JP5825020B2 - Method and apparatus for producing gas diffusion layer precursor, and method and apparatus for producing gas diffusion layer - Google Patents

Description

  The present invention relates to a method and apparatus for manufacturing a gas diffusion layer precursor, and a method and apparatus for manufacturing a gas diffusion layer.

  A fuel cell is a cell in which electrodes are arranged on both sides of an electrolyte and generates electricity by an electrochemical reaction between hydrogen and oxygen, and only water is generated during power generation. Thus, unlike the conventional internal combustion engine, it is expected to spread as a next-generation clean energy system because it does not generate environmental load gas such as carbon dioxide. In particular, the polymer electrolyte fuel cell (PEFC) has a low operating temperature, low electrolyte resistance, and uses a highly active catalyst, so it can obtain high output even in a small size. Early practical application is expected for such applications.

  The polymer electrolyte fuel cell has a structure in which catalyst layers are formed on both surfaces of an electrolyte membrane, and a gas diffusion layer is disposed on each catalyst layer. Conventionally, the gas diffusion layer has been manufactured by impregnating a resin into a sheet made of carbon fiber and heating it to carbonize the resin (see, for example, Patent Document 1). On the other hand, in recent years, a manufacturing method has been proposed in which a gas diffusion layer is formed by applying and baking a paste for a gas diffusion layer made of at least a carbon material and a resin on the substrate, and then peeling the substrate. (For example, refer to Patent Document 2).

JP-A-10-167855 JP 2006-228514 A

  However, for the gas diffusion layer described above, a manufacturing method adapted to mass production has not yet been proposed, and gas diffusion layer manufacturing that can be mass-produced efficiently is expected while the spread of solid polymer fuel cells is expected. A method was desired. Then, this invention makes it a subject to provide the manufacturing method and apparatus of a gas diffusion layer precursor suitable for mass production, and the manufacturing method and apparatus of a gas diffusion layer.

  The method for producing a gas diffusion layer precursor according to the present invention includes a step of unwinding a long substrate, and applying a paste for a gas diffusion layer containing a thermosetting resin and a solvent onto the unwound substrate. Heating the gas diffusion layer paste applied on the substrate to dry the solvent at a temperature lower than the curing temperature of the thermosetting resin; and drying the gas diffusion layer paste. Winding up the gas diffusion layer precursor formed by the step.

  According to this manufacturing method, a roll of gas diffusion layer precursor can be obtained by winding up the gas diffusion layer precursor. Therefore, when manufacturing the gas diffusion layer, this roll-shaped gas diffusion layer precursor is used. The gas diffusion layer can be produced simply by feeding while continuously unwinding and curing the thermosetting resin. This increases production efficiency and is suitable for mass production. In addition, the gas diffusion layer paste is applied to the back surface of the substrate during winding in order to dry the solvent of the gas diffusion layer paste applied on the substrate to form a gas diffusion layer precursor and then wind it. Can be prevented, and the gas diffusion layer precursor can be transported alone even if the substrate is peeled off when the gas diffusion layer is produced. In this drying, since the drying temperature is lower than the curing temperature of the thermosetting resin, the gas diffusion layer precursor is not completely cured and has flexibility, and can be wound into a roll. It becomes possible. In the step of drying the solvent, the solvent need not be completely dried as long as the gas diffusion layer precursor can be self-supported even if the base material is peeled off. Good.

  By setting the flexural modulus of the gas diffusion layer precursor to 100 to 5000 MPa, the gas diffusion layer precursor can be provided with preferable flexibility and can be easily wound.

  Moreover, it can prevent that a gas diffusion layer precursor is damaged when winding up by making the bending strength of the said gas diffusion layer precursor into 0.1-50 Mpa.

  Further, by making the peel strength between the gas diffusion layer precursor and the substrate about 0.01 to 1 N / mm, the gas diffusion layer precursor can be sufficiently supported by the substrate, and the gas diffusion layer It can be peeled from the substrate without damaging the precursor.

  Moreover, the base material is peeled from the gas diffusion layer precursor by making the tensile strength of the gas diffusion layer precursor 0.05 N / mm or more larger than the peel strength between the gas diffusion layer precursor and the base material. Sometimes it is possible to more reliably prevent the gas diffusion layer precursor from being damaged.

  Moreover, it is preferable that the said base material has a mold release layer in the surface where the paste for gas diffusion layers is apply | coated.

  The method for producing a gas diffusion layer according to the present invention includes any one of the above gas diffusion layer precursor production method, a step of unwinding the gas diffusion layer precursor wound together with the base material, and the gas diffusion layer precursor. Peeling the base material from the body, and heating the gas diffusion layer precursor from which the base material has been peeled to cure the thermosetting resin.

  According to the method for producing a gas diffusion layer, since the method for producing the gas diffusion layer precursor is included, the above-described effects are achieved, and the gas diffusion layer precursor is heated after the substrate is peeled off. Therefore, it is possible to prevent the problem that the base material is thermally contracted without being able to withstand the temperature when heated so that the thermosetting resin is cured.

  The gas diffusion layer paste may contain a binder for fixing the carbon material separately from the thermosetting resin. The resin used as the binder is not particularly limited, but preferably has water repellency. By using a resin having water repellency as a binder, water can be prevented from accumulating in the gas diffusion layer.

  The apparatus for producing a gas diffusion layer precursor according to the present invention includes a first unwinding unit for unwinding a long base material, and the unwound base material for the gas diffusion layer containing a thermosetting resin and a solvent. An application part to be applied to the upper part, and a drying part which is installed on the downstream side of the application part and heats the gas diffusion layer paste to dry the solvent at a temperature lower than the curing temperature of the thermosetting resin. And a first winding portion for winding the gas diffusion layer precursor formed by drying the gas diffusion layer paste.

  According to this gas diffusion layer precursor production apparatus, a roll body of the gas diffusion layer precursor can be obtained. Therefore, when producing the gas diffusion layer, the roll body of the gas diffusion layer precursor is continuously used. A gas diffusion layer can be produced simply by supplying while unwinding and curing the thermosetting resin. This increases production efficiency and is suitable for mass production. In addition, since the gas diffusion layer precursor is wound up after the gas diffusion layer paste is heated in the drying section to dry the solvent and become the gas diffusion layer precursor, gas diffusion is performed on the back surface of the substrate when wound up. The problem that the layer paste adheres can be prevented, and the gas diffusion layer precursor can be transported alone even when the base material is peeled off when the gas diffusion layer is manufactured. Moreover, in this drying part, since the drying temperature is set to be lower than the curing temperature of the thermosetting resin, the gas diffusion layer precursor is not completely cured and has flexibility, and is wound as a roll body. Is possible.

  The gas diffusion layer manufacturing apparatus according to the present invention peels off the base material from the gas diffusion layer precursor, a second unwinding part for unwinding the gas diffusion layer precursor formed on a long base material. A peeling unit; and a heating unit that is installed on the downstream side of the peeling unit and heats the gas diffusion layer precursor to cure the thermosetting resin.

  According to this gas diffusion layer manufacturing apparatus, since the heating part is installed downstream of the peeling part, the gas diffusion layer precursor is heated after the base material is peeled, and the thermosetting resin is cured to cause gas diffusion. A layer is formed. Thus, since the high temperature for hardening a thermosetting resin is not added to a base material, the problem that a base material is heated at high temperature and heat-shrinks can be prevented.

  The said peeling part can also be used as the 2nd winding part which winds up the base material peeled from the gas diffusion layer precursor.

  Further, it may further include a cutting part for cutting the gas diffusion layer precursor into a single sheet on the upstream side of the heating part, and this cutting part is arranged either upstream or downstream of the peeling part. May be. Moreover, the cutting part is installed downstream from the heating part, and may be configured to cut the gas diffusion layer into a single sheet.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method and apparatus of a gas diffusion layer precursor suitable for mass production, and the manufacturing method and apparatus of a gas diffusion layer can be provided.

FIG. 1 is a side view showing an outline of a gas diffusion layer precursor manufacturing apparatus according to this embodiment. FIG. 2 is a side view showing an outline of the gas diffusion layer manufacturing apparatus according to the present embodiment. FIG. 3 is a side view showing a modification of the gas diffusion layer manufacturing apparatus according to this embodiment. FIG. 4 is a side view showing a modification of the gas diffusion layer manufacturing apparatus according to this embodiment. FIG. 5 is a side view showing a modification of the gas diffusion layer manufacturing apparatus according to this embodiment.

  Hereinafter, embodiments of an apparatus and a method for producing a gas diffusion layer precursor according to the present invention will be described with reference to the drawings. Note that the left side of each drawing is the “upstream side” and the right side is the “downstream side”.

  As shown in FIG. 1, the gas diffusion layer precursor manufacturing apparatus includes a first unwinding unit 1 for unwinding the substrate A, an application unit 2 for applying a gas diffusion layer paste on the substrate A, It mainly comprises a drying unit 3 installed downstream of the application unit 2 and a first winding unit 4 that winds up the gas diffusion layer precursor.

  The first unwinding unit 1 is set by winding a long base material A into a roll shape, and is rotated downstream by a rotation drive motor (not shown) to wind the base material A downstream. put out. As the substrate A, for example, polyimide, polyethylene terephthalate, polyparvanic acid aramid, polyamide (nylon), polysulfone, polyethersulfone, polyphenylene sulfide, polyether ether ketone, polyetherimide, polyarylate, polyethylene naphthalate, polypropylene And the like. Also, ethylene-tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE) Etc. can be used. Among these, polymer films that are easily processable and easily available are preferable, and examples thereof include polyethylene terephthalate, polyethylene naphthalate, polytetrafluoroethylene (PTFE), polyimide film, and the like. It is preferable to set it to -200 micrometers. Although the speed | rate which unwinds the base material A is not specifically limited, It can be set as about 1-100 m / min. A release layer may be formed on the upper surface of the substrate A. The release layer is not particularly limited, and can be obtained by performing plasma treatment, silicon coating, fluorine coating or the like on the substrate. The release layer may be formed on the lower surface of the substrate A.

  An application unit 2 is installed on the downstream side of the first unwinding unit 1. This application part 2 is for applying the gas diffusion layer paste onto the substrate A unwound by the first unwinding part 1, and specifically includes a die. The die 2 has a discharge port extending in the width direction of the substrate A, and applies the gas diffusion layer paste sent from a gas diffusion layer paste supply source (not shown) onto the substrate A. The paste thickness by the die 2 can be 50 to 500 μm.

  The gas diffusion layer paste applied by the application unit 2 may include a carbon material such as conductive carbon particles and conductive carbon fibers, a thermosetting resin, a binder, and a solvent. The conductive carbon particles are not particularly limited as long as they are conductive carbon materials, and known or commercially available ones can be used. Examples thereof include carbon black such as channel black, furnace black, ketjen black, acetylene black and lamp black; graphite; activated carbon and the like. Examples of the conductive carbon fiber include vapor grown carbon fiber (VGCF), carbon nanotube, wire cup, and wire wall. These can be used alone or in combination of two or more. By containing these conductive carbon particles, the conductivity of the gas diffusion layer can be improved.

  When carbon black is used as the conductive carbon particles, the average particle diameter (arithmetic average particle diameter) of carbon black is not limited, and is usually about 5 to 200 nm, preferably about 5 to 100 nm. When carbon black aggregates are used, the thickness may be about 10 to 600 nm, preferably about 50 to 500 nm. When graphite, activated carbon or the like is used, the average particle size may be about 500 nm to 40 μm, preferably about 1 to 35 μm. The average particle size of the conductive carbon particles can be measured by, for example, a particle size distribution measuring device LA-920: manufactured by Horiba, Ltd. When conductive carbon fibers are used, the average fiber diameter of the conductive carbon fibers is not limited, and may be about 50 to 400 nm, preferably about 100 to 250 nm. The average fiber length of the conductive carbon fiber is not limited, and may be about 5 to 50 μm, preferably about 10 to 20 μm. The average aspect ratio of the conductive carbon fiber is about 10 to 500. The average fiber diameter, average fiber length, and average aspect ratio of the conductive carbon fiber can be measured by an image measured with a scanning electron microscope (SEM) or the like.

  The thermosetting resin is added to impart strength to the gas diffusion layer and make it difficult to crush the pores. Although this thermosetting resin is not specifically limited, a phenol resin, an epoxy resin, a melanin resin, a silicone resin, etc. can be selected suitably. These resins are selected according to the use in consideration of heat resistance, mechanical strength, flexibility, etc. For example, a phenol resin is preferable from the viewpoint of mechanical strength and heat resistance.

  The binder is used to settle the carbon material in the gas diffusion layer precursor and is not particularly limited, but an acrylic resin, a fluororesin, a urethane resin, or the like can be used as appropriate. In particular, the fluorine-based resin has water repellency and is preferable in terms of water discharge from the gas diffusion layer. Examples of the fluororesin include polytetrafluoroethylene resin (PTFE), fluorinated ethylene propylene resin (FEP), perfluoroalkoxy resin (PFA), polyvinylidene fluoride resin (PVDF), a co-polymer of fluoroolefin and hydrocarbon. A polymer etc. are mentioned.

  Examples of the solvent include, but are not limited to, water, alcohol, and organic solvents. The alcohol is not particularly limited and may be a known or commercially available one. For example, A monovalent or polyhydric alcohol having about 1 to 5 carbon atoms can be mentioned. Specific examples include methanol, ethanol, 1-propanol, isopropanol, 1-butanol, and 1-pentanol. Examples of the organic solvent include acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, toluene, and mixed solvents thereof.

  The drying unit 3 is installed on the downstream side of the coating unit 2 that applies the gas diffusion layer paste as described above. The drying unit 3 is not particularly limited as long as it can heat the gas diffusion layer paste, and examples thereof include a heating furnace, a heater, hot air drying, and an infrared heater. The heating temperature in the drying unit 3 is a temperature at which the thermosetting resin in the gas diffusion layer paste is not cured and is a temperature at which the solvent in the gas diffusion layer paste can be dried. Thus, when the gas diffusion layer precursor B is wound up by heating the gas diffusion layer paste at a temperature at which the drying unit 3 can dry the solvent in the gas diffusion layer paste, the substrate A The gas diffusion layer precursor can be prevented from adhering to the back surface of the gas diffusion layer, and when the substrate A is peeled off, the gas diffusion layer precursor B can be conveyed alone. In addition, by setting the heating temperature by the drying unit 3 to a temperature at which the thermosetting resin in the gas diffusion layer paste is not cured, the gas diffusion layer precursor B can be made flexible, and the first It becomes possible to wind up the gas diffusion layer precursor B in the winding unit 4. In addition, although the heating temperature by this drying part 3 changes also with the kind of thermosetting resin and solvent in the paste for gas diffusion layers, it can generally be about 40-150 degreeC.

  A first winding unit 4 is installed on the downstream side of the drying unit 3. The 1st winding part 4 winds up the gas diffusion layer precursor B formed by drying by the drying part 3 by rotating with a rotational drive motor (not shown) as a drive source. Here, by setting the flexural modulus of the gas diffusion layer precursor B after drying to 100 to 5000 MPa, the gas diffusion layer precursor B can be easily wound with appropriate flexibility. Moreover, when the bending strength of the gas diffusion layer precursor B after drying is set to 0.1 to 50 MPa, it is possible to prevent damage when the gas diffusion layer precursor B is wound up. The peel strength between the gas diffusion layer precursor B and the substrate A is preferably about 0.01 to 1 N / mm. When the gas diffusion layer precursor B is wound up by setting the peel strength to 0.01 N / mm or more, the gas diffusion layer precursor B can be prevented from being peeled off from the base material A, and the peel strength When the base material A is peeled from the gas diffusion layer precursor B as will be described later, the base material A can be smoothly peeled without damaging the gas diffusion layer precursor B. . Furthermore, the tensile strength of the gas diffusion layer precursor B is higher than the peel strength between the gas diffusion layer precursor B and the substrate A so that the gas diffusion layer precursor B is not damaged when the substrate A is peeled off. It is preferably 0.05 N / mm or greater.

  The production method of the gas diffusion layer precursor by the gas diffusion layer precursor production apparatus configured as described above will be described. First, the substrate A is unwound from the first unwinding portion 1 and unwound. A gas diffusion layer paste is applied onto the substrate A by the die 2. The applied gas diffusion layer paste is subsequently heated by the drying unit 3, so that the solvent is blown off to become a flexible gas diffusion layer precursor B. The drying conditions at this time vary depending on the type of the thermosetting resin and solvent in the gas diffusion layer paste, but generally, the heating temperature is about 40 to 150 ° C., and 1 to 20 minutes. It is preferable to heat to a certain extent. Thereafter, the gas diffusion layer precursor B is taken up together with the base material A by the first winding unit 4, and a roll body of the gas diffusion layer precursor is completed.

  A gas diffusion layer manufacturing apparatus and method using the gas diffusion layer precursor B manufactured in this way will be described.

  As shown in FIG. 2, the gas diffusion layer manufacturing apparatus mainly includes a second unwinding unit 5, a second winding unit (peeling unit) 6, a cutting unit 7, a conveying unit 8, and a heating unit 9. It is said.

  In the second unwinding unit 5, the gas diffusion layer precursor B with the base material A wound by the first winding unit 4 is set, and the gas diffusion layer precursor B with the base material A is set downstream. Unwind to the side. The unwinding speed is not particularly limited, but can be, for example, about 0.5 to 10 m / min.

  The second winding unit 6 is rotated by a rotation drive motor (not shown), and the base A separated from the gas diffusion layer precursor B with the base A unwound from the second unwinding unit 5 is removed. It is configured to wind up.

  The cutting part 7 is for cutting the gas diffusion layer precursor B after the substrate A is peeled into a desired length into a single sheet, and a known cutting means such as a cutting cutter is used. Can be used.

  The transport unit 8 is for transporting the gas diffusion layer precursor B cut into a sheet by the cutting unit 7 to a predetermined place. For example, an endless belt is bridged between a pair of rotation driving units. A belt conveyor can be used.

  In the heating unit 9, the gas diffusion layer precursor B is heated to make the gas diffusion layer precursor B a gas diffusion layer C. Specifically, the gas diffusion layer precursor B is heated at a temperature equal to or higher than the curing temperature of the thermosetting resin in the gas diffusion layer precursor B to cure the thermosetting resin. A gas diffusion layer C is formed. Although the heating temperature in this heating part 9 changes with kinds of thermosetting resin, it can be about 50-500 degreeC, for example.

  The gas diffusion layer manufacturing method using the gas diffusion layer manufacturing apparatus configured as described above will be described. First, the gas diffusion layer precursor B with the base material A is unwound from the second unwinding portion 5, The substrate A peeled from the gas diffusion layer precursor B is wound up by the second winding unit 6. The gas diffusion layer precursor B from which the substrate A has been peeled is cut to a desired length by the cutting unit 7 and heated by the heating unit 9 while being conveyed by the conveying unit 8. By being heated by the heating unit 9, the thermosetting resin in the gas diffusion layer precursor B is cured. Thus, the gas diffusion layer precursor B becomes the gas diffusion layer C and is transported to a desired position by passing through the heating unit 9.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to these, A various change is possible unless it deviates from the meaning of this invention.

  For example, in the above embodiment, the die is used as an example of the application part for applying the gas diffusion layer paste. However, as other methods for applying the gas diffusion layer paste, knife coating, bar coating, blade coating, etc. , Spray coating, roll coating, curtain coating, spin coating, screen printing, and the like.

  Moreover, in the said embodiment, although the heating part 9 was installed in the downstream of the cutting | disconnection part 7, That is, after cut | disconnecting the gas diffusion layer precursor B, it heated and was made into the gas diffusion layer C. The gas diffusion layer precursor B may be heated to form the gas diffusion layer C and then cut. That is, as shown in FIG. 3, the cutting unit 7 may be installed on the downstream side of the heating unit 9.

  In addition, as shown in FIG. 4, the base material A is peeled after the gas diffusion layer precursor B is cut, that is, the peeling portion 6 can be installed after the cutting portion 7. Further, as shown in FIG. 5, after the gas diffusion layer precursor B unwound from the second unwinding portion 5 is cut and the base material A is peeled off, the plurality of gas diffusion layer precursors B are heated to the heating portion. 9 can also be configured to be heated batchwise at a time.

Example 1
Conductive carbon fiber (VGCF (registered trademark) (standard), manufactured by Showa Denko KK, average fiber diameter 150 nm, average fiber length 10-20 μm, average aspect ratio 10-500) 100 parts by weight, fluoroolefin copolymer as binder Combined (Fluonate (registered trademark) K-703, manufactured by DIC Corporation) 50 parts by weight, phenol resin (PR50781, manufactured by Sumitomo Bakelite Co., Ltd.) 100 parts by weight, and toluene-methyl ethyl ketone (1: 1) mixed solvent 350 parts by weight A gas diffusion layer paste was prepared by dispersing the part by media dispersion. A polyethylene terephthalate (PET) film (SP-PET PET-O2-BU, Mitsui Chemicals) in which a release layer (silicone coat layer) is formed by unwinding this gas diffusion layer paste from the first unwinding portion. The coating was applied to a thickness of about 200 μm using a knife coating on Tosero Co., Ltd. (thickness: 38 μm). Then, after drying for 15 minutes in a drying section set at 95 ° C., the first winding section is wound using a core having an inner diameter of 3 inches and a wall thickness of 10 mm, and a gas diffusion layer precursor with a substrate is prepared. The body was made. At this time, no noticeable winding wrinkles, winding deviations, or cracks were found in the wound gas diffusion layer precursor.

  The prepared gas diffusion layer precursor with a base material is unwound from the second unwinding part, and the base material is peeled off at the second winding part, and then subjected to a heat treatment for 40 minutes in a heating part set at 250 ° C. went. Then, it cut | disconnected by the fixed space | interval and produced the gas diffusion layer. At this time, the peelability between the gas diffusion layer precursor and the substrate was good, and there was no occurrence of poor peeling.

Example 2
Conductive carbon fiber (VGCF (registered trademark) (standard), manufactured by Showa Denko KK, average fiber diameter 150 nm, average fiber length 10 to 20 μm, average aspect ratio 10 to 500) 100 parts by weight, binder, fluoroolefin 200 parts by weight of a polymer (Fluonate (registered trademark) K-703, manufactured by DIC Corporation), 200 parts by weight of a phenol resin (PR50781, manufactured by Sumitomo Bakelite Co., Ltd.), and a toluene-methyl ethyl ketone (1: 1) mixed solvent 350 A gas diffusion layer paste composition was prepared by dispersing parts by weight of media. A polyethylene terephthalate (PET) film (SP-PET PET-O2-BU) in which a release layer (silicone coat layer) is formed by unwinding this gas diffusion layer paste composition from the first unwinding portion, It was applied to a thickness of about 200 μm using a knife coating on Mitsui Chemicals Tosero Co., Ltd. (thickness: 38 μm). Then, after drying for 15 minutes in a drying section set at 95 ° C., the first winding section is wound using a core having an inner diameter of 3 inches and a wall thickness of 10 mm, and a gas diffusion layer precursor with a substrate is prepared. The body was made. At this time, no noticeable winding wrinkles, winding deviations, or cracks were found in the wound gas diffusion layer precursor.

  The prepared gas diffusion layer precursor with a base material is unwound from the second unwinding part, and the base material is peeled off at the second winding part, and then subjected to a heat treatment for 40 minutes in a heating part set at 250 ° C. went. Then, it cut | disconnected by the fixed space | interval and produced the gas diffusion layer. At this time, the peelability between the gas diffusion layer precursor and the substrate was good, and there was no occurrence of poor peeling.

Example 3
Conductive carbon particles (Furness Black Vulcan xc72R: Cabot Corporation, weight average molecular weight 1000 to 3000) 100 parts by weight, conductive carbon particle fibers (VGCF (registered trademark) (standard), Showa Denko Co., Ltd., average fiber diameter 150 nm, average fiber length of 10 to 20 μm, average aspect ratio of 10 to 500) 100 parts by weight, as binder, fluoroolefin copolymer (Fluonate (registered trademark) K-703, manufactured by DIC Corporation) 50 parts by weight, phenol resin A gas diffusion layer paste composition was prepared by dispersing 150 parts by weight (PR50781, manufactured by Sumitomo Bakelite Co., Ltd.) and 500 parts by weight of a toluene-methyl ethyl ketone (1: 1) mixed solvent by media dispersion. A polyethylene terephthalate (PET) film (SP-PET PET-O2-BU) in which a release layer (silicone coat layer) is formed by unwinding this gas diffusion layer paste composition from the first unwinding portion, It was applied to a thickness of about 200 μm using a knife coating on Mitsui Chemicals Tosero Co., Ltd. (thickness: 38 μm). Then, after drying for 15 minutes in a drying furnace set at 95 ° C., the first winding section is wound using a core having an inner diameter of 3 inches and a wall thickness of 10 mm, and a gas diffusion layer with a base material A precursor was prepared. At this time, no noticeable winding wrinkles, winding deviations, or cracks were found in the wound gas diffusion layer precursor.

  The prepared gas diffusion layer precursor with a base material is unwound from the second unwinding part, and the base material is peeled off at the second winding part, and then subjected to a heat treatment for 40 minutes in a heating part set at 250 ° C. went. Then, it cut | disconnected by the fixed space | interval and produced the gas diffusion layer. At this time, the peelability between the gas diffusion layer precursor and the substrate was good, and there was no occurrence of poor peeling.

<Measurement of flexural modulus and bending strength>
The gas diffusion layer precursor prepared in each example was peeled from the substrate, a three-point bending test was performed, and the bending elastic modulus and bending strength were measured. The results are shown in Table 1. The three-point bending test was performed in accordance with the method specified in JIS K6911 and JIS K7171. At this time, the width of the test piece was 15 mm, the length was 40 mm, and the distance between fulcrums was 15 mm. Further, the radius of curvature of the fulcrum and the indenter was 3 mm, and the test speed was 2 mm / min.

<Peel test>
The peel test between the gas diffusion layer precursor prepared in each Example and the base material was performed in accordance with the T-type peel adhesion strength test method defined in JIS K6854-3. The test piece at this time had a width of 15 mm, a length of 30 mm, and a peeling rate of 50 mm / min.

<Tensile strength measurement>
The gas diffusion layer precursor produced in each example was peeled from the substrate, a tensile test was performed, and the tensile strength was measured. The tensile test was performed in accordance with a method defined in JIS K7161. At this time, the width of the test piece was 15 mm, the length was 30 mm, and the tensile speed was 3 mm / min.

DESCRIPTION OF SYMBOLS 1 1st unwinding part 2 Application | coating part 3 Drying part 4 1st winding part 5 2nd unwinding part 6 Peeling part (2nd winding part)
7 Cutting part 8 Conveying part 9 Heating part A Base material B Gas diffusion layer precursor C Gas diffusion layer

Claims (12)

Unwinding the long substrate;
Applying a paste for a gas diffusion layer containing a thermosetting resin and a solvent onto the unwound substrate;
Heating the gas diffusion layer paste applied on the substrate and drying the solvent at a temperature lower than the curing temperature of the thermosetting resin;
Winding up the gas diffusion layer precursor formed by drying the gas diffusion layer paste;
A method for producing a gas diffusion layer precursor, comprising:   The method for producing a gas diffusion layer precursor according to claim 1, wherein the gas diffusion layer precursor has a flexural modulus of 100 to 5000 MPa.   The method for producing a gas diffusion layer precursor according to claim 1 or 2, wherein the gas diffusion layer precursor has a bending strength of 0.1 to 50 MPa.   The method for producing a gas diffusion layer precursor according to any one of claims 1 to 3, wherein a peel strength between the gas diffusion layer precursor and the substrate is 0.01 to 1 N / mm.   The gas diffusion according to any one of claims 1 to 4, wherein the tensile strength of the gas diffusion layer precursor is 0.05 N / mm or more greater than the peel strength between the gas diffusion layer precursor and the substrate. A method for producing a layer precursor.   The said base material is a manufacturing method of the gas diffusion layer precursor in any one of Claims 1-5 which has a mold release layer in the surface where the said paste for gas diffusion layers is apply | coated. A method for producing a gas diffusion layer precursor according to any one of claims 1 to 6,
Unwinding the gas diffusion layer precursor wound together with the substrate;
Peeling the substrate from the gas diffusion layer precursor;
Heating the gas diffusion layer precursor from which the substrate has been peeled to cure the thermosetting resin;
A method for producing a gas diffusion layer, comprising: A first unwinding section for unwinding a long substrate;
An application part for applying a paste for a gas diffusion layer containing a thermosetting resin and a solvent onto the unrolled substrate;
A drying unit installed on the downstream side of the application unit, heating the gas diffusion layer paste, and drying the solvent at a temperature lower than the curing temperature of the thermosetting resin;
A first winding portion for winding the gas diffusion layer precursor formed by drying the gas diffusion layer paste;
A gas diffusion layer precursor production apparatus comprising: A gas diffusion layer paste containing a thermosetting resin and a solvent is formed on a long substrate by drying the solvent at a temperature lower than the curing temperature of the thermosetting resin, and wound together with the substrate. A second unwinding section for unwinding the gas diffusion layer precursor,
A peeling portion for peeling the base material from the gas diffusion layer precursor;
A heating unit installed on the downstream side of the peeling unit and heating the gas diffusion layer precursor to cure the thermosetting resin;
A gas diffusion layer manufacturing apparatus comprising:   The gas diffusion layer manufacturing apparatus according to claim 9, wherein the peeling portion is a second winding portion that winds the base material peeled from the gas diffusion layer precursor.   11. The gas diffusion layer manufacturing apparatus according to claim 9, further comprising a cutting unit that cuts the gas diffusion layer precursor into a single sheet shape upstream of the heating unit.   11. The gas diffusion layer manufacturing apparatus according to claim 9, further comprising a cutting unit that cuts the gas diffusion layer into a sheet-like sheet on a downstream side of the heating unit.

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