JP2011233474A - Seal structure for fuel cell and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately control permeation of a molding material in manufacturing of a seal structure for a fuel cell molded together with a gasket through an impregnated part of the gasket molding material on a porous plate 10 with high stiffness.SOLUTION: A porous plate 10 is provided on a thin plate with: a gasket molding region 11 having a myriad of fine penetration air gaps; a gas flow region 12 having a myriad of fine penetration air gaps; and a permeation control region 13 which extends along between the both regions 11 and 12 and does not have fine penetration air gaps. By setting the porous plate 10 in a molding 30 for molding sealing, an inner surface of the molding 30 is closely contacted with the permeation control region 13; a liquid molding material is filled in a cavity 33 for gasket molding defined between the gasket molding region 11 and the inner surface of the molding 30; and a part of the molding material is permeated to the gasket molding region 11 and hardened.

Description

  The present invention relates to a fuel cell sealing structure in which a porous gas diffusion layer in a fuel cell is integrally provided with a gasket for sealing a flow path formed in each fuel cell, and a method for manufacturing the same. .

  As shown in FIG. 8, the fuel cell is laminated on both sides of a membrane-electrode assembly (MEA) having a pair of electrode layers on both sides of an electrolyte membrane (ion exchange membrane) and its thickness direction. A power generation body made of a porous gas diffusion layer (GDL) and a separator made of carbon or metal are alternately arranged and laminated, and a fuel gas or an oxidant gas is passed through the gas diffusion layer. -It is common to form a large number of grooves in the separator for distribution to the electrode assembly. In recent years, instead of forming a groove in the separator, a porous second gas diffusion layer is sandwiched between the power generator and the separator, and the second gas diffusion layer is used as a flow path for fuel gas or oxidizing gas. It is also known. FIG. 8 is an explanatory view showing a part of such a fuel cell.

  That is, the fuel cell shown in FIG. 8 includes a membrane-electrode assembly 111 having a pair of electrode layers on both surfaces of an electrolyte membrane, and a first gas diffusion layer 112 made of a porous body laminated on both sides in the thickness direction. Single cells 100 each including a power generation body 110 and a second gas diffusion layer (hereinafter referred to as a gas diffusion layer) 120 made of a porous body stacked on both sides in the thickness direction are alternately stacked with the separator 200 and stacked. It is comprised by doing. The gas diffusion layer 120 functions as a gas distribution means for distributing a fuel gas or an oxidizing gas for power generation in the power generator 110.

  In a fuel cell, it is necessary to seal fuel gas, oxidizing gas, water generated by the reaction, surplus gas, and the like. Therefore, the gas diffusion layer 120 is provided with a gasket 121 made of a rubber-based material and is in close contact with the separator 200. The gasket 121 is formed by curing a part of a rubber-based liquid molding material so as to permeate the end portion of the gas diffusion layer 120 at the time of molding. Therefore, the impregnation formed in the gas diffusion layer 120 is performed. The structure is integrally bonded to the gas diffusion layer 120 via the portion 122.

  However, since the porosity of the gas diffusion layer 120 made of a porous material varies, the fuel cell shown in FIG. 8 does not apply to the gas diffusion layer 120 when the gasket 121 is molded using a liquid molding material. It is difficult to properly limit the penetration of the molding material. For this reason, even if the filling pressure and viscosity of the molding material are kept constant, depending on the porosity of the gas diffusion layer 120, the area of the impregnation portion 122 becomes larger than necessary, and the gas flow in the gas diffusion layer 120 is correspondingly increased. There is a possibility that the power generation area in the power generation body 110 may be narrowed.

  Therefore, conventionally, a method as shown in FIG. 9 is known in order to appropriately limit the region of the impregnated portion 122 when the gasket 121 is formed integrally with the gas diffusion layer 120. That is, in this method, when the porous plate 120 ′ to be the gas diffusion layer 120 is set and clamped in the mold 300, the pressing protrusion 301 formed on the inner surface of the mold 300 is used to press the porous plate 120 ′. By compressing a part, a narrowed portion 120a having a reduced porosity is formed along a position adjacent to the end of the porous plate 120 ′.

  Next, a gasket molding cavity 302 defined between the end of the porous plate 120 ′ and the inner surface of the mold 300 is filled with a liquid molding material through the material injection gate 303, and a part thereof 8 is infiltrated into the end of the porous plate 120 ′, and the molding material is crosslinked and cured in this state, whereby the gasket 121 shown in FIG. 8 is formed integrally with the porous plate 120 ′ (gas diffusion layer 120). Is done. Since the porosity of the narrowed portion 120a formed in advance on the porous plate 120 ′ is reduced by compression and the molding material is less likely to penetrate, the penetration region of the molding material (impregnation portion 122 shown in FIG. 8). Can be effectively prevented from becoming larger than necessary (for example, see Patent Document 1 below).

JP 2007-26847 A

  However, when a highly rigid material such as a metal porous body is used as the porous plate 120 ′, the pressing protrusion 301 formed on the inner surface of the mold 300 as in the conventional method is caused by clamping. The formation of the narrowed portion 120a is difficult, so that the penetration of the molding material into the porous plate 120 ′ cannot be reliably restricted by the narrowed portion 120a, and as shown in FIG. There was a problem that spread more than necessary.

  In particular, the penetration of the molding material from the gasket molding cavity 302 into the porous plate 120 ′ spreads around the injection gates 303 provided at appropriate intervals along the extension direction of the cavity 302. In the region 122, the planar shape is formed in a ripple shape, and the variation becomes large, which may adversely affect the variation in power generation performance.

  The present invention has been made in view of the above points, and its technical problem is for a fuel cell in which a gasket is integrally formed on a highly rigid porous plate via an impregnation portion of a gasket molding material. In the seal structure, the penetration of the molding material is appropriately limited.

  As a means for effectively solving the technical problem described above, a manufacturing method of a fuel cell seal structure according to the invention of claim 1 includes: a thin plate, a gasket molding region having innumerable fine through-holes; A porous plate is formed by forming a gas flow region having fine through-holes and a permeation-restricted region extending between both of the regions without the fine through-holes, and setting the porous plate in a mold Then, the inner surface of the mold is brought into close contact with the permeation restriction region by clamping the mold, and a liquid molding material is filled in the gasket molding cavity defined between the gasket molding region and the inner surface of the mold. At the same time, a part thereof penetrates into the gasket forming region and is cured.

  In this manufacturing method, the liquid molding material filled in the gasket molding cavity becomes a gasket by curing, and a part of this molding material is innumerable fine penetration formed in the gasket molding region of the porous plate. The portion cured in the state of permeation into the voids is an impregnation portion continuous with the gasket, and the gas flow region of the porous plate is a gas flow path in the fuel cell by countless fine through voids, The permeation restricted area of the porous plate is to prevent unnecessary expansion of the impregnated part by blocking the penetration of the liquid molding material from the gasket molding cavity into the gas flow area by clamping with a mold. is there.

  A method for producing a fuel cell seal structure according to a second aspect of the present invention is the method according to the first aspect, wherein an infinite number of fine through-holes in the gasket molding region and the gas flow region are formed by etching, and the permeation restricted region. Is formed as a non-etched region by an etching mask pattern.

  According to a third aspect of the present invention, there is provided a method for producing a fuel cell seal structure according to the first aspect, wherein the porous plate is laminated with another porous plate and filled in a gasket molding cavity. The material is allowed to permeate into a region corresponding to the gasket forming region in the other porous plate.

  According to a fourth aspect of the present invention, there is provided a method for producing a fuel cell sealing structure according to the first aspect, wherein the porous plate is made of metal.

  A fuel cell seal structure according to a fifth aspect of the present invention is manufactured by the method according to any one of the first to fourth aspects, and is formed integrally with the porous plate and the porous plate. An impregnated portion in which a portion of the material of the gasket is joined to an infinite number of fine through gaps, and a gas flow region having an infinite number of fine through gaps. The penetration limiting region extends between the impregnation portion and the gas flow region and does not include the fine through-holes.

  According to the method for manufacturing a fuel cell seal structure according to the first aspect of the present invention, the gasket is firmly joined to the porous plate via the impregnation portion, and the molding material penetrates into the gas flow region of the porous plate. Is blocked by the permeation restriction region where no fine through-holes exist, so that it is possible to surely prevent the gas flow region and thus the power generation region from being narrowed due to the expansion of the impregnation part. Therefore, stable power generation performance can be obtained.

  According to the method of manufacturing a fuel cell seal structure according to the invention of claim 2, in addition to the effect of claim 1, in the process of producing a porous plate by etching, a gasket forming region having innumerable fine through-holes and A gas distribution region and a permeation restriction region that does not have a fine through gap can be formed simultaneously.

  According to the manufacturing method of the fuel cell seal structure according to the invention of claim 3, in addition to the effect of claim 1, the other porous plate is also integrated with the porous plate via the gasket. The number of parts can be reduced.

  According to the method for manufacturing a fuel cell seal structure according to the invention of claim 4, since the porous plate made of metal has high rigidity, it is possible to effectively prevent distortion and damage when laminated as a fuel cell. In addition, since the rigidity is high, the effect according to claim 1 can be realized in spite of difficulty in partial compression for restricting the penetration of the molding material when the mold is clamped.

  According to the fuel cell seal structure of the invention of claim 5, the gasket and the porous plate are firmly joined to each other, and there is no gas permeation leakage from the porous plate, and the impregnation portion is unnecessary. Therefore, the required power generation area can be secured.

It is a top view which shows the 1st form of the sealing structure for fuel cells which concerns on this invention. It is the II-II sectional view taken on the line of FIG. FIG. 3 is an explanatory diagram showing a process of manufacturing a porous plate in the first embodiment of the method for producing a fuel cell seal structure according to the present invention for obtaining the fuel cell seal structure of FIGS. 1 and 2. . It is explanatory drawing which shows the process of shape | molding a gasket in the 1st form of the manufacturing method of the sealing structure for fuel cells which concerns on this invention. It is explanatory drawing which shows the example of the assembly to the fuel cell of the 1st form of the sealing structure for fuel cells which concerns on this invention. It is explanatory drawing which shows the example of the assembly to the fuel cell of the 2nd form of the sealing structure for fuel cells which concerns on this invention. FIG. 7 is an explanatory diagram showing a step of molding a gasket in the second embodiment of the method for producing a fuel cell seal structure according to the present invention for obtaining the fuel cell seal structure of FIG. 6. It is explanatory drawing which shows the example of the assembly to the fuel cell of the sealing structure for fuel cells which concerns on a prior art. FIG. 5 is an explanatory view showing a state in which a laminated body of a power generator and a second gas diffusion layer is set in a mold and clamped in a preferred embodiment of a method for manufacturing a fuel cell seal structure according to the prior art. It is explanatory drawing which shows the state which the impregnation part expanded in the prior art.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a first embodiment of a fuel cell seal structure 1 according to the present invention, and FIG. 2 is a cross-sectional view taken along the line II-II in FIG.

  In the fuel cell seal structure 1 shown in FIGS. 1 and 2, reference numeral 10 is a mesh-like porous plate used as a gas diffusion layer in a fuel cell, and is made of a metal having conductivity and high rigidity. A gasket 20 made of a rubber-like elastic material (rubber material or synthetic resin material having rubber-like elasticity) is integrally formed on the porous plate 10 along an outer peripheral edge or an opening edge (not shown). .

  The porous plate 10 includes a fine mesh-shaped gasket forming region 11 having an infinite number of fine through voids, a fine mesh-shaped gas flow region 12 having an infinite number of fine through voids, and both of these regions 11 and 12. The gasket forming region 11 has a permeation restricting region 13 having an appropriate width extending along the side and having no fine through-holes, and a part of the rubber-like elastic material of the gasket 20 penetrates and cures in the fine through-holes. Therefore, the gasket 20 is integrally joined to the porous plate 10 via the impregnation portion 20a.

  The gasket 20 includes a base portion 21 formed so as to cover the gasket molding region 11 in the porous plate 10, a main lip 22 raised from one side thereof, and a secondary lip raised from the opposite side and having a smaller cross section than the main lip 22. As will be described later, the fuel gas and the oxidant gas supplied to the membrane-electrode composite are brought into contact with a separator or membrane-electrode composite (not shown) in a compressed state as appropriate. This prevents leakage to the outside.

  3 and 4 show a first embodiment of the method for producing a fuel cell seal structure according to the present invention for obtaining the above-described fuel cell seal structure 1 shown in FIGS. 1 and 2. FIG. Among these, FIG. 3 is explanatory drawing which shows the process of manufacturing a porous board, FIG. 4 is explanatory drawing which shows the process of shape | molding a gasket.

  That is, in the manufacture of the fuel cell seal structure 1 shown in FIGS. 1 and 2, first, as shown in FIG. 3, a porous plate 10 made of a metal porous body is manufactured.

  The porous plate 10 is manufactured, for example, by performing a known photoetching or other etching process on a metal plate such as titanium or stainless steel having a thickness of about 0.1 to 0.5 mm. That is, by applying a photosensitive material to the surface of the metal plate, exposing the layer of the photosensitive material through a photomask composed of a light-transmitting part or a light-shielding part, and then immersing and developing in a developer, A photoresist having a mask pattern corresponding to the photomask is formed on the surface of the metal plate, and further, etching is performed using an etchant capable of corroding the metal plate, thereby allowing innumerable numbers corresponding to the mask pattern. It becomes the porous board 10 which has the fine penetration space | gap 10a.

  In this etching process, a portion of the metal plate exposed from the mask pattern by the photoresist is corroded by the etching solution to become the fine through-hole 10a, and a portion protected by the photoresist remains without being corroded by the etching solution. The gasket forming region 11 and the gas flow region 12 in the porous plate 10 are portions in which such fine through-holes 10a are formed innumerably with an appropriate density, and the permeation limiting region 13 has a predetermined width (for example, 1 mm). This is a portion where the fine through-hole 10a is not formed over a certain degree. Therefore, the gasket molding region 11, the gas flow region 12, and the permeation restriction region 13 can be arbitrarily laid out according to the mask pattern of the photomask. After the etching is completed, the photoresist on the surface of the porous plate 10 is removed with an appropriate solvent.

  Next, the porous plate 10 manufactured in this way is set in a mold 30 for gasket molding as shown in FIG. The mold 30 includes, for example, divided molds 31 and 32, and the porous plate 10 can be positioned at a predetermined position between the divided molds 31 and 32. In the illustrated clamping state, the porous plate 10 can be positioned. A gasket forming cavity 33 is defined between the gasket forming region 11 and the gasket forming region 11.

  Specifically, the gasket forming cavity 33 has a cross-sectional shape corresponding to the gasket 20 shown in FIG. 2, that is, is located in the gasket forming region 11 in the porous plate 10 and corresponds to the base portion 21 of the gasket 20. The base molding portion 33a includes a main lip molding portion 33b corresponding to the main lip 22 of the gasket 20, and a sub lip molding portion 33c corresponding to the sub lip 23 of the gasket 20 on the opposite side. One split mold 31 is provided with a plurality of injection gates 34 for filling the gasket molding cavity 33 with a liquid molding rubber material at an appropriate interval in the extending direction of the gasket molding cavity 33. In addition, a pressing portion 31a is formed in the base molding portion 33a and for holding the permeation restricting region 13 in the porous plate 10 in close contact with the other split mold 32.

  That is, by setting the porous plate 10 to the mold 30 and clamping as shown in FIG. 4, the gasket forming cavity 33 is defined along the gasket forming region 11 in the porous plate 10. At the same time, the permeation restriction region 13 in the porous plate 10 is sandwiched between the pressing portion 31a of one split mold 31 and the other split mold 32 in a close state. The clamping pressure does not act on the gasket forming region 11 and the gas flow region 12 in the porous plate 10.

  In this mold-clamped state, a liquid molding rubber material is filled from the injection gate 34 into the gasket molding cavity 33. In this case, examples of the liquid rubber material for molding include liquid ethylene propylene rubber (EPDM), liquid fluoro rubber, liquid silicone rubber, liquid acrylic rubber, and the like. If it does not generate | occur | produce, it will not specifically limit.

  Here, since there are innumerable fine through-holes 10a in the gasket molding region 11 of the porous plate 10, a part of the liquid molding rubber material filled into the gasket molding cavity 33 is caused by the filling pressure. It penetrates so as to fill the fine through gap 10a in the gasket molding region 11.

  Further, at this time, the molding rubber material to be permeated from the gasket molding region 11 to the gas flow region 12 in the porous plate 10 is blocked in the permeation restriction region 13 where there is no fine through gap, and this permeation restriction is performed. Since the region 13 is in close contact with the inner surface of the mold 30 (the pressing portion 31a of one split mold 31 and the inner surface of the other split mold 32) with an appropriate surface pressure, the rubber material for molding in the gasket molding cavity 33 is used. However, it does not leak and penetrate from the space between the permeation restriction region 13 and the inner surface of the mold 30 to the gas flow region 12 side.

  The molding rubber material filled in the mold 30 is crosslinked and cured by heating. That is, when the molding rubber material is cured in the gasket molding cavity 33, the molding rubber material is molded into a cross-sectional shape corresponding to the shape of the inner surface thereof to become the gasket 20 shown in FIG. 2, and in the gasket molding region 11 in the porous plate 10. It is integrated with the porous plate 10 through a portion cured in the permeated state (impregnated portion 20a shown in FIG. 2). After the cross-linking and curing, the split molds 31 and 32 are separated from each other to perform mold opening, and the seal structure 1 as a molded product is taken out.

  FIG. 5 is an explanatory view showing an example of incorporating the seal structure 1 manufactured as described above into a fuel cell.

  In this example of incorporation, reference numeral 2 denotes a gas diffusion layer made of a porous material on both sides in the thickness direction of a membrane-electrode assembly (MEA) 2a made of an electrolyte membrane and a catalyst electrode layer provided on both surfaces of the electrolyte membrane. This is a power generator in which (GDL: Gas Diffusion Layer) 2b is laminated and integrated. The seal structure 1 according to the above-described embodiment is disposed on both sides in the thickness direction of the power generation body 2 such that the main lip 22 of the gasket 20 faces the power generation body 2 side. A fuel cell is formed by laminating separators 3 made of metal.

  In this fuel cell, the outer peripheral portion of the power generator 2 is tightly held by the main lip 22 of the gasket 20 in the seal structure 1 on both sides, and the sub lip 23 of the gasket 20 is in close contact with the separator 3. Further, between the one catalyst electrode layer (for example, the anode) in the membrane-electrode assembly 2a and the one separator 3 facing the catalyst electrode layer (anode), the porous plate 10 in the one seal structure 1 has innumerable fine penetration. For example, a fuel gas flow path is formed by the gas flow region 12 having the gap 10a, and the other catalyst electrode layer (for example, cathode) in the membrane-electrode assembly 2a and the other separator 3 facing the other are disposed on the other side. For example, an oxidant gas flow path is formed by the gas flow region 12 having an infinite number of fine through voids 10 a of the porous plate 10 in the seal structure 1. The fuel gas channel and the oxidant gas channel are sealed by the gasket 20 of each seal structure 1.

  Therefore, in the fuel battery cell having the above-described configuration, the fuel gas (hydrogen) is diffused in the fuel gas flow path including the gas flow region 12 of the porous plate 10 in one seal structure 1 and one gas diffusion in the power generator 2. An oxidant gas flow path that is supplied to the anode side of the membrane-electrode assembly 2a through the layer 2b and in which the oxidant gas (air) is composed of the gas flow region 12 of the porous plate 10 in the other seal structure 1 and It is supplied to the cathode side of the membrane-electrode assembly 2a via the other gas diffusion layer 2b in the power generator 2, and generates electric power by the reverse reaction of water electrolysis, that is, the reaction of generating water from hydrogen and oxygen. And although the electromotive force by each fuel cell is low, a required electromotive force can be obtained by stacking a large number of fuel cells and electrically connecting them in series.

  In the production of the seal structure 1, since the impregnation restricted region 13 provided in the porous plate 10 prevents unnecessary expansion of the impregnated portion 20a of the gasket 20, the gas flow region 12 is narrowed. In addition, since the edge of the impregnated portion 20a is accurately formed along the permeation limiting region 13, it is possible to reliably prevent variations in power generation performance due to variations in the region of the impregnated portion 20a. Can do.

  Next, FIG. 6 is an explanatory view showing an example of incorporation of the second form of the fuel cell seal structure according to the present invention into the fuel cell, and FIG. 7 shows the fuel cell seal structure shown in FIG. It is explanatory drawing which shows the process of shape | molding a gasket in the 2nd form of the manufacturing method of the sealing structure for fuel cells which concerns on this invention for obtaining.

  That is, in the first embodiment described above, the gasket 20 is integrally formed with the porous plate 10, but in the second embodiment shown in FIG. 6, the seal structure 1 includes the electrolyte membrane and its both surfaces. A power generation body 2 in which gas diffusion layers 2b are laminated and integrated on both sides in the thickness direction of a membrane-electrode assembly 2a made of a catalyst electrode layer provided on a porous plate 10 disposed on both sides in the thickness direction of the power generation body 2 And a gasket 20 made of a rubber-like elastic material is integrally formed along the outer peripheral edge of the laminate or an opening edge (not shown). And the fuel cell is comprised by laminating | stacking the separator 3 which consists of carbon or an electroconductive metal on both sides of this laminated body.

  The gasket 20 has a base portion 21 formed so as to cover the gasket molding regions 11 in the porous plates 10 on both sides, and a main lip 22 raised from both sides thereof. In the power generation body 2, an impregnation portion 20 a is formed in a region corresponding to the gasket molding region 11 by penetration and hardening of a part of the rubber-like elastic material of the gasket 20. It is integrally joined to the laminated body which consists of the porous board 10 and the electric power generation body 2 via 20a.

  The molding of the seal structure 1 is basically the same as in the first embodiment, and is a porous plate manufactured by performing a known photoetching or other etching process on a metal plate such as titanium or stainless steel. 10 is laminated on both sides in the thickness direction of the power generation body 2 in which the gas diffusion layers 2b are laminated and integrated on both sides in the thickness direction of the membrane-electrode assembly 2a composed of the electrolyte membrane and the catalyst electrode layers provided on both sides thereof, As shown in FIG. 7, the laminated body is set in a mold 30 for molding a gasket. In this embodiment, the gas diffusion layer 2b corresponds to another porous plate described in claim 3.

  The mold 30 is composed of, for example, divided molds 31 and 32, and the laminate can be positioned and arranged at a predetermined position between the divided molds 31 and 32. 10, gasket forming cavities 33 </ b> A and 33 </ b> B are defined between the gasket forming region 11 and the gasket forming region 11.

  That is, in the mold-clamped state shown in FIG. 7, the thickness of the laminated body composed of the power generation body 2 and the porous plates 10 on both sides thereof is increased along the gasket forming region 11 of each porous plate 10. Gasket forming cavities 33A and 33B that are symmetrical in the direction are defined, and the permeation limiting region 13 in the porous plate 10 is in close contact between the pressing portion 31a of one split mold 31 and the other split mold 32. Sandwiched between.

  Innumerable fine through-holes 10a exist in the gasket molding region 11 of the porous plate 10, and the gas diffusion layer 2b in the power generation body 2 is also porous. Therefore, from the injection gate 34 into the gasket molding cavity 33A, When the liquid molding rubber material is filled, a part of the molding rubber material penetrates so as to fill the fine through gap 10a in the gasket molding region 11 and the fine gap in the gas diffusion layer 2b by the filling pressure.

  In this case, the membrane-electrode composite 2a in the power generation body 2 has a size that does not reach the gasket molding region 11 as in the illustrated example, or a portion of the membrane-electrode composite 2a that has reached the gasket molding region 11 If a material flow hole is opened in the liquid, the liquid molding rubber material filled into the cavity 33A on the side of one split mold 31 from the injection gate 34 penetrates the laminate in the gasket molding region 11 in the thickness direction. Thus, it can reach the cavity 33B on the other split mold 32 side. Alternatively, the liquid molding rubber material filled in the cavity 33A on the one split mold 31 side may go around the outer periphery of the gasket molding region 11 and reach the cavity 33B on the other split mold 32 side. good.

  Even in this form, the molding rubber material to be permeated from the gasket molding region 11 to the gas flow region 12 in the porous plate 10 is blocked in the permeation limiting region 13 where the fine through gap 10a does not exist. Since the permeation restriction region 13 is in close contact with the inner surface of the mold 30 (the pressing portion 31a of one split mold 31 and the inner surface of the other split mold 32) with an appropriate surface pressure, The rubber material does not leak and penetrate from the space between the permeation restriction region 13 and the inner surface of the mold 30 to the gas flow region 12 side.

  The gas diffusion layer 2b in the power generator 2 does not have a permeation restriction region, but the gas diffusion layer 2b is extremely thin and has a certain degree of clamping between the permeation restriction regions 13 in the porous plate 10. Since the pressure is received, the molding rubber material is effectively prevented from penetrating into the gas flow region 12 in the gas diffusion layer 2b.

  The molding rubber material filled in the mold 30 is crosslinked and cured by heating to form the gasket 20 shown in FIG. 6, and penetrates into the gasket molding region 11 of the porous plate 10 and the gas diffusion layer 2b therebetween. It is integrated with the laminate composed of the power generator 2 and the porous plate 10 through the portion cured in (impregnated portion 20a shown in FIG. 6). After the cross-linking and curing, the split molds 31 and 32 are separated from each other to perform mold opening, and the seal structure 1 as a molded product is taken out.

  In addition to the above-described embodiment, for example, the gasket 20 may be integrally formed on a laminate of the porous plate 10 and the gas diffusion layer 2b. In this case as well, the porous plate 10 is formed by etching to form a gasket forming region 11 having innumerable fine through voids, a gas flow region 12 having innumerable fine through voids, and between these regions 11 and 12. It is assumed that it has a permeation restriction region 13 having an appropriate width that does not exist and has a fine through-hole, and the gasket 20 is impregnated in the gasket forming region 11 and the gas diffusion layer 2b corresponding to the gasket forming region 11 It is configured to be integrally joined to the porous plate 10 via the portion 20a.

DESCRIPTION OF SYMBOLS 1 Seal structure 10 for fuel cells Porous board 10a Fine penetration space | gap 11 Gasket formation area 12 Gas distribution area 13 Permeation restriction area 20 Gasket 20a Impregnation part 30 Mold 31a Holding part 33, 33A, 33B Gasket formation cavity 2 Power generation body 2b Gas diffusion layer (other porous plates)
3 Separator

Claims (5)

  A thin plate is formed with a gasket forming region having an infinite number of fine through-holes, a gas flow region having an infinite number of fine through-holes, and a permeation-restricted region extending between the two regions and free of the fine through-holes. By setting the porous plate in a mold and clamping it, the inner surface of the mold is brought into close contact with the permeation limiting region, and the gasket molding region and the inner surface of the mold are A method for producing a fuel cell seal structure, comprising filling a gasket molding cavity defined in between with a liquid molding material and allowing a part thereof to penetrate into the gasket molding region and curing.   2. The fuel cell seal according to claim 1, wherein an infinite number of fine through voids in the gasket forming region and the gas flow region are formed by etching, and the permeation restricted region is formed as a non-etched region by an etching mask pattern. Manufacturing method of structure.   The porous plate is laminated with another porous plate, and the liquid molding material filled in the gasket forming cavity is infiltrated into a region corresponding to the gasket forming region in the other porous plate. Item 2. A method for producing a fuel cell seal structure according to Item 1.   The method for producing a fuel cell seal structure according to claim 1, wherein the porous plate is made of metal.   An impregnated portion comprising a porous plate and a gasket integrally formed with the porous plate, wherein the porous plate is joined to the gasket and part of the gasket material is joined to innumerable fine through-holes. And a gas flow region having an infinite number of fine through-holes, and a permeation restriction region that extends between the impregnation part and the gas flow region and does not have the fine through-holes. A fuel cell seal structure produced by the method according to any one of the above.

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