JP7031620B2 - Manufacturing method of seal member for fuel cell and rubber composition for molding - Google Patents

Description

The present invention relates to a method for manufacturing a seal member for a fuel cell and a rubber composition for molding.

A typical fuel cell has a stack structure in which a plurality of cells are laminated, and each cell has a film electrode composite composed of a fuel electrode / an electrolyte membrane / an air electrode, and an electric fuel electrode or an air electrode. It is composed of a pair of separators having a flow path for separately supplying fuel or air while ensuring a proper connection, and a sealing member for preventing the reaction gas from leaking to the outside between the separators.

The sealing member is generally an elastic material, and as the material of the elastic material, Patent Documents 1 and 2 describe a fuel composed of an ethylene / α-olefin / non-conjugated polyene copolymer crosslinked (hydrosilicone crosslinked) by a hydrosilylation reaction. A battery seal component, a hard disk drive top cover gasket component, or a seal component for an electric wire connector is disclosed.

Japanese Patent No. 5334409 Japanese Patent No. 4241383 Gazette No. 4241383

Currently, as one of the product specifications of fuel cell seal parts, one in which an elastic body and a resin base material are bonded is being studied. Regarding adhesion, Patent Documents 1 and 2 only describe that the hard disk drive top cover and the gasket component are bonded with an adhesive, and for the fuel cell seal component, the copolymer and the resin base material are used. Those that are glued are not listed.

As a candidate material for such a fuel cell seal component, the present inventor adheres ethylene, propylene, diene rubber (EPDM), which has excellent properties such as heat resistance, and a bonded modified polypropylene (PP) base material. I have been studying what to do.

Initially, as an adhesive method, we considered forming EPDM and modified PP with an adhesive after molding them, but it requires an adhesive application step, it is difficult to include the position of the adhesive, and the manufacturing efficiency is high. It was difficult to adopt due to problems such as badness.

Therefore, next, we considered so-called vulcanization bonding, in which unvulcanized EPDM and modified PP are combined and bonded at the same time while vulcanizing rubber under a heating press, but it is difficult with conventional technology. there were. This is because EPDM composed of general sulfur crosslinks is generally vulcanized at a vulcanization temperature of 150 ° C. or higher, but modified PP has a melting point of around 140 ° C. depending on the molecular structure, and the above vulcanization adhesion is performed. This is because if the above is performed at the rubber vulcanization temperature, the resin melts and the laminated body is deformed or damaged.

Therefore, the present invention is a fuel cell obtained by vulcanizing and adhering an ethylene / α-olefin / non-conjugated diene copolymer and a modified PP base material without melting the base material made of modified PP by the heat during vulcanization. The purpose is to manufacture a seal member for vulcanization.

The present inventor focused on hydrosilicone cross-linking of EPDM. The vulcanization start temperature of the hydrosilicone crosslink of EPDM is lower than 90 ° C., for example, 90 ° C. is the temperature at the time of kneading, and vulcanization is usually performed at a vulcanization temperature of 150 to 160 ° C. .. It has been found that by performing the vulcanization at a vulcanization temperature lower than the melting point of the modified PP, for example, 90 to 130 ° C., a vulcanized adhesive that does not deform or break the modified PP can be obtained.

(1) The method for manufacturing a fuel cell seal member of the present invention is as follows.
The setting process of setting the base material made of modified PP in the mold, and
A molding step in which a hydrosilicone crosslinked ethylene / α-olefin / non-conjugated diene copolymer is brought into contact with the substrate and molded in the mold.
In the mold, the temperature of the mold was set to be higher than the vulcanization start temperature of the hydrosilicone crosslinked ethylene / α-olefin / non-conjugated diene copolymer and lower than the melting point of the modified PP. It is characterized by including a vulcanization step of vulcanizing the α-olefin / non-conjugated diene copolymer and at the same time vulcanizing and adhering the hydrosilicone crosslinked ethylene / α-olefin / non-conjugated diene copolymer and the base material. ..

The mold temperature is preferably 90 to 130 ° C, more preferably 100 to 130 ° C. If the mold temperature is less than 90 ° C., vulcanization by hydrosilicone crosslinking of the ethylene / α-olefin / non-conjugated diene copolymer is difficult to proceed, and if the temperature is 130 ° C. or higher, the modified PP may be melted.

The time for raising the temperature to the mold temperature may be before or during the molding step, or before or during the vulcanization step.

(Action)
In the vulcanization step, the mold temperature is set to be higher than the vulcanization start temperature of the hydrosilicone crosslinked ethylene / α-olefin / non-conjugated diene copolymer and lower than the melting point of the modified PP in the mold. At the same time as vulcanizing the hydrosilicone crosslinked ethylene / α-olefin / non-conjugated diene copolymer, the hydrosilicone crosslinked ethylene / α-olefin / non-conjugated diene copolymer and the modified PP substrate are vulcanized and adhered, so that the substrate is vulcanized. It does not melt due to the heat of vulcanization, and there is no need for a separate step of applying an adhesive.
Further, if the base material is set in the mold in the setting process (the setting itself is easy), the hydrosilicone crosslinked ethylene / α-olefin / non-conjugated diene copolymer is formed in contact with the base material in the molding process. Since it is vulcanized and adhered to the base material in the vulcanization process, it is easy (practically unnecessary) to include the position of the adhesion.

(2) The rubber composition for molding of the present invention is
Ethylene / α-olefin / 5-vinyl-2-norbornene random copolymer and
For 100 parts by mass of ethylene / α-olefin / 5-vinyl-2-norbornene random copolymer
1.0 to 10.0 parts by mass of the hydrosilicone compound as a cross-linking agent,
Hydrosilylation reaction promoting catalyst 0.1 to 1.0 parts by mass and
Contains 0.1-1.2 parts by mass of reaction inhibitor
It is characterized in that the induction time t _c (10) (JIS K6300-2) at a vulcanization temperature of 110 ° C. is 10 minutes or more.

(Action)
The mechanism by which the base material consisting of the hydrosilicone crosslinked ethylene / α-olefin / non-conjugated diene copolymer and the modified PP is vulture-bonded is the chemical interaction between the SiH group of the hydrosilicone compound and the functional group of the modified PP. Guessed. Since the hydrosilicone compound usually reacts with the ethylene / propylene / 5-vinyl-2-norbornen random copolymer at high speed to crosslink the copolymer quickly, the copolymer is preferentially the hydrosilicone compound. At the site where the reaction with the above-mentioned reaction occurs, the chemical interaction with the functional group of the modified PP does not occur, the polymer does not adhere to the modified PP, and the modified PP is microscopically separated.
The reaction rate of the hydrosilicone compound is slowed down by using the rubber composition as described above and controlling _tc (10) to 10 minutes or longer. Then, when the rubber composition flows on the surface of the modified PP base material, the hydrosilicone compound reacts with the copolymer and sufficiently chemically interacts with the functional group of the modified PP base material. The area where the rubber adheres to and adheres to the modified PP becomes large, and vulcanization adhesion can be performed with high strength. The upper limit of t _c (10) is not particularly limited, but it is preferably up to 60 minutes in terms of molding efficiency.

According to the production method of the present invention, the ethylene / α-olefin / non-conjugated diene copolymer and the modified PP substrate are vulcanized and adhered without melting the substrate composed of the modified PP by the heat at the time of vulcanization. It is possible to manufacture a seal member for a fuel cell, which does not require an adhesive application step, and has an excellent effect that the position of adhesion is easy to include.
According to the rubber composition for molding of the present invention, the vulcanization adhesiveness between the ethylene / α-olefin / non-conjugated diene copolymer and the substrate can be enhanced, and the peel strength can be improved.

FIG. 1A is a perspective view of the rubber composition for the test piece of the example and the modified PP sheet, and FIG. 1B is a side view of the test piece of the example when the test piece is pressed and vulcanized and bonded. c) is a schematic view of a 90 ° peeling test using the same test piece. FIG. 2A is a cross-sectional view of a process of setting a modified PP sheet having a shape for a fuel cell in a mold, and FIG. 2B is a cross-sectional view of a molding process of injecting the rubber composition of the embodiment into a mold and molding the mold. Is. FIG. 3 is a graph showing the relationship between t _c (10) and the peel strength in Examples 3, 4 and 5.

<1> Hydrosilicone Crosslinked Ethylene / α-olefin / Non-conjugated Diene Copolymer The α-olefin is not particularly limited, but is propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1 -Octene, 1-decene and the like can be exemplified, of which propylene or 1-butene is preferable, and propylene is particularly preferable.
The non-conjugated diene is not particularly limited, and examples thereof include 1,4-hexadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, and among these, 5-vinyl-2- Norbornene is preferred.

(Crosslinking agent)
Hydrosilicone cross-linking is imparted by the addition of a cross-linking agent consisting of a hydrosilicone compound (a compound having a SiH group). The hydrosilicone compound is represented by the following general formula [Chemical formula 1], a compound having SiH groups at both ends of the molecule and two SiH groups per molecule, and the following general formula [Chemical formula 2]. An example is a compound having SiH groups at three ends of a molecule and having three SiH groups in one molecule.

In the general formula [Chemical formula 1], R ¹ is a monovalent group having 1 to 10 carbon atoms, which is an unsaturated or substituted saturated hydrocarbon group or an aromatic hydrocarbon group, and may be the same or different in one molecule. .. Specific examples of R ¹ are methyl group, ethyl group, propyl group, isopropyl group, butyl group, amyl group, cyclopentyl group, hexyl group, cyclohexyl group, octyl group, chloromethyl group, 2-chloroethyl group and 3-chloropropyl group. A group, a phenyl group, a phenylmethyl group, a 2-phenylethyl group, a 2-phenylpropyl group and the like, preferably a methyl group, an ethyl group and a phenyl group.
a is an integer of 0 to 20, and b is an integer of 0 to 20. Preferably, both a and b are 10 or less, more preferably 5 or less, particularly preferably 2 or less, and most preferably a and b are equal to 2 or less.
^R2 is a divalent organic group or oxygen atom having 1 to 30 carbon atoms.

When the rubber composition contains a compound [Chemical Formula 1] having SiH groups at both ends of the molecule and two SiH groups per molecule, 100 parts by mass of an ethylene / α-olefin / non-conjugated diene copolymer However, it is preferably contained in an amount of 1.0 to 10.0 parts by mass.

In the general formula [Chemical formula 2], R ³ is a monovalent group having 1 to 10 carbon atoms, which is an unsaturated or substituted saturated hydrocarbon group or an aromatic hydrocarbon group, and may be the same or different in one molecule. .. Specific examples of R ³ are the same as those of R ¹ , and are preferably a methyl group, an ethyl group, and a phenyl group.
a, b and c are independently integers of 0 to 20, preferably a, b and c are both 10 or less, more preferably 5 or less, particularly preferably 2 or less, and most preferably a, b. And c are equal to or less than 2.
^R4 is a trivalent organic group having 1 to 30 carbon atoms, and preferably a silicon-containing trivalent organic group having 1 to 30 carbon atoms.

When the rubber composition contains a compound [Chemical Formula 2] having SiH groups at three ends of the molecule and having three SiH groups in one molecule, it is an ethylene / α-olefin / non-conjugated diene copolymer. It is preferably contained in an amount of 1.0 to 10.0 parts by mass with respect to 100 parts by mass.

<2> Hydrosilylation reaction promoting catalyst A catalyst (addition) that promotes the addition reaction (hydrosilylation reaction of alkene, etc.) between the alkenyl group of ethylene / α-olefin / non-conjugated diene copolymer and the SiH group of the hydrosilicone cross-linking agent. (Reaction catalyst) is preferably added.

A specific example of this hydrosilylation reaction promoting catalyst is a catalyst for an addition reaction made of platinum group elements such as a platinum-based catalyst, a palladium-based catalyst, and a rhodium-based catalyst, and is preferably a group 8 element metal of the periodic table (particularly preferable). Platinum) and a compound containing a vinyl group and / or a carbonyl group.

As the compound containing a carbonyl group, carbonyl, octanal and the like are preferable.
As the compound containing a vinyl group, a vinyl group-containing organosiloxane is preferable, and a vinyl group-containing cyclic organosiloxane is particularly preferable.
Specific examples of the complex between these and platinum include a vinylmethyl cyclic siloxane solution of a platinum-carbonyl complex, a platinum-vinylmethylcyclic siloxane complex, a platinum-divinyltetramethyldisiloxane complex, and a platinum-octanal / octanol complex. Particularly, a platinum-carbonylvinylmethyl cyclic siloxane complex is preferable.

The catalyst composed of these complexes may further contain a component (for example, a solvent) other than the compound containing a vinyl group and / or a carbonyl group. Specific examples of this solvent are various alcohols, xylene and the like.

The content of the hydrosilylation reaction promoting catalyst is not particularly limited, but may be 0.1 to 1.0 part by mass with respect to 100 parts by mass of the ethylene / α-olefin / non-conjugated diene copolymer. preferable.

<3> Reaction Inhibitor Since hydrosilicone cross-linking has a very high cross-linking rate as compared with conventional sulfur cross-linking and peroxide cross-linking, it is preferable to use a reaction inhibitor together with the above-mentioned hydrosilylation reaction promoting catalyst. Examples of the reaction inhibitor include benzotriazole, ethynyl group-containing alcohol (for example, ethynylcyclohexanol, etc.), acrylonitrile, N, N-diallyl acetamide, N, N-diallyl benzamide, N, N, N', N'-tetraallyl-o. -Amid compounds such as phthalic acid diamide, N, N, N', N'-tetraallyl-m-phthalic acid diamide, N, N, N', N'-tetraallyl-p-phthalic acid diamide, sulfur, phosphorus, nitrogen. , Amine compound, sulfur compound, phosphorus compound, tin, tin compound, tetramethyltetravinylcyclotetrasiloxane, organic peroxide such as hydroperoxide and the like.

The content of the reaction inhibitor is not particularly limited, but is preferably 0.1 to 1.2 parts by mass with respect to 100 parts by mass of the ethylene / α-olefin / non-conjugated diene copolymer.

<4> Other compounding materials In addition to the above compounding materials, fillers, plasticizers, processing aids, antiaging agents, acid receiving agents, scorch inhibitors, coloring agents and the like can be appropriately compounded.
Examples of the filler include carbon black, calcium carbonate, talc, silica, and calcined clay.
Examples of the plasticizer include process oil (paraffin-based, naphthen-based, aromatic, etc.) lubricating oil, petroleum-based plasticizers such as petroleum asphalt and vaseline, coultar-based softeners such as coultal and coultal pitch, and castor oil. , Amani oil, rapeseed oil, coconut oil and other fatty oil-based plasticizers, beeswax, carnauba wax, lanolin and other waxes, ricinolic acid, palmitic acid, barium stearate, calcium stearate, zinc laurate and other fatty acids and fatty acid salts. , Petroleum resin, atactic polypropylene, synthetic polymer substances such as Kumaron inden resin, tall oil, sub (fatty acid) and the like can be exemplified.
Examples of the processing aid include fatty acids such as stearic acid.

<5> Modified PP
The modified PP is not particularly limited, and examples thereof include acid-modified PP and chlorinated PP. Examples of the acid type of the acid-modified PP include maleic acid, itaconic acid, citraconic acid and the like.

<6> Molding step As the molding step, a method of injecting a hydrosilicone crosslinked ethylene / α-olefin / non-conjugated diene copolymer into a mold to bring it into contact with a base material and molding it in the mold, or hydrosilicone An embodiment in which a crosslinked ethylene / α-olefin / non-conjugated diene copolymer is placed on a substrate and press-molded in a mold can be exemplified.

The test pieces of Examples 1 and 2 and Comparative Examples 1, 2 and 3 shown in Table 1 below were prepared by vulcanizing and adhering the rubber compound and the base material (modified PP sheet) and evaluated. The compounding value of the rubber compound is a mass part.

Here, the details of each component used in the rubber compound are as follows.
The EPDM is an ethylene / propylene / 5-vinyl-2-norbornene random copolymer (VNB-EPDM) (ethylene content 54% by weight, diene amount 1.4% by weight, Mooney viscosity 39 at 100 ° C.). The vulcanization start temperature of the hydrosilicone crosslinked EPDM with the following crosslinking agent is 90 ° C.
-The filler is a mixture of carbon black, calcium carbonate, calcium oxide and the like.
-The plasticizer is a paraffin-based process oil.
The hydrosilicone compound of the cross-linking agent is a compound represented by the following formula [Chemical Formula 3].

-The cross-linking agent peroxide is a 40% dixyl peroxide product (60% calcium carbonate).
-The platinum-based catalyst of the hydrosilylation reaction promoting catalyst is a 0.5 wt% platinum-1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane complex isopropanol solution.
-The reaction inhibitor is 1-ethynyl-1-cyclohexanol.

The modified PP sheet as a base material is a sheet having a thickness of 0.13 mm under the trade name "Admer QE840" (maleic anhydride-modified PP) (MFR 9.2 g / 10 minutes, melting point 140 ° C.) of Mitsui Chemicals, Inc. be.

<Adjustment of rubber composition>
The rubber composition was prepared by kneading the rubber formulations of Examples 1 and 2 using a Banbury mixer and an open roll. The rubber composition of Comparative Examples 1, 2 and 3 was prepared by kneading in the same manner.

<Preparation of test piece>
As shown in FIG. 1A, each rubber composition was made into a flat plate-shaped rubber composition 1 having a width of 10 mm, a length of 70 mm, and a thickness of 1.0 mm.
This flat plate-shaped rubber composition (unvulcanized) was superposed on the surface of the modified PP sheet 2 having a width of 10 mm, a length of 70 mm, and a thickness of 0.13 mm.
Subsequently, as shown in FIG. 1 (b), the superposed product was sandwiched between two metal plates 4 and 4 maintained at the vulcanization temperature shown in Table 1 from the rubber composition 1 side. While holding the vulcanization time shown in Table 1 while pressing, the rubber composition 1 was vulcanized, and at the same time, the rubber composition 1 and the modified PP sheet 2 were vulcanized and adhered to prepare a test piece 3. The vulcanization temperature of Examples 1 and 2 is higher than the vulcanization start temperature of the hydrosilicone crosslinked EPDM and lower than the melting point of the modified PP.

<Evaluation items>
The presence or absence of vulcanization progress during this vulcanization was separately determined from a vulcanization degree test using a curast meter, and the presence was evaluated as good and the absence was evaluated as impossible.
The presence or absence of melting of the base material during this vulcanization was determined by visual judgment of the modified PP sheet after the test piece was prepared, and the absence was evaluated as good and the presence or absence was evaluated as impossible.
As shown in FIG. 1 (c), the modified PP sheet 2 side of the test piece 3 is fixed to a predetermined jig 5 with an adhesive, and the rubber composition 1 side is fixed at room temperature at a test speed of 10 mm / min. Was pulled to perform a 90 ° peeling test. The fracture form was determined from the visual inspection of the test piece 1 at the time of fracture by this peeling test, and the case of aggregate fracture was evaluated as good, and the case of interfacial fracture was evaluated as impossible.
The results of these evaluations are shown in Table 1.

In Examples 1 and 2, all the evaluation items were good, and good products that passed the comprehensive evaluation were obtained.
On the other hand, when the conventional rubber (peroxide vulcanized product) is set to a normal vulcanization temperature (140 ° C. or higher) as in Comparative Examples 1 and 3, the modified PP sheet melts and a good product cannot be obtained. As in Comparative Example 2, when the vulcanization temperature is lowered with the conventional rubber (peroxide vulcanized product), the vulcanization does not proceed due to insufficient temperature.

Subsequently, the rubber compound and the base material of Examples 3, 4, 5 and Comparative Examples 4, 5 (hereinafter, these may be referred to as “Example 3 and the like”) shown in Table 2 below are added. A vulcanized test piece was prepared and evaluated. The compounding value of the rubber compound is a mass part.

Here, the EPDM, the plasticizer, the cross-linking agent, the hydrosilylation reaction promoting catalyst, the reaction inhibitor, and the substrate are the same as those in Table 1 described above.
-Carbon black is the product name "Seast G-FY" of Tokai Carbon Co., Ltd.
-Calcium carbonate is the trade name "Whiten SB Red" of Bikita Powder Industry Co., Ltd.
-Calcium oxide is the trade name "VESTA-PP" of Inoue Lime Industry Co., Ltd.
-The paraffin-based process oil is the trade name "Diana Process Oil PW380" of Idemitsu Kosan Co., Ltd.

The preparation of the rubber composition and the preparation of the test piece 3 (FIG. 1) were carried out in Examples 1 and 2 and Comparative Examples 1, 2 and 3 (hereinafter, these are referred to as "Example 1 and the like" except for the following vulcanization conditions. I went in the same way as).
-In Example 1 and the like, the vulcanization temperature was changed to each other, but in Example 3 and the like, the vulcanization temperature was set to 110 ° C.
-In Example 1 and the like, the vulcanization time was set to 50% vulcanization time (midpoint of the vulcanization reaction) t _c (50) (JIS K6300-2), but in Example 3 and the like, the vulcanization time was 90. % Vulcanization time (optimal vulcanization point) t _c (90) (JIS K6300-2).

The following evaluation items were added to the same evaluation items as in Example 1 and the like.
-As the vulcanization property, the induction time (vulcanization start point) t _c (10) (JIS K6300-2) was measured.
-The peel strength at the time of breakage of the peel test was measured.
The results of these evaluations are shown in Table 2.

The reason why t _c (10) was 39 minutes in Example 3 is considered to be that the amount of reaction inhibitor was increased more than the others.
The reason why t _c (10) was 25 minutes in Example 4 was that as a result of removing calcium oxide that functions as a desiccant, the amount of water in the composition increased and the activity of the hydrosilylation reaction promoting catalyst was inhibited. It is thought that it was a catalyst.
The reason why t _c (10) was 10 minutes in Example 5 was that the concentration of the cross-linking agent in the composition was increased by the amount of calcium carbonate removed, but the carbon black was reduced more than the others, resulting in heat conduction. It is probable that the rate became worse and the cross-linking was delayed.
It is probable that the reason why t _c (10) was 8 minutes in Comparative Example 2 was that the concentration of the cross-linking agent in the composition was increased by the amount of calcium carbonate removed.

As described above, in Examples 3, 4 and 5, t _c (10) was 10 minutes or more, all the evaluation items were good, and good products that passed the comprehensive evaluation were obtained. Further, as shown in FIG. 3 showing the relationship between the t _c (10) of Examples 3, 4 and 5 and the peel strength, the longer the t _c (10), the higher the peel strength.
On the other hand, when the vulcanization temperature is set to 110 ° C. with conventional rubber (peroxide vulcanized product) as in Comparative Example 4, vulcanization does not proceed even if the vulcanization time is extended. Further, even in the case of hydrosilicone cross-linking as in Comparative Example 5, when _tc (10) was 8 minutes, the fracture form was interfacial fracture and the peel strength was low.

<Molding and vulcanization adhesion in the mold>
In the preparation of the test piece 3, the molding of the rubber composition 1 and the vulcanization adhesion between the rubber composition 1 and the modified PP sheet 2 were performed separately. Next, in the step described below (FIG. 2), the rubber composition 1 was vulcanized and bonded. Molding of the rubber composition 1 and vulcanization adhesion of the rubber composition 1 and the modified PP sheet 2 were simultaneously performed in the mold 6 to prepare a seal member for a fuel cell.

(1) As shown in FIG. 2A, a setting step was performed in which the modified PP sheet 2 processed into a shape for a fuel cell was set in an open mold 6.
(2) As shown in FIG. 2B, a molding step of injecting and molding the adjusted rubber composition 1 of Examples 1 to 5 into a closed mold 6 was performed.
(3) The rubber composition 1 is vulcanized in the mold 6 having the mold temperature set to the vulcanization temperature of Examples 1 to 5, and at the same time, the rubber composition 1 and the modified PP sheet 2 are vulcanized and adhered. A vulcanization step was performed.

As for the seal member for the fuel cell produced as described above, all the above evaluation items were good, and a good product having passed the comprehensive evaluation was obtained.

The present invention is not limited to the above embodiment, and can be appropriately modified and embodied without departing from the spirit of the invention.

1 Rubber composition 2 Modified PP sheet 3 Test piece 4 Metal plate 5 Jig 6 Mold

Claims (5)

The setting process of setting the base material made of modified polypropylene in the mold, and
A molding step in which a hydrosilicone crosslinked ethylene / α-olefin / non-conjugated diene copolymer is brought into contact with the substrate and molded in the mold.
In the mold, the temperature of the mold was set to be higher than the vulcanization start temperature of the hydrosilicone crosslinked ethylene / α-olefin / non-conjugated diene copolymer and lower than the melting point of the modified polypropylene. The inclusion of a vulcanization step of vulcanizing the α-olefin / non-conjugated diene copolymer rubber composition and at the same time vulcanizing and adhering the hydrosilicone crosslinked ethylene / α-olefin / non-conjugated diene copolymer to the substrate. A characteristic method for manufacturing a seal member for a fuel cell. The method for manufacturing a fuel cell seal member according to claim 1, wherein the mold temperature is 90 to 130 ° C. The hydrosilicone crosslinked ethylene / α-olefin / non-conjugated diene copolymer is a rubber composition to which a hydrosilicone compound as a crosslinking agent, a hydrosilylation reaction promoting catalyst, and a reaction inhibitor are added. Alternatively, the method for manufacturing a seal member for a fuel cell according to 2. The method for manufacturing a fuel cell seal member according to claim 3, wherein the rubber composition has an induction time t _c (10) (JIS K6300-2) at 110 ° C. of 10 minutes or more. Ethylene / α-olefin / 5-vinyl-2-norbornene random copolymer and
For 100 parts by mass of ethylene / α-olefin / 5-vinyl-2-norbornene random copolymer
1.0 to 10.0 parts by mass of the hydrosilicone compound as a cross-linking agent,
Hydrosilylation reaction promoting catalyst 0.1 to 1.0 parts by mass and
Contains 0.1-1.2 parts by mass of reaction inhibitor
A rubber composition for molding a seal member for a fuel cell, wherein the induction time t _c (10) (JIS K6300-2) at 110 ° C. is 10 minutes or more.

Images