JP2010031419A - Method for producing carbonaceous electrode material - Google Patents

Method for producing carbonaceous electrode material Download PDF

Info

Publication number
JP2010031419A
JP2010031419A JP2008194709A JP2008194709A JP2010031419A JP 2010031419 A JP2010031419 A JP 2010031419A JP 2008194709 A JP2008194709 A JP 2008194709A JP 2008194709 A JP2008194709 A JP 2008194709A JP 2010031419 A JP2010031419 A JP 2010031419A
Authority
JP
Japan
Prior art keywords
carbonaceous electrode
carbon
fibers
electrode substrate
paper
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2008194709A
Other languages
Japanese (ja)
Other versions
JP5250328B2 (en
Inventor
Makoto Nakamura
誠 中村
Mitsuo Hamada
光夫 浜田
Kazuhiro Sumioka
和宏 隅岡
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Rayon Co Ltd
Original Assignee
Mitsubishi Rayon Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Rayon Co Ltd filed Critical Mitsubishi Rayon Co Ltd
Priority to JP2008194709A priority Critical patent/JP5250328B2/en
Publication of JP2010031419A publication Critical patent/JP2010031419A/en
Application granted granted Critical
Publication of JP5250328B2 publication Critical patent/JP5250328B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a carbonaceous electrode material free from warpage and delamination defects. <P>SOLUTION: Two or more carbon staple fiber paper sheets produced by making paper sheets by a paper-making step, continuously pressing the sheets between papermaking felts and drying by contacting with a hot roll are impregnated with a phenolic resin, and the phenolic resin is carbonized to obtain the carbonaceous electrode material composed of two or more carbon staple fiber sheets laminated through carbonized phenolic resin. The carbon staple fiber is obtained by the papermaking treatment of a dispersion produced by dispersing carbon staple fibers, binder fibers, and polyethylene pulp or vinylon fibers in water. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、厚みが薄く、反りがなく、ガス透過度が高くかつ層間剥離がない炭素質電極基材及びその製造方法に関するものである。   The present invention relates to a carbonaceous electrode substrate having a small thickness, no warpage, high gas permeability, and no delamination, and a method for producing the same.

炭素繊維をベースとした炭素質電極基材は、固体高分子型燃料電池用のガス拡散層に用いられる。ガス拡散層は、電極反応に使用される水素、酸素等の反応ガスを効率良く電極反応が行われる触媒層に運搬する必要がある。前記ガス拡散層は、炭素繊維を用いて紙状にしたものが主流となっている。   A carbonaceous electrode substrate based on carbon fiber is used for a gas diffusion layer for a polymer electrolyte fuel cell. The gas diffusion layer needs to transport a reaction gas such as hydrogen or oxygen used for the electrode reaction to the catalyst layer where the electrode reaction is efficiently performed. The gas diffusion layer is mainly made of paper using carbon fiber.

特許文献１には、炭素繊維紙が、通常の紙と同様に水に分散させたシートを脱水させて得られるが、抄紙に表と裏ができ、それを１枚で焼成すると反る場合があることが記載されている。特許文献２には、炭素繊維紙の同一面が外側になるように２枚以上の炭素繊維紙を積層して、反りを防止する方法が記載されている。   In Patent Document 1, carbon fiber paper is obtained by dehydrating a sheet dispersed in water in the same manner as ordinary paper. However, the front and back of the paper can be made, and if it is baked as a single sheet, it may warp. It is described that there is. Patent Document 2 describes a method of preventing warpage by laminating two or more carbon fiber papers so that the same surface of the carbon fiber paper is on the outside.

前記方法では、抄紙時の炭素繊維紙の下面を上にして、樹脂含浸、乾燥させたり、炭素繊維紙を２枚重ねることで樹脂含浸、乾燥させても反らないようにしているが、表層と内層で樹脂の付着状態が異なる場合がある。そのため、樹脂の多い面を外側にすると層間剥離が生じ易く、樹脂の少ない面を外側にすると繊維が毛羽立ち易くなる場合があり、更なる改善が望まれている。
特開２００５−２９７５４７号公報 特開２００３−１５１５６８号公報 In the above method, the bottom surface of the carbon fiber paper at the time of paper making is made to be resin impregnated and dried, or two carbon fiber papers are stacked so as not to warp even if the resin is impregnated and dried. And the inner layer may have different resin adhesion states. For this reason, delamination is likely to occur when the resin-rich surface is on the outside, and if the surface with less resin is on the outside, the fibers may become fluffy, and further improvements are desired.
JP 2005-297547 A JP 2003-151568 A

反りがなくかつ層間剥離がない炭素質電極基材の製造方法を提供する。   Provided is a method for producing a carbonaceous electrode substrate having no warpage and no delamination.

本発明の炭素質電極基材の製造方法は抄紙後、連続して抄紙用フェルトの間に挟んで押圧し、熱ロールに接触させて乾燥した、２枚以上の炭素短繊維紙にフェノール樹脂を含浸後、該フェノール樹脂を炭素化して製造する、２枚以上の炭素短繊維紙がフェノール樹脂炭化物を介して積層されてなる炭素質電極基材の製造方法において、前記炭素短繊維紙が、炭素短繊維とバインダー繊維と、ポリエチレンパルプ又はビニロン繊維とを水に分散した分散液を抄紙したものであることを特徴とする。   In the method for producing a carbonaceous electrode substrate of the present invention, after papermaking, a phenol resin is applied to two or more carbon short fiber papers which are continuously sandwiched and pressed between papermaking felts and dried in contact with a hot roll. In the method for producing a carbonaceous electrode substrate in which two or more carbon short fiber papers are laminated through phenol resin carbide, which is produced by carbonizing the phenol resin after impregnation, the carbon short fiber paper is carbon It is characterized in that it is a paper-made dispersion liquid in which short fibers, binder fibers and polyethylene pulp or vinylon fibers are dispersed in water.

本発明の炭素質電極基材は、前記炭素質電極基材の製造方法により製造され、以下の（１）〜（３）の条件を満足する。   The carbonaceous electrode substrate of the present invention is produced by the method for producing a carbonaceous electrode substrate, and satisfies the following conditions (1) to (3).

（１）嵩密度が０．２０〜０．４０ｇ／ｃｍ3
（２）炭化樹脂比率が２０〜３５％
（３）剥離強さが２５Ｎ／４ｃｍ2以上。 (1) Bulk density is 0.20 to 0.40 g / cm 3
(2) Carbonized resin ratio is 20 to 35%
(3) Peel strength is 25 N / 4 cm 2 or more.

反りがなくかつ層間剥離がない炭素質電極基材の製造方法が提供される。また、得られる炭素質電極基材は、厚みが薄く、ガス透過度も高い。   There is provided a method for producing a carbonaceous electrode substrate that is free of warpage and delamination. Moreover, the carbonaceous electrode base material obtained is thin and has high gas permeability.

＜炭素質電極基材の製造方法＞
本発明の炭素質電極基材の製造方法は、抄紙後、連続して抄紙用フェルトの間に挟んで押圧し、熱ロールに接触させて乾燥した、２枚以上の炭素短繊維紙にフェノール樹脂を含浸後、該フェノール樹脂を炭素化して製造する、２枚以上の炭素短繊維紙がフェノール樹脂炭化物を介して積層されてなる炭素質電極基材の製造方法において、前記炭素短繊維紙が、炭素短繊維とバインダー繊維と、ポリエチレンパルプ又はビニロン繊維とを水に分散した分散液を抄紙したものであることを特徴とする。 <Method for producing carbonaceous electrode substrate>
The method for producing a carbonaceous electrode substrate according to the present invention comprises a step of making a phenolic resin on two or more carbon short fiber papers, which are continuously sandwiched between papermaking felts after paper making, pressed in contact with a hot roll and dried. In the method for producing a carbonaceous electrode substrate in which two or more carbon short fiber papers are produced by carbonizing the phenol resin after impregnating the phenol resin, the carbon short fiber papers are: It is characterized in that it is a paper-made dispersion liquid in which short carbon fibers, binder fibers, and polyethylene pulp or vinylon fibers are dispersed in water.

＜炭素短繊維＞
本発明で用いる炭素短繊維の原料である炭素繊維は、ポリアクリロニトリル系炭素繊維、ピッチ系炭素繊維及びレーヨン系炭素繊維等が挙げられるが、ポリアクリロニトリル系炭素繊維が好ましい。特に、用いる炭素繊維がポリアクリロニトリル（ＰＡＮ）系炭素繊維のみとすることが炭素質電極基材の機械的強度を比較的高くすることができるため、より好ましい。 <Short carbon fiber>
Examples of the carbon fiber that is a raw material of the short carbon fiber used in the present invention include polyacrylonitrile-based carbon fiber, pitch-based carbon fiber, and rayon-based carbon fiber, and polyacrylonitrile-based carbon fiber is preferable. In particular, it is more preferable that the carbon fiber used is only polyacrylonitrile (PAN) based carbon fiber because the mechanical strength of the carbonaceous electrode substrate can be made relatively high.

炭素短繊維の直径は、３〜９μｍであることが、炭素短繊維の生産コスト、分散性の面から好ましい。４〜８μｍであることが炭素質電極基材の平滑性の面からより好ましい。炭素短繊維の繊維長は、２〜１２ｍｍが好ましい。この範囲内であると分散性が良い。   The diameter of the short carbon fiber is preferably 3 to 9 μm from the viewpoint of production cost and dispersibility of the short carbon fiber. It is more preferable that it is 4-8 micrometers from the surface of the smoothness of a carbonaceous electrode base material. The fiber length of the short carbon fiber is preferably 2 to 12 mm. Within this range, dispersibility is good.

抄紙後、押圧前の炭素短繊維紙中の炭素短繊維の質量比率は、３０〜９０質量％であることが好ましい。機械強度の観点から３０質量％以上であることが好ましく、繊維の脱落を防止するためには９０質量％以下であることが好ましい。   After the paper making, the mass ratio of the short carbon fibers in the short carbon fiber paper before pressing is preferably 30 to 90% by mass. From the viewpoint of mechanical strength, it is preferably 30% by mass or more, and preferably 90% by mass or less in order to prevent the fibers from falling off.

＜バインダー繊維＞
本発明の製造方法では、バインダー繊維を用いることが必須である。バインダー繊維は、炭素短繊維をつなぎとめるバインダー（糊剤）として使用される。バインダー繊維としては、ポリビニルアルコール（ＰＶＡ）、ポリ酢酸ビニルなどを用いることができる。特にポリビニルアルコールは抄紙工程での結着力に優れるため、炭素短繊維の脱落が少なくバインダーとして好ましい。 <Binder fiber>
In the production method of the present invention, it is essential to use binder fibers. The binder fiber is used as a binder (glue) that holds the short carbon fibers together. As the binder fiber, polyvinyl alcohol (PVA), polyvinyl acetate, or the like can be used. In particular, polyvinyl alcohol is preferable as a binder because it has excellent binding power in the paper making process, and the short carbon fibers are not dropped off.

抄紙後、押圧前の炭素短繊維紙中のバインダー繊維の質量比率は、５〜３０質量％であることが好ましい。繊維の脱落を防止するためには５質量％以上であることが好ましく、シワなど外観不良発生を抑制するためには３０質量％以下であることが好ましい。   It is preferable that the mass ratio of the binder fibers in the short carbon fiber paper before paper pressing is 5 to 30% by mass. In order to prevent the fibers from falling off, the content is preferably 5% by mass or more, and in order to suppress appearance defects such as wrinkles, the content is preferably 30% by mass or less.

＜ポリエチレンパルプ＞
本発明の製造方法では、ポリエチレンパルプ又はビニロン繊維を用いることが必須である。ポリエチレンパルプは、炭素短繊維と一緒に分散し、炭素短繊維の再収束を防止する役割も果たす。また、フェノール樹脂は硬化の際に縮合水を生成するが、ポリエチレンパルプには、その水を吸収、排出する役割も期待できる。炭素短繊維との親和性、取り扱い性、コストの点から好ましい。 <Polyethylene pulp>
In the production method of the present invention, it is essential to use polyethylene pulp or vinylon fiber. The polyethylene pulp is dispersed together with the short carbon fibers, and also plays a role in preventing the refocusing of the short carbon fibers. In addition, the phenol resin generates condensed water upon curing, and the polyethylene pulp can be expected to absorb and discharge the water. It is preferable from the viewpoint of affinity with short carbon fibers, handleability, and cost.

さらに、架橋構造を効率的に形成するという点からポリエチレンパルプを用いることが好ましい。ポリエチレンパルプの表面自由エネルギーは炭素短繊維より大きいため、含浸樹脂が繊維に優先的に付着し、炭素化後、網状の架橋構造が形成されやすくなる。   Furthermore, it is preferable to use polyethylene pulp from the viewpoint of efficiently forming a crosslinked structure. Since the surface free energy of polyethylene pulp is larger than that of short carbon fibers, the impregnated resin preferentially adheres to the fibers, and a network-like cross-linked structure is likely to be formed after carbonization.

抄紙後、押圧前の炭素短繊維紙中のポリエチレンパルプの質量比率は、１０〜７０質量％であることが好ましい。ポリエチレンパルプを１０質量％以上含有することで、炭素質電極基材に十分な機械強度とガス透過度を付与できる。また、ポリエチレンパルプは、フェノール樹脂を押圧下で硬化する際に生じるうねりやシワ等の外力に打ち勝つための補強材としても働くため、１０質量％以上であることが好ましい。一方、ポリエチレンパルプを７０質量％以下としておけば、炭素短繊維に付着するフェノール樹脂の不足により、炭素質電極基材が崩れやすくなったり、厚み制御が難しくなるのを防ぐことができる。   It is preferable that the mass ratio of the polyethylene pulp in the carbon short fiber paper before pressing after paper making is 10 to 70% by mass. By containing 10 mass% or more of polyethylene pulp, sufficient mechanical strength and gas permeability can be imparted to the carbonaceous electrode substrate. Moreover, since polyethylene pulp also functions as a reinforcing material for overcoming external forces such as swells and wrinkles generated when a phenol resin is cured under pressure, the content is preferably 10% by mass or more. On the other hand, when the polyethylene pulp is 70% by mass or less, it is possible to prevent the carbonaceous electrode base material from being easily collapsed and the thickness control from becoming difficult due to the shortage of the phenol resin adhering to the short carbon fibers.

＜ビニロン繊維＞
ビニロン繊維とは、ポリビニルアルコール繊維を熱処理やホルムアルデヒドでアセタール化することにより耐熱性、耐水性を高めた繊維である。ビニロン繊維は、炭素化により分解してなくなるが、その周りに付着したフェノール樹脂の形状は、そのまま残り、そのフェノール樹脂がフィラメント状炭化物を形成する。 <Vinylon fiber>
The vinylon fiber is a fiber having improved heat resistance and water resistance by acetalizing polyvinyl alcohol fiber with heat treatment or formaldehyde. The vinylon fiber is not decomposed by carbonization, but the shape of the phenol resin attached around it remains as it is, and the phenol resin forms filamentary carbide.

ビニロン繊維の繊度は、特に限定されないが、０．０５〜１．５ｄｔｅｘのものが好ましい。繊度を０．０５ｄｔｅｘ以上とすることにより、ビニロン繊維一本あたりのフェノール樹脂の付着を十分なものとし、炭素化後、炭素質電極基材からフィラメント状樹脂炭化物が剥離することを防ぐことができる。繊度を１．５ｄｔｅｘ以下とすることにより、炭素質電極基材表面が粗くなることを防ぎ、燃料電池としたときに炭素質電極基材と周辺部材との接触を良好なものとすることができる。   The fineness of the vinylon fiber is not particularly limited, but is preferably 0.05 to 1.5 dtex. By setting the fineness to 0.05 dtex or more, the phenol resin can be sufficiently adhered per vinylon fiber, and after carbonization, the filamentous resin carbide can be prevented from peeling off from the carbonaceous electrode substrate. . By setting the fineness to 1.5 dtex or less, the surface of the carbonaceous electrode substrate can be prevented from becoming rough, and when the fuel cell is formed, the contact between the carbonaceous electrode substrate and the peripheral member can be improved. .

ビニロン繊維の長さは、特に限定されないが、同時に用いる炭素短繊維と同程度のものが好ましい。バインダーとの結着性や分散性の点から、２〜１２ｍｍが好ましい。   The length of the vinylon fiber is not particularly limited, but is preferably the same as the short carbon fiber used at the same time. From the viewpoint of binding properties and dispersibility with the binder, 2 to 12 mm is preferable.

ビニロン繊維は、炭素短繊維と一緒に分散することで、炭素短繊維の再収束を防止する役割も果たす。そのため、水との親和性にも優れているものが好ましい。   The vinylon fiber also serves to prevent re-convergence of the short carbon fiber by being dispersed together with the short carbon fiber. Therefore, what is excellent also in the affinity with water is preferable.

抄紙後、押圧前の炭素短繊維紙中のビニロン繊維の質量比率は、１０〜６０質量％であることが好ましい。抄紙後、押圧前の炭素短繊維紙中のビニロン繊維の質量比率を１０質量％以上とすることにより、ビニロン繊維由来のフィラメント状炭化物による補強効果が十分となる。一方、６０質量％以下であれば、フィラメント状炭化物とその他の炭化物のバランスがよく、炭素質電極基材の形態が満足いくものとすることができる。   It is preferable that the mass ratio of the vinylon fiber in the short carbon fiber paper before paper pressing is 10 to 60% by mass. By making the mass ratio of the vinylon fibers in the short carbon fiber paper before pressing after the paper making to 10 mass% or more, the reinforcing effect by the filamentous carbide derived from the vinylon fibers becomes sufficient. On the other hand, if it is 60 mass% or less, the balance of filamentous carbide and other carbides is good, and the form of the carbonaceous electrode substrate can be satisfactory.

なお、ポリエチレンパルプ又はビニロン繊維は、その一方の使用に限らず、双方を使用しても良い。   The polyethylene pulp or the vinylon fiber is not limited to one of them, and both may be used.

＜炭素短繊維紙の抄紙＞
炭素短繊維紙の抄紙方法としては、前記炭素短繊維、バインダー繊維、ポリエチレンパルプ又はビニロン繊維を分散させて抄造する湿式抄紙法を用いる。ポリエチレンパルプ又はビニロン繊維を上記量、バインダー繊維と共に湿式抄紙することで、炭素短繊維が単繊維に分散するのを助け、分散した単繊維が再び収束を防止するのを防ぐことができるため好ましい。 <Paper making of carbon short fiber paper>
As a paper making method of the short carbon fiber paper, a wet paper making method in which the short carbon fiber, the binder fiber, the polyethylene pulp, or the vinylon fiber is dispersed to make a paper is used. Wet paper making with the above amount and binder fiber of polyethylene pulp or vinylon fiber is preferable because it helps to disperse the short carbon fibers into single fibers and prevents the dispersed single fibers from preventing convergence again.

なお、本発明の製造方法において、分散とは、炭素短繊維がおおむね一つの面を形成するように横たわっているという意味である。これにより炭素短繊維による短絡や炭素短繊維の折損を防止することができる。   In addition, in the manufacturing method of this invention, dispersion | distribution means that the carbon short fiber lies so that it may form one surface in general. Thereby, the short circuit by carbon short fiber and the breakage of carbon short fiber can be prevented.

炭素短繊維とバインダー繊維と、ポリエチレンパルプ又はビニロン繊維とを混合して分散液を調製する方法としては、パルパー等の回転式の装置で混合し、離解、均一分散を行って分散液を調製する。このように有機高分子化合物を混ぜることにより、炭素繊維紙の強度を保持し、その製造途中で炭素短繊維紙から炭素短繊維が剥離したり、炭素短繊維の配向が変化したりするのを防止することができる。次に、この分散液を用いて、長網、短網、円網等のワイヤーを有する抄紙機で、抄紙を行う。これにより、炭素質電極基材に要求される目付精度・厚み精度を満足させることができる。   As a method of preparing a dispersion by mixing short carbon fibers, binder fibers, and polyethylene pulp or vinylon fibers, the dispersion is prepared by mixing with a rotary apparatus such as a pulper and performing disaggregation and uniform dispersion. . By mixing the organic polymer compound in this way, the strength of the carbon fiber paper is maintained, and the carbon short fibers are peeled off from the carbon short fiber paper during the production, or the orientation of the carbon short fibers is changed. Can be prevented. Next, using this dispersion, paper making is performed with a paper machine having a wire such as a long mesh, a short mesh, or a circular mesh. Thereby, the fabric weight precision and thickness precision requested | required of a carbonaceous electrode base material can be satisfied.

また、本発明において行なう抄紙は、特に目付のコントロールが容易であるという点、生産性及び機械的強度の観点から連続抄紙することが好ましい。   In addition, the paper making performed in the present invention is preferably made continuously from the viewpoint of easy control of basis weight, productivity and mechanical strength.

＜押圧＞
本発明の製造方法では、抄紙後の炭素短繊維紙を抄紙用フェルトの間に挟んで押圧することが必須である。 <Pressing>
In the production method of the present invention, it is essential that the carbon short fiber paper after paper making is sandwiched and pressed between paper making felts.

湿式抄紙法で得られる抄紙後の炭素短繊維紙は、水分を多く含んでいるため、熱ロールで乾燥する前に含まれる水を絞るため、抄紙用フェルトの間に挟んで押圧する（図１）。   Since the carbon short fiber paper after paper making obtained by the wet paper making method contains a lot of moisture, it is sandwiched and pressed between paper making felts in order to squeeze the water contained before drying with a hot roll (FIG. 1). ).

図１に示す方法では、抄紙後の炭素短繊維紙１を連続して抄紙用フェルト２で搬送し、２つのローラにより、抄紙用フェルト２を介して押圧する。   In the method shown in FIG. 1, the short carbon fiber paper 1 after papermaking is continuously conveyed by the papermaking felt 2 and pressed by the two rollers through the papermaking felt 2.

一般的な紙の場合は、パルプ同士が十分に絡み合っているため抄紙用フェルトの間に挟んで押圧することは問題ないが、炭素短繊維紙の場合は、紙がはがれたり抄紙用フェルトに張り付いたりする場合がある。このため、ポリエチレンパルプ又はビニロン繊維を混合して抄紙したものを抄紙用フェルトの間に挟んで押圧することが必須である。   In the case of general paper, the pulp is sufficiently entangled, so it is not a problem to press it between papermaking felts, but in the case of carbon short fiber paper, the paper is peeled off or stretched on the papermaking felt. It may be attached. For this reason, it is essential to press the paper made by mixing polyethylene pulp or vinylon fiber between papermaking felts.

抄紙用フェルトの間に挟まずに乾燥したものは、水分率にバラツキが多いため、表・裏及び同一面内のバインダーの状態にムラが生じる。抄紙用フェルトの間に挟んで押圧することで、水分率を調整することができる。水分量を調整することでバ紙の表側と裏側でバインダーの効き方に差が生じるのを抑制することができ、後の工程でフェノール樹脂を含浸する際に、樹脂の付着状態を均一にすることができる。   In the case where the paper is dried without being sandwiched between the felts for papermaking, the moisture content varies widely, so that the state of the binder on the front / back and the same surface is uneven. The moisture content can be adjusted by sandwiching and pressing between the papermaking felts. By adjusting the amount of water, it is possible to suppress the difference in the effect of the binder between the front side and the back side of the paper, and make the resin adherence uniform when impregnating with a phenol resin in the subsequent step. be able to.

＜抄紙用フェルト＞
本発明の製造方法に用いる抄紙用フェルトは、水を多く含んでいる抄紙後の炭素短繊維紙を移送する機能、水分を搾り取る機能、面を平滑にする機能を有しているものが好ましい。例えば、日本フェルト株式会社製の抄紙用フェルトが挙げられる。 <Felt for papermaking>
The papermaking felt used in the production method of the present invention preferably has a function of transporting short carbon fiber paper after papermaking containing a large amount of water, a function of squeezing moisture, and a function of smoothing the surface. For example, a papermaking felt manufactured by Nippon Felt Co., Ltd. can be mentioned.

＜水分率＞
本発明の製造方法では、押圧により、押圧後の炭素短繊維紙に含まれる水分率を６０〜８５質量％に調整することが好ましい。水分率が６０質量％より小さい場合は、乾燥させたときのバインダーの効果が弱いため炭素繊維紙の強度が出ない場合がある。水分率が８５質量％より大きい場合は、十分に水が絞れていないため、乾燥のムラが生じる場合がある。押圧後の炭素短繊維紙に含まれる水分率は、７０〜８０質量％がより好ましい。 <Moisture content>
In the manufacturing method of this invention, it is preferable to adjust the moisture content contained in the carbon short fiber paper after a press to 60-85 mass% by pressing. When the moisture content is less than 60% by mass, the strength of the carbon fiber paper may not be obtained because the effect of the binder when dried is weak. If the moisture content is greater than 85% by mass, water may not be sufficiently squeezed, and drying unevenness may occur. As for the moisture content contained in the carbon short fiber paper after a press, 70-80 mass% is more preferable.

水分率は、押圧をコントロールすることで調整することができる。圧力は、０．０５ＭＰａ〜１ＭＰａであることが好ましく、より好ましくは、０．１ＭＰａ〜０．５ＭＰａである。   The moisture content can be adjusted by controlling the pressing. The pressure is preferably 0.05 MPa to 1 MPa, more preferably 0.1 MPa to 0.5 MPa.

＜水分率の測定方法＞
水分率の測定方法としては、押圧後の炭素短繊維紙をサンプリングし、乾燥前後の重量を測定する方法と非接触式の水分計をラインにおいてモニターする方法があるが、特に限定はされない。本発明においては、加熱式水分計「ＭＳ−７０」（エー・アンド・ディー社製）を使用し水分率を算出した。測定水分率は、以下の式で算出される。
水分率（％）＝（１−乾燥後の重量／乾燥前の重量）×１００。 <Method for measuring moisture content>
As a method for measuring the moisture content, there are a method of sampling a short carbon fiber paper after pressing and measuring a weight before and after drying, and a method of monitoring a non-contact type moisture meter in a line, but there is no particular limitation. In the present invention, the moisture content was calculated using a heating moisture meter “MS-70” (manufactured by A & D). The measured moisture content is calculated by the following equation.
Moisture content (%) = (1-weight after drying / weight before drying) × 100.

＜乾燥＞
本発明の製造方法では、前記押圧後、熱ロールに接触させて乾燥することが必須である。炭素短繊維と炭素短繊維をバインダー繊維でつなぎとめるためには、水分が残っている状態で熱を加えて乾燥する。熱を加えないで乾燥した場合は、バインダー繊維が膨潤しないため、炭素短繊維紙の強度が弱くなり好ましくない。 <Dry>
In the production method of the present invention, it is essential to dry by contacting with a hot roll after the pressing. In order to connect the short carbon fiber and the short carbon fiber with the binder fiber, heat is applied in the state where moisture remains, and the carbon short fiber is dried. When dried without applying heat, the binder fibers do not swell, which is not preferable because the strength of the short carbon fiber paper becomes weak.

前記乾燥は、例えば、図１に示すように、抄紙後の炭素短繊維紙１を押圧後、連続的に熱ロール３に接触させることで、水分を蒸発させることができる。熱ロール３の温度としては、１００〜１４０℃が、安定に抄紙するための強度と伸度を保持できる点から好ましい。前記乾燥工程により、炭素短繊維紙を得ることができる。   For example, as shown in FIG. 1, the drying can evaporate the moisture by continuously contacting the short carbon fiber paper 1 after paper making and then contacting the hot roll 3. As temperature of the hot roll 3, 100-140 degreeC is preferable from the point which can hold | maintain the intensity | strength and elongation for stable papermaking. Carbon short fiber paper can be obtained by the drying step.

＜フェノール樹脂の含浸方法＞
本発明では、前記炭素短繊維紙にフェノール樹脂を含浸する。炭素繊維紙にフェノール樹脂を含浸する方法としては、炭素繊維紙にフェノール樹脂を含浸させることができればよく、特段の制限はないが、コーターを用いて炭素繊維紙表面にフェノール樹脂を均一にコートする方法、絞り装置を用いるｄｉｐ−ｎｉｐ方法、もしくは炭素繊維紙とフェノール樹脂フィルムを重ねて、フェノール樹脂を炭素繊維紙に転写する方法が、連続的に行なうことができ、生産性及び長尺ものも製造できるという点で好ましい。 <Impregnation method of phenol resin>
In the present invention, the short carbon fiber paper is impregnated with a phenol resin. The method for impregnating the carbon fiber paper with the phenol resin is not particularly limited as long as the carbon fiber paper can be impregnated with the phenol resin, and the surface of the carbon fiber paper is uniformly coated using a coater. A method, a dip-nip method using a squeezing device, or a method in which carbon fiber paper and a phenol resin film are overlapped and the phenol resin is transferred to the carbon fiber paper can be continuously performed. It is preferable in that it can be manufactured.

＜フェノール樹脂＞
本発明で用いるフェノール樹脂としては、アルカリ触媒存在下においてフェノール類とアルデヒド類の反応によって得られるレゾールタイプフェノール樹脂を挙げることができる。 <Phenolic resin>
As a phenol resin used by this invention, the resol type phenol resin obtained by reaction of phenols and aldehydes in presence of an alkali catalyst can be mentioned.

レゾールタイプフェノール樹脂は、公知の方法によって酸性触媒下においてフェノール類とアルデヒド類の反応によって生成する、固体の熱融着性を示すノボラックタイプのフェノール樹脂を溶解混入させることもできる。この場合は硬化剤、例えばヘキサメチレンジアミンを含有した、自己架橋タイプのものが好ましい。   The resol type phenol resin can also be dissolved and mixed with a novolac type phenol resin which is produced by the reaction of phenols and aldehydes in the presence of an acidic catalyst by a known method and exhibits solid heat-fusibility. In this case, a self-crosslinking type containing a curing agent such as hexamethylenediamine is preferred.

前記フェノール類としては、例えば、フェノール、レゾルシン、クレゾール、キシレノール等が用いられる。前記アルデヒド類としては、例えばホルマリン、パラホルムアルデヒド、フルフラール等が用いられる。また、これらを混合物として用いることができる。これらはフェノール樹脂として市販品を利用することも可能である。   Examples of the phenols include phenol, resorcin, cresol, xylenol, and the like. Examples of the aldehydes include formalin, paraformaldehyde, furfural and the like. Moreover, these can be used as a mixture. These can also use a commercial item as a phenol resin.

＜フェノール樹脂量＞
炭素短繊維紙に付着させるフェノール樹脂の樹脂量は、前記炭素短繊維紙中の炭素短繊維１００質量部に対し、７０〜１５０質量部とすることが好ましい。７０〜１５０質量部とすることで、炭素質電極基材中の炭化樹脂比率が２５〜４０質量％となり、ガス透過度が高い炭素質電極基材を製造することができる。 <Phenolic resin amount>
It is preferable that the resin amount of the phenol resin attached to the carbon short fiber paper is 70 to 150 parts by mass with respect to 100 parts by mass of the carbon short fibers in the carbon short fiber paper. By setting it as 70-150 mass parts, the carbonized resin ratio in a carbonaceous electrode base material will be 25-40 mass%, and a carbonaceous electrode base material with high gas permeability can be manufactured.

＜フェノール樹脂の硬化、炭素化＞
フェノール樹脂を含浸した炭素短繊維紙は、そのまま炭素化することも可能である。しかし、炭素化する前にフェノール樹脂を硬化することがフェノール樹脂の炭素化時の気化を抑制し、炭素質電極基材の強度向上のために好ましい。硬化は、フェノール樹脂を含浸した炭素短繊維紙を均等に加熱できる技術であれば、いかなる技術も適用できる。その例としては、フェノール樹脂を含浸した炭素短繊維紙の上下両面から剛板を重ね、加熱する方法や上下両面から熱風を吹き付ける方法、また連続ベルトプレス装置や連続熱風炉を用いる方法が挙げられる。 <Hardening and carbonization of phenolic resin>
Carbon short fiber paper impregnated with phenolic resin can be carbonized as it is. However, it is preferable to cure the phenol resin before carbonization to suppress the vaporization of the phenol resin during carbonization and to improve the strength of the carbonaceous electrode substrate. Any technique can be applied to the curing as long as the carbon short fiber paper impregnated with the phenol resin can be heated uniformly. Examples include a method in which rigid plates are stacked from both the upper and lower surfaces of a carbon short fiber paper impregnated with a phenol resin, a method of heating, a method of blowing hot air from both the upper and lower surfaces, and a method of using a continuous belt press apparatus and a continuous hot air furnace. .

また、フェノール樹脂を硬化させるだけでなく、加熱により炭素短繊維紙表面を平滑にする工程を含んでいることが好ましい。炭素短繊維表面を平滑にする方法としては、特に限定されないが、上下両面から平滑な剛板にて熱プレスする方法や連続ベルトプレス装置を用いて行なう方法がある。中でも連続ベルトプレス装置を用いて行なう方法が、長尺の炭素質電極基材ができるという点で好ましい。   In addition to curing the phenolic resin, it is preferable to include a step of smoothing the carbon short fiber paper surface by heating. The method of smoothing the carbon short fiber surface is not particularly limited, and there are a method of hot pressing with a smooth rigid plate from both the upper and lower surfaces and a method of using a continuous belt press apparatus. Of these, the method using a continuous belt press is preferable in that a long carbonaceous electrode substrate can be formed.

連続ベルトプレス装置におけるプレス方法としては、ロールプレスによりベルトに線圧で圧力を加える方法と液圧ヘッドプレスにより面圧でプレスする方法があるが、後者の方がより平滑な炭素質電極基材が得られるという点で好ましい。効果的に表面を平滑にするためには、フェノール樹脂が最も軟化する温度でプレスし、その後加熱又は冷却によりフェノール樹脂を固定する方法がより好ましい。   As a pressing method in a continuous belt press apparatus, there are a method of applying pressure to a belt by a roll press with a linear pressure and a method of pressing with a surface pressure by a hydraulic head press, the latter being a smoother carbonaceous electrode substrate Is preferable in that it is obtained. In order to effectively smooth the surface, a method of pressing at a temperature at which the phenol resin is most softened and then fixing the phenol resin by heating or cooling is more preferable.

炭素短繊維紙に含浸されるフェノール樹脂の比率が多い場合は、プレス圧が低くても平滑にすることが容易である。このとき必要以上にプレス圧を高くすることは、炭素質電極基材としたときその組織が緻密になりすぎ、変形する場合があるため好ましくない。プレス圧が高く緻密になりすぎた場合は、焼成時に発生するガスがうまく排出されず炭素質電極基材の組織を壊す場合がある。   When the ratio of the phenol resin impregnated in the short carbon fiber paper is large, it is easy to make it smooth even if the press pressure is low. In this case, it is not preferable to increase the press pressure more than necessary because the structure becomes too dense when the carbonaceous electrode substrate is formed, and may be deformed. If the press pressure is too high and dense, the gas generated during firing may not be discharged well, and the structure of the carbonaceous electrode substrate may be destroyed.

剛板に挟んで、又、連続ベルトプレス装置で炭素短繊維紙に含浸したフェノール樹脂の硬化を行う際は、剛板やベルトにフェノール樹脂が付着しないようにあらかじめ剥離剤を塗っておくか、炭素短繊維紙と剛板やベルトとの間に離型紙を挟んで行なうことで、表面の平滑化を行うことができるため好ましい。表面を平滑にする工程がない場合も、良好な強度とガス透過度とをともに有する炭素質電極基材が得られる。   When the phenolic resin impregnated in the carbon short fiber paper is sandwiched between the rigid plates and impregnated in the short carbon fiber paper with a continuous belt press device, a release agent is applied in advance so that the phenolic resin does not adhere to the rigid plate or belt, It is preferable to sandwich the release paper between the short carbon fiber paper and the rigid plate or belt because the surface can be smoothed. Even when there is no step of smoothing the surface, a carbonaceous electrode substrate having both good strength and gas permeability can be obtained.

炭素短繊維紙に含浸したフェノール樹脂又は硬化されたフェノール樹脂は、続いて炭素化される。炭素質電極基材の導電性を高めるために、不活性ガス中で炭素化する。炭素化は、炭素短繊維紙の全長にわたって連続して行なうことが好ましい。炭素質電極基材が長尺であれば、炭素質電極基材の生産性が高くなるだけでなく、その後工程のＭｅｍｂｒａｎｅ Ｅｌｅｃｔｒｏｄｅ Ａｓｓｅｍｂｌｙ（ＭＥＡ）製造も連続で行なうことができ、燃料電池のコスト低減化に大きく寄与することができる。   The phenolic resin impregnated in the carbon short fiber paper or the cured phenolic resin is subsequently carbonized. In order to increase the conductivity of the carbonaceous electrode substrate, carbonization is performed in an inert gas. Carbonization is preferably performed continuously over the entire length of the short carbon fiber paper. If the carbonaceous electrode base material is long, not only the productivity of the carbonaceous electrode base material is increased, but also the membrane electrode assembly (MEA) manufacturing in the subsequent process can be continuously performed, thereby reducing the cost of the fuel cell. Can greatly contribute to the development.

炭素化は、不活性処理雰囲気下にて１０００〜３０００℃の温度範囲で、炭素短繊維紙の全長にわたって連続して焼成処理することが好ましい。本発明の炭素化においては、不活性雰囲気下にて１０００〜３０００℃の温度範囲で焼成する炭素化処理の前に行われる、３００〜８００℃の程度の不活性雰囲気での焼成による前処理を行っても良い。以上の工程により、目的の炭素質電極基材を得ることができる。   Carbonization is preferably performed by continuous firing over the entire length of the short carbon fiber paper in a temperature range of 1000 to 3000 ° C. in an inert treatment atmosphere. In the carbonization of the present invention, a pretreatment by firing in an inert atmosphere of about 300 to 800 ° C. is performed before the carbonization treatment in which the firing is performed in a temperature range of 1000 to 3000 ° C. in an inert atmosphere. You can go. The target carbonaceous electrode substrate can be obtained by the above steps.

＜嵩密度＞
本発明における炭素質電極基材の嵩密度は、０．２０ｇ／ｃｍ3〜０．４０ｇ／ｃｍ3であることが好ましい。嵩密度が０．２０ｇ／ｃｍ3より小さい場合は、炭素短繊維と炭素短繊維の結着が弱いため、セルに組み込んだ際、脱落や剥離が生じる場合があるため好ましくない。また、嵩密度が０．４０ｇ／ｃｍ3より大きい場合は、炭素質電極基材が硬くなりすぎるため、周辺部材との密着性が低下したり、ガスの透過性が下がる場合がある。 <Bulk density>
The bulk density of the carbonaceous electrode substrate of the present invention is preferably 0.20g / cm 3 ~0.40g / cm 3 . When the bulk density is less than 0.20 g / cm 3, the binding between the short carbon fibers and the short carbon fibers is weak. On the other hand, when the bulk density is larger than 0.40 g / cm 3 , the carbonaceous electrode base material becomes too hard, so that the adhesion to the peripheral member may be lowered or the gas permeability may be lowered.

なお、炭素質電極基材の嵩密度は、以下の式より算出される。
嵩密度（ｇ／ｃｍ3）＝目付（ｇ／ｍ2）／厚み（μｍ）。 The bulk density of the carbonaceous electrode substrate is calculated from the following formula.
Bulk density (g / cm 3 ) = weight per unit area (g / m 2 ) / thickness (μm).

＜炭化樹脂比率＞
本発明における炭素質電極基材の炭化樹脂比率は２０〜３５％であることが好ましい。炭化樹脂比率が３５％より大きい場合は、基材が硬くなりすぎるため、周辺部材との密着性が低下したり、ガスの透過性が下がるなどの問題がある。炭化樹脂比率が２０％より小さい場合は、繊維同士の接着力が弱く、わずかな外力で繊維が基材から外れる場合がある。 <Carbonized resin ratio>
The carbonized resin ratio of the carbonaceous electrode substrate in the present invention is preferably 20 to 35%. When the carbonized resin ratio is greater than 35%, the base material becomes too hard, and there are problems such as poor adhesion to peripheral members and low gas permeability. When the carbonized resin ratio is less than 20%, the adhesive strength between the fibers is weak, and the fibers may be detached from the substrate with a slight external force.

なお、炭素質電極基材の炭化樹脂比率は、以下の式より算出される。
炭化樹脂比率（％）＝１−抄紙時炭素繊維目付×積層枚数／電極基材目付。 In addition, the carbonized resin ratio of a carbonaceous electrode base material is calculated from the following formula.
Carbonized resin ratio (%) = 1-carbon fiber weight per paper making × number of laminated sheets / electrode substrate weight.

＜剥離強さ＞
本発明における炭素質電極基材は、両面をテープで固定し、引き剥がしたときの層間の剥離強さが２５Ｎ／４ｃｍ2以上であることが好ましい。剥離強さが２５Ｎ／４ｃｍ2より小さい場合は、燃料電池に組み込んだ際、炭素質電極基材が２枚に剥がれて、そこに反応により発生した生成水が溜まり、電池性能が著しく低下するため好ましくない。 <Peel strength>
The carbonaceous electrode substrate in the present invention preferably has a peel strength between layers of 25 N / 4 cm 2 or more when both surfaces are fixed with a tape and peeled off. When peel strength of 25 N / 4 cm 2 less than, when incorporated in fuel cells, peeling the two carbonaceous electrode substrate, there evolved water reservoir generated by the reaction, since the battery performance is significantly reduced It is not preferable.

なお、燃料電池に組み込んだ際、炭素質電極基材にかかる圧力が高いほど、剥がれやすくなるため、より高い剥離強さが必要となる。   In addition, when it incorporates in a fuel cell, since it becomes easy to peel, so that the pressure concerning a carbonaceous electrode base material is high, higher peeling strength is required.

炭素質電極基材の剥離強度は、図２に示すように炭素質電極基材４（縦２ｃｍ×横２ｃｍ）の上下に両面テープ５を張り、上下の両面テープ５と金属治具６を貼り付ける。さらに上下の金属治具６をそれぞれフック７に引っ掛けたのち、上のフック７を引っ張り試験装置にて持ち上げる（下のフックは固定）。   The peel strength of the carbonaceous electrode substrate is as shown in FIG. wear. Further, after the upper and lower metal jigs 6 are respectively hooked on the hooks 7, the upper hooks 7 are lifted by a tensile test apparatus (the lower hooks are fixed).

この際、炭素質電極基材に荷重がかかり、その界面がはがれ、２枚に分かれる。そのときの強度を炭素質電極基材の剥離強度とする。なお、引き剥がすときの引っ張り速度は、３０ｍｍ／ｍｉｎで行う。   At this time, a load is applied to the carbonaceous electrode base material, the interface is peeled off, and it is divided into two. The strength at that time is defined as the peel strength of the carbonaceous electrode substrate. The pulling speed when peeling off is 30 mm / min.

＜厚み＞
本発明において、炭素質電極基材は、厚みが１５０μｍ以下であることが好ましく、１４０μｍ以下であることがより好ましく、１３０μｍ以下であることがさらに好ましい。前記範囲では、セルスタックの低コスト化、コンパクト化が可能であることから好ましい。貫通方向の電気抵抗も厚みが薄いほど低減でき、反応ガスの流速が保持されやすく、セル全体の性能も安定化する。 <Thickness>
In the present invention, the carbonaceous electrode base material preferably has a thickness of 150 μm or less, more preferably 140 μm or less, and even more preferably 130 μm or less. The above range is preferable because the cost of the cell stack can be reduced and the size can be reduced. The electrical resistance in the penetration direction can be reduced as the thickness is reduced, the flow rate of the reaction gas is easily maintained, and the performance of the entire cell is stabilized.

＜目付＞
本発明において、炭素質電極基材は、炭素短繊維の目付（単位面積あたりの重量）が１６〜４０ｇ／ｍ2であることが好ましい。このとき、半分の目付の炭素繊維紙を２枚以上重ねて上記目付とすることがより好ましい。炭素短繊維は、導電性材料であると同時に、炭素質電極基材の補強材としての役目も果たしている。 <Unit weight>
In the present invention, the carbonaceous electrode base material preferably has a short carbon fiber basis weight (weight per unit area) of 16 to 40 g / m 2 . At this time, it is more preferable to stack two or more carbon fiber papers having a half basis weight to obtain the above basis weight. The short carbon fiber is not only a conductive material but also serves as a reinforcing material for the carbonaceous electrode substrate.

炭素短繊維の目付を１６ｇ／ｍ2以上とすることにより、炭素質電極基材の強度を十分なものとすることができる。また、４０ｇ／ｍ2以下とすることにより、厚みを１５０μｍ以下としても過剰に緻密な構造とならないため好ましい。 By setting the basis weight of the short carbon fibers to 16 g / m 2 or more, the strength of the carbonaceous electrode substrate can be made sufficient. Moreover, it is preferable to set it to 40 g / m 2 or less because an excessively dense structure is not obtained even if the thickness is 150 μm or less.

また本発明において、炭素質電極基材は、連続的に巻き取ることも可能で、炭素質電極基材や燃料電池の生産性、コストの観点から好ましい。特に本発明の炭素質電極基材は、厚みを薄くできるので取り扱いやすく、連続的に巻きやすい。   Moreover, in this invention, a carbonaceous electrode base material can also be wound up continuously, and it is preferable from a viewpoint of the productivity and cost of a carbonaceous electrode base material and a fuel cell. In particular, the carbonaceous electrode substrate of the present invention is easy to handle because it can be made thin, and it is easy to wind continuously.

以下、本発明を実施例によりさらに具体的に説明するが、本発明はこれらに制限されるものではない。   Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

＜厚み測定方法＞
炭素質電極基材の厚みは、厚み測定装置（商品名：「ダイヤルシックネスゲージ７３２１」、ミツトヨ製）を使用し、測定した。このときの測定子の大きさは直径１０ｍｍであり、測定圧力は１．５ｋＰａで行った。 <Thickness measurement method>
The thickness of the carbonaceous electrode substrate was measured using a thickness measuring device (trade name: “Dial Thickness Gauge 7321”, manufactured by Mitutoyo Corporation). The size of the probe at this time was 10 mm in diameter, and the measurement pressure was 1.5 kPa.

＜ガス透過度測定方法＞
ＪＩＳ規格Ｐ−８１１７に準拠した方法によって測定した。炭素質電極基材の試験片を０．６４５ｃｍ2の透過面積の孔を有するセルに挟み、孔から３０４Ｐａの圧力で３００ｍＬのガスを流し、ガスが透過するのにかかった時間を測定し、以下の式より算出した。 <Gas permeability measurement method>
It measured by the method based on JIS specification P-8117. A test piece of carbonaceous electrode substrate was sandwiched between cells having a permeation area of 0.645 cm 2 , 300 mL of gas was passed through the hole at a pressure of 304 Pa, and the time taken for the gas to permeate was measured. It was calculated from the following formula.

ガス透過度（ｍｌ／（ｃｍ2・ｈｒ・Ｐａ））
＝気体透過量（ｍｌ）／（気体透過孔面積（ｃｍ2）・透過時間（ｈｒ）・透過圧（Ｐａ））。 Gas permeability (ml / (cm 2 · hr · Pa))
= Gas permeation amount (ml) / (gas permeation hole area (cm 2 ), permeation time (hr), permeation pressure (Pa)).

＜貫通抵抗測定方法＞
炭素質電極基材の厚さ方向の電気抵抗（貫通抵抗）は、試料３６ｍｍφを金メッキした銅板にはさみ、金メッキした銅板の上下から１．６ＭＰａで２回加圧したのち、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。 <Penetration resistance measurement method>
The electrical resistance (penetration resistance) in the thickness direction of the carbonaceous electrode substrate is obtained by sandwiching a 36 mmφ sample from a gold-plated copper plate, pressurizing it twice at 1.6 MPa from the top and bottom of the gold-plated copper plate, and then pressurizing at 1 MPa. The resistance value when a current was passed at a current density of / cm 2 was measured and determined from the following equation.

貫通抵抗（Ω・ｃｍ2）＝測定抵抗値（Ω）×試料面積（ｃｍ2）。 Penetration resistance (Ω · cm 2 ) = measured resistance value (Ω) × sample area (cm 2 ).

（実施例１）
表１に示す配合で平均繊維径が７μｍ、平均繊維長が３ｍｍのポリアクリロニトリル（ＰＡＮ）系炭素繊維（７μｍ径ＣＦ）、ポリビニルアルコール（ＰＶＡ）及びポリエチレンパルプ（ＰＥパルプ）を、水を分散媒体として均一に分散させ、湿式連続抄紙装置に連続的に抄紙した。引き続き、抄紙されたものを抄紙用フェルト（日本フェルト（株）製）の間に挟んで押圧し（圧力：０．２ＭＰａ）、押圧後に含まれる水分率を７２質量％に調整した。その後、熱ロールに接触させて乾燥し、炭素繊維の目付が約１３ｇ／ｍ2の長尺の炭素繊維紙を得て、ロール状に巻き取った。 Example 1
Polyacrylonitrile (PAN) -based carbon fiber (7 μm diameter CF), polyvinyl alcohol (PVA) and polyethylene pulp (PE pulp) having an average fiber diameter of 7 μm and an average fiber length of 3 mm in the formulation shown in Table 1, water dispersed in the medium Were uniformly dispersed and continuously made into a wet continuous paper making machine. Subsequently, the papermaking product was sandwiched and pressed between papermaking felts (manufactured by Nippon Felt Co., Ltd.) (pressure: 0.2 MPa), and the moisture content contained after pressing was adjusted to 72% by mass. Then, it was made to contact with a hot roll and dried to obtain a long carbon fiber paper having a carbon fiber basis weight of about 13 g / m 2 and wound into a roll.

この炭素繊維紙にフェノール樹脂（商品名：「フェノライトＪ−３２５」、ＤＩＣ（株）製）の２３質量％メタノール溶液を連続的に両面からコートし、最高温度９０℃で１分間乾燥することにより、熱硬化性樹脂を含む炭素繊維紙を得てロール状に巻き取った。   This carbon fiber paper is continuously coated with a 23% by weight methanol solution of phenol resin (trade name: “Phenolite J-325”, manufactured by DIC Corporation) from both sides and dried at a maximum temperature of 90 ° C. for 1 minute. Thus, carbon fiber paper containing a thermosetting resin was obtained and wound into a roll.

前記熱硬化性樹脂を含む炭素繊維紙の抄紙時における下面が表面にくるように２枚の炭素繊維紙を積層してから、離形剤コーティング基材で挟み、ダブルベルトプレス装置にて連続的に加熱プレス（プレス時最大荷重：２０ＭＰａ）し、樹脂硬化炭素繊維紙を得た。続いて、上記樹脂硬化炭素繊維紙を、窒素ガス雰囲気中にて最高温度８００℃の連続焼成炉に１０分間通した後、最高温度１９００℃の連続焼成炉において１０分間加熱し、炭素化することで長さ１００ｍの炭素質電極基材を連続的に得た。得られた炭素質電極基材の嵩密度は０．３２５ｇ／ｃｍ3、炭化樹脂比率は３２％であった。また、剥離強さは３８Ｎ／４ｃｍ2であり、層間剥離が生じにくい炭素質電極基材が得られた。 Two carbon fiber papers are laminated so that the bottom surface of the carbon fiber paper containing the thermosetting resin is on the surface, and then sandwiched with a release agent coating substrate, and continuously with a double belt press device. Were subjected to hot pressing (maximum load during pressing: 20 MPa) to obtain a resin-cured carbon fiber paper. Subsequently, the resin-cured carbon fiber paper is passed through a continuous firing furnace having a maximum temperature of 800 ° C. for 10 minutes in a nitrogen gas atmosphere, and then heated and carbonized in a continuous firing furnace having a maximum temperature of 1900 ° C. for 10 minutes. A carbonaceous electrode substrate having a length of 100 m was continuously obtained. The resulting carbonaceous electrode substrate had a bulk density of 0.325 g / cm 3 and a carbonized resin ratio of 32%. Also, peel strength was 38N / 4 cm 2, delamination hardly occurs carbonaceous electrode substrate was obtained.

（実施例２）
表１に示す配合で平均繊維径が７μｍ、平均繊維長が３ｍｍのポリアクリロニトリル（ＰＡＮ）系炭素繊維（７μｍ径ＣＦ）平均繊維径が４μｍ、平均繊維長が３ｍｍのポリアクリロニトリル（ＰＡＮ）系炭素繊維（４μｍ径ＣＦ）、ポリビニルアルコール（ＰＶＡ）及びビニロン繊維を、水を分散媒体として均一に分散させ、湿式連続抄紙装置により連続的に抄紙した。引き続き、抄紙されたものを抄紙用フェルトの間に挟んで押圧し（圧力：０．２ＭＰａ）、押圧後に含まれる水分率を７６質量％に調整した。その後、熱ロールに接触させて乾燥し、炭素繊維の目付が約１３ｇ／ｍ2の長尺の炭素繊維紙を得てロール状に巻き取った。 (Example 2)
Polyacrylonitrile (PAN) type carbon fiber (7 μm diameter CF) having an average fiber diameter of 7 μm and an average fiber length of 3 mm, and a polyacrylonitrile (PAN) type carbon having an average fiber length of 4 μm and an average fiber length of 3 mm. Fibers (4 μm diameter CF), polyvinyl alcohol (PVA), and vinylon fibers were uniformly dispersed using water as a dispersion medium, and paper was continuously produced by a wet continuous paper machine. Subsequently, the papermaking product was sandwiched and pressed between papermaking felts (pressure: 0.2 MPa), and the moisture content contained after pressing was adjusted to 76% by mass. Then, it was made to contact with a hot roll and dried to obtain a long carbon fiber paper having a carbon fiber basis weight of about 13 g / m 2 and wound into a roll.

その後、実施例１同様にフェノール樹脂を含浸させ、加熱プレス工程、炭素化工程を行うことで、長さ１００ｍの炭素質電極基材を連続的に得た。得られた炭素質電極基材の嵩密度は０．２８３ｇ／ｃｍ3、炭化樹脂比率は２６％であった。また、剥離強さは４６Ｎ／４ｃｍ2であり、層間剥離が生じにくい炭素質電極基材が得られた。 Thereafter, a phenol resin was impregnated in the same manner as in Example 1, and a carbonaceous electrode substrate having a length of 100 m was continuously obtained by performing a heating press step and a carbonization step. The resulting carbonaceous electrode substrate had a bulk density of 0.283 g / cm 3 and a carbonized resin ratio of 26%. Further, the peel strength was 46 N / 4 cm 2 , and a carbonaceous electrode substrate that hardly caused delamination was obtained.

（比較例１）
抄紙後の炭素短繊維紙を、抄紙用フェルトの間に挟んで押圧しなかった以外は、実施例２と同様の方法で炭素質電極基材を連続的に得た。なお、押圧後の炭素短繊維紙の水分率は８８％であった。得られた炭素質電極基材の嵩密度は０．３０８ｇ／ｃｍ3、炭化樹脂比率は２８％であった。また、剥離強さは２０Ｎ／４ｃｍ2であり、実施例と比較して層間剥離が生じやすい炭素質電極基材が得られた。 (Comparative Example 1)
A carbonaceous electrode substrate was continuously obtained in the same manner as in Example 2 except that the carbon short fiber paper after papermaking was not pressed between papermaking felts. In addition, the moisture content of the carbon short fiber paper after pressing was 88%. The resulting carbonaceous electrode substrate had a bulk density of 0.308 g / cm 3 and a carbonized resin ratio of 28%. Further, the peel strength was 20 N / 4 cm 2 , and a carbonaceous electrode base material in which delamination was likely to occur as compared with the Example was obtained.

（比較例２）
表１に示す配合で平均繊維径が７μｍ、平均繊維長が３ｍｍのポリアクリロニトリル（ＰＡＮ）系炭素繊維（７μｍ径ＣＦ）平均繊維径が４μｍ、平均繊維長が３ｍｍのポリアクリロニトリル（ＰＡＮ）系炭素繊維（４μｍ径ＣＦ）、ポリビニルアルコール（ＰＶＡ）を、水を分散媒体として均一に分散させ、湿式連続抄紙装置により連続的に抄紙した。 (Comparative Example 2)
Polyacrylonitrile (PAN) -based carbon fiber (7 μm diameter CF) having an average fiber diameter of 7 μm and an average fiber length of 3 mm, and a polyacrylonitrile (PAN) carbon having an average fiber diameter of 4 μm and an average fiber length of 3 mm. Fiber (4 [mu] m diameter CF) and polyvinyl alcohol (PVA) were uniformly dispersed using water as a dispersion medium, and paper was continuously made by a wet continuous paper machine.

それ以外は、実施例２と同様の方法で炭素質電極基材を連続的に得た。なお、押圧後の炭素短繊維紙の水分率は８８％であった。得られた炭素質電極基材の嵩密度は０．３３６ｇ／ｃｍ3、炭化樹脂比率は２８％であった。また、剥離強さは１５Ｎ／４ｃｍ2であり、実施例と比較して層間剥離が生じやすい炭素質電極基材が得られた。 Otherwise, a carbonaceous electrode substrate was continuously obtained in the same manner as in Example 2. In addition, the moisture content of the carbon short fiber paper after pressing was 88%. The resulting carbonaceous electrode substrate had a bulk density of 0.336 g / cm 3 and a carbonized resin ratio of 28%. Further, the peel strength was 15 N / 4 cm 2 , and a carbonaceous electrode base material in which delamination was likely to occur as compared with the Example was obtained.

実施例、比較例の結果を表１に示す。   The results of Examples and Comparative Examples are shown in Table 1.

Figure 2010031419
Figure 2010031419

本発明における抄紙後の炭素短繊維紙の押圧、乾燥工程を示す概略図である。It is the schematic which shows the press of carbon short fiber paper after papermaking in this invention, and a drying process. 本発明における剥離強さの測定手段を示す概略図である。It is the schematic which shows the measuring means of the peeling strength in this invention.

符号の説明Explanation of symbols

１ 抄紙後の炭素短繊維紙
２ 抄紙用フェルト
３ 熱ロール
４ 炭素質電極基材
５ 両面テープ
６ 金属治具
７ フック DESCRIPTION OF SYMBOLS 1 Short carbon fiber paper after paper making 2 Felt for paper making 3 Heat roll 4 Carbonaceous electrode base material 5 Double-sided tape 6 Metal jig 7 Hook

Claims (10)

抄紙後、連続して抄紙用フェルトの間に挟んで押圧し、熱ロールに接触させて乾燥した、２枚以上の炭素短繊維紙にフェノール樹脂を含浸後、該フェノール樹脂を炭素化して製造する、２枚以上の炭素短繊維紙がフェノール樹脂炭化物を介して積層されてなる炭素質電極基材の製造方法において、
前記炭素短繊維紙が、炭素短繊維とバインダー繊維と、ポリエチレンパルプ又はビニロン繊維とを水に分散した分散液を抄紙したものであることを特徴とする炭素質電極基材の製造方法。 After papermaking, two or more carbon short fiber papers, which are dried by being sandwiched and pressed between papermaking felts and dried, are impregnated with phenolic resin, and then produced by carbonizing the phenolic resin. In the method for producing a carbonaceous electrode base material in which two or more carbon short fiber papers are laminated via a phenol resin carbide,
A method for producing a carbonaceous electrode substrate, wherein the carbon short fiber paper is obtained by papermaking a dispersion of carbon short fibers, binder fibers, and polyethylene pulp or vinylon fibers dispersed in water. 前記押圧により、押圧後の炭素短繊維紙の水分率を６０〜８５質量％に調整する請求項１に記載の炭素質電極基材の製造方法。   The manufacturing method of the carbonaceous electrode base material of Claim 1 which adjusts the moisture content of the carbon short fiber paper after a press to 60-85 mass% by the said press. 前記炭素短繊維が、ポリアクリロニトリル系炭素繊維である請求項１又は２に記載の炭素質電極基材の製造方法。   The method for producing a carbonaceous electrode substrate according to claim 1, wherein the short carbon fibers are polyacrylonitrile-based carbon fibers. 前記バインダー繊維が、ポリビニルアルコールである請求項１から３のいずれか１項に記載の炭素質電極基材の製造方法。   The method for producing a carbonaceous electrode substrate according to any one of claims 1 to 3, wherein the binder fiber is polyvinyl alcohol. 前記抄紙後、押圧前の炭素短繊維紙が、炭素短繊維を３０〜９０質量％、バインダー繊維を５〜３０質量％含み、かつ、ポリエチレンパルプを１０〜７０質量％又はビニロン繊維を１０〜６０質量％含む請求項１から４のいずれか１項に記載の炭素質電極基材の製造方法。   After the paper making, the carbon short fiber paper before pressing contains 30 to 90% by mass of carbon short fibers, 5 to 30% by mass of binder fibers, and 10 to 70% by mass of polyethylene pulp or 10 to 60 of vinylon fibers. The manufacturing method of the carbonaceous electrode base material of any one of Claim 1 to 4 containing the mass%. 前記押圧における圧力が、０．０５〜１ＭＰａである請求項１から５のいずれか１項に記載の炭素質電極基材の製造方法。   The method for producing a carbonaceous electrode substrate according to any one of claims 1 to 5, wherein a pressure in the pressing is 0.05 to 1 MPa. 前記炭素短繊維紙に含浸により付着させるフェノール樹脂の量が、前記炭素短繊維紙中の炭素短繊維１００質量部に対し、７０〜１５０質量部である請求項１から６のいずれか１項に記載の炭素質電極基材の製造方法。   The amount of the phenol resin adhered to the carbon short fiber paper by impregnation is 70 to 150 parts by mass with respect to 100 parts by mass of the carbon short fibers in the carbon short fiber paper. The manufacturing method of the carbonaceous electrode base material of description. 前記炭素短繊維紙にフェノール樹脂を含浸後、炭素化する前に、フェノール樹脂を硬化する請求項１から７のいずれか１項に記載の炭素質電極基材の製造方法。   The method for producing a carbonaceous electrode substrate according to any one of claims 1 to 7, wherein the short carbon fiber paper is impregnated with a phenol resin and then cured before being carbonized. 前記２枚以上の炭素短繊維紙が、抄紙下面が表面にくるように積層する請求項１から８のいずれか１項に記載の炭素質電極基材の製造方法。   The method for producing a carbonaceous electrode substrate according to any one of claims 1 to 8, wherein the two or more carbon short fiber papers are laminated so that a papermaking lower surface is on the surface. 請求項１から９のいずれか１項に記載の炭素質電極基材の製造方法により製造され、以下の（１）〜（３）の条件を満足する炭素質電極基材。
（１）嵩密度が０．２０〜０．４０ｇ／ｃｍ3
（２）炭化樹脂比率が２０〜３５％
（３）剥離強さが２５Ｎ／４ｃｍ2以上 A carbonaceous electrode substrate produced by the method for producing a carbonaceous electrode substrate according to any one of claims 1 to 9, and satisfying the following conditions (1) to (3).
(1) Bulk density is 0.20 to 0.40 g / cm 3
(2) Carbonized resin ratio is 20 to 35%
(3) Peel strength is 25 N / 4 cm 2 or more
JP2008194709A 2008-07-29 2008-07-29 Method for producing carbonaceous electrode substrate Active JP5250328B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2008194709A JP5250328B2 (en) 2008-07-29 2008-07-29 Method for producing carbonaceous electrode substrate

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2008194709A JP5250328B2 (en) 2008-07-29 2008-07-29 Method for producing carbonaceous electrode substrate

Publications (2)

Publication Number Publication Date
JP2010031419A true JP2010031419A (en) 2010-02-12
JP5250328B2 JP5250328B2 (en) 2013-07-31

Family

ID=41736216

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2008194709A Active JP5250328B2 (en) 2008-07-29 2008-07-29 Method for producing carbonaceous electrode substrate

Country Status (1)

Country Link
JP (1) JP5250328B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012018886A (en) * 2010-07-09 2012-01-26 Mitsubishi Rayon Co Ltd Manufacturing method of porous carbon electrode base material
JP2012204073A (en) * 2011-03-24 2012-10-22 Mitsubishi Rayon Co Ltd Porous electrode substrate, and method for manufacturing the same

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62191595A (en) * 1986-02-19 1987-08-21 静岡県 Production of inorganic fiber sheet
WO2001056103A1 (en) * 2000-01-27 2001-08-02 Mitsubishi Rayon Co., Ltd. Porous carbon electrode material, method for manufacturing the same, and carbon fiber paper
JP2003151568A (en) * 2001-11-09 2003-05-23 Mitsubishi Rayon Co Ltd Electrode material for solid high polymer fuel cell and its manufacturing method
JP2004519068A (en) * 2000-09-12 2004-06-24 リダル、インコーポレイテッド Conductive non-woven fabric
JP2004214072A (en) * 2003-01-07 2004-07-29 Toho Tenax Co Ltd Carbon fiber sheet and its manufacturing method
JP2005302558A (en) * 2004-04-13 2005-10-27 Mitsubishi Rayon Co Ltd Carbon electrode base and manufacturing method thereof
JP2006190518A (en) * 2005-01-04 2006-07-20 Mitsubishi Rayon Co Ltd Electrode base material for solid polymer fuel cell and its manufacturing method

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62191595A (en) * 1986-02-19 1987-08-21 静岡県 Production of inorganic fiber sheet
WO2001056103A1 (en) * 2000-01-27 2001-08-02 Mitsubishi Rayon Co., Ltd. Porous carbon electrode material, method for manufacturing the same, and carbon fiber paper
JP2004519068A (en) * 2000-09-12 2004-06-24 リダル、インコーポレイテッド Conductive non-woven fabric
JP2003151568A (en) * 2001-11-09 2003-05-23 Mitsubishi Rayon Co Ltd Electrode material for solid high polymer fuel cell and its manufacturing method
JP2004214072A (en) * 2003-01-07 2004-07-29 Toho Tenax Co Ltd Carbon fiber sheet and its manufacturing method
JP2005302558A (en) * 2004-04-13 2005-10-27 Mitsubishi Rayon Co Ltd Carbon electrode base and manufacturing method thereof
JP2006190518A (en) * 2005-01-04 2006-07-20 Mitsubishi Rayon Co Ltd Electrode base material for solid polymer fuel cell and its manufacturing method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012018886A (en) * 2010-07-09 2012-01-26 Mitsubishi Rayon Co Ltd Manufacturing method of porous carbon electrode base material
JP2012204073A (en) * 2011-03-24 2012-10-22 Mitsubishi Rayon Co Ltd Porous electrode substrate, and method for manufacturing the same

Also Published As

Publication number Publication date
JP5250328B2 (en) 2013-07-31

Similar Documents

Publication Publication Date Title
JP5844760B2 (en) Porous electrode substrate
JP3612518B2 (en) Porous carbon electrode substrate, method for producing the same, and carbon fiber paper
JP5702218B2 (en) Porous electrode substrate for polymer electrolyte fuel cell
JP2006040886A (en) Porous electrode substrate and its manufacturing method
WO2005124907A1 (en) Porous electrode base material and process for producing the same
JP5485212B2 (en) Porous carbon electrode substrate and method for producing the same
TW200306376A (en) Carbon paper and carbon electrode base material for fuel cell made therefrom
JP2003183994A (en) Carbon fiber paper, and porous carbon electrode material for fuel battery using the same
JP4266699B2 (en) Porous electrode substrate for polymer electrolyte fuel cell and method for producing the same
JP6855843B2 (en) Electrodes for redox flow batteries and their manufacturing methods, and redox flow batteries
JP4730888B2 (en) Porous electrode substrate and method for producing the same
JP4187683B2 (en) Porous carbon electrode substrate for fuel cells
JP5398297B2 (en) Method for producing porous carbon electrode substrate
JP5250328B2 (en) Method for producing carbonaceous electrode substrate
JP5297701B2 (en) Method for producing electrode substrate for polymer electrolyte fuel cell
JP5728802B2 (en) Porous carbon electrode substrate and method for producing the same
JP6172131B2 (en) Porous carbon electrode substrate
JP4801354B2 (en) Electrode base material for polymer electrolyte fuel cell and method for producing the same
JP2016012558A (en) Gas diffusion layer for solid polymer fuel cell
JP2004134108A (en) Manufacturing method of precursor sheet-like material for porous carbon electrode base material
JP5560977B2 (en) Method for producing porous carbon electrode substrate
JP2006004858A (en) Porous electrode base material and its manufacturing method
JP2006004858A5 (en)
JP2009280437A (en) Method for producing porous carbon sheet
JP5336912B2 (en) Porous electrode substrate manufacturing method, membrane-electrode assembly using the same, and fuel cell

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20110613

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20120713

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20120724

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20120824

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20130402

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20130415

R151 Written notification of patent or utility model registration

Ref document number: 5250328

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R151

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20160419

Year of fee payment: 3

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

S533 Written request for registration of change of name

Free format text: JAPANESE INTERMEDIATE CODE: R313533

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250