JP2007141820A - Separator for polymer electrolyte fuel cell and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a separator for a polymer electrolyte fuel cell having hardly flooding (clogging with water) and superior in strength and corrosion resistance, and capable of reducing manufacturing cost, and its manufacturing method. <P>SOLUTION: The separator for polymer electrolyte fuel cell has a resin layer formed by electrodeposition so as to cover a metal substrate having grooves on at least one side and this resin layer is made to contain a conductive material and develop water repellency. The manufacturing method of this separator comprises a process of forming grooves at least on one side of the metal substrate and a process of forming a resin layer with water repellency so as to cover the metal substrate by electrodeposition using an electrodeposition liquid in which a conductive material is dispersed in a resin having at least one kind of elements and functional groups for developing water repellency in a structure. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a separator for a fuel cell, and in particular, a separator used between unit cells of a fuel cell in which a plurality of unit cells each having electrodes disposed on both sides of a solid polymer electrolyte membrane are stacked, and a method for producing such a separator. About.

A fuel cell is simply a device that continuously supplies fuel (reducing agent) and oxygen or air (oxidant) from the outside, and reacts electrochemically to extract electrical energy. It is classified by type, use, etc. In recent years, depending on the type of electrolyte used, it is largely divided into solid oxide fuel cells, molten carbonate fuel cells, phosphoric acid fuel cells, polymer electrolyte fuel cells, and alkaline aqueous fuel cells. Generally, it is classified into 5 types.
These fuel cells use hydrogen gas generated from methane or the like as a fuel. Recently, a direct methanol fuel cell (hereinafter also referred to as DMFC) that directly uses an aqueous methanol solution as a fuel is also known. Yes.
In particular, a polymer electrolyte fuel cell (hereinafter also referred to as PEFC) having a structure in which a solid polymer membrane is sandwiched between two kinds of electrodes and these members are sandwiched between separators has attracted attention.

This PEFC has a stack structure in which a plurality of unit cells each having an air electrode (oxygen electrode) and a fuel electrode (hydrogen electrode) are stacked on both sides of a solid polymer electrolyte membrane to increase the electromotive force according to the purpose. Things are common. In general, the separator disposed between the unit cells is formed with a groove for supplying fuel gas for supplying fuel gas to the adjacent unit cell on one side thereof, and adjacent to the other side. An oxidant gas supply groove for supplying an oxidant gas to the other unit cell is formed.
However, in the oxidant gas supply groove for supplying the oxidant gas to the unit cell, hydrogen ions that have permeated the unit cell and oxygen as the oxidant gas react with each other as described below to clog the generated water. As a result, so-called flooding occurs.
^{_{1 / 2O 2 + 2e - +}} 2H + → H 2 O

When such flooding occurs, there is a problem in that the gas flow in the groove for supplying the oxidant gas is hindered and the performance of the PEFC is lowered.
In order to prevent the occurrence of flooding, for example, a separator provided with a water-repellent treatment layer made of a gold plating layer, a composite plating layer of gold and carbon fluoride, or a fluororesin film on the inner surface of the groove for supplying an oxidant gas (Patent Document 1), a separator (Patent Document 2) and the like in which a drainage groove is provided on the bottom wall surface of an oxidizing gas supply groove have been developed.
JP-A-9-298064 JP 2000-123848 A

However, the separator using gold as described above has a problem of high manufacturing cost. In addition, it is difficult to form a fluororesin film or the like along the shape of the groove for supplying the oxidant gas. If an insulating film such as a fluororesin film is formed on the separator other than the groove for supplying the oxidant gas, There was also a problem of lowering.
On the other hand, in the separator in which the drainage groove is provided on the bottom wall surface of the oxidant gas supply groove, there is a problem that when there is a lot of reaction-generated water, the drainage is not in time and flooding occurs.
The present invention has been made in view of the above circumstances, and is a separator for a polymer electrolyte fuel cell that is unlikely to cause flooding (water clogging), has excellent strength and corrosion resistance, and can reduce manufacturing costs. An object of the present invention is to provide a method for producing such a separator.

In order to achieve such an object, the present invention provides a metal substrate, a groove formed on at least one surface of the metal substrate, and a resin layer formed by electrodeposition so as to cover the metal substrate. The resin layer contains a conductive material and is water repellent.
As another aspect of the present invention, the conductive material is configured to be at least one of carbon particles, carbon nanotubes, carbon nanofibers, carbon nanohorns, and corrosion-resistant metals.

  The present invention also includes a metal substrate, a groove formed on at least one surface of the metal substrate, and a resin layer formed by electrolytic polymerization so as to cover the metal substrate, and the resin layer is electrically conductive. The resin composed of a conductive polymer contains a dopant that enhances conductivity, and is water-repellent.

  The present invention also includes a metal substrate, a groove formed on at least one surface of the metal substrate, and a resin layer formed so as to cover the metal substrate, and the resin layer is formed by electrolytic polymerization. A first resin layer containing a dopant that enhances conductivity in a resin composed of a conductive polymer, and a water repellent material containing a conductive material formed by electrodeposition so as to cover the first resin layer It was set as the structure which consists of a 2nd resin layer.

As another aspect of the present invention, the conductive material is configured to be at least one of carbon particles, carbon nanotubes, carbon nanofibers, carbon nanohorns, and corrosion-resistant metals.
As another aspect of the present invention, the resin layer is configured to contain at least one element that exhibits water repellency and a functional group.
In another embodiment of the present invention, the element is fluorine or silicon, and the functional group is an alkyl group.
As another embodiment of the present invention, the resin layer has a thickness in the range of 0.1 to 100 μm.

  In the production method of the present invention, a conductive material is dispersed in a resin having a step of forming a groove on at least one surface of a metal substrate and at least one element or functional group for expressing water repellency. Forming a water-repellent resin layer so as to cover the metal substrate by electrodeposition using an electrodeposition solution.

  The production method of the present invention comprises a step of forming a groove on at least one surface of a metal substrate, and a resin comprising a conductive polymer having at least one element or functional group for expressing water repellency in the structure. And a step of forming a water-repellent resin layer containing a dopant for enhancing conductivity so as to cover the metal substrate by electrolytic polymerization.

  The manufacturing method of the present invention includes a step of forming a groove on at least one surface of a metal substrate, and a first resin layer containing a dopant that enhances conductivity in a resin made of a conductive polymer, by electrolytic polymerization. A step of forming the substrate so as to cover the substrate; and electrodeposition using an electrodeposition liquid in which a conductive material is dispersed in a resin having at least one element or functional group for expressing water repellency in the structure. And a step of forming a water-repellent second resin layer so as to cover one resin layer.

  In the present invention, since the resin layer is formed by electrodeposition or electrolytic polymerization, the resin layer is a uniform resin layer along the shape of the groove, and exhibits high corrosion resistance and also exhibits water repellency. The generated water is easily discharged to the outside by the oxidant gas, clogging of the groove portion is suppressed, and the strength is high by using a metal base, and the use of noble metal is not required, thereby reducing the manufacturing cost. It can be kept low.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a partial cross-sectional view showing an embodiment of a separator for a polymer electrolyte fuel cell of the present invention. In FIG. 1, a separator 1 according to the present invention includes a metal substrate 2, groove portions 3 formed on both surfaces of the metal substrate 2, and a resin layer 5 formed by electrodeposition so as to cover both surfaces of the metal substrate 2. It has. The resin layer 5 contains a conductive material and has water repellency.
The material of the metal substrate 2 constituting the separator 1 is preferably a material having good electrical conductivity, desired strength, and good workability, such as stainless steel, cold-rolled steel plate, aluminum, titanium, and copper. It is done.

When the separator 1 is incorporated in a polymer electrolyte fuel cell, one of the grooves 3 of the metal substrate 2 serves as a fuel gas supply groove for supplying fuel gas to adjacent unit cells, and the other is This is an oxidant gas supply groove for supplying an oxidant gas to another adjacent unit cell. Further, one of the groove portions 3 may be either a fuel gas supply groove portion or an oxidant gas supply groove portion, and the other may be a cooling water groove. Further, the groove 3 may be provided only on one surface of the metal base 2.
The shape of the groove 3 is not particularly limited, and may be a meandering continuous shape, a comb shape, or the like, and the depth, width, and cross-sectional shape are not particularly limited. Further, the shape of the groove 3 may be different between the front and back of the metal base 2.

The resin layer 5 that constitutes the separator 1 has conductivity and water repellency, and imparts corrosion resistance to the metal substrate 2. This resin layer 5 is an anionic or cationic synthetic polymer resin having electrodeposition properties, and it is electrically conductive with a synthetic polymer resin having elements and functional groups for expressing water repellency in its structure. A film can be formed by electrodeposition using an electrodeposition liquid in which a material is dispersed and then cured.
Examples of the element for expressing the water repellency contained in the resin layer 5 include fluorine and silicon. In addition, examples of the functional group for expressing water repellency include alkyl groups such as methyl, ethyl, propyl, n-butyl, isobutyl, hexyl, octyl, decyl, and lauryl.

Examples of the anionic synthetic polymer resin having an element or functional group for expressing water repellency in its structure include acrylic resin, polyester resin, maleated oil resin, polybutadiene resin, epoxy resin, polyamide resin, polyimide resin, and the like. These can be used alone or as a mixture in any combination. Such an anionic synthetic polymer resin may be used in combination with a crosslinkable resin such as a melamine resin, a phenol resin, or a urethane resin.
On the other hand, examples of the cationic synthetic polymer resin having an element or functional group for expressing water repellency in its structure include acrylic resin, epoxy resin, urethane resin, polybutadiene resin, polyamide resin, polyimide resin, and the like. These can be used alone or as a mixture in any combination. Such a cationic synthetic polymer resin may be used in combination with a crosslinkable resin such as a polyester resin or a urethane resin.
Further, in order to impart tackiness to the above-described synthetic polymer resin having electrodeposition properties, a tackifier resin such as rosin, terpene, and petroleum resin may be added as necessary.

  Such an electrodepositable synthetic polymer resin is subjected to electrodeposition in a state where it is neutralized with an alkaline or acidic substance and solubilized in water, or in an aqueous dispersion state. That is, the anionic synthetic polymer resin is neutralized with amines such as trimethylamine, diethylamine, dimethylethanolamine and diisopropanolamine, and inorganic alkalis such as ammonia and caustic potash. The cationic synthetic polymer resin is neutralized with an acid such as formic acid, acetic acid, propionic acid, or lactic acid. The neutralized water-soluble polymer resin is used in a state of being diluted in water as a water-dispersed type or a dissolved type.

  Examples of the conductive material contained in the resin layer 5 include carbon materials such as carbon particles, carbon nanotubes, carbon nanofibers, and carbon nanohorns, and corrosion-resistant metals. The conductive material is not limited to these conductive materials. In particular, fine fibrous carbon materials such as carbon nanotubes, carbon nanofibers, and carbon nanohorns are suitable for imparting conductivity to the resin layer 5. The content of such a conductive material in the resin layer 5 can be appropriately set according to the conductivity required for the resin layer 5, and can be set, for example, in the range of 30 to 90% by weight.

  Fine fibrous carbon materials such as carbon nanotubes, carbon nanofibers, and carbon nanohorns are expected to be applied to various fields such as composite materials and electronic devices as nanotechnology materials. When used as a composite material, the physical properties of these can be imparted to the composite material. For example, carbon nanotubes are excellent in terms of electrical conductivity, acid resistance, workability, mechanical strength, etc. When used as a filler in a composite material, the carbon nanotube has excellent physical properties. Can be granted.

  The water repellency of the resin layer 5 is preferably set so that the contact angle of water is in the range of 90 ° to 150 °. In the present invention, the contact angle of water is measured by a commercially available droplet contact angle measuring device. The thickness of the resin layer 5 can be in the range of 0.1 to 100 μm, preferably 3 to 30 μm. If the thickness of the resin layer 5 is less than 0.1 μm, good corrosion resistance may not be ensured due to the occurrence of pinholes, etc. If it exceeds 100 μm, the occurrence of cracks after drying and solidification, etc. Problems such as reduction and high cost occur, which is not preferable.

  In the present invention, the resin layer 5 constituting the separator 1 is formed by electrolytic polymerization, contains a dopant that enhances conductivity in a resin made of a conductive polymer, and exhibits water repellency in the structure of the conductive polymer. Therefore, it may be a resin layer having an element or a functional group. Electrolytic polymerization is basically a known method in which an electrode is immersed in an electrolytic solution containing an aromatic compound as a monomer and energized, and is electrochemically oxidized or reduced for polymerization. The inclusion of the dopant in the resin layer can be achieved by electrical doping in which the dopant is included in the electropolymerization, or liquid phase doping in which the conductive polymer is immersed in a liquid containing the dopant or a solution containing the dopant molecule after the electropolymerization. It can be carried out. Examples of the dopant include donor-type dopants such as alkali metals and alkylammonium ions, and acceptor-type dopants such as halogens, Lewis acids, proton acids, transition metal halides, and organic acids.

The amount of dopant in the resin layer 5 can be appropriately set according to the conductivity required for the resin layer 5.
Furthermore, in this invention, the resin layer 5 which comprises the separator 1 contains the 1st resin layer which contains the dopant which raises electroconductivity in resin which consists of the conductive polymer formed by electrolytic polymerization, and this 1st resin It may be a composite film structure formed by electrodeposition so as to cover the layer, comprising a conductive material, and comprising a second resin layer that is water repellent.

  FIG. 2 is a diagram for explaining the production of the separator of the present invention as described above, taking the separator 1 shown in FIG. 1 as an example. In FIG. 2, resists 9 and 9 are formed in a desired pattern on both sides of the metal plate 2 'by photolithography (FIG. 2A), and the metal plate 2' is etched from both sides using the resists 9 and 9 as a mask. Thus, the groove portions 3 and 3 are formed (FIG. 2B). Thereafter, the resists 9 and 9 are peeled off to obtain the metal substrate 2 (FIG. 2C). On both surfaces of the metal substrate 2, various anionic or cationic synthetic polymer resins having electrodeposition properties are provided with a conductive material, an element for expressing water repellency, and a functional group for expressing water repellency. A film is formed by electrodeposition using an electrodeposition liquid in which at least one kind of substance is dispersed, and then cured to form a resin layer 5 (FIG. 2D). As the electrodeposition liquid, a synthetic polymer resin having an element or a functional group for expressing water repellency in its structure, and an electrodeposition liquid in which a conductive material is dispersed can be used. In addition, a synthetic polymer resin having an element or functional group for expressing water repellency in its structure is used, and an element for expressing water repellency or a substance having a functional group for expressing water repellency Alternatively, an electrodeposition liquid in which a conductive material is dispersed can also be used. The resin layer 5 thus formed exhibits good conductivity and high corrosion resistance, and has water repellency. Thereby, the separator 1 is obtained.

Here, an example of a polymer electrolyte fuel cell using the separator of the present invention will be described with reference to FIGS. FIG. 3 is a partial configuration diagram for explaining the structure of the polymer electrolyte fuel cell, and FIG. 4 is a diagram for explaining the membrane electrode assembly constituting the polymer electrolyte fuel cell. FIG. 6 is a perspective view showing the state in which the separator of the polymer electrolyte fuel cell and the membrane electrode assembly are separated from different directions.
3 to 6, the polymer electrolyte fuel cell 11 includes a membrane electrode assembly (MEA) 21 that is a unit cell and a separator 31.

As shown in FIG. 4, the MEA 21 includes a fuel electrode (hydrogen electrode) 25 including a catalyst layer 23 and a gas diffusion layer (GDL) 24 disposed on one surface of the polymer electrolyte membrane 22. And an air electrode (oxygen electrode) 28 including a catalyst layer 26 and a gas diffusion layer (GDL) 27 disposed on the other surface of the polymer electrolyte membrane 22.
The separator 31 has a fuel gas supply groove 33a on one surface, a separator 31A having an oxidant gas supply groove 34a on the other surface, a fuel gas supply groove 33a on one surface, and the other surface. The separator 31B is provided with a cooling water groove 34b on the surface, and the separator 31C is provided with a cooling water groove 33b on one surface and an oxidant gas supply groove 34a on the other surface. Such separators 31A, 31B, and 31C are separators of the present invention, and the resin layer 5 as shown in FIG. 1 is formed on both surfaces thereof, but is omitted in the illustrated example. The separator 31B that does not include the oxidant gas supply groove 34a is coated with a resin layer that does not have water repellency to provide conductivity and corrosion resistance, that is, not the separator of the present invention. It may be.

  Two fuel gas supply holes 35a, 35b, two oxidant gas supply holes 36a, 36b, and two cooling water supplies are provided at predetermined positions of the separators 31A, 31B, 31C and the polymer electrolyte membrane 22. Holes 37a and 37b are formed as through holes. The air electrode (oxygen electrode) 28 of the MEA 21 is in contact with the surface of the separator 31A where the oxidizing gas supply groove 34a is formed, and the surface of the separator 31B where the fuel gas supply groove 33a is formed. The fuel electrode (hydrogen electrode) 25 of the MEA 21 abuts, and the surface of the separator 31B where the cooling water groove 34b is formed and the surface of the separator 31C where the cooling water groove 33b is formed abut. The separators 31A, 31B, 31C and the unit cell MEA 21 are stacked, and the polymer electrolyte fuel cell 11 is configured by repeating this process. In the stacked state, the two fuel gas supply holes 35a and 35b form fuel gas supply paths that penetrate in the stacking direction, and the two oxidant gas supply holes 36a and 36b respectively An oxidant gas supply path that penetrates the laminating method is formed, and the two cooling water supply holes 37a and 37b each form a cooling water supply path that penetrates in the laminating direction.

  The above-described embodiments of the separator of the present invention are examples, and the present invention is not limited to these embodiments.

Next, the present invention will be described in more detail by showing specific examples.
[Example]
A stainless steel plate (SUS304) having a thickness of 4.5 mm was prepared as a metal plate material, and the surface was degreased.
Next, a photosensitive material (a mixture of casein and ammonium dichromate) is applied to both surfaces of this stainless steel plate by a dip coating method to form a coating film having a thickness of 20 μm, and exposed through a photomask for groove formation. (Irradiated with a 5 kW mercury lamp for 60 seconds) and developed (sprayed with 40 ° C. hot water) to form a resist.

Next, a ferric chloride solution heated to 70 ° C. was sprayed from both sides of the stainless steel plate through the resist, and half-etching was performed to a predetermined depth. Thereafter, the resist was peeled off with an aqueous caustic soda solution at 80 ° C. and subjected to a cleaning treatment. Thus, a metal substrate having a substantially semicircular cross section having a width of 1 mm and a depth of 0.5 mm, and a groove portion having a length of 1000 mm meandering with a runout width of 100 mm and a pitch of 50 mm was obtained.
On the other hand, a water-repellent acrylic epoxy electrodeposition solution was prepared as follows.
First, 1000 parts by weight of diglycidyl ether of biphenyl A (epoxy equivalent = 910) was dissolved in 463 parts by weight of ethylene glycol monoethyl ether while maintaining at 70 ° C. with stirring, and further 80.3 parts by weight of diethylamine was added. An amine epoxy adduct (A) was prepared by reacting at 100 ° C. for 2 hours.

Coronate L (manufactured by Nippon Polyurethane Co., Ltd. diisocyanate: NCO 13% non-volatile content 75% by weight) 875 parts by weight dibutyltin laurate 0.05 parts by weight and heated to 50 ° C., to this, 390 weights of 2-ethylhexanol After that, the mixture was reacted at 120 ° C. for 90 minutes. A component (B) obtained by diluting the obtained reaction product with 130 parts by weight of ethylene glycol monoethyl ether was obtained.
Next, the mixture consisting of 1000 parts by weight of the above-described amine epoxy adduct (A) and 400 parts by weight of component (B) is neutralized with 30 parts by weight of glacial acetic acid, and then diluted with 570 parts by weight of deionized water. A resin A having a nonvolatile content of 50% by weight was prepared. 200.2 parts by weight of this resin A, 200 parts by weight of a hydroxyl group-containing fluorinated acrylic copolymer (AS-1301 manufactured by Mitsubishi Rayon Co., Ltd.), 100 parts by weight of coronate L, 1000 parts by weight of deionized water, and dibutyltin laurate 2.4 A water repellent acrylic epoxy electrodeposition solution was prepared by blending parts by weight.

Next, 60% by weight of carbon nanotubes (vapor phase carbon fiber VGCF manufactured by Showa Denko KK) as a conductive material is added to the above water-repellent acrylic epoxy electrodeposition liquid with respect to the solid content of the resin, and dispersed to perform electrodeposition. A liquid was used.
The above-mentioned electrodeposition liquid was kept at 20 ° C. and stirred, and the above-mentioned metal substrate was immersed therein, electrodeposition was performed at a gap of 40 mm and a voltage of 50 V for 1 minute, and the pulled-up metal substrate was washed with pure water. Thereafter, it was dried on a hot plate at 150 ° C. for 3 minutes, and further heat-cured at 180 ° C. for 1 hour in a nitrogen atmosphere. As a result, a uniform resin layer having a thickness of 15 μm was formed on the metal substrate including the groove portion, and a separator was obtained.

As a result of measuring the contact angle of water in the resin layer of this separator under the following conditions, it was 110 ° and it was confirmed that the separator had high water repellency.
(Measurement conditions for water contact angle)
Pure water is dropped on the surface of the object to be measured under normal temperature and pressure, the height h of the top of the water drop, and the radius a
Read directly. The angle θB formed by the line connecting the solid-liquid interface / horizon and the top of the droplet is the contact angle θA
Therefore, the contact angle of water is measured from θA = 2θB = 2 arctan (h / a).

[Comparative Example 1]
A separator was prepared in the same manner as in Example except that the water-repellent acrylic epoxy electrodeposition liquid was replaced with the epoxy electrodeposition liquid prepared as follows.
As a result of measuring the contact angle of water in the resin layer of this separator under the same conditions as in Examples, it was confirmed that the water contact angle was 60 ° and the water repellency was extremely low.

(Preparation of epoxy electrodeposition solution)
First, 1000 parts by weight of diglycidyl ether of bisphenol A (epoxy equivalent 910) was dissolved in 463 parts by weight of ethylene glycol monoethyl ether while maintaining the temperature at 70 ° C. with stirring, and further 80.3 parts by weight of diethylamine was added to 100 parts. An amine epoxy adduct (A) was prepared by reacting at 2 ° C. for 2 hours.
Coronate L (manufactured by Nippon Polyurethane Co., Ltd. diisocyanate: NCO 13% non-volatile content 75% by weight) 875 parts by weight dibutyltin laurate 0.05 parts by weight and heated to 50 ° C., to this, 390 weights of 2-ethylhexanol After that, the mixture was reacted at 120 ° C. for 90 minutes. A component (B) obtained by diluting the obtained reaction product with 130 parts by weight of ethylene glycol monoethyl ether was obtained.

  Next, the mixture consisting of 1000 parts by weight of the above-described amine epoxy adduct (A) and 400 parts by weight of component (B) is neutralized with 30 parts by weight of glacial acetic acid, and then diluted with 570 parts by weight of deionized water. A resin A having a nonvolatile content of 50% by weight was prepared. An epoxy electrodeposition solution was prepared by blending 200.2 parts by weight of this resin A (resin component 86.3 volumes), 583.3 parts by weight of deionized water, and 2.4 parts by weight of dibutyltin laurate.

[Comparative Example 2]
A metal substrate provided with a groove was produced in the same manner as in the example.
In addition, 75% by weight of carbon black (Vulcan XC-72 manufactured by Cabot Co., Ltd.) as a conductive material was added to a polytetrafluoroethylene colloid solution (ND-2 manufactured by Daikin Industries, Ltd.) based on the resin solid content. The conductive paint was dispersed.
Next, the conductive paint was spray-coated on the metal substrate, then heated in an infrared drying oven at 80 ° C. for 1 hour, and further subjected to heat treatment at 380 ° C. for 1 hour. As a result, a resin layer was formed on the metal substrate including the groove, and a separator was obtained.
As a result of measuring the contact angle of water in the resin layer of the separator under the same conditions as in the example, it was 120 °, and it was confirmed that the separator had high water repellency.
However, the resin layer of this separator is thicker than the resin layer of the example, but the thickness unevenness is large, and in particular there is a pinhole-shaped part where the resin layer is not formed on the side wall, The reliability of was low.

  The present invention can be applied to the manufacture of a fuel cell in which a plurality of unit cells each having an electrode disposed on both sides of a solid polymer electrolyte membrane are stacked.

It is a fragmentary sectional view showing one embodiment of a separator for polymer electrolyte fuel cells of the present invention. It is a figure explaining the manufacturing method of the separator of the present invention taking the separator shown in Drawing 1 as an example. It is a partial block diagram for demonstrating an example of the polymer electrolyte fuel cell using the separator of this invention. It is a figure for demonstrating the membrane electrode assembly which comprises the polymer electrolyte fuel cell shown by FIG. FIG. 4 is a perspective view showing a state in which the separator and the membrane electrode assembly of the polymer electrolyte fuel cell shown in FIG. 3 are separated from each other. FIG. 6 is a perspective view showing a state where the separator and the membrane electrode assembly of the polymer electrolyte fuel cell shown in FIG. 3 are separated from a direction different from FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Separator 2 ... Metal base | substrate 3 ... Groove part 5 ... Resin layer 11 ... Polymer electrolyte type fuel cell 21 ... Membrane electrode assembly (MEA)
31A, 31B, 31C ... separator

Claims (11)

  A metal base, a groove formed on at least one surface of the metal base, and a resin layer formed by electrodeposition so as to cover the metal base, the resin layer containing a conductive material, A separator for a polymer electrolyte fuel cell, which is water-repellent.   The separator for a polymer electrolyte fuel cell according to claim 1, wherein the conductive material is at least one of carbon particles, carbon nanotubes, carbon nanofibers, carbon nanohorns, and corrosion-resistant metals.   A metal substrate; a groove formed on at least one surface of the metal substrate; and a resin layer formed by electrolytic polymerization so as to cover the metal substrate, wherein the resin layer is a resin made of a conductive polymer. A separator for a polymer electrolyte fuel cell, which contains a dopant for enhancing conductivity and is water repellent.   A conductive polymer comprising a metal substrate, a groove formed on at least one surface of the metal substrate, and a resin layer formed so as to cover the metal substrate, the resin layer formed by electrolytic polymerization A first resin layer containing a dopant for enhancing conductivity in a resin composed of a resin and a second resin layer formed by electrodeposition so as to cover the first resin layer and containing a conductive material and having water repellency A separator for a polymer electrolyte fuel cell.   The separator for a polymer electrolyte fuel cell according to claim 4, wherein the conductive material is at least one of carbon particles, carbon nanotubes, carbon nanofibers, carbon nanohorns, and corrosion-resistant metals.   6. The separator for a polymer electrolyte fuel cell according to any one of claims 1 to 5, wherein the resin layer contains at least one element exhibiting water repellency and a functional group.   The separator for a polymer electrolyte fuel cell according to claim 6, wherein the element is fluorine or silicon, and the functional group is an alkyl group.   The separator for a polymer electrolyte fuel cell according to any one of claims 1 to 7, wherein the resin layer has a thickness in a range of 0.1 to 100 µm.   A step of forming a groove on at least one surface of the metal substrate, and an electrodeposition solution in which a conductive material is dispersed in a resin having at least one element or functional group for expressing water repellency in the structure. And a step of forming a water-repellent resin layer so as to cover the metal substrate by deposition. A method for producing a separator for a polymer electrolyte fuel cell, comprising:   A step of forming a groove on at least one surface of a metal substrate, and a dopant that enhances conductivity in a resin composed of a conductive polymer having at least one element or functional group for expressing water repellency in the structure And a step of forming the water-repellent resin layer so as to cover the metal substrate by electrolytic polymerization. A method for producing a separator for a polymer electrolyte fuel cell, comprising:   Forming a groove on at least one surface of the metal substrate, and forming a first resin layer containing a conductive polymer-containing dopant on the metal substrate by electrolytic polymerization so as to cover the metal substrate. And coating the first resin layer by electrodeposition using an electrodeposition liquid in which a conductive material is dispersed in a resin having in its structure at least one element or functional group for expressing water repellency. Forming a water-repellent second resin layer as described above, and a method for producing a separator for a polymer electrolyte fuel cell.

Images