JP4797800B2 - Composite porous body and method for producing the same - Google Patents

Description

  The present invention relates to a composite porous body used for a filter, a gas diffusion member, a heat radiating member, a water absorbing member, and the like, and a method for producing the same.

A sheet-like porous body having a three-dimensional network structure is applied to various uses such as a filter, a gas diffusion member, a heat radiating member, and a water absorbing member, and is provided in various apparatuses. Since this kind of porous body is generally low in strength and easily deformed, a frame member extending in the surface direction is provided on the side of the porous body, and the porous body and the frame member Is used as a composite porous body formed integrally. The frame member is formed of a thermosetting resin, a thermoplastic resin, a thermoplastic elastomer, or rubber as shown in Patent Document 1 below, or a rubber-like elastic material as shown in Patent Document 2 below. Is formed.
Japanese Patent Laying-Open No. 2005-029806 JP 2003-007328 A

However, in the conventional composite porous body, when the frame member is formed of a thermosetting resin or a thermoplastic resin, after the composite porous body is manufactured, the resin is already cured in the frame member for a long time. Then, the so-called post-curing, in which the curing further progresses and shrinks gradually, occurs, and a force directed toward the inside in the plane direction acts on the porous body, which may cause warping or cracking in the composite porous body.
Among these, since the thermoplastic resin has a large cure shrinkage rate from the melted state until it is cured, warping is likely to occur during the production of the composite porous body, and in such a state that a plurality of warped composite porous bodies are laminated. When placed, since a gap is generated between the composite porous bodies, when the pressing is performed in the stacking direction to close the gap, there is a possibility that the composite porous body may be cracked. There is. Furthermore, since the thermal expansion coefficient differs greatly between the thermoplastic resin frame member and the porous body, the occurrence of the warping and cracking is increased due to the difference in the thermal expansion coefficient when using the composite porous body. There is also a risk of causing it.
On the other hand, when the frame member is formed of a rubber-like elastic material such as rubber or thermoplastic elastomer, it is possible to prevent the composite porous body from warping or cracking, but the bonding strength with the porous body. It is difficult to ensure the necessary and sufficient amount, and the frame member may easily fall off from the side of the porous body. Further, since the rubber-like elastic material is easily embrittled with the passage of time, the bonding strength is likely to be greatly reduced in the process of using the composite porous body, and the life of the composite porous body may be shortened. . Furthermore, due to the low bonding strength, when forming a composite porous body by press-fitting rubber in a state where the porous body is placed in the cavity as an insert product, the mold is opened after this formation and the composite porous When the material is taken out, if the frame member is pulled by the mold, there is a possibility that it will easily come off the porous material.

  The present invention has been made in view of the above problems, and it is possible to prevent the composite porous body from being warped or cracked while maintaining the necessary and sufficient bonding strength between the frame member and the porous body. An object is to provide a mass and a method for producing the same.

  In order to solve such problems and achieve the above object, the composite porous body of the present invention includes a sheet-like porous body having a three-dimensional network structure and at least one of the side portions of the porous body. And a frame member extending in the surface direction from the portion, the frame member covering the buffer portion formed of a rubber-like elastic material and the buffer portion from the outer peripheral side. The buffer portion is bonded to a part of the side portion of the porous body or a plurality of locations spaced in the direction along the outer peripheral edge, and covers the buffer portion from the outer peripheral side in the resin portion. A portion connected to the portion in a direction along the outer peripheral edge of the porous body is joined to a side portion of the porous body.

According to this invention, since the frame member includes the buffer portion and the resin portion, the resin portion is post-cured and contracted with the passage of time after the production of the composite porous body, and the surface direction of the porous body Even when an inward force is applied, at least a part of this force can be received by the buffer portion and absorbed, and the composite porous body can be prevented from warping or cracking. . And since the part which continues in the direction along the outer periphery of a porous body in the part which covers a buffer part from the outer peripheral part side in the resin part is joined to the side part of a porous body, a buffer part and a porous body Even if the bonding strength with the side portion is low, this bonding strength can be reinforced by the bonding strength between the resin portion and the porous body. Furthermore, even if the buffer portion gradually becomes brittle in the process of using the composite porous body and the bonding strength between the buffer portion and the side of the porous body is reduced, the strength is also reduced between the resin portion and the porous body. It can be reinforced by the bonding strength.
Furthermore, since the resin part is joined not to the entire area of the part where the frame member is joined on the side part of the porous body, but to the part excluding the part where the buffer part is joined in this part, It becomes possible to minimize the joint part with the resin part in the side part, and the shrinkage when the resin part is cured from the molten state and the shrinkage when post-curing is applied to the porous body in the surface direction. The force exerted towards the can be suppressed.
As described above, it is possible to prevent the composite porous body from being warped or cracked while maintaining the necessary and sufficient bonding strength between the frame member and the porous body.

  Here, a plurality of buffer portions are provided on the outer peripheral edge of the porous body at intervals in the circumferential direction, and the resin portion covers the buffer portion from the outer peripheral portion side and fills the space between the buffer portions. , It may extend over the entire circumference of the porous body.

  Further, the buffer portion may protrude outward in the thickness direction with respect to the surfaces of the porous body and the resin portion.

  In this case, for example, in a laminated body in which a plurality of composite porous bodies are laminated such as a gas diffusion member of a fuel cell, a fluid such as gas or fuel is flowed toward the surface of the porous body. When the fluid is passed through in the stacking direction of the laminated body, the fluid leaks from between these composite porous bodies by bringing the buffer parts of the composite porous bodies adjacent in the stacking direction into close contact with each other. It is possible to prevent such problems, and the handling property can be improved, for example, the sealing property can be improved.

  Further, in the method for producing a composite porous body of the present invention, a sheet-like porous body having a three-dimensional network structure and a frame member extending in a plane direction from at least a part of a side portion of the porous body are integrated. A method for producing a composite porous body, wherein the porous body is used as an insert part, and a part of the porous body, or a plurality of locations spaced apart in the direction along the outer peripheral edge at the side of the porous body. With the gap in the surface direction of this porous body, insert molding was performed to injection-mold the resin portion extending in the surface direction from the portion excluding this part or a plurality of portions in the side portion. Later, a rubber-like elastic material is press-fitted into the gap by transfer molding, so that the resin portion covers the outer peripheral portion side, and the buffer is joined to the part or a plurality of locations on the side portion of the porous body. It is formed and to form a frame member having a the buffer portion and the resin portion and forming a composite porous body.

  In this case, in addition to being able to reliably form the composite porous body that exhibits the above-described effects, after forming the resin portion, a rubber-like elastic material is pressed into the gap to form the buffer portion. Therefore, even when the buffer part is pulled to the mold when the mold is opened after the buffer part is formed and the composite porous body is taken out of the mold, the bonding strength between the resin part and the side of the porous body Therefore, it is possible to prevent the buffer portion from being detached from the side portion of the porous body.

  ADVANTAGE OF THE INVENTION According to this invention, it can prevent that a composite porous body produces a curvature and a crack, keeping the joining strength of a frame member and a porous body necessary and sufficient.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the composite porous body 10 of the present invention includes a sheet-like porous body 11 and a frame member 12 that extends in the plane direction from at least a part of the side of the porous body 11. The formed thin plate is rectangular in plan view.

The porous body 11 is a rectangular thin plate having a three-dimensional network structure, and has air permeability and water absorption due to pores opened in the side portions in each direction, and is lightweight and has a large surface area. have. The porous body 11 may be made of metal, crystalline carbon, carbonaceous material containing amorphous carbon that is not crystalline, or a metal cloth.
Moreover, in this embodiment, the side part of the porous body 11 is comprised by the four flat plate parts 11b, and comprises the outer periphery of the porous body 11 made into the planar view rectangle by these flat plate parts 11b. . That is, the side part of the porous body 11 is configured such that end portions in the length direction of the flat plate parts 11b adjacent to each other in the direction along the outer peripheral edge of the porous body 11 are connected to form a ridge line.

  The frame member 12 has a thin plate shape, and is joined to the side of the porous body 11 with no difference in level with respect to the front and back surfaces of the porous body 11 with the same thickness as the porous body 11. The composite porous body 10 in which the porous body 11 and the frame member 12 are integrally formed in this manner is a single thin plate member as a whole, and the frame member 12 is fixed or sandwiched among them. A fluid such as gas or fuel is attached to various devices and used as a filter, a water absorbing member, a heat radiating body or the like, or a laminated body in which a plurality of composite porous bodies 10 are laminated in various devices. It is used by flowing toward the surface of the porous body 11 and passing in the stacking direction of the stack.

Here, the porous body 11 can be manufactured by various methods. For example, the porous body 11 can be manufactured by baking a green sheet obtained by thinly forming and drying a slurry containing metal powder.
The slurry is formed by mixing, for example, a metal powder such as SUS316L, an organic binder (for example, methylcellulose or hydroxypropylmethylcellulose), and a solvent (water). In addition to this, a foaming agent (for example, carbon) that is sublimated or vaporized by heat treatment. A water-insoluble hydrocarbon-based organic solvent (e.g., neopentane, hexane, heptane) of 5 to 8 or an antifoaming agent (ethanol) is added as necessary.

In the green sheet manufacturing apparatus, first, slurry is supplied from a hopper in which the slurry is stored onto a carrier sheet conveyed by a roller. Next, the slurry on the carrier sheet is stretched between the moving carrier sheet and the doctor blade and formed into a required thickness.
The formed slurry is further conveyed by a carrier sheet and passes through a heating furnace. And it dries in a heating furnace, and the green sheet of the state in which SUS316L powder was joined by the organic binder is formed.
In addition, when a foaming agent is included in the slurry, the slurry in a state of being extended on the carrier sheet is heat-treated in a high-humidity atmosphere before drying to foam the foaming agent to obtain a foamed slurry, and then dried. Processing is performed to form a green sheet.
This green sheet is removed from the carrier sheet, and then degreased and fired in a vacuum furnace, whereby the organic binder is removed and the porous body 11 is obtained by sintering metal powders.

  And in this embodiment, the frame member 12 is provided with the buffer part 13 formed with the rubber-like elastic material, and the resin part 14 which covers this buffer part 13 from the outer peripheral part side. Among these, the buffer part 13 is joined over the whole area of the thickness direction in the part of the side part of the porous body 11, or several places spaced apart in the direction along the outer periphery. Further, a portion of the resin portion 14 that covers the buffer portion 13 from the outer peripheral side thereof in a direction along the outer peripheral edge of the porous body 11 is joined to the side portion of the porous body 11.

In the illustrated example, a plurality of buffer portions 13 are provided on the side portion of the porous body 11 at intervals in the direction along the outer peripheral edge, and the resin portion 14 covers the buffer portion 13 from the outer peripheral side. And it extends over the perimeter of this porous body 11 so that between the buffer parts 13 may be filled, and it is joined to the part between buffer parts 13 in the side part of the porous body 11. FIG.
Furthermore, the buffer part 13 is joined to the corner part 11a hung from the ridge line formed by the adjacent flat plate part 11b in the direction along the outer peripheral edge of the porous body 11 to the end part connected to the ridge line in each flat plate part 11b. ing. In the present embodiment, as shown in FIG. 2 and FIG. 3, the thicknesses of the porous body 11, the buffer portion 13, and the resin portion 14 are made equal, and the front and back surfaces thereof substantially coincide with each other without a step. ing.

Here, as the buffer portion 13, a thermosetting resin having a rubber-like elasticity such as a silicone resin, a thermoplastic resin having a rubber-like elasticity such as an ethylene / vinyl acetate (EVA) copolymer resin, a polybutadiene resin, or a thermoplastic polyurethane. Among elastomers and other thermoplastic elastomers (TPE), one kind may be used alone, or two or more kinds may be used in combination. Among these, from the viewpoint of chemical resistance and heat resistance, it is desirable to employ a silicone resin or an olefin-based thermoplastic elastomer. Further, when the composite porous body 10 is used as, for example, a gas diffusion member of a fuel cell, a material that can withstand the usage environment such as temperature, for example, a fluorine-based thermoplastic elastomer or an engineering plastic-based thermoplastic elastomer is adopted. can do.
Instead of the above materials, for example, natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, chloroprene rubber, acrylonitrile butadiene rubber or other diene rubber, or butyl rubber, ethylene propylene rubber, urethane rubber, silicone rubber, chlorosulfone Although non-diene rubbers such as fluorinated rubber, chlorinated polyethylene, acrylic rubber, epichlorohydrin rubber, or fluororubber can be employed, when the composite porous body 10 is used, for example, as a gas diffusion member of a fuel cell For example, it is desirable to employ a material that can withstand the use environment such as temperature, for example, fluorine rubber, ethylene propylene rubber, or silicone rubber.

  The resin part 14 includes an ionomer resin, an ethylene / ethyl acrylate copolymer resin, an acrylonitrile / styrene / acrylic rubber copolymer (ASA) resin, an acrylonitrile / chlorinated polyethylene / styrene copolymer (ACS) resin, and an ethylene / vinyl alcohol copolymer. Polymer resin, acrylonitrile / butadiene / styrene copolymer (ABS) resin, fluorine resin, polyamide resin, polyacrylate resin, liquid crystal polymer, polyether ether ketone (PEEK) resin, polyether sulfone (PES) resin, polyethylene terephthalate, polycarbonate Resin, phenylene ether resin, polyphenylene sulfide (PPS) resin, polybutylene terephthalate (PBT), polypropylene resin, polymethylpentene, syndiotactic polices Ren (SPS), polycycloolefin (COP), may be employed a cyclic olefin copolymer (COC) thermoplastic resin such as or epoxy resin, phenol resin, polyimide resin, a thermosetting resin such as melamine resin. Further, when the composite porous body 10 is used as, for example, a gas diffusion member of a fuel cell, a resin material having a deflection temperature under load having an upper limit temperature of 120 ° C. or more in the fuel cell operating temperature range is selected from the above materials. Among these resin materials, a resin material, more preferably a crystalline resin, excellent in chemical resistance, and low in gas permeability, such as fluororesin, polyamide resin, liquid crystal polymer, polyether ether ketone (PEEK) ) Resin, polyethylene terephthalate, polyphenylene sulfide (PPS) resin, polybutylene terephthalate (PBT), and polypropylene resin can be employed, and polyphenylene sulfide (PPS) resin and polypropylene resin are more preferably employed than these resin materials. be able to.

Next, a method for forming the frame member 12 on the side portion of the porous body 11 will be described.
First, the porous body 11 is disposed as an insert part in a cavity formed between a pair of molds, and the molten resin injected from the runner through the gate is filled into the cavity. At this time, in the state in which a gap is provided in the surface direction of the porous body 11 over the entire area in the thickness direction between the corner 11a of the porous body 11 and the corner at the side of the porous body 11 Insert molding is performed in which a portion excluding 11a, that is, the resin portion 14 extending in the surface direction from the central portion in the length direction of the flat plate portion 11b is injection-molded.

And the resin part 14 is joined to the side part of the porous body 11, the intermediate member in which the resin part 14 and the porous body 11 are integrally formed is taken out from the mold, and another mold different from the mold is used. By placing the rubber-like elastic material into the gap by transfer molding, it is covered from the outer peripheral side by the resin part 14 and joined to the corner part 11a at the side part of the porous body 11 by transfer molding. The buffer part 13 is formed.
As described above, the composite porous body 10 is formed by forming and joining the frame member 12 including the buffer portion 13 and the resin portion 14 on the side portion of the porous body 11.

  As described above, according to the composite porous body 10 of the present embodiment, since the frame member 12 includes the buffer portion 13 and the resin portion 14, the time passes after the composite porous body 10 is manufactured. Even when the resin portion 14 is post-cured and contracts and a force directed toward the inside in the surface direction of the porous body 11 acts, at least a part of this force can be received by the buffer portion 13 and absorbed. Therefore, warpage and cracks can be suppressed in the composite porous body 10.

  And since the part which continues in the direction along the outer periphery of the porous body 11 in the part which covers the buffer part 13 from the outer peripheral part side in the resin part 14 is joined to the side part of the porous body 11, a buffer part Even if the bonding strength between the side portion 13 and the porous body 11 is low, the bonding strength can be reinforced by the bonding strength between the resin portion 14 and the porous body 11. Furthermore, even if the buffer portion 13 gradually becomes brittle in the process of using the composite porous body 10 and the bonding strength between the buffer portion 13 and the side portion of the porous body 11 decreases, the strength of the buffer portion 13 and the resin portion 14 is reduced. It can be reinforced by the bonding strength with the porous body 11.

Furthermore, the resin part 14 is joined not only to the entire circumference where the frame member 12 is joined at the side part of the porous body 11, but only to the central part in the longitudinal direction of the flat plate part 11b excluding the corner part 11a. Therefore, it becomes possible to minimize the joint part with the resin part 14 in the side part of the porous body 11, and the shrinkage at the time of hardening from the molten state of the resin part 14 until it hardens, or the shrinkage at the time of post-curing. The force exerted on the porous body 11 toward the inner side in the surface direction can be suppressed.
As described above, it is possible to prevent the composite porous body 10 from being warped or cracked while maintaining the necessary and sufficient bonding strength between the frame member 12 and the porous body 11.

  In addition, according to the method for producing a composite porous body of the present embodiment, in addition to being able to reliably form the composite porous body 10 having the above-described effects, after forming the resin portion 14, Since the rubber-like elastic material is press-fitted into the gap to form the buffer portion 13, when the composite porous body 10 is taken out from the mold by opening the mold after forming the buffer portion 13, the buffer portion 13 becomes the mold. Even if it is pulled, the buffer portion 13 can be prevented from coming off from the side of the porous body 11 due to the bonding strength between the resin portion 14 and the porous body 11.

The various shapes and combinations of the constituent members shown in the above embodiments are merely examples, and various modifications can be made based on design requirements without departing from the spirit of the present invention.
For example, in the embodiment, the resin portion 14 is extended over the entire circumference of the side portion of the porous body 11 and joined to a portion of the side portion excluding the corner portion 11a. A buffer part 13 joined to a part of the side part of the porous body 11 or a plurality of places spaced in the direction along the outer peripheral edge, and a resin part 14 covering the buffer part 13 from the outer peripheral side. If the part which continues in the direction along the outer periphery of the porous body 11 is joined to the part which covers the buffer part 13 from the outer peripheral part side in this resin part 14 in the direction along the outer periphery, the said implementation will be carried out. It is not limited to form.

  For example, as shown in FIG. 4, in the side part of the porous body 11, each of the pair of flat plate parts 11 b facing each other in the surface direction is joined to the buffer part 13 separately at both ends in the length direction, The resin portion 14 extending over the entire length direction of the flat plate portion 11b to which the buffer portions 13 are joined so as to cover these buffer portions 13 from the outer peripheral side is provided in the length direction of the flat plate portion 11b. You may join to the part except both ends.

  In place of this, on the side of the porous body 11, a pair of flat plate portions 11b opposed to each other in the surface direction are respectively joined to the buffer portion 13 at the center in the length direction, and these buffer portions are joined. The resin portion 14 extending over the entire length direction of the flat plate portion 11b to which the buffer portion 13 is bonded so as to cover the portion 13 from the outer peripheral portion side is excluded from the central portion in the length direction of the flat plate portion 11b. You may join to the part.

  Furthermore, instead of this, in the side portion of the porous body 11, each of the pair of flat plate portions 11 b facing each other in the plane direction is separately provided in two intermediate portions excluding the central portion in the length direction and both end portions. The buffer portion 13 is joined, and the resin portion 14 extending over the entire length direction of the flat plate portion 11b to which the buffer portion 13 is joined is covered with the flat plate so as to cover the buffer portion 13 from the outer peripheral side. You may join to the part except the two said intermediate parts in the part 11b.

  In the above-described embodiment, the frame member 12 is configured to be joined to the side of the porous body 11 with almost the same thickness as the porous body 11 without a step. These surfaces may protrude outward in the thickness direction with respect to the surfaces of the porous body 11 and the resin portion 14. For example, as shown in FIG. 5, the buffer portion 13 is thicker than the resin portion 14 and the porous body 11, and the front and back surfaces thereof are respectively opposite to the front and back surfaces of the resin portion 14 and the porous body 11. Alternatively, a configuration that protrudes outward in the thickness direction may be employed.

In this case, for example, in a laminate in which a plurality of composite porous bodies 10 such as gas diffusion members of a fuel cell are laminated and arranged, a fluid such as gas or fuel is flowed toward the surface of the porous body 11, When the fluid is used by passing in the stacking direction of the laminate, the buffer portions 13 of the composite porous bodies 10 that are adjacent in the stacking direction are brought into close contact with each other, so that the fluid flows between the composite porous bodies 10. Can be prevented from leaking, and the handling property can be improved, for example, the sealing property can be improved.
In addition, even if the thickness of the buffer part 13 and the resin part 14 is equivalent if the surface or back surface of the buffer part 13 and the side part of the porous body 11 are not joined by the resin part 14, the thickness of the buffer part 13 is the same. The direction may be thinner than the thickness of the resin portion 14.

Moreover, in the said embodiment, although the structure in which only the porous body 11 was provided as the composite porous body 10 was shown, it replaces with this and several porous bodies 11 are spaced apart in the surface direction, and several. The resin portions 14 are filled between the porous bodies 11 in a state where the buffer portions 13 are joined to at least a part of the side portions of the porous bodies 11 and the buffer portions 13 are filled with the resin portions 14. May be covered from the outer peripheral portion side, and the resin portion 14 may be joined to a portion of the side portion where the buffer portion 13 is not joined.
Furthermore, in the said embodiment, the planar view rectangular porous body 11 was shown, However For example, a circular shape or a polygon may be sufficient.

  It is possible to prevent the composite porous body from being warped or cracked while maintaining a sufficient bonding strength between the frame member and the porous body.

It is a top view which shows the composite porous body shown as 1st Embodiment of this invention. It is AA arrow sectional drawing of the composite porous body shown in FIG. It is 1st Embodiment of the BB arrow sectional drawing of the composite porous body shown in FIG. It is a top view which shows the composite porous body shown as 2nd Embodiment of this invention. It is 2nd Embodiment of the BB arrow sectional drawing of the composite porous body shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Composite porous body 11 Porous body 12 Frame member 13 Buffer part 14 Resin part

Claims (4)

A composite porous body in which a sheet-like porous body having a three-dimensional network structure and a frame member extending in a plane direction from at least a part of a side portion of the porous body are integrally formed,
The frame member includes a buffer portion formed of a rubber-like elastic material and a resin portion that covers the buffer portion from the outer peripheral side, and the buffer portion is formed on a part of the side of the porous body or on the outer periphery. Bonded to a plurality of locations spaced apart in the direction along, and the portion of the resin portion that covers the buffer portion from its outer peripheral side in the direction along the outer peripheral edge of the porous body is the side of the porous body A composite porous body characterized by being bonded. The composite porous body according to claim 1, wherein
A plurality of buffer parts are provided at intervals in the direction along the outer peripheral edge on the side part of the porous body, and the resin part covers the buffer part from the outer peripheral part side and fills the space between the buffer parts. Furthermore, the composite porous body is characterized by extending over the entire circumference of the porous body. In the composite porous body according to claim 1 or 2,
The composite porous body, wherein the buffer part protrudes outward in the thickness direction with respect to the surfaces of the porous body and the resin part. A method for producing a composite porous body in which a sheet-like porous body having a three-dimensional network structure and a frame member extending in a plane direction from at least a part of a side portion of the porous body are integrally formed. ,
Using the porous body as an insert part, gaps are formed in the surface direction of the porous body between a part of the porous body or a plurality of portions spaced in the direction along the outer peripheral edge. In a state of being provided, after performing insert molding for injection molding a resin portion extending in the surface direction from a portion excluding this part or a plurality of places in the side portion,
By transfer molding, a rubber-like elastic material is press-fitted into the gap to form a buffer portion that is covered from the outer peripheral portion side by the resin portion and joined to the part or a plurality of locations on the side portion of the porous body. A method for producing a composite porous body, comprising forming a composite porous body by forming a frame member having the buffer portion and the resin portion.

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