Electrode ink coating method and coating auxiliary device

Abstract

To provide an electrode ink coating method which eliminates waste of electrode ink and improves product yield.SOLUTION: An electrode ink coating auxiliary device 1 includes: an electrode ink receiver 4 that is placed in front, in a travel direction, of a blade 12 configured to apply an electrode ink 2, and extends in an intersecting direction perpendicular to the travel direction and receives the electrode ink 2 being supplied; and regulators 5 that are arranged at both ends in the intersecting direction of the electrode ink receiver 4, extends along the travel direction, and each have a flat portion 5a that regulates an application direction of the electrode ink.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for applying electrode ink and an application assisting device.

Background Art

[0002] Conventionally, when producing a CCM (catalyst layer-coated electrolyte membrane) by applying electrode ink to a substrate, a technique of applying the electrode ink to the substrate using a blade has been proposed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When applying to a substrate using a blade, excess electrode ink that could not be completely applied to the substrate may spread around the blade. For this reason, there have been problems such that the post-application processing is time-consuming, at the same time, there is waste of the electrode ink, and the yield is reduced.

Means for Solving the Problems

[0005] (1) The present invention relates to an application assisting device for electrode ink (for example, application assisting device 1 for electrode ink), which is disposed in front of a blade (for example, blade 12) for applying electrode ink (for example, electrode ink 2) in the advancing direction of the blade, extends in an intersecting direction orthogonal to the advancing direction, and receives the supplied electrode ink, and a regulating portion (for example, regulating portion 5) disposed at both ends of the electrode ink receiving portion in the intersecting direction and extending along the advancing direction, and having a flat portion (for example, flat portion 5a) for regulating the application direction of the electrode ink.

[0006] (2) The bottom surface portion of the electrode ink receiving portion (for example, the bottom surface portion 41) is preferably disposed at a position above the upper surface of the substrate (for example, the substrate 3) on which the electrode ink is applied.

[0007] (3) The regulating portion is preferably formed in a plate shape and has a curved portion (for example, the curved portion 5b) in which the front lower corner in the advancing direction is curved.

[0008] (4) The present invention relates to a method for applying an electrode ink, which includes an arranging step (for example, the arranging step S2 of the coating auxiliary device) of arranging a coating auxiliary device in front of the advancing direction of the blade for applying the electrode ink, and a coating step (for example, the coating step S4) of moving the coating auxiliary device together with the blade to apply the electrode ink. The coating auxiliary device includes an electrode ink receiving portion that extends in a crossing direction orthogonal to the advancing direction of the blade and receives the supplied electrode ink, and a regulating portion that is disposed at both ends of the electrode ink receiving portion in the crossing direction and extends along the advancing direction and regulates the coating direction of the electrode ink.

[0009] (5) After the coating step, it is preferably further provided with a recovery step (for example, the recovery step S5) of separating the electrode ink receiving portion from the blade and recovering the excess electrode ink.

Advantages of the Invention

[0010] According to the above (1), the electrode ink 2 is prevented from spreading in the crossing direction CD by the flat surface portion 5a of the regulating portion 5. Further, since the electrode ink receiving portion 4 receives the electrode ink 2 supplied thereto, the electrode ink 2 is also prevented from spreading in the advancing direction TD. Therefore, it is possible to suppress the leakage of the electrode ink 2 to an unintended portion, save the waste of the electrode ink 2, and improve the yield of the coated product such as the CCM.

[0011] According to the above (2), it is possible to prevent the bottom surface portion 41 from contacting the base material 3 or the applied electrode ink 2 and disturbing the coating surface. Further, since the bottom surface portion 41 is located at a position floating from the upper surface of the base material 3, no friction occurs between the bottom surface portion 41 and the surfaces of the base material 3 and the applied electrode ink 2. Therefore, the coating assist device 1 can be pushed out by the blade 12 and move smoothly. Thus, efficient coating can be realized and the yield is improved.

[0012] According to the above (3), by providing the curved portion 5b at the front lower corner in the traveling direction TD, it is possible to prevent the coating assist device 1 from stopping due to dust, friction, etc. when moving forward. As a result, the coating assist device 1 can be pushed out by the blade 12 and move smoothly. Therefore, efficient coating can be realized and the yield is improved.

[0013] According to the above (4), the electrode ink 2 is prevented from spreading in the crossing direction CD by the flat portion 5a of the restricting portion 5. Further, in order to receive the electrode ink 2 supplied to the electrode ink receiving portion 4, the electrode ink 2 is also prevented from spreading in the traveling direction TD. Therefore, it is possible to suppress the leakage of the electrode ink 2 to an unintended portion, save the waste of the protruding electrode ink 2, and improve the yield of the coated product such as the CCM.

[0014] According to the above (5), since the unused electrode ink 2 can be recovered, the waste of the electrode ink 2 is saved, and the same effect as above is achieved.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4A

Figure 4B

Figure 5A

Figure 5B

Figure 6A

Figure 6B

Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. As shown in FIG. 1, the method for coating an electrode ink according to the present embodiment is performed using a coating assist device 1 for electrode ink (hereinafter also referred to as the coating assist device 1). The coating assist device 1 is not particularly limited in its use as long as it is used for coating the electrode ink 2 using a blade coater 10. For example, it may be used in the step of coating the electrode ink 2 on a substrate 3 when manufacturing a catalyst-coated electrolyte membrane (CCM) for applications such as fuel cells, water electrolysis, and PEM pumps.

[0017] The substrate 3 is not particularly limited, and examples thereof include a sheet-like thin film, a breathable substrate, a release film, and the like. The substrate 3 may be a substrate for fuel cell gas diffusion, an electrolyte membrane for a fuel cell, or the like. The substrate 3 is disposed on a coating table 11 of a blade coater 10 described later.

[0018] The electrode ink 2 is a liquid containing a composition for forming an electrode, and may be, for example, a liquid containing a catalyst carrier carrying a catalyst, an ionomer having proton conductivity (electrolytic polymer, electrolyte solution), and a dispersion solvent for dispersing the catalyst carrier and the ionomer.

[0019] The blade coater 10 has a coating table 11 and a blade 12, and is a device for coating the electrode ink 2 while moving the blade 12 in a certain direction on a substrate 3 placed on the coating table 11. In this specification, the front side in the traveling direction TD in which the blade 12 moves is referred to as the front, and the rear side is referred to as the back. Also, the direction intersecting the traveling direction TD in which the blade 12 moves is referred to as the intersecting direction CD. As shown in FIG. 2, when the substrate 3 is rectangular, the intersecting direction CD is the width direction (short side direction) of the substrate 3. The coating table 11 has a flat surface such as a glass plate, for example. The blade 12 is attached such that its longitudinal direction extends in the intersecting direction CD and its short side direction is substantially orthogonal to the surface of the coating table 11. The tip of the blade 12 is disposed close to the surface of the substrate 3, and moves while coating the electrode ink 2 supplied to the coating assist device 1 described later onto the substrate 3. The dimension of the blade 12 along the intersecting direction CD becomes the dimension of the CCM in the intersecting direction CD.

[0020] As shown in FIG. 2, the coating assist device 1 is disposed in front of the blade 12 in the traveling direction TD and moves together with the blade 12. The coating assist device 1 has an electrode ink receiving portion 4 and a regulating portion 5.

[0021] The electrode ink receiving portion 4 is disposed in front of the blade 12 in the traveling direction TD and extends in the intersecting direction CD orthogonal to the traveling direction TD. The electrode ink receiving portion 4 has a horizontally long shape with the intersecting direction CD as the longitudinal direction. The electrode ink receiving portion 4 is a portion that receives the electrode ink 2 supplied for coating the substrate 3 and receives the electrode ink 2. As shown in FIGS. 1 and 3A and the like, the electrode ink receiving portion 4 is formed in a substantially L shape in side view and has a bottom surface portion 41 and a vertical wall portion 42.

[0022] The bottom surface portion 41 is a substantially rectangular plate surface whose longitudinal direction is along the cross direction CD and whose lateral direction is along the traveling direction TD of the blade 12. As shown in Fig. 3A, the bottom surface portion 41 is disposed at a position spaced above the upper surface of the base material 3 and is not in contact with the base material 3. As shown in Fig. 3B, the dimension of the bottom surface portion 41 in the cross direction CD is formed to be slightly shorter than the dimension of the blade 12 in the cross direction CD.

[0023] The vertical wall portion 42 has a plate-like shape and stands upward from the front end portion of the bottom surface portion 41. The vertical wall portion 42 is connected to the front end portion of the bottom surface portion 41 and has the same dimension as the bottom surface portion 41 in the cross direction CD.

[0024] The restricting portions 5 are disposed at both ends of the electrode ink receiving portion 4 in the cross direction CD. Each restricting portion 5 is formed in a plate shape and has a flat portion 5a and a curved portion 5b. The restricting portion 5 is disposed so that the pair of flat portions 5a sandwich both ends of the electrode ink receiving portion 4. The flat portions 5a are disposed so that their surfaces extend along the traveling direction TD. The flat portions 5a are formed in a roughly rectangular shape whose dimension along the traveling direction TD is shorter than the longitudinal direction of the electrode ink receiving portion 4. The curved portion 5b is formed by curving the lower front corner of the flat portions 5a.

[0025] A method for applying electrode ink using the above-described application auxiliary device 1 will now be described. 3A and 3B, first, the substrate 3 is placed on the coating table 11 of the blade coater 10 (substrate placement step S1). With the tip of the blade 12 in close proximity to the upper surface of the substrate 3, the coating auxiliary device 1 is placed ahead of the blade 12 in the traveling direction TD (coating auxiliary device placement step S2).

[0026] As shown in FIGS. 4A and 4B, by supplying the electrode ink 2 onto the bottom surface portion 41 in the electrode ink receiving portion 4 of the coating assisting device 1, the electrode ink 2 is supplied from the bottom surface portion 41 to the gap between the blade 12 and the coating assisting device 1 (electrode ink supply step S3). Then, the blade coater 10 starts coating the electrode ink 2 (coating step S4). In the coating step S4, when the blade 12 moves, since the restricting portion 5 of the coating assisting device 1 is in contact with the blade 12, the coating assisting device 1 is pushed forward together with the blade and moves forward along with the blade 12. Since the curved portion 5b of the restricting portion 5 in the coating assisting device 1 is curved, the front lower side is not angled, so it can move smoothly without getting caught.

[0027] As shown in FIGS. 5A and 5B, when the blade 12 is advanced, the electrode ink 2 is coated rearward. At this time, as shown by the dashed line in FIG. 2, if there is no restricting portion 5 of the coating assisting device 1, the electrode ink 2 will overflow in the crossing direction CD, resulting in a coating surface that is larger and more irregular than the desired coating surface. However, the flat surface portion 5a of the restricting portion 5 suppresses the spreading of the electrode ink 2 to the outside in the crossing direction CD, and the coating direction of the electrode ink 2 is restricted. Also, the electrode ink 2 supplied to the electrode ink receiving portion 4 is coated onto the base material 3 while the thickness of the coating film is adjusted by the blade 12 from the gap with the blade 12, while being suppressed from spreading forward in the traveling direction TD by the vertical wall portion 42.

[0028] As shown in FIGS. 6A and 6B, after the coating step S4, the coating assisting device 1 is separated from the blade 12. Since the surplus electrode ink 2 that has not been completely coated accumulates on the bottom surface portion 41 of the electrode ink receiving portion 4, this is recovered (recovery step S5).

[0029] According to this embodiment, the following effects are achieved. (1) The electrode ink application auxiliary device 1 is configured to include an electrode ink receiving section 4 that is arranged in front of the traveling direction TD of the blade 12 that applies the electrode ink 2, extends in a cross direction CD perpendicular to the traveling direction TD, and receives the electrode ink 2 that is supplied, and a regulating section 5 that is arranged at both ends of the electrode ink receiving section 4 in the cross direction CD, extends along the traveling direction TD, and has a flat section 5a that regulates the application direction of the electrode ink 2. The flat surface 5a of the restricting portion 5 prevents the electrode ink 2 from spreading in the cross direction CD. Furthermore, the electrode ink receiving portion 4 receives the supplied electrode ink 2, so the electrode ink 2 is also prevented from spreading in the travel direction TD. This prevents the electrode ink 2 from leaking to unintended areas, reduces waste of the electrode ink 2, and improves the yield of coated products such as CCM.

[0030] (2) According to this embodiment, the bottom surface 41 of the electrode ink receiving portion 4 is disposed at a position above and spaced apart from the upper surface of the substrate 3 onto which the electrode ink 2 is applied. This prevents the bottom surface 41 from coming into contact with the substrate 3 or the coated electrode ink 2, thereby preventing the coated surface from becoming distorted. Furthermore, because the bottom surface 41 is positioned above the upper surface of the substrate 3, no friction occurs between the bottom surface 41 and the substrate 3 or the surface of the coated electrode ink 2, allowing the coating auxiliary device 1 to be pushed out by the blade 12 and move smoothly. This therefore enables efficient coating and improves yield.

[0031] (3) According to this embodiment, the flat portion 5a is formed in a plate shape and includes the curved portion 5b, the lower front corner of which is curved in the traveling direction TD. Providing the curved portion 5b at the front lower corner in the traveling direction TD prevents the coating auxiliary device 1 from stopping due to dust, friction, etc. as it moves forward. This allows the coating auxiliary device 1 to be pushed out by the blade 12 and move smoothly. This allows for efficient coating and improved yield.

[0032] (4) According to this embodiment, a method for coating the electrode ink 2 includes a coating auxiliary device arranging step (S2) of arranging a coating auxiliary device 1 in front of the blade 12 in the advancing direction TD for coating the electrode ink 2, and a coating step (S4) of moving the coating auxiliary device 1 together with the blade 12 to coat the electrode ink 2. The coating auxiliary device 1 includes an electrode ink receiving part 4 that extends in the crossing direction CD orthogonal to the advancing direction TD of the blade 12 and receives the supplied electrode ink 2, and a regulating part 5 that is arranged at both ends of the electrode ink receiving part 4 in the crossing direction CD and extends along the advancing direction TD and has a flat part 5a for regulating the coating direction of the electrode ink 2. The electrode ink 2 is prevented from spreading in the crossing direction CD by the flat part 5a of the regulating part 5. Further, since the electrode ink receiving part 4 receives the supplied electrode ink 2, the electrode ink 2 is also prevented from spreading in the advancing direction TD. Therefore, it is possible to suppress the leakage of the electrode ink 2 to an unintended part, save the waste of the protruding electrode ink 2, and improve the yield of the coated product such as the CCM.

[0033] (5) According to this embodiment, after the coating step (S4), a recovery step (S5) of separating the electrode ink receiving part 4 from the blade 14 and recovering the excess electrode ink 2 is further included. Since the unused electrode ink 2 can be recovered, the waste of the electrode ink 2 is saved, and the same effect as above is achieved.

[0034] Note that the present invention is not limited to the above embodiment, and modifications, improvements, etc. within the scope capable of achieving the object of the present invention are included in the present invention. For example, the flat part 5a has a generally quadrangular shape in the above embodiment, but the shape is not particularly limited as long as the surface is along the advancing direction TD.

Explanation of Reference Numerals

[0035] 1 Coating auxiliary device 2 Electrode ink 3 Base material 4 Electrode ink receiving part 5 Regulating part 5a Flat part 5b Curved portion 11 Blade

Claims

1. An electrode ink receiving portion that is disposed in front of the advancing direction of a blade for applying electrode ink, extends in an intersecting direction orthogonal to the advancing direction, and receives the supplied electrode ink; A regulating portion that is disposed at both ends of the electrode ink receiving portion in the intersecting direction, extends along the advancing direction, and has a flat portion that regulates the application direction of the electrode ink. An electrode ink application assisting device having the same.

2. The electrode ink application assisting device according to claim 1, wherein the bottom surface portion of the electrode ink receiving portion is disposed at a position spaced upward from the upper surface of the base material on which the electrode ink is applied.

3. The electrode ink application assisting device according to claim 1 or 2, wherein the regulating portion is formed in a plate shape and has a curved portion where the front lower corner in the advancing direction is curved.

4. An electrode ink application method, comprising: An arranging step of arranging an application assisting device in front of the advancing direction of a blade for applying the electrode ink; An application step of moving the application assisting device together with the blade to apply the electrode ink, and The application assisting device includes: An electrode ink receiving portion that extends in an intersecting direction orthogonal to the advancing direction of the blade and receives the supplied electrode ink; A regulating portion that is disposed at both ends of the electrode ink receiving portion in the intersecting direction, extends along the advancing direction, and has a flat portion that regulates the application direction of the electrode ink. An electrode ink application method having the same.

5. The electrode ink application method according to claim 4, further comprising a recovering step of separating the electrode ink receiving portion from the blade after the application step and recovering the excess electrode ink.

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