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 a coating auxiliary device. [Background technology]

[0002] Conventionally, when producing a catalyst-coated membrane (CCM) by applying an electrode ink to a substrate, a technique has been proposed in which the electrode ink is applied to the substrate using a blade (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-1568 Summary of the Invention [Problem to be solved by the invention]

[0004] When a blade is used to coat a substrate, excess electrode ink that is not completely applied to the substrate can spread around the blade, resulting in problems such as time-consuming post-coating processing, wasted electrode ink, and reduced yield. [Means for solving the problem]

[0005] (1) The present invention relates to an electrode ink application auxiliary device (e.g., electrode ink application auxiliary device 1) having an electrode ink receiving portion (e.g., electrode ink receiving portion 4) that is arranged ahead of the traveling direction of a blade (e.g., blade 12) that applies electrode ink (e.g., electrode ink 2), extends in a cross direction perpendicular to the traveling direction, and receives the electrode ink that is supplied, and a regulating portion (e.g., regulating portion 5) that is arranged at both ends of the electrode ink receiving portion in the cross direction, extends along the traveling direction, and has a flat portion (e.g., flat portion 5a) that regulates the application direction of the electrode ink.

[0006] (2) The bottom surface of the electrode ink receiving portion (for example, bottom surface 41) is preferably located above and away from the top surface of the substrate (for example, substrate 3) onto which the electrode ink is applied.

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

[0008] (4) The present invention relates to a method for applying electrode ink, comprising: an arrangement step (e.g., coating auxiliary device arrangement step S2) of arranging a coating auxiliary device ahead of a blade in the traveling direction of the blade that applies the electrode ink; and a coating step (e.g., coating step S4) of moving the coating auxiliary device together with the blade to apply the electrode ink, wherein the coating auxiliary device has an electrode ink receiving section that extends in a cross direction perpendicular to the traveling direction of the blade and receives the electrode ink that is supplied; and regulating sections that are arranged at both ends of the electrode ink receiving section in the cross direction, extend along the traveling direction, and have flat sections that regulate the application direction of the electrode ink.

[0009] (5) It is preferable that the method further comprises, after the coating step, a recovery step (for example, recovery step S5) of separating the electrode ink receiving portion from the blade and recovering excess electrode ink. [Effects of the Invention]

[0010] According to the above (1), 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 traveling direction TD. This prevents the electrode ink 2 from leaking to unintended areas, reduces the waste of the electrode ink 2, and improves the yield of coated products such as CCM.

[0011] According to (2) above, it is possible to prevent the bottom surface portion 41 from coming into contact with the substrate 3 or the coated electrode ink 2, thereby preventing the coated surface from becoming disordered. Furthermore, because the bottom surface portion 41 is positioned above the upper surface of the substrate 3, no friction occurs between the bottom surface portion 41 and the surface of the substrate 3 or the coated electrode ink 2, and the coating auxiliary device 1 can be pushed out by the blade 12 and move smoothly. This therefore enables efficient coating and improves yield.

[0012] According to the above (3), the curved portion 5b is provided at the front lower corner in the traveling direction TD, which 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.

[0013] According to the above (4), 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 traveling direction TD. This prevents the electrode ink 2 from leaking to unintended areas, prevents the electrode ink 2 from being wasted, and improves the yield of coated products such as CCM.

[0014] According to (5) above, unused electrode ink 2 can be collected, which eliminates waste of electrode ink 2 and provides the same effect as above. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 2 is a perspective view showing an electrode ink application auxiliary device according to the present embodiment. [Figure 2] FIG. 2 is a plan view showing a state in which electrode ink is being applied by the electrode ink application method of the present embodiment. [Figure 3A] FIG. 2 is a side view showing a state before electrode ink is supplied to the electrode ink application auxiliary device of the present embodiment. [Figure 3B]FIG. 2 is a plan view showing a state before electrode ink is supplied to the electrode ink application auxiliary device of the present embodiment. [Figure 4A] FIG. 2 is a side view showing a state in which electrode ink has been supplied to the electrode ink application auxiliary device of the present embodiment. [Figure 4B] 1 is a plan view showing a state in which electrode ink is supplied to the electrode ink application auxiliary device of the present embodiment. FIG. [Figure 5A] FIG. 2 is a side view showing a state in which electrode ink is being applied by the electrode ink application auxiliary device of the present embodiment. [Figure 5B] 1 is a plan view showing a state in which electrode ink is being applied by the electrode ink application auxiliary device of the present embodiment. FIG. [Figure 6A] 10 is a side view showing a state in which the electrode ink application auxiliary device of the present embodiment is separated from the blade and the electrode ink is being collected. FIG. [Figure 6B] 10 is a plan view showing a state in which the electrode ink application auxiliary device of the present embodiment is separated from the blade and the electrode ink is being collected. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. As shown in Figure 1, the electrode ink coating method of this embodiment is performed using an electrode ink coating auxiliary device 1 (hereinafter also referred to as coating auxiliary device 1). The application of the coating auxiliary device 1 is not particularly limited as long as it is used to coat electrode ink 2 using a blade coater 10, but it may be used, for example, in the process of coating electrode ink 2 onto a substrate 3 when producing 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, but examples thereof include a sheet-like thin film, such as a breathable substrate or a release film. The substrate 3 may be a fuel cell gas diffusion substrate, a fuel cell electrolyte membrane, or the like. The substrate 3 is placed on a coating table 11 of a blade coater 10, which will be 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 (electrolytic polymer, electrolyte solution) having proton conductivity, 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. The blade 12 is moved in a fixed direction to coat the substrate 3 placed on the coating table 11 with the electrode ink 2. In this specification, the forward side of 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 rear. The direction intersecting the traveling direction TD in which the blade 12 moves is referred to as the cross direction CD. As shown in FIG. 2 , the cross direction CD is the width direction (short side direction) of the substrate 3 when the substrate 3 is rectangular. The coating table 11 has a flat surface, such as a glass plate. The blade 12 is attached so that its longitudinal direction extends in the cross direction CD and its short side is approximately perpendicular to the surface of the coating table 11. The tip of the blade 12 is positioned close to the surface of the substrate 3, and the blade 12 moves while coating the substrate 3 with the electrode ink 2 supplied to a coating auxiliary device 1 (described later). The dimension of the blade 12 along the cross direction CD is the dimension of the CCM in the cross direction CD.

[0020] 2, the coating auxiliary device 1 is disposed ahead of the blade 12 in the traveling direction TD, and moves together with the blade 12. The coating auxiliary device 1 has an electrode ink receiving section 4 and a restricting section 5.

[0021] The electrode ink receiving portion 4 is disposed ahead of the blade 12 in the direction of travel TD, and extends in a cross direction CD perpendicular to the direction of travel TD. The electrode ink receiving portion 4 has a horizontally elongated shape with the cross direction CD as its longitudinal direction. The electrode ink receiving portion 4 is a portion that receives the electrode ink 2 supplied to it for application to the substrate 3 and receives the electrode ink 2. As shown in FIGS. 1 and 3A, etc., the electrode ink receiving portion 4 is formed in a substantially L-shape when viewed from the side, 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 Figures 4A and 4B, electrode ink 2 is supplied onto the bottom surface 41 of the electrode ink receiving section 4 of the coating auxiliary device 1, and the electrode ink 2 is supplied from the bottom surface 41 into the gap between the blade 12 and the coating auxiliary device 1 (electrode ink supplying step S3). Then, the blade coater 10 starts coating the electrode ink 2 (coating step S4). In coating step S4, when the blade 12 moves, the restricting part 5 of the coating auxiliary device 1 abuts against the blade 12, so that the coating auxiliary device 1 is pushed forward together with the blade and moves forward along with the blade 12. Because the curved part 5b of the restricting part 5 of the coating auxiliary device 1 is curved, there are no sharp corners on the lower front side, so the coating auxiliary device 1 can move smoothly without getting caught.

[0027] As shown in Figures 5A and 5B, as the blade 12 advances, the electrode ink 2 is applied rearward. At this time, as shown by the dashed line in Figure 2, if the restricting portion 5 of the coating auxiliary device 1 were not present, the electrode ink 2 would spill out in the cross direction CD, resulting in a larger and more irregularly coated surface than desired. However, the flat portion 5a of the restricting portion 5 prevents the electrode ink 2 from spreading outward in the cross direction CD, thereby restricting the coating direction of the electrode ink 2. Furthermore, the electrode ink 2 supplied to the electrode ink receiving portion 4 is applied to the substrate 3 through the gap with the blade 12 while the thickness of the coating film is adjusted by the blade 12, while the vertical wall portion 42 prevents the electrode ink 2 from spreading forward in the traveling direction TD.

[0028] 6A and 6B, after the coating step S4, the coating auxiliary device 1 is moved away from the blade 12. Excess electrode ink 2 that was not completely coated accumulates on the bottom surface 41 of the electrode ink receiving part 4, and this is collected (collecting 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, the method for applying electrode ink 2 includes a coating auxiliary device arrangement step (S2) of arranging a coating auxiliary device 1 ahead of the traveling direction TD of a blade 12 that applies the electrode ink 2, and a coating step (S4) of moving the coating auxiliary device 1 together with the blade 12 to apply the electrode ink 2. The coating auxiliary device 1 includes an electrode ink receiving section 4 that extends in a cross direction CD that is perpendicular to the traveling direction TD of the blade 12 and receives the electrode ink 2 that is supplied, and restriction sections 5 that are arranged at both ends of the electrode ink receiving section 4 in the cross direction CD, extend along the traveling direction TD, and have flat sections 5a that restrict 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 traveling direction TD. This prevents the electrode ink 2 from leaking to unintended areas, prevents the excess electrode ink 2 from being wasted, and improves the yield of coated products such as CCM.

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

[0034] The present invention is not limited to the above embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. For example, although the planar portion 5a has a generally rectangular shape in the above embodiment, the shape is not particularly limited as long as the surface is aligned with the traveling direction TD. [Explanation of symbols]

[0035] 1 Coating auxiliary device 2 Electrode ink 3 Base material 4 Electrode ink receiving section 5. Regulatory Department 5a Flat part 5b Curved section 11 Blades

Claims

1. an electrode ink receiving portion that is disposed in front of the blade in a direction of travel of the blade that applies the electrode ink, extends in a direction intersecting the direction of travel at right angles, and receives the electrode ink that is supplied; and a regulating portion disposed at both ends of the electrode ink receiving portion in the intersecting direction, extending along the traveling direction, and having a flat portion that regulates the application direction of the electrode ink.

2. The electrode ink application auxiliary device according to claim 1 , wherein the bottom surface of the electrode ink receiving portion is disposed at a position spaced above the upper surface of the substrate onto which the electrode ink is to be applied.

3. The electrode ink application auxiliary device according to claim 1 or 2, wherein the restricting portion is formed in a plate shape and has a curved portion whose lower front corner in the direction of travel is curved.

4. A method for applying an electrode ink, comprising: a positioning step of positioning a coating auxiliary device ahead of a blade that applies the electrode ink in a direction of travel; a coating step of moving the coating auxiliary device together with the blade to coat the electrode ink, The coating auxiliary device is an electrode ink receiving portion extending in a direction perpendicular to the moving direction of the blade and configured to receive the supplied electrode ink; and a regulating portion disposed at both ends of the electrode ink receiving portion in the intersecting direction, extending along the traveling direction, and having a flat portion that regulates the application direction of the electrode ink.

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

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