JP2017065042A - Method for producing rubber gasket for fuel cell and fuel cell sealed body and aqueous release agent used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a method for producing a rubber gasket for a fuel cell and a fuel cell sealed body capable of improving the durability of a die or the like without giving adverse effect on the power generation property of a fuel cell, the adhesiveness of a gasket and the dimensional precision of a gasket; and an aqueous release agent used for the same.SOLUTION: There is provided a method for producing a rubber gasket for a fuel cell and a fuel cell sealed body in which an aqueous release agent having an electric conductivity of 3.7 to 7857 μs/cm which contains the following components (A) and (B) is applied on the inner peripheral surface of a die for molding a rubber gasket for a fuel cell, followed by crosslinking molding of a rubber composition inside the die. (A) A compound having a fluorine-containing group and a hydrophilic group. (B) Water.SELECTED DRAWING: None

Description

  The present invention relates to a rubber gasket for a fuel cell, a method for producing a fuel cell seal body, and an aqueous release agent used therefor.

  The fuel cell generates electricity by the electrochemical reaction of gas, has high power generation efficiency, cleans the discharged gas, and has very little influence on the environment. Among these, the polymer electrolyte fuel cell can be operated at a relatively low temperature and has a large power density. For this reason, various uses, such as a power generation and an automotive power source, are expected.

  In a polymer electrolyte fuel cell, a cell in which a membrane electrode assembly (MEA) or the like is sandwiched between separators is a power generation unit. The MEA includes a polymer membrane (electrolyte membrane) serving as an electrolyte, a pair of electrode catalyst layers (a fuel electrode (anode) catalyst layer, an oxygen electrode (cathode) catalyst layer) disposed on both sides in the thickness direction of the electrolyte membrane, Consists of. On the surface of the pair of electrode catalyst layers, a porous layer for further diffusing gas is disposed. A fuel gas such as hydrogen is supplied to the fuel electrode side, and an oxidant gas such as oxygen or air is supplied to the oxygen electrode side. Power generation is performed by an electrochemical reaction at the three-phase interface between the supplied gas, the electrolyte, and the electrode catalyst layer. The polymer electrolyte fuel cell is configured by fastening a cell laminate in which a large number of the cells are laminated with end plates or the like arranged at both ends in the cell lamination direction.

  The separator is formed with a flow path of gas supplied to each electrode and a flow path of refrigerant for relaxing heat generation during power generation. For example, when the gas supplied to each electrode is mixed, problems such as a decrease in power generation efficiency occur. The electrolyte membrane has proton conductivity in a state containing water. For this reason, it is necessary to keep the electrolyte membrane in a wet state during operation. Therefore, in order to prevent gas mixing, gas and refrigerant leakage, and to keep the inside of the cell moist, it is important to ensure the sealing performance around the MEA and the porous layer and between adjacent separators. It becomes. As a sealing member for sealing these constituent members, for example, a rubber gasket made of ethylene-propylene-diene terpolymer rubber (EPDM), ethylene-propylene copolymer rubber (EPM) or the like has been proposed (Patent Literature). 1 and 2).

JP 2009-94056 A JP 2010-146781 A

  By the way, the rubber gasket for a fuel cell as described above is a mold with a nickel surface treatment without a release agent so as not to adversely affect the power generation performance of the fuel cell, the adhesiveness of the gasket, and the dimensional accuracy of the gasket. It has been preferred to use and mold.

  However, in the method that does not use a mold release agent as described above, the rubber of the gasket material is brought into close contact with the mold surface (the inner peripheral surface of the mold) by repeatedly molding the gasket, and the nickel surface treatment functions. There is a problem that the durability of the mold is lowered. Therefore, the method described above tends to increase the maintenance cost of the mold.

  In addition, when the present inventors examined a conventionally used release agent, for example, a solvent-based fluorine release agent is present at the interface between the gasket and the fuel cell constituent member, and has an adhesive property. Since it has an adverse effect, there is a problem in that the adhesion between the gasket and the fuel cell constituent member is lowered, and its use is difficult. In addition, the silicone mold release agent has a problem that the Si component migrates and adversely affects power generation. In addition, the wax-based release agent can be applied only with a thick film (30 to 50 μm), and the coating film is destroyed due to the weak intermolecular bond of the wax-based release agent itself. Therefore, there is a problem that the dimensional accuracy of the gasket is deteriorated. Furthermore, since many of these release agents cannot be easily washed after being applied to the mold surface, they cause mold contamination and increase in maintenance costs.

  The present invention has been made in view of such circumstances, and can improve the durability of the mold without adversely affecting the power generation performance of the fuel cell, the adhesiveness of the gasket, and the dimensional accuracy of the gasket. An object of the present invention is to provide a rubber gasket for a fuel cell, a method for producing a fuel cell seal body, and an aqueous release agent used therefor.

In order to achieve the above object, the present invention provides an electrical conductivity of 3.7 to 7857 μs / cm containing the following components (A) and (B) on the inner peripheral surface of a molding die for a fuel cell rubber gasket. The first gist of the present invention is a method for producing a rubber gasket for a fuel cell, in which a water-based mold release agent is applied and then a rubber composition is subjected to cross-linking molding in the mold.
(A) A compound having a fluorine-containing group and a hydrophilic group in one molecule.
(B) Water.

The present invention also relates to a method of manufacturing a fuel cell seal body in which a fuel cell constituent member and a fuel cell rubber gasket are integrated. On the inner peripheral surface of a molding die for a fuel cell rubber gasket, After applying an aqueous release agent having a conductivity of 3.7 to 7857 μs / cm containing the components (A) and (B), the fuel cell constituent member is placed in the mold, and the rubber is placed in the mold. The manufacturing method of the fuel cell seal body, in which the composition is crosslinked and formed in contact with the fuel cell constituent member, is a second gist.
(A) A compound having a fluorine-containing group and a hydrophilic group in one molecule.
(B) Water.

The third aspect of the present invention is an aqueous mold release agent for a rubber gasket mold for a fuel cell, which contains the following components (A) and (B) and has an electric conductivity in the range of 3.7 to 7857 μs / cm. And
(A) A compound having a fluorine-containing group and a hydrophilic group in one molecule.
(B) Water.

  That is, the present inventors have intensively studied to solve the above problems. In the course of that research, we selected a mold release agent that does not adversely affect the power generation performance of the fuel cell, gasket adhesion, and gasket dimensional accuracy, and applied the mold release agent to the mold to ensure the durability of the mold. We examined the improvement of the performance and repeated various experiments. As a result, when a compound containing a fluorine-containing group and a hydrophilic group in one molecule is a release agent, it is very easy to apply to a thin film, and even if it is applied very thin like this, good release properties It was found that the durability of the mold can be improved. Further, when the above compound is a mold release agent, it has good compatibility with the rubber constituting the gasket and is unlikely to exist at the interface between the gasket and the fuel cell constituent member, and therefore does not adversely affect the adhesion between the gasket and the fuel cell constituent member. I found out. However, even when a release agent such as that described above is used, if the gasket to be molded is a rubber gasket for a fuel cell, it is due to the conductivity of the release agent that the fuel cell generates power. Adverse effects were observed. Therefore, an improvement in this point is also required in the mold release agent for molding a fuel cell rubber gasket. And it discovered that metal ion components, such as Na and Ca, contained in the tap water normally used for the dilution as a big factor of the electroconductive height of said mold release agent were mentioned. The solvent used for the dilution is also water having a small amount of metal ion components such as ion exchange water, and the conductivity of the release agent is set to a very low value of 3.7 to 7857 μs / cm. The inventors have found that the intended purpose can be achieved, and have reached the present invention.

  As described above, in the method for manufacturing a fuel cell rubber gasket and a fuel cell seal body of the present invention, a compound having a fluorine-containing group and a hydrophilic group in one molecule and water are formed on the inner peripheral surface of the molding die. An aqueous release agent having an electrical conductivity of 3.7 to 7857 μs / cm is applied. Therefore, the durability of the mold can be improved without adversely affecting the power generation performance of the fuel cell, the adhesiveness of the gasket, and the dimensional accuracy of the gasket. In addition, the adhesiveness of the gasket includes a case where it is bonded to a mating member such as a fuel cell constituent member while the gasket is being molded, and a case where the molded gasket is post bonded to the fuel cell constituent member, both of which are good. Adhesiveness can be obtained. Moreover, since the said compound contains a hydrophilic group, its dispersion | distribution with respect to water is good, Therefore, when wash | cleaning the water-type mold release agent adhering to the metal mold | die surface, it can wash easily with water.

It is sectional drawing which shows an example of a fuel cell seal body. It is sectional drawing which shows an example using the rubber gasket for fuel cells.

  Next, embodiments of the present invention will be described in detail.

As described above, the method for producing a rubber gasket for a fuel cell according to the present invention has a conductivity containing the following components (A) and (B) on the inner peripheral surface of a molding die for a fuel cell rubber gasket. This is performed by applying a water-based mold release agent of 3.7 to 7857 μs / cm and then performing cross-linking molding of the rubber composition in the mold.
(A) A compound having a fluorine-containing group and a hydrophilic group in one molecule.
(B) Water.

  As described above, an aqueous release agent having a conductivity of 3.7 to 7857 μs / cm is used. And from a viewpoint of the effect in the manufacturing method of this invention, Preferably, the water-based mold release agent whose electrical conductivity is 3.7-1100 microseconds / cm is used, More preferably, electrical conductivity is 3.7-733 microseconds / cm. An aqueous mold release agent is used. In addition, in order to set it as the above very low electrical conductivity, it is necessary to use the water used with few metal ion components, such as ion-exchange water, also for the solvent used for the dilution. The conductivity can be measured by, for example, a personal SC meter SC72, which is a conductivity meter manufactured by Yokogawa Electric Corporation.

  In the compound which is the component (A), particularly, the hydrophilic group of the compound is a phosphonic group (aminophosphoric acid group), a sulfone group (sulfonic acid group), a carboxyl group, or an ether group (having an ether bond). Because there is a good familiarity with the rubber that constitutes the gasket and it is difficult to exist at the interface between the gasket and the fuel cell constituent member, the tendency of not adversely affecting the adhesion between the gasket and the fuel cell constituent member is noticeable. preferable.

  Specific examples of the compound having a hydrophilic group as described above include a compound derived from a phosphonate, a compound derived from a sulfonate, a compound derived from a carboxylate, and an ether compound. Or in combination of two or more. Note that the reason why “the compound derived from...” Is defined as the compound of the component (A) that is obtained by dissolving the phosphonate or the like in water and ionically dissociating.

  More specifically, the compound of the component (A) is represented by the following general formula (1).

In the above formula (1), m and n are integers. M is H, K, NH ₄ , NH (CH ₃ ) ₃ . Among these, M is preferably H or K so as not to adversely affect power generation.

  The aqueous release agent preferably has a solid concentration of 0.0047 to 10% by weight from the viewpoint of the effect on the adhesion between the gasket and the fuel cell component, and from the same viewpoint, the aqueous release agent. The solid content concentration of the mold is more preferably in the range of 0.07 to 1.4% by weight.

  And it is possible to apply the aqueous mold release agent to the inner peripheral surface of the mold by applying the coating film so that the thickness after drying of the coating film is 0.001 to 10 μm. From the same viewpoint, the thickness of the aqueous release agent coating film after drying is more preferably in the range of 0.001 to 1 μm.

  Further, the aqueous mold release agent is applied to the inner peripheral surface of the mold by coating so that the weight of the coated film after drying is 0.0001036 to 1.4504 g per 400 mm × 200 mm area. It is preferable from the viewpoint of the dimensional accuracy of the gasket and the like, and from the same viewpoint, the weight of the aqueous release agent coating film after drying is more preferably 0.000259 to 0.000 per 400 mm × 200 mm area. It is in the range of 0518 g.

  Moreover, it is preferable to use the metal mold | die with which nickel surface treatment was made | formed as the said metal mold | die from the viewpoint of improving mold release property.

  As a rubber composition used as a material for forming a rubber gasket for a fuel cell of the present invention, an ethylene-propylene-diene terpolymer rubber (EPDM) or an ethylene-propylene copolymer rubber (EPM) such as an ethylene-propylene copolymer rubber (EPM) is used as the polymer. Examples include those using propylene rubber, silicone rubber, acrylonitrile-butadiene rubber (NBR), hydrogenated acrylonitrile-butadiene rubber (H-NBR), and the like. Of these, ethylene-propylene rubbers such as ethylene-propylene-diene terpolymer rubber (EPDM) and ethylene-propylene copolymer rubber (EPM) are preferably used from the viewpoint of weather resistance and acid resistance. Moreover, when using the said ethylene-propylene type rubber composition, it is preferable from a viewpoint of the influence on the electrolyte membrane surface catalyst of a solid polymer film to use the organic peroxide as the crosslinking agent. In the rubber composition, in addition to the polymer and the crosslinking agent, a vulcanization accelerator, a vulcanization aid, an antiaging agent, a process oil, and the like can be appropriately blended as necessary.

If only the rubber gasket is manufactured, as described above, after applying the specific aqueous release agent to the inner peripheral surface of the molding die, the rubber composition is formed in the die. Although it is possible to manufacture by performing cross-linking molding of the product, for example, a fuel cell component, such as a metal separator, a membrane electrode assembly (MEA), and the rubber gasket are integrated, If a fuel cell sealing body is manufactured, it can be manufactured as follows. That is, after applying an aqueous release agent containing 3.7 to 7857 μs / cm of electrical conductivity containing the following components (A) and (B) to the inner peripheral surface of a molding die for a fuel cell rubber gasket, In the production method, the battery constituent member is disposed in the mold, and the rubber composition is crosslinked and molded in the mold in contact with the fuel cell constituent member. In addition, the thing of the suitable range of each requirement thru | or each component requirement in this manufacturing method applies to the manufacturing method of the said rubber gasket for fuel cells.
(A) A compound having a fluorine-containing group and a hydrophilic group in one molecule.
(B) Water.

  Here, an example of the fuel cell seal body is shown in FIG. FIG. 1 mainly shows a single cell 1 in a fuel cell in which a plurality of cells are stacked. The cell 1 includes an MEA 2, a gas diffusion layer (GDL) 3, a gasket 4a, and a separator. 5 and the adhesive layer 6, the adhesive layer 6 is not necessary if the gasket 4 a and the separator 5 are integrated without an adhesive based on the previous manufacturing method.

  Although not shown, the MEA 2 includes a pair of electrodes disposed on both sides in the stacking direction with the electrolyte membrane interposed therebetween. The electrolyte membrane and the pair of electrodes have a rectangular thin plate shape. Gas diffusion layers 3 are disposed on both sides in the stacking direction with the MEA 2 interposed therebetween. The gas diffusion layer 3 is a porous layer and has a rectangular thin plate shape.

  The separator 5 is preferably made of a metal such as titanium, and a metal separator having a carbon thin film such as a DLC film (diamond-like carbon film) or a graphite film is particularly preferable from the viewpoint of conduction reliability. The separator 5 has a rectangular thin plate shape and is provided with a total of six grooves extending in the longitudinal direction. The cross section of the separator 5 has an uneven shape due to the grooves. The separators 5 are opposed to each other on both sides of the gas diffusion layer 3 in the stacking direction. A gas flow path 7 for supplying gas to the electrode is defined between the gas diffusion layer 3 and the separator 5 by using an uneven shape. When a fuel cell such as a solid polymer fuel cell is operated, fuel gas and oxidant gas are supplied through the gas flow paths 7 respectively.

  The gasket 4a has a rectangular frame shape. The gasket 4a is bonded to the peripheral portion of the MEA 2 and the gas diffusion layer 3 and the separator 5, and seals the peripheral portion of the MEA 2 and the gas diffusion layer 3. In FIG. 1, the gasket 4 a uses two members that are divided into upper and lower parts, but a single gasket in which both are combined may be used.

  Furthermore, another example of use using the rubber gasket for fuel cells obtained by the production method of the present invention is shown in FIG. FIG. 2 shows a rectangular thin plate shape, in which a total of six grooves extending in the longitudinal direction are recessed, and the separator 5 having the above-described cross-sectional concavo-convex shape has a rectangular shape with an adhesive layer 6 interposed therebetween. This is a member provided with a lip 4b having a convex section. The rubber gasket for a fuel cell of the present invention is used as the lip 4b. In addition, in the member shown in FIG. 2, an embodiment in which the separator 5 and the lip 4 b are directly bonded without the adhesive layer 6 being included.

  Next, examples will be described together with comparative examples. However, the present invention is not limited to these examples as long as the gist thereof is not exceeded.

  First, prior to Examples and Comparative Examples, release agents (i) to (iv) and solvents (α) to (γ) shown below were prepared.

[Release agent (i)]
Fluorine water-based mold release agent mainly composed of the compound represented by the following formula (2) (Flease GP-10, manufactured by Neos)

[Release agent (ii)]
Fluorine water-based mold release agent containing a compound represented by the following formula (3) as a main component (Futterent 212M, manufactured by Neos)

[Release agent (iii)]
Fluorine solvent release agent (Sumimold F1, manufactured by Sumiko Lubricant)

[Release agent (iv)]
Silicone release agent (Cure Coat RM1412, manufactured by Chukyo Kasei Kogyo Co., Ltd.)

[Solvent (α)]
Ion exchange water with impurities removed by ion exchange resin.

[Solvent (β)]
Organic solvent (butane)

[Solvent (γ)]
Tap water

[Examples 1-9, Comparative Examples 1-6]
In the combinations shown in Tables 1 and 2 below, the release agent and the solvent were mixed to prepare a release agent solution having a conductivity and a solid content concentration shown in the same table. The conductivity of the release agent solution was measured with a conductivity meter (Personal SC Meter SC72, manufactured by Yokogawa Electric Corporation) in the liquid state.
And regarding the said mold release agent liquid, according to the following reference | standard, each characteristic was evaluated. These results are shown in Tables 1 and 2 below.
In addition, when evaluating each characteristic, when apply | coating the said mold release agent liquid to a metal inner peripheral surface etc., the coating film thickness (thickness after drying of a coating film) shown in Table 1-Table 2 of a postscript, coating It applied so that it might become a film weight (weight per area of 400 mm x 200 mm after drying of a coating film). Moreover, as a rubber composition used for evaluation of each property, EPDM (Sumitomo Chemical Co., Esprene 505) 100 parts by weight, softener (Idemitsu Kosan Co., Ltd., Diana Process PW-150) 20 parts by weight, After 45 parts by weight of GPF grade carbon black (manufactured by Cabot Japan, Show Black IP200) was kneaded at 120 ° C. for 5 minutes using a Banbury mixer, the kneaded product was cooled, and further organic peroxide (NOF) Co., Perhexa C-40) 5 parts by weight and a crosslinking assistant (Ouchi Shinsei Chemical Co., Ltd., Barnock PM) 0.8 part by weight, kneaded at 50 ° C. for 10 minutes using an open roll, The prepared one was used. Further, as the flat rubber molded body, a flat rubber molded body having a width of 25 mm, a length of 60 mm, and a thickness of 5 mm obtained by press-molding this rubber composition was used.

<Impact on power generation>
Since the amount of metal ions has an adverse effect on power generation, it is defined by the conductivity of the release agent solution. As a reference, less than 734 (μs / cm) was evaluated as ◎, 734 to 7857 (μs / cm) as ◯, and 7857 (μs / cm) as greater as ×.

<Adhesiveness with separator>
Adhesive (AP-133, manufactured by Road Far East) is applied to the surface of a titanium plate (width 25 mm, length 60 mm, thickness 0.1 mm), which is a metal member, so that the thickness after application becomes 80 nm. Spray applied. Then, a mold release agent solution is applied onto the prepared flat rubber molded body (unvulcanized), and the application surface and the adhesive surface of the titanium plate are laminated and held at 150 ° C. for 10 minutes. By doing so, rubber was vulcanized, and a laminate (a test piece of an adhesion evaluation sample) formed by bonding a metal and a vulcanized rubber was produced. The laminated body thus obtained was subjected to visual evaluation of the adhesive interface on the titanium plate side when a 90 ° peel test based on JIS K 6256-2 (2006) was performed according to the following evaluation criteria. It was.
(Evaluation criteria)
○: Only rubber was observed at the bonding interface.
Δ: Both rubber and primer (or metal member) were observed at the bonding interface.
X: No rubber was observed at the bonding interface, and a primer or metal member was observed.

<Dimensional accuracy of gasket>
A metal titanium separator (10 cm square x 0.1 mm thick) coated with an adhesive after applying a release agent solution to a molding die for a fuel cell rubber gasket whose inner peripheral surface is nickel-treated. ) And an unvulcanized rubber molded body made of the rubber composition were placed at predetermined locations in the mold and held at 150 ° C. for 10 minutes to crosslink the unvulcanized rubber molded body. As a result, a rubber gasket (semicircular shape, thickness 2 mm × width 4 mm × length 8 cm) was adhered and formed at the center of the surface of the separator. Ten of these were prepared, and the thickness of the gasket was measured with a laser microscope (model grade name: VK-X200, manufactured by Keyence Corporation). The dimensional accuracy, that is, {(maximum value of gasket thickness−minimum value of gasket thickness) / (design value of gasket thickness (2 mm))} × 100 is less than 3%. The case of 3% to 5% was evaluated as Δ, and the case of exceeding 5% was evaluated as ×.

<Washability>
Water washability was judged by the solubility of the release agent solution in water. That is, the release agent solution was mixed in ion-exchanged water (for a release agent whose tap water is a solvent, tap water) so that the concentration of the release agent solution was 10% by weight (total 30 ml), Left for a day. Thereafter, by visual observation, the case where the release agent solution was in a transparent state was evaluated as ○, and the case where there was a precipitate was evaluated as ×.

<Mold releasability>
A sample similar to the sample used in the evaluation of the “gasket dimensional accuracy” was prepared once. And the state of the sample at that time was visually observed. That is, from the state of the sample, ◎ when the rubber was not damaged or the separator was not deformed, ○ when the rubber was damaged but the separator was not deformed, ○, the rubber was broken or the separator was deformed Things were rated as x.

<Die durability>
A sample similar to the sample used for the evaluation of the “dimensional accuracy of the gasket” was prepared. Thereafter, the mold was washed with the same solvent as that used for each release agent solution (in the case of Example 1, ion-exchanged water), and the above samples were produced again. This cycle was repeated, and after producing the sample 100 times, the state of the 100th sample was visually observed. And from the state of the sample, ◎ if the rubber was not damaged or the separator was not deformed, ○ if the rubber was damaged but the separator was not deformed, ○, the rubber was broken or the separator was deformed Things were rated as x.

  From the results in the above table, those molded using the mold release agent solution of the example have no effect on power generation due to the use of the mold release agent solution, and the mold release solution of the example is used. By doing so, it was recognized that there would be no problem in the adhesiveness to the separator, the dimensional accuracy of the gasket, the water washability, the mold releasability, and the mold durability.

  On the other hand, since the release agent liquids of Comparative Example 1 and Comparative Example 2 are based on organic solvents, there are problems in adhesiveness to the separator, water washability, and the like. In Comparative Example 3, mold molding or the like was performed without using a mold release agent solution, but the mold durability was hindered. In Comparative Examples 4 to 6, the same release agent type as in the examples is used, but the conductivity of the release agent liquid is out of the range defined in the present application, and the conductivity is too low ( In Comparative Example 4), the concentration of the mold release agent was thin, and the nickel plating layer on the inner peripheral surface of the mold was abraded because it could not be covered with the mold release agent, resulting in hindering the mold durability. Moreover, the thing with comparatively high electrical conductivity (Comparative Examples 5 and 6) resulted in an adverse effect on power generation.

  In the method for producing the fuel cell rubber gasket and the fuel cell seal body of the present invention, a specific aqueous release agent is applied to the inner peripheral surface of the molding die. The water-based mold release agent is specialized for use in the manufacture of fuel cell rubber gaskets and fuel cell seal bodies, but should be used as a mold release agent when molding other products. Is also possible.

1 cell 2 MEA
3 Gas diffusion layer 4a Gasket 4b Lip 5 Separator 6 Adhesive layer 7 Gas flow path

Claims (14)

After applying an aqueous mold release agent having a conductivity of 3.7 to 7857 μs / cm containing the following components (A) and (B) to the inner peripheral surface of a molding die for a rubber gasket for a fuel cell, the above die A method for producing a rubber gasket for a fuel cell, characterized in that the rubber composition is subjected to cross-linking molding in the inside.
(A) A compound having a fluorine-containing group and a hydrophilic group in one molecule.
(B) Water.   The method for producing a rubber gasket for a fuel cell according to claim 1, wherein the hydrophilic group of the compound as the component (A) is a phosphone group, a sulfone group, a carboxyl group, or an ether group.   The compound as the component (A) is at least one selected from the group consisting of a compound derived from a phosphonate, a compound derived from a sulfonate, a compound derived from a carboxylate, and an ether compound. The manufacturing method of the rubber gasket for fuel cells of Claim 2.   The manufacturing method of the rubber gasket for fuel cells as described in any one of Claims 1-3 whose solid content concentration of the said water-system mold release agent is 0.0047 to 10 weight%.   The coating of the water-based mold release agent on the inner peripheral surface of the mold is performed by applying the coating film so that the thickness after drying of the coating film is 0.001 to 10 μm. The manufacturing method of the rubber gasket for fuel cells of description.   Application of the aqueous release agent to the inner peripheral surface of the mold is performed by applying so that the weight after drying of the coated film is 0.0001036 to 1.4504 g per 400 mm × 200 mm area. Item 6. A method for producing a rubber gasket for a fuel cell according to any one of Items 1 to 5.   The manufacturing method of the rubber gasket for fuel cells as described in any one of Claims 1-6 which uses the metal mold | die by which the nickel peripheral surface treatment was made | formed as the said metal mold | die.   The ethylene-propylene rubber composition comprising at least one of ethylene-propylene-diene terpolymer rubber (EPDM) and ethylene-propylene copolymer rubber (EPM) as a polymer is used as the rubber composition. A method for producing a rubber gasket for a fuel cell according to any one of claims 7 to 10.   The method for producing a rubber gasket for a fuel cell according to claim 8, wherein an organic peroxide is used as a cross-linking agent for the ethylene-propylene rubber composition. A method of manufacturing a fuel cell sealing body in which a fuel cell constituent member and a fuel cell rubber gasket are integrated, on the inner peripheral surface of a molding die of the fuel cell rubber gasket, the following (A) and (B ) After applying a water-based mold release agent containing 3.7 to 7857 μs / cm containing the component, the fuel cell constituent member is placed in the mold, and the rubber composition is placed in the fuel cell in the mold. A method for producing a fuel cell seal body, characterized by carrying out cross-linking molding in a state of being in contact with a component member.
(A) A compound having a fluorine-containing group and a hydrophilic group in one molecule.
(B) Water. An aqueous mold release agent for a rubber gasket mold for a fuel cell, comprising the following components (A) and (B) and having a conductivity in a range of 3.7 to 7857 μs / cm.
(A) A compound having a fluorine-containing group and a hydrophilic group in one molecule.
(B) Water.   The water-based mold release agent for a fuel cell rubber gasket mold according to claim 11, wherein the hydrophilic group of the compound (A) is a phosphone group, a sulfone group, a carboxyl group, or an ether group.   The compound as the component (A) is at least one selected from the group consisting of a compound derived from a phosphonate, a compound derived from a sulfonate, a compound derived from a carboxylate, and an ether compound. The water-based mold release agent for a rubber gasket mold for a fuel cell according to claim 12.   The aqueous release agent for a rubber gasket mold for a fuel cell according to any one of claims 11 to 13, wherein the solid content concentration of the aqueous release agent is 0.0047 to 10% by weight.

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