JP6653634B2 - Coating device and coating method - Google Patents

Description

  The present invention relates to a coating device and a coating method.

  2. Description of the Related Art In recent years, fuel cells have attracted attention as driving power sources for automobiles and mobile phones. A fuel cell is a power generation system that generates electric power by an electrochemical reaction between hydrogen (H2) contained in fuel and oxygen (O2) in air. Fuel cells have the advantage that they have higher power generation efficiency and less environmental impact than other batteries.

  There are several types of fuel cells depending on the electrolyte used. One of them is a polymer electrolyte fuel cell (PEFC) using an ion exchange membrane (electrolyte membrane) as an electrolyte. Since the polymer electrolyte fuel cell can operate at room temperature and can be reduced in size and weight, it is expected to be applied to automobiles and portable devices.

  A polymer electrolyte fuel cell generally has a structure in which a plurality of cells are stacked. One cell is constituted by sandwiching a membrane-electrode assembly (MEA: Membrane-Electrode-Assembly) on both sides with a pair of separators. The membrane / electrode assembly is a membrane / catalyst layer assembly (CCM: Catalyst-coated membrane) in which a catalyst layer is formed on both sides of an electrolyte thin film (polymer electrolyte membrane), and gas diffusion layers are further arranged on both sides. It is. A pair of electrode layers is constituted by the catalyst layer and the gas diffusion layer disposed on both sides of the polymer electrolyte membrane. One of the pair of electrode layers is an anode electrode, and the other is a cathode electrode. When fuel gas containing hydrogen contacts the anode electrode and air contacts the cathode electrode, electric power is generated by an electrochemical reaction.

  The above-mentioned membrane / catalyst layer assembly typically applies a catalyst ink (electrode paste) in which catalyst particles containing platinum (Pt) are dispersed in a solvent such as alcohol on the surface of the electrolyte membrane, It is created by drying the catalyst ink. In applying the catalyst ink of the polymer electrolyte fuel cell, intermittent application of applying the catalyst ink intermittently to the surface of the electrolyte membrane is performed in order to eliminate the loss of the expensive platinum catalyst. Further, when performing intermittent coating, it is necessary to apply the catalyst ink to the coating area where the catalyst ink is to be applied, without any excess or shortage.

  Such an intermittent coating technique is described in, for example, Patent Document 1. In the technique disclosed in Patent Literature 1, a catalyst ink is intermittently applied from a coating nozzle to the surface of the electrolyte membrane while the electrolyte membrane is continuously run at a constant speed in a roll-to-roll system. When coating is intermittent, a pool of catalyst ink is formed at the tip of the coating nozzle. At the start of coating, the coating nozzle moves so that the distance between the tip of the coating nozzle and the surface of the electrolyte membrane becomes a contact gap different from the coating gap, and a liquid pool is formed in the coating area. By contacting the start end, the catalyst ink is applied to the application area without excess or shortage. At this time, the contact gap increases as the thickness of the coating film formed on the surface of the electrolyte membrane increases, and when the thickness exceeds a predetermined value, the contact gap increases. This describes that a uniform coating shape can be obtained at the start of coating.

JP-A-2015-178087

  However, in the method described in Patent Document 1, attention has not been paid to the relationship between the transport speed of the base material and the moving speed of the coating nozzle, and the disorder of the coating shape at the coating start end or the coating end. . FIG. 13 is a view showing a shape of a catalyst ink 9A applied to a conveyed substrate 90A in a conventional coating apparatus. The arrow in FIG. 13 indicates the transport direction of the substrate 90A. In addition, A1 in FIG. 13 indicates a coating start end of the coating ink applied to the transported substrate 90A, and A2 indicates a coating ink applied to the transported substrate 90A. Indicates the end of coating.

  As shown in FIG. 13A, when the approach speed and the separation speed of the application nozzle are appropriate for the transport speed of the substrate 90A, the catalyst ink 9A is applied in a substantially rectangular shape. On the other hand, as shown in FIG. 13 (b), when the separation speed of the coating nozzle is lower than the appropriate speed with respect to the transport speed of the base material 90A, the transporting end A2 of the catalyst ink 9A is transported. A curved portion that is convex toward the opposite direction is generated. Further, as shown in FIG. 13C, when the separation speed of the coating nozzle is faster than an appropriate speed with respect to the transport speed of the base material 90A, the catalyst ink 9A at the coating end A2 of the catalyst ink 9A. Due to the stringing phenomenon, a coating residue that partially extends to the opposite side in the transport direction occurs.

  Further, as shown in FIG. 13D, when the approach speed of the coating nozzle is lower than the appropriate speed with respect to the transport speed of the base material 90A, the transport start end A1 of the catalyst ink 9A is transported to the transport start end A1. A curved portion that becomes convex toward the direction occurs. Further, as shown in FIG. 13E, when the approach speed of the coating nozzle is faster than an appropriate speed with respect to the transport speed of the base material 90A, the transport start end A1 of the catalyst ink 9A is transported to the transport start end A1. A portion that is convex in a width direction perpendicular to the direction (hereinafter, simply referred to as “width direction”) occurs. Thus, the disturbance of the coating shape at the coating start end A1 and the coating end A2 of the catalyst ink 9A correlates with the transport speed of the substrate 90A and the moving speed of the coating nozzle. Therefore, if the moving speed of the coating nozzle can be appropriately set with respect to the conveying speed of the substrate 90A, a higher quality membrane / catalyst layer assembly can be manufactured. Further, even when the transport speed of the base material is increased, if the catalyst ink 9A can be stably applied to the base material 90A, the productivity of the coating apparatus can be improved.

  The present invention has been made in view of such circumstances, and in a coating apparatus, at a coating start end and a coating end of a substrate to be conveyed, the disturbance of the coating shape is suppressed, and the substrate is stabilized. It is an object of the present invention to provide a technique capable of applying a coating liquid.

  In order to solve the above-described problems, a first invention of the present application is a coating apparatus that applies a coating liquid to a base material of a long strip, and a transfer mechanism that transfers the base material in a longitudinal direction thereof. A coating nozzle that has a slit-shaped discharge port, discharges a coating liquid from the discharge port to the substrate, and a switching unit that executes and stops the discharge operation of the coating liquid by the coating nozzle, A moving mechanism for moving the coating nozzle toward and away from the substrate, and at least one of a moving speed and a moving speed of the coating nozzle by the moving mechanism in accordance with a transport speed of the substrate. Can be changed.

  The second invention of the present application is the coating apparatus according to the first invention, further comprising a control unit that controls a moving speed of the coating nozzle by the moving mechanism, wherein the control unit controls a transfer speed of the base material. And at least one of the approach speed and the separation speed of the coating nozzle is changed.

  A third invention of the present application is the coating apparatus according to the second invention, wherein the control unit increases at least one of the approach speed and the separation speed of the coating nozzle as the transport speed of the base material increases.

A fourth invention of the present application is the coating apparatus according to any one of the first invention to the third invention,
The moving mechanism separates the coating nozzle after the switching unit stops discharging the coating liquid.

  The fifth invention of the present application is the coating apparatus according to any one of the first invention to the fourth invention, and further includes a suction unit that suctions the coating liquid inside the coating nozzle.

  A sixth invention of the present application is the coating apparatus according to the fifth invention, wherein the moving mechanism is configured such that the suction unit simultaneously sucks the coating liquid or after sucking the coating liquid, Separate the coating nozzle.

  A seventh invention of the present application is the coating apparatus according to any one of the first invention to the sixth invention, wherein a separation speed of the coating nozzle by the moving mechanism is changed according to a transport speed of the base material. Can be changed.

  An eighth invention of the present application is the coating apparatus according to any one of the first invention to the seventh invention, wherein the approach speed of the coating nozzle by the moving mechanism is adjusted according to a transport speed of the base material. Can be changed.

  A ninth invention of the present application is the coating apparatus according to any one of the first invention to the eighth invention, wherein the coating nozzle intermittently applies the coating liquid from the discharge port to the base material. To be discharged.

  The tenth invention of the present application is a coating method for coating a coating material on a base material of a long strip, wherein a) a step of transporting the base material in a longitudinal direction thereof, and b) a slit-shaped base material. Bringing a coating nozzle having a discharge port close to the base material; c) discharging a coating liquid from the coating nozzle to the base material; d) setting the coating nozzle to And separating at least one of the approach speed of the coating nozzle in the step a) and the separation speed of the coating nozzle in the step d) according to the transport speed of the substrate. Change.

  The eleventh invention of the present application is the coating method according to the tenth invention, wherein at least one of the approach speed of the coating nozzle and the separation speed of the coating nozzle is increased as the transport speed of the substrate increases. I do.

  A twelfth invention of the present application is the coating method according to the tenth invention or the eleventh invention, wherein in the step d), after the discharge of the coating liquid from the coating nozzle is stopped, the coating nozzle is Separate.

  A thirteenth invention of the present application is the coating method according to any one of the tenth to twelfth inventions, wherein the step d) is performed at the same time as sucking the coating liquid, or After suction, the coating nozzle is separated.

  A fourteenth invention of the present application is the coating method according to any one of the tenth invention to the thirteenth invention, wherein the separation speed of the coating nozzle is changed according to a conveyance speed of the base material.

  A fifteenth invention of the present application is the coating method according to any one of the tenth to fourteenth inventions, wherein the approach speed of the coating nozzle is changed in accordance with a transport speed of the base material.

  A sixteenth invention of the present application is the coating method according to any one of the tenth to fifteenth inventions, wherein the step b), the step c), and the step d) are repeated.

  According to the first invention to the sixteenth invention, it is possible to stably apply the coating liquid to the conveyed base material while suppressing disturbance of the coating shape.

  In particular, according to the third invention or the eleventh invention of the present application, even when the transport speed of the substrate is increased, the disturbance of the coating shape is suppressed in the transported substrate, and the coating is performed stably. Liquid can be applied. Thereby, the productivity of the coating apparatus can be improved.

  In particular, according to the fourth, fifth, sixth, twelfth, or thirteenth invention of the present application, disturbance of the coating shape is further suppressed in the conveyed base material, and coating is performed more stably. Liquid can be applied.

  In particular, according to the seventh invention or the fourteenth invention of the present application, it is possible to suppress the disturbance of the coating shape at the end of coating.

  In particular, according to the eighth or fifteenth invention of the present application, it is possible to suppress the disturbance of the coating shape at the coating start end.

  In particular, according to the ninth invention or the sixteenth invention of the present application, the coating liquid can be stably intermittently applied to the conveyed substrate while suppressing the disturbance of the application shape.

It is a figure showing composition of a coating device. It is a control block diagram in a coating device. It is an enlarged view near a coating nozzle. FIG. 4 is a diagram illustrating a positional relationship between a coating nozzle and a backup roller during a coating process. FIG. 4 is a diagram illustrating a positional relationship between a coating nozzle and a backup roller during a coating process. FIG. 4 is a diagram illustrating a positional relationship between a coating nozzle and a backup roller during a coating process. It is a flowchart which shows the flow of a coating process. FIG. 7 is a diagram illustrating an example of a change in a coating shape at a coating start end when a transfer speed of a base material and a proximity speed of a coating nozzle are changed. FIG. 4 is a diagram illustrating an example of a change in a coating shape at a coating start end when a transfer speed of a base material and a separation speed of a coating nozzle are changed. It is a figure which shows the opening / closing valve of a switching part, the suckback valve of a suction part, and the operation state of a coating nozzle in the coating processing which concerns on a modification at the time of a coating process. It is a figure which shows the moving speed of the coating nozzle at the time of a coating process in the coating device which concerns on a modification. It is a figure which shows the moving speed of the coating nozzle at the time of a coating process in the coating device which concerns on a modification. FIG. 3 is a view illustrating a shape of a catalyst ink applied to a base material.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<1. About the configuration of the coating device>
FIG. 1 is a diagram showing a configuration of a coating apparatus 1 according to an embodiment of the present invention. The coating apparatus 1 is configured such that, in a manufacturing process of a membrane / catalyst layer assembly for a polymer electrolyte fuel cell, a long strip-shaped substrate 90 is conveyed in the longitudinal direction, and one surface of the substrate 90 is This is an apparatus for forming a catalyst layer to be an electrode. As shown in an enlarged manner in FIG. 1, the base material 90 has a structure in which two layers of a support film 91 and an electrolyte membrane 92 are laminated. The coating apparatus 1 applies a catalyst ink, which is a coating liquid, to a surface of the electrolyte membrane 92 that is not covered with the support film 91 (hereinafter, referred to as a “front surface”), and by drying the catalyst ink. Then, a catalyst material layer 9 is formed.

  As the electrolyte membrane 92, for example, a fluorine-based or hydrocarbon-based polymer electrolyte membrane is used. Specific examples of the electrolyte membrane 92 include polymer electrolyte membranes containing perfluorocarbon sulfonic acid (for example, Nafion (registered trademark) manufactured by DuPont, USA, Flemion (registered trademark) manufactured by Asahi Glass Co., Ltd., and Asahi Kasei Corporation) Aciplex (registered trademark), and Goreselect (registered trademark) manufactured by Gore). The thickness of the electrolyte membrane 92 is, for example, 5 μm to 30 μm. The electrolyte membrane 92 swells due to moisture in the air, and contracts when the humidity decreases. That is, the electrolyte membrane 92 has a property of easily deforming according to the humidity in the atmosphere.

  The support film 91 is a film for suppressing deformation of the electrolyte membrane 92. As the material of the support film 91, a resin having higher mechanical strength than the electrolyte membrane 92 and having an excellent shape maintaining function is used. Specific examples of the support film 91 include PEN (polyethylene naphthalate) and PET (polyethylene terephthalate) films. The thickness of the support film 91 is, for example, 25 μm to 100 μm.

  As shown in FIG. 1, the coating device 1 includes a transport mechanism 10, a coating unit 20, a drying unit 30, and a control unit 40.

  The transport mechanism 10 is a mechanism that transports the base material 90 in a transport direction along the longitudinal direction. The transport mechanism 10 of the present embodiment includes a substrate unwinding roller 11, a plurality of transport rollers 12, and a substrate winding roller 13. The substrate 90 is fed out from the substrate unwinding roller 11 and is transported along a transport path defined by the plurality of transport rollers 12. Each transport roller 12 guides the substrate 90 to the downstream side of the transport path by rotating about a horizontal axis. The transported substrate 90 is collected by the substrate winding roller 13. In addition, the position and the number of the transport rollers 12 do not necessarily have to be as shown in FIG.

  The coating unit 20 is a mechanism for coating the surface of the base material 90 transported by the transport mechanism 10 with the catalyst ink. As the catalyst ink, an electrode paste in which particles containing a catalyst material (for example, platinum (Pt)) are dispersed in a solvent such as alcohol is used. As the catalyst material, a material that causes a fuel cell reaction at an anode or a cathode of a polymer fuel cell is used. Specifically, platinum (Pt), a platinum alloy, a platinum compound, or the like can be used as a catalyst material. Examples of the platinum alloy include, for example, at least one selected from the group consisting of ruthenium (Ru), palladium (Pd), nickel (Ni), molybdenum (Mo), iridium (Ir), iron (Fe), and the like. An alloy of a metal and platinum can be mentioned. Generally, platinum is used as a catalyst material for a cathode, and a platinum alloy is used as a catalyst material for an anode. The details of the coating unit 20 will be described later.

  The substrate 90 is supported by the backup roller 14 also serving as the transport roller 12 on the upstream side of the transport path from the drying unit 30. The backup roller 14 is a columnar or cylindrical roller, and rotates about a horizontal axis while the outer peripheral surface contacts the support film 91 of the base material 90.

  The drying unit 30 is arranged downstream of the coating unit 20 in the transport path. The drying unit 30 has a drying furnace 31 for drying the catalyst ink. In the drying furnace 31, heated gas (hot air) is blown onto the electrolyte membrane 92 of the base material 90 transported by the transport mechanism 10. Then, the catalyst ink applied to the surface of the electrolyte membrane 92 is heated, and the solvent in the catalyst ink is vaporized. Thereby, the catalyst ink is dried, and the catalyst material layer 9 is formed on the surface of the electrolyte membrane 92. However, the method for drying the catalyst ink does not necessarily need to be a supply of hot air. The drying section 30 may dry the catalyst ink by another method such as light irradiation or reduced pressure.

  As described above, in the coating apparatus 1, the steps of feeding out the base material 90 from the base material unwinding roller 11, coating the surface of the electrolyte membrane 92 with the catalyst ink, and drying with the drying furnace 31 are sequentially performed. Be executed. Thereby, one catalyst material layer 9 of the membrane-catalyst layer assembly used for the polymer electrolyte fuel cell is formed on the surface of the electrolyte membrane 92. In the coating apparatus 1, the electrolyte membrane 92 is always held on the support film 91. Thereby, deformation such as swelling / shrinking of the electrolyte membrane 92 is suppressed.

  The control unit 40 is a unit for controlling the operation of each unit in the coating apparatus 1. FIG. 2 is a block diagram showing a connection between the control unit 40 and each unit in the coating apparatus 1. As conceptually shown in FIG. 2, the control unit 40 is configured by a computer having an arithmetic processing unit 41 such as a CPU, a memory 42 such as a RAM, and a storage unit 43 such as a hard disk drive. In the storage unit 43, a computer program P1 for executing a coating / drying process is installed. As shown in FIG. 2, the control unit 40 is communicably connected to the transport mechanism 10 and the drying furnace 31. The control unit 40 is also communicably connected to the on-off valve 22 of the switching unit, the motor 232 of the moving mechanism 23, and the suck back valve 242 of the suction unit 24 of the coating unit 20, which will be described later.

  The control unit 40 temporarily reads out the computer program P1 and data stored in the storage unit 43 into the memory 42, and performs the arithmetic processing by the arithmetic processing unit 41 based on the computer program P1 and the data. The operation of each unit in the processing apparatus 1 is controlled. Thereby, the coating / drying process in the coating device 1 proceeds.

<2. Composition of coating section>
Next, the configuration of the coating unit 20 will be described. FIG. 3 is an enlarged view showing the configuration near the coating unit 20. The coating unit 20 is a mechanism for coating the surface of the base material 90 transported by the transport mechanism 10 with the catalyst ink. The coating unit 20 of the present embodiment includes a coating nozzle 21, an on-off valve 22, which is a switching unit, a moving mechanism 23, and a suction unit 24.

  The coating nozzle 21 has a slit-shaped discharge port 211 extending along the width direction of the base material 90 and facing the outer peripheral surface of the backup roller 14. The coating nozzle 21 forms a liquid pool 93 of the catalyst ink at the tip of the discharge port 211. Then, the catalyst ink liquid pool 93 is brought into contact with the conveyed substrate 90. Thereby, the catalyst ink is applied to the conveyed substrate 90. The coating nozzle 21 is connected to the catalyst ink supply source 213 through a liquid supply pipe 212 in a flow path.

  The switching unit is a mechanism for executing or stopping the operation of discharging the catalyst ink by the coating nozzle 21. The switching unit of the present embodiment is configured by the on-off valve 22 inserted in the liquid supply pipe 212. When the on-off valve 22 is opened, the catalyst ink is supplied from the catalyst ink supply source 213 to the coating nozzle 21 through the liquid supply pipe 212. Then, a liquid pool 93 of the catalyst ink is formed at the tip of the discharge port 211. Thereby, the discharge operation by the coating nozzle 21 can be executed. On the other hand, when the on-off valve 22 is closed, the supply of the catalyst ink to the coating nozzle 21 is stopped. Thereby, the formation of the liquid pool 93 at the tip of the discharge port 211 is stopped, and the discharge operation by the coating nozzle 21 is stopped.

  The on-off valve 22 of the present embodiment is a three-way valve, and is connected to the catalyst ink supply source 213 via a circulation line 214 in a flow path. Further, a mohno pump 215 is installed in the liquid supply pipe 212 between the on-off valve 22 and the catalyst ink supply source 213. While the on-off valve 22 is closed, the catalyst ink circulates through the circulation line 214 between the on-off valve 22 and the catalyst ink supply source 213 due to the pressure generated by the mono pump 215.

  When the coating apparatus 1 is operated, the catalyst ink is discharged from the discharge port 211 of the coating nozzle 21 toward the electrolyte membrane 92 of the base material 90 supported by the backup roller 14. Thereby, the catalyst ink is applied to the surface of the electrolyte membrane 92. When the on-off valve 22 is closed, the supply of the catalyst ink from the catalyst ink supply source 213 to the coating nozzle 21 is shut off, and the discharge operation of the catalyst ink by the coating nozzle 21 is stopped.

  In the present embodiment, the catalyst ink is intermittently ejected from the ejection port 211 of the coating nozzle 21 by opening and closing the on-off valve 22 at a constant cycle. As a result, the catalyst ink is intermittently applied on the surface of the base material 90 at regular intervals in the transport direction. However, the on-off valve 22 may be continuously opened, and the catalyst ink may be applied to the surface of the electrolyte membrane 92 without a break in the transport direction.

  In addition, the coating nozzle 21 does not necessarily need to discharge the catalyst ink to the surface of the base material 90 supported by the backup roller 14. For example, the catalyst ink may be discharged onto the surface of the base material 90 that is stretched between adjacent rollers.

  The moving mechanism 23 is a mechanism that moves the discharge port 211 of the coating nozzle 21 toward or away from the outer peripheral surface of the backup roller 14. As shown in FIG. 3, the moving mechanism 23 according to the present embodiment includes a moving table 231, a motor 232 as a driving source, a guide rail 233, a ball screw 234, and a base 235. In the following, a direction parallel to the direction in which the catalyst nozzle is ejected from the coating nozzle 21 is referred to as a “contact / separation direction”.

  The coating nozzle 21 is fixed to an upper surface of a horizontally arranged moving table 231. The guide rail 233 is provided on the upper surface of the base portion 235 fixed and installed on the floor of the factory, and extends in the contact / separation direction. The moving table 231 is installed along the guide rail 233 so as to be able to advance and retreat in the contact and separation directions. The ball screw 234 is arranged above the guide rail 233. The ball screw 234 extends in the direction of contact and separation in parallel with the guide rail 233. A nut provided on the lower surface of the moving table 231 is attached to the ball screw 234.

  When the motor 232 is driven by a drive signal from the control unit 40, the ball screw 234 rotates. As a result, the moving table 231 and the coating nozzle 21 move in the contact / separation direction along the guide rail 233. When the coating nozzle 21 moves in the contact / separation direction, the discharge port 211 of the coating nozzle 21 approaches or separates from the outer peripheral surface of the backup roller 14 in the contact / separation direction. That is, the distance in the contact / separation direction from the discharge port 211 to the outer peripheral surface of the backup roller 14 changes.

  The suction unit 24 is a mechanism that suctions the catalyst ink filled in the internal space of the coating nozzle 21. The suction unit 24 of the present embodiment includes a liquid suction pipe 241 and a suck-back valve 242 connected to a liquid supply pipe 212 between the open / close valve 22 of the switching unit and the coating nozzle 21. When the suck back valve 242 is opened, a change in the volume inside the suck back valve 242 causes the catalyst ink inside the liquid absorbing pipe 241 and the coating nozzle 21 to be sucked toward the suck back valve 242. Thereby, the liquid pool 93 of the catalyst ink formed at the tip of the discharge port 211 is eliminated.

<3. Operation during coating process>
Next, an example of a coating process performed by the coating device 1 will be described. 4 to 6 are views showing the positional relationship between the coating nozzle 21 and the backup roller 14 during the coating process. FIG. 7 is a flowchart showing the flow of the coating process. In addition, each operation | movement of step S1-S6 of FIG. 7 is implement | achieved when the control part 40 operates each part in the coating device 1 based on the computer program P1.

  When performing the coating process in the coating apparatus 1, first, the transport of the substrate 90 by the transport mechanism 10 is started (Step S1). Thereby, the base material 90 rotates while being supported by the backup roller 14, and is transported in the transport direction at a predetermined transport speed. At this time, as shown in FIG. 4, the coating nozzle 21 is arranged at a position away from the backup roller 14. Further, the open / close valve 22 of the switching unit and the suck back valve 242 of the suction unit 24 are closed.

  Next, the control unit 40 opens the on-off valve 22 of the switching unit (Step S2). Thereby, the catalyst ink is sent toward the discharge port 211 of the coating nozzle 21. Then, a liquid pool 93 of the catalyst ink is formed at the tip of the discharge port 211. At this time, by closing the suck back valve 242, the catalyst ink may be sent from the suction unit 24 to the discharge port 211.

  Next, the control unit 40 operates the moving mechanism 23 to move the coating nozzle 21 close to the backup roller 14 (Step S3). Then, as shown in FIG. 5, when the coating nozzle 21 moves to a close position close to the backup roller 14, the base material 90 and the liquid pool 93 of the catalyst ink come into contact. Thus, the base material 90 is coated with the catalyst ink.

  In step S3, if the approach speed of the coating nozzle 21 is too high with respect to the transport speed of the substrate 90, the liquid pool 93 spreads in the width direction of the substrate 90 when the pool 93 contacts the transported substrate 90. . For this reason, there is a portion that is convex in the width direction as shown in FIG. On the other hand, if the approach speed of the coating nozzle 21 is too slow with respect to the transport speed of the base material 90, the base material 90 is moved in the transport direction before the liquid pool 93 and the base material 90 sufficiently contact in the width direction. The distance conveyed toward is increased. For this reason, as shown in FIG. 13D, a curved portion that is convex in the transport direction is generated. Therefore, in the coating apparatus 1 of the present embodiment, the control unit 40 controls the approach speed of the coating nozzle 21 according to the transport speed of the base material 90. Specifically, the controller 40 increases the approach speed of the coating nozzle 21 as the transport speed of the substrate 90 increases. Thereby, disturbance of the coating shape at the coating start end can be suppressed.

  Next, the control unit 40 closes the on-off valve 22 of the switching unit (Step S4). Accordingly, the formation of the liquid pool 93 at the tip of the discharge port 211 is stopped, and the discharge operation of the catalyst ink by the coating nozzle 21 is stopped. When the application of the catalyst ink to the base material 90 is completed, the control unit 40 opens the suck back valve 242 of the suction unit 24 (Step S5). Thereby, the catalyst ink inside the liquid suction pipe 241 and the coating nozzle 21 is sucked toward the suck back valve 242. As a result, the liquid pool 93 at the tip of the discharge port 211 is also sucked.

  Thereafter, the control unit 40 operates the moving mechanism 23. Then, as shown in FIG. 6, the coating nozzle 21 is moved to the separating position (Step S6). Thus, the coating process of the catalyst ink on the conveyed substrate 90 is completed. The control unit 40 intermittently performs the coating process of the catalyst ink on the transported base material 90 by repeating the processes of steps S2 to S6.

  In step S <b> 6, if the separation speed of the coating nozzle 21 is too high with respect to the transport speed of the base material 90, a phenomenon of stringing of the catalyst ink occurs between the base material 90 and the discharge port 211. As a result, as shown in FIG. 13 (c), at the end of coating, a coating residue that is partially convex in the direction opposite to the transport direction occurs. On the other hand, if the approach speed of the coating nozzle 21 is too slow with respect to the transport speed of the substrate 90, the substrate 90 moves in the transport direction before the liquid pool 93 and the substrate 90 are completely separated. The transported distance becomes longer. Therefore, as shown in FIG. 13B, a curved portion is formed at the end of coating so as to be convex in the direction opposite to the transport direction. Therefore, in the coating apparatus 1 of the present embodiment, the control unit 40 controls the separation speed of the coating nozzle 21 according to the transport speed of the base material 90. Specifically, the controller 40 increases the separation speed of the coating nozzle 21 as the transport speed of the base material 90 increases. Thereby, disturbance of the coating shape at the end of coating can be suppressed.

  FIG. 8 is a diagram illustrating an example of a change in the coating shape at the coating start end when the transport speed of the base material 90 and the approach speed of the coating nozzle 21 are changed in step S3. In the example of FIG. 8, when the conveying speed of the base material 90 is 0.1 to 2.0 m / min, and the approach speed of the coating nozzle 21 is 10 to 30 mm / sec, the coating at the coating start end is performed. The shape is good. Further, when the conveying speed of the base material 90 is 2.0 to 5.0 m / min, if the approach speed of the coating nozzle 21 is 30 to 60 mm / sec, the coating shape at the coating start end is good. Has become. From this result, it can be seen that the higher the conveying speed of the base material 90, the faster the approach speed of the coating nozzle 21 can suppress the disturbance of the coating shape at the coating start end.

  FIG. 9 is a diagram illustrating an example of a change in the coating shape at the end of coating when the transport speed of the base material 90 and the separation speed of the coating nozzle 21 are changed in step S6. In the example of FIG. 9, when the transport speed of the base material 90 is 0.1 to 2.0 m / min, and the separation speed of the coating nozzle 21 is 10 to 30 mm / sec, the coating shape at the end of coating is obtained. Is good. Further, when the transport speed of the base material 90 is 2.0 to 5.0 m / min, if the separation speed of the coating nozzle 21 is 30 to 60 mm / sec, the coating shape at the end of coating becomes good. ing. From this result, it can be seen that the higher the transport speed of the base material 90, the faster the separation speed of the coating nozzle 21 can suppress the disturbance of the coating shape at the end of coating.

  As described above, in the coating apparatus 1 of the present embodiment, the control unit 40 changes the approach speed and the separation speed of the coating nozzle 21 according to the transport speed of the base material 90, so that the coating start end and the coating speed can be reduced. Disturbance of the coating shape at the end of coating can be suppressed. Further, even when the transport speed of the base material 90 is increased, the catalyst ink can be stably applied, so that the productivity of the coating apparatus 1 can be improved.

  FIG. 10 is a diagram illustrating the operation states of the on-off valve 22 of the switching unit, the suck-back valve 242 of the suction unit 24, and the coating nozzle 21 during the coating process in this embodiment. The horizontal axis of FIG. 10 indicates the elapsed time. Further, L1 in FIG. 10 indicates the open / closed state of the on-off valve 22 of the switching unit, L2 indicates the open / closed state of the suck back valve 242 of the suction unit 24, and L3 indicates the close position or the separated position of the coating nozzle 21. The position state of is shown. As shown in FIG. 10, in the coating processing of the present embodiment, a step of opening the on-off valve 22 of the switching unit and a step of moving the coating nozzle 21 close to each other may be performed simultaneously. The step of closing the valve 22, the step of sucking the catalyst ink inside the coating nozzle 21, and the step of moving the coating nozzle 21 apart may be performed simultaneously.

  Further, the moving mechanism 23 of the present embodiment can switch between the approach speed when the coating nozzle 21 approaches and the separation speed when the coating nozzle 21 moves away. FIG. 11 is a diagram illustrating the moving speed of the coating nozzle 21 during the coating process in the coating apparatus 1 according to the present embodiment. The horizontal axis in FIG. 11 indicates the elapsed time, and the vertical axis indicates the moving speed of the coating nozzle 21. As shown in FIG. 11, the coating nozzle 21 reaches the proximity position while switching the proximity speed by sequentially performing acceleration movement, constant velocity movement, and deceleration movement during the proximity movement. Further, the coating nozzle 21 reaches the separated position while switching the moving speed by sequentially performing the acceleration movement, the constant velocity movement, and the deceleration movement during the separation movement. In the example of FIG. 11, the approach speed and the separation speed are the same speed.

<4. Modification>
As described above, one embodiment of the present invention has been described, but the present invention is not limited to the above embodiment.

  In the above embodiment, the step of opening the on-off valve of the switching unit (Step S2), the step of moving the coating nozzle close (Step S3), the step of closing the on-off valve of the switching unit (Step S4), the coating nozzle The coating process was performed in the order of the step of sucking the catalyst ink inside (step S5). However, the coating process in the coating device of the present invention is not limited to this.

  Further, the approach speed and the separation speed of the coating nozzle of the above embodiment were the same speed. However, the present invention is not limited to this. FIG. 12 is a diagram illustrating a moving speed of a coating nozzle during a coating process in a coating apparatus according to a modification. The horizontal axis in FIG. 12 indicates the elapsed time, and the vertical axis indicates the moving speed of the coating nozzle. As shown in FIG. 12, the maximum value of each of the approach speed and the separation speed (the speed at the time of constant speed movement) may be changed according to the transport speed of the base material.

  In the above embodiment, both the approach speed and the separation speed of the coating nozzle are changed according to the transport speed of the base material. However, if a problem occurs in only one of the coating start end and the coating end, only one of the approach speed and the separation speed may be changed according to the transport speed of the base material.

  Further, in the above embodiment, the control unit automatically changes the approach speed and the separation speed of the coating nozzle according to the transport speed of the base material. However, at least one of the approach speed and the separation speed of the coating nozzle may be changed by an operator operating an operation unit provided in the coating device.

  In the above embodiment, the coating device is a device that forms a catalyst material layer on the surface of the electrolyte membrane. However, the coating apparatus of the present invention may be an apparatus that forms a catalyst material layer on the back surface of the electrolyte membrane, or may be an apparatus that forms an electrolyte membrane on both the front and back surfaces of the electrolyte membrane. .

  Further, in the above embodiment, the base material is supported by being in contact with the outer peripheral surface of the backup roller. However, the outer peripheral surface of the backup roller may be a suction surface, and the substrate may be supported by being attracted to the outer peripheral surface of the backup roller.

  Further, the configuration of the details of the coating apparatus may be different from each drawing of the present application. In addition, the elements appearing in the above-described embodiments and the modified examples may be appropriately combined as long as no contradiction occurs.

DESCRIPTION OF SYMBOLS 1 Coating apparatus 9 Catalyst material layer 10 Transport mechanism 20 Coating part 21 Coating nozzle 22 On-off valve 23 Moving mechanism 24 Suction part 30 Drying part 90 Base material 211 Discharge port 242 Suck back valve

Claims (16)

A coating apparatus for applying a coating liquid to the base material of the long strip,
A transport mechanism for transporting the base material in a longitudinal direction thereof,
With a slit-shaped discharge port, a coating nozzle that discharges a coating liquid from the discharge port to the substrate,
A switching unit that executes and stops the discharge operation of the coating liquid by the coating nozzle,
A moving mechanism that moves the coating nozzle toward and away from the substrate,
Has,
A coating apparatus capable of changing at least one of an approach speed and a separation speed of the coating nozzle by the moving mechanism according to a transport speed of the substrate. The coating device according to claim 1,
A control unit that controls a moving speed of the coating nozzle by the moving mechanism,
The coating device, wherein the control unit changes at least one of a proximity speed and a separation speed of the coating nozzle according to a transport speed of the base material. The coating device according to claim 2,
The coating device, wherein the control unit increases at least one of the approach speed and the separation speed of the coating nozzle as the transport speed of the base material increases. The coating device according to any one of claims 1 to 3, wherein
The coating device, wherein the switching mechanism separates the coating nozzle after the switching unit stops discharging the coating liquid. The coating apparatus according to any one of claims 1 to 5, wherein
A coating apparatus further comprising a suction unit for sucking the coating liquid inside the coating nozzle. It is a coating device of Claim 5, Comprising:
The coating device, wherein the moving mechanism separates the coating nozzle at the same time that the suction unit suctions the coating liquid or after suctioning the coating liquid. The coating device according to any one of claims 1 to 6, wherein
A coating apparatus capable of changing a separation speed of the coating nozzle by the moving mechanism according to a transport speed of the base material. The coating apparatus according to any one of claims 1 to 7, wherein
A coating apparatus capable of changing an approach speed of the coating nozzle by the moving mechanism according to a transport speed of the substrate. The coating apparatus according to any one of claims 1 to 8, wherein
A coating apparatus for intermittently discharging the coating liquid from the discharge port to the substrate; A coating method for coating a coating solution on a base material of a long strip,
a) transporting the substrate in its longitudinal direction;
b) bringing a coating nozzle having a slit-shaped discharge port close to the base material;
c) a step of discharging a coating liquid from the coating nozzle to the base material;
d) separating the coating nozzle from the substrate;
Has,
A coating method in which at least one of the approach speed of the coating nozzle in the step a) and the separation speed of the coating nozzle in the step d) is changed according to the transport speed of the substrate. The coating method according to claim 10,
A coating method in which at least one of the approach speed of the coating nozzle and the separation speed of the coating nozzle is increased as the transport speed of the substrate increases. The coating method according to claim 10 or claim 11, wherein
In the step d), a coating method in which after the discharge of the coating liquid from the coating nozzle is stopped, the coating nozzle is separated. The coating method according to any one of claims 10 to 12, wherein
The step d) is a coating method in which the coating nozzle is separated at the same time as sucking the coating liquid or after sucking the coating liquid. The coating method according to any one of claims 10 to 13, wherein
A coating method in which the separation speed of the coating nozzle is changed according to a transport speed of the substrate. The coating method according to any one of claims 10 to 14, wherein
A coating method in which the approach speed of the coating nozzle is changed according to a transport speed of the substrate. The coating method according to any one of claims 10 to 15, wherein
A coating method in which the step b), the step c), and the step d) are repeated.

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