JP2014079669A - Coating device and coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology capable of excellently holding a coating state of a coating liquid in coating treatment for repeating the formation of a coating film.SOLUTION: A catalyst ink coating part 12 comprises a coating control part 110, a first valve 130a and a die head 150. The die head 150 discharges catalyst ink 2 to an electrolyte membrane 1 in carrying. The first valve 130a controls discharge of the catalyst ink 2 from the die head 150 by its opening-closing operation. The coating control part 110 controls the opening-closing operation of the first valve 130a. The coating control part 110 changes opening of the first valve 130a when the die head 150 discharges the catalyst ink 2 in a flow process of continuously forming a plurality of coating films 3 by intermittently discharging the catalyst ink 2 to the die head 150.

Description

  The present invention relates to a coating technique.

  Traditionally, coating techniques have been applied in a wide range of fields. For example, in the technique of Patent Document 1, in the fuel cell manufacturing process, an electrode of a membrane electrode assembly is formed by applying a catalyst coating liquid in which a fuel cell catalyst is dispersed to the surface of a transfer film. In the technique of Patent Document 2, a paste is applied to a substrate in order to bond a liquid crystal panel. In the technique of Patent Document 3, an optical film or a flat display panel is created by drying a coating film.

JP 2010-225421 A JP 2000-015163 A JP 2010-259986 A

  By the way, in a coating apparatus, it is generally desirable that the coating state of the coating liquid be maintained well even when the coating process is repeated. In the technique of Patent Document 1, in order to form a homogeneous catalyst layer in the flow process, the application unit executes the application of the catalyst coating liquid in a state in which the transfer film is stopped. However, in this method, since the transfer film is repeatedly stopped and restarted, the production efficiency may be reduced, and the transfer film transfer control may be complicated. Further, Patent Document 1 does not disclose a coping method when a coating failure occurs.

  In the technique of Patent Document 2, the paste application state is imaged by an imaging camera, and the quality of the paste application state is determined based on the captured image data. However, in the technique disclosed in Patent Document 2, when a paste application failure is detected, the paste application is temporarily stopped for the return operation, which obstructs the flow process and significantly lowers the manufacturing efficiency. there is a possibility.

  In the technique of Patent Document 3, the concentration of the coating solution is adjusted by feedback control in order to suppress the occurrence of coating unevenness due to the concentration difference of the coating solution. However, Patent Document 3 does not disclose a technique for dealing with an application failure or a countermeasure for application failure caused by a cause other than the concentration of the application liquid.

  Thus, conventionally, there is still room for improvement with respect to a technique for satisfactorily maintaining the coating state of the coating in a coating process in which coating is repeated, such as a flow process in a coating apparatus. In addition, in the conventional coating apparatus, it is desired to reduce the size, reduce the cost, save resources, facilitate the production, improve the usability, and the like.

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

(1) According to one form of this invention, the coating apparatus which forms a coating film is provided. The coating apparatus is a coating apparatus that forms a coating film; a paint discharge unit that discharges paint while moving relative to the coating surface; and controls the supply of the paint to the paint discharge unit A coating control unit that controls opening and closing of the valve to control discharge and stop of the paint by the paint discharge unit; and causing the paint discharge unit to repeatedly discharge and stop the paint. And a valve opening degree control unit that changes an opening degree of the valve when the coating material discharging unit discharges the coating material. According to the coating apparatus of this embodiment, in the flow step of forming a plurality of coating films intermittently continuously, it is possible to appropriately adjust the discharge amount of the paint when the formation of the coating film is started, The coating state of the paint can be maintained well.

(2) The coating apparatus according to the above aspect may further include a stay detection unit that detects stay of the paint around the discharge port of the paint discharge unit, and the valve opening degree control unit After the detection unit detects the stagnation of the predetermined amount of the paint, the opening degree of the valve when the paint discharge unit discharges the paint may be reduced. According to the coating apparatus of this embodiment, when the paint adhering to and staying around the discharge port of the paint discharge unit is detected, the discharge amount when starting the discharge of the paint is reduced. Further, it is possible to suppress an increase in the amount of the retained paint. Therefore, it is possible to prevent the coating state of the paint from deteriorating due to the paint staying around the discharge port of the paint discharge unit.

(3) In the coating apparatus according to the above aspect, the stay detection unit includes: an image pickup unit that picks up an image around the discharge port; and an image pickup analysis unit that detects the stay state of the paint based on an image picked up by the image pickup unit. And may be provided. According to this form of the coating apparatus, it is possible to ensure the detectability of the stagnation of the paint around the discharge port of the paint discharge unit.

(4) The coating apparatus according to the above aspect may further include a paint supply unit that supplies the paint to the valve; the valve is connected to the paint supply unit and the paint discharge unit. A paint filling chamber filled with the paint; and a valve body for controlling opening and closing of a connection between the paint filling chamber and the paint supply unit, the paint in the paint filling chamber being removed from the paint A valve body that moves into the paint filling chamber so as to push out to the discharge unit and opens a connection between the paint filling chamber and the paint supply unit; and the valve opening degree control unit is configured to open the valve. As an alternative, the amount of movement of the valve element may be changed. According to this form of the coating apparatus, when the valve is opened, the coating material filled in the coating material filling chamber is pushed out by the valve body to the coating material discharge portion, thereby suppressing the delay (time lag) in starting the coating material discharge. It is possible to improve the coating state at the beginning of the coating film. In addition, it is possible to accurately control the amount of paint discharged according to the opening of the valve.

(5) In the coating apparatus of the above aspect, when the valve is closed, the valve body may move toward the outside of the paint filling chamber to generate a negative pressure in the paint filling chamber. According to this form of the coating apparatus, the paint in the paint discharge section is sucked into the paint filling chamber by the negative pressure in the paint filling chamber caused by the movement of the valve body when the valve is closed. The cracking can be improved, and the coating state at the end of the coating film can be improved.

(6) In the coating apparatus of the above aspect, the paint may be a catalyst ink in which a fuel cell catalyst is dispersed. According to this coating apparatus, a catalyst electrode for a fuel cell in a good state can be formed intermittently and continuously.

(7) According to the other form of this invention, the coating method which forms a coating film is provided. In this coating method, while the paint discharge port is moved relative to the coating surface, the opening and closing of a valve that controls the discharge of the paint is controlled to repeat the discharge and stop of the paint. And a step of changing the opening of the valve when discharging the paint during the execution of the step. According to this coating method, in the flow process in which a plurality of coating films are formed intermittently and continuously, the amount of coating material discharged when starting the coating film formation can be adjusted appropriately, The state can be maintained well.

  A plurality of constituent elements of each aspect of the present invention described above are not indispensable, and some or all of the effects described in the present specification are to be solved to solve part or all of the above-described problems. In order to achieve the above, it is possible to appropriately change, delete, replace with another new component, and partially delete the limited contents of some of the plurality of components. In order to solve part or all of the above-described problems or to achieve part or all of the effects described in this specification, technical features included in one embodiment of the present invention described above. A part or all of the technical features included in the other aspects of the present invention described above may be combined to form an independent form of the present invention.

  The present invention can also be realized in various forms other than the coating apparatus and the coating method. For example, the present invention can be realized in the form of a coating apparatus control method, a computer program that realizes the control method, a non-temporary recording medium that records the computer program, and the like.

Schematic which shows the structure of the catalyst electrode formation apparatus of 1st Embodiment. Schematic which shows the structure of a catalyst ink application part. The schematic diagram for demonstrating the detailed structure of a 1st and 2nd valve | bulb, and the opening / closing control of the 1st and 2nd valve | bulb by an application | coating control part. The schematic perspective view which shows the structure of the die head with which a coating part is provided. The schematic diagram for demonstrating the malfunction which arises in the flow process which forms a some coating film continuously. The schematic diagram for demonstrating the mechanism in which the drag of a catalyst ink generate | occur | produces in a coating film. The flowchart which shows the process sequence of the coating process which an application | coating control part performs. Explanatory drawing which shows the experimental result which the inventor of this invention performed. Schematic which shows the cross-sectional shape when the coating film formed by a coating part is cut | disconnected in the coating direction. The schematic diagram which shows the state of the 1st valve | bulb and die head when the start end part and termination | terminus part of a coating film are formed. Schematic which shows the structure of the catalyst ink application part 12 of 2nd Embodiment.

A. First embodiment:
FIG. 1 is a schematic view showing a configuration of a catalyst electrode forming apparatus for forming a catalyst electrode for a fuel cell as a first embodiment of the present invention. The catalyst electrode forming apparatus 10 continuously forms a plurality of catalyst electrodes 4 for fuel cells on the surface of the strip-shaped electrolyte membrane 1 by a flow process. The catalyst electrode forming apparatus 10 includes a film feeding unit 11, a catalyst ink application unit 12, a drying unit 13, a conveyance control unit 14, and a conveyance roller 15.

  The membrane feeding unit 11 includes an electrolyte membrane roll 1r in which the belt-shaped electrolyte membrane 1 is wound in a roll shape. The membrane feeding unit 11 feeds the electrolyte membrane 1 by rotating the electrolyte membrane roll 1r in the circumferential direction. For example, a fluorine-based ion exchange resin thin film can be employed as the electrolyte membrane 1. The electrolyte membrane 1 fed out from the membrane feeding portion 11 is maintained at a predetermined speed in its extending direction while maintaining a predetermined tension (tension) by rotational driving of a plurality of transport rollers 15 arranged at predetermined intervals. It will be transported. Note that the rotation speed of the electrolyte membrane roll 1 r in the film feeding unit 11 and the rotation speed of the conveyance roller 15 are controlled by the conveyance control unit 14.

  The catalyst ink application unit 12 is disposed on the downstream side of the film feeding unit 11 and intermittently applies the catalyst ink to one surface of the electrolyte membrane 1 being conveyed at a predetermined conveyance speed. As a result, a plurality of coating films 3 of the catalyst ink arranged in a line in the transport direction are continuously formed on the surface of the electrolyte membrane 1. Here, “catalyst ink” is a particle in which conductive particles (for example, platinum-carrying carbon) supporting a catalyst for a fuel cell and an electrolyte that is the same as or similar to the electrolyte membrane 1 are dispersed in an organic solvent or an inorganic solvent. It is a body dispersion solution. The detailed configuration of the catalyst ink application unit 12 will be described later.

  The drying unit 13 is disposed on the downstream side of the catalyst ink application unit 12. Inside the drying unit 13, a plurality of dryers 13 d are arranged along the conveyance path of the electrolyte membrane 1. The drying unit 13 dries the catalyst ink coating film 3 formed on the electrolyte membrane 1 with warm air from a dryer 13d. The coating film 3 becomes the catalyst electrode 4 by removing the solvent component in the drying unit 13. In addition, although the collection | recovery part for collect | recovering the electrolyte membrane 1 in which the catalyst electrode 4 was formed is provided in the downstream of the drying part 13, such as a winding roller of the electrolyte membrane 1, the illustration and description are abbreviate | omitted. .

  The electrolyte membrane 1 on which the catalyst electrode 4 is formed in the catalyst electrode forming apparatus 10 is used to create a membrane electrode assembly that is a power generator in a fuel cell. Specifically, the membrane electrode assembly may be formed by transferring the catalyst electrode formed on the transfer film or the like to the back surface of the electrolyte membrane 1 on which the catalyst electrode 4 is formed. Alternatively, the membrane electrode assembly may be formed by surface bonding the electrolyte membranes 1 on which the catalyst electrodes 4 are formed.

  FIG. 2 is a schematic view showing the configuration of the catalyst ink application unit 12. The catalyst ink application unit 12 includes a coating unit 100 and an application failure detection unit 200. The coating unit 100 executes the application of the catalyst ink 2 to the electrolyte membrane 1. The coating unit 100 includes pipes 101 to 106, a coating control unit 110, a tank 120, a pump 121, first and second valves 130a and 130b, and a die head 150.

  The application control unit 110 is configured by a microcomputer including a central processing unit (CPU) and a main storage device. The application control unit 110 controls the driving of the pump 121 and the valve driving unit 135 to control opening and closing of the first and second valves 130a and 130b. Thereby, the application control unit 110 controls the ejection of the catalyst ink 2 from the die head 150.

  The tank 120 stores the catalyst ink 2. The inlet of the pump 121 is connected to an outlet provided on the bottom surface of the tank 120, and the outlet of the pump 121 is connected to the pipe 102. The pump 121 is normally continuously driven during operation of the coating unit 100, sucks the catalyst ink 2 in the tank 120 through the pipe 101, and outputs it to the pipe 102. The discharge amount of the catalyst ink 2 when forming the coating film 3 can be adjusted by the number of rotations of the pump 121.

  The pipe 102 is branched into pipes 103 and 104 on the downstream side, and the pipes 103 and 104 are connected to the inlets of the first and second valves 130a and 130b, respectively. As a result, the catalyst ink 2 output from the pump 121 to the pipe 102 is supplied to the first and second valves 130a and 130b via the pipes 103 and 104, respectively.

  The outlet of the first valve 130 a is connected to the inlet of the die head 150 via the pipe 105. The outlet of the second valve 130 b is connected to a supply port provided on the side surface of the tank 120 via the pipe 106. When the first valve 130 a is opened, the catalyst ink 2 supplied to the first valve 130 a is supplied via the pipe 105 to the die head 150 that functions as a discharge nozzle for the catalyst ink 2. On the other hand, when the second valve 130 b is open, the catalyst ink 2 supplied to the second valve 130 b returns to the tank 120 via the pipe 106.

  3A and 3B are diagrams for explaining the detailed configuration of the first and second valves 130a and 130b and the opening / closing control of the first and second valves 130a and 130b by the application control unit 110. FIG. FIG. FIG. 3A illustrates a state in which the first valve 130a is opened and the second valve 130b is closed. In FIG. 3B, the first valve 130a is closed, The state where the second valve 130b is opened is shown.

  In FIG. 3, the same reference numerals are assigned to the components corresponding to those in FIG. Since the first and second valves 130a and 130b have the same configuration, only the configuration of the first valve 130a will be described below, and the configuration of the second valve 130b will be Only differences from the first valve 130a will be described.

  The first valve 130 a includes a casing 131 that is a valve box, a seal portion 132, a valve body 133, and a valve drive portion 135. The casing 131 is a hollow container having a substantially cylindrical shape. The casing 131 of the first valve 130a is partitioned into a first ink chamber 131a and a second ink chamber 131b by disposing a seal portion 132 and a valve body 133 as described below.

  The seal portion 132 has a substantially annular shape, and is fixed in the middle of the casing 131 in a state where the outer peripheral surface thereof and the inner wall surface of the casing 131 are in close contact with each other. In addition, the valve body 133 has a substantially cylindrical shape that is substantially fitted in the central through hole of the seal portion 132, and is arranged so that the outer peripheral surface thereof and the inner wall surface of the through hole of the seal portion 132 are slidably rubbed. ing.

  As described above, the casing 131 includes the first and second ink chambers 131 a and 131 b that are partitioned by the seal portion 132 and the valve body 133. In the first valve 130 a, the first ink chamber 131 a is connected to the pipe 103, and the second ink chamber 131 b is connected to the pipe 105. On the other hand, in the second valve 130 b, the first ink chamber 131 a is connected to the pipe 104, and the second ink chamber 131 b is connected to the pipe 106.

  The valve body 133 is connected to a valve drive unit 135 disposed outside the casing 131 via a shaft portion 134 that passes through the center of the first ink chamber 131a. The valve drive unit 135 includes a drive force source such as a servo motor, and reciprocates the shaft unit 134 in the axial direction. The valve body 133 reciprocates between the first and second ink chambers 131a and 131b along the inner peripheral surface of the through hole of the seal portion 132 by the reciprocating movement of the shaft portion 134 in the axial direction. As the valve body 133 reciprocates, the first valve 130a opens and closes as described below.

  Here, on the side surface of the valve body 133, a plurality of parallel linear grooves 133d that run along the moving direction of the valve body 133 are provided. Each groove portion 133 d forms a flow path for the catalyst ink 2 between the seal portion 132 and the valve body 133. Each groove 133d is open at the end on the first ink chamber 131a side and closed at the end on the second ink chamber 131b side.

  When the valve body 133 moves and the closed end of each groove 133d enters the second ink chamber 131b, the first valve 130a moves the first and second ink chambers 131a and 131b. They are in a state of being spatially connected to each other through the respective groove portions 133d (FIG. 3A). On the contrary, the first valve 130 a is configured such that when the valve body 133 moves and the closed end of each groove portion 133 d of the valve body 133 is accommodated in the through hole of the seal portion 132, The two ink chambers 131a and 131b are spatially blocked and closed (FIG. 3B).

  In the first valve 130a, the degree of opening increases as the grooves 133d of the valve body 133 protrude from the seal portion 132 to the second ink chamber 131b. That is, the opening degree of the first valve 130a can be expressed by the amount of movement of the valve body 133 toward the second ink chamber 131b. Hereinafter, the amount by which each groove portion 133d of the valve body 133 protrudes from the seal portion 132 to the second ink chamber 131b is also referred to as a “lift amount”.

  The application controller 110 (FIG. 2) opens and closes the first and second valves 130a and 130b almost alternately when applying the catalyst ink 2 intermittently by repeatedly discharging and stopping the catalyst ink 2. Specifically, when causing the die head 150 to discharge the catalyst ink 2, the application control unit 110 closes the second valve 130b and then opens the first valve 130a (FIG. 3A). As a result, the catalyst ink 2 in the tank 120 is supplied to the die head 150 via the first valve 130a. On the other hand, when stopping the ejection of the catalyst ink 2 from the die head 150, the application control unit 110 opens the second valve 130b and then closes the first valve 130a (FIG. 3B). As a result, the supply of the catalyst ink to the die head 150 is stopped, and the catalyst ink 2 is circulated through the tank 120 via the second valve 130b.

  By the way, in the catalyst ink application unit 12 of the present embodiment, the discharge and stop of the catalyst ink 2 in the die head 150 are linearly executed by the first valve 130a of the mechanism described above with respect to opening and closing of the first valve 130a. ing. With this configuration, the end of the coating film 3 of the catalyst ink 2 can be satisfactorily formed, and details thereof will be described later.

  In the catalyst ink application unit 12 of this embodiment, the catalyst ink 2 continuously circulates to the tank 120 via the second valve 130b while the discharge of the catalyst ink 2 from the die head 150 is stopped. Fluidized. When the supply of the catalyst ink 2 to the first valve 130a is resumed due to the circulating flow of the catalyst ink 2 in the standby state, a loss time such as a time lag for returning the driving force of the pump 121 occurs. It is suppressed.

  FIG. 4 is a schematic perspective view showing the configuration of the die head 150 provided in the coating unit 100. FIG. 4 illustrates a state in which the die head 150 intermittently forms the coating film 3 of the catalyst ink 2 on the electrolyte film 1 being conveyed by the conveying roller 15. The die head 150 is a discharge nozzle for the catalyst ink 2 and includes first and second main body portions 151 and 152 having outer shapes that are substantially mirror surfaces of each other.

  The first and second main body portions 151 and 152 are arranged so that a slit 156 that is a flat plate-like gap for discharging the catalyst ink 2 in a thin film shape is formed between them. The second main body portion 152 is overlapped with the lower side in the gravitational direction, with the upper side in the gravitational direction. The first and second main body portions 151 and 152 are inclined so as to incline at an acute angle toward the discharge port 153 (opening end portion of the slit 156) of the catalyst ink 2 on the front end side (discharge direction side of the catalyst ink 2). It has a surface 154.

  Here, a slit 156 is connected between the first and second main body portions 151 and 152, and the catalyst ink 2 is allowed to flow into the slit 156 after spreading in the width direction of the die head 150 (the depth direction on the paper surface). A manifold 155 is formed. A pipe 105 (FIG. 2) is connected to the manifold 155, and the catalyst ink 2 is supplied from the first valve 130a. The catalyst ink 2 supplied to the manifold 155 via the pipe 105 spreads in the width direction of the die head 150 in the manifold 155, flows into the slit 156, is formed into a thin film, and is discharged from the discharge port 153.

  In the catalyst ink application unit 12 of the present embodiment, the die head 150 is disposed such that the discharge port 153 opens toward the side surface of the transport roller 15 of the electrolyte membrane 1. Accordingly, the transport roller 15 functions as a so-called back roll, and the catalyst ink 2 can be applied to the electrolyte membrane 1 stretched so as to have a predetermined tension along the side surface of the transport roller 15. The application state of the film 3 can be improved. Here, it is desirable that the curvature of the side surface of the transport roller 15 as a back roll is sufficiently large with respect to the formation size of the coating film 3.

  As described above, in the catalyst ink application unit 12 of the present embodiment, a plurality of catalyst electrodes 4 are continuously formed by intermittent coating processing in which the discharge and stop of the catalyst ink 2 from the die head 150 are repeated. However, the inventor of the present invention has found that the following problems may occur in this flow process.

  FIGS. 5A and 5B are schematic diagrams for explaining a problem that occurs in a flow process in which a plurality of coating films 3 are continuously formed. FIG. 5A is a schematic diagram showing a state in which the coating film 3 is continuously formed on the electrolyte film 1 by the die head 150. In FIG. 5A, for convenience, the electrolyte membrane 1 is illustrated in a linearly extended state. FIG. 5B is a schematic front view schematically showing an example of the coating film 3 causing a problem.

  Here, in the present specification, the end portion of the coating film 3 formed when the application of the catalyst ink 2 is started is hereinafter referred to as a “starting end portion 3b”, and the coating film 3 formed when the application of the catalyst ink 2 is stopped. Is called “terminal portion 3t”. In the flow process of continuously forming a plurality of coating films 3, the inventor of the present invention has not yet formed the normal coating film 3 until the end of the coating film 3 from the middle. It has been found that the catalyst ink 2 may begin to be dragged at 3t. The inventors of the present invention have also found that the drag of the catalyst ink 2 occurs as follows.

  FIGS. 6A and 6B are schematic diagrams for explaining a mechanism in which the catalyst ink 2 is dragged in the coating film 3. FIGS. 6A and 6B are schematic views when the die head 150 being coated is viewed in the side surface direction and the top surface direction, respectively. 6A and 6B, together with the die head 150, a part of the transport roller 15 and a part of the electrolyte membrane 1 being transported are illustrated.

  There is a possibility that the viscosity of the catalyst ink 2 may vary due to differences in the lot of paint, changes in the conditions of the usage environment such as the environmental temperature, and the like. Therefore, in the flow process for forming the catalyst electrode 4, the fluidity of the catalyst ink 2 changes during the process, and the discharge amount from the die head 150 deviates from the proper value of the assumed discharge amount. There is a case.

  In particular, when the discharge amount of the catalyst ink 2 from the die head 150 becomes larger than an appropriate value, the catalyst ink 2 is applied to the inclined surface 154 on the upper side (first main body portion 151 side) of the die head 150. It may rise (FIG. 6 (A)). Once the rising of the catalyst ink 2 to the inclined surface 154 occurs, a flow path of the catalyst ink 2 in which the catalyst ink 2 easily flows is formed between the discharge port 153 and the inclined surface 154.

  Therefore, when intermittent discharge of the catalyst ink 2 from the die head 150 is repeated, a part of the discharged catalyst ink 2 continuously flows out to the inclined surface 154 through the flow path, and the inclined surface 154 On top of this, an ink reservoir 2r in which the catalyst ink 2 is retained is generated.

  When the ink reservoir 2r becomes large, when the discharge of the catalyst ink 2 from the die head 150 is stopped, the catalyst ink 2 pulls a thread between the ink reservoir 2r and the coating film 3, and the catalyst ink from the ink reservoir 2r. 2 is dragged (FIG. 6B). As a result, the catalyst ink 2 is dragged at the end portion 3t of the coating film 3.

  As described above, the drag of the catalyst ink 2 at the end portion 3t of the coating film 3 is caused by the ink reservoir 2r generated at the tip portion of the die head 150. Therefore, in the catalyst ink application unit 12 of the present embodiment, an ink pool generated on the upper surface of the die head 150 by the application failure detection unit 200 (FIG. 2) while the coating unit 100 executes the formation of the catalyst electrode 4. The occurrence of 2r is detected.

  The application failure detection unit 200 includes an imaging camera 210, an illumination unit 220, and an image inspection unit 230. The imaging camera 210 can be constituted by, for example, a CCD camera. The imaging camera 210 periodically captures the peripheral area of the discharge port 153 including the inclined surface 154 of the die head 150 at predetermined time intervals to generate image data. In addition, it is preferable that the imaging camera 210 images the periphery of the discharge port 153 of the die head 150 from a plurality of directions (for example, the upper surface direction and the side surface direction). Thereby, the detection accuracy of the staying catalyst ink 2 can be improved.

  The illumination unit 220 irradiates the inclined surface 154 with illumination light so that the catalyst ink 2 can be easily detected on the image data. The image inspection unit 230 acquires the image data generated by the imaging camera 210 and detects the ink reservoir 2r attached to the die head 150 on the image data. Specifically, the image inspection unit 230 binarizes the image data, detects the outer peripheral contour of the ink reservoir 2r, and calculates the area of the ink reservoir 2r. Based on the calculation result, the amount of the catalyst ink 2 staying around the discharge port 153 of the die head 150 is detected. The image inspection unit 230 transmits the detection result to the application control unit 110 of the application unit 100.

  Based on the detection result received from the image inspection unit 230, the application control unit 110 executes a process for suppressing or eliminating the occurrence of scratches on the catalyst ink 2. Specifically, the application control unit 110 forms the catalyst electrode 4 while suppressing or eliminating the occurrence of scratches on the catalyst ink 2 by a coating process according to the following processing procedure.

  FIG. 7 is a flowchart showing a processing procedure of a coating process for forming the catalyst electrode 4 executed by the coating control unit 110. In step S10, the application controller 110 executes intermittent ejection of the catalyst ink 2 from the die head 150 by alternately opening and closing the first and second valves 130a and 130b as described in FIG. As a result, a plurality of coating films 3 are formed at predetermined intervals on the electrolyte membrane 1 being conveyed.

  In step S20, the application control unit 110 receives the detection result from the image inspection unit 230 described above. If the coating failure detection unit 200 detects that a predetermined amount or more of the catalyst ink 2 stays around the discharge port 153 of the die head 150, the coating film 3 may be dragged. May have increased or may have occurred.

  Accordingly, the application control unit 110 executes the process of step S30 for suppressing or eliminating the occurrence of scratches on the catalyst ink 2. In step S20, when the retention of the predetermined amount of catalyst ink 2 is not detected by the application failure detection unit 200, the application control unit 110 continues to intermittently discharge the catalyst ink 2 as it is ( Step S10). In step S30, the application control unit 110 reduces the lift amount of the valve body 133 when opening the first valve 130a from the initial set value, and returns to the process of step S10.

  Here, the discharge amount of the catalyst ink 3 when the discharge of the catalyst ink 2 from the die head 150 is started is almost pushed out from the first ink chamber 131a by the valve element 33 when the first valve 33a is opened. It depends on the amount of catalyst ink 2. Therefore, when the lift amount of the valve element 33 is reduced in step S30, the discharge amount of the catalyst ink 2 when the discharge of the catalyst ink 2 from the die head 150 for the formation of the coating film 3 is started is reduced. The

  Accordingly, the discharge amount of the catalyst ink 2 when forming the coating film 3 can be within an appropriate range, and the flow of the catalyst ink 2 to the ink reservoir 2r is suppressed. The occurrence of 2 scratches is suppressed. Even when the catalyst film 2 has already been dragged in the coating film 3, the catalyst ink 2 in the ink reservoir 2r decreases as the coating film 3 is repeatedly formed. The occurrence of scratches is eliminated.

FIG. 8 is an explanatory diagram showing the results of experiments conducted by the inventors of the present invention. In FIG. 8, the horizontal axis represents the lift amount of the valve body 133 when the first valve 130a is opened, and the vertical axis represents the number of application times of the catalyst ink 2 that could be repeated without causing the catalyst ink 2 to be dragged. The graph is shown. In this experiment, the catalyst ink 2 is a dispersion in which platinum-supported carbon and a solid electrolyte (perfluorosulfonic acid) are dispersed in water and an alcohol solution, and a perfluorosulfonic acid film is used as the electrolyte membrane 1 to form a catalyst. Ink ejection was intermittently performed a maximum of N _max times.

In this experiment, when the lift amount of the valve body 133 of the first valve 130a at the start of the discharge of the catalyst ink 2 is small, the catalyst ink 2 is discharged _Nmax without causing the coating film 3 to be dragged. I was able to repeat it. However, when the lift amount is smaller than a certain value L _lim , the shape of the start end portion 3b of the coating film 3 is broken. This is because if the lift amount of the valve body 133 of the first valve 130a at the start of discharge is too small, it is not possible to secure a good discharge amount of the catalyst ink 2 for forming the start end portion 3b of the coating film 3. it is conceivable that. On the other hand, when the lift amount of the valve body 133 of the first valve 130a at the start of the discharge of the catalyst ink 2 was increased, the catalyst ink 2 was dragged in the coating film 3 at an earlier stage as the lift amount was larger.

  From this experimental result, it can be seen that by reducing the lift amount when the first valve 130a is opened, the occurrence of drag of the catalyst ink 2 in the coating film 3 can be suppressed. In this experiment, when the occurrence of scratches on the catalyst ink 2 is visually confirmed, it is always detected by the imaging camera 210 that the ink reservoir 2r having a predetermined area is generated on the inclined surface of the die head 150. I was able to.

  By the way, the inventor of the present invention, as a reference example, intermittently applies the catalyst ink 2 by changing not the lift amount when opening the first valve 130a but the lift amount during a predetermined period when closing the first valve 130a. Experiment was conducted. In the experiment of this reference example, even when the lift amount was changed, there was only a slight difference in the number of times of application of the catalyst ink 2 that could be repeated without causing the catalyst ink 2 to be dragged. Therefore, it can be seen from the experimental results of this reference example that the drag of the catalyst ink 2 on the coating film 3 is not affected by the discharge amount of the catalyst ink 2 when the terminal portion 3t of the coating film 3 is formed.

  As described above, in the case of the catalyst ink application unit 12 of the present embodiment, the ink reservoir 2r in the die head 150 that causes the catalyst ink 2 to be dragged at the terminal end 3t of the coating film 3 by the application failure detection unit 200. Can be detected. Moreover, since the coating part 100 reduces the lift amount in the 1st valve | bulb 130a according to the detection result, generation | occurrence | production of the catalyst ink 2 at the terminal part 3t of the coating film 3 can be eliminated or suppressed. . Furthermore, in the catalyst ink application unit 12 of this embodiment, since the discharge of the catalyst ink 2 from the die head 150 is controlled by the first valve 130a, the application state of the coating film 3 is improved as follows. Yes.

  FIG. 9 is a schematic view showing a cross-sectional shape when the coating film 3 formed by the coating unit 100 of the present embodiment is cut in the coating direction (conveying direction of the electrolyte membrane 1). In FIG. 9, the direction from the left side to the right side is the coating direction. That is, the left side of the drawing is the start end 3 b of the coating film 3, and the right side of the drawing is the terminal end 3 t of the coating film 3. Further, in FIG. 9, the shape of the coating film 3a as a reference example is illustrated by a broken line.

  As will be described later, according to the coating unit 100 of the present embodiment, the discharge of the catalyst ink 2 is started linearly (immediately) at the timing when the first valve 130a is opened. Therefore, the discharge amount of the catalyst ink 2 at the start of the discharge of the catalyst ink 2 can be ensured, and the starting end portion 3b of the coating film 3 stands up at an angle close to perpendicular to the coating surface (the surface of the electrolyte film 1). It is formed to have an end face. Further, according to the coating unit 100 of the present embodiment, the discharge of the catalyst ink 2 is stopped linearly (immediately) at the timing when the first valve 130a is closed. Therefore, excessive discharge of the catalyst ink 2 at the end of the discharge of the catalyst ink 2 is suppressed, and the end portion 3t of the coating film 3 is at an angle close to perpendicular to the coating surface, like the start end portion 3b. It is formed to have a sharp end face.

  FIGS. 10A and 10B are schematic views showing the state of the first valve 130a and the die head 150 when the start end 3b and the end end 3t of the coating film 3 are formed, respectively. As described above, when the discharge of the catalyst ink 2 from the die head 150 is started, the valve body 133 of the first valve 130a protrudes into the second ink chamber 131b (FIG. 10A).

  Here, before the first valve 130a is opened, the manifold 155, the slit 156, the pipe 106, and the second ink chamber 131b of the first valve 130a are filled with the catalyst ink 2 before the first valve 130a is opened. It has become. Therefore, when the valve body 133 protrudes into the second ink chamber 131b to start discharging the catalyst ink 2, the catalyst ink 2 in the second ink chamber 131b is pushed out toward the die head 150. Therefore, the discharge of the catalyst ink 2 is started from the discharge port 153 of the die head 150 almost simultaneously with the opening of the first valve 130a.

  On the other hand, when stopping the ejection of the catalyst ink 2 from the die head 150, as described above, the valve body 133 of the first valve 130a moves from the second ink chamber 131b toward the first ink chamber 131a (FIG. 10 (B)). Therefore, as the valve body 133 moves, a negative pressure can be generated in the second ink chamber 131b, and the catalyst ink 2 of the die head 150 can flow back to the first valve 130a (suck back function). ). Therefore, the reverse flow of the catalyst ink 2 in the die head 150 promotes the cutting of the catalyst ink 2 between the coating film 3 and the discharge port 153 of the die head 150, and excessive discharge of the catalyst ink 2 at the end of the discharge of the catalyst ink 2. Is suppressed.

  In addition, when a valve of a type that does not cause extrusion or suction of the catalyst ink accompanying the movement of the valve body is used instead of the first valve 130a of the present embodiment, as shown by the broken line in FIG. There is a possibility that the shape of the start end portion 3b and the end end portion 3t of the coating film 3 is broken. Specifically, when the above-described type of valve is used, the discharge amount of the catalyst ink 2 cannot be secured immediately when the valve is opened, and the start end portion 3b of the coating film 3 is gently formed. There is a possibility. In addition, after the valve is closed, the discharge of the catalyst ink 2 is not immediately stopped, and the excess catalyst ink 2 is discharged, and an excess mass of the catalyst ink 2 is formed at the terminal portion 3 t of the coating film 3. There is a possibility.

  As described above, in the case of the catalyst ink application unit 12 of the present embodiment, the catalyst at the terminal portion 3t of the coating film 3 is not stopped by the cooperation of the coating unit 100 and the application failure detection unit 200 without stopping the flow process. The occurrence of scratches on the ink 2 can be eliminated or suppressed. Further, since the discharge of the catalyst ink 2 is controlled by the opening and closing control of the first and second valves 130a and 130b, the initial application state of the coating film 3 is improved. Therefore, the catalyst electrode forming apparatus 10 provided with the catalyst ink application unit 12 can efficiently form a good catalyst electrode 4 for a fuel cell.

B. Second embodiment:
FIG. 11 is a schematic diagram showing a configuration of a catalyst ink application unit 12A included in the catalyst electrode forming apparatus according to the second embodiment of the present invention. The catalyst ink application unit 12A of the second embodiment is the catalyst of the first embodiment, except that the first and second valves 130aA and 130bA are provided instead of the first and second valves 130a and 130b. The configuration is the same as that of the ink application unit 12. The configuration of the catalyst electrode forming apparatus of the second embodiment is the same as that of the catalyst electrode forming apparatus 10 of the first embodiment except for the catalyst ink application unit 12A.

  The first and second valves 130aA and 130bA of the second embodiment include a valve body 133A and a valve seat 136 in the casing 131. 133 A of valve bodies are connected with the valve drive part 135 via the shaft part 134 penetrated by the through-hole of the valve seat 136 center, and reciprocate with respect to the valve seat 136. FIG.

  Here, the first and second valves 130aA and 130bA are opened when the valve body 133A is separated from the valve seat 136 and the through hole of the valve seat 136 is opened, and the valve body 133A is opened. When the through hole of the valve seat 136 is closed in close contact with the valve seat 136, the valve seat 136 is closed. The valve drive unit 135 includes an air cylinder, and the valve body 133 is reciprocated together with the shaft unit 134 by the air cylinder. The amount of movement of the valve body 133 (that is, the opening degree of the first and second valves 130aA and 130bA) is controlled by the application control unit 110.

  As described above, the catalyst ink application unit 12A of the second embodiment includes the first and second valves 130aA and 130bA of a type in which the catalyst ink 2 is not pushed out or sucked by the valve body 133. However, even in the catalyst ink application unit 12A of the second embodiment, the catalyst ink 2 at the start of discharge of the catalyst ink 2 is adjusted by adjusting the opening of the first valve 130aA at the start of discharge of the catalyst ink 2. Can be reduced. Therefore, similarly to the catalyst ink application unit 12 of the first embodiment, it is possible to eliminate or suppress the occurrence of the drag of the catalyst ink 2 at the terminal end 3t of the coating film 3.

C. Variations:
C1. Modification 1:
In the above embodiment, the catalyst ink application units 12 and 12A include the application failure detection unit 200, but the application failure detection unit 200 may be omitted. In this case, for example, when the operator visually confirms the occurrence of the ink reservoir 2r and starts to discharge the catalyst ink 2 to the application control unit 110, the opening degree of the first valves 130a and 130aA decreases. May be executed.

C2. Modification 2:
In the embodiment described above, the application failure detection unit 200 detects the occurrence of scratches on the catalyst ink 2 in the application layer 3 by detecting the occurrence of the ink reservoir 2r. However, the application failure detection unit 200 may detect the occurrence of scratching of the catalyst ink 2 in the application layer 3 by another method. For example, the application failure detection unit 200 may detect the occurrence of scratching of the catalyst ink 2 in the application layer 3 based on a change in the viscosity of the catalyst ink 2. Alternatively, the application failure detection unit 200 may image the application film 3 with the imaging camera 210 and detect the occurrence of scratches on the catalyst ink 2 based on the image data.

C3. Modification 3:
In the embodiment described above, the application failure detection unit 200 detects the retention of the catalyst ink 2 in the peripheral region of the discharge port 153 of the die head 150 based on the image data generated by the imaging camera 210. However, the application failure detection unit 200 may detect the retention of the catalyst ink 2 in the peripheral region of the discharge port 153 of the die head 150 by another method.

C4. Modification 4:
In the above-described embodiment, the application control unit 110 includes the first valve 130a when starting the discharge of the catalyst ink 2 in order to suppress or eliminate the generation of the catalyst ink 2 in the application layer 3 in the flow process. The opening degree of 130aA was reduced. However, in the flow process, for example, the application control unit 110 increases the opening degree of the first valves 130a and 130aA when starting the discharge of the catalyst ink 2 in order to solve the shortage of the discharge amount of the catalyst ink 2, for example. Processing may be executed.

C5. Modification 5:
In the above embodiment, the catalyst ink application portions 12 and 12 </ b> A form the catalyst electrode 4 on the electrolyte membrane 1. However, the catalyst ink application portions 12 and 12A may form the catalyst electrode 4 for transfer on a substrate such as a resin film instead of the electrolyte membrane 1.

C6. Modification 6:
In the catalyst ink application portions 12 and 12A of the above embodiment, the catalyst ink 2 is applied to the electrolyte membrane 1 being conveyed by the die head 150 whose position is fixed. However, in the catalyst ink application units 12 and 12A, the catalyst ink 2 may be applied to the electrolyte membrane 1 that is fixedly arranged while the die head 150 is moved at a predetermined speed. The die head 150 may be moved relative to the coating surface during coating.

C7. Modification 7:
In the above embodiment, the catalyst ink 2 is circulated between the second valves 130b and 130bA and the tank 120 when the discharge of the catalyst ink 2 is stopped. However, the second valve 130b, 130bA and the circulation flow of the catalyst ink 2 when the discharge of the catalyst ink 2 is stopped may be omitted. However, it is desirable to circulate and flow the catalyst ink 2 while the discharge of the catalyst ink 2 is stopped because the discharge of the catalyst ink 2 can be restarted quickly.

C8. Modification 8:
In the above-described embodiment, the coating unit 100 executes the coating process in which the catalyst ink 2 is applied as a paint to form a coating film. However, the coating part 100 may perform the coating process which apply | coats the particle dispersion liquid in which the other particle was disperse | distributed as a coating material, and forms a coating film.

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

DESCRIPTION OF SYMBOLS 1 ... Electrolyte membrane 1r ... Electrolyte membrane roll 2 ... Catalyst ink 3, 3a ... Coating film 3b ... Start-end part 3t ... Termination part 4 ... Catalyst electrode 10 ... Catalyst electrode formation apparatus 11 ... Film | feeding-out part 12, 12A ... Catalyst ink application part DESCRIPTION OF SYMBOLS 13 ... Drying part 13d ... Dryer 14 ... Conveyance control part 15 ... Conveyance roller 100 ... Coating part 101-106 ... Piping 110 ... Application | coating control part 120 ... Tank 121 ... Pump 130a, 130aA ... 1st valve | bulb 130b, 130bA ... 1st Second valve 131 ... Casing 131a ... First ink chamber 131b ... Second ink chamber 132 ... Seal part 133, 133A ... Valve body 133d ... Groove part 134 ... Shaft part 135 ... Valve drive part 136 ... Valve seat 150 ... Die head 151 ... 1st main-body part 152 ... 2nd main-body part 153 ... Discharge port 154 ... Inclined surface 155 ... Maniho Field 156 ... slit 200 ... coating defect detecting section 210 ... imaging camera 220 ... illumination unit 230 ... image inspection unit

Claims (7)

A coating apparatus for forming a coating film,
A paint discharger that discharges the paint while moving relative to the coating surface;
A valve for controlling the supply of the paint to the paint discharge unit;
A coating control unit that controls opening and closing of the valve to control discharge and stop of the paint by the paint discharge unit;
In a coating process in which a plurality of coating films are continuously formed by repeatedly discharging and stopping the paint on the paint discharge unit, the opening degree of the valve when the paint discharge unit discharges the paint is changed. A valve opening degree control unit,
A coating apparatus comprising: The coating apparatus according to claim 1, further comprising:
A dwell detection unit that detects dwell of the paint around the discharge port of the paint discharge unit;
The valve opening control unit is a coating apparatus that reduces the opening of the valve when the paint discharge unit discharges the paint after the stay detection unit detects the stay of a predetermined amount of the paint. The coating apparatus according to claim 2,
The stay detection unit
An imaging unit for imaging the periphery of the discharge port;
An imaging analysis unit for detecting a staying state of the paint based on an image captured by the imaging unit;
A coating apparatus comprising: The coating apparatus according to any one of claims 1 to 3, further comprising:
A paint supply unit for supplying the paint to the valve;
The valve is
A paint filling chamber connected to the paint supply section and the paint discharge section and filled with the paint;
A valve body that controls opening and closing of a connection between the paint filling chamber and the paint supply unit, and moves into the paint filling chamber to push the paint in the paint filling chamber to the paint discharge unit. A valve body that opens a connection between the paint filling chamber and the paint supply unit;
With
The said valve opening degree control part is a coating apparatus which changes the moving amount | distance of the said valve body as the opening degree of the said valve. The coating apparatus according to claim 4,
When the valve is closed, the valve body moves toward the outside of the paint filling chamber to generate a negative pressure in the paint filling chamber. A coating apparatus according to any one of claims 1 to 5,
The coating apparatus is a coating apparatus, which is a catalyst ink in which a fuel cell catalyst is dispersed. A coating method for forming a coating film,
(A) While moving the discharge port of the paint relative to the coating surface, the opening and closing of the valve for controlling the discharge of the paint is controlled to repeat the discharge and stop of the paint. Forming the process,
(B) changing the opening of the valve when discharging the paint during the execution of the step (a);
A coating method comprising:

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