JP5498256B2 - Polymer electrolyte laminated film - Google Patents

Description

  The present invention relates to a polymer electrolyte laminated film in which a polymer electrolyte film is laminated on a resin support film.

A fuel cell obtains electric energy from a fuel (hydrogen source) and an oxidant (oxygen) by an electrochemical reaction in the cell, and directly converts the chemical energy of the fuel into electric energy. As fuel sources for fuel cells, pure hydrogen and other petroleum oils containing hydrogen elements, natural gas (such as methane), methanol, and the like are used.
Since the fuel cell itself has no mechanical part, the generation of noise is small, and in principle, it is possible to generate electricity semipermanently by continuously supplying fuel and oxidant from the outside.
Electrolytes used in fuel cells are classified into liquid electrolytes and solid electrolytes. Among them, those using a polymer electrolyte film as an electrolyte are called solid polymer fuel cells. In particular, polymer electrolyte fuel cells operate at lower temperatures than other types of fuel cells, and are expected to be used as alternative power sources for automobiles, household cogeneration systems, and portable generators. ing.
The polymer electrolyte fuel cell includes at least a membrane / electrode assembly in which a gas diffusion electrode in which an electrode catalyst layer and a gas diffusion layer are laminated is bonded to both surfaces of a polymer electrolyte film. The polymer electrolyte film referred to here is a material having a strongly acidic group such as a sulfonic acid group or a carboxylic acid group in a polymer chain and a property of selectively transmitting protons. As such a polymer electrolyte film, a perfluoro proton exchange resin film represented by Nafion (registered trademark, manufactured by DuPont, USA) having high chemical stability is suitably used.
Such a polymer electrolyte film is generally a flexible thin film having a thickness of 20 to 100 μm, and has a defect that wrinkles and scratches are likely to occur when handled as a thin film. Therefore, it is desirable to laminate on a resin supporting film (Backing Film) as described in Non-Patent Document 1 from the viewpoint of storage and handling until a membrane / electrode assembly is produced.
By the way, the polymer electrolyte film generally has extremely high water absorption, and the membrane swells under high humidity. Therefore, when the adhesiveness between the polymer electrolyte film and the resin support film is poor, there is a problem that the polymer electrolyte film is easily peeled off from the resin support film in the high humidity environment in summer or air bubbles are easily included. When such a problem occurs, when the laminated film is stored, or when the laminated film is cut to a predetermined size and used after being peeled off, the polymer electrolyte film becomes a defective product containing defects or other defects, There has been a problem that the fuel cell cannot be used.
As methods for solving the above problems, Patent Documents 1 and 2 disclose a method in which at least one layer of a laminated film is completely cut in the thickness direction, and at least one layer is not cut in the thickness direction.

JP 2007-114270 A JP 2007-299551 A

Dennis E. Curtin, Robert D. Lousenberg, Timothy J. Henry, Paul C. Tangeman, Monica E. Tisack, J. Power Sources, 131 (2004), 41-48

However, in general, since the polymer electrolyte film is more flexible than the resin support film, it is difficult to peel the polymer electrolyte film thoroughly after storing for a long time. Therefore, there is a problem that when the polymer electrolyte is peeled off and used, it tends to be a defective product with defects and other defects and cannot be used for a fuel cell.
In view of the above circumstances, the present invention provides a polymer that can be used by easily peeling the polymer electrolyte film without wrinkles without increasing defects such as wrinkles even when the polymer electrolyte film is stored for a long period of time. It aims at providing an electrolyte lamination film and its manufacturing method.

  The inventors of the present invention provide a polymer electrolyte laminate film in which a polymer electrolyte film is laminated on a resin support film that has been subjected to corona discharge treatment or plasma discharge treatment on at least the laminate surface side with the polymer electrolyte film. , Cut in all the thickness direction of the polymer electrolyte film and part of the laminated surface side in the thickness direction of the resin support film, in the same plane position in a single wafer shape, or in the same plane position either vertically or horizontally As a result, it was found that the above-mentioned problems can be solved, and the present invention was completed.

That is, the present invention is as follows.
[1]
A polymer electrolyte laminated film having a resin support film and a polymer electrolyte film,
A polymer electrolyte film having a thickness of 1 to 500 μm is laminated on a resin support film having a thickness of 5 to 500 μm that has been subjected to corona discharge treatment or plasma discharge treatment on at least a laminated surface side with the polymer electrolyte film,
Cut all of the polymer electrolyte film in the thickness direction and a part of the laminated surface side in the thickness direction of the resin support film into a single wafer shape at the same plane position, or vertically or horizontally at the same plane position. An embedded polymer electrolyte laminated film.
[2]
The polymer electrolyte laminate film according to the above [1], wherein the depth of the cut in the thickness direction of the resin support film is 5 to 95% with respect to the thickness of the entire resin support film.
[3]
The polymer electrolyte laminate film according to the above [1] or [2], wherein the polymer electrolyte film contains a fluorine-based polymer electrolyte having a sulfonic acid group.
[4]
A method for producing a polymer electrolyte laminate film having a resin support film and a polymer electrolyte film,
(1) A step of performing corona discharge treatment or plasma discharge treatment on the laminated surface side of the resin support film with the polymer electrolyte film,
(2) A step of laminating the polymer electrolyte film on the resin support film subjected to the corona discharge treatment or the plasma discharge treatment to obtain a laminated film,
(3) A step of cutting the laminated film into a part on the laminated surface side of all the polymer electrolyte film thickness direction and the polymer electrolyte film in the thickness direction of the resin support film;
Manufacturing method.

  The polymer electrolyte laminated film of the present invention does not increase defects such as wrinkles of the polymer electrolyte film even after long-term storage, and allows the polymer electrolyte film from the polymer electrolyte laminated film to be handed from the end without any wrinkles. Can be easily peeled off.

The schematic of the polymer electrolyte laminated film which cut | notched the sheet-fed type is shown.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiment, and can be implemented with various modifications within the scope of the gist.

The polymer electrolyte laminate film of this embodiment is
A polymer electrolyte laminated film having a resin support film and a polymer electrolyte film,
A polymer electrolyte film having a thickness of 1 to 500 μm is laminated on a resin support film having a thickness of 5 to 500 μm that has been subjected to corona discharge treatment or plasma discharge treatment on at least a laminated surface side with the polymer electrolyte film,
Cut all of the polymer electrolyte film in the thickness direction and a part of the laminated surface side in the thickness direction of the resin support film into a single wafer shape at the same plane position, or vertically or horizontally at the same plane position. It is an embedded polymer electrolyte laminated film.

  Here, as shown in FIG. 1, the “single-wafer type” means a shape in which the polymer electrolyte laminated film can be handled one by one by cutting four directions in the plane direction of the polymer electrolyte laminated film.

The polymer electrolyte constituting the polymer electrolyte film of the present embodiment is not particularly limited, but a particularly preferable one is a fluorine-based polymer electrolyte as shown below.
The fluorine-based polymer electrolyte is not particularly limited, but Nafion (registered trademark; manufactured by DuPont, USA), Aciplex (registered trademark; manufactured by Asahi Kasei Chemicals, Japan), Flemion (registered trademark; Asahi Glass, Japan) A typical example is a perfluorocarbon polymer having a proton exchange group represented by the following general formula (1).
_{^{[CF 2 CX 1 X 2]}} a - [CF 2 -CF (-O- (CF 2 -CF (CF 2 X 3)) b -Oc- (CFR 1) d - (CFR 2) e - (CF 2 _F −X ⁴ )] _g (1)
(Wherein X ¹ , X ² and X ³ each independently represents a halogen atom or a C 1 to C 3 perfluoroalkyl group, 0 ≦ a <1, 0 <g ≦ 1, a + g = 1, 0 ≦ b ≦ 8, c is 0 or 1, d, e and f each independently represent a number in the range of 0 to 6 (where d + e + f is not equal to 0), R ¹ and R ² Each independently represents a halogen atom, a C 1-10 perfluoroalkyl group or a fluorochloroalkyl group, and X ⁴ represents —COOH, —SO ₃ H, —PO ₃ H ₂ , —PO ₃ HZ ( Z represents a hydrogen atom, a metal atom (Na, K, Ca, etc.), or an amine (NH ₄ , NH ₃ R, NH ₂ R ₂ , NHR ₃ , NR ₄ (R is an alkyl group or an arene group))) Show.)

Especially, since it exists in the tendency for proton conductivity to become high, the perfluorocarbon polymer represented by the following general formula (2) or (3) is more preferable.
_{[CF 2 CF 2] a -} [CF 2 -CF (-O- (CF 2 -CF (CF 3)) b -O- (CF 2) f -X 4)] g ··· (2)
(In the formula, 0 ≦ a <1, 0 <g ≦ 1, a + g = 1, 1 ≦ b ≦ 3, 1 ≦ f ≦ 8, and X ⁴ is —COOH, —SO ₃ H, —PO ₃ H _2. or an -PO ₃ H.)
_{[CF 2 CF 2] a -} [CF 2 -CF (-O- (CF 2) f -X 4)] g ··· (3)
(In the formula, 0 ≦ a <1, 0 <g ≦ 1, a + g = 1, 1 ≦ f ≦ 8, and X ⁴ represents —COOH, —SO ₃ H, —PO ₃ H ₂ or —PO ₃ H. Show.)

  The perfluorocarbon polymer may be a copolymer further containing units derived from a perfluoroolefin such as hexafluoropropylene or chlorotrifluoroethylene, or a comonomer such as perfluoroalkyl vinyl ether.

  Examples of the method for producing a fluorine-based polymer electrolyte are described in US Pat. No. 5,281,680, Japanese Patent Application Laid-Open No. 7-252322, and US Pat. No. 5,608,022. The method can be used.

  Examples of polymer electrolytes other than fluorine-based polymer electrolytes include polyethersulfone resins, polyetheretherketone resins, phenol-formaldehyde resins, polystyrene resins, polytrifluorostyrene resins, trifluorostyrene resins, poly (2,3 -Diphenyl-1,4-phenylene oxide) resin, poly (allyl ether ketone) resin, poly (allyl ether sulfone) resin, poly (phenyl quinoxaline) resin, poly (benzyl silane) resin, polystyrene-graft-ethylenetetrafluoroethylene Resin, polystyrene-graft-polyvinylidene fluoride resin, polystyrene-graft-tetrafluoroethylene resin, polyimide resin, polybenzimidazole resin, etc. Which was introduced phospho groups, or these resins or a functional group such as phosphoric acid or polyphosphoric acid, include those of inorganic acids doped.

  Although it does not specifically limit as a proton exchange capacity | capacitance of the polymer electrolyte film in this embodiment, It is preferable that it is 0.5-4.0 milliequivalent / g, More preferably, it is 0.8-4.0 milliequivalent / g. More preferably, it is 0.9 to 1.5 meq / g. By using a polymer electrolyte film having a larger proton exchange capacity, higher proton conductivity is exhibited under high-temperature and low-humidification conditions, and when this is used in a fuel cell, a higher output can be obtained. On the other hand, when the proton exchange capacity exceeds 4.0 meq / g, dissolution in hot water tends to increase.

  Here, the proton exchange capacity of the polymer electrolyte film is determined by weighing the polymer electrolyte film, immersing it in a saturated aqueous sodium chloride solution at 25 ° C., and stirring it for 1 hour to conduct an ion exchange reaction. It is measured by adding a rain solution and performing neutralization titration with a 0.01N sodium hydroxide aqueous solution.

  Examples of the polymer electrolyte film include those reinforced by blending a porous reinforcing material, a non-woven sheet, organic or inorganic microfibers, etc. into the film containing the polymer electrolyte.

The thickness of the polymer electrolyte film in the present embodiment is 1 to 500 μm, preferably 2 to 200 μm, more preferably 5 to 100 μm, and particularly preferably 10 to 50 μm. While the durability increases as the film thickness increases, the electrical resistance and initial characteristics deteriorate when used in a fuel cell, and the durability and handleability after peeling deteriorate as the film thickness decreases. From the above viewpoint, the thickness of the polymer electrolyte film of the present embodiment is adjusted to a range of 1 to 500 μm.
Here, the thickness of the polymer electrolyte film is measured with a contact-type micrometer.

[Resin support film]
The resin support film constituting the polymer electrolyte laminate film in the present embodiment is not particularly limited. For example, polyethylene terephthalate, polyethylene naphthalate, polystyrene, polyethylene, polypropylene, polycarbonate, polyimide, polyether ketone, polyphenylene sulfide, polyether Examples thereof include general resin support films made of sulfone, polyketone, poly (ethylene / tetrafluoroethylene) copolymer, polyvinylidene fluoride, polytetrafluoroethylene, and the like. Among these, a resin film made of polyethylene terephthalate is preferable from the viewpoint of handling because the polymer electrolyte film is easily peeled off when a membrane / electrode assembly is produced.

  The thickness of the resin support film in this embodiment is 5 to 500 μm, preferably 10 to 300 μm, more preferably 15 to 200 μm, and particularly preferably 20 to 100 μm. If the thickness of the resin support film is less than 5 μm, wrinkles are likely to enter the resin support film, and if it exceeds 500 μm, it becomes difficult to join the polymer electrolyte film and the resin support film by hot pressing or lamination.

  The resin support film in this embodiment is subjected to corona discharge treatment or plasma discharge treatment at least on the side of the laminated surface with the polymer electrolyte film. By performing corona discharge treatment or plasma discharge treatment on the laminated surface side of the resin support film, the surface of the resin support film is hydrophilized, so the familiarity with the strongly hydrophilic polymer electrolyte film is improved. A polymer electrolyte laminate film having improved adhesion to the polymer electrolyte film is obtained.

  The corona discharge treatment referred to here is a discharge handbook (published by Ohm, revised in 1982, edited by the Electrotechnical Society Discharge Handbook Publishing Committee) p. As described in 102-106, a counter electrode such as a stainless steel wire or a tungsten wire is placed on the surface of the resin support film, and a corona discharge is generated in the atmosphere by applying a high frequency and a high voltage. This refers to a treatment of directly irradiating a resin support film with functional groups such as carbonyl group, carboxyl group, hydroxyl group and the like and electrons.

  In addition, the plasma discharge treatment referred to here is a discharge handbook (published by Ohm, revised in 1982, edited by the Institute of Electrical Engineers of Japan Discharge Handbook) p. As described in 281 to 329, plasma discharge is generated in the atmosphere by high-voltage arc plasma discharge, activated by performing plasma discharge electron irradiation on the surface of the resin support film, and generated by discharge activated oxygen. The process etc. which provide functional polar groups, such as carbonyl group, carboxyl group, hydroxyl group, etc. to the resin support film surface.

The wetting tension of the surface of the resin support film after the corona discharge treatment or plasma discharge treatment is preferably 40-70 mN / m, more preferably 44-68 mN / m, and still more preferably 48-66 mN / m.
Here, the wetting tension can be measured with a wetting tension test solution in accordance with JIS K-6768.

In the polymer electrolyte laminate film in the present embodiment, the polymer electrolyte film and the resin support film are laminated, and all the thickness directions of the polymer electrolyte film and the laminate surface side in the thickness direction of the resin support film. Is cut into a single wafer shape at the same plane position, or vertically or horizontally at the same plane position.
Here, “a part on the side of the laminated surface in the thickness direction” means that not only the thickness direction is cut, but a cut is made at a predetermined depth from the laminated surface. The predetermined depth is preferably 5 to 95% with respect to the thickness of the resin support film, more preferably 10 to 80%, and still more preferably 15 to 60%.
Further, “at the same plane position” means that a cut is made at the same position of the polymer electrolyte film and the resin support film when the laminated film is viewed from the top.

(Method for producing polymer electrolyte laminated film)
The method for producing the polymer electrolyte laminate film of the present embodiment is as follows:
(1) A step of performing corona discharge treatment or plasma discharge treatment on the laminated surface side of the resin support film with the polymer electrolyte film,
(2) A step of laminating the polymer electrolyte film on the resin support film subjected to the corona discharge treatment or the plasma discharge treatment to obtain a laminated film,
(3) A step of cutting the laminated film into a part on the laminated surface side of all the polymer electrolyte film thickness direction and the polymer electrolyte film in the thickness direction of the resin support film;
Is a manufacturing method.
An example using a polymer electrolyte film made of a fluorine-based polymer electrolyte will be described below.

The fluorine-based polymer electrolyte can be produced by polymerizing a precursor polymer represented by the following general formula (4) by the following method, followed by hydrolysis and acid treatment.
_{^{[CF 2 CX 1 X 2]}} a - [CF 2 -CF (-O- (CF 2 -CF (CF 2 X 3)) b -O c - (CFR 1) d - (CFR 2) e - (CF _{^{2) f -X 5)] g}} ··· (4)
(Wherein X ¹ , X ² and X ³ each independently represents a halogen atom or a C 1 to C 3 perfluoroalkyl group, 0 ≦ a <1, 0 <g ≦ 1, a + g = 1, b is a number in the range of 0-8, c is 0 or 1, d, e and f are each independently a number in the range of 0-6 (where d + e + f is not equal to 0), R ¹ and R ² each independently represent a halogen atom, a C 1-10 perfluoroalkyl group or a fluorochloroalkyl group, and X ⁵ represents —COOR ³ , —COR ⁴ or SO ₂ R ⁴ (R ³ represents An alkyl group having 1 to 3 carbon atoms (not substituted with fluorine), and R ⁴ is a halogen atom.)

The precursor polymer represented by the general formula (4) can be produced by copolymerizing a fluorinated olefin compound and a vinyl fluoride compound.
Examples of the fluorinated olefin compound include CF ₂ = CF ₂ , CF ₂ = CFCl, CF ₂ = CCl _{2 and the} like.
The fluorinated vinyl compound, _{e.g., CF 2 = CFO (CF 2} ) z -SO 2 F, CF 2 = CFOCF 2 CF (CF 3) O (CF 2) z -SO 2 F, CF 2 = CF (CF _{2) z -SO 2 F, CF} 2 F (OCF 2 CF (CF 3)) z - (CF 2) z-1 -SO 2 F, CF 2 = CFO (CF 2) z -CO 2 R, CF 2 _{= CFOCF 2 CF (CF 3)} O (CF 2) z -CO 2 R, CF 2 = CF (CF 2) z -CO 2 R, CF 2 = CF (OCF 2 CF (CF 3)) z - (CF ₂ ) _2— CO ₂ R (wherein Z is an integer of 1 to 8, R is an alkyl group having 1 to 3 carbon atoms (not substituted with fluorine)), and the like.

  As a polymerization method of the precursor polymer, for example, a solution polymerization method in which a vinyl fluoride compound is dissolved in a solvent such as chlorofluorocarbon and then reacted with a gas of a fluorinated olefin compound, without using a solvent such as chlorofluorocarbon. Examples thereof include a bulk polymerization method for polymerization, an emulsion polymerization method in which a vinyl fluoride compound is charged with water in a surfactant and emulsified, and then reacted with a gas of a fluorinated olefin compound to perform polymerization. In any of the above polymerization methods, the reaction temperature is preferably 30 to 90 ° C., and the reaction pressure is preferably 280 to 1100 kPa.

  Although it does not specifically limit as a melt flow index (henceforth "MI") measured by 270 degreeC and load 2.16kgf based on JISK-7210 of the said precursor polymer, 0.001g / 10 The amount is preferably not less than 1000 g / 10 minutes, more preferably not less than 0.01 g / 10 minutes and not more than 100 g / 10 minutes, and still more preferably not less than 0.1 g / 10 minutes and not more than 10 g / 10 minutes. When the MI of the precursor polymer is less than 0.001 g / 10 min, processing and molding tend to be difficult, and when it exceeds 1000 g / 10 min, the durability is high when the polymer electrolyte film is used in a fuel cell. It tends to get worse.

  As a method of forming the precursor polymer into a film, a general melt extrusion method (T-die method, inflation method, calendar method, etc.) is used.

  The precursor polymer molded into a film is brought into contact with the reaction liquid to hydrolyze the ion exchange group precursor to produce a polymer electrolyte film. In this case, the hydrolysis of the ion exchange group precursor can be performed in an aqueous alkali hydroxide solution, and it is preferable to use a relatively high temperature solution in order to further increase the hydrolysis reaction rate. Examples of such a method include a method of hydrolyzing at 70 to 90 ° C. for 16 hours using an aqueous solution containing 20 to 25% sodium hydroxide described in JP-A No. 61-19638. It is done.

  Further, in order to swell the film and accelerate the hydrolysis reaction rate, the mixture is hydrolyzed with a mixture of an alkali hydroxide aqueous solution and an alcohol solvent such as methyl alcohol, ethyl alcohol or propyl alcohol, or a water-soluble organic solvent such as dimethyl sulfoxide. A method of decomposing may be used. As such a method, for example, a method of hydrolyzing at 90 ° C. for 1 hour using an aqueous solution containing 11 to 13% potassium hydroxide and 30% dimethyl sulfoxide described in JP-A-57-139127 And an aqueous solution containing 15 to 50% by mass of an alkali hydroxide and 0.1 to 30% by mass of a water-soluble organic compound described in JP-A-3-6240 at 20 to 24 ° C. for 20 minutes to 24 hours. Examples of the method include hydrolysis.

  After forming an ion exchange group by the hydrolysis treatment, a polymer electrolyte film can be produced by acid treatment with an inorganic acid such as hydrochloric acid.

  As described above, the resin support film is subjected to corona discharge treatment or plasma discharge treatment at least on the side of the laminated surface with the polymer electrolyte film. The corona discharge treatment can be performed at an output of 1 kW and 50 kHz by, for example, a corona discharge surface treatment apparatus manufactured by Kasuga Electric Co., Ltd. The plasma discharge treatment can be performed, for example, with a plasma irradiation surface modification device manufactured by Kasuga Electric Co., Ltd., with an output of 600 W and an output voltage of 10 kV.

  In a state in which the polymer electrolyte film produced by the above-described method and a resin support film that has been subjected to corona discharge treatment or plasma discharge treatment are laminated, known press techniques such as hot press, roll press, vacuum press, and lamination are used. The polymer electrolyte laminate film can be obtained by bonding using a technique.

  In addition, the precursor polymer pieces (pellets, powder) were hydrolyzed in the same manner as described above, and dissolved or dispersed in an appropriate solvent to form a uniform solution dope, which was cast on a resin support film. Thereafter, the solvent may be distilled off, followed by drying and / or heat treatment at 100 to 200 ° C. to obtain a polymer electrolyte laminated film.

  This polyelectrolyte laminated film is placed on a flat table or on a rotating backup roll, and the tip of a blade that rotates in synchronization with the polyelectrolyte film surface of the polyelectrolyte laminated film that is continuously fed In this case, sequentially, (a) all the thickness direction of the polymer electrolyte film and a part of the laminated surface side in the thickness direction of the resin support film are cut into a sheet size of a predetermined size at the same plane position, Or (b) cutting into a predetermined size in either the vertical or horizontal direction at the same plane position. The term “vertical” as used herein indicates the feeding direction of the polymer electrolyte laminated film that is continuously fed, and the horizontal indicates the width direction of the film. The single wafer type refers to a state in which cuts are made in both the vertical direction and the horizontal direction. In a roll-shaped scroll, the state which cut | notched both the length direction and the width direction is pointed out.

  By making the cuts as described above, it is possible to obtain a polymer electrolyte laminated film laminated in a state where it can be easily peeled without any wrinkles. The depth of the cut in the thickness direction of the resin support film is 5% or more with respect to the entire thickness of the resin support film from the viewpoint of uniformly cutting the polymer electrolyte film. It is preferable that it is 95% or less with respect to the whole thickness of a film, More preferably, it is 10 to 80%, More preferably, it is 15 to 60%. When the polymer electrolyte film is peeled off, the resin support film is lightly bent at the notch position by making a cut with a depth of 5 to 95% with respect to the entire thickness of the resin support film in the thickness direction of the resin support film. As a result, the polymer electrolyte film can be easily peeled without being damaged.

(Membrane / electrode assembly)
When a polymer electrolyte film is used for a polymer electrolyte fuel cell, a membrane / electrode assembly (hereinafter also referred to as “MEA”) in which the polymer electrolyte film is held tightly between an anode and a cathode. .) Used as. Here, the anode is composed of an anode catalyst layer having proton conductivity, and the cathode is composed of a cathode catalyst layer having proton conductivity. A gas diffusion layer bonded to the outer surface of each of the anode catalyst layer and the cathode catalyst layer is also referred to as MEA.

  As a method for manufacturing the MEA, a known method can be used. The method for producing MEA is described in, for example, JOURNAL OF APPLIED ELECTROCHEMISTRY, 22 (1992) p. 1-7.

(Solid polymer fuel cell)
The polymer electrolyte fuel cell in the present embodiment can be obtained by bonding the MEA anode and cathode to each other via an electron conductive material located outside the polymer electrolyte film. As a method for producing the solid polymer fuel cell, a known method can be used. The polymer electrolyte fuel cell is prepared by, for example, FUEL CELL HANDBOOK (VAN NOSTRAND REINHOLD, AJ APPLEBY et.al, ISBN 0-442-31926-6), Chemical One Point, Fuel Cell (Second Edition). ), Masao Taniguchi, Manabu Senoo, Kyoritsu Shuppan (1992). The polymer electrolyte fuel cell is operated by supplying hydrogen to one electrode (anode) and supplying oxygen or air to the other electrode (cathode).

  The polymer electrolyte laminate film of the present embodiment can be easily peeled without peeling when the polymer electrolyte film is peeled off without increasing defects such as wrinkles of the polymer electrolyte film even if stored for a long period of time. It is possible to greatly reduce the defect rate during MEA manufacturing.

  Further, the polymer electrolyte film of the polymer electrolyte laminate film in the present embodiment is appropriately peeled off and used for chloralkali electrolysis, water electrolysis, hydrohalic acid electrolysis, salt electrolysis, oxygen concentrator, humidity sensor, gas sensor, etc. It is also possible. For a method of using the polymer electrolyte film in the oxygen concentrator, see, for example, Chemical Engineering, 56 (3), p. 178-180 (1992) and U.S. Pat. No. 4,879,016 can be referred to. For a method of using a polymer electrolyte film for a humidity sensor, see, for example, Journal of the Japan Ion Exchange Society, 8 (3), p. 154-165 (1997) and J.A. Fang et al. , Macromolecules, 35, 6070 (2002). For a method of using a polymer electrolyte film for a gas sensor, see, for example, Analytical Chemistry, 50 (9), p. 585-594 (2001), X. Yang, S .; Johnson, J.M. Shi, T .; Holesinger, B.M. Swanson: Sens. Reference can be made to Actuators B, 45, 887 (1997).

Hereinafter, the present embodiment will be specifically described by way of examples. However, the present embodiment is not limited to the following examples.
Each evaluation method and measurement method in the present embodiment are as follows.
[Film thickness]
The thickness of the film was measured with a contact micrometer.
[Proton exchange capacity]
The proton exchange capacity of the polymer electrolyte film is determined by weighing the polymer electrolyte film, immersing it in a saturated aqueous sodium chloride solution at 25 ° C., stirring it for 1 hour, performing an ion exchange reaction, and adding a phenolphthalein solution as an indicator to this solution. In addition, it was measured by neutralization titration with a 0.01N aqueous sodium hydroxide solution.

[Example 1]
(Production of polymer electrolyte film)
As a polymer electrolyte film, a perfluorosulfonic acid polymer represented by [CF ₂ CF ₂ ] _0.812- [CF ₂ -CF (—O— (CF ₂ ) ₂ —SO ₃ H)] _0.188 (hereinafter referred to as “PFS”). An electrolyte membrane made of “)” was prepared as follows.
First, as a PFS precursor polymer, a perfluorocarbon polymer (MI: 3.0) of tetrafluoroethylene and CF ₂ ═CFO (CF ₂ ) ₂ —SO ₂ F was produced. A film formed by melt-extruding the precursor polymer to a thickness of about 50 μm was added to a reaction liquid containing 15% by mass of potassium hydroxide, 30% by mass of dimethyl sulfoxide and 55% by mass of water at 60 ° C. The hydrolysis treatment was performed by contact for a period of time. Thereafter, the film was immersed in 60 ° C. water for 4 hours and then immersed in a 2N hydrochloric acid aqueous solution at 60 ° C. for 3 hours, and then the acid was washed out with ion-exchanged water to obtain a polymer electrolyte film.
The obtained polymer electrolyte film had a proton exchange capacity of 1.22 meq / g and a film thickness of 50 μm.

(Production of resin support film)
As the resin support film, a polyethylene terephthalate film subjected to corona discharge treatment as follows was used.
As the polyethylene terephthalate film, a Teijin ^TM Tetron film manufactured by Teijin DuPont Films Co., Ltd. having a thickness of 75 μm was used (hereinafter referred to as PET film).
Corona discharge treatment was performed at an output of 1 kW and 50 kHz on the surface of the PET film laminated with the polymer electrolyte film using a corona discharge surface treatment system manufactured by Kasuga Electric Co., Ltd. The wetting tension of the surface of the obtained resin support film was 58 mN / m.

(Manufacture of polymer electrolyte laminate film)
Next, the 10 cm square polymer electrolyte film and the corona discharge treated PET film were laminated, and both sides thereof were sandwiched between Kapton films (300H, film thickness 75 μm). This was set in a compression molding machine (manufactured by Shinfuji Kogyo Co., Ltd., VSF-10), heated to 100 ° C., and pressed at 10 kgf / cm ^{2 for} 10 minutes. After the pressing, the pressure was released and the temperature was lowered to 30 ° C., and then Sample A was taken out.
This laminated film (sample A) was placed in a constant temperature and humidity chamber, and a dry and wet cycle test was performed in which 30 ° C. and 95% RH were repeated for 3 hours and 10 ° C. and 30% RH were repeated for 3 hours. When the laminated film was taken out after 400 cycles, the polymer electrolyte film was not peeled off from the corona discharge treated PET film.
With the sample A after pressing, with the polymer electrolyte film facing up, the ceramic blade is pushed in from the top of the polymer electrolyte laminated film on a flat table, and at that time, a clearance of 50 μm is provided between the blade edge and the flat table. By cutting a plurality of single-wafer molds at the same position in the plane direction in about 1/3 of the thickness direction of the polymer electrolyte membrane and about 1/3 of the thickness direction of the resin support film (about 25 μm from the laminated surface side) The polymer electrolyte laminate film of this embodiment was obtained.
In addition, the sample A after the press is synchronized with the polymer electrolyte film surface on the polymer electrolyte laminated film continuously fed on the rotating backup roll with the polymer electrolyte film facing up. At that time, a clearance of 50 μm is provided between the blade edge and the backup roll, and the entire thickness direction of the polymer electrolyte membrane and about 1/3 of the thickness direction of the resin support film (from the laminated surface side) The polymer electrolyte laminate film of this embodiment was obtained by sequentially cutting into a plurality of single wafer molds at the same position in the plane direction at about 25 μm).
When an attempt was made to peel the polymer electrolyte film cut into a single wafer type from the end portion by hand from the obtained polymer electrolyte laminated film, it could be easily peeled off without generating wrinkles. Moreover, there was also moderate adhesiveness and it did not peel spontaneously when handling the polymer electrolyte laminated film.
Furthermore, the storage stability is also good, even after being stored for 3 months in a constant temperature and humidity chamber at 25 ° C. and 50% RH as a roll in a flat shape or as a roll, a sheet of a predetermined cut size The leaf-type polymer electrolyte film was not peeled off, and the films were not displaced or wrinkled. Further, the polymer electrolyte film was not peeled off and set off.

[Comparative Example 1]
A polymer electrolyte laminate film was obtained in the same manner as in Example 1 except that a PET film not subjected to corona discharge treatment was used. When this polymer electrolyte laminate film was subjected to a dry and wet cycle test in the same manner as in Example 1, the polymer electrolyte film was peeled off from the PET film. Moreover, when this polymer electrolyte laminated film was stacked and stored as a roll in the same manner as in Example 1, the polymer electrolyte film was partially peeled and set off.

[Comparative Example 2]
A polymer electrolyte laminate film was obtained in the same manner as in Example 1 except that the polymer electrolyte film and the resin support film were not cut. This polymer electrolyte laminated film was cut into a single wafer type in the thickness direction of the polymer electrolyte film and the resin support film, and was cut into a single wafer type from the polymer electrolyte laminated film as in Example 1. When trying to peel the polymer electrolyte film from the edge by hand, wrinkles occurred.

  The polymer electrolyte laminate film of the present invention can be easily peeled off when necessary without increasing defects such as wrinkles of the polymer electrolyte film after long-term storage, and can be easily peeled off when necessary. It is possible to greatly reduce the defect rate.

Claims (4)

A polymer electrolyte laminated film having a resin support film and a polymer electrolyte film,
A polymer electrolyte film having a thickness of 1 to 500 μm is laminated on a resin support film having a thickness of 5 to 500 μm that has been subjected to corona discharge treatment or plasma discharge treatment on at least a laminated surface side with the polymer electrolyte film,
Cut all of the polymer electrolyte film in the thickness direction and a part of the laminated surface side in the thickness direction of the resin support film into a single wafer shape at the same plane position, or vertically or horizontally at the same plane position. An embedded polymer electrolyte laminated film.   The polymer electrolyte laminate film according to claim 1, wherein the depth of a part of the cut in the thickness direction of the resin support film is 5 to 95% with respect to the thickness of the entire resin support film.   The polymer electrolyte laminate film according to claim 1 or 2, wherein the polymer electrolyte film includes a fluorine-based polymer electrolyte having a sulfonic acid group. A method for producing a polymer electrolyte laminate film having a resin support film and a polymer electrolyte film,
(1) A step of performing corona discharge treatment or plasma discharge treatment on the laminated surface side of the resin support film with the polymer electrolyte film,
(2) A step of laminating the polymer electrolyte film on the resin support film subjected to the corona discharge treatment or the plasma discharge treatment to obtain a laminated film,
(3) A step of cutting the laminated film into a part on the laminated surface side of all the polymer electrolyte film thickness direction and the polymer electrolyte film in the thickness direction of the resin support film;
Manufacturing method.

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