JP2020107430A - Device for manufacturing fuel battery cell joined body - Google Patents

Abstract

To provide a device for manufacturing a fuel battery cell joined body, which can prevent a release layer from depositing to an electrolytic sheet and which allows a back sheet to be peeled from the electrolytic sheet.SOLUTION: The electrolyte sheet is a sheet of a polymeric resin having a sulfonic group as an ion exchange group. The release layer is a halogen atom-containing resin layer. The manufacturing device 1 comprises: a pair of hot-press rolls 51 and 51 for performing hot press of a back sheet and a gas diffusion sheet 15; an anneal processing unit 52 serving to convey a bonding sheet 10B arranged by bonding the catalyst layer and the gas diffusion sheet 15 together, and serving to lower an adhesive force of the release layer to the electrolyte sheet by heating the bonding sheet until the polymeric resin of the polymeric resin sheet reaches a temperature of a rubber-like region and then cooling; and a peeling unit 53 for peeling the back sheet 14A from the electrolyte sheet together with the release layer.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to an apparatus for manufacturing a joined body of fuel cell.

As an apparatus for producing a joined body of a fuel cell, for example, in Patent Document 1, a roll-to-roll type composite sheet in which a catalyst layer is formed on a strip-shaped electrolyte sheet constituting an electrolyte membrane of a fuel cell is disclosed. There is disclosed an apparatus for producing a joined body for a fuel cell, which is joined to a strip-shaped gas diffusion sheet forming a gas diffusion layer.

Specifically, in this manufacturing apparatus, as a composite sheet, a catalyst layer was formed on one surface of the electrolyte sheet, and a back sheet was attached to the other surface of the electrolyte sheet via a release layer. It uses a composite sheet. When the composite sheet and the gas diffusion sheet are joined together, the composite sheet and the gas diffusion sheet are sandwiched between hot pressing rolls and hot pressed to produce a joined sheet in which the catalyst layer is joined to the gas diffusion sheet. After manufacturing the joining sheet, the joining sheet is continuously conveyed, the back sheet is applied to the peeling portion, and the back sheet is continuously peeled from the electrolyte sheet of the joining sheet.

JP, 2018-45841, A

However, in the manufacturing apparatus described in Patent Document 1, when the backsheet is peeled from the electrolyte sheet of the joining sheet, the release layer formed on the backsheet may be peeled from the backsheet and adhere to the electrolyte sheet. there were. According to the experiments by the inventor, it has been found that this adhesion becomes remarkable when the sulfonic acid group of the polymer resin constituting the electrolyte sheet increases at the interface between the electrolyte sheet and the release layer.

The present invention has been made in view of such a point, and as the present invention, it is possible to prevent the release sheet from adhering to the electrolyte sheet and to peel the back sheet from the electrolyte sheet. An apparatus for manufacturing a joined body is provided.

In view of the above problems, the apparatus for manufacturing a fuel cell cell assembly according to the present invention has a catalyst layer formed on one surface of a strip-shaped electrolyte sheet that constitutes an electrolyte membrane of a fuel cell, wherein the electrolyte is On the other surface of the sheet, a composite sheet in which a back sheet is attached via a release layer, and a belt-shaped gas diffusion sheet constituting a gas diffusion layer of the fuel cell, while carrying the above, The catalyst layer of the composite sheet, a device for manufacturing a joined body of fuel cells for joining the gas diffusion sheet, wherein the electrolyte sheet is a sheet of polymer resin having a sulfonic acid group as an ion exchange group. The release layer is a resin layer containing a halogen atom, the manufacturing apparatus, while sandwiching the composite sheet and the gas diffusion sheet in a state where the catalyst layer and the gas diffusion sheet are in contact with each other. While carrying, a pair of hot-press rolls that heat-press the back sheet and the gas diffusion sheet so that the catalyst layer and the gas diffusion sheet are joined, the catalyst layer, and the gas diffusion sheet are joined. The adhesive strength of the release layer to the electrolyte sheet is reduced by transporting the joined bonding sheet and heating the polymer resin of the polymer resin sheet to the temperature of the rubber-like region and then cooling. An annealing treatment part to be brought into contact with the back sheet, and the conveyance direction of the back sheet conveyed from the annealing treatment part is changed to a direction different from the conveyance direction of the electrolyte sheet, and the back sheet together with the release layer. And a peeling portion for peeling from the electrolyte sheet.

According to the present invention, when the catalyst layer and the gas diffusion sheet are joined with a hot press roll, the halogen atom contained in the release layer increases the sulfonic acid group at the interface of the electrolyte sheet in contact with the release layer. , The adhesive force between the electrolyte sheet and the release layer may increase. However, in the present invention, the annealing sheet is used to heat the bonding sheet until the polymer resin of the electrolyte sheet reaches the temperature of the rubber-like region, so that at the interface of the electrolyte sheet in contact with the release layer, The amount of sulfonic acid groups is reduced and it is cooled to maintain this state. This reduces the adhesive force of the release layer to the electrolyte sheet. As a result, the back sheet can be suitably peeled from the electrolyte sheet while preventing the release layer from adhering to the electrolyte sheet by the peeling portion.

It is a schematic diagram of the manufacturing apparatus of the joined body of the fuel cell which concerns on this embodiment of this invention. The upper and lower views of (a) are schematic cross-sectional views of the gas diffusion sheet and the composite sheet shown in FIG. 1, respectively, and (b) is a schematic cross-sectional view of the joining sheet shown in FIG. 1. , (C), upper and lower views are schematic cross-sectional views of the back sheet peeled together with the joined body and the release layer shown in FIG. 1, respectively. 3 is a viscoelastic curve showing a relationship between elastic modulus and temperature of a general polymer material. It is a flow figure explaining the process of the manufacturing method of the joined object by the manufacturing device of this embodiment. It is a graph which shows the peeling strength of reference example 2 and reference comparative examples 6-10. It is an expansion conceptual diagram explaining the state of the sulfonic acid group of the interface of the electrolyte sheet and the mold release layer of reference example 2 and reference comparative examples 6-10, (a) is reference comparative example 6 and reference example 2. , (B) is Reference Comparative Example 7, and (c) is Reference Comparative Examples 8 to 10. 5 is a viscoelastic curve showing the relationship between the storage elastic modulus and temperature according to the electrolyte sheet of Reference Example 1. It is a schematic diagram of the conventional manufacturing apparatus which manufactures the joined body of the cell for fuel cells. 8A is a schematic cross-sectional view of the joining sheet shown in FIG. 8, and the upper and lower views of FIG. 8B show the joined body with the release layer attached and the release layer peeled off, respectively. FIG. 3 is a schematic cross-sectional view of the back sheet in the cut state.

An apparatus for manufacturing a fuel cell assembly according to an embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

The manufacturing apparatus 1 of the present embodiment is used when manufacturing a polymer electrolyte fuel cell (single cell). In this manufacturing apparatus, a membrane electrode in which an electrode (catalyst) layer is laminated on both surfaces of an electrolyte membrane (MEA: Membrane Electrode Assembly) and a gas diffusion layer (GDL: Gas Diffusion Layer) is further joined on both sides. An intermediate processed product of a MEGA (Membrane Electrode & Gas diffusion Layer Assembly) is manufactured. First, the configuration of the MEGA of the present embodiment will be described, and then the manufacturing apparatus 1 for a joined body of the present embodiment and a manufacturing method using the manufacturing apparatus 1 will be described.

1. Structure of MEGA The MEGA forms a fuel cell by being sandwiched by a pair of separators, and functions as a power generation unit of the fuel cell. As described above, the MEGA includes the membrane electrode assembly and the gas diffusion layers laminated on both surfaces of the membrane electrode assembly.

The MEA includes an ion-permeable electrolyte membrane, and an anode-side catalyst layer (electrode layer) and a cathode-side catalyst layer (electrode layer) that sandwich the electrolyte membrane. Each catalyst layer is formed of, for example, porous carbon in which a catalyst such as platinum is supported on carbon particles.

The electrolyte membrane is a proton conductive ion exchange membrane formed of a solid polymer material. An example of the solid polymer material is a polymer resin having a sulfonic acid group as an ion exchange group. The amount of sulfonic acid groups contained in the polymer resin can be represented by the number of mols contained, and the resin weight per 1 mol of ion exchange groups (ion exchange group equivalent weight EW) is 500 to 1200 g/mol.

Such an electrolyte membrane includes, for example, a precursor group —SO ₂ F (sulfone fluorine group) of an F-type electrolyte membrane (electrolyte precursor membrane that does not show proton conductivity) and an H-type electrolyte membrane (proton conductivity). It can be produced by converting the ionic group of the electrolyte membrane) to —SO ₃ H (sulfonic acid group).

The gas diffusion layer on one side of the MEGA is joined to the anode side catalyst layer. The gas diffusion layer on the other side is joined to the cathode side catalyst layer. The gas diffusion layer is formed of a conductive member having gas permeability such as a carbon porous body such as carbon paper or carbon cloth, or a metal porous body such as a metal mesh or a foam metal.

Here, a fuel gas such as hydrogen gas is supplied from the separator to the gas diffusion layer on one side, and an oxidant gas such as the atmosphere is supplied from the separator to the gas diffusion layer on the other side. By supplying the fuel gas and the oxidant gas, an electrochemical reaction occurs in the MEA to generate electricity.

In the present embodiment, a bonded body (of fuel cell) which is an intermediate processed product of the MEGA described above is manufactured. Specifically, in the manufactured joined body, the gas diffusion sheet 15 corresponding to the gas diffusion layer is joined to the catalyst layer (for example, the anode side catalyst layer) 12 formed on the electrolyte sheet 11 corresponding to the electrolyte membrane. It is a sheet-shaped joined body 10D (for example, refer to the upper diagram of FIG. 2C). The manufacturing apparatus 1 for manufacturing this joined body 10D will be described below.

2. Bonded body 10D and manufacturing apparatus 1 for manufacturing the same
Here, first, as the material sheet for manufacturing the joined body 10D, the composite sheet 10A and the gas diffusion sheet 15 used in the manufacturing apparatus 1 of the present embodiment will be described, and then the manufacturing apparatus 1 shown in FIG. The configuration will be described.

2-1. Composite sheet 10A and gas diffusion sheet 15
In the composite sheet 10A, as shown in the lower side of FIG. 2(a), the anode-side or cathode-side catalyst layer 12 is formed into a strip shape on the surface of one side of the strip-shaped electrolyte sheet 11 with substantially the same width as the electrolyte sheet 11. The back sheet 14 is formed on the other surface of the electrolyte sheet 11 with the release layer 13 interposed therebetween.

The electrolyte sheet 11 and the catalyst layer 12 are respectively made of the same materials as those of the MEGA electrolyte membrane and the catalyst layer described above. The back sheet 14 is, for example, a polymer resin sheet such as polyester resin (polyethylene terephthalate, polybutylene terephthalate, etc.), polytetrafluoroethylene (PTFE), etc., and is formed to have substantially the same width as the electrolyte sheet 11. For example, the width of the electrolyte sheet 11 is 100 to 500 mm, and the length thereof is 100 to 500 m.

The release layer 13 is a resin layer containing a halogen atom. The halogen atom can include fluorine, chlorine, or bromine. Examples of the resin forming the release layer 13 include a fluorine-containing polyolefin resin.

On the other hand, the gas diffusion sheet 15 shown in the upper side of FIG. 2A is made of the same material as the above-mentioned gas diffusion layer, and is formed in a strip shape with substantially the same width as the electrolyte sheet 11. The configuration of the manufacturing apparatus 1 of the present embodiment for manufacturing the joined body 10D using the composite sheet 10A and the gas diffusion sheet 15 will be described below.

2-2. Configuration of Manufacturing Apparatus 1 As shown in FIG. 1, the manufacturing apparatus 1 mainly includes a pair of hot-press rolls 51, 51, an annealing unit 52, and a peeling unit 53.

The pair of hot-press rolls 51, 51 have a function of sandwiching and carrying the composite sheet 10A and the gas diffusion sheet 15 in a state where the catalyst layer 12 and the gas diffusion sheet 15 are in contact with each other. Further, the pair of hot-press rolls 51, 51 has a function of hot-pressing the composite sheet 10A and the gas diffusion sheet 15 so that the catalyst layer 12 and the gas diffusion sheet 15 are joined.

Specifically, although not shown in detail, each hot-press roll 51 includes a roll main body, a heating unit built in the roll main body, and a pressing unit that presses the pair of roll main bodies. Thereby, the composite sheet 10A and the gas diffusion sheet 15 can be hot pressed. Further, each roll main body is rotatable by a driving device (not shown) such as a motor, and the driving device can convey the composite sheet 10A and the gas diffusion sheet 15.

In the pair of hot-press rolls 51, 51, the bonding temperature between the composite sheet 10A and the gas diffusion sheet 15 is set to be near the glass transition temperature of the polymer resin forming the electrolyte sheet 11, for example ( Although it is set to the temperature of the transition region described later), it is not particularly limited as long as these can be joined. Further, the pressure applied to the composite sheet 10A and the gas diffusion sheet 15 is set to, for example, 2 to 8 kN. With such a pair of hot-press rolls 51, 51, as shown in FIG. 2B, a joint sheet 10B in which the catalyst layer 12 of the composite sheet 10A and the gas diffusion sheet 15 are joined is produced.

In the present embodiment, the annealing unit 52 is a heating roll and has a function of conveying the joining sheet 10B in which the catalyst layer 12 of the composite sheet 10A and the gas diffusion sheet 15 are joined. In addition to this, the annealing unit 52 heats the bonding sheet 10B until the polymer resin of the electrolyte sheet 11 reaches the temperature of the rubber-like region (region in which it is in a rubber state), and then cools the electrolyte sheet 11. It has a function of reducing the adhesive force of the release layer 13 to the.

Here, as shown in FIG. 3, a general polymer material is divided into four regions according to the relationship between temperature and elastic modulus in the viscoelastic curve, and the polymer resin of the electrolyte sheet according to the present embodiment is also divided. It is divided in the same way.

Specifically, these four regions are (1) a glassy region that maintains a high elastic modulus from the low temperature side, (2) a transition region in which the elastic modulus sharply decreases with increasing temperature, ( 3) A rubber-like region where the elastic modulus is maintained constant again when the temperature further rises, and (4) a flow region where the elastic modulus decreases again when the temperature further rises above the melting point. The glass transition temperature is near the center of the temperature of the transition region. Therefore, the “temperature of the rubber-like region” in the present invention means a temperature region in the viscoelastic curve which is higher than the glass transition temperature and in which the elastic modulus is maintained constant.

By heating to the temperature of the rubber-like region by the annealing unit 52, the polymer resin forming the electrolyte sheet 11 becomes a rubber state, and the sulfonic acid group is attracted to the halogen atom of the release layer 13 (electron attraction). Instead, the molecular movement of the polymer resin becomes dominant. As a result, the amount of sulfonic acid groups existing at the interface of the electrolyte sheet 11 that is in contact with the release layer 13 is reduced.

In this embodiment, a heating roll is used as the annealing unit 52, but a heating furnace, a lamp heater, or the like may be used, for example. Further, the annealing treatment part 52 holds the amount of the sulfonic acid group reduced at the interface of the electrolyte membrane 10 by heating the joining sheet 10B and then cooling it.

In the present embodiment, the joined sheet 10B after heating is cooled by allowing it to cool, but it may be forcibly cooled by, for example, cold air. Furthermore, the joint sheet 10B may be cooled while being transported by using the transport roll 63 in which the cooling medium is filled and cooled in the transport roll 63. The cooling rate of the joining sheet 10B is preferably 10 to 60° C./second, and it is preferable to cool the joining sheet 10B to a temperature lower than the temperature of the joining sheet 10B hot pressed by the pair of hot pressing rolls 51, 51. ..

The bonding sheet 10B is heated and then cooled by the annealing unit 52 under the above-described conditions, so that the adhesive force of the release layer 13 to the electrolyte sheet 11 increased by the pair of hot-press rolls 51, 51 is reduced. The bonding sheet 10C having the reduced adhesive strength is conveyed to the peeling section 53. In addition, in the annealing treatment section 52, it is desirable that the joining sheet 10B is sandwiched and not subjected to hot pressing.

The peeling section 53 contacts the back sheet 14 and changes the conveyance direction G of the back sheet 14 conveyed from the annealing processing section 52 to a direction different from the conveyance direction F of the electrolyte sheet 11 to change the back sheet 14 to the electrolyte sheet. It is a member to be peeled from 11.

In the embodiment shown in FIG. 1, the peeling portion 53 is a roll extending in the width direction of the back sheet 14, but may be, for example, a polygonal columnar bar extending in the width direction of the back sheet 14. The peeling temperature of the peeling portion 53 may be a temperature at which damage to the electrolyte sheet 11 due to the softening of the polymer resin can be avoided, and for example, it is preferably room temperature.

In addition to this, the manufacturing apparatus 1 includes a first unwinding portion 54 that unwinds the composite sheet 10A and a second unwinding portion 55 that unwinds the gas diffusion sheet 15. In addition, the manufacturing apparatus 1 includes a first winding unit 56 that winds the back sheet 14 peeled together with the release layer 13 and an upper side of FIG. 2C, which is illustrated in the lower side of FIG. The second winding portion 57 for winding the joined body 10D shown in FIG.

Furthermore, the manufacturing apparatus 1 transports the transport rolls 61 and 64 that transport the joining sheet 10C in addition to the transport rolls 61 that transport the composite sheet 10A and the transport roll 62 that transports the bonding sheet 10B. A transport roll 65 is provided.

By the way, as described above, at the interface of the electrolyte sheet 11 that is in contact with the release layer 13 when the hot press rolls 51, 51 are pressed, the halogen atom of the release layer 13 causes the sulfonic acid group of the polymer resin of the electrolyte sheet 11 to move. May increase. As a result, the adhesive force between the electrolyte sheet 11 and the release layer 13 increases. Since the conventional manufacturing apparatus 1′ shown in FIG. 8 is not provided with the annealing treatment section 52 shown in FIG. 1, the back sheet 14 is peeled off at the peeling section 53 with respect to the joining sheet 10B shown in FIG. 9(a). At the time of peeling, part of the release layer 13 may adhere to the electrolyte sheet 11 (see FIG. 9B).

On the other hand, in the present embodiment, the annealing unit 52 heats the joining sheet 10B until the polymer resin of the electrolyte sheet 11 reaches the temperature of the rubber-like region, and then cools it. Thereby, at the interface of the electrolyte sheet 11 in contact with the release layer 13, the amount of sulfonic acid groups increased at the time of joining with the hot press rolls 51, 51 is reduced, and the adhesive force of the release layer 13 to the electrolyte sheet 11 is reduced. To do. As a result, as shown in FIG. 2C, it is possible to prevent the release layer 13 from adhering to the electrolyte sheet 11 and peel the back sheet 14 from the electrolyte sheet 11.

3. Method for Manufacturing Bonded Body 10D Next, the manufacturing method will be described with reference to the flowchart shown in FIG. 4 for explaining the steps of the method for manufacturing the bonded body 10D by the manufacturing apparatus 1 of the present embodiment.

<Preparation process S1>
In this manufacturing method, first, a preparation step S1 is performed. In this step, first, the composite sheet 10A and the gas diffusion sheet described above are prepared (see FIG. 2A). Here, as described above, in the prepared composite sheet 10A, the amount of sulfonic acid groups at the interface between the electrolyte sheet 11 and the release layer 13 is larger than that in the sheet before catalyst coating.

Next, the prepared composite sheet 10A and the gas diffusion sheet 15 are unwound from the first and second unwinding portions 54 and 55, respectively, and conveyed between the pair of hot-press rolls 51 and 51 to be bonded to each other as described later. Carry out the process. Here, the composite sheet 10A and the gas diffusion sheet 15 are conveyed by a roll-to-roll method.

<Joining step S2>
Next, the joining step S2 is performed. In this step, the composite sheet 10A and the gas diffusion sheet 15 conveyed from the first and second unwinding portions 54 and 55, respectively, are introduced between a pair of hot-press rolls 51 and 51, and they are conveyed while being hot pressed. To do.

At the time of introduction, the composite sheet 10A and the gas diffusion sheet 15 are hot-pressed with the hot press rolls 51, 51 to bond the composite sheet 10A and the gas diffusion sheet 15. In the present embodiment, since the catalyst layer 12 faces the gas diffusion sheet 15, the gas diffusion sheet 15 is joined to the catalyst layer 12 (see FIG. 2B).

Here, as described above, in the joining sheet 10B, the amount of sulfonic acid groups at the interface of the electrolyte sheet 11 in contact with the release layer 13 is larger than that before joining due to heating during joining. The joining sheet 10B is further conveyed to the annealing processing section 52 through the conveyance rolls 62. The annealing process section 52 performs an annealing process S3 described below.

<annealing step S3>
In this step, the joining sheet 10B after the joining step S2 is conveyed and heated until the polymer resin of the electrolyte sheet 11 reaches the temperature of the rubber-like region, and then cooled to join the joining sheet 10C (FIG. 2B). Reference).

By this heating, in the polymer resin of the electrolyte sheet 11 which is in the rubber state, the sulfonic acid groups are easily moved. Therefore, as shown in FIG. 6A, at the interface of the electrolyte sheet 11 in contact with the release layer 13, the amount of sulfonic acid groups increased in the bonding step S2 is reduced. Moreover, the amount of sulfonic acid groups reduced on the interface is retained by cooling after heating. As a result, the adhesive force of the release layer 13 to the electrolyte sheet 11 is reduced. 10 C of joining sheets are conveyed to the peeling part 53 through the conveyance rolls 63 and 64. In the peeling section 53, the peeling step S4 described below is performed.

<Peeling step S4>
In this step, the back sheet 14 is peeled off from the electrolyte sheet 11 by the peeling section 53 while conveying the joining sheet 10C after the annealing step S3. Specifically, the backsheet 14 (backsheet 14A) is wound so that the backsheet 14 is wrapped around the peeling section 53 and the backsheet 14 is changed to a different transport direction G with respect to the transport direction F of the joined body 10D. It is conveyed and then wound up by the first winding section 56. At the same time, the bonded body 10D from which the back sheet 14 has been peeled off is transported by the transport rolls 65 and then wound by the second winding unit 57.

In the present embodiment, the adhesive force between the electrolyte sheet 11 and the release layer 13 of the joining sheet 10C is lower than the adhesive force immediately after the hot pressing step S2. Thereby, at the time of peeling, the release layer 13 can be prevented from adhering to the electrolyte sheet 11, and the back sheet 14 can be peeled from the electrolyte sheet 11 (see FIG. 2C).

<Reference Example 1>
First, a test material sheet corresponding to the composite sheet shown in the lower diagram of FIG. Specifically, a catalyst is applied onto the surface of the electrolyte sheet of the sheet (pre-catalyst coating sheet) in a state where the electrolyte sheet is adhered to the back sheet of polyethylene terephthalate (PET) via the release layer, This was dried to form a catalyst layer. The catalyst contained an ionomer and platinum-supporting carbon, and the drying conditions in the catalyst coating for coating and drying the catalyst were 85° C. and 5 minutes. The release layer is a resin layer made of a fluorinated polyolefin resin, and the polymer resin forming the electrolyte sheet is a resin having a sulfonic acid group.

Next, the manufactured test material sheet was annealed. Specifically, the test body was passed through a heating roll heated to 160° C. for a heating (contact) time of 1.9 seconds to heat it, and then naturally cooled to room temperature. This was used as the test body of Reference Example 1.

Note that the heating temperature of 160° C. corresponds to the temperature of the rubber-like region of the polymer resin of the electrolyte sheet. The temperature range was confirmed by measuring the dynamic viscoelasticity of the electrolyte sheet in the MD direction (JIS K 7244 compliant) (see FIG. 7).

<Reference Comparative Example 1>
A test body was prepared in the same manner as in Reference Example 1. The difference between Reference Comparative Example 1 and Reference Example 1 is that no annealing treatment was performed.

<Reference Comparative Examples 2 to 4>
A test body was prepared in the same manner as in Reference Example 1. The difference between Reference Comparative Examples 2 to 4 and Reference Example 1 lies in the heating temperature during the annealing treatment. Specifically, the heating temperatures of Reference Comparative Examples 2 to 4 were 130°C, 140°C, and 150°C, respectively. These heating temperatures are temperatures in the transition region where the polymer resin of the electrolyte sheet is lower than the temperature in the rubber-like region (see FIG. 7).

(Visual peel test and its result)
With respect to the test samples of Reference Example 1 and Reference Comparative Examples 1 to 4, the back sheet was peeled from the electrolyte sheet, and the presence or absence of the release layer adhered to the electrolyte sheet was visually confirmed. No adhesion was observed in Reference Example 1, whereas adhesion was observed in Reference Comparative Examples 1 to 4. In addition, as Reference Comparative Example 5, although pressure was applied during the annealing treatment, the test body was broken, so that peeling could not be performed. In Reference Comparative Examples 2 to 4, the heating temperature was equal to or lower than the temperature of the rubber-like region, so it is considered that the release layer adhered to the electrolyte sheet.

<Reference Example 2>
The difference between Reference Example 2 and Reference Example 1 is that the heating time during the annealing treatment is 5 minutes. The heating temperature of the annealing treatment is 160°C.

<Reference Comparative Examples 6 and 7>
The difference between Reference Comparative Example 6 and Reference Example 2 is that the test body of Reference Comparative Example 6 was a sheet before catalyst coating, and that annealing treatment was not performed. The difference between Reference Comparative Example 7 and Reference Example 2 is that no annealing treatment was performed. Reference comparative example 7 corresponds to reference comparative example 1.

<Reference Comparative Examples 8 to 10>
Reference Comparative Examples 8 to 10 are different from Reference Example 2 in the heating temperature during the annealing treatment. Specifically, Reference Comparative Examples 8 to 10 are 130° C., 140° C., and 150° C., respectively. Met.

(90°C peeling test and its result)
For Reference Example 2 and Reference Comparative Examples 6 to 10, a peeling test was conducted in which the back sheet was peeled from the electrolyte sheet at an angle of 90° to measure the peel strength. Results are shown in FIG.

The peel strength of Reference Comparative Example 7 corresponding to the composite sheet of this embodiment was larger than the peel strength of Reference Comparative Example 6 corresponding to the sheet before catalyst coating. From this result, it was found that the catalyst coating increases the adhesive force between the electrolyte sheet and the release layer of the composite sheet.

It is considered that this is because the sulfonic acid group of the polymer resin of the electrolyte sheet was easily attracted to the fluorine group of the resin of the release layer by the heating during drying of the catalyst coating. Therefore, as shown in FIG. 6B, in the composite sheet, at the interface of the electrolyte sheet in contact with the release layer, the amount of sulfonic acid groups is the sulfonic acid at the interface of the pre-catalyst sheet shown in FIG. 6A. It is considered that the amount increased from the amount of the group. As a result, it is considered that the catalyst coating increases the adhesive force between the electrolyte sheet and the release layer. As a result, as in Reference Comparative Example 1 described in Result 1, in the composite sheet, the release layer is considered to adhere to the electrolyte sheet.

Further, the peel strength of Reference Comparative Examples 8 to 10 heated at 130 to 150° C. during the annealing treatment was higher than the peel strength of Reference Comparative Example 7 not heated at the temperature. From this result, by heating at 130 to 150° C. which is the transition region, as shown in FIG. 6C, in the composite sheet after heating, the amount of sulfonic acid groups was further increased at the interface of the electrolyte sheet in contact with the release layer. It is thought to have been done. As a result, it is considered that the adhesive force of the electrolyte sheet in contact with the release layer is increased.

On the other hand, in the annealing treatment, the peeling strength of Reference Example 2 heated at 160° C., which is a rubber-like region, is lower than that of Reference Comparative Examples 8-10 heated at 130 to 150° C., and moreover, before the catalyst coating. The peel strength was similar to that of Reference Comparative Example 6 corresponding to the sheet.

From this result, the amount of sulfonic acid groups at the interface of the electrolyte sheet in contact with the release layer was about the same as that of the sheet before catalyst coating as shown in FIG. It is considered that the amount has been reduced. Further, since the reduced amount of sulfonic acid group may increase at less than 160° C., cooling after heating is preferably performed so as to ensure the reduced amount of sulfonic acid group.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention described in the claims. The design can be changed.

1: Manufacturing apparatus, 10A: Composite sheet, 10B: Joined sheet, 10D: Joined body, 11: Electrolyte sheet, 12: Catalyst layer, 13: Release layer, 14: Back sheet, 15: Gas diffusion sheet, 51, 51 : A pair of hot-press rolls, 52: annealing part, 53: peeling part, G: direction different from the transport direction of the electrolyte sheet

Claims (1)

A composite sheet in which a catalyst layer is formed on one surface of a strip-shaped electrolyte sheet that constitutes an electrolyte membrane of a fuel cell, and a back sheet is attached to the other surface of the electrolyte sheet via a release layer. And a strip-shaped gas diffusion sheet that constitutes the gas diffusion layer of the fuel cell, while transporting the gas diffusion sheet to the catalyst layer of the composite sheet Manufacturing equipment,
The electrolyte sheet is a sheet of a polymer resin having a sulfonic acid group as an ion exchange group, the release layer is a resin layer containing a halogen atom,
The manufacturing apparatus conveys while sandwiching the composite sheet and the gas diffusion sheet in a state where the catalyst layer and the gas diffusion sheet are in contact with each other, and the catalyst layer and the gas diffusion sheet are joined together. A pair of hot-press rolls that hot-press the back sheet and the gas diffusion sheet,
While carrying the bonding sheet in which the catalyst layer and the gas diffusion sheet are bonded together, the polymeric resin of the polymeric resin sheet is heated to the temperature of the rubber-like region, and then cooled, An annealing treatment section for reducing the adhesive force of the release layer to the electrolyte sheet,
Contacting the backsheet, changing the conveying direction of the backsheet conveyed from the annealing unit to a direction different from the conveying direction of the electrolyte sheet, and peeling the backsheet together with the release layer from the electrolyte sheet An apparatus for manufacturing a joined body of fuel cell, comprising:

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