JP2007123239A - Method of producing electrolyte structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology of producing an electrolyte structure which prevents an electrolyte film on a substrate from crinkling up or peeling away from the substrate. <P>SOLUTION: The method of producing electrolyte structure of this invention comprises a film forming process of forming the electrolyte film on the surface of the substrate to obtain the substrate with the film, an applying process of applying a catalyst material on the substrate with the film to obtain the substrate with the catalyst, a drying process of drying the substrate with the catalyst to obtain dried object, and a moisturizing process of moisturizing the dried object in an atmosphere adjusted to humidity equivalent to predetermined humidity. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improvement in a method for producing an electrolyte structure, which is characterized in that an electrolyte structure is obtained by applying a catalyst material to a film-coated substrate formed by forming an electrolyte membrane on the surface of the substrate.

  In recent years, a fuel cell (also referred to as a polymer electrolyte fuel cell) including an electrolyte structure has characteristics that it operates at a low temperature, has a high output density, and can be miniaturized. Therefore, the research and development is actively conducted.

  An electrolyte structure of a fuel cell is a laminate formed by forming an electrolyte membrane and a catalyst material on the surface of a base material, and it is important to establish a technique for manufacturing the electrolyte structure in a homogeneous, inexpensive and large quantity. It has become a challenge.

Conventionally, a film-coated substrate is obtained by applying an electrolyte membrane to the surface of a substrate. And the manufacturing method which dries this base material with a film | membrane and obtains a dry body is proposed (for example, refer patent document 1).
JP 2004-356075 A (FIG. 1)

Patent document 1 is demonstrated based on the following figure.
FIG. 10 is a diagram for explaining a basic configuration of a conventional technique. An electrolyte structure manufacturing apparatus 100 includes a base material unwinding apparatus 102 that unwinds a base material 101, and an electrolyte membrane solution 103 applied to the base material 101. Then, the coating device 105 for obtaining the film-coated substrate 104, the support material unwinding device 107 for unwinding the support material 106, and the electrolyte membrane 108 applied to the substrate 101 are overlapped with the support material 106 to form a film-coated member. 104, a laminating roll 110 for obtaining a laminated body 109 including 104, a dryer 111 for drying the laminated body 109 (... indicates a plurality, the same applies hereinafter), and a winding for winding the dried laminated body 109. The device includes the device 112. Then, by adjusting the rotational torque of the bobbins 114 and 115 of the base material unwinding device 102 and the support material unwinding device 107 and applying a predetermined tension to the base material 101 and the support material 106, This is to obtain a film-coated substrate 104 having no film.

  However, if the membrane-coated member 104 is immediately wound after the electrolyte membrane 108 is formed on the substrate 101, the electrolyte membrane 108 will collapse because the electrolyte membrane 108 is still soft.

  In order to increase the strength of the electrolyte membrane 108, if the electrolyte membrane 108 is rapidly dried with a dryer 111... Before being wound, the electrolyte membrane 108 is dehumidified and the electrolyte membrane 108 contracts.

The electrolyte membrane 108 is a material rich in hygroscopicity and water repellency, and when the electrolyte membrane 108 that has absorbed a large amount of moisture is dehumidified, the amount of shrinkage is large. As described above, there remains a problem that the electrolyte membrane 108 integrated on the substrate 101 is peeled off or wrinkles are generated in the electrolyte membrane 108 due to the expansion or contraction of the electrolyte membrane 108.
It is desired to establish a manufacturing method in which peeling or wrinkle does not occur in the electrolyte membrane 108 on the substrate 101.

  Then, this invention makes it a subject to provide the technique which manufactures the electrolyte structure which prevents peeling from the base material of an electrolyte membrane, or the wrinkle of the electrolyte membrane on a base material.

  The invention according to claim 1 is a film formation step of forming an electrolyte membrane on the surface of a substrate to obtain a substrate with a film in an atmosphere adjusted to a predetermined humidity, and a catalyst material is applied to the substrate with a film. Coating step for obtaining a base material with catalyst, a drying step for drying the base material with catalyst to obtain a dried body, and a humidifying step for humidifying the dried body in an atmosphere adjusted to a humidity equivalent to a predetermined humidity, It is characterized by comprising.

  The invention according to claim 2 is characterized in that another humidification step is provided at least one between the film formation step and the coating step and between the coating step and the drying step.

  In the invention according to claim 1, a catalyst material is applied to a film-coated substrate to form a catalyst-coated substrate, and the catalyst-coated substrate is dried to form a dried body, whereby a film-formed substrate is obtained. A humidifying step of humidifying in an atmosphere adjusted to a humidity equivalent to the predetermined humidity in the step was provided.

Excessive shrinkage of the electrolyte membrane by adding appropriate moisture in the humidification process of humidifying in an atmosphere adjusted to the same humidity as the atmosphere for obtaining a membrane-coated substrate on an electrolyte membrane rich in water absorption and water repellency Can be prevented. By preventing the electrolyte membrane from shrinking excessively, it is possible to prevent the problem that the electrolyte membrane peels from the base material.
As a result, there is an advantage that an electrolyte structure in which the electrolyte membrane on the substrate is difficult to peel can be manufactured.

In the invention which concerns on Claim 2, since another humidification process is provided between a film | membrane formation process and an application | coating process, a preferable moisture can be given to a base material with a film | membrane before application | coating of a catalyst material.
By applying the preferred moisture for applying the catalyst material to the substrate with a film, no peeling occurs between the electrolyte membrane and the substrate, while maintaining a good degree of adhesion between the electrolyte membrane and the substrate. A catalyst material can be applied.

Moreover, the shrinkage | contraction of the electrolyte membrane after catalyst material application | coating can be suppressed by providing another humidification process between an application | coating process and a drying process.
In this way, by providing a humidification step between each step and finely controlling the moisture of the electrolyte membrane, the electrolyte membrane contracts or expands due to excessive or insufficient moisture contained in the electrolyte structure, and the base material There is an advantage that problems such as peeling from the resin can be solved.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a manufacturing flow diagram of an electrolyte structure according to the present invention.
First, in the film formation step, an electrolyte membrane is formed on the surface of the substrate to obtain a substrate with a film.Next, in the coating step, a catalyst material is applied to the electrolyte membrane of the substrate with a film, and in the drying step, The membrane-coated substrate coated with the catalyst material is dried, and finally, in the humidification step, the film-coated substrate coated with the catalyst material is humidified in an atmosphere adjusted to a predetermined humidity, so that there is no peeling or warping. A good electrolyte structure is obtained.

Or the manufacturing method of the electrolyte structure provided the humidification process in the process which consists of the film | membrane formation process which obtains a base material with a film | membrane, the application | coating process which apply | coats a catalyst material, and the drying process which dries a base material with a catalyst. It can be said that. A humidification process shall be provided after a drying process.
Hereinafter, details of each process will be described in order.

FIG. 2 is a diagram for explaining the film forming process of the film-coated substrate according to the present invention, and a film-coated substrate 23 is obtained by forming electrolyte films 22... On the surface 21 a of the substrate 21.
In the film forming step, the electrolyte membrane 22 is formed on the surface 21a of the substrate 21 in an atmosphere adjusted to a predetermined humidity to obtain the substrate 23 with a film. The predetermined temperature is 40% to 60%, preferably 50%. The film-coated substrate 23 is supplied in the form of a roll member 24 and is obtained by unwinding the roll member 24.

The electrolyte membrane 22 formed on the surface of the substrate 21 is intermittently disposed in the unwinding direction of the roll member 24. Further, the length in the width direction of the electrolyte membrane 22 is smaller than the width of the base material 21.
Here, the base material 21 is a porous material, which is a base material for impregnating the electrolyte, and is a member that reinforces the electrolyte membrane 22.

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2 and is a diagram illustrating the structure of the film-coated member.
The unwound substrate 23 with a film is a member having a two-layer structure including a substrate 21 extending horizontally in the width direction and an electrolyte membrane 22 in close contact with the surface 21 a of the substrate 21.

FIG. 4 is a cross-sectional view of the base material with catalyst obtained in the coating step according to the present invention, and is a view for explaining the structure of the base material with catalyst 26.
When the catalyst material 25 is applied to the surface 22a of the electrolyte membrane 22 in the application step, the film-coated substrate 23 becomes the catalyst-coated substrate 26.

The base material with catalyst 26 is a member having a three-layer structure including the base material 21, the electrolyte membrane 22 disposed on the surface 21 a of the base material 21, and the catalyst material 25 disposed on the surface 22 a of the electrolyte membrane 22.
That is, in the coating step, the catalyst material 25 is applied to the film-coated substrate 23 to obtain the catalyst-coated substrate 26.

FIG. 5 is a diagram for explaining the drying process of the base material with catalyst according to the present invention, and the drying process is a process provided between the coating process (see FIG. 1) and the humidification process.
The drying process includes a drying chamber 31, and three heater units 32 that blow dry air are provided in the drying chamber 31. And the base material 26 with a catalyst is moved in the direction of the arrow 33 in the drying chamber 31, and the air heated from the heater units 32... The base material 26 is dried to obtain a dried body 34. In addition, 35 ... is a roller which supports the base material 26 with a catalyst so that rotation is possible.
That is, in the drying step, the catalyst-coated substrate 26 is dried to obtain a dried body 34.

  In the present embodiment, the number of heater units 32 is three, and intermittently heated air is applied in the process. However, the present invention is not limited to this, and the number of heater units, the capacity of the heater units, etc. are arbitrary. It shall be configurable.

FIG. 6 is a view for explaining the humidifying step of the base material with catalyst according to the present invention. The humidifying step is a step provided after the drying step (see FIG. 1).
In the humidification step, a humidification chamber 41 is provided, and three humidification units 42 for blowing humidified air into the humidification chamber 41 are provided. And the dry body 34 which dried the base material 26 with a catalyst in the direction of the figure arrow 43 is moved in the humidification chamber 41, and from the humidification unit 42 ... toward the side which apply | coated the catalyst material 25 of this dry body 34. FIG. The electrolyte structure 30 is obtained by applying humidified air and humidifying the dried body 34 in an atmosphere adjusted to a humidity equivalent to the predetermined humidity in the film forming step. Reference numerals 45... Denote rollers that rotatably support the dry body 34.
That is, in the humidification step, the dried body 34 is humidified to obtain the electrolyte structure 30.
The setting of the atmosphere in the humidifying step is the same as the humidity (40% to 60%, preferably 50%) in the film forming step, but a difference of ± 5% is acceptable.

  In the present embodiment, the number of humidifying units 42 is three and intermittently humidified air is applied, but the number of humidifying units, the capacity of the humidifying units, and the like can be arbitrarily set.

The operation of the present invention will be described below with reference to FIGS.
A catalyst material 25 is applied to a film-coated substrate 23 composed of a substrate 21 and an electrolyte membrane 22 to obtain a catalyst-coated substrate 26. The catalyst-coated substrate 26 is dried in a drying step to obtain a dried body 34. A humidifying process for humidifying the dried body 34 is provided, and moisture is added to the electrolyte membrane 22 provided in the dried body 34 in the humidifying process.

  Conventionally, in the step of applying the catalyst material, when the humidity is different from the film forming step for obtaining the electrolyte membrane, the electrolyte 22 (for example, aromatic hydrocarbon-based electrolyte) and the substrate 21 (for example, polyethylene terephthalate (PET)). .) Has a different shrinkage ratio at the time of drying, and therefore, when folding is performed by roll processing, the electrolyte membrane 22 may be peeled off from the substrate 21 or the electrolyte membrane 22 on the substrate 21 may be wrinkled. .

  In this respect, in the present invention, in order to maintain the adhesion between the base material 21 and the electrolyte membrane 22, the humidity (50) equivalent to the film formation step of applying the electrolyte membrane 22 to the base material 21 to obtain the film-coated base material 23. %)), It is possible to prevent peeling and wrinkling of the electrolyte membrane 22, and to suppress peeling and wrinkling in continuous processing of a film-coated substrate or processing by folding with a roller. , Process quality can be stabilized.

  That is, excessive shrinkage of the electrolyte membrane 22 can be suppressed by adding appropriate moisture to the electrolyte membrane 22 rich in water absorption and water repellency. Since the electrolyte membrane 22 does not shrink excessively, a large stress is not generated between the base material 21 and the electrolyte membrane 22 formed on the base material 21, and the electrolyte membrane 22 peels from the base material 21. It is possible to suppress problems such as

  As a result, an electrolyte structure in which the electrolyte membrane 22 on the substrate 21 is difficult to peel can be manufactured. Since the problem that the electrolyte membrane 22 on the base material 21 peels does not occur, a high quality electrolyte structure can be manufactured.

  The electrolyte membrane is an aromatic hydrocarbon electrolyte. In addition, perfluorosulfonic acid electrolytes (Nafion: registered by DuPont, Flemion: registered by Asahi Glass Co., Ltd., Aciplex Asahi Kasei Co., Ltd. )) And the like, the same effect is obtained without causing problems such as peeling.

FIG. 7 shows another embodiment of FIG.
First, in the film formation step, an electrolyte membrane is formed on the surface of the substrate to form a substrate with a film, and then in the first humidification step, the substrate with a film is humidified.

  Then, in the coating process, a catalyst material is applied to the electrolyte membrane of the film-coated substrate, and in the second humidification process, the catalyst-coated substrate that is the film-coated substrate coated with the catalyst material is humidified.

After apply | coating a catalyst material, a base material with a catalyst is dried in a drying process.
Finally, in the third humidification step (same as the humidification step shown in FIG. 1), the film-coated substrate coated with the catalyst material is humidified.

That is, a first humidification step is provided between the film formation step and the coating step, a second humidification step is provided between the coating step and the drying step, and a third humidification step is provided after the drying step.
Depending on the process conditions, it is possible to omit one of the humidifying steps between the film forming step and the applying step and between the applying step and the drying step.

FIG. 8 is a diagram for explaining the humidifying step of the film-coated substrate according to the present invention and shows the first humidifying step.
In the first humidification step, a humidification chamber 61 is provided after the film formation step (see FIG. 7), and three humidification units 62 for blowing humidified air into the humidification chamber 61 are provided. And the base material 23 with a film | membrane is moved in the direction of the figure arrow 63 in the humidification chamber 61, the humidified air is applied toward the side which apply | coated the electrolyte membrane 22 ... of this base material 23 with a film | membrane, The material 23 is humidified. In addition, 65 ... is a roller which supports the base material 23 with a film so that rotation is possible.

  The configurations of the humidification chamber, the humidification unit, and the roller provided for the second humidification step provided between the coating step and the drying step are the same as those in FIG.

  In a present Example, it is safe to omit either one of a 1st humidification process and a 2nd humidification process.

Returning to FIG. 7, the operation of another embodiment will be described.
If the first humidification step, which is another humidification step, is provided between the film formation step and the coating step, the substrate with film 23 can be given a preferable moisture before the application of the catalyst material 25 (see FIG. 4). .

By applying a preferable moisture for applying the catalyst material 25 (see FIG. 4) to the film-coated substrate 23, no great stress is generated between the electrolyte membrane 22 and the substrate 21. Since the generation of stress is not large, peeling or the like does not occur between the electrolyte membrane 22 and the substrate 21, and the catalyst material 25 is applied while maintaining good adhesion between the electrolyte membrane 22 and the substrate 21. Can do.
In addition, the coating quality of the catalyst material 25 on the electrolyte membrane 22 can be improved.

  By providing a second humidification step, which is another humidification step, between the application step and the drying step, the shrinkage of the electrolyte membrane 22 after application of the catalyst material 25 (see FIG. 4) can be suppressed.

  In this way, by providing the humidification steps 51, 52, 53 between each step and finely controlling the moisture of the electrolyte membrane 22 (see FIG. 4), the moisture contained in the electrolyte structure is too small or too large. The problem that the electrolyte membrane 22 peels from the substrate 21 due to contraction or expansion can be solved.

FIG. 9 is a diagram for explaining the state of the electrolyte membrane on the base material in which the conventional example and the present invention are compared.
(A) is a comparative example, in which the electrolyte membrane 22 is in close contact with the base material 21, but the electrolyte membrane 22 contracts due to low moisture content, and a part thereof peels from the base material 21. .
When the moisture is low in this way, the electrolyte membrane 22 contracts, stress is generated between the electrolyte membrane 22 and the substrate 21, and the electrolyte membrane 22 is peeled off from the substrate 21. Or the problem that the base material 23 with a film | membrane warps inside will generate | occur | produce.

  (B) is an example, and in the method for manufacturing an electrolyte structure according to the present invention, an electrolyte membrane is provided by providing a first humidification step which is a humidification step between the film formation step (see FIG. 7) and the coating step. No 22 contraction or slight. Therefore, no large stress is generated on the surface 66 between the base material 21 and the electrolyte membrane 22, indicating that the electrolyte membrane 22 remains in close contact with the base material 21 and does not peel off.

  As described above, according to the method for manufacturing an electrolyte structure according to the present invention, the shrinkage reaction of the electrolyte membrane 22 that causes wrinkles and peeling can be controlled. By moistening in an atmosphere adjusted to the same humidity (50%) as the atmosphere of the above, peeling and wrinkle can be prevented, and even when the film-coated substrate is continuously processed or folded by a roller, The quality can be stabilized.

  The present invention is suitable for manufacturing an electrolyte structure for a fuel cell.

It is a manufacturing flow figure of the electrolyte structure concerning the present invention. It is a figure explaining the film formation process of the base material with a film concerning the present invention. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. It is sectional drawing of the base material with a catalyst obtained at the application | coating process which concerns on this invention. It is a figure explaining the drying process of the base material with a catalyst which concerns on this invention. It is a figure explaining the humidification process of the base material with a catalyst which concerns on this invention. It is another Example figure of FIG. It is a figure explaining the humidification process of the base material with a film concerning the present invention. It is a figure explaining the state of the electrolyte membrane on the base material which compared the prior art example and this invention. It is a figure explaining the basic composition of the conventional technology.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 21 ... Base material, 21a ... Surface of base material, 22 ... Electrolyte, 22a ... Surface of electrolyte, 23 ... Base material with membrane, 25 ... Catalyst material, 26 ... Base material with catalyst, 30 ... Electrolyte structure.

Claims (2)

In an atmosphere adjusted to a predetermined humidity, a film forming step of forming an electrolyte membrane on the surface of the substrate to obtain a substrate with a film,
A coating step of applying a catalyst material to the film-coated substrate to obtain a catalyst-coated substrate;
A drying step of drying the catalyst-coated substrate to obtain a dried product;
A humidifying step of humidifying the dried body in an atmosphere adjusted to a humidity equivalent to the predetermined humidity;
The manufacturing method of the electrolyte structure characterized by comprising.   2. The method for manufacturing an electrolyte structure according to claim 1, wherein another humidifying step is provided between at least one of the film forming step and the applying step and between the applying step and the drying step.

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