JP2005235656A - Separator for fuel cell and its manufacturing method - Google Patents

Separator for fuel cell and its manufacturing method Download PDF

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JP2005235656A
JP2005235656A JP2004045228A JP2004045228A JP2005235656A JP 2005235656 A JP2005235656 A JP 2005235656A JP 2004045228 A JP2004045228 A JP 2004045228A JP 2004045228 A JP2004045228 A JP 2004045228A JP 2005235656 A JP2005235656 A JP 2005235656A
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separator
fuel cell
groove
molding
manufacturing
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Atsunori Satake
厚則 佐竹
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Mitsubishi Pencil Co Ltd
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    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30Hydrogen technology
    • Y02E60/50Fuel cells
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50Manufacturing or production processes characterised by the final manufactured product

Abstract

<P>PROBLEM TO BE SOLVED: To provide a separator for a fuel cell which has extremely high corrosion resistance, and superior mechanical strength, in which variations in dimension due to shrinkage after forming and/or after sintering are reduced to the minimum, and which, by suppressing the final manufacturing process to the minimum, becomes inexpensive, highly productive, and highly suitable for manufacturing the fuel cells of solid polymer type or the like, and also to provide its manufacturing method. <P>SOLUTION: The separator A for the fuel cell is composed by sintering treatment after grooves are formed by forming molds on both faces of front and rear faces. The grooves of an area ratio 90% or more out of groove part 10 in the groove pattern 20 of the rear side faces exist in plane symmetrical positions in relation to the front and the rear side faces. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

本発明は、耐腐食性が極めて高く、機械的強度に優れると共に、表面裏面にガス流路用等の溝部を容易に製造することができる固体高分子型などの燃料電池用に好適な燃料電池用セパレータ及びその製造方法に関する。   INDUSTRIAL APPLICABILITY The present invention is a fuel cell suitable for a fuel cell of a solid polymer type or the like that has extremely high corrosion resistance and excellent mechanical strength, and can easily produce a groove for a gas flow path on the front and back surfaces. The present invention relates to a separator and a manufacturing method thereof.

燃料電池は、クリーンであり、高い発電効率を発現できる次世代エネルギーとして期待が高く、特に近年、高出力が得られ作動温度域が比較的低いという利点のため固体高分子型の燃料電池が注目されている。   Fuel cells are highly anticipated as next-generation energy that is clean and can exhibit high power generation efficiency. In particular, solid polymer fuel cells have attracted attention in recent years because of their advantages of high output and relatively low operating temperature range. Has been.

この固体高分子型の燃料電池は、一般に、イオン交換膜からなる固体高分子の電解質膜と、その両側に設けた2つの電極とそれぞれの電極に水素などの燃料ガスあるいは酸素などの酸化剤ガスを供給するガス供給溝を設けたセパレータなどからなる単セルを積層したスタック、及びその外側に設けた2つの集電体から構成されている。
この燃料電池では、電解質部分に高性能の高分子電解質膜を使用している関係で作動温度が80〜100℃と低いにも拘わらず高い出力の発電が可能である。
This solid polymer fuel cell generally includes a solid polymer electrolyte membrane composed of an ion exchange membrane, two electrodes provided on both sides thereof, and a fuel gas such as hydrogen or an oxidant gas such as oxygen on each electrode. It is comprised from the stack which laminated | stacked the single cell which consists of a separator etc. which provided the gas supply groove | channel which supplies, and two collectors provided in the outer side.
In this fuel cell, high-performance power generation is possible even though the operating temperature is as low as 80 to 100 ° C. because a high-performance polymer electrolyte membrane is used for the electrolyte portion.

この固体高分子型燃料電池のセパレータには、燃料ガスと酸化ガスとを完全に分離した状態で電極に供給するために高度のガス不透過性が要求され、また、発電効率を高くするために電池の内部抵抗を小さくする必要があり、そのために導電性が高いことが必要である。更に、電池反応に伴う発熱を効率よく放散させ、電池内温度分布を均一化するために高い熱伝導性や長期耐久性の確保のために優れた耐腐食性、耐薬品性、機械的強度を備える必要がある。   This polymer electrolyte fuel cell separator is required to have a high degree of gas impermeability in order to supply fuel electrode and oxidizing gas to the electrode in a completely separated state, and to increase power generation efficiency. It is necessary to reduce the internal resistance of the battery, and for this purpose, it is necessary to have high conductivity. In addition, it efficiently dissipates the heat generated by the battery reaction and uniforms the temperature distribution in the battery to ensure high thermal conductivity and long-term durability, with excellent corrosion resistance, chemical resistance, and mechanical strength. It is necessary to prepare.

従来のセパレータとしては、例えば、金属セパレータ、炭素ブロックを切り出して樹脂を含浸させたもの、炭素材と樹脂を用いてモールド成形したもの、ガラス状炭素からなるものが知られている。
また、かさ密度0.6〜1.0の膨張黒鉛シートを粉砕して、最大粒子500μm、平均粒子径150〜300μmの粒度に調整し、これに粒状樹脂又は液体樹脂を添加、混合し、モールド成形、真空ホットプレス成型等の方法で、成形して得られる片面又は両面にガス流路となる複数のリブを有するかさ密度が1.4〜1.7の膨張黒鉛製燃料電池用セパレータ(特許文献1参照)や、カーボンと熱硬化性樹脂とを混練し、成形することで平板状のプリフォームを製造するプリフォーム製造工程と、このプリフォームを所定の形状に圧縮成形すると共に硬化温度に加熱することで燃料電池用セパレータの製造方法において、前記圧縮成形に用いる成形型の型締め速度を、前記熱硬化性樹脂の材料特性に応じて変更することを特徴とする燃料電池用セパレータの製造方法(特許文献2参照)が知られている。
As a conventional separator, for example, a metal separator, a carbon block cut out and impregnated with a resin, a carbon material and a resin molded with a resin, and a glassy carbon are known.
Also, an expanded graphite sheet having a bulk density of 0.6 to 1.0 is pulverized to adjust the particle size to a maximum particle size of 500 μm and an average particle size of 150 to 300 μm. A separator for an expanded graphite fuel cell having a bulk density of 1.4 to 1.7 having a plurality of ribs serving as gas passages on one or both sides obtained by molding, vacuum hot press molding, or the like (patented) Reference 1), a preform manufacturing process for manufacturing a flat plate preform by kneading and molding carbon and a thermosetting resin, and the preform is compression-molded into a predetermined shape and at a curing temperature. In the method for manufacturing a separator for a fuel cell by heating, a clamping speed of a mold used for the compression molding is changed according to material characteristics of the thermosetting resin. A method for manufacturing a separator for a pond (see Patent Document 2) is known.

しかしながら、金属製のセパレータの場合、腐食性が高いため、長時間の使用に耐えるには難しいという課題がある。また、炭素ブロックからの切り出し加工樹脂含浸のセパレータは、加工にコストがかかる上、機械的強度が弱いために薄く加工することは困難であるといった課題がある。
更に、モールド成形したものや、成形後に焼成工程を経る炭素材料等のセパレータ、並びに、上記特許文献1及び2のセパレータでは、成型時の内部応力の不均一性やその形状が複雑であるために成型後及び/又は焼成後の収縮時に均等収縮させるのが難しいといった課題がある。また、不均等に収縮した場合、寸法精度が不足してしまい、ひどいものになると板全体が反ったりうねったりして使い物にならず、結局平板の成形体を作製し、それに機械加工で平面度をだしたり、溝を形成する必要が出てくるなどの課題がある。更に、軽度な変形のものでも、精度を出すためには切削、ラッピング、溝加工等の余分な後工程が増え、コストを上昇させる原因となる課題がある。
特開2000−223133号公報(特許請求の範囲、実施例等) 特開2002−373666号公報(特許請求の範囲、実施例等)
However, in the case of a metallic separator, there is a problem that it is difficult to withstand long-time use because of high corrosivity. Further, a separator impregnated with resin cut out from a carbon block is expensive to process and has a problem that it is difficult to process thinly because of its low mechanical strength.
Furthermore, the molded material, the carbon material separator that undergoes a firing process after molding, and the separators of Patent Documents 1 and 2 described above are complicated in internal stress non-uniformity and shape during molding. There is a problem that uniform shrinkage is difficult after shrinkage after molding and / or firing. In addition, if it shrinks unevenly, the dimensional accuracy will be insufficient, and if it becomes terrible, the entire plate will be warped or wavy and will not be usable, eventually producing a flat molded body and flattened by machining There is a problem that it becomes necessary to form a groove or to form a groove. Furthermore, even in the case of slight deformation, in order to increase accuracy, extra post-processes such as cutting, lapping, and grooving increase, and there is a problem that causes an increase in cost.
JP 2000-223133 A (Claims, Examples, etc.) JP 2002-373666 A (Claims, Examples, etc.)

本発明は、上記従来の課題等に鑑み、これを解消しようとするものであり、耐腐食性が極めて高く、機械的強度に優れると共に、成形後や焼成後の収縮による寸法のバラツキが少なく、最終加工を最小限に抑えることにより結果的に安価で量産性のある固体高分子型などの燃料電池用に好適な燃料電池用セパレータ及びその製造方法を提供することを目的とする。   The present invention is to solve this problem in view of the above-described conventional problems, and has extremely high corrosion resistance, excellent mechanical strength, and less variation in dimensions due to shrinkage after molding or firing, An object of the present invention is to provide a separator for a fuel cell suitable for a fuel cell of a solid polymer type or the like that is inexpensive and mass-produced as a result of minimizing the final processing, and a method for manufacturing the same.

本発明者は、上記従来の課題等について、鋭意検討した結果、表面と裏面の両面に溝部を成形型により形成した後、焼成処理により構成される燃料電池用セパレータ及びその製造方法であって、該表裏面の溝パターンにおける溝部の特定の面積比が表面と裏面で面対照の位置に存在せしめることにより、また、表裏面の溝パターンにおける溝部の特定の面積比が表面と裏面で面対照の位置に存在する成形型を用いて成形することにより、上記目的の燃料電池用セパレータ及びその製造方法が得られることを見い出し、本発明を完成するに至ったのである。   As a result of intensive studies on the above-described conventional problems, etc., the present inventor is a fuel cell separator configured by firing treatment after forming grooves on both the front and back surfaces with a molding die, and a method for manufacturing the same. The specific area ratio of the groove in the groove pattern on the front and back surfaces is present at the surface contrast position on the front and back surfaces, and the specific area ratio of the groove in the groove pattern on the front and back surfaces is the surface contrast on the front surface and the back surface. The inventors have found that the above-described fuel cell separator and a method for producing the same can be obtained by molding using a mold located at a position, and the present invention has been completed.

すなわち、本発明は、次の(1)〜(5)に存する。
(1) 表面と裏面の両面に溝部を成形型により形成した後、焼成処理により構成される燃料電池用セパレータであって、該表裏面の溝パターンにおける溝部の面積比90%以上が表面と裏面で面対照の位置に存在していることを特徴とする燃料電池用セパレータ。
(2) 表裏面の溝パターンにおける溝部の面積比95%以上が表面と裏面で面対照の位置に存在している上記(1)記載の燃料電池用セパレータ。
(3) 表面と裏面の両面に溝部を成形型により形成した後、焼成処理により構成される燃料電池用セパレータの製造方法であって、上記成形型は、表裏面の溝パターンにおける溝部の面積比90%以上が表面と裏面で面対照の位置に存在する成形型を用いて成形してなることを特徴とする燃料電池用セパレータの製造方法。
(4) 成形後又は焼成後に、位置決め用の加工、孔抜き加工及び表裏面で異なる部位の溝加工から選ばれる少なくとも1種の加工処理を行う上記(3)記載の燃料電池用セパレータの製造方法。
(5) 焼成処理が非酸化雰囲気中で加熱して炭化させる上記(3)又は(4)記載の燃料電池用セパレータの製造方法。
That is, the present invention resides in the following (1) to (5).
(1) A fuel cell separator configured by forming a groove on both sides of a front surface and a back surface using a molding die and then performing a firing process, wherein the groove portion has a groove area ratio of 90% or more in the front and back surfaces. A separator for a fuel cell, wherein the separator is located in a plane-contrast position.
(2) The fuel cell separator according to the above (1), wherein an area ratio of 95% or more of the groove portions in the groove pattern on the front and back surfaces is present at the position of surface comparison between the front surface and the back surface.
(3) A manufacturing method of a fuel cell separator configured by forming a groove portion on both the front surface and the back surface using a molding die and then performing a firing process, wherein the molding die has an area ratio of the groove portion in the groove pattern on the front and back surfaces. A method for producing a separator for a fuel cell, characterized in that 90% or more is molded using a molding die in which the front surface and the back surface are present in a surface contrast position.
(4) The method for producing a fuel cell separator according to (3), wherein after molding or firing, at least one kind of processing selected from processing for positioning, hole punching, and groove processing at different sites on the front and back surfaces is performed. .
(5) The method for producing a separator for a fuel cell according to the above (3) or (4), wherein the firing treatment is carbonized by heating in a non-oxidizing atmosphere.

本発明によれば、耐腐食性が極めて高く、機械的強度に優れると共に、成形後や焼成後の収縮による寸法のバラツキが少なく、最終加工を最小限に抑えることにより結果的に安価で量産性のある固体高分子型などの燃料電池用に好適な燃料電池用セパレータ及びその製造方法が提供される。   According to the present invention, the corrosion resistance is extremely high, the mechanical strength is excellent, the dimensional variation due to shrinkage after molding and baking is small, and the final processing is minimized, resulting in low cost and mass productivity. A fuel cell separator suitable for a solid polymer type fuel cell and a method for producing the same are provided.

以下に、本発明の実施形態を詳しく説明する。
本発明の燃料電池用セパレータは、表面と裏面の両面に溝部を成形型により形成した後、焼成処理により構成される燃料電池用セパレータであって、該表裏面の溝パターンにおける溝部の面積比90%以上が表面と裏面で面対照の位置に存在していることを特徴とするものである。
また、本発明の燃料電池用セパレータの製造方法は、表面と裏面の両面に溝部を成形型により形成した後、焼成処理により構成される燃料電池用セパレータの製造方法であって、上記成形型は、表裏面の溝パターンにおける溝部の面積比90%以上が表面と裏面で面対照の位置に存在する成形型を用いて成形してなることを特徴とするものである。
以下で、「本発明」というときは、上記の燃料電池用セパレータとその製造方法の両方を含むことをいう。
Hereinafter, embodiments of the present invention will be described in detail.
The fuel cell separator according to the present invention is a fuel cell separator configured by forming a groove portion on both the front surface and the back surface using a molding die and then performing a firing treatment, and the groove portion has an area ratio of 90 in the groove pattern on the front and back surfaces. % Or more exist in the position of the surface contrast on the front surface and the back surface.
The method for manufacturing a fuel cell separator of the present invention is a method for manufacturing a fuel cell separator configured by forming a groove on both the front surface and the back surface using a molding die, and then performing a firing process. The front and back groove patterns are formed by using a mold having an area ratio of 90% or more of the front and back surfaces in the position of surface contrast between the front surface and the back surface.
Hereinafter, “the present invention” means that both the fuel cell separator and the manufacturing method thereof are included.

本発明において、燃料電池用セパレータの原材料としては、所定の溝部を成形型により形成した後、焼成処理により目的の燃料電池用セパレータが成形できる金属材料以外のものであれば、特に限定されず、例えば、炭素材料、熱硬化性樹脂、熱可塑性樹脂、及びこれらの混合材料、更に、硬化促進剤、可塑剤、溶剤などの各セパレータ成形用添加剤が挙げられる。
本発明では、上述の如く、金属材料を用いないため、金属材質に見られる腐食を考慮する必要がないものである。
In the present invention, the raw material of the fuel cell separator is not particularly limited as long as it is a metal material other than the metal material that can form the desired fuel cell separator by firing after the predetermined groove is formed by the molding die. For example, carbon material, a thermosetting resin, a thermoplastic resin, and mixed materials thereof, and further additives for forming a separator such as a curing accelerator, a plasticizer, and a solvent.
In the present invention, as described above, since no metal material is used, it is not necessary to consider the corrosion observed in the metal material.

使用することができる炭素材料としては、特に限定されず、例えば、ガラス状炭素、等方性炭素材、黒鉛粉末〔高配向性熱分解黒鉛(HOPG)、キッシュ黒鉛、天然黒鉛、人造黒鉛、フラーレンを含む〕、炭素繊維〔気相成長炭素繊維、PAN系炭素繊維、黒鉛繊維を含む〕、カーボンナノチューブ、膨張黒鉛シート等が挙げられる。これらの炭素材料は、必要とする電気伝導性値等により、適宜選択され、各単独でも2種以上の混合物でも使用することができるが、特に伝導性向上効果が高いものが望ましい。
また、炭素材料をつなぐバインダー又は熱可塑性樹脂としては、例えば、フェノール樹脂、ポリイミド樹脂、フラン樹脂、エポキシ樹脂、キシレン樹脂、不飽和ポリエステル樹脂、メラミン樹脂、アルキッド樹脂、コプナ樹脂などが挙げられ、加熱により分子間架橋を生じ三次元化して硬化し、特別の炭素前駆体化処理を行うことなく高い炭素残さ収率を示すものが好適に用いられる。
熱可塑性樹脂としては、例えば、ポリ塩化ビニル−ポリ酢酸ビニル共重合体、ポリ塩化ビニル、ポリアクリロニトリル、ポリビニルアルコール、ポリアミドなどが挙げられる。
The carbon material that can be used is not particularly limited. For example, glassy carbon, isotropic carbon material, graphite powder [highly oriented pyrolytic graphite (HOPG), quiche graphite, natural graphite, artificial graphite, fullerene Carbon fiber (including vapor-grown carbon fiber, PAN-based carbon fiber, and graphite fiber), carbon nanotube, expanded graphite sheet, and the like. These carbon materials are appropriately selected depending on the required electrical conductivity value and the like, and can be used alone or in a mixture of two or more, but those having a particularly high conductivity improving effect are desirable.
Examples of binders or thermoplastic resins that connect carbon materials include phenolic resins, polyimide resins, furan resins, epoxy resins, xylene resins, unsaturated polyester resins, melamine resins, alkyd resins, copna resins, and the like. Thus, an intermolecular cross-link is generated, which is three-dimensionally cured and exhibits a high carbon residue yield without performing a special carbon precursor treatment.
Examples of the thermoplastic resin include polyvinyl chloride-polyvinyl acetate copolymer, polyvinyl chloride, polyacrylonitrile, polyvinyl alcohol, and polyamide.

本発明では、燃料電池用セパレータに要求されるガス不透過性、導電性、熱伝導性や耐腐食性、耐薬品性、機械的強度等を考慮して、上記各原材料を種々選択して好適な配合量等となる混合物(組成物)を用いる。例えば、炭素材料、バインダー及び硬化促進剤などからなる混合物、炭素材料及び熱硬化性樹脂などからなる混合物、炭素材料、熱可塑性樹脂及び可塑剤などからなる混合物などが挙げられる。
上記で得られた混合物等は、溝部の面積比90%以上が表面と裏面で面対照の位置に存在する溝パターンの成形型に好適な量を充填して成形する(成形工程)。
成形型の溝の形状(断面V状、凹状等)、深さ、幅及びそのパターンは、特に限定されず、燃料電池種、用途、構造などにより、適宜好適な溝形状、深さ、幅、溝パターン(後述する図1参照)などに設定される。
In the present invention, in consideration of gas impermeability, conductivity, thermal conductivity, corrosion resistance, chemical resistance, mechanical strength, etc. required for a fuel cell separator, the above-mentioned raw materials are variously selected and suitable. Use a mixture (composition) that provides an appropriate blending amount. Examples thereof include a mixture composed of a carbon material, a binder and a curing accelerator, a mixture composed of a carbon material and a thermosetting resin, and a mixture composed of a carbon material, a thermoplastic resin and a plasticizer.
The mixture and the like obtained above are molded by filling a suitable amount of a groove pattern mold in which a groove area ratio of 90% or more is present at the position of the surface contrast between the front surface and the back surface (molding step).
There are no particular limitations on the groove shape (cross-section V shape, concave shape, etc.), depth, width and pattern thereof of the mold, and suitable groove shapes, depths, widths, and the like depending on the fuel cell type, application, structure, etc. A groove pattern (see FIG. 1 described later) or the like is set.

本発明では、上記成形型は、表裏面の溝パターンにおける溝部の面積比90%以上が表面と裏面で面対照の位置に存在する成形型を用いることが必要であり、好ましくは95%以上が表面と裏面で面対照の位置に存在する成形型、更に好ましくは表面と裏面で面対照で一致する(100%となる)位置に存在する成形型を用いることが望ましい。
この表裏面の溝パターンにおける溝部の面積比が90%未満の場合は、得られるセパレータは溝形状が表裏異なる部分で平面に対して凹凸状のうねりなどが発生したりして、本発明の効果を発揮する目的のセパレータが得られなくなり、好ましくない。
In the present invention, it is necessary to use a mold in which the area ratio of the groove portion in the groove pattern on the front and back surfaces is 90% or more at the position of the surface contrast between the front surface and the back surface, preferably 95% or more. It is desirable to use a mold that exists in a surface-contrast position on the front surface and the back surface, and more preferably, a mold that exists in a position where the front and back surfaces coincide with each other in the surface contrast (100%).
When the area ratio of the groove portions in the groove pattern on the front and back surfaces is less than 90%, the obtained separator may have irregular undulations with respect to the plane at portions where the groove shapes are different from the front and back surfaces. This is not preferable because a desired separator exhibiting the above cannot be obtained.

本発明において、焼成処理では、例えば、上記成形型を70〜150℃に加熱して固化処理し(乾燥工程)、得られた樹脂プレートを型から外し、更に、非酸化雰囲気下で加熱処理を行って焼成せしめ(焼成工程)、目的のセパレータが得られる。
非酸化雰囲気下としては、窒素ガス、アルゴンガスなどの不活性雰囲気中、真空中の少なくとも1種、すなわち、これらの各単独雰囲気中、または、各雰囲気中を二工程、三工程で焼成することにより、バインダー等を炭素化して表裏面の溝パターンにおける溝部の面積比90%以上が表面と裏面で面対照の位置に存在してなる燃料電池用セパレータが作製されることとなる。
上記焼成処理は、好ましくは、上記各雰囲気中で昇温速度を制御しつつ焼成することが望ましい。焼成温度は、上記炭素化を好適に発揮せしめる温度とすることが望ましい。
In the present invention, in the baking treatment, for example, the mold is heated to 70 to 150 ° C. and solidified (drying process), the obtained resin plate is removed from the mold, and further, the heat treatment is performed in a non-oxidizing atmosphere. This is done and fired (firing step) to obtain the desired separator.
As a non-oxidizing atmosphere, firing in at least one kind in an inert atmosphere such as nitrogen gas or argon gas, in vacuum, that is, in each of these single atmospheres or in each atmosphere in two or three steps. As a result, the binder or the like is carbonized to produce a fuel cell separator in which an area ratio of 90% or more of the groove portions in the groove pattern on the front and back surfaces is present at the position of surface comparison between the front surface and the back surface.
The firing treatment is preferably performed while controlling the temperature rising rate in each of the above atmospheres. The firing temperature is preferably set to a temperature at which the above carbonization can be suitably performed.

本発明において、必要に応じて、上記成形(工程)後や焼成(工程)後に、積層スタックのための位置決め用の外周部加工、孔抜き加工、及び最終仕上げのための表裏面で異なる部位の溝加工等、最低限の加工処理を行うことができる。
なお、表裏面で異なる溝加工は、この溝加工後も、表裏面の溝パターンにおける溝部の面積比90%以上が表面と裏面で面対照の位置に存在してなることが必要である。
In the present invention, if necessary, after the molding (step) or after firing (step), the outer peripheral portion for positioning for the laminated stack, the hole punching, and the different parts on the front and back for the final finish Minimum processing such as grooving can be performed.
It should be noted that different groove processing on the front and back surfaces requires that a groove area ratio of 90% or more in the groove pattern on the front and back surfaces exists at the surface-contrast position on the front and back surfaces even after this groove processing.

図1(a)は、本発明の燃料電池用セパレータの具体的実施形態を示す上面図であり、(b)は図1(a)の上面図(裏面を上からみた図)である。
本実施形態の燃料電池用セパレータAは、図1(a)及び(b)に示すように、凹状溝部10の溝パターン20を表裏96%面対照としたものである。21は、上記成形(工程)後や焼成(工程)後、孔抜き加工により形成した貫通孔である。
なお、図2(a)は、本発明の範囲外となる燃料電池用セパレータの上面図であり、(b)は図2(a)の上面図(裏面を上からみた図)である。この燃料電池用セパレータBは、溝部10の溝パターン20を表裏で70%面対照としたものであり、成形後の収縮や変形のバラツキが大きくなり、本発明の効果を発揮しないものである。
FIG. 1A is a top view showing a specific embodiment of a fuel cell separator according to the present invention, and FIG. 1B is a top view of FIG.
As shown in FIGS. 1A and 1B, the fuel cell separator A of the present embodiment uses the groove pattern 20 of the concave groove portion 10 as a front and back 96% surface contrast. 21 is a through-hole formed by punching after the molding (step) or after firing (step).
2A is a top view of the fuel cell separator that is out of the scope of the present invention, and FIG. 2B is a top view of FIG. 2A (view of the back surface as viewed from above). This fuel cell separator B has a groove pattern 20 of the groove portion 10 that is 70% surface-contrast on the front and back sides, and has a large variation in shrinkage and deformation after molding, and does not exhibit the effects of the present invention.

このように構成される本発明では、耐腐食性が極めて高く、機械的強度に優れると共に、成形後や焼成後の収縮による寸法のバラツキが少なく、最終加工を最小限に抑えることにより結果的に安価で量産性のある固体高分子型などの燃料電池用に好適な燃料電池用セパレータ及びその製造方法が得られることとなる。
すなわち、得られるセパレータは、その製造工程において、成形型を用いており、最終製品に寸法が成形工程、乾燥工程、焼成工程の少なくとも何れか一工程を経ることにより成型直後の型から取り外したものの寸法よりも小さくなるものである。この収縮が大きいほど、また、形状が複雑であるほど、均等に収縮させることは難しい。
In the present invention configured as described above, the corrosion resistance is extremely high, the mechanical strength is excellent, the dimensional variation due to shrinkage after molding and after firing is small, and the final processing is minimized as a result. A fuel cell separator suitable for a fuel cell such as a solid polymer type that is inexpensive and mass-produced, and a method for producing the same are obtained.
In other words, the obtained separator uses a molding die in its manufacturing process, and the final product is removed from the mold immediately after molding through at least one of the molding process, the drying process, and the firing process. It is smaller than the dimension. The larger the shrinkage and the more complicated the shape, the more difficult it is to shrink uniformly.

本発明では、用いる成形型を、上述の如く、表裏面の溝パターンにおける溝部の面積比90%以上が表面と裏面で面対照の位置に存在してなる成形型を用いているので、成形後の収縮や変形のバラツキを極力抑えることが可能となるものである。
そのため、寸法調整のための最終的な加工をなくすこと、または、極力減らすことができ、結果的に安価に効率よく製造することができるものとなる。また、もともと加工を必要としないものでも、寸法精度が上がるために、更に不良品率が下がり、コストダウンを図ることができる。更に、成形時の溝パターンを表裏100%面対照にて成形した場合、均一に収縮させることができるため、成形後の寸法調整のための加工部位をかなり削減することができることとなる。
In the present invention, as described above, as described above, a molding die in which an area ratio of 90% or more of the groove portions in the front and back groove patterns exists at the position of the surface contrast between the front surface and the back surface is used. It is possible to suppress variations in shrinkage and deformation as much as possible.
Therefore, the final processing for dimension adjustment can be eliminated or reduced as much as possible, and as a result, it can be manufactured efficiently at low cost. Even those that do not require processing originally have higher dimensional accuracy, so that the defective product rate can be further reduced and the cost can be reduced. Furthermore, when the groove pattern at the time of molding is molded with the front and back 100% surface contrast, the groove pattern can be uniformly shrunk, so that the processing site for dimension adjustment after molding can be considerably reduced.

また、本発明の燃料電池用セパレータは、その材質に金属材料以外の炭素材料、熱硬化性材料などを用いているため、金属材質に見られる腐食を考慮する必要がないものであり、耐腐食性、機械的強度に優れると共に、ガス不透過性、導電性、熱伝導性や耐薬品性に優れたものとなる。
更に、溝形状が表裏ほぼ同一(90%以上)であるため、溝の配置が電解質膜を通して同じ位置となるため、電気化学的反応の効率も上がり、発電効率を上げるといった効果を発揮せしめることとなる。
In addition, the fuel cell separator of the present invention uses a carbon material other than a metal material, a thermosetting material, or the like as its material, so that it is not necessary to consider the corrosion seen in the metal material. In addition to excellent properties and mechanical strength, it has excellent gas impermeability, electrical conductivity, thermal conductivity and chemical resistance.
Furthermore, since the groove shape is almost identical (90% or more) on the front and back sides, the groove arrangement is the same position through the electrolyte membrane, so that the efficiency of electrochemical reaction is increased and the power generation efficiency is increased. Become.

次に、本発明を実施例及び比較例により、更に詳述するが、本発明は下記実施例に限定されるものではない。   EXAMPLES Next, although an Example and a comparative example demonstrate this invention further in full detail, this invention is not limited to the following Example.

〔実施例1〕
フラン樹脂〔日立化成工業(株)製 ヒタフランVF−303〕90重量部と天然鱗状黒鉛(日本黒鉛工業(株)製 平均粒径5μm)10重量部に、硬化促進剤としてp−トルエンスルホン酸を1.5重量部加え、3000rpmで2分間混合撹拌した混合物を内寸法59mm×59mm×1.5mmで図1(a)及び(b)に示される表裏で面対照(96%)となる溝パターンのプレート成形用金型に適量流し込み、この型を100℃に加熱して固化処理後、できた樹脂プレートを型から外し、焼成炉を用いて1500℃の加熱処理を行い、炭素製セパレータを得た。
得られたセパレータの寸法は、47.3mm×47.3mm×1.21mm(溝部の幅
0.80mm、深さ0.48mm)であり、反りうねりはなかった。
[Example 1]
90 parts by weight of furan resin (Hitafuran VF-303 manufactured by Hitachi Chemical Co., Ltd.) and 10 parts by weight of natural scaly graphite (average particle diameter of 5 μm manufactured by Nippon Graphite Industries Co., Ltd.) are mixed with p-toluenesulfonic acid as a curing accelerator. A groove pattern in which 1.5 parts by weight is added and mixed and stirred at 3000 rpm for 2 minutes and has an inner dimension of 59 mm × 59 mm × 1.5 mm and is a surface contrast (96%) on the front and back shown in FIGS. 1 (a) and (b) Pour an appropriate amount into the mold for plate molding, heat the mold to 100 ° C. and solidify, remove the resulting resin plate from the mold, and heat-treat at 1500 ° C. using a firing furnace to obtain a carbon separator. It was.
The dimensions of the obtained separator were 47.3 mm × 47.3 mm × 1.21 mm (groove width 0.80 mm, depth 0.48 mm), and there was no warpage or undulation.

〔比較例1〕
上記実施例1と同様に、フラン樹脂〔日立化成工業(株)製 ヒタフランVF−303〕90重量部と天然鱗状黒鉛(日本黒鉛工業(株)製 平均粒径5μm)10重量部に、硬化促進剤としてp−トルエンスルホン酸を1.5重量部加え、3000rpmで2分間混合撹拌した混合物を内寸法59mm×59mm×1.5mmで図2(a)及び(b)に示される表裏で面対照70%の溝パターンのプレート成形用金型に適量流し込み、この型を100℃に加熱して固化処理後、できた樹脂プレートを型から外し、焼成炉を用いて1500℃の加熱処理を行い、炭素製セパレータを得た。
得られたセパレータの寸法は、47.3mm×47.3mm×1.21mm(溝部の幅
0.80mm、深さ0.48mm)であり、溝形状が表裏異なる部分で平面に対して0.2mmの凹凸状のうねりが発生した。
[Comparative Example 1]
In the same manner as in Example 1, 90 parts by weight of furan resin [Hitafuran VF-303 manufactured by Hitachi Chemical Co., Ltd.] and 10 parts by weight of natural scaly graphite (average particle diameter of 5 μm manufactured by Nippon Graphite Industries Co., Ltd.) 1.5 parts by weight of p-toluenesulfonic acid was added as an agent, and the mixture which was mixed and stirred at 3000 rpm for 2 minutes had an inner dimension of 59 mm × 59 mm × 1.5 mm, and the front and back surfaces shown in FIGS. 2A and 2B were compared. Pour an appropriate amount into a 70% groove pattern plate molding mold, heat the mold to 100 ° C., solidify, remove the resulting resin plate from the mold, and perform a heat treatment at 1500 ° C. using a firing furnace. A carbon separator was obtained.
The size of the obtained separator is 47.3 mm × 47.3 mm × 1.21 mm (groove width 0.80 mm, depth 0.48 mm), and the groove shape is 0.2 mm with respect to the plane at different parts. Uneven undulations occurred.

〔実施例2〕
上記実施例1において、図1(a)及び(b)に準拠するものであるが、表裏で面対照90%となる溝パターンのプレート成形用金型を用いた以外は、上記実施例1と同様にして、炭素製セパレータを得た。得られたセパレータの寸法は、47.3mm×47.3mm×1.21mm(溝部の幅0.80mm、深さ0.48mm)であり、反りうねりはなかった。
[Example 2]
In Example 1, which is based on FIGS. 1 (a) and 1 (b), except for using a plate molding die having a groove pattern of 90% surface contrast on the front and back sides, Example 1 and Similarly, a carbon separator was obtained. The dimensions of the obtained separator were 47.3 mm × 47.3 mm × 1.21 mm (groove width 0.80 mm, depth 0.48 mm), and there was no warpage or undulation.

〔実施例3〕
フラン樹脂〔日立化成工業(株)製 ヒタフランVF−303〕10重量部とポリ塩化ビニル−ポリ酢酸ビニル共重合体(新第一塩ビ社製 ZEST−C150S)40重量部との混合樹脂に、天然鱗状黒鉛(日本黒鉛工業(株)製 平均粒径5μm)50重量部を加え、更に可塑剤としてジアリルフタレートモノマーを20重量%添加した材料を、ヘンシェル・ミキサーを用いて分散し、ミキシング用二本ロールを用いて十分に混練を繰り返して組成物を得た。この組成物をミキサーで粉砕した後、ふるいにかけて100μm以下の粉末を得た。
得られた粉末を内寸法59mm×59mm×1.5mmで図1(a)及び(b)に示される表裏で面対照(96%)となる溝パターンのプレート成形用金型でプレス成形した後に、有酸素雰囲気中で300℃の温度で乾燥硬化させ、真空焼成炉を用いて1000℃の加熱処理を行い炭素製セパレータを得た。
得られたセパレータの寸法は、57.8mm×57.8mm×1.24mm(溝部の幅0.98mm、深さ0.50mm)であり、反りうねりはなかった。
Example 3
A mixed resin of 10 parts by weight of a furan resin (Hitafuran VF-303, manufactured by Hitachi Chemical Co., Ltd.) and 40 parts by weight of a polyvinyl chloride-polyvinyl acetate copolymer (ZEST-C150S, manufactured by Shin-Daiichi PVC Co., Ltd.) Two materials for mixing are dispersed by adding 50 parts by weight of scaly graphite (average particle diameter 5 μm, manufactured by Nippon Graphite Industries Co., Ltd.) and further adding 20% by weight of diallyl phthalate monomer as a plasticizer using a Henschel mixer. Mixing was sufficiently repeated using a roll to obtain a composition. This composition was pulverized with a mixer and sieved to obtain a powder of 100 μm or less.
After the obtained powder was press-molded with an inner dimension of 59 mm × 59 mm × 1.5 mm using a plate-molding die having a groove pattern, which is a surface contrast (96%) shown in FIGS. 1 (a) and 1 (b). Then, it was dried and cured at a temperature of 300 ° C. in an aerobic atmosphere, and was subjected to a heat treatment at 1000 ° C. using a vacuum firing furnace to obtain a carbon separator.
The dimensions of the obtained separator were 57.8 mm × 57.8 mm × 1.24 mm (groove width 0.98 mm, depth 0.50 mm), and there was no warping or undulation.

〔比較例2〕
上記実施例3と同様に、但し、金型が図2(a)及び(b)に示される表裏で面対照70%の溝パターンのプレート成形用金型を用いた以外は上記実施例3と同様にして炭素製セパレータを得た。
得られたセパレータの寸法は、57.8mm×57.8mm×1.24mm(溝部の幅0.98mm、深さ0.50mm)であり、溝形状が表裏異なる部分で平面に対して0.19mmの凹凸状のうねりが発生した。
[Comparative Example 2]
As in Example 3 above, except that the mold is the same as in Example 3 except that a mold for plate formation having a groove pattern of 70% surface contrast on the front and back shown in FIGS. 2 (a) and (b) is used. Similarly, a carbon separator was obtained.
The dimensions of the obtained separator are 57.8 mm × 57.8 mm × 1.24 mm (groove width 0.98 mm, depth 0.50 mm), and the groove shape is 0.19 mm with respect to the plane at different parts. Uneven undulations occurred.

本発明の燃料電池用セパレータの実施形態を示す上面図であり、(b)は(a)の上面図(裏面を上からみた図)である。It is a top view which shows embodiment of the separator for fuel cells of this invention, (b) is the top view (figure which looked at the back surface from the top) of (a). (a)は、本発明の範囲外となる燃料電池用セパレータの上面図であり、(b)は(a)の上面図(裏面を上からみた図)である。(A) is a top view of the separator for fuel cells that is outside the scope of the present invention, and (b) is a top view of (a) (view of the back surface as viewed from above).

符号の説明Explanation of symbols

A 燃料電池用セパレータ
10 凹状溝部
20 溝パターン
A Fuel cell separator 10 Concave groove 20 Groove pattern

Claims (5)

表面と裏面の両面に溝部を成形型により形成した後、焼成処理により構成される燃料電池用セパレータであって、該表裏面の溝パターンにおける溝部の面積比90%以上が表面と裏面で面対照の位置に存在していることを特徴とする燃料電池用セパレータ。   A fuel cell separator formed by forming a groove on both the front surface and the back surface using a molding die, and then firing, wherein a surface ratio of 90% or more of the groove portion in the groove pattern on the front and back surfaces is compared between the front surface and the back surface. A separator for a fuel cell, characterized by being present at the position of 表裏面の溝パターンにおける溝部の面積比95%以上が表面と裏面で面対照の位置に存在している請求項1記載の燃料電池用セパレータ。   The fuel cell separator according to claim 1, wherein an area ratio of 95% or more of the groove portions in the groove pattern on the front and back surfaces is present at the position of surface comparison between the front surface and the back surface. 表面と裏面の両面に溝部を成形型により形成した後、焼成処理により構成される燃料電池用セパレータの製造方法であって、上記成形型は、表裏面の溝パターンにおける溝部の面積比90%以上が表面と裏面で面対照の位置に存在する成形型を用いて成形してなることを特徴とする燃料電池用セパレータの製造方法。   A method for manufacturing a separator for a fuel cell, wherein a groove is formed on both surfaces of a front surface and a back surface by a molding die and then fired. The molding die has a groove area ratio of 90% or more in the groove pattern on the front and back surfaces. A method for producing a separator for a fuel cell, characterized in that it is molded using a molding die that exists in a surface-contrast position on the front surface and the back surface. 成形後又は焼成後に、位置決め用の加工、孔抜き加工及び表裏面で異なる部位の溝加工から選ばれる少なくとも1種の加工処理を行う請求項3記載の燃料電池用セパレータの製造方法。   The method for producing a fuel cell separator according to claim 3, wherein at least one kind of processing selected from processing for positioning, hole punching, and groove processing at different parts on the front and back surfaces is performed after molding or firing. 焼成処理が非酸化雰囲気中で加熱して炭化させる請求項3又は4記載の燃料電池用セパレータの製造方法。   The method for producing a separator for a fuel cell according to claim 3 or 4, wherein the baking treatment is performed by heating in a non-oxidizing atmosphere and carbonizing.
JP2004045228A 2004-02-20 2004-02-20 Separator for fuel cell and its manufacturing method Withdrawn JP2005235656A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006318822A (en) * 2005-05-13 2006-11-24 Electric Power Dev Co Ltd Separator for fuel cell

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006318822A (en) * 2005-05-13 2006-11-24 Electric Power Dev Co Ltd Separator for fuel cell

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