Ion exchange membrane wound body

Abstract

To provide an ion exchange membrane wound body having a high yield.SOLUTION: According to an embodiment, an ion exchange membrane wound body is provided. The ion exchange membrane wound body comprises: a wound ion exchange membrane in a dry state; and an air-permeable tape for fixing an end part of a short side located in the outermost circumference of the ion exchange membrane. The air permeability of the air-permeable tape is preferably 5.0 sec / 100 cc 100 μm or less. The air-permeable tape may include a support body and an adhesive supported on the support body. The support body is preferably made of a film, a woven fabric, a non-woven fabric, a porous film or paper.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an ion exchange membrane wound body. [Background technology]

[0002] An ion exchange membrane is a membrane that has an ion exchange function. Ion exchange membranes can be obtained, for example, by forming an ion exchange resin into a membrane or by filling the pores of a porous substrate with an ion exchange resin. Ion exchange membranes include cation exchange membranes that allow only cations to pass through and anion exchange membranes that allow only anions to pass through. Ion exchange membranes are used in pure water production systems, seawater desalination systems, desalination systems, fuel cells, water electrolysis systems, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-177505 [Patent Document 2] Japanese Patent Publication No. 2023-022684 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide an ion-exchange wound body with a high yield. [Means for solving the problem]

[0005] According to an embodiment, there is provided an ion exchange membrane roll, which is in a dry state and includes a wound ion exchange membrane and a breathable tape that fixes an end portion of a short side located at the outermost periphery of the ion exchange membrane. [Effects of the Invention]

[0006] According to the present invention, an ion exchange membrane roll can be provided with a high yield. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view schematically illustrating an example of an ion exchange membrane. [Figure 2] FIG. 2 is a perspective view schematically showing an example of an ion exchange membrane wound body according to the embodiment. [Figure 3] FIG. 2 is a cross-sectional view schematically showing an example of an ion exchange membrane wound body according to the embodiment. [Figure 4] FIG. 10 is a cross-sectional view schematically showing another example of an ion exchange membrane wound body according to the embodiment. [Figure 5] FIG. 1 is a schematic diagram illustrating an example of a polymerizable composition impregnation device. [Figure 6] FIG. 1 is a schematic diagram illustrating an example of an ion exchange membrane wound body manufacturing apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0008] Ion exchange membranes are sometimes manufactured as long films whose long sides are several tens of times longer than their short sides. These long film-like ion exchange membranes are cut or punched to obtain ion exchange membranes of desired sizes, which are then used in devices such as water electrolysis systems. In these devices, the ion exchange membranes can be used in a wet state where they come into contact with a solvent containing water, or in an environment where they alternate between wet and dry states.

[0009] The ion exchange function of an ion exchange membrane is exhibited under a wet condition. To maintain this quality, the ion exchange membrane may be kept in a wet condition without being dried from the time it is manufactured into a long film until it is cut to a desired size or until it is placed in an apparatus. However, from the viewpoint of transportation costs, etc., it may be desirable to transport or store the ion exchange membrane in the form of a wound body in which the dry ion exchange membrane is wound.

[0010] The end of the winding of this dry ion exchange membrane roll, i.e., the outermost edge, is sometimes fixed to the surface of the roll using commercially available adhesive tape or the like to prevent it from separating from the surface of the roll, i.e., from unwinding. The inventors have discovered that this adhesive tape can cause unevenness on the surface of the ion exchange membrane in the surface layer of the ion exchange membrane roll near the outermost edge, i.e., create areas that are recessed relative to the surrounding areas. That is, the dry ion exchange membrane roll is hygroscopic. Therefore, it can swell and shrink due to changes in humidity in the air. However, the ion exchange membrane and its underlying layers, to which the adhesive tape is applied, are isolated from air and therefore do not react with moisture in the air and are less likely to swell. Therefore, it is believed that areas where the adhesive tape is applied and its underlying layers are more likely to be recessed relative to the surrounding areas due to the adhesive tape marks. If such irregularities are found in part of the ion exchange membrane, the smoothness of the membrane surface is impaired, and gaps will occur when the ion exchange membrane is used in a stacked state, so it may be necessary to remove these irregularities. This can reduce the yield of the ion exchange membrane. If these adhesive tape marks are formed not only on the outermost ion exchange membrane but also over several tens of layers from the outermost layer toward the inside of the ion exchange membrane roll, the yield of the ion exchange membrane can be significantly reduced.

[0011] To address this issue, the ion exchange membrane roll according to the embodiment uses breathable tape as the adhesive tape that secures the outermost short edge of the ion exchange membrane. The ion exchange membrane to which the breathable tape is attached and its underlying layer are less likely to be blocked from contact with air than an ion exchange membrane to which a less breathable adhesive tape is attached. Therefore, the ion exchange membrane to which the breathable tape is attached and its underlying layer can swell and shrink in response to moisture in the air, just like the area around the adhesive tape. Therefore, the ion exchange membrane roll according to the embodiment does not produce any irregularities such as tape marks on the ion exchange membrane surface, allowing for high yields.

[0012] The ion exchange membrane wound body according to the embodiment will be described in detail below.

[0013] <Ion exchange membrane roll> The ion exchange membrane roll according to the embodiment is in a dry state and includes a wound ion exchange membrane and a breathable tape that fixes the outermost edge of the ion exchange membrane.

[0014] The ion exchange membrane of the ion exchange membrane roll is in a dry state. A dry state means that the amount of moisture in the air and the amount of moisture in the ion exchange membrane are in equilibrium. An equilibrium state means, for example, that the weight change rate is within 1%. The weight change rate can be calculated, for example, by the following method. First, the ion exchange membrane is cut into a sample measuring 50 mm x 50 mm or more. The weight of this sample is measured and allowed to stand in the air for one hour. The weight of the sample after one hour is measured, and the weight change rate before and after the test is calculated.

[0015] The ion exchange membrane is a planar membrane having long and short sides. When one turn of the ion exchange membrane is counted as one turn, the number of turns of the ion exchange membrane in the wound body is, for example, 50 or more, and may be 300 or more. There is no particular upper limit to the number of turns, but in one example, it is 3000 or less.

[0016] The length L of the long side is longer than the length W of the short side. The length L of the long side is, for example, 1 m or more and 2000 m or less. The length L may be 10 m or more and 100 m or less, or 50 m or more and 800 m or less. The length W of the short side is, for example, 50 mm or more and 1500 mm or less. The length W may be 100 mm or more and 1200 mm or less, or 400 mm or more and 1000 mm or less. The longer the lengths L and W, the better the productivity of the ion exchange membrane sheet. There is no particular upper limit to the lengths L and W, but if they are within the above ranges, deformation due to their own weight is less likely to occur. The ratio L / W of the length L of the long side to the length W of the short side is, for example, 30 or more and 2500 or less. The ratio L / W may be 100 or more and 1800 or less, or 200 or more and 1500 or less. The average thickness d of the ion exchange membrane is, for example, 10 μm or more and 200 μm or less. The average film thickness d is, for example, 15 μm or more and 150 μm or less, and may be 20 μm or more and 150 μm or less, or 25 μm or more and 100 μm or less.

[0017] Fig. 1 is a perspective view schematically illustrating an example of an ion exchange membrane. The ion exchange membrane 1 shown in Fig. 1 is a film-like membrane having a long side length L longer than a short side length W and a thickness d.

[0018] The ion exchange membrane roll is typically cylindrical. The cross-sectional shape of the ion exchange membrane roll perpendicular to the winding axis direction is typically circular. The cross-sectional shape may also be elliptical. The ion exchange membrane roll has a roll structure in which the ion exchange membrane is wound from one end of a short side to the other end of a short side. In other words, the ion exchange membrane roll is a roll of ion exchange membrane wound from one end of a long side to the other end of a long side.

[0019] The length Bw of the ion exchange membrane wound body in the direction of the winding axis is the same as the short side of the ion exchange membrane, that is, the length W of the short side.

[0020] When the ion exchange membrane wound body has a cylindrical shape, the circumferential length Bc of the ion exchange membrane wound body in a cross section perpendicular to the winding axis direction is, for example, 65 mm or more and 1800 mm or less. The length Bc may be 150 mm or more and 1500 mm or less, or 300 mm or more and 1000 mm or less. The circumferential length Bc of the ion exchange membrane wound body can be measured using a tape measure or the like.

[0021] Furthermore, the diameter Bl of the circle in the cross section is the length in the direction perpendicular to the winding axis direction of the ion exchange membrane roll, i.e., the width and height. The diameter Bl of the circle is, for example, 20 mm or more and 580 mm or less. The diameter Bl of the circle may be 45 mm or more and 480 mm or less, or 95 mm or more and 320 mm or less. The diameter Bl of the circle can be calculated from the circumferential length Bc of the ion exchange membrane roll.

[0022] The ratio Br / d of the cross-sectional radius Br (mm) of the ion exchange membrane roll to the average thickness d (mm) of the ion exchange membrane is, for example, 450 or more and 12000 or less. This ratio Br / d may be 1000 or more and 8000 or less, or 1500 or more and 6000 or less.

[0023] FIG. 2 is a perspective view schematically illustrating an example of an ion exchange membrane wound body according to an embodiment. The ion exchange membrane wound body 10 illustrated in FIG. 2 includes a winding core 2, an ion exchange membrane section 3, and two breathable tapes 4. The ion exchange membrane section 3 includes the ion exchange membrane 1 illustrated in FIG. 1. The ion exchange membrane 1 is wound around the winding core 2 so that one end of its short side contacts the winding core 2 and the other end of its short side is located at the outermost periphery. The ion exchange membrane wound body 10 illustrated in FIG. 2 has a cylindrical shape extending in the winding axis direction. The ion exchange membrane wound body 10 has a length Bw in the winding axis direction and a length Bl in a direction perpendicular to the winding axis direction. The winding core 2 illustrated in FIG. 2 has a cylindrical shape. The winding core 2 has a length Cw in the winding axis direction and a length Cl in the direction perpendicular to the winding axis direction. The breathable tape 4 is attached to the outermost surface of the ion exchange membrane roll so as to span the end of the short side of the ion exchange membrane 1.

[0024] Fig. 3 is a cross-sectional view schematically showing an example of an ion exchange membrane roll. Fig. 3 is a cross-sectional view obtained by cutting the ion exchange membrane roll 10 shown in Fig. 2 in a direction perpendicular to the winding axis direction at a portion having the breathable tape 4. The breathable tape 4 is attached between the end of the short side of the ion exchange membrane located at the outermost periphery of the ion exchange membrane roll and the ion exchange membrane located adjacent to the ion exchange membrane portion located below that end and located at the outermost periphery.

[0025] The air layer ratio of the ion exchange membrane roll is preferably greater than 5% and less than 50%. In an ion exchange membrane roll with an air layer ratio within this range, there is an appropriate amount of air between the layers of the ion exchange membrane, which prevents the ion exchange membranes from sticking together. It also prevents deformation due to volume changes when the ion exchange membranes swell. However, since the ion exchange membranes tend to unwind, it is necessary to secure the ends with breathable tape. The air layer ratio is more preferably between 7% and 40%, and even more preferably between 10% and 30%.

[0026] The air layer ratio can be calculated by the following formula (I).

[0027] Air layer rate (%) = (Aa-dL) / Aa × 100 (I) In formula (I), Aa is the average cross-sectional area of the ion exchange membrane perpendicular to the winding axis direction in the ion exchange membrane wound body, d is the average thickness of the ion exchange membrane, and L is the length of the long side of the ion exchange membrane.

[0028] The method for calculating the air layer ratio will be described with reference to the drawings.

[0029] Fig. 4 is a cross-sectional view schematically showing another example of an ion exchange membrane wound body according to an embodiment, obtained by cutting the ion exchange membrane wound body 10 shown in Fig. 2 in a direction perpendicular to the winding axis direction.

[0030] First, the circumference of the ion exchange membrane wound body 10 is measured at 10 equally spaced locations along the winding axis of the ion exchange membrane wound body using a tape measure or the like, and the circumferential length Bc of the ion exchange membrane wound body 10 is obtained from the average of the measurements. Next, the diameters of both ends of the winding core 2 are measured using a tape measure or the like, and the diameter Cl of the winding core is obtained from the average of the measurements. The diameter Bl of the ion exchange membrane wound body 10 is calculated from the circumferential length Bc of the ion exchange membrane wound body 10 and pi, which is 3.14, and then the radius Br of the ion exchange membrane wound body 10 is calculated. The cross-sectional area Ba of the ion exchange membrane wound body 10 is calculated from the obtained radius Br and pi, which is 3.14. The radius Cr is calculated from the diameter Cl of the winding core 2, and the cross-sectional area Ca of the winding core 2 is calculated from the radius Cr and pi, which is 3.14. The cross-sectional area Ca of the winding core 2 is subtracted from the cross-sectional area Ba of the ion exchange membrane wound body 10 to obtain the cross-sectional area Ba-Ca of the ion exchange membrane portion 3. The obtained cross-sectional area Ba-Ca is defined as the cross-sectional area Aa of the ion exchange membrane portion 3, i.e., the average area of the cross section of the ion exchange membrane perpendicular to the winding axis direction in the ion exchange membrane wound body.

[0031] Next, the ion exchange membrane 1 is unwound from the ion exchange membrane roll 10, and the length L of its long side is measured. The film thickness is also measured at 10 equally spaced locations along the long side of the ion exchange membrane 1. The average of the film thicknesses obtained is defined as the average thickness d of the ion exchange membrane 1. The cross-sectional area dL of the side of the ion exchange membrane 1 is calculated by multiplying the length L of the long side of the ion exchange membrane 1 by the average thickness d.

[0032] The cross-sectional area Aa-dL of the ion exchange membrane 1 in the ion exchange membrane section 3 is calculated by subtracting the cross-sectional area dL of the ion exchange membrane 1 from the cross-sectional area Aa of the ion exchange membrane section 3, i.e., the cross-sectional area Aa-dL of the air existing between the ion exchange membranes 1. The proportion of the cross section occupied by air, i.e., the air layer ratio, can be calculated by dividing this air cross-sectional area Aa-dL by the cross-sectional area Aa of the ion exchange membrane section.

[0033] The hardness of the ion exchange membrane roll is, for example, 80 to 95. This hardness can be measured using an Asker Type C durometer. Specifically, the value is measured immediately after the Asker Type C durometer is pressed perpendicularly against the top surface of the ion exchange membrane roll to bring it into close contact. Measurements are performed at 10 equally spaced locations along the length of the ion exchange membrane roll in the axial direction, excluding 20 mm from both ends in the axial direction of the roll, and the average value is taken as the hardness of the ion exchange membrane roll. That is, this hardness refers to the hardness in the direction perpendicular to the axial direction of the ion exchange membrane roll. A hardness of 100 means that the hardness of the ion exchange membrane roll is approximately equal to the hardness of the winding core, meaning that there is almost no air layer formed between the ion exchange membranes in the ion exchange membrane roll. This hardness is more preferably 82 to 94, and even more preferably 87 to 92. An ion exchange membrane wound body having a hardness within this range tends to be less susceptible to blocking and winding slippage.

[0034] Note that a dry ion exchange membrane may swell due to absorption of water from the atmosphere. Therefore, the air gap ratio and hardness measurements are performed in an environment with a temperature of 20°C to 30°C and a relative humidity of 30% to 50%. The ion exchange membrane roll that has been left standing in the above environment for 24 hours or more is used as a sample.

[0035] <Ion exchange membrane> The ion exchange membrane may be formed solely from an ion exchange resin, or may be obtained by supporting an ion exchange resin on a porous substrate. The ion exchange membrane may be a cation exchange membrane or an anion exchange membrane. The ion exchange membrane may be a bipolar membrane containing both a cation exchange membrane and an anion exchange membrane.

[0036] An ion exchange resin is a resin having ion exchange groups. The ion exchange groups may be cation exchange groups, anion exchange groups, or both. The cation exchange groups include at least one functional group selected from the group consisting of, for example, sulfonic acid groups, carboxylic acid groups, and phosphonic acid groups. The anion exchange groups include at least one functional group selected from the group consisting of, for example, quaternary ammonium groups, pyridinium groups, triazolium groups, imidazolium groups, primary amino groups, secondary amino groups, and tertiary amino groups. The ion exchange groups preferably include at least one functional group selected from the group consisting of, for example, quaternary ammonium groups, pyridinium groups, triazolium groups, and imidazolium groups, and more preferably include at least one functional group selected from the group consisting of quaternary ammonium groups and pyridinium groups.

[0037] As the ion exchange resin, at least one of a hydrocarbon-based resin and a fluorine-based resin can be used. As the hydrocarbon-based resin, a styrene-based resin, an acrylic-based resin, or the like can be used. As the fluorine-based resin, a resin having a perfluorocarbon skeleton can be used. As the ion exchange resin, a hydrocarbon-based resin is preferably used, and a copolymer of a styrene derivative and a divinylbenzene derivative is more preferably used.

[0038] The substrate functions as a support for the ion exchange resin. Examples of the substrate that can be used include porous films, woven fabrics, nonwoven fabrics, sponges, and films. The substrate is preferably a porous membrane. When a porous membrane is used as the substrate, the pores of the substrate are preferably filled with the ion exchange resin.

[0039] The substrate may be, for example, a polyolefin resin, a fluorine-based resin, polyacrylonitrile, polyvinyl chloride, polyester, polyamide, polysulfone, polyethersulfone, polyphenylenesulfone, polyphenylene sulfide, polyimide, polyethermide, polyamideimide, polycarbonate, polyacrylate, cellulose acetate, polyetheretherketone, or a copolymer thereof. Polyolefin resins include polyethylene, polypropylene, polybutadiene, polymethylpentene, polybutene, polypentene, polyhexene, polymethylheptene, and copolymers thereof. Fluorine-based resins include polytetrafluoroethylene, poly(tetrafluoroethylene-hexafluoropropylene), polyvinylidene fluoride, polyhexafluoropropylene, polychlorotrifluoroethylene, and copolymers thereof. The substrate preferably contains a polyolefin resin, and more preferably contains polyethylene or polypropylene.

[0040] The film thickness of the substrate is, for example, 10 μm or more and 200 μm or less, preferably 5 μm or more and 170 μm or less, more preferably 10 μm or more and 120 μm or less, and even more preferably 15 μm or more and 100 μm or less.

[0041] The porosity of the substrate is, for example, 10% or more and 55% or less, preferably 20% or more and 50% or less, and more preferably 30% or more and 45% or less.

[0042] <Breathable tape> The breathable tape is used to fix the end of the ion exchange membrane located at the outermost periphery of the ion exchange membrane roll. The breathable tape may be attached so as to cover the entire end of the ion exchange membrane along the winding axis direction, or may be attached at multiple locations approximately equally spaced along the winding axis direction, or may be attached at only one location. The breathable tape is, for example, rectangular or square in shape.

[0043] The breathable tape is not particularly limited as long as it is a breathable adhesive tape that does not allow any deformation of the adhesive surface. Commercially available breathable adhesive tapes, surgical tapes, kinesiology tapes, pore tapes, etc. can be used.

[0044] The thickness of the breathable tape is, for example, 0.005 mm or more and 0.250 mm or less, and preferably 0.010 mm or more and 0.100 mm or less.

[0045] The air permeability of the breathable tape is, for example, 5.0 sec / 100cc·100μm or less. The air permeability is preferably 1.0 sec / 100cc·100μm or less, and more preferably 0.5 sec / 100cc·100μm or less. There is no particular lower limit for the air permeability, but one example is 0.01 sec / 100cc·100μm or more, and another example is 0.1 sec / 100cc·100μm or more. This air permeability can be measured, for example, using an apparatus conforming to the Oken-type testing machine method of Japanese Industrial Standards P8117. For measurement, a laminate of, for example, five sheets of breathable tape is used as a sample. The measured value (sec / 100cc) is divided by the unit thickness (100μm) to calculate the air permeability per unit thickness (sec / 100cc·100μm).

[0046] The breathable tape includes, for example, a support and a pressure-sensitive adhesive supported on the support. The support is, for example, a film, a woven fabric, a nonwoven fabric, a porous film, or paper. From the viewpoint of high breathability, the support is preferably a woven fabric, a nonwoven fabric, or a porous film, and more preferably a nonwoven fabric.

[0047] The adhesive may be laminated on the surface of the support, may fill pores provided in the support, or may coat the surface of the fibers that form the pores. The adhesive may be in the form of a film, fiber, mesh, or porous. The adhesive includes, for example, at least one of a resin and a rubber. Examples of the resin include an acrylic resin, a urethane resin, an epoxy resin, a silicone resin, etc. Examples of the rubber include a silicone rubber, a natural rubber, etc.

[0048] <Core> The ion exchange membrane wound body may further include a winding core. In the ion exchange membrane wound body, the ion exchange membrane is wound around the winding core along the long side direction from an end of one short side of the ion exchange membrane to an end of the other short side of the ion exchange membrane.

[0049] The winding core may be made of, for example, paper, resin-impregnated paper, resin-coated paper, resin, or metal. Resin is preferred because it is less prone to deformation. Examples of resins include polyethylene, polystyrene, polypropylene, and ABS. Alternatively, an impregnated resin winding core may be used, which is made by winding carbon fiber or glass fiber into a cylindrical shape, impregnating the cylindrical shape with a thermoplastic resin such as phenolic resin or epoxy resin, and then curing the impregnated resin.

[0050] The winding core is typically cylindrical. The length Cw of the winding core in the direction of the winding axis when attached to the winding shaft is preferably equal to or longer than the length W of the short side of the ion exchange membrane. The length Cw of the winding core in the direction of the winding axis is, for example, 10 mm or more and 1600 mm or less. The length Cw of the winding core may be 100 mm or more and 1300 mm or less, or 400 mm or more and 1100 mm or less. The difference Cw-Bw between the length Bw of the ion exchange membrane wound body in the direction of the winding axis and the length Cw of the winding core in the direction of the winding axis is, for example, 0 mm or more and 400 mm or less. The difference Cw-Bw is preferably 20 mm or more and 300 mm or less.

[0051] In a cross section perpendicular to the winding axis direction of the winding core, the circumferential length Cc is smaller than the circumferential length Bc of the ion exchange membrane wound body. The circumferential length Cc is, for example, 30 mm or more and 630 mm or less. The length Cc may be 150 mm or more and 600 mm or less, or 200 mm or more and 560 mm or less. The ratio Bc / Cc of the circumferential length Bc of the ion exchange membrane wound body to the circumferential length Cc of the winding core is, for example, 1.05 or more and 3.30 or less. The ratio Bc / Cc is preferably 1.10 or more and 2.50 or less. The circumferential length Cc of the winding core can be measured using a tape measure or the like. The circumferential length Cc of the winding core may be calculated from the diameter Cl of the winding core.

[0052] Furthermore, the diameter Cl of the circle in the cross section of the winding core is the length in the direction perpendicular to the winding axis, i.e., the width and height. The diameter Cl of the circle is, for example, 10 mm or more and 200 mm or less. The diameter Cl of the circle may be 50 mm or more and 190 mm or less, or 70 mm or more and 180 mm or less. The diameter Cl of the circle can be measured using a tape measure or the like.

[0053] In the ion exchange membrane wound body, the ratio Br / Cr of the radius Cr of the winding core to the radius Br of the cross section of the ion exchange membrane wound body is, for example, 1.05 or more and 3.30 or less. The ratio Br / Cr may be 1.10 or more and 3.0 or less, or 1.15 or more and 2.80 or less.

[0054] <Manufacturing method> (Method of manufacturing a wet ion exchange membrane) The wet ion exchange membrane is produced, for example, by the following method. First, a polymerizable composition is brought into contact with a substrate to obtain a first structure, and then the polymerizable composition is cured to obtain a second structure. Ion exchange groups are then introduced into this second structure to obtain a wet ion exchange membrane.

[0055] The polymerizable composition contains, for example, a monomer of a precursor of an ion exchange resin or a monomer of an ion exchange resin, and a radical polymerizable monomer polymerizable with these monomers.

[0056] The polymerizable composition is typically liquid at room temperature and pressure, where room temperature means a temperature of 20° C. or higher and 40° C. or lower, and normal pressure means 1 atmosphere.

[0057] Examples of monomers for precursors of ion exchange resins include styrene derivatives such as chloromethylstyrene, bromomethylstyrene, and iodomethylstyrene. Examples of monomers for ion exchange resins include styrene derivatives having ion exchange groups such as quaternary ammonium groups. Vinylbenzyltrimethylammonium and its salts are preferred as monomers for ion exchange resins, with vinylbenzyltrimethylammonium chloride being more preferred.

[0058] In the polymerizable composition, the proportion of the ion exchange resin precursor monomer or the ion exchange resin monomer is, for example, 5% by mass or more and 95% by mass or less. This proportion is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 65% by mass or more, and even more preferably 68% by mass or more. When this proportion is high, an ion exchange resin having a large amount of ion exchange groups per unit mass tends to be obtained.

[0059] The radical polymerizable monomer includes a crosslinkable radical polymerizable monomer that functions as a crosslinking agent. The crosslinkable radical polymerizable monomer has two or more radical polymerizable groups in one molecule. Examples of the radical polymerizable group include a vinyl group, an allyl group, an acryloyl group, and a methacryloyl group, and it is preferable to use a vinyl group. The radical polymerizable monomer may also include a radical polymerizable monomer that has one radical polymerizable group in one molecule and does not function as a crosslinking agent.

[0060] As the crosslinkable radical polymerizable monomer, for example, at least one selected from the group consisting of a divinyl compound having two vinyl groups, a diallyl compound having two allyl groups, and a diene is used.

[0061] Specific examples of the crosslinkable radical polymerizable monomer include divinylbenzene, divinylbenzene derivatives, divinyl sulfone, butadiene, chloroprene, divinylphenyl, trivinylbenzenes, divinylnaphthalene, diallylamine, divinylpyridine, diallyl isocyanurate, etc. As the radical polymerizable monomer, it is preferable to use at least one selected from the group consisting of divinylbenzene and divinylbenzene derivatives.

[0062] In the polymerizable composition, the proportion of the crosslinkable radically polymerizable monomer is, for example, 0.1% by mass or more and 20% by mass or less, preferably 1% by mass or more and 18% by mass or less, and more preferably 3% by mass or more and 15% by mass or less. If this proportion is high, the mechanical strength tends to increase. If this proportion is too high, the performance of the ion exchange resin may decrease.

[0063] The polymerizable composition may further contain known additives such as a polymerization initiator, an organic solvent, a polymerization inhibitor, an antioxidant, a plasticizer, and a surfactant.

[0064] As the polymerization initiator, at least one of a thermal polymerization initiator and a photopolymerization initiator is used. Examples of the thermal polymerization initiator include benzoyl peroxide, p-chlorobenzoyl peroxide, decanoyl peroxide, lauroyl peroxide, acetyl peroxide, tert-butyl (2-ethylhexanoyl) peroxide hexanoate, and tert-butyl peroxyoctoate. Examples of the photopolymerization initiator include 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, and 2-hydroxy-4'-(2'-hydroxyethoxy)-2-methylpropiophenone.

[0065] The proportion of the polymerization initiator in the polymerizable composition is, for example, 0.1% by mass or more and 10% by mass or less.

[0066] The organic solvent is used to adjust the viscosity of the polymerizable composition and to increase the solubility of the monomers. As the organic solvent, for example, at least one selected from the group consisting of methanol, dimethyl sulfoxide (DMSO), ethylene glycol (EG), and propylene glycol is used.

[0067] The proportion of the organic solvent in the polymerizable composition is, for example, 1% by mass or more and 40% by mass or less. A high proportion of the organic solvent reduces the viscosity of the polymerizable composition, which can improve production efficiency. On the other hand, a high proportion of the organic solvent can cause pores to form in the ion exchange resin of the ion exchange membrane, which can reduce the performance of the ion exchange membrane. The proportion of the organic solvent in the polymerizable composition is preferably 30% by mass or less, and more preferably 25% by mass or less. This proportion can be measured, for example, by NMR or liquid chromatography.

[0068] As the polymerization inhibitor, for example, at least one selected from the group consisting of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4-OH-TEMPO), 4-tert-butylcatechol (TBC), cupferron, and benzoquinone is used.

[0069] The proportion of the polymerization inhibitor in the polymerizable composition is, for example, 0.0001% by mass to 2% by mass, and preferably 0.001% by mass to 1.0% by mass, which can be measured by, for example, gas chromatography.

[0070] The polymerizable composition preferably does not contain water. If the polymerizable composition contains water, components such as the crosslinking agent, a portion of the polymerizable monomer, and the polymerization initiator may precipitate. The water concentration in the polymerizable composition is preferably 10% by mass or less. The lower limit of the water concentration is, for example, 0% by mass, and, for another example, 100 ppm. This concentration can be measured, for example, by Karl Fischer water content measurement or gas chromatography.

[0071] As an example, a method for producing an ion exchange membrane using a porous substrate as the support will be described in detail below.

[0072] The method for contacting the polymerizable composition with the substrate is not particularly limited. The polymerizable composition may be applied to the substrate by spraying or dropping. Alternatively, the substrate may be immersed in the polymerizable composition. The amount of the polymerizable composition relative to the substrate is not particularly limited as long as it is an amount that fills the pores in the substrate. The amount that fills the pores can be calculated from the density of the substrate and the polymerizable composition used. In order to fill the polymerizable composition into the interior of the substrate, a method in which the substrate is immersed in the polymerizable composition is preferred. The substrate may be subjected to a surface treatment such as corona treatment, glow discharge treatment, or alkali treatment to improve adhesion to the polymerizable composition.

[0073] In the first structure, a polymerizable composition is supported on a substrate. When the polymerizable composition is cured, it is preferable to coat at least one main surface of the first structure with a resin film. Coating with a resin film can improve the surface smoothness of the ion exchange membrane. Furthermore, when the first structure is in the form of a laminate or a wound body, it can prevent the upper and lower layers from being integrated by polymerization of the polymerizable composition. As the resin for the resin film, for example, from the viewpoints of heat resistance and releasability, polyester resins such as polyethylene terephthalate, fluororesins such as perfluoroethylene propene copolymer and tetrafluoroethylene-hexaethylene propylene copolymer, and polyolefin resins such as polyethylene and polypropylene are used. The resin film may be a release film with a coating applied to its surface. The resin film may be appropriately selected depending on the components of the polymerizable composition, but from the viewpoints of heat resistance and releasability, polyester films such as polyethylene terephthalate are preferred.

[0074] The curing method of the polymerizable composition includes, for example, thermal polymerization or photopolymerization. The heating temperature during thermal polymerization may be lower than the melting point of the substrate, which is the support. For example, when a polyethylene substrate is used as the support, the heating temperature is 40°C or higher and 130°C or lower. Photopolymerization is carried out, for example, by irradiating ultraviolet light. Examples of the irradiation source include ultraviolet light-emitting diodes (LEDs), halogen lamps, xenon lamps, tungsten lamps, and mercury lamps. LEDs are preferred because of their ease of controlling the irradiation wavelength and their low heat generation. The curing method of the polymerizable composition may be, for example, a combination of thermal polymerization and photopolymerization. In this case, it is preferable to perform photopolymerization on the first structure and then thermal polymerization.

[0075] The introduction of ion exchange groups into the ion exchange resin precursor of the second structure is carried out, for example, by immersing the second structure in a treatment solution containing the ion exchange groups to be introduced. Note that when a polymerizable composition containing an ion exchange resin monomer is used, the second structure contains the ion exchange resin, so the introduction of ion exchange groups can be omitted. The ion exchange membrane obtained by the above method may further be subjected to a counterion substitution treatment.

[0076] The production of an ion exchange membrane may be carried out using a roll-to-roll method. An example of production using the roll-to-roll method will be described in more detail with reference to FIG. 5. FIG. 5 is a schematic diagram illustrating an example of a polymerizable composition impregnation apparatus. The polymerizable composition impregnation apparatus 100 shown in FIG. 5 includes an unwinding section 101, a conveying section 102, and a winding section 103. The unwinding section 101, the conveying section 102, and the winding section 103 are equipped with motors (not shown), and these motors are connected to controllers. The unwinding section 101, the conveying section 102, and the winding section 103 may each be equipped with a brake. A roll of the substrate is installed in the unwinding section 101. The conveying section 102 includes a nip roll 104, a first feed roll 105, a second feed roll 106, a third feed roll 107, and a tank T located between the first feed roll 105 and the third feed roll 107. The tank T contains the polymerizable composition PC. The second feed roll 106 is located inside the tank T. A winding core is installed in the winding section 103. Between the unwinding section and the winding section, a nip roll, a suction roll, a tension cutting mechanism such as an S-wrap mechanism using multiple rolls with a large wrap angle, a feed roll, etc. (not shown) may be installed. Furthermore, a tension control mechanism such as a dancer roll may be installed to absorb tension fluctuations. The winding section 103 may be installed with a near roll, a touch roll, etc.

[0077] First, a substrate roll is placed in the unwinding section 101, and a winding core is placed in the winding section 103. The motors of the unwinding section 101 and the winding section 103 are operated to unwind one end of the short side of the substrate from the substrate roll and transport it into the polymerizable composition tank T. In the tank T, the polymerizable composition is supported on the transported substrate. The substrate carrying the polymerizable composition is nipped with a nip roll 104 provided on a feed roll 107 to remove excess polymerizable composition. At this time, a resin film can be laminated on at least one main surface of the substrate carrying the polymerizable composition by a not-shown unwinding mechanism and nipping the resin film. The resin film can be laminated on either one or both sides of the substrate. However, if the polymerization is performed after the first structure roll is fabricated, laminating the resin film on only one side reduces costs. In this case, the nip roll 104 may be attached to the winding section 103. The obtained laminated film is further transported and wound around a core of a winding section 103 to obtain a laminated film roll. This laminated film roll is removed from the winding section 103 and placed in an oven to thermally polymerize the polymerizable composition. This results in a laminated film roll including the second structure.

[0078] The polymerizable composition impregnation apparatus 100 shown in FIG. 5 may be provided with a polymerization mechanism between the nip roll 104 and the winding unit 103. In this case, laminating a resin film on both sides of the substrate carrying the polymerizable composition makes it easier to achieve consistent smoothness on both sides of the resulting ion exchange membrane, so it is preferable to laminate the resin film on both sides. The polymerization mechanism includes at least one of an ultraviolet ray irradiation device and a heating device. For example, the polymerizable composition is cured by irradiating the laminated film transported from the nip roll 104 to the winding unit 103 with ultraviolet rays or by applying heat. The resulting laminated film containing the second structure is wound around a winding core in the winding unit 103 to obtain a wound laminated film containing the second structure.

[0079] Next, the laminated film roll containing the second structure is immersed in a treatment solution containing ion exchange groups to introduce the ion exchange groups, and then immersed in water to wash. This results in a wet ion exchange membrane roll. Note that if a polymerizable composition containing an ion exchange resin monomer is used, the introduction of ion exchange groups can be omitted. In this case, the resin film may or may not be peeled off, but peeling is preferred because peeling makes it easier to introduce the ion exchange groups.

[0080] The ion exchange membrane obtained by the above method may further be subjected to a counterion substitution treatment. The counterion substitution treatment is carried out, for example, by immersing a wound ion exchange membrane in a treatment solution containing a desired counterion, and then immersing it in water to wash it. When a polymerizable composition containing a monomer of an ion exchange resin is used, this counterion substitution treatment results in a wound ion exchange membrane in a wet state.

[0081] In cases where the introduction of ion exchange groups does not require much time, the introduction of ion exchange groups and the counterion substitution process may be carried out continuously, for example, in a roll-to-roll format. That is, the second structure may be transported before the winding section 103 into a tank containing a treatment solution containing ion exchange groups or a treatment solution having desired counter ions, and the second structure immersed in these treatment solutions may be further transported and wound up.

[0082] When the ion exchange membrane is in the form of a laminated film, for example, a wet ion exchange membrane roll may be obtained by peeling the laminated film from the laminated film and winding up only the ion exchange membrane in a roll-to-roll manner.

[0083] (Method for manufacturing ion exchange membrane roll) The ion exchange membrane roll according to the embodiment can be produced, for example, by the following method. First, a wet ion exchange membrane wound body is prepared, for example, by the method described above. Next, one short side end of the ion exchange membrane is unwound from the wet ion exchange membrane wound body, and this ion exchange membrane is transported. The transported wet ion exchange membrane is subjected to a drying treatment, and the dry ion exchange membrane is further transported toward the winding core. The transported dry ion exchange membrane is wound around the winding core to obtain a dry ion exchange membrane wound body. The end of the short side at the end of the winding of this dry ion exchange membrane is fixed with breathable tape, thereby obtaining an ion exchange membrane wound body according to the embodiment.

[0084] In this case, the air layer ratio and hardness of the ion exchange membrane roll can be adjusted by adjusting the conveying speed of the dry ion exchange membrane, the winding tension during winding, and the pressure during winding. That is, when the conveying speed of the ion exchange membrane is high, air is carried along with the ion exchange membrane, making it easier for air to be trapped between the ion exchange membranes in the ion exchange membrane roll, which tends to increase the air layer ratio. The conveying speed is preferably 0.75 m / min or more and 30 m / min or less. A conveying speed within this range tends to produce an ion exchange membrane roll with an appropriate air layer. From the viewpoint of improving production efficiency, the conveying speed is preferably 3 m / min or more, more preferably 5 m / min or more, and even more preferably 10 m / min or more. This conveying speed can be calculated, for example, from the rotation speed and outer diameter of the conveying roll installed immediately before the winding section. The rotation speed of the roll can be measured by an encoder of the motor attached to the roll.

[0085] If the winding tension when the ion exchange membrane is wound around the core is high, it becomes difficult for air to be trapped between the ion exchange membranes in the ion exchange membrane wound body, which tends to reduce the air layer ratio. The winding tension is preferably 3 N / m or more and 100 N / m or less. When the winding tension is within this range, an ion exchange membrane wound body with an appropriate air layer tends to be obtained. The winding tension is preferably 5 N / m or more and 50 N / m or less, and may be 10 N / m or more and 40 N / m or less. This winding tension can be measured, for example, using a load cell installed on the transport roll. In addition, the measured tension can be fed back to the unwinding section or winding section, and the tension can be controlled to the set value by adjusting the motor torque and the roll rotation speed.

[0086] It is preferable that no pressure be applied to the winding core or the surface of the ion exchange membrane wound around the winding core. That is, if the ion exchange membrane is wound up while applying pressure to the surface of the wound ion exchange membrane using, for example, a touch roll or the like, the air trapped between the ion exchange membrane is pushed out, which may result in the air layer ratio of the ion exchange membrane wound body being 5% or less. Therefore, when producing an ion exchange membrane wound body, it is preferable to wind the ion exchange membrane without using a touch roll or the like so that no pressure is applied to the winding core or the surface of the ion exchange membrane wound around the winding core.

[0087] The dry ion exchange membrane wound body may be manufactured by a roll-to-roll method. The roll-to-roll method of manufacturing will be described in more detail with reference to FIG. 6 . FIG. 6 is a schematic diagram illustrating an example of an ion exchange membrane wound body manufacturing apparatus. The ion exchange membrane wound body manufacturing apparatus 300 shown in FIG. 6 includes an unwinding section 301, a conveying section 302, and a winding section 303. The unwinding section 301, the conveying section 302, and the winding section 303 are equipped with motors (not shown), and these motors are connected to controllers. The unwinding section 301, the conveying section 302, and the winding section 303 may each be equipped with a brake. The unwinding section 301, the conveying section 302, and the winding section 303 are equipped with a wet ion exchange membrane wound body. The conveying section 302 includes a tension cutting mechanism 304, a feed roll 305, a near roll 306, and a cleaning mechanism and a drying mechanism (not shown). A winding core for the dry ion exchange membrane wound body is installed in the winding section 303. The near roll 306 is installed near the winding core so as not to come into contact with the winding core of the winding section 303 or the surface of the wound ion exchange membrane. The ion exchange membrane wound body manufacturing apparatus 300 may be provided with a feed roll or the like (not shown). The tension cutting mechanism 304 can be a nip roll, a suction roll, or an S-wrap mechanism using multiple rolls with a large wrap angle. It is also preferable to provide a tension control mechanism such as a dancer roll to absorb tension fluctuations. A wrinkle-smoothing mechanism such as an expander roll or pinch roll may also be provided before the winding section 303. The cleaning device and near roll 306 may be omitted, and an inspection mechanism and a static elimination mechanism may also be provided.

[0088] First, a wet ion exchange membrane roll is placed in the unwinding section 301, and a winding core is placed in the winding section 303. The motors of the unwinding section 301 and the winding section 303 are operated to unwind one of the short sides of the wet ion exchange membrane from the wet ion exchange membrane roll. The cleaning mechanism cleans the ion exchange membrane using a cleaning liquid such as water. The cleaned ion exchange membrane is then transported to the drying mechanism. The drying mechanism dries the transported cleaned ion exchange membrane by heating with a heater or hot air, for example. The resulting dry ion exchange membrane is then transported to the winding section 303 and wound around the winding core. After winding is complete, the end of the short side located at the outermost layer of the roll is fixed with breathable tape. In this way, a dry ion exchange membrane roll is obtained. The winding core may be removed from the resulting roll.

[0089] The resulting dried ion exchange membrane roll may be further subjected to slitting using a slitting device. The slitting divides the ion exchange membrane into multiple pieces parallel to the long sides. This slitting is performed in a roll-to-roll manner. That is, the ion exchange membrane transported from the ion exchange membrane roll and slit is wound onto a winding core in the same manner as the ion exchange membrane roll. The slitting may be performed continuously by further providing a slitting mechanism to the ion exchange membrane roll manufacturing apparatus 300 shown in FIG. 6. The slitting mechanism may include, for example, a blade capable of cutting the ion exchange membrane. The slitting mechanism may further include a metal roll or a ceramic roll. The ion exchange membrane may be cut by pressing a blade against the ion exchange membrane transported on a hard metal roll or ceramic roll in the slitting mechanism, or by applying the blade to the ion exchange membrane transported between transport rolls or through a hollow space such as a groove on a metal roll. The slitting mechanism may be provided, for example, before the winding unit 303. When a slitting mechanism is provided, a plurality of winding sections are provided to match the width after slitting, thereby obtaining a wound body of ion exchange membrane cut to a desired width. When a slitting mechanism is provided, a roll traverse device may be provided immediately before the slitting mechanism, so that the ion exchange membrane can be subjected to oscillation treatment while being swung from side to side.

[0090] Even when a dry ion exchange membrane roll is produced and then slit using a slitting device, the air layer ratio and hardness of the ion exchange membrane roll can be adjusted by adjusting the transport speed of the dry ion exchange membrane in the slitting device, the winding tension when winding the ion exchange membrane, and the pressure when winding the ion exchange membrane. The slitting device can be configured using the same mechanism as the slitting mechanism described above.

[0091] (Use of ion exchange membrane roll) The ion exchange membrane roll according to the embodiment is used, for example, in the manufacture of an ion exchange sheet. The ion exchange sheet is a dry ion exchange membrane that does not have a long film shape. The ion exchange sheet may be rectangular, square, polygonal, circular, or elliptical.

[0092] The ion exchange sheet is installed in, for example, a pure water production apparatus, a seawater desalination treatment apparatus, a desalination treatment apparatus, a fuel cell, or a water electrolysis apparatus, and functions as a diaphragm. The ion exchange sheet is preferably used in a membrane electrode assembly of a fuel cell or a water electrolysis apparatus.

[0093] The method for producing an ion exchange sheet includes, for example, removing the breathable tape from a dry ion exchange membrane roll, unwinding the ion exchange membrane, immersing the unwound ion exchange membrane in water, and cutting the ion exchange membrane after immersion in water. Cutting includes cutting the ion exchange membrane in a direction parallel to the short sides and punching it into a predetermined shape. The method for cutting the ion exchange membrane is not particularly limited. For example, a metal blade is used to cut the ion exchange membrane.

[0094] The membrane electrode assembly can be obtained, for example, by laminating electrodes on an ion exchange sheet. After a long membrane electrode assembly is produced by joining an ion exchange membrane and an electrode, the assembly may be cut to obtain a membrane electrode assembly having a desired shape. [Example]

[0095] The present invention will be described in detail below with reference to examples, but the present invention is not limited by these examples. It is not limited to:

[0096] Example 1 <Preparation of Polymerizable Composition> A polymerizable composition was obtained by mixing chloromethylstyrene (95 parts by mass), a 57% by mass divinylbenzene styrene solution (5 parts by mass), a polymerization initiator (trade name: Perbutyl O, 5 parts by mass), and an epoxy compound (trade name: Epolite 40E, 5 parts by mass).

[0097] <Manufacturing a roll of wet ion exchange membrane> As a substrate for the ion exchange membrane, a roll of polyethylene porous membrane with a porosity of 44%, a thickness of 25 μm, a width of 1000 mm and a length of 400 m was used.

[0098] The substrate was unwound and immersed in a tank containing the polymerizable composition to support the polymerizable composition, and then a 50 μm thick polyethylene terephthalate film was placed on one side of the substrate and taken up around a hard chrome-plated metal roll to obtain a rolled laminated film including the first structure.

[0099] The obtained wound body was heated at 80° C. for 5 hours under nitrogen pressure of 0.3 MPa to polymerize the polymerizable composition in the porous film, thereby obtaining a wound body of a laminated film including the second structure.

[0100] The laminated film was unwound from the resulting wound body, the polyethylene terephthalate film was peeled off, and the wound body was rewound again to produce a wound body containing only the second structure without the resin film. This second structure wound body was immersed in an aqueous solution containing 6% by mass of trimethylamine and 25% by mass of acetone at room temperature for 16 hours to aminated the chloromethylstyrene polymerized portion, and then immersed in a 0.5 mol / L aqueous potassium bicarbonate solution to ion-exchange the counter ions of the quaternary ammonium base in the membrane from chloride ions to bicarbonate ions. The wound body was then immersed in pure water and washed to obtain a wet ion-exchange membrane wound body.

[0101] <Production of dry ion exchange membrane roll> The wet ion exchange membrane roll was unwound, and the ion exchange membrane was dried by applying hot air at 40°C in the transport section after unwound. The dried membrane was transported to the winding section and wound around a glass fiber reinforced plastic core with an inner diameter of 153 mm, a wall thickness of 10 mm, and a width of 1200 mm. A dry ion exchange membrane roll was produced. The transport speed was 3 m / min and the winding tension was 15 N / m. A touch roll was not used during winding; instead, a near roll was used. The circumferential length of the resulting first ion exchange membrane roll was 597 mm. The average thickness of the resulting dry ion exchange membrane was 28 μm. The air layer ratio calculated from the circumferential length of the first ion exchange membrane roll and the diameter of the winding core was 21%, and the hardness was 92.

[0102] This first ion exchange membrane roll was placed in a slitting device and, while being unwound at a conveying speed of 3 m / min, cut to a width of 420 mm and wound up, to produce a second ion exchange membrane roll with an ion exchange membrane length L of 100 m. An ABS resin core with an inner diameter of 153 mm, a thickness of 8 mm, and a width of 600 mm was used as the winding core. A near roll was used instead of a touch roll during winding, and the winding tension was 10 N / m. A dancer roll was used as a tension control device, and an expander roll was installed immediately before the slitting position. The air layer ratio of the second ion exchange membrane roll was 21%, and the number of windings was 110.

[0103] At the end of winding the second ion exchange membrane roll, adhesive tape was applied to two ends of the ion exchange membrane to secure the ends. The long side of the adhesive tape was 25 mm and the short side was 15 mm. Nitos Through (registered trademark) manufactured by Nitoms Corporation was used as the adhesive tape.

[0104] (Example 2, Comparative Examples 1 and 2) A second ion exchange membrane roll was obtained in the same manner as in Example 1, except that the type of adhesive tape was changed as shown in Table 1.

[0105] (Evaluation test) <Air permeability measurement> The air permeability was measured according to the Oken Testing Machine Method of Japanese Industrial Standards P8117. Five sheets of adhesive tape measuring 50 mm x 50 mm were stacked together to form a test piece. The adhesive tapes used in Comparative Examples 1 and 2 exceeded the upper measurement limit and could not be measured. The results are shown in Table 1.

[0106] <Appearance evaluation test> The appearance of the second ion exchange membrane wound bodies obtained in Examples 1 and 2 and Comparative Examples 1 and 2 was evaluated as follows. The results are shown in Table 1. 1. Humidification test The second ion exchange membrane roll was left to stand in a thermostatic chamber at 25°C and a relative humidity of 80%RH for 24 hours, and the appearance of the outermost ion exchange membrane surface was visually inspected and evaluated as follows. The results are shown in Table 1.

[0107] ○: No wrinkles are observed around the adhesive tape.

[0108] △: Slight wrinkles are observed around the adhesive tape.

[0109] ×: Wrinkles are observed around the adhesive tape. 2.Tape mark detection test After the humidification test, the second ion exchange membrane roll was visually inspected to see how many layers had depressions, which were the marks of the tape. The results are shown in Table 1.

[0110] [Table 1]

[0111] Preferred embodiments are described below. [1] a dry, rolled ion exchange membrane; a breathable tape for fixing the end of a short side located at the outermost periphery of the ion exchange membrane; An ion exchange membrane roll comprising: [2] The ion exchange membrane wound body according to [1], wherein the breathable tape has an air permeability of 5.0 sec / 100 cc·100 μm or less. [3] The breathable tape includes a support and an adhesive supported on the support, The ion exchange membrane roll according to [1] or [2], wherein the support is a film, a woven fabric, a nonwoven fabric, a porous film, or paper. [4] The ion exchange membrane roll according to [3], wherein the support is a nonwoven fabric. [5] The ion exchange membrane roll according to any one of [1] to [4], wherein the air layer ratio is 5% or more and 50% or less. [6] The ion exchange membrane wound body according to any one of [1] to [5], further comprising a winding core, and the ion exchange membrane is wound around the winding core. [7] The ion exchange membrane roll according to any one of [1] to [6], wherein the ion exchange membrane includes a porous substrate and an ion exchange resin supported on the porous substrate. [8] The ion exchange membrane roll according to [7], wherein the porous substrate contains a polyolefin resin. [9] The ion exchange membrane roll according to any one of [1] to [8], which has a cylindrical shape.

[10] The ion exchange membrane roll according to any one of [1] to [9], wherein the ion exchange membrane is an anion exchange membrane. [Explanation of symbols]

[0112] 1... ion exchange membrane, 2... winding core, 3... ion exchange membrane section, 4... breathable tape, 10... ion exchange membrane roll, 100... polymerizable composition impregnation device, 101... unwinding section, 102... conveying section, 103... winding section, 104... nip roll, 105... feed roll, 106... feed roll, 107... feed roll, 300... ion exchange membrane roll manufacturing device, 301... unwinding section, 302... conveying section, 303... winding section, 304... tension cutting mechanism, 305... Feed roll, 306...near roll, Aa...area of the ion exchange membrane portion, Bc...circumference of the ion exchange membrane roll, Bl...diameter of the ion exchange membrane roll, Br...radius of the ion exchange membrane roll, Bw...length in the winding axis direction of the ion exchange membrane roll, Ca...area of the winding core, Cc...circumference of the winding core, Cl...diameter of the winding core, Cr...radius of the winding core, Cw...length of the winding core in the winding axis direction, d...thickness, L...length of the long side, PC...polymerizable composition, T...tank, W...length of the short side.

Claims

1. a dry, rolled ion exchange membrane; a breathable tape for fixing the end of a short side located at the outermost periphery of the ion exchange membrane; An ion exchange membrane roll comprising:

2. 2. The ion exchange membrane wound body according to claim 1, wherein the breathable tape has an air permeability of 5.0 sec / 100 cc·100 μm or less.

3. The breathable tape includes a support and an adhesive supported on the support, The ion exchange membrane roll according to claim 1 , wherein the support is a film, a woven fabric, a nonwoven fabric, a porous film, or paper.

4. The ion exchange membrane wound body according to claim 3 , wherein the support is a nonwoven fabric.

5. 2. The ion exchange membrane wound body according to claim 1, wherein the air layer ratio is 5% or more and 50% or less.

6. The ion exchange membrane wound body according to claim 1 , further comprising a winding core, wherein the ion exchange membrane is wound around the winding core.

7. The ion exchange membrane wound body according to claim 1 , wherein the ion exchange membrane includes a porous substrate and an ion exchange resin supported on the porous substrate.

8. The ion exchange membrane wound body according to claim 7 , wherein the porous substrate contains a polyolefin resin.

9. The ion exchange membrane wound body according to claim 1 , which has a cylindrical shape.

10. The ion exchange membrane wound body according to claim 1 , wherein the ion exchange membrane is an anion exchange membrane.

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