Composite particles, porous member, porous structure, and method for manufacturing porous structure

Abstract

The present invention provides: composite particles with which a porous member can be manufactured in a shorter time, or a porous member or porous structure that can be manufactured in a short time; or a method for manufacturing the porous structure.　Composite particles (1) are formed by combining a core material (2) and subparticles (3) having a smaller diameter than the core material (2) and having a viscosity of less than 104 poise in a temperature zone in which the viscosity of the core material (2) is 104 poise or more. The composite particles (1) are in an embedded state in which the subparticles (3) are embedded into the surface of the core material (2) so as to deform the surface of the core material (2), or in an attached state in which the subparticles (3) are deformed on the surface of the core material (2) and the subparticles (3) are connected to each other and attached in a film shape.

Description

Composite particles, porous members, porous structures, and methods for manufacturing porous structures.

[0001] This disclosure relates to composite particles, porous members, porous structures, and methods for manufacturing porous structures.

[0002] Conventionally, wicks with continuous voids that exhibit capillary action are used on the inner surface of heat pipes and vapor chambers to improve the evaporation efficiency of liquid refrigerants. One technique for creating such wicks is to utilize the production technology of LTCC (Low Temperature Co-fired Ceramics) substrates (see, for example, Patent Documents 1 and 2). In this technique, an organic binder is dissolved in an organic solvent, and a slurry containing alumina powder and low-melting-point glass powder is applied to a film, and the alumina powder is sintered through a heating process.

[0003] Japanese Patent Publication No. 2017-227382 Japanese Patent Publication No. 2022-70816

[0004] However, if the techniques described in Patent Documents 1 and 2 are adopted, the organic solvent must be dried slowly at a temperature of around 100°C, for example, to prevent bumping. Furthermore, in the above techniques, after drying the organic solvent, a debiosis process is required to carefully burn off the organic binder to prevent film peeling due to the blow-through of decomposition gases of the organic binder. Moreover, in the above techniques, it is necessary to lower the glass viscosity by heating at a temperature sufficiently higher than the glass softening point, allowing it to wet and spread on the surface of the plate material or the surface of the alumina powder, and the glass viscosity is 10 ５ Poise ~ 10 ４ It is essential to maintain the temperature at the poise point for about 10 minutes.

[0005] Based on the above, it was extremely difficult to create porous members in a shorter time using the technologies described in Patent Documents 1 and 2.

[0006] One aspect of this disclosure has been made to solve such problems and aims to provide composite particles that can produce porous members in a shorter time, or porous members, porous structures, or methods for manufacturing porous structures that can be produced in a shorter time.

[0007] The composite particles according to one aspect of the present disclosure include a core material and sub-particles having a diameter smaller than that of the core material and a viscosity of less than 10 Poise in a temperature range where the viscosity of the core material is 10 Poise or more. The sub-particles are driven into the surface of the core material so as to deform the surface of the core material, or the sub-particles are in an adhered state where the sub-particles are deformed on the surface of the core material and the sub-particles are connected to each other and adhered in a film shape. ４ Poise or more and less than 10 Poise in a temperature range where the viscosity of the core material is 10 Poise or more. ４ The composite particles are composite particles in which a core material and sub-particles having a diameter smaller than that of the core material and a viscosity of less than 10 Poise in a temperature range where the viscosity of the core material is 10 Poise or more are combined. The sub-particles are driven into the surface of the core material so as to deform the surface of the core material, or the sub-particles are in an adhered state where the sub-particles are deformed on the surface of the core material and the sub-particles are connected to each other and adhered in a film shape.

[0008] Further, the porous member according to one aspect of the present disclosure is a porous member in which the shells of a large number of composite particles each having a core material and a shell covering the core material are joined to form continuous voids. The porous member includes an infrared absorber that is contained or combined in the core material or the shell and has a higher infrared absorption rate than the core material and the shell. The core material and the shell are made of a material having a viscosity of 10 Poise or more for the core material and less than 10 Poise for the shell in a temperature range where the viscosity of the shell is less than 10 Poise. ４ Poise or more and less than 10 Poise in a temperature range where the viscosity of the shell is less than 10 Poise. ４ The core material and the shell are formed of a material having a viscosity of 10 Poise or more for the core material and less than 10 Poise for the shell in a temperature range where the viscosity of the shell is less than 10 Poise.

[0009] Further, the porous structure according to one aspect of the present disclosure includes the above-described porous member, an adherent joined to the shell of the composite particles constituting the porous member, and a connection layer provided on the surface of the adherent where the porous member is provided and formed of a material having a viscosity of less than 10 Poise in the temperature range. ４ The porous structure includes an adherent joined to the shell of the composite particles constituting the porous member, and a connection layer provided on the surface of the adherent where the porous member is provided and formed of a material having a viscosity of less than 10 Poise in the temperature range.

[0010] Further, the method for manufacturing a porous structure according to one aspect of the present disclosure includes a composite step of combining a core material and sub-particles having a diameter smaller than that of the core material and a viscosity of less than 10 Poise in a temperature range where the viscosity of the core material is 10 Poise or more to create a large number of composite particles, a spraying step of spraying the large number of composite particles created in the composite step onto an adherent, and a heating step of heating the large number of composite particles sprayed onto the adherent in the spraying step to the temperature range. ４ Poise or more and less than 10 Poise in a temperature range where the viscosity of the core material is 10 Poise or more. ４ The method for manufacturing a porous structure according to one aspect of the present disclosure includes a composite step of combining a core material and sub-particles having a diameter smaller than that of the core material and a viscosity of less than 10 Poise in a temperature range where the viscosity of the core material is 10 Poise or more to create a large number of composite particles, a spraying step of spraying the large number of composite particles created in the composite step onto an adherent, and a heating step of heating the large number of composite particles sprayed onto the adherent in the spraying step to the temperature range.

[0011] According to one aspect of this disclosure, it is possible to provide composite particles that can produce porous members in a shorter time, or porous members, porous structures, or methods for manufacturing porous structures that can be produced in a shorter time.

[0012] Figure 1 is a perspective view showing a thermal insulation panel manufactured by the manufacturing method of a porous structure according to this embodiment. Figure 2 is a cross-sectional view showing a thermal insulation panel manufactured by the manufacturing method of a porous structure according to this embodiment. Figure 3 is a cross-sectional view showing another example of a thermal insulation panel. Figure 4 is an enlarged view showing composite particles according to this disclosure, where (a) shows a first example and (b) shows a second example. Figure 5 is a schematic diagram showing a porous structure including a wick using the composite particles shown in Figure 4. Figure 6 is a partially enlarged view of the porous structure shown in Figure 5. Figure 7 is a process diagram showing a manufacturing method of a porous structure. Figure 8 is a configuration diagram showing an example of a stirring device for creating composite particles. Figure 9 is a configuration diagram showing an example of a spraying device. Figure 10 is a configuration diagram showing a spraying device according to a first modified example. Figure 11 is a configuration diagram showing a spraying device according to a second modified example. Figure 12 is a configuration diagram showing a spraying device according to a third modified example.

[0013] The present disclosure will be described below in accordance with preferred embodiments. However, the present disclosure is not limited to the embodiments shown below and may be modified as appropriate without departing from the spirit of the disclosure. Furthermore, in the embodiments shown below, some illustrations and descriptions of certain components are omitted. It goes without saying that, regarding the details of the omitted technologies, publicly known or well-known technologies are applied as appropriate, to the extent that they do not contradict the content described below.

[0014] Figures 1 and 2 are configuration diagrams showing an insulating panel manufactured by the porous structure manufacturing method according to this embodiment, with Figure 1 being a perspective view and Figure 2 being a cross-sectional view. The insulating panel IP shown in Figures 1 and 2 comprises two air conditioning panels 10, an insulating body 20, and a flow path 30.

[0015] The air conditioning panel 10 is a hollow body formed by processing two plate materials 11 to create an internal space IS, and then welding the edges 12 together. The internal space IS is, for example, evacuated to a reduced pressure state. The air conditioning panel 10 is a large structure with a long side of at least 60 cm. The two plate materials 11 are each made up of material with a thickness of 0.8 mm or less, so the air conditioning panel 10 is lightweight.

[0016] As shown in Figures 1 and 2, the air conditioning panel 10 has numerous protrusions 13 formed on both of its plate materials 11. The numerous protrusions 13 are formed on the two plate materials 11 facing each other, and the tops of the protrusions 13 are in contact with each other. As a result, the two plate materials 11 are separated in the internal space IS by the height of two sets of protrusions 13. Furthermore, because the tops of the protrusions 13 are in contact with each other, the air conditioning panel 10, with its vacuum-filled internal space IS, is more resistant to external pressure. In Figures 1 and 2, 32 protrusions 13 are formed, but in reality, since the plate materials 11 of the air conditioning panel 10 are thin and have a large structure, a much larger number will be formed. Specifically, in an air conditioning panel 10 with a width of 930 mm and a length of 2000 mm, for example, several thousand protrusions 13 are formed on each plate material 11.

[0017] In this embodiment, the air conditioning panel 10 has numerous protrusions 13 formed on both of the two plate materials 11, but it is not limited to this, and the numerous protrusions 13 may be formed on only one of the plate materials 11, while the other plate material 11 is flat.

[0018] These two air conditioning panels 10 are configured so that refrigerant flows through two flow paths 30. The two air conditioning panels 10 are configured so that heat from one air conditioning panel 10 can be dissipated from the other air conditioning panel 10 through the flow of refrigerant. In addition, an insulating material 20 is provided between the two air conditioning panels 10 to ensure thermal insulation. As a result, the insulating panel IP prevents heat from passing from the other side to the one side with the insulating material 20, and allows heat from one side to pass from the other side through the refrigerant circulation.

[0019] When causing such heat transfer, one of the two air conditioning panels 10 functions as an evaporator E, and the other functions as a condenser C. More specifically, the liquid refrigerant evaporates in the evaporator E due to the heat from one side. As a result, the space S1 side facing the air conditioning panel 10 on one side is deprived of the evaporation heat and cooled. On the other hand, the vapor refrigerant, which is the evaporated refrigerant, reaches the condenser C through the first flow path 31. In the condenser C, the vapor refrigerant liquefies into a liquid refrigerant due to the heat on the space S2 side facing the air conditioning panel 10 on the other side. The condensation heat when the vapor refrigerant liquefies is discarded to the space S2 side. Further, the liquefied liquid refrigerant reaches the evaporator E again through the second flow path 32. As described above, the heat insulation panel IP allows the heat on one side to pass through to the other side.

[0020] Here, at least the air conditioning panel 10 on the evaporator E side has a wick (porous member) 14 formed on at least one plate material 11 (the plate material 11 on the side far from the condenser C) from the viewpoint of promoting the evaporation of the liquid refrigerant. The wick 14 is composed of a large number of particles and has continuous voids, and sucks up and holds the liquid refrigerant stored on the lower side of the evaporator E by capillary action. With such a wick 14, the evaporation area of the evaporator E expands along the height direction, enabling efficient evaporation in the height direction.

[0021] Note that the wick 14 and the plate material 11 to which the wick 14 is joined constitute a porous structure body.

[0022] FIG. 3 is a cross-sectional view showing another example of the heat insulation panel IP according to the present embodiment. The heat insulation panel IP may have a structure that is long in, for example, one direction by connecting those shown in FIGS. 1 and 2. Here, the air conditioning panel 10 needs to be divided at predetermined intervals for refrigerant circulation. Therefore, in order to manufacture a long heat insulation panel IP, it is necessary to divide the air conditioning panel 10 at regular intervals and weld them. Such a welded portion is called a partition forming portion 15. The heat insulation panel IP can be configured to be long in one direction while allowing refrigerant circulation by being divided at regular intervals by the partition forming portion 15. Note that the partition forming portion 15 is also formed in the heat insulation panel IP shown in FIGS. 1 and 2.

[0023] Here, the wick 14 used in the air conditioning panel 10 is time-consuming to manufacture. In particular, if the air conditioning panel 10 is large, the manufacturing process takes far too long. In addition, if long sheets of material are wound onto an uncoiler and manufactured by feeding them out at a certain speed, very large equipment is required to produce the wick 14.

[0024] These points will be explained. First, as mentioned above, there are various techniques for creating the wick 14. For example, if the techniques described in Patent Documents 1 and 2 are used, heating will take at least one hour, and if the sheet material is fed out at 5 m / min, heating equipment for 300 m will be required, and even if it is fed out at 1 m / min, heating equipment for 60 m will be required.

[0025] Another method for creating the wick 14 is to cut grooves into a plate or similar material. When forming a large-area wick by cutting grooves, it is necessary to create grooves with a width of two orders of magnitude microns and a depth of approximately 100 μm or more, spaced at intervals of approximately 0.1 mm or less, thus requiring laser processing. However, when forming a wick of 1 m square using laser processing, the total length of the grooves would be as much as 10,000 m, and 5 m ２ To form a wick while feeding out the sheet material at a speed of m / s, 70 laser devices would be required at a scanning speed of 12 m / s. Therefore, forming a large-area wick 14 by groove processing is not practical.

[0026] Alternatively, the wick 14 may be formed by creating a wire mesh with an opening of approximately 10 microns and attaching the wire mesh to a plate material. However, the manufacturing of the wire mesh itself can only be done at a low speed. For example, when creating a wire mesh with an opening of 20 μm and a wire density of approximately 700 wires / inch, even using a top-of-the-line loom, it would take 1 m ２ It will take about 7 minutes to get there. Therefore, 5m ２In order to match the feeding speed of the plate material per minute, 35 such weaving machines are required, which is not practical. In particular, since such a wire mesh with such a mesh opening has a thickness of only 30 to 40 μm, a plurality of sheets are required to achieve an appropriate wick thickness, making it even less practical.

[0027] Furthermore, when forming the wick 14 with a porous member as in Patent Documents 1 and 2, it is also possible to apply powder to the plate material by an arc spraying method or a plasma spraying method. However, in these methods, the powder is sprayed onto the plate material at a high temperature and high speed, and the porosity is generally 10% or less, resulting in low wick performance. Also, especially when the thickness of the plate material 11 is 0.8 mm or less, significant deformation occurs in the plate. Therefore, even if an attempt is made to increase the porosity and suppress the deformation by reducing the spraying speed of the powder, in this case, the adhesion strength of the wick to the plate material decreases, which becomes a problem in the product.

[0028] In response to the above problems, in the present disclosure, for example, the wick 14 is manufactured using the composite particles shown below. This can shorten the manufacturing time and solve the equipment problem, and can also be manufactured for a continuously supplied plate material or the like.

[0029] FIG. 4 is an enlarged view showing the composite particles according to the present disclosure, where (a) shows the first example and (b) shows the second example. First, as shown in FIGS. 4(a) and 4(b), the composite particle 1 includes a core material 2 and sub-particles 3, and these are combined to be formed. In FIG. 4, the core material 2 is represented by a sphere, but these do not necessarily have to be strictly spherical and may have a shape close to a regular body or a angular sphere. The same applies to the sub-particles 3 in FIG. 4(a).

[0030] First, the core material 2 is a particle having a diameter larger than that of the sub-particles 3. The sub-particles 3 are particles having a diameter smaller than that of the core material 2. The composite particle 1 has a large number of sub-particles 3 combined with one core material 2.

[0031] For example, as shown in Figure 4(a), the composite particle 1 has a deformed spherical surface on the core material 2, and the sub-particles 3 are embedded in the deformed portion. In other words, the composite particle 1 shown in Figure 4(a) is composited during the manufacturing process when the sub-particles 3 are hammered into the surface of the core material 2, creating a hammered state. In this way, the hammering of the sub-particles 3 prevents them from easily detaching from the core material 2, and the composite particle 1 is maintained in a composite state.

[0032] Furthermore, as shown in Figure 4(b), the composite particles 1 are not limited to being hammered into the core material 2; they may also be composited by the deformed sub-particles 3 connecting with each other and forming a film-like adhesion. If only one sub-particle 3 is deformed and attached, there is a possibility that the sub-particle 3 may detach later. However, when the deformed sub-particles 3 connect to form a film, the sub-particles 3 do not easily detach from the core material 2, and the composite particles 1 are maintained in a composite state. Note that the term "film-like" here does not need to completely enclose the core material 2; it is sufficient if it maintains a predetermined adhesion force.

[0033] Here, the core material 2 and the subparticles 3 are made of different materials. Specifically, the subparticles 3 have a viscosity of 10 ４ Poise or more (preferably 10) ５ Poise or greater, more preferably 10 ６ In the temperature range where the viscosity is above Poise, ４ Less than 10 poise (preferably 10) ３ It is composed of materials with a melting point less than poise. Such a combination includes, for example, a case where the core material 2 is a soda-lime glass bead and the sub-particles 3 are low-melting-point glass based on borosilicate or bismuth. However, the core material 2 and sub-particles 3 are not limited to this combination.

[0034] Here, the core material 2 has a viscosity of 10 in the above temperature range. ９It is preferable to form the material with a poise coefficient or lower. This is because, during heating as described later, the core material 2 and the subparticles 3 can be firmly bonded together by mutual diffusion. Furthermore, a transition layer can be formed between them, suppressing fracture due to the difference in their thermal expansion coefficients.

[0035] Furthermore, when the average particle size of the core material 2 is 50 μm, the average particle size of the sub-particles 3 may be 1 to 2 μm or about 5 μm. More specifically, compounding proceeds more easily when the diameter of the sub-particles 3 is 1 / 20 or less of the diameter of the core material 2. Also, when the sub-particles 3 are harder than the core material 2 and are hammered in as shown in Figure 4(a), the particle size should be just right for the sub-particles 3 to adhere evenly to the surface of the core material 2 in a single layer. For example, if the volume of the sub-particles 3 acting as a binder is about 10% of the volume of the core material 2, then if the diameter of the core material 2 is 50 μm, then a diameter of about 1.5 μm for the sub-particles 3 is appropriate. On the other hand, when the sub-particles 3 are softer than the core material 2 and adhere in a film-like manner, the diameter of the sub-particles 3 may be about 5 μm.

[0036] Figure 5 is a schematic diagram showing a porous structure 100 including a wick 14 using the composite particles 1 shown in Figure 4. As shown in Figure 5, the wick 14 is made from a large number of composite particles 1. The wick 14 has a shell 4 formed by the melting and solidification of the numerous child particles 3 (see Figure 4) of the composite particles 1 in a bonded state. Therefore, the shell 4, like the child particles 3, has a viscosity of 10 in the core material 2. ４ In the temperature range where the viscosity is above Poise, ４ The wick is composed of materials with a poise of less than 100. Furthermore, the wick 14 has a structure with continuous voids, formed by covering the core material 2 with the shell 4 and joining the shells 4 together. Such a wick 14 can be manufactured by heating a large number of composite particles 1, for example, in the above temperature range.

[0037] Figure 6 is a partially enlarged view of the porous structure 100 shown in Figure 5. The wick 14 shown in Figure 5 is equipped with a pigment (infrared absorber) 5. The pigment 5 has a higher infrared absorption rate than the core material 2 and the shell 4. In the example shown in Figure 6, the pigment 5 is contained in the core material 2. The pigment 5 may also be contained in the shell 4. The pigment 5 can be contained in the core material 2 and the shell 4 by melting and mixing the pigment 5 together with other glass components in a crucible as one of the glass components of the core material 2 and the subparticles 3.

[0038] Furthermore, the pigment 5 may not only be contained but may also be compounded. In this case, the pigment 5 can be compounded with the core material 2 or shell 4 by compounding the core material 2 and subparticles 3 at the same time, or after compounding. Note that the compounding of the pigment 5 is not limited to this, and may also be carried out by compounding the core material 2 or subparticles 3 with the pigment 5 first, and then compounding the remaining particles 2 and 3. Here, the pigment may include tricobalt tetroxide, copper oxide, chromium oxide, iron oxide, manganese oxide, tin oxide, and titanium oxide, etc. ｎ O （２ｎ－１） Metal oxide pigments such as (n is a natural number) are particularly preferred. This is because the composite particle 1, which is a glass component, is a metal oxide and therefore has good compatibility.

[0039] Refer to Figure 5 again. The porous structure 100 has a connecting layer 7 on the surface of the adherend 6. The connecting layer 7 is a layer for more firmly attaching the wick 14 to the adherend 6. The connecting layer 7 is 10 in the above temperature range ４ It is formed from a material with a viscosity less than poise. Here, the composite particles 1 are firmly joined together, similar to double-sided gluing, by the melting of their respective child particles 3. On the other hand, since only the composite particles 1 have child particles 3, the bond between the composite particles 1 and the adherend 6 may be weak, resulting in a single-sided gluing state. Therefore, by providing a connecting layer 7 on the adherend 6, the wick 14 can be firmly bonded to the adherend 6, similar to a double-sided gluing state.

[0040] In particular, when the adherend 6 is stainless steel, the wettability of the glass material, which is the composite particle 1, is poor and it may repel from the stainless steel, or even if the wettability is not poor, the adhesion may be low and it may easily peel off after cooling. Furthermore, the flexibility of the wick 14 made from the composite particle 1 may be insufficient, and it may crack and peel off because it cannot follow the bending of the stainless steel. For this reason, when the adherend 6 is made of stainless steel, it is preferable to provide a connecting layer 7.

[0041] Here, it is preferable that the connecting layer 7 is made of the same material as the shell 4. This is because it facilitates the melting of the shell 4 and the connecting layer 7, resulting in a stronger bond.

[0042] The connecting layer 7 is not limited to the above. For example, glass frits with special compositions, such as enamel glazes and glass lining glazes, have been researched and formulated for stainless steel applications. Among these, those for single application combine the adhesion to stainless steel required for undercoat glazes with the water resistance required for topcoat glazes. For this reason, they may also be used as the connecting layer 7. In this case, it is preferable that the connecting layer 7 has a thermal expansion coefficient suitable for stainless steel glazes, and the shell 4 has a thermal expansion coefficient intermediate between that of the shell 7 and the core material 2.

[0043] Furthermore, it is known that adding boron oxide to stainless steel enamel improves its wettability to stainless steel, and adding phosphorus pentoxide or vanadium pentoxide corrodes the stainless steel surface, thereby improving adhesion. In addition, it is known that adding lanthanides such as samarium and erbium to metal oxides such as cobalt and nickel to the connecting layer 7 forms whiskers at the interface, dramatically improving adhesion. For this reason, these technologies may be utilized in the connecting layer 7.

[0044] Next, a method for manufacturing the porous structure 100 according to this disclosure will be described. Figure 7 is a process diagram showing the method for manufacturing the porous structure 100. The method for manufacturing the porous structure 100 generally consists of four steps: a compounding step (S1), an adhesion step (S2), a spraying step (S3), and a heating step (S4). These steps will be described in detail below.

[0045] The compounding process (S1) is a process for creating composite particles 1 by compounding the core material 2 and the sub-particles 3. Figure 8 is a configuration diagram showing an example of a stirring device for creating composite particles 1. The composite particles 1 shown in Figure 4 can be created by dry stirring using the stirring device 200 shown in Figure 8.

[0046] The stirring device 200 shown in Figure 8 comprises a roughly cylindrical housing 210 and stirring blades 220 that rotate inside the housing 210. The core material 2 and the sub-particles 3 are housed inside the housing 210 and combined by dry stirring for a predetermined time.

[0047] Here, the distance L1 between the side surface 211 of the housing 210 and the stirring blade 220 is, for example, within 2 mm. Also, the distance L2 between the top surface 212 of the housing 210 and the stirring blade 220 is within 2 mm. In this way, as the core material 2 and the sub-particles 3 pass through the narrow section NS where the distance between the side surface 211 and the top surface 212 of the housing 210 and the stirring blade 220 is narrow, they are strongly pressed against each other. As a result, composite particles 1 in the hammered and adhered state shown in Figure 4 are created.

[0048] The stirring device 200 may form a narrow section NS only between the side surface 211 and the stirring blade 220, or it may form a narrow section NS only between the top surface 212 and the stirring blade 220.

[0049] Here, it is preferable that the area on the side surface 211 and the upper surface 212 that form the narrow section NS when the stirring blade 220 is rotating is large. This is because the dry stirring time can be shortened. When creating the composite particles 1, it is necessary to optimize the above area and stirring time, and by optimizing these, composite particles 1 can be obtained.

[0050] Furthermore, the stirring device 200 is not limited to the one shown in Figure 8. The stirring device 200 shown in Figure 8 may be configured in multiple stages vertically, and the core material 2 and sub-particles 3 may be introduced from above, so that composite particles 1 are obtained when they reach the bottom. Also, in the compounding step (S1), the composite particles 1 may be obtained not only by the above method, but simply by a known or well-known method of surrounding the core material 2 with sub-particles 3.

[0051] Refer to Figure 7. After the compounding process (S1), the adhesion process (S2) is performed. The adhesion process (S2) is a process of adhering powder particles to the adherend 6. The powder particles to be adhered have a viscosity of 10 for the subparticles 3. ４ The viscosity of core material 2 becomes less than 10 ４ In the temperature range where the viscosity is above Poise, ４ It is composed of materials that are less than Poise. This process forms the connecting layer 7.

[0052] Furthermore, the adhesion step (S2) does not necessarily have to be performed after the compounding step (S1), as long as it is performed before the spraying step (S3) described later, and may also be performed before the compounding step (S1).

[0053] Next, the spraying process (S3) is performed. The spraying process (S3) is a process of spraying the numerous composite particles 1 created in the compounding process (S1) onto the adherend 6. Here, in order to form the wick 14 with a uniform thickness, it is preferable to spray the numerous composite particles 1 uniformly onto the adherend 6 in the spraying process (S3). It is also preferable to spray the numerous powder particles uniformly onto the adherend 6 in the adhesion process (S2). In this case, if the adherend 6 is a flat plate, it is also possible to achieve a constant film thickness by sweeping away the powder particles and composite particles 1 with a blade member after the adhesion of the numerous powder particles and after the spraying of the numerous composite particles 1.

[0054] On the other hand, when the adherend 6 is not a flat plate, such as the embossed plate material 11 shown in Figure 1, it is not possible to form a constant film thickness using the blade member. Therefore, it is preferable to use the spraying device shown in Figure 9.

[0055] Figure 9 is a configuration diagram showing an example of a spraying device. The spraying device 300 shown in Figure 9 uses a plate material continuously supplied from a coiled plate material as the adherend 6, and sprays composite particles 1 onto this adherend 6. In the following description, the spraying device 300 that sprays composite particles 1 will be used as an example, but it may also be used when powder particles are attached. Furthermore, the spraying device 300 may also be used on a stationary adherend 6.

[0056] The spraying device 300 shown in Figure 9 comprises a container 310, a spraying unit 320, and an electric field application unit (electric field application means) 330. This spraying device 300 charges the composite particles 1 while charging the adherend 6 with the opposite charge to the composite particles 1, thereby spraying the composite particles 1 by causing them to collide with the adherend 6 using electrostatic force, and also prevents scattering after spraying by utilizing intermolecular forces, etc.

[0057] The container 310 is positioned on the adherend 6 and is made of stainless steel. The composite particles 1 are contained within this container 310. The container 310 is preferably made of stainless steel from the viewpoint of ease of manufacture, abrasion resistance, and tolerance of abrasion particles that may be mixed in. Furthermore, because the container 310 is made of stainless steel, when the composite particles 1, which are made of glass material, are rubbed against it, the container 310 becomes positively charged, having the same charge as the dispensing unit 320, as will be described later.

[0058] The dispensing unit 320 dispensing the composite particles 1 in the container 310 onto the object to be adhered 6 comprises a rotating body 321 and a blade member (specific member) 322. Here, the container 310 has an input port (not shown) for putting the composite particles 1 into the container 310 and a dispensing-side opening 311 which serves as an opening for dispensing the composite particles 1 onto the object to be adhered 6. The rotating body 321 is provided so as to roughly close the dispensing-side opening 311 and is made of, for example, stainless steel. Furthermore, the rotating body 321 is subjected to knurling, dimple processing, etc., to form a large number of extremely small indentations.

[0059] The blade member 322 is provided either in contact with the rotating body 321 near the lower end of the spraying-side opening 311, or in close proximity with a minute gap corresponding to the diameter of the composite particles 1. This blade member 322 uses contact with the rotating body 321 or the minute gap to adhere the composite particles 1 to the rotating body 321 with a uniform thickness. The blade member 322 comprises a base material 322a and a surface portion 322b, and the surface portion 322b is composed of at least one of fluororesin, silicone resin, polyvinyl chloride, and materials mainly composed of these.

[0060] Furthermore, the rotating body 321 rotates near the lower end of the spraying-side opening 311, in a direction from the inside of the container 310 toward the outside of the spraying-side opening 311. That is, in the example shown in Figure 9, the rotating body 321 rotates counterclockwise. Because the rotating body 321 performs this rotation, a large number of composite particles 1 are attached to it by the blade member 322, and at the moment it separates from the friction point (hereinafter referred to as the friction point FP) that is in contact with or close to the blade member 322, the large number of composite particles 1 are sprayed onto the object to be attached 6. In particular, the composite particles 1 are sprayed onto the object to be attached 6 in a state that has been charged by friction with the container 310, the rotating body 321, and the blade member 322. In particular, since the container 310 and the rotating body 321 are made of stainless steel and the blade member 322 is made of the above material, the composite particles 1, which are made of glass, become positively charged.

[0061] The electric field application unit 330 applies a DC electric field that makes the adherend 6 negative and the rotating body 321 and blade member 322 (especially the base material 322a) positive. As described above, the composite particles 1 are positively charged. Therefore, if the adherend 6 is negative, the composite particles 1 are dispersed as if attracted to the adherend 6. Furthermore, by rotating the rotating body 321 and dispersing the composite particles 1 while utilizing contact or proximity with the blade member 322, uniform dispersal can be achieved according to the rotation speed of the rotating body 321. Note that if the composite particles 1 are dispersed by the rotation of the rotating body 321 when the composite particles 1 are not charged, phenomena such as the composite particles 1 flying around will occur, making it difficult to achieve a uniform film thickness.

[0062] Furthermore, the spraying device 300 can be configured such that the rotating body 321 is subjected to knurling or dimple processing to a depth corresponding to the particle size of the composite particles 1, and the blade member 322 appropriately presses the composite particles 1 against the rotating body 321, thereby preventing the composite particles 1 from falling off the rotating body 321 when the rotating body 321 stops. In particular, if the composite particles 1 are properly composited in the composite process (S1), the core material 2 and the child particles 3 will not separate, and it is also possible to prevent the two from separating and only the child particles 3 from falling.

[0063] Here, the composite particles 1 are not positively charged by the electric field application unit 330, but are positively charged by friction. The electric field application unit 330 is used to eliminate the saturation state of the rotating body 321 and blade member 322 caused by this friction. That is, the rotating body 321 and blade member 322 positively charge the composite particles 1 through friction with them, while becoming negatively charged themselves if they are not grounded. Therefore, unless the negative charge accumulated on the rotating body 321 and blade member 322 is released, the blade member 322 will become negatively saturated, and will no longer be able to positively charge the composite particles 1 through friction. Thus, the electric field application unit 330 applies a positive DC electric field to prevent the rotating body 321 and blade member 322 from becoming negatively saturated.

[0064] Here, a technique for separating powder from a rotating body using an alternating electric field is proposed in Japanese Patent Publication No. 9-1039. This technique uses electrostatic repulsion to separate the powder from the rotating body and differs from the technique of using a direct current electric field to launch and collide powder with the object to be attached 6, as in the above-mentioned dispensing device 300.

[0065] Furthermore, the spraying device 300 is equipped with a brush member (second specific member) 340. The brush member 340 is located outside the container 310 and is positioned in contact with the rotating body 321 in the direction of rotation of the rotating body 321, more so than the blade member 322. Like the blade member 322, the brush member 340 is made of at least one of fluororesin, silicone resin, polyvinyl chloride, and materials mainly composed of these materials. The brush member 340 is, for example, a brush roll with a rotating mechanism and rotates in the same direction as the rotating body 321 (counterclockwise in the state shown in Figure 9). As a result, the brush member 340 scrapes off any composite particles 1 that remain on the rotating body 321 and re-positively triboelectrically charges the composite particles 1. Therefore, it is possible to eliminate the situation in which composite particles 1 remain stuck to the rotating body 321 in some places, and the particles are not sprayed uniformly only in the corresponding areas on the adherend 6. Furthermore, a positive DC electric field is applied to the brush member 340 by the electric field application unit 330 to prevent saturation.

[0066] More specifically, the spraying device 300 should have an electric field strength of 1 kV / cm or more and 5 kV / cm or less from the electric field application unit 330, and the distance between the friction part FP (more precisely, the position slightly on the rotational side of the rotating body 321 from the friction part FP where the spraying of the numerous composite particles 1 begins) and the object to be applied 6 should be within 100 mm. For this reason, if the distance is 40 mm, for example, the voltage of the electric field application unit 330 should be set to 10 kV or the like. This is because if the electric field strength is less than 1 kV / cm, a sufficient electrostatic effect cannot be obtained, and if the electric field strength exceeds 5 kV / cm, electrostatic repulsion and sparks are likely to occur.

[0067] Furthermore, it is preferable that the distance between the friction portion FP and the workpiece 6 is within 20 mm (for example, a distance of 20 mm and a voltage of 5 kV). This allows the composite particles 1 to be scattered within 10 mm of the intersection line with the perpendicular line drawn from the friction portion FP to the workpiece 6. Also, because the composite particles 1 can be scattered within 10 mm of the intersection line, it is possible to prevent the composite particles 1 from being scattered on the area of ​​the workpiece 6 that is scheduled to be welded, for example, without using masking. Moreover, because the composite particles 1 can be scattered within 10 mm of the intersection line, a recovery device for collecting composite particles 1 that have scattered to unintended locations is unnecessary.

[0068] In the example shown in Figure 9, the adherend 6 is continuously supplied. Such adherend 6 is in contact with a device such as an uncoiler that feeds out a rolled plate material, and even if a positive electric field is applied, it will be grounded. Therefore, the spraying device 300 shown in Figure 9 applies a negative DC electric field to the adherend 6 and a positive DC electric field to the rotating body 321, blade member 322, and brush member 340, and uses a positive supply type as the high-voltage power supply, in which the box is electrically connected to the negative terminal. However, if the adherend 6 is not continuously supplied, a negative supply type as the high-voltage power supply, in which the box is electrically connected to the positive terminal, may be used, and the positive terminal and blade may be grounded. Alternatively, a positive DC electric field may be applied to the adherend 6 and a negative DC electric field to the rotating body 321, blade member 322, and brush member 340. In this case, the composite particles 1 will be negatively charged by friction, so it is necessary to appropriately select the constituent materials of each part.

[0069] In addition, in the example shown in Figure 9, a positive DC electric field is applied to both the rotating body 321 and the blade member 322. However, since the rotating body 321 and the blade member 322 are in close proximity or in contact, a positive DC electric field may be applied to only one of them. This is because saturation can be eliminated even when they are in close proximity, as well as when they are in contact.

[0070] Figure 10 is a configuration diagram showing a spraying device according to the first modified example. As shown in Figure 10, in the spraying device 300a according to the first modified example, the friction part FP is located approximately to the side of the rotating body 321. In this case, the rotating body 321 approaches the object to be adhered 6, and if the position of the rotating body 321 closest to the object to be adhered 6 is taken as the bottom dead center LD, a discharge will occur from the bottom dead center LD toward the object to be adhered 6. Furthermore, the composite particles 1 that have come into contact with the object to be adhered 6 and become negatively charged will be attracted by the rotating body 321 to which a positive DC electric field is applied, and the composite particles 1 may be scattered.

[0071] Therefore, as shown in the spraying device 300 in Figure 9, it is preferable that the friction portion FP is within a range of 45° (sign θ) from the bottom dead center LD of the rotating body 321. This makes it easier to suppress discharge and scattering of composite particles 1 by suppressing the amount of protrusion of the rotating body 321 downward from the friction portion FP. If discharge and scattering can be suppressed by other means, or if a certain degree of discharge and scattering is acceptable, the spraying device 300a shown in Figure 10 may be used.

[0072] Figure 11 is a configuration diagram showing a spraying device according to a second modified example. In the spraying device 300b shown in Figure 11, the surface portion 322b of the blade member 322 is made of a long film material F. The long film material F is equipped with a feed portion 351 and a winding portion 352 at both ends, and the friction position with the rotating body 321 on the film material F can be changed. This helps to prevent the blade member 322 from wearing down due to friction and dispersing a larger amount of composite particles 1 than intended. In addition, in the spraying device 300b shown in Figure 11, the brush member 340 is made of a material with brush-like bristles.

[0073] Figure 12 is a configuration diagram showing a spraying device according to a third modified example. The spraying device 400 shown in Figure 12 comprises a container 410, a spraying unit 420, and an electric field application unit (electric field application means) 430. The container 410 is the same as those shown in Figures 9 to 11, but is provided with a spraying-side opening 411 at the bottom.

[0074] The dispensing unit 420 comprises a rotating body 421 and a mesh (specific member) 422. The rotating body 421 is not a reciprocating agitator or squeegee, but a brush roll is used. At least the brush tip portion of the rotating body 421 that comes into contact with the composite particles 1 is made of at least one of fluororesin, silicone resin, polyvinyl chloride, and materials mainly composed of these materials.

[0075] The mesh 422 is a component provided to close the spraying-side opening 411. The mesh 422 has an opening that is greater than 100% of the average particle size of the composite particles 1 and less than or equal to 150%, and more preferably greater than 100% and less than or equal to 130%. With a mesh 422 of this size, the composite particles 1 will not fall through due to their own weight alone. The rotating body 421 is provided to sweep up such a mesh 422. The mesh 422 is made of stainless steel.

[0076] This dispensing unit 420 allows the composite particles 1 to pass through the mesh 422 due to the rotational movement of the rotating body 421, thereby dispensing an amount of composite particles 1 onto the object to be applied 6 that corresponds to the rotational speed of the rotating body 421.

[0077] The electric field application unit 430 applies a negative DC electric field to the object to be deposited 6 and a positive DC electric field to the mesh 422. Here, the rotating body 421 and the mesh 422 cause the composite particles 1 to become positively charged through friction with them, while the rotating body 421 and the mesh 422 become negatively charged themselves. Therefore, unless the accumulated negative charge is released, the rotating body 421 and the mesh 422 will become negatively saturated, and will no longer be able to positively charge the composite particles 1 through friction. Thus, the electric field application unit 430 applies a positive DC electric field to the mesh 422 to prevent the rotating body 421 and the mesh 422 from becoming negatively saturated. In addition, since the rotating body 421 is configured to sweep the mesh 422, saturation of the rotating body 421 is also prevented. Alternatively, the electric field application unit 430 may apply a positive DC electric field to the rotating body 421.

[0078] The spraying process (S3) shown in Figure 7 is carried out by uniformly spraying the material onto the substrate 6 using the spraying devices 300, 300a, 300b, and 400 described above. These spraying devices 300, 300a, 300b, and 400 also have the advantage of making it easier to achieve a consistent film thickness compared to air spray methods, including corona and tribo-type powder electrostatic coating. Note that the spraying devices 300, 300a, 300b, and 400 are not limited to those described above; air spray methods or other methods may be used as long as there are no issues with the accuracy of the film thickness. Furthermore, the spraying device 400 may also use a sieving method different from that shown in Figure 12, in which the composite particles 1 dropped by an agitator reciprocating through a mesh 422 are first received by a spraying roller before being dropped onto the substrate 6.

[0079] As shown in Figure 7, a heating step (S4) is performed after the spraying step (S3). The heating step (S4) is a step in which the numerous composite particles 1 sprayed on the adherend 6 in the spraying step (S3) are heated to the above temperature range. It is assumed that the adherend 6 is continuously transported at a speed of 1 m / min or more during this step.

[0080] The heating process (S4) can utilize a high-speed heating process. This is because no organic solvents or organic binders are used in the material to be heated, eliminating the risk of defects due to vaporization, and there are no components that take a long time to decompose thermally. Therefore, the heating process (S4) can be completed in a short time. In particular, as shown in Figures 4(a) and 4(b), since the composite particles 1 consist of sub-particles 3 surrounding the core material 2, the sub-particles 3 do not require much time to dissolve, migrate, and integrate. Therefore, for this reason as well, the heating process (S4) can be completed in a short time.

[0081] Furthermore, it is preferable to perform the heating process (S4) without contact with the object to be attached 6 while it is suspended in mid-air. After the spraying process (S3), the composite particles 1 and powder particles are lightly attached. Therefore, by performing suspended and non-contact heating, vibrations due to transport can be prevented until the wick 14 is completed after the heating and cooling of the composite particles 1.

[0082] In the heating process (S4), electromagnetic wave heating and induction heating can be considered as high-temperature heating processes. This is because these heating methods allow the adherend 6, on which the composite particles 1 etc. are attached, to be heated to approximately 700°C in less than one minute without contact. More specifically, in the case of electromagnetic wave heating, a heating rate of 100°C / second is possible using a mid-to-near-infrared heater, and a heating rate of 1000°C / second or more is possible with laser heating. Furthermore, with induction heating, a heating rate of 100 to 500°C / second is also possible.

[0083] More specifically, mid- and near-infrared heaters include near-infrared heaters, halogen heaters, and carbon filament heaters. Near-infrared heaters use a tungsten filament that glows at around 2000°C or higher inside a quartz tube filled with inert gas. Halogen heaters use a tungsten filament that glows at around 2000°C or higher inside a quartz tube filled with inert gas, and also incorporate halogen to achieve the halogen effect. Carbon filament heaters use a carbon filament that glows at around 1000°C inside a quartz tube filled with inert gas.

[0084] Of the light emitted by these filaments, the components with wavelengths of 4.5 μm or longer are mostly absorbed by the quartz tube and converted into far-infrared radiation, thus not contributing much to high-temperature heating. For example, soda-lime glass and borosilicate glass, which are suitable as core material 2, have high absorption rates at wavelengths of 2.7 μm and 2.8 μm, respectively, and low absorption rates for infrared radiation at lower wavelengths. In contrast, low-melting-point glass, which is suitable as sub-particle 3, absorbs from even shorter wavelengths depending on its composition, so heating with a heater that emits a lot of light with wavelengths between these wavelengths and 4.5 μm is efficient.

[0085] Furthermore, since the tungsten filament has an emissivity of less than 20% at wavelengths of 2.7 μm or more, it is not very efficient when compared to the wavelengths mentioned above. However, because the filament temperature is high, it can heat the composite particles 1 to a high temperature. In addition, the infrared radiation that passes through the composite particles 1 contributes to the heating of the substrate 6, and the infrared radiation reflected from the substrate 6 contributes again to the heating of the composite particles 1.

[0086] Carbon filaments have an emissivity of approximately 85% for particles larger than 2.7 μm, allowing for efficient heating. However, because the filament temperature of carbon filaments is not very high, as the temperature of the composite particles 1 being heated increases, the efficiency decreases as the temperature approaches the filament temperature.

[0087] The detailed heating time and other parameters in the heating process (S4) will be explained. First, the near-infrared heater for the tungsten filament is 300 kW / m ２ Up to approximately 150 kW / m², carbon filament mid-infrared heaters are rated for 150 kW / m². ２ Heaters with irradiation densities up to a certain level are commonly used. In the case of laser heating, energy densities of more than 10 times that can be obtained. As an example, considering the reliability of overheat prevention control, a relatively low irradiation density is used, for example, 180 kW / m² from one side of a 0.3 mm thick stainless steel plate. ２ When a near-infrared heater is applied, a heating rate of approximately 30°C / second can be obtained.

[0088] For example, when using zinc borosilicate alkali-containing glass with a softening point of 540°C as subparticle 3, at 550°C it has low fluidity and takes several minutes for sintering to proceed, but at 600°C it only takes about 10 seconds, and at 730°C it only takes about 1 second. When heating at a heating rate of 30°C / second, sintering begins about 17 seconds after reaching 540°C, and if the heating continues, sintering is fully completed by 24 seconds after reaching 730°C. In this case, when heating while transporting the plate material at 5 m / min, the heating section is improved by about 2 m.

[0089] In this heating section, if the core material 2 is soda-lime glass, it will just reach its softening point (viscosity of 10 in the temperature range). ９ (Below Poise). In this case, the core material 2 does not deform significantly, but mass transfer is active at the micro level. Therefore, the core material 2 and the shell 4 are strongly bonded by mutual diffusion, and a transition layer is created in which the glass components change continuously. As a result, the coefficient of thermal expansion changes continuously within the transition layer, and fracture due to differences in thermal expansion is suppressed.

[0090] Thus, using glass particles with a softening point relatively close to that of the shell 4 as the core material 2, rather than metal particles or high-melting-point ceramics such as alumina, has the effect of creating a strong and high-quality bond between the shell 4 and the core material 2 through diffusion and the presence of a transition layer.

[0091] Furthermore, when bismuth oxide glass with a low softening point (e.g., softening point of 390°C) is used as subparticle 3, the softening point is reached in just over 12 seconds of heating, and sintering is completed when the temperature reaches 560°C after 18 seconds. Bismuth oxide glass is characterized by its remarkable fluidization above its softening point. In this case, when heating while transporting the plate material at 5 m / min, the heating section can be reduced by about 1.5 m.

[0092] Induction heating generally allows for a higher heating rate than infrared heating, but on the other hand, it can damage the adherend 6 or composite particles 1 due to overheating, for example, when the adherend 6 is suddenly stopped during production. When the adherend 6 is a thin sheet of paramagnetic material such as austenitic stainless steel, the penetration depth of the induced current is deep, causing the currents on the front and back surfaces to cancel each other out, making it impossible to use a solenoid coil, and requiring a transverse coil. When using ferromagnetic materials such as steel plates or ferritic stainless steel, the penetration depth is shallow if the frequency is sufficiently high, so a solenoid coil can be used even for thin sheets. Here, when such an adherend 6 reaches its Curie temperature, it changes from a ferromagnetic material to a paramagnetic material, so the induced currents begin to cancel each other out, making it difficult to heat it further with a solenoid coil. The Curie temperature of iron is about 770°C, and for SUS430, a representative type of ferritic stainless steel, it is about 680°C. Therefore, for example, if ferritic stainless steel is used as the adherend 6 and a solenoid coil is used for heating, the temperature will not exceed 680°C, thus automatically preventing overheating.

[0093] Thus, a ferromagnetic substrate 6 (e.g., ferritic stainless steel) has a Curie temperature at which it changes to a paramagnetic material at room temperature (e.g., 30°C), and a viscosity 10 at that temperature. ４ Core material 2 (e.g., soda-lime glass) that is greater than poise and 10 ４ By using composite particles 1, which are formed by combining sub-particles 3 (e.g., borosilicate enamel for stainless steel) that are less than poise in diameter, and inductively heating them with a solenoid coil, it is possible to create a porous structure 100 in a very short time and heating interval while suppressing problems caused by overheating.

[0094] Furthermore, a heating furnace is not essential in the heating process (S4). When using near-infrared heating, mid-infrared heating, laser heating, and induction heating, since it is direct heating by electromagnetic waves, etc., a furnace body (a box or tunnel with insulating walls) is unnecessary.

[0095] After the heating process (S4) is completed, cooling is performed, and the manufacturing of the porous structure 100 is completed.

[0096] In this way, the composite particle 1 according to the first embodiment comprises a core material 2 and a core material 2 with a viscosity of 10 ４ 10 ４ The composite particle 1 is composed of sub-particles 3 having a viscosity of less than poise. Furthermore, the composite particle 1 is in a hammered state where the sub-particles 3 are hammered into the core material 2 so as to deform the surface of the core material 2, or in an attached state where the sub-particles 3 are deformed and connect to each other, adhering to the surface of the core material 2 in a film-like manner. In such hammered and attached states, the core material 2 and sub-particles 3 are integrated without the need for organic solvents or organic binders, and by heating in this state to, for example, the above temperature range, the sub-particles 3 can be bonded together to obtain the wick 14. In particular, since organic solvents and organic binders are not required, long heating for drying or decomposition is not necessary. Therefore, it is possible to provide a composite particle 1 that can produce the wick 14 in a shorter time.

[0097] Furthermore, the core material 2 has a viscosity of 10 in the above temperature range. ４ The above 10 ９ It is formed from a material with a poise or less. As a result, the core material 2 is not too hard, and when heated in the above temperature range, the core material 2 and the shell 4 (sub-particles 3) can be easily bonded firmly by mutual diffusion. Furthermore, a transition layer is formed between the two in which the glass component changes continuously, and the coefficient of thermal expansion also changes continuously within the transition layer, making it possible to create a wick 14 that is less susceptible to fracture due to differences in the coefficient of thermal expansion, etc.

[0098] Furthermore, the wick 14 according to the first embodiment includes a pigment 5 that is incorporated into or compounded with the core material 2 or shell 4 and has a higher infrared absorption rate than the core material 2 and shell 4. Therefore, when heating using infrared rays, the pigment 5 is efficiently heated. Consequently, a wick 14 that can be manufactured in a short time can be provided.

[0099] Furthermore, the porous structure 100 according to the first embodiment is provided on the wick 14 surface of the adherend 6, and in the above temperature range 10 ４The device includes a connecting layer 7 made of a material with a viscosity less than poise. Here, since each composite particle 1 has a shell 4, the composite particles 1 are easily firmly bonded together by the shells 4 during joining. Therefore, when the connecting layer 7 is provided, the wick 14 can be bonded more firmly to the adherend 6 by the connecting layer 7 and the shells 4.

[0100] Furthermore, the manufacturing method of the porous structure 100 according to the first embodiment involves a core material 2 and a material with a smaller diameter than the core material 2 and a viscosity of 10 ４ 10 ４ The method includes a compounding step (S1) to create a large number of compounded particles 1 by compounding sub-particles 3, which have a viscosity of less than poise, with the core material 2. Therefore, the core material 2 and sub-particles 3 can be integrated without the need for organic solvents or organic binders. Then, by scattering these compounded particles 1 onto the adherend 6 and heating them in the above temperature range, the sub-particles 3 can be joined together. In particular, this heating does not require long heating times like drying organic solvents or organic binders. Therefore, a method for manufacturing a porous structure 100 that can be produced in a short time can be provided.

[0101] Furthermore, in the heating step (S4), the adherend 6 is continuously supplied at a speed of 1 m or more per minute. Here, since the numerous composite particles 1 are integrated without the need for organic solvents or organic binders, the wick 14 can be created with short heating time, and heating can be completed even when the adherend 6 is continuously supplied. Therefore, it is possible to provide a method for manufacturing a porous structure 100 that allows for continuous supply of the adherend 6 in an even shorter time.

[0102] Furthermore, in the compounding step (S1), the core material 2 and the sub-particles 3 are dry-stirred to create a hammered or adhered state. This eliminates the need for organic solvents or organic binders, and even other liquid components, thus providing a method for producing a porous structure 100 that can be created in a short time.

[0103] Furthermore, a DC electric field is applied to the dispersing devices 300, 300a, 300b, and 400 and the adherend 6, causing the numerous composite particles 1 to be charged with the opposite charge to the adherend 6 before being dispersed. As a result, the numerous composite particles 1 are dispersed as if attracted to the adherend 6. Moreover, it is thought that intermolecular forces also act on the numerous electrostatically dispersed composite particles 1 after they collide with the adherend 6. Therefore, after a certain period of time has elapsed since the electrostatic effect subsided, the particles will not fall off even if the adherend 6 is turned upside down and lightly shaken, but they will adhere with enough adhesive force that they will easily fall off if touched with a finger. Consequently, the particles can be dispersed efficiently, and it is possible to reduce the possibility of the numerous composite particles 1 moving in subsequent processes, thus reducing the likelihood of differences in the thickness of the wick 14.

[0104] Furthermore, prior to the spraying process (S3), 10 ４ The process further includes an adhesion step (S2) in which powder particles with a viscosity of less than poise are attached to the adherend 6. Here, since each composite particle 1 has sub-particles 3, the composite particles 1 are more firmly bonded together by the bonding of the sub-particles 3 on both sides. Therefore, when the adhesion step (S2) is included, the wick 14 can be more firmly bonded to the adherend 6 by the powder particles and sub-particles 3 in the same manner.

[0105] Furthermore, the dispensing devices 300, 300a, 300b, and 400 according to this embodiment dispensing powder from stainless steel containers 310 and 410 by rotating rotating bodies 321 and 421, thereby charging the powder while friction is applied, and dispensing the powder onto the adherend 6. Therefore, the powder can be dispersed onto the adherend 6 using electrostatic force. When the powder is a glass material, at least one of fluororesin, silicone resin, polyvinyl chloride, or a material mainly composed of these materials, which have strong negative charge properties, will be used for the blade member 322 and rotating body 421 that are subject to friction. When the adherend 6 is supplied continuously, such as a coil material, the negative side is grounded. In addition, since the positive charge is lost from the blade member 322 and rotating body 421 during friction, applying a positive electric field with the electric field application unit 330 and 430 can prevent the positive charge from being lost and becoming saturated. Therefore, we can provide spraying devices 300, 300a, 300b, and 400 that can spray powder onto a continuously supplied adherend 6 using electrostatic force without the charge of the component becoming saturated.

[0106] Furthermore, the blade member 322 is positioned in contact with or close to the rotating body 321 within a 45-degree range centered on the bottom dead center LD. Therefore, the powder is sprayed from a position closer to the adherend 6, which is closer to the bottom dead center LD, making it easier to spray the powder to the targeted location on the adherend 6. Moreover, when a positive electric field is applied to the rotating body 321, the positive electric field portion in the region closer to the adherend 6 than the spraying position (friction portion FP) is reduced, making it even easier to spray the powder to the targeted location on the adherend 6.

[0107] Furthermore, the rotating body 321 has a brush member 340 provided on the side in the direction of rotation, which scrapes off powder adhering to the rotating body 321 and also causes frictional charging, and a positive DC electric field is applied to the brush member 340. Therefore, it can remove powder that has adhered to the rotating body 321 from the rotating body 321, charge it, and then disperse it, while also preventing saturation.

[0108] Furthermore, the surface portion 322b of the blade member 322 is a long film material F, and the position of the friction portion with the powder can be changed by moving the film material F. This helps to prevent the surface portion 322b from being worn away by friction, which could result in the scattering of more powder than intended.

[0109] Furthermore, the adherend 6 is a ferromagnetic material at room temperature and has a Curie temperature at which it changes to a paramagnetic material, and the composite particles 1 have a viscosity of 10 at this Curie temperature. ４ Core material 2, which has a viscosity of 10 or higher at its Curie temperature, has a viscosity of 10 ４ This material is a composite of sub-particles 3 that are less than Poise. Furthermore, in the heating process (S4), numerous composite particles 1 are heated via the adherend 6 by induction heating using a solenoid coil. This makes it difficult for the adherend 6 to rise above the Curie temperature during heating, thereby reducing the possibility of damage to the adherend 6 and composite particles 1 due to overheating.

[0110] Although the present disclosure has been described above based on embodiments, the present disclosure is not limited to the above embodiments, and modifications may be made, and publicly known or well-known technologies may be combined to the extent possible, without departing from the spirit of the present disclosure.

[0111] For example, although the wick 14 was given as an example of a porous material above, it is not limited to the wick 14, and other porous materials such as filters may also be used.

[0112] Furthermore, the following should be added:

[0113] (Note 1) In the temperature range, the viscosity of the core material is 10 ４ The above 10 ９ The composite particle according to claim 1, characterized in that it is formed from a material with a poise or less.

[0114] (Note 2) A spraying device for spraying powder onto a continuously supplied object, comprising: a stainless steel container provided on the object; a spraying means for discharging powder from the container by rotating a rotating body and charging the powder by friction with a specific member, thereby spraying the powder onto the object; and an electric field application means for making the object negative and applying a positive DC electric field to at least one of the specific member and the rotating body, wherein the powder is made of glass material, and at least one of the specific member and the rotating body that come into contact with the powder is made of at least one of fluororesin, silicone resin, polyvinyl chloride, and a material mainly composed of these.

[0115] (Note 3) The spraying device according to Note 2, wherein the specified member is a blade member that rubs against the powder, and when the bottom dead center is defined as the part of the rotating body closest to the object to be adhered to, the specified member is positioned in contact with or close to the rotating body within a 45-degree range centered on the bottom dead center.

[0116] (Note 4) The spraying device according to either Note 2 or Note 3, wherein the device has a second specific member provided on the side of the rotating body in the direction of rotation of the rotating body than the specified member, which scrapes off powder adhering to the rotating body and causes it to become triboelectrically charged, and the second specific member is subjected to a positive DC electric field by the electric field application means.

[0117] (Note 5) The spraying device according to any one of Notes 2 to 4, characterized in that the specific member is a long film material composed of at least one of fluororesin, silicone resin, polyvinyl chloride, and a material mainly composed of these, and the position of the friction portion with the powder can be changed by moving the film material.

[0118] 1: Composite particles 2: Core material 3: Sub-particles 4: Shell 5: Pigment (infrared absorber) 6: Adhesion surface 7: Connecting layer 14: Wick (porous member) 100: Porous structure 200: Stirring device 300, 300a, 300b, 400: Spraying device 310, 410: Container 321, 421: Rotating body 322: Blade member (specific member) 330, 430: Electric field application part (electric field application means) 340: Brush member (second specific member) 422: Mesh (specific member) F: Film material FP: Friction part LD: Bottom dead center NS: Narrow section S1: Composite process S2: Adhesion process S3: Spraying process S4: Heating process

Claims

1. A core material and a material with a smaller diameter than the core material and a viscosity of 10 ４ 10 ４ A composite particle comprising sub-particles having a viscosity of less than poise, characterized in that the sub-particles are hammered into the surface of the core material in a hammered state so as to deform the surface of the core material, or the sub-particles are deformed and connect to each other, adhering to the surface of the core material in a film-like manner.

2. A porous member having a core material and a shell covering the core material, wherein the shells of a plurality of composite particles are joined together to form a continuous void, and the member comprises an infrared absorbing material contained in or composited with the core material or the shell, which has a higher infrared absorption rate than the core material and the shell, wherein the core material and the shell are made of 10 ４ In the temperature range where the viscosity is less than Poise, the viscosity of the core material is 10 ４ A porous member characterized by being formed from a material with a poise greater than or equal to poise.

3. A porous member according to claim 2, an adherend bonded to the shell of the composite particles constituting the porous member, and a device provided on the surface of the adherend on which the porous member is provided, in the temperature range of 10 ４ A porous structure characterized by comprising a connecting layer formed of a material having a viscosity less than poise.

4. A core material and a material with a smaller diameter than the core material and a viscosity of 10 ４ 10 ４ A method for manufacturing a porous structure, comprising: a compounding step of compounding subparticles having a viscosity of less than poise with a number of compounded particles to create a number of compounded particles; a spraying step of spraying the number of compounded particles created in the compounding step onto a substrate; and a heating step of heating the number of compounded particles sprayed onto the substrate in the spraying step to reach a certain temperature range.

5. The method for manufacturing a porous structure according to claim 4, wherein the adherend is a plate material continuously supplied from a coiled plate material, and in the heating step, the adherend is continuously supplied at a speed of 1 m per minute or more.

6. The method for manufacturing a porous structure according to claim 4, characterized in that in the compounding step, the core material and the subparticles are dry-stirred to a state in which the subparticles are hammered into the surface of the core material so as to deform the surface of the core material, or to a state in which the subparticles are deformed and connect to each other, adhering to the surface of the core material in a film-like manner.

7. The method for manufacturing a porous structure according to claim 4, wherein the spraying step involves spraying the numerous composite particles created in the compounding step onto the adherend using a spraying device, characterized in that a DC electric field is applied to the spraying device and the adherend, thereby charging the numerous composite particles to a charge opposite to that of the adherend before spraying.

8. Prior to the spraying process, 10 in the temperature range ４ The method for manufacturing a porous structure according to claim 4, further comprising an adhesion step of adhering powder particles having a viscosity of less than poise to the adherend.

9. In the spraying step, the multiple composite particles are sprayed onto the adherent body which is ferromagnetic at normal temperature and has a Curie temperature at which it changes to paramagnetic. In the composite forming step, the core material having a viscosity of 10 ４ poise or more at the Curie temperature of the adherent body and the sub-particles having a viscosity of less than 10 ４ poise at the Curie temperature are combined. In the heating step, the multiple composite particles are heated through the adherent body by induction heating using a solenoid coil. The method for producing a porous structure according to claim 4, characterized by the above.

Images