JP5291368B2 - Fuel cell separator material, fuel cell separator using the same, fuel cell stack, and method for producing fuel cell separator material - Google Patents

Fuel cell separator material, fuel cell separator using the same, fuel cell stack, and method for producing fuel cell separator material Download PDF

Info

Publication number
JP5291368B2
JP5291368B2 JP2008086158A JP2008086158A JP5291368B2 JP 5291368 B2 JP5291368 B2 JP 5291368B2 JP 2008086158 A JP2008086158 A JP 2008086158A JP 2008086158 A JP2008086158 A JP 2008086158A JP 5291368 B2 JP5291368 B2 JP 5291368B2
Authority
JP
Japan
Prior art keywords
fuel cell
layer
cell separator
component
stainless steel
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.)
Expired - Fee Related
Application number
JP2008086158A
Other languages
Japanese (ja)
Other versions
JP2009238691A (en
Inventor
義孝 澁谷
紀充 渋谷
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.)
JX Nippon Mining and Metals Corp
Original Assignee
JX Nippon Mining and Metals Corp
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 JX Nippon Mining and Metals Corp filed Critical JX Nippon Mining and Metals Corp
Priority to JP2008086158A priority Critical patent/JP5291368B2/en
Publication of JP2009238691A publication Critical patent/JP2009238691A/en
Application granted granted Critical
Publication of JP5291368B2 publication Critical patent/JP5291368B2/en
Expired - Fee Related 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Landscapes

  • Other Surface Treatments For Metallic Materials (AREA)
  • Fuel Cell (AREA)

Description

本発明は、表面にＡｕ又はＡｕ合金（Ａｕを含む層）が形成された燃料電池用セパレータ材料、それを用いた燃料電池用セパレータ、及び燃料電池スタックに関する。   The present invention relates to a fuel cell separator material having a surface on which Au or an Au alloy (a layer containing Au) is formed, a fuel cell separator using the same, and a fuel cell stack.

固体高分子型の燃料電池用セパレータは電気伝導性を有し、各単セルを電気的に接続し、各単セルで発生したエネルギー（電気）を集電すると共に、各単セルへ供給する燃料ガス（燃料液体）や空気（酸素）の流路が形成されている。このセパレータは、インターコネクタ、バイポーラプレート、集電体とも称される。
このような燃料電池用セパレータとして、従来はカーボン板にガス流通路を形成したものが使用されていたが、材料コストや加工コストが大きいという問題がある。一方、カーボン板の代わりに金属板を用いる場合、高温で酸化性の雰囲気に曝されるために腐食や溶出が問題となる。このようなことから、ステンレス鋼板の表面にＡｕ，Ｒｕ、Ｒｈ、Ｐｄ、Ｏｓ、Ｉｒ及びＰｔ等から選ばれる貴金属とＡｕとの合金をスパッタ成膜して導電部分を形成する技術が知られている（特許文献１）。
一方、ステンレス鋼基材の酸化被膜の上に、Ｔｉ，Ｚｒ、Ｈｆ、Ｖ、Ｎｂ、Ｔａ、Ｃｒ、Ｍｏ、Ｗ等からなる中間層を介してＡｕ膜を形成する燃料電池用セパレータが知られている（特許文献２）。この中間層は、基材酸化膜との密着性、すなわちＯ（酸素原子）との結合性が良いとともに、金属または半金属のためにＡｕ膜との密着性、結合性が良いとされている。
又、ステンレス鋼板の表面に、下地処理を施さずに酸性浴にて金めっきを施す燃料電池用金属製セパレータが報告されている（特許文献３）。 The polymer electrolyte fuel cell separator has electrical conductivity, and electrically connects each single cell, collects energy (electricity) generated in each single cell, and supplies fuel to each single cell. Gas (fuel liquid) and air (oxygen) flow paths are formed. This separator is also called an interconnector, a bipolar plate, or a current collector.
Conventionally, a fuel cell separator having a gas flow path formed on a carbon plate has been used, but there is a problem that the material cost and processing cost are high. On the other hand, when a metal plate is used instead of the carbon plate, corrosion and elution become a problem because it is exposed to an oxidizing atmosphere at a high temperature. For this reason, a technique for forming a conductive portion by sputtering an alloy of a noble metal selected from Au, Ru, Rh, Pd, Os, Ir, Pt, etc. and Au on the surface of a stainless steel plate is known. (Patent Document 1).
On the other hand, a fuel cell separator is known in which an Au film is formed on an oxide film of a stainless steel substrate through an intermediate layer made of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, or the like. (Patent Document 2). This intermediate layer has good adhesion to the base oxide film, that is, good bonding with O (oxygen atom), and good adhesion and bonding to the Au film because of the metal or metalloid. .
In addition, a metal separator for fuel cells has been reported in which the surface of a stainless steel plate is subjected to gold plating in an acid bath without applying a base treatment (Patent Document 3).

特開２００１−２９７７７７号公報JP 2001-297777 A 特開２００４−１８５９９８号公報JP 2004-185998 A 特開２００４−２９６３８１号公報JP 2004-296281 A

しかしながら、上記した特許文献１記載の技術の場合、密着性の良いＡｕ合金膜を得るためには、ステンレス鋼表面の酸化皮膜を取り除く処理が必要であり、酸化被膜の除去が不充分な場合は貴金属膜の密着性が低下するという問題がある。
又、特許文献２記載の技術の場合、腐食性環境で使用すると、導電性薄膜の厚みが数１０ｎｍ以下の場合、中間層を構成する（半）金属が腐食性環境下で耐食性がないため溶出し、接触抵抗が高くなる場合がある。一方、特許文献３記載の技術の場合、湿式の金めっきの電着形状が粒状であり、金めっきの付着量が少ないと、基材表面の一部に非めっき部分となる部分が生じる。そのため、基材表面全体を均一に金めっきするためには、Ａｕの付着量を多くする必要がある。 However, in the case of the technique described in Patent Document 1 described above, in order to obtain an Au alloy film with good adhesion, it is necessary to remove the oxide film on the surface of the stainless steel, and when the removal of the oxide film is insufficient. There is a problem that the adhesion of the noble metal film is lowered.
In the case of the technique described in Patent Document 2, when used in a corrosive environment, if the thickness of the conductive thin film is several tens of nanometers or less, the (semi) metal constituting the intermediate layer does not have corrosion resistance in the corrosive environment. However, the contact resistance may increase. On the other hand, in the case of the technique described in Patent Document 3, when the electrodeposition shape of wet gold plating is granular and the amount of gold plating attached is small, a portion that becomes a non-plated portion is generated on a part of the substrate surface. Therefore, in order to uniformly plate the entire surface of the substrate with gold, it is necessary to increase the adhesion amount of Au.

すなわち、本発明は上記の課題を解決するためになされたものであり、ステンレス鋼基材表面にＡｕを含む高耐食性の導電性膜を高い密着性で成膜することができる燃料電池用セパレータ材料、それを用いた燃料電池用セパレータ、燃料電池スタック、及び燃料電池用セパレータ材の製造方法の提供を目的とする。   That is, the present invention has been made to solve the above-described problems, and is a fuel cell separator material capable of forming a highly corrosion-resistant conductive film containing Au on a stainless steel substrate surface with high adhesion. An object of the present invention is to provide a fuel cell separator, a fuel cell stack using the same, and a method for producing a fuel cell separator material.

本発明者らは種々検討した結果、ステンレス鋼基材の表面にＦｅ、Ｏ及び所定の貴金属とを含む中間層を形成させ、中間層の上にＡｕを含む層を形成させることで、含Ａｕ（合金）層をステンレス鋼基材上に強固かつ均一に形成可能であり、燃料電池用セパレータに要求される耐食性も確保できることを見出した。
上記の目的を達成するために、本発明の燃料電池用セパレータ材料は、厚みが５０〜１５０μｍの板材からなるステンレス鋼基材の表面に、Ｒｕ、Ｒｈ、Ｐｄ、Ｉｒ、Ｏｓ及びＰｔからなる群より選択される少なくとも１種類以上のＡｕより易酸化性の貴金属からなる第１成分とＡｕとの合金層、又はＡｕ単独層が形成され、前記合金層は、Ａｕを４０質量％以上含有し、かつＸ線光電子分光により前記合金層を深さ方向に分析したとき、いずれの深さにおいても前記第１成分の含有量（質量％）がＡｕ＞前記第１成分を満たし、かつ、前記合金層又はＡｕ単独層の厚みが１ｎｍ以上１０ｎｍ以下であり、前記合金層又はＡｕ単独層と前記ステンレス鋼基材との間に、ステンレス鋼の構成元素であるＦｅを含み，Ｏを１０質量％以上含有し，前記第１成分を１０質量％以上含有し，かつＸ線光電子分光により深さ方向に分析したとき、いずれの深さにおいてもＡｕの含有量（質量％）が前記第１成分≧Ａｕ＞０を満たし、厚みが１ｎｍ以上１０ｎｍ以下の中間層が形成されている。 As a result of various investigations, the present inventors have formed an intermediate layer containing Fe, O and a predetermined noble metal on the surface of the stainless steel base material, and formed a layer containing Au on the intermediate layer. It has been found that the (alloy) layer can be formed firmly and uniformly on a stainless steel substrate, and the corrosion resistance required for a fuel cell separator can be secured.
In order to achieve the above object, the fuel cell separator material of the present invention is made of a group consisting of Ru, Rh, Pd, Ir, Os, and Pt on the surface of a stainless steel substrate made of a plate material having a thickness of 50 to 150 μm. An alloy layer of Au and a first component composed of a noble metal that is more easily oxidizable than at least one or more kinds of Au selected, or an Au single layer is formed, and the alloy layer contains Au in an amount of 40% by mass or more, When the alloy layer is analyzed in the depth direction by X-ray photoelectron spectroscopy, the content (mass%) of the first component satisfies Au> the first component at any depth, and the alloy layer Alternatively, the Au single layer has a thickness of 1 nm or more and 10 nm or less, and includes Fe, which is a constituent element of stainless steel, between the alloy layer or Au single layer and the stainless steel base material, and contains 10 mass% or more of O. And When the first component is contained in an amount of 10% by mass or more and analyzed in the depth direction by X-ray photoelectron spectroscopy, the content (% by mass) of Au is the first component ≧ Au> 0 at any depth. An intermediate layer satisfying the thickness of 1 nm to 10 nm is formed.

前記合金層中のＡｕの含有割合が基材側から表面側に向かって増加することが好ましい。
前記合金層の最表面にＡｕ単独層が形成されていることが好ましい。
前記合金層は、前記第１成分と、前記貴金属のうち前記第１成分と異なる元素からなる第２成分とＡｕとの合金であるとよい。 It is preferable that the content ratio of Au in the alloy layer increases from the substrate side toward the surface side.
It is preferable that an Au single layer is formed on the outermost surface of the alloy layer.
The alloy layer includes a first component, or if there an alloy of the second component and Au made of different elements as the first component of the noble metal.

本発明の燃料電池セパレータは，前記燃料電池用セパレータ材料を用いたものである。
本発明の燃料電池スタックは、前記燃料電池セパレータを用いたものである。 The fuel cell separator of the present invention uses the fuel cell separator material.
The fuel cell stack of the present invention uses the fuel cell separator.

本発明の燃料電池用セパレータ材料の製造方法は、前記燃料電池用セパレータ材料の製造方法であって、ステンレス鋼基材表面にスパッタ法により前記第１成分を１〜１０ｎｍ被覆した後，スパッタ法によりＡｕを１〜１０ｎｍ被覆する。


Method for manufacturing a fuel cell separator material of the present invention is a manufacturing method of the fuel cell separator material, after 1~10nm covering the first component by a sputtering method to a stainless steel substrate surface by sputtering Au is coated 1 to 10 nm .


本発明によれば、ステンレス鋼基材の表面にＦｅ、Ｏ、及び所定の貴金属とを含む中間層を形成させ、中間層の上にＡｕを含む層又はＡｕ合金層を形成させることで、Ａｕ層又はＡｕを含む層をステンレス鋼基材上に強固かつ均一に形成させることができ、燃料電池用セパレータに要求される耐食性も確保できる。   According to the present invention, an intermediate layer containing Fe, O, and a predetermined noble metal is formed on the surface of a stainless steel substrate, and a Au-containing layer or an Au alloy layer is formed on the intermediate layer, whereby Au The layer or the layer containing Au can be formed firmly and uniformly on the stainless steel substrate, and the corrosion resistance required for the fuel cell separator can be ensured.

以下、本発明の実施形態に係る燃料電池用セパレータ材料について説明する。なお、本発明において％とは、特に断らない限り、質量％を示すものとする。
又、本発明において「燃料電池用セパレータ」とは、電気伝導性を有し、各単セルを電気的に接続し、各単セルで発生したエネルギー（電気）を集電すると共に、各単セルへ供給する燃料ガス（燃料液体）や空気（酸素）の流路が形成されたものをいう。セパレータは、インターコネクタ、バイポーラプレート、集電体とも称される。
従って、燃料電池用セパレータとして、板状の基材表面に凹凸状の流路を設けたセパレータの他、上記したパッシブ型ＤＭＦＣ用セパレータのように板状の基材表面にガスやメタノールの流路孔が開口したセパレータを含む。
さらに、固体高分子形燃料電池としては、固体高分子を膜材料に用いて電極で挟んだ構造を有するものであればよく、用いる燃料にも特に限定はないが、燃料としては例えば水素やメタノールが挙げられる。 Hereinafter, a fuel cell separator material according to an embodiment of the present invention will be described. In the present invention, “%” means “% by mass” unless otherwise specified.
In the present invention, the “fuel cell separator” has electrical conductivity, electrically connects each single cell, collects energy (electricity) generated in each single cell, and collects each single cell. A fuel gas (fuel liquid) or air (oxygen) flow path is formed. The separator is also referred to as an interconnector, a bipolar plate, or a current collector.
Therefore, as a separator for a fuel cell, in addition to a separator provided with an uneven channel on the surface of a plate-like substrate, a gas or methanol channel on the plate-like substrate surface like the above-described passive DMFC separator It includes a separator having holes.
Further, as the solid polymer fuel cell, any fuel cell may be used as long as it has a structure in which a solid polymer is used as a membrane material and sandwiched between electrodes, and the fuel to be used is not particularly limited. Is mentioned.

<第１の実施形態>
以下、本発明の第１の実施形態に係る燃料電池用セパレータ材料について説明する。図１に示すように、第１の実施形態に係る燃料電池用セパレータ材料は、ステンレス鋼基材２の表面に中間層２ａが形成され、中間層２ａの上に合金層６が形成されてなる。 <First Embodiment>
Hereinafter, the fuel cell separator material according to the first embodiment of the present invention will be described. As shown in FIG. 1, the fuel cell separator material according to the first embodiment has an intermediate layer 2a formed on the surface of a stainless steel substrate 2 and an alloy layer 6 formed on the intermediate layer 2a. .

<ステンレス鋼基材>
燃料電池用セパレータ材料としては、耐食性が要求され、導電性膜となる合金層（Ａｕ単独層）には耐食性と導電性が求められる。このため、基材には耐食性が求められるためステンレス鋼材を用いる。
ステンレス鋼基材２の材質はステンレス鋼であれば特に制限されない。又、ステンレス鋼基材２の形状も特に制限されず、第１成分及び金をスパッタできる形状であればよいが、セパレータ形状にプレス成形することを考えると、ステンレス鋼基材の形状は板材であることが好ましく、ステンレス鋼基材全体の厚みが５０〜１５０μｍ以上の板材であることが好ましい。
中間層２ａに含まれるＯ（酸素）は、ステンレス鋼基材２を空気中に放置することにより自然に形成されるが、酸化雰囲気で積極的にＯを形成してもよい。 <Stainless steel substrate>
The fuel cell separator material is required to have corrosion resistance, and the alloy layer (Au single layer) serving as the conductive film is required to have corrosion resistance and conductivity. For this reason, since a corrosion resistance is calculated | required for a base material, a stainless steel material is used.
The material of the stainless steel substrate 2 is not particularly limited as long as it is stainless steel. Further, the shape of the stainless steel substrate 2 is not particularly limited as long as the first component and the gold can be sputtered. However, considering the press forming into the separator shape, the shape of the stainless steel substrate is a plate material. It is preferable that the thickness of the entire stainless steel substrate is 50 to 150 μm or more.
O (oxygen) contained in the intermediate layer 2a is naturally formed by leaving the stainless steel substrate 2 in the air, but O may be positively formed in an oxidizing atmosphere.

<合金層>
ステンレス鋼基材２の表面に、Ｒｕ、Ｒｈ、Ｐｄ、Ｉｒ、Ｏｓ及びＰｔからなる群より選択される少なくとも１種類以上のＡｕより易酸化性の貴金属からなる第１成分とＡｕとの合金層６が形成されている。この合金層は、Ａｕを４０質量％以上含有し、かつ前記第１成分の含有量がＡｕ>前記第１成分を満たしている。
合金層６は、ステンレス鋼基材にＡｕの特性（耐食性、導電性、装飾性等）を付与するためのものである。又、上記貴金属は、電位-ｐＨ図からＡｕより易酸化性であり、この特性を利用し、上記第１成分を以下の中間層の構成元素として用いる。第１成分は単一の元素から成っていてもよく、複数の元素から成っていてもよいが、コストが低く酸化物を形成し易いＰｄが好ましい。 <Alloy layer>
An alloy layer of Au and a first component made of a noble metal that is more oxidizable than Au selected from the group consisting of Ru, Rh, Pd, Ir, Os, and Pt on the surface of the stainless steel substrate 2 6 is formed. This alloy layer contains 40% by mass or more of Au, and the content of the first component satisfies Au> the first component.
The alloy layer 6 is for imparting Au characteristics (corrosion resistance, conductivity, decoration, etc.) to the stainless steel substrate. Further, the noble metal is more oxidizable than Au from the potential-pH diagram, and using this characteristic, the first component is used as a constituent element of the following intermediate layer. The first component may be composed of a single element or may be composed of a plurality of elements, but Pd is preferable because it is low in cost and easily forms an oxide.

合金層は、後述するＸＰＳ分析により確認することができる。合金層の厚みは１〜１０ｎｍである。合金層の厚みが１ｎｍ未満であると、ステンレス鋼基材上に燃料電池用セパレータに要求される耐食性を確保できなくなる。合金層の厚みが１０ｎｍを超えると省金化が図られずコストアップとなる。
又、合金層において、Ａｕ濃度が４０質量％未満であると、燃料電池用セパレータに要求される耐食性を確保できなくなる。 The alloy layer can be confirmed by XPS analysis described later. The thickness of the alloy layer is 1 to 10 nm. When the thickness of the alloy layer is less than 1 nm, the corrosion resistance required for the fuel cell separator cannot be secured on the stainless steel substrate. If the thickness of the alloy layer exceeds 10 nm, it is not possible to save money and the cost increases.
Further, if the Au concentration in the alloy layer is less than 40% by mass, the corrosion resistance required for the fuel cell separator cannot be secured.

なお、合金層６の表面にＡｕ単独層が形成されていてもよい。又、合金層６が存在せず、以下の中間層の表面がすべてＡｕ単独層であってもよい。Ａｕ単独層は、ＸＰＳ分析によりＡｕの濃度がほぼ１００％の部分である。
又、合金層６の中間層側において、主に第１成分からなる組成領域（貴金属領域）を有していてもよい。 Note that an Au single layer may be formed on the surface of the alloy layer 6. Further, the alloy layer 6 may not be present, and the surfaces of the following intermediate layers may be all Au single layers. The Au single layer is a portion where the concentration of Au is almost 100% by XPS analysis.
Further, the alloy layer 6 may have a composition region (precious metal region) mainly composed of the first component on the intermediate layer side.

<中間層>
合金層（又はＡｕ単独層）６とステンレス鋼基材２との間に、ステンレス鋼の構成元素であるＦｅを含み，Ｏを１０質量％以上含有し，前記第１成分を１０質量％以上含有し，かつ，Ａｕの含有量が前記第１成分≧Ａｕを満たし厚みが１ｎｍ以上１０ｎｍ以下の中間層２ａが存在する。
通常、ステンレス鋼基材は表面に酸化層を有しており、酸化され難いＡｕ（含有）層をステンレス鋼表面に直接形成させるのは難しい。一方、上記貴金属はＡｕに比べて酸化され易く、ステンレス鋼基材の表面でＣｒ酸化物中のＯ原子と酸化物を形成し、ステンレス鋼基材表面に強固に結合するものと考えられる。
又、上記貴金属は耐食性が他の金属と比べ高い。これらの点で、Ａｕを含んだ導電性膜（上記合金層又はＡｕ単独層）の厚みが数１０ｎｍ以下の場合には、従来、中間層に用いられてきた元素であるＴｉ，Ｚｒ、Ｈｆ、Ｖ、Ｎｂ、Ｔａ、Ｃｒ、Ｍｏ、Ｗ等に比べ、前記第１成分を含む中間層の方が耐食性が高く、金属の溶出がない中間層を形成することができる。 <Intermediate layer>
Between the alloy layer (or Au single layer) 6 and the stainless steel base material 2, Fe, which is a constituent element of stainless steel, is contained in an amount of 10 mass% or more, and the first component is contained in an amount of 10 mass% or more. In addition, there is an intermediate layer 2a in which the Au content satisfies the first component ≧ Au and the thickness is 1 nm or more and 10 nm or less.
Usually, a stainless steel substrate has an oxide layer on the surface, and it is difficult to form an Au (containing) layer that is difficult to be oxidized directly on the stainless steel surface. On the other hand, it is considered that the noble metal is more easily oxidized than Au, and forms an O atom and an oxide in Cr oxide on the surface of the stainless steel substrate and is firmly bonded to the surface of the stainless steel substrate.
The noble metal has higher corrosion resistance than other metals. In these respects, when the thickness of the conductive film containing Au (the alloy layer or the Au single layer) is several tens of nm or less, Ti, Zr, Hf, which are elements conventionally used for the intermediate layer, Compared to V, Nb, Ta, Cr, Mo, W, etc., the intermediate layer containing the first component has higher corrosion resistance and can form an intermediate layer free from metal elution.

前記中間層の厚みは耐食性の観点から１ｎｍ以上とし、厚みの上限は、第１成分のコストの点から１０ｎｍ以下である。
ここでＸＰＳ（Ｘ−ｒａｙ ｐｈｏｔｏｅｌｅｃｔｒｏｎ ｓｐｅｃｔｒｏｍｅｔｅｒ）分析は、分析したい部分及び元素を指定し、深さ方向における指定元素の濃度を検出するものである。指定する元素は、Ａｕ、第１成分、Ｏ、Ｆｅ、Ｎｉ、Ｃｒであり、後述する第２成分を用いた場合は第２成分を指定に加える。 The thickness of the intermediate layer is 1 nm or more from the viewpoint of corrosion resistance, and the upper limit of the thickness is 10 nm or less from the viewpoint of the cost of the first component.
Here, XPS (X-ray photoelectron spectrometer) analysis designates a portion and element to be analyzed and detects the concentration of the designated element in the depth direction. The elements to be specified are Au, the first component, O, Fe, Ni, and Cr. When the second component described later is used, the second component is added to the specification.

Ｏの含有量を１０質量％以上とした理由は、Ｏの含有量が１０質量％未満である部分は、第１成分とＯ原子が充分な酸化物を形成しておらず、中間層として機能しないと考えられるからである。   The reason why the O content is 10% by mass or more is that the portion where the O content is less than 10% by mass does not form a sufficient oxide with the first component and O atoms, and functions as an intermediate layer. It is because it is thought that it does not do.

合金層中のＡｕの割合が基材側から表面側に向かって増加する傾斜組成になっていることが好ましい。ここで、Ａｕの割合（質量％）は、上記したＸＰＳ分析で求めることができる。合金層又はＡｕ単独層の厚みは、ＸＰＳ分析でのスパッタレート（２．６ｎｍ／ｍｉｎ）から換算した値である。
合金層を傾斜組成とすると、合金層の基材側ではＡｕより易酸化性の第１成分の割合が多くなり、ステンレス鋼基材表面との結合が強固になる一方、合金層の表面側ではＡｕの特性が強くなるので、耐食性が向上する。 It is preferable to have a gradient composition in which the proportion of Au in the alloy layer increases from the substrate side toward the surface side. Here, the ratio (mass%) of Au can be obtained by the XPS analysis described above. The thickness of the alloy layer or Au single layer is a value converted from the sputtering rate (2.6 nm / min) in XPS analysis.
When the alloy layer has a gradient composition, the ratio of the first component that is more oxidizable than Au increases on the base material side of the alloy layer, and the bond with the surface of the stainless steel base material becomes stronger, whereas on the surface side of the alloy layer Since the characteristics of Au become strong, the corrosion resistance is improved.

<燃料電池用セパレータ材料の製造>
燃料電池用セパレータ材料の中間層の形成方法としては、ステンレス鋼基材の表面酸化膜を除去せずに、この基材表面に乾式めっきにより前記第１成分を被覆した後，乾式めっきによりＡｕ又はＡｕ合金を被覆する方法が挙げられる。
本発明においては、ステンレス鋼基材の表面酸化膜を除去しないことで、表面酸化膜中のＯに第１の成分が結合し、中間層を形成することができる。又、基材２の表面酸化膜を除去後、第１の成分の酸化物を乾式めっきすることや、基材２の表面酸化膜を除去後、第１の成分をターゲットとし酸化雰囲気で乾式めっきすることによっても中間層を形成することができる。
乾式めっきによる第１成分の厚みは１〜１０ｎｍ程度とし，Ａｕ又はＡｕ合金の厚みは１〜１０ｎｍ程度とすることができる。
ここで、乾式めっきとしては、真空蒸着、イオンプレーティングやスパッタ等の物理蒸着（ＰＶＤ）、化学蒸着（ＣＶＤ）を挙げることができるがこれらに限られない。 <Manufacture of fuel cell separator materials>
As a method for forming the intermediate layer of the fuel cell separator material, the surface oxide film of the stainless steel base material is not removed, and the surface of the base material is coated with the first component by dry plating. The method of coat | covering Au alloy is mentioned.
In the present invention, by removing the surface oxide film of the stainless steel substrate, the first component is bonded to O in the surface oxide film, and an intermediate layer can be formed. Also, after removing the surface oxide film of the base material 2, dry plating the oxide of the first component, or after removing the surface oxide film of the base material 2 and dry plating in an oxidizing atmosphere using the first component as a target. By doing so, the intermediate layer can be formed.
The thickness of the first component by dry plating can be about 1 to 10 nm, and the thickness of Au or Au alloy can be about 1 to 10 nm.
Here, examples of the dry plating include, but are not limited to, vacuum vapor deposition, physical vapor deposition (PVD) such as ion plating and sputtering, and chemical vapor deposition (CVD).

特に、乾式めっきがスパッタ法であることが好ましい。スパッタ法の場合、以下のようにして成膜することができる。
まず、ステンレス鋼基材の表面酸化膜を除去せずに、第１の成分をターゲットとしてスパッタ成膜することにより、表面酸化膜中のＯに第１の成分が結合し、中間層を形成することができる。又、基材２の表面酸化膜を除去後、第１の成分の酸化物をターゲットとしてスパッタ成膜することや、基材２の表面酸化膜を除去後、第１の成分をターゲットとし酸化雰囲気でスパッタ成膜することによっても中間層を形成することができる。
なお、スパッタの際、基材の表面酸化膜を適度に除去し、基材表面のクリーニングを目的として逆スパッタ（イオンエッチング）を行ってもよい。逆スパッタは、例えばＲＦ１００Ｗ程度の出力で、アルゴン圧力０．２Ｐａ程度としてアルゴンガスを基材に照射して行うことができる。
中間層のＡｕは、以下の合金層を形成するためのＡｕスパッタにより、Ａｕ原子が中間層に入り込むことによって中間層内に含まれるようになる。又、第１成分とＡｕを含む合金ターゲットを用いて基材表面にスパッタ成膜してもよい。 In particular, dry plating is preferably a sputtering method. In the case of sputtering, the film can be formed as follows.
First, without removing the surface oxide film of the stainless steel substrate, the first component is bonded to O in the surface oxide film by forming a sputter film using the first component as a target, thereby forming an intermediate layer. be able to. Further, after removing the surface oxide film of the base material 2, sputtering is performed using the first component oxide as a target, or after removing the surface oxide film of the base material 2, an oxidizing atmosphere using the first component as a target. The intermediate layer can also be formed by sputtering.
During sputtering, the surface oxide film on the base material may be appropriately removed, and reverse sputtering (ion etching) may be performed for the purpose of cleaning the base material surface. Reverse sputtering can be performed, for example, by irradiating the substrate with argon gas at an output of about RF 100 W and an argon pressure of about 0.2 Pa.
The Au of the intermediate layer is contained in the intermediate layer by Au atoms entering the intermediate layer by Au sputtering for forming the following alloy layers. Alternatively, a sputtering film may be formed on the surface of the base material using an alloy target containing the first component and Au.

合金層の形成方法としては、例えば上記したスパッタによりステンレス鋼基材上に第１成分を成膜した後、第１成分膜の上にＡｕをスパッタ成膜することができる。この場合、スパッタ粒子は高エネルギーを持つため、第１成分膜のみが基材表面に成膜されていても、そこにＡｕをスパッタすることにより、第１成分膜にＡｕが入り込み、合金層となる。又、この場合、合金層中のＡｕの割合が基材側から表面側に向かって増加する傾斜組成となる。
基材表面に最初に第１成分とＡｕのうちＡｕ濃度が低い合金ターゲットを用いてスパッタ成膜し、その後、第１成分とＡｕのうちＡｕ濃度が高い合金ターゲットを用いてスパッタ成膜してもよい。 As a method for forming the alloy layer, for example, after the first component is formed on the stainless steel substrate by sputtering as described above, Au can be formed by sputtering on the first component film. In this case, since the sputtered particles have high energy, even if only the first component film is formed on the surface of the substrate, by sputtering Au there, Au enters the first component film, and the alloy layer and Become. Further, in this case, the gradient composition is such that the proportion of Au in the alloy layer increases from the substrate side toward the surface side.
First, sputter film formation is performed using an alloy target having a low Au concentration of the first component and Au on the surface of the base material, and then sputter film formation is performed using an alloy target having a high Au concentration of the first component and Au. Also good.

<第２の実施形態>
次に、本発明の第２の実施形態に係る燃料電池用セパレータ材料について説明する。図３に示すように、第２の実施形態に係る燃料電池用セパレータ材料は、ステンレス鋼基材２の表面に中間層２ａを介して貴金属層４が形成され、貴金属層４の表面に合金層６が形成されている。ステンレス鋼基材２及び合金層６は、第１の実施形態と同一であるので説明を省略する。
貴金属層４は上記貴金属（好ましくは中間層の第１成分と同一）から主として成り、第１成分がＡｕより酸化され易いため、酸化物層である中間層２ａとの結合性が高く、貴金属層４がない場合に比べ、合金層６とステンレス鋼基材２（中間層）との密着性が向上する。
貴金属層４は、スパッタ条件（スパッタ時間、出力）等を変えることにより、適宜形成することができる。
なお、貴金属層４中の貴金属と、合金層６中の第１成分とは同一の元素であってもよく、異なる元素であってもよいが、同一元素とすると、製造が簡易となる。 <Second Embodiment>
Next, a fuel cell separator material according to a second embodiment of the present invention will be described. As shown in FIG. 3, the fuel cell separator material according to the second embodiment has a noble metal layer 4 formed on the surface of a stainless steel substrate 2 via an intermediate layer 2 a, and an alloy layer on the surface of the noble metal layer 4. 6 is formed. Since the stainless steel substrate 2 and the alloy layer 6 are the same as those in the first embodiment, description thereof is omitted.
The noble metal layer 4 is mainly composed of the above-mentioned noble metal (preferably the same as the first component of the intermediate layer), and the first component is more easily oxidized than Au. Compared with the case where 4 is not provided, the adhesion between the alloy layer 6 and the stainless steel substrate 2 (intermediate layer) is improved.
The noble metal layer 4 can be appropriately formed by changing sputtering conditions (sputtering time, output) and the like.
The noble metal in the noble metal layer 4 and the first component in the alloy layer 6 may be the same element or different elements. However, when the same element is used, the manufacturing is simplified.

<第３の実施形態>
次に、本発明の第３の実施形態に係る燃料電池用セパレータ材料について説明する。図４に示すように、第３の実施形態に係る燃料電池用セパレータ材料は、ステンレス鋼基材２の表面に中間層２ａを介して合金層６が形成され、合金層６の表面にＡｕ単独層８が形成されている。ステンレス鋼基材２及び合金層６は、第１の実施形態と同一であるので説明を省略する。
Au単独層８は、スパッタ条件（スパッタ時間、出力）等を変えることにより、適宜形成することができる。 <Third Embodiment>
Next, a fuel cell separator material according to a third embodiment of the present invention will be described. As shown in FIG. 4, the fuel cell separator material according to the third embodiment has an alloy layer 6 formed on the surface of a stainless steel substrate 2 through an intermediate layer 2 a, and Au alone is formed on the surface of the alloy layer 6. Layer 8 is formed. Since the stainless steel substrate 2 and the alloy layer 6 are the same as those in the first embodiment, description thereof is omitted.
The Au single layer 8 can be appropriately formed by changing sputtering conditions (sputtering time, output) and the like.

なお、第２及び第３の実施形態の層構成を組み合わせ、ステンレス鋼基材２の表面に、中間層２ａを介して貴金属層４、合金層６、Ａｕ単独層８をこの順に形成した層構造としてもよい。   In addition, the layer structure which combined the layer structure of 2nd and 3rd embodiment, and formed the noble metal layer 4, the alloy layer 6, and Au single layer 8 in this order on the surface of the stainless steel base material 2 via the intermediate | middle layer 2a. It is good.

Ａｕに代えて、前記貴金属のうち前記第１成分と異なる元素からなる第２成分とＡｕとのＡｕ合金を用いてもよい。この場合、中間層はＯ及び第１成分から主になるが、合金層は第１成分、第２成分及びＡｕから主になる。   Instead of Au, an Au alloy of Au and a second component made of an element different from the first component of the noble metal may be used. In this case, the intermediate layer is mainly composed of O and the first component, whereas the alloy layer is mainly composed of the first component, the second component and Au.

本発明の実施形態に係る燃料電池用セパレータ材料によれば、Ａｕ（合金）層をステンレス鋼基材上に強固かつ均一に形成させることができ、この層が導電性と耐食性を有することから、燃料電池用セパレータ材料として好適である。又、本発明の実施形態によれば、Ａｕ（合金）層をスパッタ成膜すればこの層が均一な層となるので、湿式の金めっきに比べて表面が平滑となり、Ａｕを無駄に使用しなくて済むという利点がある。   According to the fuel cell separator material according to the embodiment of the present invention, an Au (alloy) layer can be formed firmly and uniformly on a stainless steel substrate, and this layer has conductivity and corrosion resistance. It is suitable as a separator material for fuel cells. In addition, according to the embodiment of the present invention, if an Au (alloy) layer is formed by sputtering, this layer becomes a uniform layer, so that the surface becomes smoother than wet gold plating, and Au is wasted. There is an advantage that it is not necessary.

<燃料電池用セパレータ>
次に、本発明の燃料電池用セパレータ材料を用いた燃料電池用セパレータについて説明する。燃料電池用セパレータは、上記した燃料電池用セパレータ材料を所定形状に加工してなり、燃料ガス（水素）、空気（酸素）、冷却水等を流すための反応ガス流路（溝）が形成されている。
特に、燃料電池用セパレータにおいて、プレス加工による反応ガス流路が予め前記基材に形成されていると、後工程で反応ガス流路を形成する必要がなく、中間層や合金層等を形成する前の基材をプレス加工することで、容易に反応ガス流路を形成できるので、生産性が向上する。
又、本発明の燃料電池用セパレータにおいて、基材表面に合金層又はＡｕ単独層を形成した燃料電池用セパレータ材料に対し、後からプレス加工によって反応ガス流路を形成してもよい。本発明の燃料電池用セパレータ材料は合金層やＡｕ単独層が基材表面に強固に密着しているので、被膜形成後にプレス加工しても被膜が剥がれずに反応ガス流路を形成でき、生産性が向上する。 <Separator for fuel cell>
Next, a fuel cell separator using the fuel cell separator material of the present invention will be described. The fuel cell separator is formed by processing the above-described fuel cell separator material into a predetermined shape, and a reaction gas channel (groove) for flowing fuel gas (hydrogen), air (oxygen), cooling water, and the like is formed. ing.
In particular, in a separator for a fuel cell, when a reaction gas flow path is formed on the base material in advance, there is no need to form a reaction gas flow path in a subsequent process, and an intermediate layer, an alloy layer, or the like is formed. Since the reaction gas flow path can be easily formed by pressing the previous base material, productivity is improved.
In the fuel cell separator of the present invention, the reaction gas flow path may be formed later by pressing the fuel cell separator material in which the alloy layer or the Au single layer is formed on the surface of the substrate. The separator material for fuel cells of the present invention has an alloy layer or Au single layer firmly adhered to the surface of the base material, so that a reactive gas flow path can be formed without peeling off the coating even if it is pressed after the coating is formed. Improves.

なお、反応ガス流路形成のためのプレス加工をするためには、燃料電池用セパレータ材料として、基材の厚みを５０μｍ以上とすることが好ましい。基材の厚みの上限は限定されないが、コストの点から１５０μｍ以下とすることが望ましい。   In addition, in order to perform the press work for forming the reaction gas flow path, it is preferable that the thickness of the base material is 50 μm or more as the fuel cell separator material. The upper limit of the thickness of the base material is not limited, but is desirably 150 μm or less from the viewpoint of cost.

<燃料電池用スタック>
本発明の燃料電池用スタックは、本発明の燃料電池用セパレータ材料、又は本発明の燃料電池用セパレータを用いてなる。
燃料電池用スタックは、１対の電極で電解質を挟み込んだセルを複数個直列に接続したものであり、各セルの間に燃料電池用セパレータが介装されて燃料ガスや空気を遮断する。燃料ガス（水素）が接触する電極が燃料極（アノード）であり、空気（酸素） が接触する電極が空気極（カソード）である。 <Fuel cell stack>
The fuel cell stack of the present invention comprises the fuel cell separator material of the present invention or the fuel cell separator of the present invention.
The fuel cell stack is formed by connecting a plurality of cells in which an electrolyte is sandwiched between a pair of electrodes, and a fuel cell separator is interposed between the cells to block fuel gas and air. The electrode in contact with the fuel gas (hydrogen) is the fuel electrode (anode), and the electrode in contact with the air (oxygen) is the air electrode (cathode).

<試料の作製>
ステンレス鋼基材として、厚み１００μｍのステンレス鋼材（ＳＵＳ３１６Ｌ）を用い、ＦＩＢ（集束イオンビーム加工）による前処理をした。ＦＥ−ＴＥＭ（電解放射型透過電子顕微鏡）によるエネルギー分散型蛍光Ｘ線分析（ＥＤＸ）により観察したところ、ステンレス鋼基材の表面には予め約６ｎｍの酸化物層が形成されていたのを確認した。 <Sample preparation>
A stainless steel material (SUS316L) having a thickness of 100 μm was used as a stainless steel substrate, and pretreatment was performed by FIB (focused ion beam processing). When observed by energy dispersive X-ray fluorescence analysis (EDX) using FE-TEM (electrolytic emission transmission electron microscope), it was confirmed that an oxide layer of about 6 nm was previously formed on the surface of the stainless steel substrate. did.

次に、ステンレス鋼基材のステンレス鋼酸化物層の表面に、スパッタ法を用いて目標厚みが表１の値となるようにＰｄ（貴金属膜）を成膜した。なお、スパッタの際、基材の表面酸化膜を適度に除去し、基材表面のクリーニングを目的として逆スパッタ（イオンエッチング）を行ってもよい。ターゲットには純Ｐｄを用いた。次に、スパッタ法を用いて目標厚みが表１の値となるようにＡｕを成膜し、実施例１〜９の試料を作製した。ターゲットには純Ａｕを用いた。   Next, a Pd (noble metal film) was formed on the surface of the stainless steel oxide layer of the stainless steel substrate by sputtering so that the target thickness was a value shown in Table 1. During sputtering, the surface oxide film on the base material may be appropriately removed, and reverse sputtering (ion etching) may be performed for the purpose of cleaning the base material surface. Pure Pd was used for the target. Next, Au was formed into a film using the sputtering method so that the target thickness was the value shown in Table 1, and samples of Examples 1 to 9 were produced. Pure Au was used for the target.

比較例１０として、スパッタの代わりに、湿式めっきにより、基材表面にＡｕ層を５０ｎｍ形成した。湿式めっきは、基材の電解脱脂、水洗、電解酸洗、水洗を順に行った後、金めっきを行った。
比較例１１、１２として、スパッタ時にそれぞれＡｕ膜、Ｐｄ膜のみ成膜した。
比較例１３として、Ｐｄ膜及びＡｕ膜を別個にスパッタする代わりに、Ｐｄ−Ａｕ合金（Ｐｄ７０質量％,Ａｕ３０質量％）を用いて成膜した。比較例１４として、Ｐｄ膜及びＡｕ膜を別個にスパッタする代わりに、Ｐｄ−Ａｕ合金（Ｐｄ５０質量％,Ａｕ５０質量％）を用いて成膜した。比較例１５として、Ｐｄ膜及びＡｕ膜を別個にスパッタする代わりに、Ｐｄ−Ａｕ合金（Ｐｄ３０質量％,Ａｕ７０質量％）を用いて成膜した。
比較例１６として、スパッタ時のＰｄ膜の目標厚みを０．５ｎｍに低減して成膜した。 As Comparative Example 10, an Au layer having a thickness of 50 nm was formed on the substrate surface by wet plating instead of sputtering. In wet plating, the substrate was subjected to electrolytic degreasing, water washing, electrolytic pickling, and water washing in this order, and then gold plating was performed.
As Comparative Examples 11 and 12, only Au film and Pd film were formed at the time of sputtering.
As Comparative Example 13, a Pd—Au alloy (Pd 70 mass%, Au 30 mass%) was used instead of sputtering the Pd film and Au film separately. As Comparative Example 14, a film was formed using a Pd—Au alloy (Pd 50 mass%, Au 50 mass%) instead of sputtering the Pd film and Au film separately. As Comparative Example 15, a Pd—Au alloy (Pd 30 mass%, Au 70 mass%) was used instead of sputtering the Pd film and Au film separately.
As Comparative Example 16, the target thickness of the Pd film during sputtering was reduced to 0.5 nm.

目標厚みは以下のように定めた。まず、予めステンレス鋼基材にスパッタで対象物（例えばＰｄ）を成膜し、蛍光Ｘ線膜厚計（Ｓｅｉｋｏ Ｉｎｓｔｒｕｍｅｎｔｓ製ＳＥＡ５１００、コリメータΦ０．１ｍｍ）で実際の厚みを測定し、このスパッタ条件におけるスパッタレート（ｎｍ/ｍｉｎ）を把握した。そして、スパッタレートに基づき、厚み１ｎｍとなるスパッタ時間を計算し、この条件でスパッタを行った。
Ｐｄ及びＡｕのスパッタは、株式会社アルバック製のスパッタ装置を用い、出力ＤＣ５０Ｗ アルゴン圧力０．２Ｐａの条件で行った。 The target thickness was determined as follows. First, an object (for example, Pd) is formed on a stainless steel substrate in advance by sputtering, and an actual thickness is measured with a fluorescent X-ray film thickness meter (SEA 5100 manufactured by Seiko Instruments, collimator Φ0.1 mm). The sputter rate (nm / min) was grasped. Based on the sputtering rate, the sputtering time for a thickness of 1 nm was calculated, and sputtering was performed under these conditions.
Sputtering of Pd and Au was performed using a sputtering apparatus manufactured by ULVAC, Inc. under the conditions of an output DC of 50 W and an argon pressure of 0.2 Pa.

<層構造の測定>
試料のステンレス鋼基材表面をＸＰＳで深さ方向に分析し、Ｏ、Ｐｄ等の濃度を検出した。ＸＰＳとしては、アルバックファイ社製の５６００ＭＣを用い、スパッタ条件としてイオン種Ａｒ、加速電圧３ｋＶ、掃引領域３ｍｍ×３ｍｍ、スパッタレート２．６ｎｍ／ｍｉｎで測定した。
なお、ＸＰＳによる濃度検出は、指定元素の合計１００質量％として、各元素の濃度（質量％）を分析した。又、ＸＰＳ分析で厚み方向に１ｎｍの距離とは、ＸＰＳ分析によるチャート（図２）の横軸の約０．３８分に相当する。 <Measurement of layer structure>
The stainless steel substrate surface of the sample was analyzed in the depth direction by XPS, and the concentrations of O, Pd, etc. were detected. As XPS, 5600MC manufactured by ULVAC-PHI was used, and the sputtering conditions were ion species Ar, acceleration voltage 3 kV, sweep region 3 mm × 3 mm, and sputtering rate 2.6 nm / min.
In addition, the density | concentration detection by XPS analyzed the density | concentration (mass%) of each element as a total of 100 mass% of a designated element. Further, the distance of 1 nm in the thickness direction in XPS analysis corresponds to about 0.38 minutes on the horizontal axis of the chart (FIG. 2) by XPS analysis.

図２は、試料の深さ方向のＸＰＳ分析結果である。
ステンレス鋼基材２の表面に、Ｆｅを含み，Ｏを１０質量％以上含有し，Ｐｄを１０質量％以上含有し，かつ，Ａｕの含有量がＰｄ≧Ａｕを満たす中間層２ａが存在することがわかる。又、中間層２ａの表面側に、Ａｕを４０質量％以上含有し、かつＰｄの含有量がＡｕ>Ｐｄを満たすＰｄとＡｕの合金層が形成されていることがわかる。
又、上記合金層として定義される領域の厚みを、図２の横軸から換算すると、１．３ｎｍとなった。
なお、本発明においては、中間層を定義するために、Ｏ、第１成分等の濃度を規定している。従って、中間層の境界は便宜上Ｏ、第１成分濃度によって決められるため、中間層とその上下の層（例えば基材２）との間に、中間層ともステンレス鋼基材とも異なる層が介在する場合もある。 FIG. 2 shows the result of XPS analysis in the depth direction of the sample.
On the surface of the stainless steel substrate 2, there must be an intermediate layer 2a containing Fe, containing 10 mass% or more of O, containing 10 mass% or more of Pd, and satisfying Pd ≧ Au. I understand. Further, it can be seen that an alloy layer of Pd and Au containing Au of 40 mass% or more and satisfying Au> Pd is formed on the surface side of the intermediate layer 2a.
Further, when the thickness of the region defined as the alloy layer was converted from the horizontal axis of FIG. 2, it was 1.3 nm.
In the present invention, in order to define the intermediate layer, the concentrations of O, the first component, etc. are defined. Therefore, since the boundary of the intermediate layer is determined by O and the first component concentration for convenience, a layer different from both the intermediate layer and the stainless steel substrate is interposed between the intermediate layer and the upper and lower layers (for example, the substrate 2). In some cases.

<評価>
各試料について以下の評価を行った。
Ａ．密着性
各試料の最表層の合金層に１ｍｍ間隔で碁盤の目を罫書いた後、粘着性テープをはり付け、さらに各試験片を１８０°曲げて元の状態に戻し、曲げ部のテープを急速にかつ強く引き剥がす剥離試験を行った。
剥離が全くない場合を○とし、耐食試験後に一部でも剥離があると目視で認められた場合を△とし、耐食試験前から一部でも剥離があると目視で認められた場合を×とした。
Ｂ．成膜形状
各試料の断面のＦＥ-ＴＥＭ像を撮影し、表面に数ｎｍから数百ｎｍの粒子が集まった凹凸構造が観察された場合を粒状とし、粒状に比べて表面が平滑な場合を層状とした。 <Evaluation>
The following evaluation was performed for each sample.
A. Adhesion After marking the grid of the grid at 1 mm intervals on the outermost alloy layer of each sample, apply adhesive tape, and then bend each specimen 180 ° to return it to its original state. A peeling test was conducted to peel off rapidly and strongly.
The case where there was no peeling was marked as ◯, the case where there was some peeling after the corrosion resistance test was marked as △, and the case where there was some peeling even before the corrosion resistance test was marked as x. .
B. Film formation shape FE-TEM image of the cross section of each sample is taken, and when the uneven structure where particles of several to several hundred nm are collected on the surface is made granular, the surface is smoother than the granular Layered.

Ｃ．接触抵抗
接触抵抗の測定は、試料全面に荷重を加える方法で行った。まず、４０×５０ｍｍの板状の試料の表裏にそれぞれカーボンペーパーを積層し、さらに表裏のカーボンペーパーの外側にそれぞれＣｕ／Ｎｉ／Ａｕ板を積層した。Ｃｕ／Ｎｉ／Ａｕ板は厚み１０ｍｍの銅板に１．０μｍ厚のＮｉ下地めっきをし、Ｎｉ層の上に０．５μｍのＡｕめっきした材料であり、Ｃｕ／Ｎｉ／Ａｕ板のＡｕめっき面がカーボンペーパーに接するように配置した。
さらに、Ｃｕ／Ｎｉ／Ａｕ板の外側にそれぞれテフロン（登録商標）板を配置し、各テフロン（登録商標）板の外側からロードセルで圧縮方向に１０ｋｇ／ｃｍ２の荷重を加えた。この状態で、２枚のＣｕ/Ｎｉ/Ａｕ板の間に電流密度１００ｍＡ／ｃｍ２の定電流を流した時、Ｃｕ／Ｎｉ／Ａｕ板間の電気抵抗を４端子法で測定した。
又、接触抵抗は、以下の耐食試験の前後でそれぞれ行った。耐食試験は、浴温９０℃の硫酸水溶液（ｐＨ＝１．８、液量３５０ｃｃ）に各試料を１６８時間（１週間）浸漬して行った。 C. Contact resistance The contact resistance was measured by applying a load to the entire surface of the sample. First, carbon papers were laminated on the front and back sides of a 40 × 50 mm plate-like sample, and Cu / Ni / Au plates were further laminated on the outer sides of the front and back carbon papers. The Cu / Ni / Au plate is a material in which a 10 μm thick copper plate is plated with a 1.0 μm thick Ni base, and the Ni layer is plated with a 0.5 μm Au plate. The carbon paper was placed in contact with it.
Further, a Teflon (registered trademark) plate was arranged outside the Cu / Ni / Au plate, and a load of 10 kg / cm 2 was applied in the compression direction from the outside of each Teflon (registered trademark) plate with a load cell. In this state, when a constant current with a current density of 100 mA / cm 2 was passed between the two Cu / Ni / Au plates, the electrical resistance between the Cu / Ni / Au plates was measured by the four-terminal method.
The contact resistance was measured before and after the following corrosion resistance test. The corrosion resistance test was performed by immersing each sample in a sulfuric acid aqueous solution (pH = 1.8, liquid amount 350 cc) having a bath temperature of 90 ° C. for 168 hours (one week).

表１に結果を示す。なお、表１において、中間層の厚み、最表層の厚みは、いずれもＸＰＳ分析を２回行った値の平均値とした。又、中間層の厚み、最表層の厚みは±０．２５ｎｍの幅を持ち、例えば中間層が１．０ｎｍという場合、平均値が０．７５ｎｍ以上で１．２５ｎｍ未満のものをいうとする。但し、厚みが１０ｎｍ以上の場合は±０．５ｎｍの幅とする。   Table 1 shows the results. In Table 1, the thickness of the intermediate layer and the thickness of the outermost layer were both average values obtained by performing XPS analysis twice. Further, the thickness of the intermediate layer and the thickness of the outermost layer have a width of ± 0.25 nm. For example, when the intermediate layer is 1.0 nm, the average value is 0.75 nm or more and less than 1.25 nm. However, when the thickness is 10 nm or more, the width is ± 0.5 nm.

Figure 0005291368
Figure 0005291368

表１から明らかなように、合金層とステンレス鋼基材との間に、ステンレス鋼の構成元素であるＦｅを含み，Ｏの最大ピークが１０質量％以上で，Ｐｄを１０質量％以上含有し，かつ，Ａｕの含有量がＰｄ≧Ａｕを満たす中間層が存在する実施例１〜９の場合、各層の密着性に優れ、又、スパッタにより成膜した合金層又はＡｕ層（最表層）は平滑な層状となった。さらに、耐食試験前後で試料の接触抵抗が変化せず、耐食性と導電性が優れたものとなった。
なお、各実施例の場合、最表面から基材側に向かうＡｕ４０質量％以上の領域の厚みはいずれも１ｎｍ以上であった。 As is apparent from Table 1, between the alloy layer and the stainless steel substrate, Fe, which is a constituent element of stainless steel, has a maximum peak of O of 10% by mass or more and Pd of 10% by mass or more. In the case of Examples 1 to 9 in which there is an intermediate layer satisfying Pd ≧ Au in the Au content, the adhesion of each layer is excellent, and the alloy layer or Au layer (outermost layer) formed by sputtering is A smooth layer was formed. Furthermore, the contact resistance of the sample did not change before and after the corrosion resistance test, and the corrosion resistance and conductivity were excellent.
In the case of each example, the thickness of Au 40% by mass or more from the outermost surface toward the base material was 1 nm or more.

Ａｕ層を湿式めっきで形成した比較例１０の場合、最表層が粒状となり、Ａｕの使用量が多くなった。
Ａｕのみをスパッタした比較例１１の場合、中間層が形成されずに密着性が劣化した。一方、Ｐｄのみをスパッタした比較例１２の場合、最表層がＡｕを含まず、耐食試験後に接触抵抗が大幅に増大した。これは、最表層がＡｕを含まないために耐食性が劣化したためと考えられる。
Ｐｄ-Ａｕ合金（Ｐｄ７０質量％）をターゲットとしてスパッタした比較例１３の場合も、耐食試験後に接触抵抗が大幅に増大した。これは、Ｐｄ-Ａｕ合金中のＡｕの割合が少ないために最表層にＡｕを４０質量％以上含む層が形成されず、耐食性が劣化したためと考えられる。 In the case of Comparative Example 10 in which the Au layer was formed by wet plating, the outermost layer became granular, and the amount of Au used was increased.
In the case of Comparative Example 11 in which only Au was sputtered, the adhesion was deteriorated without forming the intermediate layer. On the other hand, in the case of Comparative Example 12 in which only Pd was sputtered, the outermost layer did not contain Au, and the contact resistance significantly increased after the corrosion resistance test. This is considered because corrosion resistance deteriorated because the outermost layer did not contain Au.
In the case of Comparative Example 13 in which sputtering was performed using a Pd—Au alloy (Pd 70% by mass) as a target, the contact resistance significantly increased after the corrosion resistance test. This is considered to be because the layer containing 40 mass% or more of Au in the outermost layer was not formed because the proportion of Au in the Pd—Au alloy was small, and the corrosion resistance was deteriorated.

Ｐｄ-Ａｕ合金（Ｐｄ５０質量％）をターゲットとしてスパッタした比較例１４、及びＰｄ-Ａｕ合金（Ｐｄ３０質量％）をターゲットとしてスパッタした比較例１５の場合、いずれも中間層の厚みが１ｎｍ未満となり、密着性が劣化した。
これは、Ｐｄ-Ａｕ合金中のＰｄの割合が少ないために中間層が充分に形成されなかったためと考えられる。
Ｐｄ膜の目標厚みを低減してスパッタした比較例１６の場合も、中間層の厚みが１ｎｍ未満となり、密着性が劣化した。 In the case of the comparative example 14 which sputtered using Pd-Au alloy (Pd50 mass%) as the target and the comparative example 15 which sputtered using the Pd-Au alloy (Pd 30 mass%) as a target, the thickness of the intermediate layer was less than 1 nm. Adhesion deteriorated.
This is presumably because the intermediate layer was not sufficiently formed because of the small proportion of Pd in the Pd—Au alloy.
In the case of Comparative Example 16 in which the target thickness of the Pd film was reduced and sputtered, the thickness of the intermediate layer was less than 1 nm, and the adhesion was deteriorated.

本発明の実施形態に係る燃料電池用セパレータ材料の構成を示す模式図である。It is a schematic diagram which shows the structure of the separator material for fuel cells which concerns on embodiment of this invention. 本発明の実施形態に係る燃料電池用セパレータ材料の深さ方向のＸＰＳ分析結果を示す図である。It is a figure which shows the XPS analysis result of the depth direction of the separator material for fuel cells which concerns on embodiment of this invention. 本発明の別の実施形態に係る燃料電池用セパレータ材料の構成を示す模式図である。It is a schematic diagram which shows the structure of the separator material for fuel cells which concerns on another embodiment of this invention. 本発明のさらに別の実施形態に係る燃料電池用セパレータ材料の構成を示す模式図である。It is a schematic diagram which shows the structure of the separator material for fuel cells which concerns on another embodiment of this invention.

符号の説明Explanation of symbols

２ ステンレス鋼基材
２ａ 中間層
４ 貴金属層
６ 合金層
８ Ａｕ単独層 2 Stainless steel substrate 2a Intermediate layer 4 Noble metal layer 6 Alloy layer 8 Au single layer

Claims (7)

厚みが５０〜１５０μｍの板材からなるステンレス鋼基材の表面に、Ｒｕ、Ｒｈ、Ｐｄ、Ｉｒ、Ｏｓ及びＰｔからなる群より選択される少なくとも１種類以上のＡｕより易酸化性の貴金属からなる第１成分とＡｕとの合金層、又はＡｕ単独層が形成され、
前記合金層は、Ａｕを４０質量％以上含有し、かつＸ線光電子分光により前記合金層を深さ方向に分析したとき、いずれの深さにおいても前記第１成分の含有量（質量％）がＡｕ＞前記第１成分を満たし、かつ、前記合金層又はＡｕ単独層の厚みが１ｎｍ以上１０ｎｍ以下であり、
前記合金層又はＡｕ単独層と前記ステンレス鋼基材との間に、ステンレス鋼の構成元素であるＦｅを含み，Ｏを１０質量％以上含有し，前記第１成分を１０質量％以上含有し，かつＸ線光電子分光により深さ方向に分析したとき、いずれの深さにおいてもＡｕの含有量（質量％）が前記第１成分≧Ａｕ＞０を満たし、厚みが１ｎｍ以上１０ｎｍ以下の中間層が形成されている燃料電池用セパレータ材料。 The surface of a stainless steel substrate made of a plate material having a thickness of 50 to 150 μm is made of a noble metal that is more oxidizable than at least one kind of Au selected from the group consisting of Ru, Rh, Pd, Ir, Os, and Pt. An alloy layer of one component and Au, or an Au single layer is formed,
The alloy layer is an Au contain more than 40 wt%, and when analyzing the alloy layer in the depth direction by X-ray photoelectron spectroscopy, the content of the first component at any depth (mass%) of Au> Satisfies the first component, and the thickness of the alloy layer or Au single layer is 1 nm or more and 10 nm or less,
Between the alloy layer or Au single layer and the stainless steel base material, containing Fe which is a constituent element of stainless steel, containing 10 mass% or more of O, containing 10 mass% or more of the first component, In addition, when analyzed in the depth direction by X-ray photoelectron spectroscopy, the content (% by mass) of Au satisfies the first component ≧ Au> 0 at any depth, and an intermediate layer having a thickness of 1 nm to 10 nm. A fuel cell separator material is formed. 前記合金層中のＡｕの含有割合が基材側から表面側に向かって増加する請求項１に記載の燃料電池用セパレータ材料。 The fuel cell separator material according to claim 1, wherein the content ratio of Au in the alloy layer increases from the substrate side toward the surface side. 前記合金層の最表面にＡｕ単独層が形成されている請求項１又は２に記載の燃料電池用セパレータ材料。 The fuel cell separator material according to claim 1, wherein an Au single layer is formed on the outermost surface of the alloy layer. 前記合金層は、前記第１成分と、前記貴金属のうち前記第１成分と異なる元素からなる第２成分とＡｕとの合金である請求項１〜３のいずれかに記載の燃料電池用セパレータ材料。 4. The fuel cell separator material according to claim 1, wherein the alloy layer is an alloy of Au with the first component and a second component made of an element different from the first component of the noble metal. 5. . 請求項１〜４のいずれかに記載の燃料電池用セパレータ材料を用いた燃料電池セパレータ。 A fuel cell separator using the fuel cell separator material according to claim 1. 請求項５に記載の燃料電池セパレータを用いた燃料電池スタック。 A fuel cell stack using the fuel cell separator according to claim 5. ステンレス鋼基材表面にスパッタ法により前記第１成分を１〜１０ｎｍ被覆した後，スパッタ法によりＡｕを１〜１０ｎｍ被覆する請求項１〜３のいずれかに記載の燃料電池用セパレータ材料の製造方法。 After 1~10nm covering the first component by a sputtering method to a stainless steel substrate surface, method of manufacturing the fuel cell separator material according to any one of claims 1 to 3 1~10nm coated with Au by sputtering .
JP2008086158A 2008-03-28 2008-03-28 Fuel cell separator material, fuel cell separator using the same, fuel cell stack, and method for producing fuel cell separator material Expired - Fee Related JP5291368B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2008086158A JP5291368B2 (en) 2008-03-28 2008-03-28 Fuel cell separator material, fuel cell separator using the same, fuel cell stack, and method for producing fuel cell separator material

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2008086158A JP5291368B2 (en) 2008-03-28 2008-03-28 Fuel cell separator material, fuel cell separator using the same, fuel cell stack, and method for producing fuel cell separator material

Publications (2)

Publication Number Publication Date
JP2009238691A JP2009238691A (en) 2009-10-15
JP5291368B2 true JP5291368B2 (en) 2013-09-18

Family

ID=41252369

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2008086158A Expired - Fee Related JP5291368B2 (en) 2008-03-28 2008-03-28 Fuel cell separator material, fuel cell separator using the same, fuel cell stack, and method for producing fuel cell separator material

Country Status (1)

Country Link
JP (1) JP5291368B2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101242986B1 (en) 2010-03-22 2013-03-12 현대하이스코 주식회사 Metal separator for fuel cell and method of manufacturing the same
CN115418611A (en) * 2022-08-16 2022-12-02 浙江天能氢能源科技有限公司 Preparation method of gold-plated coating of metal bipolar plate of fuel cell

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001351642A (en) * 2000-06-08 2001-12-21 Riken Corp Separator for fuel cell
JP2002367434A (en) * 2001-06-08 2002-12-20 Daido Steel Co Ltd Corrosion resistant metal member and metal separator for fuel cell using the member
JP4147925B2 (en) * 2002-12-04 2008-09-10 トヨタ自動車株式会社 Fuel cell separator
US6866958B2 (en) * 2002-06-05 2005-03-15 General Motors Corporation Ultra-low loadings of Au for stainless steel bipolar plates
US8088536B2 (en) * 2004-09-10 2012-01-03 Neomax Materials Co., Ltd. Fuel cell separator and method for manufacturing the same
US8029943B2 (en) * 2005-02-28 2011-10-04 GM Global Technology Operations LLC Method to make conductive hydrophilic fuel cell elements
JP2007323988A (en) * 2006-06-01 2007-12-13 Daido Steel Co Ltd Metal separator for fuel cell, manufacturing method of the same, and fuel cell
JP2008004492A (en) * 2006-06-26 2008-01-10 Mitsubishi Materials Corp Composite layer-covered porous plate with less increases in contact resistance even if exposed to oxidative environment for long period
JP2008004498A (en) * 2006-06-26 2008-01-10 Mitsubishi Materials Corp Composite layer-covered metal plate with less ncreases in contact resistance even if exposed to oxidative environment for long period

Also Published As

Publication number Publication date
JP2009238691A (en) 2009-10-15

Similar Documents

Publication Publication Date Title
JP5325235B2 (en) FUEL CELL SEPARATOR MATERIAL, FUEL CELL SEPARATOR USING THE SAME, FUEL CELL STACK, AND METHOD FOR PRODUCING FUEL CELL SEPARATOR MATERIAL
EP2096698B1 (en) Surface treatment method of titanium material for electrodes
JP6160877B2 (en) Manufacturing method of fuel cell separator and fuel cell separator
JP5143842B2 (en) Fuel cell separator material and fuel cell stack
KR101301831B1 (en) Fuel cell separator material, fuel cell separator using same, and fuel cell stack
KR101609077B1 (en) Separator material for fuel cells, separator for fuel cells using same, fuel cell stack using same, and method for producing separator material for fuel cells
JP2010238577A (en) Separator material for fuel cell and fuel cell stack using the same
JP5291368B2 (en) Fuel cell separator material, fuel cell separator using the same, fuel cell stack, and method for producing fuel cell separator material
JP5419271B2 (en) FUEL CELL SEPARATOR MATERIAL, FUEL CELL SEPARATOR USING THE SAME, FUEL CELL STACK, AND METHOD FOR PRODUCING FUEL CELL SEPARATOR MATERIAL
TW201222937A (en) Separator material for fuel cell, separator for fuel cell using the same, fuel cell stack, and producing method of fuel cell separator material
JP5677758B2 (en) Fuel cell separator material, fuel cell separator and fuel cell stack using the same, and method for producing fuel cell separator material
JP2011174145A (en) Separator material for fuel cell, separator for fuel cell using the same, fuel cell stack and method for producing material for fuel cell separator
JP2011249148A (en) Fuel cell separator material, fuel cell separator using the same, fuel cell stack, and method of manufacturing fuel cell separator material
JP7484760B2 (en) Separator manufacturing method
KR20130129621A (en) Metal separator for fuel cell using carbon-metal alternately repeating coating and method of manufacturing the same
JP2011246778A (en) Surface treated stainless steel material, and method for manufacturing the same
JP2011243473A (en) Separator material for fuel cell, fuel cell separator using the same and fuel cell stack, and method of manufacturing separator material for fuel cell
JP2010238565A (en) Separator material of fuel cell and fuel cell stack using the same
JP2011249147A (en) Fuel cell separator material, fuel cell separator using the same, fuel cell stack, and method of manufacturing fuel cell separator material
JP2010123330A (en) Separator material for fuel cell, separator for fuel cell using the same, and fuel cell stack
WO2020179693A1 (en) Porous body, electrochemical cell, and method for producing porous body
JP2010238394A (en) Separator material for fuel cell and fuel cell stack using the same
TWI447989B (en) A separator for a fuel cell, a separator for a fuel cell and a fuel cell stack for use thereof, and a method for manufacturing a separator material for a fuel cell
JP2006278172A (en) Separator material for fuel sell
JP2010238569A (en) Separator material for fuel cell and fuel cell stack using the same

Legal Events

Date Code Title Description
A711 Notification of change in applicant

Free format text: JAPANESE INTERMEDIATE CODE: A712

Effective date: 20100903

A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20101005

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20121126

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20130104

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20130319

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20130419

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20130603

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20130607

LAPS Cancellation because of no payment of annual fees