JP2009140920A - Polymer electrolyte membrane laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer electrolyte membrane laminate which is a laminate of an adhesion film and polymer electrolyte membrane, and in which even if receiving the shock at the time of transportation, the environmental change at the time of storing or the like, the configuration is stable, when the adhesion film is peeled, the peeling of the adhesion film is easy, and there is little smearing to the electrolyte membrane of the adhesive. <P>SOLUTION: The polymer electrolyte membrane laminate is configured by bonding an adhesion polymer film that is configured by laminating, on a substrate layer, an adhesion layer consisting of a polymer of the same kind of the substrate layer and having crystallinity lower than that of the substrate layer on at least one side of a polymer electrolyte membrane through the adhesion layer, wherein the peel strength of the adhesion polymer film and the polymer electrolyte membrane is 0.1-2.5 N/20 mm width. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a laminate of a polymer electrolyte membrane and a pressure-sensitive adhesive polymer film, which is less susceptible to wrinkles, irregularities, peeling, etc. during transportation or storage, and has excellent shape stability. The present invention relates to a polymer electrolyte membrane laminate having excellent peelability with little transfer of an adhesive to a polymer electrolyte membrane when peeled as necessary.

  In recent years, new power generation technologies with excellent energy efficiency and environmental friendliness have attracted attention. Above all, polymer electrolyte fuel cells using polymer electrolyte membranes have high energy density, and because they have features such as being easy to start and stop because of lower operating temperatures than other types of fuel cells. Developments as power supply devices for electric vehicles and distributed power generation are advancing.

  As the polymer solid electrolyte membrane, a proton conductive ion exchange membrane is usually used. In addition to proton conductivity, the polymer solid electrolyte membrane must have characteristics such as fuel permeation deterrence and mechanical strength that prevent permeation of hydrogen and the like of the fuel. It has been found that wrinkles and irregularities of the electrolyte membrane influence the factors governing these characteristics.

  Conventionally, a method of sandwiching an electrolyte membrane between a cover sheet and a film is known as a means for preventing the occurrence of wrinkles and unevenness of the electrolyte membrane during transportation and storage, but in this method, moisture absorption, temperature, etc. There is a problem that wrinkles, irregularities, curls, and the like, which are mainly caused by changes in the dimensions of the electrolyte membrane due to environmental changes, cannot be sufficiently suppressed.

  In Patent Document 1, in the production of a fuel cell electrode structure in which an electrode catalyst layer is formed on a solid polymer electrolyte membrane, a solid polymer electrolyte membrane is placed and fixed on an adhesive sheet, and a solvent contained in a paste Although there has been reported a method for preventing the generation of wrinkles due to swelling due to swell, there is no description about transport of the polymer electrolyte membrane, stabilization of the shape during storage, and reduction of the transfer of the adhesive to the electrolyte membrane.

JP 2006-339062 A

  The present invention has been made against the background of such prior art problems. That is, the object of the present invention is not only to facilitate the lamination of the adhesive film and the polymer electrolyte membrane, and the laminated body of the obtained adhesive film and the polymer electrolyte membrane can not only stabilize the form during transportation and storage. When a pressure-sensitive adhesive film is no longer required, the pressure-sensitive adhesive film can be easily peeled off and the surface of the polymer electrolyte membrane is less contaminated. Is to provide.

As a result of intensive studies, the present inventors have found that the above problems can be solved by the following means, and have reached the present invention.
That is, this invention consists of the following structures.
[1] An adhesive polymer film in which an adhesive layer having the same type of polymer as the base material layer and having lower crystallinity than the base material layer is laminated on the base material layer is at least a polymer electrolyte membrane via the adhesive layer The peel strength between the adhesive polymer film and the polymer electrolyte membrane (23 ° C., 5 °
0% RH) is 0.1 to 2.5 N / 20 mm width, and a polymer electrolyte membrane laminate.
[2] The polymer electrolyte membrane laminate according to [1], wherein the pressure-sensitive adhesive polymer film is formed by laminating a base material layer and a pressure-sensitive adhesive layer by melt coextrusion.
[3] The polymer electrolyte membrane laminate according to [1] or [2], wherein the adhesive polymer film is obtained by laminating a release layer on a base material layer opposite to the adhesive layer by melt coextrusion.
[4] The polymer electrolyte membrane laminate according to any one of [1] to [3], wherein the adhesive polymer film is made of a polyolefin resin.
[5] The polymer electrolyte membrane according to any one of [1] to [4], wherein the base material layer is crystalline polypropylene, and the adhesive layer is a layer containing amorphous polypropylene or amorphous polypropylene and crystalline polypropylene. Laminated body.
[6] The polymer electrolyte membrane laminate according to any one of [1] to [5], wherein the dynamic hardness of the adhesive layer surface of the adhesive polymer film is 0.15 gf / μm ² or more and 1.4 gf / μm ² or less. body.
[7] The pressure-sensitive adhesive polymer film is a biaxially stretched film, and the thickness variation rate in the lateral direction, which is a direction orthogonal to the winding direction during film production, is 2.0% to 7.5%. The polymer electrolyte membrane laminate according to any one of [1] to [6].
[8] The polymer electrolyte membrane laminate according to any one of [1] to [7], wherein the adhesive polymer film is bonded and wound in a roll state with the polymer electrolyte membrane surface side inside.
[9] The polymer electrolyte membrane according to any one of [1] to [8], wherein the polymer electrolyte membrane is a non-fluorine polymer electrolyte membrane having a tensile modulus of elasticity of 1 GPa or more (based on JIS-K7127). Laminated body.

The polymer electrolyte membrane laminate in which the specific adhesive film according to the present invention is laminated not only can suppress the occurrence of wrinkles, irregularities, peeling, etc. during transportation and storage, and can stabilize the form of the polymer electrolyte membrane. When the pressure-sensitive adhesive film is no longer needed and peeled, the pressure-sensitive adhesive film can be easily peeled off, and the transfer from the pressure-sensitive adhesive layer to the electrolyte membrane can be reduced.
In particular, when the adhesive film is a coextruded film in which the base material layer and the adhesive layer are melt extrusion laminated by a coextrusion method, the adhesion between the base material layer and the adhesive layer is particularly strong, and the adhesive layer is specified. With this hardness, contamination of the polymer electrolyte thin film by the adhesive layer can be suppressed to such a level that it can only be detected by surface analysis using an ESCA analyzer.

Hereinafter, embodiments of the polymer electrolyte membrane laminate of the present invention will be described.
The pressure-sensitive adhesive film used in the present invention is a pressure-sensitive adhesive polymer film in which a pressure-sensitive adhesive layer having the same kind of polymer as the base material layer and having lower crystallinity than the base material layer is laminated on the base material layer.
Examples of the polymer constituting the base layer of the adhesive polymer film include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, polyamides such as nylon 6 and nylon 66, and the like. However, it is not limited to these.
The polymer that constitutes the adhesive layer is the same type of polymer as the base material layer, and has a lower crystallinity than the base material layer or an amorphous polymer, and inhibits the crystallinity of the homopolymer in addition to the above homopolymer components. This is a polymer in which the third and fourth components are copolymerized to reduce crystallinity or become amorphous. These polymers may be used singly or mixed, have lower crystallinity than the base material layer and can exhibit adhesiveness.

For example, in the case of a polypropylene resin, examples of the base material layer include crystalline polypropylene, a random copolymer block copolymer of propylene and a small amount of α-olefin, and the like. Examples of the polypropylene resin include an n-heptane-insoluble isotactic propylene homopolymer used in ordinary extrusion molding or the like, or a copolymer of polypropylene and other α-olefins containing 60% by mass or more of propylene. These propylene homopolymers or copolymers of propylene and other α-olefins can be used alone or in admixture.
Here, n-heptane insolubility is indicative of polypropylene crystallinity and at the same time indicates safety. In the present invention, n-heptane insolubility (at 25 ° C., 60 ° C. according to Ministry of Health and Welfare Notification No. 20 in February 1982). It is a preferred embodiment to use one that is compatible with an elution amount of 150 pPm or less (if the operating temperature exceeds 100 ° C., 30 PPm or less) at the time of partial extraction.

As the α-olefin copolymerization component of the copolymer of propylene and other α-olefin, α-olefin having 2 to 8 carbon atoms such as ethylene, 1-butene, 1-pentene, 1-hexene, 4 C4 or higher α-olefins such as -methyl-1-pentene are preferred.
Here, the copolymer is preferably a random or block copolymer obtained by polymerizing one or more α-olefins exemplified above with propylene.
In addition, two or more kinds of copolymers of propylene and other α-olefins can be mixed and used.

The pressure-sensitive adhesive layer of the pressure-sensitive adhesive film needs to be the same kind of polymer as the base material layer and have lower crystallinity or amorphousness than the base material layer.
In the case of a polypropylene resin, the same type is an olefin polymer having one or more types of α-olefin having 2 to 8 carbon atoms as a constituent component. In differential scanning calorimetry, It is preferable to use a polymer having a heat of conversion of 10 J / g or less.

Further, the adhesive layer, the dynamic hardness of the adhesive layer surface is preferably at 0.15gf / μm ² or more 1.4gf / μm ² or less.
Here, as described in Shimadzu review, 50, 3, 321 (1993), the dynamic hardness represents the hardness in the ultrafine region. In this process, the indentation depth and pressure, and the deformation resistance of the sample are measured continuously to obtain the hardness. It is expressed by 1).
DH = αP / D * D (1)
DH: Dynamic hardness α: Constant depending on indenter shape,
P: test load, D: indentation depth (μm)
This dynamic hardness is a hardness obtained from a load and an indentation depth in the process of indenting the indenter, and is a characteristic value in a state where the plastic deformation and elastic deformation of the sample are combined.

The dynamic hardness is the hardness of the film surface, indicating the hardness at a certain depth from the outermost surface of the film, and the hardness at a part having a depth of 1 μm was used as an index.
In the adhesive layer, the more preferable dynamic hardness of the adhesive layer surface is 0.20 gf / μm ² or more and 1.2 gf / μm ² or less, more preferably 0.25 gf / μm ² or more and 1.0 gf / μm ² or less. is there.
When the dynamic hardness of the pressure-sensitive adhesive layer surface is less than 0.15 gf / μm ² , the surface is soft and easily deformed. Therefore, after being bonded to the adherend, it is easily affected by the surface state of the adherend. When the surface of the adherend is smooth, the surface of the adhesive layer is deformed in accordance with the smoothness, and the fine irregularities formed on the surface of the adhesive layer gradually disappear with time. The contact area will increase, the adhesive force will be higher than the set value, and it may be difficult to peel off, or adhesive residue may occur. Moreover, when the dynamic hardness of the adhesive layer surface exceeds 1.4 gf / μm ² , the adhesive force may be too low.

In order to make the dynamic hardness within the above range, it is preferable to use an amorphous polymer having a crystal melting heat quantity and a crystallization heat quantity of 10 J / g or less singly or in a mixture of 30 mass% or more in differential scanning calorimetry.
Examples of the amorphous polymer include “Tough Selenium H3522A” manufactured by Sumitomo Chemical Co., Ltd., “Notio TX1236A” manufactured by Mitsui Chemicals, Inc., and the like. The olefin polymer mixed with the amorphous polymer is not particularly limited, but an ethylene-propylene copolymer, an ethylene-1-butene copolymer, an ethylene-1-hexene copolymer. , Ethylene-1-octene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-propylene-1-butene copolymer, ethylene-propylene-1-hexene copolymer, ethylene-1-butene -1-hexene copolymer, propylene-1-butene copolymer, propylene-1-hexene copolymer, propylene-1-octene copolymer, propylene-4-methyl-1-pentene copolymer, propylene- Examples thereof include 1-butene-1-hexene copolymer and propylene-1-butene-4-methyl-1-pentene copolymer.
Further, the melt flow rate of these polymers is preferably in the range of 1 to 10 g / 10 min, and more preferably in the range of 2 to 5 g / 10 min.

  The pressure-sensitive adhesive film used in the present invention preferably has a thickness variation rate in the lateral direction, which is a direction perpendicular to the winding direction during film production, in the range of 2.0% to 7.5%. Preferably, it is 7.0% or less, more preferably 6.5% or less. When the thickness variation rate exceeds 7.5%, when pressure-sensitive adhesive film is stuck on the adherend, pressure unevenness occurs depending on the location, causing a decrease in adhesive strength. It can be said that it is practically difficult to keep the ratio below 2.0%.

  The adhesive film used in the present invention preferably has a tensile elastic modulus of 1.0 to 4.0 GPa. If the tensile modulus is less than 1 GPa, wrinkles are likely to occur. Since the tensile elastic modulus of the electrolyte membrane that is normally laminated is 1.0 to 2.0 GPa, wrinkles are unlikely to enter the laminated layer within this range. In addition, when the tensile elastic modulus of the electrolyte membrane is less than 1 GPa, the polymer electrolyte membrane is too soft and wrinkles easily occur.

The pressure-sensitive adhesive film used in the present invention can contain known additives as required, or can be coated on the film surface. For example, a lubricant, an antiblocking agent, a heat stabilizer, an antioxidant, an antistatic agent, a light resistance agent, an impact resistance improvement agent, or the like may be contained, or the surface may be coated. However, the low molecular weight substance on the surface of the pressure-sensitive adhesive layer is preferably less than 1 mg / m ² in order to obtain the desired pressure-sensitive adhesive force. Here, the measurement of the low molecular weight substance on the surface of the adhesive layer was carried out by the following procedure. After the surface of the adhesive layer is washed with an organic solvent that does not erode the resin constituting the adhesive layer such as ethanol, the organic solvent is removed from the cleaning solution with an evaporator, and the residue obtained by weighing the residue is washed. It was obtained by dividing by the surface area of the layer surface. Here, if the residue is present in an amount of 1 mg / m ² or more, there will be foreign matter between the surface of the adhesive layer and the adherend surface, which will reduce the contact area and reduce the van der Waals force. Is not preferable. In the case of adding an additive, it is necessary to select an additive such as a polymer type or to examine an addition method so that there is no transfer or transfer to the adhesive layer.

The production method of the pressure-sensitive adhesive film used in the present invention is not particularly limited, but after forming the base material layer and the pressure-sensitive adhesive layer using an inflation film production apparatus or a T-die film production apparatus, they are bonded together by an extrusion laminating method. Alternatively, a multilayer film may be formed from the beginning by coextrusion.
In order to reduce the thickness variation rate, it is preferable to perform monoaxial stretching or biaxial stretching after forming a multilayer film by a coextrusion method. By making the stretched film, the crystal orientation of the base material layer and the adhesive layer resin occurs as compared with the unstretched film, so that the thickness variation rate can be made a suitable range by improving the planarity, As for the dynamic hardness, an appropriate hardness can be obtained, so that a suitable pressure-sensitive adhesive film having no change with time can be obtained.
In order to obtain the dynamic hardness of the adhesive layer surface, it is desirable to provide an appropriate temperature within the range where the film does not melt in the preheating and stretching temperature in the stretching process. Depending on the orientation, the hardness of the film surface may increase and the adhesive strength may be reduced, and if the temperature is too high, the crystal part of the adhesive layer will melt and become amorphous, increasing the amorphous part. May decrease, and the change in adhesive strength over time may increase.

The pressure-sensitive adhesive film used in the present invention may form a release layer on the opposite surface of the pressure-sensitive adhesive layer. For example, a layer made of a silicone resin or a fluororesin, a resin made of a propylene ethylene block copolymer, and a polyethylene resin are mixed. By doing so, a layer having a rough surface can be laminated in a mat shape. Specific examples of the resin suitable for obtaining a mat-like surface include propylene-ethylene block copolymers such as “PC523D” and “PC523A” manufactured by Sun Allomer Co., Ltd.
In this case, it is preferable that the surface has an average surface roughness SRa of 0.20 μm to 0.40 μm when formed into a film. When the average surface roughness SRa is less than 0.20 μm, the films are likely to block each other. When the average surface roughness SRa exceeds 0.40 μm, excessive irregularities are formed, which is not preferable as a film.
In order to obtain an average roughness SRa of 0.40 μm or less, it is preferable not to make the longitudinal stretching preheating temperature during stretching too low, and when the preheating temperature during stretching is made low, the propylene ethylene block copolymer and the polyethylene resin Since the unevenness | corrugation formed using incompatibility will be formed excessively, it is unpreferable. An example of a preheating temperature during preferred longitudinal stretching is 100 ° C. or more. At this time, it is preferable that the surface roughness of the release layer is such that the average roughness SRa is 0.30 μm or less.

  The polymer electrolyte membrane used in the present invention can have any film thickness depending on the purpose, but is preferably as thin as possible from the viewpoint of proton conductivity. Specifically, it is preferably 3 to 200 μm, more preferably 5 to 150 μm, and particularly preferably 5 to 100 μm. If the thickness of the polymer electrolyte membrane is less than 3 μm, handling of the polymer electrolyte membrane becomes difficult and a short circuit or the like tends to occur when a fuel cell is produced. If the thickness is greater than 200 μm, the polymer electrolyte membrane becomes too strong and handling Tend to be difficult.

As the polymer for forming the polymer electrolyte membrane in the present invention, a known polymer electrolyte can be used.
For example, as an aromatic hydrocarbon-based polymer containing an ionic group, an aromatic or aromatic ring and ether bond, sulfone bond, imide bond, ester bond, amide bond, urethane bond, sulfide bond, carbonate bond and Non-fluorine ion conductive polymer having a structure having at least one linking group selected from ketone bonds, such as polysulfone, polyethersulfone, polyphenylene oxide, polyphenylene sulfide, polyphenylene sulfide sulfone, polyparaphenylene , Polyarylene-based polymer, polyphenylquinoxaline, polyaryl ketone, polyether ketone, polybenzoxazole, polybenzthiazole, polybenzimidazole, polyimide, etc. A polymer containing a sulfonic acid group, a phosphonic acid group, a carboxyl group, and at least one of those derivatives is a polymer which has been introduced.
In addition, the ionic conductivity of a polymer is expressed by including functional groups, such as a sulfonic acid group, a phosphonic acid group, and a carboxyl group, in a polymer. Among these, a functional group that acts particularly effectively is a sulfonic acid group. Polysulfone, polyethersulfone, polyetherketone, etc. as used herein are generic names for polymers having a sulfone bond, an ether bond, and a ketone bond in their molecular chains. Polyetherketoneketone, polyetheretherketone, It includes polyether ether ketone ketone, polyether ketone ether ketone ketone, polyether ketone sulfone and the like, and is not limited to a specific polymer structure.

  Among the polymers containing the functional group, a polymer having a sulfonic acid group on the aromatic ring can be obtained by reacting a polymer having a skeleton as in the above example with an appropriate sulfonating agent. Examples of such sulfonating agents include those using concentrated sulfuric acid or fuming sulfuric acid that have been reported as examples of introducing sulfonic acid groups into aromatic hydrocarbon polymers (for example, Solid State Ionics, 106, P.219 (1998)), those using chlorosulfuric acid (for example, J. Polym. Sci., Polym. Chem., 22, P.295 (1984)), those using anhydrous sulfuric acid complex (for example, J Polym. Sci., Polym. Chem., 22, P. 721 (1984), J. Polym. Sci., Polym. Chem., 23, P. 1231 (1985)) and the like are effective. In order to obtain the ionic group-containing polymer of the present invention, in particular, a polymer whose ion conductivity is a sulfonic acid group, it can be carried out by using these reagents and selecting reaction conditions according to each polymer. . Moreover, it is also possible to use the sulfonating agent described in Japanese Patent No. 2884189.

  The aromatic hydrocarbon ionic group-containing polymer can also be synthesized using a monomer containing an acidic group in at least one of the monomers used for polymerization. For example, in a polyimide synthesized from an aromatic diamine and an aromatic tetracarboxylic dianhydride, an acidic group-containing polyimide is obtained by using a diamine containing a sulfonic acid group or a phosphonic acid group as at least one of the aromatic diamines. I can do it. Polybenzoxazole synthesized from aromatic diamine diol and aromatic dicarboxylic acid, polybenzthiazole synthesized from aromatic diamine dithiol and aromatic dicarboxylic acid, polybenzimidazole synthesized from aromatic tetramine and aromatic dicarboxylic acid In this case, an acid group-containing polybenzoxazole, polybenzthiazole, or polybenzimidazole can be obtained by using a sulfonic acid group-containing dicarboxylic acid or a phosphonic acid group-containing dicarboxylic acid as at least one kind of aromatic dicarboxylic acid. Polysulfone, polyethersulfone, polyetherketone, etc. synthesized from aromatic dihalide and aromatic diol are synthesized by using sulfonic acid group-containing aromatic dihalide or sulfonic acid group-containing aromatic diol as at least one monomer. I can do it. At this time, it is preferable to use a sulfonic acid group-containing dihalide rather than a sulfonic acid group-containing diol because the degree of polymerization tends to be high and the thermal stability of the obtained acidic group-containing polymer is high.

  Aromatic hydrocarbon ionic group-containing polymers are polyarylene ether compounds such as sulfonic acid group-containing polysulfone, polyethersulfone, polyphenylene oxide, polyphenylene sulfide, polyphenylene sulfide sulfone, polyether ketone polymer, and polyarylene compounds. More preferably.

  Among the aromatic hydrocarbon-based ionic group-containing polymers, those having a repeating unit represented by the general formula 1 are particularly preferable.

［一般式１において、Ｘは−Ｓ（＝Ｏ）_２−基又は−Ｃ（＝Ｏ）−基を、ＹはＨ又は１価の陽イオンを、Ｚ^１はＯ又はＳ原子のいずれかを、Ｚ^２は、Ｏ原子、Ｓ原子、−Ｃ（ＣＨ_３）_２−基、−Ｃ（ＣＦ_３）_２−基、−ＣＨ_２−基、シクロヘキシル基、直接結合のいずれかを、ｎ１は１以上の整数を表す。］

[In General Formula 1, X represents a —S (═O) ₂ — group or —C (═O) — group, Y represents H or a monovalent cation, and Z ¹ represents either an O or S atom. , Z ² represents an O atom, an S atom, a —C (CH ₃ ) ₂ — group, a —C (CF ₃ ) ₂ — group, a —CH ₂ — group, a cyclohexyl group, or a direct bond; It represents the above integer. ]

In the general formula 1, it is preferable that X is a —S (═O) ₂ — group because solubility in a solvent is improved. It is preferable that X is a —C (═O) — group because the softening temperature of the polymer can be lowered to further enhance the bonding property with the electrode, or the photocrosslinking property can be imparted to the electrolyte membrane. When used as a polymer electrolyte membrane, Y is preferably an H atom. However, if Y is an H atom, it is easily decomposed by heat or the like. Therefore, during processing such as manufacturing of an electrolyte membrane, Y is set as an alkali metal salt such as Na or K, and Y is converted to H atom by acid treatment after processing. A polymer electrolyte membrane can also be obtained by conversion. Z ¹ is preferably an O atom because there are advantages such as less polymer coloring and easy availability of raw materials. Z ¹ is preferably S because oxidation resistance is improved. n1 is preferably in the range of 1 to 30, and when n1 is 3 or more, a plurality of units having different n1 may be included. Z ² represents an O atom, an S atom, a —C (CH ₃ ) ₂ — group, a —C (CF ₃ ) ₂ — group, a —CH ₂ — group, a cyclohexyl group, a direct bond, It is preferable because the bondability is further improved. If Z ² is a direct bond are preferred for dimensional stability of the resulting polymer electrolyte membrane is improved. n1 When in the case of 3 or more is Z ² is O atom, preferably in particular for improving bondability between the electrode catalyst layer in the case of the polymer electrolyte membrane.

  It is preferable that the ionic group-containing polymer having a repeating unit represented by the general formula 1 further contains a repeating unit represented by the general formula 2.

［一般式２において、Ａｒ^１は二価の芳香族基を、Ｚ^３はＯ原子又はＳ原子のいずれかを、Ｚ^４は、Ｏ原子、Ｓ原子、−Ｃ（ＣＨ_３）_２−基、−Ｃ（ＣＦ_３）_２−基、−ＣＨ_２−基、シクロヘキシル基、直接結合のいずれかを、ｎ２は１以上の整数を表す。］

[In General Formula 2, Ar ¹ represents a divalent aromatic group, Z ³ represents either an O atom or an S atom, Z ⁴ represents an O atom, an S atom, a —C (CH ₃ ) ₂ — group, -C _{(CF 3) 2} - group, -CH ₂ - group, a cyclohexyl group, either a direct bond, n2 is an integer of 1 or more. ]

In the general formula 2, it is preferable that Z ³ is an O atom because there are advantages such as little coloring of the polymer and easy availability of raw materials. Z ³ is preferably an S atom since the oxidation resistance is improved. n2 is preferably in the range of 1 to 30, and when n2 is 3 or more, a plurality of units different in n2 may be included. Z ⁴ represents an O atom, an S atom, a —C (CH ₃ ) ₂ — group, a —C (CF ₃ ) ₂ — group, a —CH ₂ — group, a cyclohexyl group, a direct bond, and an O atom or an S atom. It is preferable because the bondability is further improved. Z ⁴ is preferably a direct bond because the dimensional stability of the resulting polymer electrolyte membrane is improved. n2 When the case 3 or more is Z ⁴ is O atom, preferably in particular for improving bondability between the electrode catalyst layer in the case of the polymer electrolyte membrane.

  When the ionic group-containing polymer constituting the polymer electrolyte membrane in the present invention is mainly composed of a repeating unit represented by the general formula 1 and a repeating unit represented by the general formula 2, The ratio is preferably in the range of 7:93 to 70:30. The molar ratio of 7:93 means that when the number of moles of the repeating unit represented by the general formula 1 is 7, the number of moles of the repeating unit represented by the general formula 2 is 93. When the number of repeating units represented by the general formula 1 is larger than the molar ratio of 70:30, the fuel permeability when used as a polymer electrolyte membrane may increase, which is not preferable. When the number of repeating units represented by the general formula 1 is less than the molar ratio of 7:93, it is not preferable because proton conductivity in a polymer electrolyte membrane is lowered and resistance is increased. The range of 10:90 to 50:50 is more preferable. More preferably, it is in the range of 10:90 to 40:60. The ionic group-containing polymer in the present invention has an appropriate softening temperature by having the repeating unit represented by the general formula 1 and the general formula 2, and has good bondability with an electrode when a polymer electrolyte membrane is formed. Indicates.

Ar ¹ in the general formula 2 is preferably a divalent aromatic group having an electron-withdrawing group. Examples of the electron-withdrawing group include a sulfone group, a sulfonyl group, a sulfonic acid group, a sulfonic acid ester group, a sulfonic acid amide group, a sulfonic acid imide group, a carboxyl group, a carbonyl group, a carboxylic acid ester group, a cyano group, a halogen group, Although a trifluoromethyl group, a nitro group, etc. can be mentioned, it is not limited to these, What is necessary is just a well-known arbitrary electron withdrawing group.

A preferred structure of Ar ¹ is a structure represented by Chemical Formulas 3-6. The structure of Chemical Formula 3 is preferable because it can increase the solubility of the polymer. The structure of Chemical Formula 4 is preferable because it lowers the softening temperature of the polymer to increase the bonding property with the electrode and impart photocrosslinking properties. The structure of Chemical Formula 5 or 6 is preferable because the swelling of the polymer can be reduced, and the structure of Chemical Formula 6 is more preferable. Among the chemical formulas 3 to 6, the structure of the chemical formula 6 is most preferable.

One of the more preferable embodiments of the ionic group-containing polymer constituting the polymer electrolyte membrane in the present invention is that the polymer electrolyte membrane mainly has a structure represented by the general formula 1 and a structure represented by the general formula 2. It is an ionic group-containing polymer that is constituted and that both Z ¹ and Z ² in general formula 1 are O atoms, and n1 is 3 or more. It is preferable to use such an ionic group-containing polymer because the bondability with the electrode is particularly improved.

One of the more preferable embodiments of the ionic group-containing polymer is more preferably that in Formula 2, Z ³ and Z ⁴ are both O atoms, and n2 is 3 or more. It is preferable to use such an ionic group-containing polymer because the bondability with the electrode is further improved.

  One of the more preferable embodiments of the ionic group-containing polymer constituting the polymer electrolyte membrane in the present invention includes an ionic group having a repeating unit represented by the general formula 7 in addition to the general formula 1 and the general formula 2. It is a polymer. In addition to the repeating units represented by the general formula 1 and the general formula 2, further having the repeating unit represented by the general formula 7 enhances the morphological stability of the membrane when the polymer electrolyte membrane is obtained. Is preferable.

［一般式７において、Ｘは−Ｓ（＝Ｏ）_２−基又は−Ｃ（＝Ｏ）−基を、ＹはＨ又は１価の陽イオンを、Ｚ^５はＯ又はＳ原子のいずれかを表す。］

[In General Formula 7, X represents a —S (═O) ₂ — group or —C (═O) — group, Y represents H or a monovalent cation, and Z ⁵ represents either an O or S atom. To express. ]

In General Formula 7, X is preferably a —S (═O) ₂ — group because solubility in a solvent is improved. It is preferable that X is a —C (═O) — group because the softening temperature of the polymer can be lowered to further enhance the bonding property with the electrode, or the photocrosslinking property can be imparted to the electrolyte membrane. When used as a polymer electrolyte membrane, Y is preferably an H atom. However, if Y is an H atom, it is easily decomposed by heat or the like. Therefore, during processing such as manufacturing of an electrolyte membrane, Y is set as an alkali metal salt such as Na or K, and Y is converted to H atom by acid treatment after processing. A polymer electrolyte membrane can also be obtained by conversion. Z ⁵ is preferably an O atom because it has advantages such as less coloring of the polymer and easy availability of raw materials. Z ⁵ is preferably S because oxidation resistance is improved.

When the ionic group-containing polymer constituting the polymer electrolyte membrane in the present invention has repeating units represented by the general formulas 1, 2, and 7, Z ¹ and Z ² are O atoms or S atoms and n1 of 1 are preferable because the polymer electrolyte membrane has better adhesion to the electrode catalyst layer and better membrane stability. Further, when Z ³ and Z ⁴ are O atoms or S atoms and n2 is 1, the bondability with the electrode catalyst layer in the case of a polymer electrolyte membrane and the morphological stability of the membrane are further increased. Since it becomes favorable, it is preferable.

  The ionic group-containing polymer constituting the polymer electrolyte membrane in the present invention further has a repeating unit represented by the general formula 8 in addition to the repeating units represented by the general formulas 1, 2, and 7. When a polymer electrolyte membrane is used, it is more preferable because the bondability with the electrode catalyst layer and the morphological stability of the membrane can be greatly improved.

［一般式８において、Ａｒ^２は２価の芳香族基を、Ｚ^６はＯ原子又はＳ原子のいずれかを表す。］

[In General Formula 8, Ar ² represents a divalent aromatic group, and Z ⁶ represents either an O atom or an S atom. ]

Z ⁶ in the general formula 8 is preferably an O atom because there are advantages such as little polymer coloring and easy availability of raw materials. Z ⁶ is preferably an S atom because the oxidation resistance is improved. Ar ² in Chemical Formula 8 is preferably a divalent aromatic group having an electron-withdrawing group. Examples of the electron-withdrawing group include a sulfone group, a sulfonyl group, a sulfonic acid group, a sulfonic acid ester group, a sulfonic acid amide group, a sulfonic acid imide group, a carboxyl group, a carbonyl group, a carboxylic acid ester group, a cyano group, a halogen group, Although a trifluoromethyl group, a nitro group, etc. can be mentioned, it is not limited to these, What is necessary is just a well-known arbitrary electron withdrawing group.

A preferable structure of Ar ² is a structure represented by Chemical Formulas 3-6. The structure of Chemical Formula 3 is preferable because it can increase the solubility of the ionic group-containing polymer. The structure of Chemical Formula 4 is preferable because it lowers the softening temperature of the ionic group-containing polymer to further enhance the bonding property with the electrode or impart photocrosslinkability. The structure of Chemical Formula 5 or 6 is preferable because the swelling of the ionic group-containing polymer can be reduced, and the structure of Chemical Formula 6 is more preferable. Among the chemical formulas 3 to 6, the structure of the chemical formula 6 is most preferable.

  When the ionic group-containing polymer constituting the polymer electrolyte membrane in the present invention has all the repeating units represented by the general formulas 1, 2, 7, and 8, respectively, mol% of each repeating unit, And it is preferable that mol% of other repeating units satisfy | fill the following Numerical formulas 1-3.

0.9 ≦ (n3 + n4 + n5 + n6) / (n3 + n4 + n5 + n6 + n7) ≦ 1.0
Formula 1
0.05 ≦ (n3 + n4) / (n3 + n4 + n5 + n6) ≦ 0.7 Formula 2
0.01 ≦ (n4 + n6) / (n3 + n4 + n5 + n6) ≦ 0.95 In the above formula, n3 is the mol% of the repeating unit represented by the general formula 7, and n4 is the repeating unit represented by the general formula 1. N5 represents the mol% of the repeating unit represented by the general formula 8, n6 represents the mol% of the repeating unit represented by the general formula 2, and n7 represents the mol% of the other repeating unit. )

  When (n3 + n4 + n5 + n6) / (n3 + n4 + n5 + n6 + n7) is smaller than 0.9, good characteristics cannot be obtained when a polymer electrolyte membrane is obtained, which is not preferable. More preferred is a range of 0.95 to 1.0.

  When (n3 + n4) / (n3 + n4 + n5 + n6) is smaller than 0.05, it is not preferable because sufficient proton conductivity cannot be obtained when a polymer electrolyte membrane is obtained. On the other hand, if it is larger than 0.9, the swellability of the polymer electrolyte membrane is remarkably increased. A more preferred range is from 0.1 to 0.7.

  (N3 + n4) / (n3 + n4 + n5 + n6) is preferably in the range of 0.07 to 0.5, and more preferably in the range of 0.1 to 0.4. If it is larger than 0.5, the fuel permeability may increase, which is not preferable. If it is smaller than 0.07, the proton conductivity decreases and the resistance increases, which is not preferable.

  When (n4 + n6) / (n3 + n4 + n5 + n6) is less than 0.01, it is not preferable because the bonding property with the electrode catalyst layer is lowered when a polymer electrolyte membrane is formed. If it is greater than 0.95, the swellability of the polymer electrolyte membrane may become too large, which is not preferable. 0.05 to 0.8 is a more preferable range. More preferably, it is in the range of 0.4 to 0.8.

  In the ionic group-containing polymer of the present invention, the bonding mode of each repeating unit represented by each general formula is not particularly limited, and includes random bonding, alternating bonding, bonding in a continuous block structure, and the like. Either is acceptable.

  As a method for synthesizing the ionic group-containing polymer in the present invention, a known method can be adopted and is not particularly limited. However, as a preferable example of a raw material monomer used for synthesis, a monomer having a structure represented by the following general formulas 9 to 11 Can be mentioned. Furthermore, it is preferable to further use a monomer having a structure represented by the general formula 12 because physical properties such as film form stability are improved.

In General Formulas 9 to 12, X is a —S (═O) ₂ — group or —C (═O) — group, Y is H or a monovalent cation, and Z ⁷ and Z ¹⁰ are each independently Any one of Cl atom, F atom, I atom, Br atom and nitro group, Z ⁸ and Z ¹¹ are each independently OH group, SH group, —O—NH—C (═O) —R group. , -S-NH-C (= O) -R group [R represents an aromatic or aliphatic hydrocarbon group. Z ⁹ represents any of an O atom, an S atom, a —C (CH ₃ ) ₂ — group, a —C (CF ₃ ) ₂ — group, a —CH ₂ — group, a cyclohexyl group, and Ar ⁴ represents a molecule in the molecule. And an aromatic group having an electron-withdrawing group such as a perfluoroalkyl group such as a sulfone group, a carbonyl group, a sulfonyl group, a phosphine group, a cyano group or a trifluoromethyl group, a nitro group or a halogen group.

Specific examples of the compound represented by the general formula 9 include 3,3′-disulfo-4,4′-dichlorodiphenylsulfone, 3,3′-disulfo-4,4′-difluorodiphenylsulfone, 3,3 ′. -Disulfo-4,4'-dichlorodiphenyl ketone, 3,3'-disulfo-4,4'-difluorodiphenyl ketone, 3,3'-disulfobutyl-4,4'-dichlorodiphenyl sulfone, 3,3'-disulfobutyl -4,4'-difluorodiphenyl sulfone, 3,3'-disulfobutyl-4,4'-dichlorodiphenyl ketone, 3,3'-disulfobutyl-4,4'-difluorodiphenyl ketone, and their sulfonic acid groups are 1 Examples include salts with valent cation species. The monovalent cation species may be sodium, potassium, other metal species, various amines, or the like, but is not limited thereto.
Examples of the compound represented by the general formula 9 in which the sulfonic acid group is a salt include sodium 3,3′-disulfonate-4,4′-dichlorodiphenylsulfone, 3,3′-disulfone Sodium salt-4,4′-difluorodiphenylsulfone, sodium 3,3′-disulfonate-4,4′-dichlorodiphenylketone, sodium 3,3′-disulfonate-4,4′-difluorodiphenylketone, 3, 3′-potassium disulfonate-4,4′-dichlorodiphenylsulfone, 3,3′-potassium disulfonate-4,4′-difluorodiphenylsulfone, 3,3′-potassium disulfonate-4,4′-dichlorodiphenyl Examples include ketones and potassium 3,3′-disulfonate-4,4′-difluorodiphenyl ketone.

  Specific examples of the compound represented by the general formula 10 include 2,2-bis (4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) methane, and 2,2-bis (4-hydroxyphenyl) hexafluoropropane. 4,4′-thiobisbenzenethiol, 4,4′-oxybisbenzenethiol, bis (4-hydroxyphenyl) sulfide, 4,4′-dihydroxydiphenyl ether, 1,1-bis (4-hydroxyphenyl) cyclohexane 4,4′-thiobisbenzenethiol, bis (4-hydroxyphenyl) sulfide, 1,1-bis (4-hydroxyphenyl) cyclohexane, terminal hydroxyl group-containing phenylene ether oligomer (the following chemical formula 13) Are preferred). In the chemical formula 13, n is an integer of 1 or more, and a mixture of different components of n may be used.

  The monomer having the structure represented by the general formula 10 increases the flexibility of the ionic group-containing polymer, suppresses deformation against deformation, or lowers the glass transition temperature to improve the bondability with the electrode catalyst layer. It can bring about effects such as.

  Examples of the compound represented by the general formula 11 include compounds having a leaving group in a nucleophilic substitution reaction such as halogen and nitro group on the same aromatic ring and an electron-withdrawing group that activates the same. Specific examples include 2,6-dichlorobenzonitrile, 2,4-dichlorobenzonitrile, 2,6-difluorobenzonitrile, 2,4-difluorobenzonitrile, 4,4′-dichlorodiphenylsulfone, 4,4 ′. -Difluorodiphenyl sulfone, 4,4'-difluorobenzophenone, 4,4'-dichlorobenzophenone, decafluorobiphenyl, and the like, but not limited thereto, other aromatics active in aromatic nucleophilic substitution reaction A group dihalogen compound, an aromatic dinitro compound, an aromatic dicyano compound, and the like can also be used.

Examples of the compound represented by the general formula 12 include 4,4′-biphenol, 4,4′-dimercaptobiphenol, and 4,4′-biphenol is preferable.
In the above aromatic nucleophilic substitution reaction, other various activated dihalogen aromatic compounds, dinitroaromatic compounds, bisphenol compounds, and bisthiophenol compounds may be used in combination with the compounds represented by general formulas 9-12. it can.

  Examples of other bisphenol compounds or bisthiophenol compounds include 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (3-methyl-4-hydroxyphenyl) fluorene, and bis (4-hydroxyphenyl). ) Sulfone, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 3,3-bis (4-hydroxyphenyl) pentane, 2,2-bis (4- Hydroxy-3,5-dimethylphenyl) propane, bis (4-hydroxy-3,5-dimethylphenyl) methane, bis (4-hydroxy-2,5-dimethylphenyl) methane, bis (4-hydroxyphenyl) phenylmethane , Hydroquinone, resorcin, bis (4-hydroxyphenyl) ketone, 1,4-benze Examples include dithiol, 1,3-benzenedithiol, phenolphthalein, 10- (2,5-dihydroxyphenyl) -9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide. In addition, various aromatic diols or various aromatic dithiols that can be used for polymerization of polyarylene ether compounds by aromatic nucleophilic substitution reaction can also be used, and are not limited to the above compounds. .

  In the method for producing an ionic group-containing polymer electrolyte membrane used in the present invention, the activated dihalogen aromatic compound, dinitro aromatic compound, aromatic diol or aromatic dithiol is used as a raw material, and the presence of a basic compound A polymer obtained by polymerization by a known aromatic nucleophilic substitution reaction, preferably having a logarithmic viscosity of 0.1 to 2.0 dL / g, a softening temperature of 90 ° C. or higher, and a softening temperature of 140 The thing of -250 degreeC is more preferable.

  In the polymer electrolyte membrane laminate of the present invention, the peel strength (23 ° C., 50% RH) between the adhesive film and the electrolyte membrane needs to be 0.1 to 2.5 N / 20 mm width, preferably The width is 0.2 to 1.5 N / 20 mm, more preferably 0.3 to 1.0 N / 20 mm, and still more preferably 0.4 to 0.8 N / 20 mm. When the peel strength is less than 0.1 N / 20 mm, a part to be peeled may be generated only by applying unnecessary weak external stress due to dropping, collision, etc. to the laminate, and the width exceeds 2.5 N / 20 mm. As a result, excessive stress is applied to the electrolyte membrane during the peeling operation, and there is a tendency that the amount of transfer to the electrolyte membrane increases.

  The shape of the polymer electrolyte membrane laminate of the present invention is not particularly limited, and may be a sheet or a roll, but preferably the effect of the present invention is more exhibited in a state of being wound into a roll. In that case, it is more preferable to wind the polymer electrolyte on the inner side because it is less susceptible to the shape due to changes in humidity during transportation and storage.

  EXAMPLES Hereinafter, the present invention will be specifically described using examples, but the present invention is not limited to these examples. Various measurements were performed as follows.

<Dynamic hardness>
Using a Shimadzu Dynamic Ultra Hardness Tester DUH-201, measurement was performed under the following conditions in an environment of room temperature of 20 to 23 ° C. and humidity of 40 to 80%, and calculated according to the following formula.
Test mode Soft material test (MODE3)
Indenter Triangular pan indenter 115 °
Test load 0.20gf
Load speed 10 (0.0145 gf / sec)
Holding time 1 second Displacement full scale 10μ
After five measurements, the dynamic hardness of the indentation depth of 1 μm was picked up from the analysis data, the average value was obtained, and the dynamic hardness of the sample was taken. This dynamic hardness (DH) is a hardness obtained from the load and the indentation depth in the process of indenting the indenter, and is defined by the following equation (1).
DH = αP / D * D (1)
DH: Dynamic hardness α: Constant depending on indenter shape P: Test load, D: Depth of indentation (μm)

<Thickness variation rate>
Measurement was carried out by the following method using Anritsu FILM THICKNESS TESTER KG601A and K306C.
Measurement speed 0.01 seconds Feed speed 1.5m / min HIGH CUT OFF
Thinning off
A sample having a length of 40 mm with respect to the winding direction during film production and a length of 500 mm with respect to the direction orthogonal to the winding direction was cut out, and the continuous thickness in the direction orthogonal to the winding direction was measured under the above conditions. Based on the result obtained by the measurement, the thickness variation rate was determined by the following equation (2). The measurement was performed 5 times for one sample, and the average value was defined as the thickness variation rate of the sample.
Thickness variation rate (%) = [(maximum thickness−minimum thickness) / average thickness] × 100 (2)

<Tensile modulus of adhesive film and electrolyte membrane>
In accordance with JIS-K7127, a sample with a sample width of 10 mm and a sample length of 40 mm was measured with a tensile tester (manufactured by Toyo Seiki Co., Ltd.) in a measurement chamber in which the room temperature was controlled at 23 ° C. and the humidity was controlled to 50 ± 5 RH%. It was determined from the slope of the tensile stress-strain curve when pulled at a speed of 20 mm / min.

<Peel strength of laminate>
Based on JIS-C5016, it measured by the 90 degree | times peeling method.
That is, the laminate is cut into 20 mm in width and 100 mm in length in the MD direction of the roll, a double-sided tape is applied to the adhesive film side, and is attached to a rotating drum that can be freely rotated, and then the end of the electrolyte membrane is slightly peeled off. Then, the load when peeled in the MD direction between the gripping tools of the tensile tester was measured, the average load of the stable portion was taken as the peel strength, and the average value of n = 5 was obtained.

<Average roughness SRa>
The average roughness SRa of the pressure-sensitive adhesive surface of the pressure-sensitive adhesive film was determined by measurement using the Kosaka Laboratory Model ET-30HK under the following setting conditions.
Measurement conditions X Sokutainagasa [× 10 μm]: 100
X OKURIHAYASA [μm / sec]: 100
Y Ocri pitch [× 0.1 μm]: 20
Z (vertical) Bairitsu [× 1000]: 20
Cut-off [μm]: 80
Sokutei Hoho: Session

<Quality of electrolyte membrane in laminate>
The wrinkles, peeling, unevenness, and patches of the electrolyte membrane were observed with the naked eye and evaluated in three stages.
○: Wrinkles, peeling, and patching are not observed at all.
(Triangle | delta): A wrinkle, peeling, an unevenness | corrugation, a sticking spot, etc. are recognized slightly.
X: Wrinkles, peeling, unevenness, sticking spots, etc. are remarkably recognized.
<Evaluation of contamination of electrolyte membrane surface after peeling>
When visual observation is performed and no clear transcript is observed by visual observation, the surface of the electrolyte membrane after peeling of the adhesive film is analyzed by an ESCA analyzer, and S atoms obtained based on the peak of S atoms (S2p) % Was evaluated by the ratio of the value (S ₁ ) of the electrolyte membrane surface after peeling to the value (S ₀ ) of the blank electrolyte membrane surface.
S atomic% ratio (%) = (S ₁ / S ₀ ) × 100
○: 90% or more, △: less than 90% to 30% or more,
X: Transfer and adhesive residue are recognized with the naked eye.

<Example 1>
・ Base material layer:
FS2011DG3 (manufactured by Sumitomo Chemical Co., Ltd., ethylene content 0.9 mass%, melt flow rate 2.5 g / 10 min) was melt extruded with a 60 mmφ single screw extruder (L / D; 22.4).・ Adhesive layer:
H3522A (manufactured by Sumitomo Chemical Co., Ltd., melt flow rate 3 g / 10 min) was melt extruded using a 45φ twin-screw extruder (L / D; 19).
・ Release layer:
PC523D (manufactured by Sun Allomer Co., Ltd., melt flow rate 5 g / 10 min) was melt-extruded with a 65 mmφ single screw extruder (L / D; 25).
(Creation of adhesive film)
The molten adhesive layer, substrate layer, and release layer extruded from each of the above extruders are laminated and extruded in a three-layer T die (multimanifold type, lip width 250 mm, lip gap 1.2 mm) at 260 ° C. Then, it was cooled and solidified on a 20 ° C. casting roll to obtain a sheet. The sheet was longitudinally stretched 4.5 times at 120 ° C., cooled once with a roll heated to 50 ° C., then transversely stretched 7.0 times at 155 ° C., and further in an environment of 160 ° C. 7% relaxation was carried out to obtain a three-layer three-layer film with a total of 30 μm laminated in the order of 8 μm of adhesive layer, 20 μm of base layer, and 2 μm of release layer.
The dynamic hardness of the adhesive layer was 0.27 gf / μm ² , and the thickness variation rate (%) was 7.1%. Moreover, the tensile elasticity modulus (vertical + horizontal / 2) of the adhesive film was 1.8 GPa.

(Production of polymer electrolyte membrane)
778 g of 3,3′-disulfo-4,4′-dichlorodiphenylsulfone disodium salt, 553 g of 2,6-dichlorobenzonitrile, 893 g of 4,4′-biphenol, 762 g of potassium carbonate, 5621 g of N-methyl-2-pyrrolidone The mixture was stirred at 150 ° C. for 1 hour under a nitrogen atmosphere, and then the reaction was continued by raising the reaction temperature to 200 ° C. and sufficiently increasing the viscosity of the system. After standing to cool, it was precipitated in water into strands, and the resulting polymer was washed in water for 40 hours and then dried. The logarithmic viscosity of this polymer was 1.05 dL / g, and the softening temperature was 245 ° C.
Subsequently, the polymer solution was prepared using N-methyl-2-pyrrolidone as a solvent so that the polymer concentration was 25% by mass. The prepared solution was continuously cast on a polyethylene terephthalate film as a support with a blade coater to a thickness of 200 μm at a temperature of 20 ° C., dried at a temperature of 140 ° C. for 30 minutes, and the cast film was dried. A polymer film having a self-supporting property was obtained in a state of being in close contact with the support. Subsequently, the film was immersed in a 20% by mass sulfuric acid aqueous solution at 30 ° C. without peeling off the polymer film from the support for 10 minutes, and then immersed in pure water at 30 ° C. for 20 minutes without peeling off the polymer film from the support. It was immersed in pure water for 40 minutes, and further air-dried at 25 ° C. for 30 minutes without peeling off the polymer film from the support. Thereafter, the polymer membrane was peeled off from the support to obtain a polymer electrolyte membrane having a thickness of 30 μm. The tensile elastic modulus of this electrolyte membrane was 1.5 GPa.

(Production of laminate)
The adhesive layer surface of the adhesive film and the polymer electrolyte membrane were bonded together, and passed through a nip roll under a load of 0.1 MPa to obtain a polymer electrolyte membrane laminate. The obtained polymer electrolyte membrane laminate was good without peeling or wrinkling.
Furthermore, when the polymer electrolyte membrane laminate was wound around a plastic tube with a winder using a winder, the polymer electrolyte membrane laminate could be wound into a roll without causing wrinkles or peeling.

<Example 2>
In Example 1, an adhesive film was obtained in the same manner as in Example 1 except that the thickness of the adhesive layer was 3 μm and the thickness of the base material layer was changed to 25 μm. The dynamic hardness of this adhesive layer is 0
. 55 gf / μm ² and thickness variation rate (%) was 6.0%. Moreover, the tensile elasticity modulus of the adhesive film was 1.7 GPa. The obtained adhesive film was bonded to the polymer electrolyte membrane in the same manner as in Example 1 to obtain a polymer electrolyte laminate.
The obtained polymer electrolyte membrane laminate was good without peeling or wrinkling.
Furthermore, when the polymer electrolyte membrane laminate was wound around a plastic tube with a winder using a winder, the polymer electrolyte membrane laminate could be wound into a roll without causing wrinkles or peeling.

<Example 3>
In Example 1, a pressure-sensitive adhesive film was obtained in the same manner as in Example 1 except that the resin constituting the pressure-sensitive adhesive layer was changed to 100% by mass of propylene-based resin (Pericon CAP350) manufactured by Dainichi Seika Co., Ltd. The adhesive layer had a dynamic hardness of 1.43 gf / μm ² and a thickness variation rate (%) of 5.9%. The tensile elastic modulus of the adhesive film was 1.8 GPa. The obtained adhesive film was bonded to the polymer electrolyte membrane in the same manner as in Example 1 to obtain a laminate. The obtained polymer electrolyte membrane laminate had a peel strength between the adhesive film and the polymer electrolyte membrane of 0.11 N / (20 mm width). The laminate did not peel off under normal handling, but it was easy to peel off due to impact or the like.

<Example 4>
3,3′-sodium disulfonate-4,4′-dichlorodiphenylsulfone (abbreviation: S-DCDPS) 800.0 g, 2,6-dichlorobenzonitrile (abbreviation: DCBN) 356.5 g, 4 4,4′-biphenol (abbreviation: BP) 606.5 g, 4,4′-thiobisphenol (abbreviation: BPS) 96.9 g, potassium carbonate 562.7 g, N-methyl-2-pyrrolidone (abbreviation: NMP) 4624. A polymer having a logarithmic viscosity of 1.02 dl / g and a softening temperature of 225 ° C. was obtained in the same manner as in Example 1 except that 3 g was used as a raw material. Using this polymer, a polymer electrolyte membrane was obtained in the same manner as in Example 1. This electrolyte membrane had a tensile modulus of 1.7 GPa. Furthermore, it stuck together with the adhesive film similarly to Example 1, and obtained the polymer electrolyte membrane laminated body. The obtained polymer electrolyte membrane laminate was good without peeling or wrinkling.
Furthermore, when the polymer electrolyte membrane laminate was wound around a plastic tube with a winder using a winder, the polymer electrolyte membrane laminate could be wound into a roll without causing wrinkles or peeling.

<Example 5>
310.0 g of dried S-DCDPS, 253.3 g of DCBN, terminal hydroxyl group-containing phenylene ether oligomer (SPECIANOL DPE-PL manufactured by Dainippon Ink & Chemicals, Inc. The average value is 5) (abbreviation: DPE) 1566.6 g, potassium carbonate 319.8 g, NMP 5164.3 g were used, and the reaction time was 8 hours. A polymer having a logarithmic viscosity of 0.63 dl / g and a softening temperature of 152 ° C. was obtained. Using this polymer, a polymer electrolyte membrane was obtained in the same manner as in Example 1. This electrolyte membrane had a tensile modulus of 1.7 GPa. Furthermore, it stuck together with the adhesive film similarly to Example 1, and obtained the polymer electrolyte membrane laminated body. The obtained polymer electrolyte membrane laminate was good without peeling or wrinkling.
Furthermore, when the polymer electrolyte membrane laminate was wound around a plastic tube with a winder using a winder, the polymer electrolyte membrane laminate could be wound into a roll without causing wrinkles or peeling.

<Example 6>
In Example 1, 721 g of 3,3′-disulfo-4,4′-dichlorodiphenyl ketone disodium salt was used instead of 778 g of 3,3′-disulfo-4,4′-dichlorodiphenylsulfone disodium salt in the same manner. A polymer was synthesized. The logarithmic viscosity of the obtained polymer was 0.99 dL / g. Using this polymer, a polymer electrolyte membrane was obtained in the same manner as in Example 1. The tensile elastic modulus of this electrolyte membrane was 2.0 GPa. Furthermore, it stuck together with the adhesive film similarly to Example 1, and obtained the polymer electrolyte membrane laminated body. The obtained polymer electrolyte membrane laminate was good without peeling or wrinkling.
Furthermore, when the polymer electrolyte membrane laminate was wound around a plastic tube with a winder using a winder, the polymer electrolyte membrane laminate could be wound into a roll without causing wrinkles or peeling.

<Example 7>
Weigh out 0.90 g of 9,9-bis (4-hydroxyphenyl) fluorene, 1.00 g of bisphenol S, 1.45 g of difluorodiphenyl sulfone, and 0.91 g of calcium carbonate in a 50 ml four-necked flask and 20 ml of NMP under a nitrogen stream. The reaction temperature was set at around 175 ° C. and the reaction was continued for about 5 hours. After standing to cool, it was reprecipitated in about 100 ml of methanol and washed with water three times using a mixer to obtain a polymer. The logarithmic viscosity of the obtained polymer was 0.58. The polymer sample is stirred with concentrated sulfuric acid (98%) with a magnetic stirrer at room temperature to perform a sulfonation reaction. After the reaction, the sulfuric acid solution is poured into excess ice water to stop the reaction, and the resulting precipitate is collected by filtration. The polymer was washed with water to obtain a sulfonic acid group-containing polymer. Using this polymer, a polymer electrolyte membrane was obtained in the same manner as in Example 1. The tensile elastic modulus of this electrolyte membrane was 1.1 GPa. Furthermore, it stuck together with the adhesive film similarly to Example 1, and obtained the polymer electrolyte membrane laminated body. The obtained polymer electrolyte membrane laminate was good without peeling or wrinkling.
Furthermore, when the polymer electrolyte membrane laminate was wound around a plastic tube with a winder using a winder, the polymer electrolyte membrane laminate could be wound into a roll without causing wrinkles or peeling.

<Example 8>
Weigh 15 g of 3,3 ′, 4,4′-tetraaminodiphenylsulfone, 14 g of monosodium 2,5-dicarboxybenzenesulfonate, 205 g of polyphosphoric acid (phosphorus pentoxide content 75%) and 164 g of phosphorus pentoxide in a polymerization vessel. take. The temperature was raised to 100 ° C. while flowing nitrogen and slowly stirring on an oil bath. After maintaining at 100 ° C. for 1 hour, the temperature was raised to 150 ° C. for 1 hour, and the temperature was raised to 200 ° C. and polymerized for 4 hours. After completion of the polymerization, the mixture is allowed to cool, and water is added to take out the polymer. After repeating the water washing three times using a home mixer, the water-immersed polymer is neutralized by adding sodium carbonate, and further washed with water repeatedly. It was confirmed that the pH of the solution became neutral and did not change. The obtained polymer was dried under reduced pressure at 80 ° C. overnight. The logarithmic viscosity of the polymer was 1.68. The obtained polymer and NMP were weighed out to 25% by mass, and dissolved by heating to 170 ° C. on an oil bath while stirring. Using the obtained solution, a polymer electrolyte membrane was obtained in the same manner as in Example 1. This electrolyte membrane had a tensile modulus of 1.9 GPa. Furthermore, it stuck together with the adhesive film similarly to Example 1, and obtained the polymer electrolyte membrane laminated body. The obtained polymer electrolyte membrane laminate was good without peeling or wrinkling.
Furthermore, when the polymer electrolyte membrane laminate was wound around a plastic tube with a winder using a winder, the polymer electrolyte membrane laminate could be wound into a roll without causing wrinkles or peeling.

<Example 9>
1.83 g of 3,3 ′, 4,4′-tetraaminodiphenylsulfone, 0.53 g of monosodium 2,5-dicarboxybenzenesulfonate, 1.13 g of 3,5-dicarboxyphenylphosphonic acid, polyphosphoric acid (5 (Phosphorus oxide content 75%) 25g and phosphorus pentoxide 20g are weighed in a polymerization vessel, and nitrogen is flown, and the temperature is raised to 100 ° C while stirring slowly on an oil bath.
did. After maintaining at 100 ° C. for 1 hour, the temperature was raised to 150 ° C. for 1 hour, and the temperature was raised to 200 ° C. and polymerized for 6 hours. After completion of the polymerization, the mixture is allowed to cool, and water is added to take out the polymer. After repeating the water washing three times using a home mixer, the water-immersed polymer is neutralized by adding sodium carbonate, and further washed with water repeatedly. It was confirmed that the pH of the solution became neutral and did not change. The obtained polymer was dried under reduced pressure at 80 ° C. overnight. The logarithmic viscosity of the polymer was 1.31. The obtained polymer was dissolved on an oil bath so as to have a concentration of 25% by mass together with N-methyl-2-pyrrolidone (NMP). Using the obtained solution, a polymer electrolyte membrane was obtained in the same manner as in Example 1. The tensile elastic modulus of this electrolyte membrane was 1.8 GPa. Furthermore, it stuck together with the adhesive film similarly to Example 1, and obtained the polymer electrolyte membrane laminated body. The obtained polymer electrolyte membrane laminate was good without peeling or wrinkling.
Furthermore, when the polymer electrolyte membrane laminate was wound around a plastic tube with a winder using a winder, the polymer electrolyte membrane laminate could be wound into a roll without causing wrinkles or peeling.

<Comparative Example 1>
In Example 1, an adhesive film was obtained in the same manner as in Example 1 except that H3002 (manufactured by Sumitomo Chemical Co., Ltd., melt flow rate 3 g / 10 min) was used instead of H3522A. The adhesive layer had a dynamic hardness of 0.12 gf / μm ² and a thickness variation rate (%) of 7.7%. The tensile elastic modulus of the adhesive film was 1.6 GPa. The obtained adhesive film was bonded to the polymer electrolyte membrane in the same manner as in Example 1 to obtain a laminate. The obtained polymer electrolyte membrane laminate had a peel strength between the adhesive film and the polymer electrolyte membrane of 2.9 N / (20 mm width). In the obtained laminate, wrinkles and uneven pasting were observed.

<Comparative example 2>
In Example 1, the resin constituting the adhesive layer was 20% by mass of H3522A (manufactured by Sumitomo Chemical Co., Ltd., melt flow rate 3 g / 10 min), SPX78J1 (manufactured by Sumitomo Chemical Co., Ltd., 1-butene content 25% by mass, melt flow rate) 7 g / 10 min) An adhesive film was obtained in the same manner as in Example 1 except that the content was changed to 80% by mass. This adhesive layer had a dynamic hardness of 1.65 gf / μm ² and a thickness variation rate (%) of 5.4%. The obtained adhesive film was tried to be bonded to the polymer electrolyte membrane in the same manner as in Example 1, but it was difficult to obtain a laminate.

<Comparative Example 3>
A pressure-sensitive adhesive film having a pressure-sensitive adhesive layer made of an acrylic polymer having a thickness of 10 μm by applying an acrylic pressure-sensitive adhesive (Dai Nippon Ink Chemical Co., Ltd., Boncoat PS-300) on a polyethylene terephthalate film (thickness: 38 μm). Obtained. The obtained adhesive film was bonded to the polymer electrolyte membrane in the same manner as in Example 1 to obtain a laminate. In the obtained polymer electrolyte membrane laminate, the peel strength between the adhesive film and the polymer electrolyte membrane exceeds 3 N / (20 mm width), and the adhesive remains on the polymer electrolyte membrane after the peel test. It was observed with the naked eye.

<Comparative example 4>
Using Nafion 112 (registered trademark of DuPont) (tensile modulus of 0.23 GPa), it was bonded to an adhesive film in the same manner as in Example 1 to obtain a polymer electrolyte membrane laminate. In the obtained laminate, partial wrinkles were observed, and dimensional change of the electrolyte membrane was recognized when the adhesive film was peeled off.

<Comparative Example 5>
When the polymer electrolyte membrane produced in Example 1 was wound up alone on a plastic tube with a winder, wrinkles were generated because the polymer electrolyte membrane was not slippery and could not be wound up neatly. It was.

<Comparative Example 6>
When the polymer electrolyte membrane laminate produced in Example 1 is wound around a plastic tube on the outside with a winder, the polymer electrolyte membrane can be wound into a roll without causing wrinkles or peeling. However, because the outermost layer was a polymer electrolyte membrane, wrinkles entered the polymer electrolyte membrane due to changes in humidity during storage, propagated to the inside, and a shape change was observed.
The above evaluation results are summarized in Tables 1 and 2.

  The present invention is a laminate of an ultra-thin polymer electrolyte membrane and an adhesive film, and does not cause wrinkles or peeling, making it easy to handle an ultra-thin polymer electrolyte membrane and peeling the adhesive film. Because the surface of the polymer electrolyte membrane later is less contaminated by the adhesive, it is easy to use the ultrathin polymer electrolyte membrane for polymer electrolyte fuel cells and contribute to the development of polymer electrolyte fuel cells Can be expected.

Claims (9)

  A pressure-sensitive adhesive polymer film in which a pressure-sensitive adhesive layer having the same kind of polymer as the base material layer and having lower crystallinity than the base material layer is laminated on the base material layer is attached to at least one surface of the polymer electrolyte membrane via the pressure-sensitive adhesive layer. A polymer electrolyte membrane laminate in which the peel strength (23 ° C., 50% RH) between the adhesive polymer film and the polymer electrolyte membrane is 0.1 to 2.5 N / 20 mm width.   The polymer electrolyte membrane laminate according to claim 1, wherein the adhesive polymer film is formed by laminating a base material layer and an adhesive layer by melt coextrusion.   The polymer electrolyte membrane laminate according to claim 1 or 2, wherein the pressure-sensitive adhesive polymer film is formed by laminating a release layer on a base material layer opposite to the pressure-sensitive adhesive layer by melt coextrusion.   The polymer electrolyte membrane laminate according to any one of claims 1 to 3, wherein the adhesive polymer film is made of a polyolefin resin.   The polymer electrolyte membrane laminate according to claim 4, wherein the base material layer is crystalline polypropylene, and the adhesive layer is amorphous polypropylene or a layer containing amorphous polypropylene and crystalline polypropylene. The polymer electrolyte membrane laminate according to claim 1, wherein a dynamic hardness of the adhesive layer surface of the adhesive polymer film is 0.15 gf / μm ² or more and 1.4 gf / μm ² or less.   The adhesive polymer film is a biaxially stretched film, and a lateral thickness variation rate that is a direction orthogonal to a winding direction at the time of film production is 2.0% or more and 7.5% or less. The polymer electrolyte membrane laminated body in any one of 1-6.   The polymer electrolyte membrane laminate according to any one of claims 1 to 7, wherein the adhesive polymer film is bonded and wound into a roll state with the polymer electrolyte membrane surface side inside.   The polymer electrolyte membrane laminate according to any one of claims 1 to 8, wherein the polymer electrolyte membrane is a non-fluorine polymer electrolyte membrane having a tensile elastic modulus (based on JIS-K7127) of 1 GPa or more.