JP2016195053A - Method of manufacturing membrane electrode assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a membrane electrode assembly manufacturing method that can simplify a manufacturing process as compared with prior arts, and enhance the precision of forming an electrode catalyst layer which is formed of a coating layer to be transferred to an electrolyte membrane, thereby increasing the yield of the electrolyte membrane as a constituent element of a membrane electrode assembly.SOLUTION: There is prepared a band-like transfer sheet including an electrode catalyst layer region which is provided intermittently along the longitudinal direction of the transfer sheet on one surface thereof and has a shape corresponding to an electrode catalyst layer, and a frame region which is shaped to border the electrode catalyst layer region in a frame shape, the electrode catalyst layer region and the frame region being segmented, and the frame region being subjected to a corona treatment to reduce releasability. Catalytic ink is intermittently applied in conformity with the electrode catalyst layer region of the transfer sheet to form a coating layer of the catalyst ink. A surface of the transfer sheet on which the coating layer is formed is superimposed on and in contact with the electrolyte membrane, and the coating layer in the electrode catalyst layer region is intermittently transferred onto the electrolyte membrane as an electrode catalyst layer.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for producing a membrane electrode assembly, and more particularly to formation of an electrode catalyst layer on an electrolyte membrane.

  Membrane electrode assemblies having an electrode catalyst layer and an electrolyte membrane are used in fuel cells. As a method for producing a membrane electrode assembly, there is generally a production method in which an electrode catalyst layer sheet is prepared by coating an electrode catalyst layer on a base sheet, and then the electrode catalyst layer is transferred from the electrode catalyst layer sheet to the electrolyte membrane. Are known.

  Many of the materials such as the electrolyte membrane used in the manufacture of the membrane electrode assembly and the catalyst of the electrode catalyst layer (for example, platinum catalyst) are expensive materials, and reducing the material loss that occurs during the manufacturing process reduces the manufacturing cost. It is important for reduction. As an example, an electrode catalyst in which an electrode catalyst layer is applied intermittently on a substrate sheet as an electrode catalyst layer sheet for transferring at least one electrode catalyst layer of a membrane electrode assembly to an electrolyte membrane. A layer sheet is produced, and the electrode catalyst layer is intermittently transferred from the produced electrode catalyst layer sheet to the electrolyte membrane.

  The electrode catalyst layer sheet on which the electrode catalyst layer is applied intermittently can be produced using, for example, the method described in Patent Document 1. In the method described in Patent Document 1, before coating a coating film (corresponding to a coating layer of a catalyst ink for forming an electrode catalyst layer) on a base sheet, the coating film is not applied. This is a method of coating a coating film intermittently on a substrate sheet by separating the mask after the mask is brought into close contact and coated on the substrate sheet.

JP 2012-228649 A

  However, in the production of the electrode catalyst layer sheet by the method described in Patent Document 1, it is necessary to separate the mask after coating the coating film, and there is a problem that the manufacturing process increases. In addition, there is a problem that a large-scale mask detachment mechanism is necessary as equipment for close contact and separation of the mask. Therefore, further improvement has been desired in order to reduce the material loss generated in the manufacturing process and to reduce the manufacturing cost.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

(1) According to one form of this invention, the manufacturing method of the membrane electrode assembly which transfers an electrode catalyst layer intermittently to a strip | belt-shaped electrolyte membrane is provided. The manufacturing method of this membrane electrode assembly is an electrode catalyst layer region having a shape corresponding to the electrode catalyst layer provided intermittently along the longitudinal direction of the transfer sheet on one side as a belt-shaped transfer sheet And a step of preparing a transfer sheet that is divided into a frame region having a shape that borders the electrode catalyst layer region in a frame shape and subjected to corona treatment for reducing releasability in the frame region; Applying the catalyst ink intermittently in correspondence with the electrode catalyst layer region of the transfer sheet to form a coating layer of the catalyst ink; and forming the coating layer of the transfer sheet And the step of transferring the coated layer in the electrode catalyst layer region intermittently onto the electrolyte membrane as the electrode catalyst layer.
According to the method of manufacturing a membrane electrode assembly of this embodiment, in the process of transferring the electrode catalyst layer to the electrolyte membrane, the surplus (nonstandard) applied to the frame region outside the electrode catalyst layer region of the transfer sheet The portion of the coating layer can be prevented from being transferred to the electrolyte membrane. Therefore, before the transfer step, other than for the step of separating the mask described in the prior art, the coating layer corresponding to the electrode catalyst layer is intermittently formed on the transfer sheet. It is not necessary to provide this process, and the process can be simplified as compared with the prior art. Moreover, since the formation accuracy of the electrode catalyst layer formed by the coating layer transferred to the electrolyte membrane can be improved, the interval between the coating layers as the electrode catalyst layer transferred intermittently should be set short. It is possible to improve the yield of the electrolyte membrane which is a constituent member of the membrane electrode assembly.

  The present invention can also be realized in various forms other than the method for manufacturing the membrane electrode assembly. For example, it can be realized in the form of an electrode catalyst layer sheet manufacturing method, a membrane electrode assembly manufacturing apparatus, an electrode catalyst layer sheet manufacturing apparatus, or the like.

It is explanatory drawing which shows the membrane electrode assembly in 1st Embodiment. It is explanatory drawing which shows the cathode formation part corresponding to the process of producing a cathode electrode catalyst layer sheet | seat among the manufacturing apparatuses of MEA in 1st Embodiment. It is explanatory drawing which shows the anode formation part corresponding to the process of producing an anode electrode catalyst layer sheet | seat among the manufacturing apparatuses of MEA in 1st Embodiment. It is explanatory drawing which shows the transcription | transfer part corresponding to the process of transcribe | transferring an electrode catalyst layer to an electrolyte membrane among the manufacturing apparatuses of MEA in 1st Embodiment. It is explanatory drawing which shows the cathode formation part corresponding to the process of producing a cathode electrode catalyst layer sheet | seat among the manufacturing apparatuses of MEA in 2nd Embodiment. It is explanatory drawing which shows the transcription | transfer part corresponding to the process of transcribe | transferring an electrode catalyst layer to an electrolyte membrane among the manufacturing apparatuses of MEA in 2nd Embodiment. It is explanatory drawing which shows the cathode formation part corresponding to the process of producing a cathode electrode catalyst layer sheet | seat among the manufacturing apparatuses of MEA in 3rd Embodiment. It is explanatory drawing which shows the transfer part corresponding to the process of transferring an electrode catalyst layer to an electrolyte membrane among the manufacturing apparatuses of MEA in 3rd Embodiment.

A. First embodiment:
FIG. 1 is an explanatory view showing a membrane electrode assembly in the first embodiment. Hereinafter, in this specification, a membrane electrode assembly is also referred to as “MEA”. FIG. 1A is a plan view of the cathode side of the MEA 100. FIG. 1B is an anode side plan view of the MEA 100. FIG.1 (c) is sectional drawing of MEA100 in the AA cross section of Fig.1 (a) and FIG.1 (b). In the first embodiment, as shown in FIG. 1, a plurality of MEAs 100 are manufactured as a continuous band-like MEA 200 and separated as shown by a broken line, whereby one MEA 100 is formed.

  The MEA 100 includes an anode electrode catalyst layer 12 and a cathode electrode catalyst layer 14 formed on each surface of the electrolyte membrane 10, and is used for a polymer electrolyte fuel cell. The electrolyte membrane 10 is a solid polymer electrolyte membrane that exhibits proton conductivity in a wet state. The anode electrode catalyst layer 12 and the cathode electrode catalyst layer 14 include, for example, platinum or a platinum alloy as a catalyst. More specifically, the anode electrode catalyst layer 12 and the cathode electrode catalyst layer 14 include a carbon material carrying the catalyst and an electrolyte similar to the polymer electrolyte constituting the electrolyte membrane 10. As the carbon material, carbon black particles, carbon nanotubes, or the like can be used.

  As shown in FIG. 1B, the anode electrode catalyst layer 12 is formed in a continuous band shape on the first surface 16 of the electrolyte membrane 10. As shown in FIG. 1A, the cathode electrode catalyst layer 14 is intermittently formed on the second surface 17 of the electrolyte membrane 10 along the band direction. The cathode electrode catalyst layer 14 usually has a higher catalyst content than the anode electrode catalyst layer 12. In other words, the cathode electrode catalyst layer 14 has a higher catalyst content density per unit area than the anode electrode catalyst layer 12. For this reason, it is desirable to reduce material loss in the manufacturing process of the cathode electrode catalyst layer 14, and the cathode electrode catalyst layer 14 is formed in an intermittent state with a dimensional shape corresponding to the electrode size as an electrochemical reaction region. Yes. Since the anode electrode catalyst layer 12 has a lower catalyst density than the cathode electrode catalyst layer 14 as described above, the anode electrode catalyst layer 12 is formed in a continuous band shape so as to facilitate alignment with the cathode electrode catalyst layer 14. Yes.

  By disposing a gas diffusion layer (Gas Diffusion Layer) on the cathode electrode catalyst layer 14 and the anode electrode catalyst layer 12 of the MEA 100 and sandwiching the gas diffusion layer by a pair of separators, a cell mounted on the fuel cell can be configured. . Further, a membrane electrode gas diffusion layer assembly (Membrane Electrode Gas Diffusion Layer Assembly) in which a gas diffusion layer is bonded onto the cathode electrode catalyst layer 14 and the anode electrode catalyst layer 12 of the MEA 100 is sandwiched between a pair of separators. A cell can also be constructed. Hereinafter, in this specification, the gas diffusion layer is also referred to as “GDL”, and the membrane electrode gas diffusion layer assembly is also referred to as “MEGA”.

  As will be described below, the MEA 100 produces a cathode electrode catalyst layer sheet and an anode electrode catalyst layer sheet, and uses the cathode electrode catalyst layer 14 of the cathode electrode catalyst layer sheet and the anode electrode catalyst layer 12 of the anode electrode catalyst layer sheet as an electrolyte. It is produced by transferring to the film 10.

  FIG. 2 is an explanatory view showing a cathode forming portion corresponding to a step of producing a cathode electrode catalyst layer sheet in the MEA manufacturing apparatus according to the first embodiment. The cathode forming unit 300c includes a corona processing unit 310c, a cathode coating processing unit 320c, and a cathode drying processing unit 330c. The corona treatment unit 310c includes a transfer sheet supply roll 311c and a corona treatment device 312c having an electrode 313c and a treatment roll 314c. Further, the cathode coating processing unit 320c includes a die coater 322c having a die 323c and a backup roll 324c. The cathode drying processing unit 330c includes a drying device 332c having a heating mechanism and a hot air mechanism (not shown).

  In the corona treatment unit 310c, a belt-like transfer sheet 370 is sent out from the transfer sheet supply roll 311c in conjunction with the rotation of a transfer sheet take-up roll (not shown), and the electrode 313c and the treatment roll 314c of the corona treatment device 312c. Supplied between. In the corona treatment device 312c, the surface of the transfer sheet 370 on the side of the electrode 313c that undergoes corona discharge in the gap between the electrode 313c and the treatment roll 314c and passes between the treatment roll 314c of the electrode 313c is modified (hereinafter, referred to as “reforming treatment”). (Also called “corona treatment”).

  As the transfer sheet 370, a sheet having excellent releasability and excellent heat resistance with respect to a coating layer formed with a catalyst ink described later is used. For example, a sheet made of an olefin resin such as polyethylene (PE) or polypropylene (PP) is used. In addition, polytetrafluoroethylene (PTFE), tetrafluoroperfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylenetetrafluoroethylene copolymer (ETFE) It is also possible to use a sheet made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN) or the like.

  In the corona treatment device 312c, the surface of the transfer sheet 370 on the electrode 313c side has an electrode catalyst layer region 382 formed intermittently along the longitudinal direction of the transfer sheet 370, and the electrode catalyst layer region 382 has a frame shape. Only the frame region 384 is subjected to corona treatment so as to be divided into a framed frame region 384. For example, in a state where the roll surface of the treatment roll 314c is unfolded, it is divided into an insulating portion corresponding to the electrode catalyst layer 14 in FIG. 1A and a conductive portion corresponding to another region covering the electrode catalyst layer 14. Process roll 314c. And according to rotation of the process roll 314c, it can implement by performing a corona process only to the part of the sheet | seat 370 for transfer which passes between between the electrode 313c and an electroconductive part. The electrode catalyst layer region 382 is a region corresponding to the shape of the cathode electrode catalyst layer 14 and is intermittently divided by the frame region 384 at the same interval. The same interval includes a tolerance.

  The frame region 384 that has been subjected to the corona treatment is less releasable than the electrode catalyst layer region 382 that has not been subjected to the corona treatment. For this reason, an excessive coating layer portion (hereinafter also referred to as “excess coating layer portion”) 14r of the cathode catalyst ink formed on the frame region 384 in the coating process described later is not transferred in the transfer process described later. To be suppressed. That is, in the corona treatment unit 310c, a step of preparing a transfer sheet 380 in which the frame region 384 obtained by fringing the electrode catalyst layer region 382 in a frame shape is prepared.

  In the cathode coating processing unit 320c, the transfer sheet 380 that has been corona-treated by the corona processing unit 310c is supplied between the die 323c and the backup roll 324c of the die coater 322c. In the die coater 322c, the cathode catalyst ink used for forming the cathode electrode catalyst layer 14 corresponding to the electrode catalyst layer region 382 of the transfer sheet 380 is discharged from the slits of the die 323c, and each electrode catalyst layer is discharged. The cathode catalyst ink is die-coated so as to cover the region 382. That is, in the cathode coating processing unit 320c, a step of applying the cathode catalyst ink intermittently corresponding to the electrode catalyst layer region 382 of the transfer sheet 380 is executed.

  The cathode catalyst ink is produced by mixing and stirring a catalyst-supporting carbon, an ionomer having proton conductivity, and a dispersion medium (pure water and ethanol) with a homogenizer. The anode catalyst ink used for forming the anode electrode catalyst layer 12 is the same as the cathode catalyst ink. In this embodiment, carbon black carrying platinum particles is used as the catalyst-carrying carbon. As the ionomer, a perfluorosulfonic acid resin that is a fluorine ionomer is used. Further, in the present embodiment, the cathode catalyst ink is prepared so that the density of the catalyst is higher than that of the anode catalyst ink. Hereinafter, the cathode catalyst ink and the anode catalyst ink are also simply referred to as “catalyst ink”.

  In the cathode drying processing unit 330c, the coated cathode catalyst ink is heated and dried while the transfer sheet 380 coated with the cathode catalyst ink passes through the drying device 332c. As a result, the cathode electrode catalyst layer sheet 380c having the cathode catalyst ink coating layer 14ar formed intermittently is produced. The coating layer 14ar is divided into an effective coating layer portion 14a corresponding to the electrode catalyst layer region 382 and an excess coating layer portion 14r formed in the frame region 384. The effective coating layer portion 14 a corresponding to the electrode catalyst layer region 382 is a portion corresponding to the cathode electrode catalyst layer 14. Note that the drying process performed by the cathode drying processor 330c may be included in the coating process in the cathode coating processor 320c. The produced cathode electrode catalyst layer sheet 380c is sent to the transfer unit 400 described later.

  FIG. 3 is an explanatory view showing an anode forming unit corresponding to a step of producing an anode electrode catalyst layer sheet in the MEA manufacturing apparatus according to the first embodiment. The anode forming unit 300a includes an anode coating processing unit 320a and an anode drying processing unit 330a. The anode coating processing unit 320a includes a transfer sheet supply roll 321a, and a die coater 322a having a die 323a and a backup roll 324a. The anode drying processing unit 330a includes a drying device 332a having a heating mechanism and a hot air mechanism (not shown).

  In the anode coating processing section 320a, a belt-shaped transfer sheet 372 is sent out from a transfer sheet supply roll 321a in conjunction with rotation of a transfer sheet take-up roll (not shown), and a die 323a and a backup roll of the die coater 322a. 324a. In the die coater 322a, the anode catalyst ink is discharged from the slit of the die 323a, and the anode catalyst ink is die-coated on the surface of the transfer sheet 372 on the die 323a side. The anode catalyst ink is applied on the surface of the transfer sheet 372 on the die 323a side so as to continuously extend. That is, in the anode coating processing unit 320a, a process of coating the anode catalyst ink on the transfer sheet 372 is executed. As the transfer sheet 372, a belt-like sheet having excellent releasability as in the transfer sheet 370 is used.

  In the anode drying processing unit 330a, the coated anode catalyst ink is heated and dried while the transfer sheet 372 passes through the drying device 332a. As a result, an anode electrode catalyst layer sheet 380a having the anode catalyst ink coating layer 12a formed in a continuous belt shape is produced. This coating layer 12 a is a portion corresponding to the anode electrode catalyst layer 12. Note that the drying process performed by the anode drying processor 330a may be included in the coating process in the anode coating processor 320a. The produced anode electrode catalyst layer sheet 380a is sent to the transfer unit 400 described later.

  FIG. 4 is an explanatory view showing a transfer portion corresponding to the step of transferring the electrode catalyst layer to the electrolyte membrane in the MEA manufacturing apparatus according to the first embodiment. The transfer unit 400 includes an electrolyte membrane supply roll 411, a pair of nip rolls 422 and 423, a pair of heat press rolls 432 and 433, a support sheet take-up roll 442, and transfer sheet take-up rolls 444 and 445. Prepare.

  In the transfer unit 400, the support sheet 374 on which the electrolyte membrane 10 is formed is supplied from the electrolyte membrane supply roll 411 in conjunction with the rotation of the support sheet take-up roll 442. The electrolyte membrane 10 is peeled from the support sheet 374 on the upstream side of the pair of nip rolls 422 and 423 and is conveyed between the pair of nip rolls 422 and 423 (hereinafter also referred to as “nip part”). The support sheet 374 from which the electrolyte membrane 10 has been peeled is taken up by the support sheet take-up roll 442. Further, the cathode electrode catalyst layer sheet 380c is supplied from the cathode forming portion 300c (FIG. 2) and conveyed to the nip portion of the pair of nip rolls 422 and 423. Also, the anode electrode catalyst layer sheet 380a is supplied from the anode forming unit 300a (FIG. 3) and conveyed to the nip portion of the pair of nip rolls 422 and 423. At this time, the electrolyte membrane 10 and the cathode electrode catalyst layer sheet 380c are conveyed so that the second surface 17 of the electrolyte membrane 10 and the cathode catalyst ink coating layer 14ar face each other. The electrolyte membrane 10 and the anode electrode catalyst layer sheet 380a are conveyed so that the first surface 16 of the electrolyte membrane 10 and the anode catalyst ink coating layer 12a face each other.

  The pair of nip rolls 422 and 423 join the electrolyte membrane 10, the cathode electrode catalyst layer sheet 380 c, and the anode electrode catalyst layer sheet 380 a at the nip portion, and bring them into close contact with each other to remove wrinkles and bubbles from each sheet. At this time, the cathode catalyst ink coating layer 14ar is in close contact with the second surface 17 of the electrolyte membrane 10, and the anode catalyst ink coating layer 12a is in close contact with the first surface 16 of the electrolyte membrane 10. As described above, the cathode catalyst ink coating layer 14ar is composed of the effective coating layer portion 14a and the excess coating layer portion 14r corresponding to the cathode electrode catalyst layer 14 (see FIG. 2). The anode catalyst ink coating layer 12 a is a coating layer corresponding to the anode electrode catalyst layer 12. The electrolyte membrane 10 in which the cathode electrode catalyst layer sheet 380c and the anode electrode catalyst layer sheet 380a are in close contact is conveyed to the nip portion of the pair of heat press rolls 432 and 433.

  The pair of heat press rolls 432 and 433 has only the effective coating layer portion 14a corresponding to the cathode electrode catalyst layer 14 out of the coating layer 14ar of the cathode catalyst ink at the nip portion of the second surface 17 of the electrolyte membrane 10. Heat-press on top. In addition, the pair of heat press rolls 432 and 433 thermally press-bond the anode catalyst ink coating layer 12 a corresponding to the anode electrode catalyst layer 12 onto the first surface 16 of the electrolyte membrane 10 at the nip portion.

  As described above, in the corona treatment unit 310c (see FIG. 2) of the cathode forming unit 300c, the corona treatment is performed so that the releasability of the frame region 384 of the transfer sheet 380 is lowered. Therefore, only the effective coating layer portion 14a on the electrode catalyst layer region 382 of the cathode catalyst ink coating layer 14ar on the transfer sheet 380 at the outlets of the heat press rolls 432 and 433 is the cathode electrode catalyst layer sheet 380c. The excess coating layer portion 14r on the frame region 384 is left without being peeled off. Thereby, only the effective coating layer portion 14 a is transferred as the cathode electrode catalyst layer 14 onto the second surface 17 of the electrolyte membrane 10. The transfer sheet 380 in which the surplus coating layer portion 14 r remains without being peeled off is taken up by the transfer sheet take-up roll 444.

  Further, at the outlets of the heat press rolls 432 and 433, the anode catalyst ink coating layer 12 a is further peeled off from the anode electrode catalyst layer sheet 380 a, and the anode electrode catalyst layer 12 is formed on the first surface 16 of the electrolyte membrane 10. Transcribed. The transfer sheet 372 from which the anode catalyst ink coating layer 12 a has been peeled off is taken up by a transfer sheet take-up roll 445.

  As described above, the cathode electrode catalyst layer 14 is intermittently transferred to the second surface 17 of the electrolyte membrane 10, and the anode electrode catalyst layer 12 is transferred in a continuous belt shape to the first surface 16 of the electrolyte membrane 10. Thus, a strip-shaped MEA 200 in which a plurality of MEAs 100 are continuous is manufactured. The produced belt-like MEA 200 is wound around a MEA winding roll (not shown).

  In addition, when GDL is further bonded to the MEA 100, the band-shaped MEA 200 is transported to a GDL bonding unit (not shown), and after the GDL is bonded to each MEA 100 and a plurality of MEGAs are continuous, a band-shaped MEGA is manufactured. , Wound around a MEGA winding roll. Further, when separating each manufactured MEA 100 and each MEGA, the MEA 100 and each MEGA are further transported to a cutting unit (not shown) and separated into each MEA 100 and each MEGA.

  As described above, in this embodiment, only the effective coating layer portion 14a of the cathode catalyst ink on the electrode catalyst layer region 382 excluding the frame region 384 subjected to the corona treatment can be transferred as the cathode electrode catalyst layer 14. . Thus, in the preparation of the cathode catalyst electrode layer sheet, after the cathode catalyst ink is applied to the entire surface of the transfer sheet, the coating layers corresponding to the cathode electrode catalyst layer having a desired shape are formed on the transfer sheet at the same interval. There is no need for a shaping step (for example, separation of the mask) for the intermittent formation. Therefore, the process can be simplified as compared with the prior art that requires a shaping process such as a process of separating the mask. Further, since the surplus coating layer portion 14r on the frame region 384 is not transferred, it is possible to improve the formation accuracy of the effective coating layer portion 14a of the cathode catalyst ink that becomes the cathode electrode catalyst layer 14. Further, the interval between the effective coating layer portions 14a transferred intermittently can be shortened, and the yield of the electrolyte membrane used can be improved. In the case of MEGA, it is also possible to improve the yield of GDL.

B. Second embodiment:
In the second embodiment, in the step of producing the cathode electrode catalyst layer sheet, the transfer sheet subjected to the corona treatment as in the first embodiment is not used, but as described below, the cathode catalyst ink A shaping step of shaping the coating layer into the shape of the coating layer corresponding to the shape of the cathode electrode catalyst layer;

  FIG. 5 is an explanatory view showing a cathode forming portion corresponding to a step of producing a cathode electrode catalyst layer sheet in the MEA manufacturing apparatus according to the second embodiment. The cathode forming unit 300Bc includes a cathode coating processing unit 320Bc, a cathode drying processing unit 330Bc, and a cathode shaping processing unit 340Bc.

  The cathode coating processing unit 320Bc and the cathode drying processing unit 330Bc are the same as the cathode coating processing unit 320c and the cathode drying processing unit 330c (see FIG. 2) in the first embodiment. The cathode shaping processing unit 340Bc includes an adhesive roll 342c, a backup roll 343c arranged to face the adhesive roll 342c, and a scraper 344c provided in contact with the roll surface of the adhesive roll 342c. The roll surface of the adhesive roll 342c is divided into a non-adhesive region 345c cut out in the shape of the cathode electrode catalyst layer 14 and an adhesive region 346c bordering the non-adhesive region 345c.

  In the cathode forming part 300Bc, as will be described below, a cathode electrode catalyst layer sheet 380Bc used for transferring the cathode electrode catalyst layer 14 intermittently to the strip-shaped electrolyte membrane 10 is produced.

  In the cathode coating processing unit 320Bc, the cathode catalyst ink is intermittently applied at substantially the same interval onto the transfer sheet 370 supplied from the transfer sheet supply roll 321c by the die coater 322c. That is, in the cathode coating processing unit 320Bc, a step of applying the cathode catalyst ink to the transfer sheet 370 intermittently is executed.

  In the cathode drying processing unit 330Bc, the cathode catalyst ink is heated and dried, and the cathode catalyst ink coating layer 14ar is intermittently formed on the transfer sheet 370 at substantially the same interval. The cathode catalyst ink coating layer 14ar includes an effective coating layer portion 14a corresponding to the shape of the cathode electrode catalyst layer 14 and a surplus coating layer portion 14r on the outer side (out of specification).

  In the cathode shaping processor 340Bc, the adhesive roll 342c is placed so that the non-adhesive region 345c of the adhesive roll 342c is on the cathode catalyst ink coating layer 14ar of the transfer sheet 370 conveyed from the cathode drying processor 330Bc. Rotate. As a result, the excess coating layer portion 14r of the cathode catalyst ink coating layer 14ar is adhered to the adhesive region 346c that borders the non-adhesive region 345c, peeled off from the transfer sheet 370, and corresponds to the non-adhesive region 345c. Only the effective coating layer portion 14 a is left on the transfer sheet 370. The excessive coating layer portion 14r adhered to the adhesive roll 342c is scraped off from the roll surface by the scraper 344c and sent to a collection box (not shown). As a result, a cathode electrode catalyst layer sheet 380Bc in which the effective coating layer portion 14a of the cathode catalyst ink corresponding to the shape of the cathode electrode catalyst layer 14 is formed.

  The production of the anode electrode catalyst layer sheet is the same as in the case of the first embodiment (see FIG. 3), and thus the description thereof is omitted.

  FIG. 6 is an explanatory view showing a transfer unit corresponding to the step of transferring the electrode catalyst layer to the electrolyte membrane in the MEA manufacturing apparatus according to the second embodiment. The transfer unit 400B is the same as the transfer unit 400 (FIG. 4) of the first embodiment, and includes an electrolyte membrane supply roll 411, a pair of nip rolls 422 and 423, a pair of heat press rolls 432 and 433, and a support sheet winding. A take-up roll 442 and transfer sheet take-up rolls 444 and 445 are provided. However, the cathode electrode catalyst layer sheet supplied to the nip rolls 422 and 423 is the cathode electrode catalyst layer sheet 380Bc supplied from the cathode forming portion 300Bc (FIG. 5). The transfer sheet take-up roll 444 is wound around the transfer sheet 370 after the effective coating layer portion 14a as the cathode electrode catalyst layer 14 has been peeled off at the outlets of the heat press rolls 432 and 433. is there.

  Also in the second embodiment, the cathode electrode catalyst layer 14 is intermittently transferred to the second surface 17 of the electrolyte membrane 10 and the anode electrode catalyst layer 12 is continuous with the first surface 16 of the electrolyte membrane 10. Is transferred, and a band-shaped MEA 200 in which a plurality of MEAs 100 are continuous is produced.

  In the second embodiment, the effective coating layer portion 14a corresponding to the cathode electrode catalyst layer 14 is applied from the cathode catalyst ink coating layer 14ar formed intermittently on the transfer sheet 370 using the adhesive roll 342c. The outer (out of specification) excess coating layer portion 14r is removed to produce a cathode electrode catalyst layer sheet 380Bc. Then, the effective coating layer portion 14 a of the cathode catalyst ink of the produced cathode electrode catalyst layer sheet 380 Bc is transferred to the electrolyte membrane 10 as the cathode electrode catalyst layer 14. Thereby, it is possible to improve the formation accuracy of the effective coating layer portion 14a of the cathode catalyst ink to be the cathode electrode catalyst layer 14. Further, the interval between the effective coating layer portions 14a as the cathode electrode catalyst layer 14 transferred intermittently can be shortened, and the yield of the electrolyte membrane to be used can be improved. In the case of MEGA, it is also possible to improve the yield of GDL.

C. Third embodiment:
Also in the third embodiment, in the step of producing the cathode electrode catalyst layer sheet, the transfer sheet subjected to the corona treatment as in the first embodiment is not used, but as described below, the cathode catalyst ink is used. A step of cutting the coating layer into a coating layer portion corresponding to the shape of the cathode electrode catalyst layer, and a step of intermittently pressing the cut coating layer portion onto the transfer sheet.

  FIG. 7 is an explanatory view showing a cathode forming portion corresponding to a step of producing a cathode electrode catalyst layer sheet in the MEA manufacturing apparatus according to the third embodiment. The cathode forming unit 300Cc includes a cathode coating processing unit 320Cc, a cathode drying processing unit 330Cc, a cathode cutting processing unit 340Cc, and a cathode crimping processing unit 350Cc.

  The cathode coating processing unit 320Cc and the cathode drying processing unit 330cc are the same as the cathode coating processing unit 320c and the cathode drying processing unit 330c (see FIG. 5) in the second embodiment. The cathode cutting processing unit 340Cc includes a cutting device 347c and a work shifter 348c. The cathode crimping processing unit 350Cc includes a carrier sheet supply roll 351c and a pair of press rolls 352c and 353c.

  In the cathode formation part 300Cc, as will be described below, a cathode electrode catalyst layer sheet 380Cc used to transfer the cathode electrode catalyst layer 14 intermittently to the belt-shaped electrolyte membrane 10 is produced.

  In the cathode coating processing unit 320Cc and the cathode drying processing unit 330Cc, as in the cathode coating processing unit 320Bc and the cathode drying processing unit 330Bc (see FIG. 5) of the second embodiment, the cathode catalyst ink is placed on the transfer sheet 370. The coating layer 14ar is formed intermittently at substantially the same interval.

  In the cathode cutting processing unit 340Cc, from the coating layer 14ar of the cathode catalyst ink, the effective coating layer portion 14a having a shape corresponding to the cathode electrode catalyst layer 14 and the portion of the transfer sheet 370 corresponding to this (hereinafter referred to as “transfer”). 370a is cut out by the cutting device 347c. The cutting device 347c includes, for example, a dumbbell cutter and a cutting die. The cut effective coating layer portion 14a and the transfer sheet portion 370a are supplied to the cathode pressure-bonding processing portion 350Cc by the work shifter 348c. Hereinafter, the cut effective coating layer portion 14a and the transfer sheet portion 370a are also referred to as “coating layer cut sheet 14ct”.

  In the cathode pressure-bonding processing portion 350Cc, the carrier sheet 376 is supplied from the carrier sheet supply roll 351c to the nip portion of the pair of press rolls 352c and 353c. On the upper surface of the carrier sheet 376, the coating layer cut sheet 14ct conveyed by the work shifter 348c is placed in front of the press rolls 352c and 353c with the transfer sheet 370 portion facing downward, and a pair of press rolls 352c. , 353c.

  In the pair of press rolls 352c and 353c, the applied coating layer cut sheet 14ct (the effective coating layer portion 14a of the cathode catalyst ink and the transfer sheet portion 370a) is pressurized as shown in the section AA. Is pressed (press-fit / adhered) to the carrier sheet 376. As a result, a cathode electrode catalyst layer sheet 380Cc in which the effective coating layer portion 14a of the cathode catalyst ink corresponding to the shape of the cathode electrode catalyst layer 14 is formed on the carrier sheet 376 is produced.

  In addition, as a carrier sheet, the various sheet | seat which consists of materials, such as various resin and an elastomer which have the elasticity which makes the coating layer cut sheet | seat 14ct easy to crimp can be used. For example, a polyester elastomer sheet can be used.

  The production of the anode electrode catalyst layer sheet is the same as in the case of the first embodiment (see FIG. 3), and thus the description thereof is omitted.

  FIG. 8 is an explanatory view showing a transfer portion corresponding to the step of transferring the electrode catalyst layer to the electrolyte membrane in the MEA manufacturing apparatus according to the third embodiment. The transfer section 400C is the same as the transfer section 400 (FIG. 4) of the first embodiment, and includes an electrolyte membrane supply roll 411, a pair of nip rolls 422 and 423, a pair of heat press rolls 432 and 433, and a support sheet winding. A take-up roll 442 and transfer sheet take-up rolls 444 and 445 are provided. However, the cathode electrode catalyst layer sheet supplied to the nip rolls 422 and 423 is the cathode electrode catalyst layer sheet 380Cc supplied from the cathode forming portion 300Cc (FIG. 7). Further, the transfer sheet take-up roll 444 takes up the carrier sheet 376 after the effective coating layer portion 14a as the cathode electrode catalyst layer 14 is peeled off at the outlets of the heat press rolls 432 and 433. . The carrier sheet 376 remains in a state where the crimped transfer sheet portion 370a is crimped.

  Also in the third embodiment, the cathode electrode catalyst layer 14 is intermittently transferred to the second surface 17 of the electrolyte membrane 10, and the anode electrode catalyst layer 12 is continuously formed in a strip shape continuous with the first surface 16 of the electrolyte membrane 10. Is transferred, and a band-shaped MEA 200 in which a plurality of MEAs 100 are continuous is produced.

  In the third embodiment, an effective coating layer portion 14 a corresponding to the cathode electrode catalyst layer 14 is cut out from the cathode catalyst ink coating layer 14 ar formed intermittently on the transfer sheet 370 to form a carrier sheet 376. The cathode electrode catalyst layer sheet 380Cc is produced by intermittent pressure bonding. Then, the effective coating layer portion 14 a of the cathode catalyst ink of the produced cathode electrode catalyst layer sheet 380 Cc is transferred to the electrolyte membrane 10 as the cathode electrode catalyst layer 14. Thereby, it is possible to improve the formation accuracy of the effective coating layer portion 14a of the cathode catalyst ink to be the cathode electrode catalyst layer 14. Further, the interval between the effective coating layer portions 14a as the cathode electrode catalyst layer 14 transferred intermittently can be shortened, and the yield of the electrolyte membrane to be used can be improved. In the case of MEGA, it is also possible to improve the yield of GDL.

D. Variations:
(1) In each of the above-described embodiments, a step of producing a cathode electrode catalyst layer sheet, a step of producing an anode electrode catalyst layer sheet, a cathode electrode catalyst layer 14 of the cathode electrode catalyst layer sheet, and an anode electrode catalyst layer sheet The case where the step of transferring the anode electrode catalyst layer 12 to the electrolyte membrane 10 and producing the MEA 100 is performed in conjunction with the above has been described as an example. However, the present invention is not limited to this, and each process may be performed separately.

(2) In each of the above-described embodiments, the MEA 100 is manufactured by transferring the anode electrode catalyst layer 12 and the cathode electrode catalyst layer 14 to the electrolyte membrane 10. However, the present invention is not limited to this. The anode catalyst ink is applied to the first surface 16 of the electrolyte membrane 10, and the cathode is formed on the second surface 17 of the electrolyte membrane 10 on which the anode electrode catalyst layer 12 is formed. The MEA 100 may be produced by transferring the electrode catalyst layer 14.

(3) In each of the embodiments described above, the strip-shaped anode electrode catalyst layer 12 is transferred to the electrolyte membrane 10, but the intermittent anode electrode catalyst layer 12 is transferred to the electrolyte membrane 10 in the same manner as the cathode electrode catalyst layer 14. The MEA may be produced by transferring. The anode electrode catalyst layer sheet in this case can be produced in the same manner as the cathode electrode catalyst layer sheet.

(4) In each of the embodiments described above, the coating layer 12a corresponding to the anode electrode catalyst layer 12 and the coating layer 14ar including the effective coating layer portion 14a corresponding to the cathode electrode catalyst layer 14 are formed by die coating. Forming. However, the present invention is not limited to this, and the application of the catalyst ink to the transfer sheet can be performed by various methods such as gravure printing, spraying method, screen printing, doctor blade method or ink jet method.

  The present invention is not limited to the above-described embodiments, examples, and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the above effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 10 ... Electrolyte membrane 12 ... Anode electrode catalyst layer 12a ... Coating layer 14 ... Cathode electrode catalyst layer 14ar ... Coating layer 14a ... Effective coating layer part 14r ... Excess coating layer part 14ct ... Coating layer cut sheet 16 ... 1st 1 surface 17 ... 2nd surface 300c, 300Bc, 300Cc ... cathode formation part 300a ... anode formation part 310c ... corona treatment part 311c ... transfer sheet supply roll 312c ... corona treatment device 313c ... electrode 314c ... treatment roll 320a ... anode Coating processing unit 320c, 320Bc, 320Cc ... Cathode coating processing unit 321a ... Transfer sheet supply roll 321c ... Transfer sheet supply roll 322a, 322c ... Die coater 323a, 323c ... Die 324a, 324c ... Backup roll 330a ... Anode drying Processing unit 330c , 330Bc, 330Cc ... Cathode drying processing unit 332a, 332c ... Drying device 340Bc ... Cathode shaping processing unit 340Cc ... Cathode cutting processing unit 342c ... Adhesive roll 343c ... Backup roll 344c ... Scraper 345c ... Non-adhesive region 346c ... Adhesive region 347c ... Cutting Apparatus 348c ... Work shifter 350Cc ... Cathode pressure-bonding processing part 351c ... Carrier sheet supply roll 352c, 353c ... Press roll 370, 372 ... Transfer sheet 370a ... Transfer sheet portion 374 ... Support sheet 376 ... Carrier sheet 380 ... Transfer sheet 380c , 380Bc, 380Cc ... cathode electrode catalyst layer sheet 380a ... anode electrode catalyst layer sheet 382 ... electrode catalyst layer region 384 ... frame region 400, 400B, 400C ... Copy unit 411 ... electrolyte membrane supply rolls 422, 423 ... nip roll 432, 433 ... heat press roll 442 ... support sheet take-up roll 444 ... transfer sheet take-up roll (carrier sheet take-up roll)
445 ... Transfer sheet take-up roll

Claims (1)

A method for producing a membrane electrode assembly in which an electrode catalyst layer is intermittently transferred to a strip-shaped electrolyte membrane,
As a belt-shaped transfer sheet, an electrode catalyst layer region having a shape corresponding to the electrode catalyst layer provided intermittently along the longitudinal direction of the transfer sheet on one surface, and the electrode catalyst layer region in a frame shape And a step of preparing a transfer sheet that is divided into a frame region having a shape to be bordered, and subjected to corona treatment for reducing releasability in the frame region;
Applying the catalyst ink intermittently corresponding to the electrode catalyst layer region of the transfer sheet to form a coating layer of the catalyst ink;
The surface of the transfer sheet on which the coating layer is formed is overlapped with the electrolyte membrane, and the coating layer in the electrode catalyst layer region is intermittently formed on the electrolyte membrane as the electrode catalyst layer. A transfer process;
A method for producing a membrane electrode assembly, comprising:

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