CN103117401B - Polymer Electrolyte Laminated Membrane - Google Patents

Abstract

The object of the present invention is to provide a polymer electrolyte laminated membrane and a method for producing the polymer electrolyte membrane, which does not increase defects such as wrinkles even if it is stored for a long time, and can be easily peeled off without wrinkles. use. The polymer electrolyte laminated membrane of the present invention is a polymer electrolyte laminated membrane having a resin support film and a polymer electrolyte membrane, wherein a polymer electrolyte film with a thickness of 1 to 500 μm is laminated on a resin support film with a thickness of 5 to 500 μm. An electrolyte membrane in which the resin support membrane has been subjected to corona discharge treatment or plasma discharge treatment at least on the laminated surface side of the polymer electrolyte membrane, the entire thickness direction of the polymer electrolyte membrane and the resin A part of the lamination surface side in the thickness direction of the support film is notched in a sheet shape at the same planar position, or is notched in either the longitudinal direction or the transverse direction at the same planar position.

Description

Polymer Electrolyte Laminated Membrane

technical field

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

Background technique

The fuel cell obtains electrical energy from fuel (hydrogen source) and oxidant (oxygen) through electrochemical reactions in the battery, and directly converts the chemical energy of the fuel into electrical energy. As the fuel source of the fuel cell, petroleum, natural gas (methane, etc.), methanol, etc. containing hydrogen including pure hydrogen are used.

The fuel cell itself has no mechanical parts, so it generates little noise, and by continuously supplying fuel and oxidant from the outside, it can in principle generate electricity semi-permanently.

Electrolytes used in fuel cells are classified into liquid electrolytes and solid electrolytes, among which a fuel cell using a polymer electrolyte membrane as an electrolyte is called a solid polymer fuel cell. In particular, solid polymer fuel cells operate at lower temperatures than other types of fuel cells, and thus are expected to be used as alternative power sources for automobiles, cogeneration systems for household use, and portable generators.

A solid polymer fuel cell includes at least a membrane/electrode assembly in which a gas diffusion electrode laminated with an electrode catalyst layer and a gas diffusion layer is bonded to both surfaces of a polymer electrolyte membrane. The polymer electrolyte membrane mentioned here refers to a material having strong acidic groups such as sulfonic acid groups and carboxylic acid groups in the polymer chain, and having the property of selectively permeating protons. As such a polymer electrolyte membrane, a perfluorinated proton exchange resin membrane typified by Nafion (registered trademark, manufactured by DuPont, USA) having high chemical stability is suitably used.

Such a polymer electrolyte membrane is usually a flexible thin film with a thickness of 20 to 100 μm, and has the disadvantage of being easily wrinkled and damaged if it is handled as it is in a thin film state. Therefore, from the standpoint of storage and handling until the film/electrode assembly is produced, it is desirable to laminate on the resin support film (Backing Film) described in Non-Patent Document 1.

However, polymer electrolyte membranes are generally extremely water-absorbent, and the membrane swells under high humidity. Therefore, if the adhesion between the polymer electrolyte membrane and the resin support membrane is poor, the polymer electrolyte membrane tends to be peeled off from the resin support membrane or air bubbles tend to enter in a high-humidity environment in summer. If such a problem occurs, when the laminated film is stored, or when the laminated film is cut into a predetermined size and peeled off for use, it will become a defective product with wrinkles or other defects in the polymer electrolyte membrane. Problems for fuel cells.

As means for solving the above-mentioned 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.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2007-114270

Patent Document 2: Japanese Patent Laid-Open No. 2007-299551

non-patent literature

Non-Patent Document 1: Dennis E. Curtin, Robert D. Lousenberg, Timothy J. Henry, Paul C. Tangeman, Monica E. Tisack, J. Power Sources, 131(2004), 41-48

Contents of the invention

However, since the polymer electrolyte membrane is usually softer than the resin support membrane, it is difficult to peel off the polymer electrolyte membrane without wrinkles after long-term storage. Therefore, when the polymer electrolyte is peeled off for use, defective products with wrinkles or other defects tend to be formed, and there is a problem that it cannot be used for fuel cells.

In view of the above circumstances, an object of the present invention is to provide a polymer electrolyte laminated membrane and a method for producing the same, which will not increase defects such as wrinkles even if the polymer electrolyte membrane is stored for a long time, and which can be easily and wrinkle-free. The molecular electrolyte membrane is used for stripping.

The inventors of the present invention have found that the above-mentioned problems can be solved by a polymer electrolyte laminated film in which the upper layer of the resin support film is subjected to corona discharge treatment or plasma discharge treatment at least on the side of the laminated surface on which the polymer electrolyte membrane is laminated. A polymer electrolyte membrane is deposited, wherein the entire thickness direction of the polymer electrolyte membrane and a part of the lamination surface side in the thickness direction of the resin support membrane are notched in the same plane position in the shape of a sheet (leaf leaf type), Alternatively, incisions are made in either the vertical or horizontal direction at the same plane position, and the present invention has been completed based on the above findings.

That is, the present invention is as follows.

[1]

A polymer electrolyte laminated membrane, which is a polymer electrolyte laminated membrane having a resin support film and a polymer electrolyte membrane, wherein,

A polymer electrolyte membrane with a thickness of 1 to 500 μm is laminated on a resin support film with a thickness of 5 to 500 μm, and the resin support film is subjected to corona discharge at least on the side of the lamination surface laminated with the polymer electrolyte membrane treatment or plasma discharge treatment,

The entire thickness direction of the polymer electrolyte membrane and a part of the lamination surface side in the thickness direction of the resin support membrane are cut in the same plane position in the shape of a sheet, or in the same plane position along the longitudinal or There are incisions in either direction of the cross.

[2]

The polymer electrolyte laminated membrane according to the above [1], wherein the depth of the partial cutout in the thickness direction of the resin support film is 5 to 95% of the thickness of the entire resin support film.

[3]

The polymer electrolyte laminated membrane according to the above [1] or [2], wherein the polymer electrolyte membrane contains a fluorine-based polymer electrolyte having a sulfonic acid group.

[4]

A production method, which is a production method of a polymer electrolyte laminated membrane having a resin support membrane and a polymer electrolyte membrane, the production method comprising the following steps:

(1) A step of performing corona discharge treatment or plasma discharge treatment on the lamination surface side of the resin support film to be laminated with the polymer electrolyte membrane;

(2) a step of laminating the polymer electrolyte membrane on the resin support film subjected to the corona discharge treatment or plasma discharge treatment to obtain a laminated film;

(3) With regard to the laminated membrane, the entire thickness direction of the polymer electrolyte membrane and a part of the laminated surface side of the polymer electrolyte membrane laminated with the polymer electrolyte membrane in the thickness direction of the resin support membrane are cut. The process of cutting out.

The polymer electrolyte laminated membrane of the present invention does not increase defects such as wrinkles of the polymer electrolyte membrane even after long-term storage, and can be easily peeled off from the polymer electrolyte laminated membrane by hand without wrinkles. Molecular Electrolyte Membranes.

Description of drawings

FIG. 1 is a schematic view showing a polymer electrolyte laminated film with notches cut in the shape of a paper sheet.

Symbol Description

1 Polymer electrolyte laminated film with notches cut in the shape of a sheet

2 polymer electrolyte membrane

3 resin support film

4 cuts

Detailed ways

Hereinafter, specific embodiments of the present invention (hereinafter referred to as "the present embodiment") will be described in detail. In addition, this invention is not limited to the following this embodiment, Various deformation|transformation can be implemented within the range of the summary.

The polymer electrolyte laminated membrane of the present embodiment is a polymer electrolyte laminated membrane having a resin support film and a polymer electrolyte membrane, wherein,

A polymer electrolyte membrane with a thickness of 1 to 500 μm is laminated on a resin support film with a thickness of 5 to 500 μm, and the resin support film is subjected to corona discharge at least on the side of the lamination surface laminated with the polymer electrolyte membrane treatment or plasma discharge treatment,

The entire thickness direction of the polymer electrolyte membrane and a part of the lamination surface side in the thickness direction of the resin support membrane are cut in the same plane position in the shape of a sheet, or in the same plane position along the longitudinal or There are incisions in either direction of the cross.

Here, "sheet-shaped" refers to a shape in which the polymer electrolyte laminated membrane can be handled one by one by cutting the peripheries of the polymer electrolyte laminated membrane in the planar direction as shown in FIG. 1 .

The polymer electrolyte constituting the polymer electrolyte membrane of the present embodiment is not particularly limited, but fluorine-based polymer electrolytes as shown below are particularly suitable.

The fluorine-based polymer electrolyte is not particularly limited, and Nafion (registered trademark; manufactured by DuPont Corporation of the United States), Aciplex (registered trademark; manufactured by National Asahi Kasei Chemical Co., Ltd. of Japan), Flemion (registered trademark; manufactured by National Asahi Glass Co., Ltd. of Japan) can be mentioned. ) and other perfluorocarbon polymers having a proton exchange group represented by the following general formula (1) as a representative example.

[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 independently represent a halogen atom or a perfluoroalkyl group with 1 to 3 carbon atoms, 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 (wherein, d+e+f is not equal to 0), R ¹ and R ² independently represent Halogen atom, perfluoroalkyl group or fluorochloroalkyl group with 1 to 10 carbon atoms, X ⁴ represents -COOH, -SO ₃ H, -PO ₃ H ₂ , -PO ₃ HZ (Z is hydrogen atom, metal atom (Na, K, Ca, etc.), or amines (NH ₄ , NH ₃ R, NH ₂ R ₂ , NHR ₃ , NR ₄ (R is an alkyl or aromatic hydrocarbon group))).)

Among these, perfluorocarbon polymers represented by the following general formula (2) or general formula (3) are more preferable because the proton conductivity tends to be high.

[CF ₂ CF ₂ ] _a -[CF ₂ -CF(-O-(CF ₂ -CF(CF ₃ )) _b -O-(CF ₂ ) _f -X ⁴ )] _g …(2)

(wherein, 0≤a<1, 0<g≤1, a+g=1, 1≤b≤3, 1≤f≤8, X ⁴ represents -COOH, -SO ₃ H, -PO ₃ H ₂ or _-PO3H .)

[CF ₂ CF ₂ ] _a -[CF ₂ -CF(-O-(CF ₂ ) _f -X ⁴ )] _g …(3)

(wherein, 0≤a<1, 0<g≤1, a+g=1, 1≤f≤8, X ⁴ represents -COOH, -SO ₃ H, -PO ₃ H ₂ or -PO ₃ H. )

The above 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.

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

Examples of polymer electrolytes other than fluorine-based polymer electrolytes include polyethersulfone resins, polyether ether ketone resins, phenol-formaldehyde resins, polystyrene resins, polytrifluorostyrene resins, and trifluorostyrene resins. , poly(2,3-diphenyl-1,4-phenylene ether) resin, poly(allyl ether ketone) resin, poly(allyl ether sulfone) resin, poly(phenylquinoxaline) resin, Poly(benzylsilane) resin, polystyrene-graft-ethylene tetrafluoroethylene resin, polystyrene-graft-polyvinylidene fluoride resin, polystyrene-graft-tetrafluoroethylene resin, polyimide Amine resins, polybenzimidazole resins, and other polymers with hydrocarbon moieties introduced sulfonic acid groups and carboxylic acid groups; or substances in which phosphoric acid, polyphosphoric acid, and inorganic acids were doped into these resins and functional groups.

The proton exchange capacity of the polymer electrolyte membrane in this embodiment is not particularly limited, but is preferably 0.5 to 4.0 meq/g, more preferably 0.8 to 4.0 meq/g, and still more preferably 0.9 to 1.5 meq/g. By using a polymer electrolyte membrane with a larger proton exchange capacity, it can exhibit higher proton conductivity under high-temperature and low-humidity conditions, and when it is used in a fuel cell, higher output power can be obtained. On the other hand, when the proton exchange capacity exceeds 4.0 meq/g, the dissolution in hot water tends to increase.

Here, the proton exchange capacity of the polymer electrolyte membrane is measured by weighing the polymer electrolyte membrane, dipping it into a saturated sodium chloride aqueous solution at 25°C, stirring for 1 hour to carry out ion exchange reaction, and adding Phenolphthalein solution as an indicator, and neutralized titration with 0.01N sodium hydroxide aqueous solution.

The polymer electrolyte membrane also includes a polymer electrolyte membrane reinforced by mixing a porous reinforcing material, a nonwoven sheet, organic or inorganic microfibers, etc. into the membrane containing the above polymer electrolyte.

The polymer electrolyte membrane in the present embodiment has a thickness of 1 to 500 μm, preferably 2 to 200 μm, more preferably 5 to 100 μm, particularly preferably 10 to 50 μm. The thicker the film, the higher the durability, but the lower the resistance and the initial characteristics when used in a fuel cell, and the lower the durability and the handleability after peeling when the film is thinner. In consideration of the above points, the thickness of the polymer electrolyte membrane of the present embodiment is adjusted to be in the range of 1 to 500 μm.

Here, the thickness of the polymer electrolyte membrane was measured with a contact micrometer.

[Resin support film]

The resin support film constituting the polymer electrolyte laminated film in this embodiment is not particularly limited, and examples thereof include polyethylene terephthalate, polyethylene naphthalate, polystyrene, poly Ethylene, polypropylene, polycarbonate, polyimide, polyetherketone, polyphenylene sulfide, polyethersulfone, polyketone, poly(ethylene/tetrafluoroethylene) copolymer, polyvinylidene fluoride, polytetrafluoroethylene A common resin support film made of vinyl or the like. Among the above, a resin film made of polyethylene terephthalate is preferable from the viewpoint of handling because it is easy to peel off the polymer electrolyte membrane when producing a membrane/electrode assembly or the like.

The thickness of the resin support film in this embodiment is 5-500 micrometers, Preferably it is 10-300 micrometers, More preferably, it is 15-200 micrometers, Especially preferably, it is 20-100 micrometers. If the thickness of the resin support membrane is less than 5 μm, the resin support membrane tends to wrinkle, and if it exceeds 500 μm, it is difficult to join the polymer electrolyte membrane and the resin support membrane by hot pressing or lamination.

The resin support film in this embodiment has been subjected to corona discharge treatment or plasma discharge treatment at least on the side of the lamination surface to be laminated with the polymer electrolyte membrane. 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 it has good adaptability to the highly hydrophilic polymer electrolyte membrane, and can obtain A polymer electrolyte laminated membrane having improved adhesion between a resin support membrane and a polymer electrolyte membrane.

The corona discharge treatment mentioned here refers to the following treatment, etc.: as described in the discharge handbook (Ohmsha, Ltd., the main distributor, the new edition revised in 1957, edited by the Electric Society Discharge Handbook Publishing Committee) p.102-106 , for the surface of the resin support film, facing the opposite electrodes such as stainless steel wires and tungsten wires, and applying high frequency and high voltage to generate corona discharge in the atmosphere, and directly irradiate the resulting carbonyl, carboxyl, hydroxyl and other functional groups and electrons onto the resin support membrane.

In addition, the plasma discharge treatment mentioned here refers to the following treatment, etc., as described in the discharge handbook (the main distributor Ohmsha, Ltd., the new edition revised in 1957, edited by the Electrical Society Discharge Handbook Publishing Committee) p.281-329 In the same way, plasma discharge is generated in the atmosphere by high-voltage arc plasma discharge, and the surface of the resin support film is irradiated and activated by plasma discharge electrons. Apply to the surface of the resin support film.

The wetting tension of the surface of the resin support film after corona discharge treatment or plasma discharge treatment is preferably 40-70 mN/m, more preferably 44-68 mN/m, and even more preferably 48-66 mN/m.

Here, the wetting tension can be measured using a wetting tension test solution according to JIS K-6768.

The polymer electrolyte laminated membrane in this embodiment is formed by laminating the above-mentioned polymer electrolyte membrane and the above-mentioned resin support membrane, and the entire thickness direction of the polymer electrolyte membrane and the lamination surface side of the thickness direction of the resin support membrane are A part of the paper sheet is cut in the same plane position according to the paper sheet shape, or is cut in either vertical or horizontal direction on the same plane position.

Here, "a part on the side of the lamination surface in the thickness direction" means that the incision is not made entirely in the thickness direction, but the incision is made at a predetermined depth from the lamination surface. The predetermined depth is preferably 5 to 95%, more preferably 10 to 80%, and still more preferably 15 to 60% of the thickness of the resin support film.

In addition, "at the same planar position" means that the polymer electrolyte membrane and the resin support membrane are notched at the same position when the laminated film is viewed from above.

(Manufacturing method of polymer electrolyte laminated membrane)

The manufacturing method of the polymer electrolyte laminated membrane of this embodiment includes the following steps:

(1) A step of performing corona discharge treatment or plasma discharge treatment on the lamination surface side of the resin support film to be laminated with the polymer electrolyte membrane;

(2) a step of laminating the polymer electrolyte membrane on the resin support film subjected to the corona discharge treatment or plasma discharge treatment to obtain a laminated film;

(3) With regard to the laminated membrane, the entire thickness direction of the polymer electrolyte membrane and a part of the laminated surface side of the polymer electrolyte membrane laminated with the polymer electrolyte membrane in the thickness direction of the resin support membrane are cut. The process of cutting out.

An example using a polymer electrolyte membrane 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 method described below, 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 -Oc-(CFR ¹ ) _d -(CFR ² ) _e -(CF ₂ ) _f -X ⁵ )] _g …(4)

(wherein, X ¹ , X ² and X ³ independently represent a halogen atom or a perfluoroalkyl group with 1 to 3 carbon atoms, 0≤a<1, 0<g≤1, a+g=1, b is a number in the range of 0 to 8, c is 0 or 1, d, e and f independently represent a number in the range of 0 to 6 (wherein, d+e+f is not equal to 0), R ¹ and R ² Each independently represents a halogen atom, a perfluoroalkyl group or a fluorochloroalkyl group with 1 to 10 carbon atoms, and X ⁵ represents -COOR ³ , -COR ⁴ or SO ₂ R ⁴ (R ³ is a group with 1 to 10 carbon atoms. 3's alkyl group (not substituted with fluorine), ^R4 's a halogen atom).)

The precursor polymer represented by the above general formula (4) can be produced by copolymerizing a fluorinated olefin compound and a fluorinated vinyl compound.

Examples of fluorinated olefin compounds include CF ₂ =CF ₂ , CF ₂ =CFCl, CF ₂ =CCl ₂ and the like.

Examples of fluorinated vinyl compounds include 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 (where Z represents an integer of 1 to 8, and R represents an alkyl group having 1 to 3 carbon atoms (not substituted with fluorine)) and the like.

As the polymerization method of the above-mentioned precursor polymer, for example, the following methods can be mentioned: a solution polymerization method in which a fluorinated vinyl compound is dissolved in a solvent such as freon, and then reacted with a gas of a fluorinated olefin compound to polymerize; Bulk polymerization using a solvent such as Freon; emulsion polymerization in which a fluorinated vinyl compound is put into water together with a surfactant to emulsify it, and reacts with the gas of a fluorinated olefin compound to polymerize; etc. In any one of the above polymerization methods, the reaction temperature is preferably 30-90° C., and the reaction pressure is preferably 280-1100 kPa.

The melt flow index (hereinafter abbreviated as "MI") of the above-mentioned precursor polymer measured under the conditions of 270°C and a load of 2.16kgf in accordance with JIS K-7210 is not particularly limited, but is preferably 0.001g/10 minutes to 1000g/ 10 minutes, more preferably 0.01 g/10 minutes to 100 g/10 minutes, still more preferably 0.1 g/10 minutes to 10 g/10 minutes. If the MI of the precursor polymer is less than 0.001 g/10 min, processing and molding tends to be difficult, and if it exceeds 1000 g/10 min, the durability of the polymer electrolyte membrane tends to deteriorate when used in a fuel cell.

As a method for molding the precursor polymer into a film, a common melt extrusion molding method (T-die method, inflation method, calendering method, etc.) is used.

A polymer electrolyte membrane is produced by bringing the precursor polymer formed into a film into contact with a reaction liquid to hydrolyze the ion exchange group precursor. At this time, the hydrolysis of the ion-exchange group precursor can be carried out in an aqueous alkali metal hydroxide solution, and in order to further increase the hydrolysis reaction rate, it is preferable to use a relatively high-temperature solution. Such a method includes, for example, the method of hydrolysis treatment at 70 to 90°C for 16 hours using an aqueous solution containing 20 to 25% sodium hydroxide described in JP-A-61-19638.

In addition, in order to swell the membrane and accelerate the hydrolysis reaction rate, it is also possible to use a mixture of an aqueous alkali metal hydroxide solution and an alcoholic solvent such as methanol, ethanol, and propanol; or a water-soluble organic solvent such as dimethyl sulfoxide. method of hydrolysis. As such a method, for example, the method described in JP-A-57-139127, using an aqueous solution containing 11 to 13% of potassium hydroxide and 30% of dimethyl sulfoxide at 90°C for hydrolysis treatment 1 The method of 1 hour; Japanese Patent Application Laid-Open No. 3-6240, using an aqueous solution containing 15 to 50 mass % of alkali metal hydroxide and 0.1 to 30 mass % of water-soluble organic compound at 60 to 130 ° C for 20 minutes to hydrolysis 24-hour approach; etc.

After ion exchange groups are formed by the above-mentioned hydrolysis treatment, a polymer electrolyte membrane can be produced by further acid treatment with a mineral 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 lamination surface to be laminated with the polymer electrolyte membrane. The corona discharge treatment can be performed, for example, with a corona discharge surface treatment device manufactured by Kasuga Electric Co., Ltd. at an output of 1 kW and 50 kHz. The plasma discharge treatment can be performed, for example, using 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.

The polymer electrolyte membrane produced by the above method and the resin support film subjected to corona discharge treatment or plasma discharge treatment are laminated, and in the laminated state, by using known pressing techniques such as hot pressing, roll pressing, and vacuum pressing, etc. or lamination technique to obtain a polymer electrolyte laminated film.

In addition, it is also possible to hydrolyze the above-mentioned small pieces (granules, powder) of the precursor polymer in the same manner as above, dissolve or disperse them in a suitable solvent to prepare a uniform solution dopant, and cast it on the resin support. After coating on the membrane, the solvent is distilled off, dried and/or heat-treated at 100 to 200° C. to form a polymer electrolyte laminated membrane.

The polymer electrolyte laminated membrane is brought into contact with the front end of a cutter (the cutter rotates synchronously with the polymer electrolyte membrane surface of the continuously fed polymer electrolyte laminated membrane) on a flat table or on a rotating backup roll. sequentially making (a) the entire thickness direction of the polymer electrolyte membrane and a part of the laminated surface side in the thickness direction of the resin support membrane at the same plane position to cut out a sheet shape with a predetermined size, or (b) Incisions are made with predetermined dimensions in either longitudinal or transverse directions on the same plane position. The vertical direction here means the conveyance direction of the polymer electrolyte laminated membrane continuously sent, and the horizontal direction means the width direction of the membrane. The sheet shape refers to a state in which notches are cut in both the vertical and horizontal directions. The roll-shaped wound product refers to a state in which notches are cut in both the longitudinal direction and the width direction.

By cutting the incisions as described above, it is possible to obtain a polymer electrolyte laminated film that is laminated without wrinkles and can be easily peeled off. The depth of a part of the incision in the thickness direction of the resin support membrane is preferably 5% or more relative to the total thickness of the resin support membrane from the viewpoint of uniformly cutting the polymer electrolyte membrane, and from the viewpoint of improving handleability relative to The total thickness of the resin support film is preferably 95% or less, more preferably 10 to 80%, even more preferably 15 to 60%. By cutting a slit with a depth of 5 to 95% of the total thickness of the resin support film in the thickness direction of the resin support film, when peeling off the polymer electrolyte membrane, by gently bending the resin support film at the position of the slit, the The polymer electrolyte membrane can be easily peeled off without wrinkles.

(membrane/electrode assembly)

When the polymer electrolyte membrane is used in a solid polymer fuel cell, it is used as a membrane/electrode assembly (membrane/electrode assembly) (hereinafter also referred to as "MEA") is used. 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. In addition, an object in which gas diffusion layers are bonded to the respective outer surfaces of the anode catalyst layer and the cathode catalyst layer is also referred to as an MEA.

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

(Solid Polymer Fuel Cell)

The solid polymer fuel cell in this embodiment can be obtained by connecting the anode and cathode of the above-mentioned MEA to each other through an electron conductive material located outside the polymer electrolyte membrane. A known method can be used as a method for producing a solid polymer fuel cell. The production method of solid polymer fuel cells is described in detail in, for example, FUEL CELL HANDBOOK (VAN NOSTRAND REINHOLD, A.J.APPLEBY et.al, ISBN0-442-31926-6), Chemistry One Point, Fuel Cells (Second Edition), Masao Taniguchi , Edited by Meiwei Xue, Kyoritsu Publishing (1992), etc. The solid polymer fuel cell operates by supplying hydrogen to one electrode (anode) and supplying oxygen or air to the other electrode (cathode).

The polymer electrolyte laminated membrane of this embodiment does not increase defects such as wrinkles of the polymer electrolyte membrane even if it is stored for a long period of time, and can be easily peeled off without wrinkles when peeling off the polymer electrolyte membrane, so it is possible to significantly reduce the production time of the MEA. Failure rate.

In addition, the polymer electrolyte membrane of the polymer electrolyte laminated film in this embodiment can be appropriately peeled off and used in chlor-alkali electrolysis, water electrolysis, hydrohalic acid electrolysis, salt electrolysis, oxygen concentrator, humidity sensor, gas sensor, etc. . For a method of using a polymer electrolyte membrane in an oxygen concentrator, for example, refer to the method described in Chemical Engineering, 56(3), p.178-180(1992), or US Pat. No. 4,879,016. About the method that polymer electrolyte membrane is used for humidity sensor, for example, can refer to Japan Ion Exchange Society Journal, 8 (3), p.154-165 (1997) or J.Fangetal., Macromolecules, 35, 6070 (2002 ) method described in. Regarding the method of using polymer electrolyte membranes for gas sensors, for example, refer to Analytical Chemistry, 50(9), p.585-594(2001), or X.Yang, S.Johnson, J.Shi, T.Holesinger , B. Swanson: The method described in Sens. Actuators B, 45, 887 (1997).

Example

Hereinafter, the present embodiment will be specifically described using examples, but the present embodiment is not limited to the following examples.

Each evaluation method and measurement method in this 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 membrane is measured by the following method: after weighing the polymer electrolyte membrane, immerse it in a saturated sodium chloride aqueous solution at 25°C, stir for 1 hour to carry out ion exchange reaction, and add The phenolphthalein solution was neutralized and titrated with 0.01N sodium hydroxide aqueous solution.

[Example 1]

(Production of Polymer Electrolyte Membrane)

As a _polymer electrolyte _{membrane ,} a _{perfluorosulfonic acid polymer ( hereinafter} referred to as "PFS") composed of electrolyte membranes.

First, a perfluorocarbon polymer (MI: 3.0) of tetrafluoroethylene and CF ₂ =CFO(CF ₂ ) ₂ -SO ₂ F was produced as a precursor polymer of PFS. The precursor polymer was melt-extruded and molded to a thickness of about 50 μm, and the molded film was mixed with a reaction liquid containing 15 mass % potassium hydroxide, 30 mass % dimethyl sulfoxide and 55 mass % water at 60 ° C Contact for 4 hours to carry out hydrolysis treatment. Thereafter, the membrane was immersed in 60° C. water for 4 hours, and then immersed in 60° C. 2N hydrochloric acid aqueous solution for 3 hours, and the acid was washed away with ion-exchanged water to obtain a polymer electrolyte membrane.

The obtained polymer electrolyte membrane had a proton exchange capacity of 1.22 meq/g and a membrane thickness of 50 μm.

(Production of resin support film)

As the resin support film, a film made of polyethylene terephthalate subjected to corona discharge treatment as follows was used.

As the polyethylene terephthalate film, Teijin ^™ Tetoron film (hereinafter referred to as PET film) manufactured by Teijin DuPont Film Co., Ltd. having a thickness of 75 μm was used.

Corona discharge treatment was performed on the side of the laminated surface of the PET film laminated with the polymer electrolyte membrane at an output of 1 kW and 50 kHz using a corona discharge surface treatment system manufactured by Kasuga Denki Co., Ltd. The wetting tension of the surface of the obtained resin support film was 58 mN/m.

(Manufacture of Polymer Electrolyte Laminated Membrane)

Next, the above-mentioned polymer electrolyte membrane of 10 cm square and the PET film subjected to the above-mentioned corona discharge treatment were laminated, and both sides were sandwiched between Kapton films (300H, film thickness 75 μm). This was set in a compression molding machine (manufactured by Kindo Kogyo Co., Ltd., VSF-10), heated to 100° C., and then pressed at 10 kgf/cm ² for 10 minutes. After the pressing was terminated, the pressure was released, and after the temperature was lowered to 30°C, the sample A was taken out.

This laminated film (sample A) was placed in a constant temperature and humidity chamber, and a dry-wet cycle test was performed repeating 3 hours at 30° C. 95% RH and 3 hours at 10° C. 30% RH. After 400 cycles, the laminated film was taken out. As a result, the polymer electrolyte film was not peeled off from the corona-discharge-treated PET film.

For the above pressed sample A, in the state where the polymer electrolyte membrane faces upward, a ceramic blade is pressed from above the polymer electrolyte laminated film on a flat platform, and at this time, the gap between the knife tip and the flat platform is set to 50 μm, for the entire polymer electrolyte membrane in the thickness direction and about 1/3 of the resin support membrane in the thickness direction (about 25 μm from the lamination surface side), cut out multiple paper sheets at the same position in the plane direction , thereby obtaining the polymer electrolyte laminated membrane of the present embodiment.

In addition, for the sample A after the above-mentioned pressing, with the polymer electrolyte membrane facing up, the tip of the cutter that rotates synchronously with the surface of the polymer electrolyte membrane was placed on the rotating support roll with the polymer electrolyte laminated membrane that was continuously fed. Contact, at this time, set the gap between the tip of the knife and the back-up roll to 50 μm, for the entire thickness direction of the polymer electrolyte membrane and about 1/3 of the thickness direction of the resin support membrane (about 25 μm from the lamination surface side), on the plane The polymer electrolyte laminated membrane of the present embodiment is obtained by sequentially cutting incisions at the same position in the direction according to the shape of a plurality of paper sheets.

When the polymer electrolyte membrane cut into a sheet shape was peeled from the obtained polymer electrolyte laminated membrane by hand from the end, it was easily peeled without wrinkling. In addition, it has moderate adhesiveness, and no spontaneous peeling occurs when the polymer electrolyte laminated film is handled.

In addition, the storage stability is also good, and the predetermined cut size does not appear after being stored in a constant temperature and humidity room at 25°C and 50%RH for 3 months in the form of lamination in a flat form with a certain size or in the form of a roll. The sheet-shaped polymer electrolyte membrane peels off, the membranes are dislocated, or wrinkles are generated. In addition, there was no case where the polymer electrolyte membrane peeled off and stuck to the back of the PET film.

[Comparative example 1]

A polymer electrolyte laminated film was obtained in the same manner as in Example 1 except that a PET film not subjected to corona discharge treatment was used. The polymer electrolyte laminated film was subjected to a dry-wet cycle test in the same manner as in Example 1, and as a result, the polymer electrolyte film was peeled off from the PET film. In addition, the polymer electrolyte laminated film was stored in the same manner as in Example 1 or stored in the form of a roll. As a result, the polymer electrolyte membrane was partially peeled off and adhered to the back of the PET film.

[Comparative example 2]

A polymer electrolyte laminated membrane was obtained in the same manner as in Example 1, except that no incisions were made in the polymer electrolyte membrane and the resin support membrane. The polymer electrolyte laminated membrane was cut into a sheet shape in the thickness direction of the polymer electrolyte membrane and the resin support membrane as a whole, and the polymer electrolyte laminated membrane was peeled from the end by hand in the same manner as in Example 1. When the polymer electrolyte membrane was cut into a sheet shape, wrinkles were generated as a result.

Industrial Applicability

The polymer electrolyte laminated membrane of the present invention does not increase defects such as wrinkles of the polymer electrolyte membrane even after long-term storage, and has no wrinkles when peeled off, and can be easily peeled off when necessary, so it is possible to greatly reduce the inconvenience of manufacturing MEA. Pass rate.

Claims (4)

1. a polyelectrolyte layers integrated membrane, it is the polyelectrolyte layers integrated membrane with resin support membrane and polyelectrolyte membrane, wherein,

Be that the resin support membrane of 5 μm ~ 500 μm is laminated with the polyelectrolyte membrane that thickness is 1 μm ~ 500 μm at thickness, described resin support membrane at least implements Corona discharge Treatment or plasma discharge process in the side, lamination face with described polyelectrolyte membrane lamination

The part of the overall and side, lamination face on the thickness direction of described resin support membrane of the thickness direction of described polyelectrolyte membrane in identical plan position approach according to page shape otch, or along vertical or horizontal either direction otch on identical plan position approach

Described page shape is the surrounding of the in-plane of cutting polyelectrolyte layers integrated membrane, thus can process the shape of polyelectrolyte membrane one by one.

2. polyelectrolyte layers integrated membrane as claimed in claim 1, wherein, the degree of depth of a part of otch on the thickness direction of described resin support membrane is 5% ~ 95% relative to the thickness of resin support membrane entirety.

3. polyelectrolyte layers integrated membrane as claimed in claim 1 or 2, wherein, described polyelectrolyte membrane comprises and has sulfonic fluorine system polyelectrolyte.

4. a manufacture method, it is the manufacture method of the polyelectrolyte layers integrated membrane with resin support membrane and polyelectrolyte membrane, and this manufacture method comprises following operation:

(1) operation of Corona discharge Treatment or plasma discharge process is implemented to described resin support membrane with the side, lamination face of described polyelectrolyte membrane lamination;

(2) polyelectrolyte membrane described in lamination on the resin support membrane implementing described Corona discharge Treatment or plasma discharge process, obtains the operation of laminated film;

(3) for described laminated film, the thickness direction of and described resin support membrane overall at the thickness direction of described polyelectrolyte membrane cuts out the operation of otch with a part for the side, lamination face of described polyelectrolyte membrane lamination.