Method for manufacturing laminate

Abstract

To suppress the formation of air bubbles in an adhesive layer even when employing a pressure-sensitive adhesive.SOLUTION: A method for manufacturing a laminate includes steps of: forming an adhesive layer composed of a pressure-sensitive adhesive, on at least one of a first sheet member and a second sheet member; and pressing the first sheet member and the second sheet member, which are arranged facing each other via the adhesive layer, with a pair of jigs to bond the first sheet member and the second sheet member to each other. In the bonding step, an elastic body is provided between the first sheet member and one of the pair of jigs, and / or between the second sheet member and the other of the pair of jigs. The elastic body overlaps with the adhesive layer at least partially in a pressing direction by the pair of jigs.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The technology disclosed in this specification relates to a method for manufacturing a laminate, and more particularly, to a method for manufacturing a laminate in which a plurality of sheet members including at least a first sheet member and a second sheet member are laminated.

Background Art

[0002] Patent Document 1 describes a method for manufacturing a laminate. In this manufacturing method, a first sheet member and a second sheet member disposed opposite each other via an adhesive layer are adhered to each other.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, a heat-curable adhesive has been used in the manufacture of laminates such as fuel cells. Instead of this, it is conceivable to adopt a pressure-sensitive adhesive. However, in the case of a heat-curable adhesive, a phase change from solid to liquid occurs during the adhesion process, whereas in the case of a pressure-sensitive adhesive, such a phase change does not occur. Therefore, there is a risk that bubbles trapped between the adhesive layer formed of the pressure-sensitive adhesive and the separator remain in the adhesive layer as they are.

[0005] In view of the above circumstances, this specification provides a technique for suppressing the formation of bubbles in the adhesive layer even when a pressure-sensitive adhesive is adopted.

Means for Solving the Problems

[0006] The technology disclosed in this specification is embodied in a method for manufacturing a laminate in which a plurality of sheet members including at least a first sheet member and a second sheet member are laminated. This manufacturing method includes a step of forming an adhesive layer composed of a pressure-sensitive adhesive on at least one of the first sheet material and the second sheet material, and a step of adhering the first sheet member and the second sheet member to each other by pressing the first sheet member and the second sheet member disposed opposite to each other via the adhesive layer with a pair of jigs. In the adhering step, an elastic body is provided between the first sheet member and one of the pair of jigs and / or between the second sheet member and the other of the pair of jigs, and the elastic body at least partially overlaps the adhesive layer in the pressing direction by the pair of jigs.

[0007] In the above-described manufacturing method, the first sheet member and the second sheet member disposed opposite to each other via an adhesive layer composed of a pressure-sensitive adhesive are pressed with a pair of jigs, whereby the first sheet member and the second sheet member are adhered to each other. At this time, an elastic body is provided between the first sheet member and one of the pair of jigs and / or between the second sheet member and the other of the pair of jigs. The elastic body at least partially overlaps the adhesive layer in the pressing direction by the pair of jigs. According to such a configuration, since the pressing load by the pair of jigs acts on the adhesive layer via the elastic body, bubbles are easily excluded from between the adhesive layer and the sheet member due to the flexibility of the elastic body. Thereby, formation of bubbles in the adhesive layer formed of the pressure-sensitive adhesive is suppressed.

[0008] In the second aspect, in the first aspect, the adhesive layer may be formed along a predetermined seal line. In this case, the thickness of the elastic body may be maximum at a specific location in a cross-section perpendicular to the longitudinal direction of the seal line, and may monotonically decrease as it moves away from the specific location in the width direction of the seal line. According to such a configuration, the pressing load by the pair of jigs is sequentially applied to the adhesive layer toward the outside in the width direction. Therefore, it is difficult for air bubbles to be trapped between the adhesive layer and the sheet member, and it is easy to remove them. Thereby, the formation of air bubbles in the adhesive layer formed of the pressure-sensitive adhesive is suppressed.

[0009] In the third aspect, in the first or second aspect, a specific location of the elastic body may be located at the central portion of the elastic body in a cross-section perpendicular to the longitudinal direction of the seal line. According to such a configuration, the pressing load by the pair of jigs is sequentially applied to the adhesive layer from the central portion in the width direction toward both sides. Therefore, it is more difficult for air bubbles to be trapped between the adhesive layer and the sheet member, and it is easier to remove them. Thereby, the formation of air bubbles in the adhesive layer formed of the pressure-sensitive adhesive is suppressed.

[0010] In the fourth aspect, in any one of the first to third aspects, in a cross-section perpendicular to the longitudinal direction of the seal line, the central portion of the elastic body may protrude. According to such a configuration, in the central portion in the width direction, air bubbles can be more reliably removed from between the adhesive layer and the sheet member. Thereby, the formation of air bubbles in the adhesive layer formed of the pressure-sensitive adhesive is suppressed.

[0011] In the fifth aspect, in any one of the first to fourth aspects, the laminate may be a fuel cell. In this case, the first sheet member may be a support frame that supports the membrane electrode assembly, and the second sheet member may be a separator whose one surface is adhered to the support frame via an adhesive layer. Further, the elastic body may be a gasket provided on the other surface of the separator. According to such a configuration, when the support frame and the separator arranged opposite to each other via the adhesive layer formed of a pressure-sensitive adhesive are pressed with a pair of jigs and adhered to each other, the formation of bubbles in the adhesive layer can be suppressed.

[0012] In any of the above-described aspects, the viscoelastic properties of the adhesive constituting the adhesive layer are 10 6 Mpa to 10 8 MPa may be within the range. Even when such an adhesive is used, according to the technology disclosed in this specification, the formation of bubbles in the adhesive layer can be suppressed.

[0013] In any of the above-described aspects, at least one of the thickness of the first sheet member or the thickness of the second sheet member may be 0.1 mm or less. According to such a configuration, the pressing load by the pair of jigs can be effectively transmitted to the adhesive layer.

Brief Description of Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0015] With reference to the drawings, a method for manufacturing the fuel cell 10 of the embodiment and the fuel cell 12 which is a constituent unit thereof will be described. As shown in Fig. 1, the fuel cell 10 includes a plurality of fuel cells 12. Each fuel cell 12 is arranged parallel to the X-axis and the Z-axis, and the plurality of fuel cells 12 are stacked along the Y-axis. Although details will be described later, each fuel cell 12 is a component capable of generating electricity independently. The fuel cell 10 is not particularly limited, and for example, it can be adopted in a vehicle powered by a fuel cell such as a fuel cell vehicle.

[0016] As shown in FIG. 2, each fuel cell 12 includes a membrane electrode assembly (MEA) 14, an anode separator 16, a cathode separator 18, and a support frame 20. Although not shown, the MEA 14 has an electrolyte membrane, an anode catalyst layer provided on one surface of the electrolyte membrane, and a catalyst layer provided on the other surface of the electrolyte membrane. The MEA 14 is supported by the support frame 20. The MEA 14, together with the support frame 20, is disposed between the anode separator 16 and the cathode separator 18. Although not particularly limited, each fuel cell 12 may further include an anode gas diffusion layer and a cathode gas diffusion layer on both surfaces of the MEA 14. That is, the MEA 14 may constitute a membrane electrode and gas diffusion layer assembly (MEGA) together with the anode gas diffusion layer and the cathode gas diffusion layer.

[0017] The anode separator 16 and the cathode separator 18 are plate-like members made of a gas-impermeable conductive material. Although not particularly limited, each separator 16, 18 may be formed using a metal plate (i.e., a thin metal layer) such as titanium or stainless steel, for example. In this case, the thin metal layer may be 0.1 mm or less. Each separator 16, 18 includes six manifold holes 28a-28f. These manifold holes 28a-28f constitute manifolds 30a, 30c, 30e for supplying anode gas, cathode gas, and a cooling medium to each fuel cell 12, respectively, and manifolds 30b, 30d, 30f for recovering unreacted anode gas, unreacted cathode gas, and the cooling medium from each fuel cell 12, respectively. The anode gas is hydrogen gas (or a gas containing hydrogen), and the cathode gas is oxygen gas (or a gas containing oxygen). The cooling medium is, for example, cooling water.

[0018] As shown in FIGS. 2 and 3, the support frame 20 has a frame shape with an opening 22. The MEA 14 is disposed in the opening 22 of the support frame 20. The support frame 20 surrounds the periphery of the MEA 14. Although not particularly limited, the support frame 20 is made of a thermosetting resin such as an epoxy resin or a phenolic resin. The support frame 20 is also provided with six manifold holes 28a - 28f, similar to the separators 16 and 18 described above.

[0019] The upper surface 20a of the support frame 20 faces the anode-side separator 16 and is adhered to the anode-side separator 16 via the first adhesive layer 24. The first adhesive layer 24 is composed of a pressure-sensitive adhesive (PSA). The first adhesive layer 24 is provided along a predetermined seal line on the upper surface 20a of the support frame 20. The seal line of the first adhesive layer 24 is predetermined to surround the opening 22 of the support frame 20 and each of the manifold holes 28a - 28f. The lower surface 20b of the support frame 20 faces the cathode-side separator 18 and is adhered to the cathode-side separator 18 via the second adhesive layer 26 (see FIGS. 4(A)-(C)). The second adhesive layer 26 is also composed of a pressure-sensitive adhesive (PSA). The second adhesive layer 26 is provided along a predetermined seal line on the lower surface 20b of the support frame 20. The seal line of the second adhesive layer 26 is also predetermined to surround the opening 22 of the support frame 20 and each of the manifold holes 28a - 28f.

[0020] As shown in FIGS. 4, 5(B), and 5(C), a plurality of gaskets 32a - 32e are provided on the upper surface 16a of the anode-side separator 16. Each of the gaskets 32a - 32e is an elastic body and is composed of, for example, rubber, thermoplastic resin, or the like. The upper surface 16a of the anode-side separator 16 faces the cathode-side separator 18 (not shown) of another adjacent fuel cell 12 in the fuel cell 10. The lower surface 16b of the anode-side separator 16 faces the upper surface 20a of the support frame 20 and is adhered to the support frame 20 via the first adhesive layer 24.

[0021] The plurality of gaskets 32a - 32e includes a first gasket 32a, a second gasket 32b, a third gasket 32c, a fourth gasket 32d, and a fifth gasket 32e. The first gasket 32a, the second gasket 32b, the third gasket 32c, and the fourth gasket 32d are provided so as to surround the respective manifold holes 28a - 28d. The fifth gasket 32e is provided so as to surround the range facing the MEA 14 and the two manifold holes 28e, 28f excluding the above-described four manifold holes 28a - 28d. Each of the gaskets 32a - 32e prevents fluid such as anode gas, cathode gas, or a cooling medium from leaking from the corresponding manifolds 30a - 30f in the fuel cell 10 in which a plurality of fuel cells 12 are stacked. Incidentally, hereinafter, when it is not necessary to distinguish the plurality of gaskets 32a - 32e, the alphabet of the subscript may be omitted and they may simply be referred to as "gasket 32".

[0022] Referring to FIGS. 3-5, a method for manufacturing a fuel cell 12 will be described. As shown in FIGS. 3 and 5(A), the manufacturing method includes a step of forming adhesive layers 24 and 26 on each surface 20a and 20b of a support frame 20 that supports an MEA 14. In this step, a pressure-sensitive adhesive is applied along a predetermined seal line on each surface 20a and 20b of the support frame 20. As a result, the adhesive layers 24 and 26 composed of the pressure-sensitive adhesive are respectively formed on each surface 20a and 20b of the support frame 20. The specific method of applying the adhesive is not particularly limited. Although it is an example, the adhesive can be applied by inkjet printing, screen printing, or the like.

[0023] Next, as shown in FIG. 5(B), the manufacturing method includes a step of bonding the support frame 20 and the separators 16 and 18 to each other. In this step, the support frame 20 and the separators 16 and 18 arranged opposite to each other via the adhesive layers 24 and 26 are pressed, for example, by a pressing device 34. The pressing device 34 includes a stage 34a and an upper die 34b. The anode-side separator 16, the support frame 20 on which the adhesive layers 24 and 26 are formed, and the cathode-side separator 18 are stacked on the stage 34a, and the upper die 34b is lowered, so that a pressing load is applied to the support frame 20 and the separators 16 and 18. As the pressing load is applied by the pressing device 34, as shown in FIG. 5(C), the anode-side separator 16 is bonded to the support frame 20 via the first adhesive layer 24, and the cathode-side separator 18 is bonded to the support frame 20 via the second adhesive layer 26.

[0024] As described above, a gasket 30 is provided on the upper surface 16a of the anode-side separator 16 in this embodiment. Therefore, as shown in FIG. 5(B), in the above bonding step, a gasket 32 is provided between the anode-side separator 16 and the upper die 34b of the pressing device 34. This gasket 32 is arranged at a position overlapping the adhesive layers 24 and 26 in the pressing direction by the pressing device 34.

[0025] In this embodiment, in a cross-section perpendicular to the longitudinal direction of the seal line, the surface of the gasket 32 is convex. As a result, for example, the thickness of the gasket 32 is maximum at a specific point P1, and monotonically decreases as it moves away from the specific point P1 in the width direction (i.e., the X direction) of the seal line. The so-called monotonic decrease here means a continuous or discontinuous decrease, meaning it does not increase. Note that the position of the specific point P1 where the thickness of the gasket 32 is maximum is not particularly limited. Although it is an example, in the gasket 32 of this embodiment, in a cross-section perpendicular to the longitudinal direction of the seal line, a specific point P1 is located at the center in the width direction (i.e., the X direction), and the gasket 32 has a bilaterally symmetric shape.

[0026] According to the above-described manufacturing method, since a pressing load by the pressing device 34 acts on the adhesive layers 24, 26 via the gasket 32, due to the flexibility of the gasket 32, air bubbles are easily excluded from between the adhesive layers 24, 26 and the separators 16, 18. In this embodiment, in a cross-section perpendicular to the longitudinal direction of the seal line, since a specific point P1 of the gasket 32 is located at the central portion thereof, the pressing load by the pressing device 34 is sequentially applied to the adhesive layers 24, 26 from the central portion in the width direction toward both sides. Furthermore, since the central portion of the gasket 32 protrudes, air bubbles can be more reliably excluded from between the adhesive layers 24, 26 and the separators 16, 18 at the central portion in the width direction. As a result, the formation of air bubbles in the adhesive layers 24, 26 formed of the pressure-sensitive adhesive is suppressed.

[0027] Note that the fuel cell 12 in this embodiment is an example of the laminate in this technology. The support frame 20 in this embodiment is an example of the first sheet member in this technology. The anode-side separator 16 and the cathode-side separator 18 in this embodiment are examples of the second sheet member in this technology. The pressing device 34 in this embodiment is an example of the pair of jigs in this technology. The gasket 32 in this embodiment is an example of the elastic body in this technology.

[0028] In the above-described manufacturing method, one fuel cell 12 is fabricated. As another embodiment, two or more fuel cells 12 may be fabricated simultaneously. That is, in the bonding step, the upper surface 16a of the anode separator 16 provided with the gasket 32 may face the cathode separator 18 constituting another adjacent fuel cell 12. Even in this case, the gasket 32 is interposed between the anode separator 16 and the upper die 34b of the pressing device 34. According to such a manufacturing method, by pressing a plurality of fuel cells 12 with the pressing device 34, a plurality of fuel cells 12 can be fabricated simultaneously.

[0029] Next, a modification example of the gasket 32 will be described. As shown in Fig. 6(A), the thickness of the gasket 32 provided on the upper surface 16a of the anode separator 16 may be constant.

[0030] In the present embodiment and the above modification example, the gasket 32 is provided on the anode separator 16. Instead of this, as shown in Figs. 6(B) and (C), the gasket 32 may be provided on the pressing device 34. Although it is an example, the thickness of the gasket 32 provided on the upper die 34b of the pressing device 34 may be maximum at specific positions Q1 and Q2 in a cross section perpendicular to the longitudinal direction of the seal line, and may monotonically decrease as it moves away from the specific positions Q1 and Q2 in the width direction of the seal line. Even with such a configuration, the pressing load by the pressing device 34 is applied to the adhesive layers 24 and 26 in order from the inner side to the outer side in the width direction. Therefore, it is difficult for air bubbles to be trapped between the adhesive layers 24 and 26 and the separators 16 and 18, and they are easily removed. In particular, as shown in Fig. 6(C), when the central portion of the gasket 32 protrudes, air bubbles can be more reliably removed from between the adhesive layers 24 and 26 and the separators 16 and 18 at the central portion in the width direction. As a result, the formation of air bubbles in the adhesive layers 24 and 26 formed of the pressure-sensitive adhesive is suppressed.

[0031] In the present embodiment and several of the above-described modifications, in the bonding step, the gasket 32 is provided only between the anode-side separator 16 and the upper die 34b of the pressing device 34. However, as shown in FIG. 6(D), as another embodiment, the gasket 32 may be provided between the anode-side separator 16 and the upper die 34b of the pressing device 34, and between the support frame 20 and the stage 34a of the pressing device 34. Even with such a configuration, the formation of bubbles in the adhesive layers 24 and 26 formed of the pressure-sensitive adhesive is suppressed.

[0032] As yet another embodiment, the gasket 32 may be provided only between the support frame 20 and the stage 34a of the pressing device 34.

[0033] Although several specific examples have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical utility either individually or in combination.

Description of Reference Numerals

[0034] 10: Fuel cell, 12: Fuel cell unit, 14: MEA, 16, 18: Separator, 20: Support frame, 22: Opening, 24, 26: Adhesive layer, 28a - 28f: Manifold hole, 30a - 30f: Manifold, 32, 32a - 32e: Gasket, 34: Pressing device

Claims

1. A method for manufacturing a laminate in which a plurality of sheet members including at least a first sheet member and a second sheet member are laminated, forming an adhesive layer composed of a pressure-sensitive adhesive on at least one of the first sheet material and the second sheet material; adhering the first sheet member and the second sheet member to each other by pressing the first sheet member and the second sheet member disposed opposite to each other via the adhesive layer with a pair of jigs; comprising: in the adhering step, an elastic body is provided between the first sheet member and one of the pair of jigs and / or between the second sheet member and the other of the pair of jigs, the elastic body at least partially overlaps the adhesive layer in the pressing direction by the pair of jigs, manufacturing method.

2. the adhesive layer is formed along a predetermined seal line, the thickness of the elastic body is maximum at a specific location in a cross-section perpendicular to the longitudinal direction of the seal line, and monotonically decreases as it moves away from the specific location in the width direction of the seal line. The manufacturing method according to claim 1.

3. the specific location of the elastic body is located at the central portion of the elastic body in the cross-section perpendicular to the longitudinal direction of the seal line. The manufacturing method according to claim 2.

4. in the cross-section perpendicular to the longitudinal direction of the seal line, the central portion of the elastic body protrudes. The manufacturing method according to claim 3.

5. the laminate is a fuel cell, the first sheet member is a support frame for supporting a membrane electrode assembly, the second sheet member is a separator having one surface adhered to the support frame via the adhesive layer, the elastic body is a gasket provided on the other surface of the separator. The manufacturing method according to any one of claims 1 to 4.

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