WO2006101084A1

WO2006101084A1 - Carbon fiber and processes for (continuous) production thereof, and catalyst structures, electrodes for solid polymer fuel cells, and solid polymer fuel cells, made by using the carbon fiber

Info

Publication number: WO2006101084A1
Application number: PCT/JP2006/305571
Authority: WO
Inventors: Yoshinori Iwabuchi; Shinichiro Sugi; Shinichi Toyosawa; Masato Yoshikawa
Original assignee: Bridgestone Corporation
Priority date: 2005-03-23
Filing date: 2006-03-20
Publication date: 2006-09-28

Abstract

The invention relates to processes for the (continuous) production of carbon fiber which enable the production of carbon fiber having three-dimensional continuous structure in a short time, more specifically, a process (A) for the production of carbon fiber, characterized by heating a fibrilliform polymer having three-dimensional continuous structure by irradiation with a microwave to carbonize the polymer, and thus obtaining carbon fiber having three-dimensional continuous structure; and a process (B) for the continuous production of carbon fiber with a continuous baking apparatus equipped with a heating chamber (1), a microwave generator (2), and a conveyor (3), characterized by conveying a sheet- or plate-like fibrilliform polymer having three-dimensional continuous structure into the heating chamber (1), irradiating the polymer with a microwave generated by the microwave generator (2) to bake and carbonize the polymer, and thus obtaining carbon fiber having three-dimensional continuous structure.

Description

Specification

Carbon fiber and its (continuous) production method, catalyst structure using the same, electrode for polymer electrolyte fuel cell, and polymer electrolyte fuel cell

Technical field

TECHNICAL FIELD [0001] The present invention relates to a carbon fiber and a (continuous) production method thereof, a catalyst structure using the carbon fiber, an electrode for a polymer electrolyte fuel cell, and a polymer electrolyte fuel cell. This relates to a (continuous) production method of carbon fiber.

Background art

Conventionally, carbon fibers include pitch-based carbon fibers by liquid phase carbonization, polyacrylonitrile-based and rayon-based carbon fibers by solid-phase carbonization, vapor-grown carbon fibers by vapor-phase carbonization, and laser methods, Carbon nanotubes by the arc discharge method are known. Among these, in the manufacturing process of pitch-based carbon fiber, polyacrylonitrile-based carbon fiber, and rayon-based carbon fiber, a spinning process is necessary to obtain a fibrous precursor, and the manufacturing process becomes complicated. It is difficult to obtain finer fibers. In addition, in the production of vapor-grown carbon fiber, there is a problem that a mass production method is not necessarily established because the production equipment is expensive and the yield is not high. Furthermore, the production of carbon nanotubes has the problem that the production equipment is expensive and efficient mass production technology is under investigation, and it is difficult to obtain a fiber diameter exceeding 0.1 / im.

[0003] On the other hand, Japanese Patent Application Laid-Open No. 5-178603 discloses a carbon that does not require an infusibilization step, can control electric characteristics such as conductivity, has a high residual carbon ratio, and has excellent conductivity. In this method, a polyaniline powder is used as a raw material, so that carbon fibers cannot be obtained without going through a spinning process.

[0004] On the other hand, the pamphlet of International Publication No. 2004/063438 does not require a spinning step and an infusibilization step, has a high residual carbon ratio and is excellent in electrical conductivity, and particularly has a fiber diameter of 30 to several hundred nm. A carbon fiber production method is disclosed in which the carbon fiber can be efficiently obtained, and the electrical properties such as conductivity of the obtained carbon fiber can be controlled. According to the method For example, a compound having an aromatic ring can be electropolymerized to obtain a fibril-like polymer, and the fibril-like polymer can be baked in a non-oxidizing atmosphere to obtain a three-dimensional continuous carbon fiber.

Disclosure of the invention

[0005] As described above, according to the method described in the pamphlet of International Publication No. 2004Z063438, a three-dimensional continuous carbon fiber having a high residual carbon ratio and excellent conductivity can be obtained. However, it took a very long time to sinter the fibril-like polymer into a three-dimensional continuous carbon fiber, which was problematic in terms of productivity. More specifically, in the firing process described in International Publication No. 2004/063438, the fibrillated polymer is formed by external heating such as a heater in an inert gas (Ar, N, etc.) atmosphere in a firing furnace. When the fibrillated polymer was calcined at a heating force S, for example, 850 ° C., it took 2 hours to raise the temperature, 1 hour to calcine, and several hours to cool and take out. In addition, external heating with a heater or the like has a problem that it is difficult to uniformly heat the fibril-like polymer, and warping is caused by firing.

[0006] Conventionally, in order to heat and decompose the fibrillated polymer to produce carbon fiber, an external heating type furnace represented by an electric heater is generally used. When heating a fibrillar polymer in a furnace of the type, there is a problem that the heating time of the fibrillar polymer, which is the object to be heated, has to rely on heat conduction, and the firing time becomes difficult because rapid heating is difficult. In addition, when heating a fibril polymer in an external heating furnace, a temperature difference occurs between the surface and the inside of the fibril polymer that is the object to be heated, making it difficult to heat uniformly. There is also. Furthermore, when the fibril polymer is heated in an external heating furnace, the input energy is used in addition to the temperature increase of the fibril polymer that is the object to be heated. There is also a problem of inefficiency. Furthermore, when the fibrillated polymer is continuously fired in the furnace of the above external heating method, for example, there are more problems, for example, the limit of the temperature level due to heat escape, and the arrangement of heat insulating material to prevent heat escape. In addition, it is necessary to examine the positional relationship with the heater in detail, and there is a problem that the device becomes complicated. [0007] Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional technique, and to improve productivity, which can produce carbon fibers having a three-dimensional continuous structure by firing fibrillar polymers in a short time. An object of the present invention is to provide an excellent method for producing carbon fiber and a continuous method for producing carbon fiber. Another object of the present invention is to provide a catalyst structure using the carbon fiber, an electrode for a polymer electrolyte fuel cell using the catalyst structure, and a polymer electrolyte fuel cell provided with the electrode. It is to provide.

[0008] As a result of intensive studies to achieve the above object, the inventors of the present invention have made it possible that the fibrillated polymer absorbs the microwave and self-heats by firing the fibrillated polymer by microwave irradiation. The fibrillated polymer can be heated and carbonized with high efficiency, and the fibrillated polymer is continuously carried into and out of the heating chamber, and the microwave irradiation is performed in the chamber to burn the fibrillated polymer. Then, it was found that carbon fiber can be continuously produced by carbonization, and the present invention has been completed.

That is, in the method for producing a carbon fiber of the present invention, carbon having a three-dimensional continuous structure is obtained by irradiating a fibrillar polymer having a three-dimensional continuous structure with microwaves to heat and carbonize the polymer. It is characterized by producing fibers.

[0010] Further, the carbon fiber continuous production method of the present invention is a carbon fiber continuous production method using a continuous firing device including a heating chamber, a microwave generation device, and a transport mechanism. A fibrillated polymer having a sheet-like or plate-like three-dimensional continuous structure is carried into the heating chamber of the continuous baking apparatus, and the fibrillated polymer is irradiated with microwaves generated by the microwave generating apparatus. The polymer is calcined and carbonized to produce carbon fibers having a three-dimensional continuous structure. When continuous calcination is performed by irradiating the fibrillated polymer with microwaves using the continuous baking apparatus, the fibrillated polymer absorbs the microwave and self-heats, so that the fibrillated polymer is heated with high efficiency and carbonized. Can be made.

In a preferred example of the (continuous) production method of carbon fiber of the present invention, the fibrillated polymer is irradiated with microwaves in a vacuum or in an inert gas atmosphere. In this case, disappearance of the fibrillated polymer due to microwave irradiation can be suppressed.

[0012] In another preferred embodiment of the carbon fiber (continuous) production method of the present invention, the microwave The frequency of is 28GHz (millimeter wave). In this case, the fibrillar polymer sufficiently absorbs microwaves (millimeter wave with a frequency of 28 GHz), enables uniform heating without thermal runaway, and also prevents arcing. .

[0013] In another preferred embodiment of the carbon fiber (continuous) production method of the present invention, the fibrillar polymer is a polymer obtained by electrolytic polymerization of a compound having an aromatic ring. That is, the carbon fiber production method of the present invention includes a step of electropolymerizing a compound having an aromatic ring to produce a fibrillated polymer, and irradiating the fibrillated polymer with microwaves to heat the polymer. And carbonizing to produce a carbon fiber having a three-dimensional continuous structure. Here, the fibrillar polymer strength is more preferably composed of polyaniline, polypyrrole, polythiophene or derivatives thereof.

[0014] In the (continuous) method for producing carbon fiber of the present invention, it is preferable that the fibrillated polymer is supported on a conductive substrate. More preferably, the fibrillated polymer is a polymer obtained by electropolymerizing a compound having an aromatic ring on a conductive substrate. That is, the method for producing carbon fiber of the present invention comprises a compound having an aromatic ring. It is preferable to include a step of performing the electrolytic polymerization on a conductive substrate and generating a fibrillated polymer on the conductive substrate. Here, carbon paper is preferred as the conductive substrate. The shape of the conductive substrate is preferably a sheet shape or a plate shape.

[0015] In another preferred embodiment of the method for continuously producing carbon fibers of the present invention, the fibrillar polymer is a sheet, and the transport mechanism is a roll-to-roll system transport mechanism.

[0016] In another preferred embodiment of the method for continuously producing carbon fibers of the present invention, the fibrillar polymer is plate-shaped, and the transport mechanism is composed of a plurality of drive rolls.

[0017] In another preferred embodiment of the method for continuously producing carbon fibers of the present invention, the heating chamber 1 has a heat insulating material or a vacuum heat insulating layer above and below the passage position of the fibrillated polymer. In this case, it is possible to avoid a temperature decrease due to heat radiation from the fibrillar polymer which is a sampnore. Here, it is more preferable that a heater is provided in the heat insulating material. In this case, the temperature can be raised quickly. A microwave absorber layer is further disposed on the surface of the heat insulating material facing the fibrillar polymer. It is also preferable. In this case, it is possible to easily control the heating temperature of the fibril polymer by limiting the amount of microwave absorption of the fibril polymer.

[0018] In the continuous production method of carbon fiber of the present invention, the continuous firing apparatus further includes a cooling chamber for cooling the carbon fiber generated by microwave irradiation at the subsequent stage of the heating chamber. It is preferable. Since the carbon fiber that has passed through the heating chamber is at a high temperature, the carbon fiber may be oxidized when exposed to the air atmosphere. However, the continuous firing apparatus includes a cooling chamber, and the carbon fiber is contained in the cooling chamber. By sufficiently cooling, it is possible to prevent the carbon fibers from being oxidized in an air atmosphere.

[0019] In the continuous production method of carbon fiber of the present invention, the continuous firing apparatus further generates a fibrillar polymer by electropolymerizing a compound having an aromatic ring in the previous stage of the heating chamber. It is preferable to provide an electrolytic polymerization tank. Here, the produced polymer 1 is carried into the heating chamber 1 as the fibrillated polymer. Further, when the continuous baking apparatus includes an electrolytic polymerization tank, it is preferable to further include a cleaning apparatus and a drying apparatus for the polymer between the electrolytic polymerization tank and the heating chamber.

[0020] Further, the carbon fiber of the present invention is characterized by being produced by the above-described method, and has a three-dimensional continuous structure, and the catalyst structure of the present invention comprises a catalyst supported on the carbon fiber. It is characterized by this. The catalyst structure of the present invention has a catalyst structure comprising a continuous firing device including a heating chamber, a microwave generator, and a transport mechanism, and a catalyst support device disposed at a subsequent stage of the heating chamber of the continuous firing device. It can also be produced continuously by supporting the catalyst on carbon fiber using a continuous body production apparatus. Here, it is preferable that the continuous production apparatus for the catalyst structure further includes a carbon fiber cleaning apparatus and a drying apparatus in which a catalyst is supported downstream of the catalyst supporting apparatus.

Furthermore, an electrode for a polymer electrolyte fuel cell according to the present invention includes a gas diffusion layer and a catalyst layer disposed on the gas diffusion layer, and the catalyst structure is used for the catalyst layer. It is characterized by this. Furthermore, the polymer electrolyte fuel cell of the present invention is characterized by comprising the above electrode.

[0022] According to the present invention, a fibrillated polymer is irradiated with microwaves to be heated and carbonized. Thus, a carbon fiber having a three-dimensional continuous structure can be produced in a short time. Further, according to the present invention, a fibrillated polymer having a sheet-like or plate-like three-dimensional continuous structure is continuously formed by using a continuous baking apparatus having a heating chamber, a microwave generator, and a transport mechanism. Carrying into the heating chamber of the firing device, irradiating the fibrillar polymer with the microwave generated by the microwave generator, firing and carbonizing the polymer, continuous carbon fibers having a three-dimensional continuous structure Can be manufactured automatically. In addition, carbon fibers produced by these methods, catalyst structures using the carbon fibers, electrodes for solid polymer fuel cells using the catalyst structures, and solid polymer fuel cells including the electrodes Can be provided.

Brief Description of Drawings

FIG. 1 is a schematic view of an example of a continuous firing apparatus suitable for carrying out the present invention.

FIG. 2 is a schematic view showing an example of a continuous baking apparatus suitable for continuous baking of a sheet-like fibril polymer.

FIG. 3 is a schematic view showing an example of a continuous firing apparatus suitable for continuous firing of a plate-like fibril polymer.

FIG. 4 is a schematic view showing another preferred example of a continuous baking apparatus suitable for carrying out the present invention.

FIG. 5 is a schematic view showing an example of a continuous production apparatus for a catalyst structure suitable for carrying out the present invention.

FIG. 6 is a cross-sectional view of an example of a polymer electrolyte fuel cell of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Below, the manufacturing method of the carbon fiber of this invention is demonstrated in detail. The carbon fiber production method of the present invention is characterized in that a fibrillated polymer having a three-dimensional continuous structure is irradiated with microwaves, and the polymer is heated and carbonized to produce a carbon fiber having a three-dimensional continuous structure. To do. In the method for producing carbon fiber of the present invention, the fibrillated polymer absorbs the microwave and self-heats by irradiating the fibrillated polymer with microwaves, whereby the fibrillated polymer is heated and carbonized with high efficiency. Can do. In addition, since the carbon fiber production method of the present invention does not rely on heat conduction from a heat source, the temperature can be increased in a short time. It is also a short-time and energy-saving process. Furthermore, the microwave heating used in the present invention has the advantages of excellent temperature controllability and high responsiveness. Furthermore, since microwave heating is performed by self-heating of the fibrillar polymer, uniform heating is possible, and this prevents the sample from warping and stress generation due to firing, which was a problem in the conventional method. Monkey.

[0025] In the carbon fiber production method of the present invention, the fibrillar polymer used as a raw material has a three-dimensional continuous structure. The fibril-like polymer can be obtained by polymerizing a compound having an aromatic ring, preferably electrolytic polymerization, more preferably electrolytic oxidation polymerization. Here, examples of the compound having an aromatic ring include a compound having a benzene ring and a compound having an aromatic heterocyclic ring. Specifically, as the compound having a benzene ring, aniline and aniline derivatives are preferred. Specifically, pyrrole, thiophene, and derivatives thereof are preferable as the compound having an aromatic heterocyclic ring. These compounds having an aromatic ring may be used singly or as a mixture of two or more. The fibrillated polymer is preferably composed of polyaniline, polypyrrole, polythiophene or their derivatives.

[0026] The fibrillar polymer has a diameter of 30 nm to several hundreds of nm, preferably 40 nm to 500 nm, and a length of 0.5 μm to 100 mm, preferably 1 μm to 10 mm.

[0027] For example, when the fibrillated polymer is produced by electrolytic oxidation polymerization, it is preferable to mix an acid together with the raw material compound having an aromatic ring. In this case, the negative ion of the acid is taken into the fibril polymer synthesized as a dopant to obtain a fibril polymer excellent in conductivity, and the carbon fiber finally obtained by using this fibril polymer is obtained. The electrical conductivity of can be improved. The acid mixed during the polymerization is not particularly limited, and examples thereof include HBF, HSO, HC1, and HCIO.

4 2 4 4

The acid concentration is preferably in the range of 0.1 to 3 mol / L, more preferably in the range of 0.5 to 2.5 mol / L.

[0028] In the case of obtaining a fibrillated polymer by electrolytic oxidation polymerization, the working electrode and the counter electrode are immersed in a solution containing a compound having an aromatic ring, and the compound having the aromatic ring is sandwiched between both electrodes. A voltage higher than the oxidation potential is applied, or the compound having the aromatic ring is polymerized. It is only necessary to pass an electric current under such a condition that a sufficient voltage can be secured, and a fibrillated polymer is formed on the working electrode. Here, as the working electrode and the counter electrode, it is possible to use a plate or a porous material made of a highly conductive material such as stainless steel, platinum or carbon. Also, the current density in the electrolytic oxidation polymerization, the concentration of the electrolytic solution of the compound with a 0.1-1000111 eight I 111 ² ranges preferably tool 0.2~100mA N of m ² range is more preferably tool aromatic ring, 0.05 The range of ~ 3 mol / L is preferred. The range of 0.25 to 1.5 mol / L is even more preferred. In addition to the above components, a soluble salt or the like may be appropriately added to the electrolytic solution in order to adjust the pH.

[0029] The fibrillated polymer obtained on the working electrode as described above can be suitably used in the production method of the present invention by washing with a solvent such as water or an organic solvent and drying. A fibrillar polymer can be obtained. Here, the drying method is not particularly limited, and examples thereof include a method using a fluid bed dryer, a flash dryer, a spray dryer, etc. in addition to air drying and vacuum drying.

[0030] In the method for producing carbon fiber of the present invention, the fibrillated polymer is irradiated with microwaves. Here, the frequency of the irradiated microwave is usually in the range of 300 MHz to 300 GHz, and 28 GHz (millimeter wave) is particularly preferable. Microwaves with a frequency of 2.45 GHz typified by microwave ovens are widely used. When microwaves with a frequency of 2.45 GHz are used, there are the following problems. (I) The fibrillar polymer hardly absorbs 2.45 GHz microwaves. (Ii) When the fibrillar polymer has a complicated shape, an electric field is concentrated on the protrusions, causing thermal runaway and making uniform heating difficult. (M) Arcing occurs in conductive materials (a phenomenon in which aluminum foil power sparks fly in a microwave oven). As a result of intensive studies to solve these disadvantages, it was found that the above problem can be solved by increasing the frequency of the microwave, and that a 28 GHz microwave (millimeter wave) can be used particularly suitably. In addition, when microwaves of 28 GHz are used, it is possible to heat the fibrillated polymer itself. Another feature is that arcing is extremely difficult to occur even with conductive materials. In the production method of the present invention, even when the polymer is carbonized to become conductive graphite, the occurrence of arcing can be prevented by using a 28 GHz microwave.

[0031] The heating temperature of the fibrillated polymer by microwave irradiation is determined from the fibrillated polymer. It is also possible to set the temperature to 2000 ° C or higher by suppressing the heat dissipation of heat with a heat insulating material. Here, as the heat insulating material to be used, alumina can be preferably used up to about 1800 ° C, and boron nitride (BN) or the like can be suitably used above 1800 ° C. In addition, as a microwave generator used to generate microwaves, it is possible to use a general one that is not particularly limited.

[0032] In the production method of the present invention, it is preferable to perform microwave irradiation on the fibrillated polymer in a vacuum or in an inert gas atmosphere. In this case, disappearance of the polymer due to combustion can be suppressed. Here, when microwave irradiation is performed in a vacuum, it is preferable to set the system to 3 × 10 ² Pa or less. Also, as an inert gas atmosphere, a nitrogen atmosphere, an argon atmosphere, a helium atmosphere, or the like is used. Can be mentioned.

[0033] In the carbon fiber production method of the present invention, the fibrillated polymer is preferably supported on a conductive substrate. When a fibrillated polymer supported on a conductive substrate is heated by microwaves, the conductive substrate efficiently absorbs microwaves and generates heat, so that it conducts from the conductive substrate in addition to the self-heating of the fibril polymer. Heat is applied, so to speak hybrid heating, and more efficient firing is possible. Here, examples of the conductive substrate include carbon paper, carbon non-woven fabric, carbon cloth, carbon net, and mesh-like carbon. Among these, carbon paper is preferred.

[0034] For example, when fibrillar polyaniline electropolymerized on carbon paper is baked by microwave irradiation, the temperature can be easily raised to 850 ° C in a few minutes, and the retention time of about 10 minutes is equivalent to the conventional method It was confirmed that carbon fibers with a residual carbon ratio of 5% were obtained and the carbonization process could be completed in a short time. Also, with regard to the cooling time after firing, in the conventional method, the entire furnace was high temperature and required a long time for cooling, whereas in the method of the present invention, only a limited portion of the sampnore and the peripheral heat insulating material was limited. Since it is heated, the cooling time can be shortened. For this reason, the carbon fiber production method of the present invention can produce carbon fiber in a very short time compared to the conventional method, is an energy-saving process, and has the advantages of excellent productivity. Have.

[0035] Continuous carbon fiber production method>

Below, the continuous manufacturing method of the carbon fiber of this invention is demonstrated in detail, referring a figure. FIG. 1 is an example of a continuous firing apparatus suitable for the practice of the present invention. The continuous firing apparatus shown in Fig. 1 is a heating chamber 11 and a microwave generator for firing a sheet-like or plate-like fibril-like polymer by microwave irradiation and carbonizing it into carbon fibers in the heating chamber. And a transport mechanism 3 for transporting the fibrillated polymer into the heating chamber and transporting the carbon fiber generated by microwave irradiation from the heating chamber.

[0036] Conveying mechanism 3 of the continuous firing apparatus shown in (A) of Fig. 1 is a conveying mechanism of a roll 'toe' roll system, and roll 3A in which a sheet-like fibril polymer is sprinkled and microwave irradiation A roll 3B on which the generated sheet-like carbon fiber is wound. In addition, the continuous baking apparatus shown in FIG. 1A connects the heating chamber 1 and the microwave generator 2 to guide the microwave generated by the microphone mouth wave generator 2 to the heating chamber 11. Waveguide 4A, an introduction line 4B for introducing a gas such as an inert gas into the heating chamber 11, and an exhaust line 4C for exhausting the gas from the heating chamber 11.

[0037] In the continuous firing apparatus shown in Fig. 1 (A), a sheet-like fibril polymer is supplied from a roll 3A to a heating chamber 11, and is generated by a microwave generator 2 in the heating chamber 11. The irradiated microwave is irradiated to the sheet-like fibril polymer, and the sheet-like fibril polymer is carbonized to form a sheet-like carbon fiber, and the sheet-like carbon fiber is scraped off by the roll 3B, and the roll tow 'The ability to continuously produce sheet-like carbon fibers in a roll system is possible. The sheet-like fibrillated polymer may be stacked on a sheet-like substrate, where carbon paper or the like is preferred as the sheet-like substrate.

[0038] Further, the transport mechanism 3 of the continuous firing apparatus shown in FIG. 1B is composed of a plurality of drive rolls 3C, and the plate-like fibrillar polymer is transported by the drive rolls 3C. Note that the continuous firing apparatus shown in FIG. 1B also includes a waveguide 4A, an introduction line 4B, and an exhaust line 4C, as in the apparatus shown in FIG.

In the continuous baking apparatus shown in FIG. 1 (B), a plate-like fibril polymer is supplied to the heating chamber 11 by the drive roll 3C, and the microwave generator 2 is provided in the heating chamber 11. The microwaves generated in the plate are irradiated to the plate-like fibrillar polymer, and the plate-like fibrils are irradiated. The brittle polymer is carbonized to form plate-like carbon fibers, and the plate-like carbon fibers are continuously carried out of the heating chamber 11 by the drive roller 3C, thereby continuously forming the plate-like carbon fibers. Can be manufactured. The plate-like fibrillated polymer may be stacked on a plate-like substrate, and examples of the plate-like substrate include a glass substrate.

[0040] When continuous firing is performed by irradiating the fibrillated polymer with microwaves using the continuous firing apparatus, the fibrillated polymer absorbs the microwave and self-heats, so that the fibrillated polymer can be obtained with high efficiency. It can be heated and carbonized. In addition, since it does not rely on heat conduction from the heat source, the temperature can be raised in a short time, and it is possible to realize a short time and energy saving process. Furthermore, in microwave heating, since heating is performed by self-heating of the fibrillar polymer, uniform heating is possible. Furthermore, the fibrillated polymer absorbs microwaves as the temperature rises and the carbonization progresses and can be heated well. Furthermore, microwave heating is also characterized by excellent temperature controllability and high responsiveness.

[0041] When the fibrillated polymer is continuously baked using the above continuous baking apparatus, the frequency of the microphone mouth wave to be irradiated is usually in the range of 300 MHz to 300 GHz, and 28 GHz (millimeter wave) is particularly preferable. . A microwave with a frequency of 2.45 GHz typified by a microwave oven is widely used. When a microwave with a frequency of 2.45 GHz is used, there are the following problems. (i) The fibrillar polymer hardly absorbs 2.45 GHz microwaves. (Ii) Fibrils When the polymer has a complicated shape, the electric field concentrates on the protrusions, causing thermal runaway and uniform heating is difficult. (Iii) Arcing occurs in conductive materials (a phenomenon in which sparks fly from aluminum wheels in a microwave oven). As a result of intensive studies to solve these disadvantages, it was found that the above problem can be solved by increasing the frequency of the microwave, and that a 28 GHz microwave (millimeter wave) can be used particularly suitably. In addition, when a 28 GHz microwave is used, the fibrillated polymer itself can be easily heated. Another feature is that arcing is extremely difficult to occur even with a conductive material. Even when the fibrillated polymer is carbonized to form a conductive graph, it is possible to prevent the occurrence of marking by using a 28 GHz microwave. In addition, the continuous firing conditions for the fibrillar polymer can be optimized by adjusting the input power and line speed. Note that microwaves are emitted. As the microwave generator 2 used for generation, a general one without particular limitation can be used, and examples thereof include a gyrotron oscillator.

[0042] The heating chamber 11 of the continuous baking apparatus transmits microwaves above and below the passing position of the fibrillated polymer in order to avoid a temperature drop due to heat dissipation from the fibrillated polymer that is a sampnore. It is preferable to have a heat insulating material 5. As the heat insulating material to be used, alumina is preferably used up to about 1800 ° C, and boron nitride (BN) or the like can be suitably used at 1800 ° C or higher. For example, when a sheet-like fibril polymer is made into a sheet-like carbon fiber by roll-to-roll method, as shown in Fig. 2 (A), above and below the passage position of the sheet-like fibril polymer. If the plate-like fibrillar polymer is made of carbon fiber by placing the heat insulating material 5 on the top, as shown in FIG. By disposing the heat insulating material 5 below the driving roll 3C on which the plate-like fibril polymer is placed, the temperature drop due to heat radiation from the fibril polymer is suppressed, and the heating temperature of the fibril polymer due to microwave irradiation is reduced. Can be raised easily.

[0043] It is also preferable that the heating chamber 11 of the continuous baking apparatus has a vacuum heat insulating layer 6 above and below the passing position of the fibrillated polymer. In this case as well, temperature reduction due to heat radiation from the fibrillar polymer sample can be prevented by vacuum insulation (the principle of thermos). As the vacuum heat insulating layer, a vacuum heat insulating layer made of quartz or the like that transmits microwaves can be used. For example, when a sheet-like fibril polymer is made into a sheet-like carbon fiber by a roll-to-roll method, as shown in Fig. 2 (B), above and below the passing position of the sheet-like fibril polymer. When the plate-like fibrillar polymer is made of carbon fiber by arranging the vacuum heat insulating layer 6 on the top, as shown in FIG. By disposing the vacuum heat insulating layer 6 below the driving roll 3C on which the plate-like fibril-like polymer is placed, the temperature drop due to heat radiation from the fibril-like polymer is suppressed, and the fibril-like polymer caused by microwave irradiation is suppressed. The heating temperature can be easily raised. The heating chamber 1 may have both the heat insulating material 5 and the vacuum heat insulating layer 6.

[0044] In the continuous baking apparatus, when the heating chamber 11 has a heat insulating material 5, It is preferable that the heater 7 is embedded in the heat insulating material 5. When the continuous firing equipment is in operation, the fibrillar polymer, which is a sampnore, absorbs microwaves, and even if it is rapidly heated, the surrounding heat insulating material 5 may be deprived of heat. On the other hand, by embedding the heater 7 in the heat insulating material 5, the temperature can be raised quickly, and the power S can be stabilized more quickly. For example, when a sheet-like fibril polymer is made into a sheet-like carbon fiber by the roll 'toe' roll method, as shown in Fig. 2 (C), above and below the passing position of the sheet-like fibril polymer. In the case where the heat insulating material 5 with the heater 7 embedded therein is disposed, and when the plate-like fibril polymer is made of carbon fiber, the plate-like fibril polymer is shown in FIG. By placing a heat insulating material 5 with a heater 7 embedded under the driving roll 3C placed above the plate passing position and below the driving roll 3C on which the plate-like fibrinole polymer is placed, microwaves are applied to the fibril polymer in the heating chamber 11. The temperature of the portion irradiated with can be quickly raised to stabilize the device quickly.

[0045] In the case where the fibrillated polymer is continuously fired using the continuous firing apparatus, a microwave absorber layer 8 is further disposed on the surface of the heat insulating material 5 facing the fibrillated polymer. Is preferred. In this case, the microwave absorption rate of the fibrillated polymer is limited, the heating temperature can be easily controlled, and thermal runaway can be prevented. As the microwave absorber layer, a carbon thin film, a SiC thin film, or the like can be used. For example, when a sheet-like fibril polymer is made into a sheet-like carbon fiber by the roll 'toe' roll method, as shown in Fig. 2 (D), above and below the passage position of the sheet-like fibril polymer. In addition, when the heat insulating material 5 having the microwave absorber layer 8 disposed on the surface facing the fibril polymer is disposed, and when the plate-like fibril polymer is made of carbon fiber, the carbon fiber shown in FIG. As shown in (D), the microwave absorber layer is placed on the surface facing the fibril-like polymer above the passing position of the plate-like fibril-like polymer and below the driving roll 3C on which the plate-like fibril-like polymer is placed. By disposing the heat insulating material 5 in which 8 is disposed, the microwave absorption amount of the fibrillated polymer can be limited, and the heating temperature can be easily controlled.

[0046] Further, an opening is provided in the heat insulating material 5 of the heating chamber 11, and the heating chamber

By providing a control mechanism that measures the temperature of 1 and feeds it back to the microwave power It becomes easy to appropriately cope with various processing conditions. The firing temperature is not particularly limited and can be appropriately set according to the purpose, and can be controlled by adjusting the microwave power.

[0047] When the fibrillated polymer is continuously baked using the continuous baking apparatus, it is preferable to perform microwave irradiation on the fibrillated polymer in the heating chamber 11 under a vacuum or an inert gas atmosphere. In this case, disappearance due to combustion of the fibrillar polymer can be suppressed. Here, the introduction line 4B can be used for introducing the inert gas, and the exhaust line 4C can be used for exhausting the inert gas. Further, when the heating chamber 1 is evacuated, the heating chamber 1 may be depressurized by connecting a vacuum pump or the like to the exhaust line 4C. When microwave irradiation is performed in a vacuum, it is preferable to maintain the heating chamber 1 at 3 × 10 ² Pa or lower. In addition, as the inert gas atmosphere, a nitrogen atmosphere, an argon atmosphere, a helium atmosphere, or the like is used. Can be mentioned.

[0048] When microwave irradiation is performed in an inert gas atmosphere, a constant flow rate of inert gas is passed through the heating chamber 11, and firing is performed while replacing the gas. When the fibrillar polymer is calcined, the rolls 3A and 3B can be made into a normal air atmosphere. The same applies to the case of under vacuum, and the heating chamber 1 is evacuated by a large-capacity vacuum exhaust pump, so that only the heating chamber 1 is evacuated, and in the case of a roll-to-roll system, roll 3A, The part 3B may be a normal air atmosphere, and air, tow, and air may be used. As a matter of course, the rolls 3A and 3B may also be installed in a vacuum or in an inert gas atmosphere as in the heating chamber 11. The same applies to a plate-shaped sampnore, and the disappearance of the fibrillated polymer due to combustion can be suppressed by setting the heating chamber 11 under a vacuum or an inert gas atmosphere.

[0049] Since the carbon fiber that has passed through the heating chamber 11 has a high temperature, the carbon fiber may be oxidized when exposed to the atmosphere. Therefore, it is preferable that the continuous baking apparatus further includes a cooling chamber 9 for cooling the carbon fiber generated by the microwave irradiation at the subsequent stage of the heating chamber 11. By blowing the inert gas cold air in the cooling chamber 9, the carbon fiber can be sufficiently cooled and the carbon fiber can be prevented from being oxidized in the air atmosphere. In addition, the cooling chamber By filling the carbon fiber with a cooling drum or the like while filling it with a vacuum or an inert gas, it is possible to sufficiently cool the carbon fiber and prevent the carbon fiber from being oxidized in the atmosphere. As the inert gas to be circulated through the cooling chamber 9, the same inert gas as that of the heating chamber 1 can be used. When the cooling chamber 9 is evacuated, the degree of vacuum is the same as that of the heating chamber 11. Similar levels can be achieved.

[0050] For example, when a sheet-like fibril polymer is made into a sheet-like carbon fiber by a roll 'toe' roll method, as shown in FIG. 4 (A), the sheet-like fibril polymer is fired. A cooling chamber 9 that cools the sheet-like carbon fiber that has been heated to a high temperature after the heating chamber 1 is provided, and an inert gas is circulated through the cooling chamber 9. However, even when the fibrillar polymer is plate-shaped, a cooling chamber 9 is provided after the heating chamber 11 and the generated carbon fiber is sufficiently cooled by flowing an inert gas through the cooling chamber 9. be able to. The cooling chamber 9 shown in FIG. 4A is similar to the heating chamber 1 in that the introduction line 10A for introducing a gas such as an inert gas into the cooling chamber 9 and the cooling chamber 9 And an exhaust line 10B for exhausting gas from.

[0051] Further, as shown in FIG. 4B, a cooling chamber for cooling the sheet-like carbon fiber that has been heated to a high temperature after the heating chamber 1 for firing the sheet-like fibril-like polymer. 9, the cooling chamber 9 is filled with a vacuum or an inert gas, and the carbon fibers are brought into contact with the cooling drum 11, whereby the produced carbon fibers can be sufficiently cooled. In the above continuous firing apparatus, as shown in FIG. 4 (B), a roll 3B for scraping the sheet-like carbon fiber may be disposed in the cooling chamber 9. Although not shown, when the fibrillated polymer is plate-shaped, a cooling chamber is provided after the heating chamber 1 and the cooling chamber 1 is filled with vacuum or an inert gas, and the carbon fiber is supplied to the cooling plate. By making it contact, the produced | generated carbon fiber can fully be cooled. The cooling chamber 9 shown in FIG. 4B includes an exhaust line 10B for exhausting gas from the cooling chamber 9.

[0052] The conveyance of the sheet-like or plate-like fibril polymer may be continuous conveyance at a constant speed, or may be stopped and fired after conveyance for a certain length, and then conveyed again. It may be a process of repeating the transfer and firing (stop). In the method of repeatedly carrying 'stopping', in order to keep the heating chamber 1 in a vacuum or an inert gas atmosphere, a load lock chamber (not shown) is provided before and after the heating chamber 1 to perform preliminary exhaust and gas replacement. And the heating chamber 11 may be kept under desired conditions.

[0053] When carbon fibers are continuously produced using the continuous firing apparatus, the fibrillated polymer includes a polymer obtained by electrolytic polymerization of a compound having an aromatic ring, and the polymer is usually It is fibrillar and has a three-dimensional continuous structure. The diameter and length of the fibril-like polymer having a three-dimensional continuous structure are as described above, and the compound having an aromatic ring as a raw material is also as described above.

[0054] When the fibrillated polymer is continuously baked using the continuous baking apparatus, the fibrillated polymer is preferably supported on a sheet-like or plate-like conductive substrate. When a fibrillar polymer supported on a sheet-like or plate-like conductive substrate is heated by microwaves, the conductive substrate efficiently absorbs microwaves and generates heat. The heat conducted from the substrate is applied, so to speak, hybrid heating, enabling more efficient firing. Here, examples of the conductive substrate include force-bon paper, carbon non-woven fabric, carbon cloth, carbon net, mesh-like force, and the like, and among these, carbon paper is preferable. It is also preferable to electropolymerize a compound having an aromatic ring on a conductive substrate to produce a polymer on the conductive substrate, and to supply the polymer 'conductive substrate composite as a sample to a continuous baking apparatus.

[0055] As shown in FIG. 5, the continuous baking apparatus further includes an electrolytic polymerization tank 12 for generating a polymer by electrolytic polymerization of a compound having an aromatic ring at the front stage of the heating chamber 11. It is preferable that the fibrillated polymer can be carried into the heating chamber 11. In the case of producing a polymer by electrolytic polymerization, it is preferable to mix an acid together with a raw material compound having an aromatic ring, in the same manner as in the carbon fiber production method. Here, the kind of acid mixed in the polymerization and the concentration of the acid are as described above.

[0056] In the case of obtaining a polymer by electrolytic polymerization, the working electrode and the counter electrode are immersed in a solution containing a compound having an aromatic ring, and the oxidation potential of the compound having the aromatic ring between both electrodes The above voltage may be applied, or a current having a condition sufficient to secure a voltage sufficient to polymerize the compound having an aromatic ring may be applied, and a polymer is formed on the working electrode. Here, as the working electrode and the counter electrode, it is possible to use a plate or a porous material having a good conductive material force such as stainless steel, platinum, and carbon. In addition, by using a sheet-like substrate as a working electrode, a polymer can be continuously produced on the sheet-like substrate to produce a sheet-like polymer substrate composite. The current density in the electropolymerization and the concentration of the compound having an aromatic ring in the electrolytic solution are as described above. In addition to the above components, the electrolytic solution contains a soluble salt or the like in order to adjust the pH. It may be added appropriately.

[0057] When the continuous baking apparatus includes an electrolytic polymerization tank 12, as shown in Fig. 5, a polymer washing apparatus and a drying apparatus 13A are further provided between the electrolytic polymerization tank 12 and the heating chamber 11. In this case, it is possible to prevent the residue and moisture derived from electrolytic polymerization from adhering to the polymer. As the cleaning device, a general device can be used. Examples of the drying device include a vacuum dryer, a fluidized bed dryer, an air flow dryer, and a spray dryer.

[0058] <Carbon fiber>

The carbon fiber produced by the method of the present invention has a fibril-like and three-dimensional continuous structure, and preferably has a diameter of 30 nm to several hundreds of nm, more preferably 40 nm to 500 nm, Length force 0 · 5 μ π! ~ 100m is preferred Ι μ π! Is further preferably les, it is further preferable device is preferably a surface resistance 10 ⁶ ~10- ² Ω tool 10 ⁴ ~10- ² Ω it is ~ 10 mm. The carbon fiber has a residual carbon ratio of 95 to 30%, preferably 90 to 40%. Here, the remaining charcoal rate is expressed by the following formula:

Residual carbon ratio = (mass of carbon fiber after firing) Ζ (mass of polymer before firing) X 100 force, etc. The carbon fiber obtained as described above has higher conductivity than granular carbon because the entire carbon has a three-dimensional continuous structure.

[0059] Gu catalyst structure>

The catalyst structure of the present invention is formed by supporting a metal, preferably a noble metal, on the carbon fiber having the three-dimensional continuous structure described above. The catalyst structure is a catalyst layer of a polymer electrolyte fuel cell. In addition, it can be used as a catalyst for various chemical reactions such as hydrogenation reactions. Here, Pt is particularly preferable as the noble metal supported on the carbon fiber. In the present invention, Pt is preferably used alone, or is preferably used as an alloy with other metals such as Ru. By using Pt as a noble metal and using the catalyst structure of the present invention as a catalyst layer of a polymer electrolyte fuel cell, hydrogen can be oxidized with high efficiency even at a low temperature of 100 ° C or lower. In addition, by using an alloy such as Pt and Ru, it is possible to prevent poisoning of Pt by CO and prevent a decrease in the activity of the catalyst. The metal supported on the carbon fiber is preferably in the form of fine particles, and the particle diameter of the fine particles is preferably in the range of 0.5 to 100 nm, more preferably in the range of 1 to 50 nm. The metal loading is preferably in the range of 0.05 to 5 g with respect to the carbon fiber lg. Here, the method for supporting the metal on the carbon fiber is not particularly limited, and examples thereof include an impregnation method, an electro plating method (electrolytic reduction method), an electroless plating method, and a sputtering method.

[0060] The catalyst structure includes a continuous firing device including a heating chamber, a microwave generator, and a transport mechanism, and a catalyst support device disposed at a subsequent stage of the heating chamber of the continuous firing device. It can also be produced continuously by supporting the catalyst on carbon fiber using a continuous body production apparatus. Hereinafter, the continuous production method of the catalyst structure of the present invention will be described in detail. FIG. 5 shows an example of a continuous production apparatus for a catalyst structure suitable for carrying out the present invention. The continuous production apparatus for the catalyst structure includes the above-mentioned continuous calcining apparatus and a catalyst supporting unit for supporting the catalyst on the carbon fiber in the chambers 1 and 9 of the continuous calcining apparatus, preferably in the subsequent stage of the cooling chamber 9. And a device (14). In addition, the continuous production apparatus for the catalyst structure preferably includes a cleaning device and a drying device 13B for the carbon fiber (that is, the catalyst structure) on which the catalyst is supported after the catalyst supporting device 14. In this case, it is possible to prevent the residue derived from catalyst loading and water from adhering to the catalyst structure.

[0061] According to the continuous production apparatus for the catalyst structure shown in Fig. 5, the fibrous polymer produced in the electrolytic polymerization tank 12 is supplied to the heating chamber 11 through the cleaning device and the drying device 13A, and the heating chamber 1 Microwave irradiation at 1 makes carbon fiber. The produced carbon fiber is sent to the cooling chamber 9 and cooled in the cooling chamber 9, and then the catalyst supporting device. 14, the catalyst is supported on the carbon fiber by the catalyst supporting device 14, and the catalyst structure is manufactured. Thereafter, the produced catalyst structure is washed and dried by the washing device and the drying device 13B, and the sheet-like catalyst structure is scraped off on the roll 3B.

[0062] <Polymer Fuel Cell Electrode>

An electrode for a polymer electrolyte fuel cell of the present invention comprises a gas diffusion layer and a catalyst layer disposed on the gas diffusion layer, wherein the catalyst structure described above is used for the catalyst layer. To do.

[0063] It is preferable to impregnate the catalyst layer with a polymer electrolyte. As the polymer electrolyte, an ion conductive polymer can be used, and as the ion conductive polymer, a sulfonic acid can be used. And polymers having an ion exchange group such as carboxylic acid, phosphonic acid, and phosphonous acid, and the polymer may or may not contain fluorine. Specifically, the ion conductive polymer is preferably a perfluorocarbon sulfonic acid polymer such as Nafion (registered trademark). The amount of the polymer electrolyte impregnated is preferably in the range of 10 to 500 parts by mass with respect to 100 parts by mass of carbon fibers in the catalyst layer. The thickness of the catalyst layer is not particularly limited, but is preferably in the range of 0.1 to 100 μπι. The amount of metal supported on the catalyst layer is determined by the loading rate and the thickness of the catalyst layer, and is preferably in the range of 0.001 to 0.8 mg · m ² .

[0064] The gas diffusion layer is a layer for supplying hydrogen gas or an oxidant gas such as oxygen or air to the catalyst layer to exchange generated electrons, and has a function as a gas diffusion layer. It functions as a current collector. The material used for the gas diffusion layer is particularly preferably carbon paper, which is preferably the conductive substrate described above. A compound having an aromatic ring is electropolymerized on a conductive substrate to form a fibril polymer, and the fibril polymer is irradiated with a micro mouth wave to form a carbon having a three-dimensional continuous structure on the conductive substrate. An electrode for a polymer electrolyte fuel cell can be produced by producing fibers and further supporting a metal, preferably a noble metal such as Pt, on the carbon fiber portion.

[0065] <Polymer fuel cell>

The polymer electrolyte fuel cell of the present invention comprises the above electrode for a polymer electrolyte fuel cell. Hereinafter, the solid polymer fuel cell of the present invention will be described with reference to FIG. This will be described in detail. The illustrated polymer electrolyte fuel cell includes a membrane electrode assembly (MEA) 21 and separators 22 positioned on both sides thereof. The membrane electrode assembly (MEA) 21 includes a solid polymer electrolyte membrane 23, and a fuel electrode 24A and an air electrode 24B located on both sides thereof. At the anode 24A, a reaction represented by 2H → 4H ⁺⁺ 4e— occurs, and the generated H ⁺ is solid.

2

The polymer electrolyte membrane 23 reaches the air electrode 24B, and the generated e- is taken out to become an electric current. On the other hand, in the air electrode 24B, the reaction represented by O + 4H ⁺ + 4e— → 2H 2 O

twenty two

Occurs and water is generated. At least one of the fuel electrode 24A and the air electrode 24B is the above-described polymer electrolyte fuel cell electrode of the present invention. The fuel electrode 24A and the air electrode 24B include a catalyst layer 25 and a gas diffusion layer 26, respectively, and are arranged so that the catalyst layer 25 is in contact with the solid polymer electrolyte membrane 23.

Here, the polymer electrolyte fuel cell of the present invention is characterized in that the electrode for a polymer electrolyte fuel cell described above is used for at least one of the fuel electrode 24A and the air electrode 24B. Since the electrode has high electronic conductivity, it is possible to effectively extract electric energy without increasing the internal resistance of the fuel cell.

[0067] As the solid polymer electrolyte membrane 23, an ion conductive polymer can be used, and the ion conductive polymer is exemplified as a high molecular electrolyte that can be impregnated in the catalyst layer. Can be used. Further, as the separator 22, a normal separator having a surface (not shown) formed with a flow path of fuel, air, generated water and the like can be used.

[0068] <Example>

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

[0069] (Comparative Example 1)

Carbon acid in an acidic aqueous solution containing 0.5 mol / L of an aniline monomer and 1.0 mol / L of HBF.

Four

Install a working electrode consisting of one par [Toray], use a platinum plate as the counter electrode, perform electropolymerization for 3 minutes at a constant current of 15 mA m ² at room temperature, and deposit polyaniline on the working electrode I let you. The obtained polyaniline is washed with ion-exchanged water, vacuum-dried for 24 hours, set in a firing furnace, and heated to 850 ° C in 2 hours at a heating rate of 7 ° C / min in an Ar atmosphere. Warm and then at 850 ° C 1 It was held for a time and fired. After the cooling time of 3 hours, the obtained fired product was taken out and observed with SEM, and it was confirmed that the carbon fiber strength S having a diameter of 40 to 100 nm was obtained on carbon paper. The residual carbon ratio of this carbon fiber was measured and found to be 43.7%. In addition, the sample was warped due to the shrinkage and carbonization process in the heating process of polyaniline.

[0070] (Example 1)

In the same manner as in Comparative Example 1, polyaniline was electrodeposited on carbon paper, washed and dried. Next, a sampler made of polyaniline / carbon paper was set in a microwave firing furnace with a 28 GHz gyrotron oscillator connected by a waveguide, surrounded by 50 mm thick alumina insulation. Then, it was evacuated to about 10Pa with a vacuum pump. Thereafter, the sample was irradiated with microwaves, heated to 85 ° C. in 10 minutes at a heating rate of 85 ° C./min, and then held at 850 ° C. for 10 minutes for firing treatment. After the cooling time of 30 minutes, the obtained fired product was taken out and observed by SEM. As a result of the conventional firing method, it was found that the carbon fiber strength was obtained on carbon paper having a diameter of 40 to 100 nm. confirmed. The carbon residue of this carbon fiber was measured and found to be 40.5%. In addition, the sample did not warp and maintained a flat shape.

[0071] From the above results, 28-GHz microwave (millimeter wave) heating allows the fibrillated polymer to be baked and carbonized efficiently (energy saving) in a very short time without generating arcing. It can be seen that the productivity of can be greatly improved. In addition, the internal stress of the sample after firing could be relaxed.

[Example 2]

A three-dimensional continuous structure of polyaniline was produced on carbon paper in a continuous electrolytic polymerization tank, and a long roll of polyaniline / carbon paper structure was produced. In the continuous electrolytic polymerization tank, a carbon paper as a working electrode in an acidic aqueous solution containing a Anirinmonoma 0.5 mol / L and HBF 1.0 mol / L, using a platinum plate as the counter electrode, N 15mA at room temperature m ² The carbon paper transport speed was adjusted so that electropolymerization could be performed at a constant current of 3 minutes, and polyaniline was electrodeposited on the working electrode (on the carbon paper), then washed with ion-exchanged water and dried. The obtained long roll sample with a width of 30 cm The gyrotron oscillator was set in a continuous firing device connected by a waveguide, and nitrogen gas was introduced into the heating chamber to replace the gas. The microwave power was adjusted so that the maximum temperature force was 50 ° C, and the sheet-like long roll sample was conveyed at a speed of 0.25 m / min and scraped off. A long carbon fiber sheet could be obtained by this firing. Further, when the obtained fired product was taken out and observed by SEM, carbon fibers having a diameter of 40 to 20 Onm were obtained on carbon paper in the same manner as in the conventional firing method that was not continuous, and the carbon fibers Was confirmed to have a three-dimensional continuous structure. The carbon residue rate of this carbon fiber was measured and found to be 40.5%. It was confirmed that the carbon residue rate was the same as that of sampnore fired by batch processing using a conventional furnace, and carbonization was possible even during continuous firing.

Claims

The scope of the claims

[I] A method for producing a carbon fiber, which comprises irradiating a fibrillated polymer having a three-dimensional continuous structure with microwaves and heating and carbonizing the polymer to produce a carbon fiber having a three-dimensional continuous structure.

[2] The method for producing a carbon fiber according to [1], wherein the fibrillated polymer is irradiated with microwaves in a vacuum or in an inert gas atmosphere.

[3] The method for producing a carbon fiber according to [1], wherein the frequency of the microwave is 28 GHz.

4. The method for producing carbon fiber according to claim 1, wherein the fibrillated polymer is a polymer obtained by electrolytic polymerization of a compound having an aromatic ring.

[5] The method for producing a carbon fiber according to [4], wherein the fibrillar polymer is polyaniline, polypyrrole, polythiophene or a derivative thereof.

6. The method for producing carbon fiber according to claim 1, wherein the fibrillated polymer is supported on a conductive substrate.

7. The method for producing carbon fiber according to claim 6, wherein the fibrillated polymer is a polymer obtained by electropolymerizing a compound having an aromatic ring on a conductive substrate.

8. The method for producing carbon fiber according to claim 6, wherein the conductive substrate is carbon paper.

[9] A continuous production method of carbon fiber using a continuous firing apparatus including a heating chamber, a microwave generator, and a transport mechanism,

A fibrillated polymer having a sheet-like or plate-like three-dimensional continuous structure is carried into the heating chamber of the continuous baking apparatus, and the fibrillated polymer is irradiated with microwaves generated by the microwave generator, A continuous production method of carbon fibers, characterized in that the polymer is calcined and carbonized to produce carbon fibers having a three-dimensional continuous structure.

10. The continuous production method for carbon fiber according to claim 9, wherein microwave irradiation to the fibrillated polymer in the heating chamber is performed in a vacuum or in an inert gas atmosphere.

[II] The carbon fiber according to claim 9, wherein the frequency of the microwave is 28 GHz. A continuous manufacturing method for textiles.

12. The continuous production method of carbon fiber according to claim 9, wherein the fibrillar polymer is a polymer obtained by electrolytic polymerization of a compound having an aromatic ring.

[13] The continuous production method of carbon fiber according to [9], wherein the fibrillated polymer is polyaniline, polypyrrole, polythiophene or a derivative thereof.

14. The continuous production method of carbon fiber according to claim 9, wherein the fibrillated polymer is supported on a conductive substrate.

15. The continuous carbon fiber according to claim 14, wherein the fibril polymer is a polymer obtained by electrolytic polymerization of a compound having an aromatic ring on a sheet-like or plate-like conductive substrate. Production method.

16. The carbon fiber continuous production method according to claim 14, wherein the conductive substrate is carbon paper.

[17] The continuous production method of carbon fiber according to [9], wherein the fibrillated polymer is in a sheet form, and the transport mechanism is a roll 'toe' roll type transport mechanism.

18. The continuous production method of carbon fiber according to claim 9, wherein the fibrillated polymer is plate-shaped and the transport mechanism is composed of a plurality of drive rolls.

19. The continuous production method of carbon fiber according to claim 9, further comprising a heat insulating material or a vacuum heat insulating layer above and below the passage position of the fibrillated polymer.

[20] The continuous production method of carbon fiber according to [19], wherein a heater is carried in the heat insulating material.

[21] The continuous production method of carbon fiber according to [19], wherein a microwave absorber layer is further disposed on the surface of the heat insulating material facing the fibrillated polymer. .

[22] The apparatus according to claim 9, wherein the continuous firing apparatus further includes a cooling chamber for cooling the carbon fiber generated by microwave irradiation at a subsequent stage of the heating chamber. Continuous carbon fiber production method.

[23] The continuous baking apparatus further includes an electropolymerization tank for electrolytically polymerizing a compound having an aromatic ring in the previous stage of the heating chamber to produce a fibrillated polymer. The continuous manufacturing method of the carbon fiber as described in 2.

[24] The carbon fiber as set forth in claim 23, wherein the continuous firing device further comprises a cleaning device and a drying device for the fibrillated polymer between the electrolytic polymerization tank and the heating chamber. Continuous manufacturing method.

[25] Claim: Carbon fiber having a three-dimensional continuous structure produced by the method according to any one of! To 24.

26. A catalyst structure obtained by supporting a catalyst on the carbon fiber according to claim 25.

[27] A continuous production apparatus for a catalyst structure comprising a heating chamber, a continuous firing device having a microwave generator and a transport mechanism, and a catalyst support device disposed at a subsequent stage of the heating chamber of the continuous firing device. A method for continuously producing a catalyst structure, wherein the catalyst is supported on carbon fibers.

[28] The catalyst according to claim 27, wherein the continuous production apparatus for a catalyst structure further includes a carbon fiber cleaning device and a drying device in which a catalyst is supported downstream of the catalyst support device. A continuous manufacturing method of a structure.

[29] In a polymer electrolyte fuel cell electrode comprising a gas diffusion layer and a catalyst layer disposed on the gas diffusion layer,

27. A solid polymer fuel cell electrode, wherein the catalyst structure according to claim 26 is used for the catalyst layer.

30. A polymer electrolyte fuel cell comprising the electrode according to claim 29.