JP2010062009A - Method for manufacturing membrane-electrode structure for fuel cell - Google Patents

Abstract

A method for producing a membrane-electrode structure for a fuel cell that suppresses generation of wrinkles in a reinforcing member and is excellent in mass productivity.
A membrane-electrode structure includes a strip-shaped reinforcing member for reinforcing an electrolyte membrane, a strip-shaped covering member for covering the reinforcing member, and a strip-shaped backup member for supporting the covering member. A laminated body is produced (laminated body producing step), a common opening 24 is formed in the reinforcing member 22 and the backup member (opening forming step), and the electrolyte membrane 12 is attached to the reinforcing member 22 so as to be bonded. Laminating (bonding step), peeling the backup member from the prepared bonded body (backup member peeling step), forming the catalyst layer 26 on the surface of the electrolyte membrane 12 inside the exposed opening 24 (catalyst layer forming step), The covering member is peeled off (covering member peeling step) to manufacture.
[Selection] Figure 1

Description

  The present invention relates to a method for producing a membrane-electrode structure that is one of the constituent elements of a polymer electrolyte fuel cell.

  The polymer electrolyte fuel cell has a structure in which a catalyst layer is provided on both surfaces of a proton conductive solid polymer electrolyte membrane (hereinafter referred to as “electrolyte membrane”), and a gas diffusion layer is provided on the catalyst layer. A membrane-electrode assembly (MEA) is provided. From the viewpoint of reducing the internal resistance of the polymer electrolyte fuel cell, the electrolyte membrane is preferably thin. However, when the electrolyte membrane is thinned, the mechanical strength is lowered, and the handling property of the membrane-electrode structure in the production process of the polymer electrolyte fuel cell is lowered.

Therefore, as a membrane-electrode structure, a member in which a frame portion is formed so as to surround the opening (hereinafter referred to as “reinforcing member”) is bonded so as to cover a peripheral portion of one surface of the electrolyte membrane. What has is proposed (for example, refer patent document 1). The membrane-electrode structure disclosed in Patent Document 1 is formed by adhering a reinforcing member to an electrolyte membrane in a state in which a reinforcing member and a member having the same shape as the reinforcing member (hereinafter referred to as a “coating member”) are laminated in advance. After the catalyst layer is applied to the inside of the opening, the covering member is removed to realize a structure in which the catalyst layer is formed inside the reinforcing member.
JP 2007-35612 A (paragraphs [0021], [0022], FIGS. 3A to 3E, FIG. 4, etc.)

  When the membrane-electrode structure having the structure disclosed in Patent Document 1 is manufactured, it is necessary to bond the electrolyte membrane and the reinforcing member together while being pulled with a certain force. However, since the reinforcing member is frame-shaped and has a thickness of about several tens of microns, when the reinforcing member is pulled, distortion is likely to occur near the four corners of the opening. It becomes easy to generate wrinkles near the four corners. Since this wrinkle reduces the smoothness of the reinforcing member, stress is applied to the carbon paper (gas diffusion layer) bonded to the reinforcing member, and the carbon paper tends to deteriorate. In addition, when the catalyst layer is formed by applying the catalyst paste to the electrolyte membrane in a state where wrinkles are generated in the reinforcing member, the catalyst paste that becomes the grooves of the wrinkles accumulates, and in this portion, the adhesion between the reinforcing member and the carbon paper Defects are likely to occur. Further, the adhesion between the electrolyte membrane and the reinforcing member is deteriorated, and the reinforcing effect cannot be obtained.

  The present invention has been made in view of such circumstances, and provides a method for producing a membrane-electrode structure for a fuel cell that suppresses generation of wrinkles in a reinforcing member and is excellent in mass productivity of the membrane-electrode structure. The purpose is to do.

  A method for producing a membrane-electrode structure for a fuel cell according to the present invention is a method for producing a membrane-electrode structure used for a polymer electrolyte fuel cell, and is a belt-like structure for reinforcing a polymer electrolyte membrane. The first member, the belt-like second member for covering the first member, and the belt-like third member for supporting the second member can be peeled later in this order. A laminated body production step of producing a laminated body by laminating and bonding, and an opening forming step of providing a common opening in the first member and the second member of the laminated body obtained by the laminated body production step From the bonding process obtained by the bonding process of bonding the band-shaped solid polymer electrolyte membrane to the laminate so as to be bonded to the first member, and preparing the bonded body, and the bonding process A first peeling step for peeling and removing the third member; A catalyst layer forming step of forming a catalyst layer inside the opening that appears on the surface of the bonded body after the first peeling step, and a second step of peeling the second member from the bonded body after the catalyst layer forming step. And 2 peeling processes.

  According to such a configuration, when the openings are formed in the first member and the second member, these are supported by the third member, so that generation of wrinkles in the first member is suppressed in the stacked body. The And by using such a laminated body, generation | occurrence | production of the flaw in the 1st member adhere | attached on the solid polymer electrolyte membrane can be suppressed. Moreover, since all the members (including a laminated body and a bonded body) to be handled are high and easy to handle throughout the entire manufacturing process of the membrane-electrode structure, it is excellent in productivity. Furthermore, since each process can be performed continuously by using a strip-shaped member or the like, it is excellent in mass productivity.

  In the method for producing a membrane-electrode structure for a fuel cell according to the present invention, in the laminate manufacturing step, the adhesive strength between the first member and the second member is set to the second member and the second member. It is preferable to make it larger than the adhesive strength between the third member.

  According to such a structure, when peeling a 3rd member in a 1st peeling process, it can suppress that a 2nd member peels simultaneously.

  In the method for producing a membrane-electrode structure for a fuel cell according to the present invention, in the bonding step, the solid polymer electrolyte membrane and the first member are bonded to each other with a thermosetting adhesive. It is preferable to carry out by pressing. Moreover, when using a hot press in this way, it is preferable that the thermal expansion coefficients of the second member and the third member are the same.

  According to such a configuration, the solid polymer electrolyte membrane and the first member can be bonded more firmly and tightly using the thermosetting adhesive. In addition, since a solid polymer electrolyte membrane and a laminated body can be adhere | attached continuously in a length direction by using a hot roll press as a hot press, productivity is improved. If the second member and the third member have the same thermal expansion coefficient, it is difficult for wrinkles to enter the second member when hot pressing is performed.

  In the method for producing a membrane-electrode structure for a fuel cell according to the present invention, the width of the first member is preferably narrower than the widths of both the solid polymer electrolyte membrane and the second member.

  According to such a configuration, since the second member is directly fixed to the surface of the solid polymer electrolyte membrane, it is possible to suppress displacement of the first member.

  In the method for producing a membrane-electrode structure for a fuel cell according to the present invention, the solid polymer electrolyte membrane is formed on one surface of a strip-shaped substrate, and the steps after the bonding step are the solid polymer. It is performed in a state where the electrolyte membrane is formed on the surface of the base material, and the width of the second member is wider than any of the width of the first member and the width of the solid polymer electrolyte membrane. preferable.

  According to such a structure, the 2nd member can be directly adhere | attached on a base material, and, thereby, the position shift of a 1st member can be suppressed. In addition, adhesion | attachment between a 2nd member and a base material is performed using the adhesive which has the adhesive force which can peel a 2nd member and a base material.

  According to the method for producing a membrane-electrode structure for a fuel cell according to the present invention, when the first member for reinforcing the solid polymer electrolyte membrane is bonded, the generation of wrinkles is suppressed. By using the laminated body provided with the member, the generation of wrinkles in the first member when the first member is bonded to the solid polymer electrolyte membrane is suppressed. Since the smoothness of the surface of the first member is improved in this way, it becomes difficult for non-uniform stress to be applied to the member for the gas diffusion layer such as carbon paper attached to the first member, thereby extending the life of the carbon paper. can do. In addition, since the catalyst paste hardly accumulates on the surface of the first member, it is possible to ensure good adhesion with carbon paper or the like.

  The method for producing a membrane-electrode structure for a fuel cell according to the present invention has high self-sustainability of various members (including laminates and bonded bodies) handled throughout the entire production process, and is easy to handle. Excellent in properties. Furthermore, since a continuous process can be easily performed by using a strip-shaped member or the like, it is excellent in mass productivity.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
<Structure of membrane-electrode structure>
FIG. 1 shows a schematic cross-sectional view of a membrane-electrode structure which is a constituent element of a polymer electrolyte fuel cell. The two membrane-electrode structures 10 shown in FIGS. 1 (a) and 1 (b), respectively, have a main polymer electrolyte membrane (hereinafter referred to as “electrolyte membrane”) 12 having proton conductivity sandwiched between them. The anode side gas diffusion electrode 14 is provided on the surface, and the cathode side gas diffusion electrode 16 is provided on the other main surface. As shown in FIGS. 1A and 1B, three-dimensional orthogonal coordinates (XYZ) are determined, the length direction of the electrolyte membrane 12 is defined as the X direction, and the width direction of the electrolyte membrane 12 is defined as Y. And the thickness direction of the electrolyte membrane 12 is the X direction.

  The anode-side gas diffusion electrode 14 has a frame shape surrounding only the rectangular opening 24 (only the portion on the Y direction side is clearly shown in FIGS. 1A and 1B), and the main surface of the electrolyte membrane 12. The reinforcing member 22 bonded to the reinforcing member 22, the catalyst layer 26 formed on the surface of the electrolyte membrane 12 in the opening 24 of the reinforcing member 22, and the gas diffusion layer 28 covering the reinforcing member 22 and the catalyst layer 26 are provided. The cathode side gas diffusion electrode 16 has substantially the same structure as the anode side gas diffusion electrode 14. One membrane-electrode structure 10 has a rectangular shape having one opening 24.

  In the membrane-electrode structure 10 shown in FIG. 1A, the width of the electrolyte membrane 12 is wider than the width of the reinforcing member 22, and the membrane-electrode structure 10 shown in FIG. Then, the width of the electrolyte membrane 12 and the width of the reinforcing member 22 are the same. As will be described later, the membrane-electrode structure 10 shown in FIG. 1B is obtained by cutting the width direction end of the electrolyte membrane 12 of the membrane-electrode structure 10 shown in FIG. Can do. Further, in the membrane-electrode structure 10 shown in FIG. 1B, the width of the electrolyte membrane 12 used for manufacturing the membrane-electrode structure 10 and the width of the reinforcing member 22 are the same, so that the width direction of the electrolyte membrane 12 is increased. It can also be manufactured without cutting the ends.

  For example, the catalyst layer 26 is made of a material mainly composed of platinum, the gas diffusion layer 28 is made of porous carbon cloth or porous carbon paper, and the electrolyte membrane 12 is perfluorocarbon, which is a kind of fluororesin. A sulfonic acid polymer or the like is used. As the reinforcing member 22, polyimide resin (PI), polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), polyphenylene sulfide (PPS) or the like is preferably used, and the thickness thereof is 5 to 50 μm. can do. The electrolyte membrane 12 and the reinforcing member 22 are bonded by a thermosetting resin adhesive (such as an adhesive layer not shown) such as an epoxy resin, and the gas diffusion layer 28 is also bonded to the reinforcing member 22 using an adhesive. ing.

<Method for Manufacturing Membrane-Electrode Structure>
FIG. 2 is a flowchart showing the manufacturing process of the membrane-electrode structure. The manufacturing process of the membrane-electrode structure 10 is roughly the electrolyte membrane preparation step S1, the laminate manufacturing step S2, the opening forming step S3, the temporary fixing step S4, the bonding step S5, the backup member peeling step (first peeling step). ) S6, catalyst layer forming step S7, covering member peeling step (second peeling step) S8, substrate peeling step S9, back surface treatment step S10 (from the temporary fixing step S4 to the catalyst layer forming step with respect to the back surface of the electrolyte membrane 12) Steps of repeating steps up to S7), covering member peeling step (when S8 is skipped, the covering members on both surfaces of the electrolyte membrane 12 are peeled off) S11, and gas diffusion layer forming step S12.

  FIG. 3A shows a plan view and a cross-sectional view (cross-sectional view at the position AA shown in the plan view) showing the form of the electrolyte membrane prepared in the electrolyte membrane preparation step, and FIG. 3B shows a laminate. The top view and sectional view (sectional view in the AA position shown to a top view) which represented the aspect of the process in a preparation process and an opening formation process typically are shown. Further, FIG. 4 shows a plan view and a cross-sectional view (cross-sectional view at the BB position shown in the plan view) schematically showing the process in the temporary fixing step and the bonding step, and FIG. 5 shows the backup member peeling. The top view and sectional drawing (cross-sectional view in the BB position shown to a top view) which represented the aspect of the process from a process to a covering member peeling process typically are shown. These three-dimensional orthogonal coordinates (XYZ) shown in FIGS. 3 to 5 correspond to the three-dimensional orthogonal coordinates (XYZ) shown in FIGS. Hereinafter, each process will be described with reference to these drawings.

[Electrolyte membrane preparation step S1]
In order to manufacture the membrane-electrode structure 10, an electrolyte membrane 12 is prepared. In this manufacturing method, as shown in FIG. 3A, the electrolyte membrane 12 is preferably supported on one surface of a belt-shaped electrolyte membrane support base material (hereinafter referred to as “base material”) 50. Used. By supporting the electrolyte membrane 12 with the base material 50, the handling property of the electrolyte membrane 12 in the manufacturing process of the membrane-electrode structure 10 is improved. As the base material 50, for example, a PET film having a good balance between adhesion and peelability with the electrolyte membrane 12 and being thermally stable is preferably used, and its thickness is considered in consideration of handling properties and the like. The thickness is preferably about several tens of microns.

  The width of the electrolyte membrane 12 is preferably narrower than the width of the substrate 50. For example, the width direction end of the electrolyte membrane 12 is positioned at a certain distance from the width direction end of the substrate 50. Thereby, in temporary fixing process S4 performed later, position alignment with the electrolyte membrane 12 and the reinforcement member 22 can be performed easily. The electrolyte membrane 12 supported by such a base material 50 can be prepared in a state wound in a roll shape, and is used after the temporary fixing step S4.

[Laminate Fabrication Step S2]
As shown in FIG. 3B, the laminate manufacturing step S <b> 2 includes a strip-shaped reinforcing member (first member) 22 for reinforcing the electrolyte membrane 12 and a strip-shaped covering member for covering the reinforcing member 22. The (second member) 62 and the belt-like backup member (third member) 64 for supporting the covering member 62 are aligned in this order in the order of layers, and are laminated and adhered so that they can be peeled later. This is a step of manufacturing the laminate 60. Here, the covering member 62 is an intermediate layer in the laminated body 60, but is a member that is in a state where the reinforcing member 22 is covered after the backup member peeling step S6 performed later. I will do it.

  The reinforcing member 22 is made of polyimide resin having a predetermined thickness as described above. A PET resin or the like is suitably used for the covering member 62 and the backup member 64, and the thickness thereof can be 10 to 80 μm.

  Commercially available adhesives are used for adhesion between the reinforcing member 22 and the covering member 62 and adhesion between the covering member 62 and the backup member 64, respectively. As this pressure-sensitive adhesive, one having a property that does not deteriorate due to the heat treatment in the bonding step S5 to be performed later is preferable in terms of process management. In the laminate 60, the adhesive strength between the reinforcing member 22 and the covering member 62 is preferably larger than the adhesive strength between the covering member 62 and the backup member 64. This is to prevent the covering member 62 from being peeled off together with the backup member 64 when peeling the backup member 64 in the backup member peeling step (first peeling step) S6 performed later. . By controlling the type of pressure-sensitive adhesive to be used (such as the chemical species and concentration of the pressure-sensitive adhesive component) and the thickness of the pressure-sensitive adhesive layer, it is possible to make a difference in these adhesive strengths.

  When the reinforcing member 22, the covering member 62, and the backup member 64 are laminated and bonded, it is usually preferable to apply a certain tension to each member so that air does not enter each bonding surface. As shown in FIG. 3B, the opening 24 is not formed in the reinforcing member 22 at the stage of the laminate manufacturing step S2. Further, although the opening 68 is formed in the covering member 62 in the subsequent opening forming step S3, the opening 68 is not formed in the covering member 62 in the layered body manufacturing step S2. As described above, the laminate 60 is produced using the reinforcing member 22 in which the opening 24 is not formed and the covering member 62 in which the opening 68 is not formed, so that the reinforcing member 22 and the covering member 62 are locally covered. Etc. are suppressed, and the flatness can be improved.

  Thus, when the flatness of the reinforcing member 22 is ensured, the catalyst material can be prevented from entering between the reinforcing member 22 and the covering member 62 in the catalyst layer forming step S7 performed later. Further, it is possible to avoid occurrence of poor adhesion when carbon paper or the like as the gas diffusion layer 28 is attached to the reinforcing member 22. In addition, when a cell is assembled using the produced membrane-electrode structure 10, it becomes difficult to apply stress to the carbon paper or the like as the gas diffusion layer 28 attached to the reinforcing member 22, and the destruction of the carbon paper or the like is suppressed. can do.

  The laminated body 60 is bonded to the electrolyte membrane 12 supported by the base material 50 in a temporary fixing step S4 and a bonding step S5 performed later, and a bonded body 80 (see FIGS. 4 and 5) is produced. The widths of the reinforcing member 22, the covering member 62, and the backup member 64 can be set based on the widths of the electrolyte membrane 12 and the substrate 50 so that the bonded body 80 can be easily and accurately manufactured. preferable. The setting conditions will be described in the description of the temporary fixing step S4 described later.

[Opening Step S3]
As shown in FIG. 3B, the opening forming step S3 is a step of providing common openings 24 and 68 in the reinforcing member 22 and the covering member 62 of the laminated body 60 obtained in the laminated body producing step S2. . For example, a blade having an outer peripheral shape of the openings 24 and 68 is inserted at a depth from the reinforcing member 22 side to the bonding surface between the covering member 62 and the backup member 64, and a cut is provided in the reinforcing member 22 and the covering member 62. Thereafter, the openings 24 and 68 can be formed by peeling off the regions of the openings 24 and 68. The laminated body 60 in which the openings 24 and 68 are formed may be stored in a state of being wound in a roll shape. Further, after the openings 24 and 68 are formed, they may be promptly supplied to the next temporary fixing step S4. Here, it is assumed that the laminate 60 having a length that can be bonded to each of the front surface and the back surface of the electrolyte membrane 12 is produced by the laminate production step S2 and the opening formation step S3.

[Temporary fixing step S4]
In the temporary fixing step S4, as shown in FIG. 4, in order to bond the electrolyte membrane 12 and the reinforcing member 22, the electrolyte membrane 12 supported by the substrate 50 and the laminate 60 are aligned, Is a step of closely adhering. Prior to the temporary fixing step S4, a thermosetting resin adhesive is applied to the surface of the reinforcing member 22 with a predetermined thickness (for example, several microns). However, in the temporary fixing step S4, the thermosetting resin adhesive is not cured. Note that, in the plan view of FIG. 4, only a part in the length direction (X direction) of the strip-shaped laminate 60 is drawn (the same applies to FIG. 5).

  In the present embodiment, as shown in FIG. 4, based on the fact that the width of the electrolyte membrane 12 is narrower than the width of the base material 50, the width of the base material 50 and the backup member in the laminate manufacturing step S <b> 2. 64, the width of the covering member 62 is the same as the width of the backup member 64, and the width of the reinforcing member 22 is narrower than the width of the electrolyte membrane 12. As a result, the width of the covering member 62 is wider than any of the width of the reinforcing member 22 and the width of the electrolyte membrane 12. At this time, it is preferable that the exposed surface of the covering member 62 remains in a state where the pressure-sensitive adhesive used in the laminate manufacturing step S2 is applied.

  By making the width of the base material 50 and the width of the backup member 64 the same, alignment of the base material 50 and the laminate 60 is facilitated. By making the width of the covering member 62 the same as the width of the backup member 64, the change in the thickness in the width direction of the stacked body 60 becomes small. When the supported electrolyte membrane 12 is bonded, distortion in the width direction generated in the bonded body 80 (see FIGS. 4 and 5) can be suppressed to a small value. By making the width of the reinforcing member 22 narrower than the width of the electrolyte membrane 12, the reinforcing member 22 can be directly and reliably adhered to the electrolyte membrane 12.

  Since the width of the covering member 62 is wider than either the width of the reinforcing member 22 or the width of the electrolyte membrane 12, the entire surface of the reinforcing member 22 can be supported by the covering member 62. By applying the adhesive to the exposed surface, the covering member 62 is bonded to the base member 50, and the position of the covering member 62 is stabilized. With these effects, the position of the reinforcing member 22 can be stably held, and the displacement of the reinforcing member 22 can be suppressed.

[Lamination process S5]
The bonding step S5 is a step of firmly bonding the electrolyte membrane 12 and the reinforcing member 22. As shown in FIG. 4, for example, the bonding step S <b> 5 is performed by passing between the heat rolls 70 what is temporarily fixed to the electrolyte membrane 12 and the laminate 60 supported by the base material 50 in the temporary fixing step S <b> 4. , By heating while applying a certain pressure. As a result, the thermosetting resin adhesive between the electrolyte membrane 12 and the reinforcing member 22 is cured at a constant thickness, and the electrolyte membrane 12 and the reinforcing member 22 are firmly bonded and supported by the base material 50. A bonded body 80 in which the electrolyte membrane 12 and the laminate 60 are bonded together is produced.

  In the bonding step S5, it is preferable to use materials having the same thermal expansion coefficient for the covering member 62 and the backup member 64 so that deformation such as wrinkles does not occur in the covering member 62. The set temperature and rotation speed of the heat roll 70 (the speed at which the base material 50 supporting the electrolyte membrane 12 and the laminate 60 are allowed to pass) are interposed between the electrolyte membrane 12 and the reinforcing member 22 (not shown). It is appropriately determined in consideration of the thermosetting characteristics of the thermosetting resin adhesive.

  In addition, since the base material 50 (electrolyte film | membrane 12) and the laminated body 60 are strip | belt shape, the method using a heat roll 70 is the point which can adhere | attach the electrolyte film 12 and the reinforcement member 22 continuously, Excellent productivity.

[Backup member peeling step (first peeling step) S6]
As shown in FIG. 5, in the backup member peeling step (first peeling step) S6, the backup member 64 is peeled off from the bonded body 80 produced in the bonding step S5, and the electrolyte membrane 12 in the openings 24 and 68 is removed. It is the process of exposing the surface of. The separation of the backup member 64 can be performed at room temperature. As described above, if the adhesive strength between the reinforcing member 22 and the covering member 62 is larger than the adhesive strength between the covering member 62 and the backup member 64, the reinforcing member 22 is not peeled off. It becomes easy to peel only the backup member 64.

[Catalyst layer forming step S7]
In the catalyst layer forming step S7, a material such as a paste (hereinafter referred to as “catalyst material”) that becomes the catalyst layer 26 is applied to the electrolyte membrane 12 exposed in the openings 24 and 68 by the backup member peeling step S6. This is a step of forming the layer 26. At this time, since the entire surface of the reinforcing member 22 is covered with the covering member 62, an extra catalyst application portion 26 a may be formed on the surface in the vicinity of the opening 68 of the clothing material 62, but the reinforcing member 22. The catalyst material does not adhere to the surface of the substrate. Thereby, it is possible to avoid occurrence of poor adhesion when carbon paper or the like as the gas diffusion layer 28 is attached to the reinforcing member 22 in the gas diffusion layer forming step S12 performed later.

  According to this manufacturing method, since the outer edge of the catalyst layer 26 formed in the catalyst layer forming step S7 coincides with the inner edge of the opening 24, the catalyst layer is first provided on the conventional electrolyte membrane so as to surround the catalyst layer. It does not require precise positioning of the reinforcing member, which is required in the method of providing the reinforcing member. This increases the yield and improves the productivity.

[Coating member peeling step (second peeling step) S8]
The covering member peeling step S8 is a step of peeling the covering member 62 from the base material 50 and the like after the catalyst layer 26 is formed, as shown in FIG. By completing the covering member peeling step S8, the steps up to the formation of the catalyst layer 26 on the surface of the electrolyte membrane are completed. In addition, the catalyst material of the excess catalyst application part 26a adhering to the coating | coated member 62 which peeled from the bonding body 80 is simply high efficiency by chemical means (for example, melt | dissolution etc.) and physical means (for example, peeling etc.). Thus, the recycling efficiency of the catalyst material can be increased.

  By the way, as described with reference to FIGS. 1A and 1B, in the membrane-electrode structure 10, the reinforcing members 22 are provided on both surfaces of the electrolyte membrane 12, and the catalyst layer 26 is provided in the opening 24. Is formed. For that purpose, after performing covering member peeling process S8, through base material peeling process S9 which peels the base material 50 from the electrolyte membrane 12, back surface treatment process S10 (from the temporary fixing process S4 to the back surface of the electrolyte membrane 12) The step of repeatedly performing up to the catalyst layer forming step S7) may be executed, or the base member peeling step S9 and the back surface treatment step S10 may be sequentially performed by skipping the covering member peeling step S8. The reason why the back surface treatment step is set from the temporary fixing step S4 to the catalyst layer forming step S7 is based on the assumption that the laminate 60 used for the back surface treatment step S10 has already been prepared.

  Even when the coating member peeling step S8 is performed and then the substrate peeling step S9 is performed and then the back surface processing step S10 is performed, the dimensional change due to the swelling of the electrolyte membrane 12 when the catalyst layer 26 is formed on the back surface of the electrolyte membrane 12 is It can be suppressed by the reinforcing member 22 previously provided on the surface of the electrolyte membrane 12 and can also be suppressed by the catalyst layer 26 in an auxiliary manner. Further, when the coating member peeling step S8 is skipped and the substrate peeling step S9 is followed to proceed to the back surface treatment step S10, the dimensions due to the swelling of the electrolyte membrane 12 when the catalyst layer 26 is formed on the back surface of the electrolyte membrane 12 The change is suppressed not only by the catalyst layer 26 previously provided on the surface of the electrolyte membrane 12 but also by the covering member 62, and the covering member 62 is still attached to the electrolyte membrane 12. Improved handling.

[Substrate peeling step S9]
The base material peeling step S9 is a step of peeling the base material 50 from the electrolyte membrane 12, whereby the back surface of the electrolyte membrane 12 that has been in contact with the base material 50 is exposed and can be bonded to the laminate 60. Become.

[Back treatment step S10]
In the back surface processing step S10, the laminated body 60 is positioned and temporarily fixed to the back surface of the electrolyte membrane 12 exposed in the base material peeling step S9 (temporary fixing step S4), and the laminated body 60 is bonded (bonding step S5). ), The backup member 64 is peeled from the produced bonded body 80 (backup member peeling step S6), and the catalyst layer 26 is formed (catalyst layer forming step S7).

[Coating member peeling step S11]
After the catalyst layer 26 is formed on the back surface side of the electrolyte membrane 12, the coating member 62 attached to the back surface side of the electrolyte membrane 12 is peeled off when the coating member peeling step S8 is performed first. On the other hand, when the covering member peeling step S8 is skipped first, the covering members 62 attached to both surfaces (front surface side and back surface side) of the electrolyte membrane 12 are peeled off.

[Gas diffusion layer forming step S12]
After the covering member peeling step S11 is completed, the surface of the reinforcing member 22 is exposed. Therefore, the gas diffusion layer 28 is formed by sticking carbon paper or the like to be the gas diffusion layer 28 on the surface of the reinforcing member 22 with an adhesive or the like, and then the adjacent opening 24 (see FIG. 2B as appropriate). The film-electrode structure 10 shown in FIG. 1A is obtained by cutting in parallel with the Y direction at an intermediate position. This cutting process may be performed after the covering member peeling step S11 and before the gas diffusion layer forming step S12. Then, the width direction edge part of the electrolyte membrane 12 in each membrane-electrode structure 10 (shown in FIG. 1 (a)) is cut so as to be aligned with the width direction end of the reinforcing member 22. The membrane-electrode structure 10 shown in b) is manufactured. The cutting of the end portion of the electrolyte membrane 12 may be performed immediately after the cutting process and before the formation of the gas diffusion layer 28 when the cutting process is performed immediately after the end of the covering member peeling step S11. Good.

  According to the manufacturing method of such a membrane-electrode structure 10, the various members to be handled (including the laminated body 60 and the bonded body 80) are highly self-supporting and easy to handle throughout the entire manufacturing process. Excellent productivity. Furthermore, since each step can be continuously performed as a series of flow operations by using a belt-shaped member or the like, the mass productivity is also excellent.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to an above described form. For example, the membrane-electrode structure shown in FIGS. 1A and 1B may not have the gas diffusion layer 28. In the manufacturing process of the membrane-electrode structure 10 shown in FIG. 2, the backup member 64 is peeled off after forming the bonded body 80 and the catalyst layer 26 is formed. However, the present invention is not limited to this, and the bonded body 80 was manufactured. Later, the base material 50 is peeled off, and the laminate 60 is attached to the back surface of the electrolyte membrane 12 exposed thereby, thereby producing a bonded body having a structure in which the electrolyte membrane 12 is sandwiched between the two laminates 60. Alternatively, the backup member 64 of each laminate 60 may be peeled off to form the catalyst layer 26.

  Moreover, although the form using the electrolyte membrane 12 supported by the base material 50 was demonstrated as a manufacturing process of the membrane-electrode structure 10, when the electrolyte membrane 12 can be handled as a self-supporting membrane, the electrolyte membrane is added to the laminated body 60. 12 may be bonded together. In this case, it is possible to prevent the heat roll 70 from coming into direct contact with the electrolyte membrane 12 by positioning and laminating the laminate 60 on both surfaces of the electrolyte membrane 12. Thus, for example, even when there are defects such as irregularities on the surface of the heat roll 70, the defects can be prevented from being transferred to the electrolyte membrane 12.

(A), (b) is a schematic sectional drawing which shows the membrane-electrode structure which is a component of a polymer electrolyte fuel cell, respectively. It is a flowchart which shows the manufacturing process of a membrane-electrode structure. (A) is the top view and sectional drawing which show the form of the electrolyte membrane prepared by an electrolyte membrane preparation process, (b) is the top view and cross section which show typically the aspect of the process in a laminated body preparation process and an opening formation process FIG. It is the top view and sectional drawing which show typically the aspect of the process in a temporary fixing process and a bonding process. It is the top view and sectional view which show typically the mode of processing from a backup member peeling process to a covering member peeling process.

Explanation of symbols

10 Membrane-electrode structure 12 Electrolyte membrane (solid polymer electrolyte membrane)
14 Anode-side gas diffusion electrode 16 Cathode-side gas diffusion electrode 22 Reinforcing member (first member)
24 opening 26 catalyst layer 26a (excess) catalyst application part 28 gas diffusion layer 50 base material (electrolyte membrane support base material)
60 Laminated body 62 Covering member (second member)
64 Backup member (third member)
68 Opening 70 Heat roll 80 Bonded body

Claims (6)

A method for producing a membrane-electrode structure for a fuel cell used in a polymer electrolyte fuel cell,
A strip-shaped first member for reinforcing the solid polymer electrolyte membrane, a strip-shaped second member for covering the first member, and a strip-shaped third member for supporting the second member In this order, a laminated body production step of producing a laminated body by laminating and bonding so that the members can be peeled later in this order,
An opening forming step of providing a common opening in the first member and the second member of the laminate obtained by the laminate production step;
A laminating step of laminating a band-shaped solid polymer electrolyte membrane to the laminate so as to be bonded to the first member,
A first peeling step of peeling and removing the third member from the bonded body obtained by the bonding step;
A catalyst layer forming step of forming a catalyst layer inside the opening that appeared on the surface of the bonded body after the first peeling step;
And a second peeling step of peeling the second member from the bonded body after the catalyst layer forming step. A method for producing a membrane-electrode structure for a fuel cell. In the laminate manufacturing process,
2. The adhesive strength between the first member and the second member is larger than the adhesive strength between the second member and the third member. A method for producing a membrane-electrode structure for a fuel cell. In the bonding step,
The fuel cell membrane-electrode according to claim 1 or 2, wherein the solid polymer electrolyte membrane and the first member are bonded by hot pressing using a thermosetting adhesive. Manufacturing method of structure.   The method for producing a membrane-electrode structure for a fuel cell according to claim 3, wherein the second member and the third member have the same coefficient of thermal expansion.   5. The fuel cell membrane according to claim 1, wherein a width of the first member is narrower than a width of both the solid polymer electrolyte membrane and the second member. -Manufacturing method of an electrode structure. The solid polymer electrolyte membrane is formed on one surface of a strip-shaped substrate, and the steps after the bonding step are performed in a state where the solid polymer electrolyte membrane is formed on the substrate surface,
The width of the second member is wider than any of the width of the first member and the width of the solid polymer electrolyte membrane, according to any one of claims 1 to 5. The manufacturing method of the membrane-electrode structure for fuel cells of description.

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