WO2012099036A1 - 多孔質電極基材、その製造方法、膜-電極接合体、固体高分子型燃料電池、前駆体シート、およびフィブリル状繊維 - Google Patents
多孔質電極基材、その製造方法、膜-電極接合体、固体高分子型燃料電池、前駆体シート、およびフィブリル状繊維 Download PDFInfo
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- WO2012099036A1 WO2012099036A1 PCT/JP2012/050677 JP2012050677W WO2012099036A1 WO 2012099036 A1 WO2012099036 A1 WO 2012099036A1 JP 2012050677 W JP2012050677 W JP 2012050677W WO 2012099036 A1 WO2012099036 A1 WO 2012099036A1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/88—Processes of manufacture
- H01M4/8803—Supports for the deposition of the catalytic active composition
- H01M4/8807—Gas diffusion layers
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- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F9/00—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments
- D01F9/08—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments of inorganic material
- D01F9/12—Carbon filaments; Apparatus specially adapted for the manufacture thereof
- D01F9/14—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments
- D01F9/20—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products
- D01F9/21—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D01F9/22—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds from polyacrylonitriles
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- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
- D21H13/36—Inorganic fibres or flakes
- D21H13/46—Non-siliceous fibres, e.g. from metal oxides
- D21H13/50—Carbon fibres
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/8605—Porous electrodes
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/96—Carbon-based electrodes
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/02—Details
- H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
- H01M8/023—Porous and characterised by the material
- H01M8/0234—Carbonaceous material
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/10—Fuel cells with solid electrolytes
- H01M2008/1095—Fuel cells with polymeric electrolytes
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Definitions
- the present invention relates to a porous electrode substrate that can be used in a fuel cell, a method for producing the same, a membrane-electrode assembly including the porous electrode substrate, a solid polymer fuel cell, and a method for producing the porous electrode substrate.
- the present invention relates to a precursor sheet and fibrillar fibers that can be used for production.
- gas diffusion electrode base materials installed in fuel cells are conventionally made by making short carbon fibers, binding them with organic polymers, and firing them at a high temperature to convert the organic polymers into carbon.
- a porous electrode substrate made of a carbonized carbon / carbon composite was used (see Patent Document 1).
- porous electrode base material porous carbon electrode base material
- Patent Document 1 has sufficient gas permeability and conductivity, the manufacturing process is complicated, so the manufacturing cost is low. Tended to be higher.
- porous electrode base material currently disclosed by patent document 2 has mechanical strength, surface smoothness, and gas-permeability, and also the conductivity becomes high by adding carbon powder, The manufacturing process is complicated and the manufacturing cost tends to be high.
- the carbon fiber sheet (porous electrode substrate) disclosed in Patent Document 3 can be produced at a low cost, the shrinkage during firing may be large, and the thickness of the porous electrode substrate obtained In some cases, unevenness and waviness of the sheet were large.
- the porous electrode base material disclosed in Patent Document 4 can be reduced in cost, but the acrylic pulp used may have a low carbonization rate at the time of carbonization, in order to improve handling properties Required to add more acrylic pulp.
- the porous electrode substrate disclosed in Patent Document 5 does not have a carbonization process and can be greatly reduced in cost.
- the porous electrode substrate has a fibril portion composed of a water-repellent material and a conductive material that bind carbon short fibers.
- the conductivity of the fiber may not be sufficient, and the conductivity of the porous electrode substrate may be low.
- the present invention overcomes the above points, has a high thickness accuracy, gas permeability, electrical conductivity, sufficient handling properties, low manufacturing cost, and high carbonization rate during carbonization It aims at providing an electrode base material and its manufacturing method.
- the present invention also provides a precursor sheet and fibrillar fibers that can be used to produce the porous electrode substrate, a membrane-electrode assembly and a polymer electrolyte fuel cell using the porous electrode substrate. For other purposes.
- [1] including a step (1) of producing a precursor sheet in which short carbon fibers (A) and carbon precursor fibers (b) are dispersed, and a step (2) of carbonizing the precursor sheet, A method for producing a porous electrode substrate, wherein the volumetric shrinkage of the carbon precursor fiber (b) in step (2) is 83% or less.
- the carbon precursor fiber (b) includes a carbon precursor short fiber containing an acrylonitrile polymer containing 95% by mass or more of an acrylonitrile unit, and an acrylonitrile polymer containing 95% by mass or more of an acrylonitrile unit.
- a membrane-electrode assembly comprising the porous electrode substrate according to any one of [9] to [11] above.
- a polymer electrolyte fuel cell comprising the membrane-electrode assembly according to [12].
- a precursor sheet in which short carbon fibers (A) and carbon precursor fibers containing carbon powder are dispersed is dispersed.
- Carbon fiber (A) carbon precursor short fiber composed of acrylonitrile-based polymer containing 95% by mass or more of acrylonitrile units, and fibrillar carbon containing acrylonitrile-based polymer containing 95% by mass or more of acrylonitrile units A precursor sheet in which one or both of the precursor fibers are dispersed.
- the carbon precursor fiber containing carbon powder includes an acrylonitrile polymer containing 95% by mass or more of an acrylonitrile unit and a carbon precursor short fiber made of carbon powder, and an acrylonitrile type containing 95% by mass or more of an acrylonitrile unit.
- Fibrous fiber made of carbon powder and acrylonitrile polymer.
- a porous electrode substrate having high thickness accuracy, gas permeability, electrical conductivity, sufficient handling properties, low production cost, and high carbonization rate at the time of carbonization and production method thereof Can be provided. Further, according to the present invention, a precursor sheet and a fibrillar fiber that can be used for the production of the porous electrode substrate, and a membrane-electrode assembly and a solid polymer type using the porous electrode substrate A fuel cell can be provided.
- the porous electrode substrate obtained by the production method of the present invention has a structure in which short carbon fibers (A) are joined together by carbon (B) derived from carbon precursor fibers (b).
- This porous electrode substrate can be composed of dispersed carbon short fibers (A) and carbon (B).
- the porous electrode substrate of the present invention can be used as a porous electrode substrate for a polymer electrolyte fuel cell used for a polymer electrolyte fuel cell.
- the carbon (B) is preferably carbon containing carbon powder (carbon derived from the carbon precursor fiber (b1) containing carbon powder).
- the short carbon fibers (A) in the porous electrode base material have a structure joined by network-like carbon.
- the dispersed carbon short fibers (A) are joined together by three-dimensional network carbon, and the carbon short fibers (A) and carbon (B) are entangled with each other.
- a porous electrode substrate having is more preferable.
- the porous electrode substrate can be obtained by carbonizing a carbon fiber precursor sheet in which carbon short fibers (A) and carbon precursor fibers (b) are dispersed. That is, carbon (B) is obtained by carbonizing carbon precursor fibers (b) dispersed in a precursor sheet.
- the short carbon fibers (A) and the carbon precursor fibers (b) can be dispersed in a two-dimensional plane, and can be further dispersed in three dimensions.
- at least one of entanglement treatment, heat-press molding, and oxidation treatment may be performed on the precursor sheet as necessary.
- the shape of the porous electrode substrate can be selected as necessary from known shapes in the field of fuel cells, and can be, for example, a flat plate shape or a spiral shape.
- the basis weight of the sheet-like porous electrode substrate is preferably 15 g / m 2 or more and 100 g / m 2 or less from the viewpoints of gas permeability and handling properties.
- the porosity of the sheet-like porous electrode substrate is preferably 50% or more and 90% or less from the viewpoint of gas permeability and conductivity.
- the thickness of the sheet-like porous electrode substrate is preferably 50 ⁇ m or more and 300 ⁇ m or less from the viewpoints of gas permeability, conductivity and handling properties.
- the waviness of the sheet-like porous electrode substrate is preferably less than 5 mm.
- the gas permeability of the porous electrode substrate is preferably 500 ml / hr / cm 2 / mmAq or more and 20000 ml / hr / cm 2 / mmAq or less.
- the electrical resistance (penetration direction resistance) of the thickness direction of a porous electrode base material is 50 m (ohm) * cm ⁇ 2 > or less.
- the measuring method of the gas permeability of a porous electrode base material and penetration direction resistance is mentioned later.
- the short carbon fiber (A) dispersed in the precursor sheet becomes one of the fibers constituting the porous electrode substrate.
- the short carbon fibers (A) include those obtained by cutting carbon fibers such as polyacrylonitrile-based carbon fibers (hereinafter referred to as “PAN-based carbon fibers”), pitch-based carbon fibers, and rayon-based carbon fibers into a predetermined fiber length. Is mentioned. From the viewpoint of the mechanical strength of the porous electrode substrate, PAN-based carbon fibers are preferred.
- the average fiber length of the short carbon fibers (A) is preferably 2 mm or more and 12 mm or less from the viewpoint of dispersibility.
- the average fiber length can be measured with an optical microscope and an electron microscope.
- the average fiber diameter of the short carbon fiber (A) is preferably 3 ⁇ m or more and 9 ⁇ m or less from the viewpoint of production cost and dispersibility of the short carbon fiber, and 4 ⁇ m or more and 8 ⁇ m from the smoothness surface of the porous electrode substrate. The following is more preferable.
- the average fiber diameter can be measured with an optical microscope and an electron microscope.
- the short carbon fiber (A) that is one fiber constituting the porous electrode base material is dispersed in the porous electrode base material.
- “dispersed in the porous electrode base material” means that the short carbon fiber (A) is present in the porous electrode base material even if the short carbon fiber (A) is substantially parallel to the surface of the sheet-like porous electrode base material. It means that it may exist in the thickness direction. Further, the orientation direction of the short carbon fibers (A) substantially parallel to the surface of the sheet-like porous electrode substrate may be substantially random, and the orientation in a specific direction is high. May be.
- the short carbon fibers (A) are present in a substantially linear shape in the porous electrode substrate. In the porous electrode substrate, the short carbon fibers (A) are not directly bonded to each other, but are bonded by carbon (B).
- Carbon (B) is carbon joining carbon short fibers (A).
- the carbon (B) exists in a state of being bent or curved at the joint. From the viewpoint of handling properties and electrical conductivity, carbon (B) is preferably in a network form, and carbon (B) is more preferably in a three-dimensional network form.
- the carbon (B) content in the porous electrode substrate is preferably 10% by mass or more and 90% by mass or less, and 15% by mass in order to easily maintain an appropriate mechanical strength of the porous electrode substrate. More preferably, it is 70 mass% or less.
- Carbon (B) is obtained by carbonizing the carbon precursor fiber (b). Therefore, carbon (B) is carbon derived from the carbon precursor fiber (b). From the viewpoint of conductivity and productivity, carbon (B) preferably contains carbon powder.
- the carbon powder content in the carbon (B) is preferably 10% by mass or more and 90% by mass or less.
- whether or not carbon (B) forms a three-dimensional network structure is a cross-sectional observation of the sheet-like measurement object (porous electrode base material), carbon (B) in the cross section, This can be determined by measuring the angle of the object to be measured with the sheet surface.
- the cross section which performs cross-sectional observation is a cross section when cut
- the average angle between the measured carbon (B) and the horizontal plane (sheet surface) is 3 ° or more, it is determined that a three-dimensional network structure is formed, and the measured carbon (B) and the horizontal plane If the average angle is 2 ° or less, it is determined that a three-dimensional network structure is not formed.
- an SEM (scanning electron microscope) photograph of a cross section perpendicular to the sheet surface is taken, a line is drawn on the carbon (B) to be measured, and this line and the sheet surface What is necessary is just to measure the angle.
- the straight line 7 in FIG. 3 is a line parallel to the sheet surface. Note that the number of measurement points when determining the average value of the angles can be set to 50 points, for example.
- the precursor sheet can be produced by the step (1).
- This precursor sheet is a sheet that becomes a precursor of the porous electrode substrate.
- the precursor sheet obtained in the step (1) is a precursor sheet in which short carbon fibers (A) and carbon precursor fibers (b) are dispersed.
- seat can consist of a carbon short fiber (A) and a carbon precursor fiber (b).
- the volume shrinkage of the carbon precursor fiber (b) by firing when this precursor sheet is fired (carbonization treatment) is set to 83% or less from the viewpoint of handling properties, conductivity, and productivity.
- Examples of the precursor sheet that satisfies the above conditions include the following precursor sheets.
- 1 type in these precursor sheets may be used independently, and 2 or more types may be used together.
- Carbon short fibers (A) and carbon precursor containing carbon powder Precursor sheet in which short body fibers (b1-1) are dispersed (i-2)
- Precursor in which short carbon fibers (A) and fibrillar carbon precursor fibers (b1-2) containing carbon powder are dispersed Sheet
- the volume shrinkage of the carbon precursor fiber (b) in the step (2) is set to 83% or less from the viewpoints of handling properties, conductivity, and productivity.
- the volume shrinkage of the carbon precursor fiber (b) is more preferably 60% or less.
- the smaller the volume shrinkage of the carbon precursor fiber (b) in the step (2) the better.
- shrinkage rate by process (2) is carbon (B) compared with the original carbon precursor fiber (b), when carbon precursor fiber (b) is carbonized and made into carbon (B). ) (The carbon precursor fiber is carbonized through the step (2)).
- the shrinkage rate can be obtained by the following formula 1.
- Volume shrinkage (%) ((b V ⁇ B V ) / b V ) ⁇ 100 (Formula 1) (In the formula 1, b V represents the volume of carbon precursor fibers (b), B V represents the volume of carbon (B)).
- the volume of each fiber and carbon (B) can be calculated from the fiber density, the porous electrode substrate density, the basis weight of the porous electrode substrate and the precursor sheet, and the composition ratio of each fiber in the precursor sheet.
- the volume shrinkage of the carbon precursor fiber (b) in the step (2) can be 83% or less.
- these carbon precursor fiber (b) may be used individually by 1 type, and may use 2 or more types together.
- seat and the carbon precursor fiber (b) depends on the kind etc. of the carbon short fiber (A) used, or a carbon precursor fiber (b). It can be adjusted appropriately.
- (IV-1) Carbon precursor short fiber comprising acrylonitrile-based polymer containing 95% by mass or more of acrylonitrile units and carbon powder (b4-1)
- (IV-2) Fibrous carbon precursor fiber (b4-2) containing acrylonitrile-based polymer containing 95% by mass or more of acrylonitrile units
- carbon powder (IV-2-1) Fibrous carbon precursor fiber (b4-2-1) comprising an acrylonitrile polymer containing 95% by mass or more of acrylonitrile units and carbon powder
- the carbon precursor fiber (b1) containing carbon powder contains carbon powder in each fiber of the carbon precursor fiber.
- the dispersion state of the carbon powder in the carbon precursor fiber is not particularly limited, and may be uniformly dispersed in the fiber or may be localized in the core portion or the fiber surface portion.
- Examples of the carbon precursor fiber (b1) containing carbon powder include carbon precursor short fiber (b1-1) containing carbon powder and fibrillar carbon precursor fiber (b1-2) containing carbon powder. One or both of them can be used.
- the carbon precursor fiber (b1) containing carbon powder one type of carbon precursor fiber (b1) containing carbon powder may be used. Further, as the carbon precursor fiber (b1), the carbon precursor fiber (b1) containing carbon powder has a carbon powder-to-polymer mass ratio, a freeness, a fiber diameter, a polymer species, a carbon powder species, and the like. A plurality of types of fibers may be used in combination. Further, the carbon precursor short fiber (b1-1) containing carbon powder and the fibrillar carbon precursor fiber (b1-2) may be used in combination. However, as the carbon precursor fiber (b1) containing carbon powder, it is preferable to use the fibrillar carbon precursor fiber (b1-2) containing carbon powder from the viewpoint of the handleability of the precursor sheet.
- the carbon precursor fiber (b1) containing such carbon powder is a porous electrode finally obtained depending on the type and mixing ratio, further the mixing ratio with the short carbon fiber (A), and the presence or absence of oxidation treatment.
- the remaining ratio of carbon containing carbon powder in the substrate is different.
- the carbon precursor fiber (b1) containing this carbon powder is used as the carbon precursor fiber (b)
- the mixture of the carbon short fiber (A) and the carbon precursor fiber (b1) containing the carbon powder is used.
- the ratio is preferably as follows. That is, the carbon precursor fiber (b1) containing carbon powder is preferably 50 to 300 parts by mass with respect to 100 parts by mass of the short carbon fiber (A).
- the carbon precursor fiber (b1) containing carbon powder 50 parts by mass or more By making the carbon precursor fiber (b1) containing carbon powder 50 parts by mass or more, the amount of carbon containing the carbon powder to be formed increases, so the strength of the porous electrode substrate sheet is easily improved. Can be made.
- the carbon precursor fiber (b1) containing carbon powder By setting the carbon precursor fiber (b1) containing carbon powder to 300 parts by mass or less, the short carbon fiber (A) that suppresses shrinkage of the carbon precursor fiber (b1) during carbonization is small. Shrinkage of the sheet can be more reliably suppressed, the strength of the porous electrode substrate sheet can be easily improved, and handling properties can be further enhanced.
- carbon black such as Fourness black, acetylene black, lamp black, thermal black, ketjen black, graphite powder such as flake graphite or spherical graphite, or a mixture thereof can be used. These carbon powders are preferable from the viewpoints of electrical conductivity and sheet shape maintenance.
- the carbon precursor fiber (b1) containing carbon powder can be composed of carbon powder and a polymer (polymer).
- concentration of the carbon powder in the carbon precursor fiber (b1) is preferably 10 parts by mass or more with respect to 100 parts by mass of the polymer used from the viewpoint that the carbonization rate during carbonization is clearly improved.
- the upper limit of the concentration of the carbon powder is preferably as high as possible within the range where spinning is possible, but is preferably 60 parts by mass or less from the viewpoint of spinning stability at the fiber production stage.
- the polymer used for the carbon precursor fiber (b1) containing the carbon powder has a remaining mass of 20% by mass or more in the carbonization treatment step (step (2)), which is low in cost and low in environmental load. Is preferable.
- Examples of such polymers include acrylonitrile polymers (acrylonitrile polymers), cellulose polymers, and phenol polymers.
- acrylonitrile polymers acrylonitrile polymers
- cellulose polymers cellulose polymers
- phenol polymers acrylonitrile-based polymer
- the acrylonitrile-based polymer may be an acrylonitrile-based polymer (homopolymer) obtained by homopolymerizing acrylonitrile, or an acrylonitrile-based polymer (copolymer) obtained by copolymerizing acrylonitrile and other monomers.
- the acrylonitrile-based polymer preferably contains 50% by mass or more of acrylonitrile units, and more preferably contains 95% by mass or more.
- the monomer copolymerized with acrylonitrile is not particularly limited as long as it is an unsaturated monomer constituting a general acrylic fiber.
- Methacrylic acid esters acrylic acid, methacrylic acid, maleic acid, itaconic acid, acrylamide, N-methylol acrylamide, diacetone acrylamide, styrene, vinyl toluene, vinyl acetate, vinyl chloride, vinylidene chloride, vinylidene bromide, vinyl fluoride, And vinylidene fluoride.
- the acrylonitrile-based polymer preferably has a carbonization rate of 30% by mass or more in the carbonization process.
- the weight average molecular weight of the acrylonitrile polymer is not particularly limited, but is preferably 50,000 to 1,000,000.
- the weight average molecular weight of the acrylonitrile-based polymer is 50,000 or more, the spinnability is improved and the yarn quality of the fiber tends to be improved. Further, when the weight average molecular weight of the acrylonitrile-based polymer is 1,000,000 or less, the polymer concentration that gives the optimum viscosity of the spinning dope increases, and the productivity tends to improve.
- the method for producing the carbon precursor fiber (b1) containing carbon powder is not particularly limited.
- the carbon precursor short fiber (b1-1) or the fibrillar carbon precursor fiber (b1- 2) can be used as the carbon precursor fiber (b1).
- Fibril-like fibers such as the fibril-like carbon precursor fiber (b1-2) can be composed of carbon powder and an acrylonitrile-based polymer.
- the acrylonitrile-based polymer can be one or both of an acrylonitrile homopolymer and an acrylonitrile copolymer of acrylonitrile and the other monomers described above.
- the carbon precursor short fibers (b1-1) containing carbon powder can be obtained by cutting long fiber-like carbon precursor fibers containing carbon powder to an appropriate length.
- the average fiber length of the carbon precursor short fibers (b1-1) is preferably 2 mm or more and 20 mm or less from the viewpoint of dispersibility.
- the average fiber length can be measured with an optical microscope and an electron microscope.
- the cross-sectional shape of the carbon precursor short fiber (b1-1) is not particularly limited, but a high roundness is preferable from the viewpoint of mechanical strength after carbonization and production cost.
- the average diameter of the carbon precursor short fibers (b1-1) is preferably 20 ⁇ m or less from the viewpoint of suppressing breakage due to shrinkage during carbonization.
- the average fiber diameter (diameter) can be measured with an optical microscope and an electron microscope.
- the carbon precursor short fiber (b1-1) containing carbon powder can be produced, for example, using a general spinning method using carbon powder and a polymer.
- a spinning dope prepared by dissolving an acrylonitrile-based polymer and carbon powder in a solvent or dispersed in a dispersion medium is a known spinning method such as a dry method or a wet method.
- a spinning method such as a dry method or a wet method.
- Fibrous carbon precursor fiber containing carbon powder (b1-2)
- the fibrillar carbon precursor fiber (b1-2) containing carbon powder is exemplified in, for example, Japanese Patent No. 4409911. Specifically, carbon powder has a structure in which a large number of fibrils having a diameter of several ⁇ m or less (for example, 0.1 to 3 ⁇ m) are branched from a fibrous trunk having a diameter of 100 ⁇ m or less (for example, about 0.1 to 30 ⁇ m).
- the carbon precursor fiber containing is mentioned.
- the freeness of the fibrillar carbon precursor fiber (b1-2) containing carbon powder is generally improved when the fibrillar fiber having a low freeness is used to improve the mechanical strength of the precursor sheet.
- the gas permeability of the electrode substrate tends to decrease.
- the method for producing the fibrillar carbon precursor fiber (b1-2) is not particularly limited, but it is preferably produced using a jet coagulation method in which the freeness can be easily controlled.
- the fibrillar carbon precursor fiber (b1-2) containing carbon powder by the spray coagulation method can be produced by the following method using, for example, the apparatus shown in FIG. At the same time as a spinning stock solution in which a raw material (for example, acrylonitrile polymer and carbon black) of fibrillar carbon precursor fiber containing carbon powder is dissolved in a solvent or dispersed in a dispersion medium is discharged into a mixing cell through a spinning discharge port.
- a raw material for example, acrylonitrile polymer and carbon black
- Water vapor is injected into the mixing cell at an angle of not less than 0 degrees and less than 90 degrees with respect to the discharge line direction of the spinning dope, and the fibrillar carbon precursor fiber raw material containing carbon powder in the mixing cell is subjected to a shear flow rate Solidify with.
- a fibrillated carbon precursor fiber containing carbon powder is obtained by discharging the formed solidified body together with the solvent or dispersion medium and water vapor from the mixing cell into the solidified liquid.
- the coagulation liquid water or a mixed liquid of water and the above-mentioned solvent or dispersion medium can be used.
- the fibrillar carbon precursor fiber (b1-2) containing the carbon powder thus obtained is composed of a fibril part in which fibers having a small fiber diameter are aggregated and a core part having a thick fiber diameter solidified without much contact with water vapor. have.
- the fibril part of the fibrillar carbon precursor fiber (b1-2) containing carbon powder is entangled with the fibril part of the short carbon fiber (A) or the fibrillar carbon precursor fiber (b1-2) containing carbon powder.
- the core portion of the fibrillar carbon precursor fiber (b1-2) containing carbon powder can exhibit strength as a binder.
- the fiber diameter of the fibril part is preferably 2 ⁇ m or less in order to improve the entanglement with the short carbon fibers to be mixed.
- the core part preferably has a diameter of 100 ⁇ m or less from the viewpoint of homogenization of the porous electrode substrate.
- the fibrillar carbon precursor fiber (b1-2) containing carbon powder can be more reliably prevented from being unevenly distributed, and the fibrillar carbon precursor containing a relatively small amount of carbon powder.
- the carbon short fibers (A) can be easily bound by the fibers (b1-2).
- the diameter of a core part is 10 micrometers or more from a viewpoint of expressing intensity
- the fibrillar carbon precursor fiber (b1-2) containing carbon powder entangled with the short carbon fiber the fibrillar carbon precursor fiber (b1-2) containing carbon powder for one core part. It is preferable that there are a plurality of fibril parts, and it is considered that the more fibril parts with respect to one core part, the better.
- the thickness of the core is constant or changes steplessly. Thereby, it can prevent easily that the level
- the fibrillar carbon precursor fiber (b1-2) containing carbon powder is produced by the above method, it is often difficult to keep the thickness of the core constant because water vapor scatters randomly. In such a case, the thickness of the core part may change.
- the core portion can be obtained by increasing the water vapor ejection pressure and temperature. Can be easily prevented from changing in steps.
- Fibrous carbon precursor fiber (b2) examples include fibril-like carbon precursor fibers containing carbon powder, fibril-like carbon precursor fibers containing an acrylonitrile-based polymer containing 95% by mass or more of acrylonitrile units, and this A fibrillar carbon precursor fiber containing an acrylonitrile-based polymer and carbon powder can be exemplified. These fibrillar carbon precursor fibers (b2) are the same as the fibers (b1-2), the fibers (b3-2), and the fibers (b4-2), respectively, and details will be described for each fiber.
- Carbon precursor fiber (b3) containing an acrylonitrile-based polymer containing 95% by mass or more of acrylonitrile units Since the carbon precursor fiber (b3) uses an acrylic polymer containing 95% by mass or more of an acrylonitrile unit in the spinning dope used for producing the fiber, the carbonization rate at the time of carbonization increases.
- Examples of the carbon precursor fiber (b3) include carbon precursor short fibers (b3-1) containing an acrylonitrile-based polymer containing 95% by mass or more of acrylonitrile units, and acrylonitrile-based containing 95% by mass or more of acrylonitrile units.
- One or both of the fibrillar carbon precursor fibers (b3-2) containing a polymer can be used.
- an acrylonitrile polymer containing 95% by mass or more of acrylonitrile units may be referred to as “acrylonitrile polymer I”.
- the acrylonitrile-based polymer I may be a homopolymer of acrylonitrile, or a copolymer of acrylonitrile and other monomers.
- monomers copolymerized with acrylonitrile include, for example, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, and hydroxypropyl acrylate.
- Acrylic acid esters methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, methacrylic acid Methacrylic acid esters represented by 2-hydroxyethyl acid, hydroxypropyl methacrylate, diethylaminoethyl methacrylate, etc .; acrylic acid, methacrylic acid, maleic acid, itaconic acid Acrylamide, N- methylol acrylamide, diacetone acrylamide, styrene, vinyl toluene, vinyl acetate, vinyl chloride, vinylidene chloride, vinylidene bromide, vinyl fluoride, and vinylidene fluoride is.
- the acrylonitrile-based polymer I contains 95% by mass or more of acrylonitrile, and the residual mass in the carbonization process can be 30% by mass or more. Moreover, the volumetric shrinkage of the carbon precursor fiber (b) after the carbonization process can be 83% or less. In addition, if the residual mass of the acrylonitrile-type polymer in a carbonization process is 30 mass% or more, the carbonization rate at the time of carbonization can be made high easily.
- the weight average molecular weight of the acrylonitrile polymer I is not particularly limited, but is preferably 50,000 or more and 1,000,000 or less. By setting the weight average molecular weight to 50,000 or more, the spinnability is improved and the yarn quality of the fiber tends to be good. By setting the weight average molecular weight to 1 million or less, the polymer concentration that gives the optimum viscosity of the spinning dope increases, and the productivity tends to improve.
- Short carbon precursor fiber containing acrylonitrile polymer I (b3-1))
- a carbon precursor short fiber (b3-1-1) made of acrylonitrile-based polymer I can be used as the carbon precursor short fiber (b3-1).
- the carbon precursor short fiber (b3-1) can contain carbon powder.
- the carbon precursor fiber (b3) containing carbon powder will be described in the carbon precursor fiber (b4).
- the carbon precursor short fiber (b3-1-1) can be obtained by cutting a long fiber carbon precursor fiber made of the acrylonitrile-based polymer I into an appropriate length.
- the average fiber length of the carbon precursor short fibers (b3-1-1) is preferably 2 mm or more and 20 mm or less from the viewpoint of dispersibility.
- the average fiber length can be measured with an optical microscope and an electron microscope.
- the cross-sectional shape of the carbon precursor short fibers (b3-1-1) is not particularly limited, but those having high roundness are preferable from the viewpoint of mechanical strength after carbonization and production cost.
- the average diameter of the carbon precursor short fibers (b3-1-1) is preferably 5 ⁇ m or less from the viewpoint of suppressing breakage due to shrinkage during carbonization.
- the average fiber diameter (diameter) can be measured with an optical microscope and an electron microscope.
- the carbon precursor short fibers (b3-1-1) made of the acrylonitrile-based polymer I may be one type or a plurality of types having different fiber diameters and polymer types. Mixing ratio of these carbon precursor short fibers (b3-1-1) and fibrillar carbon precursor fibers (b3-2) described later and carbon short fibers (A) at 200 ° C. or more and 300 ° C. or less. The ratio of carbon (B) remaining in the finally obtained porous electrode substrate can be adjusted by the presence or absence of the oxidation treatment.
- the total amount of b3-1) and fiber (b3-2) is preferably 10% by mass or more and 90% by mass or less from the viewpoint of imparting appropriate mechanical strength to the porous electrode substrate. It is more preferable that the content is not less than 80% and not more than 80% by mass.
- Fibrous carbon precursor fiber containing acrylonitrile polymer I (b3-2) As the fibrillar carbon precursor fiber (b3-2), for example, the following can be used.
- the carbon short fiber (A) and the fibrillar carbon precursor fiber (b3-2) are entangled well in the body sheet to obtain a precursor sheet having excellent handling properties and mechanical strength. It becomes easy.
- the freeness of the fibrillar carbon precursor fiber (b3-2) is not particularly limited. Generally, the use of a fibrillar fiber having a low freeness improves the mechanical strength of the precursor sheet. There exists a tendency for the gas gas permeability of a base material to fall.
- one type of fiber (b3-2-1-1) or one type of fiber (b3-2-2-1) may be used as the fibrillar carbon precursor fiber (b3-2).
- a plurality of these fibers having different degrees of water, fiber diameter, and mass% of acrylonitrile in the acrylonitrile polymer may be used in combination.
- the fiber (b3-2-1-1) is a carbon precursor having a structure in which a large number of fibrils having a diameter of several ⁇ m or less (for example, 0.1 to 3 ⁇ m) are branched from a fibrous trunk having a diameter of 100 ⁇ m or less. It is a body fiber.
- the fiber (b3-2-1-1) can be composed of an acrylonitrile-based polymer containing 95% by mass or more of acrylonitrile.
- the polymer used for the fiber (b3-2-1-1) is preferably an acrylonitrile-based polymer containing 95% by mass or more of acrylonitrile and having a residual mass of 30% by mass or more in the carbonization treatment step. .
- the production method of the fiber (b3-2-1-1) is not particularly limited, but it is preferable to produce the fiber (b3-2-1-1) by using a jet coagulation method with easy control of the freeness.
- FIG. 1 shows a cross-sectional view of an example of a nozzle that can be used to produce a split fiber having a fibril part.
- a method for producing the fiber (b3-2-1-1) using this nozzle by the injection coagulation method will be described.
- an spinning solution is prepared by dissolving an acrylonitrile-based polymer containing 95% by mass or more of acrylonitrile in a solvent.
- a solvent for example, dimethylamide, dimethylformamide, dimethyl sulfoxide and the like can be used.
- the spinning raw solution is supplied to the flow path (spinning raw liquid flow path for split fiber production) 1, and at the same time, water vapor is supplied from the inlet (water vapor inlet) 3 to the slit-like water vapor channel 4.
- this spinning stock solution is discharged into the mixing cell unit 5 through the discharge port (discharge port of the spinning solution for split fiber production) 2, and at the same time, water vapor is jetted into the mixing cell unit 5, and in the mixing cell unit 5.
- the acrylonitrile polymer is solidified under a shear flow rate.
- the angle C formed by the direction of the discharge line A of the spinning dope and the direction of the steam injection line B can be set to 0 degree or more and less than 90 degrees.
- the formed solidified body is discharged together with the solvent and water vapor into the coagulating liquid from the outlet 6 of the mixing cell portion, whereby the fiber (b3-2-1-1) can be obtained.
- the coagulation liquid water or a mixed liquid of water and the solvent can be used.
- the fiber (b3-2-1-1) thus obtained has, for example, a fibril part in which fibers having a small fiber diameter are gathered and a trunk part having a thick fiber diameter solidified without much contact with water vapor. .
- the fibril part of the fiber (b3-2-1-1) has good entanglement with the fibril parts of the short carbon fiber A and the fiber (b3-2-1-1), and the fiber (b3-2-1-1)
- the core part (stem part) can exhibit strength as a binder.
- the fiber diameter of the fibril part of the fiber (b3-2-1-1) is preferably 2 ⁇ m or less from the viewpoint of improving the entanglement with the mixed carbon short fiber (A).
- the core part preferably has a diameter of 100 ⁇ m or less from the viewpoint of homogenization of the porous electrode substrate.
- the diameter of the trunk is preferably 10 ⁇ m or more.
- a plurality of fibril parts of the fiber (b3-2-1-1) exist for one core part, It is considered that the more fibril parts with respect to one core part, the better.
- the thickness of the trunk is constant or changes steplessly. Thereby, it can prevent easily that the level
- the fiber (b3-2-1-1) is produced by the above method, it may be difficult to keep the thickness of the trunk constant due to the random scattering of water vapor, and the thickness of the trunk changes. Sometimes. However, since a gradual change in the thickness of the trunk tends to be observed when the water vapor to be sprayed cools into droplets, the thickness of the trunk is increased by increasing the steam jet pressure and temperature. Can be easily prevented from changing in steps.
- the fiber (b3-2-2-1) can be obtained by beating a long fiber easily split sea-island composite fiber into an appropriate length and beating it with a refiner, a pulper, or the like to form a fibril. .
- the long-fiber easy split sea-island composite fiber is dissolved in a common solvent and incompatible with two or more different polymers (at least one acrylonitrile-based polymer containing 95% by mass or more of acrylonitrile). ) Can be used.
- the at least one polymer is preferably an acrylonitrile-based polymer containing 95% by mass or more of acrylonitrile and having a residual mass of 30% by mass or more in the carbonization treatment step.
- the content of the acrylonitrile-based polymer containing 95% by mass or more of acrylonitrile in the fiber (b3-2-2-1) is 40% by mass or more from the viewpoint of increasing the carbonization rate at the time of carbonization. It is preferable.
- the content of the acrylonitrile polymer in the fiber (b3-2-2-1) and the content of the acrylonitrile polymer in the long-fiber easily split sea-island composite fiber are the same.
- the other polymer is dissolved in a solvent common to the acrylonitrile-based polymer and a spinning stock solution in which both polymers are dissolved stably exists. That is, the other polymer is incompatible with the acrylonitrile polymer when dissolved in the same solvent as the acrylonitrile polymer and has a miscibility enough to form a sea-island structure during spinning. Is desired.
- Examples of other polymers that satisfy these demands include polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, polyvinyl pyrrolidone, cellulose acetate, acrylic resin, methacrylic resin, and phenol resin. Among these, cellulose acetate, an acrylic resin, and a methacrylic resin are preferable from the viewpoint of the above-described balance of demand.
- the other polymer may be one type or two or more types.
- the easily splittable sea-island composite fiber used for the fiber (b3-2-2-1) can be produced by a normal wet spinning method.
- a spinning dope is prepared by dissolving an acrylonitrile polymer containing 95% by mass or more of acrylonitrile and another polymer in a solvent.
- a spinning stock solution obtained by dissolving an acrylonitrile polymer containing 95% by mass or more of acrylonitrile in a solvent and a spinning stock solution obtained by dissolving another polymer in a solvent are mixed with a static mixer or the like to perform spinning. It may be a stock solution.
- dimethylamide, dimethylformamide, dimethyl sulfoxide and the like can be used as the solvent.
- An easily split fiber sea-island composite fiber can be obtained by supplying these spinning stock solutions to a spinning machine, spinning from a nozzle, and performing wet heat drawing, washing, drying and dry heat drawing.
- the cross-sectional shape of the easily splittable sea-island composite fiber is not particularly limited.
- the fineness of the easily split sea-island composite fiber is preferably 1 dtex or more and 10 dtex or less.
- the average fiber length of the splittable sea-island composite fiber is preferably 1 mm or more and 20 mm or less from the viewpoint of dispersibility after beating.
- the easily splittable sea-island composite fiber is beaten by peeling of the phase separation interface by mechanical external force, and at least a part thereof is split and fibrillated.
- the beating method is not particularly limited, and for example, fibrillation can be performed by a refiner, a pulper, a beater, or a jet of pressurized water (water jet punching).
- the fibrillation state changes depending on the beating method and beating time.
- a freeness evaluation ISO-5267-2 (Canadian Standard freeness method)
- the freeness of the fiber (b3-2-2-1) is not particularly limited.
- the carbon precursor fiber (b4) contains carbon powder in each fiber.
- the dispersion state of the carbon powder in the carbon precursor fiber is not particularly limited, and may be uniformly dispersed in the fiber or may be localized in the core portion or the fiber surface portion.
- this fiber (b4) for example, a carbon precursor short fiber (b4-1) made of acrylonitrile polymer I and carbon powder, and a fibrillated carbon precursor containing acrylonitrile polymer I and carbon powder.
- a body fiber (b4-2) can be mentioned.
- the fiber (b4-2) can contain other polymers such as methacrylic resin.
- the carbon powder and acrylonitrile polymer I used for the fiber (b4) the carbon powder and polymer that can be used for the fiber (b1) and the fiber (b3) can be used in the same manner.
- the mixing ratio of the carbon short fiber (A) and the carbon precursor fiber (b) is preferably as follows. That is, it is preferable that the fiber (b4) is 50 to 300 parts by mass with respect to 100 parts by mass of the short carbon fiber (A).
- content of the carbon powder in a fiber (b4) is 10 mass parts or more with respect to 100 mass parts of polymers used from the point which the carbonization rate at the time of carbonization improves clearly.
- the upper limit of the concentration of the carbon powder is preferably as high as possible within the range where spinning is possible, but is preferably 60 parts by mass or less from the viewpoint of spinning stability at the fiber production stage.
- the fiber (b4-1) can be obtained by cutting a long fiber-like carbon precursor fiber made of the acrylonitrile polymer I and carbon powder into an appropriate length.
- the average fiber length of the fiber (b4-1) is preferably 2 mm or more and 20 mm or less from the viewpoint of dispersibility.
- the average fiber length can be measured with an optical microscope and an electron microscope.
- the average diameter of the fiber (b4-1) is preferably 5 ⁇ m or less from the viewpoint of suppressing breakage due to shrinkage during carbonization.
- the average fiber diameter (diameter) can be measured with an optical microscope and an electron microscope.
- the fiber (b4-1) can be produced from the corresponding raw materials (acrylonitrile polymer I and carbon powder) using the same method as the fiber (b1-1) described above.
- Fibrous carbon precursor fiber (b4-2) containing acrylonitrile polymer I and carbon powder examples include a fibrillar carbon precursor fiber (b4-2-1) composed of acrylonitrile-based polymer I and carbon powder, and acrylonitrile-based polymer I, carbon powder, and acrylonitrile. Mention may be made of fibrillar carbon precursor fibers (b4-2-2) comprising one or more polymers other than the polymer I.
- Examples of the fiber (b4-2-1) include a carbon precursor fiber (b4-2-1) containing carbon powder and having a structure in which a large number of fibrils are branched.
- Examples of the fiber (b4-2-2) include carbon precursor short fibers (b4-2-2-1) containing carbon powder and fibrillated by beating. These fibers can be produced from the corresponding raw materials using the same method as the above-described fiber (b3-2).
- the method for producing a porous electrode substrate of the present invention includes the following steps (1) and (2), and the volume shrinkage of the carbon precursor fiber (b) in step (2) is 83% or less. Good.
- the process (3) which entangles the precursor sheet can be included.
- a step (4) of heating and pressurizing the precursor sheet may be included between the step (1) and the step (2).
- the step (4) of heating and pressing the precursor sheet can be included between the step (3) and the step (2).
- a step (5) of oxidizing the heated and pressurized precursor sheet may be included between the step (4) and the step (2).
- ⁇ Process for producing precursor sheet (1) As a method for producing a precursor sheet, a wet method in which a short carbon fiber (A) and a carbon precursor fiber (b) are dispersed in a liquid medium to make paper, a short carbon fiber (A) in air, A paper making method such as a dry method in which the carbon precursor fiber (b) is dispersed and deposited is applicable. However, it is preferable to use a wet method from the viewpoint of high uniformity of the sheet.
- the carbon precursor fiber (b) is also used to help the short carbon fibers (A) to open into single fibers and prevent the opened single fibers from refocusing. Further, if necessary, wet papermaking can be performed using a binder.
- the binder has a role as a glue that holds the components together in a precursor sheet containing carbon short fibers (A) and carbon precursor fibers (b).
- the binder polyvinyl alcohol (PVA), polyvinyl acetate, or the like can be used.
- PVA polyvinyl alcohol
- polyvinyl alcohol is preferable because it has excellent binding power in the paper making process and the short carbon fibers (A) are less dropped.
- liquid medium in which the carbon short fibers (A) and the carbon precursor fibers (b) are dispersed examples include a medium in which the carbon precursor fibers (b) such as water and alcohol do not dissolve. Among these, it is preferable to use water from a viewpoint of productivity.
- Examples of the method of mixing the short carbon fiber (A) and the carbon precursor fiber (b) include a method of stirring and dispersing in water and a method of directly mixing these. From the viewpoint of uniform dispersion, diffusion and dispersion in water. The method of making it preferable is.
- the strength of the precursor sheet can be improved by mixing the short carbon fiber (A) and the carbon precursor fiber (b) and making a paper to produce the precursor sheet. Moreover, it can prevent that the carbon short fiber (A) peels from a precursor sheet
- the precursor sheet can be produced by either a continuous method or a batch method, but is preferably produced by a continuous method from the viewpoint of the productivity and mechanical strength of the precursor sheet.
- the basis weight of the precursor sheet may be 10 g / m 2 or more and 200 g / m 2 or less from the viewpoints of handling properties of the precursor sheet and gas permeability, conductivity, and handling properties when used as a porous electrode substrate. preferable. Moreover, it is preferable that the thickness of a precursor sheet
- the precursor sheet obtained from the step (1) can be carbonized as it is, and as described above, after forming the entangled structure (after the step (3)) or after the heat and pressure molding (step ( 4)
- the precursor sheet after the heat and pressure molding can be oxidized (after the step (5)) and the carbonization treatment can be performed.
- the mechanical strength and conductivity of the electrode substrate can be easily increased.
- the carbonization treatment is preferably performed in an inert gas in order to increase the conductivity of the obtained porous electrode substrate.
- the carbonization treatment is usually performed at a temperature of 1000 ° C. or higher.
- the temperature range for the carbonization treatment is preferably 1000 to 3000 ° C, more preferably 1000 to 2200 ° C.
- the time for performing the carbonization treatment is, for example, about 10 minutes to 1 hour.
- a pretreatment by firing in an inert atmosphere of about 300 to 800 ° C. can be performed before the carbonization treatment.
- the entanglement process for entanglement of the short carbon fibers (A) and the carbon precursor fibers (b) in the precursor sheet may be a method by which an entangled structure is formed, and can be performed by a known method.
- a mechanical entanglement method such as a needle punching method, a high pressure liquid injection method such as a water jet punching method, a high pressure gas injection method such as a steam jet punching method, or a combination thereof can be used.
- the high-pressure liquid injection method is preferable because breakage of the short carbon fibers (A) in the entanglement process can be easily suppressed and moderate entanglement can be easily obtained. This method will be described in detail below.
- a precursor sheet is placed on a support member having a smooth surface and, for example, a liquid columnar flow, a liquid fan-shaped flow, a liquid slit flow, or the like sprayed at a pressure of 1 MPa is applied to the precursor.
- This is a treatment method in which the short carbon fibers (A) and the carbon precursor fibers (b) in the sheet are entangled.
- the support member having a substantially smooth surface the pattern of the support member is not formed on the resulting entangled structure, and the ejected liquid is quickly removed as necessary. It can be selected and used. Specific examples thereof include 30-200 mesh wire nets, plastic nets or rolls. It is preferable from the viewpoint of productivity that the precursor sheet is manufactured on a support member having a substantially smooth surface, and then the high-pressure liquid injection treatment can be continuously performed because the precursor sheet is entangled.
- the liquid used for the high-pressure liquid jet treatment may be anything other than a solvent that dissolves the fibers constituting the precursor sheet, but it is usually preferable to use water or warm water.
- the hole diameter of each injection nozzle in the high-pressure liquid injection nozzle is preferably 0.01 mm or more and 1.0 mm or less, more preferably 0.05 mm or more and 0.3 mm or less from the viewpoint of obtaining a sufficient confounding effect. preferable.
- the distance between the nozzle injection hole and the laminate is preferably 0.5 cm or more and 5 cm or less.
- the pressure of the liquid is preferably 0.5 MPa or more, and more preferably 1.0 MPa or more.
- the confounding process may be performed in a single row or in a plurality of rows. When performing in a plurality of rows, it is effective to increase the pressure of the high-pressure liquid ejection processing in the second and subsequent rows rather than the first row.
- the entanglement process by high pressure liquid injection of the precursor sheet may be repeated a plurality of times. That is, after performing the precursor sheet high-pressure liquid injection treatment, the precursor sheet may be further laminated, and the high-pressure liquid injection treatment may be performed. An injection process may be performed. These operations may be repeated.
- the high pressure liquid injection nozzle having one or more rows of nozzle holes is vibrated in the width direction of the sheet, resulting in the formation of a dense structure of the sheet in the sheet forming direction. It is possible to easily suppress the formation of a streak-like locus pattern. By suppressing the streaky trajectory pattern in the sheet forming direction, the mechanical strength in the sheet width direction can be easily expressed. Further, when a plurality of high-pressure liquid jet nozzles having one or a plurality of rows of nozzle holes are used, the confounding structure precursor is controlled by controlling the frequency and the phase difference of the high-pressure liquid jet nozzles that vibrate in the width direction of the sheet. Periodic patterns appearing on the sheet can be easily suppressed.
- the precursor sheet is heated and pressed before the carbonization treatment. It is preferable. Any technique can be applied to the heat and pressure molding as long as the technique can uniformly heat and mold the precursor sheet. For example, a method of hot pressing by applying smooth rigid plates to both surfaces of the precursor sheet, a method of using a roll press device, and a continuous belt press device can be mentioned.
- a continuously manufactured precursor sheet is heat-press molded
- a method using a roll press device or a continuous belt press device is preferable. Thereby, the carbonization process can be performed continuously.
- the heating temperature in the heat and pressure molding is preferably less than 200 ° C. and more preferably 120 to 190 ° C. in order to effectively smooth the surface of the precursor sheet.
- the molding pressure is not particularly limited, but when the content ratio of the carbon precursor fiber (b) in the precursor sheet is large, the surface of the precursor sheet can be easily smoothed even if the molding pressure is low.
- the molding pressure is preferably 20 kPa or more and 10 MPa or less. If the pressing pressure is 10 MPa or less, it is easy to prevent the short carbon fibers (A) from being destroyed at the time of heat and pressure molding, and to prevent the porous electrode base material from becoming very dense. Can do.
- the time for heat and pressure molding can be, for example, 10 seconds to 10 minutes.
- the precursor sheet When the precursor sheet is sandwiched between two rigid plates, or heated and pressed with a roll press or continuous belt press, it is peeled off in advance so that carbon precursor fibers (b) do not adhere to the rigid plate or belt. It is preferable to apply an agent, or to sandwich a release paper between the precursor sheet and the rigid plate or belt.
- the heat-pressed precursor sheet is oxidized. It is preferable.
- the temperature for the oxidation treatment is preferably 200 ° C. or higher and lower than 300 ° C., more preferably 240 ° C. or higher and 290 ° C. or lower from the viewpoint of improving the carbonization rate.
- the oxidation treatment time can be, for example, 1 minute to 2 hours.
- oxidation treatment continuous oxidation treatment by direct pressure heating using a heated perforated plate or continuous oxidation treatment by intermittent direct pressure heating using a heating roll or the like is low in cost and short carbon fiber (A) Is preferable in that it can be easily bonded with the carbon precursor fiber (b).
- A carbon precursor fiber
- the porous electrode substrate of the present invention can be produced by, for example, the following method.
- the first method is a step (1) of producing a precursor sheet by dispersing the carbon short fibers (A) and the carbon precursor fibers (b) described above, and the precursor sheet is 1000 ° C. or higher. This is a method of sequentially performing the step (2) of carbonization treatment at the temperature.
- the second method is a method in which the step (1), the step (3) for forming the entangled structure by entanglement treatment of the precursor sheet obtained from the step (1), and the step (2) are sequentially performed.
- the third method includes steps (4) and (2) in which the precursor sheet obtained from step (1), step (3) and step (3) is heated and pressed at a temperature of less than 200 ° C. This is a sequential method.
- the fourth method is a method of sequentially performing the step (1), the step (4) of heating and pressing the precursor sheet obtained from the step (1) at a temperature of less than 200 ° C., and the step (2). .
- the fifth method includes a step (1), a step (3), a step (4), a step (5) of oxidizing and heating the precursor sheet at a temperature of 200 ° C. or higher and lower than 300 ° C., and a step ( This is a method of sequentially performing 2).
- the step (1), the step (4), the step (5) of oxidizing and heating the precursor sheet at a temperature of 200 ° C. or higher and lower than 300 ° C., and the step (2) are sequentially performed. Is the method.
- the gas permeability of the porous electrode substrate is measured according to ISO-5636-5, using a Gurley densometer to measure the time taken to pass 200 mL of air. The gas permeability (ml / hr / cm 2 / mmAq) was calculated.
- the thickness of the porous electrode base material was measured using a thickness measuring device dial thickness gauge (manufactured by Mitutoyo Corporation, trade name: 7321). The size of the probe was 10 mm in diameter, and the measurement pressure was 1.5 kPa.
- the electrical resistance (through-direction resistance) in the thickness direction of the porous electrode substrate is 10 mA / cm 2 when the porous electrode substrate is sandwiched between gold-plated copper plates and pressed from above and below the copper plate at 1 MPa.
- the resistance value when a current was passed at a current density of was measured from the following equation.
- Through-direction resistance (m ⁇ ⁇ cm 2 ) Measured resistance value (m ⁇ ) ⁇ Sample area (cm 2 )
- Content of carbon (B) The content of carbon (B) was calculated from the basis weight of the obtained porous electrode substrate and the basis weight of the carbon short fiber (A) used by the following formula.
- the volume shrinkage of the precursor fiber (b) is determined based on the basis weight of the obtained porous electrode base material, the basis weight of the short carbon fiber (A) used, the precursor fiber (b), and the porosity. Based on the true density of the electrode base material and the density of the short carbon fibers (A) and the precursor fibers (b) used, the following formula was used. The specific gravity was determined using a density gradient tube.
- volume shrinkage (%) of precursor fiber (b) (1 ⁇ (porous electrode substrate weight (g / m 2 )) ⁇ true density of porous electrode substrate (g / cm 3 ) ⁇ carbon short fiber ( A) basis weight (g / m 2 ) ⁇ density of short carbon fiber (A) (g / cm 3 )) / weight of precursor fiber (b) (g / m 2 ) ⁇ density of precursor fiber (b) ( g / cm 3 )) ⁇ 100.
- the obtained mixed solution (spinning stock solution) was extruded under nitrogen pressure of 0.1 MPa, and this spinning stock solution was discharged from a 12000 hole nozzle into a dimethylformamide aqueous solution having a concentration of 30% by mass and a temperature of 35 ° C. through a gear pump.
- the obtained coagulated fiber was washed and desolvated while being stretched 6 times in boiling water, and then the fiber length was cut to 3 mm, whereby an average fiber diameter of 5 ⁇ m consisting of an acrylonitrile-based polymer containing 95% by mass or more of acrylonitrile.
- Carbon precursor short fibers (b3-1-1) were obtained.
- the supply amount of the mixed solution was 36 ml / min, the supply pressure of water vapor was 350 kPa, and the mixture cell was ejected from the mixing cell outlet 6 into water at a temperature of 30 ° C.
- a carbon precursor fiber (b3-2-1-1) having the following was obtained.
- the obtained fibrillar carbon precursor fiber (b3-2-1-1) was measured by ISO-5267-2 pulp drainage test method (1) Canadian standard type, and the freeness was 175 ml. It was.
- dimethylacetamide was added so that the total polymer concentration was 25% by mass, and the mixture was stirred at room temperature for 60 minutes. The temperature was raised with a warm water jacket so that the temperature became 70 ° C., and the mixture was stirred for 60 minutes after reaching 70 ° C.
- the obtained spinning dope was heated to 80 ° C., and while being kept at that temperature, was quantitatively supplied to the spinning nozzle using a gear pump. Then, the total draw ratio is increased to 3.0 times by the wet spinning method in which the spinning solution is discharged and solidified from the nozzle base into a coagulation bath (adjusted so that dimethylacetamide is 30% by mass and water is 70% by mass). It was spun so that it might become.
- the obtained mixed solution was extruded under nitrogen pressure of 0.1 MPa, and this spinning solution was discharged from a 12000 hole nozzle into a dimethylformamide aqueous solution (concentration 30 mass%, temperature 35 ° C.) through a gear pump.
- Wet spinning The obtained coagulated fiber was washed and desolvated while being stretched 3 times in boiling water, then the fiber length was cut to 3 mm, and a disk refiner (manufactured by Kumagai Riki Kogyo Co., Ltd., trade name: KRK high concentration disk refiner,
- the carbon precursor short fibers (b3-2-2-1) fibrillated by beating were obtained by beating using a disc clearance of 0.3 mm and a rotational speed of 5000 rpm.
- Example 1 As carbon short fibers (A), a carbon precursor fiber having a structure in which 50 parts of a PAN-based carbon fiber having an average fiber diameter of 7 ⁇ m and an average fiber length of 3 mm and a large number of fibrils obtained in Production Example 2 are branched. 50 parts of (b3-2-1-1) was uniformly dispersed in water and sufficiently spread by a mixer. Then, using a standard square sheet machine (product name: No. 2555, manufactured by Kumagai Riki Kogyo Co., Ltd.), manually in a two-dimensional plane (250 mm long, horizontal) according to the ISO-5269-1 method. 250 mm) and dried to obtain a precursor sheet having a basis weight of 60 g / m 2 (step (1)). The dispersion state of the carbon short fibers (A) and the carbon precursor fibers (b3-2-1-1) having a structure in which a large number of fibrils were branched in the precursor sheet was good. The composition of the obtained precursor sheet is shown in Table 1.
- both sides of this precursor sheet were sandwiched between papers coated with a silicone release agent, and then subjected to pressure heating molding for 3 minutes under the conditions of 180 ° C. and 3 MPa in a batch press apparatus (step (4)).
- the pressure-heated precursor sheet was carbonized in a batch carbonization furnace at 2000 ° C. for 1 hour in a nitrogen gas atmosphere (step (2)) to obtain a porous electrode substrate. .
- the obtained porous electrode base material has almost no in-plane shrinkage at the time of carbonization treatment, the swell is as small as 2 mm or less, has sufficient handling properties, and the gas permeability, thickness, and penetration direction resistance are all It was good.
- the content of reticulated carbon (B) was 26%.
- the volume shrinkage of the precursor fiber (b) was 77%.
- the obtained porous electrode base material has confirmed that the carbon short fibers (A) disperse
- Example 2 After obtaining the precursor sheet in the same manner as in Example 1, and before performing the step (4), the same procedure as in Example 1 was performed, except that the step (3) of forming an entangled structure by entanglement treatment was performed.
- a porous electrode substrate was obtained.
- step (3) the following three water jet nozzles (the following three water jet nozzles) are first connected to a net drive unit and a net that is continuously rotated by connecting a flat woven mesh made of plastic net having a width of 60 cm and a length of 585 cm.
- a sheet-like material conveyance device was prepared in which a pressurized water jet treatment device equipped with nozzles a, b and c) was arranged.
- the precursor sheet is stacked on the net of the sheet-like material conveying apparatus, and the precursor water sheet is set at a pressurized water flow injection pressure of 1 MPa (nozzle a), a pressure of 2 MPa (nozzle b), and a pressure of 1 MPa (nozzle c).
- the entanglement process was added by passing nozzle a, nozzle b, and nozzle c in this order.
- Nozzle a hole diameter ⁇ (diameter) 0.15 mm ⁇ 501 holes, pitch in the width direction hole 1 mm (1001 holes / width 1 m), one line arrangement, nozzle effective width 500 mm.
- Nozzle b hole diameter ⁇ 0.15 mm ⁇ 501 holes, pitch in the width direction hole 1 mm (1001 holes / width 1 m), one line arrangement, nozzle effective width 500 mm.
- Nozzle c hole diameter ⁇ 0.15 mm ⁇ 1002 holes, width direction hole pitch 1.5 mm, three rows, row pitch 5 mm, nozzle effective width 500 mm.
- the obtained porous electrode substrate had almost no in-plane shrinkage during the carbonization treatment, the swell was as small as 2 mm or less, and the gas permeability, thickness, and penetration direction resistance were all good. Moreover, it has confirmed that the carbon short fibers (A) disperse
- Examples 3 and 4 In Examples 3 and 4, the amount of carbon short fiber (A) used, the amount of carbon precursor fiber (b3-2-1-1) having a structure in which a large number of fibrils are branched, and the basis weight of the precursor sheet are shown in Table 1.
- a porous electrode substrate was obtained in the same manner as in Example 2 except that the values shown in Table 2 were used. The obtained porous electrode substrate had almost no in-plane shrinkage during the carbonization treatment, the swell was as small as 2 mm or less, and the gas permeability, thickness, and penetration direction resistance were all good. Moreover, it has confirmed that the carbon short fibers (A) disperse
- Example 5 Short carbon fiber (A), short carbon precursor fiber (b3-1-1) obtained in Production Example 1, and carbon precursor fiber (b3-2-1) having a branched structure obtained in Production Example 2
- a porous electrode substrate was obtained in the same manner as in Example 2, except that the amount used and the basis weight of the precursor sheet were set to the values shown in Table 1.
- the obtained porous electrode substrate had almost no in-plane shrinkage during the carbonization treatment, the swell was as small as 2 mm or less, and the gas permeability, thickness, and penetration direction resistance were all good.
- distributed in the base material were joined by three-dimensional network carbon (B). The evaluation results are shown in Table 1.
- Example 6 Using carbon short fibers (A) and carbon precursor short fibers (b3-2-2-1) fibrillated by beating obtained in Production Example 3, the amounts used and the basis weight of the precursor sheet are shown in Table 1.
- a porous electrode substrate was obtained in the same manner as in Example 2 except that the values shown were used.
- the obtained porous electrode substrate had almost no in-plane shrinkage during the carbonization treatment, the swell was as small as 2 mm or less, and the gas permeability, thickness, and penetration direction resistance were all good.
- distributed in the base material were joined by three-dimensional network carbon (B). The evaluation results are shown in Table 1.
- Example 7 A porous electrode substrate was obtained in the same manner as in Example 2 except that the step (5) of oxidizing treatment was performed between the steps (4) and (2). Specifically, after both sides of the pressure-heat molded precursor sheet are sandwiched between stainless punching plates coated with a silicone-based release agent, the batch press apparatus is used under the conditions of 280 ° C. and 0.5 MPa. Oxidized for 1 minute. The obtained porous electrode substrate had almost no in-plane shrinkage during the carbonization treatment, the swell was as small as 2 mm or less, and the gas permeability, thickness, and penetration direction resistance were all good. Moreover, it has confirmed that the carbon short fibers (A) disperse
- Example 8 Porous electrode base material in the same manner as in Example 2 except that the heat and pressure molding (step (4)) was carried out in the order of steps (1), (3) and (2).
- the obtained porous electrode substrate had almost no in-plane shrinkage during the carbonization treatment, the swell was as small as 2 mm or less, and the gas permeability, thickness, and penetration direction resistance were all good.
- distributed in the base material were joined by three-dimensional network carbon (B). The evaluation results are shown in Table 1.
- the obtained porous electrode base material has almost no in-plane shrinkage during carbonization treatment, swell is as small as 2 mm or less, gas permeability and thickness are both good, and carbon dispersed in the base material Although it was confirmed that the short fibers (A) were joined by the three-dimensional network carbon (B), the volume shrinkage of the precursor fiber (b) was as high as 85%, and the penetration direction resistance was an example. Higher than 2.
- the evaluation results are shown in Table 1.
- the amount of steam supplied was determined by regulating the supply pressure with a pressure reducing valve.
- the amount of water vapor was measured by determining the increment of the water vapor amount from the nozzle shown in FIG.
- the nozzle has a Y-shaped solution discharge port 2, a cylindrical mixing cell unit 5 having a diameter of 2 mm and a length of 10 mm, and a water vapor channel 4 having a slit shape and an opening degree adjusted to 390 ⁇ m.
- the angle C formed by the center line of 1 (same as the discharge line A of the spinning dope) and the center line of the steam flow path 4 (same as the steam injection line B) was 60 degrees.
- the supply amount of the mixed liquid was 36 ml / min, the supply pressure of water vapor was 350 kPa, and the mixture cell was jetted into water at a temperature of 30 ° C.
- a mixed coagulated product of acrylonitrile polymer and carbon powder floating in the coagulation bath is collected, washed with water at room temperature overnight, and dehydrated to dehydrate the fibrillar carbon precursor fiber (b1- 2) was obtained.
- the freeness of the fibrillated carbon precursor fiber (b1-2) containing the obtained carbon powder was 90 ml.
- a disc refiner manufactured by Kumagai Riki Kogyo Co., Ltd., trade name: KRK high concentration disc refiner
- the slurry was beaten at a disc clearance of 0.3 mm and a rotational speed of 5000 rpm.
- a paper is made into a square having a basis weight of 30 g / m 2 and a side of 25 cm, and dried with a drum dryer (trade name: HP-124AP, manufactured by Hashima Co., Ltd.) at 130 ° C. for 3 minutes.
- a sheet was formed.
- seat was observed with the scanning electron microscope, it confirmed that the fiber form was a fibril form.
- Example 9 As short carbon fibers (A), fibril-like carbon precursor fibers (b1-b) containing 50 parts of PAN-based carbon fibers having an average fiber diameter of 7 ⁇ m and an average fiber length of 3 mm and the carbon powder obtained in Production Example 4. 2) 50 parts were uniformly dispersed in water and sufficiently opened by a mixer. After that, using a standard square sheet machine (product name: No. 2555, manufactured by Kumagai Riki Kogyo Co., Ltd.), manually in a two-dimensional plane (250 mm long, 250 mm wide) according to ISO-5269-1. ) And dried to obtain a precursor sheet having a basis weight of 60 g / m 2 (step (1)). The dispersion state of the short carbon fibers (A) and the fibrillar carbon precursor fibers (b1-2) containing carbon powder in the precursor sheet was good.
- both sides of this precursor sheet were sandwiched between papers coated with a silicone release agent, and then subjected to pressure heating molding for 3 minutes under the conditions of 180 ° C. and 3 MPa in a batch press apparatus (step (4)).
- the pressure-heated precursor sheet was carbonized in a batch carbonization furnace at 2000 ° C. for 1 hour in a nitrogen gas atmosphere (step (2)) to obtain a porous electrode substrate. .
- the obtained porous electrode base material has almost no in-plane shrinkage at the time of carbonization treatment, the swell is as small as 2 mm or less, has sufficient handling properties, and the gas permeability, thickness, and penetration direction resistance are all It was good.
- the content of reticulated carbon (B) including carbon powder was 44%.
- the volumetric shrinkage of the precursor fiber (b) was 51%.
- distributed in the two-dimensional plane contains the mesh
- the evaluation results are shown in Table 2.
- Example 10 and 11 The same as Example 9 except that the amount of fibrillar carbon precursor fiber (b1-2) containing carbon short fiber (A) and carbon powder and the basis weight of the precursor sheet were set to the values shown in Table 2.
- a porous electrode substrate was obtained.
- the obtained porous electrode substrate had almost no in-plane shrinkage during the carbonization treatment, the swell was as small as 2 mm or less, and the gas permeability, thickness, and penetration direction resistance were all good.
- distributed in the two-dimensional plane were joined by the network carbon (B) containing carbon powder.
- the evaluation results are shown in Table 2.
- Example 12 After sandwiching both sides of the pressure-heated precursor sheet with a stainless steel punching plate coated with a silicone mold release agent, oxidation treatment is performed for 1 minute under conditions of 280 ° C. and 0.5 MPa in a batch press apparatus ( A porous electrode substrate was obtained in the same manner as in Example 9 except that the step (5) was performed. The obtained porous electrode substrate had almost no in-plane shrinkage during the carbonization treatment, the swell was as small as 2 mm or less, and the gas permeability, thickness, and penetration direction resistance were all good. Moreover, it has confirmed that the carbon short fibers (A) disperse
- Example 13 A porous electrode substrate was obtained in the same manner as in Example 9 except that the heat and pressure molding (step (4)) was not performed.
- the obtained porous electrode substrate had almost no in-plane shrinkage during the carbonization treatment, the swell was as small as 2 mm or less, and the gas permeability, thickness, and penetration direction resistance were all good.
- distributed in the two-dimensional plane were joined by the network carbon (B) containing carbon powder.
- the evaluation results are shown in Table 2.
- Example 14 In the same manner as in Example 9, after obtaining the precursor sheet and before performing the step (4), the step (3) for forming the entangled structure by performing the entanglement process was performed. Thus, a porous electrode substrate was obtained. Specifically, in the step (3), first, the three nets shown in the second embodiment are connected to a net driving unit and a net that is continuously rotated by connecting a plain mesh made of plastic net having a width of 60 cm and a length of 585 cm in a belt shape. A sheet-like material conveyance device was prepared in which a pressurized water jet treatment device equipped with water jet nozzles (nozzles a, b and c) was arranged.
- the precursor sheet is stacked on the net of the sheet-like material conveying apparatus, and the precursor water sheet is set at a pressurized water flow injection pressure of 1 MPa (nozzle a), a pressure of 2 MPa (nozzle b), and a pressure of 1 MPa (nozzle c).
- the entanglement process was added by passing nozzle a, nozzle b, and nozzle c in this order.
- the obtained porous electrode base material had almost no in-plane shrinkage during the carbonization treatment, and the gas permeability, thickness, and penetration direction resistance were all good. Moreover, it has confirmed that the carbon short fibers (A) disperse
- Example 15 Carbon powder and acrylonitrile polymer are included in amounts of acrylonitrile polymer, carbon black carbon powder (trade name: # 3230B, manufactured by Mitsubishi Chemical Corporation) and dimethylacetamide as 134 g, 41 g, and 835 g, respectively.
- a fibrillar carbon precursor fiber (b1-2) containing carbon powder was obtained in the same manner as in Production Example 4, except that a spinning dope was prepared and the water supply pressure was 450 kPa. Further, a porous electrode substrate was obtained in the same manner as in Example 9 except that the fibrillar carbon precursor fiber (b1-2) containing this carbon powder was used.
- the obtained porous electrode substrate had almost no in-plane shrinkage during the carbonization treatment, the swell was as small as 2 mm or less, and the gas permeability, thickness, and penetration direction resistance were all good. Moreover, it has confirmed that the carbon short fibers (A) disperse
- Example 16 A fibrillar carbon precursor fiber (b1-2) containing carbon powder was obtained in the same manner as in Example 15 except that acetylene black (trade name: Denka Black, manufactured by Electrochemical Co., Ltd.) was used as the carbon powder. . Further, a porous electrode substrate was obtained in the same manner as in Example 9 except that the fibrillar carbon precursor fiber (b1-2) containing this carbon powder was used. The obtained porous electrode substrate had almost no in-plane shrinkage during the carbonization treatment, the swell was as small as 2 mm or less, and the gas permeability, thickness, and penetration direction resistance were all good. Moreover, it has confirmed that the carbon short fibers (A) disperse
- Example 17 A fibrillated carbon precursor fiber (b1-2) containing carbon powder was obtained in the same manner as in Production Example 4 except that the acrylonitrile polymer used in Production Example 3 was used as the acrylonitrile polymer.
- the fibrillar carbon precursor fiber (b1-2) is a fibrillar carbon precursor fiber composed of carbon powder and acrylonitrile-based polymer I.
- a porous electrode substrate was obtained in the same manner as in Example 14 except that this fibrillar carbon precursor fiber (b1-2) was used.
- the obtained porous electrode substrate had almost no in-plane shrinkage during the carbonization treatment, the swell was as small as 2 mm or less, and the gas permeability, thickness, and penetration direction resistance were all good.
- the evaluation results are shown in Table 2.
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Abstract
Description
本発明の製造方法により得られる多孔質電極基材は、炭素短繊維(A)同士が、炭素前駆体繊維(b)に由来する炭素(B)によって接合された構造を有する。この多孔質電極基材は、分散された炭素短繊維(A)と、炭素(B)とからなることができる。本発明の多孔質電極基材は、固体高分子型燃料電池に用いる固体高分子型燃料電池用多孔質電極基材として使用することができる。
前駆体シートに分散させた炭素短繊維(A)は、多孔質電極基材を構成する繊維の1つとなる。炭素短繊維(A)としては、例えば、ポリアクリロニトリル系炭素繊維(以下「PAN系炭素繊維」と称する)、ピッチ系炭素繊維、レーヨン系炭素繊維等の炭素繊維を所定の繊維長に切断したものが挙げられる。多孔質電極基材の機械的強度の観点から、PAN系炭素繊維が好ましい。
炭素(B)は、炭素短繊維(A)同士を接合している炭素である。その炭素(B)は、接合部において屈曲状または湾曲状になっている状態で存在している。ハンドリング性や導電性の観点から、炭素(B)は網目状となっていることが好ましく、炭素(B)は3次元網目状となっていることがさらに好ましい。
本発明において、炭素(B)が3次元網目状構造を形成しているか否かは、シート状の測定対象物(多孔質電極基材)の断面観察を行い、断面における炭素(B)と、この測定対象物のシート面との角度を測定することにより判定できる。なお、断面観察を行う断面は、シート状の測定対象物のシート面に対して垂直方向に切断した際の断面である。
本発明では、工程(1)によって前駆体シートを製造することができる。この前駆体シートは、多孔質電極基材の前駆体となるシートである。工程(1)で得られる前駆体シートは、炭素短繊維(A)と、炭素前駆体繊維(b)とが分散した前駆体シートである。前駆体シートは、炭素短繊維(A)と、炭素前駆体繊維(b)とからなることができる。また、この前駆体シートを焼成(炭素化処理)した際の、焼成による炭素前駆体繊維(b)の体積収縮率は、ハンドリング性や導電性、生産性の観点から、83%以下とする。
(i) 炭素短繊維(A)と、炭素粉を含有する炭素前駆体繊維(b1)とが分散した前駆体シート
(i-1)炭素短繊維(A)と、炭素粉を含有する炭素前駆体短繊維(b1-1)とが分散した前駆体シート
(i-2) 炭素短繊維(A)と、炭素粉を含有するフィブリル状炭素前駆体繊維(b1-2)とが分散した前駆体シート
(ii) 炭素短繊維(A)と、フィブリル状炭素前駆体繊維(b2)とが分散した前駆体シート
(iii) 炭素短繊維(A)と、アクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体を含む炭素前駆体繊維(b3)とが分散した前駆体シート
(iii-1) 炭素短繊維(A)と、アクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体を含む炭素前駆体短繊維(b3-1)、およびアクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体を含むフィブリル状炭素前駆体繊維(b3-2)のうちの一方、または両方とが分散した前駆体シート
(iii-1-1) 炭素短繊維(A)と、アクリロニトリル単位を95質量%以上含むアクリロニトリル系重合体からなる炭素前駆体短繊維(b3-1-1)、およびアクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体を含むフィブリル状炭素前駆体繊維(b3-2)のうちの一方、または両方とが分散した前駆体シート
(iv) 炭素短繊維(A)と、
アクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体及び炭素粉を含む炭素前駆体繊維(b4)と
が分散した前駆体シート
(iv-1) 炭素短繊維(A)と、
アクリロニトリル単位を95質量%以上含むアクリロニトリル系重合体及び炭素粉からなる炭素前駆体短繊維(b4-1)、ならびにアクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体及び炭素粉を含むフィブリル状炭素前駆体繊維(b4-2)のうちの一方、または両方と
が分散した前駆体シート
以下に、多孔質電極基材および前駆体シートのうちの一方、または両方を構成する各繊維について説明する。
本発明では、ハンドリング性や導電性、生産性の観点から、工程(2)による炭素前駆体繊維(b)の体積収縮率を83%以下とする。炭素前駆体繊維(b)の体積収縮率は、60%以下がより好ましい。また、工程(2)による炭素前駆体繊維(b)の体積収縮率は小さければ小さいほど良い。
(式1中、bVは炭素前駆体繊維(b)の体積を表し、BVは炭素(B)の体積を表す)。
(I) 炭素粉を含有する炭素前駆体繊維(b1)
(I-1) 炭素粉を含有する炭素前駆体短繊維(b1-1)
(I-2) 炭素粉を含有するフィブリル状炭素前駆体繊維(b1-2)
(II) フィブリル状炭素前駆体繊維(b2)
(III) アクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体を含む炭素前駆体繊維(b3)
(III-1) アクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体を含む炭素前駆体短繊維(b3-1)
(III-1-1) アクリロニトリル単位を95質量%以上含むアクリロニトリル系重合体からなる炭素前駆体短繊維(b3-1-1)
(III-2) アクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体を含むフィブリル状炭素前駆体繊維(b3-2)
(III-2-1) アクリロニトリル単位を95質量%以上含むアクリロニトリル系重合体からなるフィブリル状炭素前駆体繊維(b3-2-1)
(IV) アクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体、及び炭素粉を含む炭素前駆体繊維(b4)
(IV-1) アクリロニトリル単位を95質量%以上含むアクリロニトリル系重合体及び炭素粉からなる炭素前駆体短繊維(b4-1)
(IV-2) アクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体、及び炭素粉を含むフィブリル状炭素前駆体繊維(b4-2)
(IV-2-1) アクリロニトリル単位を95質量%以上含むアクリロニトリル系重合体及び炭素粉からなるフィブリル状炭素前駆体繊維(b4-2-1)
<(I)炭素粉を含有する炭素前駆体繊維(b1)>
炭素粉を含有する炭素前駆体繊維(b1)は、炭素前駆体繊維の繊維1本1本の中に炭素粉が含有されている。炭素前駆体繊維中の炭素粉の分散状態は特に限定されず、繊維に均一に分散していても、芯部または繊維表面部に局在していても良い。炭素粉を含有する炭素前駆体繊維(b1)としては、例えば、炭素粉を含有する炭素前駆体短繊維(b1-1)および炭素粉を含有するフィブリル状炭素前駆体繊維(b1-2)のうちの一方、または両方を用いることができる。
炭素粉を含有する炭素前駆体短繊維(b1-1)は、炭素粉を含む長繊維状の炭素前駆体繊維を適当な長さにカットしたものであることができる。
炭素粉を含有するフィブリル状炭素前駆体繊維(b1-2)は、例えば特許第4409211号公報に例示されている。具体的には、直径100μm以下(例えば、0.1~30μm程度)の繊維状の幹より直径が数μm以下(例えば0.1~3μm)のフィブリルが多数分岐した構造を有し、炭素粉を含有する炭素前駆体繊維が挙げられる。このフィブリル状炭素前駆体繊維(b1-2)を用いることにより、前駆体シート中で炭素短繊維(A)と炭素粉を含有するフィブリル状炭素前駆体繊維(b1-2)が良く絡み合い、ハンドリング性と機械的強度の優れた前駆体シートを得ることが容易となる。炭素粉を含有するフィブリル状炭素前駆体繊維(b1-2)の濾水度は、一般的に濾水度が小さいフィブリル状繊維を用いると前駆体シートの機械的強度が向上するが、多孔質電極基材のガス透気度が低下する傾向となる。
フィブリル状炭素前駆体繊維(b2)としては、例えば、炭素粉を含有するフィブリル状炭素前駆体繊維、アクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体を含むフィブリル状炭素前駆体繊維、及びこのアクリロニトリル系重合体と炭素粉とを含むフィブリル状炭素前駆体繊維を挙げることができる。これらのフィブリル状炭素前駆体繊維(b2)は、それぞれ繊維(b1-2)、繊維(b3-2)及び繊維(b4-2)と同じものであり、詳細については各繊維において説明する。
炭素前駆体繊維(b3)は、繊維を作製する際に用いる紡糸原液に、アクリロニトリル単位を95質量%以上含有するアクリル系重合体を用いるため、炭素化時の炭素化率が高くなる。
炭素前駆体短繊維(b3-1)としては、例えば、アクリロニトリル系重合体Iからなる炭素前駆体短繊維(b3-1-1)を用いることができる。また、炭素前駆体短繊維(b3-1)は、炭素粉を含有することができる。なお、炭素粉を含有する炭素前駆体繊維(b3)については、炭素前駆体繊維(b4)において説明する。
フィブリル状炭素前駆体繊維(b3-2)としては、例えば以下のものを用いることができる。
(b3-2-1-1):直径100μm以下の繊維状の幹より、直径が数μm以下(例えば0.1~3μm)のフィブリルが多数分岐した構造を有する炭素前駆体繊維
(b3-2-2):アクリロニトリル系重合体Iと、アクリロニトリル系重合体I以外の1種以上の重合体(例えば、メタクリル樹脂)とからなるフィブリル状炭素前駆体繊維
(b3-2-2-1):叩解によってフィブリル化した炭素前駆体短繊維
これらのフィブリル状炭素前駆体繊維(b3-2)を用いることにより、前駆体シート中で炭素短繊維(A)とフィブリル状炭素前駆体繊維(b3-2)が良く絡み合い、ハンドリング性と機械的強度の優れた前駆体シートを得ることが容易となる。
上述したように、繊維(b3-2-1-1)は直径100μm以下の繊維状の幹より、直径が数μm以下(例えば0.1~3μm)のフィブリルが多数分岐した構造を有する炭素前駆体繊維である。繊維(b3-2-1-1)は、アクリロニトリルを95質量%以上含有するアクリロニトリル系重合体からなることができる。また、この繊維(b3-2-1-1)に用いられるポリマーは、アクリロニトリルを95質量%以上含み、炭素化処理工程における残存質量が30質量%以上であるアクリロニトリル系重合体であることが好ましい。
繊維(b3-2-2-1)は、長繊維状の易割繊性海島複合繊維を適当な長さにカットしたものを、リファイナーやパルパーなどによって叩解しフィブリル化したものであることができる。長繊維状の易割繊性海島複合繊維は、共通の溶剤に溶解し、かつ非相溶性である2種類以上の異種ポリマー(少なくとも1種類は、アクリロニトリルを95質量%以上含有するアクリロニトリル系重合体)を用いて製造することができる。また、少なくとも1種類のポリマーは、アクリロニトリルを95質量%以上含み、炭素化処理する工程における残存質量が30質量%以上であるアクリロニトリル系重合体であることが好ましい。
上記炭素前駆体繊維(b4)は、繊維1本1本の中に炭素粉が含有されている。炭素前駆体繊維中の炭素粉の分散状態は特に限定されず、繊維に均一に分散していても、芯部または繊維表面部に局在していても良い。この繊維(b4)としては、例えば、アクリロニトリル系重合体Iと、炭素粉とからなる炭素前駆体短繊維(b4-1)、及びアクリロニトリル系重合体Iと、炭素粉とを含むフィブリル状炭素前駆体繊維(b4-2)を挙げることができる。なお、繊維(b4-2)は、メタクリル樹脂等の他のポリマーを含むことができる。繊維(b4)に用いる炭素粉及びアクリロニトリル系重合体Iは、繊維(b1)や繊維(b3)に用いることができる炭素粉及び重合体をそれぞれ同様に使用することができる。
繊維(b4-1)は、アクリロニトリル系重合体I及び炭素粉からなる長繊維状の炭素前駆体繊維を適当な長さにカットしたものであることができる。繊維(b4-1)の平均繊維長は、分散性の点から、2mm以上20mm以下が好ましい。なお、平均繊維長は、光学顕微鏡および電子顕微鏡により測定することができる。また、繊維(b4-1)の平均直径は、炭素化時の収縮による破断を抑制する観点から5μm以下であることが好ましい。なお、平均繊維径(直径)は、光学顕微鏡および電子顕微鏡により測定することができる。
繊維(b4-1)は、上述した繊維(b1-1)と同様の方法を用いて、対応する原料(アクリロニトリル系重合体I及び炭素粉)から作製することができる。
繊維(b4-2)としては、例えば、アクリロニトリル系重合体Iと炭素粉とからなるフィブリル状炭素前駆体繊維(b4-2-1)、及び、アクリロニトリル系重合体Iと、炭素粉と、アクリロニトリル系重合体I以外の1種以上の重合体とからなるフィブリル状炭素前駆体繊維(b4-2-2)を挙げることができる。
本発明の多孔質電極基材の製造方法は、以下の工程(1)と工程(2)を含み、工程(2)による炭素前駆体繊維(b)の体積収縮率が83%以下であればよい。
(1)炭素短繊維(A)と、炭素前駆体繊維(b)とが分散した前駆体シートを製造する工程(1)。
(2)前記前駆体シートを炭素化処理する工程(2)。
前駆体シートの製造方法としては、液体の媒体中に炭素短繊維(A)と、炭素前駆体繊維(b)とを分散させて抄造する湿式法、空気中に炭素短繊維(A)と、炭素前駆体繊維(b)とを分散させて降り積もらせる乾式法、などの抄紙方法を適用できる。しかし、シートの均一性が高いという観点から、湿式法を用いることが好ましい。
工程(1)より得られた前駆体シートは、そのまま炭素化処理することができ、また上述したように、交絡構造を形成した後(工程(3)後)や加熱加圧成型後(工程(4)後)に炭素化処理することもでき、加熱加圧成型後の前駆体シートを酸化処理した後(工程(5)後)に炭素化処理することもできる。炭素短繊維(A)を炭素前駆体繊維(b)で接合させ、かつ炭素前駆体繊維(b)を炭素化して炭素(B)(例えば、網目状炭素)とすることより、得られる多孔質電極基材の機械的強度および導電性を容易に高くすることができる。
前駆体シート中の炭素短繊維(A)と炭素前駆体繊維(b)とを交絡させる交絡処理は、交絡構造が形成される方法であればよく、公知の方法で実施できる。例えば、ニードルパンチング法などの機械交絡法、ウォータージェットパンチング法などの高圧液体噴射法、スチームジェットパンチング法などの高圧気体噴射法、或いはこれらの組み合わせによる方法を用いることができる。交絡工程での炭素短繊維(A)の破断を容易に抑制でき、かつ適度な交絡性が容易に得られるという点から、高圧液体噴射法が好ましい。以下に、この方法について詳しく説明する。
高圧液体噴射処理法は、表面が平滑な支持部材上に前駆体シートを載せ、例えば、1MPaの圧力で噴射される液体柱状流、液体扇形流、液体スリット流等を作用させることによって、前駆体シート中の炭素短繊維(A)と炭素前駆体繊維(b)とを交絡させる処理方法である。ここで、実質的に表面平滑な支持部材としては、支持部材の模様が、得られる交絡構造体に形成されることなく、かつ噴射された液体が速やかに除かれるようなものから必要に応じて選択して用いることができる。その具体例としては30~200メッシュの金網又はプラスチックネット或いはロール等を挙げることができる。実質的に表面平滑な支持部材上で前駆体シートを製造した後、高圧液体噴射処理することが、交絡構造前駆体シートを連続的に製造でき、生産性の観点から好ましい。
炭素短繊維(A)を炭素前駆体繊維(b)で接合させ、かつ多孔質電極基材の厚みムラを低減させるという観点から、炭素化処理の前に、前駆体シートを加熱加圧成型することが好ましい。加熱加圧成型は、前駆体シートを均等に加熱加圧成型できる技術であれば、いかなる技術も適用できる。例えば、前駆体シートの両面に平滑な剛板を当てて熱プレスする方法、ロールプレス装置、連続ベルトプレス装置を用いる方法が挙げられる。
炭素短繊維(A)を前駆体繊維(b)で良好に接合させ、かつ炭素前駆体繊維(b)の炭素化率を向上させるという観点から、加熱加圧成型した前駆体シートを酸化処理することが好ましい。酸化処理の温度は、炭素化率を向上させる観点から200℃以上300℃未満とすることが好ましく、240℃以上290℃以下とすることがより好ましい。酸化処理の時間は、例えば1分間~2時間とすることができる。
多孔質電極基材のガス透気度は、ISO-5636-5に準拠し、ガーレーデンソメーターを使用して200mLの空気が透過するのにかかった時間を測定し、ガス透気度(ml/hr/cm2/mmAq)を算出した。
多孔質電極基材の厚みは、厚み測定装置ダイヤルシックネスゲージ((株)ミツトヨ製、商品名:7321)を使用して測定した。測定子の大きさは直径10mmで、測定圧力は1.5kPaとした。
多孔質電極基材の厚さ方向の電気抵抗(貫通方向抵抗)は、金メッキした銅板に多孔質電極基材を挟み、銅板の上下から1MPaで加圧し、10mA/cm2の電流密度で電流を流したときの抵抗値を測定し、次式より求めた。
貫通方向抵抗(mΩ・cm2)=測定抵抗値(mΩ)×試料面積(cm2)
(4)炭素(B)の含有率
炭素(B)の含有率は、得られた多孔質電極基材の目付と、使用した炭素短繊維(A)の目付とから、次式より算出した。
炭素(B)の含有率(%)=[多孔質電極基材目付(g/m2)-炭素短繊維(A)目付(g/m2)]÷多孔質電極基材目付(g/m2)×100。
多孔質電極基材のうねりの指標として、平板上に縦250mm横250mmの多孔質電極基材を静置した際の、多孔質電極基材の高さの最大値と最小値の差を算出した。
前駆体繊維(b)の炭素化率は、得られた多孔質電極基材の目付と、使用した炭素短繊維(A)、前駆体繊維(b)の目付とから、次式より算出した。
前駆体繊維(b)の炭素化率(%)=[多孔質電極基材目付(g/m2)-炭素短繊維(A)目付(g/m2)]÷前駆体繊維(b)の目付(g/m2)×100。
前駆体繊維(b)の体積収縮率は、以下の式1より算出した。
体積収縮率(%)=((bV-BV)/bV)×100 ・・・式1
(bVは前駆体繊維(b)の体積を表し、BVは炭素(B)の体積を表す)。
前駆体繊維(b)の体積収縮率(%)=(1-(多孔質電極基材目付(g/m2)×多孔質電極基材の真密度(g/cm3)-炭素短繊維(A)目付(g/m2)×炭素短繊維(A)の密度(g/cm3))/前駆体繊維(b)の目付(g/m2)×前駆体繊維(b)の密度(g/cm3))×100。
水系懸濁重合法により合成したアクリロニトリル/アクリルアミド/メタクリル酸=97/2.5/0.5(質量比)の組成を有する重量平均分子量140000のアクリロニトリル系重合体250gをジメチルアセトアミド750gにスリーワンモータを用いて混合溶解させ、紡糸原液を調製した。次いで得られた混合液(紡糸原液)を0.1MPaの窒素加圧下で押し出し、ギアポンプを通して、この紡糸原液を12000ホールのノズルより濃度30質量%、温度35℃のジメチルホルムアミド水溶液中に吐出し、湿式紡糸した。得られた凝固繊維を沸水中で6倍延伸しながら洗浄及び脱溶剤したのち、繊維長を3mmに切断することで、アクリロニトリルを95質量%以上含有するアクリロニトリル系重合体からなる平均繊維径5μmの炭素前駆体短繊維(b3-1-1)を得た。
水系懸濁重合法により合成したアクリロニトリル/アクリルアミド/メタクリル酸=97/2.5/0.5(質量比)の組成を有する重量平均分子量140000のアクリロニトリル系重合体150gをジメチルアセトアミド850gにスリーワンモーターを用いて混合溶解させ、紡糸原液を調製した。次いで得られた混合液を0.1MPaの窒素加圧下で押し出し、ギアポンプを用いて図1に示したノズルの流路1へ定量供給を行なうと同時に水蒸気を流入口3から水蒸気流路4に供給した。水蒸気供給量は減圧弁により供給圧力を規定することにより行なった。Y字型の溶液吐出口2、直径が2mm、長さが10mmの円筒状の混合セル5、水蒸気流路4がスリット状で開度を390μmに調整し、溶液流路の中心線Aとスリットの中心線Bとのなす角度Cが60度になるように製作した。ノズルを用い、混合液の供給量を36ml/min、水蒸気の供給圧を350kPaとし、混合セル出口6から温度30℃の水中へ噴出した。凝固浴中に浮遊したアクリロニトリル系重合体を捕集し、更に室温の水で一晩洗浄を行い、脱水することでアクリロニトリルを95質量%以上含有するアクリロニトリル系重合体からなるフィブリルが多数分岐した構造を有する炭素前駆体繊維(b3-2-1-1)を得た。この得られたフィブリル状炭素前駆体繊維(b3-2-1-1)をISO-5267-2のパルプ濾水度試験法(1)カナダ標準型で測定したところ、濾水度が175mlであった。
水系懸濁重合法により合成したアクリロニトリル/アクリルアミド/メタクリル酸=97/2.5/0.5(質量比)の組成を有する重量平均分子量140000のアクリロニトリル系重合体200gをジメチルアセトアミド600gにスリーワンモーターにて混合溶解させ、アクリロニトリル系重合体紡糸原液を調製した。また、ポリメタクリル酸メチル200gをジメチルアセトアミド600gにスリーワンモーターにて混合溶解させ、ポリメタクリル酸メチル紡糸原液を調製した。
炭素短繊維(A)として、平均繊維径が7μmであり、平均繊維長が3mmであるPAN系炭素繊維50部と、製造例2で得られたフィブリルが多数分岐した構造を有する炭素前駆体繊維(b3-2-1-1)50部とを水中に均一に分散させて、ミキサーにより十分に開繊させた。その後、標準角型シートマシン(熊谷理機工業(株)製、商品名:No.2555)を用いて、ISO-5269-1法に準拠して、手動で二次元平面内(縦250mm、横250mm)に分散させ、乾燥させることで、目付が60g/m2の前駆体シートを得た(工程(1))。なお、前駆体シートにおける炭素短繊維(A)、およびフィブリルが多数分岐した構造を有する炭素前駆体繊維(b3-2-1-1)の分散状態は、良好であった。得られた前駆体シートの組成を表1に示す。
実施例1と同様にして前駆体シートを得たのち、工程(4)を行う前に、交絡処理して交絡構造を形成する工程(3)を行った以外は、実施例1と同様にして多孔質電極基材を得た。工程(3)では具体的に、まず、ネット駆動部及び幅60cm×長さ585cmのプラスチックネット製平織メッシュをベルト状につなぎあわせて連続的に回転させるネットに下記の3本のウォータージェットノズル(ノズルa、bおよびc)を備えた加圧水流噴射処理装置を配置したシート状物搬送装置を用意した。ついで、このシート状物搬送装置のネット上にこの前駆体シートを積載し、加圧水流噴射圧力を1MPa(ノズルa)、圧力2MPa(ノズルb)、圧力1MPa(ノズルc)として、前駆体シートをノズルa、ノズルb、ノズルcの順で通過させて交絡処理を加えた。
ノズルa:孔径φ(直径)0.15mm×501孔、幅方向孔間ピッチ1mm(1001孔/幅1m)、1列配置、ノズル有効幅500mm。
ノズルb:孔径φ0.15mm×501孔、幅方向孔間ピッチ1mm(1001孔/幅1m)、1列配置、ノズル有効幅500mm。
ノズルc:孔径φ0.15mm×1002孔、幅方向孔間ピッチ1.5mm、3列配置、列間ピッチ5mm、ノズル有効幅500mm。
実施例3および4では、炭素短繊維(A)の使用量、フィブリルが多数分岐した構造を有する炭素前駆体繊維(b3-2-1-1)の使用量および前駆体シートの目付を表1に示す値としたこと以外は、実施例2と同様にして、多孔質電極基材を得た。得られた多孔質電極基材は、炭素化処理時における面内の収縮がほとんどなく、うねりも2mm以下と小さく、ガス透気度、厚みおよび貫通方向抵抗はいずれも良好であった。また、基材中に分散した炭素短繊維(A)同士が、3次元網目状炭素(B)によって接合されていることが確認できた。評価結果を表1にそれぞれ示す。
炭素短繊維(A)と、製造例1で得られた炭素前駆体短繊維(b3-1-1)、製造例2で得られた分岐した構造を有する炭素前駆体繊維(b3-2-1-1)を用い、それぞれの使用量および前駆体シートの目付を表1に示す値としたこと以外は、実施例2と同様にして、多孔質電極基材を得た。得られた多孔質電極基材は、炭素化処理時における面内の収縮がほとんどなく、うねりも2mm以下と小さく、ガス透気度、厚みおよび貫通方向抵抗はいずれも良好であった。また、基材中に分散した炭素短繊維(A)同士が、3次元網目状炭素(B)によって接合されていることが確認できた。評価結果を表1に示す。
炭素短繊維(A)と製造例3で得られた叩解によってフィブリル化した炭素前駆体短繊維(b3-2-2-1)を用い、それぞれの使用量および前駆体シートの目付を表1に示す値としたこと以外は、実施例2と同様にして、多孔質電極基材を得た。得られた多孔質電極基材は、炭素化処理時における面内の収縮がほとんどなく、うねりも2mm以下と小さく、ガス透気度、厚みおよび貫通方向抵抗はいずれも良好であった。また、基材中に分散した炭素短繊維(A)同士が、3次元網目状炭素(B)によって接合されていることが確認できた。評価結果を表1に示す。
工程(4)と(2)との間に、酸化処理する工程(5)を行った以外は、実施例2と同様にして、多孔質電極基材を得た。具体的には、加圧加熱成型された前駆体シートの両面を、シリコーン系離型剤をコートしたステンレスパンチングプレートで挟んだ後、バッチプレス装置にて、280℃、0.5MPaの条件下で1分間酸化処理した。得られた多孔質電極基材は、炭素化処理時における面内の収縮がほとんどなく、うねりも2mm以下と小さく、ガス透気度、厚みおよび貫通方向抵抗はいずれも良好であった。また、基材中に分散した炭素短繊維(A)同士が、3次元網目状炭素(B)によって接合されていることが確認できた。評価結果を表1に示す。
加熱加圧成型(工程(4))を実施せずに、工程(1)、(3)および(2)の順で行ったこと以外は、実施例2と同様にして、多孔質電極基材を得た。得られた多孔質電極基材は、炭素化処理時における面内の収縮がほとんどなく、うねりも2mm以下と小さく、ガス透気度、厚みおよび貫通方向抵抗はいずれも良好であった。また、基材中に分散した炭素短繊維(A)同士が、3次元網目状炭素(B)によって接合されていることが確認できた。評価結果を表1に示す。
アクリロニトリル系重合体として水系懸濁重合法により合成したアクリロニトリル/酢酸ビニル=93/7(質量比)の組成を有する重量平均分子量130000のアクリロニトリル系重合体を用いた以外は製造例2と同様にしてフィブリルが多数分岐した構造を有する炭素前駆体繊維を得た。さらに、繊維(b3-2-1-1)の代わりにこのフィブリルが多数分岐した構造を有する炭素前駆体繊維を用いたこと以外は、実施例2と同様にして、多孔質電極基材を得た。得られた多孔質電極基材は、炭素化処理時における面内の収縮がほとんどなく、うねりも2mm以下と小さく、ガス透気度、厚みはいずれも良好であり、基材中に分散した炭素短繊維(A)同士が、3次元網目状炭素(B)によって接合されていることが確認できたが、前駆体繊維(b)の体積収縮率は85%と高く、貫通方向抵抗は実施例2と比較して高くなった。評価結果を表1に示す。
水系懸濁重合法により合成したアクリロニトリル/酢酸ビニル=93/7(質量比)の組成を有する質量平均分子量140000のアクリロニトリル系重合体117gと、炭素粉であるカーボンブラック(三菱化学株式会社製、商品名:♯3230B)83gとをジメチルアセトアミド800gにスリーワンモーターにて混合溶解させ、炭素粉とアクリロニトリル系重合体とを含む紡糸原液を調製した。次いで得られた混合液を0.1MPaの窒素加圧下で押し出し、ギアポンプを用いて図1に示したノズルの原液流路1へ定量供給を行なうと同時に水蒸気を流入口3から水蒸気流路4に供給した。
炭素短繊維(A)として、平均繊維径が7μmであり、平均繊維長が3mmであるPAN系炭素繊維50部と製造例4で得られた炭素粉を含むフィブリル状炭素前駆体繊維(b1-2)50部を水中に均一に分散させて、ミキサーにより十分に開繊させた。その後、標準角型シートマシン(熊谷理機工業(株)製、商品名:No.2555)を用いて、ISO-5269-1に準拠して、手動で二次元平面内(縦250mm、横250mm)に分散させ、乾燥させることで、目付が60g/m2の前駆体シートを得た(工程(1))。なお、前駆体シートにおける炭素短繊維(A)、および炭素粉を含むフィブリル状炭素前駆体繊維(b1-2)の分散状態は、良好であった。
炭素短繊維(A)及び炭素粉を含むフィブリル状炭素前駆体繊維(b1-2)の使用量と、前駆体シートの目付とを表2に示す値としたこと以外は、実施例9と同様にして、多孔質電極基材を得た。得られた多孔質電極基材は、炭素化処理時における面内の収縮がほとんどなく、うねりも2mm以下と小さく、ガス透気度、厚みおよび貫通方向抵抗はいずれも良好であった。また、2次元平面内に分散した炭素短繊維(A)同士が、炭素粉を含む網目状炭素(B)によって接合されていることが確認できた。評価結果を表2に示した。
加圧加熱成型された前駆体シートの両面を、シリコーン系離型剤をコートしたステンレスパンチングプレートで挟んだ後、バッチプレス装置にて、280℃、0.5MPaの条件下で1分間酸化処理(工程(5))したこと以外は、実施例9と同様にして、多孔質電極基材を得た。得られた多孔質電極基材は、炭素化処理時における面内の収縮がほとんどなく、うねりも2mm以下と小さく、ガス透気度、厚みおよび貫通方向抵抗はいずれも良好であった。また、2次元平面内に分散した炭素短繊維(A)同士が、炭素粉を含む網目状炭素(B)によって接合されていることが確認できた。評価結果を表2に示した。
加熱加圧成型(工程(4))を実施しなかったこと以外は、実施例9と同様にして、多孔質電極基材を得た。得られた多孔質電極基材は、炭素化処理時における面内の収縮がほとんどなく、うねりも2mm以下と小さく、ガス透気度、厚みおよび貫通方向抵抗はいずれも良好であった。また、2次元平面内に分散した炭素短繊維(A)同士が、炭素粉を含む網目状炭素(B)によって接合されていることが確認できた。評価結果を表2に示した。
実施例9と同様にして、前駆体シートを得たのち、工程(4)を行う前に、交絡処理して交絡構造を形成する工程(3)を行った以外は、実施例13と同様にして多孔質電極基材を得た。工程(3)では具体的に、まず、ネット駆動部及び幅60cm×長さ585cmのプラスチックネット製平織メッシュをベルト状につなぎあわせて連続的に回転させるネットに実施例2で示した3本のウォータージェットノズル(ノズルa、bおよびc)を備えた加圧水流噴射処理装置を配置したシート状物搬送装置を用意した。ついで、このシート状物搬送装置のネット上にこの前駆体シートを積載し、加圧水流噴射圧力を1MPa(ノズルa)、圧力2MPa(ノズルb)、圧力1MPa(ノズルc)として、前駆体シートをノズルa、ノズルb、ノズルcの順で通過させて交絡処理を加えた。
アクリロニトリル系重合体、炭素粉であるカーボンブラック(三菱化学株式会社製、商品名:♯3230B)、及びジメチルアセトアミドの配合量をそれぞれ134g、41g、及び835gとして炭素粉とアクリロニトリル系重合体とを含む紡糸原液を調製し、水蒸気の供給圧を450kPaとしたこと以外は製造例4と同様にして炭素粉を含むフィブリル状炭素前駆体繊維(b1-2)を得た。さらにこの炭素粉を含むフィブリル状炭素前駆体繊維(b1-2)を用いたこと以外は、実施例9と同様にして、多孔質電極基材を得た。得られた多孔質電極基材は、炭素化処理時における面内の収縮がほとんどなく、うねりも2mm以下と小さく、ガス透気度、厚みおよび貫通方向抵抗はいずれも良好であった。また、2次元平面内に分散した炭素短繊維(A)同士が、炭素粉を含む網目状炭素(B)によって接合されていることが確認できた。評価結果を表2に示した。
炭素粉としてアセチレンブラック(電気化学(株)製、商品名:デンカブラック)を使用したこと以外は実施例15と同様にして炭素粉を含むフィブリル状炭素前駆体繊維(b1-2)を得た。さらにこの炭素粉を含むフィブリル状炭素前駆体繊維(b1-2)を用いたこと以外は、実施例9と同様にして、多孔質電極基材を得た。得られた多孔質電極基材は、炭素化処理時における面内の収縮がほとんどなく、うねりも2mm以下と小さく、ガス透気度、厚みおよび貫通方向抵抗はいずれも良好であった。また、2次元平面内に分散した炭素短繊維(A)同士が、炭素粉を含む網目状炭素(B)によって接合されていることが確認できた。評価結果を表2に示した。
アクリロニトリル系重合体として製造例3に用いたアクリロニトリル系重合体を使用したこと以外は製造例4と同様にして炭素粉を含むフィブリル状炭素前駆体繊維(b1-2)を得た。このフィブリル状炭素前駆体繊維(b1-2)は、炭素粉とアクリロニトリル系重合体Iとからなるフィブリル状炭素前駆体繊維である。さらにこのフィブリル状炭素前駆体繊維(b1-2)を用いたこと以外は、実施例14と同様にして、多孔質電極基材を得た。得られた多孔質電極基材は、炭素化処理時における面内の収縮がほとんどなく、うねりも2mm以下と小さく、ガス透気度、厚みおよび貫通方向抵抗はいずれも良好であった。また、2次元平面内に分散した炭素短繊維(A)同士が、炭素粉を含む3次元網目状炭素(B)によって接合されていることが確認できた。評価結果を表2に示した。
炭素粉を用いず、アクリロニトリル系重合体及びジメチルアセトアミドの配合量をそれぞれ150g、及び850gとして炭素粉を含まないアクリロニトリル系重合体紡糸原液を調製し、この紡糸原液を用いた以外は製造例4と同様にして炭素粉を含まないフィブリル状炭素前駆体繊維を得た。さらにこの炭素粉を含まないフィブリル状炭素前駆体繊維を用いたこと以外は、実施例9と同様にして、多孔質電極基材を得た。得られた多孔質電極基材は、炭素化処理時における面内の収縮がほとんどなく、うねりも2mm以下と小さく、ガス透気度、厚みはいずれも良好であり、2次元平面内に分散した炭素短繊維(A)同士が、炭素粉を含まない網目状炭素(B)によって接合されていることが確認できた。しかし、貫通方向抵抗は実施例2と比較して高くなった。また炭素化時の炭素化率も実施例2と比較し小さくなった。評価結果を表2に示した。
炭素短繊維(A)を用いずに、炭素粉を含むフィブリル状炭素前駆体繊維(b1-2)の使用量を100部としたこと以外は、実施例9と同様にして多孔質電極基材を得た。しかし、得られた多孔質電極基材は、炭素粉を含むフィブリル状炭素前駆体繊維(b1-2)が炭素化する際の収縮により、シート状の構造を維持することができなかった。このため、多孔質電極基材の各物性値は測定しなかった。
2:分割繊維製造用紡糸原液の吐出口
3:水蒸気の流入口
4:スリット状水蒸気流路
5:混合セル部
6:混合セル部の出口
A:分割繊維製造用紡糸原液の吐出線
B:水蒸気の噴射線
C:AとBのなす角
7:シート面と平行な線
Claims (19)
- 炭素短繊維(A)と、炭素前駆体繊維(b)とが分散した前駆体シートを製造する工程(1)、
および
該前駆体シートを炭素化処理する工程(2)
を含み、工程(2)による該炭素前駆体繊維(b)の体積収縮率が83%以下である、多孔質電極基材の製造方法。 - 前記炭素前駆体繊維(b)が、炭素粉を含有する炭素前駆体繊維である、請求項1に記載の製造方法。
- 前記炭素前駆体繊維(b)が、フィブリル状炭素前駆体繊維である、請求項1または2に記載の製造方法。
- 前記炭素前駆体繊維(b)が、アクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体を含む炭素前駆体短繊維、およびアクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体を含むフィブリル状炭素前駆体繊維のうちの一方、または両方である、請求項1または2に記載の製造方法。
- 前記工程(1)と前記工程(2)の間に、前記前駆体シートを交絡処理する工程(3)を含む、請求項1~4のいずれか1項に記載の製造方法。
- 前記工程(1)と前記工程(2)の間に、前記前駆体シートを加熱加圧する工程(4)を含む、請求項1~4のいずれか1項に記載の製造方法。
- 前記工程(3)と前記工程(2)の間に、前記前駆体シートを加熱加圧する工程(4)を含む、請求項5に記載の製造方法。
- 前記工程(4)と前記工程(2)の間に、加熱加圧された前記前駆体シートを酸化処理する工程(5)を含む、請求項6または7に記載の製造方法。
- 請求項1~8のいずれか1項に記載の製造方法で得られる多孔質電極基材。
- 分散された炭素短繊維(A)同士が、炭素粉を含有する炭素によって接合されてなる多孔質電極基材。
- 分散された炭素短繊維(A)同士が、炭素粉を含有する3次元網目状炭素によって接合されてなる多孔質電極基材。
- 請求項9~11のいずれか1項に記載の多孔質電極基材を含む膜-電極接合体。
- 請求項12に記載の膜-電極接合体を含む固体高分子型燃料電池。
- 炭素短繊維(A)と、炭素前駆体繊維(b)とが分散した前駆体シートであって、該前駆体シートを焼成した際に、焼成による該炭素前駆体繊維(b)の体積収縮率が83%以下である前駆体シート。
- 炭素短繊維(A)と、炭素粉を含有する炭素前駆体繊維とが分散した前駆体シート。
- 炭素短繊維(A)と、炭素粉を含有するフィブリル状炭素前駆体繊維とが分散した前駆体シート。
- 炭素短繊維(A)と、
アクリロニトリル単位を95質量%以上含むアクリロニトリル系重合体からなる炭素前駆体短繊維、およびアクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体を含むフィブリル状炭素前駆体繊維のうちの一方、または両方と
が分散した前駆体シート。 - 前記炭素粉を含有する炭素前駆体繊維が、アクリロニトリル単位を95質量%以上含むアクリロニトリル系重合体および炭素粉からなる炭素前駆体短繊維と、アクリロニトリル単位を95質量%以上含有するアクリロニトリル系重合体および炭素粉を含むフィブリル状炭素前駆体繊維とのうちの一方、または両方である、請求項15に記載の前駆体シート。
- 炭素粉と、アクリロニトリル系重合体とからなるフィブリル状繊維。
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US15/391,769 US9786923B2 (en) | 2011-01-21 | 2016-12-27 | Porous electrode substrate, method for manufacturing same, membrane electrode assembly, polymer electrolyte fuel cell, precursor sheet, and fibrillar fibers |
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US15/391,769 Division US9786923B2 (en) | 2011-01-21 | 2016-12-27 | Porous electrode substrate, method for manufacturing same, membrane electrode assembly, polymer electrolyte fuel cell, precursor sheet, and fibrillar fibers |
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EP (2) | EP3222778A1 (ja) |
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Cited By (2)
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WO2014014055A1 (ja) * | 2012-07-20 | 2014-01-23 | 三菱レイヨン株式会社 | 多孔質電極基材、その製造方法、膜-電極接合体、及び固体高分子型燃料電池 |
JPWO2015146984A1 (ja) * | 2014-03-27 | 2017-04-13 | 日本バイリーン株式会社 | 導電性多孔体、固体高分子形燃料電池、及び導電性多孔体の製造方法 |
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Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03213522A (ja) * | 1990-01-12 | 1991-09-18 | Gun Ei Chem Ind Co Ltd | 活性炭繊維構造体及びその製造方法 |
JPH09324390A (ja) * | 1996-06-07 | 1997-12-16 | Toray Ind Inc | 炭素繊維紙および多孔質炭素板 |
JPH10168651A (ja) * | 1996-12-05 | 1998-06-23 | Mitsubishi Rayon Co Ltd | 表面フィブリル化繊維及びそれから得られるフィブリル含有分割繊維、並びにそれらの製造方法 |
JPH10165007A (ja) * | 1996-12-16 | 1998-06-23 | Toray Ind Inc | 園芸・農業用資材 |
JP2001056103A (ja) | 1999-08-19 | 2001-02-27 | Kawasaki Thermal Engineering Co Ltd | 消音構造を備えた多管式貫流ボイラ |
WO2002042534A1 (fr) | 2000-11-24 | 2002-05-30 | Toho Tenax Co., Ltd. | Feuille de fibres de carbone et son procede de production |
JP2003227054A (ja) * | 2002-02-01 | 2003-08-15 | Toho Tenax Co Ltd | ポリアクリロニトリル系酸化繊維紡績糸織物、炭素繊維紡績糸織物、及び炭素繊維紡績糸織物の製造方法 |
JP2004363018A (ja) | 2003-06-06 | 2004-12-24 | Mitsubishi Rayon Co Ltd | 固体高分子型燃料電池用多孔質電極基材 |
WO2006033390A1 (ja) * | 2004-09-22 | 2006-03-30 | National University Corporation Hokkaido University | 燃料電池用ガス拡散層 |
JP2006143478A (ja) | 2003-09-26 | 2006-06-08 | Toray Ind Inc | 多孔質炭素基材ならびに該基材を用いてなるガス拡散体、膜−電極接合体および燃料電池 |
JP2006299439A (ja) * | 2005-04-18 | 2006-11-02 | Mitsubishi Rayon Co Ltd | 炭素繊維およびその製造方法、並びにアクリロニトリル系前駆体繊維およびその製造方法 |
JP2006342487A (ja) * | 2006-08-18 | 2006-12-21 | Mitsubishi Rayon Co Ltd | 炭素繊維前駆体繊維束の製造方法 |
JP2006348439A (ja) * | 2005-06-20 | 2006-12-28 | Kaneka Corp | 導電性アクリル系繊維 |
JP2007273466A (ja) | 2006-03-20 | 2007-10-18 | Gm Global Technology Operations Inc | 燃料電池用ガス拡散媒体としてのアクリル繊維結合炭素繊維紙 |
JP2008044201A (ja) * | 2006-08-12 | 2008-02-28 | Toho Tenax Co Ltd | 炭素繊維シート及びその製造方法 |
JP2009129634A (ja) * | 2007-11-21 | 2009-06-11 | Mitsubishi Rayon Co Ltd | 多孔質電極基材、その製造方法、膜−電極接合体、および固体高分子型燃料電池 |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH05155672A (ja) * | 1991-12-05 | 1993-06-22 | Oji Paper Co Ltd | 多孔質炭素板及びその製造方法 |
RU2156839C2 (ru) | 1996-03-06 | 2000-09-27 | Мицубиси Рэйон Ко., Лтд. | Волокна фибрилловой системы (варианты), формованное изделие, способ изготовления волокон фибрилловой системы, прядильная фильера для изготовления волокон фибрилловой системы |
KR100425889B1 (ko) | 2000-01-27 | 2004-04-03 | 미쯔비시 레이온 가부시끼가이샤 | 다공질 탄소 전극 기재 |
JP4187683B2 (ja) * | 2000-01-27 | 2008-11-26 | 三菱レイヨン株式会社 | 燃料電池用多孔質炭素電極基材 |
JP4651787B2 (ja) | 2000-07-31 | 2011-03-16 | 日亜化学工業株式会社 | 発光装置 |
JP2003045443A (ja) | 2001-07-27 | 2003-02-14 | Toho Tenax Co Ltd | 高分子電解質型燃料電池電極材用炭素繊維不織布、及びその製造方法 |
TWI314599B (en) * | 2002-04-17 | 2009-09-11 | Mitsubishi Rayon Co | Carbon electrode base material using carbon paper for fuel cell made |
EP1612313B1 (en) | 2003-03-26 | 2012-08-22 | Toray Industries, Inc. | Porous carbon base material, method for preparation thereof, gas-diffusing material, film-electrode jointed article, and fuel cell |
GB0413324D0 (en) | 2004-06-15 | 2004-07-21 | Johnson Matthey Plc | Gas diffusion substrate |
CN100527496C (zh) * | 2004-06-21 | 2009-08-12 | 三菱丽阳株式会社 | 多孔质电极基材及其制造方法 |
JP5364976B2 (ja) * | 2005-09-29 | 2013-12-11 | 東レ株式会社 | 多孔質炭素シートおよびその製造方法 |
CA2751292C (en) | 2009-02-04 | 2016-09-06 | Mitsubishi Rayon Co., Ltd. | Porous electrode substrate, method for producing the same, membrane electrode assembly, and polymer electrolyte fuel cell |
CN102422470B (zh) * | 2009-07-08 | 2015-01-07 | 三菱丽阳株式会社 | 多孔质电极基材及其制造方法 |
EP2506353B1 (en) | 2009-11-24 | 2018-01-17 | Mitsubishi Chemical Corporation | Porous electrode base material, process for production thereof, precursor sheet, film-electrode assembly, and solid polymer fuel cell |
US20120115063A1 (en) | 2009-11-24 | 2012-05-10 | Mitsubishi Rayon Co., Ltd. | Porous electrode substrate and method for producing the same |
US9325016B2 (en) | 2010-11-01 | 2016-04-26 | Mitsubishi Rayon Co., Ltd. | Porous electrode substrate and process for production thereof, porous electrode substrate precursor sheet, membrane-electrode assembly, and polymer electrolyte fuel cell |
-
2012
- 2012-01-16 KR KR1020137018903A patent/KR101578985B1/ko not_active IP Right Cessation
- 2012-01-16 EP EP17169681.8A patent/EP3222778A1/en not_active Withdrawn
- 2012-01-16 CA CA2825294A patent/CA2825294A1/en not_active Abandoned
- 2012-01-16 WO PCT/JP2012/050677 patent/WO2012099036A1/ja active Application Filing
- 2012-01-16 JP JP2012504588A patent/JP5713003B2/ja not_active Expired - Fee Related
- 2012-01-16 EP EP12736945.2A patent/EP2667438A4/en not_active Withdrawn
- 2012-01-16 CN CN201280005730.XA patent/CN103329322B/zh not_active Expired - Fee Related
- 2012-01-16 US US13/980,774 patent/US9871257B2/en active Active
-
2016
- 2016-12-27 US US15/391,769 patent/US9786923B2/en active Active
Patent Citations (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03213522A (ja) * | 1990-01-12 | 1991-09-18 | Gun Ei Chem Ind Co Ltd | 活性炭繊維構造体及びその製造方法 |
JPH09324390A (ja) * | 1996-06-07 | 1997-12-16 | Toray Ind Inc | 炭素繊維紙および多孔質炭素板 |
JPH10168651A (ja) * | 1996-12-05 | 1998-06-23 | Mitsubishi Rayon Co Ltd | 表面フィブリル化繊維及びそれから得られるフィブリル含有分割繊維、並びにそれらの製造方法 |
JPH10165007A (ja) * | 1996-12-16 | 1998-06-23 | Toray Ind Inc | 園芸・農業用資材 |
JP2001056103A (ja) | 1999-08-19 | 2001-02-27 | Kawasaki Thermal Engineering Co Ltd | 消音構造を備えた多管式貫流ボイラ |
WO2002042534A1 (fr) | 2000-11-24 | 2002-05-30 | Toho Tenax Co., Ltd. | Feuille de fibres de carbone et son procede de production |
JP2003227054A (ja) * | 2002-02-01 | 2003-08-15 | Toho Tenax Co Ltd | ポリアクリロニトリル系酸化繊維紡績糸織物、炭素繊維紡績糸織物、及び炭素繊維紡績糸織物の製造方法 |
JP4409211B2 (ja) | 2003-06-06 | 2010-02-03 | 三菱レイヨン株式会社 | 固体高分子型燃料電池用多孔質電極基材の製造方法 |
JP2004363018A (ja) | 2003-06-06 | 2004-12-24 | Mitsubishi Rayon Co Ltd | 固体高分子型燃料電池用多孔質電極基材 |
JP2006143478A (ja) | 2003-09-26 | 2006-06-08 | Toray Ind Inc | 多孔質炭素基材ならびに該基材を用いてなるガス拡散体、膜−電極接合体および燃料電池 |
WO2006033390A1 (ja) * | 2004-09-22 | 2006-03-30 | National University Corporation Hokkaido University | 燃料電池用ガス拡散層 |
JP2006299439A (ja) * | 2005-04-18 | 2006-11-02 | Mitsubishi Rayon Co Ltd | 炭素繊維およびその製造方法、並びにアクリロニトリル系前駆体繊維およびその製造方法 |
JP2006348439A (ja) * | 2005-06-20 | 2006-12-28 | Kaneka Corp | 導電性アクリル系繊維 |
JP2007273466A (ja) | 2006-03-20 | 2007-10-18 | Gm Global Technology Operations Inc | 燃料電池用ガス拡散媒体としてのアクリル繊維結合炭素繊維紙 |
JP2008044201A (ja) * | 2006-08-12 | 2008-02-28 | Toho Tenax Co Ltd | 炭素繊維シート及びその製造方法 |
JP2006342487A (ja) * | 2006-08-18 | 2006-12-21 | Mitsubishi Rayon Co Ltd | 炭素繊維前駆体繊維束の製造方法 |
JP2009129634A (ja) * | 2007-11-21 | 2009-06-11 | Mitsubishi Rayon Co Ltd | 多孔質電極基材、その製造方法、膜−電極接合体、および固体高分子型燃料電池 |
Non-Patent Citations (1)
Title |
---|
See also references of EP2667438A4 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014014055A1 (ja) * | 2012-07-20 | 2014-01-23 | 三菱レイヨン株式会社 | 多孔質電極基材、その製造方法、膜-電極接合体、及び固体高分子型燃料電池 |
JP5664791B2 (ja) * | 2012-07-20 | 2015-02-04 | 三菱レイヨン株式会社 | 多孔質電極基材、その製造方法、膜−電極接合体、及び固体高分子型燃料電池 |
JPWO2015146984A1 (ja) * | 2014-03-27 | 2017-04-13 | 日本バイリーン株式会社 | 導電性多孔体、固体高分子形燃料電池、及び導電性多孔体の製造方法 |
Also Published As
Publication number | Publication date |
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JP5713003B2 (ja) | 2015-05-07 |
CN103329322B (zh) | 2016-06-01 |
JPWO2012099036A1 (ja) | 2014-06-30 |
EP3222778A1 (en) | 2017-09-27 |
US20170110736A1 (en) | 2017-04-20 |
US9871257B2 (en) | 2018-01-16 |
EP2667438A4 (en) | 2016-06-22 |
CN103329322A (zh) | 2013-09-25 |
KR20130108646A (ko) | 2013-10-04 |
US9786923B2 (en) | 2017-10-10 |
KR101578985B1 (ko) | 2015-12-18 |
CA2825294A1 (en) | 2012-07-26 |
EP2667438A1 (en) | 2013-11-27 |
US20130302714A1 (en) | 2013-11-14 |
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