JP2018133145A - Method for manufacturing fuel cell separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell separator which enables adhesion in a short time, and which has a satisfactory adhesive force.SOLUTION: A method for manufacturing a fuel cell separator 11 comprises the step of gluing a laminate arranged by laminating a metal layer 13, and a thermoplastic hot-melt adhesive layer 12 in this order to an adherend layer 15. In the method for manufacturing a fuel cell separator 11, the above step includes the step of heating the metal layer by electromagnetic induction heating; and the thermoplastic hot-melt adhesive includes a resin of which the acid value is 1-200 mgKOH/g. Further, in the method for manufacturing a fuel cell separator 11, the resin is preferably a hot-melt adhesive containing a copolymer of ethylene and (meth)acrylic acid, and/or polyolefin, or a copolymer of an acid-modified styrene-based aromatic carbon hydride and a conjugated diene or a hydrogenated product thereof.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing a fuel cell separator.

  A fuel cell is a device that takes out the Gibbs energy of water generated when electrochemically oxidizing hydrogen as electric energy.

  This type of fuel cell is generally put into practical use by stacking a plurality of fuel cells to form a stack. In general, a fuel battery cell includes an electrolyte electrode assembly in which an anode electrode that supplies fuel gas to one surface of an electrolyte and a cathode electrode that supplies oxidant gas to the other surface is joined to a gas flow path, a refrigerant liquid flow path, and the like. It is sandwiched between a pair of formed separators.

  In a fuel cell having such a structure, it is necessary to prevent mixing of fuel gas and oxidant gas, leakage of each gas or refrigerant, and the like. For this reason, adhesive seal members are often provided at sites where airtightness and liquid tightness are required, such as between separators and electrolytes, and between separators.

For example, as a method for manufacturing a separator, a method using an adhesive (Patent Documents 1 and 2) having a thermosetting main component such as an epoxy type as an adhesive used for a joint portion with a metal layer and an adhesion layer. Has been invented.
Epoxy adhesives need to be cured, and it took time to complete the curing, and when curing, it may cause curing failure due to the influence of impurities, etc. There was a need to do.
Therefore, Patent Document 3 uses a thermoplastic hot melt adhesive containing an olefin-based thermoplastic resin as an adhesive to heat and bond the metal layer. However, there are problems such as weak adhesive strength.

JP 2005-129343 A JP-A-7-249417 JP 2007-188718 A

In view of the above problems, an object of the present invention is to bond a laminate obtained by laminating a metal layer and a thermoplastic hot-melt adhesive layer containing a resin having an acid value of 1 to 200 mgKOH / g and an adherent layer. Thus, in the method for producing a fuel cell separator, an electromagnetic induction heating method is used in the bonding step to obtain a fuel cell separator having a short time adhesion and a good adhesion.

As a result of intensive research, the present inventors have found a fuel cell separator and a method for manufacturing the fuel cell separator that solve the problem.

That is, the present invention is a method for producing a fuel cell separator comprising a step of adhering a laminate formed by laminating a metal layer and a thermoplastic hot melt adhesive layer in this order, and an adherent layer, The method includes a step of heating a metal layer by electromagnetic induction heating, and the thermoplastic hot melt adhesive includes a resin having an acid value of 1 to 200 mgKOH / g. .

The present invention also relates to the above method for producing a fuel cell separator, wherein the resin contains a copolymer of ethylene and (meth) acrylic acid and / or polyolefin.

The present invention also relates to the method for producing a separator for a fuel cell, wherein the resin contains a copolymer of an acid-modified styrene-based aromatic hydrocarbon and a conjugated diene block, or a hydrogenated product thereof.

The present invention also relates to the method for producing a fuel cell separator, wherein the resin has a melting point of 70 to 250 ° C.

The present invention also relates to the above method for producing a fuel cell separator, wherein the thermoplastic hot melt adhesive contains a component soluble in xylene at 25 ° C., but its content is less than 5% by weight.

The present invention also relates to a method for producing the fuel cell separator, wherein the deposition layer is a metal layer.

The present invention also relates to the above method for producing a fuel cell separator, wherein the time required for heating the metal layer by electromagnetic induction heating is 5 seconds or less.

The present invention also relates to a method of manufacturing a fuel cell, comprising the method of manufacturing the fuel cell separator.

As described above, according to the method for manufacturing a separator for a fuel cell according to the present invention, the cooling liquid flow path of the separator has a short adhesion time for a conductive layer such as a carbon or metal layer, heat resistance, and good Bonding can be performed.

1 shows a representative embodiment of the fuel cell of the present invention. 1 shows a representative embodiment of the fuel cell of the present invention. 1 shows a representative embodiment of the fuel cell of the present invention.

Hereinafter, the manufacturing method of the separator of this invention is demonstrated.

[Fuel cell structure]
The structure of the fuel cell of the present invention will be described in detail. FIG. 1 shows a cross-sectional view of the fuel battery cell 1. The fuel battery cell 1 includes a power generator 18 and a separator 11. The power generator 18 includes an electrolyte membrane 71, an anode layer 41, a cathode layer 42, and gas diffusion layers 31 and 32, and the separator 11 includes a metal layer 13 adhered by a thermoplastic hot melt adhesive layer 12, a deposition layer 15, and a cooling layer. It consists of a liquid flow path.

The electrolyte membrane 71 has a function of moving hydrogen ions generated in the anode layer 41 to the cathode layer 42. As the material of the electrolyte membrane 71, a chemically stable fluororesin resin, for example, a perfluorocarbon acid (Nafyon) resin membrane is used.

  The anode layer 41 and the cathode layer 42 have a function of promoting a hydrogen oxidation reaction on the anode electrode side and an oxygen reduction reaction on the cathode electrode side. In order to increase the electrode area to be reacted, the catalyst is generally used in the form of particles and attached to the catalyst support. As the catalyst, platinum, which is a platinum group element having a smaller activation overvoltage, is used for the oxidation reaction of hydrogen and the reduction reaction of oxygen. As the catalyst carrier, a carbon material such as carbon black is used.

The gas diffusion layers 31 and 32 have a function of diffusing hydrogen gas as a fuel gas and air as an oxidant gas into the anode layer 41 and the cathode layer 42 and a function of moving electrons. . For the gas diffusion layers 31 and 32, carbon fiber woven fabric, carbon paper, or the like, which is a conductive material, is used.

[Separator]
The separator 11 of the present invention is stacked on the power generator 18 and has a function of separating fuel gas and oxidant gas in adjacent fuel cells. The separator 11 is formed by adhering to the metal layer 13 and the adherent layer 15 formed in an uneven shape with an electrically conductive material. By making the electrically conductive layer uneven, a gas flow path 17, 19 through which the fuel gas or oxidizing gas flows and a cooling liquid LLC (long-life-coolant) containing ethylene glycol or the like is used. A flow path 14 is formed.

The fuel cell separator 11 having such a structure needs to be cooled with a coolant in order to prevent heat generated during power generation. Therefore, in order to improve the cooling efficiency in the separator and to circulate the cooling liquid, the cooling liquid flow path 14 is formed. The separator 11 includes the metal layer 13 and the adherend layer 15 with the thermoplastic hot melt adhesive layer 12. It is made by bonding.

[Metal layer]
The metal layer 13 of the separator of the present invention is preferably formed of titanium (Ti), titanium alloy, gold (Au), platinum (Pt), stainless steel of SUS316 and SUS304, which is a conductor and has acid resistance.
The thickness of the metal layer 13 is preferably 10 to 500 μm, more preferably 50 to 300 μm. If the thickness of the metal layer is less than 10 μm, cooling water leaks due to fatigue of the metal layer, and if it is 500 μm or more, the weight of the cell increases, which is not practical.

[Deposition layer]
The adherent layer 15 is made of metal, ceramics, polymer, or the like, and is not necessarily a conductor.

[Thermoplastic hot melt adhesive layer]
The thermoplastic hot-melt adhesive forming the thermoplastic hot-melt adhesive layer of the present invention is in a molten state when heated, and solidifies by cooling and adheres to the adherent layer.
(Resin having an acid value of 1 to 200 mgKOH / g)
The thermoplastic hot melt adhesive contains a resin having an acid value of 1 to 200 mgKOH / g.
The acid value of the present invention is the number of mg of potassium hydroxide necessary to neutralize 1 g of free fatty acid.
The acid value of the resin contained in the thermoplastic hot melt adhesive of the present invention is characterized by 1 to 200 mgKOH / g, and more preferably 1 to 160 mgKOH / g. If the acid value of the resin is less than 1 mgKOH / g, the adhesive strength with the metal is weak and cannot be used. If the acid value is greater than 200 mgKOH / g, the resin becomes brittle and even if bonded, it will break with a simple impact. The power is greatly reduced.
Resins contained in thermoplastic hot melt adhesives include acid-modified olefins, (meth) acrylic acid copolymers, acid-modified styrene aromatic hydrocarbons, styrene-butylene-styrene block polymers (SBS), and styrene-ethylene. -Acid-modified products of copolymers with conjugated diene blocks such as propylene-styrene block polymer (SEPS), styrene-isoprene-styrene block polymer (SIS), styrene-butylene-butadiene-styrene block polymer (SBBS), or the like Examples thereof include hydrogenated products and rosin resins.

(Melting point of resin having an acid value of 1 to 200 mgKOH / g)
The melting point of the present invention is based on differential scanning calorimetry (DSC: heat flux) in JIS K7121.
The melting point of the resin having an acid value of 1 to 200 mgKOH / g contained in the thermoplastic hot melt adhesive of the invention is preferably 70 to 250 ° C, more preferably 130 to 250 ° C. If the melting point of the resin is less than 70 ° C., the resin has no heat resistance and peels at a high temperature, and if it is higher than 250 ° C., the adhesive strength decreases at a low temperature and may peel at a low temperature.

(A component soluble in xylene at 25 ° C. of a resin having an acid value of 1 to 200 mg KOH / g)
The resin having an acid value of 1 to 200 mgKOH / g contains a component soluble in xylene at 25 ° C., but its content is preferably less than 5% by weight. More preferably, it is less than 2% by weight. A component that is soluble in xylene at 25 ° C. but whose content is 5% by weight or more is a component that softens at less than 70 ° C. even if the melting point of the resin having an acid value of 1 to 200 mgKOH / g is 70 ° C. or higher. Since it is contained, the adhesive strength may decrease at a high temperature and peel off. It is preferable that the resin having an acid value of 1 to 200 mgKOH / g does not contain a component soluble in xylene at 25 ° C. However, even if it contains a component soluble in xylene at 25 ° C., the content is 5 When it is less than% by weight, it is firmly bonded. When it contains 5 weight% or more, adhesive force falls.

(Other resins)
The thermoplastic hot melt adhesive of the present invention can be used in combination with other resins in addition to the resin having an acid value of 1 to 200 mgKOH / g. A thermoplastic hot melt adhesive can be obtained by using a thermoplastic polymer, a tackifier, a wax or the like alone or in combination. The thermoplastic polymer is ABS, polyamide, polyester, polyurethane, acrylic, polycarbonate, polystyrene, polyethylene, polypropylene, poly-1-butene, polyisobutylene, polymethylpentene, propylene-ethylene copolymer, ethylene-propylene-diene copolymer. Polymer, polyolefin such as ethylene / butene-1 copolymer, ethylene / octene copolymer, cyclic polyolefin such as copolymer of cyclopentadiene and ethylene and / or propylene, ethylene / vinyl acetate copolymer (EVA), Polyolefins introduced with polar groups such as ethylene / ethyl acrylate copolymer (EEA), isobutylene / maleic anhydride copolymer, maleic anhydride modified polypropylene, maleic acid modified polypropylene, acrylic acid modified Polypropylene, styrene elastomers. Although it does not specifically limit as tackifier, Petroleum resin of phenol resin, modified phenol resin, terpene phenol resin, xylene phenol resin, cyclopentadiene-phenol resin, xylene resin, aliphatic, alicyclic, aromatic , Hydrogenated aliphatic, alicyclic and aromatic petroleum resins, phenol-modified petroleum resins, rosin ester resins, hydrogenated rosin ester resins, low molecular weight polystyrene resins, terpene resins, hydrogen Examples include tackifier resins such as added terpene resins. The waxes are carnauba wax, canderia wax, montan wax, paraffin wax, microwax, Fischer-Tropsch wax, polyethylene wax, polypropylene wax, oxides of these waxes, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer. A polymer etc. are mentioned.

(Additive)
Various types of additives can be used as necessary for the thermoplastic hot melt adhesive of the present invention. For example, anti-blocking agents, inorganic fillers, antioxidants, fillers, flame retardants, plasticizers, antistatic agents, light stabilizers, ultraviolet absorbers, heavy metal deactivators and the like.

Examples of the inorganic filler include particles such as metals, metal oxides, and metal hydroxides, and fibrous shapes. Specifically, glass fiber, carbon fiber, calcium silicate, calcium titanate, aluminum borate fiber, flaky glass, talc, kaolin, mica, hydrotalcite, calcium carbonate, zinc carbonate, zinc oxide, monohydrogen phosphate Calcium, Wollastonite, Silica, Zeolite, Alumina, Boehmite, Aluminum hydroxide, Titanium oxide, Silicon oxide, Magnesium oxide, Calcium silicate, Sodium alumina silicate, Magnesium silicate, Carbon nanotube, Graphite, Copper, Silver, Aluminum, Nickel , Iron, calcium fluoride, mica, montmorillonite, apatite and the like.
Antioxidants include high molecular weight hindered polyhydric phenols, triazine derivatives, high molecular weight hindered phenols, dialkyl phenol sulfides, 2,2-methylene-bis- (4-methyl-6-tert-butylphenol), 4 , 4-methylene-bis- (2,6-di-tert-butylphenol), 2,6-di-tert-butylphenol-p-cresol, 2,5-di-tert-butylhydroquinone, 2,2 , 4-trimethyl-1,2-dihydroquinone, 2,2,4-trimethyl-1,2-dihydroquinone, nickel dibutyl dithiocarbamate, 1-oxy-3-methyl-4-isopropylbenzene, 4,4- Examples include butylidenebis- (3-methyl-6-tert-butylphenol) and 2-mercaptobenzimidazole.

Examples of the filler include wet silica, aluminum hydroxide, aluminum oxide, magnesium oxide, montmorillonite, mica, smectite, organic montmorillonite, organic mica, and organic smectite.

Examples of the flame retardant include a phosphorus-containing compound flame retardant, a halogen-containing compound flame retardant, a sulfonic acid metal salt flame retardant, and a silicon-containing compound flame retardant.
Plasticizers include phthalate plasticizers, polyester plasticizers, aliphatic dibasic ester plasticizers, aliphatic monobasic ester plasticizers, phosphate ester plasticizers, and citrate ester plasticizers. , Epoxy plasticizers, trimellitic acid ester plasticizers, tetrahydrophthalic acid ester plasticizers, glycol plasticizers, and bisphenol A alkylene oxide derivatives.
The antistatic agent may be one that is widely used as an antistatic agent for plastics, and specifically includes nonionic surfactants (for example, fatty acid esters of polyhydric alcohols, ethylene oxide adducts of alkylamines, and alkyls). Fatty acid esters of amine ethylene oxide adducts), anionic surfactants (eg, alkylbenzene sulfonates, higher alcohol sulfates, etc.), cationic surfactants (eg, aliphatic amine salts, quaternary ammonium salts) And amphoteric surfactants (for example, imidazoline type, betaine type, etc.).

Examples of the light stabilizer include hindered amine compounds and benzoate compounds.
Examples of the ultraviolet absorber include benzophenone ultraviolet absorbers, triazine ultraviolet absorbers, and benzotriazole ultraviolet absorbers.
Examples of heavy metal deactivators include salicylic acid derivatives, hydrazide derivatives, or oxalic acid amide derivatives.

The said additive can be used individually by 1 type or in mixture of 2 or more types by arbitrary ratios as needed.

[Electromagnetic induction heating]
In the electromagnetic induction heating of the present invention, an alternating magnetic field is generated by flowing a high-frequency alternating current through a coil of an electromagnetic induction heating device, and an eddy current is generated inside a conductive material in the magnetic field. This is a heating method in which the conductive material is heated by Joule heat. The higher the frequency of the alternating current flowing through the coil, the faster the change in the magnetic field, the greater the eddy current based on that, and the shorter the heating time. The coil is, for example, a solenoid type coil and does not necessarily have a cylindrical shape, and may be provided with a magnetic body such as an iron core or ferrite.
As a heating method, heating may be performed by applying a current to the coil on or below the metal layer to be heated or an adhesion layer, or applying a current to the coil by inserting a separator in the coil. .

[Separator manufacturing method]
In the separator manufacturing method of the present invention, a thermoplastic hot melt adhesive is attached to the adherent layer 15 and sandwiched between the metal layers 13. For example, a coating of a dispenser or a thermoplastic hot melt adhesive may be used as a film in advance, and the adhesion layer 15 and the metal layer 13 may be sandwiched or bonded. Next, the metal layer 13 and the adherent layer 15 are laminated to such an extent that they can be heated by the electromagnetic induction heating device, and a current is passed through the coil of the electromagnetic induction heating device, preferably within 5 seconds. The adhesive layer 15 is heated to melt the thermoplastic hot melt adhesive. Even when the electric current of the electromagnetic induction heating device is cut off and the heating is finished, the thermoplastic hot melt adhesive is allowed to cool until the metal layer 13 and the adherend layer 15 are cooled and then bonded.

Hereinafter, the present invention will be described based on examples, but the present invention is not limited thereto.

<Synthesis example of resin A having an acid value of 1 to 200 mgKOH / g>
To 100 parts of polypropylene having a weight average molecular weight (hereinafter abbreviated as Mw), 20 parts of maleic anhydride and 375 parts of xylene were charged into a three-necked flask equipped with a nitrogen blowing port, a thermometer, and a stirrer. After raising the temperature to 130 ° C., 0.1 part of benzoyl peroxide is dissolved in 40 parts of xylene and added dropwise for 90 minutes. After dropping, the mixture is reacted at 130 ° C. for 4 hours, and then cooled to room temperature for 60 minutes. The obtained suspension was filtered, xylene was removed, and washing with methyl ethyl ketone was repeated 2 to 3 times until washing with maleic anhydride and maleic anhydride alone in the methyl ethyl ketone was hardly observed by liquid chromatography. to continue. The obtained maleic anhydride-modified propylene resin powder was obtained by air drying.
<Synthesis Example of G from Resin B with Acid Value of 1 to 200 mgKOH>
Using polypropylenes having Mw of 7,000, 20,000, 50,000, 100,000, 200,000, and 300,000, <Synthesis example of resin A having an acid value of 1 to 200 mgKOH / g> and In the same manner, maleic anhydride-modified propylene resins (resins B to G) whose Mw of the raw material polypropylene is 7,000, 20,000, 50,000, 100,000, 200,000 and 300,000 are obtained. Yeah.

<Resin H having an acid value of 1 to 200 mgKOH>
Primacor 5980I manufactured by Dow Chemical Co., which is an ethylene-acrylic acid copolymer, was used.
<Resin I having an acid value of 1 to 200 mgKOH>
As a hydrogenated product of a copolymer of an acid-modified styrene-based aromatic hydrocarbon and a conjugated diene block, Tuftec M1953 (styrene content 40% by weight, acid value 10 mgKOH / g) manufactured by Asahi Kasei Corporation was used.
<Resin J having an acid value of 1 to 200 mgKOH>
A copolymer of an acid-modified styrenic aromatic hydrocarbon and a conjugated diene block is a clayton FG1901X (styrene content 28% by weight, maleic anhydride addition amount 2.0% by weight, acid value 22 mgKOH / g) was used.
<Resin K>
Novatec LD LC600A manufactured by Nippon Polyethylene Co., Ltd., which is polypropylene, was used. Acid value: less than 1 mg KOH / g.
<Resin L>
A styrene-acrylic acid resin VS-1047 manufactured by Seiko PMC was used. Acid value: 240 mg KOH / g.

<The manufacturing method of thermoplastic hot-melt-adhesive resin (1), (2), (4)-(7)>
The thermoplastic resin of the present invention was produced by mixing the above resin with a resin having an acid value of less than 1 and / or 200 mg or more and polypropylene A (FL02A manufactured by Nippon Polypro Co., Ltd.) and blending with an extruder.
<Thermoplastic hot melt adhesive (3), (8) to (10)>
As the thermoplastic hot melt adhesives (3) and (8) to (10), the resins B, H, I and J were used as they were.

<Measurement method of components soluble in xylene at 25 ° C.>
A component soluble in xylene at 25 ° C. in a resin having an acid value of 1 to 200 mg KOH / g was calculated by the following method. The resin pellet was dissolved by heating at 130 ° C. for 3 hours with xylene at a weight of about 50 times, and then allowed to cool overnight at 25 ° C. to precipitate a crystallized product. The crystallized product was filtered, and the filtrate was collected and concentrated to dryness. Furthermore, it dried under reduced pressure at 80 degreeC overnight, the residual solvent was removed, and the component soluble in xylene of 25 degreeC was obtained. From the weight of the resin pellet and the component soluble in xylene at 25 ° C., the weight percentage of the component soluble in xylene at 25 ° C. was calculated.
Resins H, I, and J could not be measured because they could be toluene.

<Film forming method>
Using an extrusion laminator, the thermoplastic hot melt adhesives shown in Tables 2-1 and 2-2 are laminated on the release-treated PET film (thickness: 25 μm) while changing the film thickness, and wound at the winding part. To obtain a thermoplastic adhesive layer.
The processing conditions are shown below.
Extrusion laminator: 400M / M test EXT laminator die directly under Musashinokikai Resin temperature: 140-240 ° C. (adjusted appropriately by MFR of resin, etc.)
Processing speed: 30m / min T die width: 400mm
Cooling roll surface temperature: 20 ° C

<Method for producing bonded structure>
In order to evaluate the performance of the separator manufacturing method of the present invention, an adhesive structure was prepared by the following manufacturing method and evaluated. Tables 1-1 and 1-2 and Tables 2-1 and 2-2 show the compositions and evaluation results of the thermoplastic hot melt adhesives used.

An electromagnetic induction heating device having a metal layer (100 μm aluminum plate), a thermoplastic hot melt adhesive layer (film thickness: 20 to 500 μm), and an adherent layer (100 μm aluminum plate), an input voltage of 100 V, and a power consumption of 550 W By heating for 1-5 seconds, softening the thermoplastic hot melt adhesive, and finishing the heating so that the thermoplastic hot melt adhesive is cooled and solidified by an electromagnetic induction heating device to obtain an adhesive structure It is done.

<Adhesive strength>
The adhesive structure was measured for T peel strength using a tensile tester. The measurement conditions are as follows.
・ Sample width: 10mm
・ Measurement temperature: 23 ℃, 80 ℃
・ Tensile speed: 10 mm / min
In the evaluation results, 80N / 10 mm or more was marked as ◯, and less than 80 N / 10 mm was marked as x.

<Adhesive strength after warm water>
After immersing the bonded structure in warm water at 80 ° C. for 96 hours, the T peel strength of the bonded structure was measured using a tensile tester. The measurement conditions are as follows.
・ Sample width: 10mm
・ Measurement temperature: 23 ℃
・ Tensile speed: 10 mm / min
The evaluation results were set to 100 N / 10 mm or more: A, 80 N / 10 mm or more: Yes, less than 20 N / 10 mm: Δ, less than 20 N / 10 mm: x. 〇 and ◎ were accepted.

(Comparative Examples 1 and 2)
The evaluation results are shown in Comparative Example 1 using a polypropylene resin having an acid value of 1 mgKOH / g and Comparative Example 2 using a styrene-acrylic acid resin having an acid value of 240 mgKOH / g. All comparative examples had low adhesive strength.

(Comparative Example 3)
In Comparative Example 3, a sample was prepared by heat sealing (250 ° C.) using the adhesive resin (1) and evaluated. The adhesive strength was low.

By using the method for producing a separator of the present invention, a separator having a bonding strength (room temperature and 80 ° C.) and a bonding strength after warm water and a fuel cell using the same can be obtained.

1 fuel cell, 11 separator, 12 thermoplastic hot melt adhesive layer,
13 Metal layer, 14 Coolant flow path, 15 Deposit layer, 17, 19 Gas flow path,
18 power generator, 41 anode layer, 42 cathode layer, 31, 32 gas diffusion layer,
71 electrolyte membrane

Claims (8)

A method for producing a separator for a fuel cell, comprising a step of adhering a laminate formed by laminating a metal layer and a thermoplastic hot melt adhesive layer in this order, and an adherent layer, the step comprising electromagnetic induction heating A process for heating the metal layer, and the thermoplastic hot melt adhesive contains a resin having an acid value of 1 to 200 mgKOH / g. The method for producing a separator for a fuel cell according to claim 1, wherein the resin contains a copolymer of ethylene and (meth) acrylic acid and / or a polyolefin. The method for producing a fuel cell separator according to claim 1 or 2, wherein the resin contains a copolymer of an acid-modified styrene-based aromatic hydrocarbon and a conjugated diene block, or a hydrogenated product thereof. . The melting point of resin is 70-250 degreeC, The manufacturing method of the separator for fuel cells of any one of Claims 1-3 characterized by the above-mentioned. 5. The fuel cell separator according to claim 1, wherein the thermoplastic hot melt adhesive contains a component soluble in xylene at 25 ° C., but the content thereof is less than 5 wt%. Manufacturing method. The method for producing a fuel cell separator according to any one of claims 1 to 5, wherein the deposition layer is a metal layer. The method for producing a fuel cell separator according to any one of claims 1 to 6, wherein the time required for the step of heating the metal layer by electromagnetic induction heating is within 5 seconds. A method for producing a fuel cell, comprising the method for producing a separator for a fuel cell according to any one of claims 1 to 7.