JP2005216605A

JP2005216605A - Metal separator with anticorrosive coating film for fuel cell and production method thereof

Info

Publication number: JP2005216605A
Application number: JP2004019894A
Authority: JP
Inventors: Shin Yoshida; 慎吉田; Tomokazu Hayashi; 友和林
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2004-01-28
Filing date: 2004-01-28
Publication date: 2005-08-11

Abstract

【課題】立ち面の防食コート層の厚さが、塗料垂れ等によって、薄くなることを抑制することができる燃料電池用防食塗膜付きメタルセパレータの提供。
【解決手段】（１）メタルセパレータ１８ａの反応ガスが接触する側の表面が、粗面化処理されている燃料電池用防食塗膜付きメタルセパレータ１８。
（２）粗面化処理されている部位１００が、防食塗料塗布時に塗布した塗料が流れ得る部位１１０を含む。
（３）粗面化処理されている部位１００が、防食塗料塗布時に塗布した塗料が流れ得る部位１１０と、接着剤が塗布される部位１２０とを含む。
（４）防食塗料塗布時に塗布した塗料が流れ得る部位１１０が、反応ガス流路の溝側面２７ａ、２８ａである。
（５）前記防食塗料塗布時に塗布した塗料が流れ得る部位１１０が、前記メタルセパレータの反応ガス流路の溝底面２７ｂ、２８ｂである。
【選択図】図１PROBLEM TO BE SOLVED: To provide a metal separator with an anticorrosive coating film for a fuel cell capable of suppressing the thickness of an anticorrosive coating layer on a standing surface from becoming thin due to paint dripping or the like.
(1) A metal separator with an anticorrosive coating film for a fuel cell, wherein the surface of the metal separator on which the reaction gas comes into contact is roughened.
(2) The portion 100 that has been subjected to the roughening treatment includes a portion 110 through which the paint applied at the time of applying the anticorrosive paint can flow.
(3) The surface-treated portion 100 includes a portion 110 where the paint applied during the anticorrosion coating application can flow and a portion 120 where the adhesive is applied.
(4) The portions 110 where the paint applied during the application of the anticorrosive paint can flow are the groove side surfaces 27a and 28a of the reaction gas channel.
(5) The portion 110 through which the paint applied during the application of the anticorrosion paint can flow is the groove bottom surfaces 27b and 28b of the reaction gas flow path of the metal separator.
[Selection] Figure 1

Description

本発明は、燃料電池用セパレータに関し、反応ガスが接触する側の表面に防食塗膜が形成された防食塗膜付きメタルセパレータと、その製造方法に関する。 The present invention relates to a separator for a fuel cell, and relates to a metal separator with an anticorrosive coating film on which a reaction gas contacts a surface and a method for producing the same.

燃料電池、たとえば固体高分子電解質型燃料電池は、膜−電極アッセンブリ（Membrane-Electrode Assembly 、ＭＥＡ）をセパレータで挟んだものから構成される。少なくとも１つの単位燃料電池からモジュールを構成し、モジュールを複数積層して（積層方向は任意）燃料電池スタックが構成される。セパレータは、燃料ガス、酸化ガス、冷却水を分離するためのガス、水の遮断性を有し、また、電子の通路となるための導電性を有する。これらの性質を満足するために、セパレータは金属製セパレータ（メタルセパレータ）やカーボンセパレータとされる。 2. Description of the Related Art A fuel cell, for example, a solid polymer electrolyte fuel cell is configured by sandwiching a membrane-electrode assembly (MEA) between separators. A module is composed of at least one unit fuel cell, and a plurality of modules are stacked (arbitrary stacking direction is arbitrary) to form a fuel cell stack. The separator has a barrier property for separating the fuel gas, the oxidizing gas, and the cooling water, and water, and also has a conductivity for forming an electron path. In order to satisfy these properties, the separator is a metal separator (metal separator) or a carbon separator.

燃料電池のセパレータ環境は、電解質膜中のフッ素基や硫酸基が溶出すること、および電位がかかっていることから、腐食雰囲気である。この腐食雰囲気に耐えるために、
（イ）特開２００２−３６７６２２号公報に開示されているように、メタルセパレータ表面を粗面化処理後、不動態化処理によってバリア薄膜（塗膜ではない）を形成したり、あるいは、
（ロ）図５、図６に示すように、または特開平１１−３５４１４２号公報に開示されているように、メタルセパレータ１の表面に導電性をもつ防食塗膜２が形成したりする。
図５、図６の例では、防食塗膜２は、導電性をもつ防食材料、たとえば、ＳＢＲ（スチレン−ブタジエンゴム）にカーボン粉を混入させた防食材料を、ＳＢＲを加熱、溶融状態にし、スプレー塗布等により、メタルセパレータ１の全面に塗布することにより、形成される。塗布時は、セパレータ面は水平とされるので、反応ガス流路溝の溝側面はほぼ上下方向に延びる立ち面３となる。 The separator environment of the fuel cell is a corrosive atmosphere because the fluorine groups and sulfate groups in the electrolyte membrane are eluted and a potential is applied. To withstand this corrosive atmosphere,
(A) As disclosed in JP-A-2002-367622, after a roughening treatment on the surface of the metal separator, a barrier thin film (not a coating film) is formed by a passivation treatment, or
(B) As shown in FIGS. 5 and 6 or as disclosed in Japanese Patent Application Laid-Open No. 11-354142, a conductive anticorrosive coating 2 is formed on the surface of the metal separator 1.
In the examples of FIGS. 5 and 6, the anticorrosion coating 2 is made of an anticorrosion material having conductivity, for example, an anticorrosion material in which carbon powder is mixed in SBR (styrene-butadiene rubber), and SBR is heated and melted. It is formed by coating the entire surface of the metal separator 1 by spray coating or the like. At the time of application, since the separator surface is horizontal, the groove side surface of the reaction gas flow channel groove is a standing surface 3 extending substantially in the vertical direction.

しかし、従来の、表面に防食塗膜を形成したメタルセパレータには、以下の問題がある。
セパレータの立ち面３において塗料が、塗布時、固化前に自重で垂れてしまい、塗料固化後の立ち面３の防食塗膜２の厚さが他の部分に比べて薄くなる。その結果、立ち面３において、防食効果が弱く、腐食の起点となる。
防食塗膜２が、立ち面３において、塗料が垂れてもなお防食上十分な厚さを有するように、塗料を厚目に塗布すると、他の部分、たとえばセパレータ頂面４（ＭＥＡと接触してＭＥＡを押圧する面）の塗膜が厚くなり過ぎ、ＭＥＡとの接触抵抗が上昇して燃料電池出力が低下するおそれがある。塗膜の抵抗を小にするために塗膜組成中のカーボン量を増やすと塗料の粘度が高くなり過ぎて、塗料をスプレー塗布することが困難になる。
立ち面の塗料垂れの他、流路溝底面でも、表面張力によるコーナへの塗料引けによっても、類似の問題が生じる。
特開２００２−３６７６２２号公報特開平１１−３５４１４２号公報 However, the conventional metal separator having the anticorrosive coating formed on the surface has the following problems.
At the time of application of the separator, the coating material hangs down by its own weight before solidification at the time of application, and the thickness of the anticorrosion coating film 2 on the standing surface 3 after the solidification of the coating material becomes thinner than other portions. As a result, the anti-corrosion effect is weak at the standing surface 3 and becomes a starting point of corrosion.
When the paint is applied thickly so that the anticorrosion coating film 2 has a sufficient thickness to prevent corrosion even when the paint drips on the standing surface 3, the other part, for example, the separator top surface 4 (contacts with the MEA). The surface of the MEA-pressing surface) becomes too thick, and the contact resistance with the MEA increases and the fuel cell output may decrease. If the amount of carbon in the coating composition is increased in order to reduce the resistance of the coating film, the viscosity of the coating becomes too high, making it difficult to spray the coating.
Similar problems are caused by the paint dripping on the corners due to the surface tension at the bottom of the channel groove in addition to the paint dripping on the standing surface.
JP 2002-367622 A JP 11-354142 A

本発明が解決しようとする問題点は、従来の上記（ロ）の燃料電池用防食塗膜付きメタルセパレータにおける、立ち面の防食塗膜の厚さが、塗料垂れ等によって他の部位と比べて薄くなり、立ち面の塗膜の防食効果が弱く、腐食の起点になりやすいという問題である。 The problem to be solved by the present invention is that the thickness of the anticorrosion coating on the standing surface in the conventional metal separator with an anticorrosion coating for fuel cells described in (b) is higher than that of other parts due to paint dripping or the like. This is a problem that the film becomes thinner, the anticorrosion effect of the coating film on the standing surface is weak, and tends to be a starting point of corrosion.

本発明の目的は、立ち面の防食コート層の厚さが、塗料垂れ等によって、薄くなることを抑制することができる燃料電池用防食塗膜付きメタルセパレータとその製造方法を提供することにある。 An object of the present invention is to provide a metal separator with an anticorrosive coating film for a fuel cell and a method for producing the same, capable of suppressing the thickness of the anticorrosive coating layer on the standing surface from becoming thin due to paint dripping or the like. .

上記目的を達成する本発明はつぎの通りである。
（１）メタルセパレータと該メタルセパレータの反応ガスが接触する側の表面に塗布・形成された防食塗膜とを有する燃料電池用防食塗膜付きメタルセパレータであって、前記メタルセパレータの反応ガスが接触する側の表面が、前記防食塗膜を塗布・形成する前に粗面化処理されている燃料電池用防食塗膜付きメタルセパレータ。
（２）前記メタルセパレータの反応ガスが接触する側の表面のうち粗面化処理されている部位が、防食塗料塗布時に塗布した塗料が流れ得る部位を含む（１）記載の燃料電池用防食塗膜付きメタルセパレータ。
（３）前記メタルセパレータの反応ガスが接触する側の表面のうち粗面化処理されている部位が、防食塗料塗布時に塗布した塗料が流れ得る部位と、接着剤が塗布される部位とを含む（１）記載の燃料電池用防食塗膜付きメタルセパレータ。
（４）前記防食塗料塗布時に塗布した塗料が流れ得る部位が、前記メタルセパレータの反応ガス流路の溝側面である（２）または（３）記載の燃料電池用防食塗膜付きメタルセパレータ。
（５）前記防食塗料塗布時に塗布した塗料が流れ得る部位が、前記メタルセパレータの反応ガス流路の溝底面である（２）または（３）記載の燃料電池用防食塗膜付きメタルセパレータ。
（６）
前記防食塗料塗布時に塗布した塗料が流れ得る部位が、前記メタルセパレータの反応ガス流路の溝側面と溝底面である（２）または（３）記載の燃料電池用メタルセパレータ。
（７）粗面化処理がプラズマ処理である（１）記載の燃料電池用防食塗膜付きメタルセパレータ。
（８）メタルセパレータの反応ガスが接触する側の表面を粗面化処理し、粗面化処理後の表面に少なくとも耐食機能を有する塗膜を塗布・形成する燃料電池用防食塗膜付きメタルセパレータの製造方法。 The present invention for achieving the above object is as follows.
(1) A metal separator with an anticorrosive coating film for a fuel cell, which has a metal separator and an anticorrosive coating film applied and formed on the surface of the metal separator on which the reaction gas contacts, wherein the reaction gas of the metal separator is A metal separator with an anticorrosive coating film for a fuel cell, wherein the surface on the contact side is roughened before the anticorrosive coating film is applied / formed.
(2) The anticorrosive coating for a fuel cell according to (1), wherein the roughened portion of the surface of the metal separator on the side in contact with the reactive gas includes a portion through which the paint applied at the time of applying the anticorrosive coating can flow. Metal separator with membrane.
(3) The roughened portion of the surface of the metal separator on the side in contact with the reactive gas includes a portion where the coating applied during application of the anticorrosive coating can flow and a portion where the adhesive is applied. (1) The metal separator with an anti-corrosion coating film for fuel cells.
(4) The metal separator with an anticorrosive coating film for a fuel cell according to (2) or (3), wherein a portion through which the paint applied during the application of the anticorrosive paint can flow is a groove side surface of the reaction gas flow path of the metal separator.
(5) The metal separator with an anticorrosive coating film for a fuel cell according to (2) or (3), wherein a portion through which the coating material applied during application of the anticorrosion coating material can flow is a groove bottom surface of the reaction gas channel of the metal separator.
(6)
The metal separator for a fuel cell according to (2) or (3), wherein the portions where the paint applied during the application of the anticorrosion paint can flow are the groove side surface and groove bottom surface of the reaction gas flow path of the metal separator.
(7) The metal separator with an anticorrosive coating film for fuel cells according to (1), wherein the roughening treatment is a plasma treatment.
(8) A metal separator with an anticorrosive coating film for a fuel cell, wherein the surface of the metal separator on the side in contact with the reaction gas is roughened, and a coating film having at least a corrosion resistance function is applied to the surface after the roughening treatment. Manufacturing method.

上記（１）の燃料電池用防食塗膜付きメタルセパレータによれば、メタルセパレータの反応ガスが接触する側の表面が、粗面化処理されているので、粗面のアンカー効果でセパレータの表面での塗料の流れを抑制でき、塗膜の膜厚が均一化される。
上記（２）の燃料電池用防食塗膜付きメタルセパレータによれば、粗面化処理されている部位が、防食塗料塗布時に塗布した塗料が流れ得る部位（自重で流れる溝側面、表面張力で流れる溝底面）を含むので、粗面のアンカー効果でセパレータの表面での塗料の流れを抑制でき、塗膜の膜厚が均一化される。これによって、流路溝側面や溝底面で他の部位に比べて塗膜の膜厚が薄くなり過ぎることがなくなり、流路溝側面や溝底面が腐食の起点となることを抑制することができる。
上記（３）の燃料電池用防食塗膜付きメタルセパレータによれば、粗面化部分が接着剤塗布面を含むので、表面を粗した効果によって、セパレータ間に使用する接着剤のセパレータとの接着性を向上できる。
上記（４）の燃料電池用防食塗膜付きメタルセパレータによれば、防食塗料塗布時に塗布した塗料が流れ得る部位が、メタルセパレータの反応ガス流路の溝側面であるため、防食材塗布時に塗料が自重によって垂れて溝側面で塗膜が薄くなることを抑制することができる。
上記（５）の燃料電池用防食塗膜付きメタルセパレータによれば、防食塗料塗布時に塗布した塗料が流れ得る部位が、メタルセパレータの反応ガス流路の溝底面であるため、防食塗料塗布時に塗料が表面張力により溝底面両端のコーナ部へ引けて溝底面の中央部で塗膜が薄くなることを抑制することができる。
上記（６）の燃料電池用防食塗膜付きメタルセパレータによれば、防食塗料塗布時に塗布した塗料が流れ得る部位が、メタルセパレータの反応ガス流路の溝側面と溝底面であるため、防食塗料塗布時に塗料が自重によって垂れて溝側面で塗膜が薄くなることを抑制することができるとともに、塗料が「引け」によって溝底面両端のコーナ部へ移動して溝底面の中央部で塗膜が薄くなることを抑制することができる。
上記（７）の燃料電池用防食塗膜付きメタルセパレータによれば、粗面化処理がプラズマ処理であるので、塗料垂れの抑制の他、ブラスト処理、エッチング等に比べて、面の濡れ性が向上することによる塗料塗布性能の向上が得られる。
上記（８）の燃料電池用防食塗膜付きメタルセパレータの製造方法によれば、粗面化処理した後に塗膜を形成するので、塗膜形成時の塗料垂れを防止することができる。 According to the metal separator with an anticorrosive coating film for fuel cell of (1) above, the surface of the metal separator on the side where the reaction gas contacts is roughened, so the surface of the separator has a rough anchor effect. The flow of the paint can be suppressed, and the film thickness of the coating film is made uniform.
According to the metal separator with an anticorrosive coating film for fuel cells in (2) above, the roughened portion is a portion where the paint applied during the anticorrosive coating application can flow (the groove side surface that flows under its own weight, and the surface tension flows) Since the groove bottom surface is included, the flow of the paint on the surface of the separator can be suppressed by the rough anchor effect, and the film thickness of the coating film is made uniform. Thereby, the film thickness of the coating film does not become too thin compared to other parts on the side surface and the bottom surface of the flow channel, and it can be suppressed that the side surface and the bottom surface of the flow channel become the starting point of corrosion. .
According to the metal separator with an anticorrosive coating film for fuel cells in (3) above, since the roughened portion includes the adhesive-coated surface, adhesion of the adhesive used between the separators to the separator due to the effect of roughening the surface Can be improved.
According to the metal separator with an anticorrosive coating film for fuel cell (4) above, the portion where the paint applied during the anticorrosion coating application can flow is the groove side surface of the reaction gas flow path of the metal separator. Can be prevented from dripping due to its own weight and the coating film becoming thin on the side surface of the groove.
According to the metal separator with an anticorrosive coating film for the fuel cell of (5) above, the portion where the paint applied during the anticorrosion coating application can flow is the groove bottom surface of the reaction gas flow path of the metal separator. However, it is possible to prevent the coating film from being thinned at the center portion of the groove bottom surface due to the surface tension.
According to the metal separator with an anticorrosive coating film for a fuel cell according to the above (6), the portions where the paint applied during the anticorrosion coating application can flow are the groove side surface and the groove bottom surface of the reaction gas flow path of the metal separator. It is possible to prevent the paint from dripping due to its own weight during application, and to reduce the thickness of the coating on the side of the groove. Thinning can be suppressed.
According to the metal separator with an anticorrosive coating film for fuel cells in (7) above, since the roughening treatment is a plasma treatment, the wettability of the surface is less than that of blast treatment, etching, etc. in addition to suppression of paint dripping. Improvement in paint application performance due to improvement is obtained.
According to the method for producing a metal separator with an anticorrosive coating film for fuel cells described in (8) above, since the coating film is formed after the surface roughening treatment, paint dripping at the time of coating film formation can be prevented.

以下に、本発明の燃料電池用防食塗膜付きメタルセパレータとその製造方法を、図１〜図４を参照して説明する。
本発明の防食塗膜付きメタルセパレータが組み付けられる燃料電池は、低温型燃料電池であり、たとえば、固体高分子電解質型燃料電池１０である。該燃料電池１０は、たとえば燃料電池自動車に搭載される。ただし、自動車以外に用いられてもよい。 Below, the metal separator with an anti-corrosion coating film for fuel cells of this invention and its manufacturing method are demonstrated with reference to FIGS.
The fuel cell to which the metal separator with the anticorrosive coating film of the present invention is assembled is a low-temperature fuel cell, for example, a solid polymer electrolyte fuel cell 10. The fuel cell 10 is mounted on, for example, a fuel cell vehicle. However, it may be used other than an automobile.

固体高分子電解質型燃料電池１０は、図３、図４に示すように、膜−電極アッセンブリ（ＭＥＡ：Membrane-Electrode Assembly ）とセパレータ１８との積層体からなる。積層方向は上下方向に限るものではなく、任意の方向でよい。
膜−電極アッセンブリは、イオン交換膜からなる電解質膜１１とこの電解質膜の一面に配置された触媒層からなる電極（アノード、燃料極）１４および電解質膜の他面に配置された触媒層からなる電極（カソード、空気極）１７とからなる。膜−電極アッセンブリとセパレータ１８との間には、アノード側、カソード側にそれぞれ拡散層が設けられる。 As shown in FIGS. 3 and 4, the solid polymer electrolyte fuel cell 10 is composed of a laminate of a membrane-electrode assembly (MEA) and a separator 18. The stacking direction is not limited to the vertical direction, and may be any direction.
The membrane-electrode assembly includes an electrolyte membrane 11 made of an ion exchange membrane, an electrode (anode, fuel electrode) 14 made of a catalyst layer disposed on one surface of the electrolyte membrane, and a catalyst layer disposed on the other surface of the electrolyte membrane. It consists of electrodes (cathode, air electrode) 17. Between the membrane-electrode assembly and the separator 18, diffusion layers are provided on the anode side and the cathode side, respectively.

セパレータ１８は防食塗膜付きメタルセパレータ１８である。セパレータ１８には、アノード１４、カソード１７に燃料ガス（水素）および酸化ガス（酸素、通常は空気）を供給するための反応ガス流路２７、２８（燃料ガス流路２７、酸化ガス流路２８）と、その裏面に冷媒（通常、冷却水）を流すための冷媒流路２６が形成されている。また、セパレータ１８には、燃料ガス流路２７に燃料ガスを供給、排出するための燃料ガスマニホールド３０、酸化ガス流路２８に酸化ガスを供給、排出するための酸化ガスマニホールド３１、冷媒流路２６に冷媒を供給、排出するための冷媒マニホールド２９が形成されている。 The separator 18 is a metal separator 18 with an anticorrosion coating film. In the separator 18, reaction gas channels 27 and 28 (fuel gas channel 27, oxidizing gas channel 28) for supplying fuel gas (hydrogen) and oxidizing gas (oxygen, usually air) to the anode 14 and cathode 17. ) And a refrigerant flow path 26 for flowing a refrigerant (usually cooling water) is formed on the back surface thereof. Further, the separator 18 has a fuel gas manifold 30 for supplying and discharging fuel gas to and from the fuel gas channel 27, an oxidizing gas manifold 31 for supplying and discharging oxidizing gas to the oxidizing gas channel 28, and a refrigerant channel. A refrigerant manifold 29 for supplying and discharging refrigerant is formed at 26.

膜−電極アッセンブリとセパレータ１８を重ねて単位燃料電池（「単セル」ともいう）１９を構成し、少なくとも１つのセルからモジュール（図６、図７では１モジュールが１セルから構成される場合を示しており、セル１９とモジュールが等しいので、モジュールにも符号１９を付す）を構成し、モジュール１９を積層してセル積層体とし、セル積層体のセル積層方向両端に、ターミナル２０、インシュレータ２１、エンドプレート２２を配置し、セル積層体をセル積層方向に締め付け、セル積層体の外側でセル積層方向に延びる締結部材（たとえば、テンションプレート２４）、ボルト・ナット２５により固定して、燃料電池スタック２３を構成する。 A unit fuel cell (also referred to as a “single cell”) 19 is configured by stacking the membrane-electrode assembly and the separator 18, and a module is composed of at least one cell (in FIG. 6 and FIG. 7, one module is composed of one cell). Since the module is the same as the cell 19, the module is also denoted by reference numeral 19), and the module 19 is stacked to form a cell stack, and terminals 20 and insulators 21 are provided at both ends of the cell stack in the cell stacking direction. The end plate 22 is disposed, the cell stack is clamped in the cell stacking direction, and is fixed by a fastening member (for example, a tension plate 24) extending outside the cell stack in the cell stacking direction, a bolt / nut 25, and the fuel cell. The stack 23 is configured.

各セル１９の、アノード側１４では、水素を水素イオン（プロトン）と電子にする電離反応が行われ、水素イオンは電解質膜１１中をカソード側に移動し、カソード１７側では酸素と水素イオンおよび電子（隣りのＭＥＡのアノードで生成した電子がセパレータを通してくる、またはセル積層方向一端のセルのアノードで生成した電子が外部回路を通して他端のセルのカソードにくる）から水を生成する反応が行われ、かくして発電が行われる。
アノード側：Ｈ₂→２Ｈ⁺＋２ｅ^-
カソード側：２Ｈ⁺＋２ｅ^-＋（１／２）Ｏ₂→Ｈ₂Ｏ An ionization reaction that converts hydrogen into hydrogen ions (protons) and electrons is performed on the anode side 14 of each cell 19, and the hydrogen ions move to the cathode side through the electrolyte membrane 11, and oxygen, hydrogen ions, and Reaction to generate water from electrons (electrons generated at the anode of the adjacent MEA come through the separator, or electrons generated at the anode of the cell at one end in the cell stacking direction come to the cathode of the other end cell through an external circuit) Thus, power generation is performed.
Anode side: H ₂ → 2H ⁺ + 2e ⁻
Cathode side: 2H ⁺ + 2e ⁻ + (1/2) O ₂ → H ₂ O

流体流路２６、２７、２８、２９、３０、３１をシールするために、ガス側のシール材３３および冷媒側のシール３２が設けられる。図示例では、ガス側シール材３３が接着剤からなり、冷媒側シール材３２がゴムガスケットからなる場合を示してあるが、ガス側シール材３３も冷媒側シール材３２も、接着剤とゴムガスケットの何れから構成されてもよい。 In order to seal the fluid flow paths 26, 27, 28, 29, 30, 31, a gas-side sealing material 33 and a refrigerant-side seal 32 are provided. In the illustrated example, the gas side sealing material 33 is made of an adhesive and the refrigerant side sealing material 32 is made of a rubber gasket. However, both the gas side sealing material 33 and the refrigerant side sealing material 32 are made of an adhesive and a rubber gasket. Any of these may be used.

図１、図２に示すように、防食塗膜付きメタルセパレータ１８は、メタルセパレータ１８ａと、メタルセパレータ１８ａの反応ガスが接触する側の表面に塗布・形成された導電性をもつ防食塗膜１８ｂとを有する。
メタルセパレータ１８ａは、金属製の薄板であり、該金属製薄板を凹凸させて形成した反応ガス流路２７、２８を有する。メタルセパレータ１８ａの反応ガス流路２７、２８の反対側は冷却水流路２６である。メタルセパレータ１８ａの材料は、たとえばステンレスである。ただし、ステンレスに限るものではなく、アルミ、ニッケル、チタンや、それらの合金であってもよい。メタルセパレータ１８ａは、表面処理されていてもよく、表面処理には、カーボン蒸着や、金などの貴金属メッキなどを含む。表面処理は、メタルセパレータ１８ａの反応ガスと接触する側の面にも、その裏側の冷却水と接触する側の面にも施される。防食塗膜１８ｂは、メタルセパレータ１８ａの反応ガスと接触する側の面のみに形成され、メタルセパレータ１８ａに表面処理層がある場合はその上に形成される。冷却水が接触する側の表面には防食塗膜１８ｂは形成されない。
反応ガスと接触する側の表面のみに防食塗膜１８ｂを形成する理由は、反応ガス側がｐＨが１〜３の強い酸性雰囲気（腐食環境）となり得るのに対し、冷却水側は腐食環境とはいえない程度であり、全面塗装にはコストがかかるからである。 As shown in FIGS. 1 and 2, the metal separator 18 with the anticorrosion coating is composed of a metal separator 18 a and a conductive anticorrosion coating 18 b applied and formed on the surface of the metal separator 18 a on the side where the reaction gas contacts. And have.
The metal separator 18a is a metal thin plate, and has reaction gas flow paths 27 and 28 formed by making the metal thin plate uneven. The opposite side of the metal gas separator 18 a to the reaction gas channels 27 and 28 is a cooling water channel 26. The material of the metal separator 18a is, for example, stainless steel. However, it is not limited to stainless steel, but may be aluminum, nickel, titanium, or an alloy thereof. The metal separator 18a may be surface-treated, and the surface treatment includes carbon deposition, noble metal plating such as gold, and the like. The surface treatment is performed on the surface of the metal separator 18a that is in contact with the reaction gas and also on the back surface that is in contact with the cooling water. The anticorrosion coating 18b is formed only on the surface of the metal separator 18a that is in contact with the reaction gas. If the metal separator 18a has a surface treatment layer, it is formed thereon. The anticorrosion coating film 18b is not formed on the surface that comes into contact with the cooling water.
The reason why the anticorrosion coating film 18b is formed only on the surface in contact with the reaction gas is that the reaction gas side can be a strong acidic atmosphere (corrosion environment) having a pH of 1 to 3, whereas the cooling water side is a corrosive environment. This is because it cannot be said, and it is costly to paint the entire surface.

導電性をもつ防食材料からなる防食塗膜１８ｂは、（イ）ゴム（たとえば、ＳＢＲ（スチレン−ブタジエンゴム））に、導電性材料（たとえば、カーボン粉）を混合したもの、または（ロ）ゴムと熱可塑性樹脂を混合したものに、導電性材料（たとえば、カーボン粉）を混合したものからなる。防食塗膜１８ｂは、ゴム、またはゴムと樹脂を、加熱溶融した状態で、メタルセパレータ１８ａの塗布（たとえば、スプレー塗布、ロール塗布等）し、固化して形成される。 The anticorrosion coating film 18b made of a conductive anticorrosion material is obtained by mixing (a) rubber (for example, SBR (styrene-butadiene rubber)) with a conductive material (for example, carbon powder), or (b) rubber. And a mixture of a thermoplastic resin and a conductive material (for example, carbon powder). The anticorrosion coating 18b is formed by applying a metal separator 18a (for example, spray application, roll application, etc.) and solidifying rubber or rubber and resin in a heated and melted state.

図１、図２に示すように、メタルセパレータ１８ａの反応ガスが接触する側の表面は、粗面化処理されている。図２において、符号「１８ｃ」が、微小凹凸をもつ、粗面化処理した面を示す。この粗面化処理は、防食塗膜１８ｂを塗布・形成する前に行われる。
粗面化処理は、メタルセパレータ１８ａの反応ガスが接触する側の表面の全域に施されてもよいし、あるいは、メタルセパレータ１８ａの反応ガスが接触する側の表面の一部の特定部位のみに施されてもよい。
粗面化処理した面の微小凹凸の高さ（凸の平均的な頂上と凹の平均的な谷との、面直交方向の距離）は、１μｍ〜３０μｍであり、望ましくは１μｍ〜１０μｍである。防食塗膜１８ｂの厚さは、１０μｍ〜８０μｍであり、望ましくは１０μｍ〜３０μｍである。 As shown in FIGS. 1 and 2, the surface of the metal separator 18a on the side where the reaction gas contacts is roughened. In FIG. 2, reference numeral “18c” indicates a roughened surface having minute unevenness. This roughening treatment is performed before the anticorrosion coating 18b is applied and formed.
The roughening treatment may be applied to the entire surface of the metal separator 18a on the side in contact with the reaction gas, or may be applied only to a specific part of the surface of the metal separator 18a on the side in contact with the reaction gas. May be applied.
The height of the minute irregularities on the surface subjected to the roughening treatment (distance in the direction perpendicular to the plane between the average top of the convex and the average valley of the concave) is 1 μm to 30 μm, and preferably 1 μm to 10 μm. . The thickness of the anticorrosion coating 18b is 10 μm to 80 μm, and desirably 10 μm to 30 μm.

このサイズの微小凹凸をもつ粗面化処理は、サンドブラスト、ショットブラスト、液体ホーミング、プラズマ、化学的エッチング、スパッタリングなどの従来知られた粗面化方法を用いることができる。このうちプラズマ処理が望ましい、その理由は、プラズマ処理でＯＨ基が表面上に形成され、面の濡れ性が向上し、塗料塗布性能が向上するからである。メタルセパレータ１８ａの粗面化処理は、流路凹凸の形成後に行ってもよいし、あるいは流路凹凸の形成前に行ってもよい。
メタルセパレータ１８ａの粗面化処理をメタルセパレータ１８ａの全域に施してもよいし、あるいは、メタルセパレータ１８ａの一部である特定部位１００のみに施してもよい。
粗面化処理をメタルセパレータ１８ａの一部である特定部位１００のみに施す場合は、粗面化処理を施さない部位にマスキングを施した後、サンドブラストやエッチング等の粗面化処理を行い、その後マスキングを除去することにより、特定部位のみの粗面化処理を行うことができる。 For the surface roughening treatment having minute irregularities of this size, conventionally known surface roughening methods such as sand blasting, shot blasting, liquid homing, plasma, chemical etching, and sputtering can be used. Of these, plasma treatment is desirable because OH groups are formed on the surface by plasma treatment, the wettability of the surface is improved, and the coating performance is improved. The roughening treatment of the metal separator 18a may be performed after the formation of the channel irregularities, or may be performed before the formation of the channel irregularities.
The roughening treatment of the metal separator 18a may be performed on the entire area of the metal separator 18a, or may be performed only on the specific portion 100 that is a part of the metal separator 18a.
In the case where the roughening process is performed only on the specific part 100 that is a part of the metal separator 18a, the surface not subjected to the roughening process is masked, and then the roughening process such as sandblasting or etching is performed. By removing the masking, it is possible to perform a roughening process on only a specific part.

粗面化処理をメタルセパレータ１８ａの一部である特定部位１００のみに施す場合、その特定部位１００は、防食塗料塗布時に塗布した塗料が（固化する迄に）自重で流れ得る部位１１０（図１、図２に示す）であってもよいし、あるいは、防食塗料塗布時に塗布した塗料が流れ得る部位１１０と、接着剤３３が塗布される部位１２０（図４に示す）との両方であってもよい。自重で流れ得る部位１１０には、防食塗料塗布時のセパレータの姿勢等を考慮して塗料が垂れ得る想定部位も含むようにすることが望ましい。
防食塗料塗布時に塗布した塗料が流れ得る部位１１０は、（イ）塗布した塗料が自重によって下方へと流れる反応ガス流路２７、２８の溝側面２７ａ、２８ａであってもよいし、（ロ）塗布した塗料が表面張力に「引け」によってコーナへと引き寄せられる反応ガス流路２７、２８の溝底面２７ｂ、２８ｂであってもよいし、（ハ）反応ガス流路２７、２８の溝側面２７ａ、２８ａと溝底面２７ｂ、２８ｂとの両方であってもよい。 When the roughening process is performed only on the specific part 100 which is a part of the metal separator 18a, the specific part 100 is a part 110 (FIG. 1) in which the paint applied at the time of applying the anticorrosive paint can flow by its own weight. 2), or both the portion 110 where the coating applied during the application of the anticorrosion coating can flow and the portion 120 (shown in FIG. 4) where the adhesive 33 is applied. Also good. Desirably, the portion 110 that can flow under its own weight includes an assumed portion where the paint can sag in consideration of the posture of the separator when the anticorrosive paint is applied.
The part 110 through which the paint applied during the anticorrosion paint application can flow may be (i) the groove side surfaces 27a and 28a of the reaction gas flow paths 27 and 28 in which the applied paint flows downward due to its own weight. The applied paint may be the groove bottom surfaces 27b and 28b of the reaction gas channels 27 and 28 that are attracted to the corner by “slacking” the surface tension, or (c) the groove side surface 27a of the reaction gas channels 27 and 28. 28a and groove bottom surfaces 27b and 28b.

粗面化処理をメタルセパレータ１８ａの一部である特定部位１００のみに施す場合、その特定部位１００は、
１）溝側面２７ａ、２８ａのみ、
２）溝底面２７ｂ、２８ｂのみ、
３）溝側面２７ａ、２８ａと溝底面２７ｂ、２８ｂの両方のみ、４）溝側面２７ａ、２８ａと接着剤３３塗布部のみ、
５）溝底面２７ｂ、２８ｂと接着剤３３塗布部のみ、
６）溝側面２７ａ、２８ａと溝底面２７ｂ、２８ｂの両方と接着剤３３塗布部のみ、
の何れかである。 When the roughening process is performed only on the specific part 100 that is a part of the metal separator 18a, the specific part 100 is:
1) Only the groove side surfaces 27a and 28a,
2) Only groove bottom surfaces 27b and 28b,
3) Only the groove side surfaces 27a, 28a and the groove bottom surfaces 27b, 28b only. 4) Only the groove side surfaces 27a, 28a and the adhesive 33 application portion,
5) Only the groove bottom surfaces 27b and 28b and the adhesive 33 application part,
6) Both the groove side surfaces 27a and 28a and the groove bottom surfaces 27b and 28b and the adhesive 33 application part only,
Any of them.

本発明の燃料電池用防食塗膜付きメタルセパレータの製造方法は、メタルセパレータ１８ａの反応ガスが接触する側の表面を粗面化処理する第１の工程と、粗面化処理後の表面に少なくとも耐食機能を有する塗膜１８ｂを塗布・形成する第２の工程とを有し、第１の工程、第２の工程の順で実行される。 The method for producing a metal separator with a corrosion-resistant coating film for a fuel cell according to the present invention includes a first step of roughening the surface of the metal separator 18a on the side in contact with the reaction gas, and at least a surface after the roughening treatment. And a second step of applying and forming the coating film 18b having a corrosion resistance function, and the steps are executed in the order of the first step and the second step.

つぎに、本発明の作用・効果を説明する。
本発明の燃料電池用「防食塗膜付きメタルセパレータ」１８によれば、メタルセパレータ１８ａの反応ガスが接触する側の表面が、粗面化処理されているので、粗面１８ｃのアンカー効果（塗料を固定・保持する効果）でメタルセパレータ１８ａの表面での塗料塗布時の固化前の塗料の、自重または表面張力による、流れを抑制でき、塗膜１８ｂの膜厚が均一化される。塗膜１８ｂに薄厚化する部分が生じにくい。これによって、塗膜１８ｂの薄厚化した部分が、腐食の起点となることを抑制することができる。 Next, functions and effects of the present invention will be described.
According to the “metal separator with anticorrosive coating film” 18 for fuel cells of the present invention, the surface of the metal separator 18a on the side in contact with the reaction gas is roughened, so that the anchor effect (paint) (The effect of fixing and holding), the flow of the paint before solidification upon application of the paint on the surface of the metal separator 18a due to its own weight or surface tension can be suppressed, and the film thickness of the coating film 18b is made uniform. A thinned portion is less likely to occur in the coating film 18b. Thereby, it can suppress that the thinned part of the coating film 18b becomes a starting point of corrosion.

また、メタルセパレータ１８ａの粗面化処理されている部位１００が、防食塗料塗布時に塗布した塗料が流れ得る特定部位１１０（自重で塗料が流れる溝側面２７ａ、２８ａ、表面張力で塗料が流れる溝底面２７ｂ、２８ｂ）を含むので、粗面１８ｃのアンカー効果でセパレータの表面での塗料の流れを抑制でき、塗料の流れで薄厚化する部分ができることを阻止でき、塗膜１８ｂの膜厚が均一化される。これによって、流路溝側面２７ａ、２８ａや溝底面２７ｂ、２８ｂで他の部位に比べて塗膜の膜厚が薄くなり過ぎることがなくなり、流路溝側面２７ａ、２８ａや溝底面２７ｂ、２８ｂが腐食の起点となることを抑制することができる。 Further, the roughened portion 100 of the metal separator 18a is a specific portion 110 (the groove side surfaces 27a and 28a through which the paint flows by its own weight and the bottom surface of the groove through which the paint flows by surface tension). 27b, 28b), it is possible to suppress the flow of paint on the surface of the separator by the anchor effect of the rough surface 18c, to prevent the formation of a thinned portion by the flow of paint, and to make the film thickness of the coating film 18b uniform. Is done. Thereby, the film thickness of the coating film does not become too thin compared with other portions on the flow channel groove side surfaces 27a and 28a and the groove bottom surfaces 27b and 28b, and the flow channel groove side surfaces 27a and 28a and the groove bottom surfaces 27b and 28b It can suppress becoming a starting point of corrosion.

また、メタルセパレータ１８ａの粗面化処理されている部位１００が、接着剤３３の塗布面１２０を含む場合は、表面を粗した効果によって、セパレータ間に使用する接着剤３３のメタルセパレータ１８ａとの接着性を向上できる。この場合は、メタルセパレータ１８ａの表面のうち、接着剤３３の塗布面１２０には、塗膜１８ｂは形成されておらず、接着剤３３は、塗膜１８ｂを介さずに、直接、メタルセパレータ１８ａの粗面１８ｃに接着される。 Further, when the portion 100 of the metal separator 18a that has been roughened includes the application surface 120 of the adhesive 33, due to the effect of roughening the surface, the metal separator 18a of the adhesive 33 used between the separators Adhesion can be improved. In this case, the coating film 18b is not formed on the application surface 120 of the adhesive 33 among the surfaces of the metal separator 18a, and the adhesive 33 is directly applied to the metal separator 18a without the coating film 18b. It adheres to the rough surface 18c.

防食塗料塗布時に塗布した塗料が流れ得る部位１１０が、メタルセパレータの反応ガス流路の溝側面２７ａ、２８ａである場合は、防食材塗布時に塗料が自重によって垂れて溝側面２７ａ、２８ａで塗膜が薄くなることを抑制することができる。従来は溝側面２７ａ、２８ａの垂れ落ちによる塗膜の薄厚化分、全域に厚目に塗料を塗布する必要があり、ＭＥＡ押圧面の塗膜が厚くなり過ぎて接触抵抗が増大するおそれがあったが、本発明では、溝側面２７ａ、２８ａの垂れ落ち抑制によって全域に厚目に塗料を塗布する必要が無くなり、ＭＥＡ押圧面の塗膜の厚さが厚すぎて接触抵抗が増大するおそれを軽減できる。 When the portion 110 where the paint applied during the application of the anticorrosion paint can flow is the groove side surfaces 27a and 28a of the reaction gas flow path of the metal separator, the paint hangs down by its own weight when the anticorrosive material is applied, and the coating is applied at the groove side surfaces 27a and 28a. Can be prevented from becoming thin. Conventionally, it is necessary to apply a thick coating to the entire area of the coating due to the dripping of the groove side surfaces 27a and 28a, and the coating on the MEA pressing surface may become too thick, which may increase the contact resistance. However, in the present invention, it is not necessary to apply a thick coating to the entire area by suppressing the drooping of the groove side surfaces 27a, 28a, and there is a possibility that the coating resistance on the MEA pressing surface is too thick and the contact resistance increases. Can be reduced.

防食塗料塗布時に塗布した塗料が流れ得る部位１１０が、メタルセパレータの反応ガス流路の溝底面２７ｂ、２８ｂである場合は、防食塗料塗布時に塗料が表面張力により溝底面２７ｂ、２８ｂの両端のコーナ部へ引けて溝底面２７ｂ、２８ｂの中央部で塗膜が薄くなることを抑制することができる。従来は溝底面２７ｂ、２８ｂの引けによる塗膜の薄厚化分、全域に厚目に塗料を塗布する必要があり、ＭＥＡ押圧面の塗膜が厚くなり過ぎて接触抵抗が増大するおそれがあったが、本発明では、溝底面２７ｂ、２８ｂの引け抑制によって全域に厚目に塗料を塗布する必要が無くなり、ＭＥＡ押圧面の塗膜の厚さが厚すぎて接触抵抗が増大するおそれを軽減できる。 When the portion 110 where the paint applied during the application of the anticorrosion paint can flow is the groove bottom surfaces 27b and 28b of the reaction gas flow path of the metal separator, the corners at both ends of the groove bottom surfaces 27b and 28b are applied due to the surface tension when the anticorrosion paint is applied. It can suppress that a coating film becomes thin in the center part of the groove bottom face 27b and 28b by being pulled to a part. Conventionally, it is necessary to apply paint thickly over the entire area of the coating due to shrinkage of the groove bottom surfaces 27b and 28b, and the coating on the MEA pressing surface becomes too thick, which may increase contact resistance. However, in the present invention, it is not necessary to apply a thick coating to the entire area by suppressing the shrinkage of the groove bottom surfaces 27b and 28b, and the possibility that the coating resistance on the MEA pressing surface is too thick to increase the contact resistance can be reduced. .

防食塗料塗布時に塗布した塗料が流れ得る部位１１０が、メタルセパレータの反応ガス流路の溝側面２７ａ、２８ａと溝底面２７ｂ、２８ｂとの両方である場合は、防食塗料塗布時に塗料が自重によって垂れて溝側面で塗膜が薄くなることを抑制することができるとともに、塗料が「引け」によって溝底面両端のコーナ部へ移動して溝底面の中央部で塗膜が薄くなることを抑制することができる。従来は、溝側面２７ａ、２８ａの垂れ落ちによる塗膜の薄厚化分、および、溝底面２７ｂ、２８ｂの引けによる塗膜の薄厚化分、全域に厚目に塗料を塗布する必要があり、ＭＥＡ押圧面の塗膜が厚くなり過ぎて接触抵抗が増大するおそれがあったが、本発明では、溝側面２７ａ、２８ａの垂れ落ち抑制と、溝底面２７ｂ、２８ｂの引け抑制によって、全域に厚目に塗料を塗布する必要が無くなり、ＭＥＡ押圧面の塗膜の厚さが厚すぎて接触抵抗が増大するおそれを軽減できる。 When the portions 110 where the paint applied during the application of the anticorrosive paint can flow are both the groove side surfaces 27a and 28a and the groove bottom surfaces 27b and 28b of the reaction gas flow path of the metal separator, the paint droops due to its own weight when the anticorrosive paint is applied. It is possible to prevent the coating film from becoming thinner on the side surface of the groove and to prevent the paint from moving to the corners at both ends of the groove bottom due to “shrinkage” and thinning at the center of the groove bottom surface. Can do. Conventionally, it is necessary to apply a thick coating to the entire area of the thinned portion of the coating film due to the dripping of the groove side surfaces 27a and 28a and the thinned portion of the coating film due to the shrinkage of the groove bottom surfaces 27b and 28b. Although the coating film on the pressing surface may become too thick, there is a risk that the contact resistance may increase. In the present invention, it is thick in the entire area by suppressing the dripping of the groove side surfaces 27a and 28a and suppressing the contraction of the groove bottom surfaces 27b and 28b. It is no longer necessary to apply a paint to the surface of the MEA, and the possibility that the contact resistance increases due to the thickness of the coating film on the MEA pressing surface being too thick can be reduced.

本発明の燃料電池用「防食塗膜付きメタルセパレータ」の一部の断面図である。1 is a partial cross-sectional view of a “metal separator with an anticorrosive coating film” for a fuel cell of the present invention. 図１の粗面化部の拡大断面図である。It is an expanded sectional view of the roughening part of FIG. 本発明の防食塗膜付きメタルセパレータが組み付けられた燃料電池の側面図である。It is a side view of the fuel cell with which the metal separator with an anticorrosion coating film of the present invention was assembled. 図３の燃料電池の一部の拡大断面図である。FIG. 4 is an enlarged cross-sectional view of a part of the fuel cell of FIG. 3. 従来の燃料電池用「防食塗膜付きメタルセパレータ」の一部の断面図である。FIG. 6 is a partial cross-sectional view of a conventional “metal separator with anticorrosive coating film” for fuel cells. 図５の立ち面の拡大断面図である。It is an expanded sectional view of the standing surface of FIG.

Explanation of symbols

１０（固体高分子電解質型）燃料電池
１１電解質膜
１４電極（アノード、燃料極）
１７電極（カソード、空気極）
１８燃料電池用防食塗膜付きメタルセパレータ
１８ａメタルセパレータ
１８ｂ塗膜
１８ｃ粗面化部
１９セルまたはモジュール
２０ターミナル
２１インシュレータ
２２エンドプレート
２３スタック
２４外側部材または締結部材（テンションプレート）
２５ボルト
２６冷媒流路
２７燃料ガス流路
２７ａ流路溝側面
２７ｂ流路溝底面
２８酸化ガス流路
２８ａ流路溝側面
２８ｂ流路溝底面
２９冷媒マニホールド
３０燃料ガスマニホールド
３１酸化ガスマニホールド
３２冷媒側シール材（たとえば、ゴムガスケット）
３３ガス側シール材（たとえば、接着剤）
１００粗面化処理されている特定部位
１１０防食塗料塗布時に塗布した塗料が流れ得る部位
１２０接着剤３３が塗布される部位 10 (solid polymer electrolyte type) fuel cell 11 electrolyte membrane 14 electrode (anode, fuel electrode)
17 electrodes (cathode, air electrode)
18 Metal separator 18a with fuel cell anticorrosive coating 18a Metal separator 18b Coating 18c Roughening part 19 Cell or module 20 Terminal 21 Insulator 22 End plate 23 Stack 24 Outer member or fastening member (tension plate)
25 Bolt 26 Refrigerant channel 27 Fuel gas channel 27a Channel groove side surface 27b Channel groove bottom surface 28 Oxidizing gas channel 28a Channel groove side surface 28b Channel groove bottom surface 29 Refrigerant manifold 30 Fuel gas manifold 31 Oxidizing gas manifold 32 Refrigerant side Sealing material (for example, rubber gasket)
33 Gas side sealing material (for example, adhesive)
100 Part 110 which has been roughened 110 Part where coating applied when anticorrosive coating is applied 120 Part where adhesive 33 is applied

Claims

A metal separator with an anti-corrosion coating film for a fuel cell, which has a metal separator and an anti-corrosion coating film applied and formed on the surface of the metal separator on which the reaction gas comes into contact. A metal separator with an anticorrosive coating film for a fuel cell, whose surface is roughened before applying and forming the anticorrosive coating film.

The metal with the anticorrosion coating film for fuel cells according to claim 1, wherein the roughened portion of the surface of the metal separator on the side in contact with the reaction gas includes a portion through which the paint applied during the anticorrosion coating application can flow. Separator.

2. The roughened portion of the surface of the metal separator on the side in contact with the reaction gas includes a portion where a paint applied during application of an anticorrosive paint can flow and a portion where an adhesive is applied. Metal separator with anticorrosive coating film for fuel cell as described.

4. The metal separator with an anticorrosive coating film for a fuel cell according to claim 2, wherein a portion through which the coating material applied during the application of the anticorrosive coating material can flow is a groove side surface of the reaction gas flow path of the metal separator.

The metal separator with an anticorrosive coating film for a fuel cell according to claim 2 or 3, wherein a portion through which the coating material applied during the coating of the anticorrosive coating material can flow is a groove bottom surface of a reaction gas flow path of the metal separator.

The metal separator for a fuel cell according to claim 2 or 3, wherein the portions where the paint applied during the application of the anticorrosive paint can flow are the groove side surface and the groove bottom surface of the reaction gas flow path of the metal separator.

The metal separator with an anticorrosive coating film for fuel cells according to claim 1, wherein the roughening treatment is a plasma treatment.

Method for producing metal separator with anticorrosive coating film for fuel cell, by roughening the surface of the metal separator on the side in contact with the reaction gas, and applying and forming a coating film having at least a corrosion resistance function on the surface after the roughening treatment .