JP2005302714A - Electrode manufacturing device and method for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely manufacture a fine fuel cell electrode in accordance with a designed value by preventing reverse flight caused by reversed polarity of electrode material powder on the electrolyte membrane when the fuel cell electrode is manufactured by transfer printing of the electrode material powder on the electrolyte membrane by utilizing electrostatic force. <P>SOLUTION: A photoconductor drum 20 developing charged electrode material powder 5 in an electrode shape is put on the position apart from the electrolyte membrane 10 and a transfer printing roller 14, the transfer printing roller 14 is coated with resin 14a having high resistance value, or the photoconductor drum 20 is connected to a transfer printing high voltage power source 17 through resistance 18 having high resistance value to convert it to a high resistance member. A transfer printing electric field is formed by applying high voltage only for time when an electrode image on the photoconductor drum 20 is present in the upper part of the electrolyte membrane 10, and soon after transfer printing, by eliminating the transfer printing electric field of the transfer printing part by setting the transfer printing high voltage power source to 0V, reverse flight can be prevented. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to an electrode manufacturing apparatus and method for use in a polymer electrolyte fuel cell, and more particularly to an electrode manufacturing apparatus and method by a so-called dry method in which an electrode material powder is allowed to fly to an electrolyte membrane using electrostatic force. .

  A polymer electrolyte fuel cell is known as one of the fuel cells, and a membrane electrode assembly (MEA) 50 having a configuration shown in FIG. 5 is a main component. A structure in which a fuel electrode side electrode 52a and a diffusion layer 53a are stacked on one side of a membrane electrode assembly 50 and an electrolyte membrane 51 which is an ion exchange membrane, and an air electrode side electrode 52b and a diffusion layer 53b are stacked on the other side. Thus, one fuel cell called a single cell is formed by sandwiching the diffusion layers 53a, 53b side with a separator having a gas flow path.

  Usually, what is called a Nafion (registered trademark) film is used as the electrolyte film 51. The electrodes 52a and 52b are formed by preparing a mixed solution (catalyst ink) of a carbon carrier carrying a catalyst component such as platinum and an electrolyte solution which is an electrically conductive material, and screen-printing it on the electrolyte membrane 51. After forming the electrode material by applying the method and drying (wet method), and preparing the electrode material completely dry, or drying and removing the solvent from the catalyst ink, and charging the powdered electrode material Then, a method (dry method) is performed in which it is attached to a conveying roller or the like using electrostatic force, the attached electrode material powder is transferred to the electrolyte film 51, and is fixed by a fixing roller.

  As a dry method, in Patent Document 1 (Japanese Patent Laid-Open No. 2002-367616), as shown in FIG. 6, a charged electrode material powder 54 is electrostatically adhered onto a conveying roller 57, and this roller 57 and the back surface for transfer are used. A method and apparatus are described in which a voltage is applied between the electrodes 58 to electrostatically adhere the electrode material powder 54 to the electrolyte membrane 59 disposed between the roller 57 and the back electrode 58. As one embodiment, as shown in the figure, the back electrode 58 and the electrolyte membrane 59 are arranged separately from the transport roller 57, and the electrode material powder 54 adhered on the transport roller 57 is transferred to the transport roller 57 and the back electrode. Also shown is a control plate 60 that is made to fly toward the electrolyte membrane 59 by the electric field generated between the electrodes 58 and electrostatically adhere to it, and to control the transfer pattern of the electrode material powder along the conveying roller 57. . Reference numeral 61 denotes a fixing roll.

  In Patent Document 2 (Japanese Patent Laid-Open No. 2003-163010) or Patent Document 3 (Japanese Patent Laid-Open No. 2003-163011), as in an electrostatic copying machine, the charged photosensitive drum is irradiated with light to eliminate static electricity. A method and an apparatus are described in which electrode material powder is attached to a desired electrode image pattern by electrostatic force, and is transferred to an electrolyte film by pressure contact with a photosensitive drum and a pressure roller to form a desired electrode.

JP 2002-367616 A Japanese Patent Laid-Open No. 2003-163010 JP 2003-163011 A

  Production of fuel cell electrodes by using the electrostatic force described above to cause the electrode material powder on the transport roller to fly to the electrolyte film, or to transfer the electrode material powder electrostatically attached to the photosensitive drum in the required pattern to the electrolyte film. Compared with the wet method in which the catalyst ink is applied, the method is advantageous in that it can solve problems such as damage to the electrolyte membrane by the solvent, swelling / shrinkage of the electrolyte membrane, and generation of cracks in the electrode when the catalyst ink is dried. The present inventors have been involved in the production of electrodes by a dry method, but in the process, an accurate electrode image pattern of electrode material powder is formed on the transport roller when trying to obtain a precise electrode image pattern. I experienced that there was no disturbance in the electrode image transferred to the electrolyte membrane. In order to know the cause, the difference between the dry transfer of the electrostatic copying machine and the dry method in the case of producing the fuel cell electrode was considered.

  Electrostatic copying machines and laser printers also perform dry copying (transfer) using electrostatic force. First, a copier force is created by applying a high voltage between the developing roller and the photoconductive drum to the charged toner having a copy image or a printed image formed as a charge distribution on the photoconductive drum and having a thin layer deposited on the developing roller. To electrostatically adhere to the charge distribution on the photosensitive drum. Next, a high voltage is applied between the photosensitive drum and the transfer roller, and the paper is conveyed between them to electrostatically transfer the toner on the photosensitive drum onto the paper. Thereafter, a transfer method is adopted in which the toner is fixed on the paper by thermocompression with a fixing roller, and an accurate copy image in accordance with the charge distribution on the photosensitive drum is obtained on the paper.

  Regardless of the principle that the image forming method in the electrostatic copying machine and the electrode manufacturing method in the fuel cell using the electrostatic force are the same in principle, in the electrode manufacturing, as described above. An accurate transfer image may not be obtained. The reason was understood through experiments as follows.

1. The toner of the electrostatic copying machine is an insulator of about 10 ¹⁴ Ω, whereas the electrode material powder is an electrode material and is a conductor of several Ω or less. In addition, a sheet used for an electrostatic copying machine has a high surface resistivity of ^{109 to 13} Ω (which varies depending on the environment due to hygroscopicity), but the electrolyte membrane exhibits a lower resistance value than that ( Note 1) When a voltage is applied to the electrolyte membrane, that is, when a potential difference occurs between the front and back surfaces of the membrane under a high electric field, it behaves as a conductor.

Note 1: When the surface resistivity of a 5 mil thick electrolyte membrane (Nafion membrane) is measured by connecting a Model 152P-CR test probe to a surface resistance meter Model 152 manufactured by TREK, 2 × 10 ⁵ when 10 V is applied. A low resistance value was shown. Even when the probe was changed to Model 152P-2P and the resistance was measured by the two-point method, it was 2 × 10 ⁵ Ω. Even when the same electrolyte membrane is placed on an aluminum plate and one terminal of Model 152P-2P is placed on the membrane and the other terminal is placed on the aluminum plate, the measurement shows 2 × 10 ⁵ Ω, and the thickness direction It was also shown to be a low resistance material.

  2. Due to the difference in the physical properties of the materials used, when manufacturing an electrode using electrostatic force, the following problems occur at the transfer portion, which hinders the formation of a precise transfer image. .

a. In an electrostatic copying machine, a photosensitive drum, a sheet, and a transfer roller are generally transferred while the transfer roller presses the sheet against the photosensitive drum in order to improve detail reproducibility. This is because the surface resistance of the paper is as high as about 10 ^{9 to 13} Ω, and the toner can be transferred from the photosensitive drum to the paper by Coulomb force by charging only the paper surface of the paper. On the other hand, in the production of fuel cell electrodes, the resistance of the electrolyte membrane corresponding to the paper is as low as 2 × 10 ⁵ Ω and exhibits a behavior as a conductor. Therefore, as described in Patent Document 2 or 3, pressure transfer With this configuration, current flows from the transfer roller through the electrolyte membrane and electrode material powder to the surface of the photosensitive drum. For this reason, an electric current flows into the electrode material powder on the photosensitive drum to change the charge amount, which is different from the charge distribution of the photosensitive drum. As a result, the electrode material powder moves and the shape of the developed electrode image changes, which may hinder accurate transfer of the electrode image.

  b. In the apparatus described in Patent Document 1, a high electric field is created between the back electrode 58 (corresponding to the transfer roller) 58 and the conveying roller 27, that is, between the transfer portions, by a transfer high-voltage power source, and the electrode material powder is applied to the electrolyte membrane. When electrostatically adhering, the electrode material powder loses its charge due to the current flowing through the high-voltage power supply, back electrode, and electrolyte membrane, and is charged to the opposite polarity, receives electrostatic force in the direction opposite to that during transfer, and reverses to the photosensitive drum. It may cause a transfer abnormality that flies (reflection phenomenon inside the electrode of a conductor sphere placed between high electric field electrodes). In some cases, it is not easy to obtain the required amount of adhesion. In the apparatus of Patent Document 1, it can be said that the control pattern 60 for controlling the transfer pattern is provided to take measures against the shape of the electrode pattern on the electrolyte membrane by reverse flight adhesion, but the apparatus is complicated and expensive. The electrode material powder containing an appropriate catalyst adheres to the control plate and the utilization efficiency is lowered, resulting in an increase in cost. Further, no measures are taken against the loss of the charge of the charged electrode material powder due to the current flowing from the other members constituting the apparatus to the electrolyte membrane 59.

  The present invention has been made in view of the above circumstances. In an apparatus and method for manufacturing an electrode of a fuel cell by transferring an electrode material powder to an electrolyte membrane using an electrostatic force, the electrode pattern is refined. Even in such a case, the electrode image can be accurately formed on the developing portion, and further, the electrode material powder does not release the charge received once, and the formed electrode image does not cause a transfer abnormality. An object of the present invention is to provide a fuel cell electrode manufacturing apparatus and manufacturing method which can be transferred onto an electrolyte membrane as it is by an electrostatic force.

  A fuel cell electrode manufacturing apparatus according to the present invention includes a developing unit having a function of developing charged electrode material powder into an electrode shape, and a transfer having a high-voltage power source for transferring the electrode material powder from the developing unit to the electrolyte membrane by electrostatic force. At least a transfer unit, and a fixing unit that fixes the electrode material powder on the electrolyte membrane. In the transfer unit, the transfer unit and the electrolyte film are disposed separately from the developing unit, and the transfer unit The part is provided with means for preventing the electrode material powder electrostatically attached to the electrolyte membrane from being charged with a reverse polarity.

  The method for producing an electrode of a fuel cell according to the present invention includes a step of developing charged electrode material powder into an electrode shape in a developing unit, and the developed electrode material powder from the developing unit to the electrolyte membrane in the transfer unit having a high-voltage power supply for transfer. A method for producing an electrode of a fuel cell comprising at least a step of transferring by electrostatic force and a step of fixing an electrode material powder on an electrolyte membrane in a fixing portion, wherein the electrode material powder is transferred from the developing portion to the electrolyte membrane in the transfer portion. After transfer by electrostatic force, (a) by making the current from the transfer part difficult to flow into the electrode material powder, (b) by weakening or eliminating the transfer electric field of the transfer part, or (c) by both , Prevents the electrostatically attached electrode material powder from being charged to a reverse polarity, so that the electrostatically attached electrode material powder is transferred to the developing portion at the transfer portion. We were not allowed to cause transcription abnormalities reverse flying characterized.

  In the present invention, since the transfer portion and the electrolyte film are arranged apart from the developing portion, current does not substantially flow from the transfer portion or the electrolyte film to the developing portion, and the electrode image of the developing portion changes. Can be prevented. In addition, since the transfer part is provided with means for preventing the electrode material powder electrostatically attached to the electrolyte membrane from being charged in the reverse polarity, the electrode material powder electrostatically attached to the transfer part is developed in the transfer section. It is possible to reliably prevent a reverse flight to cause a transfer abnormality. As a result, even if the electrode pattern is fine, an electrode image can be accurately formed on the developing portion, and can be electrostatically attached to the electrolyte membrane as it is. Since the electrode material powder on the electrolyte membrane is sent and fixed to the fixing portion while maintaining a fine electrode pattern, a highly accurate fuel cell electrode can be obtained.

  Means for preventing the electrode material powder electrostatically attached to the electrolyte membrane from forming a reverse polarity on the transfer portion is a means for preventing current from flowing from the transfer portion to the electrode material powder as a conductor, for example, Means for producing a region that faces the electrolyte membrane of the transfer portion with a material having a high resistance value, or means for connecting the electrode of the transfer portion and a high-voltage power supply for transfer via a resistor having a high resistance value, etc. In this case, if the high resistance value is in the range of 10 MΩ to 100 GΩ, the intended purpose can be effectively achieved.

  As another means for preventing the electrode material powder electrostatically attached to the electrolyte membrane from being charged with a reverse polarity, immediately after the electrode material powder is transferred to the electrolyte membrane, the transfer high-voltage power supply is set to a low voltage or 0 V. A means for weakening or eliminating the transfer electric field of the transfer portion may be used. The Coulomb force acting on the electrode material powder is the electric charge × the electric field strength. Even if the electrode material powder is charged with a reverse polarity, if there is no electric field strong enough to reverse transfer to the developing part, the electrostatic adhesion The electrode material powder thus applied does not fly back to the developing portion, that is, does not reverse transfer. Therefore, after the electrode material powder is transferred to the electrolyte membrane, the transfer high voltage power supply is immediately set to a low voltage or 0 V so that the transfer electric field in the transfer portion is weakened or eliminated, so that no transfer abnormality is caused. Can achieve the purpose.

  In the above case, unless it is difficult for the electrode material powder to flow current from the transfer part, the electrode material powder once transferred to the electrolyte membrane during transfer is reversely charged during transfer and reverse transfer occurs. there is a possibility. Therefore, immediately after the electrode material powder is transferred to the electrolyte membrane, the transfer high-voltage power supply is set to a low voltage or 0 V to weaken or eliminate the transfer electric field of the transfer portion, and to prevent current from flowing from the transfer portion to the electrode material powder. By providing both means, it is possible to more reliably prevent a transfer abnormality in which the electrode material powder flies back to the developing portion in the transfer portion.

  In the above electrode manufacturing apparatus, the resistance value also depends on the transport speed of the electrolyte film and the rotation speed of the photosensitive drum constituting the developing unit. If the conveyance speed of the electrolyte film and the rotation speed of the photosensitive drum constituting the developing unit are increased 10 times, the time for passing through the transfer section for transferring the electrode material powder to the electrolyte film will be 1/10. It can be reduced to 1/10. Therefore, an optimum value for the high resistance value may be selected experimentally from the range of 10 MΩ to 100 GΩ in relation to the feed rate. The resistance value is determined by the time for the electrolyte membrane to pass through the transfer section. Therefore, by changing the structure such as narrowing the transfer electrode interval, the electrolyte membrane strength will increase in the future, and it will be transported at a higher speed than the present. It is considered that the intended purpose of the present invention can be achieved even with a resistance value of 10 MΩ or less. On the other hand, the higher the resistance value, the more the electrode material powder adheres to the electrolyte membrane. However, it is practical to set the upper limit to about 100 GΩ because each part needs to be neutralized before the next electrode is produced. Of course, a higher resistance value may be used when the manufacturing time of the electrode is not a problem.

  Preferably, the member other than the member constituting the transfer portion, which is in contact with the electrolyte membrane during the electrode manufacturing process, is made of a material having a high resistance value at least in a region that is in contact with the electrolyte membrane. Or connected to the earth, and the electrode material powder that is electrostatically attached to the electrolyte membrane from these members can be prevented from being charged or reduced as much as possible, thereby preventing the electrode material powder from being charged to the opposite polarity. To do. By doing so, it is possible to more reliably prevent a transfer abnormality that reversely flies to the developing portion. Examples of the member that comes into contact with the electrolyte membrane during the manufacturing process of the electrode include a fixing unit, a roll unwinding of the electrolyte membrane, a winding unit, a conveyance unit, and a storage unit.

  The present invention can also be applied to so-called batch-type electrode manufacturing in which electrode material powder is fixed to an electrolyte membrane that has been cut in a predetermined size in advance, and while the roll-shaped electrolyte membrane is being conveyed, It can also be applied to continuous electrode production in which the electrode material powder is continuously fixed. In the latter case, the number of transfer units described above may be one for the entire apparatus, but two or more transfer units may be arranged in tandem in the transport direction of the electrolyte membrane. Thereby, an electrode having an arbitrary three-dimensional structure can be produced. Further, two or more transfer units are arranged in tandem in the transport direction on one side of the electrolyte membrane, and two or more transfer units are arranged in tandem in the transport direction on the other side of the electrolyte membrane. Good. By arranging the transfer unit in this way, the air electrode and the fuel electrode in the membrane electrode assembly can be formed at the same time with an optimum structure.

  According to the present invention, when producing an electrode of a fuel cell by transferring an electrode material powder to an electrolyte membrane using an electrostatic force, even if the electrode pattern is fine, the electrode image is accurately applied to the developing portion. Can be formed. In addition, the electrode material powder can be used as it is without causing any abnormal transfer by preventing the electric charge received by the electrode material from escaping or by substantially eliminating the electric field at the transfer portion immediately after transfer. It can be transferred onto the electrolyte membrane by electrostatic force. This makes it possible to reliably manufacture the fuel cell electrode as designed.

BEST MODE FOR CARRYING OUT THE INVENTION

  Hereinafter, the present invention will be described based on embodiments and examples with reference to the drawings.

  FIG. 1 is a schematic view showing an example of a fuel cell electrode manufacturing apparatus according to the present invention. In FIG. 1, A is a transfer unit, and comprises an aluminum flat plate electrode 1 constituting a part of a developing portion having a function of developing charged electrode material powder into an electrode shape, and the electrode material powder from the developing portion to the electrolyte membrane. And an aluminum flat plate electrode 2 constituting a part of a transfer portion having a transfer high-voltage power source for transfer by electric power. A high resistance resin sheet 3 is laminated on the aluminum flat plate electrode 2, and an electrolyte membrane is provided on the high resistance resin sheet 3. 4 is pasted. The high resistance resin sheet 3 is an example of a material having a high resistance value as a means for preventing the electrode material powder referred to in the present invention from being charged with a reverse polarity. An electrode material powder 5 is placed on the aluminum plate electrode 1 in a development pattern, and the out terminal of the high voltage power source 6 is connected to the aluminum plate electrode 1 side and the return terminal is connected to the aluminum plate electrode 2 side. The high-voltage power source 6 corresponds to the “high-voltage power source for transfer that transfers the electrode material powder from the developing portion to the electrolyte membrane by electrostatic force” in the present invention. 1 does not show a fixing portion for fixing the electrode material powder on the electrolyte membrane, but the electrolyte membrane 4 to which the electrode material 5 is electrostatically transferred is removed from the aluminum plate electrode 2 and is heated and fixed by the fixing portion. Thus, it becomes a fuel cell electrode.

  An example in which the transfer unit A is actually used to produce an electrode will be described as [Example 1] together with a comparative example.

[Example 1]
First, an aluminum flat plate electrode 1 of 100 mm × 100 mm and thickness 2 mm is connected to the out terminal of the high voltage power source 6, and electrode material powder 5 (consisting of Pt-supported carbon powder having a particle diameter of 1 to 10 μm and an electrolyte resin) is 50 mm. 5.8 mg Pt / cm ^{2 was} deposited in a square shape of × 50 mm. An aluminum flat plate electrode 2 of the same size as the aluminum flat plate electrode 1 is connected to the return terminal of the high-voltage power supply 6, and a high-resistance resin sheet 3 is bonded using a double-sided conductive tape X-7001 manufactured by Sumitomo 3M Limited. . The high resistance resin sheet 3 is made of Achilles Co., Ltd. Majikiri II and has a surface resistance of 1.5 × 10 ¹² Ω, a volume resistivity of 1.5 × 10 ¹¹ Ωcm, and a thickness of 1 mm. On this, the electrolyte membrane 4 was affixed. The high voltage power supply 6 is a TREK high voltage power supply 610D. The electrode interval was 3 mm.

In the configuration of FIG. 1, a high voltage of −4000 V was applied. The electrode material powder 5 electrostatically attached to the electrolyte membrane 4 was 0.14 mg Pt / cm ² . The aluminum plate electrode 2 had no evidence of electrode material powder flying backward and adhering.

[Comparative Example 1]
The other conditions were the same, and the high resistance resin sheet 3 was changed to a vinylus manufactured by Achilles Co., Ltd., and an experiment was conducted. The vinylus has a surface resistance of 1 × 10 ¹¹ Ω, a volume resistivity of 1 × 10 ⁹ Ωcm, and a thickness of 0.2 mm. The electrode material powder 5 electrostatically attached to the electrolyte membrane 4 was reduced to 0.09 mg Pt / cm ² . Further, it was observed that the electrode material powder 5 adhered to the periphery of the electrode image deposited first on the aluminum plate electrode 2.

[Discussion]
The thickness direction resistance of the vinylus used in the comparative example is 1 × 10 ⁹ Ωcm × 0.02 cm = 20 MΩ, and the thickness direction resistance of Serpent II used in Example 1 is 1.5 × 10 ¹¹ Ωcm × 0. 1 cm = 15 GΩ, which is about three orders of magnitude higher. Therefore, in the comparative example, a part of the electrode material powder is charged with a reverse polarity and reverse flight occurs, and the reduced amount of the electrode material powder adhering to the electrolyte membrane 4 adheres to the periphery of the electrode image deposited first. It is thought that.

  FIG. 2 is a schematic view showing another example of a fuel cell electrode manufacturing apparatus according to the present invention. In this apparatus B, a roll-shaped electrolyte membrane 10 is used, and the electrolyte membrane 10 fed from the electrolyte membrane unwinding roller 11 is wound around and stored in the electrolyte membrane winding roller 12. Between the unwinding roller 11 and the take-up roller 12, a transport roller 13, a transfer roller 14, a transport roller 15, and fixing rollers 16 and 16 are arranged in this order in the transport direction of the electrolyte membrane 10. A high voltage power supply 17 for transfer, which is set to minus, is connected to the electrode of the transfer roller 14 via a high resistance 18. In this example, the electrolyte membrane 10 to be transported is sent so that the back surface is in contact with each of these rollers.

Further, in order to improve the sliding of the transfer roller 14, an aluminum pipe is coated with a resin 14a having a volume resistivity of 1 × 10 ⁹ Ωcm and a thickness of 0.2 mm. Further, the electrolyte membrane unwinding roller 11, the electrolyte membrane winding roller 12, the transport rollers 13 and 15, and the fixing rollers 16 and 16 are all resins 11a, 12a, and 13a having a volume resistivity of 1 × 10 ¹¹ Ωcm and a thickness of 2 mm or more. , 15a and 16a, respectively, and are grounded.

  The photosensitive drum 20 is disposed so as to face the transfer roller 14. The photosensitive drum 20 is located away from the electrolyte film 10 running on the transfer roller 14 and is not in contact therewith. Although they differ depending on the electric field strength, the type of electrode material powder, and the like, both are set apart by about 0.2 to 5 mm. A charging roller 21 is in contact with the photosensitive drum 20 and uniformly charges the surface of the photosensitive drum 20. A laser optical system 22 is located downstream of the charging roller 21 in the rotation direction of the photoconductive drum 20, and the surface of the photoconductive drum 20 is irradiated with laser. The irradiation pattern is a portion other than the shape of the fuel cell electrode to be formed. As a result, a charge image having the same negative charge as that of the fuel cell electrode shape is formed on the photosensitive drum 20.

  An electrode material powder tank 30 is located downstream of the laser optical system 22 in the rotation direction of the photosensitive drum 20. The electrode material powder tank 30 has a developing roller 31 and is connected to a developing high-voltage power source 32 set to be negative. Reference numeral 33 denotes a thin film forming blade that uniformly adheres the electrode material powder 5 onto the developing roller 31. The thin film forming blade 33 is connected to a high-voltage power supply 34 for charging the electrode material powder set to positive, and the electrode material powder 5 is charged positively.

  The electrode material powder 5 adhering to the developing roller 31 flies under the Coulomb force by the electric field generated between the developing roller 31 and the photosensitive drum 20, and electrostatically forms a negatively charged charge image on the photosensitive drum 20. Adhere to. Accordingly, a fuel cell electrode image of the positively charged electrode material powder 5 is formed on the photosensitive drum 20. The positively charged electrode image (electrode material powder 5) is immediately subjected to the Coulomb force by the electric field generated between the photosensitive drum 20 and the transfer roller 14, and flies and adheres to the electrolyte membrane 10.

  The electrode material powder 5 adhering to the electrolyte membrane 10 is thermocompression bonded by the fixing rollers 16 and 16 and fixed to the electrolyte membrane 10. The produced fuel cell electrode is taken up by the take-up roller 12. The electrode material powder 5 remaining on the photosensitive drum 20 is peeled off from the surface of the photosensitive drum 20 by the photosensitive drum cleaner blade 23 and stored in the electrode material powder storage box 24. This electrode material powder is reused. The drum cleaner blade 23 is grounded, and simultaneously cleans and removes the charge from the photosensitive drum 20.

  In the above apparatus, the electrolyte membrane unwinding roller 11, the electrolyte membrane winding roller 12, the transport rollers 13, 15 and the fixing rollers 16, 16 are coated with a resin having a high resistance value and are grounded. For this reason, almost no current flows into the electrode material powder transferred onto the electrolyte film 10 from these rollers, and the transfer roller 14 has a high resistance and hardly flows current. Therefore, the photosensitive drum 20 and the transfer roller 14 The electrode material powder adhering to the electrolyte membrane does not reversely charge while passing through the strong electric field between them, and does not fly back to the photosensitive drum 20.

[Example 2]
A fuel cell electrode was produced with the apparatus shown in FIG. The same electrode material powder 5 as that used in Example 1 was used. It was filled in the electrode material powder tank 30. The same electrolyte membrane as that used in Example 1 was used except that the electrolyte membrane 10 was in the form of a roll. The surface of the photosensitive drum 20 was uniformly charged to about −700 V by the charging roller 21, and then a required laser was irradiated from the laser optical system 22.

  A voltage of +200 V was applied to the thin film forming blade 33 by a high voltage power supply 34 for charging the electrode material powder, and the electrode material powder 5 was charged positively. The development high-voltage power supply 32 was set to −500 V, and the electrode material powder 5 was adhered onto the development roller 31. The adhered electrode material powder 5 was caused to fly toward the photosensitive drum 20 by Coulomb force, and electrostatically adhered to the negatively charged charge image of the photosensitive drum 20. An image as set in advance was obtained on the photosensitive drum 20.

  The photosensitive drum 20 and the transfer roller 14 were set apart by 2 mm. The electrolyte membrane 10 was transported at a speed of 20 mm / sec by transport rollers 13 and 15. A high voltage power supply 17 for transfer was connected to the electrode of the transfer roller 14 via a high resistance 18 of 10 GΩ, and the high voltage power supply 17 for transfer applied a high voltage of −4000 V to the transfer roller 14. As a result, the positively charged electrode material powder 5 on the photosensitive drum 20 immediately flies by receiving a Coulomb force by a high electric field generated between the photosensitive drum 20 and the transfer roller 14 and is transferred to the electrolyte membrane 10. . Thereafter, the electrodes fixed by the fixing rollers 16 were used.

The amount of the electrode material powder 5 attached to the electrolyte membrane 10 was 0.17 mg Pt / cm ² . Further, the electrode image adhered and transferred was the same as the electrode image electrostatically adhered to the photosensitive drum 20, and no evidence of the electrode material powder 5 flying backward and adhering was observed.

[Example 3]
In the apparatus shown in FIG. 2, the coating resin for the transfer roller 14 was replaced with one having a volume resistivity of 1 × 10 ¹¹ Ωcm and a thickness of 1 mm. The other conditions were the same as in Example 2 to produce an electrode. The amount of the electrode material powder 5 attached to the electrolyte membrane 10 increased to 0.20 mg Pt / cm ² . Further, the electrode image adhered and transferred was the same as the electrode image electrostatically adhered to the photosensitive drum 20, and no evidence of the electrode material powder 5 flying backward and adhering was observed.

[Example 4]
An electrode was produced under the same conditions as in Example 2 except that the high resistance 18 was removed from the apparatus shown in FIG. The amount of the electrode material powder 5 attached to the electrolyte membrane 10 was 0.14 mg Pt / cm ² . The electrode image adhered and transferred was the same as the electrode image electrostatically adhered to the photosensitive drum 20, but a trace of the electrode material powder 5 flying slightly backward and adhering was observed. However, the function as an electrode was not deteriorated. By removing the high resistance 18, it is understood that a very small amount of the electrode material powder 5 flies backward.

[Example 5]
An electrode was produced under the same conditions as in Example 2 except that the high resistance 18 was removed from the apparatus shown in FIG. However, the transfer high-voltage power supply 17 outputs a high voltage when the photosensitive drum 20 rotates and the tip of the electrode image of the electrode material powder 5 adhering to the photosensitive drum 20 reaches the upper part of the electrolyte membrane 10. When the rear end of the image was rotated to the top of the electrolyte membrane 10, control was performed so that the voltage was 0V. That is, a transfer electric field was formed by applying a high voltage only for a time during which the electrode image on the photosensitive drum 20 was on the electrolyte membrane 10. The amount of the electrode material powder 5 attached to the electrolyte membrane 10 was the same as that in Example 4, and the electrode image adhered and transferred was the same as the electrode image electrostatically attached to the photosensitive drum 20. And the trace which the electrode material powder 5 flew backward and adhered was not observed at all.

[Comparative Example 2]
The apparatus shown in FIG. 2 is modified so that the photosensitive drum 20 and the transfer roller 14 are in contact with each other. Using the apparatus, an electrode was produced under the same conditions as in Example 2. As a result, the electrode shape may be changed, or an electrode having a hollow or scattered powder may be produced. This is because the current flowing from the high-voltage power supply 17 for transfer to the high resistance 18, the transfer roll 14, and the electrolyte film 10 is very small, but the charge amount of the electrode material powder 5 on the photosensitive drum 20 is changed to change the electrode material powder. 5 and the photosensitive drum 20 are considered to be sufficient in some cases.

[Comparative Example 3]
In the apparatus shown in FIG. 2, an apparatus is prepared in which both the modification for removing the resistor 18 from the transfer roller 14 and the modification for removing the resin coating having a volume resistivity of 1 × 10 ⁹ Ωcm and a thickness of 0.2 mm are prepared. An electrode was produced under the same conditions as in Example 2 using the apparatus. As a result, changes in the electrode shape, voids, and generation of scattered powder occurred. Unlike the comparative example 2, since a large current flows, the charge amount of the electrode material powder 5 on the photoconductor 20 is greatly changed, and the adhesive force with the photoconductive drum 20 is changed.

  FIG. 3 is a schematic view showing still another example of the fuel cell electrode manufacturing apparatus according to the present invention. In this apparatus B1, a transfer unit including the transfer roller 14, the transfer high-voltage power supply 17, and the high resistance 18, and the photosensitive drum 20, the charging roller 21, the laser optical system 22, and the electrode material powder in the apparatus B shown in FIG. A plurality of units (three in the drawing) arranged in tandem are arranged in the transfer direction of the electrolyte membrane 10 with the developing unit including the tank 30 and the like as one transfer unit 40. In each transfer unit 40, the electrolyte membrane 10 is set so as to be conveyed with a distance from the transfer roller 14. Other configurations are the same as those shown in FIG. Of course, in all the transfer units 40, the electrolyte film 10 may be in contact with the transfer roller 14, and in only some of the transfer units 40, the electrolyte film 10 and the transfer roller 14 may be in contact.

  By arranging a plurality of transfer units 40 in tandem in this way, an electrode image having a three-dimensional change can be formed on the electrolyte membrane 10 while maintaining the above-described inherent effects of the present invention. it can.

  FIG. 4 is a schematic view showing still another example of the fuel cell electrode manufacturing apparatus according to the present invention. In this apparatus B2, a plurality of transfer units 40 are arranged in tandem (three in the figure) in the transport direction of the electrolyte membrane 10 on one surface side (for example, the fuel electrode side) of the electrolyte membrane, On the other surface side of the electrolyte membrane (for example, the air electrode side), a plurality (three in the illustrated example) are arranged in tandem in the transport direction of the electrolyte membrane 10 in the reverse direction.

  In this apparatus, an electrode image having a three-dimensional change can be formed on both surfaces of the electrolyte membrane 10 through a series of steps while maintaining the above-described intrinsic effects of the present invention. In the illustrated example, the fixing roller 16a is disposed after the transfer on the fuel electrode side, and the fixing roller 16b is disposed after the transfer on the air electrode side. However, damage due to thermocompression bonding to the electrode material powder and the electrolyte membrane 10 is illustrated. In order to reduce this, the fixing roller 16a on the preceding side, that is, the fixing roller 16a can be omitted after the transfer on the fuel electrode side.

  Although not particularly shown, in the apparatus of the present invention shown in FIGS. 2 to 4, a belt type can be used instead of the photosensitive drum 20. Further, instead of the transfer roller 14, a flat electrode can be used as in the apparatus A shown in FIG. In that case, the electrolyte membrane 10 is preferably transported in a posture parallel to both the electrode on the photosensitive belt side and the flat plate electrode for transfer.

The schematic diagram which shows an example of the electrode manufacturing apparatus of the fuel cell by this invention. The schematic diagram which shows the other example of the electrode manufacturing apparatus of the fuel cell by this invention. The schematic diagram which shows the further another example of the electrode manufacturing apparatus of the fuel cell by this invention. The schematic diagram which shows the further another example of the electrode manufacturing apparatus of the fuel cell by this invention. The schematic diagram for demonstrating the membrane electrode assembly used with a polymer electrolyte fuel cell. The schematic diagram which shows an example of the electrode manufacturing apparatus of the conventional fuel cell.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Roll-shaped electrolyte membrane, 11 ... Electrolyte membrane unwinding roller, 12 ... Electrolyte membrane winding roller, 13, 15 ... Conveyance roller, 14 ... Transfer roller, 16 ... Fixing roller, 17 ... High piezoelectricity for transfer, 18 ... High resistance, 14a, 11a, 12a, 13a, 15a, 16a ... resin coating, 20 ... photosensitive drum, 21 ... charging roller, 22 ... laser optical system, 23 ... photosensitive drum cleaner blade, 24 ... electrode material powder storage Box, 30 ... electrode material powder tank, 31 ... developing roller, 32 ... high voltage power source for development, 33 ... thin film forming blade, 34 ... high voltage power source for charging electrode material powder

Claims (10)

  A transfer unit having at least a developing unit having a function of developing the charged electrode material powder into an electrode shape, and a transfer unit having a transfer high-voltage power source for transferring the electrode material powder from the developing unit to the electrolyte film by electrostatic force; and an electrolyte membrane At least a fixing part for fixing the electrode material powder on the electrode, and in the transfer unit, the transfer part and the electrolyte film are arranged apart from the developing part, and the transfer part is an electrode electrostatically attached to the electrolyte film An apparatus for producing an electrode for a fuel cell, characterized in that means for preventing the material powder from being charged with a reverse polarity is applied.   The means for preventing the electrode material powder from being charged with a reverse polarity is a means for producing a region that faces the electrolyte membrane of the transfer portion with a material having a high resistance value. The fuel cell electrode manufacturing apparatus according to claim 1.   The means for preventing the electrode material powder from being charged with a reverse polarity is a means for connecting the electrode of the transfer portion and the high-voltage power supply for transfer via a resistor having a high resistance value. The fuel cell electrode manufacturing apparatus according to claim 1.   As a means for preventing the electrode material powder from being charged with a reverse polarity, immediately after the electrode material powder is transferred to the electrolyte membrane, the transfer high-voltage power supply is set to a low voltage or 0 V to weaken the transfer electric field of the transfer portion or 2. The fuel cell electrode manufacturing apparatus according to claim 1, wherein the device is a means for eliminating the fuel cell electrode.   The members other than the members constituting the transfer portion, which are in contact with the electrolyte membrane in the manufacturing process of the electrodes, are made of a material having a high resistance value in the region that is in contact with the electrolyte membrane. The electrode material powder that is electrostatically attached to the electrolyte membrane is prevented from being charged to prevent the electrode material powder from being charged to a reverse polarity. The fuel cell electrode manufacturing apparatus according to claim 1.   6. The fuel cell electrode manufacturing apparatus according to claim 1, wherein two or more transfer units are arranged in tandem in the transport direction of the electrolyte membrane.   Two or more transfer units are arranged in tandem in the transport direction on one surface side of the electrolyte membrane, and two or more transfer units are arranged in tandem in the transport direction on the other surface side of the electrolyte membrane. The fuel cell electrode manufacturing apparatus according to claim 6.   8. The fuel cell electrode manufacturing apparatus according to claim 2, wherein the high resistance value is in the range of 10 M [Omega] to 100 G [Omega].   A step of developing the charged electrode material powder into an electrode shape in the developing portion, a step of transferring the developed electrode material powder from the developing portion to the electrolyte membrane in the transfer portion having a high-voltage power supply for transfer, an electrode on the electrolyte membrane A method for producing an electrode of a fuel cell comprising at least a step of fixing a material powder in a fixing portion, wherein the electrode material powder is transferred from the developing portion to the electrolyte membrane by an electrostatic force in the transfer portion, and then the electrode material on the electrolyte membrane By preventing the current from the transfer part from flowing into the powder, the electrostatically attached electrode material powder is prevented from being charged with a reverse polarity, so that the electrostatically attached electrode material powder is transferred to the developing part in the transfer part. An electrode manufacturing method for a fuel cell, characterized in that a reverse transfer flying abnormality is not caused.   A step of developing the charged electrode material powder into an electrode shape in the developing portion, a step of transferring the developed electrode material powder from the developing portion to the electrolyte membrane in the transfer portion having a high-voltage power supply for transfer, an electrode on the electrolyte membrane A method of manufacturing a fuel cell electrode comprising at least a step of fixing a material powder in a fixing unit, wherein the electrode material powder is transferred from the developing unit to the electrolyte membrane by an electrostatic force in the transfer unit, and then the transfer electric field of the transfer unit is changed. By weakening or eliminating it, the electrostatically attached electrode material powder is prevented from being charged with a reverse polarity, thereby causing a transfer abnormality in which the electrostatically adhered electrode material powder flies back to the developing portion. A method for producing an electrode for a fuel cell, characterized in that it is not allowed to occur.

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