JP2007184223A - Seal material for fuel cell, its manufacturing method and separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal material for fuel cells which is cheap while demonstrating an acid resistance, and which can be manufactured easily. <P>SOLUTION: The seal material 1 for the fuel cells includes a resin 4 which constitutes a matrix phase, and particles 5 which comprise a rubbery elastic body distributed in the resin 4. This seal material 1 achieves acid resistivity by the resin 4, and at the same time resilience by the particles 5. Moreover, since the acid resistivity is assured by the resin 4 unlike a conventional seal material, it is not necessary to adopt an expensive fluororubber, and it can be manufactured cheaply. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell sealing material that seals between a separator of a fuel cell and a membrane electrode assembly, between separators, and the like, a manufacturing method thereof, and a separator.

Conventionally, a sealing material is disposed between a separator of a fuel cell and a membrane electrode assembly or between separators. In general, water generated when a fuel cell generates electricity gradually becomes more acidic as the solid polymer electrolyte membrane used in the fuel cell deteriorates. Therefore, a fluoro rubber having excellent acid resistance has been used for the sealing material. However, there has been a problem that fluororubber is expensive. Therefore, a sealing material in which the surface of silicone rubber is covered with fluoro rubber has been proposed (see, for example, Patent Document 1).
Since the surface of this sealing material is coated with fluoro rubber, it exhibits acid resistance and the inside is formed of silicone rubber, so that the manufacturing cost is reduced compared to a sealing material made of only fluoro rubber. be able to.
Japanese Patent Laying-Open No. 2004-55428 (see paragraphs 0007, 0025, and FIG. 1)

  However, since this sealing material still uses fluororubber, it cannot be said that the manufacturing cost is sufficiently reduced. Further, since this sealing material has a two-layer structure composed of silicone rubber and fluororubber, the manufacturing process is diverse and it is necessary to examine the compatibility between the layers. Therefore, this sealing material has a problem that the manufacturing process becomes complicated.

  Accordingly, the present invention provides a fuel cell sealing material that exhibits acid resistance, is inexpensive, and can be easily manufactured, a manufacturing method thereof, and a separator using the fuel cell sealing material. Let it be an issue.

A sealing material for a fuel cell according to the present invention that solves the above-described problems includes a resin constituting a matrix phase and particles made of a rubber-like elastic body dispersed in the resin.
In this fuel cell sealing material, particles made of a rubber-like elastic material are dispersed in a resin as a matrix phase, so that the sealing material provides elasticity to the sealing material while exhibiting acid resistance by the resin. Demonstrates sealing properties. Moreover, since acid resistance is ensured by the resin, it is not necessary to use expensive fluororubber unlike the conventional sealing material, and it can be manufactured at low cost.
Moreover, this fuel cell sealing material can be easily manufactured by molding a resin in which particles are dispersed.
Moreover, in this fuel cell sealing material, the elasticity of the sealing material can be controlled by adjusting the content of the particles in the sealing material. Therefore, according to the present invention, when used in a fuel cell having a stack structure of a constant-length stack that does not use a disc spring, the volume and weight can be reduced, and the fuel cell sealing material has a spring constant according to the design. Can be provided.

Moreover, in such a fuel cell sealing material, it is desirable that the content of the rubber-like elastic body is larger in the inside than in the front portion of the sealing material.
In this fuel cell sealing material, since the resin content at the front portion increases, the acid resistance of the sealing material is further improved.

Moreover, in such a fuel cell sealing material, it is desirable that the content of the rubber-like elastic body in the entire sealing material is 10 to 70% by mass.
In this fuel cell sealing material, since the content of the rubber-like elastic body is adjusted to 10 to 70% by mass, elution of the rubber-like elastic body is suppressed while imparting appropriate elasticity to the sealing material. The deterioration of the sealing material is prevented.

Further, in such a fuel cell sealing material, it is desirable that the entire surface is covered only with the matrix phase.
In this fuel cell sealing material, since the entire surface is covered with the matrix phase, that is, the resin, the elution of the rubber-like elastic body is reliably suppressed. As a result, the deterioration of the sealing material is more effectively prevented.

And the manufacturing method of the sealing material for fuel cells of this invention is the 1st process which heat-mixes resin and the particle which consists of rubber-like elastic bodies, and obtains a resin composition, The said resin composition is injection-molded in a type | mold. And a second step.
In this manufacturing method, a fuel cell sealing material can be molded by discharging a resin composition containing a resin and particles made of a rubber-like elastic body from an injection molding machine into a predetermined mold.
Further, in this manufacturing method, when the resin composition is discharged into the mold, the resin component of the resin composition is near the interface between the mold and the resin composition due to the affinity (wetability) between the resin and the mold. In addition, as the distance from the mold increases, in other words, a fuel cell sealing material in which the content of particles gradually increases from the surface side toward the inner side can be formed. And the sealing material for fuel cells by which all the surfaces were covered with resin can also be shape | molded.

  Moreover, according to this manufacturing method, unlike the manufacturing method of the conventional sealing material (for example, refer patent document 1), it is not necessary to extrude two layers. Furthermore, continuous production is facilitated by injection molding. Further, here, it is possible to cope with a more complicated shape by injection molding in which a mold is compressed after injection molding, and further, a fuel cell member can be manufactured accurately and inexpensively by insert molding in which a separator is placed in the mold. Therefore, the fuel cell sealing material can be manufactured easily and inexpensively as compared with the conventional manufacturing method of the sealing material.

  Moreover, in this manufacturing method, the compatibility of the rubber-like elastic body with respect to resin can be avoided by setting the heating temperature in the first step to a temperature lower than the glass transition point of the rubber-like elastic body. As a result, according to this manufacturing method, it is possible to manufacture a fuel cell sealing material that is more elastic.

And the separator of this invention is a separator provided with the plate-shaped metal part in which the gas flow path was formed in at least one side, and the resin part formed in the said metal part while having a sealing part which consists of a convex part, The resin portion includes a resin constituting a matrix phase and particles made of a rubber-like elastic body dispersed in the resin.
In this separator, since the seal portion formed in the resin portion includes a resin constituting the matrix phase and particles made of a rubber-like elastic body dispersed in the resin, the above-described fuel cell seal material The same effect is produced.
In addition, since the separator includes a resin in which a seal portion forms a matrix phase and particles made of a rubber-like elastic body dispersed in the resin, the sealability and structural strength are improved.
In addition, since the separator is integrated with the separator, a complicated shape having a plurality of seals can be easily formed.

Further, in such a separator, the resin portion is formed so as to surround the metal portion from the outside in the surface direction of the metal portion, and the seal portion is disposed outside the metal portion. Can be configured.
In this separator, since the resin part having the seal part is formed so as to surround the metal part, it is not necessary to separately provide a seal member for sealing the periphery of the metal part, and the number of parts of the fuel cell is reduced. be able to.

Further, in such a separator, at least one of a reaction gas supply hole, a reaction gas discharge hole, a cooling water supply hole, and a cooling water discharge hole is formed in the resin portion, The seal portion may be arranged around the hole and around a reaction gas or cooling water channel formed between the hole and the metal portion.
In this separator, at least one of the reaction gas supply hole, the reaction gas discharge hole, the cooling water supply hole, and the cooling water discharge hole is formed in the resin portion. The risk of short-circuiting between adjacent single cells is reduced.

Moreover, in such a separator, it is desirable that the resin portion is formed so as to be integrated with the metal portion.
In this separator, since the resin part and the metal part are formed so as to be integrated, the number of parts is reduced, and when a fuel cell is manufactured by stacking single cells, its assembly becomes easy, It will be certain.

  According to the present invention, the fuel cell sealing material that exhibits acid resistance, is inexpensive, and can be easily manufactured, and the manufacturing method thereof, and the seal portion that exhibits acid resistance are provided, and are inexpensive. In addition, a separator that can be easily manufactured can be provided.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is a perspective view of a fuel cell in which a separator according to an embodiment is incorporated. FIG. 2 is an exploded perspective view showing a laminated structure of single cells. FIG. 3 is a plan view of the separator disposed on the anode side as viewed from the anode side. 4A is a partial cross-sectional view taken along the line XX ′ of FIG. 3, FIG. 4B is a partial cross-sectional view taken along the line YY ′ of FIG. 3, and FIG. It is a fragmentary sectional view of a 'line. FIG. 5 is a plan view of the separator disposed on the cathode side as viewed from the cathode side. FIG. 6 is a plan view of the separator disposed on the cathode side, and shows a surface opposite to the surface shown in FIG. 7A is a partial cross-sectional view taken along the line P-P ′ of FIG. 5, FIG. 7B is a partial cross-sectional view taken along the line Q-Q ′ of FIG. 5, and FIG. It is a fragmentary sectional view of the RR 'line. FIG. 8 is a cross-sectional view of a laminate formed by the separator shown in FIG. 3 and the separator shown in FIG. 5, and (a) is taken along line XX ′ in FIG. 3 and line PP ′ in FIG. 5. (B) is a cross-sectional view corresponding to the YY 'line of FIG. 3 and Q-Q' line of FIG. 5, (c) is a ZZ 'line of FIG. 5 is a cross-sectional view corresponding to line RR ′ of FIG. FIG. 9A is a partially enlarged view of the resin portion shown in FIG. 4A, and FIG. 9B is an enlarged view of the N portion of FIG. 9A. FIG. 10 is a schematic view showing a cross section of a mold used for forming the separator. In addition, about FIG. 4 (a) and (b) and FIG. 7 (a) and (b), the line which shows one part depth is abbreviate | omitted for convenience. 8A to 8C, for the sake of convenience, a line indicating a part of the depth is indicated by a broken line, and a line indicating a part of the depth is omitted.
First, the separator will be described while explaining a fuel cell in which the separator of the present invention is incorporated.

(Fuel cell)
As shown in FIG. 1, the fuel cell FC is of an internal manifold type and includes a stacked body 32 in which a plurality of single cells 31 are stacked.
As shown in FIG. 2, the single cell 31 includes a membrane electrode assembly (MEA) 40 and a pair of conductive separators 44 and 45 that sandwich the membrane electrode assembly 10 from both sides. ing.

  The membrane electrode assembly 10 includes a solid polymer electrolyte membrane 50, an anode 42 formed on one surface of the solid polymer electrolyte membrane 50, and a cathode 43 formed on the other surface. The periphery of the solid polymer electrolyte membrane 50 extends outward from the periphery of the anode 42 and the cathode 43. The anode 42 has a gas diffusion layer (not shown) formed on the surface on the separator 44 side in substantially the same shape as the anode 42, and the cathode 43 has a gas diffusion layer (not shown) on the surface on the separator 45 side. The surface shape is substantially the same as 43.

The separator 44 is provided so as to face the surface on the anode 42 side of the membrane electrode assembly 10.
The separator 44 is a portion that faces the surface of the anode 42 so as to substantially correspond to the metal portion 26a formed of a metal plate, and the metal portion 26a is disposed on the outer side (surrounding) of the surface direction. And a resin portion 26b formed so as to surround the frame shape from the side).
A channel 44s through which hydrogen (reactive gas) flows is formed on the surface of the metal portion 26a facing the anode 42 (see FIG. 2). The flow path 44s is configured by a groove formed on the surface of the metal portion 26a so as to connect a through hole 44d and a through hole 44c formed in the resin portion 26b described later.

As shown in FIG. 3, the flow path 44s is formed such that the four flow paths 44s make a set and meander the surface of the metal portion 26a.
Through holes 44a, 44b, and 44c are formed in the upper, middle, and lower stages on the back side in FIG. 2, and through holes 44d, 44e, and 44f are formed in the upper, middle, and lower stages on the front side of FIG. Is formed. Further, as shown in FIG. 3, the resin portion 26b is formed with a communication path 44g that allows the through hole 44d and the flow path 44s to communicate with each other, and a communication path 44h that allows the flow path 44s and the through hole 44c to communicate with each other. Yes.

  As shown in FIG. 3, the communication path 44g penetrates from the through hole 44d side so as to cross the seal portion 17a and the seal portion 17b described below, and is connected to a flow channel 44s formed in the metal portion 26a. ing. The communication path 44h penetrates from the through hole 44c side so as to cross the seal portion 17a and the seal portion 17b, and is connected to a flow path 44s formed in the metal portion 26a.

Further, as shown in FIG. 3, a seal portion 17a and a seal portion 17b are formed in the resin portion 26b. That is, the seal part 17a and the seal part 17b are disposed outside the metal part 26a.
As shown in FIGS. 3 and 4 (a) to 4 (c), the seal portion 17a is formed with a convex portion (projection) protruding from the surface side where the flow path 44s of the separator 44 is formed. The seal portion 17a surrounds the peripheries of the through holes 44a, 44b, 44c, 44d, 44e, and 44f (see FIG. 3), and the seal portion 17b to be described next around the metal portion 26a (see FIG. 3). It is formed so as to be enclosed from the outside. And the seal | sticker part 17a seals between the separator 44 and the separator 45, leaving contact part 44g and 44h parts by contact | abutting with the seal | sticker part 18a formed in the separator 45 (refer FIG. 5) mentioned later. It will be.
As shown in FIGS. 3 and 4 (a) to 4 (c), the seal portion 17b is formed of a convex portion (projection) protruding from the surface side where the flow path 44s of the separator 44 is formed. The seal portion 17b is formed so as to surround the metal portion 26a (see FIG. 3) inside the seal portion 17a. The sealing portion 17b is between the sealing portion 18b formed on the separator 45 (see FIG. 5) described later and the solid polymer electrolyte membrane 50 extending to the periphery of the membrane electrode assembly 10 (see FIG. 2). By sandwiching (see FIG. 2), the gap between the separator 44 and the solid polymer electrolyte membrane 50 is sealed, leaving the communication paths 44g and 44h.

The separator 45 is provided so as to face the surface of the membrane electrode assembly 10 on the cathode 43 side.
The separator 45 is a portion facing the surface of the cathode 43 so as to substantially correspond to the metal portion 26a formed of a metal plate, and the metal portion 26a is disposed on the outer side (peripheral side) in the surface direction. ) And a resin portion 26b formed so as to surround the frame shape.
As shown in FIG. 5, a channel 45s through which air (reactive gas) flows is formed on the surface of the metal portion 26a facing the cathode 43 (see FIG. 2). The flow path 45s is constituted by a groove formed on the surface of the metal portion 26a so as to connect the through hole 45a and the through hole 45f formed in the resin portion 26b. The channel 45s is formed so that the four channels 45s meander and the surface of the metal portion 26a meanders.

Further, as shown in FIG. 6, a cooling water passage 46s through which cooling water flows is formed in the metal portion 26a on the surface opposite to the surface on which the flow passage 45s (see FIG. 5) is formed.
The cooling water channel 46s is partitioned by a plurality of mutually parallel ribs 46c formed so as to extend in a direction connecting through-holes 45a, 45b, 45c described later and through-holes 45d, 45e, 45f described later. It is formed with a groove. The cooling water cools the fuel cell FC by flowing through the cooling water passage 46s.

The resin portion 26b of the separator 45 has through holes 45a, 45b, and 45c formed in the upper, middle, and lower stages on the back side in FIG. 2, and the through holes are formed in the upper, middle, and lower stages on the front side of FIG. 45d, 45e, and 45f are formed. Further, as shown in FIG. 5, a communication path 45g that connects the through hole 45a and the flow path 45s and a communication path 45h that connects the flow path 45s and the through hole 45f are formed in the resin portion 26b. Yes.
As shown in FIG. 5, the communication path 45g penetrates from the through hole 45a side so as to cross a seal portion 18a and a seal portion 18b described later, and is connected to a flow path 45s formed in the metal portion 26a. . The communication path 45h penetrates from the through hole 45f side so as to cross a seal part 18a and a seal part 18b described later, and is connected to a flow path 45s formed in the metal part 26a.

Further, as shown in FIG. 5, a seal portion 18 a and a seal portion 18 b are formed in the resin portion 26 b of the separator 45. That is, the seal part 18a and the seal part 18b are disposed outside the metal part 26a.
As shown in FIGS. 5 and 7A to 7C, the seal portion 18a is formed of a convex portion (projection) that protrudes from the surface side where the flow path 45s of the separator 45 is formed. The seal portion 18a surrounds the peripheries of the through holes 45a, 45b, 45c, 45d, 45e, and 45f (see FIG. 5), and the seal portion 18b to be described next around the metal portion 26a (see FIG. 5). It is formed so as to be enclosed from the outside.
As shown in FIGS. 5 and 7A to 7C, the seal portion 18b is formed with a convex portion (projection) protruding from the surface side where the flow path 45s of the separator 45 is formed. The seal portion 18b is formed so as to surround the periphery of the metal portion 26a (see FIG. 5) inside the seal portion 18a. The seal portion 18b extends to the periphery of the membrane electrode assembly 10 (see FIG. 2) with the seal portion 17b (see FIG. 3) formed in the separator 44 (see FIG. 3). By sandwiching the polymer electrolyte membrane 50 (see FIG. 2), the gap between the separator 45 and the solid polymer electrolyte membrane 50 is sealed, leaving portions of the communication paths 45g and 45h.

Then, on the surface side resin portion 26b where the cooling water channel 46s of the separator 45 is formed, a communication channel 46a for communicating the through hole 45b and the cooling water channel 46s, and a communication channel for communicating the cooling water channel 46s and the through hole 45e. 46b.
As shown in FIG. 6, the communication path 46a penetrates from the through-hole 45b side so as to cross a seal part 19 described later, and is connected to a cooling water path 46s formed in the metal part 26a. The communication path 46b penetrates from the through hole 45e side so as to cross a seal part 19 described later, and is connected to a cooling water path 46s formed in the metal part 26a.
Further, as shown in FIG. 6, the resin portion 26b of the separator 45 encloses the peripheries of the through holes 45a, 45b, 45c, 45d, 45e, and 45f, and the metal portion on the side where the cooling water channel 46s is formed. A seal portion 19 is formed so as to surround the periphery of 26a. That is, the seal part 19 is disposed outside the metal part 26a. The seal portion 19 is formed by a convex portion (projection) that projects from the surface side of the separator 45. The seal portion 19 abuts on the outer surface of the separator 44 (see FIG. 3) on the side of the adjacent single cell 31 (see FIG. 1), that is, the surface opposite to the surface on which the flow path 44s is formed. The separator 45 and the separator 44 (see FIG. 3) on the side of the adjacent single cell 31 (see FIG. 1) are sealed while leaving the 46a and 46b portions.

  In this fuel cell FC, when a plurality of single cells 31 shown in FIG. 2 are stacked to form a stacked body 32 (see FIG. 1), the through hole 44d and the through hole 45d communicate with each other. A supply hole (not shown) for supplying hydrogen to the flow path 44s of the separator 44 is formed, and the through hole 44c and the through hole 45c communicate with each other to discharge hydrogen from the flow path 44s. (Not shown). Further, the through hole 44a and the through hole 45a form a supply hole (not shown) for supplying air (oxygen) to the flow path 45s (see FIG. 3) of the separator 45 by communicating with each other. The hole 44f and the through hole 45f form a discharge hole (not shown) for discharging air (oxygen) from the flow path 45s by communicating with each other. Further, the through hole 44b and the through hole 45b communicate with each other to form a supply hole (not shown) for supplying cooling water to the cooling water passage 46s of the separator 45, and the through hole 44e and the through hole 45e. Forms a discharge hole (not shown) for discharging cooling water from the cooling water passage 46s by communicating with each other. That is, the through holes 44a, 44b, 44c, 44d, 44e, 44f formed in the resin portion 26b of the separator 44, and the through holes 45a, 45b, 45c, 45d, 45e, 45f formed in the resin portion 26b of the separator 45. Corresponds to “reactive gas supply hole, reactive gas discharge hole, cooling water supply hole, and cooling water discharge hole” in the claims.

Here, in the laminated body 32, the state in which the membrane electrode assembly 10 is sandwiched between the separator 44 and the separator 45 is more specifically exemplified mainly by the state in the vicinity of the through hole 44d and the through hole 45d. explain.
As shown in FIGS. 8A and 8B, when the separators 44 and the separators 45 sandwiching the membrane electrode assembly 10 are alternately stacked, the separators 45g (see (a)) are left, When the seal portion 17a of 44 and the seal portion 18a of the separator 45 come into contact with each other, the periphery of the through hole 44d and the periphery of the through hole 45d are sealed. Then, around the through holes 44a, 44b, 44c, 44e, and 44f of the separator 44 shown in FIG. 3, the seal portion 17a shown in FIG. 3 and the separator shown in FIG. It seals because 45 seal | sticker parts 18a contact | abut. Further, the periphery of the through holes 45a, 45b, 45c, 45e, and 45f of the separator 45 shown in FIG. 5 leaves the connecting passage 45h shown in FIG. 5, and the separator 18a shown in FIG. Sealing is achieved by contact with the 44 seal portions 17a. The resin portion 26b that surrounds the metal portion 26a of the separator 44 shown in FIG. 3 and the resin portion 26b that surrounds the metal portion 26a of the separator 45 shown in FIG. 5 are also connected to the seal portion 17a shown in FIG. It seals by contact | abutting with the seal part 18a of the separator 45 shown in FIG.

  On the other hand, as shown in FIGS. 8A to 8C, the membrane / electrode assembly 10 includes the solid polymer electrolyte membrane 50 portion extending from the membrane / electrode assembly 10 and the seal portion 17b of the separator 44 and the separator 45. Between the two seal portions 18b. That is, the seal portion 17b shown in FIG. 3 and the seal portion 18b shown in FIG. 5 sandwich the peripheral edge of the solid polymer electrolyte membrane 50 extending. As a result, the gap between the separator 44 and the extended peripheral edge of the solid polymer electrolyte membrane 50 is sealed, and the gap between the separator 45 and the extended peripheral edge of the solid polymer electrolyte membrane 50 is sealed. It becomes.

  Moreover, in such a laminated body 32, as shown in FIGS. 8A and 8B, adjacent single cells 31 face each other at the separator 44 and the separator 45. The seal portion 19 of the separator 45 abuts on the resin portion 26b of the separator 44, so that the periphery of the through hole 44d and the periphery of the through hole 45d are sealed. In addition, since the seal portion 19 abuts on the resin portion 26b of the separator 44 as described above, the periphery of the through holes 45a, 45b, 45c, 45e, and 45f of the separator 45 shown in FIG. The portions 46a and 46b are sealed, and the periphery of the through holes 44a, 44b, 44c, 44e, and 44f (see FIG. 3) of the separator 44 corresponding to the through holes 45a, 45b, 45c, 45e, and 45f is also sealed. Will be. The resin portion 26b that surrounds the metal portion 26a of the separator 45 shown in FIG. 6 and the resin portion 26b that surrounds the metal portion 26a of the separator 44 (see FIG. 3) corresponding thereto are also sealed by the seal portion 19. The

  As shown in FIG. 1, in the fuel cell FC, a pair of end plates 33 and end plates 34 sandwich and support the stacked body 32 from both sides. Incidentally, the end plate 33 has through holes 44a, 44b, 44c, 44d, 44e, 44f (see FIG. 2) of the separator 44 and through holes 45a, 45b, 45c, 45d, 45e, 45f (see FIG. 2) of the separator 45. ), Through holes 33a, 33b, 33c, 33d, 33e, and 33f are formed. The through holes 33a are set as air (reaction gas) supply ports. It is set as an air (reaction gas) discharge port, the through hole 33d is set as a hydrogen (reaction gas) supply port, and the through hole 33c is set as a hydrogen (reaction gas) discharge port. The through hole 33b is set as a cooling water supply port, and the through hole 33e is set as a cooling water discharge port.

Next, the resin composition that forms the resin portion 26b will be described.
Taking the seal portion 17a of the separator 44 shown in FIG. 9A as an example, the resin portion 26b is formed in the resin 4 constituting the matrix phase as shown in FIG. It is formed of a single layer in which particles 5 made of a rubber-like elastic body (hereinafter, simply referred to as “elastic body particles 5”) are dispersed. The resin portion 26b increases in content of the elastic particles 5 from the surface side toward the inner side, and the content increases with a predetermined gradient (inclination) from the surface side toward the inner side. It is desirable that Such a gradient (inclination) of the content may be formed by gradually increasing the distribution rate of the elastic particles 5 having substantially the same diameter from the surface side to the inner side of the resin portion 26b, or elastically. The body particles 5 may be formed by gradually increasing the particle size from the surface side toward the inner side. Incidentally, in the resin part 26b in the present embodiment, compared with the content of the elastic particles 5 in the surface part 6 from the surface to a depth of about 50 μm, the resin part 26b is a deeper part from the surface part 6, The content of the elastic particles 5 in the interior 7 from the surface of the portion 26b to a depth of about 300 μm is increased.
In the resin portion 26 b, the entire surface is covered with the resin 4.

The resin 4 is not particularly limited as long as it can be molded into a desired shape, but is preferably a thermoplastic resin having no ester bond, amide bond, or imide bond. Among these, more preferable resins include, for example, polyolefin resins such as polyethylene (PE), polypropylene (PP), and polybutylene, styrene resins, polyoxymethylene (POM), polyvinyl chloride (PVC), polyphenylene sulfide (PPS), Polyphenylene ether (PPE), modified PPE, polysulfone (PSU), polyethersulfone (PESF), polyketone (PK), polyetherketone (PEK), polyetheretherketone (PEEK), polyethernitrile (PEN), and poly Acrylonitrile (PAN) is mentioned. Particularly preferred are ultra high molecular weight polyethylene, polyphenylene sulfide, polysulfone, polyether nitrile, and polyacrylonitrile. These may be used alone or in combination of two or more.
The content of such a resin 4 is preferably about 30 to 90% by mass of the resin composition forming the resin part 26b.

The rubber-like elastic body forming the elastic body particles 5 exhibits an elongation of 200% or more without breaking, and when the compressive stress or expansion stress (tensile stress) is released, the volume changes before and after the stress release. Those that remain within the range of −10% to 10% are preferable.
Among these, preferable rubber-like elastic bodies include methyl methacrylate-butadiene rubber (MBR), ethylene propylene rubber (EPR), acrylonitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), chlorosulfonated polyethylene (CSP), Synthesis of chloroprene rubber (CR), isoprene rubber (IR), butyl rubber (IIR), acrylic rubber, fluorine rubber, silicone rubber, butadiene rubber (MBS), polyphenylene sulfide (PPS), ethylene-propylene dimethyl rubber (EPDM), etc. Styrene elastomer such as rubber, styrene-butadiene-styrene (SBS) copolymer, styrene-isoprene-styrene (SIS) copolymer, olefin elastomer, urethane elastomer, polyamide elastomer, Tajien elastomers (MBS), and vinyl-based elastomer chloride (TPVC) is. These may be used alone or in combination of two or more.

The elastic particles 5 formed of such a rubber-like elastic body may be composed of a single phase or a plurality of phases. As the elastic particles 5 composed of a plurality of phases, for example, a core / shell structure in which the core portion is composed of a polymer rich in elasticity and the shell portion is composed of a polymer having a functional group that improves dispersibility in the resin 4. The body is mentioned.
The content of the elastic particles 5 (rubber-like elastic body) is preferably about 10 to 70% by mass with respect to the entire resin composition forming the resin portion 26b.

  Further, other components may be added to the resin composition forming the resin portion 26b as necessary. Other components include, for example, fillers (mica, talc, kaolin, sericite, bentonite, zonotolite, sepiolite, smectite, montmorillonite, wollastonite, silica, calcium carbonate, glass beads, glass flakes, glass microballoons, clay, Molybdenum disulfide, titanium oxide, zinc oxide, antimony oxide, calcium polyphosphate, graphite, barium sulfate, magnesium sulfate, zinc borate, calcium borate, aluminum borate whisker, potassium titanate whisker, zinc white, sulfur, etc.), Pigments, dyes, lubricants, release agents, compatibilizers, dispersants, crystal nucleating agents, plasticizers, heat stabilizers, antioxidants, anti-coloring agents, UV absorbers, fluidity modifiers, foaming agents, antibacterial agents Agents, vibration damping agents, antistatic agents, surfactants and the like. These may be used alone or in combination of two or more. These content rates can be appropriately set within a range not impairing the object of the present invention.

The separators 44 and 45 having the resin portion 26b made of such a resin composition can be molded by injecting the resin composition into a predetermined mold. FIG. 10 referred to here is a partial cross-sectional view schematically showing a mold used for forming the separators 44 and 45.
As shown in FIG. 10, the mold 13 is formed of a lower mold 13b and an upper mold 13a. And the metal part 26a is previously inserted in the upper mold | type 13a. The upper mold 13a is formed with a cavity 14a simulating the outer shape of the resin part 26b of the separators 44 and 45 so as to be connected to the metal part 26a. The upper mold 13a is formed with a gate 14b communicating with the cavity 14a.
Then, the resin composition described above is poured into the mold 13 through the gate 14b. As a result, separators 44 and 45 in which the resin portion 26b is connected to the metal portion 26a are obtained.

Next, the effect of the separators 44 and 45 according to the present embodiment will be described.
The separators 44 and 45 according to the present embodiment include the resin 4 in which the seal portions 17 a, 17 b, 18 a, 18 b, and 19 constitute a matrix phase, and particles 5 made of a rubber-like elastic material dispersed in the resin 4. As a result, sealability and structural strength are improved.
Further, since the separators 44 and 45 are integrated with the seal portions 17a, 17b, 18a, 18b and 19, a separator having a complicated shape provided with a plurality of seal portions 17a, 17b, 18a, 18b and 19 is used. It can be formed easily.

  Further, in such separators 44 and 45, the resin portion 26b having the seal portions 17a, 17b, 18a, 18b, and 19 is formed so as to surround the metal portion 26a, so that the periphery of the metal portion 26a is sealed. It is not necessary to provide a separate seal member, and the number of parts of the fuel cell FC can be reduced.

  In such separators 44 and 45, through holes 44a, 44b, 44c, 44d, 44e and 44f, and through holes 45a, 45b, 45c, 45d, 45e and 45f of the separator 45 are formed in the resin portion 26b. Therefore, the risk of short-circuiting between the single cells 31 that are adjacent to each other through these holes is reduced.

  Further, in such separators 44 and 45, since the resin portion 26b and the metal portion 26a are integrally formed, the number of parts is reduced, and the unit cell 31 is stacked to manufacture the fuel cell FC. In this case, the assembly becomes easy and reliable.

(Fuel cell sealant)
Next, embodiments of the fuel cell sealing material of the present invention will be described with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 11 is a schematic diagram showing a fuel cell using the fuel cell sealing material according to the present embodiment. FIG. 12A is a perspective view of the fuel cell sealing material according to the present embodiment, FIG. 12B is a cross-sectional view taken along the line AA ′ in FIG. 12A, and FIG. It is the B section enlarged view in 12 (b).
First, prior to description of a fuel cell sealing material (hereinafter simply referred to as “sealing material”), a fuel cell using this sealing material will be briefly described.

  As shown in FIG. 11, the fuel cell FC is formed by laminating a plurality of unit cells 12 each having a membrane electrode assembly (MEA) 10 sandwiched between conductive separators 11. Incidentally, as is well known, the membrane electrode assembly 10 is configured such that a cathode (not shown) is provided on one surface of a solid polymer electrolyte membrane (not shown) and an anode (not shown) is provided on the other surface. . The fuel cell FC generates power by supplying hydrogen to the anode and air (oxygen) to the cathode.

Next, the sealing material according to the present embodiment will be described.
As shown in FIG. 11, the sealing material 1 in this embodiment is disposed between the membrane electrode assembly 10 and the separator 11. As shown in FIG. 12A, the sealing material 1 has a rectangular frame shape, and as is apparent with reference to FIG. 11 again, the sealing material 1 is formed on the outer edges of the membrane electrode assembly 10 and the separator 11. It is arranged along. As shown in FIG. 12B, the sealing material 1 is composed of a base portion 2 that is rectangular in cross section and a protruding portion 3 that protrudes from the base portion 2 in a semicircular shape in cross section. Yes. Incidentally, the sealing material 1 in this embodiment is arranged so that the base portion 2 is in close contact with the membrane electrode assembly 10 (see FIG. 11) side and the protruding portion 3 is in close contact with the separator 11 (see FIG. 11) side. ing.

As shown in FIG. 12 (c), such a sealing material 1 includes particles 5 made of a rubber-like elastic body in a resin 4 constituting a matrix phase (hereinafter simply referred to as “elastic body particles 5”). It is formed of a single layer in which is dispersed. And the content of the elastic particles 5 increases in the sealing material 1 from the surface side toward the inner side, and this content increases with a predetermined gradient (inclination) from the surface side toward the inner side. It is desirable that Such a gradient (inclination) of the content may be formed by gradually increasing the distribution rate of the elastic particles 5 having substantially the same diameter from the surface side to the inner side of the sealing material 1 or elasticity. The body particles 5 may be formed by gradually increasing the particle size from the surface side toward the inner side. Incidentally, in the sealing material 1 in the present embodiment, compared to the content of the elastic particles 5 in the surface portion 6 from the surface to a depth of about 50 μm, a portion deeper than the surface portion 6, The content of the elastic particles 5 in the interior 7 from the surface of the material 1 to a depth of about 300 μm is increased. Here, the front portion 6 and the inner portion 7 correspond to “front portion” and “inside” in the claims.
In the sealing material 1, the entire surface is covered with the resin 4.

The resin 4 is not particularly limited as long as it can be molded into a desired shape, but is preferably a thermoplastic resin having no ester bond, amide bond, or imide bond. Among these, more preferable resins include, for example, polyolefin resins such as polyethylene (PE), polypropylene (PP), and polybutylene, styrene resins, polyoxymethylene (POM), polyvinyl chloride (PVC), polyphenylene sulfide (PPS), Polyphenylene ether (PPE), modified PPE, polysulfone (PSU), polyethersulfone (PESF), polyketone (PK), polyetherketone (PEK), polyetheretherketone (PEEK), polyethernitrile (PEN), and poly Acrylonitrile (PAN) is mentioned. Particularly preferred are ultra high molecular weight polyethylene, polyphenylene sulfide, polysulfone, polyether nitrile, and polyacrylonitrile. These may be used alone or in combination of two or more.
The content of such a resin 4 is preferably about 30 to 90% by mass of the sealing material 1.

The rubber-like elastic body forming the elastic body particles 5 exhibits an elongation of 200% or more without breaking, and when the compressive stress or expansion stress (tensile stress) is released, the volume changes before and after the stress release. Those that remain within the range of −10% to 10% are preferable.
Among these, preferable rubber-like elastic bodies include methyl methacrylate-butadiene rubber (MBR), ethylene propylene rubber (EPR), acrylonitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), chlorosulfonated polyethylene (CSP), Synthesis of chloroprene rubber (CR), isoprene rubber (IR), butyl rubber (IIR), acrylic rubber, fluorine rubber, silicone rubber, butadiene rubber (MBS), polyphenylene sulfide (PPS), ethylene-propylene dimethyl rubber (EPDM), etc. Styrene elastomer such as rubber, styrene-butadiene-styrene (SBS) copolymer, styrene-isoprene-styrene (SIS) copolymer, olefin elastomer, urethane elastomer, polyamide elastomer, Tajien elastomers (MBS), and vinyl-based elastomer chloride (TPVC) is. These may be used alone or in combination of two or more.
The elastic particles 5 formed of such a rubber-like elastic body may be composed of a single phase or a plurality of phases. As the elastic particles 5 composed of a plurality of phases, for example, a core / shell structure in which the core portion is composed of a polymer rich in elasticity and the shell portion is composed of a polymer having a functional group that improves dispersibility in the resin 4. The body is mentioned.
The content of such elastic particles 5 (rubber-like elastic body) is preferably about 10 to 70% by mass with respect to the entire sealing material 1.

  In addition, other components may be added to the sealing material 1 as necessary. Other components include, for example, fillers (mica, talc, kaolin, sericite, bentonite, zonotolite, sepiolite, smectite, montmorillonite, wollastonite, silica, calcium carbonate, glass beads, glass flakes, glass microballoons, clay, Molybdenum disulfide, titanium oxide, zinc oxide, antimony oxide, calcium polyphosphate, graphite, barium sulfate, magnesium sulfate, zinc borate, calcium borate, aluminum borate whisker, potassium titanate whisker, zinc white, sulfur, etc.), Pigments, dyes, lubricants, release agents, compatibilizers, dispersants, crystal nucleating agents, plasticizers, heat stabilizers, antioxidants, anti-coloring agents, UV absorbers, fluidity modifiers, foaming agents, antibacterial agents Agents, vibration damping agents, antistatic agents, surfactants and the like. These may be used alone or in combination of two or more. These content rates can be appropriately set within a range not impairing the object of the present invention.

(Manufacturing method of sealing material)
Next, the manufacturing method of the sealing material 1 is demonstrated.
This manufacturing method comprises a first step of heating and mixing the resin 4 and the elastic particles 5 to obtain a resin composition, and a second step of injection molding the resin composition in a mold. .

In the first step, first, the resin 4 and the elastic particles 5 are heated and mixed. Even if this 1st process is the process of adding and mixing the elastic body particle 5 to this, melting the resin 4 by heating, or what mixed the resin 4 and the elastic body particle 5 is heated. Thus, it may be a step of melting at least the resin 4. The mixing ratio of the resin 4 and the elastic particles 5 can be set according to the content ratio of the resin 4 and the elastic particles 5 in the sealing material 1 described above. And the above-mentioned other component can be added to the resin composition obtained by this 1st process.
The heating temperature in the first step can be appropriately set at a temperature equal to or higher than the melting point of the resin 4 to be used, and is preferably lower than the glass transition point of the rubber-like elastic body forming the elastic particles 5. Such a 1st process can be performed using well-known heating kneaders, such as a biaxial kneader, for example. And in the manufacturing method of this embodiment, a resin composition is pelletized and it uses for the 2nd process demonstrated below.

The injection molding in the second step includes injection compression molding, gas assist injection molding, insert molding and the like. The injection molding machine to be used may have a known structure, for example, a hopper that is an inlet for a pelletized resin composition, and a resin composition that is plasticized by kneading the resin composition under heating May be provided with a kneading mechanism for preparing the above and a nozzle for discharging the plasticized resin composition into the cavity of the mold. As is well known, the kneading mechanism includes a cylinder, a screw disposed in the cylinder, a motor that rotates the screw, and a heater that heats the inside of the cylinder.
The mold is not particularly limited as long as it can form a cavity having the shape of the sealing material 1, and includes a mold made of a known material such as a metal or a resin.
In the second step, the sealing material 1 is formed by discharging the resin composition from the injection molding machine into the mold. Incidentally, in the insert molding, the sealing material 1 can be molded so that the separator 11 and the sealing material 1 are integrated, or the membrane electrode assembly 10 and the sealing material 1 are integrated.

Next, the effect of the sealing material 1 which concerns on this embodiment, and its manufacturing method is demonstrated.
Since the elastic particles 5 are dispersed in the resin 4 as the matrix phase, the sealing material 1 exhibits the acid resistance by the resin 4 and gives elasticity to the sealing material by the elastic particles 5. Demonstrate sex. Moreover, since acid resistance is ensured with the resin 4, unlike the conventional sealing material, it is not necessary to use expensive fluororubber, and can be manufactured at low cost.
The sealing material 1 can be easily manufactured by molding a resin 4 (resin composition) in which the elastic particles 5 are dispersed.
In the sealing material 1, the elasticity of the sealing material 1 can be controlled by adjusting the content of the elastic particles 5 in the sealing material 1. Therefore, the sealing material 1 is used as a spring member having a spring constant corresponding to the design when used in a fuel cell FC having a stack structure of a constant length stack that does not use a disc spring, and can reduce volume and weight. be able to.

  Moreover, since the sealing material 1 is comprised by the single layer, unlike the conventional sealing material which consists of two layers (for example, refer patent document 1), it is not necessary to worry about interlayer separation.

  Moreover, since the sealing material 1 has a larger content of the elastic particles 5 in the inner portion 7 than the content of the elastic particles 5 in the front portion 6, the content of the resin 4 in the front portion 6. Is increasing. Therefore, the acid resistance of the sealing material 1 is further improved.

  Further, in the sealing material 1 in which the content of the elastic particles 5 is 10% by mass or more and 70% by mass or less, the elution of the rubber-like elastic body is suppressed while elasticity is imparted to the sealing material 1, and thus the sealing material 1 Deterioration is prevented.

  In addition, since all of the surface of the sealing material 1 is covered with the resin 4, elution of the rubber-like elastic body is reliably suppressed. As a result, the deterioration of the sealing material 1 is prevented more effectively.

  And in the manufacturing method of the sealing material 1, the sealing material 1 which consists of a single layer can be shape | molded by discharging the resin composition containing the resin 4 and the elastic body particle | grain 5 in a predetermined type | mold from an injection molding machine. it can.

  In this manufacturing method, when the resin composition is discharged into the mold, the resin component of the resin composition increases in the vicinity of the interface between the mold and the resin composition due to the affinity between the resin 4 and the mold. At the same time, as the distance from the mold increases, in other words, the sealing material 1 in which the content of the elastic particles 5 gradually increases from the surface side toward the inner side can be formed. And the sealing material 1 in which all the surfaces were covered with the resin 4 can also be shape | molded.

  Moreover, according to this manufacturing method, unlike the manufacturing method of the conventional sealing material (for example, refer patent document 1), it is not necessary to extrude two layers. Therefore, the sealing material 1 can be manufactured easily and inexpensively as compared with the conventional manufacturing method of the sealing material.

  Further, in this manufacturing method, the heating temperature in the first step is set to a temperature lower than the glass transition point of the rubber-like elastic body forming the elastic body particles 5, so that the compatibility between the resin 4 and the elastic body particles 5 is achieved. Can be avoided. As a result, according to this manufacturing method, it is possible to manufacture the sealing material 1 having more elasticity.

In addition, this invention is implemented in various forms, without being limited to the said embodiment.
In the separators 44 and 45 according to the embodiment, the resin portion 26b is formed so as to surround the metal portion 26a, but the present invention is not limited to this. FIG. 13 referred to here is a diagram showing a separator according to another embodiment, and is a plan view of the separator arranged on the anode side as seen from the anode side. In other embodiments, the same components as those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in FIG. 13, in this separator 44, resin portions 26b and 26b are formed on both sides of the metal portion 26a.
In such a separator 44, a seal portion 17a formed integrally with the resin portion 26b is formed around the through holes 44a, 44b, 44e, and 44f. The sealing material 17c and the sealing material 17d arranged so as to extend over both the surface of the metal portion 26a and the surface of the resin portion 26b are provided separately from the separator 44. The sealing material 17c surrounds the through holes 44c and 44d, and surrounds the flow path 44s formed in the metal portion 26a from the outside of the sealing material 17d. The sealing material 17d surrounds the flow path 44s inside the sealing material 17c, and, like the sealing portion 17b of the separator 44 according to the embodiment, the solid polymer electrolyte membrane 50 at the periphery of the membrane electrode assembly 10. And the separator 44 are sealed. Incidentally, such sealing materials 17c and 17d are preferably formed of the resin composition described above.

  In the sealing material 1 according to the above embodiment, the sealing material 1 disposed between the separator 11 and the membrane electrode assembly 10 is illustrated. However, each single cell 12 has a pair of separators 11 individually. The sealing material 1 used may be disposed between the separators 11.

  Moreover, in the sealing material 1 according to the above embodiment, the sealing material 1 having the protruding portion 3 on one side of the base portion 2 is exemplified, but the present invention is not limited to this, and the seal consisting only of the base portion 2 The sealing material which has the protrusion part 3 in both the base | substrate parts 2 may be sufficient.

Next, the present invention will be described more specifically with reference to examples.
(Example 1 to Example 8)
First, a resin composition containing the resin shown in Table 1, elastic particles made of a rubber-like elastic body, and other additives in a predetermined compounding ratio (parts by mass shown in parentheses in Table 1) was prepared.

In Table 1, PVC described in “Resin column” is polyvinyl chloride (Sekisui Co., Ltd., HA-27F), PPS is polyphenylene sulfide (Toray Co., Ltd., A-900), The polymer PE is ultra high molecular weight polyethylene (manufactured by Asahi Kasei Corporation, Sunfine (registered trademark) UH-950). MBS as a rubber-like elastic body is a butadiene-based elastomer (manufactured by Mitsubishi Rayon Co., Methbrene C-223A), NBR is acrylonitrile-butadiene rubber (manufactured by JSR, N-260S), and SBS is styrene- It is a butadiene-styrene copolymer (Taftec (registered trademark) H1052 manufactured by Asahi Kasei Co., Ltd.), TPVC is a vinyl chloride elastomer (manufactured by Denki Kagaku Kogyo Co., Ltd., Dencaleomer G), and EPDM is ethylene-propylene dimethyl rubber. (DOW, 46160), and CR is chloroprene rubber (Denka Chloroprene, manufactured by Denki Kagaku Kogyo). The glass beads as other additives are EMB-10 manufactured by Potters Barotini, and the antioxidant is Irganox (registered trademark) 1010 manufactured by Ciba Special Chemicals, which includes titanium oxide and sulfur. Stabilizer (tributyltin oxide) and stearic acid are those manufactured by Wako Pure Chemical Industries, Ltd., and the vulcanizing agent is Barnotsk DGM manufactured by Ouchi Shinsei Chemical Co., Ltd.
The resin composition was prepared by heating and mixing the components shown in Table 1. For this preparation, a twin screw extruder (Toshiba Corp., TEM-48SS) was used, and the resin composition was pelletized.

  Next, the pelletized resin composition was injection compression molded to form a sealing material. As the injection molding machine, a 350 type injection molding machine manufactured by Mitsubishi Heavy Industries, Ltd. was used. In this step, a rectangular stainless steel plate (SUS316) was disposed in the mold in plan view, and a frame-shaped sealing material was formed along the edge of the stainless steel plate. This sealing material was integrated with the stainless steel plate. Table 1 shows the mold temperature (mold temperature) at the time of molding.

Next, the formed sealing material was subjected to a sealing performance evaluation test. FIG. 14 is a schematic view of a test apparatus used for the seal performance evaluation test. As shown in FIG. 14, this test apparatus 20 is configured to supply hydrogen gas (H ₂ ) at a predetermined pressure between a pair of press plates 21, bolts 23 that fasten the press plates 21, and a stainless plate 22 described later. A gas supply pipe 24 and a pressure gauge 25 for detecting the pressure between the stainless steel plates 22 are provided.

In this seal performance evaluation test, first, as shown in FIG. 14, the sealing material 1 integrated with the stainless steel plate 22 is sandwiched between the stainless steel plates 22 having the same shape and arranged between the press plates 21 of the test apparatus 20. did. And the seal | sticker linear pressure of the sealing material 1 was set to 5 kg / cm by tightening the volt | bolt 23. FIG. Next, hydrogen gas was fed from the hydrogen gas supply pipe 24 between the stainless steel plates 22 through the holes 22 a formed in the stainless steel plate 22. The pressure of the hydrogen gas between the stainless steel plates 22 at this time was set to 200 kPa.
And after leaving for 10 minutes, if the pressure drop of the hydrogen gas between the stainless steel plates 22 was less than 5%, it determined with the sealing material 1 having a sealing performance. Those having sealing performance are shown in Table 1, and those having no sealing performance are shown in Table 1 as “X”. In addition, this evaluation test was done about the case where the temperature of the sealing material 1 is 80 degreeC, and -20 degreeC.

  Moreover, after tightening the bolt 23 so that the seal linear pressure would be 7 kg / cm and releasing it 30 times, the seal performance evaluation test at 80 ° C. was performed in the same manner as described above. The results are shown in Table 1 as “seal performance after load ON / OFF”.

Next, an acid resistance test was performed on the formed sealing material. In this acid resistance test, 10 g of the obtained sealing material was immersed in 100 ml of an acidic solution (PH2, 80 ° C.) for 100 hours, and concentrated (5 times concentrated) until the acidic solution became 20 ml to prepare a sample. The sample was analyzed for elution components with an ICP (Inductively Coupled Plasma) emission spectrometer.
And the sealing material whose elution component was less than 100 ppm was determined to be excellent in acid resistance, and is marked as “◯” in Table 1. Moreover, the sealing material whose elution component was 100 ppm or more and less than 200 ppm was determined to have acid resistance, and is described as “Δ” in Table 1. Moreover, the sealing material whose elution component was 200 ppm or more was determined as not having acid resistance, and is indicated as “x” in Table 1.

(Comparative Example 1)
A resin composition containing the resin shown in Table 2 and other additives at a predetermined compounding ratio (part by mass shown in parentheses in Table 2) was prepared. A sealing material was molded in the same manner as in Example except that this resin composition was used. And about this sealing material, the sealing performance and the acid-proof evaluation test were done like having mentioned above. The results are shown in Table 2.

(Comparative Example 2 and Comparative Example 3)
In Comparative Example 2, a sealing material (EPDM sealing material) made of ethylene-propylene dimethyl rubber was used. In Comparative Example 3, a sealing material made of silicone rubber (silicone rubber sealing material) was evaluated in the same manner as described above. Went. The results are shown in Table 2.

(Results of evaluation test)
As shown in Table 1, the sealing materials produced in Examples 1 to 8 had sealing performance. The sealing materials produced in Examples 1 to 8 all have acid resistance, and in particular, the sealing materials produced in Examples 1 to 7 have a rubbery elastic content. Since it was in the range of 10 to 70% by mass, the acid resistance was excellent.
On the other hand, since the sealing material produced in Comparative Example 1 does not contain elastic particles, it has acid resistance, but does not have sealing performance at −20 ° C., and after load ON / OFF It also has no sealing performance.
Moreover, since the sealing material in Comparative Example 2 and Comparative Example 3 does not contain resin, it has sealing performance but does not have acid resistance.

(Example 9 and Example 10)
First, a resin composition containing a resin shown in Table 3, elastic particles made of a rubber-like elastic body, and other additives at a predetermined blending ratio (parts by mass shown in parentheses in Table 3) was prepared.

  In Table 3, PVC, PPS, MBS, NBR, glass beads, antioxidants, titanium oxides, and stabilizers (tributyltin oxide) as additives described in “Resin column” are the same as in Examples 1 to 3. This is the same as that used in Example 8.

  Next, the resin composition shown in Table 3 is injected into the mold 13 (see FIG. 10) in which a stainless plate (SUS316) as the metal part 26a is inserted, thereby producing the separator 44 and the separator 45 shown in FIG. did. Table 3 shows the mold temperature (mold temperature) during molding.

Next, with respect to the obtained separators 44 and 45, the adhesion performance between the resin portion 26b and the metal portion 26a shown in FIG. 2 was evaluated, and the sealing performance in the separators 44 and 45 was evaluated. The results are shown in Table 3.
In addition, the evaluation of the adhesion performance was good in that the separators 44 and 45 were immersed in hot water at 80 ° C. for 500 hours and then there was no peeling or floating between the resin part 26b and the metal part 26a (in Table 3, It was evaluated as).

The evaluation of the sealing performance is performed by aligning the separator 44 and the separator 45 such that the surface on the flow path 44s (see FIG. 3) side and the surface on the flow path 44s (see FIG. 5) face each other. The sealing performance of the seal portion 17a (see FIGS. 3 and 5) was evaluated. The seal linear pressure was set to 5 kg / cm. The atmosphere at this time was 50% Rh at 23 ° C. In this evaluation of the sealing performance, the through holes 44a, 44b, 44c, 44e, 44f (see FIG. 3) on the separator 44 side facing each other are closed, and the through holes 45a, 45b, 45c, 45d, on the separator 45 side are closed. 45e and 45f (see FIG. 5) were blocked. Then, hydrogen was filled between the separator 44 and the separator 45 through the through hole 44d on the separator 44 side and the communication path 44g (see FIG. 3). At this time, the internal pressure of hydrogen filled between the separator 44 and the separator 45 was set to 150 kPa.
Then, after 10 minutes, those having a decrease in the internal pressure of hydrogen of 3% or less were evaluated as having good sealing performance (indicated by ◯ in Table 3).

(Result of evaluation test)
As shown in Table 3, the separators 44 and 45 produced in Example 9 and Example 10 had good adhesion performance and sealing performance.

1 is a perspective view of a fuel cell in which a separator according to an embodiment is incorporated. It is a disassembled perspective view which shows the laminated structure of a single cell. It is the top view which looked at the separator arrange | positioned at the anode side from the anode side. 3A is a partial cross-sectional view taken along the line XX ′ of FIG. 3, FIG. 3B is a partial cross-sectional view taken along the line YY ′ of FIG. 3, and FIG. It is. It is the top view which looked at the separator arrange | positioned at the cathode side from the cathode side. It is a top view of the separator arrange | positioned at the cathode side, and is a figure which shows the surface opposite to the surface shown in FIG. (A) is a partial cross-sectional view taken along the line P-P 'in FIG. 5, (b) is a partial cross-sectional view taken along the line Q-Q' in FIG. 5, and (c) is a cross-sectional view taken along the line RR 'in FIG. It is a fragmentary sectional view. FIG. 6 is a cross-sectional view of a laminate formed by the separator shown in FIG. 3 and the separator shown in FIG. 5, and (a) is a cross-sectional view corresponding to the line XX ′ in FIG. 3 and the line PP ′ in FIG. 5. (B) is a cross-sectional view corresponding to the YY ′ line in FIG. 3 and the QQ ′ line in FIG. 5, and (c) is the ZZ ′ line in FIG. 3 and the R— line in FIG. It is sectional drawing corresponding to R 'line. (A) is the elements on larger scale of the resin part shown to Fig.4 (a), (b) is the N section enlarged view of (a). It is a schematic diagram which shows the cross section of the type | mold used for shaping | molding of a separator. It is a schematic diagram which shows the fuel cell using the sealing material for fuel cells which concerns on this embodiment. (A) is a perspective view of a sealing material for a fuel cell according to the present embodiment, (b) is a cross-sectional view taken along the line AA ′ in (a), and (c) is an enlarged view of a portion B in (b). Is It is a figure which shows the separator which concerns on other embodiment, and is the top view which looked at the separator arrange | positioned at the anode side from the anode side. It is the schematic of the testing apparatus used for the evaluation test of the sealing performance in the sealing material produced in the Example and the comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell sealing material 4 Resin 5 Elastic particle 10 Membrane electrode assembly 10g Sealing material 17a Sealing part 17b Sealing part 18a Sealing part 18b Sealing part 19 Sealing part 26a Metal part 26b Resin part 31 Single cell 33a Through hole 33b Through hole 33c Through hole 33d Through hole 33e Through hole 33f Through hole 42 Anode 43 Cathode 44 Separator 44a Through hole 44b Through hole 44c Through hole 44d Through hole 44e Through hole 44f Through hole 44g Connection path 44h Connection path 44s Channel 45 Separator 45a 45b through-hole 45c through-hole 45d through-hole 45e through-hole 45f through-hole 45g connecting path 45h connecting path 45s channel 46a connecting path 46b connecting path 46s cooling water channel 50 solid polymer electrolyte membrane

Claims (9)

A resin constituting the matrix phase;
A fuel cell sealing material comprising: particles made of a rubber-like elastic material dispersed in the resin.   2. The fuel cell sealing material according to claim 1, wherein a content of the rubber-like elastic body is larger in an inner portion than in a front portion of the sealing material.   The fuel cell sealing material according to claim 1 or 2, wherein the content of the rubber-like elastic body in the whole sealing material is 10 to 70 mass%.   4. The fuel cell sealing material according to claim 1, wherein the entire surface is covered only with a matrix phase. 5. A first step of heating and mixing the resin and particles made of a rubber-like elastic body to obtain a resin composition;
And a second step of injection-molding the resin composition in a mold. A plate-like metal part having a gas flow path formed on at least one side;
A resin part formed on the metal part while having a seal part made of a convex part;
A separator comprising:
The separator, wherein the resin part includes a resin constituting a matrix phase and particles made of a rubber-like elastic body dispersed in the resin.   The said resin part is formed so that the said metal part may be surrounded from the outer side of the surface direction of the said metal part, and the said seal part is arrange | positioned on the outer side of the said metal part. Separator.   At least one of a reaction gas supply hole, a reaction gas discharge hole, a cooling water supply hole, and a cooling water discharge hole is formed in the resin portion, and the seal portion is around the hole, The separator according to claim 6 or 7, wherein the separator is disposed around a flow path of a reaction gas or cooling water formed between the hole and the metal part.   The separator according to any one of claims 6 to 8, wherein the resin portion is formed so as to be integrated with the metal portion.

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