JP6350030B2 - Electrocatalyst layer production apparatus and production method - Google Patents

Description

  The present invention relates to an electrode catalyst layer manufacturing apparatus and a manufacturing method.

  An electrode catalyst layer included in a membrane electrode assembly (MEA) of a fuel cell is composed of an electrode catalyst and a polymer electrolyte membrane. For example, an electrode catalyst ink is applied to a transfer sheet and dried. The electrode catalyst layer formed in (1) is transferred to a polymer electrolyte membrane.

  Since the solid content particles contained in the electrode catalyst ink form aggregates over time in a relatively short time, the electrode catalyst ink containing aggregates is applied to the transfer sheet, and the produced electrode catalyst There is a possibility that aggregates may remain (spotted) in the layer. Since the aggregate has low gas permeability, not only is the catalyst not used effectively, but also causes problems such as the generated water not being discharged. Therefore, the aggregate is removed before application of the electrode catalyst ink ( For example, see Patent Document 1.)

Japanese Patent Laid-Open No. 2004-253304

  However, the removal of the agglomerates is carried out by adding a filtration process using a mesh filter and a physical crushing process using a mechanical crusher. There is a possibility that aggregates may be newly formed (reaggregated) until application, and the aggregates have not been sufficiently removed.

  The present invention has been made to solve the problems associated with the above-described prior art, and an object thereof is to provide a manufacturing apparatus and a manufacturing method for manufacturing an electrode catalyst layer from which aggregates are sufficiently removed. .

In order to achieve the above object, the uniform phase of the present invention includes an application head for applying an electrode catalyst ink constituting an electrode catalyst layer to a film substrate, and an ultrasonic crushing method for crushing aggregates by ultrasonic vibration. And an electrode catalyst layer manufacturing apparatus. The coating head has a supply port, a manifold part, an aggregate removal means, and a discharge port. The electrode catalyst ink is supplied to the supply port. The manifold portion expands the electrode catalyst ink introduced from the supply port in the coating width direction. The agglomerate removing means is disposed inside the manifold part, and crushes and / or collects agglomerates contained in the electrode catalyst ink. The discharge port discharges the electrode catalyst ink that has passed through the manifold portion and the aggregate removing means toward the film base. The ultrasonic crushing means has pressure detection means and ultrasonic vibration applying means. The pressure detecting unit detects an internal pressure of the coating head, and the ultrasonic vibration applying unit applies the ultrasonic vibration to the manifold portion. When it is determined that the aggregate is accumulated inside the manifold portion based on the increase in the internal pressure of the coating head detected by the pressure detection unit, the aggregate is applied with the ultrasonic vibration. Crushed by means.

Another uniform phase of the present invention for achieving the above object is a method for producing an electrode catalyst layer having a coating step of coating an electrode catalyst ink constituting the electrode catalyst layer on a film substrate. In the coating step, the electrode catalyst ink is supplied to a supply port of a coating head, and the electrode catalyst ink introduced from the supply port is introduced to a manifold portion of the coating head. The aggregate contained in the electrocatalyst ink is crushed and / or collected by the aggregate removing means disposed inside the electrocatalyst ink, and the electrocatalyst ink is spread in the coating width direction, so that the manifold portion and the aggregate The electrode catalyst ink that has passed through the removing means is discharged from the discharge port of the coating head toward the film substrate. Further, in the coating step, it is determined that aggregates are accumulated in the manifold portion based on an increase in the internal pressure of the coating head detected by a pressure detection unit that detects an internal pressure of the coating head. In this case, the ultrasonic vibration applying means is operated to apply ultrasonic vibration to the manifold part, and the aggregates accumulated in the manifold part are crushed.

In the production apparatus and production method according to the present invention, the aggregates contained in the electrode catalyst ink are removed by the aggregate removal means. The agglomerate removing means is disposed inside the manifold portion of the coating head and applies the electrode catalyst ink immediately after the agglomerate is removed. In this case, there is no possibility that aggregates are newly generated (reaggregated). Therefore, by drying the electrode catalyst ink applied to the film substrate, an electrode catalyst layer from which aggregates have been reliably removed can be obtained. That is, it is possible to provide a production apparatus and a production method for producing an electrode catalyst layer from which aggregates are sufficiently removed. In particular, it is not required to disassemble and wash the coating head to remove the aggregates, and no adjustment time is required for reassembling the coating head, and no material loss occurs.

1 is a cross-sectional view for explaining a fuel cell having an electrode catalyst layer according to Embodiment 1. FIG. 3 is a flowchart for explaining a method of manufacturing an electrode catalyst layer according to Embodiment 1. It is the schematic for demonstrating the electrode catalyst layer manufacturing apparatus applied to the application | coating process shown by FIG. It is a top view for demonstrating the application | coating head shown by FIG. It is a perspective view for demonstrating the aggregate removal means shown by FIG. It is an enlarged view for demonstrating the outer peripheral surface shown by FIG. FIG. 6 is an enlarged view for explaining a first modification according to the first embodiment. FIG. 10 is an enlarged view for explaining a second modification according to the first embodiment. FIG. 10 is a cross-sectional view for explaining a third modification according to the first embodiment. FIG. 10 is a cross-sectional view for explaining a fourth modification according to the first embodiment. 5 is a schematic diagram for explaining an electrode catalyst layer manufacturing apparatus according to Embodiment 2. FIG. FIG. 6 is a schematic diagram for explaining an electrode catalyst layer manufacturing apparatus according to Embodiment 3. 6 is a schematic diagram for explaining an electrode catalyst layer manufacturing apparatus according to Embodiment 4. FIG. It is a top view for demonstrating intermittent application in the electrode catalyst layer manufacturing apparatus shown by FIG. It is a timing chart for demonstrating the application | coating operation | movement and ultrasonic vibration provision operation | movement in intermittent application | coating.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

  1 is a cross-sectional view for explaining a fuel cell having an electrode catalyst layer according to Embodiment 1. FIG.

  The fuel cell according to Embodiment 1 is composed of, for example, a polymer electrolyte fuel cell (PEFC) using hydrogen as a fuel, and has a stack of single cells 10 shown in FIG. The single cell 10 has a membrane electrode assembly 20 and separators 80 and 85.

  The membrane electrode assembly 20 includes a polymer electrolyte membrane 30, electrode catalyst layers 50 and 55, and gas diffusion layers (GDLs) 70 and 75.

  The electrode catalyst layer 50 includes a catalyst component, a conductive catalyst carrier that supports the catalyst component, and a polymer electrolyte. The electrode catalyst layer 50 is an anode electrode that undergoes a hydrogen oxidation reaction, and is disposed on one side of the polymer electrolyte membrane 30. Be placed. The electrode catalyst layer 55 includes a catalyst component, a conductive catalyst carrier that supports the catalyst component, and a polymer electrolyte. The electrode catalyst layer 55 is a cathode electrode in which an oxygen reduction reaction proceeds, and is disposed on the other side of the polymer electrolyte membrane 30. Be placed.

  The polymer electrolyte membrane 30 has a function of selectively permeating protons generated in the electrode catalyst layer 50 to the electrode catalyst layer 55 and does not mix the fuel gas supplied to the anode side and the oxidant gas supplied to the cathode side. Function as a partition wall.

  The gas diffusion layer 70 is an anode gas diffusion layer for dispersing the fuel gas supplied to the anode side, and is located between the separator 80 and the electrode catalyst layer 50. The gas diffusion layer 75 is a cathode gas diffusion layer for dispersing the oxidant gas supplied to the cathode side, and is located between the separator 85 and the electrode catalyst layer 55.

  The separators 80 and 85 have a function of electrically connecting the single cells 10 in series and a function of a partition that blocks fuel gas, oxidant gas, and refrigerant from each other, and have substantially the same shape as the membrane electrode assembly 20 and are made of stainless steel. Manufactured from steel. The stainless steel plate is preferable in that it is easy to perform complicated machining and has good conductivity, and it is possible to apply a corrosion-resistant coating as necessary.

  The separator 80 is an anode separator disposed on the anode side of the membrane electrode assembly 20, and constitutes a gas flow path 84 that is located between the membrane electrode assembly 20 and the separator 80, facing the electrode catalyst layer 50. Rib portion 82 and manifold holes (not shown) provided for hydrogen passage, oxygen passage, and cooling water passage, respectively. The gas flow path 84 is used for supplying fuel gas to the electrode catalyst layer 50.

  The separator 85 is a cathode separator disposed on the cathode side of the membrane electrode assembly 20, and constitutes a gas flow path 89 positioned between the membrane electrode assembly 20 and the separator 85, facing the electrode catalyst layer 55. Rib portion 87 and manifold holes (not shown) provided for passing hydrogen, passing oxygen, and passing cooling water are provided. The gas flow path 89 is used for supplying an oxidant gas to the electrode catalyst layer 55.

  Next, the material and size of each component will be described in detail.

  The polymer electrolyte membrane 30 is a porous polymer electrolyte membrane made of a perfluorocarbon sulfonic acid polymer, a porous resin membrane having a sulfonic acid group, and a porous material impregnated with an electrolyte component such as phosphoric acid or ionic liquid. A shaped film can be applied. Examples of the perfluorocarbon sulfonic acid polymer include Nafion (registered trademark) (manufactured by DuPont), Aciplex (registered trademark) (manufactured by Asahi Kasei Corporation), Flemion (registered trademark) (manufactured by Asahi Glass Co., Ltd.), and the like. The porous film is made of polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF).

  The thickness of the polymer electrolyte membrane 30 is not particularly limited, but is preferably 5 to 300 μm, more preferably 10 to 200 μm from the viewpoint of strength, durability, and output characteristics.

  The catalyst component used for the electrode catalyst layer 50 is not particularly limited as long as it has a catalytic action in the oxygen reduction reaction. The catalyst component used for the electrode catalyst layer 55 is not particularly limited as long as it has a catalytic action for the oxidation reaction of hydrogen.

  Specific catalyst components include, for example, metals such as platinum, ruthenium, iridium, rhodium, palladium, osmium, tungsten, lead, iron, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium, aluminum, and alloys thereof. Etc. are selected. In order to improve catalytic activity, poisoning resistance to carbon monoxide, heat resistance, etc., those containing at least platinum are preferable. The catalyst components applied to the cathode electrode and the anode electrode need not be the same and can be changed as appropriate.

  As long as the conductive carrier of the catalyst used for the electrode catalyst layers 50 and 55 has a specific surface area for supporting the catalyst component in a desired dispersed state and sufficient electronic conductivity as a current collector, Although not limited, the main component is preferably carbon particles. The carbon particles are composed of, for example, carbon black, activated carbon, coke, natural graphite, and artificial graphite.

  The polymer electrolyte used for the electrode catalyst layers 50 and 55 is not particularly limited as long as it is a member having at least high proton conductivity. For example, a fluorine-based electrolyte containing a fluorine atom in all or part of the polymer skeleton or a polymer A hydrocarbon-based electrolyte that does not contain a fluorine atom in the skeleton is applicable. The polymer electrolyte used for the electrode catalyst layers 50 and 55 may be the same as or different from the polymer electrolyte used for the polymer electrolyte membrane 30, but the electrode catalyst layers 50 and 55 for the polymer electrolyte membrane 30 are not limited. It is preferable that they are the same from the viewpoint of improving the adhesion.

  The gas diffusion layers 70 and 75 are configured using, as a base material, a sheet-like material having conductivity and porosity, such as a carbon woven fabric such as glassy carbon, a paper-like paper body, a felt, and a nonwoven fabric. Although the thickness of a base material is not specifically limited, 30-500 micrometers is preferable from a mechanical strength and permeability viewpoints, such as gas and water.

  The gas diffusion layers 70 and 75 preferably contain a water repellent in the base material from the viewpoint of water repellency and suppression of the flooding phenomenon. Examples of the water repellent include PTFE, PVDF, polyhexafluoropropylene, a fluoropolymer such as tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polypropylene, and polyethylene.

  Separator 80, 85 is not limited to the form which comprises stainless steel, and other metal materials (for example, aluminum and a clad material) can also be applied.

  Next, a method for manufacturing the electrode catalyst layer according to Embodiment 1 will be described.

  FIG. 2 is a flowchart for explaining the method for manufacturing the electrode catalyst layer according to the first embodiment.

  The method for producing an electrode catalyst layer according to Embodiment 1 includes an electrode catalyst ink preparation process, a coating process, a drying process, and a transfer process, as shown in FIG.

  In the electrode catalyst ink preparation step, an electrode component ink, a solvent and a dispersant are mixed to prepare an electrode catalyst ink.

  The electrode component is a catalyst component, a conductive catalyst carrier that supports the catalyst component, and a polymer electrolyte. The catalyst component used in the production of the cathode electrode (electrode catalyst layer 50) has a catalytic action in the oxygen reduction reaction, and the catalyst component used in the production of the anode electrode (electrode catalyst layer 55) is: Some have a catalytic action on the oxidation reaction of hydrogen.

  The solvent is, for example, water in which an alcohol such as ethanol, 1-propanol, or 2-propanol is dissolved. The dispersant is, for example, a surfactant, a heat stabilizer, a weather stabilizer, a lubricant, an antiblocking agent, a slip agent, or an inorganic filler.

  In the application step, the prepared electrode catalyst ink is applied to a film substrate made of a transfer sheet. At this time, as will be described later, aggregates are removed from the electrode catalyst ink immediately before coating. The transfer sheet is, for example, a PTFE (polytetrafluoroethylene) sheet, a PET (polyethylene terephthalate) sheet, or a polyester sheet.

  In the drying step, the electrode catalyst ink coating layer is dried to form an electrode catalyst layer. Thereby, the cathode electrode (electrode catalyst layer 50) or the anode electrode (electrode catalyst layer 55) is manufactured according to the electrode constituent member contained in the coating layer of the electrode catalyst ink.

  In the transfer step, the electrode catalyst layer is peeled off from the film substrate and transferred to the polymer electrolyte membrane. Thereby, the membrane electrode assembly of a fuel cell is manufactured.

  Since the aggregate of the electrode catalyst ink coating layer is removed, the electrode catalyst layer formed by drying the electrode catalyst ink coating layer does not have the aggregate. That is, since the aggregate is sufficiently removed from the electrode catalyst layer, the gas permeability is low, so that a portion where the catalyst is not effectively used does not occur and the generated moisture is not discharged.

  Since the electrode catalyst ink is not applied to the polymer electrolyte membrane, adverse effects on the polymer electrolyte membrane due to the solvent contained in the electrode catalyst ink are suppressed. If necessary, it is also possible to apply an electrode catalyst ink to the polymer electrolyte membrane. In this case, since a transfer process is not required, productivity is improved, and it is possible to avoid a decrease in yield due to transfer failure and generation of a transfer sheet as a discarded material.

  Next, the electrode catalyst layer manufacturing apparatus according to the coating process will be described.

  FIG. 3 is a schematic diagram for explaining an electrode catalyst layer manufacturing apparatus applied to the coating step shown in FIG. 2, and FIG. 4 is a plan view for explaining the coating head shown in FIG.

  The electrode catalyst layer manufacturing apparatus according to the coating process is a coating apparatus 100 for the electrode catalyst ink 40 as shown in FIG. The coating apparatus 100 includes a tank 110, a back roll 120, a coating head 130, piping systems 160 and 170, and a control unit 180.

  The tank 110 is a container used for holding the prepared electrocatalyst ink 40 and includes a shaft 112 and an electric motor 114. The shaft 112 has a stirring blade disposed at the tip. The electric motor 114 is provided to rotate the shaft 112 and stir the electrode catalyst ink 40 with a stirring blade.

  The back roll 120 is arranged inside the film substrate 90 and is configured to convey the film substrate 90 by being driven to rotate. In addition, the code | symbol L has shown the application | coating direction.

  The coating head 130 is provided to apply the electrode catalyst ink 40 to the film substrate 90 to form the coating layer 42 of the electrode catalyst ink 40. The supply head 132, the manifold part 134, and the aggregate removing means 140 are provided. And a discharge port 136.

  The supply port 132 communicates with the piping system 160 and is supplied with the electrode catalyst ink 40. The manifold portion 134 has a columnar shape, and communicates with the supply port 132 and the discharge port 136. In order to expand the electrode catalyst ink 40 introduced from the supply port 132 in the coating width direction W as shown in FIG. Is provided. Aggregate removing means 140 has a shape corresponding to the internal shape of manifold portion 134 (which is cylindrical), and is fixedly arranged inside manifold portion 134. The discharge port 136 discharges the electrode catalyst ink 40 that has passed through the manifold part 134 and the aggregate removing means 140 toward the film substrate 90.

  The manifold portion 134 is not limited to a cylindrical shape, and for example, a semi-cylindrical shape or a hanger shape can be applied. Moreover, the aggregate removal means 140 is not limited to a cylindrical shape.

  The piping system 160 connects the tank 110 and the supply port 132 of the coating head 130, and a pump 162 and a valve means 164 are provided in the middle of the piping.

  The pump 162 is used to pressure-feed the electrode catalyst ink 40 to the supply port 132 of the coating head 130. The pump 162 is, for example, a snake pump, a diaphragm pump, a gear pump, or a tube pump. The valve means 164 is disposed in the middle of the piping between the pump 162 and the supply port 132 of the coating head 130 and is used for adjusting the supply amount of the electrode catalyst ink 40 to the coating head 130.

  The piping system 170 is a bypass piping for circulating the electrode catalyst ink 40, and has one end connected between the pump 162 and the valve means 164 and the other end connected to the tank 110, and a valve Means 172 are provided. The valve means 172 controls application thickness when starting application (discharge) in intermittent application and stopping application (discharge), and adjusts the length of the application layer 42 (and non-application area). Used for.

  The control unit 180 includes a control circuit that includes, for example, a microprocessor that executes control of each unit and various arithmetic processes according to a program. For example, the motor 114 of the tank 110, the pump 162, and the valve unit 164 are provided. , 172 are used to control. That is, each function of the coating apparatus 100 is exhibited when the control unit 180 executes a program corresponding to the function.

  Next, the aggregate removal unit 140 will be described in detail.

  FIG. 5 is a perspective view for explaining the aggregate removing means shown in FIG. 3, and FIG. 6 is an enlarged view for explaining the outer peripheral surface shown in FIG.

  As shown in FIG. 5, the aggregate removing means 140 is provided for crushing the aggregate 41 contained in the electrode catalyst ink. Aggregate removing means 140 is disposed inside the manifold portion that communicates with the discharge port of the coating head, so that the electrode catalyst ink immediately after the aggregate 41 is removed is applied to the film substrate.

  Therefore, there is no possibility that the aggregate 41 is newly generated (reaggregated) between the removal of the aggregate 41 and the application of the electrode catalyst ink. Therefore, by drying the coating layer of the electrode catalyst ink formed on the film substrate, an electrode catalyst layer from which aggregates have been reliably removed can be obtained. That is, it is possible to provide a production apparatus for producing an electrode catalyst layer from which aggregates are sufficiently removed. Moreover, since the aggregate removal means 140 is incorporated in the coating head, the influence on other equipment is suppressed.

  Specifically, the agglomerate removing means 140 is composed of a static mixing type disperser and has an outer peripheral surface 142 in which an opening 143 made of mesh is formed, as shown in FIG. The opening 143 can easily crush the aggregate 41 contained in the electrode catalyst ink by applying a shearing force to the electrode catalyst ink that passes therethrough.

  Since the electrode catalyst ink has high thixotropy, applying a shear force significantly lowers the viscosity and increases the fluidity. Therefore, the leveling property at the time of application | coating of an electrode catalyst ink improves, and it has the effect that the smoothness of an application layer increases.

  The opening 143 can also be configured to collect the aggregate 41 contained in the electrode catalyst ink. Also in this case, the aggregate 41 can be easily removed. For example, the opening 143 can collect aggregates of 10 μm or more at a collection efficiency of 90% or more, and more preferably can collect aggregates of 5 μm or more at 99% or more.

  Next, a coating process to which the coating apparatus 100 is applied will be described.

  First, in order to stir the electrode catalyst ink 40 held in the tank 110, the electric motor 114 is activated, and the shaft 112 having the stirring blade disposed at the tip is rotationally driven.

  In order to circulate the electrode catalyst ink 40, after the valve means 164 arranged in the piping system 160 is set to “closed”, the valve means 172 arranged in the piping system 170 which is a bypass pipe is set to “open”. The pump 162 arranged in the piping system 160 is started. Thus, the electrode catalyst ink 40 pumped from the tank 110 by the pump 162 is introduced into the piping system 160 and returned to the tank 110 via the piping system 170 which is a bypass piping.

  On the other hand, the back roll 120 is rotationally driven, and the film substrate 90 disposed outside the back roll 120 is conveyed.

  Next, the valve means 164 disposed in the piping system 160 is set to “open”, and the valve opening degree of the valve means 164 is adjusted. At the same time, the valve opening of the valve means 172 is adjusted. Thereby, an appropriate amount of the electrode catalyst ink 40 is supplied to the supply port 132 of the coating head 130 (see FIG. 3).

  The electrode catalyst ink introduced from the supply port 132 is introduced into the manifold section 134.

  In the manifold portion 134, when the electrode catalyst ink 40 is expanded in the coating width direction W (see FIG. 4), the opening 143 of the outer peripheral surface 142 of the aggregate removing means 140 imparts a shearing force to the passing electrode catalyst ink. By doing so, the aggregate 41 contained in the electrode catalyst ink is easily crushed.

  The electrode catalyst ink 40 that has passed through the manifold portion 134 and the aggregate removing means 140 is discharged from the discharge port 136 toward the film base material 90, and the coating layer 42 of the electrode catalyst ink 40 is formed.

  In the present coating step, as described above, the aggregate 41 contained in the electrode catalyst ink 40 is removed by the aggregate removing means 140 disposed inside the manifold portion 134 that communicates with the discharge port 136 of the electrode catalyst ink 40. Therefore, the electrode catalyst ink 40 immediately after the aggregate 41 is removed is applied from the discharge port 136.

  Therefore, there is no possibility that the aggregate 41 is newly generated (reaggregated) between the removal of the aggregate 41 and the application of the electrode catalyst ink 40. Therefore, by drying the coating layer 42 of the electrode catalyst ink 40 formed on the film substrate 90, an electrode catalyst layer from which the aggregate 41 has been reliably removed can be obtained. That is, it is possible to provide a production method for producing an electrode catalyst layer from which aggregates are sufficiently removed.

  In addition, when the opening part 143 is configured to collect the aggregate 41 contained in the electrode catalyst ink 40, the aggregate 41 contained in the electrode catalyst ink 40 can be easily collected. .

  Next, modifications 1 to 5 according to the first embodiment will be sequentially described.

  FIG. 7 is an enlarged view for explaining a first modification according to the first embodiment.

  The outer peripheral surface 142 of the aggregate removing means 140 is not limited to the form having the opening 143 made of mesh. For example, as shown in FIG. 7, it is also possible to have an opening 143A formed by drilling.

  FIG. 8 is an enlarged view for explaining a second modification according to the first embodiment.

  The shape of the opening is not limited to a rectangular shape (FIG. 6) or a circular shape (FIG. 7), and may be a long and narrow slit shape, for example, like the opening 143B shown in FIG.

  FIG. 9 is a cross-sectional view for explaining a third modification according to the first embodiment.

  The agglomerate removing means 140 is not limited to a configuration composed of a static mixing type disperser, and a dynamic mixing type can also be applied.

  For example, the aggregate removing unit 140 </ b> A illustrated in FIG. 9 includes a rotating shaft 144, an electric motor 146, and a grinding medium 148. A cylindrical rotor 145 having a narrow width is fixed to the rotating shaft 144. The electric motor 146 is used to drive the rotating shaft 144. The grinding media 148 is filled in the aggregate removing means 140A. The filling amount of the grinding media 148 is 10 to 90% by volume, more preferably 50 to 90%.

  Since the grinding media 148 rotates according to the rotation of the rotor 145 (rotating shaft 144), the shearing force is applied to the electrode catalyst ink 40 that has passed through the outer peripheral surface 142 and introduced into the electrode catalyst ink. It is possible to dynamically disintegrate the contained aggregate 41.

  The grinding media 148 is, for example, alumina, zirconia, or silicon nitride. The size of the grinding media 148 is preferably φ0.03 mm to 60 mm, and more preferably φ0.1 mm to 5 mm. Further, the driving of the rotor 145 is not limited to the form using the electric motor 146, and for example, compressed air can be used.

  FIG. 10 is a cross-sectional view for explaining a fourth modification according to the first embodiment.

  The rotor 145 fixed to the rotating shaft 144 is not limited to a cylindrical shape, and for example, as shown in FIG. In addition, the rotor 145 can be integrated with the rotating shaft 144 or can be fixed to the rotating shaft 144 using a guide pin, a female screw, or the like.

  As described above, in the production apparatus and production method according to Embodiment 1, the aggregates contained in the electrode catalyst ink are removed by the aggregate removal means. The agglomerate removing means is disposed inside the manifold portion of the coating head and applies the electrode catalyst ink immediately after the agglomerate is removed. In this case, there is no possibility that aggregates are newly generated (reaggregated). Therefore, by drying the electrode catalyst ink applied to the film substrate, an electrode catalyst layer from which aggregates have been reliably removed can be obtained. That is, it is possible to produce an electrode catalyst layer from which aggregates are sufficiently removed.

  When the agglomerate removing means is constituted by a disperser having an opening through which the electrode catalyst ink passes, the aggregate contained in the electrode catalyst ink can be easily obtained by applying a shearing force to the electrode catalyst ink through the opening. It can be crushed.

  The removal of the agglomerates can also be achieved by configuring the opening of the disperser so as to collect the agglomerates contained in the electrocatalyst ink.

  Next, a second embodiment will be described. In the following, members having the same functions as those in the first embodiment are denoted by similar reference numerals, and the description thereof is omitted to avoid duplication.

  FIG. 11 is a schematic diagram for explaining the electrode catalyst layer manufacturing apparatus according to the second embodiment.

  Coating apparatus 100A, which is an electrode catalyst layer manufacturing apparatus according to the second embodiment, is generally different from coating apparatus 100 according to the first embodiment in that it includes temperature adjusting means controlled by control unit 180.

  As shown in FIG. 11, the temperature adjustment unit according to the second embodiment includes a temperature detector 150 and a temperature adjustment unit 152 connected to the control unit 180. The temperature detector 150 has, for example, a resistance temperature detector, and is configured to be able to detect the internal temperature of the coating head 130. Detection data of the temperature detector 150 is transmitted to the control unit 180. The temperature adjustment unit 152 has, for example, a Peltier element, and is configured to absorb heat from the coating head 130 to lower the temperature and generate heat to raise the temperature. The control unit 180 has a function of adjusting the internal temperature of the coating head 130 to be constant by performing feedback control of the temperature adjustment unit 152 based on detection data from the temperature detector 150.

  For example, in the case where application of the electrode catalyst ink 40 is continued for a long time while applying a shearing force to the electrode catalyst ink 40 by the aggregate removal means 140 and crushing the aggregates contained in the electrode catalyst ink 40, the coating head 130 is used. Temperature rises. As a result, the physical properties of the electrode catalyst ink 40 change over time, making it difficult to form a uniform coating layer (electrode catalyst layer). Therefore, the internal temperature of the coating head 130 is adjusted to be constant.

  As described above, in Embodiment 2, the physical property (temperature) of the electrode catalyst ink discharged from the coating head (discharge port) is stabilized by adjusting the internal temperature of the coating head to be constant. It is possible to apply the electrode catalyst ink stably over time, that is, to form a uniform coating layer (electrode catalyst layer) over a long period of time.

  The temperature detector 150 is not limited to a form using a resistance temperature detector. The temperature adjustment unit 152 can also adjust the temperature by arranging a jacket instead of the Peltier element and circulating the refrigerant.

  Next, a third embodiment will be described.

  FIG. 12 is a schematic diagram for explaining the electrode catalyst layer manufacturing apparatus according to the third embodiment.

  Coating apparatus 100B, which is an electrode catalyst layer manufacturing apparatus according to Embodiment 3, is generally different from coating apparatus 100 according to Embodiment 1 in that it has an ultrasonic crushing means controlled by control unit 180.

  The ultrasonic crushing means according to the third embodiment is used for crushing aggregates accumulated in the manifold portion 134 by ultrasonic vibration, and as shown in FIG. It has the pressure detection means 154 and the ultrasonic vibration provision means 156 which were connected. The pressure detection unit 154 includes a pressure gauge that detects the internal pressure of the coating head 130. The ultrasonic vibration applying unit 156 includes, for example, an ultrasonic vibrator that uses a piezoelectric element, and is attached to the coating head 130 in order to apply ultrasonic vibration to the manifold portion 134.

  For example, when aggregates are accumulated inside the aggregate removing unit 140, the internal pressure of the manifold part 134 in which the aggregate removing unit 140 is disposed increases, and the electrode catalyst ink from the discharge port 136 communicating with the manifold unit 134. The discharge amount of 40 becomes unstable. For this reason, in the coating process, when it is determined that the aggregates are accumulated in the manifold unit 134 based on the increase in the internal pressure of the coating head 130 detected by the pressure detection unit 154, the control unit 180 The sonic vibration providing means 156 is operated to break up the aggregate. Accordingly, aggregates do not accumulate, so that the electrode catalyst ink 40 can be stably ejected even when the coating head is not disassembled and washed.

  As described above, in the third embodiment, it is not required to disassemble and wash the coating head to remove the aggregates, and no adjustment time is required for reassembling the coating head, and no material loss occurs. It is preferable to control the intensity (amplitude) of the ultrasonic vibration according to the pressure increase value.

  Next, a fourth embodiment will be described.

  FIG. 13 is a schematic diagram for explaining the electrode catalyst layer manufacturing apparatus according to Embodiment 4, FIG. 14 is a plan view for explaining intermittent application in the electrode catalyst layer manufacturing apparatus shown in FIG. These are timing charts for explaining the application operation and the ultrasonic vibration applying operation in intermittent application.

  A coating apparatus 100C that is an electrode catalyst layer manufacturing apparatus according to the fourth embodiment is generally different from the coating apparatus 100B according to the third embodiment with respect to the control timing of the ultrasonic vibration applying means.

As shown in FIG. 13, the ultrasonic crushing unit according to the fourth embodiment includes an ultrasonic vibration applying unit 156 connected to the control unit 180, but unlike the third embodiment, the pressure detecting unit 154 is provided. I don't have it. The controller 180 controls the discharge of the electrode catalyst ink 40 as shown in FIG. 14, and alternately forms the coating layer 42 and the non-application region 92 of the electrode catalyst ink 40 as shown in FIG. It has a function as a coating control means.

  As shown in FIG. 15, the application apparatus 100 </ b> C applies ultrasonic vibration while the discharge of the electrode catalyst ink 40 is stopped when intermittently applying the electrode catalyst ink 40 by controlling the discharge of the electrode catalyst ink 40. The means 156 is operated to apply ultrasonic vibration to the coating head 130 (manifold part 134), and the aggregates accumulated in the manifold part 134 are crushed. In this case, since the ultrasonic vibration is performed while the discharge of the electrode catalyst ink 40 is stopped, interference with the discharge (application) of the electrode catalyst ink 40 can be avoided.

  When stopping the discharge of the electrode catalyst ink, in order to improve the breakage of the electrode catalyst ink 40 and clarify the boundary between the electrode catalyst ink coating layer 42 and the non-application region 92 (see FIG. 14), The discharged electrocatalyst ink 40 is instantaneously returned to the inside of the coating head 130.

  The suck back sucks the electrode catalyst ink 40 momentarily slightly, so that the inside of the coating head 130 is kept at a negative pressure for a short period of time. Specifically, the valve means 172 for controlling the circulation of the electrode catalyst ink 40 is set to “open” immediately before the valve means 164 for controlling the supply of the electrode catalyst ink 40 to the coating head 130 is set to “closed”. It is carried out by doing. The suck back is not limited to the above-described embodiment. For example, a valve means dedicated to suck back that reverses the pump 162 disposed in the piping system 160 between the tank 110 and the coating head 130 or is connected to a negative pressure source. It is also possible to implement by providing.

  As described above, in the fourth embodiment, the ultrasonic vibration is performed while the discharge of the electrode catalyst ink is stopped. Therefore, compared with the case of the third embodiment, the discharge of the electrode catalyst ink ( It is possible to avoid interference with the application.

  While discharge of the electrode catalyst ink 40 is stopped, it is also possible to change the intensity (amplitude) of the ultrasonic vibration to give a gradient. For example, the maximum strength (amplitude) can be applied immediately after the discharge of the electrode catalyst ink is stopped, and the strength (amplitude) can be set to decrease toward the restart of the discharge of the electrode catalyst ink. In this case, ultrasonic lingering at the time of resuming discharge of the electrode catalyst ink is prevented.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. For example, the first to fourth modifications of the first embodiment can be applied to the second to fourth embodiments, or the second embodiment and the third and fourth embodiments can be combined.

10 Fuel cell single cell,
20 Membrane electrode assembly,
30 Polymer electrolyte membrane,
40 electrode catalyst ink,
41 aggregates,
42 coating layer,
50, 55 Electrocatalyst layer (electrode),
60 gas diffusion layer substrate,
70,75 gas diffusion layer,
80,85 separator,
82,87 ribs,
84,89 gas flow path,
90 film substrate,
92 non-application area,
100, 100A, 100B, 100C coating device,
110 tank 112 shaft,
114 electric motor,
120 backroll,
130 coating head,
132 supply port,
134 Manifold part,
136 discharge port,
140, 140A, 140B Aggregate removing means,
142 outer peripheral surface,
143, 143A, 143B openings,
144 rotating shaft,
145 rotor,
146 electric motor,
148 grinding media,
150 temperature detector,
152 temperature control unit,
154 pressure detection means,
156 ultrasonic vibration applying means,
160 piping system,
162 pump,
164 valve means,
170 piping system,
172 valve means,
L application direction,
W Application width direction.

Claims (7)

An application head for applying the electrode catalyst ink constituting the electrode catalyst layer to the film substrate;
An ultrasonic crushing means for crushing the aggregate by ultrasonic vibration,
The application head is
A supply port to which the electrode catalyst ink is supplied;
A manifold part that expands the electrode catalyst ink introduced from the supply port in the coating width direction;
An agglomerate removing means disposed inside the manifold portion for crushing and / or collecting agglomerates contained in the electrocatalyst ink; and
A discharge port for discharging the electrocatalyst ink that has passed through the manifold part and the aggregate removing means toward the film base;
The ultrasonic crushing means includes
Pressure detecting means for detecting the internal pressure of the coating head, and
An ultrasonic vibration applying means for applying the ultrasonic vibration to the manifold portion;
When it is determined that the aggregate is accumulated inside the manifold portion based on the increase in the internal pressure of the coating head detected by the pressure detection unit, the aggregate is detected by the ultrasonic vibration applying unit. An apparatus for producing an electrode catalyst layer, which is pulverized.   The electrode according to claim 1, wherein the aggregate removing unit includes a disperser having an opening through which the electrode catalyst ink passes, and the opening applies a shearing force to the electrode catalyst ink. Catalyst layer manufacturing equipment.   The apparatus for producing an electrode catalyst layer according to claim 2, wherein the opening is configured to collect aggregates contained in the electrode catalyst ink. The apparatus for producing an electrode catalyst layer according to any one of claims 1 to 3 , further comprising temperature adjusting means for adjusting the internal temperature of the coating head to be constant. Having an application step of applying an electrode catalyst ink constituting an electrode catalyst layer to a film substrate;
In the coating step,
Supplying the electrode catalyst ink to the supply port of the coating head;
Introducing the electrocatalyst ink introduced from the supply port into the manifold portion of the coating head;
In the manifold section, aggregates contained in the electrode catalyst ink are crushed and / or collected by an aggregate removing means disposed inside the manifold section, and the electrode catalyst ink is spread in the coating width direction. ,
The electrode catalyst ink that has passed through the manifold part and the aggregate removing means is discharged from the discharge port of the coating head toward the film substrate, and
When it is determined that aggregates are accumulated in the manifold portion based on the increase in the internal pressure of the coating head detected by the pressure detecting means for detecting the internal pressure of the coating head, ultrasonic vibration is applied. A method for producing an electrode catalyst layer, comprising: actuating a means to apply ultrasonic vibration to the manifold portion to break up aggregates accumulated in the manifold portion. The opening of the agglomerate removing means comprising a disperser having an opening through which the electrode catalyst ink passes gives a shearing force to the electrode catalyst ink to break up the agglomerates contained in the electrode catalyst ink. The method for producing an electrode catalyst layer according to claim 5 . The method for producing an electrode catalyst layer according to claim 6 , wherein aggregates contained in the electrode catalyst ink are collected by the openings.