JP6701698B2 - Method for transporting electrode base material, method for manufacturing electrode base material, and method for manufacturing gas diffusion electrode - Google Patents

Description

  The present invention relates to a method for transporting an electrode base material, a method for manufacturing an electrode base material, and a method for manufacturing a gas diffusion electrode.

  Since carbon fibers have excellent heat resistance and are fibrous, they are processed into woven, non-woven, paper-shaped, etc. carbon fiber sheets, and have heat insulating materials, heat-resistant protective materials, and electrical conductivity. The application development as an electrode base material is being promoted.

  Electrode base materials that are these carbon fiber sheets are produced by carbonizing a carbon fiber sheet precursor, and in using this carbon fiber sheet as an electrode base material as described above, after carbonization treatment, The heat treatment may be performed again at a constant high temperature. Reducing the production loss of the electrode base material is an important factor for improving cost competitiveness when the second heat treatment is continuously performed.

  However, since carbon fiber sheets are not endless, it is necessary to temporarily lower the temperature of the high temperature furnace for each carbon fiber sheet, place a new carbon fiber sheet precursor on the running line, and raise the temperature of the high temperature furnace again. The process of raising and lowering the temperature of the high-temperature furnace has to spend a long time, and as a result, the operating efficiency of the high-temperature furnace is greatly reduced. Further, when heat-treating a carbon fiber sheet at a constant high temperature, it is necessary to stop the production while the temperature of the high temperature furnace rises to a predetermined temperature. In addition, the product part must be passed through the high-temperature furnace to the take-up part, and then the temperature rise of the high-temperature furnace must be started. is there.

  Japanese Patent Laid-Open No. 2004-176233 discloses that "ends of a plurality of carbon fiber sheets are overlapped with each other and spun yarns or filament bundles of a specific thickness made of polyacrylonitrile-based oxidized fibers are used for connection. "Structure that can be joined" is described, whereby "long-term carbon fiber that does not cause severing of joints, clogging of gaps, catching on guides, and wrinkles or twists of joints during high-temperature heat treatment in the subsequent process A sheet is obtained" effect is disclosed.

  Further, in Patent Document 2 (Japanese Patent Laid-Open No. 5-301781), "carbon obtained by impregnating a carbonaceous material such as a carbon fiber sheet material or a carbonizable base material with a carbonizable thermosetting resin such as a phenol resin is disclosed. A method for adhering carbonaceous materials, in which carbonaceous materials are adhered to each other using a sheet-like adhesive for materials, and then baked to carbonize the whole, is described. The effect that there is no unevenness, the adhesive strength is high, and the surfaces to be adhered can be sufficiently adhered is disclosed.

  Moreover, in patent document 3 (Unexamined-Japanese-Patent No. 2011-80161), "phenol resin and charcoal are added to the terminal part of the 1st carbon fiber sheet precursor which is going to connect, or the starting part of the 2nd carbon fiber sheet precursor. After the adhesive layer made of the material is applied discontinuously in the longitudinal direction of the carbon fiber sheet precursor, the end portion and the start end portion thereof are overlapped with each other, and the overlapping portion is joined by a hot press machine, The method for producing a long carbon fiber sheet in which the end portions of the second carbon fiber sheet precursor are connected to each other is described. The effect of obtaining a carbon fiber sheet at low cost is disclosed.

  Moreover, in patent document 4 (Unexamined-Japanese-Patent No. 2011-080160), "the phenol resin is attached to the terminal part of the first carbon fiber sheet precursor or the starting part of the second carbon fiber sheet precursor to be joined. Sheet-like adhesives made of impregnated carbon fiber precursors are temporarily tacked discontinuously in the longitudinal direction of the sheet, and then their end and start ends are overlapped with each other, and the overlapping portion is hot-pressed. A method for producing a long carbon fiber sheet which is bonded and joined together is disclosed, whereby a "nonwoven fabric-like or paper-like long carbon fiber sheet precursor or carbon fiber sheet and those carbon fiber sheet precursors or The effect that "a carbon fiber sheet can be efficiently manufactured at low cost" is disclosed.

JP, 2004-176233, A Japanese Patent Laid-Open No. 5-301781 JP, 2011-080161, A JP, 2011-080160, A

  However, in the configuration of Patent Document 1, when the ends of the carbon fiber sheet precursor are sewn together by using a needle, a crack is formed at a portion where the needle is stabbed, and the crack progresses to join the joined portion. There may be a problem of division.

  In the configuration of Patent Document 2, a sheet-shaped adhesive is sandwiched between the entire surfaces of an adherend such as a carbonaceous molding material having a predetermined shape and pressure-bonded. This is a disclosure relating to the joining of molding materials in a batch system in which sheet-shaped adhesive materials of the same shape and size that are sandwiched and pressure-bonded are laminated, and the product parts are sintered by connecting the ends of carbon fiber sheets. No suggestion has been made regarding reduction of product loss when starting to raise the temperature in the sintering furnace after the material has been conveyed through the furnace to the winding portion.

  However, in the configurations of Patent Document 3 and Patent Document 4, although a long carbon fiber sheet can be obtained by overlapping and connecting the end portions and the start end portions of the carbon fiber sheets to each other, at the start of production. No suggestion has been made regarding reduction of product loss in the case where the temperature rise in the sintering furnace is started after the product portion is conveyed to the winding portion through the sintering furnace.

  In view of the problems of the prior art, the present invention reduces the production loss when using a carbon fiber sheet as an electrode base material, even after performing a heat treatment at a constant high temperature again after the carbonization treatment. In addition to the above, a method of transporting an electrode base material, a method of manufacturing an electrode base material and a method of manufacturing a gas diffusion electrode, which can simultaneously increase temperature during heat treatment and preparatory work for other production and manufacturing condition setting and shorten the production time can be provided. The purpose is to provide.

  In order to solve such a problem, the method of transporting the electrode base material of the present invention has the following configuration.

A method of transporting an electrode base material when unrolling the electrode base material in a roll shape, passing through a high temperature furnace, and rewinding into a roll shape,
A method of transporting an electrode base material, characterized in that at least one end of the electrode base material in the transport direction is connected to a heat resistant material by using an adhesive material and transported.

  According to the method of transporting an electrode base material of the present invention, in using a carbon fiber sheet or the like as an electrode base material, even after performing a heat treatment at a constant high temperature again after the carbonization treatment, the production loss is reduced. In addition, it is possible to shorten the production time because the temperature rise during the heat treatment and the preparation work for the other production and the setting of the production conditions can be performed at the same time.

Flowchart of manufacturing the electrode base material according to the present invention Manufacturing process diagram of impregnation/drying process E Sectional drawing of a state in which a heat-resistant material 12 is connected to one end of an electrode base material 2 according to the present invention using an adhesive material 11. Sectional drawing of the state where the electrode base material 2 connected with the heat resistant material 12 by the adhesive material 11 is conveyed. Manufacturing process diagram in which the electrode base material 2 unwound from the unwinding roll 3 is wound up by the winding roll 10 through the impregnation/drying step E A manufacturing process diagram in which the electrode base material 2 unwound from the unwinding roll 3 is taken up by the take-up roll 10 through the surface coating/drying step F and the sintering step G. The top view of the state which connected the edge part of the electrode base material 2 and the heat resistant material 12 using the adhesive material 11. Side view of a state in which an end portion of the electrode base material 2 and the heat-resistant material 12 are connected using an adhesive material 11. The top view of the state which connected the edge part of the electrode base material 2 and the heat resistant material 12 using the double-sided adhesive tape 11a as an adhesive material. Side view of a state in which the end portion of the electrode base material 2 and the heat-resistant material 12 are connected using the double-sided adhesive tape 11a as an adhesive material.

  A method of transporting an electrode base material according to the present invention is a method of transporting an electrode base material when unwinding a roll-shaped electrode base material and rewinding it in a roll shape through a high temperature furnace. At least one end portion in the direction is connected to the heat-resistant material by using an adhesive material and is conveyed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present embodiment is an example of the present invention, and the present invention is not limited to this embodiment.

  FIG. 1 shows an example of the manufacturing flow of the electrode base material according to the present invention. In addition, although the case where a carbon fiber sheet (so-called carbon paper) is used as the electrode base material is described here, the electrode base material applicable in the present invention is not limited to the carbon fiber sheet, and conductive It is possible to use a sheet-like material having properties such as a nonwoven fabric (so-called felt base material).

  In the papermaking process A, short fibers including short carbon fibers are defibrated well, and then dispersed in water so as to obtain a constant amount of carbon fibers, and a resin and/or an organic substance is continuously used as a binder for papermaking. An intermediate base material which is a carbon fiber paper having a constant thickness is obtained by paper making. An organic polymer can be contained as a binder for the purpose of improving the shape retention and handling of the papermaking body. As the organic polymer, polyvinyl alcohol, polyvinyl acetate, polyacrylonitrile, cellulose or the like can be used.

  In particular, a sheet-like material such as carbon fiber paper in which dispersed short carbon fibers are bound by a resin and/or an organic carbide has a high flexural modulus, a low coefficient of static friction, and brittle properties. In addition, the dispersed state is a state in which the short carbon fibers do not have a remarkable orientation in the sheet surface and are present substantially randomly, for example, in a random direction.

  Examples of the carbon fibers in the present invention include polyacrylonitrile (PAN)-based, pitch-based, rayon-based carbon fibers and the like. Among them, PAN-based carbon fiber is preferably used because it has excellent mechanical strength.

  Further, in the carbon fiber of the present invention, the average diameter of the single yarn is preferably in the range of 3 to 20 μm, and more preferably in the range of 5 to 10 μm. When the average diameter is 3 μm or more, the electrode base material is highly flexible, which is preferable. On the other hand, when the average diameter is 20 μm or less, the electrode base material has excellent mechanical strength, which is preferable. Further, it is preferable to use two or more kinds of carbon fibers having different average diameters because the surface smoothness of the electrode base material can be improved.

  The average length of the carbon short fibers to be dispersed is preferably 3 to 20 mm, more preferably 5 to 15 mm. By setting the fiber length of the short carbon fibers to 3 to 20 mm, it is possible to improve the dispersibility of the short carbon fibers and suppress the variation in basis weight when obtaining the carbon fiber sheet by dispersing the short carbon fibers into paper. it can. When the average length is 3 mm or more, the electrode base material has excellent mechanical strength, which is preferable. On the other hand, when the average fiber length is 20 mm or less, the dispersibility of carbon fibers during papermaking is excellent and a homogeneous electrode substrate is obtained, which is preferable. Carbon fibers having such an average fiber length can be obtained by a method of cutting continuous carbon fibers into a desired length.

  Next, in the resin impregnation, drying and desolvation step B, the paper-made carbon fiber paper is impregnated with a resin and/or an organic substance, and a resin component and/or an organic substance is attached to the carbon fiber paper, followed by drying to remove the solvent. Can be obtained.

  As the resin constituting the resin component, a thermosetting resin such as phenol resin, epoxy resin, melamine resin or furan resin is preferably used. Of these, a phenol resin is preferably used because it has a high carbonization yield. In addition, as an additive that is added to the resin component as needed, a carbon-based filler can be included for the purpose of improving mechanical properties, electrical conductivity, and thermal conductivity of the electrode base material. Here, as the carbon-based filler, carbon black, carbon nanotube, carbon nanofiber, milled fiber of carbon fiber, graphite and the like can be used.

  Further, various solvents may be included for the purpose of enhancing the impregnation property into the paper body. Here, as the solvent, methanol, ethanol, isopropyl alcohol or the like can be used.

  Next, in the resin curing step C, the carbon fiber sheet precursor can be molded by intermittently conveying the impregnated and dried prepreg to cure the resin by heating and pressing.

  Next, in the carbonization step D, the carbon fiber in which the thermosetting resin is carbonized by heating the cured carbon fiber sheet precursor at a constant high temperature in an inert atmosphere in a continuous carbonization furnace while continuously conveying the carbon fiber. You can get a sheet. A carbon fiber sheet precursor obtained by carbonizing a thermosetting resin is simply referred to as a carbon fiber sheet.

  The maximum firing temperature is preferably in the range of 1500 to 3000° C., more preferably in the range of 1700 to 2800° C., and further preferably in the range of 1900 to 2600° C. When the maximum temperature is 1500° C. or higher, carbonization of the resin component proceeds, and the electrode base material has excellent electrical conductivity and thermal conductivity, which is preferable. On the other hand, when the maximum temperature is 3000° C. or lower, the operating cost of the heating furnace is reduced, which is preferable. Further, upon firing, it is preferable that the temperature rising rate is within the range of 80 to 5000° C./min. The rate of temperature increase of 80° C. or higher is preferable because the productivity is excellent. On the other hand, when the temperature is 5000° C. or less, the carbonization of the resin component gradually progresses and a dense structure is formed, so that the electrode base material has excellent electrical conductivity and thermal conductivity, which is preferable.

  Next, in the impregnation/drying step E, the carbon fiber sheet is preferably subjected to a water repellent treatment for the purpose of improving drainage. In the water repellent treatment, a dispersion liquid containing a hydrophobic resin is dipped in a carbon fiber sheet and then dried at a constant temperature. Examples of such hydrophobic resin include polychlorotrifluoroethylene resin (PCTFE), polytetrafluoroethylene resin (PTFE), polyvinylidene fluoride resin (PVDF), tetrafluoroethylene/hexafluoropropylene copolymer (FEP), tetra Examples thereof include fluororesins such as a copolymer of fluoroethylene and perfluoropropyl vinyl ether (PFA) and a copolymer of tetrafluoroethylene and ethylene (ETFE).

  Next, in the surface coating/drying step F, it is preferable to form a conductive microporous layer MPL (Micro Porous Layer) on at least one surface of the electrode base material. When the microporous layer is provided, the surface irregularities of the electrode base material are covered and become smooth, so that when the membrane-electrode assembly is constructed and the fuel cell is constructed, the electrical resistance with the catalyst layer is reduced. be able to. The microporous layer can be formed by applying a mixture of the hydrophobic resin used in the water repellent treatment described above and a carbon filler described later on the surface of the electrode base material. That is, the coating liquid for forming the microporous layer is preferably a mixture of a hydrophobic resin and a carbon filler. Examples of the carbon filler include graphite, carbon black, and graphene, as well as single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanofibers such as vapor-grown carbon fibers, and carbon fiber milled fibers. Among them, carbon black is preferable. Is preferred. Examples of carbon black include furnace black, channel black, acetylene black, thermal black and the like. Among them, it is preferable to use acetylene black which has high conductivity and contains few impurities.

  Next, in the sintering step G, the surfactant contained in the dispersion liquid is thermally decomposed, and the hydrophobic resin described above is heated at a constant temperature in order to be melted and fused. It is processed and rolled up using the unwinding and winding equipment.

  FIG. 2 shows a manufacturing process diagram of the impregnation/drying process E, the surface coating/drying process F, and the sintering process G. The roll around which the carbon fiber sheet (electrode base material 2) obtained by carbonizing the thermosetting resin in the carbonization step D is wound up is used as the unwinding roll 3 in this step. Is unwound and the electrode base material 2 is dipped in an impregnation tank 4 in which a dispersion liquid of a carbon filler and a hydrophobic resin is stored, and then dried at a constant temperature in a drier 5 to obtain the dried electrode. The substrate 2 proceeds to the surface coating/drying step F. In the surface coating/drying step F, after the dispersion liquid of the carbon filler and the hydrophobic resin is coated on one surface of the electrode substrate 2 with the carbon filler and the hydrophobic resin 7 using a slit die coater which is the surface coating machine 6 or the like. The dried electrode base material 2 proceeds to the sintering step G. In the sintering step, the PTFE particles are heated in a high temperature furnace 9 at a temperature of 150 to 400° C. to melt and fuse the PTFE particles, and then the particles are wound by a winding roll 10. In the surface coating/drying step F, applying the carbon filler and the hydrophobic resin 7 to one surface of the electrode base material 2 using a slit die coater which is the surface coating machine 6 is for forming the microporous layer. The step of applying the coating liquid, and the step of applying the coating liquid for forming the microporous layer is preferably provided before the high temperature furnace in the transport method of the present invention.

  FIG. 3 is a cross-sectional view showing a state in which an adhesive material 11 which is an adhesive is arranged at a tip portion which is one end portion 2a of the electrode base material 2 according to the present invention, and the heat resistant material 12 is adhered and connected. Show.

  In the present invention, as shown in FIG. 3, the roll-shaped electrode base material 2 is unwound from the unwinding roll 3, passed through the high temperature furnace 9, and rewound in the roll shape on the winding roll 10. At this time, the adhesive material 11 is arranged at the tip end which is the one end 2a in the transport direction of the electrode base material 2, and the electrode base material 2 and the heat resistant material 12 are connected by this.

  FIG. 4 shows a sectional view of a state in which the electrode base material 2 to which the heat resistant material 12 is connected is conveyed. The electrode base material 2 is unwound from the unwinding roll 3 with the heat-resistant material 12 at the front.

  In the sintering step G, since the treatment is carried out at a high temperature in the high temperature furnace 9, after the electrode base material 2 is conveyed to the winding roll 10 and set, the temperature rise of the high temperature furnace 9 is started and after reaching a predetermined temperature. In the procedure for feeding out the electrode base material 2, the electrode base material between the high temperature furnace 9 and the winding roll 10 has a history of temperature rise, and the thermal history becomes irregular, so it should be used as a product. Cannot be performed, and waste loss occurs, resulting in a wasteful cost. Therefore, in the present invention, the heat-resistant material 12 is used between the high temperature furnace 9 and the winding roll 10 instead of transporting the electrode substrate 2 to the winding roll 10 and setting it. It can be lost. Furthermore, the temperature rise of the high-temperature furnace 9 and other preparation work for production and setting of manufacturing conditions can be simultaneously progressed, and the production efficiency can be improved. The length of the heat-resistant material 12 is preferably set so as to straddle the steps of high temperature treatment such as the drying step 8 and the sintering step 9 so that the above-mentioned heat history does not remain in the electrode base material 2. In the present embodiment, the length of the heat resistant material is set to a length corresponding to the process length from the drying process 8 to the winding roll 10.

  3 and 4 show the structure in which the heat-resistant material is arranged at the front end which is one end of the electrode base material, the heat-resistant material is arranged at the rear end which is the other end of the electrode base material 2. Similarly, the arrangement can reduce the waste loss of the tail portion. That is, in the present invention, it is important that at least one end of the electrode base material in the transfer direction is connected to a heat-resistant material by using an adhesive material and transferred, and both ends of the electrode base material in the transfer direction are transferred. It is more preferable to connect the parts to the heat-resistant material by using an adhesive material and convey the parts.

  5 and 6 show another embodiment of a method of transporting another electrode base material in which the electrode base material 2 in a roll shape is unwound, and the high-temperature furnace 9 is used to wind the electrode base material 2 in a roll shape again.

  In FIG. 4, the impregnation/drying step E, the surface coating/drying step F, and the sintering step G are shown as one pass. On the other hand, in FIG. 5 and FIG. 6, after the impregnation/drying step E is finished, the electrode base material 2 is once taken up, and the rolled-up electrode base material is unwound again, and the surface coating/drying step F and baking are performed. It shows a mode of flowing the binding step G. This flow assumes that the impregnation/drying step E, the surface coating/drying step F, and the sintering step G are performed at different manufacturing locations.

  FIG. 5 shows a process diagram in which the electrode base material 2 unwound from the unwinding roll 3 is taken up by the winding roll 13 through the impregnation/drying step E.

  In FIG. 6, the electrode base material 2 unwound from the unwinding roll 13 passes through the surface coating/drying step F (step of applying the coating liquid for forming a microporous layer) and the sintering step G, and then is wound on the winding roll 14. The process drawing which is wound up is shown. The winding roll 13 on which the electrode substrate 2 is wound through the impregnation/drying process E shown in FIG. 5 is used as the unwinding roll 13 in this process. The winding roller 13 in FIG. 5 has a rear end, which is one end of the electrode base material 2 wound up, and serves as a tip in the unwinding roll 13 in FIG.

  The adhesive material 11 is arranged on the tip portion 2a of the electrode base material 2 on the unwinding roll 3 to connect the electrode base material 2 and the heat resistant material 12, and the heat resistant material 12 is used as a head to move the electrode material 2 from the unwinding roll 3 to the electrode material 2 Is unwound, and the heat resistant material 12 is set on the winding roll 10. The length of the heat-resistant material 12 is at least the length from the surface coater 6 for surface coating to the winding roll 10. As a result, it is possible to avoid that the electrode base material 2 as a product is subjected to an irregular heat history in the drying process or the sintering process, and it is possible to eliminate the waste loss of the electrode base material 2 after the surface application.

  Further, for the coating liquid for forming the microporous layer, for example, it is preferable to use acetylene black as the carbon filler and PTFE particles as the hydrophobic resin. The dispersion liquid of acetylene black and PTFE particles was applied to the surface of the microporous layer after sintering using a surface coating device such as a slit die coater so that the weight per unit area of the microporous layer was constant, and then dried to obtain a microporous layer. A quality layer is obtained. As described above, it is preferable to form the microporous layer on the electrode base material by providing the step of applying the coating liquid for forming the microporous layer before the high temperature furnace. Hereinafter, the embodiment having the microporous layer on the electrode base material may be referred to as a gas diffusion electrode.

  Further, in the present invention, when an end portion of the electrode base material is connected to a region where the adhesive material is used and the heat-resistant material is connected, the electrode base material and the heat-resistant material partially overlap each other in the connection portion. It is preferable that a plurality of tapes be used as the adhesive material, and that both ends in the width direction of the electrode base material be adhered to the heat resistant material by the tapes on both surfaces of the connection portion. Here, the connection portion means a portion where the electrode base material and the heat resistant material are connected by using an adhesive material. Further, the tape used in this aspect is not particularly limited, but a double-sided adhesive tape can also be used. "Both ends of the width direction are adhered to the heat-resistant material with tape" does not mean that the tape is at both ends of the electrode base material in the width direction, but it is not limited to both ends of the electrode tape in the width direction. It means focusing on a certain tape. That is, it means that the tape is used as the adhesive material at both ends in the width direction.

  The tape used as the adhesive material may have various shapes, but preferably has a polygonal shape, and more preferably has a quadrangular shape. Further, in this case, it is preferable that the electrode base material and the heat-resistant material are bonded so that the long sides of the quadrangle of the tape at both ends in the width direction are parallel to the transport direction of the electrode base material.

   FIG. 7 is a plan view showing a state in which the end portion of the electrode base material 2 and the heat resistant material 12 are connected by using the adhesive material 11, and FIG. 8 is a side view thereof. As shown in FIGS. 7 and 8, rectangular adhesive tapes 11 were attached at three positions on both ends and the center of the electrode base 2 in the width direction so that the long sides are parallel to the transport direction of the electrode base 2. An aspect is shown. This strengthens the connection between the end of the electrode base material 2 and the heat-resistant material 12, and ensures reliable adhesion even when passing through the high temperature furnace.

  Here, a configuration will be described in which the electrode base material and the heat-resistant material are adhered so that the long sides of the quadrangle of the tape at both ends in the width direction are parallel to the transport direction of the electrode base material. This "the long sides of the quadrangle of the tape at both ends in the width direction are parallel to the transport direction of the electrode base material" means that among the plurality of tapes, focusing on the tape at both ends in the width direction, This means that the long sides of the quadrangle of the two tapes are parallel to the transport direction of the electrode base material, and as described above, both ends of the electrode base material in the width direction are taped on both surfaces of the connecting portion. The fact that they are bonded to the heat-resistant material means that the long sides of the four tapes in total are parallel to the transport direction of the electrode base material. Further, “parallel” means a state in which the long side of the tape and the transport direction form an angle of −5° to +5°, and preferably, the long side of the tape and the transport direction are 0°. is there.

  Further, in the present invention, in the connection portion 15 between the electrode base material 2 and the heat resistant material 12, it is preferable that the adhesive area of the tape 11 is larger on the electrode base material 2 side than on the heat resistant material side. When the adhesive area of the tape 11 in the connecting portion 15 is larger on the electrode base material 2 side than on the heat resistant material side, the tape 11 is bonded to only one surface of the electrode base material 2 and the heat resistant material 12. It is also possible to adopt a configuration, or it is possible to employ a configuration in which both sides of the electrode base material 2 and the heat resistant material 12 are adhered.

  FIG. 7 shows a structure in which both sides of the electrode base material 2 and the heat resistant material 12 are bonded by the single-sided adhesive tape 11, and the bonding area of the tape 11 is larger on the electrode base material 2 side than on the heat resistant material side. Is. Thereby, the adhesion of the end portion of the electrode base material 2 can be made stronger.

  Further, in the present invention, the electrode base material 2 and the heat-resistant material 12 partially overlap each other at the connection portion, and it is preferable to use at least a double-sided adhesive tape as the adhesive material 11.

  FIG. 9 is a plan view showing a state where the end portions of the electrode base material 2 and the heat-resistant material 12 are connected by using the double-sided adhesive tape 11a as an adhesive material, and FIG. 10 is a side view thereof. A mode in which a quadrangular double-sided adhesive tape 11a is attached at three positions on both ends and the center of the electrode base material 2 in the width direction so that the long sides are parallel to the transport direction of the electrode base material 2 is shown. As a result, the electrode base material and the heat-resistant material can be easily aligned when they are attached to each other, and sufficient adhesive strength can be secured.

  Further, in the present invention, in the connection portion, the electrode base material 2 and the heat-resistant material 12 are partially overlapped with each other, and between the surface of the electrode base material 2 on which the microporous layer 7 is not formed and the heat-resistant material 12. It is preferable that at least the double-sided adhesive tape 11b be used as the adhesive material 11.

  As shown in FIG. 3, at the tip, which is one end 2a of the electrode base material 2, the upper surface is the surface on which the microporous layer 7 is formed, and the lower surface is the surface 2b on which the microporous layer is not formed. Then, the adhesive material 11 is arranged on the lower surface 2b and is bonded to the heat resistant material 12. This strengthens the connection between the one end of the electrode base material and the heat-resistant material, so that a gas diffusion electrode can be obtained that ensures reliable adhesion even when passing through a high temperature furnace.

  Further, in the present invention, the heat resistant material is preferably a polyimide film.

  By using a polyimide film having high heat resistance and good adhesiveness, the adhesion to the electrode base material 2 becomes strong, and the reliable adhesiveness can be secured even when passing through the high temperature furnace.

  Further, in the present invention, the adhesive material is preferably a polyimide tape having a layer containing silicon.

  By using a polyimide tape having a layer containing silicon as the adhesive material, the adhesive property is particularly stronger with respect to heat resistance, so that the adhesive material is preferably a polyimide tape having a layer containing silicon.

  Further, in the present invention, it is preferable that the temperature in the high temperature furnace is 150° C. or higher and 400° C. or lower. By setting the temperature in the furnace in the high temperature furnace to 150° C. or higher and 400° C. or lower, the surfactant contained in the dispersion liquid (coating liquid for forming the microporous layer) is thermally decomposed, and the PTFE particles are melted and melted. Can be dressed. If the temperature in the furnace in the high temperature furnace is lower than 150°C, the PTFE particles cannot be melted and fused sufficiently, and if the temperature exceeds 400°C, the PTFE particles may be thermally decomposed. The temperature in the furnace of the high temperature furnace is preferably 200° C. or higher and 390° C. or lower, more preferably 250° C. or higher and 380° C. or lower.

  Further, in the present invention, the tension during transportation is preferably 0.1 to 0.5 N/mm. If the tension during transportation is less than 0.1 N/mm, the winding end faces may not be aligned when the electrode base material 2 is wound up. Further, the transportation state of the electrode base material 27 may become unstable, which may cause meandering. If the tension during transport exceeds 0.5 N/mm, deformation or breakage may occur when the electrode substrate 2 is wound.

  Further, in the present invention, it is preferable that the speed during transportation is 0.1 to 20.0 m/min. If the speed at the time of transportation is less than 0.1 m/min, the adhesive strength of the connection portion may be reduced in the high temperature furnace, and there is a risk of breakage during transportation. If the transportation speed exceeds 20.0 m/min, the melt binding of the PTFE particles tends to be insufficient. The speed during transportation is preferably 0.5 to 15.0 m/min, more preferably 1.0 to 12.0 m/min, and even more preferably 1.5 to 10.0 m/min.

  Further, the present invention is a method for manufacturing an electrode base material, which has a step of performing the above-described transportation method.

  Further, the present invention is a method for producing a gas diffusion electrode having a microporous layer on an electrode base material, which comprises a step of carrying out the above-described transport method, and comprises a microporous layer forming coating before a high temperature furnace. It is a manufacturing method that includes a step of applying a liquid, and after passing through a high-temperature furnace, winds the gas diffusion electrode having the microporous layer again in a roll shape.

  Further, the method for producing a gas diffusion electrode base material of the present invention, as described above, in the connection portion, the electrode base material and the heat-resistant material are partially overlapped, the microporous layer of the electrode base material is formed. There is the adhesive material between the non-coated surface and the heat-resistant material, and at least a double-sided adhesive tape is used as the adhesive material.

  A dispersion liquid of acetylene black and PTFE particles (coating liquid for forming a microporous layer) is applied to the surface of an electrode substrate using a slit die coater 7, and then a sintering treatment is performed in a high temperature furnace to obtain a dispersion liquid. A good microporous layer can be formed by thermally decomposing the surfactant contained in the (microporous layer-forming coating liquid) and fusing and fusing the PTFE particles.

  A gas diffusion electrode, which is an electrode substrate provided with a microporous layer, is bonded to at least one surface of a solid polymer electrolyte membrane having catalyst layers on both sides so that the microporous layer contacts the catalyst layer, thereby forming a membrane- An electrode assembly can be constructed. A polymer electrolyte fuel cell can be constructed by stacking a plurality of such membrane-electrode assemblies sandwiched by separators on both sides with a gasket interposed therebetween. The catalyst layer is composed of a layer containing a solid polymer electrolyte and catalyst-supporting carbon. Platinum is usually used as the catalyst. In a fuel cell in which a reformed gas containing carbon monoxide is supplied to the anode side, it is preferable to use platinum and ruthenium as the catalyst on the anode side. As the solid polymer electrolyte, it is preferable to use a perfluorosulfonic acid-based polymer material having high proton conductivity, oxidation resistance, and heat resistance.

  Hereinafter, the present invention will be specifically described with reference to examples, but the following examples do not limit the present invention.

  In the example, the electrode base material was created using the manufacturing process illustrated in FIGS. 1 and 4.

<Papermaking process A>
Carbon fiber (PAN-based carbon fiber “Torayca (registered trademark)” T300-3K (manufactured by Toray Industries, Inc., average diameter of single yarn: 7 μm, number of single fiber: 3000) was thoroughly defibrated and then dispersed in water. Using polyvinyl alcohol as a binder for papermaking, papermaking was continuously carried out to obtain an intermediate base material.

<Resin impregnation, drying and desolvation process B>
The intermediate base material (papermaking carbon fiber paper) obtained in the papermaking process A is continuously added to a liquid in which scaly graphite particles (average particle diameter: 5 μm) are dispersed in a methanol solution of a novolac type phenolic resin and a resol type phenolic resin. After impregnating and pulling up, the phenol resin and the graphite particles were attached to the carbon fiber, and further dried continuously at about 100° C. for about 1 minute to obtain a prepreg from which methanol was removed.

<Resin curing step C>
The prepreg obtained in the resin impregnation, drying/solvent removal step B was intermittently conveyed, and was continuously heated and pressed by parallel hot plates to cure the phenol resin to form a sheet.

<Carbonization process D>
While continuously transporting the sheet obtained by the resin curing step C, the thermosetting resin is carbonized by heating at a maximum temperature of 2400° C. in a nitrogen atmosphere in a continuous carbonization furnace to form a carbon fiber sheet (electrode base material). did.

<Impregnation/drying process E, surface coating/drying process F, sintering process G>
As shown in FIG. 3, the electrode base material 2 obtained by the carbonization step D is a double-sided adhesive tape as an adhesive material 11 on the surface 2b at one end 2a of the electrode base material where the microporous layer is not formed. And a polyimide film 12 having a layer containing silicon as the heat resistant material 12 was adhered.

  As shown in FIG. 9 or FIG. 10, the double-sided adhesive tape 11a has a rectangular double-sided adhesive tape (long side) on both ends in the width direction on the electrode base material 2 so that the long sides are parallel to the transport direction of the electrode base material. (60 mm, short side 25 mm) was attached to three places. The width of the polyimide film 12 was 360 mm. The lateral width of the electrode base material 2 was 450 mm.

  The electrode base material 2 having the polyimide film 12 connected to the top is set on the winding roll 10 and conveyed at a tension of 0.5 N/mm during conveyance and a speed of 15.0 m/min during conveyance, and the impregnation tank 4 uses PTFE. The particles were immersed in a dispersion liquid and dried at 150°C. Then, a dispersion liquid of acetylene black and PTFE particles (coating liquid for forming a microporous layer) was applied to the surface of the electrode base material using the slit die coater 7, and dried at 150°C. Then, it was passed through a high temperature furnace 9 heated to 400°C. When the tip portion 2a of the electrode base material 2 passes through the dryer and the high temperature furnace, the temperature is already raised to the predetermined temperature, and the sintering process can be performed under the normal temperature condition, so that the waste loss of the product can be eliminated. It was

2 electrode base material 2a one end of the electrode base material 2b surface of the electrode base material on which the microporous layer is not formed 3 unwinding roll 4 impregnation tank 5 dryer 6 surface coating machine 7 microporous layer 8 drying Machine 9 High-temperature furnace 10 Winding roll 11 Adhesive material (single-sided tape)
11a Adhesive material (double-sided tape)
12 Heat resistant material 15 Connection part

Claims (11)

Rolling out the electrode base material after the carbonization treatment in a roll shape, through a high temperature furnace for applying a heat treatment, when rewinding in a roll shape, a method of transporting the electrode base material,
A method of transporting an electrode base material, comprising connecting at least one end of the electrode base material in a transport direction to a polyimide film using an adhesive material and transporting the polyimide film . The end portion of the electrode base material, using an adhesive material, and the region connected to the polyimide film as the connection portion,
In the connection portion, the electrode base material and the polyimide film are partially overlapped,
As the adhesive material, a plurality of tapes are used,
The method for transporting an electrode base material according to claim 1, wherein both ends in the width direction of the electrode base material are adhered to the polyimide film by the tape on both surfaces of the connection portion. The end portion of the electrode base material, using an adhesive material, and the region connected to the polyimide film as the connection portion,
As the adhesive material, a tape is used,
The method of transporting an electrode base material according to claim 1, wherein, in the connection portion, the adhesive area of the tape is larger on the electrode base material side than on the polyimide film side. The end portion of the electrode base material, using an adhesive material, and the region connected to the polyimide film as the connection portion,
In the connection portion, the electrode base material and the polyimide film are partially overlapped,
The method of transporting an electrode base material according to claim 1, wherein at least a double-sided adhesive tape is used as the adhesive material. Wherein the adhesive material is transported method of an electrode substrate according to any one of claims 1 to 4, which is a polyimide tape having a layer containing silicon. Any transfer method of an electrode substrate according to claim 1 to 5 temperature in the furnace is 0.99 ° C. or higher 400 ° C. or less in the high temperature furnace. Transporting method of an electrode substrate according to any one of claims 1-6 tension during conveyance is 0.1~0.5N / mm. Speed during conveyance, 0.1~20.0m / min in a claim 1-7 transfer method of an electrode substrate according to any one of. A step for conveying method according to any one of claims 1-8, a manufacturing method of the electrode substrate. A method for producing a gas diffusion electrode having a microporous layer on an electrode substrate,
Before the high-temperature furnace, comprising a step of applying a microporous layer forming coating solution, a step for conveying method according to any one of claims 1 to 9 the gas diffusion electrode production process. The end portion of the electrode base material, using an adhesive material, and the region connected to the polyimide film as the connection portion,
In the connection portion, the electrode base material and the polyimide film are partially overlapped,
Between the surface of the electrode base material on which the microporous layer is not formed and the polyimide film , the adhesive material is present,
As the adhesive material, using at least a double-sided adhesive tape, manufacturing method for a gas diffusion electrode according to claim 1 0.