JP6319940B2 - Method for producing electrolyte membrane with catalyst layer - Google Patents

Description

  The present invention relates to an electrolyte membrane with a catalyst layer for use in a polymer electrolyte fuel cell and a method for producing the membrane.

A fuel cell is a power generation system that converts a chemical energy of a fuel into electric energy and extracts it by electrochemically reacting a fuel such as hydrogen with an oxidant such as air. This power generation method is expected to be a new energy because of its advantages such as high power generation efficiency, excellent quietness, NOx and SOx that cause air pollution, and low CO ₂ emissions that cause global warming. Has been. Examples of the application of this fuel cell include a long-time power supply for portable electric devices, a stationary generation hot water supply machine for cogeneration, a fuel cell vehicle, and the like, which have various uses and scales.

The types of fuel cells are classified into solid polymer type, phosphoric acid type, molten carbonate type, solid oxide type, alkaline type, etc. depending on the electrolyte used. Is also different.
Among the various fuel cells described above, a polymer electrolyte fuel cell having many advantages is known. This polymer electrolyte fuel cell uses a cation exchange membrane as an electrolyte. The advantages are: 1) The fuel cell can be operated at a relatively low temperature, that is, it can be used near room temperature, and 2) The internal resistance can be reduced by reducing the thickness of the electrolyte membrane, so that high output and compactness are possible. A certain point is paid attention. Therefore, the polymer electrolyte fuel cell is considered promising for use in an in-vehicle power source or a home stationary power source, and various research and development have been conducted in recent years.

  In a polymer electrolyte fuel cell, a pair of gas diffusion layers are disposed on a membrane in which a pair of electrode catalyst layers are formed on both sides of a polymer electrolyte, and a membrane electrode assembly (Membrane Electrode Assembly) as a central member: MEA) is configured. A gasket is disposed on the peripheral edge of the electrode catalyst layer. And the battery is comprised by pinching the membrane electrode assembly which is a center member with a pair of separator plate. In this polymer electrolyte fuel cell, each gas flow path is formed in order to supply a fuel gas containing hydrogen to one electrode and an oxidant gas containing oxygen to the other electrode. In addition, the film | membrane in which a pair of electrode catalyst layer was formed on both surfaces of the polymer electrolyte is also called an electrolyte membrane with a catalyst layer (Catalyst Coated Membrane; CCM). A battery sandwiched between a pair of separator plates is called a single battery cell.

  A polymer electrolyte fuel cell is used by stacking a plurality of unit cells for the purpose of increasing the power density and making the entire fuel cell compact. The number of sheets to be stacked varies depending on the required electric power. For portable power sources of general portable electric devices, several to about 10 sheets, for stationary electric and hot water supply machines for cogeneration, about 60 to 90 sheets, and for automobile applications, 250 to About 400 sheets. In order to increase the output, it is necessary to increase the number of stacks, and the cost of the unit cell greatly affects the cost of the entire fuel cell. From the viewpoint of process cost, an inexpensive and simple method for producing an electrolyte membrane with a catalyst layer and a membrane electrode assembly is desired.

  Various methods have been studied as a method for producing an electrolyte membrane with a catalyst layer. For example, the following four methods are known. 1) Applying a coating solution containing a catalyst onto an ion exchange membrane to form a catalyst layer to be an electrode, and joining the electrode and the ion exchange membrane by a heat treatment such as hot pressing to produce an electrolyte membrane with a catalyst layer how to. 2) In addition to the ion exchange membrane, a catalyst layer is formed on a separately prepared substrate film, and thereafter the ion exchange membrane is laminated on the catalyst layer and hot-pressed to transfer the catalyst layer onto the ion exchange membrane. Method. 3) A method of manufacturing an electrode sheet having a catalyst layer formed on a gas diffusion layer, and bonding the electrode sheet to an ion exchange membrane. 4) A method of producing an electrolyte membrane with a catalyst layer by producing two sets (half-cells) in which a catalyst layer is formed on an ion exchange membrane and pressing the respective ion exchange membrane sides facing each other.

However, since the electrolyte membrane with a catalyst layer produced by these methods is produced by thermocompression bonding such as hot pressing when the ion exchange membrane and the electrode catalyst layer are joined, the process becomes a bottleneck. There is a problem that the tact time becomes long, resulting in a decrease in production efficiency.
As a method for solving this problem, a method of sequential lamination in which a first electrode catalyst layer is manufactured on a substrate, a polymer electrolyte layer 8 is manufactured, and finally a second electrode catalyst layer is manufactured is proposed. Has been. In this sequential lamination method, the tact time is short and the production efficiency is high, so that the manufacturing cost is low. (Patent Document 1, Patent Document 2)

  Further, as a method of forming an electrode catalyst layer having a desired shape on the polymer electrolyte layer, a covering member is disposed at a non-catalyst layer forming portion of the electrolyte layer, and an electrode catalyst ink is disposed on the electrolyte layer on which the covering member is disposed. There has been proposed a method of forming a catalyst layer by coating and drying. By controlling the shape of the covering member, a catalyst layer having a desired shape can be obtained, and the electrode catalyst ink is directly applied to the electrolyte layer, so that the manufacturing cost is reduced. (Patent Document 3)

Japanese Patent No. 4696462 Japanese Patent No. 5011867 JP 2007-294183 A

However, although the manufacturing cost of the membrane electrode assembly disclosed in Patent Literature 1 and Patent Literature 2 is low, the shape of the catalyst layer depends on the coating method, and a catalyst layer having a desired shape is obtained. There was a problem that I could not.
Moreover, in patent document 3, the catalyst layer formed on the coating | coated member becomes a loss. In the catalyst layer, a noble metal typified by platinum is present as a catalyst. Therefore, there is a problem that the loss of the catalyst layer leads to an increase in cost.

Furthermore, when the catalyst ink 70 is applied to the polymer electrolyte membrane to form the catalyst layer, only the interface between the membrane and the catalyst layer is bonded, and the catalyst layer is easily dried from the exposed cross section. There was a problem that the power generation performance was lowered under low humidification conditions such as only the required generated water.
The present invention has been accomplished in consideration of the above-mentioned problems. 1) High power generation performance under low humidification conditions, 2) low ionic resistance, 3) low loss of catalyst ink, and 4) desired shape. It is an object of the present invention to provide a catalyst layer-attached electrolyte membrane that can form a catalyst layer with high accuracy and has a short tact time and high production efficiency, and a method for producing the same.

In order to solve the above problems, the present invention employs a method for producing an electrolyte membrane with a catalyst layer having the following configuration.
Claim 1, the catalyst carrying particles to the polymer electrolyte and a solvent and a non-affinity area has no affinity for the affinity area (5) and the catalyst ink (70) having an affinity for the catalyst ink (70) containing ( 6), a pattern forming step (S100) for forming a pattern on the release substrate (1), and applying the catalyst ink (70) to the affinity area (5) to form a coating film. A cathode catalyst layer forming step (S25) for removing the solvent in the coated film to form the cathode catalyst layer (71), and an electrolyte ink containing a polymer electrolyte and a solvent on the cathode catalyst layer (71). A polymer electrolyte membrane forming step (S40) for forming a polymer electrolyte membrane (8) by removing the solvent in the formed coating film by coating to form a polymer electrolyte membrane (8); and the polymer electrolyte membrane (8) The catalyst ink (70) is applied on top to form a coating film An anode catalyst layer forming step (S50) for removing the solvent in the formed coating film to form the anode catalyst layer (72), and in the polymer electrolyte membrane forming step (S40), the cathode catalyst After forming the layer (71), the non-affinity area (6) is modified to the affinity area (5), and the polymer electrolyte membrane (8) is formed on the modified affinity area (5). ) So that the surface of the cathode catalyst layer (71) on the side of the release substrate (1) and the surface of the polymer electrolyte membrane (8) on the side of the release substrate (1) are located on the same plane. In the anode catalyst layer forming step (S50), the amount of platinum supported per unit area of the anode catalyst layer (72) is less than the amount of platinum supported per unit area of the cathode catalyst layer (71). The anode catalyst layer (72) Forming a process for preparing a catalyst layer with the electrolyte membrane, characterized by.

The pattern forming step (S100) includes a silane coupling agent forming step (S10) for forming a silane coupling agent (2) in all areas on the release substrate (1), and the affinity area (5). ) After forming the cathode catalyst layer (71) by the silane coupling agent limited removal step (S20) for removing only the silane coupling agent (2) formed above and the cathode catalyst layer formation step (S25), you comprises said a non-affinity area (6) of the remaining silane coupling agent (2) remaining silane coupling agent removing step of removing (S30).

Further, the silane coupling agent limited removal step (S20) is characterized in that it is removed by irradiating vacuum ultraviolet light (3) only on the affinity area (5) through a photomask (4). you.
Further, in the pattern forming step (S100), the in affinity areas (5) by utilizing a hydrophilic, characterized in that said non-affinity area (6) in leverage repellent pattern forming.
In addition, the water contact angle of the affinity area (5) is not more than 15 degrees, the water contact angle of said non-affinity area (6) of you, characterized in that at least 100 degrees.

According to the present invention, 1) high power generation performance under low humidification conditions, 2) low ionic resistance, 3) little loss of catalyst ink, and 4) high accuracy formation of a catalyst layer in a desired shape, 5) It is possible to provide an electrolyte membrane with a catalyst layer and a method for producing the same, which have the effect that the tact time is short and the production efficiency is high.
1) In particular, the reason why the power generation performance can be improved under low humidification conditions is that the cathode catalyst layer is covered with the polymer electrolyte layer on all sides including the cross section, so that the catalyst layer is moisturized even under low humidification conditions. This is because a membrane electrode assembly (MEA) having high proton conductivity can be formed.

2) The reason why the ionic resistance can be reduced is that the contact between the polymer electrolyte layer and the electrode catalyst layer is improved. Therefore, a better result is obtained as compared with the electrolyte membrane with a catalyst layer produced by hot pressing.
3) The reason why the loss of the catalyst ink can be reduced is that, when the cathode catalyst layer is formed, the catalyst layer is formed only in the affinity area having affinity with the catalyst ink. As a result, the manufacturing cost can be reduced.

4) The reason why the catalyst layer can be formed in a desired shape with high accuracy is that the accuracy of the photomask used in the step of removing the silane coupling agent is reflected in the shape of the cathode catalyst layer. Therefore, by using a photomask having a desired accuracy and shape, a catalyst layer having a desired shape can be formed with high accuracy.
5) The reason that the tact time can be shortened and the production efficiency can be increased is because there is no thermocompression bonding step such as hot pressing that becomes a bottleneck when joining the ion exchange membrane and the electrode catalyst layer. Further, since the cathode catalyst layer, the polymer electrolyte layer, and the anode catalyst layer are sequentially laminated, the production efficiency can be extremely increased.

Thus, according to the present invention, the production efficiency is high, and the cathode catalyst layer is covered with the polymer electrolyte layer on all sides including the cross section, so that the catalyst layer is moisturized even under low humidification conditions and is high. It is possible to provide a membrane electrode assembly having proton conductivity, an electrolyte membrane with a catalyst layer, and a method for producing the same, which have an effect of high power generation performance particularly under low humidification conditions.
Furthermore, the present invention provides a method for producing a membrane / electrode assembly that has the effect of improving the contact between the polymer electrolyte layer and the electrode catalyst layer and reducing the ionic resistance as compared with an electrolyte membrane with a catalyst layer produced by hot pressing. be able to.

In addition, according to the present invention, when the cathode catalyst layer is formed, the catalyst layer is formed only in the area having affinity with the catalyst ink, so that the loss of the catalyst ink is eliminated and the production cost is reduced. Can do.
In addition, since the shape of the cathode catalyst layer depends on the accuracy of the photomask through which the silane coupling agent is removed, a catalyst layer having a desired shape can be formed by using a photomask having a predetermined shape. Can do.

It is a schematic diagram for demonstrating one Embodiment of the manufacturing method of the electrolyte membrane with a catalyst layer by this invention to process order. It is sectional drawing which shows the ideal structure of the electrolyte membrane with a catalyst layer which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the electrolyte membrane with a catalyst layer different from the ideal of this invention. It is a flowchart for demonstrating embodiment of the manufacturing method of the electrolyte membrane with a catalyst layer which concerns on this invention to process order.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view for explaining an embodiment of a method for producing an electrolyte membrane with a catalyst layer according to the present invention in the order of steps.
The outline of the manufacturing method of the electrolyte membrane with a catalyst layer according to the present embodiment is as follows. First, on the release substrate 1, a step of patterning the affinity area 5 having affinity with the catalyst ink 70 and the non-affinity area 6 having no affinity with the catalyst ink 70 (FIG. 1B) is executed. To do. Next, the catalyst ink 70 is applied to the affinity area 5 having affinity with the catalyst ink 70 on the release substrate 1, a coating film is formed, the solvent in the formed coating film is removed, and the cathode catalyst layer A step of forming 71 (FIG. 1C) is performed. Next, the step of applying an electrolyte ink containing at least a polymer electrolyte and a solvent on the cathode catalyst layer 71 to form a coating film, removing the solvent in the formed coating film, and forming the polymer electrolyte layer 8 (FIG. 1E) is executed. Next, the step of applying the catalyst ink 70 on the polymer electrolyte membrane to form a coating film, removing the solvent in the formed coating film, and forming the anode catalyst layer 72 (FIG. 1 (f)). It consists of a process of executing.

  More specifically, in the method for producing an electrolyte membrane with a catalyst layer according to the present embodiment, first, the affinity area 5 having affinity with the catalyst ink 70 and the non-affinity area 6 having no affinity are formed on the release substrate 1. A pattern is formed. As a first step of pattern formation (silane coupling agent forming step), a silane coupling agent 2 is formed on the release substrate 1 (FIG. 1 (a)). Then, the release substrate 1 on which the silane coupling agent 2 is formed is subjected to a water repellency treatment by the low surface energy functional group of the silane coupling agent 2. The type of the silane coupling agent 2 is not particularly limited as long as it has no affinity with the catalyst ink 70 and can be removed by the vacuum ultraviolet light 3, but it has a low surface energy functional group. A fluoroalkylsilane having a bond and being easily decomposed by vacuum ultraviolet light 3 is desirable. Moreover, the formation method of the silane coupling agent 2 includes spray coating, spin coating, chemical vapor deposition, immersion, and the like, and is not particularly limited.

  Next, as a second pattern formation process (silane coupling agent limited removal process), the photomask 4 having a predetermined shape is limited only to the catalyst layer formation area of the silane coupling agent 2 formed in the first process. Is irradiated with vacuum ultraviolet light 3 (FIG. 2B). And the silane coupling agent 2 of the area irradiated with the vacuum ultraviolet light 3 is decomposed | disassembled, and only the peeling base material 1 of the area irradiated with the vacuum ultraviolet light 3 is hydrophilized. The wavelength of the vacuum ultraviolet light 3 is not particularly limited as long as the Si—C bond of the silane coupling agent 2 can be cut, but is 172 nm because the Si—C bond is easily cut. It is desirable.

Next, as a step of forming the cathode catalyst layer 71 on the release substrate 1, a second catalyst ink 70 including catalyst-supporting particles, a polymer electrolyte, and a solvent is prepared, and the patterned release substrate 1 is formed. The catalyst ink 70 is dropped on the affinity area 5 to form the cathode catalyst layer 71 (FIG. 1C). The catalyst ink 70 used in this embodiment includes fine particles of platinum or an alloy of platinum and other metals (for example, Ru, Rh, Mo, Cr, Co, Fe, etc.) (the average particle size is preferably 10 nm or less). Is a solvent in which conductive carbon fine particles such as carbon black (average particle size: about 20 to 100 nm) and a polymer solution such as perfluorosulfonic acid resin solution are not compatible with the silane coupling agent 2 What is manufactured using the ink mixed uniformly in (water etc.) can be used.
In the electrolyte membrane with a catalyst layer according to this embodiment, the amount of platinum supported on the cathode catalyst layer 71 is equal to or greater than the amount of platinum supported on the anode catalyst layer 72.

Next, as a third pattern formation process (residual silane coupling agent removal process), vacuum ultraviolet light 3 is irradiated onto the release substrate 1 on which the cathode catalyst layer 71 is formed, and the affinity with the catalyst ink 70 is increased. The silane coupling agent 2 in the area 6 formed by the absent silane coupling agent 2 is decomposed and removed (FIG. 1D).
Next, an electrolyte solution containing a polymer electrolyte and a solvent is prepared, and the electrolyte solution is applied on the cathode catalyst layer 71 to form the polymer electrolyte layer 8 (FIG. 1 (e)).

Next, the catalyst ink 70 is applied on the polymer electrolyte layer 8 to form the anode catalyst layer 72 (FIG. 1 (f)).
Finally, the electrolyte membrane with a catalyst layer composed of the cathode catalyst layer 71, the polymer electrolyte layer 8, and the anode catalyst layer 72 is peeled from the release substrate 1, whereby the electrolyte membrane with a catalyst layer of the present embodiment is obtained. Manufactured.

  FIG. 2 is a cross-sectional view showing an ideal configuration of the electrolyte membrane with a catalyst layer according to the embodiment of the present invention. Thus, in the electrolyte membrane with a catalyst layer manufactured by the manufacturing method according to the present embodiment, the cathode catalyst layer 71 and the surface of the polymer electrolyte layer 8 are formed on the same plane on the release substrate 1. . That is, the electrolyte membrane with a catalyst layer includes a polymer electrolyte membrane 8, an anode catalyst layer 72 provided on one surface of the polymer electrolyte membrane 8, and a cathode catalyst layer 71 provided on the other surface of the polymer electrolyte membrane 8. The surface of the cathode catalyst layer 71 and the surface of the polymer electrolyte membrane 8 provided with the cathode catalyst layer 71 are on substantially the same plane.

FIG. 3 is a cross-sectional view showing a configuration of an electrolyte membrane with a catalyst layer different from the ideal of the present invention. FIG. 3A shows a configuration in which the cathode catalyst layer 71 is convex, and FIG. 3B shows a configuration in which the cathode catalyst layer 71 is completely surrounded by the polymer electrolyte layer 8 and is not exposed to the outside. Is shown.
In the case where the cathode catalyst layer 71 is convex, the cathode catalyst layer 71 is not covered with the polymer electrolyte layer 8, so that the moisture retention of the cathode catalyst layer 71 is reduced (FIG. 3A). ). On the other hand, when the polymer electrolyte layer 8 is configured to enter the interface between the cathode catalyst layer 71 and the release substrate 1, that is, the cathode catalyst layer 71 is completely surrounded by the polymer electrolyte layer 8 and is not exposed to the outside. As conductivity decreases, the gas diffusibility of the cathode catalyst layer 71 decreases (FIG. 3B). A configuration in which the cathode catalyst layer 71 is completely covered with the polymer electrolyte layer 8 and the surface of the cathode catalyst layer 71 and the surface of the polymer electrolyte layer 8 are completely coincident is more desirable.

The electrolyte membrane with a catalyst layer according to this embodiment can improve power generation performance under low humidification conditions. The reason is that the cathode catalyst layer 71 is covered with the polymer electrolyte layer 8 on all sides including the cross section, so that the catalyst layer is moisturized even under a low humidification condition, and the membrane electrode assembly having high proton conductivity ( This is because the MEA can be formed.
The amount of platinum supported on the catalyst layer of the electrolyte membrane with a catalyst layer is such that the amount of platinum supported on the cathode catalyst layer 71 is greater than or equal to the amount of platinum supported on the anode catalyst layer 72. That is, platinum content of the cathode catalyst layer 71, 0.20~0.40mg / cm ^2, amount of platinum supported anode catalyst layer 72 is 0.05~0.10mg / cm ² is desirable. Moreover, since the catalyst layer formed on the peeling base material 1 can eliminate the loss of the catalyst ink 70, it is desirable that the cathode catalyst layer 71 has a large amount of platinum supported.

According to the manufacturing method of the electrolyte membrane with a catalyst layer according to the present embodiment, the loss of the catalyst ink 70 can be reduced. The reason is that when the cathode catalyst layer 71 is formed, the catalyst layer is formed only in the affinity area 5 having affinity with the catalyst ink 70. As a result, the manufacturing cost can be reduced.
In the configuration of the electrolyte membrane with a catalyst layer of the present embodiment, the surfaces of the cathode catalyst layer 71 and the polymer electrolyte layer 8 are substantially on the same plane, and the cross section of the catalyst layer is also covered with the polymer electrolyte. Therefore, particularly under low humidification conditions, the electrode catalyst layer has high moisture retention and high proton conductivity, so that power generation performance can be improved.

According to the method for producing an electrolyte membrane with a catalyst layer according to the present embodiment, the cathode catalyst layer 71, the polymer electrolyte layer 8, and the anode catalyst layer 72 are sequentially laminated, and the production efficiency can be extremely increased.
In addition, according to the method for manufacturing an electrolyte membrane with a catalyst layer according to the present embodiment, in the formation of the cathode catalyst layer 71 with a large amount of platinum used, the pattern was formed in an area having affinity with the catalyst ink 70 and an area having no affinity. Since the catalyst ink 70 is applied onto the release substrate 1, there is no loss of the catalyst ink 70, and it can be manufactured at low cost.

  Moreover, according to the manufacturing method of the electrolyte membrane with a catalyst layer according to the present embodiment, compared with the manufacturing method of the membrane electrode assembly in which the electrode catalyst layer is transferred to both surfaces of the polymer electrolyte layer 8 by hot pressing, the hot pressing is performed. The process can be omitted. When the hot pressing step is omitted, it is possible to prevent a decrease in membrane strength and a decrease in ion exchange capacity due to damage to the polymer electrolyte layer 8 due to heating and pressure during hot pressing.

According to the manufacturing method of the electrolyte membrane with a catalyst layer according to the present embodiment, the tact time can be shortened to increase the production efficiency. The reason is that there is no thermocompression bonding step such as hot pressing that becomes a bottleneck when joining the ion exchange membrane and the electrode catalyst layer. Further, since the cathode catalyst layer 71, the polymer electrolyte layer 8, and the anode catalyst layer 72 are sequentially laminated, the production efficiency can be extremely increased.
Furthermore, the present invention provides a method for producing a membrane / electrode assembly that has the effect of improving the contact between the polymer electrolyte layer 8 and the electrode catalyst layer and reducing the ionic resistance as compared with an electrolyte membrane with a catalyst layer produced by hot pressing. can do.

The reason why the electrolyte membrane with a catalyst layer according to this embodiment can reduce the ionic resistance is that the contact between the polymer electrolyte layer 8 and the electrode catalyst layer is improved. Therefore, a better result is obtained as compared with the electrolyte membrane with a catalyst layer produced by hot pressing.
As described above, according to the electrolyte membrane with a catalyst layer and the manufacturing method thereof according to the present embodiment, a membrane electrode assembly using the electrolyte membrane with a catalyst layer having high production efficiency, low cost, and sufficient power generation performance is provided. can do.

  Hereinafter, the manufacturing method of the electrolyte membrane with a catalyst layer according to the present invention will be described with reference to FIG. In addition, the Example mentioned later is one Example of this invention, and this invention is not limited only to this Example. Moreover, the electrolyte membrane with a catalyst layer according to this example is used for a polymer electrolyte fuel cell.

  FIG. 4 is a flowchart for explaining an embodiment of the method for producing an electrolyte membrane with a catalyst layer according to the present invention in the order of steps. As shown in FIG. 4A, the method for producing an electrolyte membrane with a catalyst layer includes a silane coupling agent formation step (S10), a silane coupling agent limited removal step (S20), and a cathode catalyst layer formation step ( S25), a residual silane coupling agent removing step (S30), a polymer electrolyte membrane forming step (S40), and an anode catalyst layer forming step (S50).

In the silane coupling agent forming step of (S10), the silane coupling agent 2 is formed in the entire area on the release substrate 1.
In the silane coupling agent limited removal step of (S20), the vacuum ultraviolet light 3 is irradiated only on the affinity area 5 having affinity through the photomask 4, so that the catalyst ink 70 and the affinity area 5 are irradiated. Only the formed silane coupling agent 2 is removed.

In the cathode catalyst layer forming step of (S25), the catalyst ink 70 is applied to the affinity area 5 on the release substrate 1 to form a coating film, the solvent in the formed coating film is removed, and the cathode catalyst layer is formed. 71 is formed.
In the residual silane coupling agent removing step (S30), the residual silane coupling agent 2 in the non-affinity area 6 having no affinity with the catalyst ink 70 is removed after the cathode catalyst layer 71 is formed.

In the polymer electrolyte membrane forming step of (S40), an electrolyte ink containing at least the polymer electrolyte 8 and a solvent is applied on the cathode catalyst layer 71 to form a coating film, and the solvent in the formed coating film is removed. Then, the polymer electrolyte membrane 8 is formed.
In the anode catalyst layer forming step of (S50), the catalyst ink 70 is applied on the polymer electrolyte membrane 8, a coating film is formed, the solvent in the formed coating film is removed, and the anode catalyst layer 72 is formed. .

  As shown in FIG. 4 (b), when attention is paid only to the pattern forming step (S100) in the method for manufacturing the electrolyte membrane with catalyst layer according to the present embodiment, the silane coupling agent forming step (S10) as the first step; The silane coupling agent limited removal step (S20) as the second step and the residual silane coupling agent removal step (S30) as the third step are provided. That is, in the pattern forming step (S100), the silane coupling agent forming step (S10) for forming the silane coupling agent 2 in all areas on the release substrate 1 and the silane coupling formed on the affinity area 5 are performed. After the cathode catalyst layer 71 is formed by the silane coupling agent limited removal step (S20) for removing only the agent 2 and the cathode catalyst layer formation step (S25), the remaining silane coupling in the non-affinity area 6 is performed. And a residual silane coupling agent removing step (S30) for removing the agent 2.

Further, in the silane coupling agent limited removal step (S20), the removal is performed by irradiating the vacuum ultraviolet light 3 only on the affinity area 5 through the photomask 4.
In the pattern formation step (S100) described above, the hydrophilicity is utilized in the affinity area 5 and the water repellency is utilized in the non-affinity area 6 to form a pattern.

(Silane coupling agent forming step (S10) in pattern forming step (S100))
As shown in FIG. 1A, a glass substrate (hereinafter referred to as a glass substrate 1) is used as the peeling substrate 1. The glass substrate 1 was irradiated with vacuum ultraviolet light 3 having a wavelength of 172 nm to form hydroxyl groups on the surface of the glass substrate 1. Subsequently, the hydroxyl group on the glass substrate 1 is reacted with the hydrolyzed silane coupling agent 2. Here, fluoromethoxysilane (trade name: KBM-7103, manufactured by Shin-Etsu Chemical Co., Ltd.), which is a fluoroalkyl silane coupling agent 2, and the glass substrate 1 on which the hydroxyl group is formed are heated to 160 ° C. To do. Then, the silane coupling agent 2 was formed on the glass substrate 1 by a chemical vapor deposition method (Chemical Vapor Deposition method; CVD method).

(Silane coupling agent limited removal step (S20) in pattern formation step (S100))
As shown in FIG. 1B, the glass substrate on which the silane coupling agent 2 is formed is irradiated with vacuum ultraviolet light 3 having a wavelength of 172 nm through a photomask 4 having a 50 mm square opening. Then, the affinity area 5 having affinity with the catalyst ink 70 in which the silane coupling agent 2 is decomposed and the non-affinity area 6 having no affinity with the catalyst ink 70 in which the silane coupling agent 2 remains are formed in a pattern. did.

  In addition, according to the manufacturing method of the electrolyte membrane with a catalyst layer which concerns on this embodiment, a catalyst layer can be formed in a desired shape with high precision. The reason is that the accuracy of the photomask 4 used in the silane coupling agent limited removal step (S20) is reflected in the shape of the cathode catalyst layer 71. Accordingly, by using the photomask 4 having a desired accuracy and shape, a catalyst layer having a desired shape can be formed with high accuracy.

(Cathode catalyst layer forming step (S25))
As shown in FIG. 1 (c), a platinum-supported carbon catalyst (trade name: TEC10E50E, manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.) having a 5 platinum support amount of 50% and Nafion (registered trademark, 20% by mass polymer electrolyte solution) DuPont) was mixed with water as a solvent. Subsequently, a dispersion treatment was performed with a planetary ball mill to prepare a catalyst ink 70. Then, the adjusted catalyst ink 70 was dropped onto the patterned glass substrate 1 in the affinity area 5 having affinity with the catalyst ink 70 so that the platinum carrying amount was 0.30 mg / cm 2. The coating film formed by the dropped catalyst ink 70 was dried to form a cathode catalyst layer 71.

(Remaining silane coupling agent removal step (S30) in pattern formation step (S100))
As shown in FIG. 1 (d), the glass substrate on which the cathode catalyst layer 71 is formed is irradiated with vacuum ultraviolet light 3 having a wavelength of 172 nm, and has no affinity with the catalyst ink 70 at the peripheral edge of the cathode catalyst layer 71. The silane coupling agent 2 in the affinity area 6 was decomposed and removed.

(Polymer electrolyte layer forming step (S40))
As shown in FIG. 1E, Nafion (registered trademark, manufactured by DuPont), which is a 20% by mass polymer electrolyte solution, was applied on the cathode catalyst layer 71 by a doctor blade method so as to have a film thickness of 20 μm. And the coating film was dried and the polymer electrolyte layer 8 was formed.

(Anode catalyst layer forming step (S50))
As shown in FIG.1 (f), the anode catalyst layer 72 is formed on the polymer electrolyte layer 8 which bonded the mask which has a 50 mm square opening part. That is, the catalyst ink 70 is applied onto the polymer electrolyte layer 8 by the doctor blade method so that the platinum loading is 0.10 mg / cm ² . After coating, the coating film is dried, the mask is peeled off, and the anode catalyst layer 72 is formed.
Finally, the laminated body of the cathode catalyst layer 71, the polymer electrolyte layer 8, and the anode catalyst layer 72 was peeled from the glass substrate 1 to obtain an electrolyte membrane with a catalyst layer.

[Comparative example]
(Cathode catalyst layer forming step (see S25))
A platinum-supported carbon catalyst (trade name: TEC10E50E, manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.) with a platinum-supported amount of 50%, Nafion (registered trademark, manufactured by DuPont), which is a 20% by mass polymer electrolyte solution, and water as a solvent, Mixed. Subsequently, a dispersion treatment was performed with a planetary ball mill to prepare a catalyst ink 70. And the adjusted catalyst ink 70 was apply | coated on the transfer base material with which the mask material which has a 50-mm opening part was bonded on the PTFE film. The catalyst ink 70 is applied by a doctor blade method so that the platinum carrying amount is 0.30 mg / cm ² . After being applied, the coating film is dried to form the cathode catalyst layer 71.

(Anode catalyst layer forming step (see S50))
The catalyst ink 70 is applied by a doctor blade method on a transfer base material in which a mask material having an opening of 50 mm is bonded onto a PTFE film so that the platinum carrying amount is 0.10 mg / cm ² . The coating film was dried to form an anode catalyst layer 72.
(Polymer electrolyte layer forming step (see S40))
A 20 mass% polymer electrolyte solution Nafion (registered trademark, manufactured by DuPont) is applied onto the glass substrate 1 by a doctor blade method so that the film thickness becomes 20 μm, the coating film is dried, and the polymer electrolyte layer 8 was formed.

(Hot press process)
Both electrode catalyst layers manufactured on the PTFE sheet are arranged so as to face both surfaces of the polymer electrolyte layer 8 manufactured from the polymer electrolyte solution, and hot pressing is performed at 130 ° C. and 6.0 × 10 ⁶ Pa. Then, an electrolyte membrane with a catalyst layer was produced.
As a result of examining the power generation characteristics with low humidification for the electrolyte membranes with catalyst layers produced by the Examples, the Comparative Examples, and the respective production methods, it was confirmed that the Examples had higher power generation performance.
In addition, as a result of examining the volume of the catalyst ink 70 used in each of the production methods of the example and the comparative example, it was confirmed that the use amount of the catalyst ink 70 could be reduced by 40% according to the production method of the example. did.

  According to the present invention, an electrolyte membrane with a catalyst layer capable of forming a catalyst layer in a desired shape with high power generation performance and production efficiency, less ionic resistance and catalyst ink loss, and a method for producing the same can be provided. Therefore, it can be suitably used for a single cell or stack used for a solid polymer fuel cell in a polymer electrolyte fuel cell, particularly a fuel cell vehicle or a household fuel cell.

DESCRIPTION OF SYMBOLS 1 ... Peeling base material 2 ... Silane coupling agent 3 ... Vacuum ultraviolet light 4 ... Photomask 5 ... Area with affinity with catalyst ink (affinity area)
6 ... Area with no affinity for catalyst ink (non-affinity area)
8 ... polymer electrolyte layer 70 ... catalyst ink 71 ... cathode catalyst layer 72 ... anode catalyst layer

Claims (5)

  A pattern forming step of patterning on the release substrate an affinity area having affinity for the catalyst ink containing catalyst-supporting particles, a polymer electrolyte, and a solvent, and a non-affinity area having no affinity for the catalyst ink; ,
  A cathode catalyst layer forming step of applying the catalyst ink to the affinity area to form a coating film, removing the solvent in the formed coating film, and forming a cathode catalyst layer;
  A polymer electrolyte membrane is formed by applying an electrolyte ink containing a polymer electrolyte and a solvent on the cathode catalyst layer to form a coating film, removing the solvent in the formed coating film, and forming a polymer electrolyte membrane. Forming process;
  An anode catalyst layer forming step of applying the catalyst ink on the polymer electrolyte membrane, forming a coating film, removing the solvent in the formed coating film, and forming an anode catalyst layer;
  In the polymer electrolyte membrane formation step, after forming the cathode catalyst layer, the non-affinity area is modified to the area having affinity, and the polymer electrolyte membrane is formed on the modified area, Forming the surface of the cathode catalyst layer on the side of the release substrate and the surface of the polymer electrolyte membrane on the side of the release substrate to be located on the same plane,
  In the anode catalyst layer forming step, the anode catalyst layer is formed such that the amount of platinum supported per unit area of the anode catalyst layer is smaller than the amount of platinum supported per unit area of the cathode catalyst layer. A method for producing an electrolyte membrane with a catalyst layer.   The pattern forming step includes a silane coupling agent forming step for forming a silane coupling agent in all areas on the release substrate, and a silane coupling agent for removing only the silane coupling agent formed on the affinity area. An agent-limited removal step, and a residual silane coupling agent removal step of removing the residual silane coupling agent in the non-affinity area after the cathode catalyst layer is formed by the cathode catalyst layer formation step. The manufacturing method of the electrolyte membrane with a catalyst layer of Claim 1 to do.   3. The production of the electrolyte membrane with a catalyst layer according to claim 2, wherein the silane coupling agent-limited removal step is performed by irradiating only the affinity area with vacuum ultraviolet light through a photomask. Method.   4. The pattern formation step according to claim 1, wherein the affinity area utilizes hydrophilicity and the non-affinity area utilizes water repellency to form a pattern. 5. A method for producing an electrolyte membrane with a catalyst layer.   The catalyst layer according to any one of claims 1 to 4, wherein the water contact angle of the affinity area is 15 degrees or less, and the water contact angle of the non-affinity area is 100 degrees or more. A method for producing an attached electrolyte membrane.

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