Metallic porous body and method for producing the same

Abstract

Provided is a porous metal body in the shape of a flat plate having a three-dimensional net-like skeleton, the porous metal body comprising a plurality of cells, wherein expressions (1) and (2) below are satisfied. (1): 0.4≤cell diameter ratio≤1.0, (2): 0.50<cell diameter in the direction perpendicular to the thickness direction / (thickness of porous metal body / cell diameter ratio)≤1.50. The cell diameter ratio is the ratio of the cell diameter in the thickness direction to the cell diameter in the direction perpendicular to the thickness direction in the porous metal body (cell diameter in the thickness direction / cell diameter in the direction perpendicular to the thickness direction).

Description

[Technical field]

[0001] The present invention relates to a metal porous body and a method for producing a metal porous body. This application claims priority to Japanese Application No. 2020-057177 filed on March 27, 2020, and incorporates all of the contents of said Japanese application by reference. [Background technology]

[0002] Sheet-shaped metal porous bodies having a three-dimensional mesh-like structure skeleton are used for various applications such as filters that require heat resistance, battery electrode plates, catalyst carriers, and metal composite materials. For example, Celmet (registered trademark, manufactured by Sumitomo Electric Industries, Ltd.), a nickel-made metal porous body, is widely used in various industrial fields such as electrodes for alkaline storage batteries such as nickel-metal hydride batteries and carriers for industrial deodorizing catalysts. Aluminum-Celmet (registered trademark, manufactured by Sumitomo Electric Industries, Ltd.), an aluminum-made metal porous body, is stable even in organic electrolyte solutions and can therefore be used as the positive electrode of lithium-ion batteries.

[0003] The metal porous body can be produced by subjecting the surface of the skeleton of a resin porous body having a skeleton with a three-dimensional network structure to an electrically conductive treatment, then subjecting the surface of the skeleton of the resin porous body to metal plating by electroplating, and then removing the resin porous body (see, for example, Patent Documents 1 and 2). For example, a polyurethane resin can be preferably used as the resin porous body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 05-031446 [Patent Document 2] JP 2011-225950 A Summary of the Invention

[0005] The metal porous body according to one embodiment of the present disclosure is A flat metal porous body having a skeleton of a three-dimensional mesh structure, Contains multiple cells, A metal porous body, wherein the ratio of the cell diameter in the thickness direction of the metal porous body to the cell diameter in the direction perpendicular to the thickness direction (cell diameter in the thickness direction / cell diameter in the direction perpendicular to the thickness direction) is defined as a cell diameter ratio, which satisfies the following formulas (1) and (2): 0.4≦Cell diameter ratio≦1.0 Equation (1) 0.85≦ Cell diameter in the direction perpendicular to the thickness direction / (thickness of the metal porous body / cell diameter ratio)≦1.50 Equation (2) [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of a porous metal body according to the present disclosure. [Diagram 2] FIG. 2 is a cross-sectional photograph of an example of a porous metal body according to the present disclosure. [Diagram 3] FIG. 3 is a schematic diagram of a structural unit of the three-dimensional network structure of the metal porous body according to the present disclosure. [Figure 4] FIG. 4 is a graph showing the relationship between the porosity (%) and the compressibility (%) of a porous metal body having a three-dimensional network structure skeleton. [Diagram 5] FIG. 5 is a diagram illustrating an outline of a step of cutting a porous metal body in a direction perpendicular to the thickness direction in an example of a method for producing a porous metal body according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] [Problem that this disclosure aims to solve] When a polyurethane resin is used as the resin porous body, first, a block-shaped polyurethane resin is peeled or sliced ​​to be processed into a flat plate. Then, the surface of the polyurethane resin skeleton is treated to be conductive. When the resin porous body with the skeleton surface treated to be conductive is plated with metal, a certain amount of tension is applied to the resin porous body in the plating solution. When the polyurethane resin is peeled or sliced, or subjected to conductive treatment or plating treatment, in order for the resin porous body to maintain the skeleton of a three-dimensional network structure, the thickness of the resin porous body needs to be at least twice the cell diameter in the direction perpendicular to the thickness direction. For this reason, for example, in order to manufacture a metal porous body with a thickness of 1.0 mm, it was necessary to use a resin porous body with a cell diameter in the direction perpendicular to the thickness direction of 0.50 mm or less. In other words, when a resin porous body with a thickness of 1.0 mm or less is used, it was not possible to manufacture a metal porous body with a cell diameter in the direction perpendicular to the thickness direction of more than 0.50 mm.

[0008] As a method for producing a metal porous body having a thickness of 1.0 mm or less, for example, a method of producing a metal porous body having a thickness of more than 1.0 mm and then rolling it to a thickness of 1.0 mm or less is conceivable. However, in a metal porous body having a thickness of 1.0 mm or less by rolling, the cells are crushed in the thickness direction, resulting in a small porosity. Therefore, when a metal porous body having a thickness of 1.0 mm or less by rolling is used as, for example, a filter, there is a problem that the pressure loss becomes large.

[0009] Accordingly, an object of the present disclosure is to provide a flat metal porous body having a thickness that is less than twice the cell diameter in a direction perpendicular to the thickness direction.

[0010] [Description of the embodiments of the present disclosure] First, the embodiments of the present disclosure will be listed and described. [1] A metal porous body according to one embodiment of the present disclosure, A flat metal porous body having a skeleton of a three-dimensional mesh structure, Contains multiple cells, The metal porous body is a porous body, in which the ratio of the cell diameter in the thickness direction of the metal porous body to the cell diameter in the direction perpendicular to the thickness direction (cell diameter in the thickness direction / cell diameter in the planar direction) is taken as the cell diameter ratio, and which satisfies the following formulas (1) and (2): 0.4≦Cell diameter ratio≦1.0 Equation (1) 0.50<Cell diameter in the direction perpendicular to the thickness direction / (Thickness of the metal porous body / Cell diameter ratio)≦1.50 Equation (2) According to this embodiment, it is possible to provide a flat plate-like porous metal body having a thickness that is less than twice the cell diameter in a direction perpendicular to the thickness direction.

[0011] [2] The cell diameter of the metal porous body in a direction perpendicular to the thickness direction may be more than 0.4 mm and not more than 1.70 mm. According to this embodiment, even if the cell diameter in the direction perpendicular to the thickness direction is greater than 0.4 mm, it is possible to provide a metal porous body having a thickness of 0.8 mm or less.

[0012] [3] The metal porous body is The thickness may be 0.5 mm or more and 1.2 mm or less. According to this embodiment, it is possible to provide a porous metal body having a very thin thickness of 1.2 mm or less, but with a cell diameter in a direction perpendicular to the thickness direction exceeding 0.6 mm.

[0013] [4] The metal porous body is The porosity may be 94% or more and 99% or less. According to this embodiment, a metal porous body having a high porosity can be provided.

[0014] [5] The metal porous body is Weight per unit area: 100g / m 2 More than 250g / m 2 It may be the following. According to this embodiment, a very lightweight porous metal body can be provided. The term "weight per unit area" refers to the weight of the porous metal body relative to the area calculated from the outer shape of the porous metal body when viewed from above.

[0015] [6] A method for producing a metal porous body according to one embodiment of the present disclosure includes the steps of: A method for producing the metal porous body according to the above-mentioned [1], a step of subjecting a surface of a skeleton of a flat-plate-shaped resin porous body having a skeleton with a three-dimensional network structure to an electrically conductive treatment; Next, a step of plating a surface of the skeleton of the resin porous body with a metal; Next, removing the resin porous body to obtain a thick plate-shaped metal porous body; Next, cutting the thick plate-shaped porous metal body in a direction perpendicular to the thickness direction to obtain a porous metal body; The present invention relates to a method for producing a porous metal body comprising the steps of: According to this aspect, it is possible to provide a method capable of producing a flat plate-shaped porous metal body whose thickness is less than twice the cell diameter in a direction perpendicular to the thickness direction.

[0016] [7] The method for producing the metal porous body comprises: The method may further include a step of compressing, in a thickness direction, the porous metal body cut in a direction perpendicular to the thickness direction. According to this aspect, it is possible to provide a method for producing a porous metal body that can more stably maintain a flat plate shape.

[0017] [Details of the embodiment of the present disclosure] Specific examples of the metal porous body and the method for producing the metal porous body according to the embodiments of the present disclosure are described in more detail below. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0018] <Porous metal body> Hereinafter, each component of the porous metal body 10 according to the embodiment of the present disclosure will be described with reference to Figs.

[0019] The metal porous body 10 has a skeleton 11 of a three-dimensional network structure. The metal porous body 10 has a flat plate-like appearance as a whole. In FIG. 3, a structural unit of the three-dimensional network structure is likened to a regular dodecahedron to facilitate understanding of the three-dimensional network structure. The structural unit of the three-dimensional network structure includes one cell 12. As shown in FIG. 2 and FIG. 3, the cell 12 includes a pore 13, which is a three-dimensional space formed by the skeleton 11 of the three-dimensional network structure. When the structural unit of the three-dimensional network structure is likened to a regular dodecahedron, the cell diameter is determined by the longest diagonal of the regular dodecahedron.

[0020] The skeleton 11 is typically made of a metal or alloy film, and the inside of the skeleton 11 is hollow.

[0021] Examples of the metal constituting the skeleton 11 include nickel, aluminum, copper, and the like. Examples of the alloy constituting the skeleton 11 include those obtained by unavoidably or intentionally adding other metals to the metals to form an alloy. Examples of the alloy constituting the skeleton 11 include those obtained by alloying chromium, cobalt, tin, and the like with nickel (NiCr, NiCo, NiSn, and the like). The skeleton 11 may have a layered structure having two or more layers of metal or alloy films by plating the surface of the metal or alloy with another metal.

[0022] As described above, the metal porous body 10 has a three-dimensional network structure including the pores 13, which are three-dimensional spaces. Therefore, it can be clearly distinguished from two-dimensional network structures (such as punched metals and meshes) that have only planar pores. Furthermore, as shown in Figures 1 to 3, the metal porous body 10 has a skeleton 11 with a three-dimensional mesh structure, and therefore can be clearly distinguished from structures such as nonwoven fabrics formed by intertwining fibers. Since the metal porous body 10 has such a three-dimensional network structure, it has a plurality of pores that are connected from the surface to the inside.

[0023] The cell diameter in a direction perpendicular to the thickness direction (Z-axis direction in FIG. 1) of the metal porous body 10 (any direction in a plane parallel to the XY plane in FIG. 1) is calculated by observing at least 10 fields of view of the main surface of the metal porous body 10 using a microscope or the like, determining the average number (nc) of cells 12 per inch (25.4 mm = 25,400 μm), and using the following formula (3). Cell diameter in the direction perpendicular to the thickness direction = 25400 μm / nc Equation (3) The cell number shall be measured in accordance with the method for determining the cell number of soft foamed materials in JIS K6400-1:2004, Appendix 1 (reference) (excluding the provisions regarding the dimensions of the test specimen).

[0024] The cell diameter in the thickness direction of the porous metal body 10 is calculated by the following formula (4) or refers to the actual measurement of the cell diameter of a cross section of the porous metal body 10 in the thickness direction. Cell diameter in the thickness direction = Cell diameter in the direction perpendicular to the thickness direction × (1-compression ratio / 100) Formula (4) The compression ratio (%) in formula (4) can be obtained from the graph showing the relationship between porosity and compression ratio shown in Fig. 5. In Fig. 5, the vertical axis shows the porosity (%) of the metal porous body, and the horizontal axis shows the compression ratio (%) of the metal porous body. Furthermore, when the cell diameter of a cross section in the thickness direction of the porous metal body 10 is actually measured, the cell diameter in the thickness direction is measured as follows. First, the porous metal body 10 is embedded in a resin and cut in the thickness direction, and the cross section is observed. Next, ten circles of the cells 12 are arbitrarily drawn on the cross section, and the average of their cell diameters is calculated.

[0025] The porosity of the porous metal body 10 is defined by the following formula (5). Porosity (%) = [1-{Mp / (Vp×dp)}]×100 Equation (5) Mp: Mass of the porous metal body [g] Vp: Volume of the external shape of the metal porous body [cm 3 ] dp: density of the metal constituting the metal porous body [g / cm 3 ]

[0026] The thickness of the porous metal body 10 can be measured, for example, by a digital thickness gauge.

[0027] In formula (1), the cell diameter ratio means the degree to which the porous metal body 10 is compressed in the thickness direction after production. The cell diameter ratio may be 0.4 or more and 1.0 or less, preferably 0.5 or more and 1.0 or less, and more preferably 0.7 or more and 1.0 or less. Since the shape of the cells 12 can be modeled as a regular dodecahedron, when the metal porous body 10 is not compressed in the thickness direction by rolling or the like, there is no difference between the cell diameter in the thickness direction and the cell diameter in the direction perpendicular to the thickness direction. Therefore, when the cell diameter ratio is 1.0, it means that the metal porous body 10 is not compressed in the thickness direction after production. For this reason, for example, when the metal porous body 10 is used as a filter, it is preferable that the cell diameter ratio is close to 1.0 from the viewpoint of reducing pressure loss. Note that, when the cell diameter ratio is 0.4, it means that the compression rate in the thickness direction of the metal porous body 10 is 60%. The compression ratio of the porous metal body 10 is as shown in FIG. However, when the thicknesses of the metal porous body 10 before and after compression are known, it can also be calculated as compression ratio (%) = (1 - (thickness of metal porous body after compression / thickness of metal porous body before compression)) x 100.

[0028] In formula (2), "(thickness of porous metal body / cell diameter ratio)" means the thickness of the porous metal body 10 before being compressed in the thickness direction. As described above, the cell diameter ratio means the degree to which the porous metal body 10 is compressed in the thickness direction, and therefore the thickness of the porous metal body 10 before being compressed can be calculated by dividing the thickness of the porous metal body 10 after compression by the cell diameter ratio.

[0029] The cell diameter in the direction perpendicular to the thickness direction of the metal porous body 10 may be appropriately selected depending on the application of the metal porous body 10. As an example, the cell diameter in the direction perpendicular to the thickness direction is preferably more than 0.40 mm and not more than 1.70 mm, more preferably 0.5 mm or more and not more than 1.1 mm, and even more preferably 1.0 mm or less. Even if the cell diameter of the metal porous body 10 in the direction perpendicular to the thickness direction exceeds 0.40 mm, the thickness can be reduced to, for example, 1.0 mm or less or 0.5 mm or less. Therefore, for example, when the metal porous body 10 is used as a filter, it can be made thin without being too fine, and pressure loss can be reduced. In addition, when it is used as an electrode for a battery, it can improve the filling property of the active material, and when it is used as an electrode for a hydrogen generation device, it can improve the escape property of the gas generated at the electrode.

[0030] The thickness of the porous metal body 10 may be appropriately selected depending on the application of the porous metal body 10. As an example, the thickness of the porous metal body 10 is preferably 0.5 mm or more and 1.2 mm or less. Even if the metal porous body 10 has a thickness of 1.2 mm or less, the cell diameter in the direction perpendicular to the thickness direction can be made larger than 0.6 mm.

[0031] If the porous metal body 10 is not compressed in the thickness direction, it has a porosity that is the volume of the porous resin body used as a base material during production. The porosity of the porous metal body 10 changes according to the compression ratio, as shown in the graph in Fig. 4. For example, even if the porous metal body 10 is rolled so that the compression ratio is about 60%, the porosity of the porous metal body 10 remains greater than 90%. The porosity of the metal porous body 10 may be appropriately selected depending on the application of the metal porous body 10. As an example, the porosity of the metal porous body 10 is preferably 94% or more and 99% or less, more preferably 96% or more and 99% or less, and even more preferably 97% or more and 99% or less.

[0032] The basis weight of the porous metal body 10 may be appropriately selected depending on the application of the porous metal body 10. When a very lightweight porous metal body is required, for example, the basis weight of the porous metal body 10 may be 100 g / m 2 More than 250g / m 2 It is preferable that the weight per unit area is less than 1 / 2 of the weight per unit area of ​​the porous metal body before cutting, since the porous metal body 10 is obtained by cutting a porous metal body produced by a so-called plating method in a direction perpendicular to the thickness direction. Therefore, the porous metal body 10 can be easily provided as a very lightweight body. Of course, the porous metal body may have a high weight per unit area depending on the application of the porous metal body.

[0033] <Method of manufacturing porous metal body> The method for producing a metal porous body according to an embodiment of the present disclosure includes the steps of: conducting a surface of a skeleton of a flat resin porous body having a skeleton with a three-dimensional network structure; plating a metal on the surface of the skeleton of the resin porous body whose surface has been conducted to conduct the skeleton; removing the resin porous body after plating with the metal to obtain a metal porous body; and cutting the metal porous body obtained by removing the resin porous body in a direction perpendicular to the thickness direction. Each step is described in detail below.

[0034] (Process for making the surface of the skeleton of the resin porous body conductive) In this step, first, a plate-shaped resin porous body having a three-dimensional network structure skeleton (hereinafter, simply referred to as a "resin porous body") is prepared. As the resin porous body, a polyurethane resin, a melamine resin, or the like can be used. The resin porous body is used as a substrate when producing a metal porous body, and therefore the cell size, porosity, and thickness in the direction perpendicular to the thickness direction of the resin porous body may be set to be the same as those of the metal porous body to be produced. Next, the surface of the skeleton of the porous resin body is made conductive by applying a coating material containing a conductive powder such as carbon powder to the surface of the skeleton of the porous resin body. Examples of the carbon powder include amorphous carbon powder such as carbon black, and carbon powder such as graphite.

[0035] (Metal plating process) In this step, the porous resin body having a skeleton surface treated for electrical conductivity is used as a substrate for plating with a metal. Since the skeleton surface of the porous resin body has been treated for electrical conductivity, the metal plating is preferably performed by electroplating. The type of metal to be plated on the resin porous body is not particularly limited. The type of metal may be appropriately selected depending on the application of the metal porous body. For example, in the case of metals such as nickel, aluminum, or copper, electroplating can be performed by a known plating method. Two or more metals may be plated to form an alloy. For example, after plating with nickel, chromium, cobalt, tin, or the like can be plated to form an alloy with nickel. By plating with two or more metals, it is also possible to make the skeleton 11 of the metal porous body 10 have a laminated structure having two or more layers of metal or alloy films. The amount of metal plating is not particularly limited, and the amount of plating may be adjusted so that the porous metal body 10 to be manufactured has a preferred weight per unit area. The porous metal body 10 is obtained by removing the metal-plated resin porous body and cutting the porous metal body in a direction perpendicular to the thickness direction. Therefore, in the metal plating step, the amount of metal plating may be adjusted while keeping in mind that the weight per unit area of ​​the porous metal body 10 is 1 / 2 or less of the weight per unit area of ​​the porous metal body before cutting.

[0036] (Step of removing the resin porous body) This step is a step of removing the resin porous body used as a substrate from a structure having a metal or alloy film formed on the surface of the skeleton. The resin porous body can be removed, for example, by heat treatment at a temperature of about 600°C or more and 800°C or less, preferably about 600°C or more and 700°C or less, in an oxidizing atmosphere such as air. As a result, the resin porous body used as a substrate is burned and removed, and a metal porous body having a skeleton formed by the metal or alloy film is obtained. After removing the resin porous body, the oxidized metal or alloy may be reduced by heat treatment in a reducing atmosphere as necessary.

[0037] (Step of cutting the metal porous body) In this step, as shown in FIG. 5, the thick plate-shaped porous metal body 20 obtained by removing the porous resin body is cut in a direction perpendicular to the thickness direction (Z-axis direction in FIG. 1) to obtain the porous metal body 10 according to this embodiment. As described above, if the porous resin body used as the substrate does not have a thickness of at least twice the cell diameter in the direction perpendicular to the thickness direction, the skeleton of the three-dimensional network structure cannot be maintained and the structure is broken. In contrast, the present inventors have found that after plating with metal, the strength of the skeleton is increased, and it is possible to cut the porous metal body to a thickness less than twice the cell diameter in the direction perpendicular to the thickness direction. In this step, the thick plate-shaped porous metal body 20 may be cut so as to obtain the porous metal body 10 that satisfies the formula (2). The method of cutting the thick plate-shaped porous metal body 20 is not particularly limited, and for example, the main surfaces of the thick plate-shaped porous metal body 20 may be fixed together with a jig, and the space between them may be cut with a rotary blade or the like. In the example shown in Fig. 5, the thick plate-shaped porous metal body 20 is divided into two in a direction perpendicular to the thickness direction Z, but it may be divided into three or more. For example, if the thick plate-shaped porous metal body 20 is manufactured using a resin porous body having a thickness of about 2.0 mm, it is possible to divide it into three to obtain three porous metal bodies 10 each having a thickness of about 0.66 mm.

[0038] (Step of compressing the metal porous body) This step is a step of compressing the metal porous body 10 cut in a direction perpendicular to the thickness direction in the thickness direction. By compressing the metal porous body 10 in the thickness direction, the metal porous body 10 can be made to have a desired thickness, and can more stably maintain a flat plate shape, improving handleability. When the metal porous body 10 is compressed in the thickness direction, the cells 12 are crushed and the porosity is reduced. Therefore, the metal porous body 10 may be compressed to a thickness and porosity that are preferable depending on the intended use of the metal porous body 10, within a range that satisfies formula (1). EXAMPLES

[0039] The present disclosure will be described in more detail below with reference to examples. These examples are merely illustrative and the metal porous body and the like of the present disclosure are not limited to these.

[0040] [Example 1] A polyurethane sheet with a thickness of 2.0 mm was prepared as a resin porous body having a skeleton of a three-dimensional network structure. The porosity of the resin porous body was 96%. The cell diameter in the direction perpendicular to the thickness direction was 0.85 mm. The surface of the polyurethane sheet skeleton was made conductive by immersing the polyurethane sheet in a carbon suspension and drying it. The carbon suspension contained 25% graphite and carbon black, a resin binder, a penetrating agent, and a defoaming agent. The particle size of the carbon black was 0.5 μm. The surface of the polyurethane sheet skeleton is treated to make it conductive, and the surface weight is 500g / m 2 Nickel plating was performed using a Watts bath (nickel sulfate 300 g / L, nickel chloride 50 g / L, boric acid 30 g / L). After nickel plating, the polyurethane sheet used as the substrate was burned off by heating at 650°C for 10 minutes. After removing the polyurethane sheet, the substrate was further subjected to a heat treatment at 1000°C for 20 minutes in an H2:N2=3:1 atmosphere to reduce the oxidized nickel. The metal porous body after the reduction treatment was cut into two pieces in a direction perpendicular to the thickness direction Z, as shown in Fig. 5. This resulted in two pieces of metal porous body No. 1 with a thickness of 1.0 mm.

[0041] [Example 2] The porous metal body No. 1 produced in Example 1 was compressed in the thickness direction to a thickness of 0.5 mm to produce porous metal body No. 2.

[0042] [Example 3] A polyurethane sheet having a thickness of 3.0 mm, a cell diameter in a direction perpendicular to the thickness direction of 0.85 mm, and a porosity of 96% was used, and the metal porous body after reduction treatment was cut into three pieces in a direction perpendicular to the thickness direction Z. The other conditions were the same as in Example 1, and three pieces of metal porous body No. 3 were produced.

[0043] [Example 4] The porous metal body No. 3 produced in Example 3 was compressed in the thickness direction to a thickness of 0.5 mm to produce porous metal body No. 4.

[0044] [Example 5] A polyurethane sheet having a thickness of 2.0 mm, a cell diameter in the direction perpendicular to the thickness direction of 0.54 mm, and a porosity of 96% was used. Other conditions were the same as those in the manufacturing method described in Example 1, and a 1.0 mm thick porous metal body No. 5 was manufactured.

[0045] [Example 6] The porous metal body No. 5 produced in Example 5 was compressed in the thickness direction to a thickness of 0.5 mm to produce porous metal body No. 6.

[0046] [Example 7] A polyurethane sheet having a thickness of 2.5 mm, a cell diameter in the direction perpendicular to the thickness direction of 1.27 mm, and a porosity of 96% was used. Other conditions were the same as those in the manufacturing method described in Example 1, and a metal porous body having a thickness of about 1.2 mm was manufactured. This was then rolled to a thickness of 1.0 mm to manufacture metal porous body No. 7.

[0047] [Example 8] The porous metal body No. 7 produced in Example 7 was compressed in the thickness direction to a thickness of 0.5 mm to produce porous metal body No. 8.

[0048] [Comparative Example 1] In the manufacturing method described in Example 1, the metal porous body after reduction treatment was compressed to a thickness of 0.5 mm without being cut. The other conditions were the same as in Example 1 to manufacture metal porous body No. 9.

[0049] [Comparative Example 2] In Example 7, the metal porous body after reduction treatment was cut into three pieces in a direction perpendicular to the thickness direction Z. Three pieces of metal porous body No. 10 were produced under the same conditions as in Example 7. The thickness of metal porous body No. 10 was supposed to be about 0.8 mm. However, since metal porous body No. 10 exceeds the numerical range of formula (2), it is difficult to maintain the skeleton of the three-dimensional mesh structure, and even a slight impact during or after the cutting process causes the skeleton to break, and much of the three-dimensional mesh structure is destroyed. Table 1 shows various values ​​of the metal porous body that should have been obtained after the cutting process.

[0050] [Comparative Example 3] An attempt was made to prepare a polyurethane sheet with a thickness of 1.0 mm, a cell diameter in the direction perpendicular to the thickness direction of 0.54 mm, and a porosity of 96%. However, the polyurethane sheet was unable to maintain the framework of the three-dimensional mesh structure, and much of the three-dimensional mesh structure was destroyed.

[0051] Table 1 shows the measured and calculated values ​​for the structures of the metal porous bodies No. 1 to No. 10.

[0052] [Table 1]

[0053] As shown in Table 1, all of the metal porous bodies No. 1 to No. 8 were metal porous bodies in which the "cell diameter in the direction perpendicular to the thickness direction / (metal porous body thickness / cell diameter ratio)" was greater than 0.5, and the thickness was less than twice the cell diameter in the direction perpendicular to the thickness direction. Therefore, even if the thickness was about 0.5 mm, a high porosity could be maintained. In addition, it was also possible to produce a metal porous body with a cell diameter in the thickness direction of 0.50 mm or more even if the thickness was 1.0 mm or less. Metal porous bodies with high porosity and large cell diameters can be preferably used, for example, as filters with low pressure loss. According to the metal porous body according to the embodiment of the present disclosure, it is possible to select more preferable cell size, porosity, thickness, and basis weight depending on the application of the metal porous body. [Explanation of symbols]

[0054] 10. Porous metal 11 Skeleton 12 Cells 13 Stoma 20 Thick metal porous plate

Claims

1. A flat metal porous body having a skeleton of a three-dimensional mesh structure, Contains multiple cells, A metal porous body, wherein the ratio of the cell diameter in the thickness direction of the metal porous body to the cell diameter in the direction perpendicular to the thickness direction (cell diameter in the thickness direction / cell diameter in the direction perpendicular to the thickness direction) is defined as a cell diameter ratio, and the ratio satisfies the following formulas (1) and (2): 0.4≦cell diameter ratio≦1.0 Formula (1) 0.85≦cell diameter in a direction perpendicular to the thickness direction / (thickness of the metal porous body / cell diameter ratio)≦1.50 Formula (2)

2. The cell diameter of the metal porous body in a direction perpendicular to the thickness direction is more than 0.4 mm and 1.70 mm or less. The metal porous body according to claim 1.

3. The thickness is 0.5 mm or more and 1.2 mm or less. The metal porous body according to claim 1 or 2.

4. The porosity is 94% or more and 99% or less. The metal porous body according to any one of claims 1 to 3.

5. Weight per unit area: 100g / m ２ Above, 250g / m ２ Below is the The metal porous body according to any one of claims 1 to 4.

6. A method for producing the metal porous body according to claim 1, comprising the steps of: a step of subjecting a surface of a skeleton of a flat-plate-shaped resin porous body having a skeleton with a three-dimensional network structure to an electrically conductive treatment; Next, a step of plating a surface of the skeleton of the resin porous body with a metal; Next, a step of removing the resin porous body to obtain a thick plate-shaped metal porous body; Next, cutting the thick plate-shaped porous metal body in a direction perpendicular to the thickness direction to obtain a porous metal body; The present invention relates to a method for producing a porous metal body.

7. The method further includes a step of compressing the metal porous body cut in a direction perpendicular to the thickness direction in a thickness direction. The method for producing the metal porous body according to claim 6 .

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