JP2009181718A - Manufacturing method of gas diffusion layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a gas diffusion layer advantageous for setting a relatively more carrying volume of a fluid matter at a first exposed surface side of a base material and relatively less at a second exposed surface side. <P>SOLUTION: A porous base material 2 of a sheet shape having pores and conductivity as well as a first exposed surface 21 and a second exposed surface 22 back to back on each other, and a fluid matter having fluidity containing a water-repellent material are prepared. With the base material 2 in a state supported by a support body 12, the fluid matter is coated on the first exposed surface 21 of the base material 2. The coating process is carried out with the second exposed surface 22 of the base material 2 in a state loaded on and supported by a supporting face 11 of the support body 12. After or immediately before finish, or in the middle of the coating process, more than half of the second exposed surface 22 of the base material 2 is to be in a state out of contact with the support face 11 of the support body 12. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a gas diffusion layer used in a fuel cell or the like.

  Conventionally, in Patent Literature 1, in a gas diffusion layer in which a carbon-based substrate is impregnated with a water repellent material, the amount of the water repellent material in the thickness direction of the gas diffusion layer from the side in contact with the catalyst layer toward the opposite side. A manufacturing method in which is continuously changed is disclosed. It is described that it is advantageous to improve drainage in the gas diffusion layer by adopting a structure in which the amount of the water repellent material is inclined in the thickness direction of the gas diffusion layer.

In Patent Document 2, a base material is inserted between a pair of coating rolls while transporting the base material on a transport roll group in which transport rolls are arranged in series, and a paste containing a water repellent material is applied to the surface of the base material. A method for producing a gas diffusion layer applied to the substrate is disclosed.
JP 2003-109604 A JP 2004-71508 A

  However, according to the technique according to Patent Document 2 described above, when it is desired to incline the amount of the water repellent material in the thickness direction of the base material, the paste spreads to the transport roll side due to the surface tension of the transport roll, and the base materials face each other. There is a limit in forming the slope of the amount of water repellent material on the first exposed surface and the second exposed surface.

  The present invention has been made in view of the above circumstances, and in carrying out the coating step of applying a fluid having fluidity including a water repellent material to the first exposed surface of the substrate, the amount of the fluid is based on the amount. It is an object of the present invention to provide a method for producing a gas diffusion layer that is advantageous in that it is relatively large on the first exposed surface side of the material and relatively small on the second exposed surface side of the base material.

(1) A method for producing a gas diffusion layer according to aspect 1 includes a porous base material in the form of a sheet having pores and conductivity and having a first exposed surface and a second exposed surface facing each other; A step of preparing a fluid having fluidity including a material and a support having a support surface capable of supporting the substrate; In the manufacturing method of the gas diffusion layer including the application step of applying to the exit surface, the application step is performed with the second exposed surface of the substrate placed on and supported by the support surface of the support, and after the application step is completed, Immediately before the end of the coating process or in the middle of the coating process, more than half of the second exposed surface of the substrate and the support surface of the support are brought into a non-contact state. The second exposed surface is placed on and supported by the support surface of the support. Accordingly, the position of the first exposed surface of the substrate to be coated is stabilized, and the coating amount and coating thickness are stabilized.

  As described above, the coating step is performed in a state where the second exposed surface of the base material is placed on and supported by the support surface of the support. Thereby, a fluid is apply | coated to the 1st exposed surface of a base material. The fluid applied to the first surface is impregnated in the thickness direction of the substrate over time. Here, if the contact between the second exposed surface of the base material and the support surface of the support member continues for a long time, the fluid is excessively impregnated in the thickness direction of the base material, and the first exposed surface of the base material 2 There is a risk of heading to the surface. When the impregnation further proceeds, a considerable part of the fluid may be held on the second exposed surface of the substrate. In some cases, the fluid may flow out from the second exposed surface. The reason is considered to be the influence of the surface tension between the second exposed surface of the substrate and the support surface of the support. That is, it is inferred that when the fluid flows out from the second surface of the substrate and once contacts the support surface of the support, the fluid is attracted to the support surface due to the influence of the surface tension. In particular, when the support surface of the support is hydrophilic, a significant portion of the fluid may flow to the second exposed surface of the substrate.

  In this aspect, according to this aspect, more than half of the second exposed surface of the base material and the support surface of the support body are not non-contacted after the coating process, immediately before the coating process, or in the middle of the coating process. Keep in contact. As a result, the surface tension described above is reduced or eliminated, and the fluid on the first exposed surface side is suppressed from being excessively impregnated in the thickness direction of the substrate. As a result, it is suppressed that the fluid is excessively held on the second exposed surface side of the base material or flows out. For this reason, in the said half or more area | region, the density | concentration (carrying amount per unit volume) of the water repellent material contained in the fluid can be favorably inclined in the thickness direction of the base material. That is, the amount of the water repellent material can be increased on the first exposed surface side, which is the application side, and can be decreased on the second exposed surface side, which is the non-coated side. Here, “more than half of the second exposed surface of the substrate” means 50% or more of the projected area in terms of area ratio when the second exposed surface is projected from the vertical direction. 70% or more and 90% or more are preferable. It is preferable that most of the part used as a membrane electrode assembly in the substrate is in a non-contact state with the support surface of the support. "Just before the end of the coating process" means that when the time from the start of coating to the end of coating is relatively displayed as 100, the time range from 70 to 100 from the start of coating, the time range from 80 to 100, especially 90 to 100 hours. Regions are illustrated. “After the coating process is completed” is preferably within 1 second, within 2 seconds, within 5 seconds, within 10 seconds, or within 30 seconds from the end of the coating process.

  Examples of the water repellent material contained in the fluid include a fluororesin and a silicone resin. The fluororesin is polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-ethylene copolymer Examples include coalescence, polyvinylidene fluoride, and polyphenylhydrosiloxane. The fluid can include, for example, a microconductive material. Examples of the micro conductive material include carbon-based materials such as carbon black, graphite powder, carbon nanotubes, and carbon fibers, and metal-based materials such as stainless steel. Examples of the form include particles and fibers. Examples of the substrate include conductive fibers or aggregates of conductive particles, such as carbon cloth, carbon paper, and carbon non-woven fabric.

  (2) A method for producing a gas diffusion layer according to aspect 2 includes a porous base material in the form of a sheet having pores and conductivity and having a first exposed surface and a second exposed surface facing each other; A step of preparing a fluid having fluidity including a material and a support having a support surface capable of supporting the substrate; In the method for producing a gas diffusion layer including a coating step for coating on the exit surface, the coating step is performed in a state where the second exposed surface of the substrate is placed on and supported by the support surface of the support, and the support of the support is supported. It is characterized in that it is carried out in a state having water repellency in at least a portion of the surface facing the second exposed surface of the substrate.

  The coating step is performed in a state where the second exposed surface of the substrate is placed on and supported by the support surface of the support. Accordingly, the position of the first exposed surface of the substrate to be coated is stabilized, and the coating amount is stabilized. Thereby, a fluid is apply | coated to the 1st exposed surface of a base material. The applied fluid is impregnated in the thickness direction of the substrate as time passes, and travels from the first exposed surface to the second exposed surface of the substrate. Here, when the support surface of the support has hydrophilicity, the fluid on the first exposed surface side is excessively impregnated in the thickness direction of the substrate, and a substantial part of the fluid is further exposed to the second exposed surface of the substrate. There is a risk of being held on the side. In this aspect, according to this aspect, in the coating process, water repellency exists in at least a portion of the support surface of the support that faces the second exposed surface of the base material. Therefore, excessive impregnation of the fluid applied to the first exposed surface of the substrate toward the second exposed surface in the thickness direction of the substrate is suppressed. As a result, it is suppressed that the fluid is excessively held on the second exposed surface side of the base material. For this reason, the density | concentration (carrying amount per unit volume) of the water repellent material contained in the fluid can be made to incline in the thickness direction of a base material. That is, the water repellency is ensured by the water repellent material. The amount of the water repellent material can be increased on the first exposed surface side, which is the application side, and can be decreased on the second exposed surface side, which is the non-coated side. In addition, examples of the water repellent material present on the support surface of the support include the above-described fluororesins and silicone resins. As for water repellency, the contact angle is larger than 90 degrees, desirably 100 degrees or more, more desirably 110 degrees or more.

  (3) A method for producing a gas diffusion layer according to aspect 3 includes a porous base material in the form of a sheet having pores and conductivity, and having a first exposed surface and a second exposed surface facing each other, and a water repellent A step of preparing a fluid having fluidity including a material and a support having a support surface capable of supporting the substrate; In the manufacturing method of the gas diffusion layer including the coating step of coating on the exit surface, the support has a number of holes, and the coating step supports the second exposed surface of the substrate with the support, The second exposed surface and the support surface of the support are brought into a non-contact state.

  The coating step is performed in a state where the second exposed surface of the substrate is placed on and supported by the support surface of the support. Accordingly, the position of the first exposed surface of the substrate to be coated is stabilized, and the coating amount is stabilized. The fluid is applied to the first exposed surface of the substrate. The applied fluid is impregnated in the thickness direction of the substrate as time passes. Here, after completion of the coating process, if the contact between the second exposed surface of the base material and the support surface of the support body continues for a long time, the fluid is excessively impregnated in the thickness direction of the base material. From the first exposed surface to the second exposed surface. When the impregnation further proceeds, a considerable portion of the fluid on the first exposed surface side may be held on the second exposed surface side of the substrate. This is considered to be an effect of generating surface tension between the second exposed surface of the substrate and the support surface of the support. This tendency is particularly strong when the support surface of the support has hydrophilicity.

  In this regard, according to this aspect, the support has a large number of holes, and the coating step causes the second exposed surface of the base material and the support surface of the support to be in a non-contact state in the holes. As a result, the fluid is suppressed from being excessively impregnated in the thickness direction of the base material in the holes of the support. As a result, it is suppressed that the fluid on the first exposed surface side is excessively held on the second exposed surface side of the base material. For this reason, the density | concentration (carrying amount per unit volume) of the water repellent material contained in the fluid can be made to incline in the thickness direction of a base material. That is, the amount of the water repellent material can be increased on the first exposed surface side, which is the application side, and can be decreased on the second exposed surface side, which is the non-coated side. About a hole, the area of the hole which occupies for the whole area by the side of the support surface which faces a 2nd exposed surface can be 60% or more, 70% or more, 80% or more, 90% or more by area ratio.

  According to the present invention, when applying a fluid, the possibility that the fluid containing the water repellent material flows out excessively from the second exposed surface of the porous substrate is suppressed. For this reason, the concentration of the water repellent material contained in the fluid (supported amount per unit volume) can be favorably inclined in the thickness direction of the substrate. As a result, the amount of the water repellent material can be increased on the first exposed surface side that is the application side of the base material, and can be decreased on the second exposed surface side that is the opposite side to the application side.

  Embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 schematically shows the first embodiment. FIG. 1A schematically shows a perspective view of a coating apparatus 1 having a support 12 before the substrate 2 is placed thereon. FIG. 1B schematically shows a state immediately before the fluid is applied to the substrate 2 placed on the support 12. FIG. 1C schematically shows a state immediately after the fluid is applied to the substrate 2 placed on the support 12.

  First, a base material 2 having a porous sheet shape is prepared. The base material 2 has pores and conductivity, and has a first exposed surface 21 and a second exposed surface 22 facing away from each other. The base material 2 is formed of an aggregate of carbon fibers, and examples thereof include carbon cloth, carbon paper, and carbon non-woven fabric. Further, a paste-like or ink-like fluid is prepared. The fluid has a fluidity in which a water repellent material and a fine conductive material are blended in a dispersion medium (water or alcohol), and has a property of impregnating the inside of the substrate 2.

  Further, a coating apparatus 1 having a support 12 is prepared. The coating apparatus 1 includes a fixed unit 10, a horizontal support 12 having a flat support surface 11 provided on the fixed unit 10, and an applicator movable along the support surface 11 of the support 12. 13 and a movable body 14 in the form of a pin that is held by the fixed portion 10 and moves (lifts) the support body 12 along the height direction.

  The applicator 13 includes an applicator member 16 that functions as a blade that moves and applies the fluid, and a holder 17 that is held at both ends of the applicator member 16 and moves along the guide surface 10 u of the fixed portion 10. The movable body 14 is disposed so as to be movable up and down on the terminal end 12 e side in the application direction (arrow X direction) of the support body 12. Therefore, the movable body 14 can protrude upward from the entrance / exit hole 18 formed in the support body 12 in a penetrating manner, or can be retracted below the opening of the entrance / exit hole 18. Therefore, the movable body 14 can lift the substrate 2 on the support surface 11 upward (in the direction of arrow Z1). The movable body 14 may be moved up and down by a driving mechanism, or may be moved up and down manually.

  In the coating step, first, the second exposed surface 22 (lower surface) of the substrate 2 is placed on and supported by the support surface 11 of the support 12. In this state, the first exposed surface 21 (upper surface) of the substrate 2 is exposed upward. Since the movable body 14 does not protrude upward from the opening of the access hole 18, interference between the base material 2 and the movable body 14 is suppressed, and the movable body 14 does not interfere with the base material 2. The lifting surface 14u that is the upper surface of the movable body 14 may be in contact with the second exposed surface 22 (lower surface) of the substrate 2 or may be non-contact. In the former case, since the lifting surface 14 u supports the second exposed surface 22 of the base material 2, there is an advantage that the height change of the first exposed surface 21 is suppressed in the access hole 18. In the latter case, there is an advantage that the interference between the lifting surface 14u and the substrate 2 is reliably suppressed.

  In this state, as shown schematically in FIG. 1B, the paste 3 or ink-like fluid mass 3 is placed on the first exposed surface 21 of the base 2 on the start end 2 s side. The start end means the application start end. The amount of the mass 3 is set in advance according to the amount of the water repellent material and the minute conductive material applied to the first exposed surface 21 of the base material 2. And the application body 13 is moved to the support surface 11 along an application direction (arrow X direction). As a result, the fluid is applied in the form of a film to the first exposed surface 21 of the substrate 2 on the support surface 11. The film is preferably uniform. In addition, the movement of the application body 13 may be performed automatically or manually. The moving speed of the application body 13 is preferably constant, but is not limited to this.

  The application process described above is performed in a state where the second exposed surface 22 of the substrate 2 is placed on and supported by the support surface 11 of the support 12. That is, it is performed in a state where the second exposed surface 22 of the substrate 2 and the support surface 11 of the support 12 are in contact with each other. For this reason, the height fluctuation of the 1st exposed surface 21 and the 2nd exposed surface 22 of the base material 2 is suppressed. Therefore, the fluid can be uniformly applied to the first exposed surface 21 of the substrate 2.

  After the end of the above-described application process, that is, after the application body 13 that has moved along the application direction (the direction of the arrow X) reaches the end e of the support surface 11 of the support 12 beyond the end 2e of the base material 2. As shown schematically in FIG. 1C, the movable body 14 is moved upward (in the direction of arrow Z1). Thereby, the terminal 2e side of the base material 2 on the support 12 is lifted on the upper surface of the movable body 14. Although the movable body 14 is disposed on the end 12 e side of the support 12, it is not disposed on the start end 12 s side of the support 12. For this reason, the starting end 2 s side of the substrate 2 is in contact with the support surface 11 of the support 12.

  Thereby, as schematically shown in FIG. 1C, the base material 2 is inclined upward at an angle θ <b> 1 so that the end 2 e of the base material 2 is positioned above the start end 2 s of the base material 2. As a result, after the coating step is finished, the second exposed surface 22 of the base material 2 on the support 12 and the support surface 11 of the support 12 are separated from each other, thereby improving the non-contact property.

  Here, the fluid material having fluidity applied to the first exposed surface 21 of the base material 2 depends on the viscosity of the fluid material, but in the thickness direction of the base material 2 due to capillary action or gravity over time. Impregnate gradually downward. Here, when the contact between the second exposed surface 22 of the base material 2 and the support surface 11 of the support body 12 continues for a long time after the coating process is finished, the fluid is excessive in the thickness direction of the base material 2. It impregnates and goes from the 1st exposed surface 21 (upper surface) of the base material 2 to the 2nd exposed surface 22 (lower surface). When the impregnation further proceeds, a considerable part of the fluid may flow to the second exposed surface 22 side of the substrate 2. Furthermore, the fluid may spread on the second exposed surface 22. The reason is that the surface tension between the second exposed surface 22 of the substrate 2 and the support surface 11 of the support 12 when the fluid once flows out from the second exposed surface 22 of the substrate 2 to the support surface 11. It is thought that the influence of will increase. This tendency occurs particularly when the support surface 11 of the support 12 is hydrophilic. This is the “back-through phenomenon” of fluids.

  In this regard, according to the present embodiment, as described above, the second exposed surface 22 of the substrate 2 and the support surface 11 of the support 12 are brought into contact with each other during the coating process. However, after the coating process is finished, the base material 2 is lifted in the direction of the arrow Z1, and the second exposed surface 22 of the base material 2 and the support surface 11 of the support 12 are separated to increase the non-contact property between them. As a result, the surface tension between the second exposed surface 22 of the substrate 2 and the support surface 11 of the support 12 that can attract the fluid toward the second exposed surface 22 is reduced or eliminated. Therefore, excessive impregnation of the paste-like fluid toward the second exposed surface 22 in the thickness direction of the substrate 2 is suppressed. As a result, it is suppressed that the fluid is excessively held on the second exposed surface 22 of the substrate 2. For this reason, the concentration of the water repellent material and the minute conductive material (the amount carried per unit volume) contained in the fluid can be favorably inclined in the thickness direction of the substrate 2. That is, the amount of the water repellent material and the minute conductive material can be set larger on the first exposed surface 21 side, which is the application side, of the substrate 2 and can be set smaller on the second exposed surface 22 side. As described above, the water repellent material and the minute conductive material can be set to have a gradient composition and a gradient concentration in the thickness direction of the substrate 2.

  The movable body 14 is moved upward (in the direction of the arrow Z1) not only after the application process is completed but immediately before the application process is completed, that is, immediately before the application body 13 arrives at the end 12e of the support surface 11 of the support body 12. Then, the end 2e side of the base material 2 may be lifted. Here, “immediately before the end of the coating process” can be set to a time region of 80 to 100, in particular, a time region of 90 to 100 from the start, when the coating time is schematically shown as 100. . However, it is not limited to this.

  According to the present embodiment, depending on the inclination angle θ1 of the base material 2 (see FIG. 1C), the terminal end 2e of the base material 2 and the support surface are brought into contact with the start end 2s of the base material 2 and the support surface 11. 11 can be secured. Therefore, it can be expected that the gap width of the gap between the second exposed surface 22 of the substrate 2 and the support surface 11 is gradually increased from the start end 2s to the end end 2e in the application direction (arrow X direction). For this reason, the impregnation depth (back-through amount) of the fluid applied to the first exposed surface 21 can also be gradually changed from the start end 2s to the end end 2e in the application direction (arrow X direction). In this case, it can be expected that the water repellency is gradually changed from the start end 2s to the end end 2e in the coating direction (arrow X direction) in the base material 2 serving as the gas diffusion layer. In this way, when the water repellency is gradually changed from the start end 2s to the end end 2e, an in-plane water repellency gradient can be realized corresponding to the gas flow direction. As for water repellency, the contact angle is larger than 90 degrees, desirably 100 degrees or more, more desirably 110 degrees or more.

(Embodiment 2)
FIG. 2 schematically shows the second embodiment. This embodiment has basically the same configuration and the same operation and effect as the first embodiment. In the following, different parts will be mainly described. The movable body 14 is disposed on the start end 12 s side in the application direction (arrow X direction) of the support 12, and protrudes upward from the entrance / exit hole 18 formed in the support 12 in a penetrating manner. It can be retracted below the opening. FIG. 2A schematically shows a perspective view of the support 12 before the substrate 2 is placed. FIG. 2B schematically shows a state immediately before the fluid is applied to the substrate 2 placed on the support 12. FIG. 2C schematically shows a state immediately after the fluid is applied to the substrate 2 placed on the support 12.

  First, as in the first embodiment, the first exposed surface 21 (upper surface) of the substrate 2 is exposed upward, and the second exposed surface 22 (lower surface) of the substrate 2 is placed on the support surface 11 of the support 12. To support. Here, since the movable body 14 is retracted below the opening of the entrance / exit hole 18, it does not interfere with the base material 2. In this state, the paste 3 or ink-like fluid mass 3 is placed on the start end 2 s side of the first exposed surface 21 of the substrate 2. Then, the application body 13 is moved from the start end 2s of the base material 2 to the support surface 11 along the application direction (arrow X direction) toward the terminal end 2e of the base material 2. As a result, the fluid is applied in the form of a film to the first exposed surface 21 of the substrate 2 on the support surface 11. The film is preferably uniform. Since the application step described above is performed in a state where the second exposed surface 22 of the substrate 2 is placed on and supported by the support surface 11 of the support 12, the position of the first exposed surface 21 of the substrate 2 is stabilized, and the flow It is advantageous for uniform application amount of animals.

  After the end of the coating process, that is, after the coating body 13 reaches the end 12e of the support surface 11 of the support 12 beyond the end 2e of the substrate 2, the movable body 14 is moved upward (in the direction of arrow Z1). ). Thereby, the starting end 2s side of the base material 2 on the support 12 is lifted on the upper surface of the movable body 14. Although the movable body 14 is disposed on the start end 12 s side of the support body 12, it is not disposed on the end 12 e side of the support body 12. Thereby, as schematically shown in FIG. 2C, the starting end 2s of the base material 2 is inclined upward so that the starting end 2s of the base material 2 is positioned above the terminal end 2e of the base material 2. As a result, the second exposed surface 22 of the base material 2 on the support 12 and the support surface 11 of the support 12 are separated from each other, thereby improving non-contact properties. Therefore, even when there is a surface tension that attracts the fluid between the second exposed surface 22 of the substrate 2 and the support surface 11 of the support 12, the surface tension is reduced or eliminated. For this reason, excessive impregnation of the fluid toward the second exposed surface 22 in the thickness direction of the substrate 2 is suppressed. For this reason, the concentration of the water repellent material and the minute conductive material (supported amount per unit volume) contained in the fluid can be inclined in the thickness direction of the substrate 2. That is, the amount of the water repellent material and the minute conductive material can be set larger on the first exposed surface 21 side, which is the application side, of the substrate 2 and can be set smaller on the second exposed surface 22 side. In this way, the water repellent material and the minute conductive material can be set to have a gradient composition and a gradient concentration in the thickness direction of the substrate 2. Note that the movable body 14 is moved upward (in the direction of the arrow Z1) not only after the application process is completed, but immediately before the application process is completed, that is, immediately before the application body 13 arrives at the end 12e of the support surface 11 of the support body 12. The starting end 2s side of the base material 2 may be lifted.

  Also in this embodiment, depending on the inclination angle θ2 of the base material 2 (see FIG. 2C), the clearance between the starting end 2s of the base material 2 and the support surface 11 is secured, while the end 2e of the base material 2 is The support surface 11 can be brought into contact. Therefore, it can be expected that the gap width of the gap between the second exposed surface 22 of the substrate 2 and the support surface 11 is gradually changed from the start end 2s to the end end 2e in the application direction (arrow X direction). For this reason, the impregnation depth of the fluid applied to the first exposed surface 21 can also be gradually changed from the start end 2s to the end end 2e in the application direction (arrow X direction). In this case, it can be expected that the water repellency is gradually changed from the start end 2s to the end end 2e in the coating direction (arrow X direction) in the base material 2 serving as the gas diffusion layer.

(Embodiment 3)
FIG. 3 schematically shows the third embodiment. This embodiment has basically the same configuration and the same operation and effect as the first embodiment. In the following, different parts will be mainly described. In the following, different parts will be mainly described. FIG. 3A schematically shows a perspective view of the support 12 before the substrate 2 is placed. FIG. 3B schematically shows a state immediately before the fluid is applied to the substrate 2 placed on the support 12. FIG. 3C schematically shows a state immediately after the fluid is applied to the substrate 2 placed on the support 12. The movable body 14 (14a, 14b) is disposed on one end side of the support 12 in the direction (arrow Y direction) orthogonal to the application direction (arrow X direction). The first movable body 14 a is disposed on the start end 12 s side in the application direction of the support 12. The 2nd movable body 14b is arrange | positioned in the terminal end 12e side of the application direction (arrow X direction) of the support body 12. As shown in FIG.

  In the coating step, the first exposed surface 21 (upper surface) of the substrate 2 is exposed upward and the second exposed surface 22 (lower surface) of the substrate 2 is supported by the support 12 in the same manner as in the above-described embodiment. It is placed on the surface 11 and supported. Here, since the movable body 14 is retracted below the opening of the entrance / exit hole 18, it does not interfere with the base material 2. In this state, the mass 3 of the fluid is placed on the start surface 2 s side of the first exposed surface 21 of the substrate 2. And the application body 13 is moved to the support surface 11 along an application direction (arrow X direction). As a result, the fluid is applied in the form of a film to the first exposed surface 21 of the substrate 2 on the support surface 11. The film body is preferably uniform. The application step described above is performed in a state where the second exposed surface 22 of the substrate 2 is placed on and supported by the support surface 11 of the support 12, and after the application step is completed, that is, the application body 13 is the substrate 2. After reaching the end 12e of the support surface 11 of the support 12 beyond the end 2e (immediately after), the movable body 14 is moved upward (in the direction of arrow Z1). Thereby, the starting end 2s side of the base material 2 on the support body 12 is lifted by the upper surface of the first movable body 14a. The end 2e of the substrate 2 on the support 12 is lifted by the upper surface of the second movable body 14b. Thereby, the base material 2 is lifted on one end 2a side in the direction (arrow Y direction) orthogonal to the application direction (arrow X direction), and the other end 2c in the direction (arrow Y direction) orthogonal to the application direction (arrow X direction). Does not lift on the side. As a result, the entire base material 2 is inclined so that the one end 2a in the arrow Y direction of the base material 2 is positioned above the other end 2c in the arrow Y direction. As a result, the second exposed surface 22 of the base material 2 on the support 12 and the support surface 11 of the support 12 are separated from each other, and the non-contact property between them is enhanced. Therefore, as in the above-described embodiment, the fluid is suppressed from being excessively impregnated toward the second exposed surface 22 in the thickness direction of the substrate 2. For this reason, the concentration of the water repellent material and the minute conductive material (the amount carried per unit volume) contained in the fluid can be inclined in the thickness direction of the substrate 2. That is, the amount of the water repellent material and the minute conductive material is set to be large on the first exposed surface 21 side, which is the application side, of the substrate 2 and is set to be small on the second exposed surface 22 side. In this way, the water repellent material and the minute conductive material can be set to have a gradient composition and a gradient concentration in the thickness direction of the substrate 2. The movable body 14 is moved upward (in the direction of the arrow Z) not only after the application process is finished, but immediately before the application process is finished, that is, immediately before the application body 13 arrives at the end 12e of the support surface 11 of the support body 12. The one end 2a side of the base material 2 may be lifted up.

(Embodiment 4)
FIG. 4 schematically shows the fourth embodiment. This embodiment has basically the same configuration and the same operation and effect as the first embodiment. In the following, different parts will be mainly described. FIG. 4A schematically shows a perspective view of the support 12 before the substrate 2 is placed. FIG. 4B schematically shows a state immediately before the fluid is applied to the base material 2 placed on the support 12. FIG. 4C schematically shows a state immediately after the fluid is applied to the substrate 2 placed on the support 12. The application step described above is performed in a state where the second exposed surface 22 of the substrate 2 is placed on and supported by the support surface 11 of the support 12, and after the application step is completed, that is, the application body 13 is the substrate 2. After reaching the end 12e of the support surface 11 of the support 12 beyond the end 2e, the movable body 14 is moved upward (in the direction of arrow Z1). Thereby, the base material 2 is lifted on the other end 2c side in the direction (arrow Y direction) orthogonal to the application direction (arrow X direction), and one end 2a in the direction (arrow Y direction) orthogonal to the application direction (arrow X direction). Does not lift on the side. As a result, the whole base material 2 inclines so that the other end 2c of the base material 2 in the arrow Y direction is positioned above the one end 2a in the arrow Y direction. As a result, the second exposed surface 22 of the base material 2 on the support 12 and the support surface 11 of the support 12 are separated from each other, thereby improving non-contact properties. Therefore, excessive impregnation of the fluid in the thickness direction of the base material 2 toward the second exposed surface 22 is suppressed. For this reason, the concentration of the water repellent material and the minute conductive material (the amount carried per unit volume) contained in the fluid can be inclined in the thickness direction of the substrate 2.

(Embodiment 5)
FIG. 5 schematically shows the fifth embodiment. This embodiment has basically the same configuration and the same operation and effect as the first embodiment. In the following, different parts will be mainly described. FIG. 5A schematically shows a perspective view of the support 12 before the substrate 2 is placed. FIG. 5B schematically shows a state immediately before the fluid is applied to the substrate 2 placed on the support 12. FIG. 5C schematically shows a state immediately after the fluid is applied to the substrate 2 placed on the support 12. As schematically shown in FIG. 5A, a plurality of (four) movable bodies 14 are arranged in the four corner regions of the support 12. The 1st movable body 14a and the 2nd movable body 14b are arrange | positioned in the start end s side of the application direction (arrow X direction) of the support body 12. As shown in FIG. The third movable body 14c and the second movable body 14d are arranged on the terminal end 12e side in the coating direction of the support body 12.

  In the coating step, the first exposed surface 21 (upper surface) of the substrate 2 is exposed upward and the second exposed surface 22 (lower surface) of the substrate 2 is supported by the support 12 in the same manner as in the above-described embodiment. It is placed on the surface 11 and supported. Here, the movable body 14 (14 a to 14 d) is retracted below the opening of the entrance / exit hole 18, and therefore does not interfere with the base material 2. In this state, the mass 3 of the fluid is placed on the start surface 2 s side of the first exposed surface 21 of the substrate 2. And the application body 13 is moved to the support surface 11 along an application direction (arrow X direction). As a result, the fluid is applied in the form of a film to the first exposed surface 21 of the substrate 2 on the support surface 11. The application step described above is performed in a state where the second exposed surface 22 of the substrate 2 is placed on and supported by the support surface 11 of the support 12, and after the application step is completed, that is, the application body 13 is the substrate 2. After reaching the end 12e of the support surface 11 of the support 12 beyond the end 2e, the first movable body 14a, the second movable body 14b, the third movable body 14c, and the fourth movable body 14d are moved upward (in the direction of the arrow Z1). ) Respectively. In this case, they may be moved simultaneously or sequentially. As a result, the movable body 14 lifts the start end 2s and end 2e sides of the substrate 2 on the support 12. As a result, the entire base material 2 is lifted almost horizontally. As a result, the second exposed surface 22 of the base material 2 on the support 12 and the support surface 11 of the support 12 are separated from each other, thereby improving non-contact properties. Therefore, excessive impregnation of the fluid in the thickness direction of the base material 2 toward the second exposed surface 22 is suppressed. For this reason, the concentration of the water repellent material and the minute conductive material (the amount carried per unit volume) contained in the fluid can be inclined in the thickness direction of the substrate 2. That is, the amount of the water repellent material and the minute conductive material is set to be large on the first exposed surface 21 side, which is the application side, of the substrate 2 and is set to be small on the second exposed surface 22 side. In this way, the water repellent material and the minute conductive material can be set to have a gradient composition and a gradient concentration in the thickness direction of the substrate 2. Note that the movable body 14 is moved upward (in the direction of the arrow Z1) not only after the application process is completed, but immediately before the application process is completed, that is, immediately before the application body 13 arrives at the end 12e of the support surface 11 of the support body 12. The end 2e side of the base material 2 may be lifted by moving to.

(Embodiment 6)
6 to 9 schematically show the sixth embodiment. The coating apparatus 1 includes a frame-shaped edge support 120, a center support 122 having a flat horizontal support surface 122 f that can be moved up and down with respect to the edge support 120, and a secondary support held by the edge support 120. A support body 125 and a fluid pressure device 130 that functions as a power element provided on the sub-support body 125 and capable of lifting and lowering the central support body 122 are included. The fluid pressure device 130 is connected to the fluid supply device 100 via a flexible communication tube 102. When the operation unit 101 of the fluid supply device 100 is operated, a fluid (for example, a gas such as air or a liquid such as hydraulic oil) is supplied from the fluid supply device 100 to the fluid pressure device 130, and the fluid pressure device 130 expands. Thereby, the center support body 122 is lifted in the arrow Z1 direction, and the engaging portion 122m of the center support body 122 is engaged with the engaged portion 120m of the edge support body 120. In this state, the support surface 120f of the edge support body 120 and the support surface 122f of the center support body 122 are at the same height and are in a planar state. The gaps between the central support 122 and the edge support 120 are shown as M1, M2.

  The coating process is performed in this state. In the coating process, as schematically illustrated in FIG. 6, the central region 2 y of the second exposed surface 22 (lower surface) of the base material 2 is placed on the support surface 122 f of the central support 122 as in the above-described embodiment. To support. The end region 2x of the second exposed surface 22 (lower surface) of the substrate 2 is placed on the support surface 120f of the edge support 120. At this time, the first exposed surface 21 (upper surface) of the substrate 2 is exposed upward.

  Then, the mass 3 of the fluid is placed on the start end 2 s side of the first exposed surface 21 of the substrate 2. In this state, the application body is moved along the application direction. As a result, the fluid is applied in the form of a film to the first exposed surface 21 of the substrate 2 on the support surface 11. When the operation unit 101 of the fluid supply and application apparatus 100 is operated in the reverse direction after the application process is finished, the fluid is removed from the fluid pressure device 130 and the fluid pressure device 130 contracts. As a result, as shown in FIG. 7, the center support 122 is lowered by a dimension ΔH2 in the direction of the arrow Z2, and the engagement between the engagement portion 122m of the center support 122 and the engaged portion 120m of the edge support 120 is released. . As a result, more than half of the second exposed surface 22 (lower surface) of the substrate 2 and the support surface 122f of the central support 122 are separated from each other, thereby improving non-contact properties. Therefore, as in the above-described embodiment, the applied fluid is suppressed from being excessively impregnated in the thickness direction of the base material 2 toward the second exposed surface 22. For this reason, the concentration of the water repellent material and the minute conductive material (the amount carried per unit volume) contained in the fluid can be inclined in the thickness direction of the substrate 2. That is, the amount of the water repellent material and the minute conductive material is set to be large on the first exposed surface 21 side, which is the application side, of the substrate 2 and is set to be small on the second exposed surface 22 side. In this way, the water repellent material and the minute conductive material can be set to have a gradient composition and a gradient concentration in the thickness direction of the substrate 2. Note that the center support 122 may be lowered by the dimension ΔH2 in the direction of the arrow Z2 immediately before the end of the application process or in the middle of the application.

(Embodiment 7)
FIG. 9 schematically shows the seventh embodiment. This embodiment has basically the same configuration and the same operation and effect as the first embodiment. In the following, different parts will be mainly described. FIG. 9A schematically shows a perspective view of the support 12 before the substrate 2 is placed. FIG. 9B schematically shows a state immediately before the fluid is applied to the substrate 2 placed on the support 12. FIG. 9C schematically shows a state immediately after the fluid is applied to the substrate 2 placed on the support 12. As schematically shown in FIG. 9A, the coating process is performed in a state where the second exposed surface 22 of the substrate 2 is placed on and supported by the support surface 11 of the support 12. The support surface 11 of the support 12 is covered with a water repellent film 11r. The water repellent material film 11r is formed of a fluororesin film (for example, PTFE, FEP, PFA) and has a thickness of, for example, 1 to 500 micrometers. However, the thickness is not limited to this.

  The coating process is performed in a state where the second exposed surface 22 of the base material 2 is placed on and supported by the water repellent film 11r on the support surface 11 of the support 12. As a result, the fluid is applied to the first exposed surface 21 of the substrate 2. The applied fluid is impregnated in the thickness direction of the substrate 2 over time, and travels from the first exposed surface 21 of the substrate 2 to the second exposed surface 22. Here, when the support surface 11 of the support 12 has hydrophilicity, the fluid is excessively impregnated in the thickness direction of the substrate 2, and a substantial part of the fluid is further removed from the second exposed surface 22 of the substrate 2. There is a risk of spilling outward. In this regard, according to the present embodiment, the coating step is performed in a state where the second exposed surface 22 of the base material 2 is placed on and supported by the water repellent film 11r on the support surface 11 of the support body 12. For this reason, excessive impregnation of the fluid applied to the first exposed surface 21 of the substrate 2 toward the second exposed surface 22 in the thickness direction of the substrate 2 is suppressed. For this reason, it is possible to incline the concentration of the water repellent material and / or the fine conductive material (supported amount per unit volume) contained in the fluid in the thickness direction of the substrate 2. That is, the amount of the water repellent material and / or the minute conductive material can be increased on the first exposed surface 21 side, which is the application side, and decreased on the second exposed surface 22 side. In the present embodiment, the movable body 14 that lifts the substrate 2 is not provided.

(Embodiment 8)
FIG. 10 schematically shows the eighth embodiment. This embodiment has basically the same configuration and the same operation and effect as the first embodiment. In the following, different parts will be mainly described. FIG. 10A schematically shows a perspective view of the support 12 before the substrate 2 is placed. FIG. 10B schematically shows a state immediately before the fluid is applied to the substrate 2 placed on the support 12. FIG. 10C schematically shows a state immediately after the fluid is applied to the substrate 2 placed on the support 12. As schematically shown in FIG. 10A, the support 12 has a flat plate shape and has a large number of holes 12w. The coating process is performed in a state where the second exposed surface 22 of the substrate 2 is placed on and supported by the support surface 11 of the support 12. As a result, the fluid is applied to the first exposed surface 21 of the substrate 2. The applied fluid is impregnated in the thickness direction of the substrate 2 over time. Here, when the contact between the second exposed surface 22 of the base material 2 and the support surface 11 of the support body 12 continues for a long time after the coating process is finished, the fluid is excessive in the thickness direction of the base material 2. It impregnates and goes from the first exposed surface 21 of the substrate 2 to the second exposed surface 22. In particular, when the support surface 11 of the support 12 has hydrophilicity, a considerable part of the fluid may be directed to the second exposed surface 22 side of the substrate 2.

  In this regard, according to the present embodiment, the support 12 has a large number of holes 12w (may be through holes or bottomed holes). The coating process is performed in a state where the second exposed surface 22 of the substrate 2 is supported by the support 12. As a result, in the hole 12w of the support body 12, the 2nd exposed surface 22 of the base material 2 and the support surface 11 of the support body 12 are always non-contact. For this reason, in the area | region which faces the hole 12w among base materials, it is suppressed that a fluid impregnates the thickness direction of the base material 2 excessively. For this reason, it is possible to incline the amount of the water repellent material and the minute conductive material (supported amount per unit volume) contained in the fluid in the thickness direction of the substrate 2. That is, the amount of the water repellent material and / or the minute conductive material can be increased on the first exposed surface 21 side, which is the application side, and decreased on the second exposed surface 22 side. In addition, you may form as a support body by the net-like member which has many holes.

(Embodiment 9)
FIG. 11 schematically shows the ninth embodiment. This embodiment has basically the same configuration and the same operation and effect as the first embodiment. The coating apparatus 1 includes a frame-shaped edge support 120, a central support 122 having a flat horizontal support surface 122 f that can be moved up and down with respect to the edge support 120, and a lifting mechanism that lifts and lowers the central support 122. 129. The elevating mechanism 129 includes an elevating body 129m and a drive unit 129n that elevates and lowers the elevating body 129m. In the coating process, first, the elevating mechanism 129 is moved up so that the support surface 122f of the central support 122 and the support surface 120f of the edge support 120 are at the same height position. In this state, the edge region 2x of the substrate 2 is placed on the support surface 120f, and the central region 2y of the substrate 2 is placed on the support surface 122f. Then, after the application is completed, immediately before the application is completed, and at least one of the application is in progress, the elevating mechanism 129 is lowered to lower the support surface 122f of the central support 122 by a dimension ΔH2 lower than the support surface 120f of the edge support 120. Let As a result, the center region 2y of the second exposed surface 22 (lower surface) of the substrate 2 and the support surface 122f of the center support 122 are separated from each other, thereby improving non-contact properties. Therefore, in the central region 2y of the base material 2, it is suppressed that the fluid is excessively impregnated in the thickness direction of the base material 2, and as a result, excessive support on the second exposed surface 22 is suppressed.

(Test example)
The water repellent paste (fluid) having the same composition was applied to the first exposed surface 21 of the substrate 2 using the coating apparatus 1 according to the first to seventh embodiments. In this case, the water repellent paste has a PTFE dispersion (Daikin Kogyo Co., Ltd., PTFE content: 60 mass%) as the water repellent material, carbon black (manufactured by Electrochemical Co., Ltd.) as the micro conductive material, and water as the dispersion medium. It was formed by dispersing in In this case, as a solid content ratio, a carbon black / PTFE mass ratio was set to 60/40, and a water repellent paste (fluid) set to a specified viscosity (1650 cps) using a surfactant was formed. As the base material 2, carbon paper (manufactured by Toray Industries, Inc., TGP-060) was used.

The second exposed surface 22 of the substrate 2 was supported on the support surface 11 of a plate-like support 12 made of metal (material: SUS316). In this state, the water repellent paste was uniformly applied to the first exposed surface 21 of the substrate 2 with a blade (applied body) having a gap set to 300 micrometers. The coating amount was about 4.65 mg / cm ² . Thereafter, the coated base material 2 was inserted into a drying furnace and dried at a predetermined temperature (70 ° C.) for a predetermined time (1 hour) in an air atmosphere. The dried base material 2 was inserted into a firing furnace and fired at a predetermined temperature (350 ° C.) for a predetermined time (1 hour) in an air atmosphere. Thus, the gas diffusion layer for fuel cells according to Embodiments 1 to 5 was formed. The water contact angle and the water fall angle were measured as the water repellency parameters of the gas diffusion layer thus prepared. The contact angle means the angle between the tangent line of the outline of the water droplet placed on the gas diffusion layer and the gas diffusion layer. In addition, a water droplet is placed on the gas diffusion layer held on the horizontal holding surface, the holding surface is inclined in this state, and the inclination angle with respect to the horizontal line of the holding surface when the water droplet starts to slide is schematically shown as a falling angle. The strike-through rate was calculated by using image processing software (Image Pro, Plus 5.0J, manufactured by Microsoft) to calculate the ratio of the strike-through portion per unit area. The measurement results are schematically shown in Tables 1 and 2. It measured similarly about the comparative example. The comparative example used the coating apparatus 1 similar to the coating apparatus 1 schematically shown in FIG. However, the water repellent film is not formed on the support surface of the support according to the comparative example.

  Here, a large contact angle indicates strong water repellency. A small falling angle indicates strong water repellency. As schematically shown in Tables 1 and 2, according to the comparative example, the strike-through rate is 100%, and the contact angle of the second exposed surface 22 is larger than the contact angle of the first exposed surface 21. Yes. This is because the fluid containing the water repellent material penetrates from the first exposed surface 21 that is the coated surface of the base material 2 to the second exposed surface 22 that is the non-coated surface, and as a result, from the first exposed surface 21. 2 also shows that the second exposed surface 22 is stronger in water repellency.

  On the other hand, according to the first to seventh embodiments, the strike-through rate is 0%, and the contact angle of the first exposed surface 21 that is the coated surface is larger than that of the second exposed surface 22 that is the non-coated surface. The contact angle is small. This is presumably because the water repellent paste containing the water repellent material is prevented from penetrating from the first exposed surface 21 which is the coated surface to the second exposed surface 22 which is the non-coated surface. As a result, the first exposed surface 21 that is the coated surface shows higher water repellency than the second exposed surface 22 that is the non-coated surface. That is, it shows that a structure in which the water repellent material has a gradient composition in the thickness direction of the substrate 2 is obtained.

  The coating amount, the drying temperature, the drying time, the firing temperature, and the firing time are not limited to the above numerical values, and can be changed as appropriate.

(Application 1)
FIG. 12 schematically shows Application Mode 1. As schematically shown in FIG. 12, the fuel cell includes a membrane electrode assembly 50, a conductive fuel distribution plate 51 having a groove 51a for distributing fuel (for example, hydrogen-containing gas), and an oxidant (for example, oxygen). And a conductive oxidant flow plate 52 having grooves 52a for distributing the contained gas). The membrane electrode assembly 50 includes a fuel gas diffusion layer 54, a fuel catalyst layer 55, a conductive film 56 having ionic conductivity (proton conductivity), an oxidant catalyst layer 57, and an oxidant gas diffusion layer 58. It is formed by stacking. The conductive film 56 is formed of a fluorine type (for example, perfluorocarbon sulfonic acid) or a hydrocarbon type. The fuel catalyst layer 55 includes a catalyst and an ion conductive material, and contributes to a power generation reaction. The oxidizing agent catalyst layer 57 has a catalyst and an ion conductive material, and contributes to a power generation reaction.

  The first exposed surface 21 of the oxidant gas diffusion layer 58 faces the oxidant catalyst layer 57 that mainly performs a power generation reaction. Water is generated in the power generation reaction. When the generated water accumulates, it is preferable to have a high drainage because the gas flow path is narrowed to reduce the power generation performance.

  According to this application mode, the first exposed surface 21 of the oxidant gas diffusion layer 58 faces the oxidant catalyst layer 57 that easily generates water by a power generation reaction. For this reason, it is preferable to improve the drainage of the first exposed surface 21 of the oxidant gas diffusion layer 58 that directly faces the oxidant catalyst layer 57. Therefore, in the oxidant gas diffusion layer 58, the concentration of the water repellent material (the amount carried per unit volume) is inclined in the thickness direction of the substrate 2. That is, in the oxidant gas diffusion layer 58, the amount of the water repellent material is set to be large on the first exposed surface 21 side (the side facing the oxidant catalyst layer 57) on which the fluid is applied, A small drainage structure is employed on the second exposed surface 22 side (the side facing away from the oxidant catalyst layer 57).

  The first exposed surface 21 of the fuel gas diffusion layer 54 faces the fuel catalyst layer 55 and preferably has high drainage. Therefore, in the fuel gas diffusion layer 54, the amount of water repellent material (the amount carried per unit volume) is inclined in the thickness direction of the substrate 2. That is, the amount of the water repellent material in the fuel gas diffusion layer 54 is set to be large on the first exposed surface 21 side, which is the side on which the fluid is applied, and is set to be small on the second exposed surface 22 side. Is adopted.

(Application 2)
FIG. 13 schematically shows Application Mode 2. According to this application mode, the second exposed surface 22 of the oxidant gas diffusion layer 58 faces the oxidant catalyst layer 57, and the first exposed surface 21 faces away from the oxidant catalyst layer 57. Yes. Therefore, the amount of the water repellent material in the oxidant gas diffusion layer 58 is large on the first exposed surface 21 side (the side facing away from the oxidant catalyst layer 57), which is the side on which the fluid is applied, and second. The number is set to be small on the exposed surface 22 side (side facing the oxidant catalyst layer 57). As a result, in the thickness direction of the oxidant gas diffusion layer 58, from the second exposed surface 22 side (side facing the oxidant catalyst layer 57), the first exposed surface 21 side (back to the oxidant catalyst layer 57). A drainage structure is adopted in which the amount of water repellent material gradually increases as it goes to the opposite side.

  Further, as schematically shown in FIG. 13, the second exposed surface 22 of the fuel gas diffusion layer 54 faces the fuel catalyst layer 55, and the first exposed surface 21 faces away from the fuel catalyst layer 55. is doing. The amount of the water repellent material in the fuel gas diffusion layer 54 is large on the first exposed surface 21 side (the side facing away from the fuel catalyst layer 55), which is the side on which the fluid is applied, and the second exposed surface 22. The number is set to be small on the side (the side facing the fuel catalyst layer 55). As a result, in the thickness direction of the fuel gas diffusion layer 54, from the second exposed surface 22 side (side facing the fuel catalyst layer 55) to the first exposed surface 21 side (side facing the fuel catalyst layer). A drainage structure in which the amount of the water repellent material gradually increases as it goes to is adopted.

(Other embodiments)
When applying the fluid to the first exposed surface 21 of the substrate 2, it may be applied by spraying. In addition to the water repellent material, the fluid contains carbon black as a fine conductive material, but may contain no fine conductive material. The support body 12 is fixed and the application body 13 is moved along the support surface 11 of the support body 12. However, the present invention is not limited to this, and the application body 13 is fixed and together with the support surface 11 of the support body 12, The material 2 may be moved. Although the pin-shaped movable body 14 is raised and the base material 2 is lifted so as not to be in contact with the support surface 11 of the support body 12, it is not limited to the movable body 14. In addition, the present invention is not limited to the embodiment described above and shown in the drawings, and can be implemented with appropriate modifications without departing from the scope of the invention. Structures and functions specific to one embodiment can be applied to other embodiments.

The following technical idea can also be grasped from the above description.
(Additional Item 1) A porous base material in the form of a sheet having pores and conductivity and having a first exposed surface and a second exposed surface facing each other, and a fluid having fluidity including a water repellent material, A step of preparing a support having a support surface capable of supporting the base material, and a coating step of applying a fluid to the first exposed surface of the base material while the base material is supported by the support. In the method for producing a gas diffusion layer, the coating step is performed in a state where the second exposed surface of the substrate is placed on and supported by the support surface of the support.

  The present invention can be used, for example, for a porous gas diffusion layer used in a fuel cell for stationary use, vehicle use, portable use, portable use, electronic equipment, and electric equipment.

FIG. 1A is a perspective view of a support body before placing a substrate, and FIG. 1B schematically shows a state immediately before applying a fluid to the substrate placed on the support according to the first embodiment. FIG. 1C is a configuration diagram schematically showing a state immediately after a fluid is applied to a substrate placed on a support. FIG. 2 (A) is a perspective view of a support body before placing a substrate, and FIG. 2 (B) schematically shows a state immediately before applying a fluid to the substrate placed on the support according to the second embodiment. FIG. 2C is a configuration diagram schematically showing a state immediately after the fluid is applied to the substrate placed on the support. FIG. 3A is a perspective view of the support body before placing the substrate, and FIG. 3B schematically shows a state immediately before applying the fluid to the substrate placed on the support according to the third embodiment. FIG. 3C is a configuration diagram schematically showing a state immediately after the fluid is applied to the substrate placed on the support. FIG. 4 (A) is a perspective view of the support body before placing the substrate, and FIG. 4 (B) schematically shows a state immediately before applying the fluid to the substrate placed on the support according to the fourth embodiment. FIG. 4C is a configuration diagram schematically showing a state immediately after the fluid is applied to the substrate placed on the support. FIG. 5 (A) is a perspective view of a support body before placing a substrate, and FIG. 5 (B) schematically shows a state immediately before applying a fluid to the substrate placed on the support according to the fifth embodiment. FIG. 5C is a configuration diagram schematically showing a state immediately after the fluid is applied to the substrate placed on the support. FIG. 10 is a cross-sectional view of an apparatus according to Embodiment 6 in which the central support is raised toward the edge support. FIG. 10 is a cross-sectional view of an apparatus according to Embodiment 6 in which a central support is lowered from an edge support. FIG. 10 is a perspective view schematically showing a device according to the sixth embodiment and having a central support body and an edge support body. FIG. 9A is a perspective view of the support body before placing the substrate, and FIG. 9B is a state immediately before applying the fluid to the substrate placed on the support according to the seventh embodiment. FIG. 9C is a configuration diagram schematically showing a state immediately after the fluid is applied to the substrate placed on the support. FIG. 10A is a perspective view of the support body before placing the substrate, and FIG. 10B is a state immediately before applying the fluid to the substrate placed on the support according to the eighth embodiment. FIG. 10C is a configuration diagram schematically showing a state immediately after the fluid is applied to the substrate placed on the support. FIG. 10 is a cross-sectional view of an apparatus according to Embodiment 9 in which the central support is lowered with respect to the edge support. FIG. 6 is a cross-sectional view of the main part of the fuel cell according to Application Mode 1. It is sectional drawing of the principal part of a fuel cell concerning the application form 2. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 is a coating device, 10 is a fixing | fixed part, 11 is a support surface, 12 is a support body, 12w is a hole, 14 is a movable body, 130 is a water repellent material film 11r, 2 is a base material, 21 is a 1st exposed surface, 22 Is the second exposed surface, 3 is a mass, 50 is a membrane electrode assembly, 51 is a fuel distribution plate, 52 is an oxidant distribution plate, 54 is a gas diffusion layer for fuel, 55 is a catalyst layer for fuel, and 56 is a conductive membrane. , 57 schematically shows an oxidant catalyst layer, and 58 schematically shows an oxidant gas diffusion layer.

Claims (3)

A porous base material in the form of a sheet having pores and conductivity and having a first exposed surface and a second exposed surface facing each other; a fluid having a fluidity including a water repellent material; and A step of preparing a support having a support surface that can be supported, and an application step of applying the fluid to the first exposed surface of the base material in a state where the base material is supported by the support. In the method for producing the gas diffusion layer,
The application step is performed in a state where the second exposed surface of the base material is placed on and supported by the support surface of the support,
After completion of the coating process, immediately before the end of the coating process or in the middle of the coating process, more than half of the second exposed surface of the substrate and the support surface of the support are in a non-contact state A method for producing a gas diffusion layer, characterized in that A porous base material in the form of a sheet having pores and conductivity and having a first exposed surface and a second exposed surface facing each other; a fluid having a fluidity including a water repellent material; and A step of preparing a support having a support surface that can be supported, and an application step of applying the fluid to the first exposed surface of the base material in a state where the base material is supported by the support. In the method for producing the gas diffusion layer,
The coating step is performed in a state where the second exposed surface of the base material is placed on and supported by the support surface of the support body, and at least the first surface of the base material among the support surfaces of the support body. 2. A method for producing a gas diffusion layer, which is performed in a state having water repellency at a portion facing the exposed surface. A porous base material in the form of a sheet having pores and conductivity and having a first exposed surface and a second exposed surface facing each other; a fluid having a fluidity including a water repellent material; and A step of preparing a support having a support surface that can be supported, and an application step of applying the fluid to the first exposed surface of the base material in a state where the base material is supported by the support. In the method for producing the gas diffusion layer,
The support has a plurality of holes, and the coating step supports the second exposed surface of the substrate with the support, and the second exposed surface of the substrate and the support in the hole. A method for producing a gas diffusion layer, wherein the support surface is brought into a non-contact state.

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