes its direction of movement in a direction parallel to the bottom surface of the container and moves, contacting the side surfaces of the first roller, the second roller, and the last roller in turn. Since the rotation direction of the rollers is the same as the rotation direction of the second roller, the fabric or nonwoven fabric that has contacted the side surfaces of the rollers in turn moves through the suspension without changing its direction of movement and contacts the side surface of the second-to-last roller. Since the rotation direction of the roller is the same as the rotation direction of the second-to-last roller, the fabric or nonwoven fabric that has come into contact with the side of the second-to-last roller moves along with the second-to-last roller, with the side of the roller that is close to 1 / 4 of the way around, then changes its direction of movement upward, moves forward, and comes up from the suspension and comes into contact with the side of the last roller. Since the rotation direction of the last roller is opposite to the rotation direction of the second-to-last roller, the fabric or nonwoven fabric that has come into contact with the side of the last roller moves along with the last roller. The side of the fabric or nonwoven fabric that is approximately 1 / 4 of the length of the roll contacts the side of the last roller and moves together with the last roller, and then changes its moving direction toward the gap between two work rolls that make up the multi-stage rolling mill used in the third step. This series of processes for the fabric or nonwoven fabric, from the scene where the fabric or nonwoven fabric unwound from the roll contacts the first roller to the scene where the fabric or nonwoven fabric contacts the last roller and changes its moving direction toward the gap between two work rolls that make up the multi-stage rolling mill, isa second step carried out as a continuous treatment on the fabric or nonwoven fabric; First, two work rolls constituting a multi-stage rolling mill have five characteristics: first, they have the same width, which is wider than the width of the sheet to be produced; second, they have the same diameter, which is smaller than 1 / 10 of the width of the sheet; third, the gap is set to the thickness of the sheet to be produced; fourth, they rotate in opposite directions to each other at the same peripheral speed as the peripheral speed at which the plurality of rollers rotate in the first step; and fifth, they are heated to a temperature 10°C higher than the boiling point of the alcohol constituting the suspension in the first step. A spreading machine is prepared. Next, the tip of the fabric or nonwoven fabric that has been processed in the second step is inserted into the gap between the two work rolls. As a result, the tip of the fabric or nonwoven fabric is drawn into the gap between the two work rolls, and the fabric or nonwoven fabric is continuously subjected to a compressive stress according to the size of the gap between the two work rolls. At this time, first, alcohol evaporates from the suspension that has been evenly attached to the fabric or nonwoven fabric, and the powder that constitutes the suspension is deposited on the fabric or nonwoven fabric in layers, and the fabric or nonwoven fabric is then compressed. The cloth is covered with the powder mass, and then a compressive stress begins to be applied to the overlapping and deposited powder masses and the cloth or nonwoven fabric, and first the surface layer of the powder mass collapses, and the surface layer of the powder mass deposited on the edge of the cloth or nonwoven fabric moves to the edge and overlaps at the edge, and the surface layer of the powder mass deposited other than the edge moves to the rear side of the gap between the two work rolls, and then the compressive stress is applied to the powder mass and the cloth or nonwoven fabric, and the powder mass is compressed. The fabric or nonwoven fabric is compressed and deformed, and the fabric or nonwoven fabric is broken and divided by the shear stress applied by the contacting powder. The powder moves to the broken parts of the fabric or nonwoven fabric and to the voids in the fabric or nonwoven fabric, and the divided fabric or divided nonwoven fabric is covered with the powder clusters. A compressive stress is applied to the powder clusters, and the powder clusters covering the divided fabric or divided nonwoven fabric are dispersed at all contact points where adjacent powders come into contact with each other.The powder particles are joined together by friction welding, and the group of powder particles joined by friction welding is joined to the divided fabric or the divided nonwoven fabric by friction welding, covering the entirety of the divided fabric or the divided nonwoven fabric. Furthermore, the overlapping groups of powder particles are joined together by friction welding at all contact points where the powder particles come into contact with each other, and further, the group of powder particles joined by friction welding is joined by friction welding to the group of powder particles joined by friction welding that covers the entirety of the divided fabric or the divided nonwoven fabric. As a result, the entirety of the divided fabric or the divided nonwoven fabric is separated from the group of powder particles joined by friction welding. a third step in which the divided fabric or the divided nonwoven fabric is covered with a coating consisting of an aggregate of powder joined by friction welding, and the aggregate of powder sandwiched between the two work rolls and the fabric or the nonwoven fabric are successively covered with a coating consisting of an aggregate of powder joined by friction welding, and a sheet consisting of the divided fabric or the divided nonwoven fabric entirely covered with the coating is discharged from the gap between the two work rolls, and the discharged sheet is wound up by a winding device that rotates at the same rotational speed as the two work rolls; By continuously carrying out all of these three steps, a sheet is continuously produced in which a cloth or nonwoven fabric is entirely covered with a coating formed by an aggregation of micron-sized powder particles made of one of a metal, alloy, metal oxide, or nitride material joined by friction welding; a method for continuously producing a sheet in which a cloth or nonwoven fabric is entirely covered with a coating formed by an aggregation of micron-sized powder particles made of one of a metal, alloy, metal oxide, or nitride material joined by friction welding.

[0012] By continuously carrying out all of the treatments in the three steps described below, a sheet can be continuously produced in which a woven or nonwoven fabric is entirely covered with a coating formed by an aggregation of micron-sized powder particles made of one type of material, either metal, alloy, metal oxide, or nitride, which are joined by friction welding. Here, the details of the treatments in the three steps and the effects of the treatments will be explained. The first step involves determining the required weight of powder—a metal, alloy, metal oxide, or nitride—for continuous sheet production. A larger weight of powder than the previously determined weight is then poured into a container fitted with multiple cylindrical rollers, the container having a width greater than the width of the sheet to be produced and a length long enough to accommodate the multiple cylindrical rollers. Furthermore, alcohol with a viscosity of 3-11 mPa·sec at 20°C is poured into the container in an amount sufficient to immerse all but the first and last cylindrical rollers. The alcohol is then stirred to create a suspension in which the powder particles are dispersed. While fabrics and nonwoven fabrics contain numerous microscopic voids, the alcohol that makes up the suspension has a viscosity of 3-11 mPa·sec at 20°C, allowing the suspension to fill the voids and adhere to the surfaces of the fabrics and nonwoven fabrics. In addition, a plurality of cylindrical rollers, each having the same length and diameter as the width of the container, are installed in the container at a distance from each other and parallel to the width of the container. The first roller is a roller for conveying the fabric or nonwoven fabric used in the second step, the fabric or nonwoven fabric being drawn out from a roll of fabric around which the fabric or nonwoven fabric is wound. on the side of the roller The second roller is placed in the container at a position where it contacts the top and is at least 1 cm away from one side surface that defines the width of the container. The second roller is placed at a position where it contacts the top and is at least 1 cm away from one side surface that defines the width of the container. moreoverThe penultimate roller is installed at a position in the container that is at least 1 cm away from the bottom of the container. The last roller is installed at a position in the container that is at least 1 cm away from the other side surface that forms the width of the container and at the same height as the first roller. The penultimate roller is installed at a position at which the last roller is installed at a position at which the second to last roller is at a position at which the last roller is installed at a position at which the last roller is at a position at which the second to last roller is at a position at which the last roller is installed at a position at which the last roller is at a position at which the last roller is at a position at which the second to last roller is at a position at which the last roller is installed at a position at which the last roller is at a position at which the second to last roller is at a position at which the last roller is at a position at which the last roller is installed at a position at which the second to last roller is at a position at which the last roller is at a position at which the last roller is installed at a position at which the second to last roller is at a position at which the last roller is at a position at which the last roller is installed at a position at which the second to last roller is at a position at which the last roller is installed at a position at which the last roller is at a position at which the second to last roller is at a position at which the last roller is installed ... moreover The remaining rollers are placed at equal intervals, with a distance of no more than twice the diameter of the cylindrical roller between the second roller and the penultimate roller, at least 1 cm from the bottom of the same container as the second roller. Important elements involved in the production of the sheet in the present invention include, first, a method for continuously producing the sheet, second, the coating having airtightness to block gas, and third, the sheet having mechanical strength. First, to continuously produce a sheet, the moving speeds of the fabric or nonwoven fabric described below were set to the same speed. That is, the fabric or nonwoven fabric was continuously unwound from the roll at a speed equivalent to the peripheral speed of the cylindrical rollers installed inside the container, and the two work rolls constituting the multi-stage rolling mill were rotated in opposite directions at the same peripheral speed as the cylindrical rollers. Furthermore, the sheet discharged from the gap between the two work rolls was wound up on a winding device rotating at the same speed as the two work rolls. For this reason, the speed at which the fabric or nonwoven fabric was continuously unwound from the roll was set to the same speed as the peripheral speed of the cylindrical rollers, the peripheral speed of the two work rolls was set to the same speed as the peripheral speed of the cylindrical rollers, and the winding device for winding the sheet was rotated at the same speed as the two work rolls. Second, all voids in the coating are confined within the coating, resulting in a coating with no voids communicating with the outside world. To achieve this, the required number of powder particles must be deposited on the surface of the fabric or nonwoven fabric in overlapping layers, and then the overlapping powder particles must be uniformly compressed to join all contact points between adjacent powder particles by friction welding. This requires sufficient time for the powder particles and the fabric or nonwoven fabric to come into contact with the two work rolls and be subjected to compressive stress from the two work rolls. For this reason, the two work rolls were rotated at a slow peripheral speed, similar to multiple cylindrical rollers, with one rotation taking longer than 20 seconds. Furthermore, because the fabric or nonwoven fabric moves slowly through the suspension, the suspension adheres evenly to the entire fabric or nonwoven fabric with a thickness corresponding to the viscosity of the alcohol. Since each powder has a specific shape, particle size distribution, and hardness, the amount of powder required to form a coating that does not have voids communicating with the outside world and the appropriate gap between the two work rolls were determined in advance by repeated experiments for each powder used. Third, in a coating made of a collection of powder particles bonded by friction welding, adjacent powder particles are bonded by friction welding at all contact points, and overlapping powder particles are bonded by friction welding at all contact points. Therefore, the coating has mechanical strength based on the bonding force between the powder particles. Therefore, the sheet has mechanical strength based on the bonding force between the powder particles. Next, we will explain why the viscosity of the alcohol that makes up the suspension is varied. The suspension is applied to a fabric or nonwoven fabric, and then the alcohol is evaporated, causing powder to deposit on the fabric or nonwoven fabric in an overlapping manner. The overlapping and deposited powder mass is then compressed. At this time, the behavior of the compressed powder differs depending on the shape of the powder and also on the plastic deformation of the powder. In other words, since the size of the powder varies in the powder mass, many voids are formed in the overlapping and deposited powder mass. Next, when the powder mass is compressed, the more symmetrical the powder is in its shape, the more the powder moves to fill the voids in the powder mass. However, the movement of the powder does not fill all the voids. After this, adjacent powders are joined by friction welding at all contact points. However, it is not possible to confine all the voids in the powder mass joined by friction welding within the joined powder mass. For this reason, the overlapping In a collection of powder By joining powder particles together by friction welding, all voids in the group of powder particles joined by friction welding can be confined within the joined group of powder particles. On the other hand, when the group of powder particles is compressed, the powder particles move to fill the voids in the group of powder particles, but the more symmetrical the shape of the powder, the less voids in the group of powder particles are filled by the powder particles. Therefore, the more symmetrical the shape of the powder, the more powder particles are overlapped and joined together by friction welding, thereby confining all voids in the group of powder particles joined by friction welding within the joined group of powder particles. Therefore, when using powder particles with a less symmetrical shape, a high-viscosity alcohol is used. On the other hand, there are powders that have a relatively low hardness and undergo plastic deformation under compressive stress. In other words, when compressive stress is applied evenly to a group of powders, the powders undergo plastic deformation, and the plastically deformed powders fill adjacent voids, reducing the voids. However, not all voids are filled by the plastic deformation of the powders. For this reason, overlapping particles In a collection of powderThe powder particles are joined together by friction welding, and all voids in the group of powder particles joined by friction welding are enclosed within the group of joined powder particles. Therefore, when using powder particles that undergo a large proportion of plastic deformation under compressive stress, the number of powder particles that are overlapped is smaller than that of powder particles that undergo a small proportion of plastic deformation under compressive stress. In a collection of powder By joining powders together by friction welding, all voids in the group of powders joined by friction welding are confined within the group of joined powders. Therefore, when using powders that undergo a large proportion of plastic deformation under compressive stress, an alcohol with a lower viscosity is used compared to when using powders that undergo a small proportion of plastic deformation under compressive stress. Furthermore, powders are small, on the order of microns, and light in weight, but the size of the powder varies greatly depending on the type of powder. Meanwhile, the surface area of ​​the powder is proportional to the size of the powder. Therefore, in order to join overlapping powder particles by friction welding and confine all voids within the joined powder particles, the smaller the powder size, the greater the number of overlapping powder particles required. Therefore, the smaller the powder size, the higher the viscosity of the alcohol used. As a result, the smaller the powder size, the thicker the suspension adsorbed to the surface of the fabric or nonwoven fabric. As explained above, the behavior of compressed powder varies depending on the shape of the powder and the plastic deformation of the powder. Therefore, the thickness of the suspension applied to the entire woven or nonwoven fabric should be increased for powders with poor symmetry, high hardness, or small size. The gap between the two work rolls and the applied compressive stress are also changed depending on the hardness of the powder. For these reasons, the viscosity of the alcohol was changed depending on the symmetry, hardness, and size of the powder used. The gap between the two work rolls was also changed depending on the hardness of the powder used, changing the magnitude of the compressive stress applied to the powder mass. In the second step, a roll of fabric or nonwoven fabric having the width of the sheet to be produced is first prepared and set in a drawing device, and then the fabric or nonwoven fabric is continuously drawn from the roll at a speed equivalent to the peripheral speed of the cylindrical rollers in the first step. Also, a plurality of cylindrical rollers are rotated at the same peripheral speed such that the time required for one rotation is longer than 20 seconds. Furthermore, the drawn out fabric or nonwoven fabric is SideThe fabric or nonwoven fabric comes into contact with the top, then comes into contact with the side of the first roller approximately one-quarter of the way up, moving together with the first roller, then changes direction downward and moves, immersed in the suspension, and then comes into contact with the side of the second roller. Because the rotation direction of the second roller is opposite to that of the first roller, the fabric or nonwoven fabric that comes into contact with the side of the second roller comes into contact with the side of the second roller approximately one-quarter of the way up, moving together with the second roller, then changes direction and moves in a direction parallel to the bottom of the container, coming into contact with the side of the multiple rollers in sequence, excluding the second roller and the last roller. Because the rotation direction of the multiple rollers is the same as that of the second roller, the fabric or nonwoven fabric that comes into contact with the side of the multiple rollers in sequence continues through the suspension without changing direction, and comes into contact with the side of the penultimate roller. Because the rotation direction of the penultimate roller is the same as the rotation direction of the second roller, the fabric or nonwoven fabric that has come into contact with the side of the penultimate roller comes into contact with the side of the penultimate roller about one-quarter of the way around and moves together with the penultimate roller, then changes its direction of movement upward, moves forward, rises from the suspension, and comes into contact with the side of the last roller. Because the rotation direction of the last roller is opposite to the rotation direction of the penultimate roller, the fabric or nonwoven fabric that has come into contact with the side of the last roller comes into contact with the side of the last roller about one-quarter of the way around and moves together with the last roller, then changes its direction of movement toward the gap between two work rolls that make up the multi-stage rolling mill used in the third step. As the fabric or nonwoven fabric moves horizontally from the second roller to the penultimate roller at a slow speed equivalent to the peripheral speed of the cylindrical rollers, the powder constituting the suspension adsorbed on the surface of the fabric or nonwoven fabric is subjected to a load because the powder is small (micron-sized) and lightweight. This load causes the powder to rearrange in the suspension depending on the symmetry of its shape. The suspension also adsorbs to the edges of the fabric or nonwoven fabric, covering them, thereby covering the entire fabric or nonwoven fabric with the suspension.The processing of the fabric or nonwoven fabric described above is carried out as a continuous process on the fabric or nonwoven fabric, because the moving speed of the fabric or nonwoven fabric is the same from the moment the fabric or nonwoven fabric is pulled out from the roll and comes into contact with the side of the first roller to the moment the fabric or nonwoven fabric comes into contact with the side of the last roller and changes direction and moves toward the gap between the two work rolls that make up the multi-stage rolling mill. Furthermore, the suspension adheres to the entire surface of the fabric or nonwoven fabric immersed in the suspension, with a thickness corresponding to the viscosity of the suspension. The third process involves preparing a multi-high rolling mill having two work rolls with the following five characteristics: first, the two work rolls have the same width, wider than the width of the sheet to be produced; second, the same diameter, smaller than 1 / 10 of the width of the sheet; third, the gap is set to the thickness of the sheet to be produced; fourth, they rotate in opposite directions at the same peripheral speed as the rollers in the first process; and fifth, they are heated to a temperature 10°C higher than the boiling point of the alcohol constituting the suspension in the first process. The reason for using a multi-high rolling mill is that although the width of the two work rolls is wider than the width of the sheet to be produced, the diameter of the two work rolls is smaller than 1 / 10 of the width of the sheet. Therefore, when the two work rolls rotate in opposite directions, they elastically deform. A multi-high rolling mill was used to suppress this elastic deformation of the two work rolls by rotating the other backup rolls. As a result, the compressive stress applied from the gap between the two work rolls to the woven or nonwoven fabric and the powder mass is continuously and uniformly applied. An example of a multi-stage rolling mill is a 12-stage rolling mill. difference Furthermore, the rotational speed of the two work rolls is such that the time required for one rotation is longer than 20 seconds, ensuring sufficient contact time between the two work rolls, the fabric or nonwoven fabric, and the powder mass, and preventing the powder mass that has deposited on top of the fabric or nonwoven fabric from falling off. Next, the leading end of the fabric or nonwoven fabric that has been processed in the second step is inserted into the nip between the two work rolls, and the leading end of the fabric or nonwoven fabric is pulled into the nip between the two work rolls, and the powder mass and the fabric or nonwoven fabric are continuously subjected to compressive stress from the nip between the two work rolls, the magnitude of which depends on the gap between the two work rolls. At this time, when the fabric or nonwoven fabric that has been processed in the second step approaches the gap between the two work rolls, The entire surface of The alcohol evaporates from the suspension adhering to the surface, and powder particles are deposited in piles at the site where the alcohol has evaporated. Next, compressive stress begins to be applied to the pile of powder particles deposited on the fabric or nonwoven fabric, and the surface layer of the powder particles collapses first, and the powder particles deposited at the edge of the fabric or nonwoven fabric collapse. end The surface layer of the majority of the powder mass that has deposited outside the edges moves to the rear side of the gap between the two work rolls. After this, compressive stress is applied to the powder mass and the fabric or nonwoven fabric. At this time, the fabric or nonwoven fabric is compressed and deformed, and furthermore, the shear stress applied by the powder in contact with it causes Fabric or nonwoven fabricThe fabric or nonwoven fabric is broken. On the other hand, because the powder is small, on the order of microns, and the fabric or nonwoven fabric is covered with a cluster of powder, a great deal of powder comes into contact with the fabric or nonwoven fabric, forming a great number of broken locations in the fabric or nonwoven fabric. This causes the fabric or nonwoven fabric to break. Furthermore, because compressive stress is applied to the clusters of powder, the powder moves to the broken locations in the fabric or nonwoven fabric and into the voids in the fabric or nonwoven fabric, and the broken fabric or nonwoven fabric is filled with powder. In other words, as described in paragraph 1, the fabric has a great number of voids on its surface, but because compressive stress is applied to the clusters of powder, the powder moves and a great number of voids are filled with powder. Furthermore, as described in paragraph 1, nonwoven fabrics are porous and have many voids, but because compressive stress is applied to the powder clusters, the powder moves and the voids on the front and back surfaces of the nonwoven fabric are filled with powder. Furthermore, compressive stress is continuously applied to the powder clusters, and the powder clusters covering the divided fabric or divided nonwoven fabric are joined by friction welding at all contact points where adjacent powder clusters come into contact, and the powder clusters joined by friction welding cover the entire divided fabric or divided nonwoven fabric. Furthermore, the overlapping powder clusters are joined by friction welding at all contact points where powder clusters come into contact, The new powder particles joined by the friction welding are The divided fabric or divided nonwoven fabric is joined by friction welding that covers the entire surface. The aforementioned The powder is joined to the aggregate by friction welding. As a result, the divided fabric or divided nonwoven fabric is entirely covered with a coating made of the aggregate of powder joined by friction welding. This phenomenon from the evaporation of the alcohol to the entire divided fabric or divided nonwoven fabric being covered with a coating made of the aggregate of powder joined by friction welding occurs continuously for the aggregate of powder sandwiched between the two work rolls and the fabric or nonwoven fabric. As a result, the entire divided fabric or divided nonwoven fabric is entirely covered with a coating made of the aggregate of powder joined by friction welding. coveredA sheet covered with a film is discharged from the gap between the two work rolls and wound up by a winding device that rotates at the same speed as the two work rolls. As a result, the speed of the fabric or nonwoven fabric is the same from the time it is pulled out of the roll to the time it is wound up by the winding device, allowing for continuous production of the sheet. The powder mass joined by friction welding traps all voids within the joined powder mass, forming a coating with no voids communicating with the outside world. The coating, consisting of agglomerated powder particles, is made up of overlapping and bonded micron-sized particles, with a thickness of less than 0.25 mm. In other words, the thinner the coating, consisting of agglomerated powder particles bonded by friction welding, the less powder is required, making it cheaper to manufacture the sheet. This also means that the sheet is lighter and easier to cut. Furthermore, if the powder is plastically deformable, the cut sheet can be easily bent. However, because each powder has a unique shape, particle size distribution, and hardness, the amount of powder required to form a coating without voids communicating with the outside world and the appropriate gap between the two work rolls were determined through repeated experiments using different powders. By performing all three of these steps in succession in order, sheets are continuously produced, resulting in the continuous production of sheets consisting of a woven or nonwoven fabric entirely covered with a coating formed by an aggregation of one type of powder made of a metal, alloy, metal oxide, or nitride, each of which is micron-sized and joined by friction welding. The sheet thus manufactured exhibits the following effects and solves the 13 problems described in paragraph 10. First, the sheet can be produced continuously. That is, the peripheral speed at which multiple cylindrical rollers installed inside the vessel rotate at the same speed corresponds to the speed at which the fabric or nonwoven fabric is continuously drawn off the roll of material, and the peripheral speed at which the two work rolls of the multi-stage rolling mill rotate is the same as the peripheral speed at which the multiple cylindrical rollers rotate. Furthermore, the sheet discharged from the gap between the two work rolls is wound up by a winding device that rotates at the same speed as the rotational speed of the two work rolls. Therefore, the moving speed of the fabric or nonwoven fabric is the same, and the sheet can be produced continuously. Second, the sheet can be cut. In other words, the coating, which is made of a group of powder particles joined by friction welding, is made up of overlapping groups of micron-sized powder particles, and the thickness of the joined powder particles is less than 0.25 mm. Therefore, even if the powder is very hard, the sheet can be cut. This allows it to be processed into sheets of various sizes and shapes. Third, the cut sheet can be pressure-bonded to substrates or parts of various materials. In other words, when the sheet is placed on the surface of a substrate or part made of various materials and shapes and the surface of the sheet is compressed, the convex parts of the uneven surface of the sheet come into contact with the surface of the substrate or part, and the frictional heat generated at this contact point bonds the sheet to the surface of the substrate or part. Fourth, the sheet is non-flammable. In other words, in the third step of paragraph 11, when the alcohol evaporates, a cluster of powder particles that overlaps with no gaps is deposited on the fabric or nonwoven fabric. At this time, because there is variation in the size of the powder particles, and depending on the symmetry of the powder shape, many voids are formed in the cluster of powder particles that are deposited overlapping with each other. Next, when the cluster of powder particles is compressed, the more symmetrical the powder is, the more the powder moves to fill the voids in the cluster of powder. However, the movement of the powder does not fill all the voids. After this, adjacent powder particles are joined by friction welding at all contact points. However, it is not possible to confine all the voids in the cluster of powder particles that are joined by friction welding within the joined cluster of powder. For this reason, In a collection of powder The powders are joined together by friction welding, and then the powders joined by friction welding are subjected to the following process: A new collection of powderBy joining by friction welding, all voids in the powder mass joined by friction welding can be confined within the joined powder mass. On the other hand, when powder has a shape that is less symmetrical, when the powder mass is compressed, the powder moves to fill the voids in the powder mass, but because the powder has poor symmetry, many of the voids in the powder mass are not filled with the powder. Therefore, when powder has a shape that is less symmetrical, more powder masses are overlapped and joined together by friction welding, so that all voids in the powder mass joined by friction welding can be confined within the joined powder mass. Furthermore, the size of the powder varies greatly depending on the type of powder. Since the surface area of ​​a powder depends on the size of the powder, when the powder size is small, more powder particles can be overlapped and joined by friction welding, thereby confining all voids in the group of powder particles joined by friction welding within the group of joined powder particles. There are also powders that have low hardness and are easily plastically deformed by compressive stress. In other words, when compressive stress is applied evenly to a collection of powders, the powders undergo plastic deformation, and the plastically deformed powders fill adjacent voids, reducing the voids. However, not all voids are filled by the plastic deformation of the powders. For this reason, overlapping powders In a collection of powder The powder particles are joined together by friction welding, and all voids in the group of powder particles joined by friction welding are By friction welding It can be trapped inside a mass of bonded powder. As a result, all voids in the powder mass joined by friction welding are By friction welding It is trapped inside the cluster of joined powder particles. By friction welding The coating, made of a collection of bonded powder particles, provides the fabric or nonwoven fabric with airtightness, blocking out gases. This makes the flammable fabric or nonwoven fabric nonflammable, not only preventing the fabric or nonwoven fabric from burning but also preventing the release of flammable substances produced when the fabric or nonwoven fabric thermally decomposes. Therefore, the sheet acts as a nonflammable sheet that prevents the spread of fire and also suppresses the generation of harmful gases that accompany the spread of fire. Fifth, the cut sheets are also non-flammable. In other words, in the third step of paragraph 11, when compressive stress is applied to the powder clusters and the fabric or nonwoven fabric, the fabric or nonwoven fabric undergoes compressive deformation. Furthermore, the powder in contact with the fabric or nonwoven fabric applies shear stress to the fabric or nonwoven fabric, causing it to break at the locations where shear stress is applied. Meanwhile, because the powder is micron-sized and the entire fabric or nonwoven fabric is covered with the powder clusters, a large amount of powder comes into contact with the fabric or nonwoven fabric, creating a large number of breaks in the fabric or nonwoven fabric. This causes the fabric or nonwoven fabric to break apart. In addition, the collection of powders covering the entire divided fabric or divided nonwoven fabric has adjacent powder particles joined by friction welding at all contact points where they come into contact, and the collection of powders joined by friction welding covers the entire divided fabric or divided nonwoven fabric. Furthermore, the collection of overlapping powder particles has overlapping powder particles joined by friction welding at all contact points where they come into contact. Newly Friction welding that joins and covers the entire divided fabric or divided nonwoven fabric already The powder particles are then friction-welded to the divided fabric or nonwoven fabric. As a result, the entire divided fabric or nonwoven fabric is covered with a coating made of the powder particles bonded by friction welding. This coating does not have any voids that communicate with the outside world. Therefore, even if a portion of the divided fabric or nonwoven fabric is exposed to a flammable atmosphere on the cross section of a cut sheet, the powder particles are firmly bonded to the divided fabric or nonwoven fabric by friction welding, so that the burn damage to the fabric or nonwoven fabric is limited to the portion of the divided fabric or nonwoven fabric that is exposed on the cross section of the cut sheet. Therefore, the cut sheet is non-flammable. Sixth, it has the mechanical strength of a sheet. In other words, when the powder mass is compressed in the third step of paragraph 11, the powder mass is joined by friction welding at all contact points where adjacent powder masses come into contact, and the joined powder mass forms a coating. already formed Compressive stress is applied evenly to the entire coating, NewThe coating is bonded to the entirety of the divided woven fabric or divided nonwoven fabric by friction welding, so the coating provides bonding strength between the powder particles, and the sheet covered with the coating has the mechanical strength of a sheet. Seventh, if the powder is made of a metal or an alloy, the sheet becomes a conductive sheet, and if the powder is made of a metal oxide or nitride, the sheet becomes an insulating sheet. In other words, a coating made of a collection of powder particles that are joined by friction welding at all contact points where adjacent powder particles come into contact covers the entire divided fabric or divided nonwoven fabric. Therefore, if the powder is made of a metal or alloy, a continuous path for current to flow is formed in the coating. As a result, the sheet has conductivity based on the conductivity of the powder made of a metal or alloy. Also, if the powder is made of a metal oxide or nitride, the coating forms an insulating coating. On the other hand The resistance of the sheet is proportional to the resistivity of the metal oxide or nitride, inversely proportional to the cross-sectional area of ​​the coating, and proportional to the length of the coating. Because the thickness of the coating is extremely thin, the insulation resistance of the sheet is high. Eighth, the multiple rollers from the second roller to the penultimate roller constantly agitate the suspension, ensuring consistent dispersion of the powder in the suspension. Therefore, the fabric or nonwoven fabric passes through the constantly agitated suspension at a low speed, ensuring consistent powder volumetric ratios in the suspension adsorbed to the fabric or nonwoven fabric. Furthermore, the gap between the two work rolls remains constant. This allows for continuous production of sheets with a predetermined conductivity when using powders made of metals or alloys. Furthermore, for powders made of metal oxides or nitrides, continuous production of sheets with a predetermined insulating property is achieved. Ninth, the sheet is water-repellent, meaning it repels all liquids. In other words, a coating formed by a collection of powder particles bonded by friction welding covers the entirety of the divided fabric or divided nonwoven fabric. Because the surface of this coating is composed of a collection of powder particles bonded by friction welding, the surface of the coating is water-repellent, meaning that all liquids are repelled by the surface tension of the liquid. This allows the sheet to function as a corrosion-resistant sheet based on the corrosion resistance of the powder. On the other hand, powders made of metal oxides or nitrides have better corrosion resistance than powders made of metals or alloys, so a sheet made of a collection of metal oxide or nitride powders functions as an even more corrosion-resistant sheet. Tenth, the sheet has heat resistance equivalent to the heat resistance temperature of the powder. In other words, a coating formed by the aggregation of powders joined by friction welding covers the entirety of the divided fabric or divided nonwoven fabric. This coating has heat resistance equivalent to the heat resistance temperature of the powder. Note that the heat resistance temperature of many of the powders is significantly higher than the thermal decomposition temperature of the fabric or nonwoven fabric. Therefore, when the coating is heated to a temperature above the temperature at which the fabric or nonwoven fabric thermally decomposes, the fabric or nonwoven fabric thermally decomposes, but the thermally decomposed substances are trapped within the coating. Therefore, the coating remains nonflammable even when heated to a temperature above the temperature at which the fabric or nonwoven fabric thermally decomposes. On the other hand, powders made of metal oxides or nitrides have better heat resistance than powders made of metals or alloys, so a sheet covered with a coating formed by an aggregation of powders made of metal oxides or nitrides functions as an even more heat-resistant sheet. Furthermore, since only a portion of the woven fabric or nonwoven fabric exposed at the cut surface of the cut sheet is burned, the cut sheet also has heat resistance equivalent to the heat resistance temperature of the powder. Eleventh, there are no restrictions on the material of the powder used to form the sheet. In other words, the coating is formed by applying compressive stress to a group of powder particles and joining all contact points between adjacent powder particles by friction welding, so there are no restrictions on the material of the powder used to form the coating. As a result, the sheet has the inherent properties of the powder that makes up the coating. On the other hand, powders made of metals, alloys, metal oxides, or nitrides have inherent properties for each powder material. Therefore, the sheet has the various properties of the powder, allowing it to be used for an extremely wide range of applications. Twelfth, the friction welding is performed to join the powder particles. vinegar The woven or nonwoven fabrics used are not limited in material or size, making it possible to form lightweight, versatile sheets. Thirteenth, the sheet can be manufactured using an inexpensive manufacturing method. In other words, all three steps described in paragraph 11 are extremely simple. Furthermore, the materials used are powders of micron-sized metals, alloys, metal oxides, or nitrides, which are general-purpose industrial materials; woven or nonwoven fabrics, which are extremely inexpensive industrial products; and alcohol, which is a general-purpose organic solvent. Therefore, the sheet can be manufactured inexpensively. This allows the sheet to be used for a variety of purposes. As described above, the method for producing a sheet of the present invention satisfies the 13 requirements described in paragraph 10. Therefore, all of the 13 problems described in paragraph 10 are solved. As explained in paragraph 1, fabric is made by weaving warp and weft threads made of natural or synthetic fibers. There are three types of weaving: plain weave, twill weave, and satin weave. Plain weave is the simplest method, in which warp and weft threads alternate. Because the front and back fabrics are woven in the same way, it is resistant to friction and durable. This makes it suitable for creating thin, lightweight fabrics. Twill weave is a weaving method in which warp threads cross multiple weft threads. While plain weave tends to produce stiff fabrics, twill weave produces softer fabrics. Satin weave, also known as satin, is a weaving method in which the intersections between warp and weft threads are minimized, leaving long warp or weft threads floating on the surface of the fabric. The fabric used in this invention does not require a more expensive satin weave; it is appropriate to use a cheaper plain weave or twill weave. Furthermore, the fabric has an extremely large number of uneven recesses and voids on its surface, and these uneven recesses and voids serve as a means for supporting the aggregation of fine powder in the present invention. For this reason, the fabric is suitable as a frame for supporting the aggregation of powder. As explained in paragraph 1, nonwoven fabrics are fabrics made by collecting fibers in a unidirectional or random manner and chemically bonding them with adhesive resins, mechanically entangling them, entangling them with a pressurized water stream, or bonding them with heat-sealed fibers. This makes them porous and provides breathability, filtering, and moisture retention. Therefore, nonwoven fabrics can be formed into sheets directly from fibers, eliminating the need for fiber spinning, as is the case with woven and knitted fabrics. This allows for lower production costs than woven and knitted fabrics. Nonwoven fabrics also contain an extremely large number of voids, which serve as a means for supporting the fine powder clusters described in this invention. Therefore, nonwoven fabrics are suitable as frames for supporting powder clusters. Natural fibers, chemical fibers, and glass fibers are used as raw materials for nonwoven fabrics.

[0013] The method for continuously producing a sheet having a structure in which a woven fabric or nonwoven fabric is entirely covered with a coating formed by an aggregation of powder particles made of one of the materials of metal, alloy, metal oxide, or nitride, each having a micron size, which are joined together by friction welding as described in paragraph 11, is as follows: The alcohol having a viscosity of 3-11 mPa·s at 20°C as described in paragraph 11 is any one of 1-butanol, 1-pentanol, 2-pentanol, 3-methyl-1-butanol, 2-methyl-2-butanol, 2-butanol, 2-heptanol, isobutyl alcohol, 2-methyl-1-butanol, 1-hexanol, 1-heptanol, 2-octanol, 3-pentanol, 1-octanol, 2-ethyl-1-hexanol, isooctyl alcohol, and 1-nonanol. and any one of the alcohols described in paragraph 11 having a viscosity of 3-11 mPa·sec at 20°C is used, and the method of continuously carrying out all of the three steps described in paragraph 11 is a method for continuously producing a sheet having a configuration in which a woven fabric or nonwoven fabric is entirely covered with a coating formed by an aggregation of micron-sized powder particles made of one of metals, alloys, metal oxides, and nitrides described in paragraph 11, which are joined by friction welding.

[0014] In other words, there are 17 types of alcohols with viscosities of 3-11 mPa·sec at 20°C. 1-Butanol CH3(CH2)3OH has a viscosity of 3.0 mPa·s at 20°C and a boiling point of 117°C. 1-Pentanol CH3(CH2)4OH has a viscosity of 3.3 mPa·s at 20°C and a boiling point of 138°C. 2-Pentanol CH3(CH2)2CH(OH)CH3 has a viscosity of 3.5 mPa·s at 20°C and a boiling point of 119°C. 3-Methyl-1-butanol (CH3)2CH(CH2)2OH has a viscosity of 3.7 mPa·s at 20°C and a boiling point of 131°C. 2-Methyl-2-butanol CH3CH2C(CH3)2OH has a viscosity of 3.8 mPa·s at 25°C and a boiling point of 103°C. 2-Butanol CH3CHOHCH2CH3 has a viscosity of 3.9 mPa·s at 20°C and a boiling point of 99°C. 2-Heptanol CH3(CH2)4CHOHCH3 has a viscosity of 4.0 mPa·s at 20°C and a boiling point of 159°C. Isobutyl alcohol (CH3)2CHCH2OH has a viscosity of 4.0 mPa·s at 20°C and a boiling point of 108°C. 2-Methyl-1-butanol CH3CH2CH(CH3)CH2OH has a viscosity of 5.1 mPa·s at 20°C and a boiling point of 128°C. 1-Hexanol CH3(CH2)5OH has a viscosity of 5.3 mPa·s at 20°C and a boiling point of 157°C. 1-Heptanol CH3(CH2)6OH has a viscosity of 5.8 mPa·s at 20°C and a boiling point of 176°C. 2-Octanol CH3(CH2)5CH(OH)CH3 has a viscosity of 6.2 mPa·s at 20°C and a boiling point of 178°C. 3-Pentanol (C2H5)2CHOH has a viscosity of 6.5 mPa·s at 20°C and a boiling point of 116°C. 1-Octanol CH3(CH2)7OH has a viscosity of 7.3 mPa·s at 20°C and a boiling point of 194°C. 2-Ethyl-1-hexanol, CH3(CH2)3CH(C2H5)CH2OH, has a viscosity of 9.8 mPa·s at 20°C and a boiling point of 185°C. Isooctyl alcohol (CH3)2CH(CH2)5OH has a viscosity of 10.6 mPa·s at 20°C and a boiling point of 188°C. 1-Nonanol CH3(CH2)8OH has a viscosity of 10.8 mPa·s at 20°C and a boiling point of 212°C. Therefore, by using any one of these 17 types of alcohol as the alcohol having a viscosity of 3-11 mPa·sec at 20°C described in paragraph 11 and performing all of the three steps described in paragraph 11 in sequence, a sheet can be continuously produced in which the entire surface of a fabric or nonwoven fabric is covered with a coating formed by an aggregation of powders bonded by friction welding. Furthermore, because the boiling points of these 17 types of alcohol are 212°C or less, the temperature to which the two work rolls of the multi-high rolling mill are heated in the third step described in paragraph 11 is low, making the third step easier.

[0015] A method for cutting a sheet produced by the method described in paragraph 11 into a predetermined shape and bonding the cut sheet to a predetermined position on the surface of a substrate or a part includes the steps of: A method for continuously producing sheets by the method described in paragraph 11, cutting the sheets into a predetermined shape, overlapping the cut sheets at predetermined positions on the surface of a substrate or a part, and evenly compressing the entire surface of the cut sheets, thereby causing the convex portions of the uneven surface of the cut sheets to come into contact with the surface of the substrate or the part on which the cut sheets are overlapped, and generating frictional heat at the contact points, which bonds the contact points together and bonds the cut sheets to the predetermined positions on the surface of the substrate or the part.

[0016] In other words, the coating made of powder particles joined by friction welding is a coating made of overlapping and bonded micron-sized powder particles, and the thickness of the bonded powder is less than 0.25 mm. This allows for cutting sheets even if the powder material is a hard alloy or metal oxide. This allows for processing into sheets of various sizes and shapes. The thickness of the produced sheet is determined by the gap between the two work rolls, so the thickness can be set in advance. Meanwhile, because the cut sheet is covered with a coating made of powder particles joined by friction welding, the surface of the cut sheet has irregularities similar to the size of the joined powder particles, as well as irregularities of the powder surface that appear on the cut sheet surface. Therefore, when the cut sheet is placed at a predetermined position on the surface of a substrate or part and the entire surface of the cut sheet is evenly compressed, the convex parts of the irregularities on the surface of the cut sheet come into contact with the surface of the substrate or part, generating frictional heat at the contact points, which then bond the contact points together. This allows the cut sheet to be bonded to a predetermined position on the surface of a substrate or part. The convex portions of the unevenness on the surface of the cut sheet are composed of convex portions of unevenness similar in size to the bonded powder and convex portions of the powder surface that appear on the surface of the cut sheet. Therefore, a huge number of these convex portions are formed, and the cut sheet bonds to the surface of the substrate or part through these extremely large convex portions, firmly bonding the cut sheet to the predetermined position on the surface of the substrate or part. Furthermore, frictional heat generated at the contact point on the surface of the substrate or part is generated and dissipated in a short time. Furthermore, the contact area where frictional heat is generated is extremely small. Therefore, even for substrates or parts made of materials with low heat resistance, such as synthetic resins, the cut sheet can be friction-welded to a predetermined position on the surface of the substrate or part. As a result, the cut sheet can be bonded to a predetermined position on the surface of substrates or parts made of various materials, imparting various powder properties to the predetermined position on the substrate or part. Although the fabric or nonwoven fabric may be visible in the cross section of a cut sheet, the fabric or nonwoven fabric inside the sheet is divided into countless pieces by aggregates of powder joined by friction welding, and furthermore, there are no voids communicating with the outside world in the aggregates of powder joined by friction welding. Therefore, even if the fabric or nonwoven fabric is exposed in the cross section of a cut sheet and is exposed to a flammable atmosphere, the burn damage of the fabric or nonwoven fabric is limited to the fabric or nonwoven fabric exposed in the cross section of the cut sheet, and the fabric or nonwoven fabric remains non-flammable except for the cross section of the cut sheet.

[0017] The method for continuously producing a sheet having a structure in which a woven fabric or nonwoven fabric is entirely covered with a coating formed by an aggregation of powder particles made of one of the materials of metal, alloy, metal oxide, or nitride, each having a micron size, which are joined together by friction welding as described in paragraph 11, is as follows: The powder described in paragraph 11 is a powder having any of a spherical, granular, or agglomerated shape, and the method of using the powder described in paragraph 11 and sequentially carrying out all of the three steps described in paragraph 11 is a method of continuously producing a sheet having a configuration in which a woven fabric or nonwoven fabric is entirely covered with a coating formed by an aggregation of micron-sized powders of one material selected from the group consisting of metals, alloys, metal oxides, and nitrides described in paragraph 11, which are joined by friction welding.

[0018] That is, there are eight types of shapes of powder made of a material of metal, alloy, metal oxide or nitride, each of which has a size on the micron scale, as explained below. First, there are powders with spherical, granular, or agglomerated shapes; second, powders with columnar, rod-like, needle-like, or fibrous shapes; third, powders with angular or horn-like shapes; fourth, powders with spongy shapes; fifth, powders with sponge-like shapes; sixth, powders with dendritic and porous shapes; seventh, powders with teardrop or spindle shapes; and eighth, powders with plate-like, flake-like, or scaly shapes with a high aspect ratio. These powder shapes are uniquely formed depending on the powder manufacturing method. The aspect ratio of a powder is the ratio of the long axis to the thickness of the powder. Therefore, powders with plate-like, flake-like, or scaly shapes have a larger aspect ratio than powders with other shapes. On the other hand, the coating formed by the friction-welded powder clusters in the present invention is a coating formed by overlapping and bonding micron-sized powder clusters, and the thickness of the bonded powder clusters is less than 0.25 mm. This allows the sheet to be cut, which is the second property described in paragraph 12. On the other hand, the shape of the powder used is limited in order for the coating formed by overlapping and bonding powder clusters to have the fourth property described in paragraph 12, which is airtightness that blocks gas. That is, the second step described in paragraph 11 ensures that the suspension is evenly applied to the entire fabric or nonwoven fabric. Furthermore, in the third step described in paragraph 11, after the alcohol evaporates from the suspension, the powder clusters that have been deposited on the fabric or nonwoven fabric are compressed. In this case, the more symmetrical the powder shape, the more easily the powder moves and fills voids in the powder clusters when compressed. Furthermore, the lower the hardness of the powder, the more the powder undergoes plastic deformation, and the plastically deformed powder fills adjacent voids and joins the adjacent powders by friction welding. Furthermore, the larger the powder size, the larger the powder's surface area. Therefore, the larger the powder size, the fewer powders are required to fill the voids in the powder cluster. On the other hand, all contact points between adjacent powders are joined by friction welding. Also, overlapping powder clusters are joined by friction welding. If all voids are confined within the powder cluster joined by friction welding, the coating formed by the joined powder cluster will have no voids communicating with the outside world and will be airtight, blocking gas. On the other hand, the more symmetrical the powder, the less likely it is to undergo plastic deformation. Symmetrical powders with high hardness are even more difficult to plastically deform, so the number of overlapping powder clusters must be increased. Therefore, the number of overlapping powder particles required for the coating to be airtight and block gas varies depending on the symmetry of the powder shape, the hardness of the powder, and the size of the powder. That is, powders with excellent symmetry, powders with low hardness, and powders with large size require relatively fewer overlapping powder particles. As mentioned above, micron-sized powders made of metals, alloys, metal oxides, or nitrides come in eight different shapes, with the most symmetrical shapes being spherical, granular, and agglomerated. Meanwhile, in the second step described in paragraph 11, the fabric or nonwoven fabric pulled from the roll moves horizontally through the suspension at a slow speed from the second roller to the penultimate roller. During this process, the powder particles adsorbed onto the surface of the fabric or nonwoven fabric are small and lightweight (micron-sized), so the movement of the fabric or nonwoven fabric places a load on the powder particles. This load causes the powder particles to rearrange in the suspension according to the symmetry of their shape. Because the powder particles vary in size, the alcohol causes them to overlap, filling in the gaps between them, increasing the density of the powder particles. Furthermore, if there are gaps in the powder mass, powder particles smaller than the gaps will enter and fill them. Therefore, among the eight types of powder shapes, the most symmetrical ones—spherical, granular, or agglomerated—have the smallest proportion of voids in the overlapping powder masses separated by alcohol. When the fabric or nonwoven fabric finishes moving through the suspension, the entire fabric or nonwoven fabric is evenly covered by the powder mass, interposed between the alcohol. Furthermore, as the fabric or nonwoven fabric approaches the gap between the two work rolls, the alcohol evaporates, and the powder precipitates on the fabric or nonwoven fabric, overlapping and covering it evenly. When this powder mass is evenly compressed, the initial small voids in the powder mass are further reduced by the movement of the powder due to the powder's highly symmetrical shape. Next, if the powder has low hardness, the powder undergoes plastic deformation, and the plastically deformed powder comes into contact with adjacent powder and is joined by friction welding. Furthermore, all adjacent powders are joined by friction welding at all contact points. Also, overlapping powders are joined at all contact points. As a result, all voids present in the group of joined powders are confined within the group of powders joined by friction welding, and no voids communicate with the outside world. Therefore, the coating has airtightness that blocks gas.Therefore, when a powder with excellent symmetry is used, the proportion of voids in the powder mass is minimized after the alcohol evaporates. Furthermore, when the powder mass is compressed, the small voids in the powder mass are further reduced by the movement of the powder, allowing for a thinner powder mass where overlapping powder particles are joined. Therefore, the thickness of the suspension applied to the fabric or nonwoven fabric is thin. Furthermore, when the powder has low hardness, the powder undergoes plastic deformation, and the plastically deformed powder fills the small voids and contacts adjacent powder particles, joining them by friction welding. However, the more symmetric the powder mass, the less likely it is to undergo plastic deformation, and powders with high hardness are even less susceptible to plastic deformation. Applying excessive compressive stress to such powders will result in their pulverization. Therefore, for powders with excellent symmetry, the gap between the two work rolls and the compressive stress applied to the powder are adjusted depending on the powder's hardness. As explained above, the thickness of the suspension to be applied to the fabric or nonwoven fabric required to form an airtight coating that blocks gas is thin when powders having a spherical, granular, or agglomerated shape are used. Therefore, of the eight types of powder shapes mentioned above, powders having a spherical, granular, or agglomerated shape are suitable for forming an airtight coating that blocks gas.

[0019] The powders described in paragraph 17, which are spherical, granular or agglomerated in shape, The powders produced by gas atomization include copper powder, tin powder, copper-tin alloy powder, tantalum powder, niobium powder, Fe-based alloy having a composition of Fe-17Cr-12Ni-Mo, Ni-based alloy having a composition of Ni-16Cr-16Mo-5Fe-4W, Co-based alloy powder having a composition of Co-29Cr-6Mo, alloy powder having a composition of Fe-49Co-2V, precipitation hardened martensitic stainless steel powder having a composition of SUS630, austenitic stainless steel powder having a composition of SUS316L, martensitic stainless steel powder having a composition of SUS420J2, and low-oxygen titanium powder, Or, Copper powder or silver powder produced by water atomization, The powder consisting of these 15 types of powder is a powder having a spherical, granular, or agglomerated shape as described in paragraph 17.

[0020] In other words, powders having a spherical, granular, or agglomerated shape are manufactured by a manufacturing method specific to the powder. Here, the manufacturing method of powders having a spherical, granular, or agglomerated shape, the material of the manufactured powder, the specific properties of the powder, and the uses of the sheet will be explained. The first manufacturing method is the gas atomization method, in which compressed gas consisting of air, argon gas, or nitrogen gas is sprayed onto a molten metal flowing down from a molten metal nozzle to produce powders made of various materials. The powder produced by the first gas atomization method is copper powder, which has a nearly spherical shape and excellent ductility and malleability. Therefore, it easily undergoes plastic deformation when subjected to compressive stress. Therefore, when overlapping copper powder particles are compressed, the copper powder particles move and fill the voids between the particles. Furthermore, the compressive stress causes the copper powder particles to plastically deform, bringing them into contact with adjacent particles and joining them by friction welding. Therefore, the number of overlapping copper powder particles required to seal the voids within the copper powder particles joined by friction welding is relatively small. Furthermore, the larger the copper powder particles, the greater the surface area of ​​the copper powder particles, so fewer copper powder particles need to be overlapped. Therefore, the thickness of the suspension applied to the entire fabric or nonwoven fabric can be reduced. Furthermore, the compressive stress applied to the copper powder particles is relatively small. Thus, copper powder produced by the gas atomization method is suitable for forming an airtight coating that blocks gases. On the other hand, copper powder has both high electrical and thermal conductivity among metals, so sheets made of copper powder joined by friction welding and covered with a coating formed by the aggregation of copper powder, or cut sheets, are used as lightweight electrically conductive or thermally conductive sheets, or as substrates or electrodes for electrical circuits. The powder produced by the second gas atomization method is tin powder, which, like copper powder, has a nearly spherical shape and, due to its excellent ductility and malleability, easily undergoes plastic deformation when subjected to compressive stress. Therefore, like copper powder produced by gas atomization, tin powder is suitable for forming airtight coatings that block gases. Meanwhile, tin has high electrical and thermal conductivity, low density, and is solderable, so cut sheets are used as lightweight electrical circuit boards. However, because tin's melting point is low at 232°C, it is not used for electrical circuit boards that are subject to high temperatures. The powder produced by the third gas atomization method is a copper-tin alloy powder that is nearly spherical in shape and has excellent ductility and malleability, so it easily undergoes plastic deformation when subjected to compressive stress. For example, there is copper-tin alloy powder with a composition of 90Cu-10Sn. For this reason, copper-tin alloy powder, like copper powder produced by gas atomization, is suitable as a powder for forming an airtight coating that blocks gases. Furthermore, copper-tin alloy powder has a higher melting point than tin, and cut sheets are used for electrical circuit boards, semiconductor lead frames, and heat sinks that have a heat resistance temperature of 300°C or less. The powders produced by the fourth gas atomization method are tantalum and niobium powders, and are nearly spherical in shape. Therefore, when a group of overlapping tantalum or niobium powders is compressed, the tantalum or niobium powders first move, reducing the voids in the group of tantalum or niobium powders. Next, adjacent powders in the group of powders are joined by friction welding at all contact points, and overlapping groups of powders are also joined by friction welding. As a result, the entire fabric or nonwoven fabric is covered with a coating made of the joined group of powders, and voids are trapped inside the group of tantalum or niobium powders joined by friction welding. Therefore, tantalum and niobium powders produced by the gas atomization method are suitable for forming a gas-tight coating that blocks gases. Since tantalum powder and niobium powder are harder than the copper powder, tin powder, or copper-tin alloy powder, a large compressive stress is required to generate frictional heat at the contact points between the tantalum or niobium powder particles. Therefore, the gap between the two work rolls is narrowed depending on the hardness of the tantalum or niobium powder. On the other hand, tantalum powder has excellent heat resistance and corrosion resistance, and therefore, sheets made of tantalum powder particles bonded by friction welding and covered with a coating, or cut sheets, are used as sheets for use in high-temperature, corrosive environments used in chemical processing processes. Similarly, niobium powder has excellent heat resistance and corrosion resistance, and therefore, sheets made of niobium powder particles bonded by friction welding and covered with a coating, or cut sheets, are used as sheets for use in high-temperature, corrosive environments used in chemical processing processes. The powders produced by the fifth gas atomization method are the following three types of alloy powders, all of which are nearly spherical in shape. Therefore, when overlapping alloy powder particles are compressed, the alloy powder particles first move, reducing the voids between the particles. Next, adjacent particles in the alloy powder particle group are friction-welded at all contact points, and overlapping particles are also friction-welded. As a result, the entire fabric or nonwoven fabric is covered with a coating made of the joined powder particles, sealing the voids within the friction-welded alloy powder particles. Therefore, alloy powders produced by the gas atomization method are suitable for forming gas-tight coatings. Furthermore, alloy powders are harder than the copper powder, tin powder, or copper-tin alloy powder described above, and therefore require a greater compressive stress to generate frictional heat at the contact points between the alloy powder particles. Therefore, the gap between the two work rolls is narrowed depending on the hardness of the alloy powder. The Fe-based alloy consisting of Fe-17Cr-12Ni-Mo has a composition similar to that of SUS316L austenitic stainless steel and has excellent corrosion resistance, so sheets, cut sheets, or folded sheets covered with a coating formed by an assembly of Fe-based alloy consisting of Fe-17Cr-12Ni-Mo joined by friction welding are used as sheets to be used in highly corrosive liquids. The Ni-based alloy consisting of Ni-16Cr-16Mo-5Fe-4W is an Ni-based alloy equivalent to Hastelloy C276 and has excellent corrosion resistance. Therefore, sheets, cut sheets, or folded sheets covered with a coating formed by an assembly of Ni-based alloy consisting of Ni-16Cr-16Mo-5Fe-4W joined by friction welding are used as sheets to be used in highly corrosive liquids. Co-based alloy powder made of Co-29Cr-6Mo has excellent corrosion resistance and high fatigue strength, so sheets, cut sheets, or folded sheets covered with a coating formed by an aggregation of Co-based alloy powder made of Co-29Cr-6Mo joined by friction welding are used as sheets that are constantly subjected to load in highly corrosive liquids. The sixth type of powder produced by gas atomization is an alloy powder consisting of Fe-49Co-2V, known as permendur alloy powder, which is nearly spherical in shape. Therefore, when overlapping alloy powder particles are compressed, the particles first shift, reducing the voids within the particles. Next, adjacent particles in the alloy powder particle group are friction-welded at all contact points, and overlapping particles are also friction-welded. This results in a coating made of the joined alloy powder particles covering the entire fabric or nonwoven, trapping voids within the friction-welded particles. Therefore, the Fe-49Co-2V alloy powder produced by gas atomization is suitable for forming gas-tight coatings. This alloy powder has a high magnetic flux density (B25) of 2.3 Tesla, a coercivity of 46 A / m, and a maximum magnetic permeability of 10,000. On the other hand, its Rockwell hardness is low at HRB 40 (equivalent to a Vickers hardness HV of 80), making it easy to process. For this reason, cut or folded sheets are used for the iron cores of high-power motors and generators. The powders produced by the seventh gas atomization method are the following three types of stainless steel powder, all of which have a nearly spherical shape. Therefore, when overlapping stainless steel powder particles are compressed, the stainless steel powder particles first move, reducing the voids in the particles. Next, adjacent particles in the particles are friction-welded at all contact points, and overlapping particles are also friction-welded. As a result, the entire fabric or nonwoven fabric is covered with a coating made of the joined particles, sealing the voids within the particles joined by friction welding. Therefore, like the alloy powder described above, this powder is suitable for forming an airtight coating that blocks gases. Furthermore, because stainless steel powder is hard, a large compressive stress is required to generate frictional heat at the contact points between the particles. Therefore, the gap between the two work rolls is narrowed depending on the hardness of the stainless steel powder. Precipitation hardened martensitic stainless steel powder with the composition of SUS630 has heat resistance and corrosion resistance equivalent to that of SUS304, so sheets, cut sheets, or folded sheets covered with a coating formed by the aggregation of precipitation hardened martensitic stainless steel powder are used in sheets for use in highly corrosive high-temperature environments. Austenitic stainless steel powder with a SUS316L composition has excellent ductility and toughness, as well as high corrosion resistance and high formability. Therefore, sheets covered with a coating formed by aggregations of austenitic stainless steel powder with a SUS316L composition, cut sheets, or folded sheets are thin and easy to process, so they can be used as sheets with complex shapes in highly corrosive environments. Martensitic stainless steel powder with a SUS420J2 composition is a high-strength stainless steel, so sheets, cut sheets, or folded sheets covered with a coating formed by the aggregation of martensitic stainless steel powder with a SUS420J2 composition are used for sheets that are constantly subjected to heavy loads in highly corrosive environments. Because martensitic stainless steel powder with a SUS420J2 composition has high hardness, the sheets are annealed after production, which makes the folded sheets easier to process. The powder produced by the eighth gas atomization method is low-oxygen titanium powder and has a nearly spherical shape. Therefore, when overlapping low-oxygen titanium powder particles are compressed, the low-oxygen titanium powder particles first move, reducing the voids in the low-oxygen titanium powder particles. Next, adjacent particles in the low-oxygen titanium powder particles are friction-welded at all contact points. Furthermore, overlapping low-oxygen titanium powder particles are friction-welded. Because low-oxygen titanium powder is hard, a large compressive stress is required to generate frictional heat at the contact points between the low-oxygen titanium powder particles. Therefore, the gap between the two work rolls is narrowed depending on the hardness of the low-oxygen titanium powder. As a result, the entire fabric or nonwoven fabric is covered with a coating made of the joined low-oxygen titanium powder particles, trapping voids within the friction-welded low-oxygen titanium powder particles. For this reason, low-oxygen titanium powder is suitable for forming an airtight coating that blocks gases. Low-oxygen titanium powder has excellent corrosion resistance and is suitable for producing high-strength parts, so sheets covered with a coating formed by aggregations of low-oxygen titanium powder, or cut sheets, are used as sheets in the aerospace and medical fields. A second method for producing powders in the form of spheres, granules, or chunks is the water atomization method, in which a water jet is applied to a thin stream of molten metal flowing down from a nozzle to pulverize it, producing powders made of various materials. The powders produced by the first water atomization method are copper powder and silver powder, both of which are granular in shape and have excellent symmetry, second only to the spherical powder mentioned above. Furthermore, both copper powder and silver powder have excellent ductility and malleability, and easily undergo plastic deformation when subjected to compressive stress. Therefore, like copper powder produced by gas atomization, they are suitable for forming gas-tight coatings that block gases. Copper and silver have high electrical and thermal conductivities among metals, so sheets, cut sheets, or folded sheets covered with a coating formed by a collection of copper or silver powder joined by friction welding can be used as lightweight conductive or thermally conductive sheets or lightweight heat sinks. A third method for producing powders is a reduction method, which uses metal oxide ore as a starting material and reduces the ore with a highly reducing gas at high temperature to produce metal powder, producing iron powder, copper powder, nickel powder, cobalt powder, tungsten powder, and molybdenum powder. However, because the powder is spongy and porous, many voids are formed in the overlapping metal powder particles, and many voids remain in the coating formed by compressing the overlapping metal powder particles, making this method unsuitable for producing airtight sheets. Furthermore, a fourth method for producing powder involves dissolving scrap in a solvent and reducing the resulting product to produce metal powder. However, as with the ore reduction method described above, the metal powder is porous, so many voids are formed in the overlapping metal powder particles, and furthermore, voids remain in the coating formed by compressing the overlapping metal powder particles, making this method unsuitable for producing an airtight sheet. Furthermore, a fifth method for producing powder is a method for producing metal powder by electrolysis, which produces copper powder, silver powder, and iron powder. However, because the metal powder is sponge-like or dendritic, many voids are formed in the overlapping metal powder particles, and further, voids remain in the coating formed by compressing the overlapping metal powder particles, making it unsuitable for producing airtight sheets. As described above, powders in spherical, granular, or agglomerated shapes are produced using gas atomization and water atomization to produce powders made of 15 types of metals or alloys. Metal or alloy powders have inherent properties depending on the material, in addition to electrical conductivity. As a result, the sheet possesses the inherent properties of the powder in addition to the electrical conductivity, non-flammability, corrosion resistance, and heat resistance described in paragraph 12. Therefore, the sheet can be used for a variety of applications based on the inherent properties of the powder.

[0021] The method for continuously producing a sheet having a structure in which a woven fabric or nonwoven fabric is entirely covered with a coating formed by an aggregation of powder particles made of one of the materials of metal, alloy, metal oxide, or nitride, each having a micron size, which are joined together by friction welding as described in paragraph 11, is as follows: The powder described in paragraph 11 is a powder that has a sponge-like shape but is not porous and that undergoes plastic deformation when compressed in the third step described in paragraph 11, and the method of using this powder as the powder described in paragraph 11 and continuously carrying out all of the three steps described in paragraph 11 in order is a method of continuously producing a sheet consisting of a fabric or nonwoven fabric entirely covered with a coating formed by an aggregation of micron-sized powders of one material selected from the group consisting of metals, alloys, metal oxides, and nitrides described in paragraph 11, which are joined by friction welding.

[0022] The coating formed by the powder particles bonded by friction welding in the present invention is a coating formed by overlapping and bonding together powder particles, and the thickness of the bonded powder particles is less than 0.25 mm. This allows the sheet to be cuttable, which is the second property described in paragraph 12. On the other hand, the shape of the powder used is limited in order for the coating formed by overlapping and bonding together powder particles to have the fourth property described in paragraph 12, which is airtightness that blocks gas. That is, the second step described in paragraph 11 ensures that the suspension is evenly applied to the entire fabric or nonwoven fabric. Furthermore, in the third step described in paragraph 11, after evaporating the alcohol from the suspension, the powder particles that have been deposited on the fabric or nonwoven fabric in an overlapping state are evenly compressed. During this process, low-hardness powder undergoes plastic deformation, and the plastically deformed powder fills adjacent voids, reducing the voids. Furthermore, all contact points between adjacent powder particles are bonded by friction welding. Furthermore, the overlapping powder particles are joined by friction welding. If all voids are confined within the joined powder particles, the coating made up of the joined powder particles will have no voids communicating with the outside world and will be airtight, blocking out gases. As described in paragraph 18, there are eight types of powder shapes. Among these eight types of powder, there is powder with a spongy shape. If the spongy powder has the properties of, first, not being porous, and, second, undergoing plastic deformation when compressed in the third step described in paragraph 11, the coating made of the aggregate of spongy powder will have airtightness that blocks gas. Specifically, in the second step described in paragraph 11, as the fabric or nonwoven fabric immersed in the suspension moves horizontally through the suspension at a slow speed from the second roller to the penultimate roller, the powder particles adsorbed onto the surface of the fabric or nonwoven fabric are subjected to stress due to their small, micron-sized size and light weight. This stress causes the powder particles to overlap with each other in a spongy shape via the alcohol. Because the powder particles vary in size, when they are adsorbed onto the fabric or nonwoven fabric along with the alcohol, the powder particles overlap with each other, filling the gaps between them, increasing the density of the powder particles. However, compared to the spherical, granular, or agglomerated powders described in paragraph 18, spongy powders are less symmetrical, resulting in many voids where no powder is present, which are filled with alcohol. Therefore, many voids remain in the coating formed by compressing the powder mass, and voids that communicate with the coating are formed, so the coating does not have the airtightness to block gas. 。 On the other hand, when a spongy powder with a relatively low hardness is subjected to compressive stress, it undergoes plastic deformation in a direction perpendicular to the compression direction. Also, spongy powders are prone to plastic deformation because they lack symmetry. For this reason, after evaporating the alcohol, compressive stress according to the hardness of the powder is evenly applied to the piled-up spongy powder mass, causing the powder to plastically deform in a direction perpendicular to the compression direction. If there are voids in the adjacent powder, the plastically deformed powder will enter the voids and reduce the voids. In other words, regardless of the size of the voids, if there are voids in the adjacent powder, the plastically deformed powder will reduce the voids. However, not all voids are filled by the plastic deformation of the powder. For this reason, the overlapping and precipitated powders In a collection of powderThe powder particles must be bonded together, and all voids must be contained within the bonded powder mass by a bonding layer made up of the bonded powder particles. Therefore, a relatively high-viscosity alcohol must be used to thicken the layer of overlapping powder particles. The larger the spongy powder, the greater its surface area, so the fewer overlapping powder particles are required. On the other hand, plastically deformed powder particles form a bond with adjacent powder particles that is nearly flat, and the powder particles are joined by friction welding at this bond. The bond between these powder particles has a larger contact area than the spherical, granular, or agglomerated powder particles described in paragraph 18. Therefore, the bonding strength between powder particles in a spongy powder mass is greater than the bonding strength between powder particles in a spherical, granular, or agglomerated powder mass described in paragraph 18. Furthermore, because the spongy powder is not porous, by using a relatively viscous alcohol and increasing the thickness of the overlapping powder layer, all voids can be trapped inside the joined powder mass by the joined layer made up of the overlapping and joined powder mass. In other words, if the powder is porous, voids will remain in the areas where porosity is formed, even if the thickness of the overlapping powder layer is increased. On the other hand, the smaller the size of the non-porous spongy powder, the smaller the surface area of ​​the powder. Therefore, when using small non-porous spongy powder, an alcohol with a relatively high viscosity is used to increase the thickness of the overlapping powder layer. Through these processes, the coating formed by the collection of powders in which non-porous spongy powders are friction-welded together does not have any voids communicating with the outside world. As a result, the coating is airtight. As described above, powder that is sponge-like but not porous and that undergoes plastic deformation when compressed in the third step described in paragraph 11 undergoes plastic deformation in a direction perpendicular to the compression direction, with the plastically deformed powder filling the voids between adjacent powders and reducing the voids where no powder is present. Furthermore, a bonding layer formed by a group of overlapping and bonded powder particles confines all voids within the bonded group of powder particles. This allows the coating formed by the group of powder particles to have airtight properties that block gas. Therefore, powder that is sponge-like but not porous and that undergoes plastic deformation when compressed in the third step described in paragraph 11 is suitable for forming an airtight coating.

[0023] The powder described in paragraph 21, which has a spongy shape but is not porous, and which undergoes plastic deformation when compressed in the third step described in paragraph 11, Iron powder or bronze powder produced by water atomization, These two types of powders have a spongy shape as described in paragraph 21 but are not porous, and when compressed in the third step as described in paragraph 11, they undergo plastic deformation.

[0024] That is, the powder, which has a spongy shape but is not porous and which undergoes plastic deformation when compressed in the third step described in paragraph 11, is produced by a method specific to the powder. Here, the method for producing the powder, which has a spongy shape but is not porous and which undergoes plastic deformation when compressed in the third step described in paragraph 11, the material of the produced powder, the specific properties of the powder, and the use of the sheet are described. The first powder is iron powder produced by the water atomization method described in paragraph 20. Iron powder produced by the water atomization method has a spongy shape but is not porous. Meanwhile, metals have the most ductile properties in the following order: silver, iron, nickel, copper, aluminum, zinc, and tin. Furthermore, metals have the most malleable properties in the following order: silver, copper, aluminum, tin, zinc, iron, and nickel. Therefore, when iron powder produced by the water atomization method is compressed, the iron powder undergoes plastic deformation perpendicular to the compression direction. As a result, the plastically deformed iron powder shrinks the voids formed in the cluster of iron powder particles. However, the plastically deformed iron powder does not fill all the voids in the cluster of iron powder particles. Therefore, the number of overlapping iron powder particles increases, increasing the number of overlapping and bonded iron powder particles. As a result, all voids in the cluster of bonded iron powder particles are enclosed within the cluster of iron powder particles. In other words, metal powders with excellent ductility and malleability do not necessarily have to be spherical, granular, or clump-shaped. Because less symmetrical metal powders are more susceptible to plastic deformation, metal powders with excellent ductility and malleability allow all voids in the joined metal powder particles to be trapped within the particles. Furthermore, the larger the metal powder particles, the greater their surface area, meaning fewer particles need to be stacked. Meanwhile, iron is the only ferromagnetic soft magnetic material that has a constant magnetic permeability in an alternating current magnetic field. Therefore, a sheet, cut, or folded sheet made of iron powder particles joined by friction welding effectively functions as a magnetic shielding sheet. The second type of powder is bronze powder, an alloy of copper and tin produced by water atomization, such as bronze powder with a composition of 90Cu-10Sn. Bronze powder produced by water atomization has a spongy shape but is not porous. Because bronze powder has excellent ductility and malleability, when compressed, it undergoes plastic deformation perpendicular to the direction of compression. This causes the voids formed in the bronze powder aggregate to shrink. However, the plastically deformed bronze powder cannot fill all of the voids in the bronze powder aggregate. Therefore, the number of overlapping bronze powder particles is increased, increasing the number of overlapping and bonded bronze powder particles. This results in all of the voids in the bonded bronze powder aggregate being enclosed within the bronze powder aggregate. Bronze powder, an alloy of copper and tin, has antibacterial properties, so sheets made of a mixture of bronze powder particles joined by friction welding are used as sheets that people will touch. Also, depending on the tin content, bronze powder emits a lustrous reddish-copper to golden color, so it is used as a lightweight sheet that emits a reddish-copper to golden color. As explained above, iron powder and bronze powder produced by water atomization are powders that are sponge-like but not porous and undergo plastic deformation under compressive stress. These powders have inherent properties depending on the material, in addition to electrical conductivity. As a result, a sheet consisting of a woven or nonwoven fabric covered with a coating formed by a collection of powder particles joined by friction welding possesses the inherent properties of the powder in addition to the electrical conductivity, non-flammability, corrosion resistance, and heat resistance described in paragraph 12. This allows the sheet to be used for a variety of applications based on the inherent properties of the powder.

[0025] The method for continuously producing a sheet having a structure in which a woven fabric or nonwoven fabric is entirely covered with a coating formed by an aggregation of powder particles made of one of the materials of metal, alloy, metal oxide, or nitride, each having a micron size, which are joined together by friction welding as described in paragraph 11, is as follows: The powder described in paragraph 11 is teardrop-shaped or spindle-shaped and undergoes plastic deformation when compressed in the third step described in paragraph 11, and the method of using the powder described in paragraph 11 and sequentially carrying out all of the three steps described in paragraph 11 is a method of continuously producing a sheet consisting of a fabric or nonwoven fabric entirely covered with a coating formed by an aggregation of micron-sized powders of one material selected from the group consisting of metals, alloys, metal oxides, and nitrides described in paragraph 11, joined by friction welding.

[0026] Specifically, in the second step described in paragraph 11, as the fabric or nonwoven fabric immersed in the suspension moves horizontally through the suspension at a low speed from the second roller to the penultimate roller, the powder particles adsorbed onto the surface of the fabric or nonwoven fabric are subjected to stress because they are micron-sized and extremely lightweight. This stress causes teardrop- or spindle-shaped particles to gradually overlap over the entire fabric or nonwoven fabric, with the alcohol interposed between them. Because the powder particles vary in size and shape, they overlap with each other, filling in the gaps between them, gradually increasing the density of the powder particles. In this way, the entire fabric or nonwoven fabric is covered with particles of powder interposed between them. However, compared to the spherical, granular, or agglomerated powders described in paragraph 18, teardrop- or spindle-shaped powders are less symmetrical, and so the powder particles overlapping each other through the alcohol have many voids where no powder is present, which are filled with alcohol. Because of these voids, the coating formed by compressing the powder particles has many voids, and the coating does not have the airtightness to block gases. On the other hand, teardrop-shaped or spindle-shaped powders with relatively low hardness undergo plastic deformation in a direction perpendicular to the compression direction when compressive stress is applied. For this reason, if the entire pile of powder is compressed evenly after evaporating the alcohol, the powder undergoes plastic deformation in a direction perpendicular to the compression direction, and the plastically deformed powder fills in the voids between adjacent powders, and voids where no powder is present are reduced by the plastically deformed powder. In other words, regardless of the size of the voids where no powder is present, if there are voids in adjacent powders, the powder undergoes plastic deformation, and the plastically deformed powder fills the voids, reducing the voids. However, not all voids are filled by the plastic deformation of the powder. For this reason, the piled-up and precipitated powder In a collection of powder The powders are bonded together, and all voids must be contained within the bonded powder mass by a bonding layer consisting of the overlapping and bonded powder mass. In other words, metal powders with relatively low hardness do not necessarily need to be spherical, granular, or agglomerated. Metal powders with less symmetry are more susceptible to plastic deformation, allowing all voids in the bonded metal powder mass to be contained within the metal powder mass. Furthermore, the larger the metal powder, the greater the surface area of ​​the metal powder, so fewer metal powder particles need to be layered together. Furthermore, teardrop-shaped or spindle-shaped powders are not porous, so no voids exist in the bonded powder mass. In contrast, if the powder is porous, voids remain in the porous areas even when the thickness of the overlapping powder layer is increased. Furthermore, the plastically deformed powder forms a bond with adjacent powder particles as a near-surface bond, and the powder particles are joined by friction welding at this bond. The bonded portions between these powder particles have a larger contact area than the contacted portions between spherical, granular, or agglomerated powder particles described in paragraph 18. Therefore, the bonding strength between the powder particles in the teardrop-shaped or spindle-shaped powder mass is greater than the bonding strength between the powder particles in the spherical, granular, or agglomerated powder mass described in paragraph 18. On the other hand, the smaller the size of non-porous teardrop-shaped or spindle-shaped powder, the smaller the surface area of ​​the powder. Therefore, when using small non-porous teardrop-shaped or spindle-shaped powder, a relatively high viscosity alcohol is used to increase the number of overlapping powder particles. These processes result in a coating formed by the accumulation of powder particles joined by friction welding, which has no voids and therefore no voids communicating with the outside world. This makes the coating airtight and able to block gas. As described above, powders that are teardrop- or spindle-shaped and that undergo plastic deformation when compressed in the third step described in paragraph 11 undergo plastic deformation perpendicular to the compression direction, and the plastically deformed powder fills the voids between adjacent powders, reducing the voids where no powder is present. Furthermore, overlapping powders are joined by friction welding. This confines all voids within the joined powder mass. Therefore, the coating formed by the friction-welded powder mass has no voids communicating with the outside world. This gives the coating airtightness, blocking gas. Therefore, powders that are teardrop- or spindle-shaped and that undergo plastic deformation when compressed in the third step described in paragraph 11 are suitable for forming airtight coatings.

[0027] The powder described in paragraph 25, which has a teardrop-shaped or spindle-shaped shape and which undergoes plastic deformation when compressed in the third step described in paragraph 11, Aluminum powder produced by gas atomization, or nickel powder, Fe-3Si alloy powder, 47Ni-Fe alloy powder, 78Ni-4Mo-Fe alloy powder, or brass powder produced by water atomization, A powder consisting of these six types of powder has a teardrop-shaped or spindle-shaped shape as described in paragraph 25, and undergoes plastic deformation when compressed in the third step as described in paragraph 11.

[0028] That is, the powder having a teardrop or spindle shape and undergoing plastic deformation when compressed in the third step described in paragraph 11 is produced by a method specific to the powder. Here, the method for producing the powder having a teardrop or spindle shape and undergoing plastic deformation when compressed in the third step described in paragraph 11, the material of the produced powder, the specific properties of the powder, and the use of the sheet are described. The first powder is aluminum powder produced by the gas atomization method described in paragraph 20. Aluminum powder is teardrop-shaped and has excellent malleability and ductility, so when aluminum powder produced by the gas atomization method is compressed, the aluminum powder undergoes plastic deformation in a direction perpendicular to the compression direction. As a result, voids formed in the aggregate of aluminum powder are reduced by the plastically deformed aluminum. Furthermore, when aluminum powder is piled up and precipitated, In a mass of aluminum powder The aluminum powder particles are bonded together, and a bonding layer consisting of a group of overlapping and bonded aluminum powder particles confines all voids within the group of bonded aluminum powder. Note that, like copper powder, aluminum powder has high electrical and thermal conductivity, so a sheet composed of a group of aluminum powder particles bonded by friction welding, or a cut sheet, can be used as a lightweight conductive sheet or thermally conductive sheet, a lightweight heat sink, or a substrate or electrode for an electric circuit. The second powder is nickel powder produced by the water atomization method described in paragraph 20. Nickel powder has a shape similar to a teardrop, with variations in shape. Furthermore, as mentioned above, nickel powder has excellent ductility and malleability. Therefore, when nickel powder is compressed, the nickel powder undergoes plastic deformation in a direction perpendicular to the direction of compression. As a result, the plastically deformed nickel enters the voids formed in the clusters of nickel powder, reducing the voids. Furthermore, when nickel powder is piled up and precipitated, In a collection of nickel powderNickel powder particles are bonded together, and a bonding layer consisting of a group of overlapping and bonded nickel powder particles confines all voids within the bonded nickel powder group. Nickel has high corrosion resistance against strong acids and alkalis and is easy to process, so sheets made of a structure covered with a group of nickel powder bonded by friction welding, or cut sheets, are used as lightweight corrosion-resistant sheets in chemical manufacturing plants, etc. Nickel also has excellent heat resistance, so sheets made of a structure covered with a group of nickel powder bonded by friction welding are used as lightweight sheets for engines. The third type of powder is Fe-3Si alloy powder (3% silicon iron), which is produced by the water atomization method. This alloy powder is teardrop-shaped or spindle-shaped. In addition, because the Vickers hardness of the alloy powder is high at around 200HV, when the alloy powder is compressed, the amount of plastic deformation of the alloy powder in the direction perpendicular to the compression direction is small. Therefore, the amount of plastically deformed alloy powder that enters the voids formed in the collection of alloy powder particles and the amount of void reduction is small. For this reason, alcohol with a relatively high viscosity is used, and when the alcohol evaporates from the suspension, the number of alloy powder particles that are piled up and precipitated increases. Furthermore, when the alloy powder particles are piled up and precipitated, In a collection of alloy powders The alloy powders are bonded together, and the bonding layer, consisting of the overlapping and bonded alloy powders, confines all voids within the bonded alloy powder mass. The magnetic permeability of Fe-3Si alloy powder does not change depending on the direction. For this reason, it is used as soft magnetic steel sheet with complex shapes, such as motor armatures. Therefore, sheets covered with a friction-welded Fe-3Si alloy powder mass can be cut thinly and cut to the shape of an armature for use. The fourth type of powder is 47Ni-Fe alloy powder (equivalent to PB Permalloy) manufactured by water atomization. The shape of this powder is teardrop-shaped or spindle-shaped. In addition, since the Vickers hardness of the alloy powder is low at around 100HV, when the alloy powder is compressed, the alloy powder undergoes plastic deformation in the direction perpendicular to the compression direction. As a result, the plastically deformed alloy powder enters the voids formed in the cluster of alloy powder, reducing the voids. Furthermore, when the alloy powder is piled up and precipitated, In a collection of alloy powders The alloy powders are bonded together, and the bonding layer, consisting of a group of overlapping and bonded alloy powders, confines all voids within the group of bonded alloy powders. 47Ni-Fe alloy powder has a high initial permeability of 5,000, a high maximum permeability of 50,000, and a high maximum magnetic flux density of 1.55 Tesla. In contrast, its coercive force is low at 12 A / m. For this reason, sheets covered with a group of 47Ni-Fe alloy powders bonded by friction welding, or cut sheets, are used in magnetic shielding sheets, magnetic sensor sheets, cores for various inductors, shielding cases for measuring instrument noise reduction, and inverter motor control devices. The fifth type of powder is 78Ni-4Mo-Fe alloy powder (equivalent to PC permalloy) produced by water atomization. The shape of this powder is teardrop-shaped or spindle-shaped. In addition, since the Vickers hardness of the alloy powder is low at around 100HV, when the alloy powder is compressed, the alloy powder undergoes plastic deformation in the direction perpendicular to the compression direction. As a result, the plastically deformed alloy enters the voids formed in the cluster of alloy powder, reducing the voids. Furthermore, when the alloy powder is piled up and precipitated, In a collection of alloy powders The alloy powders are bonded together, and the bonding layer, consisting of the overlapping and bonded alloy powders, confines all voids within the bonded alloy powder mass. The 78Ni-4Mo-Fe alloy powder has an extremely high initial permeability of 60,000, a very high maximum permeability of 180,000, and a maximum magnetic flux density of 0.72 Tesla. In contrast, its coercive force is extremely low at 0.8 A / m. For this reason, like the 47Ni-Fe alloy powder, sheets or cut sheets made of a friction-welded 78Ni-4Mo-Fe alloy powder covered with the powder are used in magnetic shielding sheets, magnetic sensor sheets, cores for various inductors, shielding cases for measuring instrument noise reduction, and inverter motor control devices. The sixth powder is brass powder, an alloy of copper and zinc produced by water atomization, such as brass powder with a composition of 60Cu-40Sn. The shape of this powder is teardrop-like and varies. Furthermore, because brass powder has excellent ductility and malleability, when compressed, it undergoes plastic deformation perpendicular to the compression direction. This allows the plastically deformed brass powder to fill voids formed in the brass powder clusters, reducing the voids. Furthermore, when brass powder is piled up and deposited, the bonded layer formed by the overlapping and bonded brass powder clusters confines all voids within the bonded brass powder clusters. Furthermore, brass powder has a beautiful golden appearance, and therefore, sheets composed of friction-welded brass powder clusters, or cut sheets, are used as lightweight, golden-colored sheets. Brass is also easy to process, so it is used to make sheet parts for precision machinery such as banknote printing machines and scientific and chemical instruments. As explained above, there are various metal and alloy powders that are teardrop- or spindle-shaped and undergo plastic deformation when compressed. These metal and alloy powders have inherent properties according to their materials, in addition to electrical conductivity, as described above. As a result, a sheet consisting of a woven or nonwoven fabric covered with a coating formed by a collection of powder particles joined by friction welding possesses the inherent properties of the powder in addition to the electrical conductivity, non-flammability, corrosion resistance, and heat resistance described in paragraph 12. This allows the sheet to be used for a variety of purposes.

[0029] The method for continuously producing a sheet having a structure in which a woven fabric or nonwoven fabric is entirely covered with a coating formed by an aggregation of powder particles made of one of the materials of metal, alloy, metal oxide, or nitride, each having a micron size, which are joined together by friction welding as described in paragraph 11, is as follows: The powder described in paragraph 11 is a powder having a plate-like, flake-like, or scale-like shape with a large aspect ratio, and the method of using the powder described in paragraph 11 and sequentially carrying out all of the three steps described in paragraph 11 is a method of continuously producing a sheet having a configuration in which a woven fabric or nonwoven fabric is entirely covered with a coating formed by an aggregation of micron-sized powder particles of one material selected from the group consisting of metals, alloys, metal oxides, and nitrides described in paragraph 11, which are joined by friction welding.

[0030] The coating formed by the powder particles bonded by friction welding in this invention is a coating formed by overlapping and bonding together powder particles, and the thickness of the bonded powder particles is less than 0.25 mm. This allows the sheet to be cuttable, which is the second property described in paragraph 12. On the other hand, the shape of the powder used is limited in order for the coating formed by overlapping and bonding together powder particles to have the fourth property described in paragraph 12, which is airtightness that blocks gas. That is, the suspension is evenly applied to the entire fabric or nonwoven fabric by the third step described in paragraph 11. Furthermore, after evaporating the alcohol from the suspension, the powder particles that have been deposited on the fabric or nonwoven fabric are compressed. During this process, low-hardness powder undergoes plastic deformation, filling adjacent voids with the plastically deformed powder, thereby reducing the voids. Furthermore, all contact points between adjacent powder particles are bonded by friction welding. Furthermore, the overlapping powder particles are joined by friction welding. If all voids are confined within the joined powder particles, the coating made up of the joined powder particles will have no voids communicating with the outside world and will be airtight, blocking out gases. As described in paragraph 18, micron-sized powders made of metals, alloys, metal oxides, or nitrides come in eight different shapes. Meanwhile, in the first step described in paragraph 11, when alcohol is stirred to create a suspension in which the powder is dispersed, plate-shaped, flake-shaped, or scale-shaped powders with a large aspect ratio are moved through the alcohol with their flat surface facing up, because this minimizes stress on the powder. Therefore, a collection of powder particles with their flat surface facing up forms a suspension in which the powder is dispersed in the alcohol. Furthermore, in the second step described in paragraph 11, the fabric or nonwoven fabric moves horizontally through the suspension at a slow speed from the second roller to the penultimate roller. However, the powder constituting the suspension adsorbed on the surface of the fabric or nonwoven fabric is small and lightweight, so stress is placed on the powder. This load causes the powder particles, with their flat surfaces facing up, to overlap and adhere to the fabric or nonwoven fabric via the alcohol, until the entire fabric or nonwoven fabric is covered with a cluster of powder particles whose flat surfaces overlap. Furthermore, in the third step described in paragraph 11, when the alcohol evaporates, the clusters of powder particles overlap with each other. Furthermore, compressive stress is applied to the clusters of powder particles whose flat surfaces overlap, causing all contact areas where the flat surfaces overlap to be friction-welded, forming a coating made of the clusters of powder particles whose flat surfaces are welded together. Furthermore, because the overlapping powder particles are welded together, even though the number of overlapping powder particles is smaller than with other powder shapes, all voids present in the clusters of powder particles are trapped within the clusters of powder particles, forming a coating with no voids communicating with the outside world. This makes the coating airtight. However, when the powder size is small, the surface area of ​​the powder is small, so in order to confine all the voids present in the joined powder mass within the powder mass, the number of overlapping powders must be increased. In other words, powders with an average particle size of 10 μm or less exist in plate-shaped, flaky, or scale-shaped powders with a high aspect ratio. In plate-shaped, flaky, or scale-shaped powders with a high aspect ratio, a difference of 5 times in the average particle size of the powders results in a difference of nearly 25 times in the average surface area of ​​the powders.Therefore, the smaller the average surface area of ​​a powder, the more overlapping powder particles are required. Furthermore, a group of powder particles with flat surfaces bonded together has a larger bonding area between the flat surfaces, and therefore the bonding strength between the powder particles is greater than that of a group of powder particles with other shapes. Therefore, the mechanical strength of a sheet covered with a coating is greater than that of a sheet covered with a coating formed by a group of powder particles with other shapes. In addition, in the case of plate-shaped, flaky, or scale-shaped powders with a relatively low hardness and a large aspect ratio, the powder particles overlap with each other at their flat surfaces. On the other hand, because the powder has a relatively low hardness, even a small compressive stress applied to the powder mass causes the powder to plastically deform, narrowing the gaps between the overlapping powder particles at their flat surfaces. Furthermore, the contact area between the powder particles increases, resulting in a strong bond between the powder particles at their flat surfaces. In contrast, in the case of plate-shaped, flaky, or scale-shaped powders with a relatively high hardness and a large aspect ratio, applying a compressive stress to the powder mass narrows the gaps between the overlapping powder particles at their flat surfaces. However, because the powder does not plastically deform, voids remain between the powder particles. Therefore, applying a relatively large compressive stress to the powder mass narrows the gaps and forms contact areas between the overlapping powder particles at their flat surfaces. These areas allow the flat surfaces to be joined by friction welding. Therefore, the bonding strength between the powder particles is weaker than the bonding strength between powder particles having a relatively low hardness. As described above, powder particles having a plate-like, flake-like, or scale-like shape with a large aspect ratio are applied to the entire fabric or nonwoven fabric with the powder particles stacked flat-side up via alcohol. When the alcohol evaporates, the powder particles stack flat-side up and cover the entire fabric or nonwoven fabric. Then, when the powder particles are uniformly compressed, all contact points between the flat surfaces are friction-welded, forming an airtight coating. Therefore, powder particles having a plate-like, flake-like, or scale-like shape with a large aspect ratio are suitable for forming an airtight coating.

[0031] The powder described in paragraph 29 has a plate-like, flake-like, or scaly shape with a large aspect ratio, A soft metal flake powder made of gold powder, silver powder, copper powder, tin powder, zinc powder, or aluminum powder, which is obtained by pulverizing soft metal powder using a stamp mill; Or, Atomized soft magnetic powder or reduced soft magnetic powder is attrited using a media agitation mill to produce silicon steel powder with an added amount of silicon of less than 10%, permalloy powder with an added amount of nickel of 50% or less, sendust powder with an added amount of aluminum of 1 / 2 or more of the added amount of silicon, or a flat powder of soft magnetic alloy made of electromagnetic stainless steel powder with an added amount of aluminum of less than 2%, Or, The metal oxide flat powder is made of alumina powder produced by hydrothermal synthesis of aluminum hydroxide, mica powder produced by finely grinding muscovite, glass flake powder produced by crushing molten glass that has been expanded into a hollow shape, or hematite powder precipitated by hydrothermal treatment of yellow iron oxide in an alkaline aqueous solution, Or, It is a boron nitride powder with a hexagonal crystal system produced by pulverizing block boron nitride, The powder consisting of these 15 types of powder is a powder having a plate-like, flake-like, or scale-like shape with a large aspect ratio, as described in paragraph 29.

[0032] That is, powders having a plate-like, flaky, or scale-like shape with a large aspect ratio are manufactured by a method specific to the powder. Here, the method for manufacturing powders having a plate-like, flaky, or scale-like shape with a large aspect ratio, the material of the manufactured powder, the specific properties of the powder, and the uses of the sheet will be described. The first type of powder is soft metal flake powder, which is produced by crushing soft metal powder using a stamp mill. Using a stamp mill, which is equivalent to a stamping machine, multiple metal pestles are used to crush a collection of powder made of soft metals such as gold, silver, copper, tin, zinc, or aluminum, thereby flattening the soft metal powder into thin flakes. This process results in soft metal flake powder with a high aspect ratio (the ratio of the long axis to the powder thickness) and a smooth, nearly flat surface. Therefore, even with expensive gold or silver flake powder, a small amount of flake powder can be used to form a sheet with a metallic color, consisting of a coating of flat surfaces bonded together. The raw metal powder is often high-purity, lead-free electrolytic metal powder. On the other hand, when producing aluminum flake powder, stearic acid is added as a grinding aid to crush the granular powder or foil cut pieces produced by atomization, because aluminum powder is prone to combustion and adhesion when crushed in a stamp mill. The heat resistance temperature of flake powder of soft metals other than tin is determined by their softening point, and even electrolytic copper, which has a low softening point, can reach a high temperature of 800°C. Furthermore, soft metals other than tin do not exhibit low-temperature brittleness, allowing them to be used at extremely low temperatures. The melting point of 99.5% pure aluminum powder is 650°C. Therefore, coatings in which the flat surfaces overlap and the powder are bonded together can be used even in harsh environments such as high temperatures, extremely low temperatures, vacuums, and high pressures. On the other hand, tin has a melting point of 232°C and exhibits low-temperature brittleness at around -40°C, limiting the usable temperature of coatings made from tin flake powder alone. In addition, the surface of soft metal flake powder is flat and smooth, with a nearly uniform thickness of submicrons. Furthermore, soft metal flake powder has low hardness. Therefore, when a relatively small compressive stress is applied to a collection of flake powder in which flat surfaces overlap each other without gaps, the flat surfaces come into contact and bond together. Because the area of ​​the bonded portions made of flat surfaces is large, the bonding strength between the flake powders is strong. Furthermore, the surface of a sheet made of bonded flat surfaces has a smooth surface that is nearly flat, resulting in a sheet with excellent lubricity. The uses of flake powder are the same as those of powders described in paragraphs 20 and 28. The second type of powder is a flat powder made of a soft magnetic alloy. It is known that flattening soft magnetic powder in the plane direction, which is the easy axis of magnetization, reduces the demagnetizing factor, and the greater the flatness, the greater the imaginary part μ" of the complex permeability. On the other hand, it is also known that the absorption of electromagnetic waves in soft magnetic materials depends on the magnitude of the imaginary part μ" of the complex permeability and the magnitude of the electrical conductivity. Therefore, the use of conductive soft magnetic flat powder improves the ability to absorb electromagnetic noise. Furthermore, the flattening process for soft magnetic powder does not rely on long-term batch processing using a ball mill. Instead, atomized soft magnetic powder or reduced soft magnetic powder is subjected to attrition processing using a media agitation mill to produce soft magnetic flat powder. This allows for continuous production of flat powder in a short period of time, and the flat powder is produced through inexpensive processing. Furthermore, because the sheet is formed from a collection of flat powder with flat surfaces directly overlapping each other, a large-area soft magnetic sheet can be formed using a small amount of flat powder.Furthermore, many flat powder particles can participate in absorbing electromagnetic waves, resulting in a soft magnetic sheet with high electromagnetic wave reception sensitivity and excellent electromagnetic wave absorption performance.This soft magnetic sheet maximizes the flatness effect of the flat powder.In addition, since the magnitude of the imaginary part of the complex permeability of the flat powder depends on the frequency band of the electromagnetic wave, the material of the flat powder is selected depending on the frequency of the electromagnetic noise to be absorbed. These soft magnetic alloy flake powders include silicon steel powder with less than 10% silicon content, permalloy powder with less than 50% nickel content, sendust powder with more than half the amount of aluminum, and electromagnetic stainless steel powder with less than 2% aluminum content. In other words, silicon steel becomes brittle with increasing silicon content, making it impossible to flake, so the silicon content must be kept below 10%. Furthermore, slight variations in the amount of silicon content significantly affect the permeability characteristics of silicon steel. Therefore, the amount of silicon content is determined based on the required permeability characteristics. Furthermore, while the manufacturing cost of permalloy increases with increasing nickel content, the permeability decreases with decreasing nickel content, so the nickel content is kept below 50%. Therefore, the amount of nickel content is determined based on the required permeability characteristics. Sendust is hard and brittle, but adding a small amount of aluminum and reducing the amount of silicon makes it possible to flake. Furthermore, since Permendur is an alloy with cobalt, its manufacturing costs are high and it is not suitable for use as flattened powder to absorb electromagnetic noise.Furthermore, adding aluminum to electromagnetic stainless steel makes it easier to flatten. The complex permeability of the soft magnetic flat powders made from these four types of alloys changes significantly with slight changes in the composition of the components other than iron. Furthermore, the hardness of the atomized or reduced powders of the four types of alloys differs depending on the alloy composition, so the flatness of the flat powder differs depending on the alloy composition, and the magnitude of the imaginary part of the complex permeability also differs. Furthermore, the frequency characteristics of the complex permeability differ significantly depending on the alloy composition. Therefore, soft magnetic sheets used for absorbing electromagnetic waves or preventing electromagnetic noise interference use different soft magnetic flat powder materials depending on the frequency band of the electromagnetic waves to be absorbed. Furthermore, the hardness of the soft magnetic flake powder made of four types of alloys is higher than that of the flake powder made of the soft metal described above. Therefore, the compressive stress applied to the flat powder is large. Therefore, the gap between the two work rolls is narrowed depending on the hardness of the flat powder. Furthermore, even when a large compressive stress is applied, the flat powder particles do not bond together across the entire overlapping flat surfaces, so the bonding force between the flat powder particles is weaker than the bonding force between flake powder particles made of soft metal. Furthermore, the size of the soft magnetic flaky powder made of four types of alloys is nearly one order of magnitude smaller than the size of the soft metal flake powder described above, and the aspect ratio of the soft magnetic flaky powder made of four types of alloys is close to the aspect ratio of the soft metal flake powder. Therefore, the thickness of the overlapping soft magnetic flaky powder made of four types of alloys is nearly one order of magnitude thinner than the thickness of the soft metal flake powder. On the other hand, the thickness of the overlapping soft magnetic flaky powder is nearly two orders of magnitude thinner than the thickness of the fabric or nonwoven fabric. Therefore, by narrowing the gap between the two work rolls by nearly two orders of magnitude compared to the thickness of the soft magnetic flaky powder covering the entire fabric or nonwoven fabric, the necessary compressive stress is applied to the soft magnetic flaky powder, causing the flat surfaces to bond together. The third powder is a metal oxide powder made of alumina, mica, glass, or hematite in the form of plates, flakes, or scales. The first alumina Al2O3 flake powder is produced by a method called hydrothermal synthesis, in which aluminum hydroxide is reacted with water under high temperature and pressure conditions. 14 It has a high volume resistivity of Ω·cm, a high Mohs hardness of 9, and high heat resistance of over 1500°C, preventing deterioration due to frictional heat. In addition, the thermal conductivity of alumina flake powder is low at 36 W / mK, providing heat insulation. For example, if a coating made by friction welding a collection of alumina flake powder measures 100 cm x 100 cm and is 12 μm thick, the resistance of the coating made from the collection of alumina flake powder will be 0.8 x 10 17Ω. Therefore, sheets using alumina flake powder have extremely high insulation resistance. These insulating sheets can also be used as high-temperature fireproof insulation materials and as lining and sealing materials for industrial furnaces such as heating and baking furnaces. Furthermore, the surface of the coating has irregularities similar in size to the alumina flake powder, as well as the irregularities of the alumina flake powder that appear on the surface of the coating. Therefore, when cut sheets are placed on the surface of substrates or parts made of various materials and shapes and the surface of the cut sheets is uniformly compressed, the convex parts of the irregularities on the coating surface come into contact with the surface of the substrate or part, and the cut sheets are joined to the surface of the substrate or part by friction welding at the contact points. This allows the formation of an insulating layer with extremely high insulation resistance and high heat resistance on the surface of substrates or parts made of various materials. Secondary mica K2Al4(Al2Si6O 20 )(OH)4 (also known as potassium aluminum silicate or mica) is a flaky powder obtained by pulverizing and purifying muscovite mica. Mica powder has a high thermal decomposition temperature of 600-800°C, an extremely low thermal conductivity of 0.67 W / mK, a constant tensile strength of 250-300 MPa, and a volume resistivity of 10 14 -10 16 Mica powder has a high dielectric constant (Ω·cm) and a high breakdown voltage (18–25 kV / 0.1 mm). Therefore, sheets made with mica powder have extremely high insulation resistance. Like alumina, these insulating sheets can be used as high-temperature refractory insulation materials and as linings and sealing materials for industrial furnaces such as heating and baking furnaces. Furthermore, because mica flaky powder has a low Mohs hardness of 2.8–3.2, coatings made from mica flaky powder can be easily cut into any shape. Furthermore, the coating surface has irregularities similar to the size of the mica flaky powder, as well as irregularities that appear on the surface of the mica flaky powder. Therefore, when a cut sheet is placed on the surface of a substrate or part made of various materials and shapes and compressed evenly, the convex parts of the coating surface come into contact with the surface of the substrate or part, and the cut sheet is joined to the surface of the substrate or part by friction welding at the contact points. As a result, an insulating layer with extremely high insulation resistance and excellent heat insulating effect is formed on the surface of substrates or components made of various materials. The size of the alumina flake powder is nearly one order of magnitude smaller than the size of the soft metal flake powder described above, and the aspect ratio of the alumina flake powder is close to that of the soft metal flake powder. Therefore, the thickness of the alumina flake powder is nearly one order of magnitude thinner than that of the soft metal flake powder. Furthermore, alumina powder is a hard powder with a Mohs hardness of nearly 9, and does not undergo plastic deformation. On the other hand, the thickness of the overlapping alumina powder is nearly two orders of magnitude thinner than that of the fabric or nonwoven fabric. Therefore, by narrowing the gap between the two work rolls by nearly two orders of magnitude compared to the thickness of the alumina powder cluster covering the entire fabric or nonwoven fabric, the necessary compressive stress is applied to the alumina powder cluster, causing the flat surfaces to bond together. In contrast, the size of the mica flake powder varies by an order of magnitude. Furthermore, the aspect ratio of the mica flake powder is close to that of the soft metal flake powder. Furthermore, the Mohs hardness of the mica flake powder is around 3, and it undergoes plastic deformation. Therefore, if the size of the mica flake powder is nearly one order of magnitude smaller than the size of the soft metal flake powder, the thickness of the overlapping mica powder is nearly two orders of magnitude thinner than the thickness of the fabric or nonwoven fabric. Therefore, by narrowing the gap between the two work rolls by nearly two orders of magnitude, relative to the thickness of the mica powder covering the entire fabric or nonwoven fabric, the necessary compressive stress is applied to the mica powder cluster, causing the flat surfaces to bond together. On the other hand, if the size of the mica flake powder is close to that of flake powder made from soft metal, the gap between the two work rolls can be narrowed by nearly an order of magnitude compared to the thickness of the mica powder covering the entire cloth or nonwoven fabric, and the necessary compressive stress will be applied to the mica powder, causing the flat surfaces to bond together. The third type of glass flake powder is produced by expanding molten glass into a hollow shape, thinning the film thickness, and then crushing it to produce scaly glass flake powder. The glasses used to produce glass flake powder are C-glass and E-glass. C-glass contains 8 wt% of Na2O and K2O in its chemical composition, so it is mainly used in applications that make use of its acid-resistant properties. In contrast, E-glass contains only 0.3 wt% of Na2O and K2O, and is used as a general-purpose glass. The density of E-glass is 2.6 g / cm 3 The softening point is 840°C, the tensile strength is 3.4 GPa, the thermal conductivity is 1.03 W / mK, and the volume resistivity is 10 15 Glass flakes are an excellent insulator, with a high dielectric constant (Ω·cm), a dielectric constant (6.13) at 1 MHz, and a dissipation factor (DTF) of 0.0035 at 1 GHz. Therefore, a lightweight glass sheet composed of glass flakes combines thermal insulation, insulation, and tensile strength. Furthermore, glass flakes have a Mohs hardness of 5-6, allowing them to be cut by bending without producing chips. Therefore, coatings composed of glass flakes can be cut into any shape. Furthermore, the coating surface has irregularities similar to the size of the glass flakes. Therefore, when a cut sheet is placed on the surface of a substrate or part made of various materials and shapes and compressed evenly, the convex portions of the coating surface come into contact with the surface of the substrate or part, and the cut sheet is joined to the surface of the substrate or part by friction welding at the contact points. This allows a lightweight glass sheet layer to be formed on the surface of a variety of substrates or parts, combining thermal insulation, insulation, and tensile strength. The glass flake powder has a particle size similar to that of the soft metal flake powder described above, but is one order of magnitude thicker than the soft metal flake powder, has an aspect ratio similar to that of the soft metal flake powder, and has a Mohs hardness of around 5, which is about twice that of the soft metal flake powder, making it less susceptible to plastic deformation. On the other hand, the thickness of the overlapping glass flake powder is nearly one order of magnitude thinner than the thickness of the fabric or nonwoven fabric. Therefore, by narrowing the gap between the two work rolls by nearly one order of magnitude relative to the thickness of the glass flake powder covering the entire fabric or nonwoven fabric, the necessary compressive stress is applied to the glass flake powder cluster, causing the flat surfaces to bond together. The fourth hematite (α-Fe2O3) powder is produced by hydrothermally treating yellow iron oxide (hydrated iron oxide α-FeOOH) in an alkaline aqueous solution to precipitate flaky hematite. The volume resistivity of hematite as an insulator is 10 8 Although hematite has a low resistance (Ω·cm), its melting point is high (1565°C), making it a non-flammable powder. Hematite powder is also used as a red pigment (red iron oxide) in lacquerware. Therefore, sheets made with hematite powder have a bright red color and excellent heat resistance. Hematite has a high Mohs hardness of 6.3, but the coating made of the hematite powder is thin, allowing the sheets to be cut into any shape. Furthermore, the surface of the sheet has irregularities similar in size to the hematite flakes, as well as irregularities that appear on the surface of the hematite flakes. Therefore, when a cut sheet is placed on the surface of a substrate or part made of various materials and shapes and the surface of the cut sheet is compressed evenly, the convex parts of the irregularities on the surface of the cut sheet come into contact with the surface of the substrate or part, and the cut sheet is joined to the surface of the substrate or part by friction welding at the contact points, forming a bright red non-flammable layer with excellent heat resistance on the surface of the substrate or part. The scaly hematite powder has a small average particle size of 12-15 μm and a thin thickness of 0.2-0.3 μm. Therefore, similar to the flat powder of alumina powder, by narrowing the gap between the two work rolls by nearly two orders of magnitude compared to the thickness of the scaly hematite powder cluster covering the entire woven or nonwoven fabric, the necessary compressive stress is applied to the scaly hematite powder cluster, causing the flat surfaces to bond together. The fifth type of powder is boron nitride powder, which has a scaly shape. Scaly hexagonal boron nitride (BN) does not exist in nature but is artificially produced. Specifically, boron carbide is sintered at high temperature and pressure in a nitrogen-pressurized atmosphere. The resulting sintered material is mixed with a boron source, heated to a temperature at which decarburization can begin, and then heated to a high temperature in a nitrogen atmosphere and maintained in this atmosphere to obtain bulk boron nitride. The bulk boron nitride is then crushed to obtain micron-sized hexagonal scaly boron nitride powder. Hexagonal boron nitride has a layered structure similar to graphite particles. Within the layers, boron and nitrogen atoms are bonded by strong covalent bonds, but the layers are held together by weak van der Waals forces, allowing for easy delamination and the production of bulk boron nitride flakes. Thus, hexagonal scaly boron nitride powder possesses anisotropy. For this reason, a coating in which the flat crystal faces overlap acts as an excellent lubricating coating. Also, since it does not react with corrosive chemicals and does not get wet with molten metal or molten glass, the coating acts as a lubricating coating with excellent corrosion resistance. Furthermore, the thermal conductivity in the direction parallel to the crystal faces is 410 W / mK, and the thermal conductivity in the direction perpendicular to the crystal faces is 2 W / mK. Therefore, a coating in which the flat crystal faces overlap easily conducts heat in the direction of the flat faces, which has high thermal conductivity, and the thermal conductivity of the coating is close to that in the direction parallel to the crystal faces, and it exhibits thermal conductivity close to that of silver. It is also an excellent insulator with a dielectric constant of 3.9 and a volume resistivity of 10 15The dielectric constant is high at Ω·cm, and the overlapping flat crystal planes form an insulating film with extremely high insulation resistance. Furthermore, it has heat resistance of 900°C in an oxidizing atmosphere, 1200-1300°C in a vacuum, 2000°C in an inert atmosphere, and 3000°C under nitrogen pressure, making it an excellent thermally conductive or insulating sheet in high-temperature environments. Furthermore, the dielectric dissipation factor is extremely low at 0.0008 at 1 MHz, and the breakdown voltage is high at 20 kV / mm, making the overlapping flat crystal planes function as an insulating sheet in the high-frequency range. Note that flake boron nitride powder has an average particle size ranging from 10 to 80 μm and an aspect ratio ranging from 2 to 30. Therefore, for flake boron nitride powder with a relatively small average particle size and a relatively large aspect ratio, similar to flat alumina powder, the required compressive stress is applied to the flake boron nitride powder clusters, bonding their flat surfaces together, by narrowing the gap between the two work rolls by nearly two orders of magnitude relative to the thickness of the flake boron nitride powder clusters covering the entire cloth or nonwoven fabric. For other flake boron nitride powder clusters, the required compressive stress is applied to the flake boron nitride powder clusters, bonding their flat surfaces together, by narrowing the gap between the two work rolls by nearly one order of magnitude relative to the thickness of the flake boron nitride powder clusters covering the entire cloth or nonwoven fabric. Furthermore, because the Mohs hardness of scaly boron nitride powder is less than 2, it undergoes plastic deformation under compressive stress. As a result, the flat surfaces are directly joined by friction welding, resulting in a large joining area, and the collection of boron nitride powder joined by friction welding has excellent mechanical strength. As explained above, there are various types of powders with large aspect ratios, such as plate-like, flake-like, or scale-like shapes. These 15 types of powders have unique properties according to their material. As a result, sheets covered with a coating formed by a collection of powders joined by friction welding have the properties unique to the powder. Therefore, the sheets can be used for a variety of purposes based on the unique properties of the powder.

[0033] The method for continuously manufacturing a soft magnetic sheet that absorbs electromagnetic waves or a soft magnetic sheet that prevents interference from electromagnetic noise using flat powders of the four types of soft magnetic alloys described in paragraph 31 is as follows: A method for continuously manufacturing a soft magnetic sheet that absorbs electromagnetic waves or a soft magnetic sheet that prevents electromagnetic noise interference using flat powders of four types of soft magnetic alloys as described in paragraph 31, comprising: selecting from the flat powders of four types of soft magnetic alloys those types of soft magnetic flat powders whose imaginary part of complex permeability has a value equal to or greater than a certain value in different frequency bands; mixing the selected flat powders of multiple types of soft magnetic alloys in a predetermined ratio; using the mixed collection of flat powders of multiple types of soft magnetic alloys as the powder as described in paragraph 11; and sequentially carrying out all three steps as described in paragraph 11 in order;

[0034] In other words, the frequency characteristics of the imaginary part of the complex permeability of the four types of soft magnetic alloy flat powder described in paragraph 31 vary significantly depending on the alloy composition. Therefore, soft magnetic sheets used for absorbing electromagnetic waves or preventing electromagnetic noise interference use different soft magnetic flat powder materials depending on the frequency band of the electromagnetic waves to be absorbed. Therefore, if the magnitude of the imaginary part of the complex permeability of multiple types of soft magnetic flat powders exceeds a certain value in different frequency bands, these multiple types of soft magnetic flat powders can be mixed and used as the powder described in paragraph 11 to produce a soft magnetic sheet using the mixture of multiple types of soft magnetic flat powders according to the sheet manufacturing method described in paragraph 11. The soft magnetic sheet will have the effect of absorbing electromagnetic waves over a wide frequency band or preventing electromagnetic noise interference over a wide frequency band. That is, among the flat powders made of four types of soft magnetic alloys, multiple types of soft magnetic flat powders are selected from the four types of soft magnetic alloys, and the magnitude of the imaginary part of the complex permeability of the multiple types of soft magnetic flat powders is a certain value or more in different frequency bands. Further, the selected multiple types of soft magnetic flat powders are mixed in a predetermined mixing ratio so that the magnitude of the imaginary part of the complex permeability of the multiple types of soft magnetic flat powders is a certain value or more in different frequency bands. The mixed flat powders are stacked with their flat surfaces facing each other, and a soft magnetic sheet is formed from the multiple types of soft magnetic flat powders joined together. The characteristics of the imaginary part of the complex permeability of this soft magnetic sheet are the sum of the characteristics of the imaginary part of the complex permeability of the multiple types of soft magnetic flat powders, so that the value of the imaginary part of the complex permeability has a constant magnitude over a wide frequency range. This results in a soft magnetic sheet that has the effect of absorbing electromagnetic waves over a wide frequency band or preventing interference from electromagnetic noise, which was previously impossible. For example, the imaginary part of the complex permeability of permalloy powder peaks at 3.3 MHz, and the imaginary part of the complex permeability of silicon steel peaks at 5.6 MHz. When a soft magnetic sheet is formed from a flat powder obtained by mixing the two flat powders in a 1:1 volume ratio, the imaginary part of the complex permeability of the soft magnetic sheet has a wider frequency range over which the imaginary part of the complex permeability has a constant value, for example, a value of 6 or more, compared to when a soft magnetic sheet is formed from flat permalloy powder and flat silicon steel powder alone. That is, the imaginary part of the complex permeability of permalloy powder is 6 or more in the frequency band of 1-6.7 MHz, and the imaginary part of the complex permeability of silicon steel powder is 6 or more in the frequency band of 3-10 MHz. However, the frequency range over which the imaginary part of the complex permeability of the mixed powder is 6 or more extends to 1-10 MHz. Furthermore, the peak value of the imaginary part of the complex permeability of electromagnetic stainless steel flat powder is 7.5 at 5 MHz, and when a soft magnetic sheet is formed from flat powders that are a mixture of electromagnetic stainless steel flat powder, permalloy flat powder, and silicon steel flat powder in a volume ratio of 2:1:1, the imaginary part of the complex permeability of the soft magnetic sheet made from the mixture of permalloy flat powder and silicon steel flat powder drops to a valley in the frequency band of 4-6 MHz, but the imaginary part of the complex permeability in this valley frequency band is supplemented by the electromagnetic stainless steel flat powder. In this way, by mixing multiple types of soft magnetic flat powders in a predetermined mixing ratio so that the magnitude of the imaginary part of the complex permeability of the multiple types of soft magnetic flat powders is equal to or greater than a certain value in different frequency bands, and using the mixed multiple types of soft magnetic flat powders as the powder described in paragraph 11, and manufacturing a soft magnetic sheet from the mixture of multiple types of soft magnetic flat powders according to the method for manufacturing a sheet described in paragraph 11, the soft magnetic sheet becomes a soft magnetic sheet that has the effect of absorbing electromagnetic waves consisting of a wide frequency band or preventing interference from electromagnetic noise. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 1 is a schematic diagram illustrating an enlarged cross section of a sheet made of a piece of intermittently divided fabric with clusters of copper powder frictionally welded to the entire surface. DETAILED DESCRIPTION OF THE INVENTION

[0036] Example 1 In this example, a sheet was continuously produced, consisting of a fabric entirely covered with a coating formed by a collection of spherical copper powder particles joined by friction welding. The fabric was a 50 cm wide, 10 m long roll of fabric made of 100% cotton plain woven with 0.5 mm thick yarn. The powder used was spherical copper powder produced by gas atomization (FAM-QCU45-105 μm, manufactured by Fukuda Metal Foil and Powder Co., Ltd.). The copper powder size ranged from 10 to 45 μm, with an average particle size of 29.2 μm, a 10% D of 16.4 μm, a 50% D of 29.5 μm, and a 90% D of 40.6 μm. The alcohol used was 1-hexanol, which has a viscosity of 5.3 mPa·s at 20°C and a boiling point of 157°C. 1-hexanol has a viscosity of 5.3 mPa·s at 20°C, which is not considered low among alcohols with viscosities of 3–11 mPa·s at 20°C. On the other hand, copper powder produced by gas atomization is spherical and highly symmetrical. Therefore, when subjected to compressive stress, many copper particles move to fill the voids in the copper powder clusters. However, its average particle size of 29.2 μm is small for a powder. Therefore, the voids in the copper powder clusters joined by friction welding must be contained by joining the overlapping copper powder. Furthermore, because the copper powder is spherical, its plastic deformation is suppressed, preventing adjacent voids from filling through plastic deformation. Therefore, the number of overlapping copper powder particles must be increased. Furthermore, the gap between the two work rolls cannot be narrowed because plastic deformation of the copper powder is suppressed. For these reasons, 1-hexanol, which is not particularly low in viscosity, was used as the alcohol that made up the suspension. After evaporating the 1-hexanol, the required number of copper powder particles, which have relatively small particle sizes, were layered on top of each other. First, eight cylindrical rollers, each 3 cm in diameter, were placed parallel to and spaced apart from one another on the sides of a container measuring 52 cm in width, 54 cm in length (corresponding to its vertical width), and 8 cm in depth. These rollers were continuously rotated by a roller drive device at the same peripheral speed of one rotation per 25 seconds. The first roller was positioned so that its center was 3 cm from one side of the container that formed the width and 1.5 cm from the top edge of the container, extending beyond the container by 1.5 cm. The second roller was positioned so that its center was 6 cm from one side of the container that formed the width and 3 cm from the bottom of the container. The seventh roller was positioned so that its center was 6 cm from the other side of the container that formed the width opposite the second roller, and 3 cm from the bottom of the container, the same as the second roller. The centers of the four rollers, the third through sixth, were all 3 cm from the bottom of the container, just like the second and seventh rollers, and were spaced 5.4 cm apart between the second and seventh rollers. The center of the eighth roller was 3 cm from the other side of the container that formed the width opposite the first roller, and like the first roller, it was 1.5 cm from the top of the container, and it extended outside the container by 1.5 cm. Thereafter, a 12-high rolling mill (for example, a product of Kobe Steel, Ltd.) was prepared. The two work rolls of the 12-high rolling mill were cylindrical with a diameter of 3 cm and a length of 52 cm, and the gap between the two work rolls was set to 0.6 mm. The work rolls were rotated in opposite directions at the same rotational speed as the eight cylindrical rollers described above, and the temperature was raised to 167°C, which is 10°C higher than 157°C, the boiling point of 1-hexanol. Next, 10 kg of copper powder and 12 kg of 1-hexanol were placed in a container, and the 1-hexanol was stirred to prepare a suspension of copper powder immersed in 1-hexanol. Note that the suspension was formed to a depth of 5.2 cm, so that six rollers (from the second roller to the seventh roller) were immersed in the suspension. Furthermore, the roll of fabric is set in the drawing device, and the fabric is continuously drawn out from the roll at a speed corresponding to the peripheral speed of the eight cylindrical rollers. In addition, the roller drive unit rotates eight cylindrical rollers continuously at the same peripheral speed of one rotation per 25 seconds, and The drawn fabric was brought into contact with the first roller of the container, and then the fabric immersed in the suspension was brought into contact with the second through seventh rollers in succession. After this, the fabric that had contacted the seventh roller changed direction of movement upward, continued moving, and after being pulled up from the suspension, came into contact with the eighth roller. After contacting the eighth roller, the fabric changed direction of movement by 90 degrees and moved toward the gap between the two work rolls that make up the multi-stage rolling mill. Then, the leading edge of the fabric immersed in the suspension was inserted into the gap between the two work rolls of the multi-stage rolling mill, and the fabric was compressed between the two work rolls. The sheet discharged from the gap between the two work rolls was then wound up by a winder that rotated at the same speed as the eight cylindrical rollers. The prepared sheet was cut into three pieces with a length of 50 cm, and the cut sheets were analyzed. First, the cut sheets were observed and analyzed using an electron microscope. An ultra-low accelerating voltage SEM from JFE Techno-Research Corporation was used as the electron microscope. This device is capable of surface observation at ultra-low accelerating voltages starting from 100 volts, and has the advantage of being able to directly observe the surface of a sample without forming a conductive coating on the sample. The sheet was 0.6 mm thick. Next, secondary electron beams between 900-1000 volts, reflected from the cross section, were extracted and image-processed. Above and below the 0.15 mm thick, intermittently divided organic material, 8-9 layers of spherical powder, some of which had undergone plastic deformation, were stacked, forming an average thickness of approximately 225 μm and joining together to cover the entire organic material. Furthermore, the energy and intensity of the characteristic X-rays were image-processed, and the elements that make up the powder were analyzed. These results indicated that the powder was copper. The resulting sheet consisted of spherical copper powder particles overlapping each other in 8-9 layers across the entire fabric. The copper powder particles were then compressed against the fabric, causing the fabric to break at points where they came into contact, splitting the fabric intermittently. The copper powder then penetrated the fractured areas, causing some of the copper powder particles to plastically deform, resulting in friction welding of all contact points between the copper powder particles. The friction-welded copper powder particles then covered the intermittently split fabric. Figure 1 shows a schematic, enlarged cross-section of a sheet consisting of split fabric particles joined together by friction welding. 1 represents the copper powder particles, and 2 represents the split fabric. The thickness of the coating formed by frictionally compressing the overlapping copper powder particles, forming 8-9 layers, was approximately 225 μm. This coating thickness was thin compared to the size of the overlapping copper powder particles. In other words, the thickness of the overlapping copper powder particles that did not undergo plastic deformation, forming 8-9 layers, is thought to be 240-270 μm on average. The thickness of the fabric was close to 0.5 mm. In contrast, in Example 1, the thickness of the divided fabric was 0.15 mm, and the thickness of the copper powder bonded by frictionally compressing was 0.225 mm. Therefore, the spherical copper powder underwent plastic deformation at a rate of 6-17%. Although copper has low hardness and is prone to plastic deformation, the spherical shape of the copper powder prevented the plastic deformation of the copper powder. That is, in Example 1, when the fabric evenly covered with the suspension approaches the gap between the two work rolls, 1-hexanol evaporates from the suspension, and then the fabric evenly covered with the copper powder clusters is drawn into the gap between the two work rolls. First, the surface layer of the copper powder clusters comes into contact with the two work rolls, and the surface layer of the copper powder clusters moves backward. Then, compressive stress is applied to the fabric evenly covered with the copper powder clusters. First, the copper powder moves to fill the gaps in the copper powder clusters, and when it becomes difficult for the copper powder to move, compressive stress is applied to the copper powder clusters and the fabric, causing plastic deformation of the copper powder and the fabric, which then causes plastic deformation of the fabric, and finally, the copper powder begins to break the fabric. When the copper powder's plastic deformation is complete, the fabric is broken, and the fabric is separated, frictional heat is generated at the contact points between the copper powder particles, causing all contact points to be joined by friction welding, and the broken parts of the fabric are also filled with copper powder that has been friction-welded. As a result, the entire broken fabric is intermittently covered with copper powder particles that have been joined at the contact points where the copper powder particles have completed plastic deformation. As a result, a coating consisting of copper powder particles that have been joined by friction compression, forming 8-9 layers, is formed, with a thickness of approximately 225 μm. Next, a portion of the cut sheet was immersed in water, and after that, the sheet was pulled out of the water and the surface was observed. As a result, several water droplets were present on the surface, and when the sheet was tilted diagonally, the water droplets easily fell off, indicating that the surface of the sheet was water-repellent. Furthermore, the surface resistance of several points on the sheet surface was measured using a surface resistance meter (Simco Japan Co., Ltd. surface resistance meter ST-4).3 The surface resistance of the sample was less than Ω / □, close to that of metal. After this, using a portion of the cut sheet, the gas permeability was examined using a gas permeability measuring device (a product of GTR Tech Co., Ltd.) using the JISK7126A method (differential pressure method) differential pressure gas chromatography. The results showed that air did not permeate at atmospheric pressure. Therefore, the cut sheet is non-flammable and has the heat resistance of copper. Furthermore, the tensile strength of a portion of the cut sheet was tested in accordance with JIS C6515, a copper foil testing method for printed wiring boards, and was found to be 400±20 MPa. This value is close to the tensile strength of 450 MPa found in 12 μm-thick copper foil made by low-roughness rolling tough-pitch copper, demonstrating that the sheet has sufficient mechanical strength. For this reason, the cut sheet can be used as a lightweight conductive or thermally conductive sheet, or as a substrate or electrode for electrical circuits. The cut sheets were then further cut into 10cm x 10cm pieces and placed on top of a 1mm thick, 10cm x 10cm plastic sheet. Nine 10kg weights were placed evenly spaced on the surface of the overlapping sheets to bond them together. The bond strength of the bonded surfaces was then measured at a peel speed of 300mm / min in accordance with the 180-degree peel test of JIS Z0237:2022 (Test Methods for Adhesive Tapes and Adhesive Sheets). The peel force was 280mN / 50mm, indicating sufficient bond strength. This imparts the electrical and thermal conductivity of copper to the surface of the plastic sheet. In this example, spherical copper powder produced by gas atomization was used as a representative of powders having a spherical, granular, or agglomerated shape. However, the present invention is not limited to spherical copper powder produced by gas atomization, and powders having a spherical, granular, or agglomerated shape made of various materials as described in paragraph 18 can also be used.

[0037] Example 2 In this example, a sheet is continuously produced, consisting of a roll of fabric used in Example 1 covered with a coating formed by an aggregation of spongy iron powder joined by friction welding. The iron powder used was pure iron powder (JIP300A from JFE Steel Corporation) produced by the water atomization method. Because the iron powder was produced by the water atomization method, it had a spongy, dense structure and was not porous like iron powder produced by the reduction method. The median diameter at which the cumulative distribution was 50% was 77.0 μm, and the green density was 6.86 g / cm. 3 The particle size distribution was +106 μm 27.8%, +75 μm 23.7%, +63 μm 9.6%, +45 μm 14.9%, and -45 μm 24.0%. The alcohol used was 2-heptanol, which has a viscosity of 4.0 mPa·s at 20°C and a boiling point of 159°C. 2-heptanol has a viscosity of 4.0 mPa·s at 20°C, which is lower than the viscosity of 1-hexanol used in Example 1. Meanwhile, the copper powder produced by gas atomization in Example 1 is spherical, with the highest symmetry, while the iron powder produced by water atomization in Example 2 is spongy and less symmetrical than the copper powder. However, the size of the iron powder produced by water atomization is nearly three times larger on average than the copper powder produced by gas atomization. Therefore, the surface area of ​​the iron powder is larger than that of the copper powder. Therefore, 2-heptanol, which has a lower viscosity than the 1-hexanol used in Example 1, was used as the alcohol constituting the suspension. After evaporating the 2-heptanol, the iron powder, which has a relatively large powder size, was stacked in fewer layers than the copper powder used in Example 1. Furthermore, when the iron powder mass is compressed, the iron powder has a spongy shape, so the plastically deformed iron powder fills the adjacent voids. For this reason, the gap between the two work rolls was narrower than in Example 1, when using spherical copper powder, to apply a greater compressive stress to the spongy iron powder, allowing the plastic deformation of the iron powder to fill the voids in the iron powder mass. Therefore, the gap between the two work rolls was set to 0.4 mm. The vessel used was the same as that used in Example 1, and eight cylindrical rollers were installed in this vessel as in Example 1. Furthermore, the 12-high rolling mill used in Example 1 was used, except that the gap between the two work rolls was set to 0.4 mm, and the temperature was raised to 169°C, which is 10°C higher than the boiling point of 2-heptanol. Next, 10 kg of iron powder and 12 kg of 2-heptanol were placed in a container, and the 2-heptanol was stirred to prepare a suspension of iron powder immersed in 2-heptanol. Note that the suspension was formed to a depth of 5.2 cm, so that six rollers, from the second roller to the seventh roller, were immersed in the suspension. Furthermore, similarly to Example 1, a roll of fabric was set in the drawing device, and the fabric was continuously drawn out from the roll at a speed corresponding to the peripheral speed of the eight cylindrical rollers. In addition, the roller drive unit rotates eight cylindrical rollers continuously at the same peripheral speed of one rotation per 25 seconds. The pulled-out fabric was brought into contact with the first roller of the container. The fabric, immersed in the suspension, was then brought into contact with the second through seventh rollers in succession. After this, the fabric, which had contacted the seventh roller, changed direction and continued moving upward, and after being pulled up from the suspension, came into contact with the eighth roller. After contacting the eighth roller, the fabric changed direction by 90 degrees and moved toward the gap between the two work rolls of the multi-roll rolling mill. The leading edge of the fabric, immersed in the suspension, was inserted into the gap between the two work rolls of the multi-roll rolling mill, and the fabric was compressed between the two work rolls. The sheet discharged from the gap between the two work rolls was then wound up by a winder rotating at the same speed as the eight cylindrical rollers. The prepared sheet was cut into three pieces with a length of 50 cm, and the cut sheets were analyzed. First, as in Example 1, the cut sheet was observed and analyzed using an electron microscope. The sheet thickness was 0.4 mm. Next, secondary electron beams between 900 and 1000 volts, reflected from the cross section, were extracted and image-processed. Six to seven layers of plastically deformed powder were stacked above and below the 0.05 mm thick, intermittently divided organic material, forming a bonded layer with an average thickness of approximately 170 μm, covering the entire divided organic material. Furthermore, the energy and intensity of the characteristic X-rays were image-processed, and the elements constituting the powder were analyzed. As a result, the powder was found to be iron. Therefore, the sheet that was created had spongy iron powder piled up in 6-7 layers across the entire fabric, the parts of the fabric that came into contact with the iron powder broke, the iron powder entered the broken parts, all contact points between the iron powder particles were plastically deformed and joined by friction welding, and the collection of iron powder joined by friction welding covered the intermittently divided fabric. The thickness of the coating formed by friction compression of overlapping iron powder particles forming 6-7 layers was approximately 170 μm. In contrast, the thickness of the iron powder particles before compression, which overlapped each other forming 6-7 layers, is estimated to be 450-520 μm. The thickness of the fabric was close to 0.5 mm. Therefore, since the gap between the two work rolls of the multi-high rolling mill was 0.4 mm, the thickness of the fabric evenly covered with the iron powder particles was approximately 3.5-3.8 times thicker. In contrast, the results of Example 2 showed that the thickness of the divided fabric was 0.05 mm, and the thickness of the iron powder particles joined by friction compression was approximately 0.17 mm. Therefore, the spongy iron powder underwent plastic deformation at an average rate of approximately 65% ​​and was joined by friction welding. That is, when the fabric evenly covered with the suspension approaches the gap between the two work rolls, 2-heptanol evaporates from the suspension, and then the fabric evenly covered with the iron powder clusters is pulled into the gap between the two work rolls. Furthermore, the surface layer of the iron powder clusters comes into contact with the two work rolls, causing the surface layer of the iron powder clusters to move backward. Then, compressive stress is applied to the fabric evenly covered with the iron powder clusters. First, the iron powder moves to fill the gaps in the iron powder clusters. When this movement of the iron powder becomes difficult, compressive stress is applied to the iron powder clusters and the fabric, causing plastic deformation of the iron powder, compressive deformation of the fabric, and finally, the fabric, compressed and deformed by the iron powder, begins to break. Furthermore, once the iron powder has completed its plastic deformation and the fabric has broken, frictional heat is generated at the contact points between the plastically deformed iron powder particles, causing all contact points to be friction-welded, and the broken sections of the fabric are also filled with the friction-welded iron powder. As a result, the entire intermittently divided fabric is covered with a collection of overlapping and bonded iron powder particles. The resulting coating, consisting of 6-7 layers of overlapping iron powder particles bonded by friction compression, is approximately 170 μm thick. Note that JFE Steel Corporation's atomized iron powder is hard due to the high carbon and oxygen content of the raw powder obtained during the atomization process, so its hardness is reduced by decarburization and reduction in a reduction heat treatment furnace. Next, a portion of the cut sheet was immersed in water, and after that, the sheet was pulled out of the water and the surface was observed. As a result, several water droplets were present on the surface, and when the sheet was tilted diagonally, the water droplets easily fell off, indicating that the surface of the sheet was water-repellent. Furthermore, the surface resistance of multiple points on the sheet surface was measured using a surface resistance meter (Simco Japan Co., Ltd. surface resistance meter ST-4). 3 The surface resistance of the sample was less than Ω / □, close to that of metal. After this, using a portion of the cut sheet, the gas permeability was examined using a gas permeability measuring device (a product of GTR Tech Co., Ltd.) using the JISK7126A method (differential pressure method) differential pressure gas chromatography. The results showed that air did not permeate at atmospheric pressure. This means that the sheet is non-flammable and has the heat resistance of iron. Furthermore, the tensile strength of a portion of the cut sheet was tested in accordance with JIS C6515, a copper foil testing method for printed wiring boards. The result was a tensile strength of 440±10 MPa. This value is close to the tensile strength of 450 MPa for a 12 μm-thick copper foil made by low-roughness rolling tough-pitch copper, demonstrating that the sheet has sufficient mechanical strength. Therefore, the manufactured sheet, cut sheet, or folded sheet can effectively act as a shielding sheet for magnetic shielding. Similarly to Example 1, the cut sheet was further cut into 10 cm x 10 cm pieces and placed on top of a 1 mm thick, 10 cm x 10 cm plastic sheet. Nine 12 kg weights were placed evenly spaced on the surface of the overlapping sheets to bond them together. Next, the bond strength of the bonded surfaces was measured at a peel rate of 300 mm / min in accordance with the 180-degree peel test of JIS Z0237:2022 (Test Methods for Adhesive Tapes and Adhesive Sheets). The peel force was 320 mN / 50 mm, indicating sufficient bond strength. This imparts the electrical conductivity and magnetic properties of iron to the surface of the plastic sheet. In this example, iron powder produced by water atomization was used as the powder that is sponge-like but not porous and that undergoes plastic deformation when compressed. However, the powder is not limited to iron powder produced by water atomization, and bronze powder, an alloy of copper and tin, produced by water atomization as described in paragraph 22, can also be used.

[0038] Example 3 In this example, a sheet was continuously produced, consisting of a roll of nonwoven fabric covered with a coating formed by teardrop-shaped aggregates of aluminum powder joined by friction welding. The nonwoven fabric was made of polypropylene, and a roll of fabric measuring 50 cm x 10 m was used, with a thickness of 250 μm. The aluminum powder was teardrop-shaped and produced by gas atomization, with an average particle size of 24-27 μm (350M from Minalco Corporation). The alcohol used was 3-pentanol, which has a viscosity of 6.5 mPa·s at 20°C and a boiling point of 116°C. 3-Pentanol has a viscosity of 6.5 mPa·sec at 20°C, slightly higher than the viscosity of 1-hexanol used in Example 1. Meanwhile, the copper powder produced by gas atomization in Example 1 is spherical, with the highest symmetry, while the aluminum powder produced by gas atomization in Example 3 is teardrop-shaped and less symmetrical than the copper powder, but more susceptible to plastic deformation than the spherical copper powder. Meanwhile, the size of the aluminum powder produced by gas atomization is slightly smaller than that of the copper powder produced by gas atomization. Therefore, the surface area of ​​the aluminum powder is slightly smaller than that of the copper powder. Taking the rate of plastic deformation into consideration, 3-pentanol, which has a slightly higher viscosity than the 1-hexanol used in Example 1, was used as the alcohol constituting the suspension. After the 3-pentanol was vaporized, the aluminum powder, which has less symmetry, was stacked in a greater number of layers than the copper powder in Example 1. Furthermore, when the aluminum powder mass is compressed, the teardrop-shaped aluminum powder, which has low hardness, is more susceptible to plastic deformation than the spherical copper powder of Example 1, and the plastically deformed aluminum powder fills adjacent voids. For this reason, the gap between the two work rolls was narrower than that of the spherical copper powder of Example 1, applying a greater compressive stress to the teardrop-shaped aluminum powder and allowing the plastic deformation of the aluminum powder to fill the voids in the aluminum powder mass. Therefore, the gap between the two work rolls was set to 0.3 mm, half that of Example 1. The vessel used was the same as in Example 1, and eight cylindrical rollers were installed in this vessel as in Example 1. The eight cylindrical rollers were rotated continuously at the same peripheral speed of one rotation per 25 seconds as in Example 1. Furthermore, the 12-high rolling mill used in Example 1 was used. However, the gap between the two work rolls was set to 0.3 mm, and the temperature was raised to 126°C, 10°C higher than 116°C, the boiling point of 3-pentanol. Next, 10 kg of aluminum powder and 12 kg of 3-pentanol were placed in a container, and the 3-pentanol was stirred to prepare a suspension of aluminum powder immersed in 3-pentanol. Note that the suspension was formed to a depth of 5.2 cm, so that six rollers from the second roller to the seventh roller were immersed in the suspension. Furthermore, the roll of nonwoven fabric is set in the drawing device, and the fabric is continuously drawn out from the nonwoven fabric at a speed corresponding to the peripheral speed of the eight cylindrical rollers. In addition, the roller drive unit rotates eight cylindrical rollers continuously at the same peripheral speed of one rotation per 25 seconds, and The pulled-out fabric was brought into contact with the first roller of the container. Furthermore, the fabric immersed in the suspension was brought into contact with the second through seventh rollers in succession. After this, the fabric, which had contacted the seventh roller, changed direction and continued moving upward, and after being pulled up from the suspension, came into contact with the eighth roller. After contacting the eighth roller, the fabric changed direction by 90 degrees and moved toward the gap between the two work rolls of the multi-roll rolling mill. The leading edge of the fabric immersed in the suspension was inserted into the gap between the two work rolls of the multi-roll rolling mill, and the fabric was compressed between the two work rolls. Furthermore, the sheet discharged from the gap between the two work rolls was wound up by a winder rotating at the same speed as the eight cylindrical rollers. The prepared sheet was cut into three pieces with a length of 50 cm, and the cut sheets were analyzed. First, as in Example 1, the cut sheet was observed and analyzed using an electron microscope. The sheet thickness was 0.3 mm. Next, secondary electron beams between 900 and 1000 volts, reflected from the cross section, were extracted and image-processed. Plastically deformed teardrop-shaped powder was stacked in 11-12 layers above and below the 0.05 mm-thick, intermittently divided organic material, forming an average thickness of approximately 75 μm and bonding, completely covering the intermittently divided organic material. Furthermore, the energy and intensity of the characteristic X-rays were image-processed, and the elements constituting the powder were analyzed. As a result, the powder was found to be aluminum. Therefore, the sheet that was created was made up of teardrop-shaped aluminum powder, which is easily plastically deformed, stacked together to form 11-12 layers across the entire nonwoven fabric, and the parts of the nonwoven fabric that came into contact with the aluminum powder broke, the aluminum powder penetrated into the broken areas, and all contact points between the aluminum powder particles were plastically deformed and joined by friction welding, with the collection of aluminum powder joined by friction welding covering the intermittently divided nonwoven fabric. The thickness of the coating formed by friction compression of the overlapping aluminum powder particles forming the 11-12 layers was approximately 75 μm. This coating thickness is too thin compared to the size of the aluminum powder particles. The thickness of the overlapping aluminum powder particles forming the 11-12 layers before compression is estimated to be 265-320 μm. The thickness of the nonwoven fabric is close to 0.25 mm. Therefore, since the gap between the two work rolls of the multi-high rolling mill is 0.3 mm, the thickness of the nonwoven fabric evenly covered with the aluminum powder particles is 2.6-3.0 times thicker. In contrast, the results of Example 3 show that the thickness of the divided nonwoven fabric is 0.05 mm, and the thickness of the teardrop-shaped aluminum powder particles joined by friction compression is approximately 0.075 mm. Therefore, the teardrop-shaped aluminum powder particles were plastically deformed at a rate of 70-76% and joined by friction welding. That is, when the nonwoven fabric evenly covered with the suspension approaches the gap between the two work rolls, 3-pentanol evaporates from the suspension. The nonwoven fabric evenly covered with the aluminum powder aggregates is then drawn into the gap between the two work rolls. Furthermore, the surface layer of the aluminum powder aggregates comes into contact with the two work rolls, causing the surface layer of the aluminum powder aggregates to move backward. Then, compressive stress is applied to the nonwoven fabric evenly covered with the aluminum powder aggregates. Initially, the aluminum powder moves to fill the gaps in the aluminum powder aggregates. When this movement becomes difficult, compressive stress is applied to the aluminum powder aggregates and the nonwoven fabric. Plastic deformation of the aluminum powder begins. Then, compressive deformation of the nonwoven fabric begins. Finally, the aluminum powder begins to fracture the nonwoven fabric. Furthermore, once the aluminum powder has completed its plastic deformation and the nonwoven fabric has broken, frictional heat is generated at the contact points between the plastically deformed aluminum powder particles, causing all contact points to be joined by friction welding, and the broken parts of the nonwoven fabric are also filled with aluminum powder particles joined by friction welding. As a result, the entire nonwoven fabric, which had been intermittently divided, is covered with a collection of aluminum powder particles that have overlapped and joined together, forming 11-12 layers. As a result, a coating made of aluminum powder particles joined by friction compression was formed, with a thickness of approximately 75 μm. Next, a portion of the cut sheet was immersed in water, and after that, the sheet was pulled out of the water and the surface was observed. As a result, several water droplets were present on the surface, and when the sheet was tilted diagonally, the water droplets easily fell off, indicating that the surface of the sheet was water-repellent. Furthermore, the surface resistance of multiple points on the sheet surface was measured using a surface resistance meter (Simco Japan Co., Ltd. surface resistance meter ST-4). 3 The surface resistance of the sample was less than Ω / □, close to that of metal. After this, using a portion of the cut sheet, the gas permeability was examined using a gas permeability measuring device (a product of GTR Tech Co., Ltd.) using the JISK7126A method (differential pressure method) differential pressure gas chromatography. The results showed that air did not permeate at atmospheric pressure. This means that the sheet is non-flammable and has the heat resistance of iron. Furthermore, the tensile strength of a portion of the cut sheet was tested in accordance with JIS C6515, a copper foil test method for printed wiring boards, and was found to be 470±10 MPa. This figure is close to the tensile strength of 450 MPa of a 12 μm thick copper foil made by low-roughness rolling tough-pitch copper, and therefore the sheet was found to have sufficient mechanical strength. Like copper powder, aluminum powder has high electrical and thermal conductivity, and therefore a sheet made of a material covered with a collection of aluminum powder joined by friction welding, or a cut sheet, can be used as a lightweight electrically conductive sheet or thermally conductive sheet, a lightweight heat sink, or a substrate or electrode for an electrical circuit. Similarly to Example 1, the cut sheet was further cut into 10 cm x 10 cm pieces and placed on the surface of a 1 mm thick, 10 cm x 10 cm plastic sheet. Nine 9 kg weights were placed evenly spaced on the surface of the overlapping sheets to bond them together. Next, the bond strength of the bonded surface was measured at a peel rate of 330 mm / min in accordance with the 180-degree peel test of JIS Z0237:2022 (Test Methods for Adhesive Tapes and Adhesive Sheets). The peel force was 350 mN / 50 mm, indicating sufficient bond strength. This imparts both the electrical conductivity and thermal conductivity of aluminum to the surface of the plastic sheet. In this example, teardrop-shaped aluminum powder produced by gas atomization was used as the powder that has a teardrop or spindle shape and undergoes plastic deformation when compressed. However, the powder is not limited to aluminum powder produced by gas atomization, and powders that have a teardrop or spindle shape and undergo plastic deformation when compressed and are made of various materials as described in paragraph 26 can also be used.

[0039] Example 4 In this example, a sheet is continuously produced, in which the nonwoven fabric used in Example 3 is covered with a coating formed by a collection of alumina flat powder joined by friction welding. The alumina flat powder is produced by hydrothermal synthesis, has a large aspect ratio of 30 on average, and a small average particle size of 9 μm (BMF series from Kawai Lime Industry Co., Ltd.). Therefore, the average thickness of the alumina is thin at 0.3 μm. Furthermore, the alumina flat powder has a high Mohs hardness of around 9 depending on the purity of the alumina. Therefore, the alumina flat powder does not deform under compressive stress. Therefore, when compressive stress is applied, the gaps between the alumina flat surfaces narrow, causing the nonwoven fabric to deform, but the alumina flat powder does not deform, and the flat surfaces come into contact with each other, and the contact areas between the flat surfaces are joined by friction welding. The alcohol used was isooctyl alcohol, which has a viscosity of 10.6 mPa·sec at 20°C and a boiling point of 188°C. It should be noted that isooctyl alcohol has a viscosity of 10.6 mPa·sec at 20°C, which is higher than the viscosity of any of the alcohols used in Examples 1-3. In other words, the flat alumina powder produced by hydrothermal synthesis in Example 4 has an average particle size of 9 μm, which is significantly smaller than any of the powders used in Examples 1-3. Therefore, the surface area of ​​the alumina powder is significantly smaller than that of any of the powders used in Examples 1-3. Furthermore, the alumina powder does not undergo plastic deformation. Therefore, isooctyl alcohol, which has a higher viscosity than the alcohol used in Examples 1-3, must be used as the alcohol constituting the suspension. After the isooctyl alcohol is evaporated, the alumina powder must be stacked in a greater number than the powder used in Examples 1-3. Furthermore, the powder used is flat, does not undergo plastic deformation, and is thin, with an average thickness of 0.3 μm. Therefore, even when the nonwoven fabric to which the flat powder is attached is compressed, the flat powder does not break, but simply undergoes compressive deformation. On the other hand, although the thickness of the nonwoven fabric is close to 0.25 mm, the gap between the two work rolls is narrow at 0.07 mm. Therefore, the nonwoven fabric in the manufactured sheet is crushed to 1 / 4-1 / 5 of its original thickness by the compressive stress. The vessel used was the same as in Example 1, and eight cylindrical rollers were installed in this vessel as in Example 1. The eight cylindrical rollers were continuously rotated at the same peripheral speed of one rotation per 25 seconds as in Example 1. Furthermore, the 12-high rolling mill used in Example 1 was used. However, the gap between the two work rolls was set to a narrow gap of 0.07 mm so that the alumina powder would not undergo plastic deformation in the thickness direction, and the temperature was raised to 198°C, which is 10°C higher than 188°C, the boiling point of isooctyl alcohol. Next, 10 kg of alumina powder and 12 kg of 1-heptanol were placed in a container, and the 1-heptanol was stirred to prepare a suspension of aluminum powder immersed in 1-heptanol. Note that the suspension was formed to a depth of 5.2 cm, so that six rollers, from the second roller to the seventh roller, were immersed in the suspension. Furthermore, the roll of nonwoven fabric is set in the drawing device, and the fabric is continuously drawn out from the nonwoven fabric at a speed corresponding to the peripheral speed of the eight cylindrical rollers. In addition, the roller drive unit rotates eight cylindrical rollers continuously at the same peripheral speed of one rotation per 25 seconds, andThe drawn fabric was brought into contact with the first roller of the container, and then successively with the second through seventh rollers. After this, the fabric, which had contacted the seventh roller, changed direction and continued moving upward, rising from the suspension and contacting the eighth roller. After contacting the eighth roller, the fabric changed direction by 90 degrees and moved toward the gap between the two work rolls of the multi-roll rolling mill. The leading edge of the fabric, immersed in the suspension, was inserted into the gap between the two work rolls of the multi-roll rolling mill, where the fabric was compressed. The sheet discharged from the gap between the two work rolls was then wound up by a winder rotating at the same speed as the eight cylindrical rollers. The prepared sheet was cut into three pieces with a length of 50 cm, and the cut sheets were analyzed. First, as in Example 1, the cut sheet was observed and analyzed using an electron microscope. The sheet thickness was 0.07 mm. Next, secondary electron beams between 900 and 1000 volts, reflected from the cross section, were extracted and image-processed. Above and below the 0.055 mm-thick organic material, flat, fine powder particles were stacked in 24-25 layers, with the flat surfaces facing each other, forming a bonded layer with an average thickness of approximately 7.4 μm, covering the entire organic material. Furthermore, the energy and intensity of the characteristic X-rays were image-processed, and the elements constituting the powder were analyzed. As a result, the powder was found to be alumina. The resulting sheet consisted of 24-25 layers of flat, fine alumina powder overlapping the entire nonwoven fabric, with the flat surfaces joining together via friction welding. The overlapping alumina powder particles then covered the nonwoven fabric, which had been crushed by compressive stress. The thickness of this alumina powder cluster was close to the size of the alumina powder before compression. In other words, assuming the gap between the flat surfaces was 10% of the average thickness of alumina, the thickness of the 24-25 overlapping layers of alumina powder before compression was estimated to be approximately 8 μm on average. The thickness of the nonwoven fabric was also close to 0.25 mm. Therefore, the thickness of the nonwoven fabric evenly covered with the alumina powder clusters was close to 266 μm on average. Because the gap between the two work rolls of the multi-high rolling mill was 0.07 mm, the thickness of the nonwoven fabric evenly covered with the flat alumina powder clusters was nearly 3.8 times thicker. On the other hand, in the results of Example 4, the thickness of the nonwoven fabric crushed by compressive stress was close to 55 μm, and the thickness of the alumina flat powder aggregate joined by friction welding was approximately 7.4 μm on average. Therefore, the alumina flat powder did not deform in the thickness direction, and the flat surfaces were joined by frictional heat. As a result, a sheet with a thickness of 70 μm was formed. That is, when the nonwoven fabric evenly covered with the suspension approaches the gap between the two work rolls, 1-heptanol evaporates from the suspension, and then the nonwoven fabric evenly covered with the alumina powder aggregates, where the flat powder particles are overlapping, is pulled into the gap between the two work rolls. Furthermore, the surface layer of the alumina powder aggregates comes into contact with the two work rolls, and the surface layer of the alumina powder aggregates moves backward. Next, compressive stress is applied to the nonwoven fabric evenly covered with the alumina powder aggregates, where the flat powder particles are overlapping. First, the gaps between the flat surfaces of the alumina powder aggregates narrow, and compressive deformation of the nonwoven fabric begins. Furthermore, the compressive deformation of the nonwoven fabric due to the alumina powder advances. After this, the contacting flat surfaces of the alumina powder aggregates begin to bond, and the compressive deformation of the nonwoven fabric due to the alumina powder advances further. Furthermore, the flat surfaces of the alumina powder particles are bonded together at the contact points, completing the compressive deformation of the nonwoven fabric. As a result, the overlapping alumina powder particles form 24-25 layers, forming a coating of approximately 7.8 μm thick, made up of a collection of alumina powder particles bonded together by friction compression. The nonwoven fabric is also crushed by compressive stress to a thickness of 55 μm. Next, a portion of the cut sheet was immersed in water, and after that, the sheet was pulled out of the water and the surface was observed. As a result, several water droplets were present on the surface, and when the sheet was tilted diagonally, the water droplets easily fell off, indicating that the surface of the sheet was water-repellent. Furthermore, when the surface resistance of several points on the cut sheet was measured with an insulation resistance meter, the needle swung off the scale and the resistance value was greater than 100 MΩ. The static and dynamic friction coefficients of the multiple surfaces of the cut sheets were measured using a measuring device (a friction coefficient measuring device consisting of a Shimadzu Corporation tabletop precision universal testing machine, Autograph AGS-X). The static friction coefficient was 0.15±0.03, and the dynamic friction coefficient was 0.10±0.02. Both coefficients of friction were small. After this, using a portion of the cut sheet, the gas permeability was examined using a gas permeability measuring device (a product of GTR Tech Co., Ltd.) using the JISK7126A method (differential pressure method) differential pressure gas chromatography. The results showed that air did not permeate at atmospheric pressure. This means that the sheet is non-flammable and has the heat resistance of iron. Furthermore, the tensile strength of a cut portion of the sheet was tested in accordance with JIS C6515, a copper foil test method for printed wiring boards, and was found to be 500±10 MPa. This value is close to the tensile strength of 450 MPa found in 12 μm-thick copper foil made by low-roughness rolling tough-pitch copper, demonstrating that the sheet has sufficient mechanical strength. Because of its high insulation resistance, this sheet can also be used as a high-temperature fireproof insulation material, and as a lining or sealing material for industrial furnaces such as heating and baking furnaces. Similarly to Example 1, the cut sheet was further cut into 10 cm x 10 cm pieces and placed on the surface of a 1 mm thick copper sheet measuring 10 cm x 10 cm. Nine 18 kg weights were placed evenly spaced on the surface of the overlapping sheets to bond them together. Next, the bond strength of the bonded surfaces was measured at a peel rate of 300 mm / min in accordance with the 180-degree peel test of JIS Z0237:2022 (Test Methods for Pressure-Sensitive Adhesive Tapes and Sheets). The peel force was 380 mN / 50 mm, indicating sufficient bond strength. This provides the copper sheet surface with the insulating, heat-resistant, and heat-insulating properties of alumina, as well as the lubricity of the sheet. In this embodiment, flat powder of alumina produced by hydrothermal synthesis was used as powder having a plate-like, flaky, or scale-like shape with a large aspect ratio. However, this is not limited to flat powder of alumina produced by hydrothermal synthesis, and powder having a plate-like, flaky, or scale-like shape made of various materials as described in paragraph 30 can also be used.

[0040] Example 5 In this example, a sheet is continuously produced by covering the nonwoven fabric used in Example 3 with a coating formed by an assembly of three types of soft magnetic flat powders joined by friction welding. The three types of soft magnetic flat powders have peak values ​​of the imaginary part of their complex permeability at different frequencies, and a magnetic sheet is continuously produced by randomly joining the flat surfaces of the three types of flat powders together using frictional heat. The complex permeability of this magnetic sheet is the sum of the complex permeabilities of the three types of flat powders, resulting in a magnetic sheet that absorbs electromagnetic waves over a wider frequency range or prevents electromagnetic noise interference over a wider frequency range than if each of the three types of flat powders were used individually. The three types of alloy flat powders consist of permalloy flat powder, silicon steel flat powder with 3% silicon, and electromagnetic stainless steel flat powder. The alcohol used was 2-ethyl-1-hexanol, which has a viscosity of 9.8 mPa·sec at 20°C and a boiling point of 185°C. 2-Ethyl-1-hexanol has a viscosity of 9.8 mPa·s at 20°C, which is lower than the viscosity of the isooctyl alcohol used in Example 4. On the other hand, the three types of soft magnetic flat powders used in Example 5 have average particle sizes of 9 μm, 12 μm, and 14 μm, which are slightly larger than the average particle size of the alumina used in Example 4 but are small in terms of powder size. Furthermore, because the flatness of the three types of soft magnetic flat powders is high, their thicknesses are thin and close to that of alumina. Therefore, the surface area of ​​the three types of soft magnetic flat powders is slightly larger than that of the alumina powder. Therefore, 2-ethyl-1-hexanol, which has a lower viscosity than the isooctyl alcohol used in Example 4, was used as the alcohol constituting the suspension. After evaporating the 2-ethyl-1-hexanol, the three types of soft magnetic flat powders were stacked in fewer layers than the alumina powder used in Example 4. The three types of soft magnetic flat powder have a relatively high Vickers hardness of over 200 HV, making them less likely to deform under compressive stress. Furthermore, the powder used is flat, as in Example 4, does not undergo plastic deformation, and has a thin average thickness of 0.37 μm. Therefore, even when the nonwoven fabric to which the flat powder is attached is compressed, the flat powder does not break but merely undergoes compressive deformation. On the other hand, although the thickness of the nonwoven fabric is close to 0.25 mm, the gap between the two work rolls is narrow at 0.065 mm. Therefore, the nonwoven fabric in the produced sheet is crushed to nearly 1 / 5 of its original thickness by the compressive stress. The flat permalloy powder used is a flat permalloy powder made of 50% nickel (for example, a product developed by Sanyo Special Steel). The flatness of this flat powder is 38, and the average particle size is 14 μm. Therefore, the average thickness of the flat permalloy powder is 0.37 μm. The imaginary part of the complex permeability rises sharply from around 100 MHz, reaches a peak value of 8.8 at 3.3 GHz, decreases from around 4 GHz, and reaches a value of 3.5 at 10 GHz. Therefore, in the frequency band of 1-8 GHz, the imaginary part of the complex permeability has a value of 5 or more. In contrast, in a DC magnetic field, the initial relative permeability is 1×10 4 The maximum relative permeability is 1.4 x 10 5 and is excellent. Flat powder made from 3% silicon steel (such as the product developed by Sanyo Special Steel) has an aspect ratio of 34 and an average particle size of 9 μm. Therefore, the average thickness of 3% silicon steel flat powder is 0.26 μm. Furthermore, in contrast to Permalloy, the imaginary part of the complex permeability has the required magnitude in the high-frequency range. That is, it gradually increases from around 10 MHz, reaches a value of 2.3 at 1 GHz, intersects with the imaginary part of the complex permeability of Permalloy at 4.7 GHz, reaches a peak value of 8.7 at 5.9 GHz, gradually decreases from around 6.3 GHz, reaches a value of 5.9 at 10 GHz, and reaches a value of 3.7 at 12 GHz. Therefore, above 4.7 GHz, the imaginary part of the complex permeability is larger than that of Permalloy. Flat powder made of electromagnetic stainless steel, which is made by adding 7% chromium, 1% silicon, and 1.6% aluminum to iron (for example, a product developed by Sanyo Special Steel), has an aspect ratio of 29 and an average particle size of 12 μm. Therefore, the average thickness of flat powder of electromagnetic stainless steel is 0.41 μm. Furthermore, the imaginary part of the complex permeability increases sharply from around 10 MHz, reaching a value of 3.4 at 1 GHz, intersecting with the imaginary part of silicon steel with 3% silicon at 4.2 GHz, reaching a peak value of 7.5 at 4.8 GHz, and gradually decreasing from around 5.5 GHz, reaching a value of 4.8 at 10 GHz and 3.1 at 12 GHz. Therefore, when three types of flat powders are used - Permalloy flat powder, silicon steel flat powder with 3% silicon, and electromagnetic stainless steel flat powder - the characteristics of the imaginary part of the complex permeability of the three types of flat powder are added together, improving the performance of absorbing electromagnetic noise in the intermediate frequency band from 2 to 8 GHz. In particular, the performance of absorbing electromagnetic noise in the frequency band from 3.3 GHz, where the imaginary part of the complex permeability of Permalloy reaches its peak, to 4.8 GHz, where the imaginary part of the complex permeability of 3% silicon steel reaches its peak, is improved. The container used was the same as that used in Example 1, and eight cylindrical rollers were installed in this container as in Example 1. Furthermore, the 12-high rolling mill used in Example 1 was used. However, because the soft magnetic flat powder does not undergo plastic deformation in the thickness direction, the gap between the two work rolls was set to a narrow gap of 0.065 mm, and the temperature was raised to 195°C, which is 10°C higher than the boiling point of 2-ethyl-1-hexanol. Next, a total of 10 kg of three types of fine flat powders were weighed out: Permalloy flat powder, 3% silicon silicon steel flat powder, and electromagnetic stainless steel flat powder, in a weight ratio of 10:9:20. The three types of flat powders were then mixed. Therefore, the arithmetic average thickness of the mixed powder consisting of the three types of soft magnetic flat powders was equivalent to 0.365 μm. This mixed powder and 12 kg of 2-ethyl-1-hexanol were then loaded into a container, and the 2-methyl-1-hexanol was stirred to create a suspension in which the mixed powder was dispersed in the 2-methyl-1-hexanol. The suspension was immersed in the suspension to a depth of 5.1 cm, with six rollers (from the second roller to the seventh roller). Furthermore, the roll of nonwoven fabric is set in the drawing device, and the fabric is continuously drawn out from the nonwoven fabric at a speed corresponding to the peripheral speed of the eight cylindrical rollers. In addition, the roller drive unit rotates eight cylindrical rollers continuously at the same peripheral speed of one rotation per 25 seconds, and The drawn fabric was brought into contact with the first roller of the container, and then successively with the second through seventh rollers. After this, the fabric, which had contacted the seventh roller, changed direction and continued moving upward, rising from the suspension and contacting the eighth roller. After contacting the eighth roller, the fabric changed direction by 90 degrees and moved toward the gap between the two work rolls of the multi-roll rolling mill. The leading edge of the fabric, immersed in the suspension, was inserted into the gap between the two work rolls of the multi-roll rolling mill, where the fabric was compressed. The sheet discharged from the gap between the two work rolls was then wound up by a winder rotating at the same speed as the eight cylindrical rollers. The prepared sheet was cut into pieces of 50 cm length, and the cut sheets were analyzed. First, as in Example 1, the cut sheet was observed and analyzed using an electron microscope. The sheet thickness was 0.065 mm. Next, secondary electron beams between 900 and 1000 volts, reflected from the cross section, were extracted and image processed. Above and below the 0.05 mm thick organic material, 21-22 layers of flat, fine powder were piled up, forming a bond with an average thickness of approximately 7.5 μm, covering the entire organic material. Therefore, the resulting sheet consisted of three types of flat soft magnetic powders overlapping each other in 21-22 layers across the entire nonwoven fabric. The overlapping soft magnetic powders were friction-welded, and the resulting friction-welded soft magnetic powder clusters covered the nonwoven fabric, which had been crushed by compressive stress. The thickness of this soft magnetic powder cluster was close to the thickness of the soft magnetic powder cluster before compression. In other words, the average thickness of the three types of flat soft magnetic powders overlapping each other in 21-22 layers before compression was estimated to be around 8 μm, assuming the gap between the flat surfaces was 10% of the thickness of the flat powder. The thickness of the nonwoven fabric was also close to 0.250 mm. Therefore, since the gap between the two work rolls of the multi-stage rolling mill was 0.065 mm, the thickness of the nonwoven fabric, evenly covered with the flat soft magnetic powder clusters, was nearly four times thicker. On the other hand, in Example 5, the thickness of the nonwoven fabric crushed by compressive stress was 0.05 mm, and the thickness of the three types of flat soft magnetic powder bonded by friction compression was approximately 7.5 μm. Therefore, the flat soft magnetic powder did not deform in the thickness direction, and the flat surfaces were bonded together by frictional heat. As a result, a sheet with a thickness of 65 μm was formed. Specifically, when the nonwoven fabric, evenly covered with the suspension, approaches the gap between the two work rolls, 2-methyl-1-hexanol evaporates from the suspension. The nonwoven fabric, then evenly covered with the three types of flat, overlapping soft magnetic powder particles, is drawn into the gap between the two work rolls. The surface layer of the three types of flat, overlapping soft magnetic powder particles then comes into contact with the two work rolls, causing the surface layer to move backward. Next, compressive stress is applied to the nonwoven fabric, which is evenly covered with the three types of flat, overlapping soft magnetic powder particles. First, the gap between the flat surfaces of the soft magnetic powder particles narrows, and the soft magnetic powder begins to compress and deform the nonwoven fabric. Then, the flat surfaces of the soft magnetic powder begin to bond together, further compressing and deforming the nonwoven fabric. After this, the flat surfaces of the soft magnetic powder are bonded together, and when the compression deformation of the nonwoven fabric is complete, all of the soft magnetic powder is bonded together at the flat surfaces, and the nonwoven fabric, which has been crushed by the compressive stress, is covered with soft magnetic flat powder bonded by friction welding. As a result, the overlapping soft magnetic powders forming layers 21-22 form a coating with a thickness of about 65 μm, made up of a collection of soft magnetic powder bonded by friction compression. Next, a portion of the cut sheet was immersed in water, and after that, the sheet was pulled out of the water and the surface was observed. As a result, several water droplets were present on the surface, and when the sheet was tilted diagonally, the water droplets easily fell off, indicating that the surface of the sheet was water-repellent. After this, using a portion of the cut sheet, the gas permeability was examined using a gas permeability measuring device (a product of GTR Tech Co., Ltd.) using the JISK7126A method (differential pressure method) differential pressure gas chromatography. The results showed that air did not permeate at atmospheric pressure. This means that the sheet is non-flammable and has the heat resistance of iron. Furthermore, the tensile strength of a portion of the cut sheet was tested in accordance with JIS C6515, a copper foil test method for printed wiring boards, and was found to be 430±10 MPa. This figure is close to the tensile strength of 450 MPa of a 12 μm thick copper foil made by low-roughness rolling tough-pitch copper, and therefore proves to have sufficient mechanical strength as a sheet. Next, the electromagnetic noise absorption performance of the magnetic sheet was tested by placing a microstrip line (140mm long, 30mm wide, and with a characteristic impedance of 50Ω) on a substrate, aligning the length of the sheet with the length of the microstrip line and arranging the sheet so that their centers coincided, creating a noise-absorbing sheet. After this, the S-parameters were measured using a network analyzer (Agilent Technologies product N5230A) connected to the microstrip line. The S-parameter S due to reflection was 11 and the S-parameter S due to transmission 12 Therefore, the transmission loss in the microstrip line is the amount of electromagnetic wave absorption according to the following formula 1. (Formula 1) Reflection amount (dB)=20log|S 11 | Transmission amount (dB)=20log|S 12 | Absorption amount (%) = (1 - |S 11 | 2 -|S 12 | 2 ) x 100 The absorption 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 was over 8% in the wide frequency band from 1 to 10 GHz. Similarly to Example 1, the cut sheet was further cut into 10 cm x 10 cm pieces and placed on top of a 1 mm thick, 10 cm x 10 cm plastic sheet. Nine 9 kg weights were placed evenly spaced on the surface of the overlapping sheets to bond them together. Next, the bonding strength of the bonded surfaces was measured at a peel rate of 300 mm / min in accordance with the 180-degree peel test of JIS Z0237:2022 (Test Methods for Adhesive Tapes and Adhesive Sheets). The peel force was 360 mN / 50 mm, indicating sufficient bonding strength. This provides the surface of the plastic sheet with the functionality of a magnetic sheet, absorbing electromagnetic waves over a wide frequency range or preventing electromagnetic noise interference over a wide frequency range. Note that the case of combining soft magnetic flat powders made of multiple types of alloys is not limited to Example 5. In other words, when flat powders are combined so that the imaginary part of the complex permeability has a constant value over a wide frequency band, a collection of flat powders in which the flat surfaces overlap and bond together will exhibit the characteristics of the imaginary part of the complex permeability, which is the sum of the characteristics of the imaginary part of the complex permeability of each flat powder, and as a result, a sheet that absorbs electromagnetic noise over a wide frequency band can be realized. [Explanation of symbols]

[0041] 1 Copper Powder 2 Splintered Fabric

Claims

1. A method for continuously producing a sheet having a structure in which a woven fabric or nonwoven fabric is entirely covered with a coating formed by an aggregation of micron-sized powder particles made of one of metals, alloys, metal oxides, and nitrides, which are joined together by friction welding, comprises the steps of: First, a container in which a plurality of cylindrical rollers are provided in the width direction of the container is wider than the width of a sheet to be produced and has a vertical length long enough to accommodate the plurality of cylindrical rollers, and the plurality of cylindrical rollers are provided in the container, spaced apart from one another and parallel to the width of the container, and rotate at the same peripheral speed with a time required for one rotation being longer than 20 seconds, and have the same length and diameter as the width of the container.The plurality of cylindrical rollers are arranged in the container so that the first roller is at a height corresponding to the height at which the top of its side surface comes into contact with the fabric or nonwoven fabric used in the second step that is pulled out from a roll of fabric or nonwoven fabric wound around the fabric or nonwoven fabric, and is at a position in the container that is 1 cm or more away from one side surface that forms the width of the container, and the second roller is at a position larger than the position at which the first roller is provided, the last roller is installed in the container at a position further away from one side surface that defines the width of the container and at a position 1 cm or more away from the bottom of the container, the last roller is installed in the container at a position 1 cm or more away from the other side surface that defines the width of the container and at a position at the same height as the first roller, the second-to-last roller is installed in the container at a position further away from the other side surface that defines the width of the container by the size of the last roller compared to the installation position of the last roller and at a position 1 cm or more away from the bottom of the container as the second roller, and the remaining rollers are arranged at positions 1 cm or more away from the bottom of the container as the second roller, with a distance of not more than twice the diameter of the cylindrical roller between the second roller and the second-to-last roller, and each roller is equally spaced Next, a first step of filling the container with a mass of powder made of one of micron-sized metals, alloys, metal oxides, and nitrides, in a weight greater than that required for continuous sheet production, and filling the container with alcohol having a viscosity of 3-11 mPa·sec at 20°C, the smaller the size of the powder, the less symmetrical the shape of the powder, and the harder the powder, the higher the viscosity of the alcohol, and filling the container with an amount of alcohol sufficient to immerse all rollers except the first roller and the last roller, stirring the alcohol to prepare a suspension in which the mass of powder is dispersed in the alcohol, and immersing all rollers of the plurality of cylindrical rollers except the first roller and the last roller in the suspension; A roll of fabric or nonwoven fabric having the width of the sheet to be manufactured is set in a roll-drawing device, and the fabric or nonwoven fabric is continuously drawn out from the roll of fabric at a speed equivalent to the peripheral speed of the plurality of cylindrical rollers in the first step. Furthermore, the plurality of cylindrical rollers are rotated at the same peripheral speed so that the time required for one rotation is longer than 20 seconds. Thereafter, the drawn-out fabric or nonwoven fabric comes into contact with the top of the side of the first roller, and the side of the first roller that is approximately 1 / 4 of the length of the roll of fabric or nonwoven fabric comes into contact with the side of the first roller. The fabric or nonwoven fabric moves together with the first roller, then changes its moving direction downward, moves, is immersed in the suspension, and further comes into contact with the side of the second roller. Since the rotation direction of the second roller is opposite to the rotation direction of the first roller, the fabric or nonwoven fabric that has come into contact with the side of the second roller moves together with the second roller, with the side of the second roller being in contact with the side of the second roller at a position close to 1 / 4 of the second roller. Then, changes its moving direction to a direction parallel to the bottom surface of the container, and moves, and the first roller and the second roller The fabric or nonwoven fabric comes into contact with the side of the second roller from the end of the suspension in order, since the rotation direction of the rollers is the same as the rotation direction of the second roller, and the fabric or nonwoven fabric that comes into contact with the side of the second roller from the end of the suspension in order moves forward in the suspension without changing its moving direction, and comes into contact with the side of the second roller from the end of the suspension. Since the rotation direction of the second roller from the end of the suspension is the same as the rotation direction of the second roller, the fabric or nonwoven fabric that comes into contact with the side of the second roller from the end of the suspension moves forward in order The side of the roller, which is close to 1 / 4 of the way up, comes into contact with the side of the second to last roller and moves together with the second to last roller, then changes its direction of movement upward and moves forward, and after being pulled up from the suspension, comes into contact with the side of the last roller. Since the rotation direction of the last roller is opposite to the rotation direction of the second to last roller, the fabric or nonwoven fabric that has come into contact with the side of the last roller, which is close to 1 / 4 of the way up, comes into contact with the side of the last roller and moves together with the last roller, thena second step in which the suspension is applied to the entire surface of the fabric or nonwoven fabric immersed in the suspension, to a thickness corresponding to the viscosity of the suspension; and a third step in which the suspension is applied to the entire surface of the fabric or nonwoven fabric immersed in the suspension, to a thickness corresponding to the viscosity of the suspension. First, two work rolls constituting a multi-stage rolling mill have five characteristics: first, they have the same width, which is wider than the width of the sheet to be produced; second, they have the same diameter, which is smaller than 1 / 10 of the width of the sheet; third, the gap is set to the thickness of the sheet to be produced; fourth, they rotate in opposite directions to each other at the same peripheral speed as the peripheral speed at which the plurality of rollers rotate in the first step; and fifth, they are heated to a temperature 10°C higher than the boiling point of the alcohol constituting the suspension in the first step. A rolling mill is prepared. Next, the leading end of the fabric or nonwoven fabric that has been subjected to the second process is inserted into the gap between the two work rolls. As a result, the leading end of the fabric or nonwoven fabric is drawn into the gap between the two work rolls, and the fabric or nonwoven fabric is continuously subjected to a compressive stress according to the size of the gap between the two work rolls. At this time, first, alcohol evaporates from the suspension that has been evenly adhered to the entire surface of the fabric or nonwoven fabric, and the powder that constitutes the suspension overlaps and spreads over the entire surface of the fabric or nonwoven fabric. The powder particles are deposited on the fabric or nonwoven fabric, and the entire surface of the fabric or nonwoven fabric is covered with the powder particles. Next, compressive stress begins to be applied to the overlapping deposited powder particles and to the fabric or nonwoven fabric, and first the surface layer of the powder particles collapses. The surface layer of the powder particles deposited on the edge of the fabric or nonwoven fabric moves to the edge and overlaps at the edge, and the surface layer of the powder particles deposited in areas other than the edge moves to the rear side of the gap between the two work rolls. Next, the powder particles and the fabric or nonwoven fabric are subjected to compressive stress. A compressive stress is applied, compressing the powder clusters, compressing and deforming the fabric or nonwoven fabric, and the shear stress applied by the contacting powder causes the fabric or nonwoven fabric to break and split, the powder then moves to the broken parts of the fabric or nonwoven fabric and to the voids in the fabric or nonwoven fabric, and the split fabric or split nonwoven fabric is covered with the powder clusters, and a compressive stress is applied to the powder clusters, and the powder clusters covering the split fabric or split nonwoven fabric areAt all contact points where adjacent powder particles come into contact with each other, the powder particles are joined by friction welding, and the groups of powder joined by friction welding are joined to the divided cloth or the divided nonwoven fabric by friction welding, covering the entirety of the divided cloth or the divided nonwoven fabric. Furthermore, at all contact points where the overlapping groups of powder come into contact with each other, the powder particles are joined by friction welding, and a new group of powder joined by friction welding is joined by friction welding to the group of powder joined by friction welding that covers the entirety of the divided cloth or the divided nonwoven fabric. a third step in which the divided fabric or the divided nonwoven fabric is covered with a coating made of an aggregate of powder bonded by friction welding, and the process from the evaporation of the alcohol to the entirety of the divided fabric or the divided nonwoven fabric being covered with a coating made of an aggregate of powder bonded by friction welding occurs continuously on the aggregate of powder sandwiched between the two work rolls and on the fabric or the nonwoven fabric, whereby a sheet made of the divided fabric or the divided nonwoven fabric entirely covered with the coating is discharged from the gap between the two work rolls, and the discharged sheet is wound up by a winding device rotating at the same rotational speed as the two work rolls; By continuously carrying out all of the treatments consisting of these three steps, a sheet is continuously produced in which a cloth or nonwoven fabric is entirely covered with a coating formed by an aggregation of micron-sized powder particles made of one type of material selected from metals, alloys, metal oxides, and nitrides and joined together by friction welding; a method for continuously producing a sheet in which a cloth or nonwoven fabric is entirely covered with a coating formed by an aggregation of micron-sized powder particles made of one type of material selected from metals, alloys, metal oxides, and nitrides and joined together by friction welding.

2. A method for continuously producing a sheet having a structure in which a woven fabric or a nonwoven fabric is entirely covered with a coating formed by an aggregation of powder particles which are made of one material selected from the group consisting of metals, alloys, metal oxides and nitrides and have micron-sized particles joined together by friction welding as described in claim 1, comprising the steps of: The alcohol having a viscosity of 3 to 11 mPa·sec at 20°C as described in claim 1 is any one of 1-butanol, 1-pentanol, 2-pentanol, 3-methyl-1-butanol, 2-methyl-2-butanol, 2-butanol, 2-heptanol, isobutyl alcohol, 2-methyl-1-butanol, 1-hexanol, 1-heptanol, 2-octanol, 3-pentanol, 1-octanol, 2-ethyl-1-hexanol, isooctyl alcohol, and 1-nonanol. wherein any one of the alcohols is an alcohol having a viscosity of 3-11 mPa·sec at 20°C as described in claim 1, and a method for continuously carrying out all of the treatments consisting of the three steps as described in claim 1 is a method for continuously producing a sheet having a configuration in which a woven fabric or nonwoven fabric is entirely covered with a coating formed by an aggregation of powder particles made of one type of material selected from the group consisting of metal, alloy, metal oxide, and nitride, each having a micron size as described in claim 1, joined by friction welding.

3. A method for cutting the sheet produced by the method of claim 1 into a predetermined shape and bonding the cut sheet to a predetermined position on the surface of a substrate or a part comprises the steps of:

10. A method for continuously producing sheets by the method described in claim 1, cutting the sheets into a predetermined shape, overlapping the cut sheets at predetermined positions on the surface of a substrate or a part, and evenly compressing the entire surface of the cut sheets, thereby causing the convex portions of the uneven surface of the cut sheets to come into contact with the surface of the substrate or the part on which the cut sheets are overlapped, and further generating frictional heat at the contact points, which bonds the contact points together and bonds the cut sheets to the predetermined positions on the surface of the substrate or the part.

4. The method for continuously producing a sheet having a structure in which a woven fabric or a nonwoven fabric is entirely covered with a coating formed by an aggregation of powder particles which are made of one material selected from the group consisting of metals, alloys, metal oxides and nitrides and have micron-sized particles joined together by friction welding as described in claim 1, comprises the steps of: The powder described in claim 1 is a powder having any one of spherical, granular, and agglomerated shapes, and a method for continuously carrying out all of the three steps described in claim 1 in order using the powder described in claim 1 is a method for continuously producing a sheet having a configuration in which a woven fabric or nonwoven fabric is entirely covered with a coating formed by an aggregation of powder particles made of one type of material selected from metals, alloys, metal oxides, and nitrides having micron-sized particles as described in claim 1 and joined together by friction welding.

5. The powder having a spherical, granular or agglomerated shape according to claim 4 is The powder is a powder produced by gas atomization, which is made of copper powder, tin powder, copper-tin alloy powder, tantalum powder, niobium powder, an Fe-based alloy having a composition of Fe-17Cr-12Ni-Mo, an Ni-based alloy having a composition of Ni-16Cr-16Mo-5Fe-4W, a Co-based alloy powder having a composition of Co-29Cr-6Mo, an alloy powder having a composition of Fe-49Co-2V, a precipitation hardened martensitic stainless steel powder having a composition of SUS630, an austenitic stainless steel powder having a composition of SUS316L, a martensitic stainless steel powder having a composition of SUS420J2, or a low-oxygen titanium powder, Or, Copper powder or silver powder produced by water atomization, The powder consisting of these 15 types of powder is a powder having a spherical, granular or agglomerated shape as described in claim 4.

6. The method for continuously producing a sheet having a structure in which a woven fabric or a nonwoven fabric is entirely covered with a coating formed by an aggregation of powder particles which are made of one material selected from the group consisting of metals, alloys, metal oxides and nitrides and have micron-sized particles joined together by friction welding as described in claim 1, comprises the steps of: The powder described in claim 1 is a powder that has a spongy shape but is not porous and that undergoes plastic deformation when compressed in the third step described in claim 1, and a method for using said powder as the powder described in claim 1 and continuously carrying out all of the three steps described in claim 1 in order is a method for continuously producing a sheet consisting of a fabric or nonwoven fabric entirely covered with a coating formed by an aggregation of powder particles that are made of one type of material selected from metals, alloys, metal oxides, and nitrides, each having a micron size, and that are joined together by friction welding.

7. The powder having a sponge-like shape but not porous as described in claim 6 and undergoing plastic deformation when compressed in the third step as described in claim 1 is Iron powder or bronze powder produced by water atomization, These two types of powder are in a sponge-like shape but are not porous as described in claim 6, and are powders that undergo plastic deformation when compressed in the third step as described in claim 1.

8. The method for continuously producing a sheet having a structure in which a woven fabric or a nonwoven fabric is entirely covered with a coating formed by an aggregation of powder particles which are made of one material selected from the group consisting of metals, alloys, metal oxides and nitrides and have micron-sized particles joined together by friction welding as described in claim 1, comprises the steps of: The powder described in claim 1 is teardrop-shaped or spindle-shaped and undergoes plastic deformation when compressed in the third step described in claim 1, and a method for using the powder described in claim 1 and sequentially carrying out all of the three steps described in claim 1 is a method for continuously producing a sheet consisting of a fabric or nonwoven fabric entirely covered with a coating formed by an aggregation of powder particles made of one type of material selected from the group consisting of metal, alloy, metal oxide, and nitride, each having a micron size, joined by friction welding as described in claim 1.

9. The powder having a teardrop-shaped or spindle-shaped shape as set forth in claim 8 and undergoing plastic deformation when compressed in the third step as set forth in claim 1 is aluminum powder produced by gas atomization, or nickel powder, Fe-3Si alloy powder, 47Ni-Fe alloy powder, 78Ni-4Mo-Fe alloy powder, or brass powder produced by water atomization; The powder consisting of these six types of powder has a teardrop-shaped or spindle-shaped shape as described in claim 8, and is a powder that undergoes plastic deformation when compressed in the third step as described in claim 1.

10. The method for continuously producing a sheet having a structure in which a woven fabric or a nonwoven fabric is entirely covered with a coating formed by an aggregation of powder particles which are made of one material selected from the group consisting of metals, alloys, metal oxides and nitrides and have micron-sized particles joined together by friction welding as described in claim 1, comprises the steps of: The powder described in claim 1 is a powder having a plate-like, flake-like, or scale-like shape with a large aspect ratio, and the method of using the powder described in claim 1 and continuously carrying out all of the three steps described in claim 1 in order is a method of continuously producing a sheet having a configuration in which a woven fabric or nonwoven fabric is entirely covered with a coating formed by an aggregation of powder particles made of one type of material selected from metal, alloy, metal oxide, and nitride, each having a micron-sized size, as described in claim 1, joined by friction welding.

11. The powder having a plate-like, flake-like, or scale-like shape with a large aspect ratio according to claim 10 is A soft metal flake powder made of gold powder, silver powder, copper powder, tin powder, zinc powder, or aluminum powder, which is obtained by pulverizing soft metal powder using a stamp mill; Or, A flat powder of a soft magnetic alloy consisting of silicon steel powder with an added amount of silicon of less than 10% obtained by attriting atomized soft magnetic powder or reduced soft magnetic powder using a media agitation mill, permalloy powder with an added amount of nickel of 50% or less, sendust powder with an added amount of aluminum of 1 / 2 or more of the added amount of silicon, or electromagnetic stainless steel powder with an added amount of aluminum of less than 2%, Or, The metal oxide flat powder is made of alumina powder produced by hydrothermal synthesis of aluminum hydroxide, mica powder produced by finely grinding muscovite, glass flake powder produced by crushing molten glass that has been expanded into a hollow shape, or hematite powder precipitated by hydrothermal treatment of yellow iron oxide in an alkaline aqueous solution, Or, It is a boron nitride powder with a hexagonal crystal system produced by pulverizing block boron nitride, The powder consisting of these 15 types of powder is a powder having a plate-like, flake-like or scale-like shape with a large aspect ratio as described in claim 10.

12. A method for continuously producing a soft magnetic sheet that absorbs electromagnetic waves or a soft magnetic sheet that prevents interference of electromagnetic noise using the four types of flat powders of soft magnetic alloys according to claim 11, comprising the steps of: A method for continuously manufacturing a soft magnetic sheet that absorbs electromagnetic waves or a soft magnetic sheet that prevents electromagnetic noise interference using flat powders of four types of soft magnetic alloys as described in claim 11, in which, among the flat powders consisting of four types of soft magnetic alloys as described in claim 11, multiple types of soft magnetic flat powders are selected from the flat powders consisting of the four types of soft magnetic alloys, such that the magnitude of the imaginary part of the complex permeability of the multiple types of soft magnetic flat powders has a certain value or more in different frequency bands, the selected flat powders consisting of multiple types of soft magnetic alloys are mixed in a predetermined ratio, the mixed collection of flat powders consisting of multiple types of soft magnetic alloys is used as the powder as described in claim 1, and all of the three steps as described in claim 1 are performed in order and continuously.

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