JP2010198948A - Membrane-electrode assembly and method of manufacturing the same, and polymer electrolyte fuel cell - Google Patents

Abstract

A membrane electrode for producing a polymer electrolyte fuel cell with high productivity and stable quality at a relatively low cost by joining a polymer electrolyte membrane and a catalyst electrode while excluding air. To provide a joined body, a method for producing the same, and a polymer electrolyte fuel cell.
A pair of catalyst electrodes is positioned on a support and sandwiched between polymer electrolyte membranes to form a laminate, and air contained in each layer of the laminate including the catalyst electrodes and the polymer electrolyte membrane is excluded. And a laminate electrode from which air has been removed is heated and pressurized to join the catalyst electrode and the polymer electrolyte membrane.
[Selection] Figure 1

Description

  The present invention relates to a membrane electrode assembly, a manufacturing method thereof, and a solid polymer fuel cell, and more particularly to a membrane electrode assembly that bonds a polymer electrolyte membrane and a catalyst electrode while excluding air, a manufacturing method thereof, and a solid high The present invention relates to a molecular fuel cell.

  A fuel cell using hydrogen and oxygen is attracting attention as a power generation system that has almost no adverse environmental impact because its reaction product is essentially only water. In recent years, a polymer electrolyte fuel cell using a polymer electrolyte membrane having hydrogen ion conductivity as an electrolyte among fuel cells has a low operating temperature, a high output density, and can be easily downsized. It is expected to be used for in-vehicle power sources and household stationary power sources.

  A polymer electrolyte fuel cell is generally configured by laminating a large number of single cells. As shown in FIG. 8, the single cell is formed by sequentially laminating a separator 21, a gas diffusion layer 24, a catalyst electrode 22, a polymer electrolyte membrane 23 having hydrogen ion conductivity, a catalyst electrode 22, a gas diffusion layer 24, and a separator 21. Configured. The gas diffusion layer 24 is made of a material having gas diffusibility and electron conductivity, and for example, carbon paper or carbon cloth is used. Further, the catalyst electrode 22 is configured by supporting a platinum catalyst on carbon particles to form particles, and fixing the particles with a hydrogen ion conductive polymer electrolyte.

  Among these, what the catalyst electrode 22 was joined to the polymer electrolyte membrane 23 which has hydrogen ion conductivity is generally called a membrane electrode assembly (MEA: Membrane Electrode Assembly).

Then, hydrogen gas is supplied from the reaction gas channel 21 a provided in one separator 21, and oxygen gas is supplied from the reaction gas channel 21 a provided in the other separator 21. When these hydrogen gas and oxygen gas react on the platinum catalyst in the catalyst electrode 22 as shown in the following equation, an electromotive force is generated between the two electrodes.
Anode reaction (fuel electrode): H ₂ → 2H ⁺ + 2e ⁻
Cathode reaction (oxygen electrode): 2H ⁺ + 2e ⁻ + (1/2) O ₂ → H ₂ O

  In producing the MEA, a hot press is generally used as a method of joining the catalyst electrode 22 to the polymer electrolyte membrane 23. In hot pressing, heating and pressurization are performed in a state in which the catalyst electrode 22 and the polymer electrolyte membrane 23 are laminated, and the MEAs are manufactured by bonding each of them. While hot pressing has the advantage that the catalyst electrode 22 and the polymer electrolyte membrane 23 can be joined by a relatively simple device, the formation process of the catalyst electrode 22 is generally performed continuously, whereas the hot pressing is in principle a sheet. Since the treatment is performed with leaves, it is necessary to separate the forming step of the catalyst electrode 22 and the joining step of the polymer electrolyte membrane 23, and it cannot be said that the method is excellent in productivity. In addition, since the press pressure within the pressurization surface is likely to vary, it is difficult to form a uniform catalyst electrode 22 on the polymer electrolyte membrane 23, and there is a risk that a portion to which a high pressure is applied locally is damaged. There is a problem.

  Hereinafter, regarding the combination of the polymer electrolyte membrane 23 and the catalyst electrode 22, the one before joining is referred to as a laminate, and the joined state is referred to as MEA.

  In order to solve the problems in the hot press described above, a method of joining a catalyst electrode and a polymer electrolyte membrane using a roll press is often proposed.

  For example, Patent Document 1 discloses a method in which a transfer film in which a catalyst layer is formed on a long base film is used on both sides of a long polymer electrolyte membrane and is intermittently transferred at a desired interval. Are listed. In Patent Document 2, when an MEA is manufactured by laminating a catalyst layer, a gas diffusion layer, and a gasket formed on a laminate support before hot pressing to produce an MEA, the support and the adherend on the support are prepared. The method is described in which the adhesive force is reduced by heating, actinic ray irradiation, stretching of the support, and ultrasonic irradiation to perform transfer smoothly. Patent Document 3 describes a method in which a laminate is set in a jig that can be sealed with a flexible sheet and sealed, and hot pressing is performed in a state where the internal space of the jig is evacuated. Since the portion where the catalyst electrode is not disposed on the polymer electrolyte membrane is suppressed by the flexible sheet by evacuation, wrinkle generation during hot pressing can be suppressed. Furthermore, a method for preventing sticking of the flexible sheet to the MEA by introducing gas into the jig after hot pressing is described.

  On the other hand, when the catalyst electrode and the polymer electrolyte membrane are joined by a roll press, the laminate is sandwiched between a pair of rolls, and the laminate is conveyed in a certain direction while being pressurized and heated. When the roll press is performed in a state where air is mixed between body layers, if air cannot be completely removed before pressurization, pressurization / heating is performed while the air is being caught. As a result, it may cause wrinkles on the polymer electrolyte membrane, or it may cause adverse effects on power generation characteristics due to non-uniform heating and pressurization in the surface. It was a cause of deterioration.

  For the problem of air entrapment, the method of joining while evacuating as described in Patent Document 3 is very effective. However, when this method is applied to a roll press, the entire apparatus system is used. Since it is necessary to evacuate, a large-scale vacuum device is required, and both the introduction cost and running cost of the vacuum device are required.

JP 2006-185762 A JP 2003-303599 A JP 2008-146833 A

  The present invention is a membrane for producing a polymer electrolyte fuel cell with high quality and stable quality at a relatively low cost by joining a polymer electrolyte membrane and a catalyst electrode while excluding air. An object of the present invention is to provide an electrode assembly, a method for producing the same, and a polymer electrolyte fuel cell.

  As a result of repeating earnest studies on the bonding method, the present inventor has positioned the catalyst electrode with respect to the polymer electrolyte membrane to form a laminate, and before the laminate is made into a MEA by a roll press, It has been found that the above-mentioned problems can be solved by eliminating air contained in each layer of the laminate including the polymer electrolyte membrane.

  According to the first aspect of the present invention, a pair of catalyst electrodes is positioned on a support and sandwiched between polymer electrolyte membranes to form a laminate, and each of the laminates including a catalyst electrode and a polymer electrolyte membrane is provided. It is a method for producing a membrane electrode assembly, characterized in that air contained between layers is excluded, and the laminated body from which air is excluded is heated and pressurized to join the catalyst electrode and the polymer electrolyte membrane. .

  The invention according to claim 2 of the present invention is such that the air contained in each layer of the laminate including the catalyst electrode and the polymer electrolyte membrane is excluded by pressurizing the laminate in the thickness direction while pressing the laminate in the thickness direction. One side is moved to the surface direction of a laminated body, It is set as the manufacturing method of the membrane electrode assembly of Claim 1 characterized by the above-mentioned.

  The invention according to claim 3 of the present invention is a membrane electrode according to claim 1 or 2, wherein as a means for pressurizing the laminate in the thickness direction, the laminate is pressurized in the thickness direction using a roll press. This is a method for manufacturing a joined body.

  The invention according to claim 4 of the present invention is characterized in that the roll temperature in the roll press is lower than the glass transition temperature of either the polymer component in the catalyst electrode or the polymer electrolyte membrane. It is a manufacturing method of the membrane electrode assembly according to any one of 1 to 3.

  The invention according to claim 5 of the present invention is the membrane electrode according to claim 2, wherein as a means for pressurizing the laminate in the thickness direction, the laminate is pressed by being held on a roll while applying tension to the laminate. This is a method for manufacturing a joined body.

  The invention according to claim 6 of the present invention is characterized in that the roll temperature is lower than the glass transition temperature of either the polymer component in the catalyst electrode or the polymer electrolyte membrane. This is a manufacturing method of the membrane electrode assembly.

  The invention according to claim 7 of the present invention is a membrane electrode assembly manufactured by the method for manufacturing a membrane electrode assembly according to any one of claims 1 to 6.

  The invention according to claim 8 of the present invention is characterized in that the membrane electrode assembly according to claim 7 is sandwiched between a pair of gas diffusion layers, and the pair of gas diffusion layers is sandwiched between a pair of separators. And a solid polymer fuel cell.

  The invention according to claim 9 of the present invention is an apparatus for manufacturing a polymer electrolyte fuel cell, characterized in that a membrane electrode assembly is manufactured by the manufacturing method according to any one of claims 1 to 6. is there.

  According to the present invention, a membrane electrode assembly that can prevent air entrapment and prevents poor appearance such as wrinkles of a polymer electrolyte membrane, and deterioration of power generation characteristics due to insufficient heating and pressurization, a manufacturing method thereof, and a solid polymer type A fuel cell can be provided.

  In addition, according to the present invention, air between the laminates can be eliminated without introducing a large vacuum system, and therefore, a membrane electrode assembly that prevents air entrapment at a relatively low cost, a manufacturing method thereof, and a solid polymer A fuel cell can be provided.

It is a schematic explanatory drawing which shows an example of the manufacturing method of the membrane electrode assembly which concerns on embodiment of this invention. It is a schematic explanatory drawing which shows an example of the manufacturing method of the membrane electrode assembly which concerns on embodiment of this invention. It is a schematic explanatory drawing which shows an example of the manufacturing method of the membrane electrode assembly which concerns on embodiment of this invention. It is a schematic explanatory drawing which shows an example of the manufacturing method of the membrane electrode assembly which concerns on embodiment of this invention. It is a schematic explanatory drawing which shows an example of the manufacturing method of the membrane electrode assembly which concerns on embodiment of this invention. It is a schematic explanatory drawing which shows an example of the manufacturing method of the membrane electrode assembly which concerns on embodiment of this invention. It is a schematic bird's-eye view which shows an example of the manufacturing method of the membrane electrode assembly which concerns on embodiment of this invention. It is a disassembled perspective view of the conventional polymer electrolyte fuel cell.

  Hereinafter, a membrane electrode assembly, a manufacturing method thereof, and a polymer electrolyte fuel cell according to embodiments of the present invention will be described with reference to the drawings. In the following description, a combination of the polymer electrolyte membrane 3 and the catalyst electrode 2 is referred to as a laminated body, and a joined state is referred to as a MEA (membrane electrode assembly). .

  FIG. 1 is a schematic explanatory view showing an example of a method for producing a membrane electrode assembly according to an embodiment of the present invention. As shown in FIG. 1, in the method for manufacturing a membrane electrode assembly according to the embodiment of the present invention, the catalyst electrode 2 formed on the support 8 is positioned with respect to the polymer electrolyte membrane 3, and the polymer electrolyte membrane The laminated body 5 is formed in such a manner as to sandwich 3. The support 8 on which the laminated body 5 is formed is applied to a pair of roll presses 6 and is sent out by the roll press 6 so that the laminated body 5 is conveyed. This roll press 6 is responsible for pressurization and heating for forming a membrane electrode assembly (hereinafter sometimes referred to as “MEA”). In front of the roll press 6, an air extruding roll press 7 is provided, and in the process of transporting the support 8 to the roll press 6, the air extruding roll press 7 passes through the air extruding roll press 7. The air contained between the layers is removed, and heated and pressurized in the subsequent roll press 6 to be MEA.

  1, 3, 4, 5, and 6, it is assumed that the catalyst electrode 2 constituting the stacked body 5 is directly formed on the support 8. As shown in FIG. 1, the MEA is a support 8—catalyst electrode 2—polymer electrolyte membrane 3—catalyst electrode 2—support 8, and the support 8 also serves as a transfer substrate. . Among these, what is called the laminate 5 corresponds to the catalyst electrode 2 -the polymer electrolyte membrane 3 -the catalyst electrode 2. Here, the support 8 may be continuously conveyed in a web shape, and the polymer electrolyte membrane 3 at this time may be continuously supplied in a web shape.

  In the embodiment of the present invention, it is not necessary to form the catalyst electrode 2 directly on the support 8. For example, the catalyst electrode 2 is formed on another transfer substrate 9 as shown in FIG. It can also be used by installing on the support 8 after being cut out to the size of. In this method, compared with the case where the catalyst electrode 2 is directly formed on the support 8, the positioning of the catalyst electrode 2 on the support 8 is easy. The size of the catalyst electrode 2 can be easily selected. In particular, since there is no need to produce the catalyst electrode 2, there are many merits such as the loss of a very expensive catalyst material can be suppressed. When the cut-out catalyst electrode 2 is placed on the support 8, an adhesive or a pressure-sensitive adhesive is used or a transfer substrate 9 is placed on the support 8 in order to prevent displacement of the support 8 during transportation. It is more desirable to fix the catalyst electrode 2 by using a method such as insertion or attachment by electrostatic force.

  Regarding the pressure, temperature, roll material, and conveyance speed of the roll press 6, it is desirable to adopt different settings depending on the characteristics required for MEA, or the material and composition of the polymer electrolyte membrane 3 and the catalyst electrode 2, but the pressure is too low. When roll pressing is performed under a low temperature condition, the catalyst electrode 2 does not adhere to the polymer electrolyte membrane 3, and the MEA may not be formed. Therefore, it is desirable that the pressure at the time of performing the roll press is 1.5 MPa or more, and the temperature is a condition not less than the glass transition temperature of the polymer electrolyte membrane 3. Regarding the roll material, there is a step at a place where the catalyst electrode 2 in the support 8 is not installed, and it is necessary to absorb and pressurize this, so at least one side is desirably rubber, Although it depends on the set pressure, the hardness is more preferably A70 or less. If the material of the roll is a rigid body such as metal both above and below, a region where no pressure is applied to the polymer electrolyte membrane 3 is generated when the catalyst electrode 2 is pressurized, and the region is heated in a free state. Will cause wrinkles and kinks. The transport speed is preferably about 0.01 m / min to 5 m / min, although there are tradeoffs with temperature, roll size, and required tact.

  Regarding the setting conditions of the air-exclusion roll press 7, regarding the temperature, if the catalyst electrode 2 and the polymer electrolyte membrane 3 are joined, there is a possibility that air may be caught during the joining. It is necessary that the temperature be such that no bonding occurs. Although it depends on the material to be selected, it is necessary that the polymer component contained in the polymer electrolyte membrane 3 and the catalyst electrode 2 is lower than the glass transition temperature thereof, and a temperature lower by 10 ° C. or more than the glass transition temperature is desirable. . The pressure is not particularly specified, but is preferably about 0.3 MPa to 1.0 MPa in order to prevent damage to the polymer electrolyte membrane 3. When an excessive pressure is applied, the polymer electrolyte membrane 3 is stretched or the end of the catalyst electrode 2 is recessed, which may cause gas leakage during power generation. Regarding the roll material, since it is necessary to absorb the steps in the support 8, at least one of them is desirably rubber. As for the roll width, it is more desirable that the width of the roll is wider than the width of the support 8 so that the entire air in the support 8 is uniformly removed throughout the entire area.

  Note that it is not always necessary to use a roll press for the mechanism for removing air before the MEA. For example, as shown in FIG. 3, it is also effective to hold the air-exclusion roll 10 while applying tension to the support 8 that holds the laminate 5 before the roll press. By transporting the support 8 while applying tension to the support 8 and pressing the support 8 against the air removal roll 10, the air in the support 8 can be removed by the air removal roll 10. In FIG. 3, the air evacuation roll 10 is applied from the lower side, but air may escape from the air evacuation roll 10 toward the roll press 6 when applied from the upper side. For this reason, a shape in which the roll is applied from the lower side is more desirable.

  When the catalyst electrode 2 and the polymer electrolyte membrane 3 are not fixed to the support 8, the support 8 cannot be kept horizontal by being held by the air-exclusion roll 10. There is a possibility that displacement of the polymer electrolyte membrane 3 occurs. As a means for preventing this, as shown in FIG. 4, before the support 8 is held on the air removal roll 10, tension is also applied to the auxiliary roll 11 to bring the upper and lower supports 8 into close contact with each other. It is effective to sandwich the catalyst electrode 2 and the polymer electrolyte membrane 3.

  Further, the number of the air evacuation rolls 10 is not necessarily one. Rather, since a plurality of such rolls are provided and the support 8 is held in each of them, the stability of the air evacuation is increased. Therefore, it is more desirable to provide a plurality of air-exclusion rolls 10.

  Regarding the setting conditions of the air exclusion roll 10, in order to prevent the catalyst electrode 2 and the polymer electrolyte membrane 3 from joining while excluding air when passing through the roll, the polymer electrolyte membrane 3 and the catalyst electrode 2 is required to be not higher than the glass transition temperature thereof, and the roll temperature is 10 ° C. or higher than the glass transition temperature depending on the number of the air-exclusion roll 10 and the auxiliary roll 11. It is desirable to set it to a low temperature. The roll material is desirably rubber because it is necessary to absorb the steps in the support 8. It is desirable that the holding angle of the support 8 to the air evacuation roll 10 is 45 ° or more. Regarding the roll width, it is more desirable that the roll width is larger than the width of the support 8 in order to evenly exclude the air in the entire support 8.

  In the method shown in FIG. 1 or FIG. 3, a method is used in which air is removed while transporting the support body 8 holding the laminated body 5, but it is not always necessary to transport the support body 8. It is not a continuous forming method typified by roll-to-roll, but when performing MEA production with single wafers, it is more time-consuming to set the device by moving the mechanism itself that excludes air instead of the support 8. It may be effective because it is less. For example, as shown in FIG. 5, after the support 8 is fixed and the support 8 is sandwiched between the air-exclusion roll press 7, the air-exclusion roll press 7 is placed on the surface of the support 8 so as to pass over the laminate 5. Air can be eliminated by moving in the direction. Similarly, as shown in FIG. 6, the support 8 is fixed, and the support 8 is held by the air evacuation roll 10 in such a manner that the air evacuation roll 10 is pressed against a place where the laminated body 5 is not disposed. The same effect can be obtained by a method in which the air removing roll 10 is moved in the surface direction of the support 8 so as to pass over the laminated body 5 after the application. The support 8 can be fixed by nipping the support 8 at both ends of the support 8 using a fixture 12 having a length equal to or longer than the river width direction of the support 8. As a specific fixing tool 12, a clip provided with rubber at a contact portion with the support 8 is effective. In addition, it is more desirable to always apply a tension that does not sag to the support 8 in terms of preventing air from entering from the outside.

  In addition, after the air around the laminated body 5 was removed by the method shown in FIGS. 5 and 6, the air remained in another place in the support 8 in a state where the air remained in another place in the support 8. There is a possibility that air flows again in the vicinity of the laminate 5. In order to prevent this, the laminate 5 is installed from the outside of the nip portion 13 by niping the support 8 from which air has been removed, with two full width nips in the river width direction before and after the laminate 5 in the flow direction. It is effective to prevent air from entering inside. A schematic bird's-eye view from above at the time of implementation is shown in FIG.

  Next, a polymer electrolyte fuel cell using the membrane electrode assembly according to the embodiment of the present invention will be described. The polymer electrolyte fuel cell using the membrane electrode assembly according to the embodiment of the present invention is not shown so as to face the polymer electrolyte membrane 3 and the pair of catalyst electrodes 2 of the membrane electrode assembly, but is on the air electrode side. A gas diffusion layer and a fuel electrode side gas diffusion layer are disposed. Thereby, an air electrode (cathode) and a fuel electrode (anode) are formed. Then, a set of separators made of a conductive and impermeable material, which is provided with a gas flow path for gas flow and has a cooling water flow path for cooling water flow on the opposing main surface, is disposed.

  A polymer electrolyte fuel cell using a membrane electrode assembly according to an embodiment of the present invention can be manufactured at a relatively low cost with a high quality and a stable quality.

  Next, various materials used for the membrane electrode assembly according to the embodiment of the present invention will be described.

  For forming the catalyst electrode 2 according to the embodiment of the present invention, for example, a dispersion liquid in which a catalyst material and a hydrogen ion conductive polymer serving as a binder are dispersed in a dispersion medium is coated on a transfer substrate, The method of drying is taken. As a dispersion medium, a solvent such as alcohol, ether, and ketone can be used in the form of a simple substance or a mixed solution with water, etc. Among them, about 1 to 4 carbon atoms such as methanol, ethanol, propanol, and butanol are used. A mixed solution of alcohols and water is preferable from the viewpoints of material dispersibility, solution stability, safety, and material cost. As the catalyst material, it is possible to use various carbon materials in which platinum or platinum-based metal fine particles are dispersedly supported. As the carbon material, porous powders such as carbon black, Vulcan, and Ketjen black are suitable, and for metal fine particles, platinum alone or an alloy of platinum and ruthenium, iron, cobalt, palladium, nickel, etc. should be used. Can do. In general, hydrogen ion conductive polymers as binders are those in which a sulfonic acid group is introduced into a perfluorocarbon skeleton represented by Nafion (registered trademark, manufactured by DuPont). For the purpose of maintaining and strengthening the strength and fine structure holding force in the catalyst electrode, a material added with polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), or the like may be used.

  Examples of the transfer substrate on which the catalyst electrode 2 according to the embodiment of the present invention is formed include polyethylene terephthalate (PET), polyamide (nylon), polyimide (PI), polyethylene naphthalate (PEN), polytetrafluoroethylene (PTFE). ), An ethylene-tetrafluoroethylene copolymer (ETFE) molded into a film, or the like can be used. The transfer substrate is inexpensive and easy to handle, and since the catalyst electrode 2 needs to be peeled off after being bonded to the polymer electrolyte membrane 3, it is required to have excellent peelability. If it is to be made, a readily available material such as polyethylene terephthalate is preferable. On the other hand, if releasability is important, a fluorine-based polymer material such as polytetrafluoroethylene is preferable. Alternatively, a polyethylene terephthalate surface coated with a release material to improve the peelability may be used.

  Examples of the polymer electrolyte membrane 3 include perfluorosulfonic acid-based materials such as Nafion (DuPont, registered trademark), Gore Select (Japan Gore-Tex), Flemion (Asahi Glass, registered trademark), and Aciplex (Asahi Kasei, registered trademark). The solid polymer electrolyte membrane can be used. In addition to high hydrogen ion conductivity, ease of handling and mechanical strength are required as characteristics, but hydrogen ion conductivity is inversely proportional to film thickness, and mechanical strength is proportional to film thickness. Off relationship. Therefore, considering the handling, the film thickness is preferably about 50 μm to 100 μm. However, a thinner electrolyte film to which polytetrafluoroethylene, ultrahigh molecular weight polyethylene (UHPE) or the like is added as a reinforcing material may be used. The thickness of the electrolyte membrane to which the reinforcing material is added is, for example, about 20 to 50 μm.

  In the present invention, since air between the laminates can be eliminated by using the roll press 6 and the air extruding roll press 7 without introducing a large vacuum system, air can be prevented from being caught relatively inexpensively. It is possible to obtain a membrane / electrode assembly, a method for producing the membrane / electrode assembly, and a solid polymer fuel cell that can prevent the appearance of wrinkles of the polymer electrolyte membrane 3 from being deteriorated and the deterioration of power generation characteristics due to insufficient heating and pressurization. it can.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, it cannot be overemphasized that this invention is not limited only to these Examples.

  The first embodiment will be described with reference to FIG. For the polymer electrolyte membrane 3, Nafion 212 (registered trademark) manufactured by DuPont, which is a commercially available fluorine-based hydrogen ion conductive membrane, was used. For the catalyst electrode 2, a platinum-supported carbon catalyst and a commercially available Nafion (registered trademark) solution, which is a hydrogen ion conductive polymer, are mixed in a mixed solvent of water: methanol: ethanol = 1: 1: 1, and then planetary type. A catalyst dispersion prepared by applying a dispersion treatment with a ball mill (Pulversette 7 manufactured by FRITSCH) was applied onto the transfer substrate 9 and dried to be used. As the transfer substrate 9, a PTFE sheet (Nitoflon film manufactured by Nitto Denko Corporation) was used.

  After the two catalyst electrodes 2 described above are prepared and the polymer electrolyte membrane 3 is sandwiched to form the laminate 5, the laminate 5 is sandwiched between the long supports 8, and the roll press 6 is once opened. The air extruding roll press 7 is passed between the air press roll press 7 and a tension of 18 gf per 1 cm width of the support 8 is applied to the support 8. It was. As the support 8, a PTFE sheet (Nitoflon film manufactured by Nitto Denko Corporation) was used. The pressure in the roll press 6 was 2.5 MPa, and the roll temperature was 120 ° C. on both the upper and lower sides. The pressure in the air extruding roll press 7 was 0.5 MPa, and the temperature was 80 ° C.

  The second embodiment will be described with reference to FIG. As the polymer electrolyte membrane 3, Nafion 211 (registered trademark) manufactured by DuPont, which is a commercially available fluorine-based hydrogen ion conductive membrane, was used. The catalyst electrode 2 is prepared by mixing a platinum-supported carbon catalyst and a commercially available Nafion solution, which is a hydrogen ion conductive polymer, in a mixed solvent of water: methanol: ethanol = 1: 1: 1, and then a planetary ball mill (FRITSCH). A catalyst dispersion prepared by applying a dispersion treatment with Pulverisette 7) manufactured on the transfer substrate 9 and dried was used. As the transfer substrate 9, Aflex manufactured by Asahi Glass Co., Ltd., which is a fluororesin sheet, was used.

  After preparing the two catalyst electrodes 2 described above and sandwiching the polymer electrolyte membrane 3 to form the laminate 5, the laminate 5 is sandwiched between the long supports 8, and the support 8 is held in this state. The air evacuation roll 10 was held at a holding angle of 90 °, and a tension of 25 gf was applied per 1 cm width of the support. As the support 8, a PTFE sheet (Nitoflon film manufactured by Nitto Denko Corporation) was used. The temperature of the air exclusion roll 10 was room temperature. The pressure in the roll press 6 was 2.5 MPa, and the roll temperature was 120 ° C. on both the upper and lower sides.

(Comparative example)
A comparative example will be described. In the comparative example, neither the air-exclusion roll press 7 nor the air-exclusion roll 10 was used, and the other conditions were the same as those in Examples 1 and 2.

  In Examples 1 and 2, the support 8 is transported at a transport speed of 0.2 m / min, and the laminate 5 is passed through the air-exclusion roll press 7 or the air-exclusion roll 10. A MEA was formed by passage. On the other hand, in the comparative example, the support 8 was similarly transported at a transport speed of 0.2 m / min, and passed through the roll press 6 to form an MEA.

  A plurality of MEAs were formed under the conditions of Examples 1 and 2 and the comparative example, and the occurrence probability of floating between the polymer electrolyte membrane 3 and the catalyst electrode 2 was examined. The probability of occurrence of floating due to air entrapment. It was confirmed that Examples 1 and 2 were smaller than Comparative Example 1.

  In addition, according to Examples 1 and 2, since the joining of the polymer electrolyte membrane 3 and the catalyst electrode 2 is formed while preventing air from being caught, good power generation characteristics can be obtained. A membrane electrode assembly, a manufacturing method thereof, and a polymer electrolyte fuel cell could be formed at a relatively low cost.

2 ... Catalyst electrode 3 ... Polymer electrolyte membrane 5 ... Laminated body 6 ... Roll press 7 ... Air press roll press 8 ... Support 9 ... Transfer substrate 10 ... Air exhaust roll 11 ... Auxiliary roll 12 ... Fixing tool 13 ... Nip part 21 ... Separator 21a ... reactive gas flow path 22 ... catalyst electrode 23 ... polymer electrolyte membrane 24 ... gas diffusion layer

Claims (9)

A pair of catalyst electrodes are positioned on the support and sandwiched between the polymer electrolyte membranes to form a laminate,
Eliminating air contained between the layers of the laminate including the catalyst electrode and the polymer electrolyte membrane;
A method for producing a membrane electrode assembly, comprising heating and pressurizing the laminate excluding air to join the catalyst electrode and the polymer electrolyte membrane.   Exclusion of air contained between each layer of the laminate including the catalyst electrode and the polymer electrolyte membrane can be achieved by pressing one of the pressurization mechanism or the laminate while pressing the laminate in the thickness direction. The method of manufacturing a membrane electrode assembly according to claim 1, wherein the membrane electrode assembly is moved in a surface direction.   The method for producing a membrane electrode assembly according to claim 1 or 2, wherein the laminate is pressed in the thickness direction using a roll press as means for pressing the laminate in the thickness direction.   4. The roll temperature in the roll press is set to a temperature lower than the glass transition temperature of either the polymer component in the catalyst electrode or the polymer electrolyte membrane. 5. The manufacturing method of the membrane electrode assembly.   The method for producing a membrane / electrode assembly according to claim 2, wherein as the means for pressing the laminate in the thickness direction, the laminate is pressurized by being held on a roll while applying tension to the laminate.   6. The method for producing a membrane / electrode assembly according to claim 5, wherein the roll temperature is lower than the glass transition temperature of either the polymer component in the catalyst electrode or the polymer electrolyte membrane. .   A membrane / electrode assembly produced by the method for producing a membrane / electrode assembly according to claim 1.   8. A polymer electrolyte fuel cell, wherein the membrane electrode assembly according to claim 7 is sandwiched between a pair of gas diffusion layers, and the pair of gas diffusion layers is sandwiched between a pair of separators. An apparatus for producing a polymer electrolyte fuel cell, wherein a membrane electrode assembly is produced by the production method according to claim 1.

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