JP4278406B2 - Fuel cell separator - Google Patents

Description

〔式中、R1は水素、アルキル、置換アルキル、ハロゲンをあらわし、R2はアルカリ金属、水素、アルキル、置換アルキル、置換アミノ基をあらわす〕
（２）燃料電池用セパレーターであって、該セパレータは、ステンレス鋼板の表面上にダイレクトに形成した膜厚５〜２０ｎｍの金又は金合金層を有し、該金又は金合金層がインヒビターとして下記式（１）で表されるメルカプトベンゾチアゾール誘導体の1種もしくは２種以上により封孔処理されていることを特徴とする燃料電池用セパレーター
【化６】

〔式中、R1は水素、アルキル、置換アルキル、ハロゲンをあらわし、R2はアルカリ金属、水素、アルキル、置換アルキル、置換アミノ基をあらわす〕、
（３）ステンレス鋼セパレータの表面上にダイレクトに膜厚５〜２０ｎｍの金又は金合金めっきを形成した後、インヒビターとして下記式（１）で表されるメルカプトベンゾチアゾール誘導体の1種もしくは２種以上を合計で１０〜５００００ｐｐｍ含有する水溶液中で該ステンレス鋼セパレータを陽極として、極間電圧Eが０．１〜５．０Vの範囲で直流電解したことを特徴とする前記（２）記載の燃料電池用セパレータの製造方法、
【化７】

〔式中、R1は水素、アルキル、置換アルキル、ハロゲンをあらわし、R2はアルカリ金属、水素、アルキル、置換アルキル、置換アミノ基をあらわす〕、
（４）ステンレス鋼セパレータの表面上にダイレクトに膜厚５〜２０ｎｍの金又は金合金めっきを形成した後、インヒビターとして下記式（１）で表されるメルカプトベンゾチアゾール誘導体の1種もしくは２種以上を合計で１０〜５０００ｐｐｍ含有する水溶液中で該ステンレス鋼セパレータを陽極として、極間電圧Eが０．１〜５．０Vの範囲で直流電解したことを特徴とする前記（２）記載の燃料電池用セパレータの製造方法、
【化８】

〔式中、R1は水素、アルキル、置換アルキル、ハロゲンをあらわし、R2はアルカリ金属、水素、アルキル、置換アルキル、置換アミノ基をあらわす〕、
（５）前記（３）または（４）記載の方法で製造された燃料電池用セパレータ
に関する。
なお、前記（１）の貴金属めっきした金属板は、これを成形加工及び切断加工して燃料電池用セパレータとすることができる。
【００１２】
金めっき層のピンホールを埋めるいわゆる封孔処理は、すでに述べたとおり、コネクタ用の銅合金上の金めっきに対しては知られている。ただし、コネクタにおいては低接触抵抗、耐食性のほかに潤滑性を必要とすること、また、密着性を高めるために下地めっきとしてニッケルめっきを施すことが一般的であること等で、燃料電池用セパレータとは要求特性が異なり、そのままの条件を適用することは望ましくなかった。特に燃料電池用セパレータでは潤滑性は必要でなく、潤滑性付与のために処理が不要もしくは悪影響を与える可能性がある。
【００１３】
また、コネクタでは挿抜を繰り返すため、挿抜抵抗が低いことが要求され、結果としてたとえば１０ｋｇｆ程度の接触部の圧力が低い状態での低接触抵抗が必要とされる。一方、燃料電池用セパレータでは、一度セットした後は分解することはほとんど無く、また、接触圧力も、ボルト締めによるたとえば２０ｋｇ／ｃｍ²程度の高い接触圧が可能である。コネクタでは１点当たりの接触圧力で評価することが多く、ボルト締めと圧力の単位が異なり、一概に比較することは難しい。しかし、ボルトの場合、ミクロで看た場合、局所的に接触している部分に圧力が集中しているため、コネクタでの接触部の圧力換算では１００ｋｇｆを越える高い接触圧となっていると考えられる。
【００１４】
【発明の実施の形態】
本発明の実施の形態について説明する。
SUS304、SUS316Lといったステンレス鋼を電解脱脂→水洗→電解酸洗→水洗の前処理の後、ダイレクト金めっきを施す。本発明はピンホールを封孔して金めっき厚を薄くすることが目的であるため、そのめっき厚は燃料電池用セパレータとして導通を確保するため５ｎｍ以上必要であるが、２０nm以下で十分である。しかし、それ以上厚くてもかまわない。そして本発明においては、前記の用に薄い金めっき後に下記一般式（１）に示すメルカプトベンゾチアゾール誘導体の水溶液に浸漬して当該ステンレスを陽極に分極してたとえば約3秒処理することで封孔処理を行う。その後、水洗もしくは湯洗して乾燥する。
【００１５】
【化９】

〔式中、R1は水素、アルキル、置換アルキル、ハロゲンをあらわし、R2はアルカリ金属、水素、アルキル、置換アルキル、置換アミノ基をあらわす〕
一般式（１）で表される化合物の中で、好ましいものは、
【００１６】
【化１０】

等を挙げることができる。
【００１７】
メルカプトベンゾチアゾール誘導体の濃度は１０〜５００００ｐｐｍ、好ましくは１０〜５０００ｐｐｍである。これより低いと耐食性を高める効果を得るのに長い処理時間が必要になる。また、５０００ｐｐｍより高いと、有機物が厚くなり均一に被覆することが難しくなる。特にこの有機物は封孔効果によって耐食性を向上している関係から、厚くついた部分の効果は少ないと考えられる。さらに、有機物が厚くなることによって接触抵抗が高くなる傾向がある。ただし、前述の様に燃料電池用セパレータではコネクタと異なり、導通部の接触圧力を高くすることが可能であるため、耐食性を優先して高濃度で封孔処理を行い、接触圧力の増加で接触抵抗を下げることが可能である。
【００１８】
また、陽極に分極せずに浸漬のみでも効果はあるが、陽極に分極する方が短時間で処理が終了する。分極電位は槽電圧で０．１〜５．０Vの範囲とするのが望ましい。槽電流はメルカプトベンゾチアゾール誘導体の水溶液の場合、導電率が低いため、ほとんど電流が流れない。このため電解で一般的に制御する電流密度では無く、槽電圧で制御する方が制御しやすい。ただし、電流密度で制御できないわけでは無く、槽電圧が上記の範囲に入るような電流密度制御をおこなってもかまわない。
この様にしてメルカプトベンゾチアゾール誘導体で封孔処理した燃料電池用セパレータは薄い金めっき厚でも、厚い金めっきと同等の耐食性と低接触抵抗を兼ね備える。
【００１９】
【実施例】
実施例にて本発明を説明する。
厚さ０．３ｍｍのＳＵＳ３１６Ｌを電解陽極脱脂→水洗→電解陰極酸洗→水洗の前処理を施した後、ダイレクト金めっきを施した。各前処理および金めっき条件は以下の通り。
【００２０】
電解脱脂
パクナＰ１０５ ４０ｇ／Ｌ
温度： ６０℃
電流密度：６Ａ／ｄｍ²
陽極電解
電解時間：３０秒
【００２１】
酸洗
硫酸 ：２００ｇ／Ｌ
温度：常温
時間 ：３０秒
【００２２】
金めっき
添加剤：ダイレクト金めっき浴
金濃度： １〜４ｇ／Ｌ
浴温：２０〜４０℃
電流密度：６Ａ／ｄｍ²
めっき厚 ：１０、２０ｎｍ
【００２３】
封孔処理
メルカプトベンゾチアゾールのＮａ塩：１００，１０００，１００００ｐ
ｐｍ
温度：常温
カソード：ＳＵＳ３１６Ｌ
槽電圧：２Ｖ
時間：３秒
【００２４】
この様にして作成したステンレス金めっき材の接触抵抗、アノード分極、硫酸浸漬後の鉄溶出量を以下の条件で調査した。
接触抵抗
山崎試験機製：電気接点シミレータ ＣＲＳ−１
プローブ：金
接圧：１０ｇｆ
測定数： ４００点
【００２５】
アノード分極測定条件
温度：常温
測定液： 硫酸５％
脱酸素： アルゴン ２００ｍｌ／ｍｉｎ
スイープ速度：２０ｍＶ／ｍｉｎ
試料面積：１ｃｍ²
【００２６】
硫酸浸漬試験
溶液：硫酸 ５％
温度：８０℃
液量：５ｃｃ
供試材： １０×５０ｍｍ 浸漬
浸漬時間： 〜３０日
測定方法：ＩＣＰ分析にてＦｅイオンを定量
【００２７】
接触抵抗測定結果を図１、２に示す。
この測定条件はコネクタで一般的に用いられる条件であり、接触圧は10gfと低い。この条件下では、メルカプトベンゾチアゾールＮａ（図中ではＭＢＴと略す）が１００００ｐｐｍの濃度では高い接触抵抗を示すことがわかる。ただし、この条件でも接触圧力を上昇することにより、図３，４に示すように接触抵抗が低下することがわかる。また、１０００ｐｐｍの濃度の場合、目視で表面にまだら状に有機物の模様が観察された。これは、有機物の厚さが不均一になっているものと考えられた。
【００２８】
分極測定結果を図５に示す。封孔処理なしに比較して封孔処理を施すことで腐食電流密度が減少していることがわかる。また、封孔処理ＭＢＴの処理濃度が高いほど腐食電流密度が低い。このことから、封孔処理によって耐食性が向上していることがわかる。
【００２９】
【表１】

【００３０】
比較例
封孔処理なしで同様に供試材を作成した。結果は実施例の図および表に併記した。
【００３１】
【発明の効果】
以上説明したように、本発明によれば薄い貴金属めっきで燃料電池用セパレータに要求される十分な耐食性を備えるとともに同時に低い接触抵抗を有することができる。また、本発明によれば、該セパレータとするための貴金属めっきした金属板を得ることができる。
【００３２】
【図面の簡単な説明】
【図１】実施例のセパレータの接触抵抗測定結果を示すグラフ。
【図２】同上
【図３】実施例のセパレータの接触圧力と接触抵抗の関係を示すグラフ。
【図４】同上
【図５】実施例のセパレータの分極測定結果を示すグラフ。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a metal separator for a solid polymer electrolyte battery, a method for producing the same, and a noble metal-plated metal plate therefor.
[0002]
[Prior art]
The metal separator for a solid polymer electrolyte fuel cell is a member constituting a fuel cell stack in which a plurality of single cells are stacked, and has sufficient gas impermeability and electric conductivity for conducting between cells. is required. Furthermore, high corrosion resistance is required for the battery reaction. Conventionally, carbon materials or metal materials have been used for such fuel cell gas separators. In particular, metal materials have been widely studied in recent years because they are superior in strength and can be made thinner than carbon materials.
[0003]
In particular, a stainless steel plate is suitable as a separator material compared to an expensive metal such as a special corrosion resistant steel such as titanium or Hastelloy because it has high corrosion resistance and is inexpensive. However, since stainless steel maintains corrosion resistance with an oxide film on its surface, there is a problem that contact resistance is high and electrical resistance between cells is high. In order to solve this problem, a method of coating stainless steel with a noble metal having low contact resistance has been developed.
[0004]
Japanese Patent Application Laid-Open No. 10-228914 (Patent Document 1) introduces a technique in which a gold plating layer having a thickness of 0.01 to 0.06 μm is formed on SUS304.
However, since the resistance is high due to the effect of the oxide film simply by performing the gold plating, a technique for removing the oxide film and performing the gold plating is disclosed in Japanese Patent Laid-Open No. 13-6713 (Patent Document 2).
[0005]
In addition, pin holes are unavoidable in plating, and the corrosion resistance of those portions is reduced. Although it is said that there is no problem in the above-mentioned patent, Japanese Patent Laid-Open No. 14-260681 (Patent Document 3) discloses a technique of eliminating the pinhole by rolling after plating in order to reduce the pinhole.
Furthermore, as an attempt to easily coat gold, Japanese Patent Laid-Open No. 14-237311 (Patent Document 4) discloses a technique for coating a gold foil using ultrasonic waves.
[0006]
From these facts, it is clear that only gold plating on stainless steel has a problem in corrosion resistance in thin gold plating of about 0.01 μm due to the problem of pinholes.
Furthermore, since the oxide film inside the pinhole is not strong because the oxide film is removed, the corrosion resistance tends to be lower.
In order to solve this, it was necessary to increase the gold plating thickness to reduce pinholes.
In fact, Japanese Patent Laid-Open No. 13-345109 (Patent Document 5) discloses a technique for partially increasing the gold plating thickness to maintain corrosion resistance and reducing contact resistance. However, the formation of a thick gold plating film naturally affects the cost and is not practical.
[0007]
By the way, a so-called sealing process for filling a gold-plated pinhole is widely used in gold plating on a copper alloy for a connector. For example, Japanese Patent Application Laid-Open No. 7-258887 (Patent Document 6), Japanese Patent Application Laid-Open No. 8-260194 (Patent Document 7), etc. disclose a technique for performing a gold plating sealing treatment with an organic substance. However, the required performance for the connector and the required performance for the fuel cell separator are different, and therefore the sealing treatment for the connector cannot be applied as it is.
[0008]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-228914 [Patent Document 2]
Japanese Patent Laid-Open No. 13-6713 [Patent Document 3]
Japanese Patent Laid-Open No. 14-260681 [Patent Document 4]
JP-A-14-237311 [Patent Document 5]
Japanese Patent Laid-Open No. 13-345109 [Patent Document 6]
Japanese Patent Application Laid-Open No. 7-258887 [Patent Document 7]
Japanese Patent Laid-Open No. 8-260194
[Problems to be solved by the invention]
The present invention has been made to solve such problems, and reduces the contact resistance of stainless steel by applying precious metal plating, and a metal separator for a fuel cell having sufficient corrosion resistance even with a thin precious metal plating thickness and It aims at providing the manufacturing method. Another object of the present invention is to provide a noble metal plated metal plate.
[0010]
[Means for Solving the Problems]
As a result of intensive investigations to reduce the contact resistance of the metal separator for fuel cells and to ensure corrosion resistance, the present inventor has provided a noble metal plating layer on the surface of the metal separator, and the plating layer is formed with a specific sealing agent. It has been found that the sealing treatment can provide corrosion resistance and low contact resistance even with a thin plating thickness, and the present invention has been achieved.
[0011]
That is, the present invention
(1) have a gold or gold alloy layer having a thickness 5~20nm formed directly on the surface of the stainless steel plate, mercaptobenzothiazole which the gold or gold alloy layer is represented by the following formula as an inhibitor (1) one or two or more by using the separator for corrosion resistant fuel cell characterized by being sealing treatment gold or gold alloy plated stainless steel plate of derivatives,
[Chemical formula 5]

[In the formula, R1 represents hydrogen, alkyl, substituted alkyl or halogen, and R2 represents an alkali metal, hydrogen, alkyl, substituted alkyl or substituted amino group]
(2) A separator for a fuel cell, the separator is on the surface of the stainless steel plate having a gold or gold alloy layer having a thickness 5~20nm formed directly, the gold or gold alloy layer as an inhibitor A fuel cell separator characterized by being sealed with one or more mercaptobenzothiazole derivatives represented by the following formula (1):

[Wherein R1 represents hydrogen, alkyl, substituted alkyl, halogen, R2 represents an alkali metal, hydrogen, alkyl, substituted alkyl, substituted amino group],
(3) One or more mercaptobenzothiazole derivatives represented by the following formula (1) as an inhibitor after forming gold or gold alloy plating with a film thickness of 5 to 20 nm directly on the surface of the stainless steel separator The fuel cell according to (2), wherein the stainless steel separator is used as an anode in an aqueous solution containing 10 to 50000 ppm in total, and direct current electrolysis is performed in a range of an interelectrode voltage E of 0.1 to 5.0 V Separator manufacturing method,
[Chemical 7]

[Wherein R1 represents hydrogen, alkyl, substituted alkyl, halogen, R2 represents an alkali metal, hydrogen, alkyl, substituted alkyl, substituted amino group],
(4) One or more mercaptobenzothiazole derivatives represented by the following formula (1) are used as inhibitors after directly forming gold or gold alloy plating with a film thickness of 5 to 20 nm on the surface of the stainless steel separator. The fuel cell according to (2), wherein the stainless steel separator is used as an anode in an aqueous solution containing a total amount of 10 to 5000 ppm, and direct current electrolysis is performed in a range of an interelectrode voltage E of 0.1 to 5.0 V Separator manufacturing method,
[Chemical 8]

[Wherein R1 represents hydrogen, alkyl, substituted alkyl, halogen, R2 represents an alkali metal, hydrogen, alkyl, substituted alkyl, substituted amino group],
(5) The present invention relates to a fuel cell separator produced by the method according to (3) or (4).
In addition, the metal plate plated with the noble metal (1) can be formed and cut to form a fuel cell separator.
[0012]
The so-called sealing treatment for filling the pin holes in the gold plating layer is known for gold plating on a copper alloy for connectors as already described. However, in addition to low contact resistance and corrosion resistance, connectors require lubricity, and nickel plating is generally applied as a base plating to improve adhesion. It was not desirable to apply the same conditions as required. In particular, the fuel cell separator does not require lubricity, and there is a possibility that the treatment is unnecessary or has an adverse effect to impart lubricity.
[0013]
Further, since the connector is repeatedly inserted and extracted, it is required that the insertion / extraction resistance is low, and as a result, a low contact resistance is required in a state where the pressure at the contact portion is about 10 kgf, for example. On the other hand, the fuel cell separator hardly decomposes after being set once, and the contact pressure can be as high as about 20 kg / cm ² by bolting. Connectors are often evaluated by contact pressure per point, and the units of bolting and pressure are different, making it difficult to make a general comparison. However, in the case of bolts, when viewed microscopically, the pressure is concentrated on the part that is in local contact, so the contact pressure of the connector is considered to be a high contact pressure exceeding 100 kgf. It is done.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described.
Stainless steel, such as SUS304 and SUS316L, is subjected to direct gold plating after pretreatment of electrolytic degreasing → water washing → electrolytic pickling → water washing. The purpose of the present invention is to seal the pinhole and reduce the gold plating thickness. Therefore, the plating thickness is required to be 5 nm or more to ensure conduction as a fuel cell separator, but 20 nm or less is sufficient. . However, it may be thicker. In the present invention, after the thin gold plating for the above-described purpose, the stainless steel is immersed in an aqueous solution of a mercaptobenzothiazole derivative represented by the following general formula (1), and the stainless steel is polarized to the anode and treated for about 3 seconds. Process. Then, it is washed with water or hot water and dried.
[0015]
[Chemical 9]

[In the formula, R1 represents hydrogen, alkyl, substituted alkyl or halogen, and R2 represents an alkali metal, hydrogen, alkyl, substituted alkyl or substituted amino group]
Among the compounds represented by the general formula (1), preferred are
[0016]
[Chemical Formula 10]

Etc.
[0017]
The concentration of the mercaptobenzothiazole derivative is 10 to 50000 ppm, preferably 10 to 5000 ppm. If it is lower than this, a long treatment time is required to obtain the effect of enhancing the corrosion resistance. On the other hand, if it is higher than 5000 ppm, the organic matter becomes thick and it becomes difficult to coat uniformly. In particular, this organic substance is considered to have little effect on the thickened portion because the corrosion resistance is improved by the sealing effect. Furthermore, the contact resistance tends to increase as the organic matter becomes thicker. However, as described above, unlike the connector for the fuel cell separator, it is possible to increase the contact pressure of the conducting part. Therefore, the sealing treatment is performed at a high concentration giving priority to corrosion resistance, and the contact is increased by increasing the contact pressure. It is possible to reduce the resistance.
[0018]
In addition, although the immersion alone is effective without being polarized on the anode, the treatment is completed in a shorter time when the anode is polarized. The polarization potential is preferably in the range of 0.1 to 5.0 V as the cell voltage. In the case of an aqueous solution of a mercaptobenzothiazole derivative, since the electrical conductivity is low, the battery current hardly flows. For this reason, it is easier to control by controlling the cell voltage rather than the current density generally controlled by electrolysis. However, the current density cannot be controlled, and current density control may be performed so that the cell voltage falls within the above range.
Thus, the fuel cell separator sealed with the mercaptobenzothiazole derivative has the same corrosion resistance and low contact resistance as the thick gold plating, even with a thin gold plating thickness.
[0019]
【Example】
The examples illustrate the invention.
SUS316L having a thickness of 0.3 mm was subjected to pretreatment of electrolytic anode degreasing → water washing → electrolytic cathodic pickling → water washing, followed by direct gold plating. Each pretreatment and gold plating conditions are as follows.
[0020]
Electrolytic degreasing pakuna P105 40g / L
Temperature: 60 ° C
Current density: 6 A / dm ²
Anode electrolysis time: 30 seconds [0021]
Pickling sulfuric acid: 200 g / L
Temperature: Room temperature Time: 30 seconds [0022]
Gold plating additive: Direct gold plating bath gold concentration: 1-4 g / L
Bath temperature: 20-40 ° C
Current density: 6 A / dm ²
Plating thickness: 10, 20 nm
[0023]
Sealed mercaptobenzothiazole Na salt: 100,1000,10000p
pm
Temperature: Room temperature Cathode: SUS316L
Cell voltage: 2V
Time: 3 seconds [0024]
The contact resistance, anodic polarization, and iron elution after immersion in sulfuric acid of the stainless gold plating material thus prepared were investigated under the following conditions.
Contact Resistance Yamazaki Test Machine: Electric contact simulator CRS-1
Probe: Gold contact pressure: 10 gf
Number of measurements: 400 points
Anode polarization measurement condition Temperature: Room temperature Measurement solution: Sulfuric acid 5%
Deoxygenation: Argon 200ml / min
Sweep speed: 20 mV / min
Sample area: 1 cm ²
[0026]
Sulfuric acid immersion test solution: sulfuric acid 5%
Temperature: 80 ° C
Liquid volume: 5cc
Test material: 10 × 50 mm Immersion immersion time: ˜30 days Measuring method: Quantitative determination of Fe ions by ICP analysis
The contact resistance measurement results are shown in FIGS.
This measurement condition is a condition generally used in connectors, and the contact pressure is as low as 10 gf. Under these conditions, it can be seen that mercaptobenzothiazole Na (abbreviated as MBT in the figure) exhibits high contact resistance at a concentration of 10,000 ppm. However, it can be seen that by increasing the contact pressure even under these conditions, the contact resistance decreases as shown in FIGS. In the case of a concentration of 1000 ppm, a mottled organic pattern was visually observed on the surface. This was considered that the thickness of the organic substance was uneven.
[0028]
The result of polarization measurement is shown in FIG. It can be seen that the corrosion current density is reduced by performing the sealing treatment as compared with the case without the sealing treatment. Moreover, the higher the treatment concentration of the sealing treatment MBT, the lower the corrosion current density. This shows that the corrosion resistance is improved by the sealing treatment.
[0029]
[Table 1]

[0030]
Comparative Example A test material was prepared in the same manner without sealing treatment. The results are shown in the examples and tables.
[0031]
【The invention's effect】
As described above, according to the present invention, the thin noble metal plating can provide sufficient corrosion resistance required for a fuel cell separator and at the same time have a low contact resistance. Moreover, according to this invention, the metal plate plated with the noble metal for making this separator can be obtained.
[0032]
[Brief description of the drawings]
FIG. 1 is a graph showing measurement results of contact resistance of a separator of an example.
FIG. 2 is a graph showing the relationship between the contact pressure and the contact resistance of the separator of the example.
FIG. 4 is a graph showing the polarization measurement result of the separator of the example.

Claims (5)

On the surface of the stainless steel plate having a gold or gold alloy layer having a thickness 5~20nm formed directly, 1 mercaptobenzothiazole derivatives which the gold or gold alloy layer is represented by the following formula as an inhibitor (1) gold or gold alloy plated stainless steel plate used in a separator for a corrosion resistant fuel cell characterized by being sealing treatment by species or two or more.

[In the formula, R1 represents hydrogen, alkyl, substituted alkyl or halogen, and R2 represents an alkali metal, hydrogen, alkyl, substituted alkyl or substituted amino group] A separator for a fuel cell, the separator is on the surface of the stainless steel plate having a gold or gold alloy layer having a thickness 5~20nm formed directly, the following formula wherein gold or gold alloy layer as an inhibitor ( A separator for a corrosion-resistant fuel cell, which is sealed with one or more of the mercaptobenzothiazole derivatives represented by 1).

[In the formula, R1 represents hydrogen, alkyl, substituted alkyl or halogen, and R2 represents an alkali metal, hydrogen, alkyl, substituted alkyl or substituted amino group] After directly forming gold or gold alloy plating with a film thickness of 5 to 20 nm on the surface of the stainless steel separator, one or more of mercaptobenzothiazole derivatives represented by the following formula (1) as an inhibitor in total 3. The corrosion-resistant fuel cell separator according to claim 2, wherein the stainless steel separator is used as an anode in an aqueous solution containing 10 to 50000 ppm, and direct current electrolysis is performed in a range of an interelectrode voltage E of 0.1 to 5.0V. Production method.

[In the formula, R1 represents hydrogen, alkyl, substituted alkyl or halogen, and R2 represents an alkali metal, hydrogen, alkyl, substituted alkyl or substituted amino group] After forming gold or gold alloy plating with a film thickness of 5 to 20 nm directly on the surface of the stainless steel separator, one or more of mercaptobenzothiazole derivatives represented by the following formula (1) as an inhibitor in total 3. The corrosion-resistant fuel cell separator according to claim 2, wherein the stainless steel separator is used as an anode in an aqueous solution containing 10 to 5000 ppm, and direct current electrolysis is performed in a range of an interelectrode voltage E of 0.1 to 5.0V. Production method.

[In the formula, R1 represents hydrogen, alkyl, substituted alkyl or halogen, and R2 represents an alkali metal, hydrogen, alkyl, substituted alkyl or substituted amino group] A separator for a corrosion-resistant fuel cell produced by the method according to claim 3 or 4.

Images